FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
CENTRIFUGAL AIR-SENDING DEVICE AND AIR-CONDITIONING APPARATUS;
MITSUBISHI ELECTRIC CORPORATION, A CORPORATION ORGANISED AND
EXISTING UNDER THE LAWS OF JAPAN, WHOSE ADDRESS IS 7-3,
MARUNOUCHI 2-CHOME, CHIYODA-KU, TOKYO 100-8310, JAPAN
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION
AND THE MANNER IN WHICH IT IS TO BE PERFORMED.
2
DESCRIPTION
Title of Invention
CENTRIFUGAL AIR-SENDING DEVICE AND AIR-CONDITIONING APPARATUS
5 Technical Field
[0001]
The present disclosure relates to a centrifugal air-sending device that includes
an impeller and an air-conditioning apparatus that includes the centrifugal air-sending
device.
10 Background Art
[0002]
There has been a centrifugal air-sending device that has a scroll casing that is
scroll-shaped and has a bell mouth formed at an air inlet and an impeller that is
installed in the scroll casing and is configured to rotate about an axial center (refer to,
15 for example, Patent Literature 1). The impeller disclosed in Patent Literature 1 and
included in the centrifugal air-sending device has a main plate that is disk-shaped, a
side plate that is ring-shaped, and blades radially arranged. The blades included in
this impeller are arranged such that their inner diameter increases from the main plate
toward the side plate. The blades also are sirocco vanes, which are forward-curved
20 blades, and that each have a blade outlet angle of greater than or equal to 100
degrees and have inducer portions of turbo vanes, which are backward-curved blades,
at an inner circumference of the blades.
Citation List
Patent Literature
25 [0003]
Patent Literature 1: Japanese Unexamined Patent Application Publication No.
2000-240590
Summary of Invention
Technical Problem
30 [0004]
3
In a case in which an impeller is resin-molded, to prevent its side plate from
sticking to a mold, such a side plate has been ring-shaped and provided to outer
circumferential side face of the impeller. In a centrifugal air-sending device that has
an impeller that has such a configuration, an airflow blown in a radial direction of the
5 impeller may pass outward around the side plate as its center and along an inner side
surface of a bell mouth and flow into the impeller again. In the centrifugal airsending device disclosed in Patent Literature 1, portions of blades that are located
further outward than an inner circumferential side end portion of the bell mouth are
formed only by portions formed as sirocco vane portions. When an airflow blown out
10 from the impeller and along an inner wall surface of the bell mouth flows into the
impeller again, the airflow thus collides with the sirocco vane portions, which each
have a large outlet angle and at which the airflow passes at increased inflow velocity.
Noise generated from the centrifugal air-sending device may be thus caused and
deterioration in input may be caused as well.
15 [0005]
The present disclosure is to solve the above problem and to provide a
centrifugal air-sending device, in which, when an airflow that passes along the inner
wall surface of the bell mouth passes into the impeller again, noise generated from
the airflow and deterioration in input are prevented, and an air-conditioning apparatus
20 that includes the centrifugal air-sending device.
Solution to Problem
[0006]
A centrifugal air-sending device according to an embodiment of the present
disclosure has an impeller that has a main plate that is to be driven to rotate, a side
25 plate that is ring-shaped and located such that the side plate faces the main plate,
and a plurality of blades that each have one end connected to the main plate and an
other end connected to the side plate and are arranged in a circumferential direction
centered on a rotation axis of the main plate that is virtual; and a scroll casing that
houses the impeller and has a circumferential wall that is scroll-shaped and a side
30 wall that has a bell mouth that forms a suction port that communicates with a space
4
defined by the main plate and the plurality of blades, in which the plurality of blades
each have an inner circumferential end that is closer to the rotation axis than is an
outer circumferential end in a radial direction centered on the rotation axis, the outer
circumferential end that is closer to an outer circumference than is the inner
5 circumferential end in the radial direction, a sirocco vane portion that includes the
outer circumferential end and forms a forward-curved blade at which an outlet angle
is formed larger than 90 degrees, a turbo vane portion that includes the inner
circumferential end and forms a backward-curved blade, a first region that is located
closer to the main plate than is an intermediate position in an axial direction of the
10 rotation axis, and a second region that is located closer to the side plate than is the
first region, the plurality of blades have a blade outer diameter of the respective outer
circumferential ends of the plurality of blades and the blade outer diameter is larger
than an inner diameter of the bell mouth, the plurality of blades each have a vane
length in the first region that is greater than a vane length in the second region, the
15 plurality of blades each have a portion at which a proportion for which the turbo vane
portion accounts is higher in the radial direction than a proportion for which the
sirocco vane portion accounts in the first region and the second region, and, in a case
in which portions of the plurality of blades that are located closer to the outer
circumference than is an inner circumferential side end portion that is an end portion
20 of the bell mouth that is located closest to an inner circumference in the radial
direction are defined as a blade outer circumferential portion, the blade outer
circumferential portion is formed such that the proportion for which the sirocco vane
portion accounts is higher in the radial direction than or equal to the proportion for
which the turbo vane portion accounts in the first region and the second region.
25 [0007]
An air-conditioning apparatus according to another embodiment of the present
disclosure has the centrifugal air-sending device, which has a configuration described
above.
Advantageous Effects of Invention
30 [0008]
5
According to an embodiment of the present disclosure, the blade outer
circumferential portion is formed such that the proportion for which the sirocco vane
portion accounts is higher in the radial direction than or equal to the proportion for
which the turbo vane portion accounts in the first region and the second region. The
5 centrifugal air-sending device that has the configuration described above is
configured to further increase an air volume and a pressure of an airflow blown out
from the impeller in comparison with a centrifugal air-sending device that does not
have the configuration described above. In the centrifugal air-sending device that
has the configuration described above, an airflow that passes along an inner wall
10 surface of the bell mouth into the impeller again thus collides with the turbo vane
portions, which each have a small outlet angle and at which the airflow passes at
decreased inflow velocity. As a result, in the centrifugal air-sending device, when the
airflow that passes along the inner wall surface of the bell mouth passes into the
impeller again, noise generated from the airflow is thus prevented and deterioration in
15 input is prevented as well.
Brief Description of Drawings
[0009]
[Fig. 1] Fig. 1 is a perspective view that schematically illustrates a centrifugal
air-sending device according to Embodiment 1.
20 [Fig. 2] Fig. 2 is an external view that schematically illustrates a configuration of
the centrifugal air-sending device according to Embodiment 1 with the configuration
viewed parallel to a rotation axis RS.
[Fig. 3] Fig. 3 is a sectional view that schematically illustrates a section of the
centrifugal air-sending device illustrated in Fig. 2 taken along line A-A.
25 [Fig. 4] Fig. 4 is a perspective view that illustrates an impeller included in the
centrifugal air-sending device according to Embodiment 1.
[Fig. 5] Fig. 5 is a perspective view that illustrates the impeller illustrated in Fig.
4 with the impeller viewed opposite to the perspective view illustrated in Fig. 4.
[Fig. 6] Fig. 6 is a plan view that illustrates the impeller included in the
30 centrifugal air-sending device according to Embodiment 1 with the impeller viewed
6
toward one face of the main plate.
[Fig. 7] Fig. 7 is a plan view that illustrates the impeller included in the
centrifugal air-sending device according to Embodiment 1 with the impeller viewed
toward the other face of the main plate.
5 [Fig. 8] Fig. 8 is a sectional view that illustrates the impeller illustrated in Fig. 6
taken along line B-B.
[Fig. 9] Fig. 9 is a side view that illustrates the impeller illustrated in Fig. 4.
[Fig. 10] Fig. 10 is a schematic view that illustrates a section of blades included
in the impeller illustrated in Fig. 9 taken along line C-C.
10 [Fig. 11] Fig. 11 is a schematic view that illustrates a section of the blades
included in the impeller illustrated in Fig. 9 taken along line D-D.
[Fig. 12] Fig. 12 is a schematic view that illustrates a relationship between the
impeller and a scroll casing included in the centrifugal air-sending device illustrated in
Fig. 2 with the centrifugal air-sending device viewed in a section taken along line A-A.
15 [Fig. 13] Fig. 13 is a schematic view that illustrates a relationship between the
blades and a bell mouth with the impeller illustrated in Fig. 12 viewed parallel to the
rotation axis RS.
[Fig. 14] Fig. 14 is a schematic view that illustrates a relationship between the
impeller and the scroll casing included in the centrifugal air-sending device illustrated
20 in Fig. 2 with the centrifugal air-sending device viewed in the section taken along line
A-A.
[Fig. 15] Fig. 15 is a schematic view that illustrates a relationship between the
blades and the bell mouth with the impeller illustrated in Fig. 14 viewed parallel to the
rotation axis RS.
25 [Fig. 16] Fig. 16 is a schematic view that illustrates a relationship between the
impeller and the bell mouth included in the centrifugal air-sending device illustrated in
Fig. 2 with the centrifugal air-sending device viewed in the section taken along line AA.
[Fig. 17] Fig. 17 is a schematic view that illustrates a relationship between the
30 blades and the bell mouth with the impeller illustrated in Fig. 16 viewed in a second
7
section and viewed parallel to the rotation axis RS.
[Fig. 18] Fig. 18 is a conceptual view that illustrates a relationship between the
impeller and the bell mouth illustrated in Fig. 16 and Fig. 17.
[Fig. 19] Fig. 19 is a sectional view that illustrates a centrifugal air-sending
5 device according to a comparative example.
[Fig. 20] Fig. 20 is a sectional view that schematically illustrates a centrifugal
air-sending device according to Embodiment 2.
[Fig. 21] Fig. 21 is a sectional view that schematically illustrates a centrifugal
air-sending device according to Embodiment 3.
10 [Fig. 22] Fig. 22 is an enlarged view that illustrates a portion of the impeller
included in the centrifugal air-sending device according to Embodiment 3 that is in
range E in the impeller illustrated in Fig. 6.
[Fig. 23] Fig. 23 is a sectional view that schematically illustrates a centrifugal
air-sending device according to Embodiment 4.
15 [Fig. 24] Fig. 24 is an enlarged view that illustrates a portion of the impeller
included in the centrifugal air-sending device according to Embodiment 4 that is in
range E in the impeller illustrated in Fig. 6.
[Fig. 25] Fig. 25 is a conceptual view that illustrates a relationship between
impellers and a motor included in a centrifugal air-sending device according to
20 Embodiment 5.
[Fig. 26] Fig. 26 is a conceptual view that illustrates a centrifugal air-sending
device that is a modification 1 of the centrifugal air-sending device according to
Embodiment 5.
[Fig. 27] Fig. 27 is a conceptual view that illustrates a centrifugal air-sending
25 device that is a modification 2 of the centrifugal air-sending device according to
Embodiment 5.
[Fig. 28] Fig. 28 is a sectional view that schematically illustrates a centrifugal
air-sending device according to Embodiment 6.
[Fig. 29] Fig. 29 is a sectional view that schematically illustrates a centrifugal
30 air-sending device according to a comparative example.
8
[Fig. 30] Fig. 30 is a sectional view that schematically illustrates an operation of
the centrifugal air-sending device according to Embodiment 6.
[Fig. 31] Fig. 31 is a sectional view that illustrates a centrifugal air-sending
device that is a first modification of the centrifugal air-sending device according to
5 Embodiment 6.
[Fig. 32] Fig. 32 is a sectional view that illustrates a centrifugal air-sending
device that is a second modification of the centrifugal air-sending device according to
Embodiment 6.
[Fig. 33] Fig. 33 is a schematic view that illustrates a relationship between the
10 bell mouth and a blade included in a centrifugal air-sending device according to
Embodiment 7.
[Fig. 34] Fig. 34 is a schematic view that illustrates a relationship between a
bell mouth and a blade included in a centrifugal air-sending device that is a
modification of the centrifugal air-sending device according to Embodiment 7.
15 [Fig. 35] Fig. 35 is a sectional view that schematically illustrates a centrifugal
air-sending device according to Embodiment 8.
[Fig. 36] Fig. 36 is a schematic view that illustrates blades included in the
impeller illustrated in Fig. 35 with the blades viewed parallel to the rotation axis RS.
[Fig. 37] Fig. 37 is a schematic view that illustrates the blades included in the
20 impeller illustrated in Fig. 35 with the blades viewed in a section taken along line D-D.
[Fig. 38] Fig. 38 is a perspective view of an air-conditioning apparatus
according to Embodiment 9.
[Fig. 39] Fig. 39 is a perspective view of an internal configuration of the airconditioning apparatus according to Embodiment 9.
25 Description of Embodiment
[0010]
A centrifugal air-sending device and an air-conditioning apparatus according to
embodiments are described below with reference to the drawings and other reference.
In the drawings below, which include Fig. 1, the relative dimensions, shapes, and
30 other details of various components may differ from those of the actual components.
9
In addition, components given the same reference signs in the following drawings are
the same as or equivalent to each other, and these reference signs are common
through the full text of the specification. In addition, the directional terms, such as
"upper", "lower", "right", "left", "front", and "back", used as appropriate for ease of
5 comprehension are merely so written for convenience of explanation, and the
placement or orientation of a device or a component is not limited by the directional
terms.
