FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
MOTOR, BLOWER, AND AIR CONDITIONER;
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
5
TECHNICAL FIELD
[0001]
The present disclosure relates to a motor, a blower and an
air conditioner.
10
BACKGROUND ART
[0002]
There has been proposed a motor including a stator and a
rotor of a consequent-pole type. See Patent Reference 1, for
15 example. In the rotor of the consequent-pole type, magnet
magnetic poles and virtual magnetic poles are formed in a rotor
core.
[0003]
The motor of the Patent Reference 1 further includes a
20 bearing that supports a rotary shaft of the rotor and a bearing
holding part that holds the bearing. Incidentally, there are
cases where an outer ring of the bearing is fixed to the bearing
holding part by means of clearance fitting.
25 PRIOR ART REFERENCE
PATENT REFERENCE
[0004]
Patent Reference 1: Japanese Patent Application Publication
No. 2003-309953 (see paragraph 0033 and Fig. 1, for example)
30
SUMMARY OF THE INVENTION
PROBLEM TO BE SOLVED BY THE INVENTION
[0005]
However, when a load acts on the outer ring in the state of
3
having been fixed to the bearing holding part by means of
clearance fitting, there can occur a creep in which the outer
ring rotates while contacting the bearing holding part. When the
creep occurs, there arises a trouble such as wearing of contact
5 surfaces of the outer ring and the bearing holding part or an
increase in vibration and noise in the bearing.
[0006]
In a rotor of the consequent-pole type like the rotor in
the Patent Reference 1, there can occur a difference between
10 magnetic flux density in a magnet magnetic pole and magnetic flux
density in a virtual magnetic pole. In this case, the magnitude
of magnetic attraction acting between the rotor and the stator
becomes not constant in a circumferential direction, and thus
there are cases where the rotor is decentered and exciting force
15 acts on the outer ring. Thus, in a motor including a rotor of the
consequent-pole type, a load causing a creep is likely to act on
an outer ring of a bearing.
[0007]
An object of the present disclosure is to prevent an
20 occurrence of the creep at the bearing in a motor including a
rotor of the consequent-pole type.
MEANS FOR SOLVING THE PROBLEM
[0008]
25 A motor according to an aspect of the present disclosure
includes a stator, a rotor of a consequent-pole type including a
rotary shaft, a bearing as a rolling bearing that supports the
rotary shaft, a bearing holding part that is fixed to the stator
and holds an outer ring of the bearing, and a creep prevention
30 part that is arranged between the outer ring of the bearing and
the bearing holding part and increases friction resistance in a
circumferential direction of the outer ring between the outer
ring of the bearing and the bearing holding part.
4
EFFECT OF THE INVENTION
[0009]
According to the present disclosure, an occurrence of a
creep at a bearing can be prevented in a motor including a rotor
5 of the consequent-pole type.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010]
Fig. 1 is a configuration diagram showing a partial cross
10 section and a side face of a motor according to a first
embodiment.
Fig. 2 is a cross-sectional view of the motor shown in Fig.
1 taken along the line A2 - A2.
Fig. 3 is an enlarged sectional view showing a
15 configuration of a rotor shown in Fig. 2.
Fig. 4 is a cross-sectional view showing a configuration of
a metallic bracket of the motor according to the first
embodiment.
Fig. 5 is a schematic diagram for explaining a creep of a
20 bearing in the motor.
Fig. 6 is a magnetic flux diagram showing the result of a
simulation of the flow of magnetic flux in the motor according to
the first embodiment.
Fig. 7 is an enlarged sectional view showing a
25 configuration around a load-side bearing of the motor shown in
Fig. 1.
Fig. 8(A) is a plan view showing an O-ring shown in Fig. 7,
and Fig. 8(B) is a cross-sectional view showing the O-ring shown
in Fig. 8(A).
30 Fig. 9 is an enlarged sectional view showing a
configuration of a load-side bearing and surrounding components
in a motor according to a second embodiment.
Fig. 10 is an enlarged sectional view showing a
configuration of a load-side bearing and surrounding components
5
in a motor according to a third embodiment.
Fig. 11 is an enlarged sectional view showing a
configuration of a load-side bearing and surrounding components
in a motor according to a modification of the third embodiment.
5 Fig. 12(A) is an enlarged sectional view showing a
configuration of a load-side bearing and surrounding components
in a motor according to a fourth embodiment, and Fig. 12(B) is a
partial front view of an outer ring of the load-side bearing
shown in Fig. 12(A).
10 Fig. 13 is an enlarged sectional view showing a
configuration of a load-side bearing and surrounding components
in a motor according to a fifth embodiment.
Fig. 14 is a configuration diagram showing a partial cross
section and a side face of a motor according to a sixth
15 embodiment.
Fig. 15 is a configuration diagram showing a partial cross
section and a side face of a motor according to a first
modification of the sixth embodiment.
Fig. 16 is an enlarged sectional view showing a
20 configuration of an anti-load-side bearing and surrounding
components in the motor shown in Fig. 15.
Fig. 17 is a configuration diagram showing a partial cross
section and a side face of a motor according to a second
modification of the sixth embodiment.
25 Fig. 18 is a configuration diagram showing a partial cross
section and a side face of a motor according to a third
modification of the sixth embodiment.
Fig. 19 is a diagram showing a configuration of an air
conditioner employing the motor according to any one of the first
30 to sixth embodiments.
Fig. 20 is a cross-sectional view showing a configuration
of an outdoor unit shown in Fig. 19.
MODE FOR CARRYING OUT THE INVENTION
6
[0011]
A rotor, a motor, a blower and an air conditioner according
to each embodiment of the present disclosure will be described
below with reference to the drawings. The following embodiments
5 are just examples and it is possible to appropriately combine
embodiments and appropriately modify each embodiment.
[0012]
An xyz orthogonal coordinate system is shown in the
drawings to facilitate the understanding of the description. A z10 axis is a coordinate axis parallel to an axis line of a rotor. An
x-axis is a coordinate axis orthogonal to the z-axis. A y-axis is
a coordinate axis orthogonal to both the x-axis and the z-axis.
[0013]
15 (First Embodiment)

Fig. 1 is a configuration diagram showing a partial cross
section and a side face of a motor 100 according to a first
embodiment. The motor 100 includes a rotor 1 and a mold stator 9
20 as a stator. The rotor 1 is arranged inside the mold stator 9.
Namely, the motor 100 is a motor of the inner rotor type.
[0014]
The rotor 1 includes a shaft 15 as a rotary shaft. The
rotor 1 is rotatable around an axis line C1 of the shaft 15. The
25 shaft 15 projects from the mold stator 9 towards the +z-axis
side. To a tip end part 15a of the shaft 15, a fan of a blower
(i.e., a blade wheel 704 of an outdoor blower 150 which will be
described later) is attached, for example. Incidentally, in the
following description, a direction along a circumference of a
30 circle centering at the axis line C1 of the shaft 15 is referred
to as a "circumferential direction" (e.g., the arrow R1 shown in
Fig. 2). Further, the z-axis direction is referred to as an
"axial direction", and a direction orthogonal to the axial
direction is referred to as a "radial direction". Furthermore,
7
the projecting side (i.e., the +z-axis side) of the shaft 15 is
referred to as a "load side", and a side of the shaft 15 opposite
to the load side is referred to as an "anti-load side".
[0015]
5 The motor 100 further includes a bearing 21 that supports
the load side of the shaft 15 and a bearing 22 that supports the
anti-load side of the shaft 15. The bearing 21 and the bearing 22
are respectively arranged on sides opposite to each other across
a stator core 50 of the mold stator 9. The bearing 21 supports a
10 part 15c of the shaft 15 on the load side relative to the mold
stator 9. The bearing 22 supports an end part 15b of the shaft 15
on the -z-axis side (i.e., a part on the anti-load side) via an
insulation sleeve 60. The bearing 21 and the bearing 22 are
rolling bearings, such as ball bearings, for example.
15 [0016]
The insulation sleeve 60 is arranged between the end part
15b of the shaft 15 on the -z-axis side and the bearing 22. The
insulation sleeve 60 is in a substantially cylindrical shape, for
example. The insulation sleeve 60 is formed of thermosetting
20 resin, for example. In the first embodiment, the insulation
sleeve 60 is formed of BMC (Bulk Molding Compound) resin.
