JP2022120085A - motor unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor unit that cools a motor from the inside and the outside of the motor and also simplifies the structure of an oil passage to reduce the cost.

SOLUTION: A motor unit 1 includes: a motor 2; a housing 6 including a container space 80 for containing the motor 2; oil O remaining in a lower region of the container space 80 in a vertical direction; and an oil passage 90 for guiding the oil O from a lower region of the container space 80 in a vertical direction to a lower region of the container space 80 in a vertical direction through the motor 2. The oil passage 90 has a first oil passage 91 through the inside of the motor 2 and a second oil passage 92 through the outside of the motor 2, and one of the first oil passage 91 and the second oil passage 92 is provided with a cooler 97 for cooling the oil O.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2022,JPO&INPIT

Description

The present invention relates to a motor unit.

Patent Literature 1 discloses a structure including a flow path passing through the inside of the shaft to cool the motor, and a flow path supplying oil from the upper side of the stator to cool the motor.

Japanese Patent No. 5911033

In the conventional structure, in addition to the two flow paths, a flow path is provided by joining the two flow paths, and a cooling device for cooling the coolant is provided in the flow path that has been joined. There is a risk that the configuration of the flow path will become complicated and the cost will increase.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of one aspect of the present invention to provide a motor unit that cools the motor from the inside and the outside and that achieves cost reduction by simplifying the configuration of the oil passages.

One aspect of the motor unit of the present invention includes a motor, a housing provided with an accommodation space for accommodating the motor, oil accumulated in a region below the accommodation space in the vertical direction, and the oil in the accommodation space. an oil passage leading from a vertically lower region to a vertically lower region of the accommodation space through the motor, the oil passage comprising a first oil passage passing through the interior of the motor; and a second oil passage passing through the outside of the oil passage, wherein either one of the first oil passage and the second oil passage is provided with a cooler for cooling the oil.

According to one aspect of the present invention, there is provided a motor unit that cools the motor from the inside and outside and that achieves cost reduction by simplifying the configuration of the oil passages.

FIG. 1 is a conceptual diagram of a motor unit of one embodiment. FIG. 2 is a perspective view of the motor unit of one embodiment. FIG. 3 is a side view of the motor unit of one embodiment. 4 is a cross-sectional view of the motor unit taken along line IV-IV in FIG. 3. FIG. FIG. 5 is a cross-sectional view of a rotor of one embodiment. FIG. 6 is a plan view of the end plate. 7 is a cross-sectional view of the end plate along line VII-VII of FIG. 6. FIG. FIG. 8 is a cross-sectional view of the end plate of the first modified example. FIG. 9 is a plan view of the end plate of the second modification. FIG. 10 is a cross-sectional view of the motor unit of one embodiment, showing a second oil passage. FIG. 11 is a perspective view of the motor unit of one embodiment with part of the housing omitted. FIG. 12 is a plan view of the second reservoir of one embodiment. FIG. 13 is a perspective view of a modified second reservoir. FIG. 14 is a cross-sectional view of the motor unit of one embodiment, showing an outline of the sub-reservoir. FIG. 15 is a front view of a septum opening of one embodiment. FIG. 16 is a graph showing the relationship between the level of the oil pooled on the lower side of the motor chamber and the area of the first region in the motor unit of one embodiment. FIG. 17 is a front view of a partition opening of a modification. FIG. 18 is a graph showing the relationship between the level of the oil pooled below the motor chamber and the area of the first region in the motor unit provided with the partition wall opening of the modification. FIG. 19 is a side view showing the arrangement of gears positioned inside the gear chamber in the motor unit of one embodiment. FIG. 20 is a plan view of a parking mechanism that can be employed in the motor unit of one embodiment; FIG. 21 is a partial cross-sectional view showing a motor unit detachment mechanism of Modification 1. FIG. FIG. 22 is a conceptual diagram showing a state in which the motor and the reduction gear are connected by the disconnection mechanism. FIG. 23 is a conceptual diagram showing a state in which the motor and the reduction gear are separated by the separation mechanism.

Hereinafter, motors according to embodiments of the present invention will be described with reference to the drawings. It should be noted that the scope of the present invention is not limited to the following embodiments, and can be arbitrarily changed within the scope of the technical idea of the present invention. Also, in the drawings below, in order to make each configuration easier to understand, there are cases where the actual structure and the scale, number, etc. of each structure are different.

In the following description, the gravitational direction is defined based on the positional relationship when the motor unit 1 is mounted on a vehicle positioned on a horizontal road surface. Also, 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 (that is, the vertical direction), the +Z direction is the upper side (the side opposite to the direction of gravity), and the −Z direction is the lower side (the direction of gravity). The X-axis direction is perpendicular to the Z-axis direction and indicates the longitudinal direction of the vehicle in which the motor unit 1 is mounted. However, the +X direction may be the rear of the vehicle and the -X direction may be the front of the vehicle. The Y-axis direction is a direction orthogonal to both the X-axis direction and the Z-axis direction, and is the width direction (horizontal direction) of the vehicle.

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", and the radial direction about the motor axis J2 is simply referred to as the "radial direction". The circumferential direction around the motor shaft J2, that is, the circumference of the motor shaft J2 is simply called the "circumferential direction". Furthermore, in the following description, "planar view" means a state viewed from the axial direction. However, the above-mentioned "parallel direction" also includes substantially parallel directions. Moreover, the above-mentioned "perpendicular direction" includes a substantially perpendicular direction.

A motor unit (electric drive device) 1 according to an exemplary embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a conceptual diagram of a motor unit 1 of one embodiment. FIG. 2 is a perspective view of the motor unit 1. FIG. FIG. 3 is a side view of the motor unit 1. FIG. FIG. 4 is a cross-sectional view of the motor unit 1 taken along line IV-IV in FIG. A part of the internal structure of the differential gear 5 is omitted in FIG.

The motor unit 1 is mounted on a vehicle using a motor as a power source, such as a hybrid vehicle (HEV), a plug-in hybrid vehicle (PHV), an electric vehicle (EV), and is used as the power source.

As shown in FIG. 1, the motor unit 1 includes a motor (main motor) 2, a reduction gear 4, a differential gear 5, a housing 6, an oil O, and an oil passage 90 for supplying the oil O to the motor 2. And prepare. In addition, the motor unit 1 may have a parking mechanism 7 as indicated by the phantom lines in FIG.

As shown in FIG. 1, the motor 2 includes a rotor 20 that rotates around a horizontally extending motor shaft J2, and a stator 30 positioned radially outside the rotor 20. As shown in FIG. The reduction gear 4 is connected to the rotor 20 of the motor 2 . The differential gear 5 is connected to the motor 2 via the reduction gear 4 . An accommodation space 80 is provided inside the housing 6 to accommodate the motor 2 , the reduction gear 4 and the differential gear 5 . The oil O is used for lubricating the reduction gear 4 and the differential gear 5 and for cooling the motor 2 . The oil O accumulates in the vertically lower area of the accommodation space 80 . Since the oil O functions as both a lubricating oil and a cooling oil, it is preferable to use a low-viscosity lubricating oil equivalent to automatic transmission fluid (ATF). The oil passage 90 is a path for the oil O that supplies the oil O to the motor 2 from the area below the accommodation space 80 . The oil passage 90 has a first oil passage 91 and a second oil passage 92 .

In this specification, the term “oil passage” means a route of oil O circulating in the accommodation space 80 . Therefore, "oil passage" means not only a "flow path" that forms a steady flow of oil in one direction, but also a path that temporarily retains oil (for example, a reservoir) and a path where oil drips. This is a concept that also includes routes.

<Housing> A housing space 80 provided inside the housing 6 houses the motor 2 , the reduction gear 4 and the differential gear 5 . The housing 6 holds the motor 2 , the reduction gear 4 and the differential gear 5 in the accommodation space 80 . The housing 6 has a partition 61c. A housing space 80 of the housing 6 is partitioned into a motor chamber 81 and a gear chamber 82 by a partition wall 61c. The motor 2 is housed in the motor chamber 81 . The gear chamber 82 accommodates the reduction gear 4 and the differential gear 5 .

An oil reservoir P in which the oil O is accumulated is provided in a region below the accommodation space 80 . In this embodiment, the bottom portion 81 a of the motor chamber 81 is located above the bottom portion 82 a of the gear chamber 82 . A partition wall opening 68 is provided in a region below the partition wall 61 c that separates the motor chamber 81 and the gear chamber 82 . The partition wall opening 68 allows the motor chamber 81 and the gear chamber 82 to communicate with each other. The partition wall opening 68 moves the oil O accumulated in the lower region of the motor chamber 81 to the gear chamber 82 . Therefore, in this embodiment, the oil reservoir P is provided in the area below the gear chamber 82 .

A part of the differential gear 5 is immersed in the oil pool P. The oil O accumulated in the oil reservoir P is scooped up by the operation of the differential gear 5 , partly supplied to the first oil passage 91 , and partly diffused into the gear chamber 82 . The oil O diffused into the gear chamber 82 is supplied to each gear of the reduction gear 4 and the differential gear 5 in the gear chamber 82 to spread the oil O over the gear tooth flanks. The oil O used in the reduction gear 4 and the differential gear 5 drops and is collected in the oil reservoir P located below the gear chamber 82 . The capacity of the oil reservoir P of the accommodation space 80 is set to such an extent that a part of the bearing of the differential gear 5 is immersed in the oil O when the motor unit 1 is stopped.

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

The motor housing portion 61 has a cylindrical peripheral wall portion 61a that surrounds the motor 2 from the outside in the radial direction, and a side plate portion 61b positioned on one axial side of the peripheral wall portion 61a. A space inside the peripheral wall portion 61 a constitutes a motor chamber 81 . The side plate portion 61b has a partition wall 61c and a projecting plate portion 61d. The partition wall 61c covers the opening on one axial side of the peripheral wall portion 61a. The partition wall 61c is provided with an insertion hole 61f through which the shaft 21 of the motor 2 is inserted, in addition to the partition wall opening 68 described above. The side plate portion 61b has a partition wall 61c and a protruding plate portion 61d protruding radially outward with respect to the peripheral wall portion 61a. The projecting plate portion 61d is provided with a first axle passage hole 61e through which a drive shaft (not shown) that supports a wheel passes.

The closing portion 63 is fixed to the motor housing portion 61 . The closing portion 63 is the peripheral wall portion 6
The opening on the opposite side in the axial direction of 1a is closed. That is, the closing portion 63 closes the opening of the cylindrical motor accommodating portion 61 . The closing portion 63 has a closing portion main body 63a and a lid member 63b. The closing portion main body 63 a has a cylindrical protruding portion 63 d that protrudes into the housing space 80 located inside the motor housing portion 61 . The projecting portion 63d extends along the inner peripheral surface of the peripheral wall portion 61a. A window portion 63c is provided through the closing portion main body 63a in the axial direction. The lid member 63b closes the window 63c from the outside of the housing space 80. As shown in FIG.

The gear housing portion 62 is fixed to the side plate portion 61 b of the motor housing portion 61 . The gear housing portion 62 has a concave shape that opens toward the side plate portion 61b. The opening of the gear housing portion 62 is covered with the side plate portion 61b. A space between the gear accommodating portion 62 and the side plate portion 61b constitutes a gear chamber 82 that accommodates the reduction gear 4 and the differential gear 5. As shown in FIG. The gear housing portion 62 is provided with a second axle passage hole 62e. The second axle passage hole 62e overlaps the first axle passage hole 61e when viewed in the axial direction.

As shown in FIG. 3 , the gear housing portion 62 has a first reservoir (reservoir) 93 and a shaft supply channel 94 . The first reservoir 93 is located on the surface of the gear housing portion 62 facing the gear chamber 82 in the axial direction and extends along the axial direction. A first reservoir 93 receives the oil O scooped up by the differential gear 5 . A shaft feed channel 94 extends from the bottom of the first reservoir 93 towards the shaft 21 of the motor 2 . The shaft supply channel 94 is a channel for supplying the oil O received by the first reservoir 93 to the inside of the hollow portion 22 of the shaft 21 .

<Reduction Device> As shown in FIG. 4, the reduction device 4 has a function of decreasing the rotational 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 .

The reduction gear 4 has 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 passes through the shaft 21 of the motor 2, the first gear 41, the second gear 42, the intermediate shaft 45 and the third gear 43 to the ring gear (gear) 51 of the differential device 5. transmitted. The gear ratio of each gear, the number of gears, and the like can be changed variously according to the required reduction ratio. The speed reducer 4 is a parallel shaft gear type speed reducer in which the axes of the gears are arranged in parallel.

A first gear 41 is provided on the outer peripheral surface of the shaft 21 of the motor 2 . The first gear 41 rotates together with the shaft 21 about the motor axis J2.

The intermediate shaft 45 extends along an intermediate axis J4 parallel to the motor axis J2. The intermediate shaft 45 has a cylindrical shape centered on the intermediate axis J4. The intermediate shaft 45 rotates around the intermediate axis J4. The intermediate shaft 45 is rotatably supported by a pair of intermediate shaft holding bearings 87 . One of the pair of intermediate shaft holding bearings 87 is held on the surface of the partition wall 61c facing the gear chamber 82 side. The other of the pair of intermediate shaft holding bearings 87 is held by the gear housing portion 62 .

The second gear 42 and the third gear 43 are provided on the outer peripheral surface of the intermediate shaft 45 . The second gear 42 and third gear 43 are connected via an intermediate shaft 45 . The second gear 42 and the third gear 43 rotate around the intermediate shaft J4. The second gear 42 meshes with the first gear 41 . The third gear 43 meshes with the ring gear 51 of the differential gear 5 . The third gear 43 is located on the partition wall 61c side with respect to the second gear 42 . In this embodiment, the intermediate shaft 45 and the third gear 43 are a single member.

<Differential Device> The differential device 5 is a device for transmitting the torque output from the motor 2 to the wheels of the vehicle. The differential gear 5 has a function of transmitting the same torque to the axle shafts 55 of both the left and right wheels while absorbing the speed difference between the left and right wheels when the vehicle is turning. The differential gear 5 has a ring gear 51, a gear housing 57, a pair of pinion gears (not shown), a pinion shaft (not shown), and a pair of side gears (not shown).

The ring gear 51 rotates around a differential shaft J5 parallel to the motor shaft J2. 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 another gear. Ring gear 51 is fixed to the outer periphery of gear housing 57 .

Gear housing 57 accommodates a pair of pinion gears and a pair of side gears. The gear housing 57 rotates around the differential shaft J5 together with the ring gear 51 when torque is transmitted to the ring gear 51 . A pair of pinion gears are bevel gears facing each other. A pair of pinion gears are supported by the pinion shaft. The pair of side gears are bevel gears that mesh perpendicularly with the pair of pinion gears. A pair of side gears each have a fitting portion. Axles are fitted to the fitting portions, respectively. A pair of axles fitted in different fitting portions rotates around the differential shaft J5 with the same torque.

<Motor> As shown in FIG. 4 , the motor 2 is an inner rotor type motor including a stator 30 and a rotor 20 rotatably arranged inside the stator 30 . The rotor 20 rotates when power is supplied to the stator 30 from a battery (not shown). Torque of the motor 2 is transmitted to the differential gear 5 via the reduction gear 4 .

(Stator) The stator 30 has a stator core 32 , a coil 31 , and an insulator (not shown) interposed between the stator core 32 and the coil 31 . Stator 30 is held in housing 6 .

The stator core 32 has a plurality of magnetic pole teeth (not shown) radially inward from the inner peripheral surface of the annular yoke. The stator core 32 of this embodiment has 48 slots formed between the magnetic pole teeth. A coil 31 is constructed by winding a coil wire between the magnetic pole teeth.

Coil 31 has coil ends 31 a protruding from the axial end surface of stator core 32 . That is, the stator 30 has coil ends 31a. The coil ends 31 a protrude axially beyond the ends of the rotor core 24 of the rotor 20 . The coil ends 31 a protrude axially from both sides of the rotor core 24 .

(Rotor) The rotor 20 includes a shaft (motor shaft) 21, a rotor core 24, a rotor magnet (permanent magnet) 25, a pair of plate-like end plates 26, a nut 29, a washer (cover) 28, have

(Shaft) The shaft 21 extends around a motor shaft J2 that extends 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 coaxially connected to each other.

The shaft 21 is a hollow shaft provided with a hollow portion 22 having an inner peripheral surface extending along the motor shaft J2. 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.

The first shaft portion 21A is arranged in the motor chamber 81 of the accommodation space 80 . The first shaft portion 21A is positioned radially inside the stator 30 and passes through 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 (that is, the reduction gear 4 side) and a second end portion 21f located on the opposite side.

