Unit

Abstract

[Problem] To reduce the amount of oil penetration into a breather chamber. [Solution] This unit has a housing having a motor housing chamber in which a motor is housed and a motive power transmission mechanism chamber in which a motive power transmission mechanism is housed. The housing has a breather chamber that is in communication with a breathing part. The breather chamber has a breather chamber inlet port and an oil return port in the motor housing chamber. The oil return port is disposed at a position facing the outer peripheral surface of the stator of the motor.

Description

unit

[0001] The present invention relates to a unit.

[0002] Patent Document 1 discloses a breather structure.

[0003] JP 2012-77898 A

[0004] In a unit having a breather structure, it is required to reduce the amount of oil that enters the breather chamber.

[0005] In one aspect of the present invention, the unit has a housing having a motor accommodating chamber in which a motor is accommodated and a power transmission mechanism chamber in which a power transmission mechanism is accommodated, the housing has a breather chamber communicating with a breathing section, the breather chamber has a breather chamber inlet and an oil return port within the motor accommodating chamber, and the oil return port is positioned opposite the outer peripheral surface of the stator of the motor.

[0006] According to one aspect of the present invention, the amount of oil entering the breather chamber can be reduced.

[0007] FIG. 1 is a diagram illustrating a unit. FIG. 2 is a diagram illustrating a breather chamber. FIG. 3 is a diagram illustrating a breather chamber. FIG. 4 is a diagram illustrating the flow of oil within the unit. FIG. 5 is a diagram illustrating an oil supply member. FIG. 6 is a diagram illustrating an oil supply member. FIG. 7 is a diagram illustrating an oil supply member. FIG. 8 is a diagram illustrating an oil supply member. FIG. 9 is a diagram illustrating an oil supply member. FIG. 10 is a diagram illustrating the positional relationship between a lid and the breather chamber. FIG. 11 is a diagram illustrating the positional relationship between the lid and the breather chamber. FIG. 12 is a diagram illustrating the function and effect of the lid. FIG. 13 is a diagram illustrating a unit according to a comparative example. FIG. 14 is a diagram illustrating a lid according to a modified example.

[0008] First, definitions of terms used in this specification will be explained. A "unit" is also called a "motor unit," a "power transmission device," etc. A motor unit is a unit that has at least a motor. A power transmission device is a device that has at least a power transmission mechanism, and the power transmission mechanism is, for example, a gear mechanism and / or a differential gear mechanism. A unit that is a device that has a motor and a power transmission mechanism belongs to the concepts of both a motor unit and a power transmission device.

[0009] The "housing" contains the motor, gears, and inverter. The housing is made up of one or more cases.

[0010] The term "motor" refers to a rotating electric machine having a motor function and / or a generator function.

[0011] When it is stated that an element B (component, part, etc.) is connected to an element A (component, part, etc.), an element B (component, part, etc.) is connected downstream of an element A (component, part, etc.), or an element B (component, part, etc.) is connected upstream of an element A (component, part, etc.), it means that the elements A and B are connected so that power can be transmitted. The power input side is the upstream side, and the power output side is the downstream side. Furthermore, the elements A and B may be connected via another element (a clutch, another gear mechanism, etc.).

[0012] "Overlapping when viewed in a predetermined direction" means that multiple elements are lined up in a predetermined direction, and is synonymous with "overlapping in a predetermined direction." The "predetermined direction" is, for example, the axial direction, the radial direction, the direction of gravity, the vehicle traveling direction (the forward direction of the vehicle, the backward direction of the vehicle), etc. When a drawing shows that multiple elements (components, parts, etc.) are lined up in a predetermined direction, it may be assumed that the description in the specification contains a sentence explaining that they overlap when viewed in the predetermined direction.

[0013] "Not overlapping when viewed in a predetermined direction" and "offset when viewed in a predetermined direction" mean that multiple elements are not lined up in a predetermined direction, and are synonymous with "not overlapping in a predetermined direction" and "offset in a predetermined direction." Examples of the "predetermined direction" include the axial direction, radial direction, gravity direction, and vehicle travel direction (vehicle forward direction, vehicle backward direction). When a drawing shows that multiple elements (components, parts, etc.) are not lined up in a predetermined direction, it may be assumed that the description in the specification includes a sentence explaining that they are not overlapping when viewed in a predetermined direction.

[0014] The phrase "element A (component, part, etc.) is located between element B (component, part, etc.) and element C (component, part, etc.) when viewed from a predetermined direction" means that element A can be observed to be located between element B and element C when viewed from a predetermined direction. The "predetermined direction" is, for example, the axial direction, the radial direction, the direction of gravity, the vehicle traveling direction (the forward direction of the vehicle, the backward direction of the vehicle), etc. For example, when element B, element A, and element C are lined up in this order along the axial direction, it can be said that element A is located between element B and element C when viewed from a radial direction. When a drawing shows that element A is located between element B and element C when viewed from a predetermined direction, it can be considered that the description in the specification includes a sentence explaining that element A is located between element B and element C when viewed from the predetermined direction.

[0015] When two elements (parts, portions, etc.) overlap in an axial view, the two elements are coaxial.

[0016] "Axial direction" means the axial direction of the rotation axis of the component that constitutes the unit. "Radial direction" means the direction perpendicular to the rotation axis of the component that constitutes the unit. The component is, for example, a motor, a gear mechanism, a differential gear mechanism, etc.

[0017] This embodiment will be described below. In this embodiment, a unit 1 mounted on a vehicle will be described as an example. FIG. 1 is a diagram illustrating the unit 1. FIG. 1 schematically illustrates a cross section along the rotation axis X of the motor 2. In FIG. 1, the power transmission mechanism 3 is shown in phantom lines. FIG. 2 is a diagram illustrating the breather chamber 7. FIG. 2 is a schematic diagram of the A-A cross section of FIG. 3 (described later). FIG. 3 is a diagram illustrating the breather chamber 7. FIG. 3 is a view taken along the A-A arrow in FIG. 2. Note that in FIG. 3, the oil supply member 6 is shown in phantom lines to expose the breather chamber 7. To facilitate understanding of the positional relationship, different types of hatching are used on the support portion 16 and the wall portions forming the breather chamber 7. FIG. 4 is a diagram illustrating the flow of oil OL within the unit 1. FIG. 4 is a schematic diagram of the B-B cross section of FIG. 2. 4, a portion of the stator 22 is cut away in the region on the right side of the vertical line VL to show the oil groove 117 formed in the support wall 111. Furthermore, the "vertical direction" in these drawings refers to the direction of the vertical line VL when the unit 1 is mounted on the vehicle. Therefore, when the term "upper side" is used, it means "upper side" in the direction of the vertical line VL, and when the term "lower side" is used, it means "lower side" in the direction of the vertical line VL.

