FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
CENTRIFUGAL BLOWER, AND INDOOR UNIT
MITSUBISHI ELECTRIC CORPORATION, A CORPORATION ORGANISED AND
EXISTING UNDER THE LAWS OF JAPAN, WHOSE ADDRESS IS 7-3,
MARUNOUCHI 2-CHOME, CHIYODA-KU, TOKYO 1008310, JAPAN
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE
INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.
2
[DESCRIPTION]
[Technical Field]
[0001]
The present disclosure relates to a centrifugal blower and an indoor unit.
5 [Background Art]
[0002]
A ceiling-embedded type indoor unit of an air conditioner has an air inlet and an
air outlet formed on a device lower surface facing a room to be air-conditioned. A
temperature of air suctioned into a case from the air inlet is regulated by a heat exchanger
10 in the case, and then the air is sent out from the air outlet to the room. The
above-described air flow of the indoor unit is created by a centrifugal blower that
suctions air upward from below and blows out the air by diverting the flow outward in a
radial direction. The centrifugal blower includes a shroud, a main plate, and a plurality
of vane portions that connect the shroud and the main plate to each other. In such a
15 centrifugal blower, a main flow that is directed radially outward is formed between the
main plate and the shroud.
[0003]
In addition to the above-described main flow, a structure in which a sub-flow
that is directed radially inward on an upper side of the main plate is generated to cool a
20 fan motor is disclosed in Patent Document 1. In the centrifugal blower of Patent
Document 1, a blowing-out direction of the sub-flow is set to a rear side in a rotation
direction of the main plate by an air guide portion, thereby suppressing generation of
noise accompanying the merging of the sub-flow and the main flow.
[Citation List]
25 [Patent Document]
3
[0004]
[Patent Document 1]
PCT International Publication No. WO2004/055380
[Summary of Invention]
5 [PROBLEM TO BE SOLVED BY THE INVENTION]
[0005]
In the indoor unit as described above, a flow path resistance of the sub-flow is
increased in order to abruptly bend a flow direction of the air of the sub-flow. Therefore,
in the structure in the related art, there is a problem in that an air volume of the sub-flow
10 is reduced and a cooling efficiency of the fan motor is likely to deteriorate.
[0006]
In view of the above circumstances, an object of the present disclosure is to
provide a centrifugal blower and an indoor unit capable of sufficiently securing a flow
rate of a sub-flow while suppressing noise.
15 [MEANS TO SOLVE THE PROBLEM]
[0007]
According to one aspect of the present disclosure, there is provided a centrifugal
blower including: a drive portion having a rotary shaft that rotates about a rotation axis;
and an impeller that is disposed on one side in an axial direction of the rotation axis with
20 respect to the drive portion and is configured to be rotated forward in a rotation direction
around the rotation axis by the drive portion, in which the impeller includes a main plate
fixed to the rotary shaft, a shroud having an annular shape and facing the main plate in
the axial direction, and a plurality of vane portions connecting the main plate and the
shroud, the main plate has a hub that covers the drive portion from the one side in the
25 axial direction and from an outside in a radial direction of the rotation axis, the hub has a
4
plurality of guide portions protruding outward in the radial direction and arranged in the
rotation direction, air holes that are open outward in the radial direction are formed in the
plurality of guide portions, and each outer peripheral surfaces of the plurality of guide
portions has a pair of peripheral surface portions located on a front side and a rear side in
5 the rotation direction with respect to the air hole and facing outward in the radial
direction.
[0008]
According to another aspect of the present disclosure, there is provided an
indoor unit including: the above-described centrifugal blower; and a heat exchanger
10 disposed around the centrifugal blower.
[EFFECTS OF THE INVENTION]
[0009]
According to the present disclosure, a centrifugal blower and an indoor unit
capable of sufficiently securing a flow rate of a sub-flow while suppressing noise are
15 provided.
[Brief Description of Drawings]
[0010]
FIG. 1 is a schematic diagram showing a schematic configuration of an air
conditioner in an embodiment.
20 FIG. 2 is a perspective view showing an indoor unit in the embodiment.
FIG. 3 is a schematic sectional view showing the indoor unit in the embodiment.
FIG. 4 is a perspective view of an impeller in the embodiment.
FIG. 5 is a perspective view of the vicinity of a lower end portion of a hub in the
embodiment.
25 FIG. 6 is a plan view of a guide portion in the embodiment.
5
FIG. 7 is a sectional view of the guide portion taken along the line VII-VII of
FIG. 6.
[Description of Embodiments]
[0011]
5 Hereinafter, an embodiment of the present disclosure will be described with
reference to the drawings. The scope of the present disclosure is not limited to the
following embodiment, and can be changed in any way within the scope of technical
ideas of the present disclosure. In addition, in the following drawings, a scale and the
number in each structure may be different from a scale and the number in an actual
10 structure to facilitate understanding of each configuration.