The first shaft portion 21A is rotatably supported by a pair of first bearings 89 . A pair of first bearings 89 support the first end 21e and the second end 21f of the first shaft portion 21A. One of the pair of first bearings 89 is held by the closing portion 63 . The other of the pair of first bearings 89 is held on the surface of the partition wall 61c facing the motor chamber 81 side.

FIG. 5 is a cross-sectional view of the rotor 20. FIG. In addition, in FIG. 5, the second shaft portion 21B is illustrated by a phantom line. A pair of communication holes 23 are provided in the first shaft portion 21A. The communication hole 23 extends in the radial direction and allows the outside of the shaft 21 and the hollow portion 22 to communicate with each other. That is, the shaft 21 is provided with a pair of communication holes 23 . The pair of communication holes 23 are arranged along the axial direction. In this specification, one communication hole 23 is defined as a hole extending from the outer peripheral surface of the shaft 21 through the hollow portion to the outer peripheral surface.

A collar portion (lid portion) 21c and a screw portion 21d are provided along the axial direction on the outer peripheral surface of the first shaft portion 21A. That is, the outer peripheral surface of the shaft 21 is provided with a collar portion 21c and a screw portion 21d. The rotor core 24 is axially positioned between the collar portion 21c and the screw portion 21d. A nut 29 is fastened to the screw portion 21d.

As shown in FIG. 4, the second shaft portion 21B is positioned coaxially with the first shaft portion 21A. The second shaft portion 21b has a third end portion 21g located on the first shaft portion 21A side and a fourth end portion 21h located on the opposite side. The second shaft portion 21B is connected at the third end portion 21g to the first end portion 21e of the first shaft portion 21A.

The second shaft portion 21B is arranged in the gear chamber 82 of the accommodation space 80 . A third end portion 21g of the second shaft portion 21B protrudes toward the motor chamber 81 through an insertion hole 61f provided in the partition wall 61c and is connected to the first shaft portion 21A. A first gear 41 is provided on the outer peripheral surface of the second shaft portion 21B. The first gear 41 is part of the reduction gear 4 . The first gear 41 meshes with the second gear 42 to transmit the output of the shaft 21 to the second gear.

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 on the surface of the partition wall 61c facing the gear chamber 82 side. The other of the pair of second bearings 88 is held by the gear housing portion 62 .

The hollow portion 22 is axially opened 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 of the shaft 21 through the communication hole 23 . In the following description, the side of the fourth end 21h may be referred to as the upstream side of the hollow portion 22 in the flow direction, and the side of the second end 21f may be referred to as the downstream side of the hollow portion 22 in the flow direction.

As shown in FIG. 5, the first hollow portion 22A includes a first region 22p having an inner peripheral surface with a different diameter, a second region (small-diameter hollow portion) 22q, a third region (large-diameter hollow portion) 22r, have The first region 22p, the second region 22q, and the third region 22r have inner diameters that increase in this order. That is, the second region 22q has a larger inner diameter than the first region 22p, and the third region 22r has a larger inner diameter than the first region 22p and the third region 22r. The first region 22p, the second region 22q, and the third region 22r are arranged in this order from the downstream side to the upstream side in the flow direction. The first region 22p is located on the second end 21f side. The second region 22q is located between the first region 22p and the third region 22r in the axial direction. The third region 22r is located on the first end 21e side. That is, the third region 22r is positioned closer to the second shaft portion 21B than the second region 22q.

One of the pair of communication holes 23 on the upstream side in the flow direction opens to the third region 22r. Further, the other communication hole 23 on the downstream side in the flow direction of the pair of communication holes 23 opens to the second region 22q.

In addition, the inner peripheral surface of the first hollow portion 22A is located between the first stepped surface 22s located between the first region 22p and the second region 22q and between the second region 22q and the third region 22r. and a second stepped surface (stepped surface) 22t. First step surface 22
s and the second step surface 22t face the second shaft portion 21B side. In addition, the first stepped surface 22s and the second stepped surface 22t are inclined toward the upstream side in the flow direction as they extend radially outward.

The third end portion 21g of the second shaft portion 21B is inserted into the third region 22r of the first shaft portion 21A. A female spline 22e is provided in the third region 22r. On the other hand, a male spline 22g is provided on the outer peripheral surface of the third end portion 21g of the second shaft portion 21B. Female spline 22e and male spline 22g are fitted together. Thereby, the first shaft portion 21A and the second shaft portion 21B are connected.

A gap is provided between the end surface of the second shaft portion 21B facing the first shaft portion 21A side (that is, the end surface of the third end portion 21g) and the second stepped surface 22t. A gap between the end surface of the third end portion 21g and the second stepped surface 22t constitutes a groove 22u on the inner peripheral surface of the hollow portion 22. As shown in FIG. That is, a groove 22u extending in the circumferential direction is provided on the inner peripheral surface of the hollow portion 22, and the groove 22u extends between the end surface of the third end portion 21g of the second shaft portion 21B and the third region. 22r and a second stepped surface 22t.

Of the pair of communication holes 23, one of the communication holes 23 located on the upstream side in the flow direction of the oil O opens into the hollow portion 22 at the groove 22u. A centrifugal force is applied to the oil O supplied into the hollow portion 22 as the shaft 21 rotates. Since the groove 22u is provided on the inner peripheral surface of the hollow portion 22, the oil O accumulates in the groove 22u due to the centrifugal force. According to this embodiment, since the communication hole 23 opens into the groove 22u, the oil O accumulated in the groove 22u can be efficiently guided to the communication hole 23. As shown in FIG.

According to the present embodiment, the oil O can be stored by using the gap at the connecting portion between the first shaft portion 21A and the second shaft portion 21B as the concave groove 22u. Therefore, it is not necessary to apply special processing to provide the concave groove 22u for storing the oil O.

When a plurality of communication holes 23 arranged along the axial direction are provided, the oil O easily flows into the communication hole 23 positioned downstream in the flow direction of the oil O, and flows into the communication hole 23 upstream in the flow direction of the oil O. Oil O may be insufficient. According to this embodiment, since the communicating hole 23 located upstream in the flow direction opens in the recessed groove 22u, the oil O can sufficiently flow into the communicating hole 23 located upstream in the flow direction.

According to this embodiment, the diameter of the hollow portion 22 decreases stepwise from the upstream side to the downstream side in the flow direction. This makes it easier for the oil O to spread from the upstream side of the hollow portion 22 to the downstream side. One of the pair of communication holes 23 on the upstream side opens to the third region 22r, and the other on the downstream side opens to the second 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 communication hole 23 on the upstream side. Therefore, it is possible to allow the oil O to flow sufficiently into the communication holes 23 located on the downstream side as well.

A part of the female spline 22e is positioned in the gap between the end surface of the third end portion 21g and the second stepped surface 22t. Therefore, the inner peripheral surface of the hollow portion 22 is provided with protrusions and recesses that are arranged along the circumferential direction due to the female splines 22e. If the cross-sectional shape of the hollow portion is a circle centered on the motor shaft, even if the shaft rotates, the oil O inside the hollow portion may idle with respect to the shaft and centrifugal force may not be applied to the oil O. . On the other hand, by providing convex portions and concave portions arranged along the circumferential direction in the hollow portion 22, the oil O can be rotated with the rotation of the shaft 21, and a centrifugal force is applied to the oil O in the hollow portion 22. be able to. Thereby, the oil O can be smoothly guided to the communication hole 23 .

According to this embodiment, the outer peripheral surface of the second shaft portion 21B and the inner peripheral surface of the third region 22r are provided with splines (a male spline 22g and a female spline 22e) that are spline-fitted with each other. A part of the spline (female spline 22e) of the third region 22r is positioned inside the concave groove 22u. Therefore, centrifugal force can be applied to the oil O in the hollow portion 22 using the female spline 22e used for fitting. That is, in order to apply centrifugal force to the oil O, it is not necessary to process the inner peripheral surface of the hollow portion 22 to provide an uneven shape.

(Rotor Core) The rotor core 24 is configured by laminating silicon steel plates. The rotor core 24 is a cylindrical body extending along the axial direction. The rotor core 24 has a pair of axial end faces 24a facing axially opposite sides and an outer peripheral face 24b facing radially outward.

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

The rotor core 24 is provided with one fitting hole 24c, a plurality of magnet holding holes 24d, and a plurality of core through holes 24e which are located in the center when viewed in the axial direction and penetrate along the axial direction. The fitting hole 24c, the magnet holding hole 24d, and the core through hole 24e open at the pair of axial end faces 24a.

The fitting hole 24c has a circular shape centered on the motor shaft J2. The shaft 21 is inserted and fitted into the fitting hole 24c. Therefore, the rotor core 24 surrounds the shaft 21 from the radial outside. The fitting between the shaft 21 and the fitting hole 24c is clearance fitting. Therefore, deformation of the rotor core 24 due to fitting of the shaft 21 is suppressed. A protrusion (not shown) protruding radially inward is provided on the inner peripheral surface of the fitting hole 24c. This protrusion fits into a key groove (not shown) provided on the outer peripheral surface of the shaft 21 . Thereby, relative rotation between the rotor core 24 and the shaft 21 is suppressed.

The plurality of core through-holes 24e are arranged side by side along the circumferential direction. The core through hole 24e is positioned radially inward of the magnet holding hole 24d. The core through hole 24e serves to flow the oil O between the pair of axial end faces 24a.

The plurality of magnet holding holes 24d are arranged side by side along the circumferential direction. A rotor magnet 25 is inserted into the magnet holding hole 24d. The magnet holding hole 24 d holds the rotor magnet 25 . That is, the rotor 20 of the present embodiment is of an interior permanent magnet (IPM) type in which the rotor magnet 25 is embedded inside the rotor core 24 .

The rotor magnet 25 is a permanent magnet. The plurality of rotor magnets 25 are fixed to the rotor core 24 by being inserted into the plurality of magnet holding holes 24d arranged in the circumferential direction. A plurality of rotor magnets 25 are arranged along the circumferential direction.

(End Plate) FIG. 6 is a plan view of the end plate 26. FIG. FIG. 7 is a cross-sectional view of the end plate 26 along line VII-VII in FIG. 6 and 7, other members of the motor unit 1 are indicated by phantom lines.

As shown in FIG. 6, the end plate 26 is circular in plan view. The end plate 26 is a metal plate. The end plate 26 is provided with a circular central hole 26i extending therethrough along the axial direction. A key portion 26q is provided on the inner peripheral surface of the central hole 26i. The key portion 26q fits into a key groove 21k provided on the shaft 21. As shown in FIG. The end plate 26 and the shaft 21 are prevented from rotating relative to each other by fitting the key portion 26q into the key groove 21k.

As shown in FIG. 5, the end plate 26 has a first surface 26a and a second surface 26b. The first surface 26 a faces the axial end surface 24 a of the rotor core 24 . The second surface 26b faces away from the first surface 26a.

A pair of end plates 26 are positioned on both sides of the rotor core 24 in the axial direction. The pair of end plates 26 are in contact with the pair of axial end faces 24a of the rotor core 24, respectively. One of the pair of end plates 26 (first end plate 26A) is located between one axial end surface 24a of the rotor core 24 and the flange 21c. The other of the pair of end plates 26 (second end plate 26</b>B) is positioned between the other axial end face 24 a of rotor core 24 and washer 28 . The end plate 26 contacts the axial end surface 24a on a first surface 26a. Also, the end plate 26 contacts the collar portion 21c or the washer 28 on the second surface 26b.

According to this embodiment, the rotor core 24 and the pair of end plates 26 are sandwiched between the flange portion 21 c and the nut 29 . As a result, the pair of end plates 26 are pressed against the axial end surfaces 24a of the rotor core 24 from both sides in the axial direction. A frictional force is generated at the contact portion between the first surface 26 a of the end plate 26 and the axial end surface 24 a of the rotor core 24 , thereby suppressing relative rotation between the rotor core 24 and the shaft 21 . When the rotor core and the shaft are fixed by press-fitting, the rotor core is deformed and the magnetic path passing through the rotor core is changed, resulting in an increase in iron loss. Particularly, in a motor for driving a vehicle as in the present embodiment, since the driving force is large, it is necessary to secure a large interference for press-fitting, and the iron loss of the rotor core tends to increase. According to this embodiment, the rotor core 24 is fixed to the shaft 21 via the end plates 26 . Therefore, the fitting hole 24c of the rotor core 24 and the shaft 21 can be fitted with a clearance fit, so that the deformation of the rotor core 24 can be suppressed, and the motor 2 with high efficiency can be provided.

As shown in FIG. 7, the first surface 26a is provided with a recess 26f and an inclined surface 26e surrounding the recess 26f from the radially outer side. The concave portion 26f has a circular shape centered on the motor shaft J2 in plan view. The recess 26f has a recess bottom surface 26g and a recess inner peripheral surface 26h. The bottom surface 26g of the recess is a plane perpendicular to the motor shaft J2. The recess inner peripheral surface 26h is positioned between the recess bottom surface 26g and the inclined surface 26e. The inner circumferential surface 26h of the recess is inclined in a direction to make the recess 26f shallower from the radially inner side to the radially outer side. A gap is provided between the recessed portion 26 f and the axial end surface 24 a of the rotor core 24 . Oil O is collected in this gap and cools the axial end surface 24 a of the rotor core 24 .

The inclined surface 26e is provided in the radially outermost region of the first surface 26a and extends along the circumferential direction. The inclined surface 26e is inclined at an inclination angle θ toward the rotor core 24 as it extends radially outward. Here, the inclination angle .theta. is an angle formed between a plane perpendicular to the motor shaft J2 and the inclined surface 26e.

The end plate 26 contacts the axial end surface 24a of the rotor core 24 at the inclined surface 26e of the first surface 26a. Since the inclined surface 26e inclines toward the rotor core 24 as it extends radially outward, the inclined surface 26e contacts the axial end surface 24a in the radially outermost region. As a result, the frictional force generated by the contact between the inclined surface 26e and the axial end surface 24a can be generated radially outward as much as possible. Also, the normal stress between the inclined surface 26e and the axial end surface 24a can be increased radially outward. Thereby, the limit value of the static friction force can be increased toward the radially outer side. The holding torque that restrains relative rotation between 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 between the end plate 26 and the rotor core 24 , so that the rotor core 24 can be firmly held with respect to the end plate 26 . In order to obtain such an effect, it is preferable that the inclination angle θ of the inclined surface 26e is 0.1° or more and 5° or less.

Also, the end plate 26 of the present embodiment contacts the axial end surface 24a of the rotor core 24 at the inclined surface 26e. Therefore, the contact position between the end plate 26 and the rotor core 24 can be stabilized. Therefore, variations in the torque transmitted between the end plates 26 and the rotor core 24 can be suppressed, and the rotor core 24 can be reliably fixed to the shaft 21 .

Further, according to the present embodiment, since the end plate 26 is provided with the inclined surface 26e, even if there is variation in the flatness of the contact portion between the end plate 26 and the axial end surface 24a of the rotor core 24, the contact can be ensured. be able to. As will be described later, an oil flow path 26t (see FIG. 5) is provided radially inside the inclined surface 26e. In general, when oil enters between the rotor core and the stator, the rotational efficiency of the rotor core decreases. When the inclined surface 26e contacts the axial end surface 24a of the rotor core 24, the oil O in the oil flow path 26t enters the gap between the outer peripheral surface 24b of the rotor core 24 and the stator 30 from between the end plate 26 and the rotor core 24. can be suppressed. Note that the inclined surface 26e may have a configuration in which the inclination angle changes toward the radially outer side. Also, the inclined surface 26e may be a curved surface whose angle of inclination changes toward the radially outer side.

As shown in FIG. 5, the inclined surface 26e blocks the opening of the magnet holding hole 24d of the rotor core 24. As shown in FIG. This prevents the rotor magnet 25 held inside the magnet holding hole 24d from jumping out of the opening of the magnet holding hole 24d. As a result, part of the rotor magnet 25 is prevented from entering the drive portion inside the housing recess.

As shown in FIG. 7, the second surface 26b is provided with a flat portion 26c and a chamfered portion 26d located at the outer edge of the flat portion 26c. The plane portion 26c is orthogonal to the motor shaft J2. The chamfered portion 26d is inclined toward the first surface 26a toward the radially outer side.

As shown in FIG. 5, the end plate 26 has two sets of a plate through hole 26p, a first concave groove (first concave portion) 26j, and a second concave groove (second concave portion) 26k. be provided. One of the two sets of plate through hole 26p, first groove 26j and second groove 26k will be described below, but the other set has the same configuration.

