U.S. patent application number 13/996223 was filed with the patent office on 2013-10-24 for rotary machine.
This patent application is currently assigned to IHI Corporation. The applicant listed for this patent is Norihisa Handa, Satoru Ohashi, Masahiro Tanida, Shusaku Yamasaki. Invention is credited to Norihisa Handa, Satoru Ohashi, Masahiro Tanida, Shusaku Yamasaki.
Application Number | 20130278091 13/996223 |
Document ID | / |
Family ID | 46313515 |
Filed Date | 2013-10-24 |
United States Patent
Application |
20130278091 |
Kind Code |
A1 |
Ohashi; Satoru ; et
al. |
October 24, 2013 |
ROTARY MACHINE
Abstract
A rotary machine capable of preventing leakage of a coolant and
simply and efficiently cooling a rotor is provided. A motor 1 has a
rotor 20 made by laminating magnetic steel sheets, a stator 30
arranged around the rotor 20, a rotary shaft 10 passed through a
central part of the rotor 20, and an annular sleeve 27 arranged
between the rotary shaft 10 and the rotor 20. On an outer
circumferential face of the rotary shaft 10, a groove 12 serving as
a coolant flow path for guiding a coolant is formed. The groove 12
may be formed only on the outer circumferential face of the rotary
shaft 10, or only on an inner circumferential face of the sleeve
27, or on both the outer circumferential face of the rotary shaft
10 and the inner circumferential face of the sleeve 27.
Inventors: |
Ohashi; Satoru; (Tokyo,
JP) ; Yamasaki; Shusaku; (Tokyo, JP) ; Handa;
Norihisa; (Tokyo, JP) ; Tanida; Masahiro;
(Tokyo, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Ohashi; Satoru
Yamasaki; Shusaku
Handa; Norihisa
Tanida; Masahiro |
Tokyo
Tokyo
Tokyo
Tokyo |
|
JP
JP
JP
JP |
|
|
Assignee: |
IHI Corporation
Tokyo
JP
|
Family ID: |
46313515 |
Appl. No.: |
13/996223 |
Filed: |
April 22, 2011 |
PCT Filed: |
April 22, 2011 |
PCT NO: |
PCT/JP2011/059978 |
371 Date: |
June 20, 2013 |
Current U.S.
Class: |
310/58 |
Current CPC
Class: |
H02K 3/345 20130101;
H02K 9/22 20130101; H02K 3/48 20130101; H02K 5/20 20130101; H02K
1/32 20130101; H02K 3/24 20130101; H02K 9/005 20130101; H02K 3/34
20130101; H02K 5/10 20130101; H02K 9/197 20130101 |
Class at
Publication: |
310/58 |
International
Class: |
H02K 9/00 20060101
H02K009/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 22, 2010 |
JP |
2010-286586 |
Mar 25, 2011 |
JP |
2011-068204 |
Claims
1. A rotary machine comprising: a rotor made by laminating magnetic
steel sheets; a stator arranged around the rotor; a rotary body
passed through a central part of the rotor; an annular sleeve
member arranged between the rotary body and the rotor; and a recess
formed on at least one of an outer circumferential face of the
rotary body and an inner circumferential face of the sleeve member
and serving as a coolant flow path to guide a coolant.
2. The rotary machine as set forth in claim 1, wherein the rotary
body includes a first rotary body part having a first flow path to
guide the coolant in an axial direction of the rotary body and a
second rotary body part that has a larger diameter than the first
rotary body part and incorporates a second flow path to connect the
first flow path and the coolant flow path to each other.
3. The rotary machine as set forth in claim 2, wherein the recess
is formed on an outer circumferential face of the second rotary
body part.
4. The rotary machine as set forth in claim 1, wherein the recess
is a groove having a linear, spiral, or winding shape formed in the
axial direction of the rotary body.
5. The rotary machine as set forth in claim 4, wherein the recess
has a rectangular, arc, or triangular sectional shape.
6. The rotary machine as set forth in claim 1, wherein the recess
is formed in the same number as the number of permanent magnets
arranged in the rotor.
7. The rotary machine as set forth in claim 6, wherein the rotary
body and sleeve member are positioned in a rotation direction of
the rotor so that the recesses come closest to the permanent
magnets, respectively.
8. The rotary machine as set forth in claim 1, wherein the sleeve
member is sealed with respect to the rotary body at each axial end
of the rotary body.
9. The rotary machine as set forth in claim 1, wherein the stator
has a stator core and a coil attached to the stator core with a
coil end part protruding from each end of the stator core and the
rotary machine further comprises: a mold member formed at each end
of the stator core, to cover a base part of the coil end part; and
a partition member attached in contact with the mold member, to
separate a first space in which the rotor is arranged from a second
space in which the coil end part is arranged.
10. The rotary machine as set forth in claim 9, further comprising
a mold member arranged inside the stator core, to fill a gap in a
slot that is formed in the stator core to accommodate the coil, the
mold member formed at each end of the stator core and the mold
member arranged inside the stator core being made of different
materials having different thermal conductivities.
Description
TECHNICAL FIELD
[0001] The present invention relates to a rotary machine employing
a coolant to cool a motor.
BACKGROUND ART
[0002] Cooling a rotary machine used for an electric vehicle and
the like with the use of a coolant is useful to efficiently
generate driving force (torque) by use of electric power. As an
example of such a cooling technique for a rotary machine, there is
a technique of cooling a rotor incorporating permanent magnets with
a coolant. Related arts are disclosed in Japanese Unexamined Patent
Application Publications No. 2002-345188, No. 2010-220340, and No.
2010-252544 and Japanese Patent Publication No. 4469670.
CITATION LIST
Patent Literature
[0003] Patent Literature 1: Japanese Unexamined Patent Application
Publication No. 2002-345188 [0004] Patent Literature 2: Japanese
Unexamined Patent Application Publication No. 2010-220340 [0005]
Patent Literature 3: Japanese Unexamined Patent Application
Publication No. 2010-252544 [0006] Patent Literature 4: Japanese
Patent Publication No. 4469670
SUMMARY OF INVENTION
Problem to be Solved by Invention
[0007] In connection with using a coolant to cool a rotor
incorporating permanent magnets of a rotary machine, the present
inventors have studied the structural details of the rotary machine
to further improve cooling efficiency. During the studying process,
it has been found that further suppressing a mechanical loss of the
rotary machine has a room for improvement in connection with a
structure for cooling the rotor that incorporates permanent magnets
with a coolant. The present invention has been made in
consideration of this issue and an object of the present invention
is to provide a rotary machine that converts electric power into
torque, or torque into electric power at higher efficiency.
Means to Solve Problem
[0008] An aspect of the present invention provides a rotary machine
including a rotor made by laminating magnetic steel sheets; a
stator arranged around the rotor; a rotary body passed through a
central part of the rotor; an annular sleeve member arranged
between the rotary body and the rotor; and a recess formed on at
least one of an outer circumferential face of the rotary body and
an inner circumferential face of the sleeve member and serving as a
coolant flow path to guide a coolant.