[0017]
Since the insulation sleeve 60 is arranged between the end
part 15b of the shaft 15 on the -z-axis side and the bearing 22,
25 the shaft 15 and the bearing 22 are insulated from each other.
Accordingly, an axial current causing electrolytic corrosion is
prevented from flowing from the shaft 15 into the bearing 22.
Further, the prevention of the flowing of the axial current into
the bearing 22 prevents the axial current from flowing into the
30 bearing 21 via the bearing 22, the mold stator 9 and a metallic
bracket 6. Incidentally, it is also possible to arrange the
insulation sleeve 60 between the shaft 15 and the bearing 21, or
both between the shaft 15 and the bearing 21 and between the
shaft 15 and the bearing 22.
8
[0018]
As shown in Fig. 1, the motor 100 further includes a cap 8.
The cap 8 is fixed to the shaft 15 so as to cover a part of the
metallic bracket 6. The cap 8 is a member that prevents entry of
5 foreign matter (e.g., water or the like) into the inside of the
motor 100.
[0019]

Next, the configuration of the mold stator 9 will be
10 described below by using Figs. 1 and 2. Fig. 2 is a crosssectional view of the rotor 1 and the mold stator 9 shown in Fig.
1 taken along the line A2 - A2. Incidentally, illustration of a
mold resin part 56 of the mold stator 9 is left out in Fig. 2.
[0020]
15 As shown in Figs. 1 and 2, the mold stator 9 includes the
stator core 50, a coil 55 wound around the stator core 50, and
the mold resin part 56 that covers the stator core 50.
[0021]
The stator core 50 includes a yoke 51 in a ring-like shape
20 centering at the axis line C1 and a plurality of teeth 52
extending inward in the radial directions from the yoke 51. The
plurality of teeth 52 are arranged at regular intervals in the
circumferential direction R1. A tip end part of each of the
plurality of teeth 52 faces the rotor 1 in the radial direction
25 via an air gap. The coil 55 is wound around the teeth 52 via an
insulator 53.
[0022]
The mold resin part 56 is formed of thermosetting resin
such as BMC resin, for example. The mold resin part 56 includes
30 an opening part 56a. The opening part 56a is formed on the +zaxis side of the mold resin part 56. The metallic bracket 6 as a
bearing holding part is fixed to the opening part 56a. The loadside bearing 21 is held by the metallic bracket 6. Namely, in the
first embodiment, the bearing holding part holding the load-side
9
bearing 21 is formed of metal. The bearing holding part holding
the bearing 21 may also be formed of resin as shown in Fig. 17 or
18 which will be explained later.
[0023]
5 The mold resin part 56 further includes a holding part 56b
formed on the -z-axis side. The bearing 22 is held by the holding
part 56b. Namely, in the first embodiment, a bearing holding part
holding the anti-load-side bearing 22 is formed of resin.
Incidentally, the bearing holding part holding the bearing 22 may
10 also be formed of metal as shown in Figs. 15 to 17 which will be
explained later.
[0024]
A circuit board 7 is embedded in the mold resin part 56.
To the circuit board 7, wires such as power supply lead wires for
15 supplying electric power to the coil 55 are connected.
[0025]

Next, the configuration of the rotor 1 will be described
below by using Figs. 2 and 3. Fig. 3 is an enlarged sectional
20 view showing the configuration of the rotor 1 shown in Fig. 2. As
shown in Figs. 2 and 3, the rotor 1 includes a rotor core 10 and
the shaft 15.
[0026]
The rotor core 10 is a member in a ring-like shape
25 centering at the axis line C1. The rotor core 10 is formed by
fixing a plurality of electromagnetic steel sheets stacked in the
axial direction together by means of crimping, for example.
[0027]
The rotor core 10 is provided with permanent magnets 40.
30 In the first embodiment, the permanent magnets 40 are embedded in
the rotor core 10. Namely, the rotor 1 has the IPM (Interior
Permanent Magnet) structure. Incidentally, the rotor 1 may also
have the SPM (Surface Permanent Magnet) structure in which the
permanent magnets 40 are attached to the outer periphery of the
10
rotor core 10.
[0028]
The rotor core 10 includes first core parts 11 to which
permanent magnets 40 are attached and second core parts 12 to
5 which no permanent magnets 40 are attached. In the first
embodiment, the rotor core 10 includes a plurality of (e.g.,
five) first core parts 11 and a plurality of (e.g., five) second
core parts 12. The plurality of first core parts 11 and the
plurality of second core parts 12 are arranged alternately in the
10 circumferential direction R1.
[0029]
The first core part 11 includes a magnet insertion hole
11a. The magnet insertion hole 11a is formed on an inner side in
the radial direction relative to an outer periphery of the first
15 core part 11. The shape of the magnet insertion hole 11a is a
linear shape in a plan view, for example. In the first
embodiment, one permanent magnet 40 is inserted in one magnet
insertion hole 11a. Incidentally, the shape of the magnet
insertion hole 11a may also be a V-shape in a plan view, pointing
20 its convexity inward in the radial direction or pointing its
convexity outward in the radial direction. Further, it is also
possible to insert two or more permanent magnets 40 in one magnet
insertion hole 11a.
[0030]
25 The permanent magnet 40 is a rare-earth magnet, for
example. In the first embodiment, the permanent magnet 40 is a
neodymium rare-earth magnet containing Nd (neodymium), Fe (iron)
and B (boron), for example.
[0031]
30 As shown in Fig. 3, the plurality of permanent magnets 40
include magnetic poles having the same polarity as each other
(e.g., north poles) on their outer sides in the radial
directions. Accordingly, magnet magnetic poles P1 are formed on
the outer peripheries of the first core parts 11. Incidentally,
11
in the following description, a straight line extending in the
radial direction through the center of the magnet magnetic pole
P1 in the circumferential direction R1 (i.e., pole center) is
referred to as a "pole center line M1" (see Fig. 6).
5 [0032]
The plurality of permanent magnets 40 include magnetic
poles having the same polarity as each other (e.g., south poles)
on their inner sides in the radial directions. Magnetic flux
emitted from the inner side of the permanent magnet 40 in the
10 radial direction flows into the second core part 12, by which a
virtual magnetic pole P2 (e.g., south pole) is formed on the
outer side of the second core part 12 in the radial direction.
Thus, the plurality of second core parts 12 include virtual
magnetic poles P2 having the same polarity as each other on their
15 outer sides in the radial directions.
[0033]
The rotor 1 is a rotor of the consequent-pole type in which
the magnet magnetic poles P1 and the virtual magnetic poles P2
are arranged alternately in the circumferential direction R1. In
20 the rotor 1 of the consequent-pole type, the number of permanent
magnets 40 can be reduced to half compared to a rotor of a nonconsequent-pole type having the same number of poles.
Accordingly, the manufacturing cost of the rotor 1 is reduced.
Incidentally, while the pole number of the rotor 1 is 10 in the
25 first embodiment, the pole number is not limited to 10; it is
permissible if the pole number is an even number greater than or
equal to 2. Further, in the rotor 1, it is permissible even if
the magnet magnetic poles P1 are south poles and the virtual
magnetic poles P2 are north poles.
30 [0034]
The first core part 11 further includes a plurality of flux
barriers 11b as leakage flux inhibition holes. The flux barrier
11b is formed on each side of the magnet insertion hole 11a in
the circumferential direction R1. Since a part between the flux
12
barrier 11b and the outer periphery of the first core part 11 is
formed as a thin wall, leakage flux between the magnet magnetic
pole P1 and the virtual magnetic pole P2 adjoining each other is
inhibited.
5 [0035]
The second core part 12 includes a crimping part 14. The
crimping part 14 is a crimping mark formed when the plurality of
electromagnetic steel sheets stacked in the axial direction are
fixed together by means of crimping. In the first embodiment, the
10 shape of the crimping part 14 as viewed in the axial direction is
a circular shape, for example. The shape of the crimping part 14
is not limited to the circular shape but can also be a different
shape such as a rectangular shape.
[0036]
15 The rotor 1 further includes a connection part 30 that
connects the rotor core 10 and the shaft 15 to each other. The
connection part 30 is formed of resin material having the
electrical insulation property. The connection part 30 is formed
of thermoplastic resin such as PBT (PolyButylene Telephthalate),
20 for example. The rotor core 10, the shaft 15 and the insulation
sleeve 60 are integrated together via the connection part 30.