[0012]
In addition, in the drawings, a Z axis indicating a vertical direction is shown as
appropriate. A side (+Z side) to which an arrow of the Z axis points in the vertical
direction is an upper side, and a side (-Z side) opposite to the side to which the arrow of
15 the Z axis points in the vertical direction is a lower side. A posture of an indoor unit 10
in the vertical direction described in the embodiment is merely an example, and does not
limit an assembly posture of the indoor unit 10.
[0013]
FIG. 1 is a schematic diagram showing a schematic configuration of an air
20 conditioner 100 according to the present embodiment. As shown in FIG. 1, the air
conditioner 100 includes an indoor unit 10, an outdoor unit 20, and a circulation path
portion 30. The indoor unit 10 is disposed indoors. The outdoor unit 20 is disposed
outdoors. The indoor unit 10 and the outdoor unit 20 are connected to each other by the
circulation path portion 30 through which a refrigerant 33 circulates. The indoor unit 10
25 and the outdoor unit 20 are heat exchange units that perform heat exchange with air.
6
[0014]
The air conditioner 100 can regulate a temperature of indoor air by exchanging
heat between the refrigerant 33 flowing inside the circulation path portion 30 and air
inside a room in which the indoor unit 10 is disposed. Examples of the refrigerant 33
5 include a fluorine-based refrigerant having a low global warming potential (GWP) and a
hydrocarbon-based refrigerant.
[0015]
The outdoor unit 20 has a compressor 21, an outdoor heat exchanger 23, a flow
regulating valve 24, a blower 25, and a four-way valve 22. The compressor 21, the
10 outdoor heat exchanger 23, the flow regulating valve 24, and the four-way valve 22 are
connected by the circulation path portion 30.
[0016]
The four-way valve 22 is provided in a portion of the circulation path portion 30
connected to a discharge side of the compressor 21. The four-way valve 22 can reverse
15 a direction of the refrigerant 33 flowing inside the circulation path portion 30 by
switching a part of the circulation path portion 30. When a path connected by the
four-way valve 22 is a path indicated by a solid line in the four-way valve 22 in FIG. 1,
the refrigerant 33 flows inside the circulation path portion 30 in a direction indicated by a
solid line arrow in FIG. 1. On the other hand, when the path connected by the four-way
20 valve 22 is a path indicated by a broken line in the four-way valve 22 in FIG. 1, the
refrigerant 33 flows inside the circulation path portion 30 in a direction indicated by a
broken line arrow in FIG. 1.
[0017]
The indoor unit 10 has a centrifugal blower 40 and an indoor heat exchanger
25 (heat exchanger) 14 disposed around the centrifugal blower 40. The indoor unit 10 can
7
perform a cooling operation of cooling the air inside the room in which the indoor unit 10
is disposed and a heating operation of warming the air inside the room in which the
indoor unit 10 is disposed.
[0018]
5 When the indoor unit 10 performs the cooling operation, the refrigerant 33
flowing inside the circulation path portion 30 flows in the direction indicated by the solid
line arrow in FIG. 1. That is, when the indoor unit 10 performs the cooling operation,
the refrigerant 33 flowing inside the circulation path portion 30 circulates to return to the
compressor 21 after circulating through the compressor 21, the outdoor heat exchanger
10 23 of the outdoor unit 20, the flow regulating valve 24, and the indoor heat exchanger 14
of the indoor unit 10 in this order. In the cooling operation, the outdoor heat exchanger
23 inside the outdoor unit 20 functions as a condenser, and the indoor heat exchanger 14
inside the indoor unit 10 functions as an evaporator.
[0019]
15 On the other hand, when the indoor unit 10 performs the heating operation, the
refrigerant 33 flowing inside the circulation path portion 30 flows in the direction
indicated by the broken line in FIG. 1. That is, when the indoor unit 10 performs the
heating operation, the refrigerant 33 flowing inside the circulation path portion 30
circulates to return to the compressor 21 after circulating through the compressor 21, the
20 indoor heat exchanger 14 of the indoor unit 10, the flow regulating valve 24, and the
outdoor heat exchanger 23 of the outdoor unit 20 in this order. In the heating operation,
the outdoor heat exchanger 23 inside the outdoor unit 20 functions as an evaporator, and
the indoor heat exchanger 14 inside the indoor unit 10 functions as a condenser.
[0020]
25 Next, the indoor unit 10 of the present embodiment will be described in more
8
detail.
FIG. 2 is a perspective view showing the indoor unit 10. FIG. 3 is a schematic
sectional view showing the indoor unit 10.
