U.S. patent application number 16/334779 was filed with the patent office on 2019-08-01 for pump device.
The applicant listed for this patent is Nidec Tosok Corporation. Invention is credited to Kazuhiro HOMMA, Yosuke ITO.
Application Number | 20190234404 16/334779 |
Document ID | / |
Family ID | 61763208 |
Filed Date | 2019-08-01 |
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United States Patent
Application |
20190234404 |
Kind Code |
A1 |
HOMMA; Kazuhiro ; et
al. |
August 1, 2019 |
PUMP DEVICE
Abstract
A pump device includes a shaft, a motor that rotates the shaft,
and a pump that is driven by the motor via the shaft and discharges
oil. The pump device includes a first flow path for the oil that
connects an interior of the pump and an interior of a housing, a
second flow path for the oil provided between a stator and a rotor
of the motor, and a third flow path for the oil that is connected
to a suction port of a pump through an outside of the stator and
the rotor in a radial direction from the second flow path. In the
first flow path, oil passes through at least one of a space between
the shaft and a bearing, a space between the bearing and a pump
case, and an interior of the bearing.
Inventors: |
HOMMA; Kazuhiro; (Zama-shi,
JP) ; ITO; Yosuke; (Zama-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Nidec Tosok Corporation |
Zama-shi, Kanagawa |
|
JP |
|
|
Family ID: |
61763208 |
Appl. No.: |
16/334779 |
Filed: |
September 25, 2017 |
PCT Filed: |
September 25, 2017 |
PCT NO: |
PCT/JP2017/034513 |
371 Date: |
March 20, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F04C 15/0088 20130101;
F04C 2240/81 20130101; H02K 9/19 20130101; F04C 2240/50 20130101;
F04C 2/102 20130101; F04C 2/10 20130101; F04C 2240/40 20130101;
F04C 15/00 20130101; F04C 2210/206 20130101; H02K 7/14
20130101 |
International
Class: |
F04C 15/00 20060101
F04C015/00; F04C 2/10 20060101 F04C002/10 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 30, 2016 |
JP |
2016-195283 |
Claims
1-19. (canceled)
20. A pump device comprising: a shaft that rotates around a central
axis that extends in an axial direction; a motor that rotates the
shaft; and a pump that is positioned on one side of the motor in
the axial direction, is driven by the motor via the shaft, and
discharges oil; wherein the motor includes: a rotor that rotates
around the shaft; a stator that faces the rotor; and a housing in
which the rotor and the stator are accommodated; the pump includes:
a pump rotor that is attached to the shaft; a bearing that
rotatably supports the shaft; and a pump case in which a suction
port into which the oil is sucked and a discharge port from which
the oil is discharged are provided and the pump rotor is
accommodated; the pump device further comprises: a first flow path
for the oil that connects an interior of the pump and an interior
of the housing; a second flow path for the oil provided between the
stator and the rotor; and a third flow path for the oil that is
connected to a pump suction port through an outside of the stator
and the rotor in a radial direction from the second flow path; and
in the first flow path, the oil passes through at least one of a
space between the shaft and the bearing, a space between the
bearing and the pump case, and an interior of the bearing.
21. The pump device according to claim 20, wherein the pump case
includes a pump cover and a pump body; the pump body is open at
both ends in the axial direction and the shaft extends
therethrough; and the pump rotor rotates according to rotation of
the shaft.
22. The pump device according to claim 21, wherein the pump body
includes the bearing and the pump body includes a sliding bearing
structure; and in the first flow path, the oil passes between the
shaft and the pump body.
23. The pump device according to claim 22, wherein the first flow
path includes a first connector in which a cutout is provided in at
least one of the shaft and the pump body.
24. The pump device according to claim 21, wherein, in the first
flow path, the oil passes between the bearing and the pump
body.
25. The pump device according to claim 24, wherein the first flow
path includes a second connector in which a cutout or a
through-hole is provided in at least one of the bearing and the
pump body.
26. The pump device according to claim 21, wherein the bearing is a
ball bearing including a plurality of balls; and in the first flow
path, the oil passes between adjacent ones of the plurality of
balls.
27. The pump device according to claim 21, wherein the stator and
the pump body are capable of contacting each other.
28. The pump device according to claim 20, wherein the stator is an
integrally molded article made of a resin.
29. The pump device according to claim 20, wherein the rotor is an
integrally molded article made of a resin.
30. The pump device according to claim 20, wherein the stator is
positioned radially outward from the rotor; and the third flow path
includes a flow path connected to the pump suction port through the
outside of the stator in the radial direction from the second flow
path.
31. The pump device according to claim 30, wherein the third flow
path includes a space between an outer peripheral surface of the
stator and an inner peripheral surface of the housing of the
motor.
32. The pump device according to claim 31, wherein the third flow
path includes a through-hole or a cutout provided in the stator or
a cutout provided in the housing.
33. The pump device according to claim 30, wherein one end on a
side of the motor of the first flow path is provided at or adjacent
to a location on the side of the motor of the opening through which
the shaft extends in the pump case; and the second flow path is
connected to one end on the side of the motor of the first flow
path.
34. The pump device according to claim 30, further comprising a
flow path that is provided between an outer peripheral surface of
the shaft and an inner peripheral surface of the rotor.
35. The pump device according to claim 30, further comprising a
flow path through which a through-hole provided in the rotor
extends.
36. A pump device comprising; a shaft that rotates a central axis
that extends in an axial direction; a motor that rotates the shaft;
and a pump that is positioned on one side of the motor in the axial
direction, is driven by the motor via the shaft, and discharges
oil; wherein the motor includes: a rotor that rotates around the
shaft; a stator that faces an inner side of the rotor in a radial
direction; a housing in which the rotor and the stator are
accommodated; the pump includes: a pump rotor that is attached to
the shaft; a bearing that rotatably supports the shaft; and a pump
case in which a suction port into which the oil is sucked and a
discharge port from which the oil is discharged are provided and
the pump rotor is accommodated; the pump device further comprises:
a first flow path for the oil that connects an interior of the pump
and an interior of the housing; a second flow path for the oil
provided between the stator and the rotor; and a third flow path
for the oil including a flow path that is connected to the second
flow path through an inside of the stator and the rotor in a radial
direction from the first flow path and a flow path that is
connected to a pump suction port from the second flow path; and in
the first flow path, the oil passes through at least one of a space
between the shaft and the bearing, a space between the bearing and
the pump case, and an inside of the bearing.
37. The pump device according to claim 20, wherein the rotor and
the stator face each other in the axial direction; and the third
flow path includes a flow path that is provided inside the stator
and the rotor in the radial direction and a flow path that is
provided outside the stator and the rotor in the radial
direction.
38. The pump device according to claim 34, wherein the motor
includes two rotors attached to the shaft with a predetermined
interval therebetween in the axial direction; the stator is
disposed between the two rotors; and the second flow path includes
a flow path provided between a first of the two rotors and the
stator, and a flow path provided between a second of the two rotors
and the stator.
Description
1. TECHNICAL FIELD
[0001] The present disclosure relates to a pump device.
2. BACKGROUND ART
[0002] In recent years, responsiveness has been required for
electric oil pumps used for a transmission and the like. In order
to realize responsiveness in an electric oil pump, it is necessary
for an electric oil pump motor to have a high output.
[0003] When an electric oil pump motor is made to have a high
output, a large current flows through a coil included in the motor,
the temperature of the motor becomes high, and, for example, a
permanent magnet included in the motor may be demagnetized.
Therefore, in order to prevent the temperature of the motor from
increasing, it is necessary to provide a cooling structure in the
motor.
[0004] Japanese Unexamined Patent Application, Publication No.
2008-125235 discloses an electric motor having an oil supply
mechanism that displaces a relative positional relationship between
a stator and a rotor in an axial direction with a hydraulic
pressure of oil according to a rotational speed of a rotor and
thereby cools the rotor with oil.
[0005] However, in the electric motor disclosed in Japanese
Unexamined Patent Application, Publication No. 2008-125235, it is
not possible to cool the stator and the rotor with oil at the same
time.
SUMMARY OF THE DISCLOSURE
[0006] Example embodiments of the present disclosure provide pump
devices each including a structure that achieves an excellent
cooling effect in which a stator and a rotor are cooled at the same
time.
[0007] A first example embodiment of the present disclosure
provides a pump device including a shaft that rotates around a
central axis that extends in an axial direction, a motor that
rotates the shaft, and a pump that is positioned on one side of the
motor in the axial direction, is driven by the motor via the shaft,
and discharges oil, wherein the motor includes a rotor that rotates
around the shaft, a stator that faces the rotor, and a housing in
which the rotor and the stator are accommodated, wherein the pump
includes a pump rotor that is attached to the shaft, a bearing that
rotatably supports the shaft, and a pump case in which a suction
port into which the oil is sucked and a discharge port from which
the oil is discharged are provided and the pump rotor is
accommodated, wherein the pump device includes a first flow path
for the oil that connects an interior of the pump and an interior
of the housing, a second flow path for the oil provided between the
stator and the rotor, a third flow path for the oil that is
connected to a pump suction port through an outside of the stator
and the rotor in a radial direction from the second flow path, and
a fourth flow path through which the oil flows from the second flow
path or the third flow pat into the pump, and in the first flow
path, the oil passes through at least one of a space between the
shaft and the bearing, a space between the bearing and the pump
case, and an interior of the bearing.
[0008] According to the exemplary first disclosure of the present
disclosure, it is possible to provide a pump device having a
structure having an excellent cooling effect in which the stator
and the rotor are cooled at the same time.
[0009] The above and other elements, features, steps,
characteristics and advantages of the present disclosure will
become more apparent from the following detailed description of
example embodiments with reference to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a cross-sectional view showing a pump device
according to a first example embodiment of the present
disclosure.
[0011] FIG. 2 is a diagram schematically showing main portions of
the pump device according to the first example embodiment of the
present disclosure.
[0012] FIG. 3A is an enlarged view of a portion of flow paths in
the first example embodiment of the present disclosure.
[0013] FIG. 3B is an enlarged view of a portion of flow paths in
the first example embodiment of the present disclosure.
[0014] FIG. 4A is an enlarged view of a portion of flow paths in
the first example embodiment of the present disclosure.
[0015] FIG. 4B is an enlarged view of a portion of flow paths in
the first example embodiment of the present disclosure.
[0016] FIG. 5A is an enlarged view of a portion of flow paths in
the first example embodiment of the present disclosure.