The plate through hole 26p extends along the axial direction. The first groove 26j is located on the first surface 26a. The first groove 26j extends radially inward from the opening of the plate through hole 26p. The first groove 26j opens radially inward on the inner peripheral surface of the central hole 26i. The second groove 26k is located on the second surface 26b. The second groove 26k extends radially outward from the opening of the plate through hole 26p. The second groove 26k opens radially outward at the chamfered portion 26d.

The axial opening of the first recessed groove 26j of the end plate 26 is covered with the axial end surface 24a of the rotor core 24 . A radial opening of the first groove 26 j is connected to the communication hole 23 of the shaft 21 .

The oil O supplied to the inside of the hollow portion 22 of the shaft 21 flows radially outward through the communication hole 23 . Also, the oil O flows into the first recessed groove 26j from the radially outer opening of the communication hole 23 . Further, the oil O passes through the plate through hole 26p, flows toward the first surface 26a and the second surface 26b, and is discharged to the outside of the rotor 20 through the second concave groove 26k. As shown in FIG. 4 , coil ends 31 a of the stator 30 are provided radially outside the end plates 26 . The oil O released to the outside of the rotor 20 is supplied to the coil ends 31a to cool the coil ends 31a.

The first groove 26j, the plate through hole 26p and the second groove 26k of the end plate 26 function as an oil flow path 26t. That is, the oil flow path 26t is composed of a first groove 26j, a plate through hole 26p and a second groove 26k. Each of the pair of end plates 26 is provided with an oil flow path 26t that communicates with the communication hole 23, extends along the radial direction, and opens.

According to the end plate 26 of this embodiment, the plate through hole 26p, the first groove 26j and the second groove 26k form the oil flow path 26t. Therefore, according to the present embodiment, the oil flow path 26t can be configured with an inexpensive component (the end plate 26) manufactured by die molding.

The first grooves 26j of the pair of end plates 26 communicate with the core through holes 24e. That is, the core through hole 24e connects the first grooves 26j of the pair of end plates 26 with each other. In other words, the core through hole 24e connects the oil passages 26t of the pair of end plates 26 with each other. Moreover, at least part of the opening of the core through-hole is located radially outside the plate through-hole 26p.

According to the present embodiment, since the core through-hole 24e connects the first grooves 26j of the pair of end plates 26, part of the oil O passing through the first grooves 26j is directed to the core through-hole 24e. can flow. As a result, the rotor core 24 can be cooled from the inside by the oil O in the core through hole 24e. Also, the rotor magnet 25 held by the rotor core 24 can be cooled via the rotor core 24 .

According to the present embodiment, the opening of the core through-hole 24e is located radially outside the plate through-holes 26p of the pair of end plates 26. As shown in FIG. As a result, the centrifugal force of the rotor 20 accumulates the oil O inside the core through hole 24e, and the oil O can be supplied to the first concave grooves 26j of the end plates 26 on both sides from the core through hole 24e. Further, when the oil O is insufficient in the first recessed groove 26j on one side of the pair of end plates 26, the oil O can be supplied from the other side through the core through hole 24e. Therefore, substantially the same amount of oil O can be discharged from each end plate 26 to the coil end 31a, and the coil 31 can be stably cooled.

As shown in FIG. 5, one of the pair of end plates 26 sandwiched between the flange portion 21c and the rotor core 24 serves as a first end plate 26A, which is sandwiched between the nut 29 and the rotor core 24. The other is the second end plate 26B.

In the first end plate 26A, a portion of the radial inner side of the plate through hole 26p is covered with the collar portion 21c. In addition, in the first end plate 26A, the opening facing the axial direction of the second groove 26k faces the outside in the axial direction. In other words, in the first end plate 26A, the axial opening of the second groove 26k is entirely exposed when viewed in the axial direction. That is, the second recessed groove 26k of the first end plate 26A communicates with the outside through an opening facing the axial direction. In the first end plate 26A, the second recessed groove 26k functions as a first open portion 26s in which a portion of the plate through hole 26p and the entire opening facing the axial direction are released from the washer 28 . In the first end plate 26A, the oil O that has passed through the plate through hole 26p is discharged from the first opening 26s.

A washer 28 is interposed between the second end plate 26B and the nut 29 . In the second end plate 26B, a washer 28 covers a part of the radially inner side of the axially facing openings of the plate through hole 26p and the second groove 26k. A portion of the opening facing the axial direction of the second groove 26k that is covered with the washer 28 is called a covered portion, and a portion that is not covered with the washer 28 is called an open portion. That is, in the second end plate 26B, the axial opening of the second groove 26k has a covered portion covered with the washer 28 and a second open portion 26r not covered with the washer. The second groove 26k of the second end plate 26B faces axially outward at a second open portion 26r located at the radially outer end of the second groove 26k. In other words, the second groove 26k of the second end plate 26B is exposed at the second opening 26r when viewed from the axial direction. That is, the second groove 26k of the second end plate 26B communicates with the outside at the second open portion 26r. The second open portion 26r is positioned at the radially outer end of the second groove 26k. In the second end plate 26B, the oil O that has passed through the plate through hole 26p is discharged from the second opening 26r.

According to the first end plate 26A and the second end plate 26B of the present embodiment, the second surface 26b is provided with the second recessed groove 26k, so that the second surface 26b through the plate through hole 26p. The oil O flowing to the 26b side can be moved radially outward along the second groove 26k. Therefore, it is possible to stably flow the oil O up to the second open portion 26r, so that the oil O can be stably supplied to the coil end 31a of the stator 30. As shown in FIG.

According to this embodiment, the flange portion 21c or the washer 28 functions as a lid portion covering the axial opening of the second groove 26k of the first end plate 26A and the second end plate 26B. do. That is, the rotor 20 has a pair of cover portions (the collar portion 21 c and the washer 28 ) located at the axial end portions of the rotor core 24 with the end plates 26 interposed therebetween. The lid portion (the flange portion 21c and the washer 28) covers the opening facing the axial direction of the plate through-hole 26p from the outside, so that the oil O flowing out from the plate through-hole 26p toward the second surface 26b is prevented from entering the second concave portion. It is guided to flow along the groove 26k. According to this embodiment, the behavior of the oil O can be controlled by the lid portion (the collar portion 21 c and the washer 28 ) to prevent the oil O from entering between the rotor core 24 and the stator 30 .

According to the second end plate 26B of the present embodiment, the axial opening of the second groove 26k is partially covered with the washer 28 and faces outward in the axial direction at the second open portion 26r. That is, in the region of the second recessed groove 26k reaching 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. As a result, the oil O can be stably discharged from the second opening 26r, and the oil O can be stably supplied to the coil end 31a.

According to this embodiment, the second groove 26k faces axially outward at the second open portion 26r located at the radial end. Therefore, the oil O that has passed through the second recessed groove 26k can be scattered in the axial direction from the second open portion 26r. As a result, the oil O can be scattered toward the coil ends 31a projecting axially from the ends of the rotor core 24, and the coils 31 of the coil ends 31a can be effectively cooled.

In addition, in the first end plate 26A of the present embodiment, a first open portion 26s is provided over a portion of the plate through-hole 26p and the entire opening facing the axial direction. However, as shown in phantom lines in FIG. 5, the flange portion 21c may cover part of the axial opening of the second groove 26k. In this case, the first opening portion 26s of the first end plate 26A is located at the radially outer end, similarly to the second opening portion 26r of the second end plate 26B, and the second opening portion 26s An effect similar to that of the open portion 26r can be obtained.

In addition, in the present embodiment, the end plate 26 is provided with a groove-shaped first groove 26j and a second groove 26k. However, even with recesses that are not groove-shaped, the above-described certain effects can be obtained. By providing the first groove 26j and the second groove 26k extending in the radial direction, the oil O can be guided smoothly in the radial direction.

(First Modification of End Plate) FIG. 8 is a cross-sectional view of an end plate 126 of a first modification that can be employed in the present embodiment. In addition, the same code|symbol is used and demonstrated about the component of the same aspect as the above-mentioned embodiment. The end plate 126 of the first modified example has a first surface 126a facing the rotor core 24 and a second surface 126b facing away from the first surface 126a, as in the above-described embodiment. . The end plate 126 is also provided with a pair of plate through holes 126p, a pair of first grooves 126j and a pair of second grooves 126k. The plate through hole 126p extends axially. The first groove 126j is located on the first surface 126a. The first groove 126j extends radially inward from the plate through hole 126p. second
The groove 126k of is located on the second surface 126b. The second groove 126k extends radially outward from the plate through hole 126p. The opening facing the axial direction of the second groove 126k is partially covered with a lid portion 128 and faces outward in the axial direction at an open portion 126r. Here, the lid portion 128 is the washer 28 or the collar portion 21c (see FIG. 5).

In this modified example, the bottom of the second groove 126k is provided with an inclined surface 126u in which the depth of the second groove 126k becomes shallower toward the radially outer side. The inclined surface 126u overlaps the open portion 126r when viewed in the axial direction. According to this modified example, by providing the inclined surface 126u in the second groove 126k, the flow of the oil O can be imparted with an axial component. The oil O can be scattered in the axial direction so that the oil O can be effectively scattered toward the coil ends 31 a that protrude axially from the ends of the rotor core 24 .

(Second Modification of End Plate) FIG. 9 is a plan view of an end plate 226 of a second modification that can be employed in this embodiment. In addition, the same code|symbol is used and demonstrated about the component of the same aspect as the above-mentioned embodiment. The end plate 226 of the second variant has a first surface 226a and a second surface 226b facing away from the first surface 226a, as in the previous embodiment. The end plate 226 also has a pair of plate through holes 226p, a pair of first grooves 226j and a pair of second grooves 226k. The plate through hole 226p extends axially. The first groove 226j is located on the first surface 226a. The first groove 226j extends radially inward from the plate through hole 226p. The second groove 226k is located on the second surface 226b. The second groove 226k extends radially outward from the plate through hole 226p. The opening facing the axial direction of the second groove 226k is partially covered with a lid portion 228 and faces outward in the axial direction at an open portion 226r. Here, the lid portion 228 is the washer 28 or the collar portion 21c (see FIG. 5).

The second concave groove 226k is a groove extending along the radial direction. Also, when viewed from the axial direction, the extending direction of the second groove 226k is inclined with respect to the radial direction. Also, the second groove 226k curves so as to increase the angle of inclination with respect to the radial direction as it goes radially outward. According to this modification, since the second groove 226k is inclined with respect to the radial direction, the oil O passing through the second groove 226k is subjected to a centrifugal force from the inclined wall surface of the second groove 226k. can be given. As a result, the speed of the oil O scattering from the open portion 226r can be increased, and even if the distance to the coil end 31a is long, the oil O can reliably hit the coil end 31a.

The pair of second grooves 226k of this modified example have different shapes when viewed from the axial direction. One of the pair of second grooves 226k, the second groove 226kA, is slightly curved when viewed from the axial direction and has a smaller inclination angle with respect to the radial direction than the other second groove 226kB. That is, according to the present embodiment, the extending directions of the plurality of second grooves 226kA and 226kB when viewed from the axial direction have different angles with respect to the radial direction. Therefore, the magnitude of the centrifugal force applied to the oil O by the pair of second grooves 226kA and 226kB is different from each other. The oil O that scatters from one of the second grooves 226kA is faster than the oil O that scatters from the other of the second grooves 226kB, and scatters over a farther range. That is, according to this modified example, it is possible to scatter the oil O to different regions in the plurality of second grooves 226kA and 226kB, and to apply the oil O to a wide range of the coil end 31a.

<Oil Path> As shown in FIG. 1 , the oil path 90 is positioned inside the housing 6 , that is, in the accommodation space 80 . The oil passage 90 is configured across the motor chamber 81 and the gear chamber 82 of the accommodation space 80 . The oil passage 90 is a path of the oil O that leads the oil O from the oil sump P (that is, the area below the housing space 80) to the oil sump P again via the motor 2 . The oil passage 90 has a first oil passage (oil passage) 91 passing inside the motor 2 and a second oil passage (oil passage) 92 passing outside the motor 2 . The oil O cools the motor 2 from inside and outside in the first oil passage 91 and the second oil passage 92 . The oil passage 90 constitutes an oil cooling mechanism.

The first oil passage 91 and the second oil passage 92 are paths for supplying the oil O from the oil sump P to the motor 2 and recovering it to the oil sump P again. In the first oil passage 91 and the second oil passage 92, the 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 to the lower area of the gear chamber 82 (that is, the oil reservoir P) through the partition wall opening 68 .

A cooler 97 for cooling the oil O is provided in the route of the first oil passage 91 . The oil O that has passed through the first oil passage 91 and has been cooled by the cooler 97 joins the oil O that has passed through the second oil passage 92 in the oil reservoir P. In the oil reservoir P, the oil O that has passed through the first oil passage 91 and the second oil passage 92 is mixed with each other and exchanges heat. Therefore, the cooling effect of the cooler 97 arranged in the first oil passage 91 can also be exerted on the oil O passing through the second oil passage 92 . According to this embodiment, one cooler 97 provided in one of the first oil passage 91 and the second oil passage 92 is used to cool the oil O in both oil passages. .

Generally, the cooler is placed in a channel through which liquid is constantly flowing. In order to cool the two oil passages, it is conceivable to arrange a cooler in each of the flow paths included in the two oil passages. In this case, it is necessary to use two coolers, which increases the cost. Moreover, in order to cool the two oil passages, a configuration is conceivable in which a flow passage is provided in a region where the two oil passages are merged, and a cooler is installed in this flow passage. In this case, since it is necessary to provide a flow path in the area where the exchange occurs, it is necessary to complicate the structure of the flow path in the oil path, resulting in an increase in cost. According to the present embodiment, a cooler is provided only in the first oil passage 91, and the oil O passing through the first oil passage 91 and the second oil passage 92 is mixed in the oil reservoir P, whereby the second The oil passage 92 can be indirectly cooled. Thus, one cooler 97 can cool the oil O in the first oil passage 91 and the second oil passage 92 without complicating the configuration of the flow paths in the oil passage 90 . In addition, such an effect is obtained by having a cooler 97 for cooling the oil O in either one of the first oil passage 91 and the second oil passage 92, and the first oil passage 91 and the second oil passage This effect can be achieved when the oil O flowing through the path 92 joins the oil reservoir P.

The heat of the oil O is mainly radiated through the cooler 97 . Further, part of the heat of the oil O is radiated through the housing 6 because the oil O contacts the inner surface of the housing 6 . In addition, as shown in FIG. 1, the outer surface of the housing 6 may be provided with an uneven heat sink portion 6b. The heat sink portion 6b facilitates cooling of the motor 2 through the housing 6. FIG.

(First Oil Passage) In the first oil passage 91 , the oil O is scooped up from the oil reservoir P by the differential gear 5 and guided into the rotor 20 . Inside the rotor 20 , the centrifugal force accompanying the rotation of the rotor 20 is applied to the oil O . As a result, the oil O diffuses evenly toward the stator 30 surrounding the rotor 20 from the outside in the radial direction, thereby cooling the stator 30 .

The first oil passage 91 has a rake-up passage 91a, a shaft supply passage (oil passage) 91b, an in-shaft passage 91c, and an in-rotor passage 91d. Also, a first reservoir 93 is provided in the route of the first oil passage 91 . The first reservoir 93 is provided in the accommodation space 80 (especially the gear chamber 82).

The raking-up path 91a is a path for raking up the oil O from the oil reservoir P by the rotation of the ring gear 51 of the differential gear 5 and receiving the oil O in the first reservoir 93 (see FIG. 3).

As shown in FIG. 3, the first reservoir 93 is positioned above the motor shaft J2, the intermediate shaft J4 and the differential shaft J5 in the vertical direction. The first reservoir 93 is positioned between the intermediate shaft J4 and the differential shaft J5 in the vehicle front-rear direction (horizontal direction, X-axis direction). The first reservoir 93 is positioned between the motor shaft J2 and the differential shaft J5 in the vehicle longitudinal direction (horizontal direction, X-axis direction). A first reservoir 93 is arranged on the side of the first gear 41 . The first reservoir 93 opens upward.

As used herein, the term "reservoir" means a structure that has the function of accumulating oil in the absence of a constant unidirectional flow of liquid. A "reservoir" differs from a "channel" in that there is no constant liquid flow. A first reservoir 93, a second reservoir 98 and a sub-reservoir 95 are provided in the housing space 80 of the motor unit 1 of this embodiment.