[0011]
Embodiment 1
10 [Centrifugal Air-sending Device 100]
Fig. 1 is a perspective view that schematically illustrates a centrifugal airsending device 100 according to Embodiment 1. Fig. 2 is an external view that
schematically illustrates a configuration of the centrifugal air-sending device 100
according to Embodiment 1 with the configuration viewed parallel to a rotation axis
15 RS. Fig. 3 is a sectional view that schematically illustrates a section of the
centrifugal air-sending device 100 illustrated in Fig. 2 taken along line A-A. A basic
structure of the centrifugal air-sending device 100 is described below with reference
to Fig. 1 to Fig. 3.
[0012]
20 The centrifugal air-sending device 100 is a multi-blade air-sending device and
has an impeller 10 configured to generate an airflow and a scroll casing 40, which
houses the impeller 10. The centrifugal air-sending device 100 is also a doublesuction centrifugal air-sending device through which air is sucked from both sides of
the scroll casing 40 in an axial direction of the rotation axis RS, which is virtual, of the
25 impeller 10.
[0013]
[Scroll Casing 40]
The scroll casing 40 houses the impeller 10 for the centrifugal air-sending
device 100 and rectifies air blown out from the impeller 10. The scroll casing 40 has
30 a scroll portion 41 and a discharge portion 42.
10
[0014]
Scroll Portion 41
The scroll portion 41 forms an air passage through which a dynamic pressure
of an airflow generated by the impeller 10 is converted into a static pressure. The
5 scroll portion 41 has side walls 44a that each cover the impeller 10 in the axial
direction of the rotation axis RS of the boss portion 11b included in the impeller 10
and each have a casing suction port 45 formed in the side wall 44a and through
which air is sucked and a circumferential wall 44c that surrounds the impeller 10 in
radial directions from the rotation axis RS of the boss portion 11b.
10 [0015]
In addition, the scroll portion 41 has a tongue portion 43, located between a
discharge portion 42 and a scroll start portion 41a of the circumferential wall 44c, that
has a curved surface and guides an airflow generated by the impeller 10 toward a
discharge port 42a through the scroll portion 41. The radial directions from the
15 rotation axis RS are each a direction perpendicular to the rotation axis RS. The
scroll portion 41 has an internal space, defined by the circumferential wall 44c and the
side walls 44a, in which air blown out from the impeller 10 flows along the
circumferential wall 44c.
[0016]
20 Side Walls 44a
The side walls 44a are located at both respective faces of the impeller 10 in the
axial direction of the rotation axis RS of the impeller 10. The side walls 44a of the
scroll casing 40 each have the casing suction port 45 formed in the side wall 44a
such that air is allowed to flow between the impeller 10 and an outside of the scroll
25 casing 40.
[0017]
The casing suction port 45 is formed in a circular shape and the impeller 10 is
located such that the center of the casing suction port 45 and the center of the boss
portion 11b of the impeller 10 substantially coincide with each other. The shape of
30 the casing suction port 45 is not limited to the circular shape and may also be another
11
shape, such as an elliptical shape.
[0018]
The scroll casing 40 of the centrifugal air-sending device 100 is a doublesuction casing that has the side walls 44a, which have the respective casing suction
5 ports 45 at both faces of the main plate 11 in the axial direction of the rotation axis RS
of the boss portion 11b.
[0019]
The centrifugal air-sending device 100 has the two side walls 44a in the scroll
casing 40. The two side walls 44a are formed such that the side walls 44a face each
10 other across the circumferential wall 44c. More specifically, as illustrated in Fig. 3,
the scroll casing 40 has a first side wall 44a1 and a second side wall 44a2 as the side
walls 44a.
[0020]
The first side wall 44a1 has a first suction port 45a formed in the first side wall
15 44a1. The first suction port 45a faces a plate surface of the main plate 11 on which
a first side plate 13a, which is described later, is located. The second side wall 44a2
has a second suction port 45b formed in the second side wall 44a2. The second
suction port 45b faces a plate surface of the main plate 11 on which a second side
plate 13b, which is described later, is located. The first suction port 45a and the
20 second suction port 45b are collectively referred to as the casing suction ports 45
described above.
[0021]
The casing suction port 45 located in the side wall 44a is formed by a bell
mouth 46. In other words, the bell mouth 46 forms the casing suction port 45, which
25 communicates with a space defined by the main plate 11 and a plurality of blades 12.
The bell mouth 46 rectifies a flow of gas to be sucked into the impeller 10 and causes
the gas to flow into the air inlet 10e of the impeller 10.
[0022]
The bell mouth 46 has an opening of which a diameter gradually decreases
30 from the outside toward the inside of the scroll casing 40. Such a configuration of
12
each of the side walls 44a allows air around the casing suction ports 45 to smoothly
flow along the bell mouths 46 and efficiently flow from the casing suction ports 45 into
the impeller 10.
[0023]
5 Circumferential Wall 44c
The circumferential wall 44c is a wall that has a curved wall surface along
which an airflow generated by the impeller 10 is guided toward the discharge port 42a.
The circumferential wall 44c is located between the side walls 44a, which face each
other, and forms a curved surface that extends along the rotation direction R of the
10 impeller 10. The circumferential wall 44c is located, for example, parallel to the axial
direction of the rotation axis RS of the impeller 10 and covers the impeller 10. The
circumferential wall 44c may also be shaped such that the circumferential wall 44c is
inclined to the axial direction of the rotation axis RS in the impeller 10 and is not
limited to be located parallel to the axial direction of the rotation axis RS.
15 [0024]
The circumferential wall 44c has an inner circumferential surface that covers
the impeller 10 in the radial directions of the boss portion 11b and faces the plurality
of blades 12, which are described later. The circumferential wall 44c faces air
outlets of the blades 12 in the impeller 10. As illustrated in Fig. 2, the circumferential
20 wall 44c is located over an area from the scroll start portion 41a located at a boundary
between the circumferential wall 44c and the tongue portion 43 to a scroll end portion
41b located at a boundary between the scroll portion 41 and an end of the discharge
portion 42 that is located farthest from the tongue portion 43 along the rotation
direction R of the impeller 10.
25 [0025]
The scroll start portion 41a is an upstream end portion of the circumferential
wall 44c, which forms a curved surface, in a direction in which gas is caused by
rotation of the impeller 10 to flow along the circumferential wall 44c in an internal
space in the scroll casing 40. The scroll end portion 41b is a downstream end
30 portion of the circumferential wall 44c, which forms the curved surface, in the direction
13
in which gas is caused by rotation of the impeller 10 to flow along the circumferential
wall 44c in the internal space in the scroll casing 40.
[0026]
The circumferential wall 44c is formed in a spiral shape. The spiral shape is,
5 for example, a shape formed by a logarithmic spiral, an Archimedean spiral, or an
involute curve. The inner circumferential surface of the circumferential wall 44c has
the curved surface, which is smoothly curved along a circumferential direction of the
impeller 10 from the scroll start portion 41a, which is a starting end of the spiral shape,
to the scroll end portion 41b, which is a terminating end of the spiral shape. Such a
10 configuration allows air sent out from the impeller 10 to smoothly flow through a gap
between the impeller 10 and the circumferential wall 44c in a direction toward the
discharge portion 42. A static pressure of air from the tongue portion 43 toward the
discharge portion 42 in the scroll casing 40 thus efficiently increases.
[0027]
15 Discharge Portion 42
The discharge portion 42 forms the discharge port 42a through which an airflow
that is generated by the impeller 10 and has passed through the scroll portion 41 is
discharged. The discharge portion 42 is formed by a hollow pipe that has a
rectangular section orthogonal to a direction in which air flows along the
20 circumferential wall 44c. Such a sectional shape of the discharge portion 42 is not
limited to a rectangular shape. The discharge portion 42 forms a flow passage
through which air that is sent out from the impeller 10 and flows through the gap
between the circumferential wall 44c and the impeller 10 is guided to be discharged
out from the scroll casing 40.
25 [0028]
As illustrated in Fig. 1, the discharge portion 42 is formed by an extension plate
42b, a diffuser plate 42c, a first side plate portion 42d, a second side plate portion 42e,
and other components. The extension plate 42b is formed integrally with the
circumferential wall 44c such that the extension plate 42b smoothly continues to the
30 scroll end portion 41b, which is located downstream of the circumferential wall 44c.
14
The diffuser plate 42c is formed integrally with the tongue portion 43 of the scroll
casing 40 and faces the extension plate 42b. The diffuser plate 42c is formed at a
predetermined angle to the extension plate 42b such that a sectional area of the flow
passage gradually increases along a direction in which air flows in the discharge
5 portion 42.
[0029]
The first side plate portion 42d is formed integrally with the first side wall 44a1
of the scroll casing 40, and the second side plate portion 42e is formed integrally with
the second side wall 44a2 of the scroll casing 40, which is located opposite to the first
10 side wall 44a1. The first side plate portion 42d and the second side plate portion
42e are formed between the extension plate 42b and the diffuser plate 42c. The
discharge portion 42 thus has a rectangular-sectional flow passage defined by the
extension plate 42b, the diffuser plate 42c, the first side plate portion 42d, and the
second side plate portion 42e.
15 [0030]
Tongue Portion 43
In the scroll casing 40, the tongue portion 43 is formed between the diffuser
plate 42c of the discharge portion 42 and the scroll start portion 41a of the
circumferential wall 44c. The tongue portion 43 is formed with a predetermined
20 radius of curvature such that the circumferential wall 44c is smoothly connected to the
diffuser plate 42c through the tongue portion 43.
[0031]
The tongue portion 43 reduces inflow of air from a scroll ending portion to a
scroll starting portion of the flow passage, which is spiral-shaped. The tongue
25 portion 43 is located upstream in an air duct and separates an airflow along the
rotation direction R of the impeller 10 and an airflow from a downstream portion in the
air duct toward the discharge port 42a. In addition, while an airflow is passing
through the scroll casing 40, the airflow, which then passes into the discharge portion
42, rises in static pressure to be higher in pressure than the airflow in the scroll casing
30 40. For this reason, the tongue portion 43 is formed to separate such different
15
pressures.
[0032]
[Impeller 10]
Fig. 4 is a perspective view that illustrates the impeller 10 included in the
5 centrifugal air-sending device 100 according to Embodiment 1. Fig. 5 is a
perspective view that illustrates the impeller 10 illustrated in Fig. 4 with the impeller 10
viewed opposite to the perspective view illustrated in Fig. 4. Fig. 6 is a plan view
that illustrates the impeller 10 included in the centrifugal air-sending device 100
according to Embodiment 1 with the impeller 10 viewed toward one face of the main
10 plate 11. Fig. 7 is a plan view that illustrates the impeller 10 included in the
centrifugal air-sending device 100 according to Embodiment 1 with the impeller 10
viewed toward the other face of the main plate 11. Fig. 8 is a sectional view that
illustrates the impeller 10 illustrated in Fig. 6 taken along line B-B. The impeller 10 is
described below with reference to Fig. 4 to Fig. 8.
15 [0033]
The impeller 10 is a centrifugal fan. The impeller 10 is connected to an
unillustrated motor that has a drive shaft. The impeller 10 is driven by the motor into
rotation. The rotation generates a centrifugal force with which the impeller 10
forcibly sends out air outward in the radial directions. The impeller 10 is driven by
20 the motor or other drive source to rotate in the rotation direction R, which is illustrated
by an arrow. As illustrated in Fig. 4, the impeller 10 has the main plate 11, which is
disk-shaped, side plates 13, which are each ring-shaped, and the plurality of blades
12 arranged on a circumferential edge portion of the main plate 11 and arranged
radially around the rotation axis RS as their center.
25 [0034]
Main Plate 11
The main plate 11 is only required to be plate-shaped and may also be formed
in a polygonal shape or other shape other than such a disk shape. The main plate
11 may also be formed such that the thickness of the main plate 11 increases toward
30 the center of the main plate 11 in the radial direction centered on the rotation axis RS
16
as illustrated in Fig. 3. Alternatively, the main plate 11 may also be formed such that
the thickness of the main plate 11 is constant in the radial direction centered on the
rotation axis RS. In addition, the main plate 11 is not limited to one plate component.
The main plate 11 may also be a plurality of plate components that are integrally fixed
5 to each other.
[0035]
The boss portion 11b, to which the drive shaft of the motor is connected, is
located at the center portion of the main plate 11. In the boss portion 11b, a shaft
hole 11b1 is opened. To the shaft hole 11b1, the drive shaft of the motor is inserted.
10 The boss portion 11b is described to be circular-cylindrical-shaped. The boss portion
11b is, however, not limited to such a circular cylindrical shape. The boss portion
11b is only required to be pillar-shaped. The boss portion 11b may also be, for
example, polygonal-pillar-shaped. The main plate 11 is driven to rotate by the motor
by use of the boss portion 11b.