In each of FIG. 3 and subsequent figures, a rotation axis R is appropriately
5 shown. The rotation axis R is an imaginary line passing through the center of the
centrifugal blower 40 in the following embodiment. An impeller 60 of the centrifugal
blower 40 rotates around the rotation axis R. A direction in which the rotation axis R of
the present embodiment extends is a vertical direction.
[0021]
10 In the following description, an axial direction of the rotation axis R, that is, a
direction parallel to the Z axis may be simply referred to as an “axial direction”, a radial
direction about the rotation axis R may be simply referred to as a “radial direction”, and a
circumferential direction about the rotation axis R may be simply referred to as a
“circumferential direction”. In addition, in the following description, a lower side in the
15 vertical direction (-Z side) may be referred to as one side in the axial direction, and an
upper side in the vertical direction (+Z side) may be referred to as the other side in the
axial direction. Furthermore, in the following description, the term “outside in the
radial direction (outward in the radial direction)” means a side apart from the rotation
axis R in the radial direction, and the “inside in the radial direction (inward in the radial
20 direction)” means a side approaching the rotation axis R on an opposite side to the
“outside in the radial direction” in the radial direction.
[0022]
The indoor unit 10 of the present embodiment is a ceiling-embedded indoor unit
that is installed by being embedded in a ceiling. As shown in FIG. 3, the indoor unit 10
25 includes a housing 11 in addition to the centrifugal blower 40 and the indoor heat
9
exchanger 14. The housing 11 includes a housing body portion 12 that covers the
centrifugal blower 40 and the indoor heat exchanger 14 from the upper side, and a
decorative panel 13 that is located on the lower side of the centrifugal blower 40 and the
indoor heat exchanger 14. The housing body portion 12 has a flat plate-shaped top plate
5 portion 12a orthogonal to the rotation axis R. The indoor heat exchanger 14 and the
centrifugal blower 40 are fixed to a lower surface of the top plate portion 12a. In
addition, an air inlet 10a and an air outlet 10b are formed in the decorative panel 13.
[0023]
The centrifugal blower 40 has a drive portion 50 and an impeller 60. The drive
10 portion 50 is, for example, a fan motor. The drive portion 50 has a drive portion body
51 and a rotary shaft 52. The drive portion body 51 is fixed to the top plate portion 12a
of the housing 11. The rotary shaft 52 rotates about the rotation axis R. The impeller
60 is disposed on the lower side (one side in the axial direction) with respect to the drive
portion 50. The impeller 60 is rotated around the rotation axis R by the drive portion
15 50.
[0024]
When the drive portion 50 is driven and the impeller 60 is rotated, the air in the
room in which the indoor unit 10 is installed is suctioned into the indoor unit 10 from the
air inlet 10a. The air suctioned into the indoor unit 10 is further suctioned into the
20 impeller 60 from an intake port 60a of the impeller 60. The air suctioned into the
impeller 60 flows outward in the radial direction inside the impeller 60 as a vane portion
63 of the impeller 60 rotates, and is blown out of the centrifugal blower 40 from an
exhaust port facing outward in the radial direction. The air blown out from the
centrifugal blower 40 passes through the indoor heat exchanger 14, is subjected to heat
25 exchange and humidity regulation while passing through the indoor heat exchanger 14,
10
and then is blown out from the air outlet 10b into the room by changing a flow direction
thereof downward.
[0025]
Here, a flow of air generated by the centrifugal blower 40 will be described.
5 The centrifugal blower 40 generates a main flow AF and a sub-flow BF inside the indoor
unit 10.
[0026]
The main flow AF is an air flow that flows into the impeller 60 from the intake
port 60a, is directed to the outside in the radial direction in a space between the main
10 plate 61 and the shroud 62, and is blown out from the exhaust port 60b toward the indoor
heat exchanger 14 on the outside in the radial direction. The main flow AF is formed to
cause the indoor air to pass through the indoor heat exchanger 14 and return to the indoor
space again.
[0027]
15 The sub-flow BF is an air flow that diverges from the main flow AF at the
exhaust port 60b, passes through the upper side (between the main plate 61 and the top
plate portion 12a) of the impeller 60, flows downward around the drive portion 50, and
merges with the main flow AF through an air hole 61f formed in the main plate 61. The
sub-flow BF cools the drive portion 50 by taking heat from the drive portion 50 when
20 passing around the drive portion 50. Therefore, the cooling efficiency of the drive
portion 50 can be increased by sufficiently securing the flow rate of the sub-flow BF.
[0028]
Next, the impeller 60 of the present embodiment will be described in detail.
FIG. 4 is a perspective view of the impeller 60. In each of FIG. 4 and
25 subsequent figures, a rotation direction T of the impeller 60 is indicated by an arrow. In
11
the present embodiment, the rotation direction T is a counterclockwise direction in the
circumferential direction when the impeller 60 is viewed from the lower side. In the
following description, a direction toward the rotation direction T may be referred to as a
front side in the rotation direction T, and a direction opposite to the front side may be
5 referred to as a rear side in the rotation direction T. The impeller 60 is rotated forward
in the rotation direction T by the drive portion 50.