In the present embodiment, the differential shaft J5, which is the center of rotation of the ring gear 51, is arranged on the vehicle rear side with respect to the reduction gear 4. As shown in FIG. The differential gear 5 rotates upward in a region opposite to the reduction gear 4 when the vehicle moves forward. The oil O drawn up by the ring gear 51 of the differential gear 5 flows around the side opposite to the reduction gear 4 and falls onto the upper side of the first reservoir 93 and accumulates in the first reservoir 93 . That is, the first reservoir 93 receives the oil O scooped up by the ring gear 51 . Further, when the liquid level of the oil pool P is high, such as immediately after the motor 2 is driven, the second gear 42 and the third gear 43 come into contact with the oil O in the oil pool P and scoop up the oil O. As shown in FIG. In such a case, the first reservoir 93 also receives the oil O scooped up by the second gear 42 and the third gear 43 in addition to the ring gear 51 .

The housing 6 has a gear chamber ceiling portion (ceiling portion) 64 that constitutes the upper wall of the gear chamber 82 . The gear chamber ceiling portion 64 is positioned above the reduction gear 4 and the differential gear 5 . Here, an imaginary line (third line segment to be described later) L3 that virtually connects the motor shaft J2 and the differential shaft J5 as viewed from the axial direction of the motor shaft J2 is defined. The gear chamber ceiling portion 64 is substantially parallel to the imaginary line L3. By making the gear chamber ceiling portion 64 substantially parallel to the imaginary line L3, a sufficient area is secured for the oil O that is scooped up by the ring gear 51 and scattered in the direction in which the imaginary line L3 extends. It can efficiently contact the first gear 41 rotating about the motor shaft J. Further, by making the gear chamber ceiling portion 64 substantially parallel to the imaginary line L3, it is possible to prevent the housing 6 from increasing in size in the vertical direction. Here, the gear chamber ceiling portion 64 and the imaginary line L3 being "substantially parallel" means that the angle formed by the gear chamber ceiling portion 64 and the imaginary line L3 is within 10°. When the gear chamber ceiling portion 64 is curved, the angles formed by the tangent lines at all points of the curved line and the imaginary line L3 are within 10°. Further, within the range of 10°, it is preferable that the gear chamber ceiling portion 64 approaches the imaginary line L3 toward the differential shaft J5 side or the motor shaft J2 side. Thereby, the housing 6 can be miniaturized.

Further, the gear chamber ceiling portion 64 is a curved surface that curves slightly in a direction approaching the imaginary line L3 side from the differential shaft J5 side toward the motor shaft J2 side. The curved shape of the gear chamber ceiling portion 64 is substantially the same as the parabola drawn by the oil O drawn up by the ring gear 51 or is a curved surface slightly separated from the ring gear 51 . A portion of the oil O scooped up by the ring gear 51 reaches the first reservoir 93 directly. Another portion of the oil O scooped up by the ring gear 51 reaches the first reservoir 93 through the gear chamber ceiling portion 64 of the housing 6 . That is, the gear chamber ceiling portion 64 plays a role of guiding the oil O to the first reservoir 93 .

The gear chamber ceiling portion 64 has a convex portion 65 protruding downward. The convex portion 65 is positioned above the first reservoir 93 . The oil O running along the gear chamber ceiling portion 64 becomes large droplets at the lower end of the convex portion 65 , drops downward, and accumulates in the first reservoir 93 . That is, the convex portion 65 guides the oil O flowing along the gear chamber ceiling portion 64 to the first reservoir 93 . In this embodiment, the motor housing portion 61 and the gear housing portion 62 are fixed to each other by bolts 67 . The convex portion 65 is provided on the gear chamber ceiling portion 64 by utilizing the thick portion around the screw hole into which the bolt 67 is inserted. In FIG. 3, other bolts for fixing the motor accommodating portion 61 and the gear accommodating portion 62 and other thick portions around the screw holes are omitted.

The gear chamber ceiling portion 64 has a plate-like eaves portion 66 extending along the axial direction. The eaves portion 66 protrudes downward. A lower end of the eaves portion 66 is positioned above the first reservoir 93 . A portion of the oil O that is scooped up by the ring gear 51 and scatters hits the eaves portion 66 and travels along the surface of the eaves portion 66 . Similarly, the oil O that is scooped up and scattered by the second gear 42 and the third gear is received by the eaves portion 66 and propagates along the surface of the eaves portion 66 . The oil O forms large droplets at the lower end of the eaves portion 66 , drops downward, and accumulates in the first reservoir 93 . That is, the eaves portion 66 guides the scooped up oil O to the first reservoir 93 . The eaves portion 66 inclines from the side of the differential shaft J5 toward the side of the motor shaft J2 as it goes from the upper side to the lower side. Since the ring gear 51 has a larger diameter than the second gear 42 and the third gear 43, the scattering angle of the scattering oil O is close to horizontal. By arranging the eaves portion 66 inclined in the above-described direction, the oil O scattered from the ring gear 51 can be smoothly adhered to the surface of the eaves portion 66 and dropped downward.

The first reservoir 93 is located directly above the ring gear 51 , the second gear 42 and the third gear 43 . The opening of the first reservoir 93 overlaps the ring gear 51, the second gear 42 and the third gear 43 when viewed from the vertical direction. Most of the oil scooped up by the gear scatters directly above the scooped up gear. By arranging the first reservoir 93 directly above the ring gear 51, the second gear 42 and the third gear 43, the oil O scooped up by each gear can be efficiently received.

The first reservoir 93 has a bottom portion 93a, a first side wall portion 93b and a second side wall portion 93c. The bottom portion 93a, the first side wall portion 93b and the second side wall portion 93c extend axially between the wall surfaces of the gear housing portion 62 and the projecting plate portion 61d of the motor housing portion. The first side wall portion 93b and the second side wall portion 93c extend upward from the bottom portion 93a. The first side wall portion 93b forms a wall surface of the first reservoir 93 on the differential gear 5 side. The second side wall portion 93c forms a wall surface of the first reservoir 93 on the reduction gear 4 side. That is, the first side wall portion 93b extends upward from the end of the bottom portion 93a on the differential shaft J5 side, and the second side wall portion 93c extends upward from the end portion of the bottom portion 93a on the motor shaft J2 side. The first reservoir 93 is formed in a region surrounded by a bottom portion 93a, a first side wall portion 93b, a second side wall portion 93c, and wall surfaces of the gear housing portion 62 and the projecting plate portion 61d of the motor housing portion. , the oil O is temporarily stored.

The height of the upper end of the first side wall portion 93b is positioned below the upper end of the second side wall portion 93c. The oil O is scooped up by the differential gear 5 and splashes from the opposite side of the reduction gear 4 toward the first reservoir 93 . By reducing the height of the upper end portion of the first side wall portion 93b, the oil O scooped up by the differential gear 5 can be efficiently stored in the first reservoir 93. As shown in FIG. Further, of the oil O that is scooped up and scattered by the ring gear 51 , the oil O that has exceeded the first side wall portion 93 b can be directed to the first reservoir 93 by hitting the second side wall portion 93 c.

The second side wall portion 93 c extends obliquely upward along the circumferential direction of the first gear 41 . That is, the second side wall portion 93c inclines toward the motor shaft J2 as it goes upward. As a result, the second side wall portion 93c can receive the oil O that has been scooped up by the differential gear 5 in a wide range. In addition, the second side wall portion 93c can receive droplets of the oil O running along the ceiling of the accommodation space 80 in a wide range.

A shaft supply channel 94 opens toward the inside of the first reservoir 93 at the boundary between the bottom portion 93a and the second side wall portion 93c. The bottom portion 93a is slightly inclined downward toward the motor shaft J2 in plan view. That is, the bottom portion 93a is slightly inclined so as to be the lower end on the side of the second side wall portion 93c. Therefore, by providing the opening of the shaft supply channel 94 between the bottom portion 93 a and the second side wall portion 93 c , the oil O in the first reservoir 93 can be efficiently supplied to the shaft supply channel 94 .

A shaft feed path 91 b guides oil O from the first reservoir 93 to the motor 2 . The shaft supply path 91 b is configured by a shaft supply channel 94 . A shaft feed channel 94 extends from the first reservoir 93 toward the shaft 21 end. The shaft supply channel 94 extends linearly. The shaft supply channel 94 slopes downward from the first reservoir 93 toward the end of the shaft 21 . The shaft supply passage 94 is formed by processing a hole penetrating the inside and outside of the housing space 80 in the gear housing portion 62 . An opening outside the machined hole is closed with a cap (not shown). The shaft supply channel 94 guides the oil O accumulated in the first reservoir 93 from the end of the shaft 21 to the hollow portion 22 .

As shown in FIG. 1 , the in-shaft path 91 c is a path through which the oil O passes through the hollow portion 22 of the shaft 21 . The rotor internal path 91d is a path from the communicating hole 23 of the shaft 21 through the end plate 26 located on the axial end face 24a of the rotor core 24 and scattering to the stator 30 (see FIG. 5). That is, the first oil passage 91 has a path extending from the inside of the shaft 21 through the rotor core 24 .

Centrifugal force is applied to the oil O inside the rotor 20 in the shaft inner path 91c as the rotor 20 rotates. As a result, the oil O is continuously splashed radially outward from the end plate 26 . Further, as the oil O scatters, the inside of the passage inside the rotor 20 becomes negative pressure, the oil O accumulated in the first reservoir 93 is sucked into the inside of the rotor 20, and the passage inside the rotor 20 is filled with the oil O. . The movement of the oil O into the rotor 20 is promoted also by the capillary force in the first oil passage 91 . The oil O that reaches the stator 30 takes heat from the stator 30 .

(Second Oil Path) As shown in FIG. 1 , the oil O is pulled up from the oil reservoir P to the upper side of the motor 2 in the second oil path 92 and supplied to the motor 2 . The oil O supplied to the motor 2 absorbs heat from the stator 30 while running along the outer peripheral surface of the stator 30 to cool the motor 2 . The oil O running along the outer peripheral surface of the stator 30 drips downward and accumulates in the lower region of the motor chamber 81 . The oil O in the second oil passage 92 joins the oil O in the first oil passage 91 in the area below the motor chamber 81 . The oil O accumulated in the lower area of the motor chamber 81 moves to the lower area of the gear chamber 82 (that is, the oil reservoir P) through the partition wall opening 68 .

10 is a sectional view of the motor unit 1. FIG. Note that the cut plane in FIG. 10 is shifted in the axial direction in each region. The second oil passage 92 has a first passage 92a, a second passage 92b and a third passage 92c. A pump 96 , a cooler 97 and a second reservoir 98 are provided in the route of the second oil passage 92 . In the second oil passage 92, the oil O passes through the first passage 92a, the pump 96, the second passage 92b, the cooler 97, the third passage 92c, and the second reservoir 98 in this order. and supplied to the motor 2.

Pump 96 is an electric pump driven by electricity. The pump 96 is mounted in a pump mounting recess 6c provided on the outer surface of the housing 6. As shown in FIG. The pump 96 has a suction port 96a and a discharge port 96b. The suction port 96 a and the discharge port 96 b are connected via an internal flow path of the pump 96 . In addition, the suction port 96a is connected to the first flow path 92a. The discharge port 96b is connected to the second flow path 92b. The discharge port 96b is positioned above the suction port 96a. The pump 96 sucks up the oil O from the oil sump P via the first flow path 92a and supplies it to the motor 2 via the second flow path 92b, the cooler 97, the third flow path 92c and the second reservoir 98. supply to

The amount of oil O supplied to the motor 2 by the pump 96 is appropriately controlled according to the driving state of the motor 2 . Therefore, when the temperature of the motor 2 rises, such as when driving for a long time or when high output is required, the driving output of the pump 96 is increased and the amount of oil O supplied to the motor 2 is increased.

The cooler 97 has an inlet 97a and an outlet 97b. The inflow port 97a and the outflow port 97b are connected through an internal channel of the cooler 97 . Also, the inflow port 97a is connected to the second flow path 92b. The outflow port 97b is connected to the third channel 92c. The inflow port 97a is positioned closer to the pump 96 (that is, lower) than the outflow port 97b. A cooling water pipe (not shown) through which cooling water supplied from the radiator passes is provided inside the cooler 97 . The oil O passing through the cooler 97 is cooled by heat exchange with cooling water.

Pump 96 and cooler 97 are fixed to the outer peripheral surface of motor accommodating portion 61 of housing 6 . When viewed from the axial direction of the motor shaft J2, the pump 96 and the cooler 97 are positioned horizontally opposite to the differential gear 5 with the motor shaft J2 interposed therebetween. Also, the pump 96 and the cooler 97 are arranged vertically. Cooler 97 is located above pump 96 . The cooler 97 overlaps the pump 96 when viewed vertically.

According to this embodiment, the pump 96 and the cooler 97 are located on the opposite side of the differential gear 5 with the motor shaft J2 interposed therebetween, so that the space around the motor 2 can be effectively used. As a result, the horizontal dimension of the entire motor unit 1 can be reduced, and the size of the motor unit 1 can be reduced.

According to this embodiment, the pump 96 and cooler 97 are fixed to the outer peripheral surface of the housing 6 . Therefore, compared to the case where the pump 96 and the cooler 97 are provided outside the housing 6, the size of the motor unit 1 can be reduced. In addition, by fixing the pump 96 and the cooler 97 to the outer peripheral surface of the housing 6, a first flow path 92a, a second flow path 92b and a third flow path 92a passing through the inside of the wall portion 6a of the housing 6 are provided. The flow path 92c can constitute a flow path that connects the accommodation space 80, the pump 96, and the cooler 97. As shown in FIG.

According to this embodiment, since the cooler 97 is fixed to the outer peripheral surface of the housing 6, the distance between the accommodation space 80 and the cooler 97 can be shortened. As a result, the length of 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 at a low temperature.

The first flow path 92 a , the second flow path 92 b and the third flow path 92 c pass through the inside of the wall portion 6 a of the housing 6 surrounding the accommodation space 80 . The first flow path 92a can form a first flow path 92a, a second flow path 92b and a third flow path 92c as holes formed in the wall portion 6a. Therefore, there is no need to prepare a separate pipe material, which contributes to a reduction in the number of parts. The first flow path 92a passes through the inside of the portion of the wall portion 6a located below the motor 2. As shown in FIG. The second flow path 92b passes through the inside of the portion of the wall portion 6a that is located on the 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 located above the motor 2. As shown in FIG.

The first flow path 92 a connects the oil reservoir P and the pump 96 . The first flow path 92a has a first end 92aa and a second end 92ab. The first end 92aa is located upstream of the second oil passage 92 compared to the second end 92ab. The first end 92aa opens into the accommodation space 80 below the differential gear 5 . The first end 92aa overlaps the motor 2 when viewed in the vertical direction. The second end 92ab opens into the pump mounting recess 6c and connects to the suction port 96a of the pump 96 .

As described above, the differential gear 5 and the pump 96 are horizontally opposite to each other across the motor shaft J2. The first flow path 92a extends across the motor 2 on the opposite side in the horizontal direction. Also, the first flow path 92 a passes under the motor 2 .

According to this embodiment, since the first flow path 92a passes under the motor 2, the area under the motor 2 can be effectively used, and the dimensions of the motor unit 1 can be reduced. As a result, the size of the motor unit 1 can be reduced.

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. As a result, the size of the motor unit 1 when viewed from the axial direction can be reduced, and the size of the motor unit 1 can be reduced. In this embodiment, 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 gear 5, the 2 gear 42 and the ring gear 51 overlap the first flow path 92a when viewed from the axial direction. However, if at least one of the plurality of gears connected between the motor 2 and the differential gear 5 overlaps with the first flow path 92a when viewed in the axial direction, the above effects can be obtained. .

The first flow path 92 a extends from the underside of the differential 5 to the suction port 96 a of the pump 96 . The first flow path 92a slopes upward from the first end 92aa toward the second end 92ab and extends linearly. A suction port 96a of the pump 96 is located above the lower end of the differential gear 5 and below the motor shaft J2.

The pump 96 is preferably placed away from the road surface in order to avoid being hit by flying stones from the road surface when the motor unit 1 is mounted on the vehicle. On the other hand, by arranging the suction port 96a of the pump 96 below the oil surface of the oil reservoir P, it is possible to suppress air entrainment.

The suction port 96a of this embodiment is positioned below the motor shaft J2. As a result, the suction port 96a can be easily arranged below the oil surface of the oil reservoir P. Further, the intake port 96 a of the present embodiment is positioned above the lower end of the differential gear 5 . Thereby, a structure in which the pump 96 is separated from the road surface can be realized. Further, by arranging the suction port 96a below the motor shaft J2, it becomes easier to form the first flow path 92a in a straight line. Therefore, when adopting a structure in which the first flow path 92a passes through the inside of the wall portion 6a of the housing 6, the ease of processing of the first flow path 92a can be enhanced.

