Motor unit

Abstract

The present invention provides a motor unit comprising: a motor; a housing having a housing space for housing the motor; oil accumulating in a region on the lower vertical side of the housing space; and an oil passage that guides the oil from the region on the lower vertical side of the housing space and supplies the oil to the motor, wherein the motor comprises: a rotor that rotates about a motor axis; and a stator located radially outside the rotor, the rotor comprising: a shaft extending along the motor axis; a rotor core surrounding the shaft from the outer radial side; a rotor magnet fixed to the rotor core; and a plate-shaped end plate located on the axial end face of the rotor core, the end plate having: a first surface facing the axial end face of the rotor core; and a second surface facing the side opposite to the first surface, wherein an oil flow path extending radially and opening is provided on the end plate.

Description

[0001] This application is a divisional application of the application for an invention patent for which application number is 201780049229.6 (international application number PCT / JP2017 / 028690), date of filing is August 8, 2017, and the name of the invention is "Motor unit". TECHNICAL FIELD

[0002] The present application relates to a motor unit. BACKGROUND

[0003] In Japanese Patent No. 3570450, a motor is disclosed in which oil accumulated in a gear case is lifted by rotation of a gear and introduced into a flow path inside a shaft.

[0004] In the conventional configuration, when viewed in the axial direction, the central axis of the motor, the central axis of the reduction device, and the central axis of the differential device are arranged in order along the horizontal direction. Therefore, there is a problem that the distance between the central axis of the differential device and the central axis of the motor is large, and oil lifted by the differential device is not easily supplied to the gear of the motor shaft. SUMMARY

[0005] One embodiment of the present application, which is made in view of the above-described problems, has an object to provide a motor unit capable of effectively supplying oil to the tooth surface of the gear of each shaft.

[0006] One embodiment of the exemplified motor unit of the present application has a motor having a rotor that rotates with a motor axis as the center, a reduction device connected to the motor and having an intermediate gear that rotates with an intermediate axis as the center, a differential device connected to the reduction device and having a ring gear that rotates with a differential axis as the center, a housing provided with a housing space that houses the motor and the differential device, oil accumulated in a region on the lower side in the vertical direction of the housing space, and an oil passage that guides the oil from the region on the lower side in the vertical direction of the housing space and supplies the oil to the motor, at least a part of the ring gear is located at a position on the lower side than the liquid surface of the oil accumulated in the region on the lower side in the vertical direction of the housing space, the motor axis, the intermediate axis, and the differential axis extend in parallel with each other in the horizontal direction, the intermediate axis and the differential axis are located on the lower side with respect to the motor axis, and when a line segment that virtually links the motor axis and the intermediate axis is regarded as a first line segment, a line segment that virtually links the intermediate axis and the differential axis is regarded as a second line segment, and a line segment that virtually links the motor axis and the differential axis is regarded as a third line segment, the first line segment extends in the substantially vertical direction, and the second line segment extends in the substantially horizontal direction.

[0007] According to one embodiment of the present application, a motor unit is provided which is capable of effectively supplying oil to the tooth surfaces of the gears of each shaft.

[0008] The above and other features, elements, steps, characteristics and advantages of the present application will become more apparent from the following detailed description of preferred embodiments of the present application with reference to the attached drawings. BRIEF DESCRIPTION OF DRAWINGS

[0009] Figure 1 FIG. 1 is a schematic view of a motor unit of one embodiment.

[0010] Figure 2 FIG. 2 is a perspective view of the motor unit of one embodiment.

[0011] Figure 3 FIG. 3 is a side view of the motor unit of one embodiment.

[0012] Figure 4 FIG. 4 is a cross-sectional view of the motor unit taken along the IV-IV line of FIG. 1. Figure 3

[0013] Figure 5 FIG. 5 is a cross-sectional view of the rotor of one embodiment.

[0014] Figure 6 FIG. 6 is a plan view of an end plate.

[0015] Figure 7 FIG. 7 is a cross-sectional view of the end plate taken along the VII-VII line of FIG. 6. Figure 6

[0016] Figure 8 FIG. 8 is a cross-sectional view of the end plate of a first modification.

[0017] Figure 9 FIG. 9 is a plan view of the end plate of a second modification.

[0018] Figure 10 FIG. 10 is a cross-sectional view of the motor unit of one embodiment, which is a view showing a second oil passage.

[0019] Figure 11 FIG. 11 is a perspective view of the motor unit of one embodiment, in which a portion of the housing is omitted.

[0020] Figure 12 FIG. 12 is a plan view of a second reservoir of one embodiment.

[0021] Figure 13 FIG. 13 is a perspective view of the second reservoir of a modification.

[0022] Figure 14 FIG. 14 is a cross-sectional view of the motor unit of one embodiment, which is a view showing an outline of a sub-reservoir.

[0023] ​​Figure 15 is a front view of the partition wall opening of one embodiment.

[0024] Figure 16 is a graph showing a relationship between a height of a level of oil accumulated on a lower side of a motor chamber in a motor unit provided with the partition wall opening of one embodiment and an area of the first region.

[0025] Figure 17 is a front view of the partition wall opening of a modification.

[0026] Figure 18 is a graph showing a relationship between a height of a level of oil accumulated on a lower side of a motor chamber in a motor unit provided with the partition wall opening of the modification and an area of the first region.

[0027] Figure 19 is a side view showing a configuration of each gear located inside a gear chamber in the motor unit of one embodiment.

[0028] Figure 20 is a plan view of a parking mechanism that can be employed in the motor unit of one embodiment.

[0029] Figure 21 is a partial cross-sectional view showing the cut-off mechanism of the motor unit of Modification 1.

[0030] Figure 22 is a schematic view showing a state in which the motor and the speed reducer are connected by the cut-off mechanism.

[0031] Figure 23 is a schematic view showing a state in which the motor and the speed reducer are cut off by the cut-off mechanism. DETAILED DESCRIPTION

[0032] Hereinafter, a motor of an embodiment of the present application will be described with reference to the drawings. In addition, the scope of the present application is not limited to the following embodiment, and can be arbitrarily changed within the scope of the technical idea of the present application. In addition, in the following drawings, the scale or the number or the like in each configuration is sometimes made different from that of the actual configuration in order to easily understand each configuration.

[0033] In the following description, the gravitational direction is defined and described based on the positional relationship in the case where the motor unit 1 is mounted on a vehicle located on a horizontal road surface. 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 indicates the vertical direction (i.e., the up-down direction), the +Z direction is the upper side (the opposite side of the gravitational direction), and the -Z direction is the lower side (the gravitational direction). In addition, the X-axis direction is a direction perpendicular to the Z-axis direction, indicates the front-rear direction of the vehicle on which the motor unit 1 is mounted, the +X direction is the front of the vehicle, and the -X direction is the rear of the vehicle. However, it can also be that the +X direction is the rear of the vehicle and the -X direction is the front of the vehicle. The Y-axis direction is a direction perpendicular to both the X-axis direction and the Z-axis direction, and is the width direction (the left-right direction) of the vehicle.

[0034] In the following description, unless otherwise specified, the direction parallel to the motor axis J2 of the motor 2 (the Z-axis direction) is simply referred to as the "axial direction", the radial direction centered on the motor axis J2 is simply referred to as the "radial direction", and the circumferential direction centered on the motor axis J2, i.e., the direction around the motor axis J2 is simply referred to as the "circumferential direction". In addition, in the following description, "plan view" refers to a state observed in the axial direction. However, the "parallel direction" described above also includes a substantially parallel direction. In addition, the "perpendicular direction" described above also includes a substantially perpendicular direction.

[0035] Hereinafter, the motor unit (electric drive device) 1 of one embodiment of the present application will be described with reference to the drawings.

[0036] Figure 1 is a schematic view of the motor unit 1 of one embodiment. Figure 2 is a perspective view of the motor unit 1. Figure 3 is a side view of the motor unit 1. Figure 4 is a cross-sectional view of the motor unit 1 taken along the IV-IV line of Figure 3 . In Figure 4 , a part of the internal structure of the differential device 5 is omitted.

[0037] The motor unit 1 is mounted on a vehicle, such as a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHV), an electric vehicle (EV), or the like, which uses a motor as a power source, and is used as the power source thereof.

[0038] As shown in Figure 1 , the motor unit 1 includes a motor (main motor) 2, a reduction device 4, a differential device 5, a housing 6, oil O, and an oil passage 90 that supplies the oil O to the motor 2. In addition, the motor unit 1 can have a parking mechanism 7 as indicated by the dashed line in Figure 2 .

[0039] As shown in Figure 1As shown, the motor 2 has a rotor 20 that rotates about a motor axis J2 extending in the horizontal direction, and a stator 30 located radially outward of the rotor 20. The reduction device 4 is connected to the rotor 20 of the motor 2. The differential device 5 is connected to the motor 2 via the reduction device 4. A housing 6 has a receiving space 80 in which the motor 2, the reduction device 4, and the differential device 5 are received. Oil O is used for lubrication of the reduction device 4 and the differential device 5, and for cooling of the motor 2. The oil O is accumulated in a region on the lower side in the vertical direction of the receiving space 80. The oil O functions as both a lubricating oil and a cooling oil, and therefore it is preferable to use oil equivalent to Automatic Transmission Fluid (ATF) having low viscosity. An oil passage 90 is a path through which the oil O is supplied from the region on the lower side of the receiving space 80 to the motor 2. The oil passage 90 has a first oil passage 91 and a second oil passage 92.

[0040] In addition, in the present specification, an "oil passage" refers to a path of the oil O circulating in the receiving space 80. Therefore, the "oil passage" is a concept that includes not only a "flow path" that forms a stable flow of oil in one direction, but also a path in which oil is temporarily retained (for example, an oil reservoir) and a path in which oil droplets fall.

[0041] <HOUSING>

[0042] The motor 2, the reduction device 4, and the differential device 5 are received in a receiving space 80 provided inside the housing 6. The housing 6 holds the motor 2, the reduction device 4, and the differential device 5 in the receiving space 80. The housing 6 has a partition wall 61c. The receiving space 80 of the housing 6 is divided into a motor chamber 81 and a gear chamber 82 by the partition wall 61c. The motor 2 is received in the motor chamber 81. The reduction device 4 and the differential device 5 are received in the gear chamber 82.

[0043] An oil storage portion P in which the oil O is accumulated is provided in a region on the lower side of the receiving space 80. In the present embodiment, a bottom portion 81a of the motor chamber 81 is located at a position higher than a bottom portion 82a of the gear chamber 82. In addition, an opening 68 of the partition wall is provided in a region on the lower side of the partition wall 61c that divides the motor chamber 81 and the gear chamber 82. The opening 68 of the partition wall 61c communicates the motor chamber 81 with the gear chamber 82. The opening 68 of the partition wall 61c moves the oil O accumulated in the region on the lower side of the motor chamber 81 to the gear chamber 82. Therefore, in the present embodiment, the oil storage portion P is provided in a region on the lower side of the gear chamber 82.

[0044] A part of the differential device 5 is immersed in the oil reservoir portion P. The oil O stored in the oil reservoir portion P is lifted by the operation of the differential device 5, and a part of the oil O is supplied to the first oil passage 91, and a part of the oil O is diffused into the gear chamber 82. The oil O diffused into the gear chamber 82 is supplied to each gear of the reduction device 4 and the differential device 5 in the gear chamber 82, and the oil O is spread to the tooth surfaces of the gears. The oil O for the reduction device 4 and the differential device 5 drips down and is recovered to the oil reservoir portion P located on the lower side of the gear chamber 82. The capacity of the oil reservoir portion P of the accommodation space 80 is set to the extent that a part of the bearings of the differential device 5 is immersed in the oil O at the time of stop of the motor unit 1.

[0045] The housing 6 is, for example, an aluminum die cast. The housing 6 constitutes an outer frame of the motor unit 1. The housing 6 has a motor accommodation portion 61, a gear accommodation portion 62, and a closing portion 63. The gear accommodation portion 62 is located on the left side of the motor accommodation portion 61. The closing portion 63 is located on the right side of the motor accommodation portion 61.

[0046] The motor accommodation portion 61 has a cylindrical peripheral wall portion 61a that surrounds the motor 2 from the radially outer side, and a side plate portion 61b that is located on the axial one side of the peripheral wall portion 61a. The space on the inner side of the peripheral wall portion 61a constitutes a motor chamber 81. The side plate portion 61b has a partition wall 61c and a protruding plate portion 61d. The partition wall 61c covers the opening on the axial one side of the peripheral wall portion 61a. On the partition wall 61c, in addition to the above-mentioned partition wall opening 68, a through-insertion hole 61f is provided through which the shaft 21 of the motor 2 is inserted. The side plate portion 61b has the partition wall 61c and the protruding plate portion 61d that protrudes to the radially outer side with respect to the peripheral wall portion 61a. On the protruding plate portion 61d, a first axle passing hole 61e is provided through which a drive shaft (not shown) that supports a wheel passes.

[0047] The closing portion 63 is fixed to the motor accommodation portion 61. The closing portion 63 closes the opening on the axially opposite side of the peripheral wall portion 61a. That is, the closing portion 63 closes the opening of the cylindrical motor accommodation portion 61. The closing portion 63 has a closing portion main body 63a and a cover member 63b. The closing portion main body 63a has a cylindrical protruding portion 63d that protrudes to the accommodation space 80 located on the inner side of the motor accommodation portion 61. The protruding portion 63d extends along the inner peripheral surface of the peripheral wall portion 61a. In addition, on the closing portion main body 63a, a window portion 63c that penetrates in the axial direction is provided. The cover member 63b closes the window portion 63c from the outside of the accommodation space 80.

[0048] The gear housing 62 is fixed to the side plate 61b of the motor housing 61. The gear housing 62 has a concave shape that opens toward the side plate 61b. The opening of the gear housing 62 is covered by the side plate 61b. The space between the gear housing 62 and the side plate 61b forms a gear chamber 82 for housing the reduction gear 4 and the differential gear 5. A second axle passage hole 62e is provided in the gear housing 62. When viewed axially, the second axle passage hole 62e overlaps with the first axle passage hole 61e.

[0049] like Figure 3 As shown, the gear housing 62 has a first reservoir 93 and a shaft supply flow path 94. The first reservoir 93 is located on the axial side of the gear housing 62 facing the gear chamber 82 and extends axially. The first reservoir 93 receives oil O lifted by the differential device 5. The shaft supply flow path 94 extends from the bottom of the first reservoir 93 toward the shaft 21 of the motor 2. The shaft supply flow path 94 is a flow path that supplies the oil O received in the first reservoir 93 to the inside of the hollow portion 22 of the shaft 21.

[0050] <Speed ​​Reduction Device>

[0051] like Figure 4 As shown, the reduction gear 4 has the function of reducing the speed of the motor 2 and increasing the torque output from the motor 2 according to the reduction ratio. The reduction gear 4 transmits the torque output from the motor 2 to the differential gear 5.

[0052] The reduction gear 4 includes a first gear (intermediate drive gear) 41, a second gear (intermediate gear) 42, a third gear (final drive gear) 43, and an intermediate shaft 45. The torque output from the motor 2 is transmitted to the ring gear 51 of the differential gear 5 via the motor 2 shaft 21, the first gear 41, the second gear 42, the intermediate shaft 45, and the third gear 43. The gear ratio and number of gears can be varied according to the desired reduction ratio. The reduction gear 4 is a parallel-shaft gear type reducer with the shafts of each gear arranged in parallel.

[0053] The first gear 41 is disposed on the outer circumferential surface of the shaft 21 of the motor 2. The first gear 41 and the shaft 21 rotate together about the motor axis J2.

[0054] The intermediate shaft 45 extends along an intermediate axis J4 parallel to the motor axis J2. The intermediate shaft 45 is cylindrical in shape and centered on the intermediate axis J4. The intermediate shaft 45 rotates around the intermediate axis J4. The intermediate shaft 45 is supported by a pair of intermediate shaft retaining bearings 87 for free rotation. One of the pair of intermediate shaft retaining bearings 87 is held on the side of the spacer wall 61c facing the gear chamber 82. The other of the pair of intermediate shaft retaining bearings 87 is held in the gear housing 62.

[0055] The second gear 42 and the third gear 43 are disposed on the outer peripheral surface of the intermediate shaft 45. The second gear 42 and the third gear 43 are connected via the intermediate shaft 45. The second gear 42 and the third gear 43 rotate about the intermediate axis J4. The second gear 42 meshes with the first gear 41. The third gear 43 meshes with the ring gear 51 of the differential device 5. The third gear 43 is located on the side of the spacer wall 61c relative to the second gear 42. In this embodiment, the intermediate shaft 45 and the third gear 43 are a single component.

[0056] <Differential Device>

[0057] The differential 5 is a device used to transmit the torque output from the motor 2 to the wheels of the vehicle. The differential 5 has the following functions: when the vehicle is turning, it absorbs the speed difference between the left and right wheels and transmits the same torque to the axles 55 of both wheels. The differential 5 includes: a ring gear 51, a gear housing 57, a pair of pinions (not shown), a pinion shaft (not shown), and a pair of half-shaft gears (not shown).

[0058] The ring gear 51 rotates around a differential axis J5 parallel to the motor axis J2. The torque output from the motor 2 is transmitted to the ring gear 51 via the reduction gear 4. That is, the ring gear 51 is connected to the motor 2 via other gears. The ring gear 51 is fixed to the outer periphery of the gear housing 57.

[0059] The gear housing 57 houses a pair of pinions and a pair of half-shaft gears. When torque is transmitted to the ring gear 51, the gear housing 57 rotates together with the ring gear 51 about the differential axis J5.

[0060] The pair of pinions are bevel gears facing each other. The pair of pinions are supported on the pinion shaft.

[0061] A pair of half-shaft gears are bevel gears that mesh at right angles with a pair of pinions. Each half-shaft gear has a meshing portion. An axle is meshed into each of these meshing portions. The pair of axles meshing into their different meshing portions rotate about the differential axis J5 with the same torque.

[0062] <Motor>

[0063] like Figure 4 As shown, motor 2 is an internal rotor type motor, which has: a stator 30; and a rotor 20, which is rotatably disposed inside the stator 30. The rotor 20 rotates by supplying power to the stator 30 from a battery (not shown). The torque of motor 2 is transmitted to differential device 5 via reduction gear 4.

[0064] (stator)

[0065] The stator 30 has a stator core 32, a coil 31, and an insulating member (omitted from the drawing) interposed between the stator core 32 and the coil 31. The stator 30 is held to the housing 6.

[0066] The stator core 32 has a plurality of magnetic pole teeth (omitted from the drawing) from the inner peripheral surface of the yoke toward the radially inner side. In the stator core 32 of the present embodiment, the number of slots formed between the magnetic pole teeth and the magnetic pole teeth is 48. The coil 31 is constituted by winding a coil wire between the magnetic pole teeth.