[0029]
The impeller 60 includes the main plate 61, the shroud 62, and a plurality of the
vane portions 63. The main plate 61, the shroud 62, and the vane portions 63 are each
10 formed of a resin material. The main plate 61, the shroud 62, and the vane portions 63
are fixed to each other and rotate around the rotation axis R.
[0030]
The main plate 61 is fixed to the rotary shaft 52 of the drive portion 50 (refer to
FIG. 3). The main plate 61 is rotated around the rotation axis R by the drive portion 50.
15 The main plate 61 has a hub 61b, a shaft holding portion 61e, and a base 61a.
[0031]
The hub 61b bulges downward (one side in the axial direction) at a central
portion (the rotation axis R of the centrifugal blower 40 and the vicinity thereof) of the
main plate 61. The hub 61b covers the drive portion 50 from the lower side (one side in
20 the axial direction) and from the outside in the radial direction. That is, an
accommodation space for accommodating the drive portion 50 is formed inside the hub
61b in the radial direction.
[0032]
The hub 61b has a diameter that decreases toward the lower side. The hub 61b
25 has a flat plate portion 61d and a conical portion 61c. The flat plate portion 61d is
12
located on the lower side of the drive portion 50. The flat plate portion 61d has a flat
plate shape that is orthogonal to the rotation axis R. The flat plate portion 61d is
circular in plan view. The conical portion 61c extends upward from an outer edge of the
flat plate portion 61d. The conical portion 61c has a conical shape that is widened
5 outward in the radial direction toward the upper side. The conical portion 61c
surrounds the drive portion 50 from the outside in the radial direction. A curved portion
61ca smoothly connected to the flat plate portion 61d is formed at a lower end portion of
the conical portion 61c. The conical portion 61c is curved at a certain curvature at the
curved portion 61ca. The conical portion 61c gradually increases in inclination toward
10 the upper side from the flat plate portion 61d at the curved portion 61ca. In addition,
the conical portion 61c has a certain inclination in a region on the upper side of the
curved portion 61ca.
[0033]
The hub 61b has a plurality of (seven in the present embodiment) guide portions
15 70 protruding outward in the radial direction. In the present embodiment, the guide
portion 70 is formed in the curved portion 61ca of the conical portion 61c. That is, the
guide portion 70 protrudes outward in the radial direction from an outer peripheral
surface of the curved portion 61ca. The plurality of guide portions 70 are disposed at
intervals from each other in the rotation direction of the rotation axis R. One air hole
20 61f is formed in each of the guide portions 70. The air hole 61f guides air from a space
inside the hub 61b in the radial direction to a space outside in the radial direction. The
guide portion 70 will be described in more detail below.
[0034]
The shaft holding portion 61e is disposed at the center of the flat plate portion
25 61d of the hub 61b. The shaft holding portion 61e has a cylindrical shape centered on
13
the rotation axis R. The rotary shaft 52 is disposed inside the shaft holding portion 61e.
In addition, a connecting member 53 is fixed to an inner peripheral surface of the shaft
holding portion 61e. The connecting member 53 connects an outer peripheral surface of
the rotary shaft 52 and the inner peripheral surface of the shaft holding portion 61e.
5 [0035]
The base 61a extends outward in the radial direction from an upper end of the
hub 61b. The base 61a has a flat plate shape extending along a plane orthogonal to the
rotation axis R. The base 61a is an annular portion whose outer peripheral edge is
circular in plan view.
10 [0036]
An upper surface (surface facing the other side in the axial direction) of the base
61a faces the top plate portion 12a of the housing 11 with a gap therebetween. The
sub-flow BF flows through a gap between the upper surface of the base 61a and the top
plate portion 12a. An upper support portion 61p to which the plurality of vane portions
15 63 are fixed by fixing means such as welding is formed on a lower surface (surface
facing one side in the axial direction) of the base 61a.
[0037]
The shroud 62 is an annular plate member. The shroud 62 faces the main plate
61 in the axial direction. A gap through which the main flow AF flows is formed
20 between the main plate 61 and the shroud 62. An inner edge of the shroud 62 protrudes
downward in a tubular shape to form the intake port 60a for guiding air to the main flow
AF.
[0038]
A lower support portion 62p to which the plurality of vane portions 63 are fixed
25 by fixing means such as welding is formed in the shroud 62. The lower support portion
14
62p has a recessed portion that is recessed downward and into which the vane portion 63
is inserted, and the vane portion 63 is fixed in the recessed portion.
[0039]
The plurality of vane portions 63 connect the main plate 61 and the shroud 62.