Effects of Invention
[0009] According to the rotary machine of the present invention, a
mold member is formed at each end of a stator core, to cover a base
part of a coil end part. A partition member is attached in contact
with the mold member, to separate a first space accommodating the
rotor from a second space accommodating the coil end part.
Accordingly, there is provided an effect of realizing efficient
cooling without increasing costs or deteriorating performance.
BRIEF DESCRIPTION OF DRAWINGS
[0010] FIG. 1 is a sectional side view illustrating the structure
of a motor, i.e., a rotary machine according to a first embodiment
of the present invention.
[0011] FIG. 2 is a sectional view taken along a line A-A of FIG. 1
as seen from an arrowed direction.
[0012] FIG. 3 is a perspective view of a rotary shaft of the motor,
i.e., the rotary machine according to the first embodiment of the
present invention.
[0013] FIG. 4 is a view illustrating grooves formed on the rotary
shaft of the motor, i.e., the rotary machine according to the first
embodiment of the present invention.
[0014] FIG. 5 is a sectional side view illustrating the structure
of a motor, i.e., a rotary machine according to a second embodiment
of the present invention.
[0015] FIG. 6 is a sectional view taken along a line B-B of FIG. 5
as seen from an arrowed direction;
[0016] FIG. 7 is a sectional view illustrating a sectional shape of
a groove formed on a sleeve of FIG. 1 or 5.
[0017] FIG. 8 is a sectional view illustrating a sectional shape of
a groove formed on the rotary body and sleeve of FIG. 1 or 5.
[0018] FIG. 9 is a sectional side view illustrating the structure
of a motor, i.e., a rotary machine according to a third embodiment
of the present invention.
[0019] FIG. 10 is a sectional side view illustrating a stator
extracted from the rotary machine according to the third embodiment
of the present invention.
[0020] FIG. 11 is a sectional view taken along a line D-D of FIG.
10 as seen from an arrowed direction.
[0021] FIG. 12 is a sectional view taken along a line C-C of FIG. 9
as seen from an arrowed direction.
[0022] FIG. 13 is a view illustrating sealing methods for a
partition member according to the third embodiment of the present
invention.
[0023] FIG. 14 is a sectional side view illustrating the structure
of a motor, i.e., a rotary machine according to a fourth embodiment
of the present invention.
[0024] FIG. 15 is a sectional side view illustrating the structure
of a motor, i.e., a rotary machine according to a fifth embodiment
of the present invention.
MODE OF IMPLEMENTING INVENTION
[0025] Rotary machines according to embodiments of the present
invention will be explained in detail with reference to the
drawings. In the embodiments mentioned below, the rotary machines
each are, as an example, a motor (an electric motor) driven and
rotated with an externally supplied current (such as a three-phase
AC current).
First Embodiment
[0026] FIG. 1 is a sectional side view illustrating the structure
of a motor, i.e., a rotary machine according to the first
embodiment of the present invention. FIG. 2 is a sectional view
taken along a line A-A of FIG. 1 as seen from an arrowed
direction.
[0027] As illustrated in FIG. 1, the motor 1 has a rotary shaft 10,
a rotor (rotator) 20, a sleeve (sleeve member) 27, a stator
(stationary element) 30, and a housing 40. An externally supplied
current creates electromagnetic force between the rotor 20 and the
stator 30, to rotate the rotor 20, thereby rotationally driving the
rotary shaft 10. In the following explanation, a left-right
direction of FIG. 1 in which the rotary shaft 10 extends is
referred to as "axial direction".
[0028] The rotary shaft 10 is a shaft member to transmit torque of
the rotor 20 to the outside and includes a first shaft part (first
rotary body part) 10a and a second shaft part (second rotary body
part) 10b. The first shaft part 10a has a cylindrical shape and
extends leftward in the axial direction from a central part of a
left side face of the second shaft part 10b and rightward in the
axial direction from a central part of a right side face of the
second shaft part 10b. The second shaft part 10b has a cylindrical
shape having a larger diameter than the first shaft part 10a.
[0029] In the rotary shaft 10, the second shaft part 10b is passed
through a central part of the rotor 20, and together with the
sleeve 27, is fixed to the rotor 20. A first side of the first
shaft part 10a leftward protrudes from the housing 40 and a second
side of the first shaft part 10a rightward protrudes from the
housing 40. The first shaft part 10a is freely rotatably supported
with bearings B1 and B2 arranged in the housing 40. Accordingly,
the rotary shaft 10, rotor 20, and sleeve 27 integrally rotate
around a rotation axis of the rotary shaft 10. The bearings B1 and
B2 are, for example, antifriction bearings such as angular ball
bearings.
[0030] Inside the first shaft part 10a of the rotary shaft 10, a
coolant flow path (first flow path) 11 is formed along a center
axis up to the inside of the second shaft part 10b. On an outer
circumferential face of the second shaft part 10b of the rotary
shaft 10, a groove (recess) 12 is formed as a coolant flow path to
guide a coolant (such as cooling oil) to cool permanent magnets 23
arranged in the rotor 20. As illustrated in FIG. 2, this embodiment
forms eight grooves 12 each having a rectangular sectional shape at
regular intervals in a circumferential direction of the second
shaft part 10b.
[0031] FIG. 3 is a perspective view of the rotary shaft of the
motor 1, i.e., the rotary machine according to the embodiment. As
illustrated in FIG. 3(a), the grooves 12 are linearly formed in the
axial direction on the second shaft part 10b of the rotary shaft
10. The grooves 12 are formed not to reach each axial end of the
second shaft part 10b but they are formed to extend from the
vicinity of one axial end of the second shaft part 10b up to the
vicinity of the other axial end thereof. This is to at most prevent
the coolant supplied to the grooves 12 serving as coolant flow
paths from leaking outside through a gap between the rotary shaft
10 (second shaft part 10b) and the sleeve 27.
[0032] The grooves 12 formed on the outer circumferential face of
the rotary shaft 10 may be spiral in the axial direction as
illustrated in FIG. 3(b), or may be winding in the axial direction
as illustrated in FIG. 3(c). When the grooves 12 are spiral as
illustrated in FIG. 3(b), a circumferential temperature
distribution of the rotor 20 will be equalized compared with the
linearly formed grooves illustrated in FIG. 3(a). When the grooves
12 are winding as illustrated in FIG. 3(c), the cooling efficiency
of the rotor 20 will improve compared with the linearly formed
grooves 12 illustrated in FIG. 3(a).
[0033] FIG. 4 is a view illustrating sectional shapes of grooves
formed on the rotary shaft of the motor 1, i.e., the rotary machine
according to the embodiment. As illustrated in FIG. 4(a), the
embodiment forms the grooves each into a rectangular sectional
shape on the outer circumferential face of the second shaft part
10b of the rotary shaft 10. The sectional shape of each groove 12
may be an arc shape (a convex arc oriented toward the rotation
axis) as illustrated in FIG. 4(b), or a triangular shape (with one
vertex oriented toward the rotation axis) as illustrated in FIG.