15 [0036]
Side Plates 13
The impeller 10 has side plates 13, which are each ring-shaped, are each
attached to the corresponding end portions of the plurality of blades 12 that are
opposite to the main plate 11 in the axial direction of the rotation axis RS of the boss
20 portion 11b. The side plates 13 are located at an outer circumferential side face 10a
of the impeller 10. In the impeller 10, the side plates 13 each face the main plate 11.
The side plates 13 are located outside the blades 12 in the radial directions centered
on the rotation axis RS. The side plates 13 define the respective air inlets 10e of the
impeller 10. The side plates 13 each connect the plurality of blades 12 with each
25 other and thus maintain a positional relationship between tips of the blades 12 and
reinforce the plurality of blades 12.
[0037]
The side plates 13 includes the first side plate 13a, which is ring-shaped and
faces the main plate 11, and the second side plate 13b, which is ring-shaped and
30 faces the main plate 11 at a position opposite to a position at which the first side plate
17
13a is located. The first side plate 13a and the second side plate 13b are
collectively referred to as the side plates 13. The impeller 10 has the first side plate
13a, which is spaced from one face of the main plate 11, and the second side plate
13b, which is spaced from the other face of the main plate 11, in the axial direction of
5 the rotation axis RS.
[0038]
Blades 12
As illustrated in Fig. 4, the plurality of blades 12 each have one edge
connected to the main plate 11 and the other edge connected to the corresponding
10 one of the side plates 13. The plurality of blades 12 are arranged in a
circumferential direction CD centered on the rotation axis RS, which is virtual, of the
main plate 11. The plurality of blades 12 are each located between the main plate 11
and the corresponding one of the side plates 13. The plurality of blades 12 are
located at both respective faces of the main plate 11 in the axial direction of the
15 rotation axis RS of the boss portion 11b. Each of the blades 12 is regularly spaced
from another one of the blades 12 on the circumferential edge portion of the main
plate 11.
[0039]
Fig. 9 is a side view that illustrates the impeller 10 illustrated in Fig. 4. As
20 illustrated in Fig. 4 and Fig. 9, the impeller 10 has a first vane portion 112a and a
second vane portion 112b. The first vane portion 112a and the second vane portion
112b are each formed by the corresponding ones of the plurality of blades 12 and the
corresponding one of the side plates 13. More specifically, the first vane portion
112a is formed by the first side plate 13a, which is ring-shaped, and ones of the
25 plurality of blades 12 that are located between the main plate 11 and the first side
plate 13a. The second vane portion 112b is formed by the second side plate 13b,
which is ring-shaped, and ones of the plurality of blades 12 that are located between
the main plate 11 and the second side plate 13b.
[0040]
30 The first vane portion 112a is located at one plate surface of the main plate 11
18
and the second vane portion 112b is located at the other plate surface of the main
plate 11. In other words, sets of the plurality of blades 12 are located at both
respective faces of the main plate 11 in the axial direction of the rotation axis RS.
The first vane portion 112a and the second vane portion 112b are located opposite to
5 each other across the main plate 11. In Fig. 3, the first vane portion 112a is located
at the left face of the main plate 11 and the second vane portion 112b is located at the
right face of the main plate 11. The first vane portion 112a and the second vane
portion 112b are, however, only required to be located opposite to each other across
the main plate 11. The first vane portion 112a may also be located at the right face
10 of the main plate 11 and the second vane portion 112b may also be located at the left
face of the main plate 11. In description below, unless otherwise noted, the blades
12 included in the first vane portion 112a and the blades 12 included in the second
vane portion 112b are collectively referred to as the blades 12.
[0041]
15 As illustrated in Fig. 4 and Fig. 5, the impeller 10 is formed in a tube shape by
the plurality of blades 12 located at the main plate 11. Furthermore, the impeller 10
has the air inlets 10e, through which gas flows into a space defined by the main plate
11 and the plurality of blades 12. The air inlets 10e are located at the respective
side plates 13, which are opposite to the main plate 11 in the axial direction of the
20 rotation axis RS of the boss portion 11b. The impeller 10 has the blades 12 and the
side plates 13 at both respective faces of the plate surfaces of the main plate 11.
The air inlets 10e of the impeller 10 are formed at both respective faces of the plate
surfaces of the main plate 11.
[0042]
25 When the unillustrated motor drives the impeller 10, the impeller 10 rotates
about the rotation axis RS as its center. When the impeller 10 rotates, gas outside
the centrifugal air-sending device 100 passes through the casing suction ports 45
formed in the scroll casing 40 and the air inlets 10e of the impeller 10, which are
illustrated in Fig. 1, and is sucked into the space defined by the main plate 11 and the
30 plurality of blades 12. When the impeller 10 rotates, air sucked into the space
19
defined by the main plate 11 and the plurality of blades 12 then passes through a
space between ones of the blades 12 that are next to each other and is sent outward
in the radial directions of the impeller 10.
[0043]
5 Details of Configuration of Blades 12
Fig. 10 is a schematic view that illustrates the blades 12 included in the
impeller 10 illustrated in Fig. 9 with the blades 12 viewed in a section taken along line
C-C. Fig. 11 is a schematic view that illustrates the blades 12 included in the
impeller 10 illustrated in Fig. 9 with the blades 12 viewed in a section taken along line
10 D-D. An intermediate position MP in the impeller 10 illustrated in Fig. 9 is an
intermediate position of the plurality of blades 12 included in the first vane portion
112a in the axial direction of the rotation axis RS. Another intermediate position MP
in the impeller 10 illustrated in Fig. 9 is an intermediate position of the plurality of
blades 12 included in the second vane portion 112b in the axial direction of the
15 rotation axis RS.
[0044]
In the plurality of blades 12 included in the first vane portion 112a, a range from
the intermediate position MP to the main plate 11 in the axial direction of the rotation
axis RS is defined as a main-plate-side blade region 122a, which is a first region in
20 the impeller 10. In the plurality of blades 12 included in the first vane portion 112a, a
range from the intermediate position MP to the corresponding one of the side plates
13 in the axial direction of the rotation axis RS is defined as a side-plate-side blade
region 122b, which is a second region in the impeller 10. In other words, in the axial
direction of the rotation axis RS, the plurality of blades 12 have the first region, which
25 is located closer to the main plate 11 than is the intermediate position MP, and the
second region, which is located closer to the corresponding one of the side plates 13
than is the first region.
[0045]
The section taken along line C-C illustrated in Fig. 9 is, as illustrated in Fig. 10,
30 a section of the plurality of blades 12 that are located close to the main plate 11 of the
20
impeller 10, that is, at the main-plate-side blade region 122a, which is the first region.
The section of the blades 12 close to the main plate 11 is a first flat surface 71, which
is perpendicular to the rotation axis RS, and is a first section of the impeller 10, which
is obtained by cutting a portion of the impeller 10 close to the main plate 11. The
5 portion of the impeller 10 close to the main plate 11 is a portion in the main-plate-side
blade region 122a that is closer to the main plate 11 than is the intermediate position
of the main-plate-side blade region 122a in the axial direction of the rotation axis RS
or is a portion at which end portions of the blades 12 closest to the main plate 11 in
the axial direction of the rotation axis RS is located.
10 [0046]
The section taken along line D-D illustrated in Fig. 9 is, as illustrated in Fig. 11,
a section of the plurality of blades 12 that are located close to the corresponding one
of the side plates 13 of the impeller 10, that is, at a side-plate-side blade region 122b,
which is the second region. The section of the blades 12 close to the corresponding
15 one of the side plates 13 is a second flat surface 72, which is perpendicular to the
rotation axis RS, and is a second face of the impeller 10, which is obtained by cutting
a portion of the impeller 10 close to the corresponding one of the side plates 13.
The portion of the impeller 10 close to the corresponding one of the side plates 13 is
a portion in the side-plate-side blade region 122b that is closer to the corresponding
20 one of the side plates 13 than is the intermediate position of the side-plate-side blade
region 122b in the axial direction of the rotation axis RS or is a portion at which end
portions of the blades 12 closest to the corresponding one of the side plates 13 in the
axial direction of the rotation axis RS is located.
[0047]
25 The basic configuration of the blades 12 included in the second vane portion
112b is similar to the basic configuration of the blades 12 included in the first vane
portion 112a. In other words, in the plurality of blades 12 included in the second
vane portion 112b, a range from the intermediate position MP to the main plate 11 in
the axial direction of the rotation axis RS is defined as the main-plate-side blade
30 region 122a, which is the first region in the impeller 10. In the plurality of blades 12
21
included in the second vane portion 112b, a range from the intermediate position MP
to the second side plate 13b in the axial direction of the rotation axis RS is also
defined as the side-plate-side blade region 122b, which is a second region in the
impeller 10.
5 [0048]
The basic configuration of the first vane portion 112a and the basic
configuration of the second vane portion 112b are described above to be similar to
each other. The configuration of the impeller 10 is, however, not limited to the
configuration described above and the first vane portion 112a and the second vane
10 portion 112b may also have different configurations. The configuration of the blades
12 described below may also include both or either one of the first vane portion 112a
and the second vane portion 112b.
[0049]
As illustrated in Fig. 9 to Fig. 11, the plurality of blades 12 include a plurality of
15 first blades 12A and a plurality of second blades 12B. In the plurality of blades 12,
the first blades 12A and the second blades 12B are alternately arranged in the
circumferential direction CD of the impeller 10 such that one or a plurality of second
blades 12B are located between the first blades 12A.
[0050]
20 As illustrated in Fig. 9 to Fig. 11, in the impeller 10, two of the second blades
12B are located between one of the first blades 12A and another one of the first
blades 12A that is located next to the one of the first blades 12A in the rotation
direction R. The number of the second blades 12B located between one of the first
blades 12A and another one of the first blades 12A that is located next to the one of
25 the first blades 12A in the rotation direction R is not limited to two and may also be
one or three or more. In other words, at least one second blade 12B of the plurality
of second blades 12B is located between two of the plurality of first blades 12A that
are next to each other in the circumferential direction CD.
[0051]
30 As illustrated in Fig. 10, in the first section of the impeller 10, which is obtained
22
by cutting portions with the first flat surface 71, which is perpendicular to the rotation
axis RS, the first blades 12A each have an inner circumferential end 14A and an outer
circumferential end 15A. The inner circumferential ends 14A are located closest to
the rotation axis RS in the radial directions centered on the rotation axis RS. The
5 outer circumferential ends 15A are located closer to an outer circumference than are
the inner circumferential ends 14A in the radial directions. In each of the first blades
12A, the inner circumferential end 14A is further forward than is the outer
circumferential end 15A in the rotation direction R of the impeller 10.
[0052]
10 As illustrated in Fig. 4, the inner circumferential ends 14A are each a leading
edge 14A1 of the first blade 12A and the outer circumferential ends 15A are each a
trailing edge 15A1 of the first blade 12A. As illustrated in Fig. 11, the impeller 10 has
the 14 first blades 12A. The number of the first blades 12A is, however, not limited
to 14 and may also be less than 14 or more than 14.
15 [0053]
As illustrated in Fig. 10, in the first section of the impeller 10, which is obtained
by cutting portions with the first flat surface 71, which is perpendicular to the rotation
axis RS, the second blades 12B each have an inner circumferential end 14B and an
outer circumferential end 15B. The inner circumferential ends 14B are located
20 closest to the rotation axis RS in the radial directions centered on the rotation axis RS.
The outer circumferential ends 15B are located closer to the outer circumference than
are the inner circumferential ends 14B in the radial directions. In each of the second
blades 12B, the inner circumferential end 14B is further forward than is the outer
circumferential end 15B in the rotation direction R of the impeller 10.
25 [0054]
As illustrated in Fig. 4, the inner circumferential ends 14B are each a leading
edge 14B1 of the second blade 12B and the outer circumferential ends 15B are each
a trailing edge 15B1 of the second blade 12B. As illustrated in Fig. 10, the impeller
10 has the 28 second blades 12B. The number of the second blades 12B is,
30 however, not limited to 28 and may also be less than 28 or more than 28.
23
[0055]
Next, the relationship of each of the first blades 12A and the corresponding one
of the second blades 12B is described below. As illustrated in Fig. 4 and Fig. 11, a
vane length of the first blade 12A is designed to be more closely equal to a vane
5 length of the second blade 12B as the first blade 12A is closer to the corresponding
one of the first side plate 13a and the second side plate 13b than the intermediate
position MP in a direction along the rotation axis RS.
[0056]
On the other hand, as illustrated in Fig. 4 and Fig. 10, the vane length of the
10 first blade 12A is designed to be greater than the vane length of the second blade
12B at a location at which the first blade 12A is closer to the main plate 11 than the
intermediate position MP in the direction along the rotation axis RS. In addition, the
vane length of the first blade 12A is designed to be increased as the first blade 12A is
closer to the main plate 11 in the direction along the rotation axis RS. As described
15 above, in Embodiment 1, the vane length of the first blade 12A is designed to be
greater than the vane length of the second blade 12B at a least some location in the
rotation axis RS. The vane length described here refers to the length of the first
blade 12A in a radial direction of the impeller 10 or the length of the second blade 12B
in a radial direction of the impeller 10.