5 That is, the plurality of (seven in the present embodiment) vane portions 63 are disposed
between the main plate 61 and the shroud 62. The vane portion 63 has a hollow plate
shape extending along the rotation axis R. The vane portion 63 is welded and fixed to
the shroud 62 at a lower end portion, and is welded and fixed to the main plate 61 at an
upper end portion.
10 [0040]
The vane portion 63 is inclined to the rear side in the rotation direction T as it
extends from the inside in the radial direction to the outside in the radial direction. The
plurality of vane portions 63 push out air between the main plate 61 and the shroud 62
outward in the radial direction as the impeller 60 rotates around the rotation axis R.
15 Accordingly, the impeller 60 forms the main flow AF in which the air is sent from the
intake port 60a to the exhaust port 60b.
[0041]
Next, the guide portion 70 of the present embodiment will be described in detail.
FIG. 5 is a perspective view of the vicinity of a lower end portion of the hub 61b.
20 FIG. 6 is a plan view of the guide portion 70. FIG. 7 is a sectional view of the guide
portion 70 taken along the line VII-VII of FIG. 6.
[0042]
As shown in FIG. 5, the air hole 61f formed in the guide portion 70 penetrates
the hub 61b in a thickness direction. The air hole 61f is open outward in the radial
25 direction. The air hole 61f has a substantially rectangular shape when viewed from the
15
opening direction. The opening direction of the air hole 61f need only have a
component facing outward in the radial direction, and need not necessarily match the
radial direction in a strict sense.
[0043]
5 According to the present embodiment, since the air hole 61f is open outward in
the radial direction, the air of the sub-flow BF flowing downward in the space inside the
hub 61b in the radial direction can be smoothly guided to the outside of the hub 61b in
the radial direction. Therefore, a flow path resistance of the sub-flow BF can be
reduced to increase the flow rate of the sub-flow BF, and the cooling efficiency of the
10 drive portion 50 can be increased.
[0044]
As shown in FIG. 6, an outer peripheral surface 70a of the guide portion 70 has
a first peripheral surface portion (peripheral surface portion) 72, a second peripheral
surface portion (peripheral surface portion) 73, a third peripheral surface portion 74, an
15 overhang surface portion 75, a connection surface portion 76, a front side surface portion
77, and a rear side surface portion 78.
[0045]
The first peripheral surface portion 72, the second peripheral surface portion 73,
and the third peripheral surface portion 74 are surfaces facing outward in the radial
20 direction. Each of the first peripheral surface portion 72, the second peripheral surface
portion 73, and the third peripheral surface portion 74 extends in the rotation direction.
The first peripheral surface portion 72, the second peripheral surface portion 73, and the
third peripheral surface portion 74 are curved surfaces that are gently curved around the
rotation axis R.
25 [0046]
16
The first peripheral surface portion 72 is located on the front side in the rotation
direction T with respect to the air hole 61f. On the other hand, the second peripheral
surface portion 73 is located on the rear side in the rotation direction T with respect to the
air hole 61f. That is, the outer peripheral surface 70a of the guide portion 70 has a pair
5 of peripheral surface portions 72 and 73 located on the front side and the rear side in the
rotation direction T with respect to the air hole 61f.
[0047]
The guide portion 70 of the present embodiment has the first peripheral surface
portion 72 and the second peripheral surface portion 73 that are disposed on both sides of
10 the air hole 61f in the rotation direction (that is, both sides in the circumferential
direction). Accordingly, the main flow AF flowing on one side and the other side in the
circumferential direction of the guide portion 70 can pass apart from the air hole 61f in
the circumferential direction. The air of the sub-flow BF blown out from the air hole
61f merges with the main flow AF in a state of being sufficiently diffused. As a result,
15 it is possible to suppress the generation of turbulent flow when the sub-flow BF merges
with the main flow AF and to suppress the noise accompanying the merging.
[0048]
Lengths d1 and d2 of the first peripheral surface portion 72 and the second
peripheral surface portion 73 (a pair of peripheral surface portions located on both sides
20 of the air hole 61f in the rotation direction) in the rotation direction are preferably shorter
than a length D of the air hole 61f in the rotation direction. In order to reduce the flow
path resistance of the sub-flow BF and increase the flow rate of the sub-flow BF, it is
preferable to make the length D of the air hole 61f in the rotation direction as large as
possible. On the other hand, the noise at the time of the merging of the sub-flow BF
25 and the main flow AF is easily suppressed by increasing the lengths d1 and d2 of the first
17
peripheral surface portion 72 and the second peripheral surface portion 73 in the rotation
direction. However, when the lengths d1 and d2 of the first peripheral surface portion
72 and the second peripheral surface portion 73 in the rotation direction are too long, the
circumferential dimension of the guide portion 70 increases, which may hinder the flow
5 of the main flow AF along the outer peripheral surface of the hub 61b.