4(c).
[0034] Instead of arranging the plurality of thin and long axial
grooves 12 in the circumferential direction of the second shaft
part 10b as illustrated in FIGS. 4(a) to 4(c), the outer
circumferential face of the second shaft part 10b may generally be
recessed as illustrated in FIG. 4(d). Namely, the outer
circumferential face of the second shaft part 10b except axial ends
thereof may generally be hollowed to form a recess. Such a recess
may be realized by forming, for example, a countless number of the
linear grooves 12 of FIG. 4(a) in the circumferential
direction.
[0035] Inside the second shaft part 10b of the rotary shaft 10, a
communicating flow path (second flow path) 13 is formed to connect
the coolant flow path 11 formed in the first shaft part 10a to each
groove 12 formed on the outer circumferential face of the second
shaft part 10b. As illustrated in FIG. 2, the communicating flow
paths 13 are formed to extend from the coolant flow path 11 toward
the grooves 12 in diametral directions of the second shaft part 10b
(more precisely, in different eight directions).
[0036] As illustrated in FIG. 2, the rotary shaft 10 is positioned
in a rotation direction of the rotor 20 so that the grooves 12
formed on the outer circumferential face of the second shaft part
10b come nearest to the permanent magnets 23 of the rotor 20,
respectively. This is to increase the cooling efficiency of the
rotor 20 by bringing the grooves 12 serving as the coolant flow
paths for guiding the coolant closest to the permanent magnets 23
as heat generating sources.
[0037] The rotor 20 has a rotor core 21, end rings 22, and the
permanent magnets 23, is attached together with the sleeve 27 to
the rotary shaft 10, and is rotatable around the rotation axis of
the rotary shaft 10. As illustrated in FIG. 1, the rotor core 21 is
made by laminating magnetic steel sheets made of magnetic material
with an adhesive and is an annular member with the rotary shaft 10
being passed through a central part of the rotor core 21.
[0038] The permanent magnet 23 is, for example, a rectangular
parallelepiped magnet extending in the axial direction and is
inserted into an insertion hole formed in the rotor core 21. The
permanent magnets 23 are arranged at regular intervals along an
outer circumferential face of the rotor core 21. According to the
example illustrated in FIG. 2, eight permanent magnets 23 each
having a rectangular sectional shape are arranged at regular
intervals in a circumferential direction of the rotor core 21.
Alternating magnetic fields along the outer circumferential face of
the rotor core 21 is formed by way of this arrangements.
[0039] The end ring 22 is arranged at each axial side (in the
laminated direction of the magnetic steel sheets) of the rotor core
21. The end rings 22 are annular members that axially hold the
rotor core 21 from each side. An axial length of the rotor core 21
is set so that the length of the rotor core 21 including the end
rings 22 arranged at each axial side of the rotor core 21 is equal
to an axial length of the second shaft part 10b of the rotary shaft
10.
[0040] The sleeve 27 is an annular member arranged between the
second shaft part 10b of the rotary shaft 10 and the rotor 20 and
is made of, for example, the same material as the rotary shaft 10.
An axial length of the sleeve 27 is set to be equal to an axial
length of the second shaft part 10b of the rotary shaft 10. The
sleeve 27 is fitted to the outer circumferential face of the second
axial part 10b of the rotary shaft 10 by, for example, shrinkage
fitting. When the sleeve 27 is fitted to the outer circumferential
face of the second shaft part 10b of the rotary shaft 10, the
grooves 12 form coolant flow paths between the rotary shaft 10 and
the sleeve 27.
[0041] The coolant guided into the grooves 12 serving as the
coolant flow paths flows between the rotary shaft 10 (the second
shaft part 10b) and the sleeve 27. Even if the rotor 20 is rotated
at a high speed under a condition that the bonding strength of the
adhesive that adheres the magnetic steel sheets of the rotor core
21 together decreases due to a temperature increase of the motor 1,
this configuration prevents the coolant guided into the grooves 12
serving as the coolant flow paths from leaking. The rotor core 21
mentioned above is fitted to the outer circumferential face of the
sleeve 27 by, for example, shrinkage fitting.
[0042] Since the sleeve 27 is fitted to the outer circumferential
face of the second shaft part 10b by, for example, shrinkage
fitting, the coolant guided into the grooves 12 almost causes no
leakage. There will be leakage if the pressure of the coolant
guided into the grooves 12 is high. To deal with this, at each
axial end, the sleeve 27 is soldered or welded to the second shaft
part 10b of the rotary shaft 10, or a sealing material such as an
O-ring is arranged between the sleeve 27 and the second shaft part
10b of the rotary shaft 10, to seal the location.
[0043] The stator 30 has a stator core 31 and a coil 32 and is
fixed to an inner circumferential face of a body member 41 forming
part of the housing 40, to surround the rotor 20 in the rotation
direction of the rotary shaft 10. According to a current externally
supplied to the coil 32, the stator 30 forms a rotating magnetic
field in the circumferential direction of the rotor 20. Like the
rotor core of the rotor 20, the stator core 31 is an annular member
formed by laminating a plurality of magnetic steel sheets made of
magnetic material. The rotor 20 is arranged on an inner
circumferential side of the stator core 31. An inner diameter of
the stator core 31 is so set to form an annular gap (an air gap G
illustrated in FIG. 1) having preset dimensions between the inner
circumferential face of the stator core 31 and the outer
circumferential face of the rotor 20.
[0044] The coil 32 is inserted into a slot (not illustrated) formed
in the stator core 31, to form magnetic poles according to an
externally supplied current. The coil 32 includes a first coil to
which a U-phase current of three-phase AC is supplied, a second
coil to which a V-phase current is supplied, and a third coil to
which a W-phase current is supplied. These first to third coils are
sequentially arranged in the circumferential direction of the
stator core 31. When a three-phase AC current is supplied to the
coil 32, a rotating magnetic field is formed along the inner
circumferential face of the stator core 31. As illustrated in FIG.
1, the coil 32 is attached to the stator core 31 so that a coil end
part protrudes from each end of the stator core 31.
[0045] The housing 40 includes the body member 41, a left sidewall
member 42, and a right sidewall member 43, accommodates part of the
rotary shaft 10, the rotor 20, the sleeve 27, and the stator 30,
and forms an external shape of the motor 1. The body member 41 is
made of iron alloy and the like and is a cylindrical member with
each axial end being open. To the inner circumferential face of the
body member 41, the above-mentioned stator 27 is fixed. The left
sidewall member 42 is a disk-shaped member, has a fitting hole for
the bearing B1 at a central part thereof, and is attached to a left
end of the body member 41. The right sidewall member 43 is a
disk-shaped member, has a fitting hole for the bearing B2 at a
central part thereof, and is attached to a right end of the body
member 41.