[0018] 1, the unit 1 includes a motor 2, a power transmission mechanism 3 that transmits the rotational driving force of the motor 2, and an inverter 4 that is a power conversion device for the motor 2. The power transmission mechanism 3 includes an input gear 31 that rotates integrally with the motor 2, and a counter gear 32 that reduces the rotation of the input gear 31 and transmits it to an output gear (not shown).

[0019] The input gear 31 is coaxial with the rotation axis X of the motor 2, and the counter gear 32 rotates around a rotation axis X1 that is parallel to the rotation axis X of the motor 2. Note that, although Fig. 1 shows an example in which the power transmission mechanism 3 includes one counter gear 32, a plurality of counter gears 32 may be interposed between the input gear 31 and the output gear.

[0020] In the unit 1, the rotational driving force of the motor 2 is reduced in speed by the power transmission mechanism 3 and then output from the output gear to a differential mechanism (not shown). The rotational driving force output to the differential mechanism is transmitted to left and right drive wheels (not shown) via drive shafts (not shown).

[0021] 1, the housing HS of the unit 1 accommodates the motor 2 and the power transmission mechanism 3. The housing HS has, for example, a motor case 10 that accommodates the motor 2 and a gear case 13 that accommodates the power transmission mechanism 3. The motor case 10 and the gear case 13 are joined in the direction of the rotation axis X.

[0022] The motor case 10 includes a case member 11 and a cover member 12 joined to the case member 11 in the direction of the rotation axis X. The case member 11 includes a support wall portion 111 that surrounds the rotation axis X. The support wall portion 111 is oriented along the rotation axis X. The motor 2 is housed inside the support wall portion 111. A gear case 13 is connected to one end 111a (one axial side) of the support wall portion 111 with a bolt (not shown). A cover member 12 is connected to the other end 111b (the other axial side) of the support wall portion 111 with a bolt (not shown).

[0023] A wall 113 is provided on one end 111a of the support wall 111, extending radially inward between the motor 2 and the power transmission mechanism 3. The wall 113 is oriented perpendicular to the rotation axis X. An opening 113a is provided in a region of the wall 113 that intersects with the rotation axis X. The motor shaft 20 passes through the opening 113a of the wall 113 in the direction of the rotation axis X.

[0024] A motor support portion 114 surrounding the opening 113a is provided on the surface of the wall portion 113 facing the motor 2 (the right side in the figure). The motor support portion 114 is cylindrical and extends toward the motor 2. A bearing Bm is supported on the inner periphery of the motor support portion 114. The outer periphery of the motor shaft 20 is supported by the motor support portion 114 via the bearing Bm.

[0025] Furthermore, a counter gear support portion 115 is provided on the surface of the wall portion 113 facing the power transmission mechanism 3 (left side in the figure). The counter gear support portion 115 is cylindrical and surrounds the rotation axis X1. The counter gear support portion 115 extends along the rotation axis X1 toward the opposite side from the motor 2. A bearing Bg is supported on the inner periphery of the counter gear support portion 115. The bearing Bg supports the counter gear 32.

[0026] The space formed inside the housing HS is divided into two by a wall 113. The space on the motor 2 side from the wall 113 (on the right side in the drawing) is a motor accommodating chamber Sa that accommodates the motor 2. The space on the power transmission mechanism 3 side from the wall 113 (on the left side in the drawing) is a power transmission mechanism chamber Sb that accommodates the power transmission mechanism 3.

[0027] The cover member 12 has a wall portion 120 perpendicular to the rotation axis X and a peripheral wall portion 121 surrounding the outer periphery of the wall portion 120. The peripheral wall portion 121 is joined to the other end 111b of the support wall portion 111 of the case member 11 from the direction of the rotation axis X. In this state, the opening of the case member 11 on the other end 111b side is closed by the cover member 12.

[0028] A motor support portion 125 is provided on the surface of the wall portion 120 of the cover member 12 facing the motor 2. The motor support portion 125 is cylindrical and surrounds the rotation axis X with a gap therebetween.

[0029] A bearing Bm is supported on the inner periphery of the motor support portion 125. The outer periphery of the motor shaft 20 is supported by the motor support portion 125 via the bearing Bm.

[0030] The motor 2 has a motor shaft 20, a cylindrical rotor 21 fitted onto the motor shaft 20, a stator 22 surrounding the outer periphery of the rotor 21 at a distance, and a coil 23 provided on the stator 22.

[0031] Bearings Bm, Bm are fitted onto one side and the other side of the motor shaft 20 in the direction of the rotation axis X, sandwiching the rotor 21. The motor shaft 20 is rotatably supported by the motor case 10 via the bearings Bm, Bm.

[0032] The rotor 21 is formed by laminating a plurality of silicon steel plates, each of which is fitted onto the motor shaft 20 in a state where its relative rotation with the motor shaft 20 is restricted. When viewed from the direction of the rotation axis X of the motor shaft 20, the silicon steel plates are ring-shaped, and on the outer periphery of the silicon steel plates, N-pole and S-pole magnets (not shown) are provided alternately in the circumferential direction around the rotation axis X.

[0033] The stator 22 surrounding the outer periphery of the rotor 21 is formed by laminating a plurality of electromagnetic steel plates, and is fixed to the inner periphery of the support wall 111 of the case member 11. The stator 22 has a ring-shaped yoke portion 221 fixed to the inner periphery of the support wall 111, and teeth portions 222 protruding from the inner periphery of the yoke portion 221 toward the rotor 21. The coil 23 is provided across the plurality of teeth portions 222.

[0034] The motor shaft 20 extends to the power transmission mechanism chamber Sb in the direction of the rotation axis X. In the power transmission mechanism chamber Sb, an input gear 31 of the power transmission mechanism 3 is spline-fitted to the outer periphery of the motor shaft 20. A counter gear 32 of the power transmission mechanism 3 is meshed with the input gear 31. This allows the rotation of the motor shaft 20 to be transmitted from the input gear 31 to the counter gear 32.