[0067] The coil 31 has a coil end portion 31a protruding from the axial end surface of the stator core 32. That is, the stator 30 has the coil end portion 31a. The coil end portion 31a protrudes in the axial direction more than the end portion of the rotor core 24 of the rotor 20. The coil end portion 31a protrudes to both sides in the axial direction with respect to the rotor core 24.

[0068] (Rotor)

[0069] The rotor 20 has a shaft (motor shaft) 21, a rotor core 24, a rotor magnet (permanent magnet) 25, a pair of plate-shaped end plates 26, a nut 29, and a washer (cover portion) 28.

[0070] (Shaft)

[0071] The shaft 21 extends around the motor axis J2 extending in the horizontal direction and in the width direction of the vehicle (direction perpendicular to the traveling direction of the vehicle). The shaft 21 has a first shaft portion 21A and a second shaft portion 21B joined to each other on the same axis.

[0072] The shaft 21 is a hollow shaft in which a hollow portion 22 having an inner peripheral surface extending along the motor axis J2 is provided inside. The hollow portion 22 includes a first hollow portion 22A located inside the first shaft portion 21A and a second hollow portion 22B located inside the second shaft portion 21B. The first hollow portion 22A and the second hollow portion 22B are arranged along the axial direction and communicate with each other.

[0073] The first shaft portion 21A is disposed in the motor chamber 81 of the accommodation space 80. The first shaft portion 21A is located radially inside the stator 30 and penetrates the rotor core 24 along the motor axis J2. The first shaft portion 21A has a first end portion 21e located on the output side (i.e., the side of the speed reduction device 4) and a second end portion 21f located on the opposite side thereof.

[0074] The first shaft portion 21A is rotatably supported by a pair of first bearings 89. The pair of first bearings 89 supports the first end portion 21e and the second end portion 21f of the first shaft portion 21A. One of the pair of first bearings 89 is held to the closing portion 63. The other of the pair of first bearings 89 is held to the face of the partition wall 61c toward the motor chamber 81 side.

[0075] Figure 5 is a cross-sectional view of the rotor 20. Also, in Figure 5 , the second shaft portion 21B is illustrated by an imaginary line.

[0076] A pair of communication holes 23 are provided in the first shaft portion 21A. The communication holes 23 extend in the radial direction to communicate the outside of the shaft 21 with the hollow portion 22. That is, a pair of communication holes 23 are provided in the shaft 21. The pair of communication holes 23 are arranged in the axial direction. Also, in the present specification, a hole that reaches the outer peripheral surface from the outer peripheral surface of the shaft 21 through the hollow portion is regarded as one communication hole 23.

[0077] A flange portion (cover portion) 21c and a threaded portion 21d are provided in the outer peripheral surface of the first shaft portion 21A and arranged in the axial direction. That is, the flange portion 21c and the threaded portion 21d are provided in the outer peripheral surface of the shaft 21. The rotor core 24 is located between the flange portion 21c and the threaded portion 21d in the axial direction. A nut 29 is fastened to the threaded portion 21d.

[0078] As shown in Figure 4 , the second shaft portion 21B is coaxial with the first shaft portion 21A. The second shaft portion 21B has a third end portion 21g on the first shaft portion 21A side and a fourth end portion 21h on the opposite side thereof. The second shaft portion 21B is connected to the first end portion 21e of the first shaft portion 21A at the third end portion 21g.

[0079] The second shaft portion 21B is disposed in the gear chamber 82 of the accommodation space 80. The third end portion 21g of the second shaft portion 21B protrudes toward the motor chamber 81 side via the through insertion hole 61f provided in the partition wall 61c to be connected to the first shaft portion 21A. A first gear 41 is provided in the outer peripheral surface of the second shaft portion 21B. The first gear 41 is a part of the speed reduction device 4. The first gear 41 is engaged with a second gear 42 to transmit the output of the shaft 21 to the second gear.

[0080] The second shaft portion 21B is rotatably supported by a pair of second bearings 88. One of the pair of second bearings 88 is held to the face of the partition wall 61c toward the gear chamber 82 side. The other of the pair of second bearings 88 is held to the gear accommodation portion 62.

[0081] The hollow portion 22 is open in the axial direction at the second end portion 21f of the first shaft portion 21A and the fourth end portion 21h of the second shaft portion 21B. Oil O is supplied to the hollow portion 22 from the opening of the fourth end portion 21h. The oil O supplied to the hollow portion 22 flows from the fourth end portion 21h side toward the second end portion 21f side. The oil O supplied to the hollow portion 22 flows out to the outside of the shaft 21 via the communication holes 23.

[0082] In addition, in the following description, the fourth end 21h side is sometimes referred to as the upstream side of the flow direction of the hollow section 22, and the second end 21f side is referred to as the downstream side of the flow direction of the hollow section 22.

[0083] like Figure 5 As shown, the first hollow portion 22A has a first region 22p, a second region (small-diameter hollow portion) 22q, and a third region (large-diameter hollow portion) 22r with different diameters on their inner circumferential surfaces. The diameters of the inner circumferential surfaces of the first region 22p, the second region 22q, and the third region 22r increase sequentially. That is, the inner diameter of the second region 22q is larger than that of the first region 22p, and the inner diameter of the third region 22r is larger than that of both the first region 22p and the third region 22r. The first region 22p, the second region 22q, and the third region 22r are arranged sequentially from the downstream side to the upstream side in the flow direction. The first region 22p is located on the side of the second end 21f. The second region 22q is located axially between the first region 22p and the third region 22r. The third region 22r is located on the side of the first end 21e. That is, the third region 22r is located closer to the second shaft portion 21B than the second region 22q.

[0084] One of the connecting holes 23 on the upstream side in the flow direction opens in the third region 22r. The other connecting hole 23 on the downstream side in the flow direction opens in the second region 22q.

[0085] Furthermore, the inner peripheral surface of the first hollow portion 22A has a first step surface 22s located between the first region 22p and the second region 22q, and a second step surface (step surface) 22t located between the second region 22q and the third region 22r. The first step surface 22s and the second step surface 22t face the second shaft portion 21B. In addition, the first step surface 22s and the second step surface 22t are inclined towards the upstream side of the flow direction as they move radially outward.

[0086] The third end portion 21g of the second shaft portion 21B is inserted into the third region 22r of the first shaft portion 21A. An internal spline 22e is provided in the third region 22r. On the other hand, an external spline 22g is provided on the outer peripheral surface of the third end portion 21g of the second shaft portion 21B. The internal spline 22e and the external spline 22g engage with each other. Thus, the first shaft portion 21A and the second shaft portion 21B are connected.

[0087] A gap is provided between the end surface of the 2nd shaft portion 21B toward the 1st shaft portion 21A side (i.e., the end surface of the 3rd end portion 21g) and the 2nd step surface 22t. The gap between the end surface of the 3rd end portion 21g and the 2nd step surface 22t constitutes a groove 22u in the inner peripheral surface of the hollow portion 22. That is, the groove 22u extending in the circumferential direction is provided in the inner peripheral surface of the hollow portion 22, and is constituted by the end surface of the 3rd end portion 21g of the 2nd shaft portion 21B, the inner peripheral surface of the 3rd region 22r, and the 2nd step surface 22t.

[0088] One of the pair of communication holes 23 on the upstream side in the flow direction of the oil O opens into the hollow portion 22 in the groove 22u. The oil O supplied into the hollow portion 22 is given a centrifugal force with the rotation of the shaft 21. The groove 22u is provided in the inner peripheral surface of the hollow portion 22, and thus the oil O is accumulated in the groove 22u with the centrifugal force. According to the present embodiment, the communication hole 23 opens in the groove 22u, and thus the oil O accumulated in the groove 22u can be effectively guided to the communication hole 23.

[0089] According to the present embodiment, the gap of the connection portion of the 1st shaft portion 21A and the 2nd shaft portion 21B can be used as the groove 22u to accumulate the oil O. Thus, it is not necessary to perform a special process to provide the groove 22u to accumulate the oil O.

[0090] In the case where a plurality of communication holes 23 are provided aligned in the axial direction, the oil O sometimes easily flows to the communication hole 23 on the downstream side in the flow direction of the oil O, and the oil O flowing into the communication hole 23 on the upstream side in the flow direction of the oil O is insufficient. According to the present embodiment, the communication hole 23 on the upstream side in the flow direction opens in the groove 22u, and thus the oil O can be sufficiently caused to flow into the communication hole 23 on the upstream side in the flow direction.

[0091] According to the present embodiment, the diameter of the hollow portion 22 is gradually reduced from the upstream side toward the downstream side in the flow direction. Thus, the oil O is easily caused to spread from the upstream side to the downstream side in the hollow portion 22. In addition, one of the pair of communication holes 23 on the upstream side opens in the 3rd region 22r, and the other on the downstream side opens in the 2nd region 22q. That is, the opening of the communication hole 23 on the downstream side is provided in a region where the diameter of the hollow portion 22 is smaller than that of the opening of the communication hole 23 on the upstream side. Thus, the oil O can also be sufficiently caused to flow into the communication hole 23 on the downstream side.

[0092] A portion of the inner spline 22e is located in a gap between the end surface of the third end portion 21g and the second step surface 22t. Thus, the inner peripheral surface of the hollow portion 22 is provided with the convex portions and the concave portions that originate from the inner spline 22e and are arranged in the circumferential direction. In the case where the cross-sectional shape of the hollow portion is circular with the motor axis as the center, there is a concern that even if the shaft rotates, the oil O in the hollow portion idles with respect to the shaft, and the oil O cannot be given a centrifugal force. In contrast, the convex portions and the concave portions arranged in the circumferential direction are provided in the hollow portion 22, so it is possible to rotate the oil O along with the rotation of the shaft 21, and it is possible to give the oil O in the hollow portion 22 a centrifugal force. Thus, it is possible to smoothly guide the oil O to the communication hole 23.

[0093] According to the present embodiment, the spline (the outer spline 22g and the inner spline 22e) that is engaged with each other is provided to the outer peripheral surface of the second shaft portion 21B and the inner peripheral surface of the third region 22r. In addition, a portion of the spline (the inner spline 22e) of the third region 22r is located in the groove 22u. Thus, it is possible to give the oil O in the hollow portion 22 a centrifugal force by the inner spline 22e for engagement. That is, it is not necessary to perform processing on the inner peripheral surface of the hollow portion 22 to provide a concave-convex shape in order to give the oil O a centrifugal force.

[0094] (Rotor Core)

[0095] The rotor core 24 is configured by laminating silicon steel sheets. The rotor core 24 is a circular cylinder that extends in the axial direction. The rotor core 24 has a pair of axial end surfaces 24a that face opposite sides in the axial direction, respectively, and an outer peripheral surface 24b that faces the radially outer side.

[0096] The rotor core 24 is sandwiched between the nut 29 and the flange portion 21c together with the pair of end plates 26. The washer 28 is sandwiched between the nut 29 and the end plate 26.

[0097] The rotor core 24 is provided with one engagement hole 24c that is located in the center when viewed in the axial direction and that penetrates in the axial direction, a plurality of magnet holding holes 24d, and a plurality of core penetration holes 24e. The engagement hole 24c, the magnet holding hole 24d, and the core penetration hole 24e are open at the pair of axial end surfaces 24a.

[0098] The engagement hole 24c is circular with the motor axis J2 as the center. The shaft 21 is inserted and engaged so as to penetrate the engagement hole 24c. Thus, the rotor core 24 surrounds the shaft 21 from the radially outer side. The engagement of the shaft 21 and the engagement hole 24c is clearance fit. Thus, it is possible to suppress the deformation of the rotor core 24 due to the engagement of the shaft 21. A protrusion (omitted from the drawing) that protrudes toward the radially inner side is provided to the inner peripheral surface of the engagement hole 24c. The protrusion is engaged into a key groove (omitted from the drawing) provided to the outer peripheral surface of the shaft 21. Thus, it is possible to suppress the relative rotation of the rotor core 24 and the shaft 21.

[0099] The plurality of core through holes 24e are arranged along the circumferential direction. The core through holes 24e are located radially inward of the magnet holding holes 24d. The core through holes 24e function to allow the oil O to flow between the pair of axial end faces 24a.

[0100] The plurality of magnet holding holes 24d are arranged along the circumferential direction. The rotor magnets 25 are inserted into the magnet holding holes 24d. The magnet holding holes 24d hold the rotor magnets 25. That is, the rotor 20 of the present embodiment is an interior permanent magnet (IPM) in which the rotor magnets 25 are embedded in the rotor core 24.

[0101] The rotor magnets 25 are permanent magnets. The plurality of rotor magnets 25 are respectively inserted into the plurality of magnet holding holes 24d arranged along the circumferential direction and fixed to the rotor core 24. The plurality of rotor magnets 25 are arranged along the circumferential direction.

[0102] (end plate)

[0103] Figure 6 is a plan view of the end plate 26. Figure 7 is a cross-sectional view of the end plate 26 along the line VII-VII of Figure 6 In Figure 6 and Figure 7 , other components of the motor unit 1 are shown by imaginary lines.

[0104] As shown in Figure 6 , the end plate 26 is a planar circle. The end plate 26 is a metal plate. A circular central hole 26i is provided in the end plate 26 so as to pass through in the axial direction. A key portion 26q is provided on the inner peripheral surface of the central hole 26i. The key portion 26q is fitted into a key groove 21k provided in the shaft 21. The end plate 26 and the shaft 21 are inhibited from rotating relative to each other by the fitting of the key portion 26q and the key groove 21k.

[0105] As shown in Figure 5 , the end plate 26 has a first face 26a and a second face 26b. The first face 26a opposes the axial end face 24a of the rotor core 24. The second face 26b faces the side opposite the first face 26a.

[0106] A pair of end plates 26 are located on opposite axial sides of the rotor core 24. Each pair of end plates 26 contacts a pair of axial end faces 24a of the rotor core 24. One end plate 26 (first end plate 26A) is located between one axial end face 24a of the rotor core 24 and the flange portion 21c. The other end plate 26 (second end plate 26B) is located between the other axial end face 24a of the rotor core 24 and the washer 28. The end plate 26 contacts the axial end face 24a on the first surface 26a. Additionally, the end plate 26 contacts either the flange portion 21c or the washer 28 on the second surface 26b.

[0107] According to this embodiment, the rotor core 24 and a pair of end plates 26 are clamped between the flange portion 21c and the nut 29. This presses the pair of end plates 26 against the axial end face 24a of the rotor core 24 from both axial sides. Friction is generated at the contact portion between the first surface 26a of the end plate 26 and the axial end face 24a of the rotor core 24, thereby suppressing relative rotation between the rotor core 24 and the shaft 21.

[0108] When the rotor core and shaft are fixed by pressing, the rotor core deforms, causing changes in the magnetic circuit within the rotor core and increasing iron losses. Especially in vehicle drive motors, as in this embodiment, the driving force is relatively large, thus requiring a large interference fit during pressing, which can easily increase iron losses in the rotor core. According to this embodiment, the rotor core 24 is fixed to the shaft 21 via the end plate 26. Therefore, the engagement hole 24c of the rotor core 24 and the shaft 21 can be made into a clearance engagement, suppressing deformation of the rotor core 24 and providing a highly efficient motor 2.

[0109] like Figure 7 As shown, a recess 26f and an inclined surface 26e surrounding the recess 26f radially outward are provided on the first surface 26a. The recess 26f, when viewed from above, is circular with the motor axis J2 as its center. The recess 26f has a bottom surface 26g and an inner circumferential surface 26h. The bottom surface 26g is a plane perpendicular to the motor axis J2. The inner circumferential surface 26h is located between the bottom surface 26g and the inclined surface 26e. The inner circumferential surface 26h slopes in a direction that makes the recess 26f shallower as it moves from the radially inward to the radially outward. A gap is provided between the recess 26f and the axial end face 24a of the rotor core 24. Oil O accumulates in this gap, thereby cooling the axial end face 24a of the rotor core 24.

[0110] An inclined surface 26e is provided on the first surface 26a in the region located at the outermost radial direction and extends circumferentially. The inclined surface 26e is inclined toward the rotor core 24 side at an inclination angle θ as it moves radially outward. Here, the inclination angle θ refers to the angle between the plane perpendicular to the motor axis J2 and the inclined surface 26e.

[0111] The end plate 26 contacts the axial end surface 24a of the rotor core 24 on the inclined surface 26e of the first surface 26a. The inclined surface 26e is inclined toward the rotor core 24 side as it goes toward the radially outer side, and thus the inclined surface 26e contacts the axial end surface 24a in a region that is radially outermost. Thereby, it is possible to generate a frictional force that is generated by the contact of the inclined surface 26e and the axial end surface 24a as much as possible on the radially outer side. In addition, it is possible to increase the perpendicular stress of the inclined surface 26e and the axial end surface 24a as it goes toward the radially outer side. Thereby, it is possible to increase the limit value of the static frictional force as it goes toward the radially outer side. The holding torque that suppresses the relative rotation of the end plate 26 and the rotor core 24 is proportional to the distance from the rotation axis and the frictional force. Therefore, according to the present embodiment, it is possible to increase the holding torque that suppresses the relative rotation of the end plate 26 and the rotor core 24, and it is possible to firmly hold the rotor core 24 with respect to the end plate 26. In order to achieve such an effect, it is preferable that the inclination angle θ of the inclined surface 26e be 0.1° or more and 5° or less.

[0112] In addition, the end plate 26 of the present embodiment contacts the axial end surface 24a of the rotor core 24 on the inclined surface 26e. Therefore, it is possible to stabilize the contact position of the end plate 26 and the rotor core 24. Therefore, it is possible to suppress the variation in the transmission torque of the end plate 26 and the rotor core 24, and it is possible to reliably fix the rotor core 24 with respect to the shaft 21.

[0113] In addition, according to the present embodiment, the inclined surface 26e is provided to the end plate 26, and thus it is possible to reliably contact even if there is a variation in the flatness of the contact portion of the end plate 26 and the axial end surface 24a of the rotor core 24. As explained in the following paragraphs, an oil flow path 26t (refer to Figure 5 ) is provided on the radially inner side of the inclined surface 26e. Generally, when oil enters between the rotor core and the stator, the rotation efficiency of the rotor core decreases. By contacting the inclined surface 26e and the axial end surface 24a of the rotor core 24, it is possible to suppress the entry of the oil O of the oil flow path 26t from between the end plate 26 and the rotor core 24 into the gap between the outer peripheral surface 24b of the rotor core 24 and the stator 30.

[0114] In addition, the inclined surface 26e can also be a structure in which the inclination angle changes as it goes toward the radially outer side. In addition, the inclined surface 26e can also be a curved surface in which the inclination angle changes as it goes toward the radially outer side.