[0046] Operation of the motor 1 with the above-mentioned structure
will briefly be explained. When an external three-phase AC current
is supplied to the motor 1, each phase current of the three-phase
AC current passes through the coil 32 (first to third coils)
arranged in the stator 30, to form a rotating magnetic field in the
rotation direction of the rotor 20 according to the supplied
current. The rotor core 21 with alternating magnetic fields formed
along the outer circumference thereof interacts with the rotating
magnetic field, to create attractive force and repulsive force.
This results in rotating the rotor 20 to rotate the rotary shaft
10, rotor 20, and sleeve 27 together, thereby transmitting torque
of the rotary shaft 10 to the outside.
[0047] When the motor 1 is driven, a pump (not illustrated)
supplies a coolant to the coolant flow path 11 at a first side of
the first shaft part 10a of the rotary shaft 10. The coolant
supplied to the coolant flow path 11 is guided through the
communicating flow paths 13 at a first end side (left side) of the
second shaft part 10b to the grooves 12 formed on the outer
circumferential face of the second shaft part 10b. Between the
rotary shaft 10 and the sleeve 27, the grooves 12 form coolant flow
paths. Accordingly, the coolant guided into the grooves 12 cools
the permanent magnets 23. These coolant flow paths are formed to be
nearest to the permanent magnets 23 arranged in the rotor 20, and
therefore, the rotor core 21 and permanent magnets 23 are
efficiently cooled. The coolant passed through the grooves 12
serving as the coolant flow paths is guided through the
communicating flow paths 13 at a second end side (right side) of
the second shaft part 10b to the coolant flow path 11 at a second
side of the first shaft part 10a and is discharged outside.
[0048] As mentioned above, this embodiment forms the grooves
serving as coolant flow paths on the outer circumferential face of
the rotary shaft 10 and arranges the annular sleeve 27 between the
rotary shaft 10 on which the grooves 12 are formed and the rotor
20, so that a coolant guided into the grooves 12 passes between the
rotary shaft 10 and the sleeve 27. Even if the rotor 20 is rotated
at a high speed under a condition that the bonding strength of the
adhesive fixing the magnetic steel sheets of the rotor core 21
together decreases due to a temperature increase of the motor 1,
the embodiment prevents the coolant guided into the grooves 12 from
leaking.
[0049] This embodiment forms the grooves 12 on the outer
circumferential face of the second shaft part 10b of the rotary
shaft 10 that is larger in diameter than the first shaft part 10a
and arranges the sleeve 27 between the second shaft part 10b on
which the grooves 12 are formed and the rotor 20, thereby
positioning the coolant flow paths closest to the permanent magnets
23. Accordingly, the rotor 20 including the permanent magnets 23 is
simply and efficiently cooled.
[0050] The number, length, and shape (including sectional shape) of
the grooves 12 formed on the rotary shaft 10 are not limited to
those of the above-mentioned embodiment.
[0051] The rotation-direction (circumferential-direction)
arrangements and positional relationships of the grooves 12 formed
on the rotary shaft 10 and the permanent magnets 23 arranged in the
rotor 20 are not limited to those of the above-mentioned
embodiment. These arrangements and positional relationships are
optional.
[0052] Although the above-mentioned embodiment has explained, as an
example, the rotary shaft 10 that has the first shaft part 10a and
second shaft part 10b that are integrated into one body, the
present invention is applicable to a rotary shaft made of a first
shaft part 10a and second shaft part 10b that are discrete members.
For example, the rotary shaft 10 may be made of a cylindrical shaft
member whose outer diameter is similar to that of the first shaft
part 10a and a cylindrical auxiliary member that has an outer
diameter similar to that of the second shaft part 10b and an inner
diameter similar to that of the first shaft part 10a and is fixed
to the cylindrical shaft member.
Second Embodiment
[0053] FIG. 5 is a sectional side view illustrating the structure
of a motor, i.e., a rotary machine according to the second
embodiment of the present invention. The motor 1 of the first
embodiment illustrated in FIGS. 1 to 4 is of an inner ring rotating
type that turns the rotor 20 together with the rotary shaft 10. On
the other hand, the motor 2 of the second embodiment illustrated in
FIG. 5 is of an outer ring rotating type that turns a rotor 20
around a fixed center shaft 70.
[0054] The motor 2 of this embodiment attaches outer housings 61
and 62 to left and right outer sides of a housing 40 as illustrated
in FIG. 5. Fitting holes 61c and 62c of the outer housings 61 and
62 fixedly support ends of the center shaft 70. With bearings B1
and B2, the center shaft 70 rotatably supports a cylindrical rotary
body 80 (second rotary body part) that forms part of the rotor 20.
On an outer circumferential face of the rotary body 80, a sleeve 27
is attached, and on an outer circumferential face of the sleeve 27,
the rotor 20 is attached.
[0055] Inside the center shaft 70, a rotor oil introducing flow
path 71 is formed to open at each end of the center shaft 70. To
the rotor oil introducing flow path 71, an oil supply unit such as
an oil pump (not illustrated) supplies oil for cooling the rotor
20.
[0056] To end faces of the rotary body 80, rotary support members
25 and 26 (first rotary body part) are attached with their center
axes being positionally aligned to each other. The rotary support
members 25 and 26 are inserted into openings 42c and 43c formed at
centers of left sidewall member 42 and right sidewall member 43 of
the housing 40 with proper gaps interposed between them, are
axially outwardly protruded from the left and right sidewall
members 42 and 43, respectively, and are rotatably supported by the
center shaft 70 through the bearings B1 and B2. The rotary support
members 25 and 26 form part of the rotor 20.
[0057] The rotary support members 25 and 26 have paths to connect
an oil flow path 24 and inner spaces of the bearings B1 and B2 to
each other. These paths guide oil from the oil flow path 24 through
the inner spaces of the bearings B1 and B2 to the open sides of the
rotary support members 25 and 26.
[0058] The rotary support members 25 and 26 form, with respect to
the center shaft 70, annular gaps 25a and 26a (first flow path) for
guiding oil in the axial direction of the center shaft 70. The
rotary body 80 has a larger diameter than the rotary support
members 25 and 26.
[0059] Between an inner circumferential face of the rotary body 80
and an outer circumferential face of the center shaft 70, an
annular gap 28 is formed. The gap 28 communicates with the rotor
oil introducing flow path 71 opened to the outer circumferential
face of the center shaft 70 and the oil flow path 24 of the rotary
body 80.
[0060] The oil flow path 24 includes a gap flow path 35 extending
along the outer circumferential face of the rotary body 80 in the
axial direction of the rotary body 80 and an inlet flow path 37 and
an outlet flow path 39 that extend in a diametral direction of the
rotary body 80 and connect both ends of the gap flow path 35 to the
gap 28.
[0061] A plurality of the oil flow paths 24 are arranged in a
circumferential direction for permanent magnets 23, respectively.
Namely, as illustrated in FIG. 6, the oil flow paths 24 are formed
in the vicinities of the permanent magnets 23 on the outer
circumferential face of the rotary body 80. The oil flow paths 24
formed in the circumferential direction of the rotary body 80
alternate the flowing directions of oil passing therethrough.