[0017] FIG. 5B is an enlarged view of a portion of flow paths in
the first example embodiment of the present disclosure.
[0018] FIG. 6 is a top view of a stator in the first example
embodiment of the present disclosure.
[0019] FIG. 7A is an enlarged view of a portion of flow paths in
the first example embodiment of the present disclosure.
[0020] FIG. 7B is an enlarged view of a portion of flow paths in
the first example embodiment of the present disclosure.
[0021] FIG. 8 is a diagram showing a modified example of the flow
paths in the first example embodiment of the present
disclosure.
[0022] FIG. 9 is a cross-sectional view showing a pump device
according to a second example embodiment of the present
disclosure.
[0023] FIG. 10 is a cross-sectional view showing a pump device
according to a third example embodiment of the present
disclosure.
[0024] FIG. 11 is a cross-sectional view showing a modified example
of the pump device according to the third example embodiment of the
present disclosure.
DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS
[0025] Pump devices according to example embodiments of the present
disclosure will be described below with reference to the drawings.
Here, the scope of the present disclosure is not limited to the
following example embodiments, and can be arbitrarily changed
within the spirit and scope of the present disclosure. In addition,
in the following drawings, in order to allow respective
configurations to be easily understood, the sizes and numbers in
the structures may be different those in actual structures.
[0026] In addition, in the drawings, an XYZ coordinate system is
appropriately shown as a three-dimensional orthogonal coordinate
system. In the XYZ coordinate system, the Z axis direction is a
direction parallel to one axial direction with respect to a central
axis J shown in FIG. 1. The X axis direction is a direction
parallel to a lengthwise direction of a bus bar assembly 60 shown
in FIG. 1, that is, the left to right direction in FIG. 1. The Y
axis direction is a direction parallel to a width direction of the
bus bar assembly 60, that is, a direction orthogonal to both the X
axis direction and the Z axis direction.
[0027] In addition, in the following description, the positive side
(+Z side) in the Z axis direction will be referred to as "front
side" and the negative side (-Z side) in the Z axis direction will
be referred to as "rear side." Here, the rear side and the front
side are terms that are simply used for explanation, and do not
limit actual positional relationships and directions. In addition,
unless otherwise noted, a direction (Z axis direction) parallel to
the central axis J is simply defined as an "axial direction," a
radial direction with respect to the central axis J is simply
defined as a "radial direction," and a circumferential direction
with respect to the central axis J, that is, a circumference
(.theta. direction) around the central axis J is simply defined as
a "circumferential direction."
[0028] Here, in this specification, the term "extending in the
axial direction" includes not only extending strictly in the axial
direction (Z axis direction) but also extending in a direction
inclined in a range of less than 45.degree. with respect to the
axial direction. In addition, in this specification, the term
"extending in the radial direction" includes not only extending
strictly in the radial direction, that is, extending in a direction
perpendicular to the axial direction (Z axis direction), but also
extending in a direction inclined in a range of less than
45.degree. with respect to the radial direction.
First Example Embodiment
[0029] FIG. 1 is a cross-sectional view showing a pump device 10 of
the present example embodiment.
[0030] The pump device 10 of the present example embodiment
includes a shaft 41, a motor unit 20, a housing 12, a cover 13, and
a pump unit 30. The shaft 41 rotates around the central axis J that
extends in the axial direction. The motor unit 20 and the pump unit
30 are provided in the axial direction side by side.
[0031] As shown in FIG. 1, the motor unit 20 includes the cover 13,
a rotor 40, a stator 50, a bearing 42, a control device 70, the bus
bar assembly 60, and a plurality of O-rings. The plurality of
O-rings include a front side O-ring 81 and a rear side O-ring
82.
[0032] The rotor 40 is fixed to the outer peripheral surface of the
shaft 41. The stator 50 is positioned radially outward from the
rotor 40. That is, the motor unit 20 is an inner rotor type motor.
The bearing 42 rotatably supports the shaft 41. The bearing 42 is
held by the bus bar assembly 60. The bus bar assembly 60 is
connected to an external power supply and supplies a current to the
stator 50.
[0033] The housing 12 holds the motor unit 20 and the pump unit 30.
The housing 12 opens to the rear side (-Z side), and the front side
(+Z side) end of the bus bar assembly 60 is inserted into an
opening of the housing 12. The cover 13 is fixed to the rear side
of the housing 12. The cover 13 covers the rear side of the motor
unit 20. That is, the cover 13 covers at least a part of the rear
side (-Z side) of the bus bar assembly 60 and is fixed to the
housing 12.
[0034] The control device 70 is disposed between the bearing 42 and
the cover 13. The front side O-ring 81 is provided between the bus
bar assembly 60 and the housing 12. The rear side O-ring 82 is
provided between the bus bar assembly 60 and the cover 13.
Hereinafter, respective components will be described in detail.
<Housing>
[0035] As shown in FIG. 1, the housing 12 has a tubular shape. More
specifically, the housing 12 has a multi-stage cylindrical shape of
which both ends around the central axis J are open. The material of
the housing 12 is, for example, a metal. The housing 12 holds the
motor unit 20 and the pump unit 30. The housing 12 has a
cylindrical part 14 and a flange part 15.
[0036] The flange part 15 extends radially outward from the rear
side end of the cylindrical part 14. The cylindrical part 14 has a
cylindrical shape around the central axis J. The cylindrical part
14 has a bus bar assembly insertion part 21a, a stator holding part
21b, and a pump body holding part 21c in the axial direction (Z
axis direction) from the rear side (-Z side) to the front side (+Z
side) in this order.
[0037] The bus bar assembly insertion part 21a surrounds the front
side (+Z side) end of the bus bar assembly 60 from the outer side
in the radial direction of the central axis J. The bus bar assembly
insertion part 21a, the stator holding part 21b, and the pump body
holding part 21c have concentric cylindrical shapes, and their
diameters decrease in this order.
[0038] That is, the front side end of the bus bar assembly 60 is
positioned inside the housing 12. The outer surface of the stator
50, that is, the outer surface of a core back part 51 to be
described below, is fitted to the inner surface of the stator
holding part 21b. Accordingly, the stator 50 is held in the housing
12. The outer peripheral surface of a pump body 31 is fixed to the
inner peripheral surface of the pump body holding part 21c.
<Rotor>
[0039] The rotor 40 has a rotor core 43 and a rotor magnet 44. The
rotor core 43 surrounds the shaft 41 around the axis (0 direction)
and is fixed to the shaft 41. The rotor magnet 44 is fixed to the
outer surface along the axis of the rotor core 43. The rotor core
43 and the rotor magnet 44 rotate together with the shaft 41.
<Stator>
[0040] The stator 50 surrounds the rotor 40 around the axis (0
direction) and rotates the rotor 40 around the central axis J. The
stator 50 includes the core back part 51, a tooth part 52, a coil
53, and a bobbin (insulator) 54. The shape of the core back part 51
has a cylindrical shape concentric with the shaft 41.
[0041] The tooth part 52 extends from the inner surface of the core
back part 51 toward the shaft 41. A plurality of tooth parts are
provided and are disposed at equal intervals in the circumferential
direction of the inner surface of the core back part 51 (FIG. 6).
The coil 53 is formed by winding a conductive wire 53a. The coil 53
is provided on the bobbin (insulator) 54. The bobbin (insulator) 54
is attached to each of the tooth parts 52.
<Bearing>
[0042] The bearing 42 is disposed on the rear side (-Z side) of the
stator 50. The bearing 42 is held by a bearing holding part 65 of a
bus bar holder 61 to be described below. The bearing 42 supports
the shaft 41. The configuration of the bearing 42 is not
particularly limited, and any known bearing may be used.
<Control Device>
[0043] The control device 70 controls driving of the motor unit 20.
The control device 70 includes a circuit board (not shown), a
rotation sensor (not shown), a sensor magnet holding member (not
shown), and a sensor magnet 73. That is, the motor unit 20 includes
the circuit board, the rotation sensor, the sensor magnet holding
member, and the sensor magnet 73.
[0044] The circuit board outputs a motor driving signal. The sensor
magnet holding member is positioned by fitting the center hole to a
small diameter part of the rear side (+Z side) end of the shaft 41.
The sensor magnet holding member is rotatable together with the
shaft 41. The sensor magnet 73 has an annular shape and N poles and
S poles are alternately disposed in the circumferential direction.
The sensor magnet 73 is fitted to the outer peripheral surface of
the sensor magnet holding member.
[0045] Accordingly, the sensor magnet 73 is held by the sensor
magnet holding member, and is disposed so that it is rotatable
together with the shaft 41 around the axis (+.theta. direction) of
the shaft 41 on the rear side (-Z side) of the bearing 42.
[0046] The rotation sensor is attached to a front surface of the
circuit board on the front side (+Z side) of the circuit board. The
rotation sensor is provided at a position that faces the sensor
magnet 73 in the axial direction (Z axis direction). The rotation
sensor detects change in the magnetic flux of the sensor magnet 73.
The rotation sensor is, for example, a Hall IC or an MR sensor.
Specifically, when Hall ICs are used, three are provided.
<Cover>
[0047] The cover 13 is attached to the rear side (-Z side) of the
housing 12. The material of the cover 13 is, for example, a metal.
The cover 13 includes a tubular part 22a, a lid part 22b, and a
flange part (cover side) 24. The tubular part 22a opens to the
front side (+Z side).
[0048] The tubular part 22a surrounds the bus bar assembly 60, and
more specifically, the rear side (-Z side) end of the bus bar
holder 61, from the outer side in the radial direction of the
central axis J. The tubular part 22a is connected to the rear side
end of the bus bar assembly insertion part 21a in the housing 12
with the flange part (housing side) 15 and the flange part (cover
side) 24 therebetween.
[0049] The lid part 22b is connected to the rear side end of the
tubular part 22a. In the present example embodiment, the lid part
22b has a flat plate shape. The lid part 22b blocks a rear side
opening of the bus bar holder 61. A front side surface of the lid
part 22b is in contact with the entire circumference of the rear
side O-ring 82. Accordingly, the cover 13 is indirectly in contact
with the rear surface of the main body part on the rear side of the
bus bar holder 61 via the rear side O-ring 82 over one
circumference around an opening of the bus bar holder 61.
[0050] The flange part (cover side) 24 extends radially outward
from the front side end of the tubular part 22a. In the housing 12
and the cover 13, the flange part (housing side) 15 and the flange
part (cover side) 24 are bonded in an overlapping manner.