20 [0057]
In the first section, which is illustrated in Fig. 9 and is closer to the main plate
11 than the intermediate position MP, as illustrated in Fig. 10, the diameter of a circle
C1, which passes the inner circumferential ends 14A of the plurality of first blades 12A
around the rotation axis RS as its center, that is, the inner diameter of the first blades
25 12A is referred to as an inner diameter ID1. The diameter of a circle C3, which
passes the outer circumferential ends 15A of the plurality of first blades 12A around
the rotation axis RS as its center, that is, the outer diameter of the first blades 12A is
referred to as an outer diameter OD1. Half of a difference between the outer
diameter OD1 and the inner diameter ID1 is defined as a vane length L1a of the first
30 blade 12A in the first section (vane length L1a = (outer diameter OD1 − inner
24
diameter ID1)/2).
[0058]
Here, the ratio of the inner diameter of the first blade 12A to the outer diameter
of the first blade 12A is lower than or equal to 0.7. In other words, the plurality of first
5 blades 12A have a ratio of lower than or equal to 0.7 of the inner diameter ID1 of the
respective inner circumferential ends 14A of the plurality of first blades 12A to the
outer diameter OD1 of the respective outer circumferential ends 15A of the plurality of
first blade 12A.
[0059]
10 In a typical centrifugal air-sending device, a vane length of a blade in a section
perpendicular to a rotation axis is shorter than a width dimension of the blade in a
direction of the rotation axis. In Embodiment 1, the maximum possible vane length
of the first blade 12A, that is, the vane length of the first blade 12A close to the main
plate 11 is designed to be shorter than a width dimension W (refer to Fig. 9) in a
15 direction of the rotation axis of the first blade 12A.
[0060]
In the first section, the diameter of a circle C2, which passes the inner
circumferential ends 14B of the plurality of second blades 12B around the rotation
axis RS as its center, that is, the inner diameter of the second blades 12B, is referred
20 to as an inner diameter ID2, which is larger than the inner diameter ID1 (inner
diameter ID2 > inner diameter ID1). The diameter of a circle C3, which passes the
outer circumferential ends 15B of the plurality of second blades 12B around the
rotation axis RS as its center, that is, the outer diameter of the second blades 12B is
referred to as an outer diameter OD2, which is equal to the outer diameter OD1 (outer
25 diameter OD2 = outer diameter OD1). Half of a difference between the outer
diameter OD2 and the inner diameter ID2 is defined as a vane length L2a of the
second blade 12B in the first section (vane length L2a = (outer diameter OD2 − inner
diameter ID2)/2). The vane length L2a of the second blade 12B in the first section is
shorter than the vane length L1a of the first blade 12A in the first section (vane length
30 L2a < vane length L1a).
25
[0061]
Here, the ratio of the inner diameter of the second blade 12B to the outer
diameter of the second blade 12B is lower than or equal to 0.7. In other words, the
plurality of second blades 12B have a ratio of lower than or equal to 0.7 of the inner
5 diameter ID2 of the respective inner circumferential ends 14B of the plurality of
second blades 12B to the outer diameter OD2 of the respective outer circumferential
ends 15B of the plurality of second blades 12B.
[0062]
On the other hand, in the second section, which is illustrated in Fig. 9 and is
10 closer to the corresponding one of the side plates 13 than the intermediate position
MP, as illustrated in Fig. 11, the diameter of a circle C7, which passes the inner
circumferential ends 14A of the plurality of first blades 12A around the rotation axis
RS as its center is referred to as an inner diameter ID3. The inner diameter ID3 is
larger than the inner diameter ID1 in the first section (inner diameter ID3 > inner
15 diameter ID1). The diameter of a circle C8, which passes the outer circumferential
ends 15A of the first blades 12A around the rotation axis RS as its center is referred
to as an outer diameter OD3. Half of a difference between the outer diameter OD3
and the inner diameter ID1 is defined as a vane length L1b of the first blade 12A in
the second section (vane length L1b = (outer diameter OD3 − inner diameter ID3)/2).
20 [0063]
In the second section, the diameter of a circle C7, which passes the inner
circumferential ends 14B of the second blades 12B around the rotation axis RS as its
center is referred to as an inner diameter ID4. The inner diameter ID4 is equal to the
inner diameter ID3 in the second section (inner diameter ID4 > inner diameter ID3).
25 The diameter of a circle C8, which passes the outer circumferential ends 15B of the
second blades 12B around the rotation axis RS as its center is referred to as an outer
diameter OD4. The outer diameter OD4 is equal to the outer diameter OD3 in the
second section (outer diameter OD4 = outer diameter OD3). Half of a difference
between the outer diameter OD4 and the inner diameter ID4 is defined as a vane
30 length L2b of the second blade 12B in the second section (vane length L2b = (outer
26
diameter OD4 − inner diameter ID4)/2). The vane length L2b of the second blade
12B in the second section is equal to the vane length L1b of the first blade 12A in the
second section (vane length L2b = vane length L1b).
[0064]
5 When the first blade 12A is viewed parallel to the rotation axis RS, the first
blade 12A in the second section illustrated in Fig. 11 overlaps the first blade 12A in
the first section illustrated in Fig. 10 such that the first blade 12A in the second section
does not protrude out from the outline of the first blade 12A in the first section. The
impeller 10 is thus designed to satisfy relationships of outer diameter OD3 = outer
10 diameter OD1, inner diameter ID3 ≥ inner diameter ID1, and vane length L1b ≤ vane
length L1a.
[0065]
Similarly, when the second blade 12B is viewed parallel to the rotation axis RS,
the second blade 12B in the second section illustrated in Fig. 11 overlaps the second
15 blade 12B in the first section illustrated in Fig. 10 such that the second blade 12B in
the second section does not protrude out from the outline of the second blade 12B in
the first section. The impeller 10 is thus designed to satisfy relationships of outer
diameter OD4 = outer diameter OD2, inner diameter ID4 ≥ inner diameter ID2, and
vane length L2b ≤ vane length L2a.
20 [0066]
Here, as described above, the ratio of the inner diameter ID1 of the first blades
12A to the outer diameter OD1 of the first blades 12A is lower than or equal to 0.7.
Since the blade 12 is designed to satisfy relationships of inner diameter ID3 ≥ inner
diameter ID1, inner diameter ID4 ≥ inner diameter ID2, inner diameter ID2 > inner
25 diameter ID1, the inner diameter of the first blades 12A is defined as a blade inner
diameter of the blades 12. Since the blade 12 is designed to satisfy relationships of
outer diameter OD3 = outer diameter OD1, outer diameter OD4 = outer diameter OD2,
outer diameter OD2 = outer diameter OD1, the outer diameter of the first blades 12A
is also defined as a blade outer diameter of the blades 12. When the blades 12
30 included in the impeller 10 is viewed as a whole, a ratio of the inner diameter of the
27
blades 12 to the outer diameter of the blades 12 is lower than or equal to 0.7.
[0067]
The blade inner diameter of the plurality of blades 12 is a diameter of the
respective inner circumferential ends of the plurality of blades 12. In other words,
5 the blade inner diameter of the plurality of blades 12 is a diameter of the leading
edges 14A1 of the plurality of blades 12. The blade outer diameter of the plurality of
blades 12 is also a diameter of the respective outer circumferential ends of the
plurality of blades 12. In other words, the blade outer diameter of the plurality of
blades 12 is a diameter of the trailing edges 15A1 and the trailing edges 15B1 of the
10 plurality of blades 12.
[0068]
Configurations of First Blades 12A and Second Blades 12B
The first blade 12A has a relationship of vane length L1a > vane length L1b in
comparison between the first section illustrated in Fig. 10 and the second section
15 illustrated in Fig. 11. In other words, the plurality of blades 12 each have a portion at
which the vane length in the first region is formed greater than the vane length in the
second region. More specifically, the first blade 12A has a portion at which the vane
length of the first blade 12A decreases from the main plate 11 to the corresponding
one of the side plates 13 in the axial direction of the rotation axis RS.
20 [0069]
Similarly, the second blade 12B has a relationship of vane length L2a > vane
length L2b in comparison between the first section illustrated in Fig. 10 and the
second section illustrated in Fig. 11. In other words, the second blade 12B has a
portion at which the vane length of the second blade 12B decreases from the main
25 plate 11 to the corresponding one of the side plates 13 in the axial direction of the
rotation axis RS.
[0070]
As illustrated in Fig. 3, the leading edges of the first blades 12A and the second
blades 12B are inclined such that the blade inner diameter increases from the main
30 plate 11 to the corresponding one of the side plates 13. In other words, the plurality
28
of blades 12 are formed such that the blade inner diameter is increased from the main
plate 11 to the corresponding one of the side plates 13 and have inclination portions
141A, which are each inclined such that the inner circumferential ends 14A included
in the leading edges 14A1 are away from the rotation axis RS. Similarly, the plurality
5 of blades 12 are formed such that the blade inner diameter is increased from the main
plate 11 to the corresponding one of the side plates 13 and have inclination portions
141B, which are each inclined such that the inner circumferential ends 14B included
in the leading edges 14B1 are away from the rotation axis RS.
[0071]
10 Sirocco Vane Portion and Turbo Vane Portion
As illustrated in Fig. 10 and Fig. 11, the first blades 12A each have a first
sirocco vane portion 12A1, which includes the outer circumferential end 15A and is
formed as a forward-curved blade, and a first turbo vane portion 12A2, which includes
the inner circumferential end 14A and is formed as a backward-curved blade. In a
15 radial direction of the impeller 10, the first sirocco vane portion 12A1 forms a portion
of the first blade 12A that is closer to the outer circumference than is the first turbo
vane portion 12A2, which forms a portion of the first blade 12A that is closer to an
inner circumference than is the first sirocco vane portion 12A1. In other words, the
first blade 12A is formed such that the first turbo vane portion 12A2 and the first
20 sirocco vane portion 12A1 are arranged sequentially from the rotation axis RS toward
the outer circumference in the radial direction of the impeller 10.
[0072]
In the first blade 12A, the first turbo vane portion 12A2 and the first sirocco
vane portion 12A1 are integrally formed with each other. The first turbo vane portion
25 12A2 forms the leading edge 14A1 of the first blade 12A and the first sirocco vane
portion 12A1 forms the trailing edge 15A1 of the first blade 12A. The first turbo vane
portion 12A2 linearly extends from the inner circumferential end 14A included in the
leading edge 14A1 toward the outer circumference in a radial direction of the impeller
10.
30 [0073]
29
In a radial direction of the impeller 10, a region of the first blade 12A in which
the first sirocco vane portion 12A1 is located is defined as a first sirocco region 12A11
and a region of the first blade 12A in which the first turbo vane portion 12A2 is located
is defined as a first turbo region 12A21. In the first blade 12A, the first turbo region
5 12A21 is larger than the first sirocco region 12A11 in a radial direction of the impeller
10.
[0074]
In the main-plate-side blade region 122a, which is the first region, and the sideplate-side blade region 122b, which is the second region, illustrated in Fig. 9, the
10 impeller 10 has a portion that has a relationship of first sirocco region 12A11 < first
turbo region 12A21 in a radial direction of the impeller 10. In the main-plate-side
blade region 122a, which is the first region, and the side-plate-side blade region 122b,
which is the second region, in the impeller 10 and the first blades 12A, a proportion
for which the first turbo vane portion 12A2 accounts is higher in a radial direction of
15 the impeller 10 than a proportion for which the first sirocco vane portion 12A1
accounts.
[0075]
Similarly, as illustrated in Fig. 10 and Fig. 11, the second blade 12B each have
a second sirocco vane portion 12B1, which includes the outer circumferential end 15B
20 and is formed as a forward-curved blade, and a second turbo vane portion 12B2,
which includes the inner circumferential end 14B and is formed as a backward-curved
blade. In a radial direction of the impeller 10, the second sirocco vane portion 12B1
forms a portion of the second blade 12B that is closer to the outer circumference than
is the second turbo vane portion 12B2, which forms a portion of the second blade 12B
25 that is closer to the inner circumference than is the second sirocco vane portion 12B1.
In other words, the second blade 12B is formed such that the second turbo vane
portion 12B2 and the second sirocco vane portion 12B1 are arranged sequentially
from the rotation axis RS toward the outer circumference in the radial direction of the
impeller 10.
30 [0076]
30
In the second blade 12B, the second turbo vane portion 12B2 and the second
sirocco vane portion 12B1 are integrally formed with each other. The second turbo
vane portion 12B2 forms the leading edge 14B1 of the second blade 12B and the
second sirocco vane portion 12B1 forms the trailing edge 15B1 of the of the second
5 blade 12B. The second turbo vane portion 12B2 linearly extends from the inner
circumferential end 14B included in the leading edge 14B1 toward the outer
circumference in a radial direction of the impeller 10.
[0077]
In a radial direction of the impeller 10, a region of the second blade 12B in
10 which the second sirocco vane portion 12B1 is located is defined as a second sirocco
region 12B11 and a region of the second blade 12B in which the second turbo vane
portion 12B2 is located is defined as a second turbo region 12B21. In the second
blade 12B, the second turbo region 12B21 is larger than the second sirocco region
12B11 in a radial direction of the impeller 10.