[0062] On the outer circumferential face of the rotary body 80,
grooves (recesses) 12 are formed to form the gap flow paths 35 with
respect to the inner circumferential face of the sleeve 27.
According to this embodiment, eight grooves 12 each having a
rectangular sectional shape are formed at regular intervals in the
circumferential direction of the rotary body 80 as illustrated in
FIG. 6.
[0063] As illustrated in FIG. 6, the rotary body 80 is positioned
in a rotation direction of a rotor core 21 so that the grooves 12
formed on the outer circumferential face of the rotary body 80 come
closest to the permanent magnets 23 of the rotor core 21,
respectively. This is to improve the cooling efficiency of the
rotor 20 by way of bringing the grooves 12 forming the gap flow
paths 35 of the oil flow paths 24 for guiding oil as close to the
permanent magnets 23, i.e., heat generating sources as
possible.
[0064] The rotor 20 has the rotor core 21, the permanent magnets
23, and end rings 22, is attached together with the sleeve 27 to
the rotary body 80, and is rotatable with the rotary body 80 around
the center shaft 70. As illustrated in FIG. 5, the rotor core 21 is
made by laminating magnetic steel sheets made of magnetic material
with an adhesive and is an annular member with the rotary body 80
and sleeve 27 being passed through a central part of the rotor core
21.
[0065] The end ring 22 is arranged at each axial side (in the
laminated direction of the magnetic steel sheets) of the rotor core
21. The end rings 22 are annular members that axially hold the
rotor core 21 from each side. An axial length of the rotor core 21
is set so that the length of the rotor core 21 including the end
rings 22 arranged at each axial side of the rotor core 21 is equal
to an axial length of the rotary body 80.
[0066] The sleeve 27 is an annular member arranged between the
rotary body 80 and the rotor 20 and is made of, for example, the
same material as the center shaft 70 and rotary body 80. An axial
length of the sleeve 27 is set to be equal to an axial length of
the rotary body 80 and is fitted to the outer circumferential face
of the rotary body 80 by, for example, shrinkage fitting. When the
sleeve 27 is fitted to the outer circumferential face of the rotary
body 80, the grooves 12 form the gap flow paths 35 between the
rotary body 80 and the sleeve 27.
[0067] The oil guided into the grooves 12 forming part of the oil
flow paths 24 flows between the rotary body 80 and the sleeve 27.
Even if the rotor 20 is rotated at a high speed under a condition
that the bonding strength of the adhesive that adheres the magnetic
steel sheets of the rotor core 21 together decreases due to a
temperature increase of the motor 2, this configuration prevents
the oil guided into the grooves 12 forming part of the oil flow
paths 24 from leaking. The rotor core 21 mentioned above is fitted
to the outer circumferential face of the sleeve 27 by, for example,
shrinkage fitting.
[0068] Since the sleeve 27 is fitted to the outer circumferential
face of the rotary body 80 by, for example, shrinkage fitting, the
oil guided into the grooves 12 almost causes no leakage. There will
be leakage if the pressure of the oil guided into the grooves 12 is
high. To deal with this, at each axial end, the sleeve 27 is
soldered or welded to the rotary body 80, or a sealing material
such as an O-ring is arranged between the sleeve 27 and the rotary
body 80, to seal the location.
[0069] Operation of the motor 2 with the above-mentioned structure
will briefly be explained. When the motor 2 is driven, a pump (not
illustrated) supplies oil from an end opening of the center shaft
70 into the oil introducing flow path 71. The introduced oil flows
from the oil introducing flow path 71 to the gap 28 on the outer
circumferential side of the center shaft 70, passes the gap 28 in
an axial outward direction, and flows into the oil flow paths
24.
[0070] The oil flowed into the oil flow paths 24 is guided into the
grooves 12 formed on the outer circumferential face of the rotary
body 80. Between the rotary body 80 and the sleeve 27, the grooves
12 form the gap flow paths 35, and therefore, the oil guided into
the grooves 12 cools the permanent magnets 23. The grooves 12 are
arranged to be closest to the permanent magnets 23 incorporated in
the rotor core 21, and therefore, the rotor core 21 and permanent
magnets 23 are efficiently cooled.
[0071] The oil passing through the gap flow paths 34 formed by the
grooves 12 passes through the oil flow paths 24 and the internal
spaces of the bearings B1 and B2 and reaches the openings of the
rotary support members 25 and 26. Thereafter, the oil passes
through the gaps 25a and 26a between the rotary support members 25
and 26 and the center shaft 70 and is discharged into spaces
between the left sidewall member 42 and right sidewall member 43 of
the housing 40 and the left sidewall member 61b and right sidewall
member 62b of the outer housings 61 and 62.
[0072] As mentioned above, this embodiment forms the grooves 12 on
the outer circumferential face of the rotary body 80 of the rotor
20 to form the gap flow paths 35 of the oil flow paths 24, and
between the rotary body 80 on which the grooves 12 are formed and
the rotor core 21, arranges the annular sleeve 27, so that the oil
introduced into the grooves 12 may pass between the rotary body 80
and the sleeve 27. Even if the rotor 20 is rotated at a high speed
under a condition that the bonding strength of the adhesive that
adheres the magnetic steel sheets of the rotor core 21 together
decreases due to a temperature increase of the motor 2, this
configuration prevents the coolant guided into the grooves 12 from
leaking.
[0073] This embodiment forms the grooves 12 on the outer
circumferential face of the rotary body 80 that is larger in
diameter than the rotary support members 25 and 26 and arranges the
sleeve 27 between the rotary body 80 on which the grooves 12 are
formed and the rotor core 21, thereby positioning the gap flow
paths 35 closest to the permanent magnets 23. Accordingly, the
rotor 20 incorporating the permanent magnets 23 is simply and
efficiently cooled.
[0074] The number, length, and shape (including sectional shape) of
the grooves 12 formed on the rotary body 80 are not limited to
those mentioned above. The rotation-direction
(circumferential-direction) arrangements and positional
relationships of the grooves 12 formed on the outer circumferential
face of the rotary body 80 and the permanent magnets 23 arranged in
the rotor core 21 are not limited to those mentioned above. These
arrangements and positional relationships are optional.
[0075] Although the above-mentioned embodiment integrates the
rotary support members 25 and 26 and the rotary body 80 into one
body, the rotary support members 25 and 26 and the rotary body 80
may be discrete members.
[0076] According to the first embodiment of FIGS. 1 to 4, the
grooves 12 that are recesses to form coolant flow paths are formed
on the outer circumferential face of the rotary shaft 10. According
to the second embodiment of FIGS. 5 and 6, the grooves 12 that are
recesses to form the gap flow paths 35 of the oil flow paths 24 are
formed on the outer circumferential face of the rotary body 80. The
grooves 12 may be formed on the inner circumferential face of the
sleeve 27 as illustrated in FIG. 7, or may be formed on the outer
circumferential face of the rotary shaft 10 (rotary body 80) and
the inner circumferential face of the sleeve 27.