[0115] As Figure 5 indicated, the inclined surface 26e encloses the opening of the magnet holding hole 24d of the rotor core 24. Thereby, it is possible to suppress the ejection of the rotor magnet 25 that is held inside the magnet holding hole 24d from the opening of the magnet holding hole 24d. Thereby, it is possible to suppress the entry of a portion of the rotor magnet 25 into the drive portion inside the accommodation recess.

[0116] AsFigure 7 As shown in FIG. 6, the second surface 26b is provided with a flat portion 26c and a chamfered portion 26d located at an outer edge of the flat portion 26c. The flat portion 26c is perpendicular to the motor axis J2. The chamfered portion 26d is inclined toward the first surface 26a side as it goes toward the radially outer side.

[0117] As shown in FIG. 6, the end plate 26 is provided with two sets of plate through holes 26p, a first recess (first recessed portion) 26j, and a second recess (second recessed portion) 26k. Hereinafter, one set of the two sets of plate through holes 26p, the first recess 26j, and the second recess 26k will be described, and the other set also has the same structure. Figure 5 The plate through hole 26p extends along the axial direction. The first recess 26j is located at the first surface 26a. The first recess 26j extends from the opening of the plate through hole 26p toward the radially inner side. The first recess 26j is open to the radially inner side at the inner peripheral surface of the central hole 26i. The second recess 26k is located at the second surface 26b. The second recess 26k extends from the opening of the plate through hole 26p toward the radially outer side. The second recess 26k is open to the radially outer side at the chamfered portion 26d.

[0118] The opening of the first recess 26j of the end plate 26 along the axial direction is covered by the axial end surface 24a of the rotor core 24. In addition, the radially open portion of the first recess 26j is connected to the communication hole 23 of the shaft 21.

[0119] The oil O supplied to the inside of the hollow portion 22 of the shaft 21 flows toward the radially outer side via the communication hole 23. In addition, the oil O flows into the first recess 26j from the radially outer side opening of the communication hole 23. In addition, the oil O flows toward the first surface 26a and the second surface 26b side through the plate through hole 26p, and is released to the outside of the rotor 20 via the second recess 26k. As shown in FIG. 6, the coil end portion 31a of the stator 30 is provided radially outward of the end plate 26. The oil O released to the outside of the rotor 20 is supplied to the coil end portion 31a to cool the coil end portion 31a.

[0120] Figure 4 The first recess 26j, the plate through hole 26p, and the second recess 26k of the end plate 26 function as an oil flow path 26t. That is, the oil flow path 26t is constituted by the first recess 26j, the plate through hole 26p, and the second recess 26k. The pair of end plates 26 are each provided with an oil flow path 26t that communicates with the communication hole 23 and is open along the radial direction.

[0121] According to the end plate 26 of the present embodiment, the plate through hole 26p, the first recess 26j, and the second recess 26k constitute the oil flow path 26t. Therefore, according to the present embodiment, the oil flow path 26t can be constituted by inexpensive components (end plates 26) that are manufactured by molding.

[0122] According to the end plate 26 of the present embodiment, the plate through hole 26p, the first recess 26j, and the second recess 26k constitute the oil flow path 26t. Therefore, according to the present embodiment, the oil flow path 26t can be constituted by inexpensive components (end plates 26) that are manufactured by molding. ​

[0123] The first groove 26j of the pair of end plates 26 communicates with the core through hole 24e. That is, the core through hole 24e connects the first groove 26j of each of the pair of end plates 26 to each other. In other words, the core through hole 24e connects the oil flow path 26t of each of the pair of end plates 26 to each other. In addition, at least a portion of the opening of the core through hole is located radially outward of the plate through hole 26p.

[0124] According to this embodiment, the core through-hole 24e connects the first grooves 26j of the pair of end plates 26 to each other, thus allowing a portion of the oil O passing through the first grooves 26j to flow into the core through-hole 24e. Therefore, the oil O passing through the core through-hole 24e can cool the rotor core 24 from the inside. Furthermore, the rotor magnet 25 held in the rotor core 24 can be cooled through the rotor core 24.

[0125] According to this embodiment, the opening of the core through-hole 24e is located radially outward from the plate through-hole 26p of the pair of end plates 26. Therefore, oil O can be accumulated inside the core through-hole 24e by the centrifugal force of the rotor 20, and oil O can be supplied from the core through-hole 24e to the first grooves 26j of the end plates 26 on both sides. Furthermore, if there is insufficient oil O in the first groove 26j on one side of the pair of end plates 26, oil O can be supplied from the other side through the core through-hole 24e. Therefore, approximately equal amounts of oil O can be released from each end plate 26 to the coil end 31a, enabling stable cooling of the coil 31.

[0126] like Figure 5 As shown, the end plate 26 between the flange 21c and the rotor core 24 is designated as the first end plate 26A, and the end plate 26 between the nut 29 and the rotor core 24 is designated as the second end plate 26B.

[0127] In the first end plate 26A, a portion of the radially inner side of the plate through hole 26p is covered by the flange portion 21c. Furthermore, in the first end plate 26A, the axial opening of the second groove 26k faces axially outwards. In other words, in the first end plate 26A, when viewed axially, the axial opening of the second groove 26k is entirely exposed. That is, the second groove 26k of the first end plate 26A communicates with the outside through its axial opening. In the first end plate 26A, a portion of the plate through hole 26p and the entire axial opening in the second groove 26k function as a first opening 26s for release from the washer 28. In the first end plate 26A, oil O is released from the first opening 26s through the plate through hole 26p.

[0128] The washer 28 is interposed between the second end plate 26B and the nut 29. In the second end plate 26B, a portion of the plate through-hole 26p and the radially inner side of the axial opening of the second recess 26k is covered by the washer 28. The portion of the axial opening of the second recess 26k covered by the washer 28 is referred to as a covered portion, and the portion not covered by the washer 28 is referred to as an open portion. That is, in the second end plate 26B, the axial opening of the second recess 26k has a covered portion covered by the washer 28 and a second open portion 26r not covered by the washer. The second recess 26k of the second end plate 26B faces the axial outer side in the second open portion 26r at the end portion radially outside the second recess 26k. In other words, the second recess 26k of the second end plate 26B is exposed in the second open portion 26r when viewed in the axial direction. That is, the second recess 26k of the second end plate 26B communicates with the outside in the second open portion 26r. The second open portion 26r is at the end portion radially outside the second recess 26k. In the second end plate 26B, the oil O passing through the plate through-hole 26p is released from the second open portion 26r.

[0129] According to the first end plate 26A and the second end plate 26B of the present embodiment, the second recess 26k is provided in the second face 26b, so that the oil O flowing to the second face 26b side via the plate through-hole 26p can be moved to the radially outer side along the second recess 26k. Therefore, the oil O can be stably caused to flow to the second open portion 26r, and the oil O can be stably supplied to the coil end portion 31a of the stator 30.

[0130] According to the present embodiment, for the second recess 26k of the first end plate 26A and the second end plate 26B, the flange portion 21c or the washer 28 functions as a cover portion covering the axial opening, respectively. That is, the rotor 20 has a pair of cover portions (the flange portion 21c and the washer 28) located at the axial end portions of the rotor core 24 with the end plate 26 interposed. The cover portions (the flange portion 21c and the washer 28) cover the axial opening of the plate through-hole 26p from the outside, so that the oil O flowing from the plate through-hole 26p to the second face 26b side is guided to flow along the second recess 26k. According to the present embodiment, the action of the oil O can be controlled by the cover portions (the flange portion 21c and the washer 28), so that the oil O can be suppressed from entering between the rotor core 24 and the stator 30.

[0131] According to the second end plate 26B of the present embodiment, the axial opening of the second recess 26k is partially covered by the washer 28, and faces the axial outer side in the second open portion 26r. That is, in the region of the second recess 26k up to the second open portion 26r, the oil O does not overflow in the axial direction, and the oil O can be reliably moved to the second open portion 26r. Thus, the oil O can be stably released from the second open portion 26r, and the oil O can be stably supplied to the coil end portion 31a.

[0132] According to the present embodiment, the second recess 26k faces the axial outer side in the axial direction at the second open portion 26r located at the radial end portion. Therefore, it is possible to cause the oil O that has passed through the second recess 26k to scatter in the axial direction from the second open portion 26r. Thus, it is possible to cause the oil O to scatter toward the coil end portion 31a that protrudes in the axial direction from the end portion of the rotor core 24, and to effectively cool the coil 31 of the coil end portion 31a.

[0133] In addition, in the first end plate 26A of the present embodiment, the first open portion 26s is provided at a portion of the plate through-hole 26p and the entire opening in the axial direction. However, as shown by the broken line in FIG. 12, the flange portion 21c can cover a portion of the opening in the axial direction of the second recess 26k. In this case, the first open portion 26s of the first end plate 26A, like the second open portion 26r of the second end plate 26B, is located at the end portion on the radial outer side, and can have the same effect as the second open portion 26r. Figure 5

[0134] In addition, in the present embodiment, the first recess 26j and the second recess 26k that are grooves are provided in the end plate 26. However, even if the recesses are not grooves, the above-described certain effects can be obtained. In addition, by providing the first recess 26j and the second recess 26k that extend in the radial direction, the oil O can be smoothly guided in the radial direction.

[0135] (First Modification of the End Plate)

[0136] Figure 8 is a cross-sectional view of an end plate 126 that is a first modification that can be employed in the present embodiment. In addition, for structural elements of the same mode as in the above-described embodiment, the same reference numerals are used for explanation.

[0137] The end plate 126 of the first modification, like the above-described embodiment, has a first face 126a that opposes the rotor core 24 and a second face 126b that faces the side opposite the first face 126a. In addition, the end plate 126 is provided with a pair of plate through-holes 126p, a pair of first recesses 126j, and a pair of second recesses 126k. The plate through-holes 126p extend in the axial direction. The first recesses 126j are located at the first face 126a. The first recesses 126j extend from the plate through-holes 126p toward the radial inner side. The second recesses 126k are located at the second face 126b. The second recesses 126k extend from the plate through-holes 126p toward the radial outer side. The openings in the axial direction of the second recesses 126k are partially covered by the cover portions 128, and the open portions 126r face the axial outer side. In addition, here, the cover portions 128 are the gaskets 28 or the flange portions 21c (refer to FIG. 11). Figure 5

[0138] ​​In the present modification example, an inclined surface 126u is provided at the bottom of the second groove 126k so that the depth of the second groove 126k becomes shallower as it goes toward the radially outer side. The inclined surface 126u overlaps the open portion 126r when viewed in the axial direction. According to the present modification example, by providing the inclined surface 126u in the second groove 126k, it is possible to impart an axial component to the flow of the oil O. It is possible to cause the oil O to scatter in the axial direction so as to effectively scatter the oil O toward the coil end portion 31a that protrudes in the axial direction from the end portion of the rotor core 24.

[0139] (Second Modification Example of End Plate)

[0140] Figure 9 is a plan view of an end plate 226 that is a second modification example that can be employed in the present embodiment. Note that, for structural elements of the same kind as in the above-described embodiment, the same reference numerals are used for description.

[0141] The end plate 226 of the second modification example, like the above-described embodiment, has a first surface 226a and a second surface 226b that faces the opposite side from the first surface 226a. Further, the end plate 226 has a pair of plate through holes 226p, a pair of first grooves 226j, and a pair of second grooves 226k. The plate through holes 226p extend in the axial direction. The first grooves 226j are located at the first surface 226a. The first grooves 226j extend toward the radially inner side from the plate through holes 226p. The second grooves 226k are located at the second surface 226b. The second grooves 226k extend toward the radially outer side from the plate through holes 226p. The openings of the second grooves 226k in the axial direction are partially covered by the cover portions 228, and face the axially outer side in the open portions 226r. Note that, here, the cover portions 228 are the gaskets 28 or the flange portions 21c (refer to FIG. 2) of the rotor core 24. Figure 5 ).

[0142] The second grooves 226k are grooves that extend in the radial direction. Further, when viewed in the axial direction, the direction of extension of the second grooves 226k is inclined with respect to the radial direction. Further, the second grooves 226k are curved in such a way that the angle of inclination with respect to the radial direction increases as it goes toward the radially outer side. According to the present modification example, the second grooves 226k are inclined with respect to the radial direction, and thus it is possible to impart a centrifugal force to the oil O that passes through the second grooves 226k from the wall surface of the inclined second grooves 226k. Thereby, it is possible to increase the speed of the oil O that scatters from the open portions 226r, and it is possible to reliably bring the oil O into contact with the coil end portion 31a even in the case where the distance to the coil end portion 31a is long.

[0143] In this modified example, the shapes of the pair of second grooves 226k differ when viewed axially. One of the second grooves 226kA, relative to the other second groove 226kB, has a smaller curvature and a smaller angle of inclination relative to the radial direction when viewed axially. That is, according to this embodiment, when viewed axially, the extension directions of the grooves of each of the plurality of second grooves 226kA and 226kB are at different angles relative to the radial direction. Therefore, the magnitudes of the centrifugal forces exerted on the oil O by the pair of second grooves 226kA and 226kB are different. Oil O scattering from one second groove 226kA travels at a higher speed and scatters over a greater distance than oil O scattering from the other second groove 226kB. In other words, according to this modified example, among the plurality of second grooves 226kA and 226kB, oil O can be scattered to different areas, allowing the oil O to contact a wider area of ​​the coil end 31a.

[0144] <Oil Circuit>

[0145] like Figure 1 As shown, the oil passage 90 is located inside the housing 6, i.e., the storage space 80. The oil passage 90 is configured to span the motor chamber 81 and the gear chamber 82 of the storage space 80. The oil passage 90 is the path through which oil O is introduced from the oil reservoir P (i.e., the area below the storage space 80) via the motor 2 and then reintroduced into the oil reservoir P. The oil passage 90 has a first oil passage 91 passing through the interior of the motor 2 and a second oil passage 92 passing through the exterior of the motor 2. The oil O cools the motor 2 from the inside and outside through the first oil passage 91 and the second oil passage 92. The oil passage 90 constitutes an oil cooling mechanism.

[0146] Both the first oil passage 91 and the second oil passage 92 are paths that supply oil O from the oil reservoir P to the motor 2 and then return it to the oil reservoir P. In the first oil passage 91 and the second oil passage 92, oil O drips from the motor 2 and accumulates in the lower area of ​​the motor chamber. The oil O accumulated in the lower area of ​​the motor chamber 81 moves through the partition wall opening 68 to the lower area of ​​the gear chamber 82 (i.e., the oil reservoir P).

[0147] A cooler 97 for cooling oil O is provided in the path of the first oil passage 91. The oil O that passes through the first oil passage 91 and is cooled by the cooler 97 merges with the oil O passing through the second oil passage 92 in the oil reservoir P. In the oil reservoir P, the oil O passing through the first oil passage 91 and the second oil passage 92 mix and exchange heat. Therefore, the cooling effect of the cooler 97 located in the path of the first oil passage 91 can also affect the oil O passing through the second oil passage 92. According to this embodiment, the oil O in both oil passages is cooled using a cooler 97 located in one of the oil passages, the first oil passage 91 and the second oil passage 92.

[0148] Generally, a cooler is arranged in a flow path in which liquid stably flows. In order to cool two oil paths, a structure in which a cooler is arranged in a flow path included in each of the two oil paths is also considered. In this case, two coolers are required, and the cost increases. In order to cool the two oil paths, a structure in which a flow path is provided in a region in which the two oil paths are combined and a cooler is provided in the flow path is considered. In this case, a flow path needs to be provided in a region in which the oil paths communicate, and as a result, the structure of the flow path in the oil paths needs to be complicated, and the cost increases.

[0149] According to the present embodiment, a cooler is provided only in the first oil path 91, and oil O that has passed through the first oil path 91 and the second oil path 92 is mixed in the oil reservoir P, and thus the second oil path 92 can be indirectly cooled. Thus, the oil O in the first oil path 91 and the second oil path 92 can be cooled by one cooler 97 without complicating the structure of the flow path in the oil paths 90.

[0150] Further, such an effect is an effect that can be achieved when either one of the first oil path 91 and the second oil path 92 has a cooler 97 that cools the oil O and the oil O that flows in the first oil path 91 and the second oil path 92 is combined in the oil reservoir P.

[0151] The heat of the oil O is mainly dissipated through the cooler 97. Further, since the oil O is in contact with the inner surface of the housing 6, a part of the heat of the oil O is also dissipated through the housing 6. Further, as shown in Figure 1 , a concave-convex radiator portion 6b can be provided on the outer side surface of the housing 6. The radiator portion 6b promotes cooling of the motor 2 via the housing 6.

[0152] (First Oil Path)

[0153] In the first oil path 91, the oil O is introduced into the inside of the rotor 20 by being lifted from the oil reservoir P by the differential device 5. In the inside of the rotor 20, the oil O is given a centrifugal force that accompanies rotation of the rotor 20. Thus, the oil O is uniformly diffused toward the stator 30 that surrounds the rotor 20 from the radially outer side, and the stator 30 is cooled.

[0154] The first oil path 91 has a lift path 91a, a shaft supply path (oil flow path) 91b, an inner shaft path 91c, and an inner rotor path 91d. Further, a first reservoir 93 is provided in the path of the first oil path 91. The first reservoir 93 is provided in the accommodation space 80 (particularly, the gear chamber 82).

[0155] The lift path 91a is a path in which the oil O is lifted from the oil reservoir P by rotation of the ring gear 51 of the differential device 5 and the oil O is received by the first reservoir 93 (refer to Figure 3 ).

[0156] As Figure 3As shown, the first oil reservoir 93 is located on the upper side of the motor axis J2, the intermediate shaft axis J4, and the differential axis J5 in the vertical direction. The first oil reservoir 93 is located between the intermediate shaft axis J4 and the differential axis J5 in the vehicle front-rear direction (horizontal direction, X-axis direction). The first oil reservoir 93 is located between the motor axis J2 and the differential axis J5 in the vehicle front-rear direction (horizontal direction, X-axis direction). The first oil reservoir 93 is disposed on the side of the first gear 41. The first oil reservoir 93 is open to the upper side.

[0157] In the present specification, an "oil reservoir" refers to a configuration body having a function of accumulating oil in a state in which there is no stable flow of liquid in one direction. The "oil reservoir" differs from a "flow path" in that there is no stable flow of liquid. The first oil reservoir 93, the second oil reservoir 98, and the sub oil reservoir 95 are provided in the accommodation space 80 of the motor unit 1 of the present embodiment.

[0158] In the present embodiment, the differential axis J5, which is the center of rotation of the ring gear 51, is disposed on the vehicle rear side with respect to the reduction device 4. The differential device 5 rotates toward the upper side in the region on the side opposite to the reduction device 4 when the vehicle is advancing. The oil O lifted by the ring gear 51 of the differential device 5 falls to the upper side of the first oil reservoir 93 around the side opposite to the reduction device 4 and is accumulated in the first oil reservoir 93. That is, the first oil reservoir 93 receives the oil O lifted by the ring gear 51. In addition, in the case where the liquid level of the oil storage portion P is high after the motor 2 is just driven, and the like, the second gear 42 and the third gear 43 contact the oil O of the oil storage portion P and lift the oil O. In such a case, the first oil reservoir 93 receives the oil O lifted by the second gear 42 and the third gear 43 in addition to the oil O lifted by the ring gear 51.