15 [0078]
In the main-plate-side blade region 122a, which is the first region, and the sideplate-side blade region 122b, which is the second region, illustrated in Fig. 9, the
impeller 10 has a portion that has a relationship of second sirocco region 12B11 <
second turbo region 12B21 in a radial direction of the impeller 10. In the main-plate20 side blade region 122a, which is the first region, and the side-plate-side blade region
122b, which is the second region, in the impeller 10 and the second blades 12B, a
proportion for which the second turbo vane portion 12B2 accounts is higher in a radial
direction of the impeller 10 than a proportion for which the second sirocco vane
portion 12B1 accounts.
25 [0079]
In the configuration described above, in the main-plate-side blade region 122a
and the side-plate-side blade region 122b in the plurality of blades 12, a region in
which a turbo vane portion is ranged is larger than a region in which a sirocco vane
portion is ranged in a radial direction of the impeller 10. In other words, in the main30 plate-side blade region 122a and the side-plate-side blade region 122b, the plurality
31
of blades 12 have a portion in which a proportion for which a turbo vane portion
accounts is higher in a radial direction of the impeller 10 than a proportion for which a
sirocco vane portion accounts and thus has a portion that has a relation of sirocco
portion < turbo portion. In other words, the plurality of blades 12 each have a portion
5 in which the proportion for which the turbo vane portion accounts is higher in the
radial direction than the proportion for which the sirocco vane portion accounts in the
first region and the second region. Such a relationship on the proportion for which
the sirocco vane portion accounts and the proportion for which the turbo vane portion
accounts in a radial direction from the rotation axis RS may also be satisfied through
10 all regions of the main-plate-side blade region 122a, which is the first region, and the
side-plate-side blade region 122b, which is the second region.
[0080]
Through all regions of the main-plate-side blade region 122a and the sideplate-side blade region 122b, the plurality of blades 12 are not limited to the ones in
15 which a proportion for which a turbo vane portion accounts is higher in a radial
direction of the impeller 10 than a proportion for which a sirocco vane portion
accounts and is not limited to have a relation of sirocco portion < turbo portion. The
plurality of blades 12 may also be each formed such that the proportion for which the
sirocco vane portion accounts is lower in the radial direction than or equal to the
20 proportion for which the turbo vane portion accounts in the first region and the second
region.
[0081]
Outlet Angle
As illustrated in Fig. 10, an outlet angle at the first sirocco vane portion 12A1
25 included in the first blade 12A in the first section is defined as an outlet angle α1.
The outlet angle α1 refers to an angle located at an intersection of a circular arc of the
circle C3 centered on the rotation axis RS and the outer circumferential end 15A and
formed between a tangent line TL1 of the circle and a center line CL1 of the first
sirocco vane portion 12A1 at the outer circumferential end 15A. This outlet angle α1
30 is larger than 90 degrees.
32
[0082]
An outlet angle at the second sirocco vane portion 12B1 included in the second
blade 12B in the first section is defined as an outlet angle α2. The outlet angle α2
refers to an angle located at an intersection of a circular arc of the circle C3 centered
5 on the rotation axis RS and the outer circumferential end 15B and formed between a
tangent line TL2 of the circle and a center line CL2 of the second sirocco vane portion
12B1 at the outer circumferential end 15B. The outlet angle α2 is larger than 90
degrees.
[0083]
10 The outlet angle α2 at the second sirocco vane portion 12B1 is equal to the
outlet angle α1 at the first sirocco vane portion 12A1 (outlet angle α2 = outlet angle
α1). When the first sirocco vane portion 12A1 and the second sirocco vane portion
12B1 are viewed parallel to the rotation axis RS, the first sirocco vane portion 12A1
and the second sirocco vane portion 12B1 are each arcuate and convex and protrude
15 in a direction opposite to the rotation direction R.
[0084]
As illustrated in Fig. 11, also in the second section of the impeller 10, the outlet
angle α1 at the first sirocco vane portion 12A1 is equal to the outlet angle α2 at the
second sirocco vane portion 12B1. In other words, the plurality of blades 12 each
20 have the sirocco vane portion located from the main plate 11 and the corresponding
one of the side plates 13 and formed as a forward-curved blade at which the outlet
angle is formed larger than 90 degrees.
[0085]
As illustrated in Fig. 10, an outlet angle at the first turbo vane portion 12A2
25 included in the first blade 12A in the first section is defined as an outlet angle β1.
The outlet angle β1 refers to an angle located at an intersection of a circular arc of the
circle C4 centered on the rotation axis RS and the first turbo vane portion 12A2 and
formed between a tangent line TL3 of the circle and a center line CL3 of the first turbo
vane portion 12A2. This outlet angle β1 is smaller than 90 degrees.
30 [0086]
33
An outlet angle at the second turbo vane portion 12B2 included in the second
blade 12B in the first section is defined as an outlet angle β2. The outlet angle β2
refers to an angle located at an intersection of a circular arc of the circle C4 centered
on the rotation axis RS and the second turbo vane portion 12B2 and formed between
5 a tangent line TL4 of the circle and a center line CL4 of the second turbo vane portion
12B2. The outlet angle β2 is smaller than 90 degrees.
[0087]
The outlet angle β2 at the second turbo vane portion 12B2 is equal to the outlet
angle β1 at the first turbo vane portion 12A2 (outlet angle β2 = outlet angle β1).
10 [0088]
An illustration is not provided in Fig. 11 that, also in the second section of the
impeller 10, the outlet angle β1 at the first turbo vane portion 12A2 is equal to the
outlet angle β2 at the second turbo vane portion 12B2. The outlet angle β1 and the
outlet angle β2 are also each smaller than 90 degrees.
15 [0089]
Radial Vane Portion
As illustrated in Fig. 10 and Fig. 11, the first blades 12A each have a first radial
vane portion 12A3, which connects between the corresponding one of the first turbo
vane portions 12A2 and the corresponding one of the first sirocco vane portions 12A1.
20 The first radial vane portion 12A3 is formed as a radial vane that linearly extends in a
radial direction of the impeller 10.
[0090]
Similarly, the second blades 12B each have a second radial vane portion 12B3,
which connects between the corresponding one of the second turbo vane portions
25 12B2 and the corresponding one of the second sirocco vane portions 12B1. The
second radial vane portion 12B3 is formed as a radial vane that linearly extends in a
radial direction of the impeller 10.
[0091]
The vane angle of the first radial vane portion 12A3 and the vane angle of the
30 second radial vane portion 12B3 are each 90 degrees. More specifically, an angle
34
formed between a tangent line at an intersection of a center line of the first radial
vane portion 12A3 and the circle C5 centered on the rotation axis RS and the center
line of the first radial vane portion 12A3 is 90 degrees. An angle formed between a
tangent line at an intersection of a center line of the second radial vane portion 12B3
5 and the circle C5 centered on the rotation axis RS and the center line of the second
radial vane portion 12B3 is also 90 degrees.
[0092]
Vane Interval
When the interval between two blades 12 of the plurality of blades 12 that are
10 next to each other in the circumferential direction CD is defined as an vane interval,
as illustrated in Fig. 10 and Fig. 11, the vane intervals of the plurality of blades 12
each expand from the corresponding one of the leading edges 14A1 toward the
corresponding one of the trailing edges 15A1. Similarly, the vane intervals of the
plurality of blades 12 each expand from the corresponding one of the leading edges
15 14B1 toward the corresponding one of the trailing edges 15B1.
[0093]
Specifically, the vane intervals of the turbo vane portions, which include the first
turbo vane portions 12A2 and the second turbo vane portions 12B2, each expand
from the inner circumference to the outer circumference. In other words, the vane
20 intervals of the turbo vane portions of the impeller 10 each expand from the inner
circumference to the outer circumference. The vane intervals of the sirocco vane
portions, which include the first sirocco vane portions 12A1 and the second sirocco
vane portions 12B1, each are wider than the vane interval of the turbo vane portions
and expand from the inner circumference to the outer circumference.
25 [0094]
In other words, the vane interval between each of the first turbo vane portions
12A2 and the corresponding one of the second turbo vane portions 12B2 expands
from the inner circumference to the outer circumference. The vane interval between
any ones of the second turbo vane portions 12B2 that are next to each other also
30 expands from the inner circumference to the outer circumference. The vane interval
35
between each of the first sirocco vane portions 12A1 and the corresponding one of
the second sirocco vane portions 12B1 is also wider than the vane interval of the
turbo vane portions and expands from the inner circumference to the outer
circumference. The vane interval between any ones of the second sirocco vane
5 portions 12B1 that are next to each other is also wider than the vane interval of the
turbo vane portions and expands from the inner circumference to the outer
circumference.
[0095]
Relationship between Impeller 10 and Scroll Casing 40
10 Fig. 12 is a schematic view that illustrates a relationship between the impeller
10 and the scroll casing 40 included in the centrifugal air-sending device 100
illustrated in Fig. 2 with the centrifugal air-sending device 100 viewed in a section
taken along line A-A. Fig. 13 is a schematic view that illustrates a relationship
between the blades 12 and the bell mouth 46 with the impeller 10 illustrated in Fig. 12
15 viewed parallel to the rotation axis RS. As illustrated in Fig. 12 and Fig. 13, the
blade outer diameter OD of the respective outer circumferential ends of the plurality of
blades 12 is larger than an inner diameter BI of the bell mouth 46 included in the
scroll casing 40. The blade outer diameter OD of the plurality of blades 12 is equal
to the outer diameter OD1 and the outer diameter OD2 of the first blades 12A
20 illustrated in Fig. 10 and the outer diameter OD3 and the outer diameter OD4 of the
second blades 12B illustrated in Fig. 11 (blade outer diameter OD = outer diameter
OD1 = outer diameter OD2 = outer diameter OD3 = outer diameter OD4).
[0096]
The impeller 10 has a portion in which the first turbo region 12A21 is larger
25 than the first sirocco region 12A11 in the radial direction from the rotation axis RS. In
other words, the impeller 10 and the plurality of first blades 12A have a portion in
which a proportion for which the first turbo vane portion 12A2 accounts is higher in
the radial direction from the rotation axis RS than a proportion for which the first
sirocco vane portion 12A1 accounts and thus have a portion that has a relation of first
30 sirocco vane portion 12A1 < first turbo vane portion 12A2. Such a relationship on
36
the proportion for which the first sirocco vane portion 12A1 accounts and the
proportion for which the first turbo vane portion 12A2 accounts in a radial direction
from the rotation axis RS may also be satisfied through all regions of the main-plateside blade region 122a, which is the first region, and the side-plate-side blade region
5 122b, which is the second region.
[0097]
The impeller 10 and the plurality of first blades 12A are not limited to the ones
in which a proportion for which the first turbo vane portion 12A2 accounts is higher in
a radial direction from the rotation axis RS than a proportion for which the first sirocco
10 vane portion 12A1 accounts and thus have a relation of first sirocco vane portion
12A1 < first turbo vane portion 12A2. The impeller 10 and the first blades 12A may
also be formed such that a proportion for which the first turbo vane portion 12A2
accounts is lower in a radial direction from the rotation axis RS than or equal to a
proportion for which the first sirocco vane portion 12A1 accounts.
15 [0098]
Similarly, the impeller 10 has a portion in which the second turbo region 12B21
is larger than the second sirocco region 12B11 in the radial direction from the rotation
axis RS. In other words, the impeller 10 and the second blades 12B have a portion
in which a proportion for which the second turbo vane portion 12B2 accounts is higher
20 in a radial direction from the rotation axis RS than a proportion for which the second
sirocco vane portion 12B1 accounts and thus have a portion that has a relation of
second sirocco vane portion 12B1 < second turbo vane portion 12B2. Such a
relationship on the proportion for which the second sirocco vane portion 12B1 and the
proportion for which the second turbo vane portion 12B2 accounts in a radial direction
25 from the rotation axis RS may also be satisfied through all regions of the main-plateside blade region 122a, which is the first region, and the side-plate-side blade region
122b, which is the second region.
[0099]
The impeller 10 and the second blades 12B are not limited to the ones in which
30 a proportion for which the second turbo vane portion 12B2 accounts is higher in a
37
radial direction from the rotation axis RS than a proportion for which the second
sirocco vane portion 12B1 accounts and thus have a relation of second sirocco vane
portion 12B1 < second turbo vane portion 12B2. The impeller 10 and the second
blades 12B may also be formed such that a proportion for which the second turbo
5 vane portion 12B2 accounts is lower in a radial direction centered on the rotation axis
RS than or equal to a proportion for which the second sirocco vane portion 12B1
accounts.
[0100]
Fig. 14 is a schematic view that illustrates a relationship between the impeller
10 10 and the scroll casing 40 included in the centrifugal air-sending device 100
illustrated in Fig. 2 with the centrifugal air-sending device 100 viewed in the section
taken along line A-A. Fig. 15 is a schematic view that illustrates a relationship
between the blades 12 and the bell mouth 46 with the impeller 10 illustrated in Fig. 14
viewed parallel to the rotation axis RS. An open arrow L illustrated in Fig. 14
15 represents a direction in which the impeller 10 is viewed parallel to the rotation axis
RS.