[0035] The inverter 4 is provided on the upper part of the support wall 111 of the case member 11. The inverter 4 has a main body 40 equipped with a smoothing capacitor, a power semiconductor element, a driver board, etc., and wiring 41 extending from the main body 40. The connection terminal of the wiring 41 is connected to a terminal block T. The terminal block T is supported by a support portion 16 of the case member 11, which will be described later.

[0036] A bus bar Bs is connected to the terminal block T from the motor 2 side. The bus bar Bs electrically connects the inverter 4 and the coil 23 of the motor 2 via the terminal block T. When power is supplied from the inverter 4 to the coil 23 of the motor 2 via the bus bar Bs, a magnetic field is generated around the stator 22. This causes the rotor 21 and the motor shaft 20 to rotate around the rotation axis X.

[0037] As shown in Figure 1, oil OL is stored within the housing HS to cool the motor 2 and lubricate the meshing parts of the power transmission mechanism 3. When the oil OL is stirred up and splashed by the rotation of the rotor 21 of the motor 2 and the power transmission mechanism 3, the air pressure within the housing HS may rise. For this reason, the housing HS is provided with a vent 5 to release the increased air pressure.

[0038] As shown in Fig. 1, the case member 11 has a roof portion 15 that covers the upper portion of the other end 111b of the support wall portion 111. The breathing portion 5 is provided on the roof portion 15. As shown in Fig. 2, the roof portion 15 branches upward from between the one end 111a and the other end 111b of the support wall portion 111 and extends toward the other end 111b. A cover member 12 is connected to an end surface 15a of the roof portion 15 in the direction of the rotation axis X with a bolt (not shown).

[0039] As shown in FIG. 3, when viewed from the direction of the rotation axis X, the roof portion 15 is provided on the case member 11 above a horizontal line HL passing through the rotation axis X and on one side (the left side in the figure) of a vertical line VL passing through the rotation axis X.

[0040] 2, the roof portion 15 is formed in a stepped shape. Specifically, the roof portion 15 has a peripheral wall 151 that covers the support wall portion 111, and a bottom wall 152 that connects the peripheral wall 151 to the support portion 111. The bottom wall 152 connects the end of the peripheral wall 151 opposite the cover member 12 in the direction of the rotation axis X to the support wall portion 111. The roof portion 15 also has a bulging wall 153 at the connection portion of the bottom wall 152 with the support wall portion 111 that bulges out in a direction away from the cover member 12 in the direction of the rotation axis X.

[0041] The bottom wall 152 is provided in a direction perpendicular to the rotation axis X. The bottom wall 152 is provided with a through hole 152a that penetrates in the direction of the rotation axis X, and a cylindrical support portion 16 that surrounds the through hole 152a. The support portion 16 extends in the direction of the rotation axis X from a surface 152b of the bottom wall 152 that faces the cover member 12. The terminal block T described above is inserted into the through hole 152a. As a result, the terminal block T is supported by the support portion 16.

[0042] The bottom wall 152 is provided with a rib 17 extending in the direction of the rotation axis X below the support portion 16. The rib 17 is provided across a surface 152b of the bottom wall 152 and a lower surface 162 of the support portion 16.

[0043] A tip surface 171 of the rib 17 in the direction of the rotation axis X is offset toward the bottom wall 152 relative to a tip surface 161 of the support portion 16. The tip surface 171 of the rib 17 is provided at the same position in the direction of the rotation axis X as the other end 111b of the support wall portion 111. In other words, the tip surface 171 and the other end 111b are provided flush with each other.

[0044] As shown in Fig. 3 , when viewed from the direction of the rotation axis X, the rib 17 is provided in the direction of a straight line La that is parallel to the horizontal line HL. Connecting walls 18, 19 are connected to both ends of the rib 17 in the direction of the straight line La. The connecting walls 18, 19 extend downward from the rib 17 and are connected to the support wall portion 111. The tip surfaces of the connecting walls 18, 19 are provided at the same position in the direction of the rotation axis X as the tip surface 171 of the rib 17 and the other end 111b of the support wall portion 111, and are flush with each other (see Fig. 2 ).

[0045] As a result, when viewed from the direction of the rotation axis X, a space is formed in the motor accommodation chamber Sa that is surrounded by the ribs 17, the connecting walls 18 and 19, and the support wall portion 111. The breathing section 5 is in communication with the space surrounded by the ribs 17, the connecting walls 18 and 19, and the support wall portion 111. Therefore, the space in the motor accommodation chamber Sa that is surrounded by the ribs 17, the connecting walls 18 and 19, and the support wall portion 111 constitutes the breather chamber 7.

[0046] 2, the breather chamber 7 has an inlet 7a (breather chamber inlet) that opens to the tip end surfaces of the rib 17, the support wall 111, and the connecting walls 18 and 19 (see FIG. 3). The inlet 7a of the breather chamber 7 is located in the motor housing chamber Sa and faces the cover member 12 in the direction of the rotation axis X (the other end side in the axial direction).

[0047] Here, the amount of oil OL scattered by the motor 2 due to the rotation of the motor 2 and the rotation of the power transmission mechanism 3 is smaller than that of the motor 2. The inlet 7a of the breather chamber 7 is provided in the motor accommodation chamber Sa and faces the cover member 12 in the direction of the rotation axis X. This allows the amount of oil OL that enters the breather chamber 7 to be reduced compared to, for example, when the inlet 7a of the breather chamber 7 is provided on the power transmission mechanism chamber Sb (see FIG. 1) side.

[0048] The breather chamber 7 is composed of a first chamber 71 between the rib 17 and the support wall portion 111 in the vertical direction, and a second chamber 72 between the bulging wall 153 and the support wall portion 111. The first chamber 71 and the second chamber 72 are in communication with each other in the direction of the rotation axis X.

[0049] The ventilation section 5 is provided on the bulging wall 153 of the roof section 15. The ventilation section 5 has a main body section 50, a breather pipe 51 connected to the main body section 50, and a through-hole 153a in the bulging wall 153 through which the breather pipe 51 passes.

[0050] In the breathing section 5, the breather pipe 51 is provided so as to penetrate the through-hole 153a from the upper side of the bulging wall 153. The opening 51a of the breather pipe 51 is exposed inside the second chamber 72 of the breather chamber 7. Note that the breathing section 5 does not have to have the breather pipe 51, and may be composed of, for example, a breathing hole formed in the housing HS. Furthermore, the breathing section 5 may be composed of, for example, a breathing hole formed in the housing HS and a filter provided in the breathing hole. For example, the through-hole 153a formed in the housing HS can be used as the breathing hole.