[0051] An external power supply is connected to the motor unit 20
via a connector part 63. The connected external power supply is
electrically connected to a bus bar 91 and a wiring member 92 that
protrude from a bottom surface of a power supply opening 63a of the
connector part 63. Accordingly, a drive current is supplied to the
coil 53 of the stator 50 and the rotation sensor through the bus
bar 91 and the wiring member 92. The drive current supplied to the
coil 53 is controlled according to, for example, a rotation
position of the rotor 40 measured by the rotation sensor. When a
drive current is supplied to the coil 53, a magnetic field is
generated and the rotor 40 rotates according to this magnetic
field. In this manner, the motor unit 20 obtains a rotational
driving force.
<Pump Unit>
[0052] The pump unit 30 is positioned on one side of the motor unit
20 in the axial direction, and specifically, on the front side (+Z
axis side). The pump unit 30 is driven by the motor unit 20 via the
shaft 41. The pump unit 30 includes the pump body 31, a pump rotor
35, and a pump cover 32. Hereinafter, the pump cover 32 and the
pump body 31 are referred to as a pump case. In other words, the
pump case includes the pump body 31 and the pump cover 32.
[0053] The pump body 31 is fixed into the housing 12 on the front
side of the motor unit 20. An O-ring 71 is attached to the pump
body 31. The O-ring 71 is provided between the outer peripheral
surface of the pump body 31 and the inner peripheral surface of the
housing 12 in the radial direction. Therefore, a gap between the
outer peripheral surface of the pump body 31 and the inner
peripheral surface of the housing 12 in the radial direction is
sealed. The pump body 31 has a pump chamber 33 in which the pump
rotor 35 recessed from the front side (+Z side, one side in the
axial direction) surface to the rear side (-Z side, the other side
in the axial direction) is accommodated. The shape of the pump
chamber 33 when viewed in the axial direction is a circular
shape.
[0054] The pump body 31 has a through-hole 31a which is open at
both ends in the axial direction, through which the shaft 41
passes, and of which the front side opening opens to the pump
chamber 33. The rear side opening of the through-hole 31a opens
toward the motor unit 20. The through-hole 31a functions as a
bearing member that rotatably supports the shaft 41.
[0055] The pump body 31 has an exposed part 36 that is positioned
on the front side relative to the housing 12 and is exposed to the
outside of the housing 12. The exposed part 36 is a part of the
front side end of the pump body 31. The exposed part 36 has a
columnar shape that extends in the axial direction. The exposed
part 36 overlaps the pump chamber 33 in the radial direction.
[0056] The pump rotor 35 is attached to the shaft 41. More
specifically, the pump rotor 35 is attached to the front side end
of the shaft 41. The pump rotor 35 includes an inner rotor 37
attached to the shaft 41 and an outer rotor 38 surrounding the
outer side of the inner rotor 37 in the radial direction. The inner
rotor 37 has an annular shape. The inner rotor 37 is a gear having
teeth on the outer surface in the radial direction.
[0057] The inner rotor 37 is fixed to the shaft 41. More
specifically, the front side end of the shaft 41 is press-fitted
into the inner rotor 37. The inner rotor 37 rotates around the axis
(.theta. direction) together with the shaft 41. The outer rotor 38
has an annular shape surrounding the outer side of the inner rotor
37 in the radial direction. The outer rotor 38 is a gear having
teeth on the inner surface in the radial direction.
[0058] The inner rotor 37 and the outer rotor 38 are engaged with
each other, and when the inner rotor 37 rotates, the outer rotor 38
rotates. That is, the pump rotor 35 rotates according to rotation
of the shaft 41. In other words, the motor unit 20 and the pump
unit 30 have the same rotation axis. Therefore, it is possible to
prevent the size of the electric oil pump from increasing in the
axial direction. When the inner rotor 37 and the outer rotor 38
rotate, a volume between engaged parts of the inner rotor 37 and
the outer rotor 38 changes. An area in which the volume decreases
is defined as a pressurized area and an area in which the volume
increases is defined as a negative pressure area. A suction port
32c is disposed on one side of the negative pressure area of the
pump rotor 35 in the axial direction. In addition, a discharge port
32d is disposed on one side of the pressurized area of the pump
rotor 35 in the axial direction. Here, oil sucked from the suction
port 32c into the pump chamber 33 is accommodated in a volume part
between the inner rotor 37 and the outer rotor 38 and can be sent
toward the discharge port 32d. Then, the oil is discharged from the
discharge port 32d.
[0059] The pump cover 32 is attached to the front side of the pump
body 31. The pump cover 32 includes a pump cover main body 32a and
a pump discharge cylindrical part 32b. The pump cover main body 32a
has a disc shape that extends in the radial direction. The pump
cover main body 32a blocks the front side opening of the pump
chamber 33. The pump discharge cylindrical part 32b has a
cylindrical shape that extends in the axial direction. The pump
discharge cylindrical part 32b is open at both ends in the axial
direction. The pump discharge cylindrical part 32b extends from the
pump cover main body 32a to the front side.
[0060] The pump unit 30 has the discharge port 32d and the suction
port 32c. The discharge port 32d and the suction port 32c are
provided on the pump cover 32. The discharge port 32d includes the
inside of the pump discharge cylindrical part 32b. The discharge
port 32d and the suction port 32c open on the front side surface of
the pump cover 32. The discharge port 32d and the suction port 32c
are connected to the pump chamber 33, and it is possible to suck
oil into the pump chamber 33 and discharge oil from the pump
chamber 33.
[0061] When the shaft 41 rotates in one circumferential direction
(-.theta. direction), oil is sucked into the pump chamber 33 from
the suction port 32c. The oil sucked into the pump chamber 33 is
sent by the pump rotor 35 and is discharged to the discharge port
32d. In addition, in the pump device 10 of the present example
embodiment, oil sucked into the pump chamber 33 is sent by the pump
rotor 35, and flows into the motor unit 20 through the shaft 41.
Specifically, most of the oil is discharged from the pressurized
area to the discharge port 32d, but a part thereof passes through
the gap between the inner rotor 37 and the pump body 31 in the
axial direction and flows to the vicinity of the shaft 41. Then,
the oil passes between the shaft 41 and the pump body 31, and flows
into the motor unit 20. Accordingly, it is possible to cool the
motor unit 20.
[0062] Next, a cooling structure of the pump device 10 according to
the present example embodiment will be described. In the present
example embodiment, oil supplied from an external device flows from
the suction port 32c to the discharge port 32d due to the pump
rotor 35, is sucked into the motor unit 20, and circulates in the
motor unit 20, and thus cooling of the stator 50 and the rotor 40
is realized.
[0063] FIG. 2 is a diagram schematically showing main parts of the
pump device 10 in order to allow easy understanding of oil flow
paths in the pump device 10 shown in FIG. 1.
[0064] As shown in FIG. 2, the pump device 10 includes a first flow
path 1 that connects the inside of the pump unit 30 and the inside
of the housing 12, a second flow path 2 that is provided between
the stator 50 and the rotor 40, and third flow paths 3a and 3b that
are connected to the suction port (pump suction port) 32c of the
pump unit 30 through the outside of the stator 50 and the rotor 40
in the radial direction from the second flow path 2. Hereinafter,
the flow paths will be described in detail.
<First Flow Path>
[0065] The first flow path 1 in FIG. 2 is provided between the pump
body 31 of the pump unit 30 and the shaft 41. When the pump device
10 operates, most of oil sucked from the suction port 32c is
discharged from a pressurized area of the pump rotor 35 to the
discharge port 32d (refer to FIG. 1), but a part thereof passes
through the gap between the inner rotor 37 and the pump body 31 in
the axial direction and flows to the vicinity of the shaft 41.
Then, the oil passes between the shaft 41 and the pump body 31,
that is, flows into the motor unit 20 through the first flow path
1. Here, for convenience of description, FIG. 2 shows a state in
which oil sucked from the suction port 32c is directly led to the
first flow path 1. That is, as indicated by arrows showing flow
paths in FIG. 2, oil sucked from the suction port 32c passes
through the gap between the inner rotor 37 and the pump body 31 in
the axial direction from the pressurized area of the pump rotor 35,
and a path that flows through the first flow path 1 is omitted.
[0066] In the present example embodiment, the pump body 31 has a
sliding bearing structure, and the first flow path 1 passes between
the shaft 41 and the pump body 31. Specifically, as shown in FIG.
3A, the first flow path 1 is positioned between the outer
peripheral surface of the shaft 41 and the inner peripheral surface
of the pump body 31. In this case, oil flowing from the pump unit
30 in the first flow path 1 can be used as a lubricating oil, and
the oil can be efficiently sucked into the motor unit 20.
[0067] FIG. 3B is a cross-sectional view taken along the line A-A'
in FIG. 3A. As shown in FIG. 3B, in the first flow path 1, a cutout
part may be provided in at least one of the outer peripheral
surface of the shaft 41 and the inner peripheral surface of the
pump body 31. Therefore, a flow path resistance of the first flow
path 1 decreases and oil can be sucked from the pump unit 30 to the
motor unit 20 more efficiently.
[0068] Here, a bearing member 31b is not limited to a sliding
bearing structure. For example, any ball bearing may be used as the
bearing member 31b. FIG. 4A is a diagram showing a case in which
the pump body 31 includes the bearing member 31b (bearing). As
shown in FIG. 4A, the first flow path 1 is positioned between the
bearing member 31b (bearing) and the pump body 31.
[0069] FIG. 4B is a cross-sectional view taken along the line B-B'
in FIG. 4A. As shown in FIG. 4B, in the first flow path 1, a cutout
part may be provided in at least one of the bearing member 31b
(bearing) and the pump body 31. In addition, a through-hole (not
shown) may be provided in at least one of the bearing member 31b
(bearing) and the pump body 31. When a cutout part or a
through-hole is provided, a flow path resistance of the first flow
path 1 decreases and oil can be sucked from the pump unit 30 into
the motor unit 20 more efficiently.
[0070] FIG. 5A is a diagram showing a case in which the bearing
member 31b is a ball bearing having a plurality of balls. As shown
in FIG. 5A, the first flow path 1 is positioned inside the bearing
member 31b (ball bearing). Specifically, the first flow path 1 is
positioned between adjacent balls of the ball bearing.