[0159] The housing 6 has a gear chamber top portion (top portion) 64 that constitutes a wall on the upper side of the gear chamber 82. The gear chamber top portion 64 is located on the upper side of the reduction device 4 and the differential device 5. Here, an imaginary line (the third line segment L3 described in the paragraph below) that virtually connects the motor axis J2 and the differential axis J5 is defined from the axial direction of the motor axis J2. The gear chamber top portion 64 is substantially parallel to the imaginary line L3. By making the gear chamber top portion 64 substantially parallel to the imaginary line L3, it is possible to sufficiently secure a region through which the oil O lifted by the ring gear 51 and flying in the direction extending to the imaginary line L3 passes, and thereby it is possible to make the oil O effectively contact the first gear 41 that rotates with the motor axis J2 as the center. In addition, by making the gear chamber top portion 64 substantially parallel to the imaginary line L3, it is possible to suppress the housing 6 from being large in the vertical direction.

[0160] In addition, here, the "substantially parallel" between the gear chamber top 64 and the imaginary line L3 means that the angle between the gear chamber top 64 and the imaginary line L3 is within 10°. In the case where the gear chamber top 64 is curved, the angle between the tangent line of all points of the curved line and the imaginary line L3 is within 10°.

[0161] In addition, if the range is within 10°, it is preferable that the gear chamber top 64 approach the imaginary line L3 as it goes from the differential axis J5 side toward the motor axis J2 side. By this, it is possible to downsize the housing 6.

[0162] In addition, the gear chamber top 64 is a curved surface that is slightly curved in the direction of approaching the imaginary line L3 as it goes from the differential axis J5 side toward the motor axis J2 side. The curved shape of the gear chamber top 64 is substantially the same as the parabola described by the oil O lifted by the ring gear 51, or a curved surface that is slightly separated from the ring gear 51. A part of the oil O lifted by the ring gear 51 directly reaches the first reservoir 93. In addition, another part of the oil O lifted by the ring gear 51 flows along the gear chamber top 64 of the housing 6 to reach the first reservoir 93. That is, the gear chamber top 64 functions to guide the oil O to the first reservoir 93.

[0163] The gear chamber top 64 has a protrusion 65 that protrudes to the lower side. The protrusion 65 is located on the upper side of the first reservoir 93. The oil O flowing along the gear chamber top 64 becomes larger droplets at the lower end of the protrusion 65, falls to the lower side, and accumulates in the first reservoir 93. That is, the protrusion 65 guides the oil O flowing along the gear chamber top 64 to the first reservoir 93.

[0164] In the present embodiment, the motor housing portion 61 and the gear housing portion 62 are fixed to each other by the bolt 67. The protrusion 65 is provided in the gear chamber top 64 by a thick wall portion around the threaded hole into which the bolt 67 is inserted. In addition, in the Figure 3 In the present embodiment, the other bolts and the other thick wall portions around the threaded holes into which the other bolts are inserted that fix the motor housing portion 61 and the gear housing portion 62 are omitted from the illustration.

[0165] The gear chamber top 64 has a plate-shaped eave portion 66 that extends in the axial direction. The eave portion 66 protrudes to the lower side. The lower end of the eave portion 66 is located on the upper side of the first reservoir 93. A part of the oil O that is scattered by the lifting of the ring gear 51 contacts the eave portion 66 and flows along the surface of the eave portion 66. Likewise, the oil O that is scattered by the lifting of the second gear 42 and the third gear is blocked by the eave portion 66 and flows along the surface of the eave portion 66. The oil O becomes larger droplets at the lower end of the eave portion 66, falls to the lower side, and accumulates in the first reservoir 93. That is, the eave portion 66 guides the lifted oil O to the first reservoir 93.

[0166] The eave portion 66 is inclined from the differential axis J5 side toward the motor axis J2 side as it goes from the upper side toward the lower side. The ring gear 51 is larger in diameter than the 2nd gear 42 and the 3rd gear 43, so the scattering angle of the oil O that scatters is close to horizontal. By arranging the eave portion 66 inclined in the above-described direction, the oil O that scatters from the ring gear 51 can be caused to adhere to the surface of the eave portion 66 and fall to the lower side smoothly.

[0167] The 1st reservoir 93 is located directly above the ring gear 51, the 2nd gear 42, and the 3rd gear 43. The opening of the 1st reservoir 93 overlaps the ring gear 51, the 2nd gear 42, and the 3rd gear 43 when viewed in the vertical direction. Most of the oil lifted by the gears scatters directly above the gears that lifted it. By arranging the 1st reservoir 93 directly above the ring gear 51, the 2nd gear 42, and the 3rd gear 43, the oil O lifted by each of the gears can be efficiently received.

[0168] The 1st reservoir 93 has a bottom portion 93a, a 1st side wall portion 93b, and a 2nd side wall portion 93c. The bottom portion 93a, the 1st side wall portion 93b, and the 2nd side wall portion 93c extend in the axial direction between the wall surface of the gear housing portion 62 and the protruding plate portion 61d of the motor housing portion. The 1st side wall portion 93b and the 2nd side wall portion 93c extend upward from the bottom portion 93a. The 1st side wall portion 93b constitutes the wall surface of the 1st reservoir 93 on the differential device 5 side. The 2nd side wall portion 93c constitutes the wall surface of the 1st reservoir 93 on the reduction device 4 side. That is, the 1st side wall portion 93b extends upward from the end portion of the bottom portion 93a on the differential axis J5 side, and the 2nd side wall portion 93c extends upward from the end portion of the bottom portion 93a on the motor axis J2 side. The 1st reservoir 93 temporarily stores the oil O in the region surrounded by the bottom portion 93a, the 1st side wall portion 93b, the 2nd side wall portion 93c, and the wall surface of the gear housing portion 62 and the protruding plate portion 61d of the motor housing portion.

[0169] The height of the upper end portion of the 1st side wall portion 93b is located at a position lower than the upper end portion of the 2nd side wall portion 93c. The oil O is lifted by the differential device 5 and scatters toward the 1st reservoir 93 from the opposite side of the reduction device 4. By lowering the height of the upper end portion of the 1st side wall portion 93b, the oil O lifted by the differential device 5 can be efficiently stored in the 1st reservoir 93. In addition, the oil O that scatters from the ring gear 51 that exceeds the 1st side wall portion 93b can be guided to the 1st reservoir 93 by coming into contact with the 2nd side wall portion 93c.

[0170] The 2nd side wall portion 93c extends obliquely upward along the circumference of the 1st gear 41. That is, the 2nd side wall portion 93c is inclined toward the motor axis J2 as it goes upward. Thereby, the 2nd side wall portion 93c can accept the oil O lifted by the differential device 5 in a wider range. In addition, the 2nd side wall portion 93c can accept the droplets of the oil O flowing along the top of the accommodation space 80 in a wider range.

[0171] At the boundary between the bottom portion 93a and the 2nd side wall portion 93c, the shaft supply flow path 94 opens toward the inside of the 1st oil reservoir 93. The bottom portion 93a is slightly inclined downward as it goes toward the motor axis J2 side when viewed from above. That is, the bottom portion 93a is slightly inclined in such a manner that the 2nd side wall portion 93c side lower end is formed. Therefore, by providing the opening of the shaft supply flow path 94 between the bottom portion 93a and the 2nd side wall portion 93c, the oil O in the 1st oil reservoir 93 can be efficiently supplied to the shaft supply flow path 94.

[0172] The shaft supply path 91b guides the oil O from the 1st oil reservoir 93 to the motor 2. The shaft supply path 91b is constituted by the shaft supply flow path 94. The shaft supply flow path 94 extends from the 1st oil reservoir 93 toward the end portion of the shaft 21. The shaft supply flow path 94 extends in a straight line. The shaft supply flow path 94 is inclined toward the lower side as it goes from the 1st oil reservoir 93 toward the end portion of the shaft 21. The shaft supply flow path 94 is formed by machining a hole that penetrates the inside and outside of the accommodation space 80 in the gear accommodation portion 62. The opening of the outside of the machined hole is closed by a cap portion (omitted from the drawing). The shaft supply flow path 94 guides the oil O accumulated in the 1st oil reservoir 93 from the end portion of the shaft 21 to the hollow portion 22.

[0173] As Figure 1 shown, the shaft inner path 91c is a path through which the oil O passes in the hollow portion 22 of the shaft 21. In addition, the rotor inner path 91d is a path through which the oil O scatters from the communication hole 23 of the shaft 21 to the inside of the end plate 26 positioned at the axial end surface 24a of the rotor iron core 24, to the stator 30 (refer to Figure 5 ). That is, the 1st oil passage 91 has a path that passes from the inside of the shaft 21 through the rotor iron core 24.

[0174] In the shaft inner path 91c, the oil O in the inside of the rotor 20 is given a centrifugal force as the rotor 20 rotates. Thereby, the oil O continuously scatters to the radially outer side from the end plate 26. In addition, as the oil O scatters, the path in the inside of the rotor 20 becomes under pressure, and the oil O accumulated in the 1st oil reservoir 93 is drawn to the inside of the rotor 20, and the path in the inside of the rotor 20 is filled with the oil O. The movement of the oil O to the inside of the rotor 20 can also be promoted by the capillary force in the 1st oil passage 91. The oil O that reaches the stator 30 absorbs heat from the stator 30.

[0175] (2nd Oil Passage)

[0176] AsFigure 1 As shown, in the second oil passage 92, the oil O is supplied to the motor 2 from the oil storage portion P to the upper side of the motor 2. The oil O supplied to the motor 2 flows along the outer peripheral surface of the stator 30 while absorbing heat from the stator 30, thereby cooling the motor 2. The oil O flowing along the outer peripheral surface of the stator 30 drips to the lower side and is accumulated in the region on the lower side of the motor chamber 81. The oil O of the second oil passage 92 and the oil O of the first oil passage 91 join in the region on the lower side of the motor chamber 81. The oil O accumulated in the region on the lower side of the motor chamber 81 moves to the region on the lower side of the gear chamber 82 (i.e., the oil storage portion P) via the partition wall opening 68.

[0177] Figure 10 is a cross-sectional view of the motor unit 1. In addition,The cut surface of the motor unit 1 is axially offset in each region. Figure 10

[0178] The second oil passage 92 has a first flow passage 92a, a second flow passage 92b, and a third flow passage 92c. The pump 96, the cooler 97, and the second reservoir 98 are provided in the path of the second oil passage 92. In the second oil passage 92, the oil O is supplied to the motor 2 in the order of the first flow passage 92a, the pump 96, the second flow passage 92b, the cooler 97, the third flow passage 92c, and the second reservoir 98.

[0179] The pump 96 is an electric pump that is driven by electricity. The pump 96 is mounted to a pump mounting recess 6c provided on the outer side surface of the housing 6. The pump 96 has a suction port 96a and a pump outlet 96b. The suction port 96a and the pump outlet 96b are connected via an internal flow passage of the pump 96. In addition, the suction port 96a is connected to the first flow passage 92a. The pump outlet 96b is connected to the second flow passage 92b. The pump outlet 96b is located at a position on the upper side than the suction port 96a. The pump 96 sucks up the oil O from the oil storage portion P via the first flow passage 92a and supplies the oil O to the motor 2 via the second flow passage 92b, the cooler 97, the third flow passage 92c, and the second reservoir 98.

[0180] The amount of supply of the oil O to the motor 2 by the pump 96 is appropriately controlled according to the driving state of the motor 2. Therefore, in the case where long-time driving or high output is required, the driving output of the pump 96 is increased by increasing the temperature of the motor 2, thereby increasing the amount of supply of the oil O to the motor 2.

[0181] The cooler 97 has an inflow port 97a and an outflow port 97b. The inflow port 97a and the outflow port 97b are connected via an internal flow path of the cooler 97. In addition, the inflow port 97a is connected to the second flow path 92b. The outflow port 97b is connected to the third flow path 92c. The inflow port 97a is located on the side (i.e., the lower side) closer to the pump 96 than the outflow port 97b. In addition, a cooling water pipe (omitted from illustration) through which cooling water supplied from a radiator passes is provided inside the cooler 97. The oil O passing through the inside of the cooler 97 is cooled by exchanging heat with the cooling water.

[0182] The pump 96 and the cooler 97 are fixed to the outer peripheral surface of the motor housing portion 61 of the housing 6. When viewed in the axial direction of the motor axis J2, the pump 96 and the cooler 97 are located on the side opposite the differential device 5 in the horizontal direction, sandwiching the motor axis J2. In addition, the pump 96 and the cooler 97 are arranged in the vertical direction. The cooler 97 is located on the upper side of the pump 96. When viewed in the vertical direction, the cooler 97 overlaps the pump 96.

[0183] According to the present embodiment, the pump 96 and the cooler 97 are located on the side opposite the differential device 5, sandwiching the motor axis J2, and thus the space around the motor 2 can be effectively utilized. Thus, the size of the motor unit 1 in the horizontal direction can be reduced, and the motor unit 1 can be made smaller.

[0184] According to the present embodiment, the pump 96 and the cooler 97 are fixed to the outer peripheral surface of the housing 6. Thus, compared to a case in which the pump 96 and the cooler 97 are provided outside the housing 6, the motor unit 1 can be made smaller. In addition, by fixing the pump 96 and the cooler 97 to the outer peripheral surface of the housing 6, the flow path connecting the accommodation space 80 and the pump 96 and the cooler 97 can be formed using the first flow path 92a, the second flow path 92b, and the third flow path 92c inside the wall portion 6a of the housing 6.

[0185] According to the present embodiment, the cooler 97 is fixed to the outer peripheral surface of the housing 6, and thus the distance between the cooler 97 and the accommodation space 80 can be made close. Thus, the third flow path 97c connecting the cooler 97 and the accommodation space 80 can be shortened, and the cooled oil O can be supplied to the accommodation space 80 in a low-temperature state.

[0186] The first flow path 92a, the second flow path 92b, and the third flow path 92c pass through the inside of the wall portion 6a of the housing 6 that surrounds the accommodation space 80. For the first flow path 92a, the first flow path 92a, the second flow path 92b, and the third flow path 92c can be formed as holes formed in the wall portion 6a. Thus, the number of components can be reduced without the need to additionally prepare a pipe material.

[0187] Further, the first flow path 92a passes through the inside of the portion of the wall portion 6a that is located on the lower side of the motor 2. The second flow path 92b passes through the inside of the portion of the wall portion 6a that is located on the lateral side of the motor 2 in the horizontal direction. Further, the third flow path 92c passes through the inside of the portion of the wall portion 6a that is located on the upper side of the motor 2.

[0188] The first flow path 92a connects the oil reservoir portion P and the pump 96. The first flow path 92a has a first end portion 92aa and a second end portion 92ab.

[0189] The first end portion 92aa is located on the upstream side of the second oil passage 92 as compared with the second end portion 92ab. The first end portion 92aa opens in the lower side of the differential device 5 in the accommodation space 80. The first end portion 92aa overlaps the motor 2 when viewed in the vertical direction.

[0190] The second end portion 92ab opens in the pump mounting recess 6c to be connected to the suction port 96a of the pump 96.

[0191] As described above, the differential device 5 and the pump 96 are located on the opposite sides in the horizontal direction of each other with the motor axis J2 interposed therebetween. The first flow path 92a extends in a manner of being erected on the opposite sides in the horizontal direction with the motor 2 interposed therebetween. Further, the first flow path 92a passes through the lower side of the motor 2.

[0192] According to the present embodiment, the first flow path 92a passes through the lower side of the motor 2, and thus it is possible to effectively utilize the region of the lower side of the motor 2 and to reduce the size of the motor unit 1. Thus, it is possible to achieve the downsizing of the motor unit 1.

[0193] At least a portion of the first flow path 92a overlaps the second gear 42 and the ring gear 51 when viewed in the axial direction. Thus, it is possible to reduce the size of the motor unit 1 when viewed in the axial direction, and it is possible to achieve the downsizing of the motor unit 1.

[0194] Further, in the present embodiment, the case where the second gear 42 and the ring gear 51 among the plurality of gears (the first gear 41, the second gear 42, the third gear 43, and the ring gear 51) connected between the motor 2 and the differential device 5 overlap the first flow path 92a when viewed in the axial direction is described. However, as long as at least one of the plurality of gears connected between the motor 2 and the differential device 5 overlaps the first flow path 92a when viewed in the axial direction, the above-described effects can be achieved.

[0195] The first flow path 92a extends from the lower side of the differential device 5 to the suction port 96a of the pump 96. The first flow path 92a is inclined toward the upper side and extends in a straight line as it goes from the first end portion 92aa toward the second end portion 92ab. Further, the suction port 96a of the pump 96 is located on the upper side of the lower end of the differential device 5 and on the lower side of the motor axis J2.

[0196] In order to avoid the pump 96 from being hit by a flying stone from the road in a state where the motor unit 1 is mounted on a vehicle, it is preferable to arrange the pump 96 at a position away from the road. On the other hand, the suction port 96a of the pump 96 is arranged at a position lower than the oil level of the oil reservoir portion P, so that the intake of air can be suppressed.

[0197] The suction port 96a of the present embodiment is located at a position lower than the motor axis J2. Thereby, it is easy to arrange the suction port 96a at a position lower than the oil level of the oil reservoir portion P. In addition, the suction port 96a of the present embodiment is located at a position higher than the lower end of the differential device 5. Thereby, it is possible to realize a configuration in which the pump 96 is away from the road. In addition, by arranging the suction port 96a at a position lower than the motor axis J2, it is easy to configure the first flow path 92a to be linear. Therefore, in the case of adopting a configuration in which the first flow path 92a passes through the inside of the wall portion 6a of the housing 6, it is possible to improve the ease of processing of the first flow path 92a.

[0198] The suction port 96a of the present embodiment is located at a position lower than the liquid level of the oil reservoir portion P of the accommodation space 80. In addition, the height of the liquid level of the oil reservoir portion P varies due to the supply of oil O from the oil reservoir portion P to the first oil passage 91 and the second oil passage 92. The suction port 96a is located at a position lower than the liquid level even in the case where the height of the liquid level of the oil reservoir portion P is the lowest.

[0199] In Figure 1 the suction port 96a is depicted as being located above the liquid level of the oil reservoir portion P. However, Figure 1 the actual suction port 96a is located at a position lower than the liquid level of the oil reservoir portion P.