According to the present embodiment, the lengths d1 and d2 of the first
peripheral surface portion 72 and the second peripheral surface portion 73 in the rotation
direction are made smaller than the length D of the air hole 61f in the rotation direction,
whereby it is possible to prevent the guide portion 70 from being too large while securing
10 the flow rate of the sub-flow BF.
[0049]
The first peripheral surface portion 72 is a surface formed on a surface of a
protrusion portion 71 protruding outward in the radial direction with respect to an
opening 61fa of the air hole 61f. Therefore, the first peripheral surface portion 72 is
15 disposed on the outside in the radial direction with respect to the opening 61fa of the air
hole 61f.
In the present specification, the opening 61fa of the air hole 61f means a region
surrounded by an edge on the outside of the air hole 61f in a penetration direction.
[0050]
20 When the impeller 60 rotates, the guide portion 70 rotates relatively with respect
to the air inside the impeller 60. Therefore, a relative air flow (hereinafter, referred to
as a swirling flow CF) toward the side opposite to the rotation direction T of the impeller
60 is generated around the guide portion 70.
[0051]
25 According to the present embodiment, the first peripheral surface portion 72
18
located on the front side in the rotation direction T with respect to the air hole 61f is
disposed on the outside in the radial direction with respect to the opening 61fa of the air
hole 61f. A direction of the swirling flow CF is changed by the protrusion portion 71 on
the front side in the rotation direction T of the air hole 61f, and the swirling flow CF
5 flows in the circumferential direction along the first peripheral surface portion 72.
According to the present embodiment, the first peripheral surface portion 72 is located on
the outside in the radial direction with respect to the opening 61fa of the air hole 61f, so
that, the swirling flow CF can pass apart from the opening 61fa of the air hole 61f
outward in the radial direction. Accordingly, it is possible to prevent the sub-flow BF
10 blown out from the air hole 61f from colliding with the swirling flow CF, and it is
possible to suppress the generation of turbulent flow and the like when the sub-flow BF
merges with the swirling flow CF and to suppress the noise accompanying the merging.
In addition, by causing the swirling flow CF to pass apart from the air hole 61f, it is
possible to prevent the air of the swirling flow CF from flowing into the air hole 61f and
15 to secure the flow rate of the sub-flow BF blown out from the air hole 61f. Furthermore,
it is possible to prevent the swirling flow CF from colliding with an edge portion of the
air hole 61f and to suppress the noise generation due to the vibration of the edge portion.
[0052]
The second peripheral surface portion 73 is disposed to be continuous to the
20 opening 61fa of the air hole 61f. Therefore, a radial position of the opening 61fa of the
air hole 61f matches a radial position of the second peripheral surface portion 73. In
addition, the second peripheral surface portion 73 is disposed on the inside in the radial
direction with respect to the first peripheral surface portion 72.
[0053]
25 According to the present embodiment, the second peripheral surface portion 73
19
on the rear side in the rotation direction T of the air hole 61f does not protrude from the
opening 61fa of the air hole 61f. Therefore, it is possible to cause the air blown out
from the air hole 61f to smoothly flow to the rear side in the rotation direction T, and to
promote the smooth merging of the swirling flow CF and the sub-flow BF.
5 [0054]
The third peripheral surface portion 74 is located on the lower side (one side in
the axial direction) of the air hole 61f. The third peripheral surface portion 74 is
disposed to be continuous to the opening 61fa of the air hole 61f. Therefore, the second
peripheral surface portion 73 and the third peripheral surface portion 74 are disposed to
10 be continuous to each other in the rotation direction.
[0055]
The overhang surface portion 75 is located on the lower side (one side in the
axial direction) of the air hole 61f. In addition, the overhang surface portion 75 faces
the lower side (one side in the axial direction). The overhang surface portion 75 is a
15 surface extending in the rotation direction. The entire rotation direction of the overhang
surface portion 75 includes the entire rotation direction of the air hole 61f. That is, an
end portion of the overhang surface portion 75 on one side in the circumferential
direction is located closer to one side in the circumferential direction than an end portion
of the air hole 61f on one side in the circumferential direction, and an end portion of the
20 overhang surface portion 75 on the other side in the circumferential direction is located
closer to the other side in the circumferential direction than an end portion of the air hole
61f on the other side in the circumferential direction. The overhang surface portion 75
is connected to the first peripheral surface portion 72, the second peripheral surface
portion 73, and the third peripheral surface portion 74 via a corner portion.