[0101]
As illustrated in Fig. 14 and Fig. 15, a circle is defined as a circle C1a that
passes the inner circumferential ends 14A of the plurality of first blades 12A centered
20 on the rotation axis RS at a connection position at which the first blades 12A and the
main plate 11 are connected to each other when the circle is viewed parallel to the
rotation axis RS. The diameter of the circle C1a, that is, an inner diameter of the first
blades 12A at the connection position, at which the first blades 12A and the main
plate 11 are connected to each other, is defined as an inner diameter ID1a.
25 [0102]
A circle is also defined as a circle C2a that passes the inner circumferential
ends 14B of the plurality of second blades 12B centered on the rotation axis RS at a
connection position at which the second blades 12B and the main plate 11 are
connected to each other when the circle is viewed parallel to the rotation axis RS.
30 The diameter of the circle C2a, that is, an inner diameter of the second blades 12B at
38
the connection position, at which the first blades 12A and the main plate 11 are
connected to each other, is defined as an inner diameter ID2a. The inner diameter
ID2a is larger than the inner diameter ID1a (inner diameter ID2a > inner diameter
ID1a).
5 [0103]
When the circle C3a is viewed parallel to the rotation axis RS, the diameter of
the circle C3a, which passes the outer circumferential ends 15A of the plurality of first
blades 12A and the outer circumferential ends 15B of the second blades 12B around
the rotation axis RS as its center, that is, the outer diameter of the plurality of blades
10 12 is also referred to as a blade outer diameter OD.
[0104]
A circle is also defined as a circle C7a that passes the inner circumferential
ends 14A of the plurality of first blades 12A centered on the rotation axis RS at a
connection position at which the first blades 12A and the corresponding one of the
15 side plates 13 are connected to each other when the circle is viewed parallel to the
rotation axis RS. The diameter of the circle C7a, that is, an inner diameter of the first
blades 12A at the connection position, at which the first blades 12A and the
corresponding one of the side plates 13 are connected to each other, is defined as an
inner diameter ID3a.
20 [0105]
A circle is also defined as a circle C7a that passes the inner circumferential
ends 14B of the plurality of second blades 12B centered on the rotation axis RS at a
connection position at which the second blades 12B and the corresponding one of the
side plates 13 are connected to each other when the circle is viewed parallel to the
25 rotation axis RS. The diameter of the circle C7a, that is, an inner diameter of the
second blades 12B at the connection position, at which the second blades 12B and
the corresponding one of the side plates 13 are connected to each other, is defined
as an inner diameter ID4a.
[0106]
30 As illustrated in Fig. 14 and Fig. 15, when the bell mouth 46 is viewed parallel
39
to the rotation axis RS, the position of the inner diameter BI of the bell mouth 46 is
located between the inner diameter ID1a of the first blades 12A, which is at the main
plate 11, and the inner diameter ID3 of the first blades 12A, which is at the
corresponding one of the side plates 13, and in the regions of the first turbo vane
5 portions 12A2 and the second turbo vane portions 12B2. More specifically, the inner
diameter BI of the bell mouth 46 is larger than the inner diameter ID1a of the first
blades 12A, which is at the main plate 11, and smaller than the inner diameter ID3a of
the first blades 12A, which is at the corresponding one of the side plates 13.
[0107]
10 In other words, the inner diameter BI of the bell mouth 46 is larger than the
blade inner diameter of the plurality of blades 12 that is at the main plate 11 and
smaller than the blade inner diameter of the plurality of blades 12 that is at the
corresponding one of the side plates 13. In other words, when the inner
circumferential edge portion 46a is viewed parallel to the rotation axis RS, the inner
15 circumferential edge portion 46a, which forms the inner diameter BI of the bell mouth
46, is located between the circle C1a and the circle C7a and in the regions of the first
turbo vane portions 12A2 and the second turbo vane portions 12B2.
[0108]
As illustrated in Fig. 14 and Fig. 15, when the bell mouth 46 is viewed parallel
20 to the rotation axis RS, the position of the inner diameter BI of the bell mouth 46 is
located between the inner diameter ID2a of the second blades 12B, which is at the
main plate 11, and the inner diameter ID4a of the second blades 12B, which is at the
corresponding one of the side plates 13, and in the regions of the first turbo vane
portions 12A2 and the second turbo vane portions 12B2. More specifically, the inner
25 diameter BI of the bell mouth 46 is larger than the inner diameter ID2a of the second
blades 12B, which is at the main plate 11, and smaller than the inner diameter ID4a of
the second blades 12B, which is at the corresponding one of the side plates 13.
[0109]
In other words, the inner diameter BI of the bell mouth 46 is larger than the
30 blade inner diameter of the plurality of blades 12 that is at the main plate 11 and
40
smaller than the blade inner diameter of the plurality of blades 12 that is at the
corresponding one of the side plates 13. More specifically, the inner diameter BI of
the bell mouth 46 is larger than the blade inner diameter of the respective inner
circumferential ends of the plurality of blades 12 in the first region and smaller than
5 the blade inner diameter of the respective inner circumferential ends of the plurality of
blades 12 in the second region. In other words, when the inner circumferential edge
portion 46a is viewed parallel to the rotation axis RS, the inner circumferential edge
portion 46a, which forms the inner diameter BI of the bell mouth 46, is located
between the circle C2a and the circle C7a and in the regions of the first turbo vane
10 portions 12A2 and the second turbo vane portions 12B2.
[0110]
As illustrated in Fig. 14 and Fig. 15, a radial length of each of the first sirocco
vane portions 12A1 and the second sirocco vane portions 12B1 in a radial direction of
the impeller 10 is defined as a distance SL. The closest-approach distance between
15 which the plurality of blades 12 in the impeller 10 are closest to the circumferential
wall 44c of the scroll casing 40, in the centrifugal air-sending device 100 is also
defined as a distance MS. In this case, the distance MS in the centrifugal airsending device 100 is larger than twice the distance SL (distance MS > distance SL ×
2). The distance MS, which is marked in the section of the centrifugal air-sending
20 device 100 taken along line A-A illustrated in Fig. 14, is the closest-approach distance
between which the plurality of blades 12 are closest to the circumferential wall 44c of
the scroll casing 40 and is not necessarily marked in the section taken along line A-A.
[0111]
Fig. 16 is a schematic view that illustrates a relationship between the impeller
25 10 and the bell mouth 46 included in the centrifugal air-sending device 100 illustrated
in Fig. 2 with the centrifugal air-sending device 100 viewed in the section taken along
line A-A. Fig. 17 is a schematic view that illustrates a relationship between the
blades 12 and the bell mouth 46 with the impeller 10 illustrated in Fig. 16 viewed in a
second section and viewed parallel to the rotation axis RS. The blades 12 located
30 outside the inner diameter BI of the bell mouth 46 are across the first sirocco vane
41
portions 12A1 and the first turbo vane portion 12A2. The blades 12 located outside
the inner diameter BI of the bell mouth 46 are also across the second sirocco vane
portions 12B1 and the second turbo vane portions 12B2.
[0112]
5 In addition, when the bell mouth 46 is viewed parallel to the rotation axis RS, a
region of portions of the plurality of blades 12 located closer to the outer
circumference than is an inner circumferential side end portion 46b, which is an inner
circumferential end portion of the bell mouth 46 in the radial directions from the
rotation axis RS, is defined as an outer circumferential region 12R. The impeller 10
10 is formed such that the proportion for which the first sirocco vane portion 12A1
accounts is higher than or equal to the proportion for which the first turbo vane portion
12A2 accounts in the outer circumferential region 12R. In other words, when the first
sirocco region 12A11 is viewed parallel to the rotation axis RS, in the outer
circumferential region 12R, which is located closer to the outer circumference than is
15 the inner circumferential side end portion 46b of the bell mouth 46, the first sirocco
region 12A11 is larger than the first turbo region 12A21a in the radial directions from
the rotation axis RS. The inner circumferential side end portion 46b is ring-shaped
centered on the rotation axis RS and forms the inner circumferential edge portion 46a.
[0113]
20 When the first turbo region 12A21a is viewed parallel to the rotation axis RS,
the first turbo region 12A21a is a region in the first turbo region 12A21 and closer to
the outer circumference than is the inner circumferential side end portion 46b of the
bell mouth 46. When the first turbo vane portions 12A2 that define the first turbo
region 12A21a are defined as first turbo vane portions 12A2a, the outer
25 circumferential region 12R of the impeller 10 preferably has the proportion for which
the first sirocco vane portion 12A1 accounts larger than or equal to the proportion for
which the first turbo vane portion 12A2a accounts. Such a relationship on the
proportion for which the first sirocco vane portion 12A1 and the proportion for which
the first turbo vane portion 12A2a accounts in the outer circumferential region 12R
30 may also be satisfied through all regions of the main-plate-side blade region 122a,
42
which is the first region, and the side-plate-side blade region 122b, which is the
second region.
[0114]
The impeller 10 is further preferably formed such that the proportion for which
5 the second sirocco vane portion 12B1 accounts is higher than or equal to the
proportion for which the second turbo vane portion 12B2 accounts in the outer
circumferential region 12R. In other words, when the impeller 10 is viewed parallel
to the rotation axis RS, in the outer circumferential region 12R of the impeller 10,
which is located closer to the outer circumference than is the inner circumferential
10 side end portion 46b of the bell mouth 46, the second sirocco region 12B11 is larger
than the second turbo region 12B21a in the radial direction from the rotation axis RS.
[0115]
When the second turbo region 12B21a is viewed parallel to the rotation axis RS,
the second turbo region 12B21a is a region in the second turbo region 12B21 and
15 closer to the outer circumference than is the inner circumferential side end portion
46b of the bell mouth 46. When the second turbo vane portions 12B2 that define the
second turbo region 12B21a are defined as second turbo vane portions 12B2a, the
outer circumferential region 12R of the impeller 10 preferably has the proportion for
which the second sirocco vane portions 12B1 account larger than or equal to the
20 proportion for which the second turbo vane portions 12B2a account. Such a
relationship on the proportion for which the second sirocco vane portion 12B1 and the
proportion for which the second turbo vane portion 12B2a accounts in the outer
circumferential region 12R may also be satisfied through all regions of the main-plateside blade region 122a, which is the first region, and the side-plate-side blade region
25 122b, which is the second region.
[0116]
Fig. 18 is a conceptual view that illustrates a relationship between the impeller
10 and the bell mouth 46 illustrated in Fig. 16 and Fig. 17. As illustrated in Fig. 18,
the blades 12 have blade inner portions 22, which extend further inward than the
30 inner circumferential side end portion 46b of the bell mouth 46 in the radial directions
43
from the rotation axis RS. The blade inner portions 22 are located at regions of the
plurality of blades 12 in which the inner diameter BI of the bell mouth 46 is located.
[0117]
The plurality of blades 12 each have the vane length in the first region, which is
5 formed greater than the vane length in the second region. The plurality of blades 12
also each have, in the vane length of the blades 12 in the radial direction, a portion in
which the proportion for which the turbo vane portion 24 accounts is higher in a radial
direction than the proportion for which the sirocco vane portion 23 accounts in any of
the first region and the second region. As described above, the first region is the
10 main-plate-side blade region 122a and the second region is the side-plate-side blade
region 122b.
[0118]
In the radial directions, portions of the plurality of blades 12 that are further
outside than is an outer diameter BO of the inner circumferential side end portion 46b
15 of the bell mouth 46 is defined as an blade outer circumferential portion 26. The
blade outer circumferential portion 26 is formed such that the proportion for which the
sirocco vane portion 23 accounts is higher in the radial direction than or equal to the
proportion for which the turbo vane portion 24 accounts in any of the first region and
the second region. In other words, as illustrated in Fig. 18, in the radial length of the
20 blades 12, the proportion for which an outer sirocco vane portion 23a, which is
located further outside than is the outer diameter of the inner circumferential side end
portion 46b of the bell mouth 46, accounts is specified to be higher than or equal to
the proportion for which an outer turbo vane portion 24a accounts.
[0119]
25 The first sirocco vane portions 12A1 and the second sirocco vane portions
12B1 are collectively referred to as the sirocco vane portions 23 illustrated in Fig. 18.
The first turbo vane portions 12A2 and the second turbo vane portions 12B2 are
collectively referred to as the turbo vane portions 24 illustrated in Fig. 18. The first
sirocco vane portions 12A1 and the second sirocco vane portions 12B1, which are
30 further outside than is the inner circumferential side end portion 46b of the bell mouth
44
46 when the sirocco vane portions are viewed parallel to the rotation axis RS, are
collectively referred to as the outer sirocco vane portions 23a illustrated in Fig. 18.
The outer turbo vane portions 24a are also portions of the first turbo vane portions
12A2 and the second turbo vane portions 12B2 that are closer to the outer
5 circumference than is the inner circumferential side end portion 46b of the bell mouth
46 when the turbo vane portions are viewed parallel to the rotation axis RS. The first
turbo vane portions 12A2a and the second turbo vane portions 12B2a are also
collectively referred to as the outer turbo vane portions 24a.