[0037]
The connection part 30 includes an inner cylinder part 31,
a plurality of ribs 32, and an outer cylinder part 33. The inner
25 cylinder part 31 is in a ring-like shape and is in contact with
an outer peripheral surface 15d of the shaft 15. The outer
cylinder part 33 is in contact with an inner peripheral surface
10a of the rotor core 10. The plurality of ribs 32 connect the
inner cylinder part 31 and the outer cylinder part 33 to each
30 other. The plurality of ribs 32 radially extend outward in the
radial directions from the inner cylinder part 31. The plurality
of ribs 32 are arranged centering at the axis line C1 and at
equal intervals in the circumferential direction R1. Between ribs
32 adjoining each other in the circumferential direction R1, a
13
hollow part 35 penetrating in the axial direction is formed.
Incidentally, the rotor core 10 and the shaft 15 may also be
fixed to each other directly via no connection part 30.
[0038]
5 As shown in Fig. 1, the rotor 1 further includes a sensor
magnet 16. For example, the sensor magnet 16 is attached to a
part on the -z-axis side relative to the rotor core 10 and faces
the circuit board 7. A magnetic field of the sensor magnet 16 is
detected by a magnetic sensor (not shown) provided on the circuit
10 board 7, by which the position of the rotor 1 in the
circumferential direction R1 is detected.
[0039]

Next, the configuration of the metallic bracket 6 will be
15 described below by using Fig. 4. Fig. 4 is a cross-sectional view
showing the configuration of the metallic bracket 6. The metallic
bracket 6 is formed of a galvanized steel sheet, for example. The
material of the metallic bracket 6 is not limited to a galvanized
steel sheet; the metallic bracket 6 may be formed of different
20 metallic material such as aluminum alloy.
[0040]
The metallic bracket 6 includes a cylinder part 61, a
flange part 62, a fixation part 63 and a base part 64. The
cylinder part 61 extends substantially in parallel with the axis
25 line C1. When the metallic bracket 6 is fixed to the shaft 15,
the cylinder part 61 faces an outer ring 21b (see Fig. 7) of the
bearing 21 in the radial directions. The flange part 62 is formed
integrally with the cylinder part 61 and extends outward in the
radial directions from an end part of the cylinder part 61 on the
30 anti-load side. The fixation part 63 extends towards the +z-axis
side from an end part of the flange part 62 on the outer side in
the radial directions. The fixation part 63 is a part of the
metallic bracket 6 that is fixed to the mold resin part 56 (see
Fig. 1). The fixation part 63 is fixed to the mold resin part 56
14
by means of press fitting, for example.
[0041]
The base part 64 is formed integrally with the cylinder
part 61 and extends inward in the radial directions from an end
5 part of the cylinder part 61 on the load side. The cylinder part
61, the flange part 62 and the base part 64 are formed by
performing a drawing process on the aforementioned galvanized
steel sheet, for example. A shaft penetration part 65 which the
shaft 15 (see Fig. 1) penetrates is formed in the base part 64.
10 The shaft penetration part 65 projects towards the +z-axis side
from an end part of the base part 64 on the inner side in the
radial directions.
[0042]
For example, to facilitate the assembly of the metallic
15 bracket 6 and the bearing 21, the outer ring 21b of the bearing
21 shown in Fig. 1 is fixed to the cylinder part 61 by means of
clearance fitting. When a load acts on the outer ring 21b in the
state of having been fixed to the cylinder part 61 by means of
clearance fitting during the rotation of the motor 100, there can
20 occur a creep in which the outer ring 21b rotates with respect to
the cylinder part 61.
[0043]
Fig. 5 is a schematic diagram for explaining a creep in the
bearing 21. As shown in Fig. 5, the bearing 21 includes an inner
25 ring 21a that supports the shaft 15, the outer ring 21b that is
fixed to the cylinder part 61 of the metallic bracket 6 via a
clearance , and balls 21c as rolling members arranged between
the inner ring 21a and the outer ring 21b. While the clearance 
is exaggerated in Fig. 5, the size of the clearance  is
30 approximately 10 m. A length of the outer ring 21b in a
circumferential direction is shorter than a length of the
cylinder part 61 in a circumferential direction.
[0044]
Thus, when a load Fr acts on the outer ring 21b during the
15
rotation of the motor 100, there occurs a creep in which the
outer ring 21b rotates in the direction indicated by the arrow R2
while contacting the cylinder part 61. When the creep occurs,
fitting surfaces of the outer ring 21b and the cylinder part 61
5 wear down and there occurs a trouble such as an occurrence of
vibration and noise in the bearing 21 or entry of abrasion powder
into the inside of the bearing 21.
[0045]
The load Fr acting on the outer ring 21b occurs as a
10 contact rotation radial load when the shaft 15 of the rotor 1 is
decentered, for example. In the motor 100 including the rotor 1
of the consequent-pole type, decentering is likely to occur to
the shaft 15 of the rotor 1 due to a difference between surface
magnetic flux density in the magnet magnetic pole P1 and surface
15 magnetic flux density in the virtual magnetic pole P2 as shown in
Fig. 6 which will be explained below.
[0046]
Fig. 6 is a magnetic flux diagram showing the result of a
simulation of the flow of magnetic flux in the motor 100.
20 Incidentally, reference characters 40a, 40b, 40c, 40d and 40e are
assigned to the permanent magnets in Fig. 6 to facilitate the
understanding of the description.
[0047]
As shown in Fig. 6, the magnetic flux emitted from the
25 inner side of the permanent magnet 40a in the radial direction
flows into the second core parts 12 situated on both sides in the
circumferential direction R1 with reference to the pole center
line M1, by which the virtual magnetic poles P2 (see Fig. 3) are
formed. However, in the rotor 1 of the consequent-pole type,
30 there can occur variation in the magnetic flux density between
the second core parts 12 situated on both sides in the
circumferential direction R1 with reference to the pole center
line M1 as shown in Fig. 6. Thus, there are cases where the
difference between the surface magnetic flux density in the
16
magnet magnetic pole P1 and the surface magnetic flux density in
the virtual magnetic pole P2 becomes great in the circumferential
direction R1 of the rotor 1.
[0048]
5 In such cases, the magnitude of magnetic attraction acting
between the stator core 50 and the rotor 1 becomes imbalanced in
the circumferential direction R1. Accordingly, the axis line C1
of the shaft 15 is decentered and exciting force a radial
direction acts on the rotor 1. Thus, in the motor 100 according
10 to the first embodiment, on the bearing 21 or the bearing 22
supporting the shaft 15 of the rotor 1, the exciting force in the
radial direction acts as the load Fr shown in Fig. 5.
[0049]
Further, when a fan of a blower is attached to the tip end
15 part 15a (see Fig. 1) of the shaft 15, the fan's own weight also
acts on the bearing 21 as the load Fr shown in Fig. 5.
Accordingly, the load Fr is greater in the bearing 21 than in the
bearing 22 and thus creep is more likely to occur in the bearing
21. Therefore, in the first embodiment, a description will be
20 given of a creep prevention part (in the first embodiment, a
ring-shaped elastic body 23 shown in Fig. 1 or 7) that prevents
creep from occurring in the bearing 21.
[0050]
Fig. 7 is an enlarged sectional view showing a
25 configuration around the bearing 21 of the motor 100 shown in
Fig. 1. As shown in Fig. 7, the motor 100 includes the ringshaped elastic body 23 as an elastic member as the creep
prevention part. The ring-shaped elastic body 23 is arranged
between an outer circumferential surface 21f of the outer ring
30 21b and an inner circumferential surface 61a of the cylinder part
61, and is compressed in the radial directions.
[0051]
A friction coefficient between the ring-shaped elastic body
23 and the cylinder part 61 is greater than a friction
17
coefficient between the outer ring 21b and the cylinder part 61.
Namely, by providing the ring-shaped elastic body 23 between the
outer ring 21b and the cylinder part 61, friction resistance
(i.e., frictional force) in the circumferential direction R1
5 between the outer circumferential surface 21f of the outer ring
21b and the inner circumferential surface 61a of the cylinder
part 61 increases. Accordingly, the outer ring 21b becomes
unlikely to rotate with respect to the cylinder part 61, and thus
an occurrence of a creep at the bearing 21 can be inhibited.