[0071] FIG. 5B is a cross-sectional view taken along the line C-C'
in FIG. 5A. As shown in FIG. 5B, in the first flow path 1, a cutout
part may be provided in at least one of the bearing member 31b
(ball bearing) and the pump body 31. In addition, a through-hole
(not shown) may be provided in at least one of the bearing member
31b (ball bearing) and the pump body 31. When a cutout part or a
through-hole is provided, a flow path resistance of the first flow
path 1 decreases and oil can be sucked from the pump unit 30 into
the motor unit 20 more efficiently.
[0072] As shown in FIG. 2 to FIG. 5, the first flow path 1 is
provided in at least one of a space between the shaft 41 and the
bearing member 31b, a space between the bearing member 31b and the
pump case (the pump body 31), and the inside of the bearing member
31b. That is, in the first flow path 1, oil passes through at least
one of a space between the shaft 41 and the bearing member 31b, a
space between the bearing member 31b and the pump case, and the
inside of the bearing member 31b.
<Second Flow Path>
[0073] The second flow path 2 in FIG. 2 is provided between the
stator 50 and the rotor 40. In the example shown in FIG. 2, the
second flow path 2 is positioned between the inner peripheral
surface of the stator 50 and the outer peripheral surface of the
rotor 40. Oil flowing into the first flow path 1 flows from the
front side one end to the rear side one end of the second flow path
2.
[0074] Here, the second flow path 2 is not limited to between the
inner peripheral surface of the stator 50 and the outer peripheral
surface of the rotor 40. For example, a through-hole is provided in
the core back part 51 of the stator 50 (refer to FIG. 1) or the
rotor core 43, and the through-hole may be used as the second flow
path 2. That is, the second flow path 2 may be provided at an
arbitrary position between the stator 50 and the rotor 40.
Accordingly, it is possible to cool the coil 53 of the stator 50
more efficiently and it is possible to cool the rotor.
[0075] As shown in FIG. 2, one end on the side of the motor unit 20
of the first flow path 1 is provided in the vicinity of the side of
the motor unit of the opening (the through-hole 31a) through which
the shaft 41 passes in the pump case (the pump body 31). Therefore,
when the second flow path 2 is provided at a position (near)
connected to one end on the side of the motor unit 20 of the first
flow path 1, most of oil is discharged from the discharge port 32d
(refer to FIG. 1). That is, since a distance from the discharge
port 32d to the first flow path 1 is long, an amount of oil flowing
toward the first flow path 1 is smaller than an amount of oil
discharged from the discharge port 32d. Thereby, since a discharge
pressure of the pump is not impaired, it is possible to prevent the
performance of the pump from deteriorating.
<Third Flow Path>
[0076] The third flow path is a flow path that is connected to the
suction port (pump suction port) 32c of the pump unit 30 through
the outside of the stator 50 and the rotor 40 in the radial
direction from the second flow path 2, and includes the flow paths
3a and 3b in the example shown in FIG. 2. The third flow path 3a is
a flow path that is provided radially outward from the stator 50
and the rotor 40, and the third flow path 3b is provided in the
pump body 31 and is a flow path connecting the third flow path 3a
and the inside of the pump unit 30.
[0077] In the example shown in FIG. 2, the third flow path 3a is
positioned between the outer peripheral surface of the stator 50
and the inner peripheral surface of the housing 12. Here, the third
flow paths 3a and 3b are not limited to the example shown in FIG.
2. For example, it may be a flow path connected to the suction port
(pump suction port) 32c of the pump unit 30 through the outside of
the pump device 10 as the outside of the stator 50 and the rotor 40
in the radial direction. In this case, the third flow path may
include the outside of the pump device 10.
[0078] Hereinafter, the third flow path 3a will be described.
[0079] Oil flowing into the first flow path 1 flows from the rear
side one end to the front side one end of the third flow path 3a
through the second flow path 2. When the third flow path 3a is
provided, since it is possible to increase a surface area of the
stator 50 in contact with oil, it is possible to cool the stator 50
more efficiently. Generally, in the motor, the coil generates heat
most intensively. Heat generated in the coil is transmitted to the
stator core. That is, an amount of heat generated in the stator 50
in the motor unit 20 is large. Thereby, when it is described that
it is possible to efficiently cool the stator 50, it means that it
is possible to efficiently cool the motor unit 20.
[0080] As shown in FIG. 6, the third flow path 3a may have a cutout
part 51a on the outer peripheral surface of the core back part 51
of the stator 50. In addition, the third flow path 3a may have a
cutout part 12a on the inner peripheral surface of the housing 12.
The third flow path 3a may have both or either of the cutout part
51a and the cutout part 12a. Here, a part in which a cutout part is
provided in the stator 50 is not limited to the outer peripheral
surface, but it may be provided, for example, on the inner
peripheral surface.
[0081] When the stator 50 has the cutout part 51a, since it is
possible to increase a surface area of the stator 50 in contact
with oil, it is possible to cool the inside of the motor unit 20
more efficiently. In addition, when the stator 50 has the cutout
part 51a or the housing 12 has the cutout part 12a, since it is
possible to increase a flow rate of oil flowing into the third flow
path 3a, it is possible to circulate oil more efficiently.
[0082] Here, the third flow path 3a is not limited to a path
between the outer peripheral surface of the stator 50 and the inner
peripheral surface of the housing 12. For example, as shown in FIG.
6, a through-hole 52b is provided in the core back part 51 of the
stator 50, and the through-hole 52b may be used as the third flow
path. Accordingly, it is possible to cool the coil 53 of the stator
50 more efficiently. In addition, a space between adjacent tooth
parts 52 may be used as the third flow path 3a.
[0083] In the present example embodiment, the stator 50 and the
pump body 31 are in contact with each other. As shown in FIG. 7A
and FIG. 7B, the stator 50 is molded with a resin. That is, the
stator 50 is an integrally molded article made of a resin, and has
a structure in which a front side one end 50a of the stator 50 and
the pump body 31 are in contact with each other. Specifically,
parts except for the inner peripheral surface of the tooth part 52
and the outer end of the core back 51 are molded with a resin. That
is, the entire coil is covered with a resin. As shown in FIG. 7B,
when the stator 50 and the pump body 31 molded with a resin are in
contact with each other so that they have an annular contact part
in the circumferential direction, an area A into which oil flows
from the first flow path 1 and an area B connected from the third
flow path 3a to the third flow path 3b are separated. Therefore,
oil flowing from the first flow path 1 into the area A does not
flow into the area B. Thus, oil flowing into the motor unit 20 can
flow through the first flow path 1, the second flow path 2, and the
third flow path 3 in this order, and an unnecessary circulation
path is not formed. That is, the circulating oil is unlikely to
accumulate. Therefore, oil is efficiently and sequentially
transferred in the flow paths.
[0084] Here, in the present example embodiment, since the stator 50
is an integrally molded article made of a resin, the front side one
end in which the stator 50 is in contact with the pump body 31 is
provided. However, the present disclosure is not limited thereto.
For example, the stator 50 and the pump body 31 may be brought into
contact with each other using a ring member fitted between the
stator 50 and the pump body 31. As shown in FIG. 7A, it is not
necessary cover all coil ends of the stator 50 with a resin, and
the front side one end 50a of the stator 50 may have any shape in
which the area A and the area B are separated.
[0085] When the stator 50 is an integrally molded article made of a
resin, it is possible to increase a surface area of the stator 50
in contact with oil in the second flow path 2 and the third flow
path 3a. Therefore, it is possible to cool the inside of the motor
unit 20 more efficiently.
[0086] Like the stator 50, the rotor 40 may be molded with a resin.
That is, the rotor 40 may be an integrally molded article made of a
resin. When the rotor 40 is an integrally molded article made of a
resin, it is possible to increase a surface area of the rotor 40 in
contact with oil in the second flow path 2. Therefore, it is
possible to cool the rotor magnet 44, it is possible to prevent
demagnetization of the rotor magnet 44, and it is possible to cool
the motor unit 20 more efficiently.
[0087] In addition, in the example shown in FIG. 2, the third flow
path 3a and the third flow path 3b are disposed in the pump device
10, but the present disclosure is not limited thereto. The third
flow path 3a and the third flow path 3b may be a flow path
connected to the pump suction port through the outside of the
stator 50 and the rotor 40 in the radial direction. For example, a
part or all of the third flow path may be disposed outside the
housing 12. A modified example of the third flow path will be
described below with reference to FIG. 8.
[0088] Next, the third flow path 3b will be described.
[0089] The third flow path 3b in FIG. 2 is provided in the pump
body 31 and connects the third flow path 3a and the inside of the
pump unit 30. Specifically, the third flow path 3b has a first
opening 31c in the vicinity of the front side one end of the third
flow path 3a of the motor unit 20 and a second opening 31d in the
vicinity of the suction port 32c of the pump chamber 33. The third
flow path 3b connects the third flow path 3a of the motor unit 20
and the pump chamber 33. When the third flow path 3b is provided,
oil sucked into the motor unit 20 through the first flow path 1 can
circulate from the inside of the motor unit 20 to the inside of the
pump unit 30. Oil flowing into the motor unit 30 from the first
flow path 1 returns to the inside of the pump unit 30 from the
third flow path 3b without passing through a wasteful circulation
path as described above. Since the temperature of oil that passes
through the first flow path 1 is lower than the temperature of oil
that passes through the third flow path 3b, oil with a low
temperature always circulates the inside of the motor unit 30.
Accordingly, it is possible to efficiently cool the stator 50 and
the rotor 40.
[0090] The first flow path 1 is positioned radially inward from the
third flow path 3b. Therefore, it is possible to secure a distance
between the first flow path 1 and the third flow path 3b in a
direction orthogonal to the axial direction. When the distance
between the first flow path 1 and the third flow path 3b is short,
there is a risk of oil with a high temperature returned to the
inside of the pump unit 30 through the third flow path 3b returning
to the first flow path 1. However, in the present example
embodiment, since it is possible to secure a distance between the
first flow path 1 and the third flow path 3b in a direction
orthogonal to the axial direction, it is possible to prevent
formation of a flow path through which oil with a high temperature
returned to the inside of the pump unit 30 returns to the first
flow path 1. Thereby, it is possible to efficiently cool the inside
of the motor unit 20.
[0091] A cross-sectional area of the first opening 31c which is a
rear side opening of the third flow path 3b is smaller than a
cross-sectional area of the discharge port 32d of the pump unit 30.