[0051] 2, a drain hole 8 (oil return port) is open in the second chamber 72 of the breather chamber 7. The drain hole 8 is a through-hole that passes through the support wall portion 111 in the vertical direction. The drain hole 8 faces the breather pipe 51 and the through-hole 153a at an interval on the upper side, and faces the outer peripheral surface 22a of the stator 22 at a gap CL on the lower side.

[0052] As described above, the amount of oil OL scattered by the motor 2 due to the rotation of the motor 2 and the rotation of the power transmission mechanism 3 is smaller. Therefore, by providing the drain hole 8 in the motor accommodation chamber Sa, the amount of scattered oil OL that flows back through the drain hole 8 and enters the breather chamber 7 can be reduced compared to, for example, when the drain hole 8 is provided on the power transmission mechanism chamber Sb (see FIG. 1) side.

[0053] Furthermore, the stator 22, which is a non-rotating member, acts as a shield to restrict the movement of the scattered oil OL toward the outer periphery of the stator 22. Therefore, by providing the drain hole 8 at a position facing the outer periphery 22a of the stator 22, the scattered oil OL is less likely to reach the drain hole 8. This makes it less likely that the scattered oil OL will flow back through the drain hole 8 and enter the breather chamber 7.

[0054] An oil groove 9 is connected to the lower end of the drain hole 8. The oil groove 9 is formed by recessing the inner circumferential surface 111c of the support wall portion 111 upward. A gap CL between the inner circumferential surface 111c of the support wall portion 111 and the outer circumferential surface 22a of the stator 22 locally expands in the radial direction of the rotation axis X in the region where the oil groove 9 is formed.

[0055] 4, the oil groove 9 is provided along the inner circumferential surface 111c of the support wall portion 111. The oil groove 9 is provided in a range that crosses from above to below a horizontal line HL that passes through the rotation axis X. The oil groove 9 communicates with the breather chamber 7 at its upper end via a drain hole 8.

[0056] The oil OL that has entered the breather chamber 7 moves downward through the drain hole 8 and the oil groove 9, and is finally returned to the oil reservoir OT at the bottom of the motor housing chamber Sa.

[0057] When viewed from the direction of the rotation axis X, the support wall portion 111 of the case member 11 is provided with an oil discharge passage 118 in an area that overlaps with the oil reservoir OT when viewed from the direction of the horizontal line HL. The oil discharge passage 118 is connected to the oil pump OP via a strainer SR. Therefore, the oil OL that constitutes the oil reservoir OT is sucked by the oil pump OP through the oil discharge passage 118. The oil OL is filtered by the strainer SR as it moves from the oil discharge passage 118 to the oil pump OP.

[0058] The oil pump OP is connected to one end of an oil passage 119 that delivers the sucked oil OL. The other end of the oil passage 119 is connected to an oil hole Pa provided in the case member 11.

[0059] An oil filter F and an oil cooler OC are interposed between one end and the other end of the oil passage 119. Therefore, oil OL sucked by the oil pump OP passes through the oil filter F and the oil cooler OC, where it is filtered and cooled, and then supplied to the oil hole Pa.

[0060] The oil passage 119 may be an internal oil passage formed inside the case member 11, or may be a pipe routed outside the case member 11. The oil passage 119 may also be a combination of an internal oil passage and a pipe.

[0061] As shown in Fig. 3, the oil hole Pa is provided in the connection between the connecting wall 18 and the support wall 111 in the wall portion that forms the breather chamber 7. An oil supply member 6 (see phantom lines in the figure) having an oil passage therein is connected to the oil hole Pa. Oil OL supplied to the oil hole Pa from the oil pump OP (see Fig. 4) passes through the oil passage in the oil supply member 6 and is sent to a predetermined cooling region.

[0062] (Oil Supply Member 6) FIG. 5 is a diagram illustrating the oil supply member 6. FIG. 5 is a perspective view of the oil supply member 6. FIG. 6 is a diagram illustrating the oil supply member 6. FIG. 6 is a perspective view illustrating the lid portion 64 of the oil supply member 6. FIG. 7 is a diagram illustrating the oil supply member 6. FIG. 7 is a schematic cross-sectional view of the oil supply member 6 of FIG. 5 taken along plane A. Note that in FIG. 7, the case member 11 that supports the oil supply member 6 is shown in phantom lines. FIG. 8 is a diagram illustrating the oil supply member 6. FIG. 8 is a schematic cross-sectional view taken along line A-A in FIG. 7. FIG. 9 is a diagram illustrating the oil supply member 6. FIG. 9 is a schematic cross-sectional view taken along line B-B in FIG. 7. FIG. 10 is a diagram illustrating the positional relationship between the lid portion 64 and the breather chamber 7. FIG. 10 is a view taken along line A-A in FIG. 9. FIG. 11 is a view taken along line A-A in FIG. 10. 12 is a diagram illustrating the effect of the lid portion 64. FIG. 12 is a schematic cross-sectional view taken along line BB in FIG.

[0063] 5, the oil supply member 6 has a first cylindrical portion 61 and a second cylindrical portion 62 that are oriented along parallel straight lines Lm1 and Lm2, and a third cylindrical portion 63 that connects the ends of the first cylindrical portion 61 and the second cylindrical portion 62. The third cylindrical portion 63 is oriented along a straight line Ln that is perpendicular to the straight lines Lm1 and Lm2. The first cylindrical portion 61, the second cylindrical portion 62, and the third cylindrical portion 63 are integrally formed.

[0064] The first cylindrical portion 61, the second cylindrical portion 62, and the third cylindrical portion 63 are each hollow. As shown in Fig. 6, the hollow portion 610 of the first cylindrical portion 61 opens to an end face 61a of the first cylindrical portion 61 in the direction of the straight line Lm1. The hollow portion 620 of the second cylindrical portion 62 opens to an end face 62a of the second cylindrical portion 62 in the direction of the straight line Lm2.

[0065] 7 , the hollow portion 610 of the first cylindrical portion 61 extends in the direction of the straight line Lm1 and is connected to the hollow portion 630 of the third cylindrical portion 63. The hollow portion 620 of the second cylindrical portion 62 extends in the direction of the straight line Lm2 and is connected to the hollow portion 630 of the third cylindrical portion 63. These hollow portions 610, 620, 630 form a single oil passage formed inside the oil supply member 6.