10 [0052]
Fig. 8(A) is a plan view showing the ring-shaped elastic
body 23 shown in Fig. 7, and Fig. 8(B) is a cross-sectional view
showing the ring-shaped elastic body 23 shown in Fig. 8(A). As
shown in Figs. 8(A) and 8(B), the ring-shaped elastic body 23 is
15 an elastic member in a ring-like shape centering at the axis line
C1. A cross-sectional shape of the ring-shaped elastic body 23 is
a circular shape, for example. In the first embodiment, the ringshaped elastic body 23 is an O-ring. The cross-sectional shape of
the ring-shaped elastic body 23 is not limited to the circular
20 shape but can also be a different shape such as a quadrangular
shape.
[0053]
In the case where the ring-shaped elastic body 23 is an Oring, the friction coefficient between the O-ring and the
25 opposing surface is a value within a range of 1.03 to 1.25, for
example. Here, the friction coefficient between iron forming the
outer ring 21b and the metallic bracket 6 and the opposing
surface is approximately 0.2. Thus, the friction coefficient
between the O-ring and the opposing surface is greater than the
30 friction coefficient between the iron and the opposing surface.
[0054]
The ring-shaped elastic body 23 is, for example, rubber
containing thermosetting elastomer. The rubber containing
thermosetting elastomer is fluororubber, silicone rubber,
18
ethylene propylene rubber, nitrile rubber or the like, for
example.
[0055]
As shown in Fig. 7, the ring-shaped elastic body 23 is
5 arranged in a groove part 21d formed on the outer circumferential
surface 21f of the outer ring 21b. The groove part 21d is a long
groove extending in the circumferential direction R1 on the outer
circumferential surface 21f. It is also possible to form the
groove part 21d on the inner circumferential surface 61a of the
10 cylinder part 61.
[0056]
Here, regarding the outer ring 21b, its axial direction
central part overlaps with the center of the ball 21c in regard
to the axial direction position and so needs to have a sufficient
15 wall thickness to withstand the load from the ball 21c.
Therefore, in the first embodiment, the groove part 21d is formed
at a position on the outer circumferential surface 21f that is
deviated towards one side in the axial direction (the +z-axis
side in Fig. 7) with reference to the axial direction central
20 position P of the ball 21c. This makes it possible to arrange the
ring-shaped elastic body 23 in the outer ring 21b while the axial
direction central part has a sufficient wall thickness in the
outer ring 21b. It is also possible to form the groove part 21d
at a position on the outer circumferential surface 21f that is
25 deviated towards the -z-axis side with reference to the axial
direction central position P of the ball 21c.
[0057]
Further, the ring-shaped elastic body 23 is arranged
between the outer ring 21b and the cylinder part 61 and on the
30 base part 64's side with reference to the axial direction central
position P of the ball 21c. As mentioned earlier, the cylinder
part 61, the flange part 62 and the base part 64 are formed by
performing the drawing process on a galvanized steel sheet, for
example. As the die (i.e., punch) advances in the drawing
19
process, in the inner circumferential surface 61a of the cylinder
part 61, the flange part 62's side is more likely to expand in
diameter outward in the radial direction than the base part 64's
side. Namely, on the inner circumferential surface 61a of the
5 cylinder part 61, higher dimensional accuracy is likely to be
obtained as the position becomes closer to the base part 64.
Thus, compressive force acting on the ring-shaped elastic body 23
is stabilized by arranging the ring-shaped elastic body 23
between the outer ring 21b and the cylinder part 61 and on the
10 base part 64's side with reference to the axial direction central
position P of the ball 21c. Accordingly, frictional force
preventing the rotation of the outer ring 21b with respect to the
cylinder part 61 is stabilized, by which an occurrence of a creep
at the bearing 21 can be prevented further.
15 [0058]
The motor 100 further includes a precompression spring 45
arranged between the base part 64 of the metallic bracket 6 and
the bearing 21. The precompression spring 45 applies force to an
end face 21i of the outer ring 21b in regard to the axial
20 direction so as to press the end face 21i towards the mold stator
9 shown in Fig. 1. Accordingly, an internal clearance in the
bearing 21 becomes a negative clearance, by which rigidity of the
bearing 21 is increased. The precompression spring 45 has a
through hole 45a which the shaft 15 penetrates. The
25 precompression spring 45 is a wave washer, for example.
[0059]

With the motor 100 according to the first embodiment
described above, the following effects are obtained:
30 [0060]
With the motor 100 according to the first embodiment, the
ring-shaped elastic body 23 increasing the friction resistance in
the circumferential direction R1 between the outer
circumferential surface 21f of the outer ring 21b of the bearing
20
21 and the inner circumferential surface 61a of the cylinder part
61 of the metallic bracket 6 is arranged. With this
configuration, an occurrence of a creep at the bearing 21 can be
prevented. Accordingly, a trouble in the motor 100 such as the
5 occurrence of vibration and noise due to the creep can be
prevented and the quality of the motor 100 is improved.
[0061]
With the motor 100 according to the first embodiment, in
the outer ring 21b, the groove part 21d in which the ring-shaped
10 elastic body 23 is arranged is formed at a position that is
deviated towards one side in the axial direction with reference
to the axial direction central position P of the ball 21c. This
makes it possible to arrange the ring-shaped elastic body 23 in
the outer ring 21b while the axial direction central part has a
15 sufficient wall thickness in the outer ring 21b.
[0062]
With the motor 100 according to the first embodiment, the
ring-shaped elastic body 23 is arranged between the outer ring
21b and the cylinder part 61 and on the base part 64's side with
20 reference to the axial direction central position P of the ball
21c. In the case where the metallic bracket 6 is formed by the
drawing process, on the inner circumferential surface 61a of the
cylinder part 61, higher dimensional accuracy is likely to be
obtained as the position becomes closer to the base part 64.
25 Thus, the compressive force acting on the ring-shaped elastic
body 23 is stabilized when the ring-shaped elastic body 23 is
arranged between the outer ring 21b and the cylinder part 61 and
on the base part 64's side. Accordingly, the frictional force
preventing the rotation of the outer ring 21b with respect to the
30 cylinder part 61 is also stabilized, by which an occurrence of a
creep at the bearing 21 can be prevented further.
[0063]
With the motor 100 according to the first embodiment, the
bearing holding part holding the load-side bearing 21 is the
21
metallic bracket 6 formed of a galvanized steel sheet. By using
the galvanized steel sheet, higher dimensional accuracy is likely
to be obtained compared to resin, and thus the dimensional
accuracy between the outer ring 21b of the bearing 21 and the
5 metallic bracket 6 can be managed with high accuracy. Further,
since the bearing holding part holding the the anti-load-side
bearing 22 (i.e., the holding part 56b) is formed of BMC resin,
the manufacturing cost of the motor 100 can be reduced.
[0064]
10 With the motor 100 according to the first embodiment, there
is provided the ring-shaped elastic body 23 for preventing a
occurrence of a creep at the bearing 21 where a creep is likely
to occur. With this configuration, the cost for the motor 100 can
be reduced compared to a configuration for preventing a
15 occurrence of a creep at both of the bearing 21 and the bearing
22.
[0065]
Further, in the rotor 1 of the consequent-pole type, when
exciting force in a radial direction acts on the bearing 21, 22
20 supporting the shaft 15, oil film formed between the ball 21c and
an orbital ring (the inner ring 21a or the outer ring 21b) can be
lost. In this case, the ball 21c and the orbital ring contact
each other directly via no oil film, and thus the electrolytic
corrosion is likely to occur when an axial current flows into the
25 bearing 21, 22. According to the first embodiment, the insulation
sleeve 60 is arranged between the end part 15b of the shaft 15 on
the -z-axis side and the bearing 22. With this configuration, the
flow of the axial current into the bearing 21, 22 supporting the
shaft 15 is prevented, and thus an occurrence of electrolytic
30 corrosion can be prevented.
[0066]
With the motor 100 according to the first embodiment, the
connection part 30 formed of resin material having the electrical
insulation property connects the rotor core 10 and the shaft 15
22
to each other, and thus the axial current is prevented from
flowing between the rotor core 10 and the shaft 15. Accordingly,
the axial current is prevented from flowing between the rotor
core 10 and the shaft 15 and then flowing into the bearing 21,
5 22, and thus occurrence of electrolytic corrosion can be
prevented.