25 [0056]
20
As shown in FIG. 7, a part of the main flow AF flowing outward in the radial
direction along the outer peripheral surface of the hub 61b hits the guide portion 70, and
passes through the lower side of the overhang surface portion 75 and the outside in the
radial direction of the third peripheral surface portion 74. According to the present
5 embodiment, the third peripheral surface portion 74 is disposed on the lower side (one
side in the axial direction) of the air hole 61f, so that the main flow AF flowing on the
lower side of the overhang surface portion 75 can pass apart from the opening 61fa of the
air hole 61f in the axial direction. Accordingly, it is possible to prevent the collision
between the main flow AF and the sub-flow BF at the time of the merging of the main
10 flow AF and the sub-flow BF, and to smoothly merge the main flow AF and the sub-flow
BF.
[0057]
According to the present embodiment, the main flow AF flowing upward toward
the guide portion 70 changes its flow outward in the radial direction when hitting the
15 overhang surface portion 75 located on the lower side of the air hole 61f and facing the
lower side. Accordingly, it is possible to prevent the main flow AF from flowing into
the air hole 61f that is open outward in the radial direction, and to secure the flow rate of
the sub-flow BF. Furthermore, it is possible to prevent the main flow AF from colliding
with an edge portion of the air hole 61f and to suppress the noise generation due to the
20 vibration of the edge portion.
[0058]
As shown in FIG. 6, the front side surface portion 77 faces the front side in the
rotation direction T. The front side surface portion 77 is a surface extending in the
radial direction. The front side surface portion 77 is located on the front side in the
25 rotation direction T with respect to the first peripheral surface portion 72. The front side
21
surface portion 77 receives the swing flow CF.
[0059]
The connection surface portion 76 connects the first peripheral surface portion
72 and the front side surface portion 77. The connection surface portion 76 faces in a
5 direction slightly inclined outward in the radial direction with respect to the front side in
the rotation direction T on the front side in the rotation direction T. The connection
surface portion 76 is a surface formed on the surface of the protrusion portion 71. The
connection surface portion 76 is inclined inward in the radial direction from the first
peripheral surface portion 72 toward the front side surface portion 77.
10 [0060]
The swirling flow CF changes its flow outward in the radial direction when
hitting the front side surface portion 77, and flows along the first peripheral surface
portion 72. According to the present embodiment, since the connection surface portion
76 connecting the first peripheral surface portion 72 and the front side surface portion 77
15 is formed on the outer peripheral surface of the guide portion 70, the swirling flow CF
that has hit the front side surface portion 77 can be smoothly guided along the first
peripheral surface portion 72. Accordingly, it is possible to suppress the occurrence of
turbulent flow in the swirling flow CF and to increase the rotation efficiency of the
impeller 60.
20 [0061]
In the present embodiment, the connection surface portion 76 is a curved surface
that is concavely curved. However, the connection surface portion 76 may be a
convexly curved surface that smoothly connects the first peripheral surface portion 72
and the front side surface portion 77 with a uniform radius of curvature. In addition, the
25 connection surface portion 76 may be a flat tapered surface that linearly connects the first
22
peripheral surface portion 72 and the front side surface portion 77.
[0062]
The rear side surface portion 78 faces the rear side in the rotation direction T.
The front side surface portion 77 is a surface extending in the radial direction. The rear
5 side surface portion 78 is located on the rear side in the rotation direction T with respect
to the second peripheral surface portion 73. The rear side surface portion 78 is
connected to the second peripheral surface portion 73 via a corner portion.
[0063]
As shown in FIG. 4, in the present embodiment, the plurality of guide portions
10 70 are disposed at intervals from each other in the rotation direction. Similarly, the
plurality of vane portions 63 are disposed at intervals from each other in the rotation
direction. Furthermore, the number of the guide portions 70 matches the number of the
vane portions 63. The intervals between the plurality of guide portions 70 in the
rotation direction and the intervals between the plurality of vane portions 63 in the
15 rotation direction may be the same as or different from each other. According to the
present embodiment, by making the guide portions 70 and the vane portions 63 equal in
number and disposing the guide portions 70 and the vane portions 63 at intervals from
each other, it is possible to suppress variation in weight balance in the rotation direction
of the impeller 60 and to increase the rotation efficiency of the impeller 60.
20 [0064]
In addition, according to the present embodiment, by making the guide portions
70 and the vane portions 63 equal in number and disposing the guide portions 70 and the
vane portions 63 at intervals from each other, it is possible to suppress variation in flow
velocity of the air blown out from the air hole 61f of the guide portion 70 and sent to the
25 outside in the radial direction by the vane portions 63. Therefore, it is possible to
23
suppress variation in air resistance in the rotation direction of the impeller 60 and to
increase the rotation efficiency of the impeller 60.
[0065]
Although the embodiment of the present disclosure has been described, the
5 present disclosure is not limited to the configurations of the embodiment described above,
and the following configurations and methods can also be adopted.
[0066]
In the above-described embodiment, the main plate, the shroud, and the plurality
of vane portions of the impeller have been described as being separate members and
10 being fixed to each other. However, the main plate, the shroud, and the plurality of vane
portions may be parts of a single member. In addition, the main plate, the shroud, and
the vane portion may each be formed by combining a plurality of members.