[0120]
10 [Operation of Centrifugal Air-sending Device 100]
Operation of the centrifugal air-sending device is described below with
reference to Fig. 18. When the motor 50 operates, the plurality of blades 12 in the
centrifugal air-sending device 100 rotate about the rotation axis RS through a motor
shaft 51 and the main plate 11. Air outside the scroll casing 40 of the centrifugal air15 sending device 100 is thus sucked from the casing suction ports 45 into the impeller
10 and blown out from the impeller 10 into the scroll casing 40 through pressurerising action performed by the impeller 10. The air blown out from the impeller 10
into the scroll casing 40 is decelerated at an expansion air passage partly defined by
the circumferential wall 44c of the scroll casing 40, recovers static pressure, and is
20 blown out from the discharge port 42a illustrated in Fig. 1 to the outside.
[0121]
[Advantageous Effects of Centrifugal Air-sending Device 100]
Fig. 19 is a sectional view that illustrates a centrifugal air-sending device 100L
according to a comparative example. In the centrifugal air-sending device 100L
25 according to the comparative example, portions of the blades 12 that are indicated by
a region WS and located further outside than is the inner circumferential side end
portion 46b of the bell mouth 46 are only portions formed as sirocco vane portions 23.
An airflow AR that is blown out from an impeller 10L and passes along the inner wall
surface of the bell mouth 46 thus collides with portions of the sirocco vane portions 23,
30 which each have a large outlet angle and at which the airflow passes at increased
45
inflow velocity when the airflow passes into the impeller 10L again. The airflow AR
that collides with the sirocco vane portions 23 thus causes noise generated from the
centrifugal air-sending device 100L and deterioration in input.
[0122]
5 On the other hand, the blade outer circumferential portion 26 in the centrifugal
air-sending device 100 according to Embodiment 1 is formed such that the proportion
for which the sirocco vane portion 23 accounts is higher in the radial direction than or
equal to the proportion for which the turbo vane portion 24 accounts in the first region
and the second region. The centrifugal air-sending device 100, which has the
10 configuration described above, is configured to further increase a pressure of an
airflow blown out from the impeller 10 and an air volume in comparison with a
centrifugal air-sending device that does not have the configuration described above.
The centrifugal air-sending device 100 has an increased proportion for which the
sirocco vane portions 23 account and is thus configured to further increase dynamic
15 pressure and thus increase both the air volume of an airflow and the pressure of the
airflow. In the centrifugal air-sending device 100, which has the configuration
described above, an airflow AR that passes along an inner wall surface of the bell
mouth 46 passes into the impeller 10 again thus collides with the turbo vane portions
24, which each have a small outlet angle and at which the airflow passes at
20 decreased inflow velocity. As a result, in the centrifugal air-sending device 100,
when the airflow that passes along the inner wall surface of the bell mouth 46 passes
into the impeller 10 again, noise generated from the airflow is thus prevented and
deterioration in input is prevented as well. The centrifugal air-sending device 100
allows an airflow to pass into the turbo vane portions 24 when the airflow passes into
25 the impeller 10 again and thus reduces loss at a time when the airflow collides with
the blades 12 and resistance at a time when the impeller 10 rotates. Input is thus
reduced.
[0123]
The centrifugal air-sending device according to Embodiment 1, in which the
30 proportion for which the sirocco vane portion 23 accounts is higher than or equal to
46
the proportion for which the turbo vane portion 24 accounts at portions of the plurality
of blades 12 that are further outside than is the inner circumferential side end portion
46b of the bell mouth 46, is also configured to increase pressure and an air volume.
[0124]
5 Embodiment 2
Fig. 20 is a sectional view that schematically illustrates a centrifugal air-sending
device 100 according to Embodiment 2. Components that are the same in
configuration as those of the centrifugal air-sending device 100 or other devices
illustrated in Fig. 1 to Fig. 18 are given the same reference signs and description of
10 such components is omitted. The centrifugal air-sending device 100 according to
Embodiment 2 is to be further specified in relationship between the impeller 10 and
the scroll casing 40 included in the centrifugal air-sending device 100 according to
Embodiment 1.
[0125]
15 The blades 12 of the impeller 10 have a third region 122c and a fourth region
122d.
The third region 122c is in the side-plate-side blade region 122b, which is the second
region, and is a portion in which the proportion for which the turbo vane portion 24
accounts is higher in the radial direction than the proportion for which the sirocco
20 vane portion 23 accounts. The fourth region 122d is in the side-plate-side blade
region 122b, which is the second region, and is a portion in which the proportion for
which the turbo vane portion 24 accounts is lower in the radial direction than the
proportion for which the sirocco vane portion 23 accounts.
[0126]
25 The third region 122c is closer to the main plate 11 than is the fourth region
122d in the axial direction of the rotation axis RS. The fourth region 122d is closer to
the corresponding one of the side plates 13 than is the third region 122c in the axial
direction of the rotation axis RS. The impeller 10 is formed such that, in the sideplate-side blade region 122b, which is the second region, the proportion for which the
30 third region 122c accounts in the axial direction of the rotation axis RS is higher in the
47
axial direction of the rotation axis RS than the proportion for which the fourth region
122d accounts.
[0127]
[Advantageous Effects of Centrifugal Air-sending Device 100]
5 The centrifugal air-sending device 100 according to Embodiment 2 has the
third region 122c and the fourth region 122d in the side-plate-side blade region 122b,
which is the second region. The centrifugal air-sending device 100 according to
Embodiment 2, which has a proportion for which the sirocco vane portions 23 that is
increased from the main plate 11 to the corresponding one of the side plates 13, is
10 configured to further increase pressure and an air volume in comparison with the
centrifugal air-sending device 100 according to Embodiment 1. The centrifugal airsending device 100 according to Embodiment 2, which has the same configuration as
the centrifugal air-sending device 100 according to Embodiment 1, is also configured
to produce the same effects as the centrifugal air-sending device 100 according to
15 Embodiment 1.
[0128]
Embodiment 3
Fig. 21 is a sectional view that schematically illustrates a centrifugal air-sending
device 100 according to Embodiment 3. Fig. 22 is an enlarged view that illustrates a
20 portion of the impeller 10 included in the centrifugal air-sending device 100 according
to Embodiment 3 that is in range E in the impeller 10 illustrated in Fig. 6.
Components that are the same in configuration as those of the centrifugal air-sending
device 100 or other devices illustrated in Fig. 1 to Fig. 20 are given the same
reference signs and description of such components is omitted. The centrifugal air25 sending device 100 according to Embodiment 3 is to be further specified in
configuration of the impeller 10 included in the centrifugal air-sending device 100
according to Embodiment 1 and Embodiment 2.
[0129]
As illustrated in Fig. 21 and Fig. 22, the blades 12 have the turbo vane portions
30 24 and the sirocco vane portions 23 separated from each other in the side-plate-side
48
blade region 122b, which is the second region. The blades 12 have separation
portions 25 between the turbo vane portions 24 and the sirocco vane portions 23 in
the radial directions centered on the rotation axis RS.
[0130]
5 The separation portions 25 are each a through-hole that passes through the
blades 12 in the radial directions centered on the rotation axis RS. The separation
portions 25 are portions that are recessed from ends of the blades 12 located closest
to the corresponding one of the side plates 13 toward the main plate 11 in the axial
direction of the rotation axis RS. The separation portions 25 are opened only in the
10 side-plate-side blade region 122b, which is the second region.
[0131]
[Advantageous Effects of Centrifugal Air-sending Device 100]
The centrifugal air-sending device 100 according to Embodiment 3, in which
the turbo vane portions 24 and the sirocco vane portions 23 are separated from each
15 other, is configured to reduce loss caused by an airflow that passes into the sirocco
vane portions 23. After an airflow leaks from the turbo vane portions 24, which are
separated from the sirocco vane portions 23, and passes behind the turbo vane
portions 24, the airflow is recovered at the sirocco vane portions 23, which are
located behind the turbo vane portions 24, and loss is thus reduced. The centrifugal
20 air-sending device 100 according to Embodiment 3, which has the same configuration
as the centrifugal air-sending device 100 according to Embodiment 1, is also
configured to produce the same effects as the centrifugal air-sending device 100
according to Embodiment 1.
[0132]
25 Embodiment 4
Fig. 23 is a sectional view that schematically illustrates a centrifugal air-sending
device 100 according to Embodiment 4. Fig. 24 is an enlarged view that illustrates a
portion of the impeller 10 included in the centrifugal air-sending device 100 according
to Embodiment 4 that is in range E in the impeller 10 illustrated in Fig. 6.
30 Components that are the same in configuration as those of the centrifugal air-sending
49
device 100 or other devices illustrated in Fig. 1 to Fig. 22 are given the same
reference signs and description of such components is omitted. The centrifugal airsending device 100 according to Embodiment 4 is to be further specified in
configuration of the impeller 10 included in the centrifugal air-sending device 100
5 according to Embodiment 3.
[0133]
As illustrated in Fig. 23 and Fig. 24, the blades 12 have the turbo vane portions
24 and the sirocco vane portions 23 separated from each other in the main-plate-side
blade region 122a, which is the first region, and the side-plate-side blade region 122b,
10 which is the second region. The blades 12 have separation portions 25a between
the turbo vane portions 24 and the sirocco vane portions 23 in the radial directions
centered on the rotation axis RS.
[0134]
The separation portions 25a are each a through-hole that passes through the
15 blades 12 in the radial directions centered on the rotation axis RS. The separation
portions 25a are portions that are recessed from ends of the blades 12 located
closest to the corresponding one of the side plates 13 toward the main plate 11 in the
axial direction of the rotation axis RS. The separation portions 25a are opened in
the main-plate-side blade region 122a, which is the first region, and the side-plate20 side blade region 122b, which is the second region. The bottom portions of the
separation portions 25a in the axial direction of the rotation axis RS may also be
located at the main plate 11.
[0135]
[Advantageous Effects of Centrifugal Air-sending Device 100]
25 The centrifugal air-sending device 100 according to Embodiment 4, in which
the turbo vane portions 24 and the sirocco vane portions 23 are separated from each
other, is configured to reduce loss caused by an airflow that passes into the sirocco
vane portions 23. The centrifugal air-sending device 100 according to Embodiment
4, which has the same configuration as the centrifugal air-sending device 100
30 according to Embodiment 1, is also configured to produce the same effects as the
50
centrifugal air-sending device 100 according to Embodiment 1.
[0136]
Embodiment 5
Fig. 25 is a conceptual view that illustrates a relationship between the impellers
5 10 and the motor 50 included in a centrifugal air-sending device 100 according to
Embodiment 5. Dotted lines FL illustrate an example of airflows that pass from the
outside of the scroll casings 40 into the insides of the scroll casings 40. As
illustrated in Fig. 25, the centrifugal air-sending device 100 may also have, in addition
to the impellers 10 and the scroll casings 40, the motor 50, which is configured to
10 rotate the main plates 11 of the respective impellers 10. In other words, the
centrifugal air-sending device 100 may also have the impellers 10, the scroll casings
40, which house the respective impellers 10, and the motor 50, which is configured to
rotate the impellers 10.
[0137]
15 The motor 50 is located next to the side walls 44a of the respective scroll
casings 40. The motor shaft 51 is connected to the main plates 11 and serves as the
rotation axis of the main plates 11. The motor shaft 51 of the motor 50 extends on
the rotation axis RS of the impellers 10, passes through side faces of the scroll
casings 40, and is inserted into the scroll casings 40.
20 [0138]
The main plates 11 are each located along one of the side walls 44a of the
respective the scroll casings 40 that is closest to the motor 50 and located
perpendicular to the rotation axis RS. The boss portion 11b, to which the motor shaft
51 is connected, is located at the center portion of each of the main plates 11. The
25 motor shaft 51, which is inserted into the scroll casings 40, is fixed at the boss
portions 11b of the main plates 11. The motor shaft 51 of the motor 50 is connected
to and fixed at the main plates 11 of the respective impellers 10.
[0139]
As illustrated in Fig. 25, an outer circumferential wall 52 of the motor 50 is
30 located between an extension surface VF1 and an extension surface VF3. The
51
extension surface VF1 is a virtual surface that extends from the blade inner diameter
of the blades 12 close to the corresponding one of the main plates 11 in the axial
direction of the rotation axis RS. The extension surface VF3 is a virtual surface that
extends from the blade inner diameter close to the corresponding one of the side
5 plates 13 in the axial direction of the rotation axis RS. The outer circumferential wall
52 of the motor 50 defines an outer diameter MO1 of end portions 50a of the motor
50. A portion of the outer circumferential wall 52, which defines the outer diameter
MO1 of the end portions 50a of the motor 50, is located such that the portion of the
outer circumferential wall 52 faces the first turbo vane portions 12A2 and the second
10 turbo vane portions 12B2 in the axial direction of the rotation axis RS. More
specifically, the outer diameter MO1 of the end portions 50a of the motor 50 is larger
than the inner diameter ID1 of the plurality of first blades 12A close to the
corresponding one of the main plates 11 and smaller than the inner diameter ID3 of
the plurality of first blades 12A close to the corresponding one of the side plates 13.