[0066] The second cylindrical portion 62 has oil holes 621 and 622 that connect the hollow portion 620 to the outside. The oil holes 621 and 622 are provided on the third cylindrical portion 63 side and the end face 62a side in the direction of the straight line Lm2, respectively.

[0067] As shown in FIG. 7, the hollow portion 630 of the third cylindrical portion 63 communicates with the hollow portion 610 of the first cylindrical portion 61 at one end 630a in the direction of the straight line Ln, and communicates with the hollow portion 620 of the second cylindrical portion 62 at the other end 630b.

[0068] As shown in FIG. 8 , the third cylindrical portion 63 has a rectangular shape in a cross section perpendicular to the line Ln. In the third cylindrical portion 63, a side surface 63a on one side and a side surface 63b on the other side, sandwiching the hollow portion 630 in the direction of the line Lm2, are arranged parallel to each other. In addition, in the third cylindrical portion 63, an upper surface 63c and a lower surface 63d, which connect the ends of the side surface 63a on one side and the side surface 63b on the other side, are arranged parallel to each other. The side surface 63a on one side and the side surface 63b on the other side are flat surfaces perpendicular to the line Lm2. The upper surface 63c and the lower surface 63d are flat surfaces that extend along the line Lm2.

[0069] As shown in Fig. 7, the third cylindrical portion 63 is provided with an oil hole 635 that connects the hollow portion 630 to the outside. The oil hole 635 is provided on the second cylindrical portion 62 side in the direction of the straight line Ln. As shown in Fig. 8, the oil hole 635 opens to the other side surface 63b. The oil hole 635 is inclined so that the further away from the hollow portion 630 it is, the closer it is to the lower surface 63d.

[0070] As shown in FIG. 5 , a lid portion 64 is provided on the third cylindrical portion 63 of the oil supply member 6. The lid portion 64 is formed integrally with the third cylindrical portion 63. The lid portion 64 protrudes upward from an upper surface 63c of the third cylindrical portion 63. The lid portion 64 is plate-shaped and extends in a direction perpendicular to a line Lm4 that is parallel to the lines Lm1 and Lm2. The lid portion 64 is provided in a region between the first cylindrical portion 61 and the oil hole 635 in the direction of the line Ln. A through-hole 640 is formed in the lid portion 64 at a position where the line Lm4 passes.

[0071] 6, the cover portion 64 has a back surface 64a on one side of the straight line Lm4 and a front surface 64b on the other side. The back surface 64a is flush with the side surface 63a on one side of the third cylindrical portion 63. The back surface 64a and the front surface 64b are each flat surfaces perpendicular to the straight line Lm4. The back surface 64a and the front surface 64b form a substantially rectangular shape when viewed from the direction of the straight line Lm4.

[0072] 5, the cover portion 64 has a thickness in the direction of the straight line Lm4, and side surfaces 64c, 64d, and 64e are formed between the back surface 64a and the front surface 64b. The side surface 64c connects the back surface 64a and the front surface 64b on the side of the first cylindrical portion 61 in the direction of the straight line Ln. The side surface 64d connects the back surface 64a and the front surface 64b on the side of the second cylindrical portion 62 in the direction of the straight line Ln. The side surface 64e connects the back surface 64a, the front surface 64b, and the side surfaces 64c and 64d.

[0073] As shown in Figure 6, the lid portion 64 has a groove 66 formed by cutting out a portion of the lid portion 64. The groove 66 is provided across the back surface 64a and side surface 64d of the lid portion 64. The groove 66 has a first opening 661 that opens to the side surface 64d of the lid portion 64 and a second opening 662 that opens to the back surface 64a. The groove 66 constitutes an opening provided in the lid portion 64.

[0074] The groove 66 has a length L66 (L66>T19) that is longer than the thickness T19 (see FIG. 3) of the connecting wall 19. As shown in FIG. 5, the groove 66 is not exposed when the cover 64 is viewed from the surface 64b side.

[0075] 5, a connecting piece 65 is provided at the connection between the second cylindrical portion 62 and the third cylindrical portion 63. The connecting piece 65 protrudes in the direction of the straight line Ln, away from the third cylindrical portion 63. A through hole 650 is formed in the connecting piece 65. The through hole 650 is oriented along a straight line Lm3 that is parallel to the straight line Lm2.

[0076] 5, in the oil supply member 6, bolts B1 and B2 are inserted into the through-hole 640 of the lid portion 64 and the through-hole 650 of the connecting piece 65, respectively. The bolts B1 and B2 are screwed into bolt holes Ba and Bb (see FIG. 3) provided in the case member 11.

[0077] 3, when viewed from the direction of the rotation axis X, the bolt hole Ba is provided in the connection between the connecting wall 19 and the support wall 111 among the walls that form the breather chamber 7. The bolt hole Bb is provided on the opposite side of the vertical line VL that passes through the rotation axis X from the bolt hole Ba.

[0078] The case member 11 also has a counterbore 152c in the wall that defines the breather chamber 7. The counterbore 152c is formed by recessing the connection between the connecting wall 18 and the support wall 111 toward the back of the page. The counterbore 152c is provided to surround the oil hole Pa. The case member 11 also has a support hole 152d that is provided on a vertical line VL that passes through the rotation axis X.

[0079] 7 , the oil supply member 6 has the first cylindrical portion 61 inserted into the counterbore portion 152c and the second cylindrical portion 62 inserted into the support hole 152d. As a result, the straight line Lm1 of the first cylindrical portion 61 and the straight line Lm2 of the second cylindrical portion 62 are arranged to extend along the rotation axis X. The straight line Ln of the third cylindrical portion 63 is arranged to extend along the radial direction of the rotation axis X. In this state, the third cylindrical portion 63 is disposed so as to cross the breather chamber 7 in the radial direction of the rotation axis X (the up-down direction in the figure).

[0080] In this state, the through hole 650 of the connecting piece 65 and the bolt hole Bb are coaxially aligned on the straight line Lm3. Although not shown, the through hole 640 (see FIG. 5) of the lid 64 and the bolt hole Ba (see FIG. 3) are coaxially aligned on the straight line Lm4 (see FIG. 5). The oil supply member 6 is fixed to the case member 11 by threading and tightening the bolts B1 and B2 into the bolt holes Ba and Bb, respectively (see FIG. 10).