Therefore, an amount of oil flowing from the inside of the motor
unit 20 to the inside of the pump unit 30 becomes smaller than a
discharge amount of the pump, and it is possible to prevent an
amount of oil flowing into the motor unit 20 from becoming
excessive. That is, it is possible to prevent deterioration of the
pump efficiency due to an excess amount of oil flowing into the
motor unit 20 and it is possible to cool the inside of the motor
unit 20 more efficiently.
<Modified Example of Flow Path>
[0092] In the example shown in FIG. 2, the third flow path 3a and
the third flow path 3b are provided inside the pump device 10, but
the present disclosure is not limited thereto. For example, the
third flow path may include a flow path provided outside the pump
device 10. FIG. 8 is a diagram for explaining a case in which a
part of the third flow path passes through the outside of the pump
device 10 as an example. In the example shown in FIG. 8, the third
flow path 3a and the third flow path 3b include the third flow path
3a provided outside the housing 12 and the third flow path 3b
connecting the third flow path 3a and the inside of the pump unit
30. The housing 12 includes a first through-hole 12b and a second
through-hole 12c.
[0093] In the example shown in FIG. 8, the third flow path 3a is
provided in an external device (not shown) to which the pump device
10 and the pump device 10 are attached. The third flow path 3a may
be provided in any manner as long as it is a flow path connecting
the first through-hole 12b and the second through-hole 12c. That
is, the third flow path 3a may include an arbitrary flow path
connecting the first through-hole 12b and the second through-hole
12c. The positions of the first through-hole 12b and the second
through-hole 12c are not limited to the positions shown in FIG. 8,
but they may be provided at arbitrary positions such as the side
surface of the housing 12 and the lid part 22b of the cover 13. Oil
from the second flow path 2 is discharged to the outside of the
housing 12 through the first through-hole 12b, flows into the third
flow path 3a, and thus flows from the rear side to the front side
of the pump device 10, and flows into the third flow path 3b
through the second through-hole 12c.
[0094] Here, in the example shown in FIG. 8, the third flow path 3b
is provided in the pump body 31, and is a flow path connecting the
second through-hole 12c and the second opening 31d, but the present
disclosure is not limited thereto. For example, a through-hole
connecting the outside of the pump device 10 and the suction port
(pump suction port) 32c of the pump unit 30 is provided in the
exposed part 36 of the pump body 31, and the through-hole may serve
as the third flow path 3b. In this case, since it is not necessary
to provide a through-hole in both the housing 12 and the pump body
31, and a through-hole may be provided only in the exposed part 36,
that is, the pump body 31, processing is easy. In addition, in the
example shown in FIG. 8, the third flow path 3b is provided in the
pump body 31, but the present disclosure is not limited thereto,
and the third flow path 3b may be provided in, for example, the
pump cover 32.
[0095] For example, the pump device 10 may additionally have a flow
path provided between the outer peripheral surface of the shaft 41
and the inner peripheral surface of the rotor 40 as another flow
path. In addition, for example, a through-hole (not shown) is
provided in the rotor 40, and the through-hole may be used as a
flow path. In this manner, when another flow path is provided in
addition to the first to fourth flow paths, it is possible to
circulate oil between the pump unit 30 and the motor unit 20 more
efficiently and it is possible to cool the motor unit 20 with high
efficiency.
[0096] According to the present example embodiment, the pump device
10 includes the shaft 41 that rotates around the central axis that
extends in the axial direction, the motor unit 20 that rotates the
shaft 41, and the pump unit 30 that is positioned on one side of
the motor unit 20 in the axial direction, is driven by the motor
unit 20 via the shaft 41 and discharges oil. The motor unit 20
includes the rotor 40 that rotates around the shaft 41, the stator
50 that is disposed to face the rotor 40, and the housing 12 in
which the rotor 40 and the stator 50 are accommodated. The pump
unit 30 includes the pump rotor 35 attached to the shaft 41, the
bearing member 31b that rotatably supports the shaft, and pump
cases 31 and 32 in which the suction port 32c into which oil
sucked, and the discharge port 32d from which oil is discharged are
provided and the pump rotor 35 is accommodated. The pump device 10
includes the first oil flow path 1 connecting the inside of the
pump unit 30 and the inside of the housing 12, the second oil flow
path 2 provided between the stator 50 and the rotor 40, and the
third oil flow paths 3a and 3b connected to the suction port 32c of
the pump through the outside of the stator 50 and the rotor 40 in
the radial direction from the second flow path 2. In the first flow
path 1, oil passes through at least one of a space between the
shaft 41 and the bearing member 31b, a space between the bearing
member 31b and the pump case (the pump body 31), and the inside of
the bearing member 31b.
[0097] The pump device 10 allows oil to flow into the motor unit 20
using pressurization by the pump rotor 35. Here, the first flow
path 1 is provided in at least one of a space between the shaft 41
and the bearing member 31b, a space between the bearing member 31b
and the pump case (the pump body 31), and the inside of the bearing
member 31b. That is, in the first flow path 1, oil passes through
at least one of a space between the shaft 41 and the bearing member
31b, a space between the bearing member 31b and the pump case (the
pump body 31), and the inside of the bearing member 31b. When the
first flow path 1 is provided, oil can be sucked into the motor
unit 20 without deteriorating the pressure of the pump, and it is
possible to circulate the oil efficiently. When the oil efficiently
circulates in the motor unit 20, it is possible to prevent
generation of heat in the rotor magnet 44 and it is possible to
prevent demagnetization. In addition, it is possible to provide a
structure in which the rotor 40 and the stator 50 are cooled at the
same time. That is, it is possible to provide a structure having an
excellent cooling effect for preventing the temperature of the
motor unit 20 from increasing.
Second Example Embodiment
[0098] Next, a pump device according to a second example embodiment
of the present disclosure will be described. In the first example
embodiment, the motor unit has an inner rotor type motor
configuration in which the stator is positioned radially outward
from the rotor. On the other hand, a motor unit in the present
example embodiment has an axial gap type motor configuration
including two rotors attached to the shaft 41 with a predetermined
interval in the axial direction and a stator disposed between the
two rotors. Hereinafter, parts different from those in the first
example embodiment will be mainly described. In the pump device
according to the present example embodiment, components the same as
those of the pump device according to the first example embodiment
will be denoted with the same reference numerals and descriptions
thereof will be omitted.
[0099] FIG. 9 is a cross-sectional view showing a pump device 100
of the present example embodiment.
[0100] As shown in FIG. 9, the pump device 100 includes the shaft
41, a motor unit 200, a housing 141, and a pump unit 300. The shaft
41 rotates around the central axis J that extends in the axial
direction. The motor unit 200 and the pump unit 300 are provided in
the axial direction side by side.
[0101] The motor unit 200 includes an upper rotor 401, a lower
rotor 402, a stator 501, an upper bearing member 421, a lower
bearing member 422, a bus bar assembly (not shown), and a connector
(not shown). Both the lower rotor 402 and the upper rotor 401 have
a disk shape that extends in the radial direction. The upper rotor
401 includes a plurality of upper magnets 441 that are arranged in
the circumferential direction on the surface (-Z side surface) that
faces the stator 501 and an upper rotor yoke 431 that holds the
upper magnet 441.
[0102] The lower rotor 402 includes a lower magnet 442 and a lower
rotor yoke 432. The lower rotor 402 includes a plurality of lower
magnet 442 that are arranged in the circumferential direction on
the surface (-Z side surface) that faces the stator 501 and the
lower rotor yoke 432 that holds the lower magnet 442. That is, the
upper magnet 441 and the lower magnet 442 are disposed to face each
other on both surfaces of the stator 501 in the axial direction.
The upper rotor yoke 431 and the lower rotor yoke 432 are coaxially
fixed to the outer peripheral surface of the shaft 41.
[0103] The upper bearing member 421 and the lower bearing member
422 rotatably support the shaft 41. The upper bearing member 421 is
fixed to the housing 141. The stator 501 includes a plurality of
(12 in the second example embodiment) fan-shaped cores in a plan
view arranged in the circumferential direction, coils provided in
the cores, coil lead wires drawn out from the coils of the cores, a
molding resin for integrally fixing the plurality of cores, and a
plurality of lead wire supports provided at the outer peripheral
end of the stator 501.
[0104] The housing 141 constitutes a casing of the motor unit 200.
The stator 501 is held substantially at the center of the housing
141 in the axial direction. The lower rotor 402 is accommodated on
the rear side (-Z side) of the stator 501. Here, a bus bar assembly
(not shown) may be accommodated. The upper rotor 401 is
accommodated on the front side (+Z side) of the stator 501. The
housing 141 has a first housing 121 having a lidded cylindrical
shape of which the rear side is open and a second housing (cover)
131 having a bottomed cylindrical shape connected to the rear side
(-Z side) of the first housing 121. The material of the housing 141
is, for example, a metal or a resin.
[0105] A step part 121c is formed on the inner peripheral surface
of a cylindrical part 121b of the first housing 121. The stator 501
is held by the step part 121c. The first housing 121 includes a
disk-shape top wall 121a and an upper bearing holding part 651
provided at the center of the top wall 121a. The upper bearing
holding part 651 is fitted to the rear side opening of the pump
unit 300. The upper bearing holding part 651 holds the upper
bearing member 421.
[0106] The second housing 131 includes a disk-shaped bottom wall
131a, a cover cylindrical part 131b that extends from the
peripheral part of the bottom wall 131a to the front side (+Z
side), and the lower bearing holding part 652 provided at the
center of the bottom wall 131a. The cover cylindrical part 131b is
fixed to the rear side (-Z side) opening of the first housing 121.
More specifically, the first housing 121 and the second housing 131
are fixed by a method such as bolt fastening using flange parts 111
and 112 of the second housing 131 and flange parts 113 and 114 of
the first housing 121.
[0107] When a bus bar assembly (not shown) is accommodated in the
second housing 131, a through-hole (not shown) penetrating in the
axial direction is provided at the bottom wall 131a of the second
housing 131 and a connector (not shown) is attached to the
through-hole. An external connection terminal (not shown) that
extends from the bus bar assembly to the rear side (-Z side)
through the bottom wall 131a is disposed in the connector.