The suction port 96a of the present embodiment is positioned below the liquid surface of the oil pool P in the accommodation space 80 . The height of the liquid surface of the oil reservoir P varies as the oil O is supplied from the oil reservoir P to the first oil passage 91 and the second oil passage 92 . The suction port 96a is positioned below the liquid level even when the liquid level of the oil pool P is the lowest. In FIG. 1, the suction port 96a is depicted as positioned above the liquid surface of the oil reservoir P. As shown in FIG. However, FIG. 1 is only a schematic diagram, and the actual suction port 96a is located below the liquid surface of the oil pool P. As shown in FIG.

A second flow path 92 b connects the pump 96 and the cooler 97 . The second flow path 92b has a first end 92ba and a second end 92bb. The first end 92ba opens into the pump mounting recess 6c and connects to the discharge port 96b of the pump 96. As shown in FIG. 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 92bb connects to the inlet 97a of the cooler 97 . The second end 92bb is located above the first end 92ba.

The second flow path 92b has a first path 92bd and a second path 92be. The first passage 92bd extends upward from the pump mounting recess 6c. The second path 92be extends horizontally from the upper end of the first path 92bd. The first path 92bd and the second path 92be are formed by processing holes extending from different directions and intersecting each other in the wall portion 6a of the housing 6, respectively.

A third flow path 92 c connects the cooler 97 and the housing space 80 . The third flow path 92c extends linearly along the horizontal direction. The third flow path 92c has a first end 92ca and a second end 92cb. The first end portion 92ca is located upstream of the second oil passage 92 compared to the second end portion 92cb. The first end 92ca is connected to the outlet 97b of the cooler 97 . The second end 92cb opens into the accommodation space 80 above the motor 2 . That is, the third flow path 92c opens above the motor 2 in the accommodation space 80. As shown in FIG. A 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 housing space 80. As shown in FIG. That is, the second oil passage 92 supplies the oil O to the second reservoir 98 at the supply portion 99 .

The outflow port 97b of the cooler 97 overlaps with the motor 2 in the axial direction of the motor shaft J2. That is, the outflow port 97b of the cooler 97 is arranged so as to overlap the motor 2 when viewed from the radial direction. In other words, the outlet 97b of the cooler 97 is located between the ends of the stator 30 in the axial direction. Therefore, the third flow path 92c connecting the outlet 97b of the cooler 97 and the accommodation space 80 can be shortened, and the cooled oil O can be supplied to the accommodation space 80 at a low temperature. Further, by arranging the third flow path 97c so as to overlap with the motor 2 in the radial direction, the axial dimension of the motor unit 1 can be reduced, and the size of the motor unit 1 can be reduced.

(Second Reservoir) FIG. 11 is a perspective view of the motor unit 1. FIG. 12 is a plan view of the second reservoir 98. FIG. 11, illustration of the motor accommodating portion 61 and the closing portion 63 of the housing 6 is omitted.

As shown in FIG. 11 , the second reservoir (main reservoir) 98 is located in the motor chamber 81 of the accommodation space 80 . A second reservoir 98 is located above the motor. The second reservoir 98 has a bottom portion (a first bottom portion 98c and a second bottom portion 98g) and sidewall portions extending upward from the bottom portion (a first sidewall portion 98d, a second sidewall portion 98e, and a third sidewall portion). 98f, a fourth sidewall portion 98h, a fifth sidewall portion 98i, a sixth sidewall portion 98j and a seventh sidewall portion 98n). The second reservoir 98 stores the oil O supplied to the motor chamber 81 through the supply portion 99 of the third flow path 92c in the space surrounded by the bottom and side walls. The second reservoir 98 has a plurality of outlets (first outlet 98r, second outlet 98o, third outlet 98x, fourth outlet 98t, fifth outlet 98u and sixth outlet 98u). It has an outflow port 98v). Each outlet supplies the motor 2 with the oil O that has accumulated in the second reservoir 98 . That is, the second reservoir 98 supplies the stored oil O to each part of the motor 2 from above through the outlet.

According to this embodiment, the second reservoir 98 is positioned above the motor 2 and supplies the stored oil O to the upper side of the motor 2 through a plurality of outlets. Since the oil O flows along the outer peripheral surface of the motor 2 from the top to the bottom and takes heat from the motor 2, the entire motor 2 can be cooled.

As shown in FIG. 12, the second reservoir 98 has a first end 98p axially located on the side of the gear chamber 82 and a second end 98p axially located on the opposite side of the first end 98p. and an end 98q. The second reservoir 98 includes a gutter-shaped first storage portion 98A extending along the axial direction, and a second storage portion located on the second end portion 98q side of the first storage portion 98A. 98B.

The first storage portion 98A has a first bottom portion 98c, a first side wall portion 98d, a second side wall portion 98e, and a third side wall portion 98f. Further, the first reservoir 98A is provided with a first outflow port 98r, a second outflow port 98o and a third outflow port 98x.

The first bottom portion 98c has a rectangular shape whose longitudinal direction is the axial direction. Both axial ends of the first bottom portion 98 c are located above coil ends 31 a provided at both ends of the stator 30 . A first outlet 98r is provided in the first bottom portion 98c. The first outflow port 98r is located in a region of the first bottom portion 98c on the side of the first end portion 98p.

The first side wall portion 98d and the second side wall portion 98e extend along the axial direction. Also, the first and second side wall portions 98e face each other in the circumferential direction of the motor shaft J2. An inflow port 98s is provided in the first side wall portion 98d. The inflow port 98s is a U-shaped notch that opens upward. A supply portion 99 is connected to the inflow port 98s. The inflow port 98s is located in the axial middle of the first side wall portion 98d. Thereby, the inflow port 98s can flow the oil O to the first end portion 98p and the second end portion 98q side of the second reservoir 98, respectively.

The second side wall portion 98e is provided with a convex portion 98w that protrudes toward the first side wall portion 98d. The convex portion 98w is positioned in front of the inlet 98s. The protruding portion 98w has an inclined surface whose protruding height decreases from the center toward the first end portion 98p side and the second end portion 98q side. The convex portion 98w smoothly divides the oil O flowing from the inlet 98s to the second reservoir 98 into the first end portion 98p side and the second end portion 98q side.

A second outlet 98o is provided in the second side wall portion 98e. The second outflow port 98o is located in a region of the second side wall portion 98e on the side of the first end portion 98p. The second outlet 98o is located near the first outlet 98r.

As shown in FIG. 11, the third side wall portion 98f is located on the first end portion 98p side of the second reservoir 98 . The third side wall portion 98 f is located above one coil end 31 a of the stator 30 . The height of the top end of the third side wall portion 98f is lower than the height of the top end portions of the first side wall portion 98d and the second side wall portion 98e. Also, the height of the upper end of the third side wall portion 98f is substantially equal to the height of the lower end of the opening of the second outflow port 98o. The space above the second side wall portion 98e functions as a third outflow port 98x through which the oil O flows out when the liquid level of the oil O accumulated in the second reservoir 98 rises.

The second reservoir 98B extends along the circumferential direction of the stator 30. As shown in FIG. The second storage portion 98B includes a second bottom portion 98g, a fourth side wall portion 98h, a fifth side wall portion 98i, a sixth side wall portion 98j, a seventh side wall portion 98n, and a stepped portion 98k. , has Further, the second reservoir 98B is provided with a fourth outflow port 98t, a fifth outflow port 98u, a sixth outflow port 98v and an overflow portion 98y.

The second bottom portion 98g is located on the second end portion 98q side with respect to the first bottom portion 98c. The second bottom portion 98g is located below the first bottom portion 98c. A stepped portion 98k is provided at the boundary between the first bottom portion 98c and the second bottom portion 98g. The second reservoir 98B is located below the first reservoir 98A. The oil O that has flowed to the second end portion 98q side in the first reservoir 98A accumulates in the second reservoir 98B.

The second bottom portion 98 g is located above one coil end 31 a of the stator 30 . The second bottom portion 98 g curves along the outer peripheral 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 dimensions of the motor unit 1 . The second bottom portion 98g inclines downward toward both sides in the circumferential direction from a portion overlapping the motor shaft J2 as viewed in the vertical direction. The second reservoir 98B is connected to the first reservoir 98A on one side with the motor shaft J2 interposed therebetween when viewed in the vertical direction.

As shown in FIG. 12, the second reservoir 98B is a region on one side of the motor shaft J2 when viewed in the vertical direction, and the region connected to the first reservoir 98A is a first region 98gA. The area on the other side of the motor shaft J2 is divided into a second area 98gB. The second bottom portion 98g is highest at the boundary line between the first region 98gA and the second region 98gB. The oil O flowing from the first reservoir 98A into the second reservoir 98B first accumulates in the first region 98gA, and when the liquid level in the first region 98gA reaches the boundary line, the oil O flows into the second region 98gB. The border thus functions as a weir 98gC provided in the second bottom portion 98g. That is, the second bottom portion 98g is provided with a weir 98gC that protrudes upward and partitions the second storage portion 98B of the second reservoir 98 into a first region 98gA and a second region 98gB. The oil O flows into one region (first region 98gA) and when the liquid level exceeds the weir 98gC, it flows into the other region (second region 98gB).

As will be described later, the sixth side wall portion 98j extending along the circumferential direction is provided with a fourth outflow port 98t, a fifth outflow port 98u, and a sixth outflow port 98v arranged along the circumferential direction. An overflow portion 98y is provided on the fifth side wall portion 98i. The fourth outflow port 98t and the fifth outflow port 98u open into the first region 98gA, and the sixth outflow port 98v and the overflow portion 98y open into the second region 98gB. That is, the second reservoir 98 is provided with outlets in a plurality of regions (first region 98gA and second region 98gB) partitioned by the weir 98gC. Therefore, the oil O flows out only from the fourth outflow port 98t and the fifth outflow port 98u until the liquid level in the first region 98gA exceeds the weir 98gC. After the liquid level in the first region 98gA exceeds the weir 98gC, the oil O flows out from the fourth outflow port 98t, the fifth outflow port 98u, the sixth outflow port 98v and the overflow portion 98y. Therefore, according to the present embodiment, the second reservoir 98 can increase the number of outlets from which the oil O flows out as the stored amount of the oil O increases. In particular, when the load on the motor 2 increases and the temperature of the motor 2 increases, the amount of oil O supplied to the second reservoir 98 by the pump 96 increases. Therefore, according to the present embodiment, when the temperature of the motor 2 becomes high, the supply points of the oil O to the motor 2 are increased to widen the cooling range, and the supply amount of the oil O supplied by the motor 2 is increased. be able to.

The fourth side wall portion 98h and the fifth side wall portion 98i are located at both circumferential ends of the second storage portion 98B. The fourth side wall portion 98h and the fifth side wall portion 98i face each other in the circumferential direction. The fourth side wall portion 98h and the fifth side wall portion 98i extend along the axial direction. The fourth side wall portion 98h continues to the first side wall portion 98d and extends toward the second end portion 98q.

The fifth side wall portion 98i is provided with an overflow portion 98y. The overflow portion 98y is a portion provided at the upper end of the fifth side wall portion 98i and having a locally low height. The overflow portion 98y is located above the lower ends of the openings of the fourth outflow port 98t, the fifth outflow port 98u and the sixth outflow port 98v of the second reservoir 98B. Therefore, the oil O overflows from the overflow portion 98y after the liquid level in the second storage portion 98B becomes higher than the fourth outlet 98t, the fifth outlet 98u and the sixth outlet 98v. A sub-reservoir 95, which will be described later, is provided below the overflow portion. The oil O overflowing from the overflow portion 98y is stored in the auxiliary reservoir 95. As shown in FIG. In this specification, "overflowing" means flowing out of the reservoir when the liquid in the reservoir reaches a certain liquid level. Therefore, "overflow" does not apply, such as when liquid flows out of the bottom of the reservoir.

The sixth side wall portion 98j is located on the second end portion 98q side of the second reservoir 98 . The sixth side wall portion 96j extends along the circumferential direction. The sixth side wall portion 98 j is positioned above one coil end 31 a of the stator 30 . The sixth side wall portion 98j is provided with a fourth outflow port 98t, a fifth outflow port 98u and a sixth outflow port 98v. The fourth outflow port 98t, the fifth outflow port 98u and the sixth outflow port 98v are holes provided in the sixth side wall portion 98j and penetrating the second reservoir 98 from inside to outside. The fourth outflow port 98t, the fifth outflow port 98u and the sixth outflow port 98v are arranged along the circumferential direction. As shown in FIG. 11, the fourth outlet 98t, the fifth outlet 98u and the sixth outlet 98v have different heights. Therefore, according to the present embodiment, the number of outlets through which the oil O flows out can be increased according to the liquid level of the oil O in the second reservoir 98 . As a result, the supply points of the oil O to the motor 2 can be increased to widen the cooling range, and the supply amount of the oil O supplied by the motor 2 can be increased. Such an effect can be obtained if at least two of the plurality of outlets provided in the second reservoir 98 have different heights.

The seventh side wall portion 98n extends along the circumferential direction. The seventh side wall portion 98n axially faces the sixth side wall portion 98j. The seventh side wall portion 98n continues to the stepped portion 98k along the circumferential direction. A housing portion 98na for housing a fixing screw of the stator core 32 is provided in the seventh side wall portion 97n.

According to this embodiment, the second oil passage 92 supplies the oil O stored in the second reservoir 98 to the motor 2 from the plurality of outlets. Since the respective outlets supply the oil O to the motor 2 at a constant flow rate, the cooling efficiency of the motor 2 by the oil O can be enhanced.

According to this embodiment, the second reservoir 98 has a plurality of outlets (first outlet 98r, second outlet 98o, third outlet 98x, fourth outlet 98t, fifth outlet 98t). It has an outlet 98u and a sixth outlet 98v). Therefore, the second reservoir 98 can simultaneously supply the oil O to the motor 2 from a plurality of locations, and can cool each part of the motor 2 at the same time.

According to this embodiment, the second reservoir 98 extends along the axial direction. Further, the second reservoir 98 is provided with outlets at both ends in the axial direction. Outflow ports located at both ends in the axial direction of the second reservoir 98 are located above the coil ends 31a. As a result, the coils 31 can be directly cooled by applying the oil O to the coil ends 31a located at both ends of the stator 30 in the axial direction. More specifically, the oil O applied to the coil 31 seeps through the gaps between the conductors forming the coil 31 . The oil O that has permeated the coil 31 absorbs heat from the coil while permeating the entire coil 31 due to capillary force and gravity acting on the conducting tube. Furthermore, the oil O accumulates at the lowest portion of the inner peripheral surface of the stator core 32 and drips down from both ends of the coil 31 in the axial direction. The effect of directly cooling the oil O by directly supplying the oil O to the coil end 31 a is that at least two of the plurality of outlets are located in the axial direction of the second reservoir 98 . This is an effect that can be achieved by being positioned at both ends.

According to this embodiment, the supply portion 99 that supplies the oil O to the second reservoir 98 is located between the outlets located at both ends of the second reservoir 98 in the axial direction. Therefore, the oil O supplied from the supply portion 99 can flow out from the outlets respectively located at the both ends.

(Modification of Second Reservoir) FIG. 13 is a perspective view of a modification of the second reservoir 198 that can be employed in the present embodiment. In addition, the same code|symbol is used and demonstrated about the component of the same aspect as the above-mentioned embodiment. The modified second reservoir 198 is a rectangular shallow box with an open top. The second reservoir 198 has a central reservoir 198a and four oil supplies 198b positioned around the central reservoir 198a. The central reservoir 198a and the four oil supplies 198b are partitioned from each other.

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

The four oil supplies 198b are arranged around the central oil reservoir 198a. The oil supply portion 198b has a substantially rectangular shape. An outflow port 198c that communicates with the inside and outside of the oil supply portion 198b is provided in the vicinity of the corner between the two outer walls 198ba extending in different directions of the oil supply portion 198b. One of the two outlets 198c opens in the axial direction of the motor 2, and the other opens in the circumferential direction. Since each of the four oil supplies 198b has two outlets 198c, the second reservoir 198 has a total of eight outlets 198c.

The second reservoir 198 is installed above the stator 30 so that its bottom surface is horizontal. When the oil O supplied from the supply portion 99 fills the central oil storage portion 198a, it overflows the cylindrical wall 198aa and flows into the four oil supply portions 198b. Since the second reservoir 198 is installed horizontally and the cylindrical wall 198aa has the same height all around, the oil O evenly flows into the four oil supply portions 198b. The oil O accumulates in the four oil supply portions 198b and flows out from the outflow port 198c.

The axial length of the second reservoir 198 is longer than the axial length of the stator core 32 . The oil O is supplied to the motor 2 from one oil supply portion 198b through two outlets 198c directed in the axial direction and the circumferential direction. According to this modification, the second reservoir 198 can supply the oil O to the motor 2 from a plurality of outlets in a plurality of directions.