[0200] The second flow path 92b connects the pump 96 and the cooler 97. The second flow path 92b has a first end portion 92ba and a second end portion 92bb. The first end portion 92ba is open in the pump mounting recess 6c and is connected to the pump outlet 96b of the pump 96. The first end portion 92ba is located on the upstream side of the second oil passage 92 compared to the second end portion 92bb. The second end portion 92bb is connected to the flow inlet 97a of the cooler 97. The second end portion 92bb is located at a position higher than the first end portion 92ba.

[0201] The second flow path 92b has a first path 92bd and a second path 92be. The first path 92bd extends upward from the pump mounting recess 6c. The second path 92be extends from the upper end of the first path 92bd in the horizontal direction. The first path 92bd and the second path 92be are each formed by machining holes that extend in different directions and intersect each other on the wall portion 6a of the housing 6.

[0202] The third flow path 92c connects the cooler 97 and the accommodation space 80. The third flow path 92c extends in a straight line along the horizontal direction. The third flow path 92c has a first end portion 92ca and a second end portion 92cb. The first end portion 92ca is located on the upstream side of the second oil path 92 compared with the second end portion 92cb. The first end portion 92ca is connected with the flow outlet 97b of the cooler 97. The second end portion 92cb is opened in the accommodation space 80 on the upper side of the motor 2. That is, the third flow path 92c is opened in the accommodation space 80 on the upper side of the motor 2. The second end portion 92cb of the third flow path 92c functions as a supply portion 99 that supplies the oil O to the second reservoir 98 located in the accommodation space 80. That is, the second oil path 92 supplies the oil O to the second reservoir 98 in the supply portion 99.

[0203] The flow outlet 97b of the cooler 97 overlaps with the motor 2 in the axial direction of the motor axis J2. That is, the flow outlet 97b of the cooler 97 is arranged to overlap with the motor 2 when viewed in the radial direction. In other words, the flow outlet 97b of the cooler 97 is located between the both end portions of the stator 30 in the axial direction. Therefore, it is possible to shorten the third flow path 92c that connects the flow outlet 97b of the cooler 97 and the accommodation space 80, and it is possible to supply the cooled oil O to the accommodation space 80 in a low temperature state. In addition, by arranging the third flow path 97c to overlap with the motor 2 in the radial direction, it is possible to reduce the axial dimension of the motor unit 1, and it is possible to achieve the downsizing of the motor unit 1.

[0204] (Second reservoir)

[0205] Figure 11 is a perspective view of the motor unit 1. In addition, Figure 12 is a plan view of the second reservoir 98. In addition, in Figure 11 , the motor accommodation portion 61 of the housing 6 and the closing portion 63 are omitted from the illustration.

[0206] As Figure 11As shown, the second reservoir (main reservoir) 98 is located in the motor chamber 81 of the receiving space 80. The second reservoir 98 is located above the motor. The second reservoir 98 has a bottom (first bottom 98c and second bottom 98g) and sidewall portions extending upward from the bottom (first sidewall portion 98d, second sidewall portion 98e, third sidewall portion 98f, fourth sidewall portion 98h, fifth sidewall portion 98i, sixth sidewall portion 98j, and seventh sidewall portion 98n). The second reservoir 98 stores oil O supplied to the motor chamber 81 via the supply portion 99 of the third flow path 92c in the space surrounded by the bottom and sidewall portions. The second reservoir 98 has multiple outlets (first outlet 98r, second outlet 98o, third outlet 98x, fourth outlet 98t, fifth outlet 98u, and sixth outlet 98v). Each outlet supplies the oil O stored in the second reservoir 98 to the motor 2. That is, the second reservoir 98 supplies the stored oil O to each part of the motor 2 from above through the outlet.

[0207] According to this embodiment, the second reservoir 98 is located above the motor 2, and the stored oil O is supplied to the upper side of the motor 2 from multiple outlets. The oil O flows from the upper side to the lower side along the outer peripheral surface of the motor 2 and absorbs the heat of the motor 2, thus cooling the entire motor 2.

[0208] like Figure 12 As shown, the second reservoir 98 has a first end 98p located axially on the side of the gear chamber 82 and a second end 98q located axially on the side opposite to the first end 98p. Additionally, the second reservoir 98 has a groove-shaped first storage section 98A extending axially and a second storage section 98B located relative to the first storage section 98A on the side of the second end 98q.

[0209] The first storage section 98A has a first bottom 98c, a first side wall 98d, a second side wall 98e, and a third side wall 98f. In addition, the first storage section 98A is provided with a first outlet 98r, a second outlet 98o, and a third outlet 98x.

[0210] The first bottom 98c is rectangular in shape along its length. The two ends of the first bottom 98c are located above the coil ends 31a located at both ends of the stator 30. A first outlet 98r is provided in the first bottom 98c. The first outlet 98r is located in the region on the side of the first end 98p of the first bottom 98c.

[0211] The first sidewall portion 98d and the second sidewall portion 98e extend axially. In addition, the first sidewall portion 98e and the second sidewall portion 98e are circumferentially opposite each other on the motor axis J2.

[0212] An inlet 98s is provided on the first sidewall portion 98d. The inlet 98s is a U-shaped notch that opens upward. The inlet 98s is connected to a supply portion 99. The inlet 98s is located at the axial center of the first sidewall portion 98d. Thus, the inlet 98s allows oil O to flow from the second reservoir 98 to the first end 98p and the second end 98q, respectively.

[0213] A protrusion 98w protruding toward the first sidewall 98d is provided on the second sidewall 98e. The protrusion 98w is located on the front of the inlet 98s. The protrusion 98w has an inclined surface whose protrusion height decreases as it moves from the center toward the first end 98p side and the second end 98q side. The protrusion 98w facilitates the smooth diversion of oil O flowing from the inlet 98s to the second reservoir 98 to the first end 98p side and the second end 98q side.

[0214] A second outlet 98o is provided on the second sidewall portion 98e. The second outlet 98o is located in the region on the side of the first end portion 98p of the second sidewall portion 98e. The second outlet 98o is located near the first outlet 98r.

[0215] like Figure 11 As shown, the third sidewall portion 98f is located on the side of the first end 98p of the second reservoir 98. The third sidewall portion 98f is located above one coil end 31a of the stator 30. The height of the upper end of the third sidewall portion 98f is lower than the height of the upper ends of the first sidewall portion 98d and the second sidewall portion 98e. In addition, the height of the upper end of the third sidewall portion 98f is approximately equal to the height of the lower end of the opening of the second outlet 98o. The space above the second sidewall portion 98e functions as the third outlet 98x for supplying oil O when the level of oil O accumulated in the second reservoir 98 becomes high.

[0216] The second storage section 98B extends circumferentially along the stator 30. The second storage section 98B has a second bottom 98g, a fourth side wall 98h, a fifth side wall 98i, a sixth side wall 98j, a seventh side wall 98n, and a stepped section 98k.

[0217] In addition, the second storage section 98B is provided with a fourth outlet 98t, a fifth outlet 98u, a sixth outlet 98v, and an overflow section 98y.

[0218] The second bottom 98g is located on the second end 98q side relative to the first bottom 98c. The second bottom 98g is located lower than the first bottom 98c. A stepped portion 98k is provided at the boundary between the first bottom 98c and the second bottom 98g. The second storage section 98B is located lower than the first storage section 98A. Oil O flowing from the first storage section 98A to the second end 98q side is stored in the second storage section 98B.

[0219] The second bottom 98g is located above one coil end 31a of the stator 30. The second bottom 98g is curved along the outer circumferential surface of the motor 2. As a result, the capacity of the oil O stored in the second reservoir 98 can be increased without increasing the size of the motor unit 1. When viewed in the vertical direction, the second bottom 98g tilts downward from the portion overlapping with the motor axis J2 toward both circumferential sides. When viewed in the vertical direction, the second reservoir 98B clamps the motor axis J2 and is connected to the first reservoir 98A on one side.

[0220] like Figure 12 As shown, regarding the second storage section 98B, the area on one side that clamps the motor shaft J2 when viewed vertically, i.e., the area connected to the first storage section 98A, is divided into the first region 98gA, and the area on the other side that clamps the motor shaft J2 is divided into the second region 98gB. The second bottom 98g is the highest point on the boundary line between the first region 98gA and the second region 98gB. Oil O flowing from the first storage section 98A to the second storage section 98B first accumulates in the first region 98gA. When the liquid level in the first region 98gA reaches the height of the boundary line, the oil O flows into the second region 98gB. Thus, the boundary line functions as a weir 98gC provided at the second bottom 98g. That is, a weir 98gC is provided at the second bottom 98g in an upward-protruding manner, dividing the second storage section 98B of the second reservoir 98 into the first region 98gA and the second region 98gB. Oil O flows into one area (area 1, 98gA) and causes the liquid level to exceed the weir 98gC, thus flowing into another area (area 2, 98gB).

[0221] As described below, a fourth outlet 98t, a fifth outlet 98u, and a sixth outlet 98v, arranged circumferentially, are provided on the sixth sidewall portion 98j extending circumferentially. Additionally, an overflow portion 98y is provided on the fifth sidewall portion 98i. The fourth outlet 98t and the fifth outlet 98u open in the first region 98gA, and the sixth outlet 98v and the overflow portion 98y open in the second region 98gB. That is, the second reservoir 98 has outlets in each of the multiple regions (first region 98gA and second region 98gB) divided by the weir 98gC. Therefore, oil O flows out only from the fourth outlet 98t and the fifth outlet 98u before the liquid level in the first region 98gA exceeds the weir 98gC. Furthermore, after the level of oil O in the first region 98gA exceeds the weir 98gC, it flows out from the fourth outlet 98t, the fifth outlet 98u, the sixth outlet 98v, and the overflow portion 98y. Therefore, according to this embodiment, the number of outlets from which oil O flows out when the stored amount increases in the second reservoir 98 can be increased. In particular, when the load on the motor 2 increases and the motor 2 becomes hot, the amount of oil O supplied to the second reservoir 98 by the pump 96 increases. Therefore, according to this embodiment, when the motor 2 becomes hot, the number of oil O supply points to the motor 2 can be increased to widen the cooling range, and the amount of oil O supplied to the motor 2 can be increased.

[0222] The fourth sidewall portion 98h and the fifth sidewall portion 98i are located at the two circumferential ends of the second storage portion 98B. The fourth sidewall portion 98h and the fifth sidewall portion 98i are circumferentially opposite each other. The fourth sidewall portion 98h and the fifth sidewall portion 98i extend axially. The fourth sidewall portion 98h connects to the first sidewall portion 98d and extends to the second end portion 98q side.

[0223] An overflow portion 98y is provided on the fifth side wall portion 98i. The overflow portion 98y is located at the upper end of the fifth side wall portion 98i and is partially lower in height. The overflow portion 98y is located above the lower end of the openings of the fourth outlet 98t, the fifth outlet 98u, and the sixth outlet 98v of the second storage portion 98B. Therefore, after the liquid level of oil O in the second storage portion 98B becomes higher than that of the fourth outlet 98t, the fifth outlet 98u, and the sixth outlet 98v, it overflows from the overflow portion 98y. A secondary reservoir 95, described later, is provided below the overflow portion. The oil O overflowing from the overflow portion 98y is stored in the secondary reservoir 95.

[0224] Furthermore, in this specification, "overflow" refers to the liquid flowing out of the reservoir when the liquid level in the reservoir reaches a certain point. Therefore, situations such as liquid flowing out from the bottom of the reservoir are not considered "overflow".

[0225] The sixth sidewall portion 98j is located on the second end 98q side of the second reservoir 98. The sixth sidewall portion 96j extends circumferentially. The sixth sidewall portion 98j is located above one coil end 31a of the stator 30. The sixth sidewall portion 98j is provided with a fourth outlet 98t, a fifth outlet 98u, and a sixth outlet 98v. The fourth outlet 98t, the fifth outlet 98u, and the sixth outlet 98v are holes provided in the sixth sidewall portion 98j and penetrate the inside and outside of the second reservoir 98. The fourth outlet 98t, the fifth outlet 98u, and the sixth outlet 98v are arranged circumferentially. Figure 11 As shown, the heights of the fourth outlet 98t, the fifth outlet 98u, and the sixth outlet 98v are all different. Therefore, according to this embodiment, the number of outlets from which oil O flows out can be increased based on the oil O level in the second reservoir 98. This increases the number of oil O supply points to the motor 2, widening the cooling range, and also increases the amount of oil O supplied to the motor 2.

[0226] Furthermore, this effect can be achieved simply by ensuring that at least two of the multiple outlets of the second reservoir 98 have different heights.

[0227] The 7th side wall portion 98n extends circumferentially. The 7th side wall portion 98n is axially opposed to the 6th side wall portion 98j. The 7th side wall portion 98n and the stepped portion 98k are continuous circumferentially. A storage portion 98na is provided in the 7th side wall portion 97n for storing the fixing screws of the stator core 32.

[0228] According to this embodiment, the second oil passage 92 supplies oil O stored in the second reservoir 98 to the motor 2 from multiple outlets. Each outlet supplies oil O to the motor 2 at a certain flow rate, thereby improving the cooling efficiency of oil O on the motor 2.

[0229] According to this embodiment, the second reservoir 98 has multiple outlets (first outlet 98r, second outlet 98o, third outlet 98x, fourth outlet 98t, fifth outlet 98u, and sixth outlet 98v). Therefore, the second reservoir 98 can simultaneously supply oil O to the motor 2 from multiple locations, and can simultaneously cool various parts of the motor 2.

[0230] According to this embodiment, the second reservoir 98 extends axially. Furthermore, the second reservoir 98 has outlets at both axial ends. The outlets located at both axial ends of the second reservoir 98 are situated above the coil ends 31a. This allows for direct cooling of the coil 31 by applying oil O to the coil ends 31a located at both axial ends of the stator 30. More specifically, the oil O applied to the coil 31 seeps in through the gaps between the conductors constituting the coil 31. The oil O absorbed into the coil 31 absorbs heat from the coil while permeating the entire coil 31 through capillary force and gravity acting on the conductor tubes. Additionally, the oil O accumulates at the lowest part of the inner circumferential surface of the stator core 32 and drips from both axial ends of the coil 31.

[0231] In addition, the effect of directly cooling the oil O by supplying oil O directly to the coil end 31a is achieved by having at least two of the multiple outlets located at both ends of the axial direction of the second reservoir 98.

[0232] According to this embodiment, the supply section 99 for supplying oil O to the second reservoir 98 is located axially between the outlets located at both ends of the second reservoir 98. Therefore, the oil O supplied from the supply section 99 can flow out from the outlets located at both ends respectively.

[0233] (A variation of the second liquid reservoir)

[0234] Figure 13 This is a perspective view of the second reservoir 198, a modified example that can be used in this embodiment. Furthermore, structural elements that are the same as those in the above embodiment are described using the same reference numerals.

[0235] The modified second reservoir 198 is a shallow rectangular box-shaped vessel with an opening at the top. The second reservoir 198 has a central oil storage section 198a and four oil supply sections 198b located around the central oil storage section 198a. The central oil storage section 198a and the four oil supply sections 198b are spaced apart from each other.

[0236] The central oil storage section 198a stores the oil O flowing in from the supply section 99. The central oil storage section 198a is separated from the oil supply section 198b by a circular bottom surface 198ab and a cylindrical wall 198aa extending upward from the bottom surface 198ab.

[0237] Four oil supply sections 198b are configured to surround the central oil reservoir 198a. Each oil supply section 198b is generally rectangular. Near the corners of the two outer walls 198ba of each oil supply section 198b extending in opposite directions, there are outlets 198c that communicate with the interior and exterior of the oil supply section 198b. One of the two outlets 198c opens axially on the motor 2, and the other opens circumferentially. Each of the four oil supply sections 198b has two outlets 198c, therefore the second reservoir 198 has a total of eight outlets 198c.

[0238] The second reservoir 198 is configured such that its bottom surface is horizontal above the stator 30. Oil O supplied from the supply section 99 overflows from the cylindrical wall 198aa and flows into the four oil supply sections 198b when the central oil reservoir 198aa is full. Because the second reservoir 198 is horizontal and the cylindrical wall 198aa is at the same height throughout its circumference, oil O flows evenly into the four oil supply sections 198b. Oil O accumulates in the four oil supply sections 198b and flows outward from the outlet 198c.

[0239] The second reservoir 198 is longer along the axial direction than the stator core 32. Oil O is supplied to the motor 2 from an oil supply section 198b via two outlets 198c along the axial and circumferential directions. According to this variation, the second reservoir 198 can supply oil O to the motor 2 from multiple outlets in multiple directions.

[0240] (Auxiliary reservoir)

[0241] Figure 14 This is a cross-sectional view of the motor unit 1, showing the auxiliary reservoir 95. Additionally, in... Figure 14 In the diagram, the protrusion 63d of the closed portion 63 provided on the housing 6 is shown by imaginary lines. Additionally, in... Figure 14 In the image, the oil O stored in the auxiliary reservoir 95 is highlighted with a dotted pattern.

[0242] The auxiliary reservoir 95 receives oil O overflowing from the second reservoir 98 in the second oil passage 92. That is, an auxiliary reservoir 95 for storing oil O is provided in the path of the second oil passage 92. The second reservoir 98 functions as the main reservoir relative to the auxiliary reservoir 95. The second reservoir 98 is located upstream of the second oil passage 92 relative to the auxiliary reservoir 95.

[0243] The auxiliary reservoir 95 is located directly below the overflow portion 98y. That is, the auxiliary reservoir 95 and the overflow portion 98y overlap when viewed vertically. Thus, the auxiliary reservoir 95 can receive the oil O overflowing from the second reservoir 98.

[0244] The auxiliary reservoir 95 has a first portion 95A located on one circumferential side relative to the second reservoir 98 and a second portion 95B located on the other circumferential side. The first portion 95A and the second portion 95B are connected to each other. The auxiliary reservoir 95 has two outlets 61k in each of the first portion 95A and the second portion 95B, for a total of four outlets 61k. The four outlets 61k are arranged along the circumference of the motor 2. In addition, the heights of the multiple outlets 61k are different from each other.

[0245] The auxiliary reservoir 95 is formed by the inner surface 61g of the motor housing 61 and the inner wall surface of the protrusion 63d of the sealing portion 63. The inner surface 61g of the motor housing 61 has an inner circumferential surface 61i facing radially inward and an opposing surface 61h facing the sealing portion 63 in the axial direction. The opposing surface 61h contacts the axial surface of the protrusion 63d. Oil O will not flow out from the contact portion between the protrusion 63d and the opposing surface 61h. According to this embodiment, the auxiliary reservoir 95 is configured as a gap between other components, so there is no need to use other components, and the increase in the number of components can be suppressed.