[0067]
(Second Embodiment)
10 Fig. 9 is an enlarged sectional view showing a
configuration of a load-side bearing 221 and surrounding
components in a motor 200 according to a second embodiment. In
Fig. 9, each component identical or corresponding to a component
shown in Fig. 7 is assigned the same reference character as in
15 Fig. 7. The motor 200 according to the second embodiment differs
from the motor 100 according to the first embodiment in that a
plurality of ring-shaped elastic bodies 23, 24 are arranged
between an outer ring 221b of the load-side bearing 221 and the
cylinder part 61 of the metallic bracket 6.
20 [0068]
As shown in Fig. 9, the motor 200 includes the load-side
bearing 221 that supports the load side of the shaft 15, the
metallic bracket 6 that holds the load-side bearing 221, and the
plurality of (two in Fig. 9) ring-shaped elastic bodies 23, 24 as
25 the creep prevention parts.
[0069]
The plurality of ring-shaped elastic bodies 23, 24 are
arranged between an outer circumferential surface 221f of the
outer ring 221b and the inner circumferential surface 61a of the
30 cylinder part 61. Incidentally, the number of ring-shaped elastic
bodies 23, 24 arranged between the outer ring 221b and the
cylinder part 61 is not limited to two but can also be three or
more.
[0070]
23
The outer ring 221b includes a first groove part 21d and a
second groove part 221e formed at different axial direction
positions on the outer circumferential surface 221f. In the
second embodiment, the first groove part 21d and the second
5 groove part 221e are arranged at positions symmetrical with each
other with reference to the axial direction central position P of
the ball 21c, for example. The ring-shaped elastic body 23 is
arranged in the first groove part 21d. The ring-shaped elastic
body 24 is arranged in the second groove part 221e. The ring10 shaped elastic body 24 is rubber containing thermosetting
elastomer, for example, similarly to the ring-shaped elastic body
23. The ring-shaped elastic body 24 is an O-ring, for example,
similarly to the ring-shaped elastic body 23.
[0071]
15 A friction coefficient between the ring-shaped elastic body
24 and the cylinder part 61 is greater than a friction
coefficient between the outer ring 21b and the cylinder part 61.
Thus, when the plurality of ring-shaped elastic bodies 23, 24
arranged between the outer circumferential surface 21f of the
20 outer ring 21b and the inner circumferential surface 61a of the
cylinder part 61 are compressed in the radial directions, the
ring-shaped elastic bodies 23, 24 increase the friction
resistance in the circumferential direction R1 between the outer
ring 21b and the cylinder part 61. Accordingly, the outer ring
25 21b becomes unlikely to rotate with respect to the cylinder part
61, and thus an occurrence of a creep at the bearing 21 can be
prevented.
[0072]
With the motor 200 according to the second embodiment
30 described above, a plurality of ring-shaped elastic bodies 23, 24
are arranged between the outer circumferential surface 221f of
the outer ring 221b and the inner circumferential surface 61a of
the cylinder part 61. With this configuration, the friction
resistance in the circumferential direction R1 between the outer
24
circumferential surface 221f of the outer ring 221b and the inner
circumferential surface 61a of the cylinder part 61 increases
further. Accordingly, an occurrence of a creep at the load-side
bearing 221 can be prevented further.
5 [0073]
Further, with the motor 200 according to the second
embodiment, the plurality of ring-shaped elastic bodies 23, 24
are arranged at positions symmetrical with reference to the axial
direction central position P of the ball 21c. This makes it
10 possible to arrange the plurality of ring-shaped elastic bodies
23, 24 in the outer ring 21b while the axial direction central
part on which the load from the ball 21c acts has a sufficient
wall thickness, in the outer ring 21b.
[0074]
15 Except for the above-described features, the motor 200
according to the second embodiment is the same as the motor 100
according to the first embodiment.
[0075]
20 (Third Embodiment)
Fig. 10 is an enlarged sectional view showing a
configuration of a load-side bearing 321 and surrounding
components in a motor 300 according to a third embodiment. In
Fig. 10, each component identical or corresponding to a component
25 shown in Fig. 7 is assigned the same reference character as in
Fig. 7. The motor 300 differs from the motor 100 or 200 according
to the first or second embodiment in the configuration of the
creep prevention part.
[0076]
30 As shown in Fig. 10, the motor 300 includes the load-side
bearing 321 that supports the load side of the shaft 15, the
metallic bracket 6 that holds the load-side bearing 321, and a
resin member 323 as the creep prevention part. The resin member
323 is arranged between an outer circumferential surface 321f of
25
an outer ring 321b of the load-side bearing 321 and the inner
circumferential surface 61a of the cylinder part 61 of the
metallic bracket 6.
[0077]
5 The resin member 323 is formed of thermoplastic elastomer,
for example. The resin member 323 is previously fixed to the
outer ring 321b by, for example, integrating the resin member 323
with the outer ring 321b by means of integral molding. The resin
member 323 may also be previously fixed to the outer ring 321b by
10 means of an adhesive agent or the like. Further, the resin member
323 may also be previously fixed to the metallic bracket 6.
[0078]
A friction coefficient between the resin member 323 and the
cylinder part 61 is greater than a friction coefficient between
15 the outer ring 321b and the cylinder part 61. Namely, when the
resin member 323 is arranged between the outer circumferential
surface 321f of the outer ring 321b and the inner circumferential
surface 61a of the cylinder part 61, the resin member 323
increases the friction resistance in the circumferential
20 direction R1 between the outer ring 321b and the cylinder part
61. Accordingly, the outer ring 321b becomes unlikely to rotate
with respect to the cylinder part 61, and thus an occurrence of a
creep at the load-side bearing 321 can be prevented.
[0079]
25 With the motor 300 according to the third embodiment
described above, the resin member 323 increasing the friction
resistance in the circumferential direction R1 between the outer
ring 321b and the cylinder part 61 is arranged. With this
configuration, the outer ring 321b becomes unlikely to rotate
30 with respect to the cylinder part 61, and thus an occurrence of a
creep at the load-side bearing 321 can be prevented.
[0080]
Except for the above-described features, the third
embodiment is the same as the first or second embodiment.
26
[0081]
(Modification of Third Embodiment)
Fig. 11 is an enlarged sectional view showing a
5 configuration of a load-side bearing 321 and surrounding
components in a motor 300A according to a modification of the
third embodiment. In Fig. 11, each component identical or
corresponding to a component shown in Fig. 7 or 10 is assigned
the same reference character as in Fig. 7 or 10. The motor 300A
10 differs from the motor according to any one of the first to third
embodiments in the configuration of the creep prevention part.
[0082]
As shown in Fig. 11, in the motor 300A, an adhesive agent
323A exists between the outer ring 321b of the load-side bearing
15 321 and the inner circumferential surface of the cylinder part 61
of the metallic bracket 6. In the motor 300A, the outer
circumferential surface 321f of the outer ring 321b and the inner
circumferential surface 61a of the cylinder part 61 are fixed to
each other by the adhesive agent 323A. With this configuration,
20 the outer ring 321b becomes unlikely to rotate with respect to
the cylinder part 61.
[0083]
With the motor 300A according to the modification of the
third embodiment described above, the adhesive agent 323A exists
25 between the outer circumferential surface 321f of the outer ring
321b and the inner circumferential surface 61a of the cylinder
part 61, by which the outer circumferential surface 321f of the
outer ring 321b and the inner circumferential surface 61a of the
cylinder part 61 are fixed to each other. With this
30 configuration, the outer ring 321b becomes unlikely to rotate
with respect to the cylinder part 61, and thus an occurrence of a
creep at the load-side bearing 321 can be prevented.
[0084]
27
(Fourth Embodiment)
Fig. 12(A) is an enlarged sectional view showing a
configuration of a load-side bearing 400 and surrounding
components in a motor 400 according to a fourth embodiment. Fig.
5 12(B) is a partial front view of an outer circumferential surface
421f of an outer ring 421b shown in Fig. 12(A). In Fig. 12(A),
each component identical or corresponding to a component shown in
Fig. 7 is assigned the same reference character as in Fig. 7. The
motor 400 differs from the motor according to any one of the
10 first to third embodiments in the configuration of the creep
prevention part.