(Sub-Reservoir) FIG. 14 is a cross-sectional view of the motor unit 1 showing an outline of the sub-reservoir 95 . In FIG. 14, the projecting portion 63d provided on the closing portion 63 of the housing 6 is indicated by a phantom line. In FIG. 14, the oil O stored in the sub-reservoir 95 is highlighted with a dot pattern. The auxiliary reservoir 95 receives the oil O overflowing from the second reservoir 98 in the second oil passage 92 . That is, a secondary reservoir 95 that stores the oil O is provided in the route of the second oil passage 92 . A second reservoir 98 functions as a primary reservoir for secondary reservoir 95 . The second reservoir 98 is located upstream of the second oil passage 92 with respect to the sub-reservoir 95 .

The sub-reservoir 95 is positioned directly below the overflow portion 98y. That is, the sub-reservoir 95 and the overflow portion 98y overlap when viewed from the vertical direction. Thereby, the oil O overflowing from the second reservoir 98 can be received by the auxiliary reservoir 95 .

The sub-reservoir 95 has a first portion 95A located on one side in the circumferential direction with respect to the second reservoir 98 and a second portion 95B located on the other side in the circumferential direction. The first portion 95A and the second portion 95B are connected to each other. The sub-reservoir 95 has a total of four outlets 61k, two each in the first portion 95A and the second portion 95B. The four outlets 61k are arranged along the circumferential direction of the motor 2 . Moreover, the plurality of outlets 61k have different heights.

The sub-reservoir 95 is composed of the inner wall surface 61g of the motor accommodating portion 61 and the inner wall surface of the projecting portion 63d of the closing portion 63 . The inner side surface 61g of the motor accommodating portion 61 has an inner peripheral surface 61i facing radially inward and a facing surface 61h facing toward the closing portion 63 in the axial direction. The facing surface 61h contacts the axially facing surface of the projecting portion 63d. The oil O does not flow out from the contact portion between the projecting portion 63d and the opposing surface 61h. According to this embodiment, since the sub-reservoir 95 is configured as a gap between other members, there is no need to use other members, and an increase in the number of parts can be suppressed.

The facing surface 61h is provided with recesses 61j that are arranged along the circumferential direction and recessed in the axial direction. The recessed portion 61j is recessed in a direction to increase the gap between the inner wall surface 61g of the motor accommodating portion 61 and the inner wall surface of the projecting portion 63d. The oil O flows downward from the recess 61j. That is, the recess 61j constitutes the outflow port 61k. Outflow port 61 k is positioned above coil end 31 a of stator 30 . Therefore, the oil O flowing out from the outlet 61k cools the coil 31 of the coil end 31a. In the present embodiment, the recess 61j is provided on the inner side surface 61g at the contact portion between the inner side surface 61g of the motor accommodating portion 61 and the inner wall surface of the projecting portion 63d. However, a concave portion may be provided on the inner wall surface of the projecting portion 63d.

According to the present embodiment, by providing the sub-reservoir 95 in addition to the second reservoir 98, the oil O can flow out from the outflow port 61k of the sub-reservoir 95 in addition to the outflow port of the second reservoir 98. and the motor 2 can be cooled over a wide range. Also, a plurality of outflow ports 61k of the sub-reservoir 95 are arranged side by side along the circumferential direction. As a result, the coil ends 31a of the stator 30 can be cooled over a wide range. Furthermore, since the plurality of outflow ports 61k have different heights, the outflow timing can be varied according to the liquid level of the oil O accumulated in the sub-reservoir 95 .

According to this embodiment, the oil O overflowing from the second reservoir 98 is stored in the auxiliary reservoir 95 . The pump 96 increases the amount of oil O supplied to the second reservoir 98 when the load on the motor 2 becomes high and the temperature rises. Therefore, when the load on the motor 2 becomes high, the oil O overflows from the second reservoir 98 and can be supplied to the motor 2 also from the outflow port 61 k of the auxiliary reservoir 95 . According to this embodiment, a wide range of the motor 2 can be cooled by the oil O when the load on the motor 2 becomes high. That is, by providing the auxiliary reservoir 95, the supply range of the oil O supplied to the motor 2 can be automatically expanded when the operation of the motor 2 changes from the steady state to the high load state.

Also, the lower end of the sub-reservoir 95 of this embodiment is located above the motor shaft J2. Therefore, the outflow port 61k of the sub-reservoir 95 is located above the motor shaft J2. The motor 2 has a substantially cylindrical shape. By locating the lower end of the sub-reservoir 95 above the motor shaft J2, the motor 2 can be cooled by causing the oil O that flows out from the outflow port 61k to travel along the surface of the motor 2 . Also, the motor 2 is widest in a horizontal cross section passing through the motor shaft J2. Since the lower end of the sub-reservoir 95 is positioned above the motor shaft J2, the oil O running on the surface of the motor 2 passes through the widest region in the horizontal direction of the motor. Thereby, the motor 2 can be efficiently cooled.

(Common Portion of First Oil Path and Second Oil Path) As shown in FIG. It is supplied to the motor 2. The oil O supplied to the motor 2 drops downward while cooling the motor 2 and accumulates in the lower region of the motor chamber 81 . The oil O accumulated in the area below the motor chamber 81 moves to the gear chamber 82 through the partition wall opening 68 provided in the partition wall 61c.

FIG. 15 is a front view of the partition wall 61c of the housing 6 viewed from the motor chamber 81 side. The partition wall opening 68 is located below the insertion hole 61f through which the shaft 21 is inserted. The partition 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 communicate the motor chamber 81 and the gear chamber 82, respectively.

As shown in FIG. 19, the lower end of the partition wall opening 68 (that is, the lower end of the first opening 68a) is positioned above the lower limit height Lmin of the liquid level of the oil O in the gear chamber 82 when the motor 2 is stationary. do. Therefore, the partition wall opening 68 can move as much oil O as possible to the oil reservoir P when the driving of the motor 2 is stopped.

As shown in FIG. 15, the first opening 68a is circular in plan view. The lower end of the first opening 68 a is located below the lower end of the stator 30 . The first opening 68 a is located near the bottom 81 a of the motor chamber 81 . Therefore, the first opening 68a allows the oil O to move to the gear chamber 82 until the oil O accumulated in the lower region of the motor chamber 81 is substantially depleted.

The first opening 68a overlaps the motor shaft J2 when viewed in the vertical direction. Also, the first opening 68a is positioned in a recess 61q provided in the inner peripheral surface of the peripheral wall 61a. Here, the peripheral wall portion 61a and the recessed portion 61q will be described. The motor accommodating portion 61 of the housing 6 has a cylindrical peripheral wall portion 61 a along the outer peripheral surface of the stator 30 . A concave portion 61q that is concave radially outward is provided on the inner peripheral surface of the peripheral wall portion 61a. The recess 61q extends along the axial direction. The recess 61q is positioned directly below the motor shaft J2. That is, the recessed portion 61q overlaps the motor shaft J2 when viewed in the vertical direction. Since the peripheral wall portion 61a has a cylindrical shape, the oil O in the motor chamber 81 runs along the inner peripheral surface of the peripheral wall portion 61a and gathers inside the concave portion 61q. Since the first opening 68a is located in the recess 61q, the oil O in the motor chamber 81 collected inside the recess 61q can be efficiently moved to the gear chamber .

The second opening 68b is located above the first opening 68a. The second opening 68b has a rectangular shape whose longitudinal direction is the horizontal direction in plan view. The second opening 68b has a larger opening area than the first opening 68a. Also, 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 along the horizontal direction.

Driving the motor 2 increases the amount of oil O supplied to the motor 2 from the oil passage 90 (that is, the first oil passage 91 and the second oil passage 92) per unit time. As a result, the liquid level of the oil O accumulated in the lower region of the motor chamber 81 rises. In the partition wall opening 68, a region located below the liquid surface of the oil O accumulated in the region below the motor chamber 81 is called a first region S, and a region located above the liquid surface is called a second region R. call. The partition opening 68 allows the oil O to move to the gear chamber 82 in the first region S. When the liquid level of the oil O accumulated in the lower region of the gear chamber 82 rises, the area of the first region S increases and the area of the second region R decreases. As the area of the first region S increases, the amount of movement of the oil O from the motor chamber 81 to the gear chamber 82 via the partition wall opening 68 increases.

The partition wall opening 68 of this embodiment is arranged so that when the liquid level of the oil O in the motor chamber 81 rises, the movement amount of the oil O from the motor chamber 81 to the gear chamber 82 via the partition wall opening 68 increases. be done. Therefore, the liquid level of the oil O in the motor chamber 81 is prevented from becoming too high. That is, it is possible to prevent the rotor 20 in the motor chamber 81 from being immersed in the oil O or excessively raking up the oil O. Therefore, it is possible to prevent the rotation efficiency of the motor 2 from decreasing due to the flow resistance of the oil O. In addition, according to the present embodiment, by moving the oil O in the motor chamber 81 toward the gear chamber 82 in accordance with the height of the liquid surface of the oil O in the motor chamber 81, the oil in the motor unit 1 is O can be used effectively. As a result, not only can the weight of the motor unit 1 be reduced by suppressing the amount of oil O used, but also the energy efficiency required for cooling the oil O can be increased.

As shown in FIG. 19, the lower end of the second opening 68b is at the level 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. located higher. Therefore, the second opening 68b is not submerged on the gear chamber 82 side. The second opening 68b can move the oil O to the gear chamber 82 regardless of the liquid level in the gear chamber 82, and can prevent the rotor 20 from being soaked in the oil O.

A change in the amount of movement of the oil O that moves through the partition wall opening 68 as the liquid level of the oil O accumulated in the lower side of the motor chamber 81 rises will be described more specifically. Here, the liquid level of the oil O accumulated on the lower side of the motor chamber 81 and reaching the lower end 68c of the second opening 68b is defined as a first liquid level OL. That is, the lower end of the second opening 68b is positioned at the first liquid level OL. The first liquid level OL is positioned above the lower end of the stator 30 and below the lower end of the rotor 20 .

FIG. 16 is a graph showing the relationship between the liquid level of the oil O accumulated in the lower side of the motor chamber 81 and the area of the first region S. As shown in FIG. The area of the first region S has a correlation (substantially proportional relationship) with the flow rate of the oil O flowing out from the partition wall opening 68 .

The oil O is supplied to the motor 2 as the motor 2 is driven, and begins to accumulate in the area below the motor chamber 81 . The oil O accumulated in the lower region of the motor chamber 81 moves from the motor chamber 81 to the gear chamber 82 via the first opening 68a. When the amount of oil O supplied to the motor 2 per unit time exceeds the flow rate of the oil O that moves from the motor chamber 81 to the gear chamber 82 through the first opening 68a, the lower side of the motor chamber 81 The liquid level of the oil O that accumulates in the area of increases. When the liquid level reaches the first liquid level OL, the oil O flows out from the second opening 68b in addition to the first opening 68a. Since the second opening 68b has a larger width in the horizontal direction than the first opening 68a, the area of the first region S rapidly increases before and after the liquid level reaches the first liquid level OL. do. Accordingly, the flow rate of the oil O flowing from the motor chamber 81 into the gear chamber 82 via the partition wall opening 68 increases rapidly. As described above, the first liquid level OL is set below the lower end of the rotor 20 . Therefore, according to the present embodiment, it is possible to prevent the rotational efficiency of the rotor 20 in the motor chamber 81 from decreasing due to the flow resistance of the oil O.

The width of the second opening 68b in the horizontal direction is such that the flow rate of the oil O flowing out from the partition wall opening 68 when the liquid level reaches above the first liquid level OL is supplied to the motor 2 in the oil passage 90. It is preferable to set the width to be larger than the oil O that is used. As a result, the liquid level of the oil O accumulated in the lower area of the motor chamber 81 can be prevented from greatly exceeding the first liquid level OL, and the rotor 20 can be prevented from being immersed in the oil O.

As shown in FIG. 1, the first oil passage 91 includes a rake-up passage 91a and an in-rotor passage 91d. The raking path 91 a moves the oil O from the gear chamber 82 to the motor chamber 81 by raking the oil O by the differential device 5 . The amount of oil O scooped up by the differential gear 5 depends on the rotational speed of the differential gear 5 . Therefore, the raking path 91a increases or decreases the movement amount of the oil O to the motor chamber 81 depending on the vehicle speed. Further, the in-rotor path 91 d draws the oil O from the gear chamber 82 side to the motor chamber 81 side due to the centrifugal force of the rotor 20 . Centrifugal force depends on the rotation speed of the rotor 20 . Therefore, the in-rotor path 91d increases or decreases the movement amount of the oil O to the motor chamber 81 depending on the vehicle speed. That is, the first oil passage 91 increases or decreases the amount of movement of the oil O to the motor chamber 81 depending on the vehicle speed.

On the other hand, the second oil passage 92 moves oil O from the gear chamber 82 to the motor chamber 81 by a pump (electric pump) 96 . The amount of oil O supplied to the pump 96 is controlled based on the temperature measurement result of the motor 2, for example. Therefore, in the second oil passage 92, the amount of movement of the oil O to the motor chamber 81 increases or decreases regardless of the vehicle speed.

The second oil passage 92 stops the supply of the oil O to the motor 2 when the motor 2 is stationary. Also, the second oil passage 92 starts the movement of the oil O to the motor chamber 81 when the motor 2 is started. Therefore, the liquid level of the oil reservoir P in the gear chamber 82 can be raised when the engine is stopped. As a result, the rotation of the motor 2 immediately after startup rotates the second gear 42, the third gear 43, and the ring gear 51 within the oil reservoir P, allowing the oil O to spread over the tooth flanks.

According to this embodiment, the second oil passage 92 pulls up the oil O from the oil sump P regardless of the speed of the vehicle. Therefore, the second oil passage 92 can lower the level of the oil surface of the oil sump P even when the vehicle travels at a low speed. As a result, it is possible to prevent the rotational efficiency of the gears in the gear chamber 82 from being lowered by the oil O in the oil reservoir P during low-speed running.

(Modified Example of Partition Opening) FIG. 17 is a front view of a modified partition opening 168 that can be employed in the present embodiment. In addition, the same code|symbol is used and demonstrated about the component of the same aspect as the above-mentioned embodiment. The partition wall opening 168 of the modified example has a long hole portion 168a extending along the vertical direction and a wide extension portion 168b connected to the long hole portion 168a above the long hole portion 168a. A lower end of the long hole portion 168 a is positioned near the bottom portion 81 a of the motor chamber 81 . The elongated hole portion 168a overlaps the motor shaft J2 when viewed from above and below. Extension 1
68b is wide along the horizontal direction with respect to the long hole portion 168a. The extended portion 168b has a rectangular shape whose longitudinal direction is the horizontal direction in a plan view. The extended portion 168b has a lower end 168c extending along the horizontal direction. The lower end 168c is positioned at the first liquid level OL described above. In the partition wall opening 168, a region located below the liquid surface of the oil O is called a first region S, and a region located above the liquid surface is called a second region R.

FIG. 18 is a graph showing the relationship between the liquid level of the oil O accumulated in the lower side of the motor chamber 81 and the area of the first region S in this modified example. In this modified example, when the liquid level reaches the first liquid level OL, the oil O flows out from the extended portion 168b in addition to the elongated hole portion 168a, and the area of the first region S increases rapidly. Accordingly, the flow rate of the oil O flowing from the motor chamber 81 into the gear chamber 82 via the partition wall opening 168 increases rapidly. Since the first liquid level OL is set below the lower end of the rotor 20 , it is possible to prevent the rotational efficiency of the rotor 20 from being lowered due to the flow resistance of the oil O.

(Fluid Level of Oil Pool) As shown in FIG. 1 , the first oil passage 91 supplies oil O from the oil pool P to the motor 2 when the motor 2 is driven by the pump 96 . The first oil passage 91 moves the oil O from the oil reservoir P to the first reservoir 93 by raking up the differential gear 5 when the motor 2 is driven, and supplies the oil O to the inside of the motor 2 . do. That is, both the first oil passage 91 and the second oil passage 92 supply the oil O from the oil reservoir P to the motor 2 when the motor 2 is in the driving state. Therefore, in the driving state of the motor 2, the liquid level of the oil pool P located in the lower region of the gear chamber 82 is lowered. In addition, since the oil O supplied to the motor 2 accumulates in the space below the motor chamber 81, the liquid level of the oil O accumulated in the area below the motor chamber 81 rises when the motor 2 is driven. .