15 In other words, the outer diameter MO1 of the end portions 50a of the motor 50 is
larger than the blade inner diameter of the plurality of blades 12 close to the
corresponding one of the main plates 11 and is smaller than the blade inner diameter
of the plurality of blades 12 close to the corresponding one of the side plates 13.
When the portion of the outer circumferential wall 52 at the end portions 50a of the
20 motor 50 is viewed parallel to the rotation axis RS, the portion of the outer
circumferential wall 52 is located between the circle C1a and the circle C7a described
above (refer to Fig. 14 and Fig. 15) and in the regions of the first turbo vane portions
12A2 and the second turbo vane portions 12B2. As for the dimension of the outer
diameter MO2 of the motor 50 other than the dimension at the end portions 50a in the
25 centrifugal air-sending device 100, the size of the outer diameter MO2 is not limited.
[0140]
Fig. 26 is a conceptual view that illustrates a centrifugal air-sending device
100A that is a modification 1 of the centrifugal air-sending device 100 according to
Embodiment 5. The centrifugal air-sending device 100A is formed such that the
30 outer circumferential wall 52 of a motor 50A is located between the extension surface
52
VF1 and the extension surface VF3. The extension surface VF1 is a virtual surface
that extends from the blade inner diameter of the blades 12 close to the
corresponding one of the main plates 11 in the axial direction of the rotation axis RS.
The extension surface VF3 is a virtual surface that extends from the blade inner
5 diameter close to the corresponding one of the side plates 13 in the axial direction of
the rotation axis RS. The outer circumferential wall 52 of the motor 50A defines an
outer diameter MO of the motor 50A. The outer circumferential wall 52, which
defines the outer diameter MO of the motor 50A, is located such that the outer
circumferential wall 52 faces the first turbo vane portions 12A2 and the second turbo
10 vane portions 12B2 in the axial direction of the rotation axis RS. More specifically,
the outer diameter MO of the motor 50A is larger than the inner diameter ID1 of the
plurality of first blades 12A close to the corresponding one of the main plates 11 and
smaller than the inner diameter ID3 of the plurality of first blades 12A close to the
corresponding one of the side plates 13. In other words, the outer diameter MO of
15 the motor 50A is larger than the blade inner diameter of the plurality of blades 12
close to the corresponding one of the main plates 11 and is smaller than the blade
inner diameter of the plurality of blades 12 close to the corresponding one of the side
plates 13. When the outer circumferential wall 52 of the motor 50A is viewed parallel
to the rotation axis RS, the outer circumferential wall 52 of the motor 50A is located
20 between the circle C1a and the circle C7a described above (refer to Fig. 14 and Fig.
15) and in the regions of the first turbo vane portions 12A2 and the second turbo vane
portions 12B2.
[0141]
Fig. 27 is a conceptual view that illustrates a centrifugal air-sending device
25 100B that is a modification 2 of the centrifugal air-sending device 100 according to
Embodiment 5. As illustrated in Fig. 27, a portion of an outer circumferential wall
52a, which defines an outer diameter MO1a of the end portions 50a of the motor 50B,
is located between the rotation axis RS and the extension surface VF1, which is a
virtual surface that extends from the blade inner diameter close to the corresponding
30 one of the side plates 13 in the axial direction of the rotation axis RS. The outer
53
circumferential walls 52a, which each define the outer diameter MO1a of the end
portions 50a of the motor 50B, are each located such that the outer circumferential
wall 52a faces the first turbo vane portions 12A2 and the second turbo vane portions
12B2 in the axial direction of the rotation axis RS. More specifically, the outer
5 diameter MO1a of the end portions 50a of the motor 50B is smaller than the inner
diameter ID1 of the plurality of first blades 12A close to the corresponding one of the
main plates 11. In other words, the outer diameter MO1a of the end portions 50a of
the motor 50B is formed such that the outer diameter MO1a is smaller than the blade
inner diameter of the plurality of blades 12 close to the corresponding one of the main
10 plates 11. When the outer circumferential walls 52a at the end portions 50a of the
motor 50B are viewed parallel to the rotation axis RS, the outer circumferential walls
52a at the end portions 50a of the motor 50B is located in the circle C1a described
above.
[0142]
15 The centrifugal air-sending device 100B is formed such that the outer
circumferential wall 52b of the motor 50B is located between the extension surface
VF1 and the extension surface VF3. The extension surface VF1 is a virtual surface
that extends from the blade inner diameter of the blades 12 close to the
corresponding one of the main plates 11 in the axial direction of the rotation axis RS.
20 The extension surface VF3 is a virtual surface that extends from the blade inner
diameter close to the corresponding one of the side plates 13 in the axial direction of
the rotation axis RS. The outer circumferential wall 52b of the motor 50B defines an
outermost diameter MO2a of the motor 50B. The outer circumferential wall 52b,
which defines the outermost diameter MO2a of the motor 50B, is also located such
25 that the outer circumferential wall 52b faces the first turbo vane portions 12A2 and the
second turbo vane portions 12B2 in the axial direction of the rotation axis RS. More
specifically, the outermost diameter MO2a of the motor 50B is larger than the inner
diameter ID1 of the plurality of first blades 12A close to the corresponding one of the
main plates 11 and smaller than the inner diameter ID3 of the plurality of first blades
30 12A close to the corresponding one of the side plates 13. In other words, the
54
outermost diameter MO2a of the motor 50B is larger than the blade inner diameter of
the plurality of blades 12 close to the corresponding one of the main plates 11 and is
smaller than the blade inner diameter of the plurality of blades 12 close to the
corresponding one of the side plates 13. When the outer circumferential wall 52b of
5 the motor 50B, which defines the outermost diameter MO2a, is viewed parallel to the
rotation axis RS, the outer circumferential wall 52b of the motor 50B is located
between the circle C1a and the circle C7a described above (refer to Fig. 14 and Fig.
15) and in the regions of the first turbo vane portions 12A2 and the second turbo vane
portions 12B2.
10 [0143]

We Claim :
[Claim 1]
A centrifugal air-sending device comprising:
an impeller that has a main plate that is to be driven to rotate, a side plate that
5 is ring-shaped and located such that the side plate faces the main plate, and a
plurality of blades that each have one end connected to the main plate and an other
end connected to the side plate and are arranged in a circumferential direction
centered on a rotation axis of the main plate that is virtual; and
a scroll casing that houses the impeller and has a circumferential wall that is
10 scroll-shaped and a side wall that has a bell mouth that forms a suction port that
communicates with a space defined by the main plate and the plurality of blades,
the plurality of blades each having
an inner circumferential end that is closer to the rotation axis than is an outer
circumferential end in a radial direction centered on the rotation axis,
15 the outer circumferential end that is closer to an outer circumference than is the
inner circumferential end in the radial direction,
a sirocco vane portion that includes the outer circumferential end and forms a
forward-curved blade at which an outlet angle is formed larger than 90 degrees,
a turbo vane portion that includes the inner circumferential end and forms a
20 backward-curved blade,
a first region that is located closer to the main plate than is an intermediate
position in an axial direction of the rotation axis, and
a second region that is located closer to the side plate than is the first region,
the plurality of blades having a blade outer diameter of the respective outer
25 circumferential ends of the plurality of blades, the blade outer diameter being larger
than an inner diameter of the bell mouth,
the plurality of blades each having a vane length in the first region that is
greater than a vane length in the second region,
the plurality of blades each having a portion at which a proportion for which the
30 turbo vane portion accounts is higher in the radial direction than a proportion for
83
which the sirocco vane portion accounts in the first region and the second region,
in a case in which portions of the plurality of blades that are located closer to
the outer circumference than is an inner circumferential side end portion that is an
end portion of the bell mouth that is located closest to an inner circumference in the
5 radial direction is defined as a blade outer circumferential portion,
the blade outer circumferential portion being formed such that the proportion for
which the sirocco vane portion accounts is higher in the radial direction than or equal
to the proportion for which the turbo vane portion accounts in the first region and the
second region.
10 [Claim 2]
The centrifugal air-sending device of claim 1, wherein
the plurality of blades each have a third region that is in the second region and
in which a proportion for which the turbo vane portion accounts is higher in the radial
direction than a proportion for which the sirocco vane portion accounts,
15 the plurality of blades each have a fourth region that is in the second region
and in which a proportion for which the turbo vane portion accounts is lower in the
radial direction than a proportion for which the sirocco vane portion accounts, and
the plurality of blades are each formed such that, in the second region, a
proportion for which the third region accounts in the axial direction is larger than a
20 proportion for which the fourth region accounts in the axial direction.
[Claim 3]
The centrifugal air-sending device of claim 1 or 2, wherein the plurality of
blades are each formed such that the turbo vane portion and the sirocco vane portion
are separated from each other in the second region.
25 [Claim 4]
The centrifugal air-sending device of claim 1 or 2, wherein the plurality of
blades are each formed such that the turbo vane portion and the sirocco vane portion
are separated from each other in the first region and the second region.
[Claim 5]
30 The centrifugal air-sending device of any one of claims 1 to 4, wherein the
84
plurality of blades each have an inclination portion that is inclined away from the
rotation axis from the main plate toward the side plate.
[Claim 6]
The centrifugal air-sending device of claim 5, wherein the inclination portion is
5 inclined to the rotation axis at an angle of larger than 0 degrees and smaller than or
equal to 60 degrees.
[Claim 7]
The centrifugal air-sending device of any one of claims 1 to 6, wherein a ratio
of a blade inner diameter of the respective inner circumferential ends of the plurality
10 of blades to a blade outer diameter of the respective outer circumferential ends of the
plurality of blades is lower than or equal to 0.7.
[Claim 8]
The centrifugal air-sending device of any one of claims 1 to 7, wherein,
when an interval between two blades of the plurality of blades that are next to
15 each other in the circumferential direction is defined as a vane interval,
the vane interval of the turbo vane portions expands from the inner
circumference toward the outer circumference in the radial direction, and
the vane interval of the sirocco vane portions is wider than the vane interval of
the turbo vane portions and expands from the inner circumference toward the outer
20 circumference in the radial direction.
[Claim 9]
The centrifugal air-sending device of any one of claims 1 to 8, wherein the
turbo vane portion linearly extends from the inner circumferential end toward the outer
circumference in the radial direction.
25 [Claim 10]
The centrifugal air-sending device of any one of claims 1 to 9, wherein
the plurality of blades each have a radial vane portion that connects between
the turbo vane portion and the sirocco vane portion, and
the radial vane portion has a vane angle that is formed at 90 degrees.
30 [Claim 11]
85
The centrifugal air-sending device of any one of claims 1 to 10, wherein
the plurality of blades include
a plurality of first blades, and
a plurality of second blades,
5 in a first section of the plurality of blades that is obtained by cutting the plurality
of blades at the first region with a first flat surface that is perpendicular to the rotation
axis, the plurality of first blades each have a vane length that is greater than a vane
length of each of the plurality of second blades, and
at least one second blade of the plurality of second blades is located between
10 each two first blades of the plurality of first blades that are next to each other in the
circumferential direction.
[Claim 12]
The centrifugal air-sending device of claim 11, wherein a ratio of an inner
diameter of the respective inner circumferential ends of the plurality of second blades
15 to an outer diameter of the respective outer circumferential ends of the plurality of
second blades is lower than or equal to 0.7.
[Claim 13]
The centrifugal air-sending device of any one of claims 1 to 12, wherein
a blade outer diameter of the respective outer circumferential ends of the
20 plurality of blades is larger than the inner diameter of the bell mouth, and
the plurality of blades each have a level-difference portion formed at an end
portion of the turbo vane portion that are located closest to the side plate.
[Claim 14]
The centrifugal air-sending device of any one of claims 1 to 13, wherein the
25 inner diameter of the bell mouth is larger than a blade inner diameter of the respective
inner circumferential ends of the plurality of blades in the first region and smaller than
a blade inner diameter of the respective inner circumferential ends of the plurality of
blades in the second region.
[Claim 15]
30 The centrifugal air-sending device of any one of claims 1 to 14, wherein a
86
closest-approach distance between which the plurality of blades are closest to the
circumferential wall is larger than twice a radial length of the sirocco vane portion.
[Claim 16]
The centrifugal air-sending device of any one of claims 1 to 15, further
5 comprising
a motor that is located outside the scroll casing and has a motor shaft that is
connected to the main plate and serves as the rotation axis of the main plate, wherein
an outer diameter of the motor is larger than a blade inner diameter of the
plurality of blades at the main plate and is smaller than a blade inner diameter of the
10 plurality of blades at the side plate.
[Claim 17]
The centrifugal air-sending device of any one of claims 1 to 15, further
comprising
a motor that is located outside the scroll casing and has a motor shaft that is
15 connected to the main plate and serves as the rotation axis of the main plate, wherein
an outer diameter of an end portion of the motor is larger than a blade inner
diameter of the plurality of blades at the main plate and is smaller than a blade inner
diameter of the plurality of blades at the side plate.
[Claim 18]
20 An air-conditioning apparatus comprising the centrifugal air-sending device of
any one of claims 1 to 17.