[0246] A recess 61j is provided on the opposing surface 61h, arranged circumferentially and recessed axially. The recess 61j is recessed in a direction that increases the gap between the inner surface 61g of the motor housing 61 and the inner wall surface of the protrusion 63d. Oil O flows out from the recess 61j to the lower side. That is, the recess 61j constitutes an outlet 61k. The outlet 61k is located above the coil end 31a of the stator 30. Therefore, the oil O flowing out from the outlet 61k cools the coil 31 at the coil end 31a.

[0247] In this embodiment, a recess 61j is provided on the inner side 61g at the contact point between the inner side 61g of the motor housing 61 and the inner wall surface of the protrusion 63d. However, a recess may also be provided on the inner wall surface of the protrusion 63d.

[0248] According to this embodiment, in addition to the second reservoir 98, a secondary reservoir 95 is also provided, so that oil O can flow out from the outlet 61k of the secondary reservoir 95 in addition to the outlet of the second reservoir 98, enabling cooling of the motor 2 over a wider range. Furthermore, the multiple outlets 61k of the secondary reservoir 95 are arranged circumferentially. This allows for cooling of the coil ends 31a of the stator 30 over a wider range. Additionally, the heights of the multiple outlets 61k are different, so the timing of outflow can vary depending on the level of oil O accumulated in the secondary reservoir 95.

[0249] According to this embodiment, oil O overflowing from the second reservoir 98 is stored in the auxiliary reservoir 95. When the motor 2 experiences a high load and its temperature increases, the pump 96 increases the amount of oil O supplied to the second reservoir 98. Therefore, when the motor 2 is under high load, oil O overflowing from the second reservoir 98 can also be supplied to the motor 2 through the outlet 61k of the auxiliary reservoir 95. According to this embodiment, when the motor 2 is under high load, a wide range of cooling for the motor 2 can be achieved in the oil O. That is, by providing the auxiliary reservoir 95, the range of oil O supplied to the motor 2 can be automatically widened when the operation of the motor 2 changes from a stable state to a high load state.

[0250] Furthermore, in this embodiment, the lower end of the auxiliary reservoir 95 is located above the motor axis J2. Therefore, the outlet 61k of the auxiliary reservoir 95 is located above the motor axis J2. The motor 2 is approximately cylindrical. By positioning the lower end of the auxiliary reservoir 95 above the motor axis J2, the oil O flowing from the outlet 61k can flow along the surface of the motor 2, thereby cooling the motor 2. Additionally, the motor 2 is the widest part of its horizontal cross-section through the motor axis J2. With the lower end of the auxiliary reservoir 95 located above the motor axis J2, the oil O flowing along the surface of the motor 2 passes through the widest area in the horizontal direction of the motor. This allows for effective cooling of the motor 2.

[0251] (The common section between oil lines 1 and 2)

[0252] like Figure 1 As shown, when the motor 2 is driven, oil O is supplied to the motor 2 via the first oil passage 91 and the second oil passage 92. The oil O supplied to the motor 2 cools the motor 2 while dripping down and accumulating in the lower area of ​​the motor chamber 81. The oil O accumulated in the lower area of ​​the motor chamber 81 moves to the gear chamber 82 through the partition wall opening 68 provided in the partition wall 61c.

[0253] Figure 15 This is a front view of the spacer wall 61c of the housing 6 as seen from the motor chamber 81 side.

[0254] The partition wall opening 68 is located below the through insertion hole 61f through which the shaft 21 is inserted. The partition wall opening 68 has a first opening 68a and a second opening 68b located above the first opening 68a. The first opening 68a and the second opening 68b connect the motor chamber 81 and the gear chamber 82, respectively.

[0255] like Figure 19As shown, the lower end of the partition wall opening 68 (i.e., the lower end of the first opening 68a) is located above the lower limit height Lmin of the oil level in the gear chamber 82 when the motor 2 is stationary. Therefore, the partition wall opening 68 can move a large amount of oil O to the oil reservoir P when the motor 2 is stopped.

[0256] like Figure 15 As shown, the first opening 68a is circular when viewed from above. The lower end of the first opening 68a is located below the lower end of the stator 30. The first opening 68a is located near the bottom 81a of the motor chamber 81. Therefore, the first opening 68a allows oil O to move to the gear chamber 82 until the oil O accumulated in the lower area of ​​the motor chamber 81 is substantially depleted.

[0257] Viewed vertically, the first opening 68a overlaps with the motor axis J2. Furthermore, the first opening 68a is located in a recess 61q on the inner circumferential surface of the peripheral wall portion 61a. Here, the peripheral wall portion 61a and the recess 61q will be described. The motor housing portion 61 of the housing 6 has a peripheral wall portion 61a, which has a cylindrical shape along the outer circumferential surface of the stator 30. A recess 61q is provided on the inner circumferential surface of the peripheral wall portion 61a, recessed radially outward. The recess 61q extends axially. The recess 61q is located directly below the motor axis J2. That is, when viewed vertically, the recess 61q overlaps with the motor axis J2. Because the peripheral wall portion 61a has a cylindrical shape, oil O in the motor chamber 81 flows along the inner circumferential surface of the peripheral wall portion 61a and collects inside the recess 61q. The first opening 68a is located in the recess 61q, so the oil O collected in the motor chamber 81 inside the recess 61q can be effectively moved to the gear chamber 82.

[0258] The second opening 68b is located above the first opening 68a. When viewed from above, the second opening 68b is a rectangle with its length along the horizontal direction. The second opening 68b has a larger opening area than the first opening 68a. Furthermore, the second opening 68b has a larger width along the horizontal direction than the first opening 68a. The second opening 68b has a lower end 68c extending horizontally.

[0259] Driven by motor 2, the supply of oil O per unit time from oil passages 90 (i.e., first oil passage 91 and second oil passage 92) to motor 2 increases. As a result, the level of oil O accumulated in the lower region of motor chamber 81 rises. In the partition wall opening 68, the region located below the level of oil O accumulated in the lower region of motor chamber 81 is called the first region S, and the region located above the level of oil O is called the second region R. The partition wall opening 68 moves oil O to gear chamber 82 in the first region S. As the level of oil O accumulated in the lower region of gear chamber 82 rises, the area of ​​the first region S increases, and the area of ​​the second region R decreases. When the area of ​​the first region S increases, the amount of oil O moving from motor chamber 81 to gear chamber 82 through partition wall opening 68 increases.

[0260] In this embodiment, the partition wall opening 68 is configured such that when the oil level in the motor chamber 81 increases, the amount of oil O moving from the motor chamber 81 to the gear chamber 82 via the partition wall opening 68 increases. Therefore, excessively high oil levels in the motor chamber 81 can be prevented. That is, it can prevent the rotor 20 in the motor chamber 81 from being immersed in the oil O or from being excessively raised. Therefore, it can prevent the rotational efficiency of the motor 2 from decreasing due to the flow resistance of the oil O.

[0261] Furthermore, according to this embodiment, based on the height of the oil O in the motor chamber 81, the oil O in the motor chamber 81 is moved to the gear chamber 82 side, thereby enabling efficient utilization of the oil O in the motor unit 1. This not only reduces the amount of oil O used and makes the motor unit 1 lighter, but also improves the energy efficiency required for cooling the oil O.

[0262] like Figure 19 As shown, the lower end of the second opening 68b is positioned above the height of the oil O in the gear chamber 82 (upper limit height Lmin and lower limit height Lmin) regardless of whether the motor 2 is stationary or driven. Therefore, the second opening 68b will not be submerged on the gear chamber 82 side. The second opening 68b allows the oil O to move into the gear chamber 82 regardless of the oil level, thereby preventing the rotor 20 from being immersed in the oil O.

[0263] The change in the amount of movement of the oil O moving through the partition wall opening 68 as the level of the oil O accumulated on the lower side of the motor chamber 81 rises will be explained in more detail. Here, the level of the oil O accumulated on the lower side of the motor chamber 81, that is, the level reaching the lower end 68c of the second opening 68b, is defined as the first level OL. That is, the lower end of the second opening 68b is located at the first level OL. The first level OL is located above the lower end of the stator 30 and below the lower end of the rotor 20.

[0264] Figure 16This is a graph showing the relationship between the height of the oil O accumulated on the lower side of the motor chamber 81 and the area of ​​the first region S. The area of ​​the first region S is correlated with the flow rate of oil O flowing out from the partition wall opening 68 (approximately proportional).

[0265] Oil O is supplied to motor 2 as it is driven, and begins to accumulate in the lower region of motor chamber 81. The oil O accumulated in the lower region of motor chamber 81 moves from motor chamber 81 to gear chamber 82 through the first opening 68a. When the amount of oil O supplied to motor 2 per unit time exceeds the flow rate of oil O moving from motor chamber 81 to gear chamber 82 through the first opening 68a, the level of oil O accumulated in the lower region of motor chamber 81 rises. When the level reaches the first level OL, oil O flows out from both the first opening 68a and the second opening 68b. The second opening 68b is wider horizontally than the first opening 68a, so the area of ​​the first region S increases sharply before and after the level reaches the first level OL. Simultaneously, the flow rate of oil O flowing from motor chamber 81 to gear chamber 82 through partition wall opening 68 increases sharply. As described above, the first liquid level OL is set at a position lower than the lower end of the rotor 20. Therefore, according to this embodiment, it is possible to suppress the decrease in the rotational efficiency of the rotor 20 in the motor chamber 81 due to the flow resistance of the oil O.

[0266] Preferably, the horizontal width of the second opening 68b is such that when the liquid level reaches a position higher than the first liquid level OL, the flow rate of oil O flowing out from the partition wall opening 68 is greater than the oil O supplied to the motor 2 in the oil passage 90. This prevents the oil level in the lower region of the motor chamber 81 from significantly exceeding the first liquid level OL, and prevents the rotor 20 from being immersed in the oil O.

[0267] like Figure 1 As shown, the first oil passage 91 includes a lifting path 91a and an internal rotor path 91d. The lifting path 91a moves oil O from the gear chamber 82 to the motor chamber 81 by using a differential device 5 to lift the oil. The amount of oil O lifted by the differential device 5 depends on the rotational speed of the differential device 5. Therefore, the lifting path 91a increases or decreases the amount of oil O moving towards the motor chamber 81 according to the vehicle speed. Meanwhile, the internal rotor path 91d draws oil O from the gear chamber 82 side to the motor chamber 81 side by the centrifugal force of the rotor 20. The centrifugal force depends on the rotational speed of the rotor 20. Therefore, the internal rotor path 91d increases or decreases the amount of oil O moving towards the motor chamber 81 according to the vehicle speed. In other words, the first oil passage 91 increases or decreases the amount of oil O moving towards the motor chamber 81 according to the vehicle speed.

[0268] On the other hand, the second oil passage 92 moves oil O from the gear chamber 82 to the motor chamber 81 via a pump (electric pump) 96. The supply of oil O to the pump 96 is controlled, for example, based on the temperature measurement results of the motor 2. Therefore, the second oil passage 92 does not increase or decrease the amount of oil O moving to the motor chamber 81 according to the vehicle speed.

[0269] When the motor 2 is stationary, the second oil passage 92 stops supplying oil O to the motor 2. However, when the motor 2 starts, the second oil passage 92 begins moving oil O into the motor chamber 81. Therefore, when the motor 2 stops, the oil level in the oil reservoir P of the gear chamber 82 can be increased. As a result, the rotation of the motor 2 immediately after startup causes the second gear 42, the third gear 43, and the ring gear 51 to rotate within the oil reservoir P, allowing oil O to be distributed throughout the gear teeth.

[0270] According to this embodiment, the second oil passage 92 lifts oil O from the oil reservoir P regardless of the vehicle speed. Therefore, the second oil passage 92 can lower the oil level in the oil reservoir P even when the vehicle is traveling at low speeds. As a result, at low speeds, the reduction in the rotational efficiency of the gears in the gear chamber 82 due to the oil O in the oil reservoir P can be suppressed.

[0271] (Example of a variation with an opening in the partition wall)

[0272] Figure 17 This is a front view of the partition wall opening 168, a modified example that can be used in this embodiment. Furthermore, structural elements that are the same as those in the above embodiment are described using the same reference numerals.

[0273] In the modified example, the partition wall opening 168 has an elongated orifice 168a extending in the vertical direction and a wide extension 168b connected to the elongated orifice 168a on its upper side. The lower end of the elongated orifice 168a is located near the bottom 81a of the motor chamber 81. When viewed in the vertical direction, the elongated orifice 168a overlaps with the motor axis J2. The extension 168b is wider in the horizontal direction than the elongated orifice 168a. When viewed from above, the extension 168b is a rectangle with the horizontal direction as its length. The extension 168b has a lower end 168c extending in the horizontal direction. The lower end 168c is located at the aforementioned first liquid level OL.

[0274] In the partition wall opening 168, the region located below the liquid surface of oil O is called the first region S, and the region located above the liquid surface is called the second region R.

[0275] Figure 18 It is a graph showing the relationship between the height of the oil O accumulated on the lower side of the motor chamber 81 in this modified example and the area of ​​the first region S.

[0276] In this modified example, when the liquid level reaches the first liquid level OL, oil O flows out from the extension portion 168b in addition to the elongated orifice 168a, and the area of ​​the first region S increases sharply. Simultaneously, the flow rate of oil O from the motor chamber 81 to the gear chamber 82 via the partition wall opening 168 increases sharply. The first liquid level OL is set at a position lower than the lower end of the rotor 20, thus suppressing the decrease in the rotational efficiency of the rotor 20 due to the flow resistance of the oil O.

[0277] (Liquid level in the oil reservoir)

[0278] like Figure 1 As shown, in the first oil passage 91, when the motor 2 is driven, the pump 96 drives the pump to supply oil O from the oil reservoir P to the motor 2. Additionally, when the motor 2 is driven, the first oil passage 91, via the lifting mechanism 5, moves the oil O from the oil reservoir P to the first reservoir 93, supplying oil O into the interior of the motor 2. That is, both the first oil passage 91 and the second oil passage 92 supply oil O from the oil reservoir P to the motor 2 when the motor 2 is driven. Therefore, when the motor 2 is driven, the oil level in the oil reservoir P, located in the area below the gear chamber 82, drops. Furthermore, the oil O supplied to the motor 2 accumulates in the space below the motor chamber 81; therefore, when the motor 2 is driven, the oil level in the area below the motor chamber 81 that has accumulated rises.

[0279] On the other hand, when the motor 2 is stopped, the first oil passage 91 and the second oil passage 92 stop supplying oil O to the motor 2. As a result, the oil O that drips onto the bottom of the motor 2 temporarily accumulates in the area below the motor chamber 81, and moves through the partition wall opening 68 to the oil reservoir P in the area below the gear chamber 82. Therefore, when the motor 2 is stopped, the level of oil O accumulated in the area below the motor chamber drops, and the level of oil in the oil reservoir P in the area below the gear chamber 82 rises.

[0280] Figure 19 This is a side view showing the arrangement of the gears located inside the gear chamber 82. Additionally, in Figure 19 In this version, the gear housing 62 and the bearings that support each shaft of the housing 6 are omitted.

[0281] like Figure 19 As shown, according to this embodiment, the height of the oil O accumulated in the oil storage section P varies between the upper limit height Lmax and the lower limit height Lmin by supplying oil O to the oil passages 90 (the first oil passage 91 and the second oil passage 92). Figure 1 As shown, a first reservoir 93 is provided in the first oil passage 91. Additionally, a second reservoir 98 and an auxiliary reservoir 95 are provided in the second oil passage 92. Figure 1 The middle part is omitted; please refer to the following: Figure 14Furthermore, oil O accumulates in the area below the motor chamber 81 where the first oil passage 91 and the second oil passage 92 merge. Thus, multiple oil O accumulation points are provided along the path of the first oil passage 91 and the second oil passage 92. Consequently, by supplying oil O to the motor 2, the oil O accumulated in the oil reservoir P moves to a reservoir or similar device along the aforementioned path, causing the liquid level in the oil reservoir P to drop. As a result, the gears inside the gear chamber 82 can be exposed from the oil O in the oil reservoir P, thereby improving the gear rotation efficiency.

[0282] like Figure 19 As shown, in a pair of gears (second gear 42 and third gear 43) that rotate around the central axis J4, the lower end of the second gear 42, which has the larger diameter and is connected to the motor 2, is located below the upper limit height Lmax of the liquid surface. Additionally, the lower end of the second gear 42 is located above the lower limit height Lmin of the liquid surface.

[0283] Similarly, the lower end of the third gear 43, which is the minor diameter of the pair of gears (second gear 42 and third gear 43) rotating around the central axis J4 and connected to the differential device 5, is located below the upper limit height Lmax of the liquid surface. Additionally, the lower end of the third gear 43 is located above the lower limit height Lmin of the liquid surface.

[0284] The upper limit height Lmax of the oil level in the oil reservoir P refers to the state where the motor 2 stops supplying oil O from the oil reservoir P to the motor 2. According to this embodiment, when the motor 2 is stopped, a portion of the second gear 42 and the third gear 43 can be immersed in the oil O in the oil reservoir P. Therefore, when the motor 2 is driven, the oil O can immediately cover the tooth surfaces of the second gear 42 and the third gear 43, improving the transmission efficiency between the gears.

[0285] The lower limit height Lmin of the oil level in the oil reservoir P refers to the state in which the motor 2 is driven under high load, maximizing the supply of oil O from the oil reservoir P to the motor 2. According to this embodiment, when the motor 2 is driven, the second gear 42 and the third gear 43 are located above the oil level in the oil reservoir P, thus suppressing the reduction in the rotational efficiency of the second gear 42 and the third gear 43 due to the flow resistance of the oil O. This improves the driving efficiency of the motor unit 1.

[0286] The ring gear 51, which is installed in the differential device 5, connected to the reduction device 4, and rotates around the differential axis J5, has its lower end positioned below the liquid surface when the upper limit height Lmax and lower limit height Lmin are both of the liquid surface.

[0287] According to this embodiment, regardless of changes in the oil level in the oil reservoir P, at least a portion of the ring gear 51 is positioned below the oil level of the oil O in the oil reservoir P. Therefore, even when the oil level in the oil reservoir P is lowered due to driving the motor 2, the ring gear 51 can still lift the oil O from the oil reservoir P and supply the oil O to the tooth surfaces of each gear in the gear chamber 82, thereby improving the torque transmission efficiency between the gears.

[0288] (Summary of the oil system)

[0289] Reference Figure 1 The flow of oil O in the oil circuit 90 that accompanies the drive of motor unit 1 will be explained.

[0290] When the motor unit 1 is installed in a hybrid electric vehicle or a plug-in hybrid electric vehicle, the vehicle can travel in any one of the following modes: engine mode, which is driven by the engine only; motor mode, which is driven by the motor only; and hybrid mode, which is driven by both the engine and the motor.

[0291] In engine mode, motor 2 stops, but differential 5 is driven by the engine, so oil O is lifted from oil reservoir P. The lifted oil O accumulates in the first reservoir 93, but rotor 20 does not rotate, so oil O does not scatter towards stator 30. In addition, in engine mode, pump 96 is not driven, and oil O is not supplied to the second oil passage 92.