Third Embodiment
[0077] A motor 3 according to the third embodiment illustrated in
FIGS. 9 to 13 uses oil as a coolant to cool a stator 30, which is
the same as the stator of the motor 1 of the first embodiment. In
FIG. 9, the internal structures of a rotary shaft 10 and rotor 20
are omitted. The details of the structure of the motor 3 according
to the third embodiment will be explained.
[0078] The stator 30 has a stator core 31 and a coil 32 and is
fixed to an inner circumferential face of a body member 41 forming
part of a housing 40, to surround the rotor 20 in a rotation
direction of the rotary shaft 10. According to a current externally
supplied to the coil 32, the stator forms a rotating magnetic field
in a circumferential direction of the rotor 20. FIG. 10 is a
sectional side view illustrating the stator 30 extracted from the
motor 3. FIG. 11 is a sectional view taken along a line D-D of FIG.
10 and seen from an arrowed direction.
[0079] As illustrated in FIG. 11, the stator core 31 has an annular
yoke 31a and teeth 31b that are arranged in a circumferential
direction of the yoke 31a and protrude toward a center axis of the
yoke 31a. A clearance between the adjacent teeth 31b is a slot 31c
into which the coil 32 is inserted. To avoid complication, FIG. 11
illustrates the stator core 31 having eight teeth 31b and eight
slots 31c. These numbers may optionally be set.
[0080] The teeth 31b of the stator core 31 function as magnetic
poles when three-phase AC is supplied to the coils 32 in the slots
31c. The stator core 31 is arranged around the rotor 20 so that the
teeth 31b protrude toward a rotation axis of the rotary shaft 10.
In this arrangement, a protrusion amount of the teeth 31b is set so
that a gap between the teeth 31b and the rotor core forms an air
gap G.
[0081] The coils 32 are inserted in the slots 31c formed in the
stator core 31. The coils 32 are attached to the stator core 31 so
that coil end parts 32a protrude from each end of the stator core
31. Namely, as illustrated in FIG. 10, the coil end parts 32a
leftward protrude from a left end E1 of the stator core 31 and the
coil end parts 32a protrude from a right end E2 of the stator core
31. Every coil 32 is attached to the stator core 31 as mentioned
above, and therefore, the coil end parts 32a are circularly
arranged along the ends E1 and E2 of the stator core 31 as
illustrated in FIG. 10.
[0082] The ends E1 and E2 of the stator core 31 are provided with
annular mold members 33a and 33b that extend along the ends E1 and
E2 to cover base parts of the coil end parts 32a. The reason why
the mold members 33a and 33b cover only the base parts of the coil
end parts 32a instead of entirely covering the coil end parts 32a
is to realize cooling with cooling oil OL and prevent the cooling
oil from entering the air gap G between the rotor 20 and the stator
30.
[0083] Namely, covering only the base parts of the coil end parts
32a with the mold members 33a and 33b and exposing the remaining
parts thereof realize that the cooling oil OL is directly poured
onto the exposed parts of the coil end parts 32a, to efficiently
cool the stator 30 (coils 32). As will be explained later in
detail, front ends of partition parts 42b and 43b that are part of
left sidewall member 42 and right sidewall member 43 of the housing
40 are sealed with the mold members 33a and 33b, to separate a
space S1 (first space) accommodating the rotor 20 from a space S2
(second space) accommodating the coil end parts 32a, thereby
preventing the oil from entering the air gap G.
[0084] The thickness of the mold members 33a and 33b is determined
in consideration of a sealing degree and cooling efficiency. If the
front ends of the partition parts 42b and 43b are not sealed, the
oil will enter the air gap G. Accordingly, the thickness of the
mold members 33a and 33b must be sufficient at least to seal the
front ends of the partition parts 42b and 43b. As the thickness of
the mold members 33a and 33b increases, the exposed part of the
coil end parts 32a reduces to lower the cooling efficiency with
oil. Accordingly, the thickness of the mold members 33a and 33b
must be smaller than a thickness capable of securing a necessary
cooling efficiency. The thickness of the mold members 33a and 33b
is, for example, about 50% of the protruding amount of the coil end
part 32a, preferably, about 20 to 30% of the protruding amount of
the coil end part 32a.
[0085] As illustrated in FIG. 11, the inside of the stator core 31
is provided with a mold member 33c, which is similar to the mold
members 33a and 33b, to bury an inner gap of each slot 31c formed
in the stator core 31. The mold member 33c is arranged to fix the
coil 32 inserted in the slot 31c so as to prevent the coil 32 from
vibrating in the slot 31c and improve the cooling efficiency of the
coil 32.
[0086] When a current is applied, the coil 32 becomes a heat
generating source, and therefore, the mold members 33a and 33b
covering the base parts of the coil end parts 32a and the mold
member 33c fixing each coil 32 in each slot 31c are required to
have a high thermal conductivity. It is preferable to form the mold
members 33a, 33b, and 33c with thermally conductive resin mixed
with thermally conductive fillers having an insulating
characteristic, such as silicon oxide (SiO2) and aluminum oxide
(Al2O3).
[0087] The mold members 33a and 33b and the mold member 33c may be
made of material having the same thermal conductivity, or materials
having different thermal conductivities. Each coil 32 attached to
the stator core 31 has a higher wire concentration (wires that form
the coil 32) at part inserted in the slot 31c and a front end of
the coil end part 32a and a lower wire concentration at the base of
the coil end part 32a. Heat resistance is higher at the part where
the wire concentration is low (the base of the coil end part 32a)
than at the part where the wire concentration is high (the inside
of the slot 31c and the front end of the coil end part 32a).
Accordingly, it is preferable to form the mold members 33a and 33b
with a material whose thermal conductivity is higher than that of a
material used to form the mold member 33c.
[0088] In connection with the mold resin 33a and 33b formed at the
ends E1 and E2 of the stator core 31, a viscosity when forming them
may be given priority to a thermal conductivity after forming them.
In this case, the mold resin 33a and 33b may be formed with a
material that has a lower thermal conductivity and viscosity than
those of a material used to form the mold member 33c. Such a
material is required when the material for the mold member 33c is
insufficient to fill gaps at the base part of the coil end part 32a
(gaps among the wires that form the coil 32).
[0089] In consideration of a functional difference between the mold
members 33a and 33b and the mold member 33c, the mold members 33a
and 33b and the mold member 33c may be formed from different
materials. The mold members 33a and 33b are used to seal the front
ends of the partition parts 42b and 43b, and therefore, they may be
formed with a material having resiliency after the material
hardens. On the other hand, the mold member 33c must surely fix the
coil 32 in the slot 31c, and therefore, it may be formed from a
material that increases hardness after the material hardens.
[0090] As illustrated in FIG. 9, vertically above the body member
41 of the housing 40, an oil supply port P1 (coolant supply port)
is arranged to guide externally supplied cooling oil OL to the coil
end parts 32a arranged inside the housing 40. The oil supply port
P1 is arranged at a plurality of locations in the rotation
direction of the rotary shaft 10 above an exposed part (a part not
covered with the mold member 33a) of each coil end part 32a
leftward protruding from the end E1 of the stator core 31 and above
an exposed part (a part not covered with the mold member 33b) of
each coil end part 32a rightward protruding from the end E2 of the
stator core 31.