[0081] This allows communication between the oil hole Pa of the case member 11 and the hollow portion 610 of the first cylindrical portion 61, the hollow portion 630 of the third cylindrical portion 63, and the hollow portion 620 of the second cylindrical portion 62 of the oil supply member 6. Therefore, the oil OL supplied to the oil hole Pa from the oil pump OP is sent from the hollow portion 610 of the first cylindrical portion 61, through the hollow portion 630 of the third cylindrical portion 63, to the hollow portion 620 of the second cylindrical portion 62.

[0082] As shown in Fig. 8, the third cylindrical portion 63 is provided with an oil hole 635. Therefore, a portion of the oil OL passing through the hollow portion 630 of the third cylindrical portion 63 is discharged from the oil hole 635 to the outside of the oil supply member 6. As shown in Fig. 10, the oil OL discharged from the oil hole 635 falls due to its own weight. The fallen oil OL lubricates the bearing Bm (see Fig. 1) supported by the motor support portion 125 located below the oil supply member 6.

[0083] As shown in FIG. 9, when the oil supply member 6 is attached to the case member 11, the second cylindrical portion 62 is disposed in a range that crosses the stator 22 of the motor 2 from one side to the other side in the direction of the rotation axis X.

[0084] In this state, the oil hole 621 of the second cylindrical portion 62 faces, with a gap therebetween, the outer peripheral surface 22 a of the stator 22 on the other side in the direction of the rotation axis X. The oil hole 622 of the second cylindrical portion 62 faces, with a gap therebetween, the outer peripheral surface 22 a of the stator 22 on one side in the direction of the rotation axis X.

[0085] The case member 11 is also provided with a slit 111d formed by cutting out a portion between the support hole 152d and the inner circumferential surface 111c of the support wall portion 111. The slit 111d faces the coil end 23a of the coil 23 with a gap therebetween on one side in the direction of the rotation axis X.

[0086] A portion of the oil OL flowing through the hollow portion 620 of the second cylindrical portion 62 is injected from the oil hole 621 and reaches the stator 22. After reaching the stator 22, the oil OL falls under its own weight and reaches the coil ends 23b. The stator 22 and the coil ends 23b are cooled by heat exchange with the oil OL.

[0087] Furthermore, part of the oil OL flowing through the hollow portion 620 of the second cylindrical portion 62 passes through the oil hole 621 and is ejected from the oil hole 622 to reach the stator 22. The stator 22 is cooled by heat exchange with the oil OL.

[0088] In this embodiment, the opening area of ​​oil hole 622 is larger than the opening area of ​​oil hole 621. The amount of oil OL injected from oil hole 622, which is located downstream of oil hole 621, is likely to decrease due to pressure loss. Therefore, by making the opening area of ​​oil hole 622 larger than the opening area of ​​oil hole 621, the decrease in the amount of oil OL injected from oil hole 622 is reduced.

[0089] As shown in FIG. 9, when viewed from the radial direction of the rotation axis X, an oil groove 117 is provided on the inner circumferential surface 111c of the support wall portion 111 at a position facing the oil hole 622 in the vertical direction.

[0090] As shown in Fig. 4, the oil groove 117 is provided along the inner circumferential surface 111c of the support wall portion 111 and has an arc shape when viewed from the direction of the rotation axis X. The oil groove 117 faces the outer circumferential surface 22a of the stator 22 at a distance from the outer circumferential surface 22a, radially outward of the rotation axis X. The oil groove 117 is provided in a range that crosses a horizontal line HL passing through the rotation axis X from above to below in the circumferential direction around the rotation axis X. The upper end of the oil groove 117 is provided near the oil supply member 6, and the lower end is provided near the aforementioned oil discharge passage 118.

[0091] As shown in Figure 9, a portion of the oil OL injected from the oil hole 622 of the second cylindrical portion 62 flows into the oil groove 117. The oil OL that flows into the oil groove 117 falls downward while contacting the outer peripheral surface 22a of the stator 22 (see Figure 4). The stator 22 is cooled by heat exchange with the oil OL. The oil OL that passes through the oil groove 117 is eventually returned to the oil reservoir OT in the motor housing chamber Sa.

[0092] Furthermore, some of the oil OL flowing through the hollow portion 620 of the second cylindrical portion 62 passes through the oil holes 621 and 622 and reaches the end face 62a. The oil OL that has reached the end face 62a passes through the slit 111d due to its own weight and reaches the coil end 23a. The coil end 23a is cooled by heat exchange with the oil OL.

[0093] 10 , a lid portion 64 is provided on the third cylindrical portion 63 of the oil supply member 6. When the oil supply member 6 is attached to the case member 11, the lid portion 64 is positioned so as to overlap with the breather chamber 7 (see the dashed line in the drawing) when viewed from the direction of the rotation axis X.

[0094] Specifically, the area of ​​the cover portion 64 on the side surface 64e side overlaps with the rib 17. The area on the side surface 64c side overlaps with the connecting wall 18. The area on the side surface 64d side overlaps with the connecting wall 19. Furthermore, the third cylindrical portion 63 overlaps with the support wall portion 111.

[0095] 12 , in the oil supply member 6, the back surface 64 a of the lid portion 64 abuts against the tip surface 171 of the rib 17 from the direction of the rotation axis X, and one side surface 63 a of the third cylindrical portion 63 abuts against the other end 111 b of the support wall portion 111 from the direction of the rotation axis X. Although not shown, the back surface 64 a of the lid portion 64 also abuts against the tip surfaces of the connecting walls 18 and 19 (see FIG. 10 ) from the direction of the rotation axis X. As a result, the inlet portion 7 a of the breather chamber 7 is completely blocked by the lid portion 64 of the oil supply member 6.

[0096] As shown in FIG. 12, the side surface 64e of the cover portion 64 is provided so as to overlap the support portion 16 of the terminal block T in the vertical direction.

[0097] 6, a groove 66 is formed in the cover 64, spanning the rear surface 64a and the side surface 64d. As described above, the groove length L66 of the groove 66 is set to be longer than the thickness T19 (see FIG. 3) of the connecting wall 19 (L66>T19).

[0098] 10, when the breather chamber 7 is closed with the cover 64 as viewed from the direction of the rotation axis X, the groove 66 is located in a portion of the cover 64 that overlaps with the connecting wall 19, and a portion of the groove 66 extends into the breather chamber 7. In this state, the drain hole 8 is located below the groove 66 (see FIG. 12).