[0292] In motor mode and hybrid mode, when the vehicle is climbing a hill, the output of motor 2 increases, and the heat generated by motor 2 increases. In such cases, the injection rate of pump 96 is increased to supply more oil O to stator 30, thereby accelerating cooling. On the other hand, when the vehicle is going downhill (i.e., when no load is applied to motor 2), or when motor 2 has not reached a high temperature, such as when the vehicle is starting or when used in cold regions, the injection rate of pump 96 is reduced.

[0293] The second oil passage 92 can adjust the supply amount of pump 96 to motor 2 according to the temperature of motor 2, vehicle drive mode, etc. According to this embodiment, the energy required for cooling motor 2 can be optimized. This effect is achieved when pump 96 is an electrically driven pump.

[0294] The pump output of pump 96 can be managed based on temperature data detected by a temperature sensor installed in motor 2. Furthermore, by combining data such as vehicle operating history, operating status, vehicle posture, external air temperature, and the weight of occupants and cargo, the temperature change of motor 2 can be predicted. Management can be implemented based on this predicted temperature change to prevent motor 2 from becoming overheated.

[0295] According to this embodiment, the oil passage 90 supplies oil O to the stator 30 from multiple locations, thus effectively cooling the stator 30 as a whole. Furthermore, according to this embodiment, the oil O functions as both cooling oil and lubricating oil. Therefore, there is no need to separately provide paths for cooling oil and lubricating oil, achieving cost reduction.

[0296] (Countermeasures against contaminants in the oil system)

[0297] The oil O used for cooling the motor unit 1 is also used for lubricating the differential device 5 and the reduction gear 4. Therefore, there is concern that contaminants such as metal powder generated during mechanical contact may contaminate the oil O. There is also concern that contaminants in the first oil passage 91 and the second oil passage 92 may degrade the flowability of the oil O. Contaminants are removed through periodic replacement of the oil O. Alternatively, a contaminant-capturing unit may be installed in either or both of the first oil passage 91 and the second oil passage 92. For example, such as… Figure 9 As shown, a permanent magnet 98m can be installed in the second reservoir 98 to capture contaminants magnetically and suppress their diffusion. In this case, the deterioration of the fluidity of oil O can be suppressed.

[0298] (Configuration of each axis)

[0299] The motor shaft J2, intermediate shaft J4, and differential shaft J5 extend parallel to each other in the horizontal direction. The intermediate shaft J4 and differential shaft J5 are located below the motor shaft J2. Therefore, the reduction gear 4 and differential gear 5 are located below the motor 2.

[0300] When viewed from the axial direction of the motor shaft J2, the line segment that imaginarily connects the motor shaft J2 and the intermediate shaft J4 is designated as the first line segment L1, the line segment that imaginarily connects the intermediate shaft J4 and the differential shaft J5 is designated as the second line segment L2, and the line segment that imaginarily connects the motor shaft J2 and the differential shaft J5 is designated as the third line segment L3.

[0301] According to this embodiment, the second line segment L2 extends in a generally horizontal direction. That is, the intermediate axis J4 and the differential axis J5 are arranged in a generally horizontal direction. Therefore, the reduction gear 4 and the differential gear 5 can be arranged in a horizontal direction, and the vertical dimension of the motor unit 1 can be reduced. In addition, the oil O lifted by the differential gear 5 can be effectively contacted with the reduction gear 4. As a result, the oil O can be supplied to the tooth surface of the gear constituting the reduction gear 4, thereby improving the gear transmission efficiency. In addition, the diameter of the gears (second gear 42 and third gear 43) that rotate around the intermediate axis J4 is smaller than the diameter of the ring gear 51 that rotates around the differential axis J5. According to this embodiment, the second line segment L2 extends in a generally horizontal direction, so the intermediate axis J4 and the differential axis J5 are arranged in a generally horizontal direction. Therefore, depending on the height of the oil level in the oil reservoir P, only the ring gear 51 is immersed in the oil reservoir P, while the second gear 42 and the third gear 43 are not immersed in the oil reservoir P. Therefore, the oil O in the oil reservoir P can be increased by the ring gear 51, and the reduction in the rotational efficiency of the second gear 42 and the third gear 43 can be suppressed.

[0302] In addition, in this embodiment, the second line segment L2 being approximately horizontal means being within ±10° of the horizontal direction.

[0303] According to this embodiment, the angle α formed by the second line segment L2 and the third line segment L3 is 30°±5°. Therefore, the oil O lifted by the differential device 5 can improve the transmission efficiency of the first gear 41 and the second gear 42, and the desired gear ratio can be achieved.

[0304] When the angle α exceeds 35°, it becomes difficult to supply the oil boosted by the differential to the gear (first gear) that rotates around the motor axis. This raises concerns about reduced transmission efficiency between the first and second gears. On the other hand, when the angle α is less than 25°, it is impossible to sufficiently increase the output gear in the transmission process, making it difficult to achieve the desired gear ratio across the three axes (motor axis, intermediate axis, and differential axis).

[0305] According to this embodiment, the first segment L1 extends in a generally vertical direction. That is, the motor shaft J2 and the intermediate shaft J4 are arranged in a generally vertical direction. Therefore, the motor 2 and the reduction gear 4 can be arranged in a vertical direction, and the horizontal dimension of the motor unit 1 can be reduced. In addition, by arranging the first segment L1 in a generally vertical direction, the motor shaft J2 can be positioned close to the differential shaft J5, and oil O lifted by the differential gear 5 can be supplied to the first gear 41, which rotates around the motor shaft J2. As a result, the transmission efficiency between the first gear 41 and the second gear 42 can be improved.

[0306] In addition, in this embodiment, the first line segment L1 along the approximately vertical direction means the direction is within ±10° relative to the vertical direction.

[0307] The lengths L1 of the first line segment, L2 of the second line segment, and L3 of the third line segment satisfy the following relationship.

[0308] L1:L2:L3=1:1.4~1.7:1.8~2.0

[0309] In addition, the reduction ratio in the reduction mechanism from motor 2 to differential device 5 is 8 or more and 11 or less.

[0310] According to this embodiment, a desired gear ratio (8 or more and 11 or less) can be achieved while maintaining the positional relationship of the motor shaft J2, intermediate shaft J4 and differential shaft J5 as described above.

[0311] Parking facilities

[0312] Figure 20 This is a diagram showing the parking mechanism 7 that can be used in the motor unit 1 of this embodiment.

[0313] The parking mechanism 7 is effective when the motor unit 1 is used in an electric vehicle (EV).

[0314] In engine-driven manual transmission vehicles, in addition to engaging the side brakes, the transmission is positioned in a position other than neutral to apply load to the engine and thus achieve a braking effect. In automatic transmission vehicles, in addition to engaging the side brakes, the gear lever is positioned in the parking position to lock the transmission.

[0315] On the other hand, in electric vehicles, there is no braking mechanism to apply braking to the vehicle except for the side brakes, so a parking mechanism 7 is required in the motor unit 1.

[0316] The parking mechanism 7 includes: a ring-shaped parking gear 71, a parking pawl 72, a parking lever 73, and a parking operating lever 74. The parking gear 71 is coaxially configured with the second gear (intermediate gear) 42, the third gear 43, and the intermediate gear. The parking gear 71 is fixed to an intermediate shaft 45. The parking pawl 72 has a protrusion 72a that engages with a groove in the parking gear 71, preventing rotation of the parking gear 71. The parking lever 73 is connected to the parking pawl 72, allowing the protrusion 72a to move radially along the parking gear. The parking operating lever 74 is connected to the parking lever 73, driving the parking lever 73.

[0317] When the motor 2 is activated, the parking pawl 72 disengages from the parking gear 71. On the other hand, when the gear lever is in the parking position, the parking pawl 72 engages with the parking gear 71 and prevents the parking gear 71 from rotating.

[0318] The parking pawl 72 is controlled by a parking motor (not shown) connected to the parking lever. When the parking motor is used, the parking mechanism 7 is electrified, thus simplifying the structural components that drive the parking mechanism 7. Furthermore, when the parking motor is used, the parking pawl 72 can be actuated by pushing a button or paddle shifter, thus improving driver operability. This mechanism is called a drive-by-wire system.

[0319] Alternatively, the parking mechanism 7 can be replaced by a manual mechanism instead of an electric one using a drive-by-wire system. That is, the driver can mechanically pull the cable connected to the parking lever to actuate the parking pawl.

[0320] According to this embodiment, the parking mechanism 7 is provided on the intermediate shaft 45. Therefore, during the torque transmission from the motor 2 to the axle 55, compared to the case where the parking mechanism 7 is provided on a gear located further back from the intermediate shaft, the braking torque required to prevent the rotation of the parking gear 71 can be reduced. This allows for a smaller and lighter design of the parking mechanism. Furthermore, when the parking mechanism 7 is electric, a smaller motor can be used as the parking motor. Additionally, when the parking mechanism is manual, the driver's workload is reduced.

[0321] Furthermore, according to this embodiment, the parking mechanism 7 is located below the reduction gear 4. Therefore, the parking pawl 72 is immersed in the oil O in the oil reservoir P, and oil O is sandwiched between the parking gear 71 and the protrusion 72a of the parking pawl 72, thereby enabling the smooth loading and unloading of the protrusion 72a.

[0322] Furthermore, the parking mechanism 7 in this embodiment is one example, and other conventionally known structures may also be used. Additionally, the parking mechanism 7 may be configured to apply braking force to the shaft 21 or the ring gear 51 connected to the motor 2.

[0323] <Variation Example 1>

[0324] <Cutting Mechanism>

[0325] Figure 21 This is a partial cross-sectional view showing the cutting mechanism 107 of the motor unit 101 in Modified Example 1.

[0326] As a variation 1, a modified motor unit 101 with a cutting mechanism 107 in the torque transmission path from motor 2 to axle 55 will be described. The main difference of this modified motor unit 101 is that the cutting mechanism 107 is provided on the shaft 121 of motor 2. In addition, structural elements that are the same as those in the above embodiment will be described using the same reference numerals.

[0327] The cutting-off mechanism 107 is installed when the motor unit 101 is mounted in a hybrid electric vehicle (HEV) or a plug-in hybrid electric vehicle (PHV). In both HEVs and PHVs, the vehicle operates in one of three modes: engine mode (driven only by the engine), motor mode (driven only by the motor 2), or a hybrid mode (driven by both the engine and the motor). In the engine mode, the cutting-off mechanism 107 cuts off the power transmission mechanism of the motor unit 101 (rotor 20 of the motor 2, reduction gear 4, differential gear 5) from the axle 55 in a manner that prevents the stationary motor 2 from becoming a load.

[0328] like Figure 21 As shown, in this modified example, shaft 121 has a first shaft portion 121A, a connecting shaft portion 121C, and a second shaft portion 121B arranged coaxially, and a cutting mechanism 107 located between the connecting shaft portion 121C and the second shaft portion 121B. The first shaft portion 121A, the connecting shaft portion 121C, and the second shaft portion 121B are arranged sequentially along the axial direction. That is, the connecting shaft portion 121C is located between the first shaft portion 121A and the second shaft portion 121B.

[0329] Shaft 121 is a hollow shaft with a hollow portion 122 having an inner circumferential surface extending along the motor axis J2. The hollow portion 122 includes a first hollow portion 122A located inside the first shaft portion 121A, a second hollow portion 122B located inside the second shaft portion 121B, and a third hollow portion 122C located inside the connecting shaft portion 121C. The first hollow portion 122A, the second hollow portion 122B, and the third hollow portion 122C are arranged side by side along the axial direction and communicate with each other.

[0330] The first shaft portion 121A is disposed in the motor chamber 81 of the storage space 80. The first shaft portion 121A is located radially inside the stator 30 and passes through the rotor core 24 along the motor axis J2.

[0331] The first shaft portion 121A has a first end portion 121e located on the output side (i.e., the side of the reduction gear 4).

[0332] The first end portion 121e extends from the motor chamber 81 side through a through insertion hole 61f provided in the spacer wall 61c. The first hollow portion (second recess) 122A opens along the axial direction of the first end portion 121e. The first end portion 121e is supported by a first bearing 89, which is held in contact with the surface of the spacer wall 61c facing the motor chamber 81 side, and is rotatable.

[0333] By holding the first bearing 89 in contact with the surface of the spacer wall 61c facing the motor chamber 81, the first shaft portion 121A can be aligned on the motor chamber 81 side of the housing 6. This allows for high-precision alignment of the first shaft portion 121A relative to the stator 30.

[0334] The connecting shaft portion 121C is disposed inside the through insertion hole 61f. The connecting shaft portion 121C is rotatably supported by a second bearing 188A, which is held in contact with the surface of the spacer wall 61c facing the gear chamber 82. The second bearing 188A is a ball bearing. A stepped surface 121q facing the spacer wall 61c is provided on the connecting shaft portion 121C. The stepped surface 121q contacts the inner ring of the second bearing 188A.

[0335] According to this modified example, the second bearing 188A is held on the side of the spacer wall 61c facing the gear chamber 82. Therefore, after the shaft alignment of the first shaft portion 121A is performed, the connecting shaft portion 121C can be assembled to the first shaft portion 121A. Thus, the assembly process of the connecting shaft portion 121C can be simplified.

[0336] The outer diameter of the second bearing 188A is larger than that of the first bearing 89. When the cutting mechanism 107 is activated, a large load is applied to the second bearing 188A in both the axial and circumferential directions. According to this modified example, the second bearing 188A, having a larger diameter than the first bearing 89, ensures sufficient strength to withstand the load during the operation of the cutting mechanism 107.

[0337] The connecting shaft portion 121C has a second end portion 121f, a third end portion 121g, and a connecting flange portion 121h.

[0338] The second end portion 121f protrudes towards the motor housing 81. Located on the side of the first shaft portion 121A, the second end portion 121f connects to the first end portion 121e of the first shaft portion 121A. The second end portion 121f is housed within the first hollow portion 122A, which opens into the first end portion 121e. The outer peripheral surface of the second end portion 121f fits into the inner peripheral surface of the first hollow portion 122A. By fitting the second end portion 121f into the first hollow portion 122A, the connection between the first end portion 121e and the second end portion 121f can be miniaturized radially. This ensures sufficient space for the first bearing 89 to be positioned radially outward from the first end portion 121e.

[0339] The third end portion 121g protrudes toward the gear chamber 82. The third end portion 121g is located on the side of the second shaft portion 121B, which is opposite to the second end portion 121f. A first recess 121p is provided at the axial end of the third end portion 121g.

[0340] The connecting flange portion 121h extends radially outward toward the third end portion 121g. The diameter of the connecting flange portion 121h is larger than the smallest diameter portion of the through insertion hole 61f.

[0341] According to this modification, the connecting shaft portion 121C and the first shaft portion 121A are separate components. Therefore, after the assembly process of the motor 2, the connecting shaft portion 121C is assembled to the first shaft portion 121A, allowing assembly to be performed in the same order as in the case without the cutting mechanism 107. Consequently, the shapes of components other than the shaft 121 are the same as in the case without the cutting mechanism 107. That is, according to this modification, component commonality can be achieved between the motor unit 101 with the cutting mechanism 107 and the motor unit 1 without the cutting mechanism 107. Furthermore, since the assembly order is the same regardless of whether the cutting mechanism 107 is present, the complexity of component shapes or the increase in the number of components can be suppressed. Therefore, according to this modification, a highly versatile and low-cost motor unit 101 can be provided.

[0342] The second shaft 121B is disposed in the gear chamber 82 of the storage space 80.

[0343] The second shaft portion 121B has a fourth end portion 121i and a fifth end portion 121j.

[0344] The fourth end 121i is located on the side of the third end 121g of the connecting shaft portion 121C. The connecting flange portion 121h of the fourth end 121i and the connecting shaft portion 121C selectively cuts off the transmission of power through the cutting mechanism 107.

[0345] The fourth end portion 121i is received in the first recess 121p provided at the third end portion 121g. A needle roller bearing (bearing) 121n is provided in the radial gap between the third end portion 121g and the fourth end portion 121i. That is, according to this modified example, the second shaft portion 121B is supported at the fourth end portion 121i by the connecting shaft portion 121C and is rotatable. Therefore, according to this modified example, when the second shaft portion 121B and the connecting shaft portion 121C are cut off by the cutting mechanism 107, stable holding can be achieved without hindering relative rotation. In addition, this effect can be achieved when either the third end portion 121g or the fourth end portion 121i is provided with a first recess for receiving the other via the needle roller bearing 121n.

[0346] In this modified example, the needle roller bearing 121n is composed of multiple cylindrical components arranged in a ring, but other bearing mechanisms such as ball bearings can be used instead of the needle roller bearing 121n. However, by using needle roller bearings, the radial dimensions of the third end 121g and the fourth end 121i can be reduced, and the motor unit 101 can be miniaturized.

[0347] As described above, hollow portions 122 extending axially and communicating with each other are provided in the first shaft portion 121A, the connecting shaft portion 121C, and the second shaft portion 121B. Similarly to the embodiment described above, oil O is supplied to the hollow portions 122 from the second shaft portion 121B side toward the first shaft portion 121A side to cool the interior of the motor.

[0348] According to this modified example, the connecting shaft portion 121C and the second shaft portion 121B are connected via a needle roller bearing 121n. Therefore, the third hollow portion 122C of the connecting shaft portion 121C and the second hollow portion 122B of the second shaft portion 121B can be connected to each other. As a result, oil O can be supplied to the hollow portion 122, which can be used as an oil flow path.

[0349] The fifth end 121j is located on the opposite side of the fourth end 121i. The fifth end is supported by the third bearing 188B held in the housing and is rotatable. That is, the second shaft portion 121B is supported by the third bearing 188B at the fifth end 121j.

[0350] According to this modified example, the second shaft portion 121B is supported by two bearings (needle roller bearing 121n and third bearing 188B) arranged axially. Similarly, the connecting shaft portion 121C is supported by two bearings (second bearing 188A and needle roller bearing 121n) arranged axially. The second shaft portion 121B and the connecting shaft portion 121C are supported at two points arranged axially for free rotation, thereby enabling stable rotation without shaft misalignment.

[0351] A first gear 41 is provided on the outer peripheral surface of the second shaft portion 121B. The first gear 41 is located between the fourth end portion 121i and the fifth end portion 121j. The first gear 41 transmits power to the second gear 42 of the reduction gear 4. According to this modified example, the first gear 41 is located between the second bearing 188A and the third bearing 188B. Therefore, the first gear 41 can rotate stably relative to the motor axis J2, and the torque generated by the motor 2 can be stably transmitted to the second gear 42.