[0108] The pump unit 300 is positioned on one side of the motor
unit 200 in the axial direction, and specifically, on the front
side (+Z axis side). A pump rotor 351 is driven by the motor unit
200 via the shaft 41. The pump unit 300 includes a pump case, and
the pump rotor 351. The pump case includes a pump body 311 and a
pump cover 321. Hereinafter, the pump body 311 and the pump cover
321 are referred to as a pump case. The pump rotor 351 includes an
inner rotor 371 and an outer rotor 381. The pump cover 321 includes
the suction port 32c and the discharge port 32d. Since respective
members of the pump unit 300 are the same as those of the first
example embodiment, descriptions thereof will be omitted.
[0109] Next, a cooling structure of the pump device 100 according
to the present example embodiment will be described. As in the
first example embodiment, oil supplied from an external device
flows from the suction port 32c to the discharge port 32d due to
the pump rotor 351, and is sucked into the motor unit 200, and
circulates in the motor unit 200, and thus the stator 501, the
upper rotor 401 and the lower rotor 402 are cooled. Hereinafter,
regarding oil flow paths in the pump device 100, description will
focus on parts different from those in the first example
embodiment.
[0110] As shown in FIG. 9, the pump device 100 includes the first
flow path 1 connecting the inside of the pump unit 300 and the
inside of the housing 141, second flow paths 2a and 2b provided
between the stator 501, and the upper rotor 401 and the lower rotor
402, and the third flow paths 3a to 3c connected to the pump
suction port through the inside of the stator 501 and the rotor 401
in the radial direction or the outside thereof in the radial
direction from the second flow path 2a or 2b.
[0111] The first flow path of the present example embodiment is
provided in at least one of a space between the shaft 41 and the
upper bearing member 421, a space between the upper bearing member
421 and the pump case (the pump body 311), and the inside of the
upper bearing member 421. In the example shown in FIG. 9, the first
flow path 1 is provided between the upper bearing member 421
(bearing) and the shaft 41, and between the pump body 311 and the
shaft 41.
[0112] Here, the position of the upper bearing member 421 is not
limited to the position shown in FIG. 9. The pump body 311 may
include the upper bearing member 421. In this case, the first flow
path 1 may be provided between the pump body 311 and the upper
bearing member 421. In addition, the upper bearing member 421 is
not provided and the pump body 311 may have a sliding bearing
structure. In this case, first flow path may be provided between
the shaft 41 and the pump body having a sliding bearing
structure.
[0113] In addition, the upper bearing member 421 may be a ball
bearing. In this case, the first flow path 1 may be provided
between adjacent balls of the ball bearing, that is, inside the
bearing member. Here, a cutout part or a through-hole may be
provided in at least one of the bearing member 421, the pump body
311, and the shaft 41 in which the first flow path 1 is provided.
Since details thereof are the same as those in the first example
embodiment, descriptions thereof will be omitted.
[0114] In the present example embodiment, as shown in FIG. 9, the
second flow path includes the second flow path 2a and the second
flow path 2b. The second flow path 2a, which is the first flow
path, is positioned between the upper rotor 401 and one end of the
stator 501 in the axial direction that faces the upper magnet 441
of the upper rotor 401. The second flow path 2b, which is the
second flow path, is positioned between the lower rotor 402 and one
end of the stator 501 in the axial direction that faces the lower
magnet 442 of the lower rotor 402. Thereby, it is possible to cool
the stator 501, the upper rotor 401, and the lower rotor 402 at the
same time.
[0115] In the present example embodiment, the third flow path
includes the third flow path 3a to the third flow path 3c as shown
in FIG. 9. The third flow path 3a, which is the first flow path, is
positioned between the stator 501 and the shaft 41, that is, inside
of the stator 501, the upper rotor 401, and the lower rotor 402 in
the radial direction. The third flow path 3b, which is the second
flow path, is positioned between the stator 501 and the housing 141
that holds the stator 501.
[0116] That is, the third flow path 3b is positioned radially
outward from the stator 501, the upper rotor 401, and the lower
rotor 402. The third flow path 3c, which is the third flow path, is
provided in the pump body 311 and is a flow path connecting the
third flow path 3b and the inside of the pump unit 300. Here, the
third flow path 3b is provided in the pump body 311 in the example
shown in FIG. 9, but the present disclosure is not limited thereto.
As in the first example embodiment, the third flow path 3c may
include an arbitrary flow path as long as it is a flow path
connecting the third flow path 3b and the suction port 32c of the
pump unit 300. As in the first example embodiment, in the present
example embodiment, the pump device 100 has a structure having an
excellent cooling effect in which the stator 501, the upper side
401 and the lower rotor 402 are cooled at the same time.
[0117] Here, as in the first example embodiment, the stator 501 or
the upper side 401 and the lower rotor 402 may be an integrally
molded article made of a resin. In the case of the integrally
molded article made of a resin, it is possible to increase a
surface area of the stator 501 or the upper side 401 and the lower
rotor 402 in contact with oil. Therefore, it is possible to cool
the inside of the motor unit 200 more efficiently.
[0118] According to the present example embodiment, the pump device
100 includes the shaft 41 that rotates around the central axis that
extends in the axial direction, the motor unit 200 that rotates the
shaft 41, and the pump unit 300 that is positioned on one side of
the motor unit 200 in the axial direction, is driven by the motor
unit 200 via the shaft 41, and discharges oil. The motor unit 200
includes the upper rotor 401 or the lower side 402 that rotates
around the shaft 41, the stator 501 that is disposed to face the
upper rotor 401 or the lower side 402 in the axial direction, and
the housing 141 in which the upper rotor 401 or the lower side 402
and the stator 501 are accommodated. The pump unit 300 includes the
pump rotor 351 attached to the shaft 41, the bearing member 421
that rotatably supports the shaft 41, and pump cases 311 and 321 in
which the suction port 32c into which oil is sucked and the
discharge port 32d from which oil is discharged are provided and
the pump rotor 351 is accommodated. The pump device 100 includes
the first oil flow path 1 connecting the inside of the pump unit
300 and the inside of the housing 141, the second oil flow path 2a
or the second flow path 2b provided between the stator 501 and the
upper rotor 401 or the lower side 402, and the third oil flow path
3a to the third flow path 3c connected to the pump suction port
through the outside of the stator 501 and the upper rotor 401 or
the lower side 402 in the radial direction from the second flow
path 2a or the second flow path 2b. In the first flow path 1, oil
passes through at least one of a space between the shaft 41 and the
bearing member 31b, a space between the bearing member 31b and the
pump case (the pump body 31), and the inside of the bearing member
31b.
[0119] The pump device 100 allows oil to flow into the motor unit
200 using pressurization by the pump rotor 351. Here, the first
flow path 1 is provided in at least one of a space between the
shaft 41 and the bearing member 421, a space between the bearing
member 421 and the pump case (the pump body 311), and the inside of
the bearing member 421. That is, in the first flow path 1, oil
passes through at least one of a space between the shaft 41 and the
bearing member 421, a space between the bearing member 421 and the
pump case (the pump body 311), and the inside of the bearing member
421. When the first flow path 1 is provided, oil can be sucked into
the motor without deteriorating the pressure of the pump, and it is
possible to circulate the oil efficiently. When the oil efficiently
circulates in the motor unit 200, it is possible to prevent
generation of heat in the magnets 441 and 442, and it is possible
to prevent demagnetization. In addition, it is possible to provide
a structure in which the upper rotor 401, the lower rotor 402 and
the stator 501 are cooled at the same time. That is, it is possible
to provide a structure having an excellent cooling effect for
preventing the temperature of the motor unit 200 from
increasing.
[0120] Here, in the present example embodiment, a ring member 601
is provided between the front side one end of the stator 501 in the
axial direction and the top wall 121a of the first housing 121.
Accordingly, the ring member 601 is in contact with the stator 501
and the pump body 311 so that it has an annular contact part, and
as in the first example embodiment, an area into which oil flows
from the first flow path 1 and an area connected from the third
flow path 3b to the third flow path 3c are separated. Thereby, oil
flowing from the first flow path 1 does not flow through the third
flow path 3c. Therefore, in the motor unit 200, not only is it
possible to circulate only oil from the first flow path 1 to the
fourth flow path 4, but it is also possible to provide al
circulation path of oil in the stator 501, the upper rotor 401, and
the lower rotor 402, and a structure having an excellent cooling
effect inside the motor unit 200 is provided.
[0121] Here, as in the first example embodiment in FIG. 8, a
through-hole is provided in the housing 141, and oil from the
second flow path 2b may be discharged to the outside of the housing
141. In this case, a part of the third flow path 3b is positioned
outside the housing 141.
[0122] In addition, while a case in which the stator 501 is fixed
to the cylindrical part 121b which is a side surface of the housing
141 has been described in the pump device 100 of the present
example embodiment, the present disclosure is not limited thereto.
Even if the stator 501 of the pump device 100 is fixed to the shaft
41, the present disclosure can be applied, and the pump device 100
has a cooling structure with similar flow paths.
[0123] In addition, while a case in which the motor unit 200 of the
pump device 100 includes both the upper rotor 401 and the lower
rotor 402 has been described in the present example embodiment, the
present disclosure is not limited thereto. For example, the present
disclosure can also be applied to the pump device 100 including
only the lower rotor 402. In this case, the pump device 100
includes only the second flow path 2b as the second flow path.
Third Example Embodiment
[0124] Next, a pump device according to a third example embodiment
of the present disclosure will be described. In the first example
embodiment, the motor unit 20 of the pump device 10 has an inner
rotor type motor configuration. In the second example embodiment,
the motor unit 200 of the pump device 100 has an axial gap type
motor configuration. On the other hand, the motor unit in the
present example embodiment has an outer rotor type motor
configuration in which a stator is positioned on the inner side of
the rotor in the radial direction. Hereinafter, parts different
from those in the first example embodiment and the second example
embodiment will be mainly described. In the pump device according
to the present example embodiment, components the same as those of
the pump device according to the first example embodiment or the
second example embodiment will be denoted with the same reference
numerals and descriptions thereof will be omitted.
[0125] FIG. 10 is a cross-sectional view showing a pump device 1000
of the present example embodiment.
[0126] The pump device 1000 of the present example embodiment
includes the shaft 41, a motor unit 2000, and the pump unit 300.
The shaft 41 rotates around the central axis J that extends in the
axial direction. The motor unit 2000 and the pump unit 300 are
provided in the axial direction side by side.