[0099] As shown in Fig. 11 , the groove 66 has a first opening 661 that opens to the side surface 64d and faces in a direction that intersects with the rotation axis X. The first opening 661 faces the motor housing chamber Sa. As shown in Fig. 12 , a second opening 662 that opens to the back surface 64a faces in the direction of the rotation axis X. The second opening 662 faces the breather chamber 7. As a result, the breather chamber 7 maintains communication with the motor housing chamber Sa via the groove 66 even when the inlet portion 7a is closed by the lid portion 64.

[0100] FIG. 13 is a diagram illustrating a unit 100 according to a comparative example. FIG. 13 illustrates an oil supply member 600 without a lid portion 64. As shown in FIG. 13 , the air pressure inside the case member 11 increases as the oil OL is scattered by the rotation of the motor 2. The increased air pressure is released through the breathing portion 5. Therefore, an air flow from the motor housing chamber Sa toward the breather chamber 7 is generated inside the case member 11. Because the inlet portion 7a of the breather chamber 7 opens in the direction of the rotation axis X, the air flow toward the breather chamber 7 is along the rotation axis X. The scattered oil OL also moves toward the breather chamber 7 along the direction of the rotation axis X on this air flow.

[0101] As shown in FIG. 13 , for example, in the case of a unit 100 having an oil supply member 600 without a lid portion 64, a large amount of oil OL enters the breather chamber 7 along with the flow of air Air toward the breather chamber 7 in the direction of the rotation axis X.

[0102] The oil OL that has entered the breather chamber 7 may affect the ventilation function of the breathing section 5. For example, the oil OL that has entered the breather chamber 7 may be biased to one side in the direction of the rotation axis X due to centrifugal force or the like when the vehicle turns, and may block the opening 51 a and the through-hole 153 a of the breather pipe 51 of the breathing section 5 (see the imaginary lines in the drawing). In this case, the breathing section 5 may not be able to properly perform its ventilation function.

[0103] In contrast, in this embodiment, as shown in FIG. 12 , the oil supply member 6 is provided with a lid portion 64. The lid portion 64 closes the inlet portion 7 a of the breather chamber 7. As shown in FIG. 6 , the lid portion 64 has a groove 66 that spans the back surface 64 a and the side surface 64 d. ​​As shown in FIG. 11 , when the breather chamber 7 is closed with the lid portion 64, a first opening 661 of the groove 66 faces in a direction intersecting the rotation axis X, and a second opening 662 faces in the direction of the rotation axis X. As a result, the breather chamber 7 communicates with the motor housing chamber Sa via the groove 66. Air passing through the groove 66 flows from the first opening 661 side to the second opening 662 side.

[0104] Here, the oil OL that is scooped up and scattered is heavier than air and therefore more difficult to suddenly change its direction of movement than air. Therefore, by orienting the first opening 661, which serves as an entrance to the breather chamber 7, in the groove 66 in a direction intersecting the rotation axis X, the oil OL moving in the direction of the rotation axis X collides with the surface 64b of the lid portion 64, the support portion 16, the bottom wall 152, or the like before changing direction to pass through the first opening 661 (see FIG. 12 ). In this way, the lid portion 64 can reduce the intrusion of the oil OL while allowing air to flow into the breather chamber 7.

[0105] 12 , when viewed from the top and bottom, the side surface 64e of the lid portion 64 is arranged to overlap the support portion 16 of the terminal block T. This allows the support portion 16 to act as a shield, reducing the amount of oil OL dripping from the peripheral wall 151 of the roof portion 15 that passes between the lid portion 64 and the rib 17 and enters the breather chamber 7.

[0106] In this embodiment, the drain hole 8 and the oil groove 9 are provided in the breather chamber 7 at a position facing the breathing portion 5 in the vertical direction. Here, the clearance CL between the outer peripheral surface 22a of the stator 22 and the inner peripheral surface 111c of the support wall portion 111 is narrow. Therefore, the oil OL discharged from the drain hole 8 may remain in the clearance CL due to, for example, surface tension. This may reduce the oil return speed from the drain hole 8 to the oil reservoir OT (see FIG. 4 ). Therefore, the oil groove 9 is formed in the inner peripheral surface 111c of the support wall portion 111 and connected to the drain hole 8, thereby expanding the clearance CL in the area around the drain hole 8. This prevents the oil OL discharged from the drain hole 8 from remaining in the clearance CL and allows it to smoothly return to the oil reservoir OT.

[0107] As described above, in this embodiment, even if some of the scattered oil OL enters the breather chamber 7 through the first opening 661 of the groove 66 (see FIG. 11), it is quickly discharged to the outside of the breather chamber 7 through the drain hole 8 and the oil groove 9. This allows the function of the breathing section 5 to be maintained even when the vehicle is turning, for example.

[0108] Furthermore, in the present embodiment, the lid portion 64 is formed integrally with the oil supply member 6, but the present invention is not limited to this. For example, the lid portion 64 may be formed separately from the oil supply member 6. Note that forming the lid portion 64 integrally with the oil supply member 6 is preferable to forming the lid portion 64 separately, as this eliminates the need for bolts or the like to fasten the lid portion 64 to the case member 11, thereby reducing the number of parts and the number of assembly steps.

[0109] Examples of unit 1 according to certain aspects of the present invention are listed below. (1) Unit 1 has a housing HS having a motor accommodation chamber Sa in which a motor 2 is accommodated and a power transmission mechanism chamber Sb in which a power transmission mechanism 3 is accommodated. The housing HS has a breather chamber 7 that communicates with a breathing section 5. The breather chamber 7 has an inlet portion 7a (breather chamber inlet) and a drain hole 8 (oil return port) within the motor accommodation chamber Sa. The drain hole 8 is positioned opposite an outer peripheral surface 22a of a stator 22 of the motor 2.

[0110] The amount of oil OL scattered is smaller in the motor housing chamber Sa than in the power transmission mechanism chamber Sb. Therefore, by configuring as described above and providing the inlet 7a of the breather chamber 7 and the drain hole 8 in the motor housing chamber Sa, the amount of oil OL entering through the inlet 7a of the breather chamber 7 and the drain hole 8 can be reduced. Furthermore, the stator 22, which is a non-rotating member, acts as a shield, restricting the movement of scattered oil OL toward the outer periphery of the stator 22. Therefore, by providing the drain hole 8 at a position facing the outer periphery 22a of the stator 22, the scattered oil OL is less likely to reach the drain hole 8. This makes it possible to further reduce the amount of oil OL that flows back through the drain hole 8 and enters the breather chamber 7 (backflow amount).