[0091] FIG. 12 is a sectional view taken along a line C-C of FIG. 9
and seen in an arrowed direction. As illustrated in FIG. 12, the
oil supply ports P1 are arranged above the exposed parts of the
coil end parts 32a at three locations in the rotation direction of
the rotary shaft 10. The oil supply ports P1 are arranged at
intervals of, for example, 20 to 70.degree. in the rotation
direction of the rotary shaft 10. Oil supplied from the oil supply
ports P1 drops on different parts of the coil end parts 32a and
flows downward along the exposed parts of the coil end parts 32a as
indicated with arrows in FIG. 12. The bottom of the body member 41
is an oil pool OP where the oil downwardly moved along the exposed
parts of the coil end parts 32a is temporarily kept.
[0092] Compared with dropping the oil OL only from one oil supply
port P1, arranging the oil supply ports P1 at three locations in
the rotation direction of the rotary shaft 10 and dropping the oil
OL from these oil supply ports P1 are able to spread the oil OL
over the whole of the exposed parts of the coil end parts 32a,
thereby improving cooling efficiency. Although the example
illustrated in FIG. 12 forms the oil supply ports P1 at three
locations in the rotation direction of the rotary shaft 10, the oil
supply ports P1 may be formed at two locations or more than four
locations in the rotation direction of the rotary shaft 10
according to the size of the motor and the like. It is not always
necessary to linearly arrange the oil supply ports P1 in the
rotation direction of the rotary shaft 10. They may be axially
shifted from one another.
[0093] As illustrated in FIG. 9, the left sidewall member 42 has a
disk-shaped bottom plate part 42a and the cylindrical partition
part (partition member) 42b. In the left sidewall member 42, the
bottom plate part 42a is attached to a left end of the body member
41 so that the partition part 42b is arranged inside the body
member 41. The bottom plate part 42a that forms part of the left
sidewall member 42 has, at a central part thereof, a hole to fit
the bearing B1. At an outer peripheral part of the bottom plate
part 42a, an oil discharge port P2 is arranged to discharge the oil
OL from the oil pool OP to the outside.
[0094] The partition part 42b that forms part of the left sidewall
member 42 has an outer diameter substantially equal to an inner
diameter of the stator core 31 (the mold member 33a). A front end
of the partition part 42b is in contact with the mold member 33a,
to separate the space S1 in which the rotor 20 is arranged from the
space S2 in which the coil end parts 32a are arranged on the left
side of the stator core 31. Namely, the front end of the partition
part 42b is sealed with the mold member 33a, to separate the spaces
S1 and S2 from each other.
[0095] Similar to the left sidewall member 42, the right sidewall
member 43 has a disk-shaped bottom plate part 43a and the
cylindrical partition part (partition member) 43b. In the right
sidewall member 43, the bottom plate part 43a is attached to a
right end of the body member 41 so that the partition part 43b is
arranged inside the body member 41. The bottom plate part 43a that
forms part of the right sidewall member 43 has, at a central part
thereof, a hole to fit the bearing B2. At an outer peripheral part
of the bottom plate part 43a, an oil discharge port P2 is arranged
to discharge the oil OL from the oil pool OP to the outside.
[0096] The partition part 43b that forms part of the right sidewall
member 43 has an outer diameter substantially equal to the inner
diameter of the stator core 31 (the mold member 33b). A front end
of the partition part 43b is in contact with the mold member 33b,
to separate the space S1 in which the rotor 20 is arranged from the
space S2 in which the coil end parts 32a are arranged on the right
side of the stator core 31. Namely, the front end of the partition
part 43b is sealed with the mold member 33b, to separate the spaces
S1 and S2 from each other.
[0097] FIG. 13 is a view illustrating sealing methods for the
partition member according to the embodiment. As mentioned above,
the partition parts 42b and 43b of the left sidewall member 42 and
right sidewall member 43 are sealed with their front ends being in
contact with the mold members 33a and 33b. There will be various
methods (sealing methods) of bringing the front ends of the
partition parts 42b and 43b in contact with the mold members 33a
and 33b, as illustrated in FIG. 13. Methods of sealing the
partition part 42b with the mold member 33a will be explained.
These method are also applicable to seal the partition part 43b
with the mold member 33b.
[0098] The sealing method illustrated in FIG. 13(a) tapers an outer
circumferential face of the front end of the partition part 42b and
an inner circumferential face of the mold member 33a and wholly
fits the front end of the partition part 42b to the inner
circumferential face of the mold member 33a, thereby increasing a
contact area between the partition part 42b and the mold member
33a. The sealing method illustrated in FIG. 13(b) tapers the outer
circumferential face of the front end of the partition part 42b and
forms steps in the inner circumferential face of the mold member
33a and wholly fits the front end of the partition part 42b to the
inner circumferential face of the mold member 33a, thereby
increasing contact locations between the partition part 42b and the
mold member 33a.
[0099] The sealing method illustrated in FIG. 13(c) forms a flange
F at the front end of the partition part 42b and a groove M on the
inner circumferential face of the mold member 33a and fits the
whole of the flange F formed at the front end of the partition part
42b to the groove M formed in the inner circumferential face of the
mold member 33a, thereby improving a sealing degree between the
partition part 42b and the mold member 33a. The sealing method
illustrated in FIG. 13(d) forms a groove at the front end of the
partition part 42b, arranges an O-ring R in the groove, and brings
the whole of the O-ring R arranged at the front end of the
partition part 42b in contact with the inner circumferential face
of the mold member 33a, thereby improving a sealing degree between
the partition part 42b and the mold member 33a.
[0100] The sealing method illustrated in FIG. 13(e) forms a
protrusion Q entirely along the outer circumferential face of the
front end of the partition part 42b and wholly brings the
protrusion Q in contact with the inner circumferential face of the
mold member 33a, thereby improving a sealing degree between the
partition part 42b and the mold member 33a. The sealing method
illustrated in FIG. 13(f) forms a notch K in the inner
circumferential face of the mold member 33a and wholly fits the
front end of the partition part 42b to the notch K formed in the
mold member 33a, thereby improving a sealing degree between the
partition part 42b and the mold member 33a.
[0101] Operation of the motor 3 with the above-mentioned
configuration will briefly be explained. When the motor 3 is
driven, a pump or the like (not illustrated) supplies cooling oil
OL to the oil supply ports P1 and the oil drops onto a plurality of
locations of the exposed parts of the coil end parts 32a arranged
in the space S2. The oil OL dropped on the coil end parts 32a
downwardly moves along the exposed parts of the coil end parts 32a
as indicated with arrows in FIG. 12. Since the oil OL drops onto
the plurality of locations of the coil end parts 32a, the oil OL
wholly spreads over the coil end parts 32a arranged along the ends
of the stator core 31, thereby efficiently cooling the coil end
parts 32a.