[0085]
As shown in Figs. 12(A) and 12(B), the motor 400 includes
the load-side bearing 421 that supports the load side of the
15 shaft 15, the metallic bracket 6 that holds the load-side bearing
421, and an undulating surface 423 as the creep prevention part.
The undulating surface 423 is formed on the outer circumferential
surface 421f of the outer ring 421b. The undulating surface 423
is formed on the whole of the outer circumferential surface 421f
20 in regard to the axial direction, for example. It is permissible
even if the undulating surface 423 is formed on at least part of
the outer circumferential surface 421f.
[0086]
As shown in Fig. 12(B), the undulating surface 423 includes
25 convex parts 423g and concave parts 423h. The undulating surface
423 is formed by, for example, performing shot blasting
processing on the outer circumferential surface 421f of the outer
ring 421b. Surface roughness Ra of the undulating surface 423 on
the outer circumferential surface 421f after the processing is
30 greater than surface roughness Ra of the outer circumferential
surface 421f before the processing. The surface roughness Ra of
the outer circumferential surface 421f before the processing is
0.025 m to 0.2 m, for example. The surface roughness Ra of the
outer circumferential surface 421f after the processing is 0.2 m
28
to 20 m, for example. Here, the surface roughness Ra is the
"arithmetic mean roughness" defined in JIS B0601: 2013.
[0087]
A friction coefficient between the undulating surface 423
5 and the inner circumferential surface 61a of the cylinder part 61
is greater than a friction coefficient between the outer
circumferential surface 421f before the processing (i.e., surface
other than the undulating surface 423) and the inner
circumferential surface 61a of the cylinder part 61. Accordingly,
10 the friction resistance in the circumferential direction R1
between the outer ring 421b and the cylinder part 61 increases.
[0088]
With the motor 400 according to the fourth embodiment
described above, the undulating surface 423 increasing the
15 friction resistance in the circumferential direction R1 between
the outer ring 421b and the cylinder part 61 is formed on the
outer circumferential surface 421f of the outer ring 421b. With
this configuration, the outer ring 421b becomes unlikely to
rotate with respect to the cylinder part 61, and thus an
20 occurrence of a creep at the load-side bearing 421 can be
prevented.
[0089]
Except for the above-described features, the fourth
embodiment is the same as any one of the first to third
25 embodiments.
[0090]
(Fifth Embodiment)
Fig. 13 is an enlarged sectional view showing a
30 configuration of a load-side bearing 521 and surrounding
components in a motor 500 according to a fifth embodiment. In
Fig. 13, each component identical or corresponding to a component
shown in Fig. 7 is assigned the same reference character as in
Fig. 13. The motor 500 differs from the motor according to any
29
one of the first to fourth embodiments in the configuration of
the creep prevention part.
[0091]
As shown in Fig. 13, the motor 500 includes the load-side
5 bearing 521 that supports the load side of the shaft 15, the
metallic bracket 6 that holds the load-side bearing 521, the
precompression spring 45 arranged between the metallic bracket 6
and the load-side bearing 521, and a resin member 546 as the
creep prevention part.
10 [0092]
The resin member 546 is arranged between the load-side
bearing 521 and the precompression spring 45. The resin member
546 is in contact with the precompression spring 45 and an end
face 521i of an outer ring 521b. In other words, in the fifth
15 embodiment, the precompression spring 45 applies force to the end
face 521i of the outer ring 521b via the resin member 546 so as
to press the end face 521i towards the mold stator 9 (see Fig.
1). The resin member 546 is formed of thermoplastic elastomer,
for example. The resin member 546 is a member in a ring-like
20 shape centering at the axis line C1, for example. The resin
member 546 has a through hole 546a which the shaft 15 penetrates.
[0093]
A friction coefficient between the resin member 546 and the
outer ring 521b is greater than a friction coefficient between
25 the outer ring 521b and the precompression spring 45. By
arranging the resin member 546 between the outer ring 521b and
the precompression spring 45, the friction resistance between the
outer ring 521b and the precompression spring 45 is increased.
With this configuration, the pressing force of the precompression
30 spring 45 is stabilized, and thus the friction resistance in the
circumferential direction R1 of the outer ring 521b between the
outer ring 521b and the cylinder part 61 also increases.
Accordingly, the outer ring 521b becomes unlikely to rotate with
respect to the cylinder part 61, and an occurrence of a creep at
30
the load-side bearing 521 can be prevented. Incidentally, in the
fifth embodiment, the creep prevention part arranged between the
load-side bearing 521 and the precompression spring 45 is not
limited to the resin member 546 but can also be a different
5 member such as an elastic body (e.g., rubber) or an adhesive
agent.
[0094]
With the motor 500 according to the fifth embodiment
described above, the creep prevention part (e.g., the resin
10 member 546) increasing the friction resistance between the outer
ring 521b and the precompression spring 45 is arranged between
the outer ring 521b and the precompression spring 45. With this
configuration, the friction resistance in the circumferential
direction R1 between the outer ring 521b and the cylinder part 61
15 also increases. Accordingly, the outer ring 521b becomes unlikely
to rotate with respect to the cylinder part 61, and thus an
occurrence of a creep at the load-side bearing 521 can be
prevented.
[0095]
20 Except for the above-described features, the fifth
embodiment is the same as any one of the first to fourth
embodiments.
[0096]
25 (Sixth Embodiment)
Fig. 14 is a configuration diagram showing a partial cross
section and a side face of a motor 600 according to a sixth
embodiment. In Fig. 14, each component identical or corresponding
to a component shown in Fig. 1 is assigned the same reference
30 character as in Fig. 1. The motor 600 differs from the motor 100
according to the first embodiment in further including a second
creep prevention part that prevents a creep at an anti-load-side
bearing 622.
[0097]
31
As shown in Fig. 14, the motor 600 includes the ring-shaped
elastic body 23 as a first creep prevention part and a plurality
of (two in Fig. 14) ring-shaped elastic bodies 623, 624 as the
second creep prevention part. The plurality of ring-shaped
5 elastic bodies 623, 624 are arranged between an outer ring 622b
of the bearing 622 and the holding part 56b of the mold resin
part 56. Each of the plurality of ring-shaped elastic bodies 623,
624 is rubber containing thermosetting elastomer, for example.
Further, each of the plurality of ring-shaped elastic bodies 623,
10 624 is an O-ring, for example, similarly to the ring-shaped
elastic body 23. Incidentally, the number of ring-shaped elastic
bodies 623, 624 arranged between the outer ring 622b and the
holding part 56b is not limited to two; it is permissible if the
number is one or more.
15 [0098]
The ring-shaped elastic bodies 623, 624 arranged between
the outer ring 622b and the holding part 56b are compressed in
the radial directions and accordingly, frictional force
preventing the rotation of the outer ring 622b with respect to
20 the holding part 56b works. Namely, when the ring-shaped elastic
bodies 623, 624 are arranged between the outer ring 622b and the
holding part 56b, the friction resistance in the circumferential
direction R1 between the outer ring 622b and the holding part 56b
increases. Accordingly, an occurrence of a creep is prevented
25 also at the anti-load-side bearing 622.
[0099]
With the motor 600 according to the sixth embodiment
described above, an occurrence of a creep can be prevented at
each of the load-side bearing 21 and the anti-load-side bearing
30 622.
[0100]
Except for the above-described features, the sixth
embodiment is the same as any one of the first to fifth
embodiments.
32
[0101]
(First Modification of Sixth Embodiment)
Next, a first modification of the sixth embodiment will be
5 described below. Fig. 15 is a configuration diagram showing a
partial cross section and a side face of a motor 600A according
to the first modification of the sixth embodiment. In Fig. 15,
each component identical or corresponding to a component shown in
Fig. 14 is assigned the same reference character as in Fig. 14.
10 The motor 600A differs from the motor 600 according to the sixth
embodiment in the material of a holding part 82 holding the loadside bearing 622 and in the number of ring-shaped elastic bodies
624 arranged between the bearing 622 and the holding part 82.
[0102]
15 As shown in Fig. 15, the motor 600A includes a cover member
80 fixed to an end part of the mold resin part 56 on the -z-axis
side. The cover member 80 is formed of metal. The cover member
80 is formed of a molten zinc-aluminum-magnesium alloy-plated
steel sheet, for example. By using the molten zinc-aluminum20 magnesium alloy-plated steel sheet, high dimensional accuracy is
easily obtained due to excellent workability since the press work
is possible, and further, thermal conductivity is high compared
to standard resin such as BMC and PBT.