[0111] (2) The power transmission mechanism chamber Sb is disposed on one end side of the motor 2 in the direction of the rotation axis X. The inlet 7a of the breather chamber 7 is disposed on the other end side of the motor 2 in the direction of the rotation axis X.

[0112] With this configuration, by orienting the inlet 7a of the breather chamber 7 away from the power transmission mechanism chamber Sb, where a large amount of oil OL is scattered, the amount of oil OL entering the breather chamber 7 can be reduced. As shown in FIG. 2 , from the perspective of the location of the drain hole 8, the gap CL (see FIG. 2 ) is narrower between the stator 22 of the motor 2 and the support wall 111 of the housing HS than near the end (coil end 23b) of the motor 2, where there is a large amount of free space. Therefore, scattered oil OL is less likely to enter the area between the stator 22 and the support wall 111 of the housing HS, where there is little free space. Therefore, by locating the drain hole 8 in an area with less free space than the inlet 7a of the breather chamber 7, scattered oil OL is less likely to flow back into the drain hole 8, which can be seen as reducing the amount of oil OL flowing back from the drain hole 8 into the breather chamber 7.

[0113] (3) The inlet 7a of the breather chamber 7 is covered by the lid 64. The lid 64 has a groove 66 (opening) that opens to a side surface 64d and a back surface 64a. A first opening 661 of the groove 66 opens to the side surface 64d of the lid 64. A second opening 662 of the groove 66 opens to the back surface 64a of the lid 64. The breather chamber 7 communicates with the motor housing chamber Sa via the groove 66.

[0114] By configuring in this manner and forming the groove 66 in the lid portion 64, it is possible to limit the area of ​​the region that serves as the entrance to the breather chamber 7. This makes it possible to reduce the amount of oil OL that enters the breather chamber 7.

[0115] (4) The drain hole 8 is located at a lower position than the groove 66 .

[0116] With this configuration, the oil OL accumulated in the breather chamber 7 can be efficiently discharged by utilizing gravity.

[0117] (5) The oil supply member 6 is provided to supply oil OL to the stator 22. The lid portion 64 is formed integrally with the oil supply member 6.

[0118] For example, if the lid portion 64 were separate from the oil supply member 6, a separate fastener (e.g., bolt) would be required to secure the lid portion 64, which would increase the number of parts and the number of assembly steps. Therefore, by configuring the lid portion 64 as described above and integrating it with the oil supply member 6, it is possible to contribute to reducing the number of parts and the number of assembly steps.

[0119] (6) The housing HS has a case member 11 that houses the motor 2. The case member 11 has a support wall portion 111 that faces the outer peripheral surface 22a of the stator 22. An oil groove 9 that communicates with the drain hole 8 and extends downward from the drain hole 8 in the direction of gravity is formed on the inner peripheral surface 111c (inner wall surface) of the support wall portion 111.

[0120] As shown in FIG. 2 , the gap CL between the outer peripheral surface 22a of the stator 22 and the inner peripheral surface 111c of the support wall portion 111 is narrow. Therefore, the oil OL discharged from the drain hole 8 may remain in the gap CL due to, for example, surface tension. This may reduce the speed at which the oil returns from the drain hole 8 to the oil reservoir OT (see FIG. 4 ). Therefore, by forming the oil groove 9 on the inner peripheral surface 111c of the support wall portion 111 using the above configuration, the gap CL between the inner peripheral surface 111c of the support wall portion 111 and the support wall portion 111 can be enlarged. This prevents the oil OL discharged from the drain hole 8 from remaining in the gap CL and allows it to smoothly return to the oil reservoir OT in the motor housing chamber Sa.

[0121] (Modification) FIG. 14 is a diagram illustrating a lid portion 64A according to a modification. In the above embodiment, as shown in FIG. 6, the first opening 661 of the groove 66 is provided on the side surface 64d of the lid portion 64 as an entrance to the breather chamber 7. However, this is not limited to this. For example, as shown in FIG. 14, a groove 66A may be configured such that the first opening 661 opens on the side surface 64c of the lid portion 64A and the second opening 662 opens on the back surface 64a. Although not shown, the lid portion 64 may be provided with two grooves, the groove 66 (see FIG. 6) and the groove 66A (see FIG. 14).

[0122] Although the embodiment of the present invention has been described above, the above embodiment merely shows one application example of the present invention, and the technical scope of the present invention is not intended to be limited to the specific configuration of the above embodiment. Appropriate modifications are possible within the scope of the technical concept of the invention.

[0123] 1: unit, 2: motor, 3: power transmission mechanism, 4: inverter, 5: breathing section, 6: oil supply member, 7: breather chamber, 7a: inlet section (breather chamber inlet), 8: drain hole (oil return port), 9: oil groove, 11: case member, 15: roof section, 20: motor shaft, 21: rotor, 22: stator, 22a: outer circumferential surface, 61: first cylindrical section, 62: second cylindrical section, 63: 3. Cylindrical portion, 64: lid portion, 64a: back surface, 64b: front surface, 64c to 64e: side surfaces, 66: groove (opening), 71: first chamber, 72: second chamber, 111: support wall portion, 111a: one end, 111b: other end, 111c: inner peripheral surface, 661: first opening, 662: second opening, HS: housing, OL: oil, Sa: motor accommodating chamber, Sb: power transmission mechanism chamber, VL: vertical line, X: rotation axis

Claims

1. A unit having a housing with a motor chamber that houses a motor and a power transmission mechanism chamber that houses a power transmission mechanism, the housing having a breather chamber that communicates with a breathing section, the breather chamber having a breather chamber inlet and an oil return port within the motor chamber, and the oil return port being positioned opposite the outer peripheral surface of the stator of the motor.

2. A unit according to claim 1, wherein the power transmission mechanism chamber is located at one axial end of the motor, and the breather chamber inlet is located at the other axial end of the motor.

3. A unit according to claim 1, wherein the breather chamber inlet is covered by a lid having an opening.

4. A unit according to claim 3, wherein the oil return port is positioned lower than the opening of the lid portion.

5. A unit according to claim 3, further comprising an oil supply member for supplying oil to the stator, and the lid portion is formed integrally with the oil supply member.

6. A unit according to claim 1, wherein the housing has an oil groove formed on its inner wall surface facing the outer peripheral surface of the stator, the oil groove communicating with the oil return port and extending downward from the oil return port in the direction of gravity.

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