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

FIG. 19 is a side view showing the arrangement of gears positioned inside the gear chamber 82. As shown in FIG. 19, the gear accommodating portion 62 of the housing 6 and the bearings that support the shafts are omitted. As shown in FIG. 19, according to the present embodiment, the height of the liquid surface of the oil O accumulated in the oil reservoir P is such that the oil O reaches the oil passage 90 (the first oil passage 91 and the second oil passage 92). , the height fluctuates between the upper limit height Lmax and the lower limit height Lmin. As shown in FIG. 1 , the first oil passage 91 is provided with a first reservoir 93 . Further, the second oil passage 92 is provided with a second reservoir 98 and a sub-reservoir 95 (not shown in FIG. 1, see FIG. 14). Furthermore, oil O accumulates in the lower region of the motor chamber 81 where the first oil passage 91 and the second oil passage 92 join. In this manner, several locations where the oil O accumulates are provided in the route of the first oil passage 91 and the second oil passage 92 . As a result, by supplying the oil O to the motor 2, the oil O accumulated in the oil reservoir P moves to the reservoir or the like in the above-described path, and the liquid level of the oil reservoir P is lowered. As a result, the gear in the gear chamber 82 can be exposed from the oil O in the oil reservoir P, and the rotation efficiency of the gear can be improved.

As shown in FIG. 19, of the pair of gears (the second gear 42 and the third gear 43) rotating about the intermediate shaft 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. In addition, the lower end of the second gear 42 is located above the lower limit height Lmin of the liquid surface. Similarly, of the pair of gears (the second gear 42 and the third gear 43) that rotate about the intermediate shaft J4, the lower end of the third gear 43, which has a small diameter and is connected to the differential gear 5, It is positioned below the upper limit height Lmax of the surface. Further, the lower end of the third gear 43 is located above the lower limit height Lmin of the liquid surface.

The liquid level of the oil pool P reaches the upper limit height Lmax when the motor 2 is stopped and the supply of the oil O from the oil pool P to the motor 2 is stopped. According to this embodiment, part of the second gear 42 and the third gear 43 can be submerged in the oil O in the oil reservoir P when the motor 2 is stopped. As a result, when the motor 2 is driven, the oil O can be immediately spread over the tooth flanks of the second gear 42 and the third gear 43, and the transmission efficiency between the gears can be improved.

The liquid surface of the oil reservoir P reaches the lower limit height Lmin when the motor 2 is driven at a high load and the supply of the oil O from the oil reservoir P to the motor 2 is most accelerated. According to the present embodiment, when the motor 2 is driven, the second gear 42 and the third gear 43 are positioned above the liquid surface of the oil reservoir P. It is possible to suppress a decrease in rotational efficiency of the gear 42 and the third gear 43. Thereby, the drive efficiency of the motor unit 1 can be improved.

A ring gear 51 provided in the differential gear 5, connected to the reduction gear 4, and rotating around the differential shaft J5 has its lower end located below the liquid level at the upper limit height Lmax and the lower limit height Lmin of the liquid level. . According to the present embodiment, at least a portion of the ring gear 51 is positioned below the liquid level of the oil O in the oil reservoir P regardless of fluctuations in the liquid level of the oil reservoir P. Therefore, even when the motor 2 is driven and the liquid level of the oil pool P becomes low, the ring gear 51 can scoop up the oil O from the oil pool P, and the oil O is transferred to each gear in the gear chamber 82. By supplying oil O to the tooth flanks of the gears, the torque transmission efficiency between the gears can be enhanced.

(Overview of Oil Path) The flow of the oil O in the oil path 90 accompanying the driving of the motor unit 1 will be described with reference to FIG. When the motor unit 1 is installed in a hybrid vehicle or a plug-in hybrid vehicle, it is in one of an engine mode in which it is driven only by the engine, a motor mode in which it is driven only by the motor 2, and a hybrid mode in which it is driven by both the engine and the motor. run in one mode.

In the engine mode, the motor 2 is stopped, but the differential gear 5 is driven by the engine, so the oil O is scooped up from the oil reservoir P. The scooped-up oil O accumulates in the first reservoir 93, but is not splashed toward the stator 30 because the rotor 20 does not rotate. Also, in the engine mode, the pump 96 is not driven and the oil O is not supplied to the second oil passage 92 .

In the motor mode and the hybrid mode, when the vehicle climbs a slope, the output of the motor 2 increases and the amount of heat generated by the motor 2 increases. In such a case, cooling is accelerated by increasing the discharge amount of the pump 96 and supplying more oil O to the stator 30 . On the other hand, when the vehicle descends a slope (i.e., when no load is applied to the motor 2), or when the motor 2 has not reached a high temperature state, such as when the vehicle is started or when used in cold climates, the pump 96 is reduced.

The second oil passage 92 can adjust the amount of oil supplied to the motor 2 by the pump 96 according to the temperature of the motor 2, the drive mode of the vehicle, and the like. According to this embodiment, the energy required for cooling the motor 2 can be made more efficient. Such an effect can be exhibited when the pump 96 is an electrically driven pump. The discharge amount of the pump 96 can be managed based on temperature data detected by a temperature sensor provided in the motor 2 . In addition, the temperature change of the motor 2 can be predicted by combining various data such as vehicle operation history, driving condition, vehicle attitude, outside air temperature, and the weight of passengers and luggage. Based on this predicted value of temperature change, the motor 2 may be managed so as not to reach a high temperature state.

According to this embodiment, the oil passage 90 supplies the oil O to the stator 30 from a plurality of locations, so that the entire stator 30 can be efficiently cooled. Moreover, according to this embodiment, the oil O functions as a cooling oil and a lubricating oil. Therefore, there is no need to separately provide a path for the cooling oil and a path for the lubricating oil, and cost reduction can be achieved.

(Countermeasures against Contamination in Oil Path) The oil O used for cooling the motor unit 1 is used for lubricating the differential gear 5 and the reduction gear 4 . Therefore, the oil O may contain contaminants such as metal powder generated by mechanical contact. Contamination may deteriorate the fluidity of the oil O in the first oil passage 91 and the second oil passage 92 . Contaminants are removed by regular oil O changes. Also, one or both of the first oil passage 91 and the second oil passage 92 may be provided with means for trapping contaminants. As an example, as shown in FIG. 9, a permanent magnet 98m may be installed in the second reservoir 98 to magnetically capture contaminants and suppress diffusion of the contaminants. In this case, deterioration of the fluidity of the oil O can be suppressed.

(Arrangement of Shafts) The motor shaft J2, the intermediate shaft J4 and the differential shaft J5 extend parallel to each other along the horizontal direction. The intermediate shaft J4 and the differential shaft J5 are positioned below the motor shaft J2. Therefore, the reduction gear 4 and the differential gear 5 are positioned below the motor 2 .

When viewed from the axial direction of the motor shaft J2, a line segment that virtually connects the motor shaft J2 and the intermediate shaft J4 is defined as a first line segment L1, and a line segment that virtually connects the intermediate shaft J4 and the differential shaft J5. is a second line segment L2, and a line segment virtually connecting the motor shaft J2 and the differential shaft J5 is a third line segment L3.

According to this embodiment, the second line segment L2 extends substantially horizontally. That is, the intermediate shaft J4 and the differential shaft J5 are arranged substantially horizontally. Therefore, the reduction gear 4 and the differential gear 5 can be horizontally arranged, and the vertical dimension of the motor unit 1 can be reduced. In addition, the oil O scooped up by the differential gear 5 can be applied efficiently to the reduction gear 4 . As a result, the oil O can be supplied to the tooth flanks of the gears that constitute the reduction gear 4, and the transmission efficiency of the gears can be enhanced. The diameter of the gears (the second gear 42 and the third gear 43) rotating about the intermediate shaft J4 is smaller than the diameter of the ring gear 51 rotating about the differential shaft J5. According to this embodiment, since the second line segment L2 extends substantially horizontally, the intermediate shaft J4 and the differential shaft J5 are arranged substantially horizontally. Therefore, depending on the height of the oil pool P, only the ring gear 51 is submerged in the oil pool P, and the second gear 42 and the third gear 43 are not submerged in the oil pool P. Therefore, it is possible to prevent the rotation efficiency of the second gear 42 and the third gear 43 from decreasing while raking up the oil O in the oil pool P by the ring gear 51 . In this embodiment, the substantially horizontal direction of the second line segment L2 is a direction within ±10° with respect to the horizontal direction.

According to this embodiment, the angle α between the second line segment L2 and the third line segment L3 is 30°±5°. As a result, the transmission efficiency of the oil O scooped up by the differential gear 5 can be increased between the first gear 41 and the second gear 42, and a desired gear ratio can be achieved. If the angle α exceeds 35°, it becomes difficult to supply the oil scooped up by the differential to the gear (first gear) rotating about the motor shaft. As a result, the transmission efficiency between the first gear and the second gear may decrease. On the other hand, if the angle α is less than 25°, the gear on the output side in the transmission process cannot be made large enough to achieve the desired gear ratio on the three axes (motor shaft, intermediate shaft and differential shaft). becomes difficult.

According to this embodiment, the first line segment L1 extends substantially in the vertical direction. That is, the motor shaft J2 and the intermediate shaft J4 are arranged substantially vertically. Therefore, the motor 2 and the reduction gear 4 can be arranged vertically, and the horizontal dimension of the motor unit 1 can be reduced. Further, by setting the first line segment L1 in a substantially vertical direction, the motor shaft J2 can be arranged close to the differential shaft J5, and the first gear 41 rotating about the motor shaft J2 can The oil O scooped up by the differential gear 5 can be supplied. Thereby, the transmission efficiency between the first gear 41 and the second gear 42 can be enhanced. In this embodiment, the substantially vertical direction of the first line segment L1 is a direction within ±10° with respect to the vertical direction.

The length L1 of the first line segment, the length L2 of the second line segment, and the length L3 of the third line segment satisfy the following relationship. L1:L2:L3=1:1.4-1.7:1.8-2.0 Further, the speed reduction ratio of the speed reduction mechanism from the motor 2 to the differential gear 5 is 8 or more and 11 or less. According to this embodiment, a desired gear ratio (8 or more and 11 or less) can be achieved while maintaining the above-described positional relationship among the motor shaft J2, the intermediate shaft J4, and the differential shaft J5.

<Parking Mechanism> FIG. 20 is a diagram showing a parking mechanism 7 that can be employed in the motor unit 1 of this embodiment. Parking mechanism 7 is effective when motor unit 1 is used in an electric vehicle (EV). In addition to activating the parking brake, on engine-driven manual transmission vehicles, the transmission can be set to any position other than neutral to load the engine and provide braking action. In addition to activating the handbrake on automatic transmission vehicles, the transmission can be locked by setting the shift lever to the parking position. On the other hand, since the electric vehicle does not have a brake mechanism for braking the vehicle other than the side brake, the motor unit 1 needs the parking mechanism 7 .

The parking mechanism 7 comprises a ring-shaped parking gear 71 , a parking pole 72 , a parking rod 73 and a parking lever 74 . The parking gear 71 is arranged coaxially with the second gear (intermediate gear) 42 and the third gear 43 . Parking gear 71 is fixed to intermediate shaft 45 . The parking pole 72 has a protrusion 72a that engages with the groove of the parking gear 71 to prevent the parking gear 71 from rotating. The parking rod 73 is connected to the parking pole 72 and moves the protrusion 72a along the radial direction of the parking gear. The parking lever 74 is connected to the parking rod 73 to drive the parking rod 73 .

During operation of the motor 2 , the parking pole 72 is retracted from the parking gear 71 . On the other hand, when the shift lever is in the parking position, the parking pole 72 engages the parking gear 71 to prevent the parking gear 71 from rotating.

Parking pole 72 is controlled by a parking motor (not shown) connected to a parking lever. Since the parking mechanism 7 can be electrified by using the parking motor, the components for driving the parking mechanism 7 can be simplified. Further, if a parking motor is used, the parking pole 72 can be driven by a push button, a paddle lever, or the like, thereby improving operability for the driver. Such a mechanism is called a shift-by-wire system. The parking mechanism 7 may be of a manual type instead of an electric type using a shift-by-wire system. That is, the driver may drive the parking pole by mechanically pulling a wire connected to the parking lever.

According to this embodiment, the parking mechanism 7 is provided on the intermediate shaft 45 . As a result, in the torque transmission process from the motor 2 to the axle 55, the braking torque for preventing the rotation of the parking gear 71 can be reduced compared to the case where the parking mechanism 7 is provided in the gear behind the intermediate shaft. As a result, the structure of the parking mechanism can be reduced in size and weight. Further, when the parking mechanism 7 is of an electric type, a small motor can be used as the parking motor. Furthermore, if the parking mechanism is of manual type, the burden of operation on the driver can be reduced.

Further, according to this embodiment, the parking mechanism 7 is positioned below the reduction gear 4 . Therefore, the parking pole 72 is immersed in the oil O of the oil reservoir P, and the oil O is interposed between the parking gear 71 and the projection 72a of the parking pole 72, so that the projection 72a can be smoothly attached and detached. be able to. It should be noted that the parking mechanism 7 of the present embodiment is an example, and other conventionally known structures may be employed. Also, the parking mechanism 7 may be arranged to apply a braking force to the shaft 21 or the ring gear 51 connected to the motor 2 .

<Modification 1> <Separation Mechanism> FIG. 21 is a partial cross-sectional view showing the separation mechanism 107 of the motor unit 101 of Modification 1. As shown in FIG. As Modified Example 1, a modified motor unit 101 having a disconnection mechanism 107 in the torque transmission path from the motor 2 to the axle 55 will be described. The motor unit 101 of this modified example is mainly different in that a disconnection mechanism 107 is provided on the shaft 121 of the motor 2 . In addition, the same code|symbol is used and demonstrated about the component of the same aspect as the above-mentioned embodiment.

Separation mechanism 107 is provided when motor unit 101 is mounted on a hybrid electric vehicle (HEV) or a plug-in hybrid electric vehicle (PHV). Hybrid vehicles and plug-in hybrid vehicles run in one of an engine mode driven only by the engine, a motor mode driven only by the motor 2, and a hybrid mode driven by both the engine and the motor. The decoupling mechanism 107 connects the power transmission mechanism (the rotor 20 of the motor 2, the reduction gear 4, and the differential gear 5) of the motor unit 101 to the axle so that the stopped motor 2 does not become a load in the automobile running in the engine mode. Separate from 55.

As shown in FIG. 21, in this modification, the shaft 121 includes a first shaft portion 121A, a connecting shaft portion 121C and a second shaft portion 121B which are coaxially arranged, and a connecting shaft portion 121C and the second shaft portion 121B. and a decoupling mechanism 107 located therebetween. The first shaft portion 121A, the connecting shaft portion 121C and the second shaft portion 121B are arranged in this order along the axial direction. That is, the connecting shaft portion 121C is positioned between the first shaft portion 121A and the second shaft portion 121B.

The shaft 121 is a hollow shaft provided with a hollow portion 122 having an inner peripheral surface extending along the motor shaft 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 122B located inside the connecting shaft portion 121C. and a hollow portion 122C. The first hollow portion 122A, the second hollow portion 122B, and the third hollow portion 122C are arranged along the axial direction and communicate with each other.

The first shaft portion 121A is arranged in the motor chamber 81 of the accommodation space 80 . The first shaft portion 121A is positioned radially inside the stator 30 and passes through the rotor core 24 along the motor axis J2. The first shaft portion 121A has a first end portion 121e located on the output side (that is, the reduction gear 4 side).

The first end portion 121e passes through an insertion hole 61f provided in the partition wall 61c from the motor chamber 81 side. A first hollow portion (second recessed portion) 122A opens in the axially facing surface of the first end portion 121e. The first end portion 121e is rotatably supported by a first bearing 89 held in contact with the surface of the partition wall 61c facing the motor chamber 81 side. By holding the first bearing 89 in contact with the surface of the partition wall 61c facing the motor chamber 81 side, the first shaft portion 121A can be aligned with the portion of the housing 6 on the motor chamber 81 side. As a result, the first shaft portion 121A can be aligned with the stator 30 with high accuracy.

The connection shaft portion 121C is arranged inside the insertion hole 61f. The connecting shaft portion 121C is rotatably supported by a second bearing 188A held in contact with the surface of the partition wall 61c facing the gear chamber 82 side. The second bearing 188A is a ball bearing. The connection shaft portion 121C is provided with a step surface 121q facing the partition wall 61c. The step surface 121q contacts the inner ring of the second bearing 188A.

According to this modification, the second bearing 188A is held on the surface of the partition wall 61c facing the gear chamber 82 side. Therefore, the connection shaft portion 121C can be assembled to the first shaft portion 121A after the first shaft portion 121A is aligned. Therefore, the assembly process of the connection shaft portion 121C can be simplified.