[0127] As shown in FIG. 10, the motor unit 2000 includes a housing
1401, a rotor 4000, the stator 5000, a bearing housing 6501, the
upper bearing member 421, the lower bearing member 422, a control
device (not shown), and a bus bar assembly (not shown). Here, the
control device and the bus bar assembly may not be built into the
motor unit 2000, but it may be, for example, attached to the rear
side one end of the housing 1401 in the axial direction or may be
attached to a side surface 1401a of the housing 1401.
[0128] The rotor 4000 includes a rotor magnet 4401 and a rotor yoke
4301. The rotor yoke 4301 has a cup shape (front side opening) and
includes a disc-shaped top plate part 4301b with the center to
which the shaft 41 is connected and a cylindrical part 4301a
provided so that the outer periphery of the top plate part 4301b
extends toward the front side. The rotor magnet 4401 is disposed on
the inner peripheral surface of the cylindrical part 4301a of the
rotor yoke 4301, and the inner peripheral surface thereof faces the
stator 5000 in the radial direction. The rotor 4000 is fixed to the
shaft 41.
[0129] he bearing housing 6501 includes a bearing housing
cylindrical part 6501b having a cylindrical shape, an annular
protrusion 6501a provided on the inner peripheral surface of the
bearing housing cylindrical part 6501b, and a flange part 6501c
provided on the outer peripheral surface of the bearing housing
cylindrical part 6501b. The annular protrusion 6501a protrudes
inward so that the inner diameter of the bearing housing
cylindrical part 6501b decreases.
[0130] On the inner peripheral surface of the bearing housing
cylindrical part 6501b, the upper bearing member 421 is provided on
the front side. On the inner peripheral surface of the bearing
housing cylindrical part 6501b, the lower bearing member 422 is
provided on the rear side. The upper bearing member 421 and the
lower bearing member 422 are fitted to the shaft 41. The upper
bearing member 421 and the lower bearing member 422 support the
shaft 41 so that it is rotatable with respect to the bearing
housing 6501.
[0131] The stator 5000 is fixed to the outer periphery of the
bearing housing 6501. Specifically, the bearing housing 6501 is
fitted into the inner peripheral surface of an annular core back of
the stator 5000. A top wall 1401c of the housing 1401 connected to
the rear side opening of the pump unit 300 is disposed on the front
side of the stator 5000 and supports the bearing housing 6501. The
control device (not shown) is disposed between a bottom wall 1401b
of the housing 1401 and the stator 5000.
[0132] Next, a cooling structure of the pump device 1000 according
to the present example embodiment will be described. As in the
first example embodiment, oil supplied from an external device
flows from the suction port 32c to the discharge port 32d due to
the pump rotor 351, is sucked into the motor unit 2000, and
circulates in the motor unit 2000. According to this circulation,
the stator 5000 and the rotor 4000 are cooled. Hereinafter,
regarding oil flow paths in the pump device 1000, description will
focus on parts different from those in the first example embodiment
and the second example embodiment.
[0133] As shown in FIG. 10, the pump device 1000 includes the first
flow path 1 connecting the inside of the pump unit 300 and the
inside of the housing 1401, the second flow path 2 provided between
the stator 5000 and the rotor 4000, and third flow paths including
the third flow paths 3a and 3b connected to the second flow path 2
through the inside of the stator 5000 and the rotor 4000 in the
radial direction from the first flow path 1 and the third flow path
3c connected to the pump suction port from the second flow path
2.
[0134] The first flow path 1 of the present example embodiment is
provided in at least one of a space between the shaft 41 and the
upper bearing member 421, a space between the upper bearing member
421 and the pump case (the pump body 311), and the inside of the
upper bearing member 421. In the example shown in FIG. 10, the
first flow path 1 is provided between the upper bearing member 421
(bearing) and the shaft 41, and between the pump body 311 and the
shaft 41.
[0135] Here, the position of the upper bearing member 421 is not
limited to the position shown in FIG. 10, and the pump body 311 may
include the upper bearing member 421. In this case, the first flow
path 1 may be provided between the pump body 311 and the upper
bearing member 421. In addition, the upper bearing member 421 is
not provided, and the pump body 311 may have a sliding bearing
structure. In this case, the first flow path 1 may be provided
between the shaft 41 and the pump body.
[0136] In addition, the upper bearing member 421 may be a ball
bearing. In this case, the first flow path 1 may be provided
between adjacent balls of the ball bearing (bearing member), that
is, inside the bearing member. Here, a cutout part or a
through-hole may be provided in at least one of the upper bearing
member 421, the pump body 311, and the shaft 41 in which the first
flow path 1 is provided. Since details thereof are the same as
those in the first example embodiment, descriptions thereof will be
omitted.
[0137] In the present example embodiment, the second flow path 2 is
positioned between the outer peripheral surface of the stator 5000
and the inner peripheral surface of the rotor 4000 as shown in FIG.
10. In the present example embodiment, as shown in FIG. 10, the
third flow path includes three flow paths including the third flow
path 3a to the third flow path 3c. The third flow path 3a, which is
the first flow path, is positioned between the bearing housing 6501
and the shaft 41. The third flow path 3b, which is the second flow
path, is positioned between the stator 5000 and the bearing housing
6501. That is, the third flow path 3a and the third flow path 3b
are both positioned on the inner side of the stator 5000 and the
rotor 4000 in the radial direction and are flow paths connected to
the second flow path 2 through the inner side of the stator 5000
and the rotor 4000 in the radial direction from the first flow path
1.
[0138] The third flow path 3c, which is the third flow path, is a
flow path connected from the second flow path 2 to the pump suction
port. Here, the third flow path 3c is provided in the pump body 311
in the example shown in FIG. 10, but the present disclosure is not
limited thereto. The third flow path 3c may include an arbitrary
flow path as long as it is a flow path connecting the second flow
path 2 and the suction port of the pump unit 300. In the present
example embodiment, as in the first example embodiment and the
second example embodiment, the pump device 1000 has a structure
having an excellent cooling effect in which the stator 5000 and the
rotor 4000 are cooled at the same time.
[0139] In the present example embodiment, oil flowing into the
first flow path 1 flows through the second flow path 2 through the
third flow path 3a or the third flow path 3b. Then, the second flow
path 2 is connected to the third flow path 3c and the oil is
returned to the pump unit 300. Here, the oil may flow from the
second flow path 2 to the outer peripheral surface of the rotor
yoke 4301 and the inner peripheral surface of the housing 1401. In
this case, the oil accumulates on the bottom wall 1401b of the
housing 1401 and eventually, the oil flows in a direction of the
pump unit 300 between the outer peripheral surface of the rotor
yoke 4301 and the inner peripheral surface of the housing 1401.
Arrows indicating flow paths between the rotor yoke 4301 and the
housing 1401 as shown in FIG. 10 indicate the above case.
[0140] Here, as in the first example embodiment (FIG. 8) and the
second example embodiment (FIG. 9), a through-hole is provided in
the housing 1401, and oil from the second flow path 2 may be
discharged to the outside of the housing 1401. In this case, the
third flow path is positioned outside the housing 141, and is
positioned radially outward from the stator 5000 and the rotor
4000. In addition, as in the first example embodiment, the stator
5000 and the rotor 4000 may be an integrally molded article made of
a resin. In the case of the integrally molded article made of a
resin, it is possible to increase a surface area of the stator or
the rotor in contact with oil. Therefore, it is possible to cool
the inside of a motor unit 2001 more efficiently.
[0141] According to the present example embodiment, the pump device
1000 includes the shaft 41 that rotates around the central axis
that extends in the axial direction, the motor unit 2000 that
rotates the shaft 41, and the pump unit 300 that is positioned on
one side of the motor unit 2000 in the axial direction, is driven
by the motor unit 2000 via the shaft 41, and discharges oil. The
motor unit 2000 includes the rotor 4000 that rotates around the
shaft 41, the stator 5000 that is disposed to face the rotor 4000,
and the housing 1401 in which the rotor 4000 and the stator 5000
are accommodated. The pump unit 300 includes the pump rotor 351
attached to the shaft 41, the upper bearing member 421 that
rotatably supports the shaft 41, and pump cases 311 and 321 in
which the suction port 32c into which oil is sucked and the
discharge port 32d from which oil is discharged are provided and
the pump rotor 351 is accommodated. The pump device 1000 includes
the first oil flow path 1 connecting the inside of the pump unit
300 and the inside of the housing 1401, the second oil flow path 2
provided between the stator 5000 and the rotor 4000, and the third
oil flow paths 3a to 3c including the third flow paths 3a and 3b
connected to the second flow path 2 through the inside of the
stator 5000 and the rotor 4000 in the radial direction from the
first flow path 1 and the third flow path 3c connected to the pump
suction port from the second flow path 2. In the first flow path 1,
oil passes through at least one of a space between the shaft 41 and
the upper bearing member 421, a space between the upper bearing
member 421 and the pump case 311, and the inside of the upper
bearing member 421.
[0142] The pump device 1000 allows oil to flow into the motor unit
2000 using pressurization by the pump rotor 351. Here, the first
flow path 1 is provided in at least one of a space between the
shaft 41 and the bearing member (the upper bearing member 421), a
space between the bearing member (the upper bearing member 421) and
the pump case (the pump body 31), and the inside of the bearing
member (the upper bearing member 421). That is, in the first flow
path, oil passes through at least one of a space between the shaft
and bearing member (the upper bearing member 421), a space between
the bearing member (the upper bearing member 421) and the pump case
(the pump body 31) and the inside of the bearing member (the upper
bearing member 421). When the first flow path 1 is provided, oil
can be sucked into the motor unit 2000 without deteriorating the
pressure of the pump, and it is possible to circulate the oil
efficiently. When the oil efficiently circulates in the motor unit
2000, it is possible to prevent generation of heat in the rotor
magnet 4401 and it is possible to prevent demagnetization. In
addition, it is possible to provide a structure in which the rotor
4000 and the stator 5000 are cooled at the same time. That is, it
is possible to provide a structure having an excellent cooling
effect for preventing the temperature of the motor unit 2000 from
increasing.
[0143] FIG. 11 is a cross-sectional view of another pump device
1001 according to the present example embodiment.
[0144] The pump device 1001 of the present example embodiment
includes the shaft 41, the motor unit 2001, and the pump unit 300.
The shaft 41 rotates around the central axis J that extends in the
axial direction. The motor unit 2001 and the pump unit 300 are
provided in the axial direction side by side.
[0145] The motor unit is different between the pump device 1000
shown in FIG. 10 and the pump device 1001 shown in FIG. 11.