[0103]
25 The cover member 80 includes a flange part 81 fixed to the
mold resin part 56 and the holding part 82 situated on the inner
side in the radial directions relative to the flange part 81. The
holding part 82 holds the bearing 622. Namely, in the first
modification of the sixth embodiment, the holding part 82 as a
30 second holding part for holding the anti-load-side bearing 622 is
formed of metal.
[0104]
Fig. 16 is an enlarged sectional view showing a
configuration of an anti-load-side bearing 622 and surrounding
33
components in the motor 600A shown in Fig. 15. As shown in Fig.
16, the bearing 622 includes an inner ring 622a that supports the
end part 15b of the shaft 15 on the -z-axis side via the
insulation sleeve 60, the outer ring 622b fixed to the holding
5 part 82 by means of clearance fitting, and balls 622c as rolling
members arranged between the inner ring 622a and the outer ring
622b.
[0105]
The flange part 81 includes a first surface 81a in contact
10 with an axial direction end face of an end part 556b of the mold
resin part 56 on the -z-axis side and a second surface 81b in
contact with an inner surface of the end part 556b.
[0106]
The holding part 82 has a cylindrical surface 83, a contact
15 surface 84 and a separation surface 85. The cylindrical surface
83 faces a part of an outer circumferential surface 622f of the
outer ring 622b in the radial directions. The contact surface 84
is in contact with an end face 622g of the outer ring 622b on the
-z-axis side in regard to the axial direction. The separation
20 surface 85 disjunctively adjoins the inner side of the contact
surface 84 in the radial directions and is separate from the
inner ring 622a of the bearing 622 and the shaft 15 towards the -
z-axis side. Namely, the holding part 82 is not in contact with
the inner ring 622a or the shaft 15 while being in contact with
25 the outer ring 622b. With this configuration, the axial current
flowing in the shaft 15 is inhibited from passing through the
balls 622c via the holding part 82 and the inner ring 622a.
[0107]
The ring-shaped elastic body 624 is arranged between the
30 outer circumferential surface 622f of the outer ring 622b and the
cylindrical surface 83 of the holding part 82. The ring-shaped
elastic body 624 is arranged in a groove part 622d formed on the
outer circumferential surface 622f of the outer ring 622b. The
groove part 622d is formed on the outer circumferential surface
34
622f on the -z-axis side with reference to the axial direction
position of the center of the ball 622c.
[0108]
A friction coefficient between the ring-shaped elastic body
5 624 and the cylindrical surface 83 is greater than a friction
coefficient between the outer circumferential surface 622f and
the cylindrical surface 83. Namely, when the ring-shaped elastic
body 624 is arranged between the outer circumferential surface
622f and the cylindrical surface 83, the friction resistance in
10 the circumferential direction R1 between the outer ring 622b and
the cylindrical surface 83 of the holding part 82 increases.
Accordingly, the outer ring 622b becomes unlikely to rotate with
respect to the holding part 82 and an occurrence of a creep at
the bearing 622 can be prevented.
15 [0109]
With the motor 600A according to the first modification of
the sixth embodiment described above, in a case where both of the
bearing holding part holding the load-side bearing 21 and the
bearing holding part holding the anti-load-side bearing 622 are
20 formed of metal, an occurrence of a creep at each of the loadside bearing 21 and the anti-load-side bearing 622 can be
prevented.
[0110]
25 (Second Modification of Sixth Embodiment)
Next, a second modification of the sixth embodiment will be
described below. Fig. 17 is a configuration diagram showing a
partial cross section and a side face of a motor 600B according
to the second modification of the sixth embodiment. In Fig. 17,
30 each component identical or corresponding to a component shown in
Fig. 15 is assigned the same reference character as in Fig. 15.
The motor 600B differs from the motor 600A according to the first
modification of the sixth embodiment in the material of a holding
part 556c holding the load-side bearing 21 and the number of
35
ring-shaped elastic bodies 23, 24 arranged between the bearing 21
and the holding part 556c.
[0111]
As shown in Fig. 17, the mold stator 9 of the motor 600B
5 includes a mold resin part 556 that covers the stator core 50.
The mold resin part 556 includes the holding part 556c as a first
holding part formed on the +z-axis side. The bearing 21 is held
by the holding part 556c. Namely, in the second modification of
the sixth embodiment, the bearing holding part holding the load10 side bearing 21 is formed of resin. The precompression spring 45
that applies force to the end face of the outer ring 21b on the
+z-axis side so as to press the end face towards the mold stator
9 is arranged between the bearing 21 and the holding part 556c.
[0112]
15 A plurality of (two in Fig. 17) ring-shaped elastic bodies
23, 24 are arranged between the outer ring 21b of the bearing 21
and the holding part 556c. A friction coefficient between the
ring-shaped elastic body 23, 24 and the holding part 556c is
greater than a friction coefficient between the outer ring 21b
20 and the holding part 556c. Namely, when the ring-shaped elastic
bodies 23, 24 are arranged between the outer ring 21b and the
holding part 556c, the friction resistance in the circumferential
direction R1 between the outer ring 21b and the holding part 556c
increases. Accordingly, the outer ring 21b becomes unlikely to
25 rotate with respect to the holding part 556c, and thus an
occurrence of a creep at the bearing 21 can be prevented.
Incidentally, the number of ring-shaped elastic bodies 23, 24
arranged between the outer ring 21b and the holding part 556c is
not limited to two; it is permissible if the number is one or
30 more.
[0113]
With the motor 600B according to the second modification of
the sixth embodiment described above, in a case the bearing
holding part holding the load-side bearing 21 is formed of resin
36
and the bearing holding part holding the anti-load-side bearing
622 is formed of metal, an occurrence of a creep at each of the
load-side bearing 21 and the anti-load-side bearing 622 can be
prevented.
5 [0114]
Further, in a case the holding part 556c holding the loadside bearing 21 is formed of resin, the holding part 556c is
likely to wear down when the creep occurs to the bearing 21. With
the motor 600B according to the second modification of the sixth
10 embodiment, an occurrence of a creep at the bearing 21 is
prevented, and thus wear on the holding part 556c can be
prevented.
[0115]
15 (Third Modification of Sixth Embodiment)
Next, a third modification of the sixth embodiment will be
described below. Fig. 18 is a configuration diagram showing a
partial cross section and a side face of a motor 600C according
to the third modification of the sixth embodiment. In Fig. 18,
20 each component identical or corresponding to a component shown in
Fig. 14 is assigned the same reference character as in Fig. 14.
The motor 600C differs from the motor 600 according to the sixth
embodiment in the material of the bearing holding part (resin
bracket 90 which will be described later) holding the bearing 21
25 and the number of ring-shaped elastic bodies 23, 24 arranged
between the bearing 21 and the holding part 556c.
[0116]
As shown in Fig. 18, the motor 600C includes the resin
bracket 90 as the first holding part that holds the bearing 21.
30 The resin bracket 90 is fixed to the opening part 56a of the mold
resin part 56. The resin bracket 90 is fixed to the opening part
56a by means of press fitting, for example. The resin bracket 90
is formed of BMC resin, for example. The resin bracket 90
includes a cylinder part 91 facing the outer ring 21b of the
37
bearing 21 in the radial directions. The resin bracket 90 extends
substantially in parallel with the axis line C1. The
precompression spring 45 that applies force to the end face of
the outer ring 21b on the +z-axis side so as to press the end
5 face towards the mold stator 9 is arranged between the bearing 21
and the resin bracket 90. Incidentally, the shape of the resin
bracket 90 is not limited to the shape shown in Fig. 18; the
resin bracket 90 can also be in a different shape as long as the
resin bracket 90 includes the cylinder part 91 facing the outer
10 ring 21b in the radial directions.
[0117]
A plurality of (two in Fig. 18) ring-shaped elastic bodies
23, 24 are arranged between the outer ring 21b of the bearing 21
and the cylinder part 91 of the resin bracket 90. With this
15 configuration, an occurrence of a creep is prevented at the
bearing 21. Incidentally, the number of ring-shaped elastic
bodies 23, 24 arranged between the outer ring 21b and the
cylinder part 91 is not limited to 2; it is permissible if the
number is 1 or more.