[0102] The partition part 42b of the left sidewall member 42 is
sealed with the mold member 33a and the partition part 43b of the
right sidewall member 43 is sealed with the mold member 33b, so
that, on both the left and right sides of the stator core 31, the
space S1 in which the rotor 20 is arranged is separated from the
space S2 in which the coil end parts 32a are arranged. This
prevents the oil OL supplied from the oil supply ports P1 into the
space S2 from entering the air gap G.
[0103] As mentioned above, this embodiment forms the mold members
33a and 33b at both ends of the stator core 31, to cover the base
parts of the coil end parts 32a and arranges the partition parts
42b and 43b in contact with the mold members 33a and 33b,
respectively, to separate the space S1 in which the rotor 20 is
arranged from the space S2 in which the coil end parts 32a are
arranged. This realizes efficient cooling without increasing costs
or deteriorating performance.
Fourth Embodiment
[0104] FIG. 14 is a sectional side view illustrating the structure
of a motor 4, i.e., a rotary machine according to the fourth
embodiment of the present invention. The motor 4 of this embodiment
illustrated in FIG. 14 differs from the motor 3 illustrated in FIG.
9 in that it attaches a resolver 50 to a rotary shaft 10, arranges
a mold member 51 instead of the mold member 33a, and employs left
sidewall member 52 and right sidewall member 53 instead of the left
sidewall member 42 and right sidewall member 43.
[0105] The resolver 50 is a sensor to detect a rotation angle of
the rotary shaft 10, and in the example illustrated in FIG. 14, is
arranged on a right side of a bearing B2. The mold member 51 is
formed to have an asymmetric shape with respect to a mold member
33b formed on a right side of a stator core 31 in connection with
the axial direction of the rotary shaft 10. More precisely, the
mold member 51 has an annular part 51a formed in an annular shape
along an end (end E1) of the stator core 31 to cover base parts of
coil end parts 32a and a cylindrical protrusion 51b leftward
protruding from the annular part 51a. The annular part 51a has the
same shape as the mold member 33a illustrated in FIG. 9.
[0106] Similar to the left sidewall member 42 illustrated in FIG.
9, the left sidewall member 52 is a member having a disk-shaped
bottom plate part 52a and a cylindrical partition part (partition
member) 52b. The partition part 52b of the left sidewall member 52
is shorter in the axial direction than the partition part 42b of
the left sidewall member 42. This is because the above-mentioned
mold member 51 has the cylindrical protrusion 51b leftward
protruding from the annular part 51a, and therefore, the partition
part 52b is able to be in contact with the mold member 51 without
extended up to the annular part 51a of the mold member 51.
[0107] The right sidewall member 53 has a disk-shaped bottom plate
part 53a, a cylindrical support part 53b, and a cylindrical
partition part (partition member) 53c. The support part 53b
supports, with its inner circumferential face, part of the bearing
B2 and resolver 50. The partition part 53c is similar to the
partition part 43b illustrated in FIG. 9 but is shorter in the
axial direction than the partition part 43b by the portion of the
support part 53b. In this way, the motor 4 of this embodiment has
the resolver 50, and for this, the mold members 33b and 51 have
asymmetrical shapes and the left sidewall member 52 and right
sidewall member 53 have asymmetrical shapes.
[0108] According to this embodiment, the mold member 51 and mold
member 33b are formed at ends of the stator core 31 to cover the
base parts of the coil end parts 32a. The partition parts 52b and
53c are in contact with the mold members 51 and 33b, to separate a
space S1 in which a rotor 20 is arranged from a space S2 in which
the coil end parts 32a are arranged. Like the first embodiment,
this embodiment is capable of carrying out efficient cooling
without increasing costs or deteriorating performance.
Fifth Embodiment
[0109] A motor 5 according to the fifth embodiment illustrated in
FIG. 15 employs oil as a coolant to cool the stator 30 of the motor
2 of the second embodiment. In FIG. 15, the internal structures of
a rotary shaft 10 and rotor 20 are omitted. The structure of the
motor 5 according to the fifth embodiment will be explained in
detail.
[0110] In the motor 5 of this embodiment, a first end of a center
shaft 70 is fixedly supported with an outer housing 61 that is on
the left side of FIG. 15. The outer housing 61 has a body member
61a fixed to a left sidewall member 42 of a housing 40 and a left
sidewall member 61b that closes a side of the body member 61a
opposite to the housing 40. At the center of the left sidewall
member 61b, a fitting hole 61c is formed to fix an outwardly
protruding first end of the center shaft 70.
[0111] Similarly, a second end of the center shaft 70 is fixedly
supported with an outer housing 62 that is on the right side of
FIG. 15. The outer housing 62 has a body member 62a fixed to a
right sidewall member 43 of the housing 40 and a right sidewall
member 62b that closes a side of the body member 62a opposite to
the housing 40. At the center of the right sidewall member 62b, a
fitting hole 62c is formed to fix an outwardly protruding second
end of the center shaft 70.
[0112] According to this embodiment, the motor 5 is of an outer
ring rotating type with the rotor 20 rotating around the center
shaft 70. Mold members 33a and 33b are formed at both ends of a
stator core 31 to cover base parts of coil end parts 32a. Partition
parts 42b and 43b are in contact with the mold members 33a and 33b,
respectively, to separate a space S1 in which the rotor 20 is
arranged from a space S2 in which the coil end parts 32a are
arranged. Similar to the fourth embodiment, this embodiment is
capable of carrying out efficient cooling without increasing costs
or deteriorating performance.
INDUSTRIAL APPLICABILITY
[0113] The present invention is applicable not only to motors of
electric vehicles but also generally and widely to rotary machines
that convert electric power into torque, or rotary machines such as
generators that convert torque into electric power.
EXPLANATION OF REFERENCE NUMERALS
[0114] 1, 2, 3, 4, 5: Motor [0115] 10: Rotary shaft (Rotor shaft)
[0116] 10a: First shaft part (First rotary body part) [0117] 10b:
Second shaft part (Second rotary body part) [0118] 11: Coolant flow
path [0119] 12: Groove [0120] 13: Communicating flow path [0121]
20: Rotor [0122] 21: Rotor core [0123] 23: Permanent magnet [0124]
24: Oil flow path (Coolant flow path, Second flow path) [0125] 25,
26: Rotary support member (First rotary body part) [0126] 25a, 26a:
Gap (First flow path) [0127] 27: Sleeve (Sleeve member) [0128] 30:
Stator [0129] 31: Stator core [0130] 32: Coil [0131] 32a: Coil end
part [0132] 33a, 33b: Mold member [0133] 33c: Mold member [0134]
42b, 43b: Partition part (Partition member) [0135] 51: Mold member
[0136] 51a: Annular part [0137] 51b: Protrusion [0138] 52b, 53c:
Partition part (Partition member) [0139] 70: Center shaft (Rotor
shaft) [0140] 80: Rotary body (Second rotary body part) [0141] P1:
Oil supply port (Coolant supply port) [0142] S1: First space [0143]
S2: Second space
* * * * *