[0067]
In the above-described embodiment, a case in which the centrifugal blower is
15 adopted in the ceiling-embedded indoor unit has been described. However, the
centrifugal blower of the embodiment can also be used for other types of indoor units,
and can be widely used for various devices provided with blowing means other than the
air conditioner. The heat exchanger shown in the above-described embodiment is
merely an example of a pressure loss body placed in a flow path of air generated by the
20 centrifugal blower in the air conditioner. Therefore, for example, as the pressure loss
body placed in the flow path of the air generated by the centrifugal blower in an air
purification device, an air purification filter can be used. That is, the centrifugal blower
described in the above-described embodiment can also be adopted as a blower in the air
purification device.
25 [0068]
24
As described above, each configuration and each method described in the
present specification can be combined as appropriate to the extent that they are consistent
with each other.
[Reference Signs List]
5 [0069]
10: Indoor unit
14: Indoor heat exchanger (heat exchanger)
40: Centrifugal blower
50: Drive portion
10 52: Rotary shaft
60: Impeller
61: Main plate
61b: Hub
61f: Air hole
15 61fa: Opening
62: Shroud
63: Vane portion
70: Guide portion
70a: Outer peripheral surface
20 72: First peripheral surface portion (peripheral surface portion)
73: Second peripheral surface portion (peripheral surface portion)
74: Third peripheral surface portion
75: Overhang surface portion
76: Connection surface portion
25 77: Front side surface portion
25
D, d1, d2: Length
R: rotation axis
T: Rotation direction

WE CLAIM
[Claim 1]
A centrifugal blower comprising:
a drive portion having a rotary shaft that rotates about a rotation axis; and
5 an impeller that is disposed on one side in an axial direction of the rotation axis
with respect to the drive portion and is configured to be rotated forward in a rotation
direction around the rotation axis by the drive portion,
wherein the impeller includes
a main plate fixed to the rotary shaft,
10 a shroud having an annular shape and facing the main plate in the axial direction,
and
a plurality of vane portions connecting the main plate and the shroud,
the main plate has a hub that covers the drive portion from the one side in the
axial direction and from an outside in a radial direction of the rotation axis,
15 the hub has a plurality of guide portions protruding outward in the radial
direction and arranged in the rotation direction,
air holes that are open outward in the radial direction are formed in the plurality
of guide portions, and
each outer peripheral surfaces of the plurality of guide portions has a pair of
20 peripheral surface portions located on a front side and a rear side in the rotation direction
with respect to the air hole and facing outward in the radial direction.
[Claim 2]
The centrifugal blower according to Claim 1,
wherein a first peripheral surface portion, which is located on the front side in
25 the rotation direction with respect to the air hole, of the pair of peripheral surface
27
portions is disposed on the outside in the radial direction with respect to an opening of
the air hole.
[Claim 3]
The centrifugal blower according to Claim 2,
5 wherein the outer peripheral surface of the guide portion has
a front side surface portion located on the front side in the rotation direction with
respect to the first peripheral surface portion and facing the front side in the rotation
direction, and
a connection surface portion connecting the first peripheral surface portion and
10 the front side surface portion, and
the connection surface portion is inclined inward in the radial direction from the
first peripheral surface portion toward the front side surface portion.
[Claim 4]
The centrifugal blower according to any one of Claims 1 to 3,
15 wherein a second peripheral surface portion, which is located on the rear side in
the rotation direction with respect to the air hole, of the pair of peripheral surface
portions is disposed to be continuous to an opening of the air hole in the rotation
direction.
[Claim 5]
20 The centrifugal blower according to any one of Claims 1 to 4,
wherein a length of each of the pair of peripheral surface portions in the rotation
direction is shorter than a length of the air hole in the rotation direction.
[Claim 6]
The centrifugal blower according to any one of Claims 1 to 5,
25 wherein the outer peripheral surface of the guide portion has a third peripheral
28
surface portion located on one side of the air hole in the axial direction and facing
outward in the radial direction.
[Claim 7]
The centrifugal blower according to any one of Claims 1 to 6,
5 wherein the outer peripheral surface of the guide portion has an overhang
surface portion located on one side of the air hole in the axial direction and facing the one
side in the axial direction.
[Claim 8]
The centrifugal blower according to any one of Claims 1 to 7,
10 wherein the plurality of guide portions are disposed at intervals from each other
in the rotation direction,
the plurality of vane portions are disposed at intervals from each other in the
rotation direction, and
the number of the guide portions matches the number of the vane portions.
15 [Claim 9]
An indoor unit comprising:
the centrifugal blower according to any one of Claims 1 to 8; and
a heat exchanger disposed around the centrifugal blower