[0352] The cutting mechanism 107 surrounds the connecting flange 121h of the connecting shaft portion 121C and the fourth end portion 121i of the second shaft portion 121B from the radial outside. The cutting mechanism 107 uses the drive unit 175 to switch between a state in which the connecting flange 121h and the fourth end portion 121i are not mechanically connected and a state in which the two are connected.

[0353] The cutting mechanism 107 is axially located between the axial end face of the motor 2 and the first gear 41. The motor unit 101 has a three-axis structure: a motor axis J2, an intermediate axis J4, and a differential axis J5. Furthermore, the third gear 43 is axially located between the axial end face of the motor 2 and the first gear 41. Additionally, the second gear 42 rotates synchronously with the second gear 42 connected to the first gear 41. A gap larger than the thickness of the third gear 43 is provided between the axial end face of the motor 2 and the first gear 41. According to this modified example, the cutting mechanism 107 is positioned between the axial end face of the motor 2 and the first gear 41. That is, the third gear 43 and the cutting mechanism 107 are positioned in an axially overlapping position. This allows for efficient utilization of the internal space of the gear chamber 82, thereby enabling miniaturization of the motor unit 101.

[0354] According to this modification, the cutting mechanism is provided on the shaft 121 of the motor 2. That is, the cutting mechanism 107 is provided in the part of the power transmission path from the motor 2 to the axle 55 where the torque is the least. According to this modification, the torque transmitted via the cutting mechanism 107 is relatively small, thus enabling the cutting mechanism to be miniaturized.

[0355] The cutting mechanism 107 in this modification is referred to as a rotary synchronizing device or a synchronizing engagement mechanism. Furthermore, in this modification, the cutting mechanism 107 is just one example. As a cutting mechanism, for example, a claw-type clutch mechanism or a multi-stage clutch mechanism can be employed.

[0356] The cutting mechanism 107 includes: a sleeve 171, a clutch hub 172, a synchronizing ring 173, a key 174, and a drive unit (not shown).

[0357] The clutch hub 172 is fixed to the outer peripheral surface of the second shaft portion 121B. The clutch hub 172 and the second shaft portion 121B rotate together around the motor axis J2. External toothed splines are provided on the outer peripheral surface of the clutch hub 172.

[0358] Sleeve 171 is axially movable. Sleeve 171 engages with the external spline of clutch hub 172 and rotates together with it. Additionally, a spline is provided on the inner circumferential surface of sleeve 171. After clutch hub 172 and connecting flange 121h rotate synchronously, the spline of sleeve 171 engages with the spline provided on the outer circumferential surface of connecting flange 121h. This connects the second shaft portion 121B and the connecting shaft portion 121C.

[0359] Key 174 is held in the sleeve 171. Key 174 moves axially together with the sleeve 171. Key 174 makes the phase of the splines respectively provided in the sleeve 171 and the connecting flange 121h synchronized.

[0360] The synchronizing ring 173 moves axially together with the sleeve 171. The synchronizing ring 173 has a conical surface whose inner diameter increases as it approaches the connecting flange 121h. On the other hand, the connecting flange 121h has a protrusion that protrudes axially toward the synchronizing ring 173. The protrusion has a conical surface opposite to the synchronizing ring 173. The synchronizing ring 173 and the connecting flange 121h rotate synchronously through contact with each other via their respective conical surfaces.

[0361] The drive unit, which is not shown in the figure, is connected to the sleeve 171. The drive unit causes the sleeve 171 to move axially.

[0362] Figure 22 This is a schematic diagram showing the state in which the motor 2 and the reduction gear 4 are connected by the cutting mechanism 107. Figure 23 This is a schematic diagram showing the state in which the motor 2 and the reduction gear 4 are cut off by the cutting mechanism 107.

[0363] As described above, the motor unit 101 with the cutting-off mechanism 107 is mounted in a hybrid electric vehicle or a plug-in hybrid electric vehicle. In such a vehicle, when switching between a mode that uses only the engine power and a mode that uses the power of the motor 2, the drive unit 175 is activated to switch the connection and disconnection between the connecting shaft 121C and the second shaft 121B.

[0364] The control related to the cutting mechanism 107 will be explained. When the cutting mechanism 107 switches from the cutting state to the connecting state, it first calculates the rotational speed of the second shaft portion 121B based on the rotational speed of the axle 55. Next, the rotational speed of the motor 2 is increased to the calculated rotational speed of the second shaft portion 121B. During the increase in the rotational speed of the motor 2, the sleeve is moved by the drive unit 175, thereby connecting the second shaft portion 121B to the connecting shaft portion 121C. Then, based on the accumulated rotational speed of the drive unit 175, the position where the connection between the second shaft portion 121B and the connecting shaft portion 121C is completed is calculated. Finally, if the rotational speed of the motor 2 is found to be the same as the rotational speed of the second shaft portion 121B calculated based on the rotational speed of the axle 55, the engagement state is determined to be complete.

[0365] <Control>

[0366] The motor 2 of motor unit 1, pump 96, drive unit 175 of cut-off mechanism 107, and parking motor of parking mechanism 7 are all controlled one-dimensionally by microcontroller unit (MCU). The microcontroller unit can be integrated with motor unit 1 or located externally.

[0367] <Carry-on capability>

[0368] The motor unit 1 can be applied to any of the following: hybrid electric vehicles (HEV), plug-in hybrid electric vehicles (PHV), and electric vehicles (EV). Furthermore, the motor unit 1 is not limited to passenger cars, but can also be applied to trucks and the like. The motor unit 1 can be mounted on either the front or rear side of the vehicle, preferably on the rear side. The motor unit 1 of this embodiment has a small vertical dimension, therefore it can be compactly installed even on the rear side where installation space is limited due to constraints on the cargo compartment and minimum ground clearance.

[0369] The embodiments and variations of the present invention have been described above. However, each structure and combination thereof in the embodiments is an example only, and additions, omissions, substitutions, and other changes to the structure can be made without departing from the spirit of the present invention. Furthermore, the present invention is not limited to the embodiments.

Claims

1. A motor unit having: a motor; a housing provided with a housing space that houses the motor; oil accumulated in a region on a vertically lower side of the housing space; and an oil passage that guides the oil from the region on the vertically lower side of the housing space and supplies the oil to the motor, characterized in that the motor has: a rotor that rotates about a motor axis; and a stator that is located on a radially outer side of the rotor, the rotor has: a shaft that extends along the motor axis; a rotor core that surrounds the shaft from a radially outer side; a rotor magnet that is fixed to the rotor core; and a plate-shaped end plate that is located on an axial end surface of the rotor core, the end plate has: a first surface that opposes the axial end surface of the rotor core; and a second surface that faces a side opposite to the first surface, an oil flow path that extends along a radial direction and has an opening is provided in the end plate, the end plate has a central hole, the oil flow path has a first groove that is provided in the first surface that opposes the axial end surface of the rotor core and extends from an inner periphery of the central hole toward a radially outer side, and a depth of an entirety of the first groove is the same.

2. The motor unit according to claim 1, characterized in that a hollow portion having an inner peripheral surface that extends along an axial direction is provided in the shaft, an inner side of the hollow portion is supplied with oil, a communication hole that extends in a radial direction is provided to communicate the hollow portion with an outside of the shaft, the hollow portion has a first region, a second region, and a third region in which diameters of the inner peripheral surface are different, and the diameters of the inner peripheral surface of the first region, the second region, and the third region increase in order.

3. The motor unit according to claim 2, characterized in that one of a pair of communication holes on an upstream side in a flow direction is opened in the third region.

4. The motor unit according to claim 2, characterized in that one of a pair of communication holes on a downstream side in the flow direction is opened in the second region.

5. The motor unit according to claim 2, characterized in that the motor unit has: a first step surface that is located between the first region and the second region; and a second step surface that is located between the second region and the third region, and the first step surface and the second step surface are inclined toward an upstream side in the flow direction as they face the radially outer side.

6. The motor unit according to claim 1, characterized in that the motor unit has a pair of plate-shaped end plates that are located on end surfaces on both axial sides of the rotor core, a core through-hole that extends through the rotor core in the axial direction is provided in the rotor core, and the core through-hole connects the oil flow paths of the pair of end plates to each other.

7. The motor unit according to claim 6, characterized in that the first groove provided in the first surface of the pair of end plates communicates with the core through-hole, and the second groove provided in the second surface of the pair of end plates communicates with the outside in an opening that faces the axial direction.

8. The motor unit according to claim 7, characterized in that ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ A hollow portion having an inner peripheral surface extending in the axial direction is provided in the shaft, an inner side of the hollow portion is supplied with oil, and a communication hole extending in the radial direction is provided to communicate the hollow portion with the outside of the shaft, The first recess of the pair of end plates is connected to the communication hole of the shaft in the radial direction.

9. The motor unit according to claim 2, wherein The communication hole opens to the hollow portion in the recess, The recess is formed by the inner peripheral surface of the hollow portion and a step surface located between the second region and the third region.

10. The motor unit according to claim 9, wherein The shaft has: a first shaft portion located on the radially inner side of the stator; and a second shaft portion coaxial with the first shaft portion and connected to the first shaft portion, The recess is formed by an end surface of the second shaft portion toward the first shaft portion side, the inner peripheral surface of the hollow portion of the third region, and the step surface.

11. The motor unit according to claim 2, wherein The communication hole opens to the hollow portion in the recess, The recess is provided only in one of the pair of communication holes.

12. The motor unit according to claim 2, wherein The axial center of the second region is located on the oil supply side of the axial center of the rotor core.

13. The motor unit according to claim 1, wherein The motor unit has: a reduction device connected to the motor and having an intermediate gear that rotates about an intermediate axis; and a differential device connected to the reduction device and having a ring gear that rotates about a differential axis, The housing has the accommodation space that accommodates the motor and the differential device.

14. A motor unit having: a motor; a housing provided with an accommodation space that accommodates the motor; oil accumulated in a region on the vertically lower side of the accommodation space; and an oil passage that guides the oil from the region on the vertically lower side of the accommodation space and supplies the oil to the motor, The motor has: a rotor that rotates about a motor axis; and a stator located on the radially outer side of the rotor, The rotor has: a shaft that extends along the motor axis; a rotor core that surrounds the shaft from the radially outer side; a rotor magnet fixed to the rotor core; and a pair of end plates that are plate-shaped and located on the axial both sides of the rotor core, The end plates have: a first surface that opposes the axial end surface of the rotor core; and a second surface that faces the side opposite to the first surface, An oil flow path that extends in the radial direction and has an opening is provided in the pair of end plates, The end plates have a central hole, the oil flow path has a first recess provided in the first surface that opposes the axial end surface of the rotor core and extending from the inner peripheral edge of the central hole toward the radially outer side, and the depth of the entire first recess is the same, ​ A hollow portion having an inner peripheral surface extending in the axial direction is provided in the shaft, an inner side of the hollow portion is supplied with oil, and a communication hole extending in the radial direction is provided to communicate the hollow portion with the outside of the shaft, The hollow portion has a first region and a second region having different diameters of the inner peripheral surface, The diameters of the inner peripheral surfaces of the first region and the second region increase in order, The axial center of the second region is located at a position on the oil supply side than the axial center of the rotor core.

15. The motor unit according to claim 14, wherein The motor unit further has: a reduction device connected to the motor, having an intermediate gear rotating around an intermediate axis; and a differential device connected to the reduction device, having a ring gear rotating around a differential axis, The housing has the accommodation space that accommodates the motor and the differential device.

16. A motor unit having: a motor; a housing provided with an accommodation space that accommodates the motor; oil accumulated in a region on a vertically lower side of the accommodation space; and an oil passage that guides the oil from the region on the vertically lower side of the accommodation space and supplies the oil to the motor, characterized in that the motor has: a rotor rotating around a motor axis; and a stator located on a radially outer side of the rotor, the rotor has: a shaft extending along the motor axis; a rotor core surrounding the shaft from a radially outer side; a rotor magnet fixed to the rotor core; and a plate-shaped end plate located on an axial end surface of the rotor core, the end plate has: a first surface facing a side opposite to the axial end surface of the rotor core; and a second surface facing a side opposite to the first surface, the end plate is provided with an oil flow path extending in the radial direction and having an opening, the end plate has a central hole, the oil flow path has a first groove provided on the first surface facing the axial end surface of the rotor core and extending from an inner peripheral edge of the central hole toward the radially outer side, and the depth of the entire first groove is the same, the first groove provided on the first surface of the end plate communicates with a core through hole opened on the axial end surface of the rotor core, the second groove provided on the second surface of the end plate communicates with the outside in an opening toward the axial direction.

17. The motor unit according to claim 16, wherein the motor unit has a pair of plate-shaped end plates located on both sides in the axial direction of the rotor core, the pair of end plates are respectively provided with oil flow paths extending in the radial direction and having openings, the first grooves provided on the first surfaces of the pair of end plates communicate with the core through hole, the second grooves provided on the second surfaces of the pair of end plates communicate with the outside in openings toward the axial direction.

18. The motor unit according to claim 16, wherein The motor unit further has: a reduction device connected to the motor, having an intermediate gear rotating around an intermediate axis; and a differential device connected to the reduction device, having a ring gear rotating around a differential axis, A differential device is connected to the reduction device and has a ring gear that rotates around a differential axis, and the housing's accommodation space accommodates the motor and the differential device.

19. A motor unit having: a motor; a housing provided with an accommodation space that accommodates the motor; oil accumulated in a region on a vertically lower side of the accommodation space; and an oil passage that guides the oil from the region on the vertically lower side of the accommodation space and supplies the oil to the motor, characterized in that the motor has: a rotor that rotates around a motor axis; and a stator located radially outside the rotor, the rotor has: a shaft that extends along the motor axis; a rotor core that surrounds the shaft from the radially outside; a rotor magnet fixed to the rotor core; and a plate-shaped end plate located at an axial end surface of the rotor core, the end plate has: a first surface that opposes the axial end surface of the rotor core; and a second surface that faces a side opposite the first surface, an oil flow path that extends along the radial direction and has an opening is provided in the end plate, the end plate has a central hole, the oil flow path has a first groove provided in the first surface that opposes the axial end surface of the rotor core and extending from an inner periphery of the central hole toward the radially outside, and the depth of the entire first groove is the same, a hollow portion having an inner peripheral surface that extends along the axial direction is provided in the shaft, an inside of the hollow portion is supplied with oil, and a communication hole that extends along the radial direction is provided to communicate the hollow portion with an outside of the shaft, the communication hole opens into the hollow portion in a groove, and the groove is provided only in one of a pair of communication holes.

20. The motor unit according to claim 19, further having: a reduction device connected to the motor and having an intermediate gear that rotates around an intermediate axis; and a differential device connected to the reduction device and having a ring gear that rotates around a differential axis, the housing's accommodation space accommodating the motor and the differential device.

21. The motor unit according to claim 19, having a pair of plate-shaped end plates located on both axial sides of the rotor core, the pair of end plates each having the first surface and the second surface, and the pair of end plates each having an oil flow path that extends along the radial direction and opens.

22. A motor unit having: a motor; a housing provided with an accommodation space that accommodates the motor; oil accumulated in a region on a vertically lower side of the accommodation space; and an oil passage that guides the oil from the region on the vertically lower side of the accommodation space and supplies the oil to the motor, characterized in that the motor has: a rotor that rotates around a motor axis; and a stator located radially outside the rotor, the rotor has: a shaft that extends along the motor axis; a rotor core that surrounds the shaft from the radially outside; a rotor magnet fixed to the rotor core; and a plate-shaped end plate located at an axial end surface of the rotor core, the end plate has: a first surface that opposes the axial end surface of the rotor core; and a second surface that faces a side opposite the first surface, an oil flow path that extends along the radial direction and has an opening is provided in the end plate, the end plate has a central hole, the oil flow path has a first groove provided in the first surface that opposes the axial end surface of the rotor core and extending from an inner periphery of the central hole toward the radially outside, and the depth of the entire first groove is the same, a hollow portion having an inner peripheral surface that extends along the axial direction is provided in the shaft, an inside of the hollow portion is supplied with oil, and a communication hole that extends along the radial direction is provided to communicate the hollow portion with an outside of the shaft, the communication hole opens into the hollow portion in a groove, and the groove is provided only in one of a pair of communication holes. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ A plate-shaped end plate is located at an axial end surface of the rotor core, The end plate has: a first surface facing an axial end surface of the rotor core; and a second surface facing a side opposite to the first surface, An oil flow path extending in the radial direction and having an opening is provided in the end plate, The oil flow path is provided in the first surface facing the axial end surface of the rotor core, The oil flow path has a first recess recessed from an end portion on one axial side toward the other axial side of the end plate, A second recess recessed from an end portion on the other axial side toward one axial side of the end plate is provided in the second surface of the end plate, The first recess and the second recess extend in the radial direction, The radial length of the second recess is longer than the radial length of the first recess.

23. A motor unit having: a motor; a housing provided with a housing space that houses the motor; oil accumulated in a region on a vertically lower side of the housing space; and an oil path that guides the oil from the region on the vertically lower side of the housing space and supplies the oil to the motor, characterized in that the motor has: a rotor that rotates around a motor axis; and a stator located radially outward of the rotor, the rotor has: a shaft that extends along the motor axis; a rotor core that surrounds the shaft from the radially outer side; a rotor magnet fixed to the rotor core; and a plate-shaped end plate located at an axial end surface of the rotor core, the end plate has: a first surface facing an axial end surface of the rotor core; and a second surface facing a side opposite to the first surface, an oil flow path extending in the radial direction and having an opening is provided in the end plate, the end plate has a central hole, the oil flow path has a first recess provided in the first surface facing the axial end surface of the rotor core and extending from an inner periphery of the central hole toward the radially outer side, a radially outer end portion of the first recess is located radially inward of a radially intermediate portion from the inner periphery of the central hole to a radially outer end portion of the end plate.

24. A motor unit having: a motor; a housing provided with a housing space that houses the motor; oil accumulated in a region on a vertically lower side of the housing space; and an oil path that guides the oil from the region on the vertically lower side of the housing space and supplies the oil to the motor, characterized in that the motor has: a rotor that rotates around a motor axis; and a stator located radially outward of the rotor, the rotor has: a shaft that extends along the motor axis; a rotor core that surrounds the shaft from the radially outer side; a rotor magnet fixed to the rotor core; and a plate-shaped end plate located at an axial end surface of the rotor core, the end plate has: a first surface facing an axial end surface of the rotor core; and a second surface facing a side opposite to the first surface, an oil flow path extending in the radial direction and having an opening is provided in the end plate, the oil flow path is provided in the first surface facing the axial end surface of the rotor core, The oil flow path has a first recessed portion recessed from an end portion of an axial one side of the end plate toward an axial other side, A second recessed portion is provided on the second face of the end plate, the second recessed portion being recessed from an end portion of the axial other side of the end plate toward the axial one side, The axial length of the first recessed portion is longer than the axial length of the second recessed portion.

Images