The outer diameter of the second bearing 188A is larger than the outer diameter of the first bearing 89. During operation of the decoupling mechanism 107, a large amount of load is applied to the second bearing 188A in the axial and circumferential directions. According to the second bearing 188A of this modified example, by making the diameter larger than that of the first bearing 89, it is possible to ensure sufficient strength against the load during operation of the decoupling mechanism 107. .

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

The second end 121f protrudes toward the motor chamber 81 side. The second end portion 121f is positioned on the first shaft portion 121A side and connected to the first end portion 121e of the first shaft portion 121A. The second end portion 121f is accommodated in a first hollow portion 122A that opens to 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 connecting portion between the first end portion 121e and the second end portion 121f can be made compact in the radial direction. Thereby, it is possible to secure a space for arranging the first bearing 89 on the radially outer side of the first end portion 121e.

The third end portion 121g protrudes toward the gear chamber 82 side. The third end portion 121g is located on the side opposite to the second end portion 121f and on the second shaft portion 121B side. A first concave portion 121p is provided at an axial end of the third end 121g. The connection flange portion 121h extends radially outward from the third end portion 121g. The diameter of the connection flange portion 121h is larger than the smallest diameter portion of the insertion hole 61f.

According to this modification, the connecting shaft portion 121C is a separate member from the first shaft portion 121A. Therefore, by assembling the connecting shaft portion 121C to the first shaft portion 121A after the assembly process of the motor 2, assembly can be performed in the same order as the assembly order in the case where the detachment mechanism 107 is not provided. Along with this, the shapes of parts other than the shaft 121 can be made the same as when the detachment mechanism 107 is not provided. That is, according to this modified example, parts can be shared between the motor unit 101 having the disconnecting mechanism 107 and the motor unit 1 not including the disconnecting mechanism 107 . In addition, since the assembly order can be the same regardless of the presence or absence of the detachment mechanism 107, it is possible to suppress the complication of the component shape and the increase in the number of components. Therefore, according to this modification, the motor unit 101 with high versatility and low cost can be provided.

The second shaft portion 121B is arranged in the gear chamber 82 of the accommodation space 80 . The second shaft portion 121B has a fourth end portion 121i and a fifth end portion 121j.

The fourth end portion 121i is located on the third end portion 121g side of the connecting shaft portion 121C. A disconnection mechanism 107 selectively disconnects power transmission between the fourth end portion 121i and the connection flange portion 121h of the connection shaft portion 121C.

The fourth end 121i is accommodated in a first recess 121p provided in the third end 121g. Third end 121g and fourth end 121i
A needle bearing (bearing) 121n is provided in the radial gap of the . That is, according to this modification, the second shaft portion 121B is rotatably supported by the connecting shaft portion 121C at the fourth end portion 121i. Therefore, according to this modification, when the second shaft portion 121B and the connecting shaft portion 121C are separated by the separation mechanism 107, stable holding can be realized without hindering relative rotation. Such an effect can be obtained when one of the third end portion 121g and the fourth end portion 121i is provided with a first recess for accommodating the other via the needle bearing 121n. be.

In this modification, the needle bearing 121n is formed by annularly arranging a plurality of cylindrical members, but the needle bearing 121n may be replaced with another bearing mechanism such as a ball bearing. However, by adopting the needle bearing, the size of the motor unit 101 can be reduced by reducing the radial dimension of the third end portion 121g and the fourth end portion 121i.

As described above, the first shaft portion 121A, the connecting shaft portion 121C, and the second shaft portion 121B are provided with the hollow portions 122 extending in the axial direction and communicating with each other. As in the above embodiment, the hollow portion 122 is supplied with the oil O for cooling the inside of the motor from the second shaft portion 121B side toward the first shaft portion 121A side. According to this modification, the connecting shaft portion 121C and the second shaft portion 121B are connected via the needle 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. Thereby, the oil O can be supplied to the hollow portion 122 and used as an oil flow path.

The fifth end 121j is located opposite to the fourth end 121i. The fifth end is rotatably supported by a third bearing 188B held in the housing. That is, the second shaft portion 121B is supported by the third bearing 188B at the fifth end portion 121j. According to this modification, the second shaft portion 121B is supported by two axially aligned bearings (needle bearing 121n and third bearing 188B). Similarly, the connecting shaft portion 121C is supported by two axially aligned bearings (the second bearing 188A and the needle bearing 121n). The second shaft portion 121B and the connecting shaft portion 121C are rotatably supported at two points aligned in the axial direction, so that they can be stably rotated without causing shaft shake.

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 121i and the fifth end 121j. The first gear 41 transmits power to the second gear 42 of the reduction gear 4 . According to this modification, the first gear 41 is positioned between the second bearing 188A and the third bearing 188B. Therefore, the first gear 41 can stably rotate with respect to the motor shaft J2, and the torque generated by the motor 2 can be stably transmitted to the second gear .

The separating mechanism 107 radially surrounds the connecting flange portion 121h of the connecting shaft portion 121C and the fourth end portion 121i of the second shaft portion 121B. The decoupling mechanism 107 uses the drive unit 175 to switch between a state in which the connecting flange portion 121h and the fourth end portion 121i are not mechanically connected and a state in which they are connected.

The decoupling mechanism 107 is axially positioned between the axial end surface of the motor 2 and the first gear 41 . The motor unit 101 employs a three-axis structure including a motor shaft J2, an intermediate shaft J4 and a differential shaft J5. A third gear 43 is positioned between the axial end face of the motor 2 and the first gear 41 in the axial direction. 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 modification, the decoupling mechanism 107 is arranged between the axial end face of the motor 2 and the first gear 41 . That is, the third gear 43 and the decoupling mechanism 107 are arranged at positions overlapping each other in the axial direction. As a result, the internal space of the gear chamber 82 can be effectively used, and the size of the motor unit 101 can be reduced.

According to this modification, the decoupling mechanism is provided on the shaft 121 of the motor 2 . That is, the decoupling mechanism 107 is provided at a portion of the power transmission path from the motor 2 to the axle 55 where the torque is the smallest. According to this modified example, the torque transmitted via the decoupling mechanism 107 is small, so the decoupling mechanism can be made compact.

The decoupling mechanism 107 of this modified example is called a rotation synchronizer or a synchromesh mechanism. In addition, in this modified example, the detachment mechanism 107 is an example. As the decoupling mechanism, for example, a dog clutch mechanism or a multi-stage clutch mechanism may be adopted.

The decoupling mechanism 107 has a sleeve 171, a clutch hub 172, a synchronizer ring 173, a key 174, and a driving portion (not shown).

The clutch hub 172 is fixed to the outer peripheral surface of the second shaft portion 121B. The clutch hub 172 rotates around the motor shaft J2 together with the second shaft portion 121B. An external spline is provided on the outer circumference of the clutch hub 172 .

The sleeve 171 is axially movable. The sleeve 171 meshes with the external splines of the clutch hub 172 and rotates together with the sleeve 171 . A spline is provided on the inner peripheral surface of the sleeve 171 . The splines of the sleeve 171 are fitted to the splines provided on the outer peripheral surface of the connection flange portion 121h after the clutch hub 172 and the connection flange portion 121h rotate synchronously. Thereby, the second shaft portion 121B and the connecting shaft portion 121C are connected.

A key 174 is retained in the sleeve 171 . Key 174 moves axially with sleeve 171 . The key 174 matches the phases of the splines respectively provided on the sleeve 171 and the connecting flange portion 121h.

Synchronizer ring 173 moves axially with sleeve 171 . The synchronizer ring 173 has a tapered surface whose inner diameter increases toward the connecting flange portion 121h side. On the other hand, the connection flange portion 121h is provided with a boss portion protruding toward the synchronizer ring 173 along the axial direction. The boss portion is provided with a tapered surface facing the synchronizer ring 173 . The synchronizer ring 173 and the connecting flange portion 121h rotate synchronously by bringing their tapered surfaces into contact with each other.

A drive unit (not shown) is connected to the sleeve 171 . The drive unit moves the sleeve 171 in the axial direction.

22 is a conceptual diagram showing a state in which the motor 2 and the reduction gear 4 are connected by the separation mechanism 107, and FIG. 23 conceptually shows a state in which the motor 2 and the reduction gear 4 are separated by the separation mechanism 107. It is a diagram. As described above, the motor unit 101 with the decoupling mechanism 107 is mounted on a hybrid vehicle or a plug-in hybrid vehicle. In such a vehicle, when the vehicle is switched between a mode of running only by the power of the engine and a mode of running by using the power of the motor 2, the drive section 175 operates to operate the connecting shaft section 121C and the second shaft section 121B. Switch between connection and disconnection with

Control regarding the detachment mechanism 107 will be described. When the disconnection mechanism 107 switches from the disconnection state to the connection state, first, the rotation speed of the second shaft portion 121B is calculated from the rotation speed of the axle 55 . Next, the rotation speed of the motor 2 is increased to the calculated rotation speed of the second shaft portion 121B. While the number of rotations of the motor 2 is increasing, the sleeve is moved by the driving portion 175, and the connection between the second shaft portion 121B and the connecting shaft portion 121C is realized. After that, the position at which the connection between the second shaft portion 121B and the connection shaft portion 121C is completed is calculated from the cumulative number of rotations of the drive portion 175 . Finally, it is detected that the number of revolutions of the motor 2 and the number of revolutions of the second shaft portion 121B calculated from the number of revolutions of the axle 55 are the same, and it is finally determined that the joining state is completed. be done.

<Control> Elements such as the motor 2 of the motor unit 1, the pump 96, the driving section 175 of the decoupling mechanism 107 and the parking motor of the parking mechanism 7 are centrally controlled by a micro control unit (MCU). The micro control unit may be provided integrally with the motor unit 1 or may be provided externally.

<Vehicle Mountability> The motor unit 1 can be applied to any of a hybrid vehicle (HEV), a plug-in hybrid vehicle (PHV), and an electric vehicle (EV). Further, the motor unit 1 can be applied not only to passenger cars but also to trucks and the like. The motor unit 1 may be mounted on either the front side or the rear side of the vehicle, but is preferably mounted on the rear side. Since the motor unit 1 of the present embodiment has a small vertical dimension, it can be installed compactly even on the rear side where the installation space is limited due to the restrictions of the luggage compartment and the minimum ground clearance.

The embodiments and modifications of the present invention have been described above, but each configuration and combination thereof in the embodiments are examples, and additions, omissions, replacements, and modifications of configurations can be made without departing from the scope of the present invention. Other changes are possible. Moreover, the present invention is not limited by the embodiments.

DESCRIPTION OF SYMBOLS 1, 101... Motor unit (electric drive apparatus) 2... Motor 4... Reduction gear 5... Differential gear 6... Housing 6a... Wall part 20... Rotor 21, 121... Shaft 21A, 121A... First shaft portion 21B, 121B Second shaft portion 21c Flange portion 21c Flange portion (lid portion) 21d Screw portion 21e, 121e First end portion 21f, 121f Second end portion , 21g, 121g... third end 21h, 121i... fourth end 22, 122... hollow portion 22A, 122A... first hollow portion 22q... second region (small-diameter hollow portion) 22r... third Region (large-diameter hollow portion) 22t Second step surface (step surface) 22u Groove 23 Communication hole 24 Rotor core 24a Axial end surface 24b Peripheral surface 24d Magnet holding hole 24e... Core through hole 25... Rotor magnet 26, 126, 226... End plate 26a, 126a, 226a... First surface 26b, 126b, 226b... Second surface 26e, 126u... Inclined surface 26f , 61j, 61q... recesses, 26j, 126j, 226j... first recesses (first recesses), 26k, 126k, 226k, 226kA, 226kB... second recesses (second recesses), 26p, 126p , 226p... plate through hole, 26r... second opening (opening part), 26s... first opening (opening part), 26t... oil flow path, 28... washer (lid part), 29... nut, 30 ... Stator 31 ... Coil 31a ... Coil end 32 ... Stator core 41 ... First gear 42 ... Second gear (intermediate gear) 43 ... Third gear 51 ... Ring gear 61 ... Motor housing , 61c... Partition wall 61f... Insertion hole 61k, 97b, 98r, 98o, 98x, 98t, 98u, 98v, 198c... Outflow port 63... Closing part 63d... Protruding part 64... Gear chamber ceiling (ceiling part ), 65... Convex portion, 66... Eaves part, 68, 168... Partition wall opening, 68a... First opening, 68b... Second opening, 80... Housing space, 81... Motor chamber, 82... Gear chamber, 88, 188A... Second bearing, 89... First bearing, 90... Oil passage, 91... First oil passage (oil passage), 91a... Scraping passage, 91b... Shaft supply passage (oil passage), 92... second oil passage (oil passage), 92a... first passage, 92b... second passage, 92c, 92aa, 92ba, 92ca... first end,
92ab, 92bb, 92cb... second end 97c... third flow path 93... first reservoir (reservoir) 95... auxiliary reservoir 96... pump (electric pump) 96a... inlet 97... Cooler 98, 198 Second reservoir (main reservoir) 98y Overflow portion 99 Supply portion 107 Separation mechanism 121C Connection shaft portion 121h Connection flange portion 121j Fifth end portion 121n Needle bearing (bearing) 121p First concave portion 121q Step surface 126r, 226r Opening portion 128, 228 Lid portion 168a Long hole portion 168b Extended portion 98gC Weir J2 Motor Axes J4 Intermediate axis J5 Differential axis L1 First line segment L2 Second line segment L3 Third line segment (virtual line) Lmax Upper limit height Lmin Lower limit Height, O... Oil, OL... First liquid level, P... Oil reservoir, S... First area

An object of one aspect of the present invention is to provide a motor unit in which a cost reduction is achieved by simplifying the configuration of an oil passage.

One aspect of the motor unit of the present invention includes a motor, a plurality of gears for transmitting torque of the motor, a housing provided with a housing space for housing the motor and the plurality of gears , and a vertical direction of the housing space. oil stored in an oil reservoir provided in a region on the lower side in the direction, and an oil passage for supplying the oil from the oil reservoir to the motor and recovering the oil in the oil reservoir, the housing having a partition wall, The partition wall divides the accommodation space into a motor chamber in which the motor is accommodated and a gear chamber in which the plurality of gears are accommodated, and the partition wall communicates the gear chamber and the motor chamber. The bottom of the motor chamber is located above the bottom of the gear chamber, and the oil reservoir is provided in the lower region of the gear chamber in the path of the oil passage. is provided with an electric pump, and the oil passage connects the oil reservoir and the electric pump, and connects the electric pump and the motor chamber.

According to one aspect of the present invention, there is provided a motor unit that achieves cost reduction by simplifying the configuration of oil passages.

Claims (7)

a motor; a housing provided with an accommodation space for accommodating the motor; oil accumulated in a region below the accommodation space in the vertical direction; an oil passage leading to a vertically lower region of the housing space, wherein the oil passage includes a first oil passage passing through the interior of the motor and a second oil passage passing through the exterior of the motor; A motor unit, wherein either one of the first oil passage and the second oil passage is provided with a cooler for cooling the oil. The first oil passage and the second oil passage are circulation paths that return from a vertically lower area of the accommodation space to a vertically lower area of the accommodation space via the motor, and 2. The motor unit according to claim 1, wherein the first oil passage and the second oil passage merge in a vertically lower region of the accommodation space. The motor has a rotor that rotates about the motor shaft and has a shaft that extends along the motor shaft and a rotor core that surrounds the shaft from the outside in the radial direction, and a stator that is positioned radially outside the rotor. 3. The motor unit according to claim 1, wherein said first oil passage has a path passing through said rotor core from inside said shaft. a gear arranged in the accommodation space and connected to the motor, at least a portion of the gear being positioned below a liquid surface of the oil accumulated in a vertically lower region of the accommodation space; A first reservoir located in the accommodation space is provided in the path of one oil passage, and the first oil passage is an oil flow that guides the oil from the first reservoir to the inside of the shaft. and a raking-up path through which the oil accumulated in the vertically lower region of the housing space is scooped up by the rotation of the gear and receives the oil in the first reservoir. Motor unit as described. The motor unit according to any one of claims 1 to 4, wherein the second oil passage supplies the oil accumulated in a vertically lower region of the accommodation space to the motor from above the motor. . A second reservoir that is positioned above the motor and stores the oil is provided in the path of the second oil passage, and the second reservoir stores the oil that has accumulated in the second reservoir. 6. A motor unit according to claim 5, comprising an outlet for supplying a to said motor. 7. The motor unit according to claim 5, wherein a pump and an oil cooler fixed to an outer peripheral surface of said housing and arranged vertically are provided in said second oil passage.

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