Components the same as those in FIG. 10 are denoted with the same
reference numerals and descriptions thereof will be omitted. As
shown in FIG. 11, the motor unit 2001 includes a housing 1402, a
rotor 4001, the stator 5000, a bearing housing 6502, the upper
bearing member 421, the lower bearing member 422, a control device
(not shown), and a bus bar assembly (not shown). Here, the control
device and the bus bar assembly need not to be built into the motor
unit 2001, and may be, for example, attached to the rear side one
end of the housing 1402 in the axial direction or attached to a
side surface 1402a of the housing 1402.
[0146] The rotor 4001 includes a rotor magnet 4402 and a rotor yoke
4302. Unlike the pump device 1000 in FIG. 10, the rotor yoke 4302
has a cup shape with a rear side opening and includes a disc-shaped
top plate part 4302b with the center to which the shaft 41 is
connected and a cylindrical part 4302a provided so that the outer
periphery of the top plate part 4302b extends toward the rear side.
The rotor magnet 4402 is disposed on the inner peripheral surface
of the cylindrical part 4302a of the rotor yoke 4302 and the inner
peripheral surface thereof aces the stator 5000 in the radial
direction. The rotor 4001 is fixed to the shaft 41.
[0147] The bearing housing 6502 includes a bearing housing
cylindrical part 6502b having a cylindrical shape, an annular
protrusion 6502a provided on the inner peripheral surface of the
bearing housing cylindrical part 6502b, and a flange part 6502c
provided on the outer peripheral surface of the bearing housing
cylindrical part 6502b. The annular protrusion 6502a protrudes
inward so that the inner diameter of the bearing housing
cylindrical part 6502b decreases.
[0148] On the inner peripheral surface of the bearing housing
cylindrical part 6502b, the lower bearing member 422 is provided on
the rear side. On the inner peripheral surface of the bearing
housing cylindrical part 6502b, the upper bearing member 421 is
provided on the front side. The upper bearing member 421 and the
lower bearing member 422 are fitted to the shaft 41. The upper
bearing member 421 and the lower bearing member 422 support the
shaft 41 so that it is rotatable with respect to the bearing
housing 6502.
[0149] The stator 5000 is fixed to the outer periphery of the
bearing housing 6502. Specifically, the bearing housing 6502 is
fitted into the inner peripheral surface of an annular core back
part (not shown) of the stator 5000. A bottom wall 1402b of the
housing 1402 is disposed on the rear side of the stator 5000 and
supports the bearing housing 6502. The control device (not shown)
is disposed between the bottom wall 1402b of the housing 1402 and
the stator 5000.
[0150] Next, a cooling structure of the pump device 1001 according
to the present example embodiment will be described. Parts
different from those in FIG. 10 will be mainly described. As shown
in FIG. 11, the pump device 1001 includes the first flow path 1
connecting the inside of the pump unit 300 and the inside of the
housing 1402, the second flow path 2 provided between the stator
5000 and the rotor 4001, and the third flow paths 3a to 3c
connected to the suction port (pump suction port) 32c of the pump
unit 30 through the inside of the stator 5000 and the rotor 4001 in
the radial direction and the outside thereof in the radial
direction from the second flow path 2.
[0151] The first flow path 1 of the present example embodiment is
provided in at least one of a space between the shaft 41 and the
pump body 311 as a bearing member or the upper bearing member 421,
a space between the upper bearing member 421 and the pump body 311,
and the inside of the upper bearing member 421. In the example
shown in FIG. 11, the pump body 311 has a sliding bearing
structure, and the first flow path 1 is provided between the shaft
41 and the pump body 311 functioning as a bearing member.
[0152] Here, the position of the upper bearing member 421 is not
limited to the position shown in FIG. 11. The pump body 311 may
include the upper bearing member 421. In this case, the first flow
path 1 may be provided between the pump body 311 and the upper
bearing member 421. In addition, the upper bearing member 421 may
be a ball bearing.
[0153] When the pump body 311 includes the upper bearing member 421
and the upper bearing member 421 is a ball bearing, the first flow
path 1 may be provided between adjacent balls of the ball bearing,
that is, inside the ball bearing. Here, a cutout part or a
through-hole may be provided in at least one of the upper bearing
member 421, the pump body 311, and the shaft 41 in which the first
flow path 1 is provided. Since details thereof are the same as
those in the first example embodiment, descriptions thereof will be
omitted.
[0154] In the present example embodiment, oil flowing from the
first flow path 1 into the motor unit 2001 flows along the top
plate part 4302b of the rotor yoke 4302 and flows between the
cylindrical part 4302a and a side surface 1402a of the housing
1402. In the present example embodiment, the ring member 6502
connecting the rear side coil end of the stator 5000 and a side
surface of the housing 1402 is provided. Accordingly, oil flowing
between the cylindrical part 4302a of the rotor yoke 4302 and the
side surface 1402a of the housing 1402 flows through the second
flow path 2 provided between the stator 5000 and the rotor
4001.
[0155] In the present example embodiment, the third flow paths are
flow paths connected to the suction port (pump suction port) 32c of
the pump unit 300 through the inside of the stator 5000 and the
rotor 4001 in the radial direction and the outside thereof in the
radial direction from the second flow path 2, and include the third
flow path 3a to the third flow path 3c in the example shown in FIG.
11. The third flow path 3a is provided between the stator 5000 and
the shaft 41. That is, the third flow path 3a is positioned
radially inward from the stator 5000 and the rotor 4001.
[0156] The third flow path 3b is provided outside the housing 1402
via a through-hole 1402c provided on the side surface 1402a of the
housing 1402. Like the case described with reference to FIG. 8 in
the first example embodiment, the flow path provided outside the
housing 1402 may include an arbitrary flow path connecting the
first through-hole 1402c and a second through-hole 321c.
[0157] In addition, the positions of the first through-hole 1402c
and the second through-hole 321c are not limited to the positions
shown in FIG. 11, and they may be provided at arbitrary positions
on the side surface 1402a of the housing 1402 or the pump cover
321. The third flow path 3c is provided in the pump body 311 and
connects the second through-hole 321c and the inside of the pump
unit 300. When the third flow path 3c is provided, oil sucked into
the motor unit 2001 through the first flow path 1 can circulate
from the inside of the motor unit 2001 to the inside of the pump
unit 300.
[0158] Accordingly, it is possible to efficiently cool the stator
5000 and the rotor 4001. Here, in the example shown in FIG. 11, the
third flow path 3c is provided in the pump body 311, but the
present disclosure is not limited thereto. The third flow path 3c
may include an arbitrary flow path outside the pump device 1001 as
long as it is a flow path connected to the pump suction port from
the third flow path 3b.
[0159] According to the present example embodiment, as in the first
example embodiment and the second example embodiment, the pump
device 1001 has a structure having an excellent cooling effect in
which the stator 5000 and the rotor 4001 are cooled at the same
time. Here, as in the first example embodiment, the stator 5000 and
the rotor 4001 may be an integrally molded article made of a resin.
In the case of the integrally molded article made of a resin, it is
possible to increase a surface area of the stator 5000 or the rotor
4001 in contact with oil. Therefore, it is possible to cool the
inside of the motor unit 2001 more efficiently.
[0160] According to the present example embodiment, the pump device
1001 includes the shaft 41 that rotates around the central axis
that extends in the axial direction, the motor unit 2001 that
rotates the shaft 41, and the pump unit 300 that is positioned on
one side of the motor unit 2001 in the axial direction, is driven
by the motor unit 2001 via the shaft 41, and discharges oil. The
motor unit 2001 includes the rotor 4001 that rotates around the
shaft 41, the stator 5000 that is disposed to face the rotor 4001,
and the housing 1402 in which the rotor 4001 and the stator 5000
are accommodated. The pump unit 300 includes the pump rotor 351
attached to the shaft 41, the upper bearing member 421 that
rotatably supports the shaft 41, and pump cases 311 and 321 in
which the suction port 32c into which oil is sucked and the
discharge port 32d from which oil is discharged are provided and
the pump rotor 351 is accommodated. The pump device 1001 includes
the first oil flow path 1 connecting the inside of the pump unit
300 and the inside of the housing 1402, the second oil flow path 2
provided between the stator 5000 and the rotor 4001, and the third
oil flow path 3a to the third flow path 3c connected to the suction
port 32c of the pump unit 300 through the inside of the stator 5000
and the rotor 4001 in the radial direction and the inside thereof
in the radial direction from the second flow path 2. In the first
flow path 1, oil passes through at least one of a space between the
shaft 41 and bearing member (the upper bearing member 421), a space
between the bearing member (the upper bearing member 421) and the
pump case (the pump body 31) and the inside of the bearing member
(the upper bearing member 421).
[0161] The pump device 1001 allows oil to flow into the motor unit
2001 using pressurization by the pump rotor 351. Here, the first
flow path 1 is provided in at least one of a space between the
shaft 41 and the bearing member (the upper bearing member 421), a
space between the bearing member (the upper bearing member 421) and
the pump case (the pump body 31), and the inside of the bearing
member (the upper bearing member 421). That is, in the first flow
path 1, oil passes through at least one of a space between the
shaft 41 and bearing member (the upper bearing member 421), a space
between the bearing member (the upper bearing member 421) and the
pump case (the pump body 31) and the inside of the bearing member
(the upper bearing member 421). When the first flow path 1 is
provided, oil can be sucked into the motor unit 1001 without
deteriorating the pressure of the pump, and it is possible to
circulate the oil efficiently. When the oil efficiently circulates
in the motor unit 2001, it is possible to prevent generation of
heat in the rotor magnet 4402 and it is possible to prevent
demagnetization. In addition, it is possible to provide a structure
in which the rotor 4001 and the stator 5000 are cooled at the same
time. That is, it is possible to provide a structure having an
excellent cooling effect for preventing the temperature of the
motor unit 2001 from increasing.
[0162] While preferable example embodiments of the present
disclosure have been described above, the present disclosure is not
limited to these example embodiments, and various modifications and
changes can be made within the spirit and scope of the
disclosure.
[0163] Priority is claimed on Japanese Patent Application No.
2016-195283, filed Sep. 30, 2016, the content of which is
incorporated herein by reference.
[0164] While example embodiments of the present disclosure have
been described above, it is to be understood that variations and
modifications will be apparent to those skilled in the art without
departing from the scope and spirit of the present disclosure. The
scope of the present disclosure, therefore, is to be determined
solely by the following claims.
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