20 [0118]
According to the third modification of the sixth embodiment
described above, with the motor 600C according to the first
modification of the sixth embodiment described above, in a case
both of the bearing holding part holding the load-side bearing 21
25 and the bearing holding part holding the anti-load-side bearing
622 are formed of resin, an occurrence of a creep at each of the
load-side bearing 21 and the anti-load-side bearing 622 can be
prevented.
30 [0119]
(Air Conditioner)
Next, a description will be given of an air conditioner 700
employing the motor according to any one of the above-described
first to sixth embodiments. The following description will be
38
given by taking an air conditioner 700 employing the motor 100
according to the first embodiment as an example.
[0120]
Fig. 19 is a diagram showing the configuration of the air
5 conditioner 700. As shown in Fig. 19, the air conditioner 700
includes an outdoor unit 701, an indoor unit 702, and refrigerant
piping 703 connecting the outdoor unit 701 and the indoor unit
702 together. The air conditioner 700 is capable of executing an
operation such as a cooling operation of blowing out cool air or
10 a heating operation of blowing out warm air, from the indoor unit
702, for example.
[0121]
The outdoor unit 701 includes an outdoor blower 150 as a
blower, a frame 707 that supports the outdoor blower 150, and a
15 housing 708 that covers the outdoor blower 150 and the frame 707.
[0122]
Fig. 20 is a cross-sectional view showing a configuration
of the outdoor unit 701 shown in Fig. 19. As shown in Fig. 20,
the outdoor blower 150 of the outdoor unit 701 includes the motor
20 100 attached to the frame 707 and a blade wheel 704 attached to
the shaft 15 of the motor 100. The blade wheel 704 includes a
boss part 705 fixed to the shaft 15 and blades 706 provided on an
outer periphery of the boss part 705. The blade wheel 704 is a
propeller fan, for example.
25 [0123]
When the motor 100 drives the blade wheel 704, the blade
wheel 704 rotates and an airflow is generated. By this operation,
the outdoor blower 150 is capable of blowing out air. For
example, in the cooling operation of the air conditioner 700,
30 heat emitted when the refrigerant compressed by a compressor (not
shown) is condensed in a condenser (not shown) is discharged to
the outside of the room by the air blowing operation of the
outdoor blower 150.
[0124]
39
In the motor according to any one of the above-described
first to sixth embodiments, a vibration and a noise due to a
creep are prevented, and thus quietness of the outdoor blower 150
is increased. Accordingly, quietness of the outdoor unit 701
5 including the outdoor blower 150 is also increased. Further,
since an occurrence of a creep at the bearing 21 is prevented at
a low cost in the motor 100 according to the first embodiment,
cost reduction of the air conditioner 700 including the motor 100
can be achieved.
10 [0125]
Incidentally, the motor in any one of the first to sixth
embodiments may be provided also in a blower (e.g., indoor blower
of the indoor unit 702) other than the outdoor blower 150 of the
outdoor unit 701. Further, the motor in any one of the first to
15 sixth embodiments may be provided also in a household electrical
appliance other than an air conditioner.
DESCRIPTION OF REFERENCE CHARACTERS
[0126]
20 1: rotor, 6: metallic bracket (bearing holding part, first
holding part), 9: mold stator (stator), 15: shaft (rotary
shaft), 15b: part on anti-load side, 15c: part on load side,
21: bearing (first bearing), 21b: outer ring, 21b: outer
circumferential surface, 21i: end face, 22: bearing (second
25 bearing), 23, 24, 623, 624: ring-shaped elastic body (elastic
member), 45: precompression spring, 56b: holding part (bearing
holding part, second holding part), 61a: inner circumferential
surface (inner surface), 82: holding part (bearing holding part,
second holding part), 90: resin bracket (bearing holding part,
30 first holding part), 100, 200, 300, 300A, 400, 500, 600, 600A,
600B, 600C: motor, 150: outdoor blower (blower), 323: resin
member, 323A: adhesive agent, 423: undulating surface, 546:
resin member, 556c: holding part (bearing holding part, first
holding part), 700: air conditioner, P: central position.

We Claim :
1. A motor comprising:
a stator;
5 a rotor of a consequent-pole type including a rotary shaft;
a bearing as a rolling bearing that supports the rotary
shaft;
a bearing holding part that is fixed to the stator and
holds an outer ring of the bearing; and
10 a creep prevention part that is arranged between the outer
ring and the bearing holding part and increases friction
resistance in a circumferential direction of the outer ring
between the outer ring and the bearing holding part.
2. The motor according to claim 1, wherein the creep
prevention part includes an elastic member arranged between an
outer circumferential surface of the outer ring and an inner
circumferential surface of the bearing holding part.
3. The motor according to claim 2, wherein
the outer ring includes a groove part formed on the outer
circumferential surface, and
the elastic member is arranged in the groove part.
25 4. The motor according to claim 2 or 3, wherein the elastic
member is an O-ring.
5. The motor according to any one of claims 1 to 4, wherein
the creep prevention part includes a resin member arranged
30 between an outer circumferential surface of the outer ring and an
inner circumferential surface of the bearing holding part.
6. The motor according to any one of claims 1 to 5, wherein
the creep prevention part includes an adhesive agent arranged

between an outer circumferential surface of the outer ring and an
inner circumferential surface of the bearing holding part.
7. The motor according to any one of claims 1 to 6, wherein
5 the creep prevention part is arranged between an outer
circumferential surface of the outer ring and an inner
circumferential surface of the bearing holding part and at a
position that is deviated towards one side in an axial direction
of the rotary shaft with reference to a center of a rolling
10 member of the bearing.
8. The motor according to any one of claims 1 to 7, wherein
the bearing holding part includes a cylinder part that
faces the outer ring in radial directions of the rotary shaft and
15 a base part that extends inward in the radial directions from the
cylinder part, and
the creep prevention part is arranged between an outer
circumferential surface of the outer ring and an inner
circumferential surface of the cylinder part and on the base
20 part's side with reference to an axial direction central position
of a rolling member of the bearing.
9. The motor according to any one of claims 1 to 8, wherein
the creep prevention part is formed on an outer circumferential
25 surface of the outer ring and has an undulating surface in
contact with an inner circumferential surface of the bearing
holding part.
10. The motor according to claim 9, wherein a first friction
30 coefficient between the undulating surface and the inner
circumferential surface of the bearing holding part is greater
than a second friction coefficient between a surface of the outer
ring other than the undulating surface and the inner
circumferential surface of the bearing holding part

11. The motor according to any one of claims 1 to 10, further
comprising a precompression spring that is arranged between the
bearing and the bearing holding part and applies force to an end
5 face of the outer ring in regard to an axial direction of the
rotary shaft so as to press the end face towards the stator,
wherein the creep prevention part includes a member
arranged between the end face of the outer ring and the
precompression spring.

12. The motor according to any one of claims 1 to 11, wherein
the bearing supports a load-side part or an anti-load-side part
of the rotary shaft.
15 13. The motor according to any one of claims 1 to 12, wherein
the bearing holding part is formed of at least one of metal and
resin.
14. The motor according to any one of claims 1 to 13, wherein
20 the bearing includes a first bearing and a second bearing
respectively arranged on sides opposite to each other across the
stator,
the bearing holding part includes a first holding part that
holds a first outer ring of the first bearing and a second
25 holding part that holds a second outer ring of the second
bearing, and
the creep prevention part includes a first creep prevention
part that increases the friction resistance in the
circumferential direction of the first outer ring between the
30 first outer ring and the first holding part and a second creep
prevention part that increases the friction resistance in the
circumferential direction of the second outer ring between the
second outer ring and the second holding part.

15. The motor according to claim 14, wherein
the first holding part is formed of metal, and
the second holding part is formed of resin.
16. The motor according to claim 14 or 15, wherein
the first holding part is formed of a galvanized steel
sheet, and
the second holding part is formed of BMC resin.
17. The motor according to claim 14, wherein both of the first
holding part and the second holding part are formed of metal.
18. The motor according to claim 14, wherein both of the first
holding part and the second holding part are formed of resin.

19. A blower comprising:
the motor according to any one of claims 1 to 18; and
a blade wheel that is rotated by the motor.
20. An air conditioner comprising:
an outdoor unit; and
an indoor unit connected to the outdoor unit by refrigerant
piping,
wherein at least one of the outdoor unit and the indoor
25 unit includes the blower according to claim 19.