Drive device

Abstract

A drive device according to one embodiment of the present invention is provided with: a motor having a rotor that rotates about a motor axis and a stator that surrounds the rotor; a housing having a cylindrical peripheral wall portion surrounding the motor from the outside in the radial direction of the motor axis, and a cover portion covering an opening on one side in the axial direction of the peripheral wall portion; a fluid which is stored in a storage part in the housing; a first supply unit that is disposed within the housing and supplies a fluid to the motor; an inverter that supplies power to the motor; and a bus bar located between the stator and the cover portion in the axial direction and electrically connecting the inverter and the stator. The housing is provided with a first flow path extending from the storage part to the cover part, and a second flow path passing through the interior of the cover part. The second flow path has a first end connected to the first flow path and a second end connected to the first supply unit. When viewed from the axial direction, the bus bar is disposed between the first end portion and the second end portion. The second flow path is disposed at a position different from that of the bus bar when viewed from the axial direction.

Description

Technical Field

[0001] The present invention relates to a drive device.

[0002] This application claims priority based on Japanese Patent Application No. 2022-134249 filed in Japan on August 25, 2022, the contents of which are cited here. Background Art

[0003] In recent years, the development of drive devices mounted on electric vehicles and the like has become popular. Such drive devices are equipped with a cooling structure for cooling the motor. Patent document 1 discloses a rotating electric machine that allows a refrigerant to flow through a tubular refrigerant passage provided on the outer peripheral side of a stator, and supplies the refrigerant to the stator from a refrigerant discharge port provided in the refrigerant passage.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2012-105465 Summary of the invention

[0007] Problems to be solved by the invention

[0008] A flow path passing through the wall is provided on the housing of the drive device having a cooling structure. In addition, a bus bar is provided on the drive device as a path for supplying power to the stator. A sufficient insulation distance needs to be maintained between the bus bar and the wall of the housing. However, when the wall is provided with the flow path, the bus bar and the wall are easily accessible.

[0009] One object of one embodiment of the present invention is to provide a driving device that can easily ensure an insulation distance between a bus bar and a case.

[0010] Means for solving problems

[0011] A drive device according to one embodiment of the present invention comprises: a motor having a rotor rotating about a motor axis and a stator surrounding the rotor; a housing having a cylindrical peripheral wall portion surrounding the motor from the radially outer side of the motor axis and a cover portion covering an opening on one axial side of the peripheral wall portion; a fluid stored in a storage portion in the housing; a first supply portion arranged in the housing and supplying the fluid to the motor; an inverter supplying power to the motor; and a bus bar located axially between the stator and the cover portion and electrically connecting the inverter to the stator. The housing is provided with a first flow path extending from the storage portion to the cover portion and a second flow path passing through the inside of the cover portion. The second flow path has a first end connected to the first flow path and a second end connected to the first supply portion. When viewed from the axial direction, the bus bar is arranged between the first end and the second end. When viewed from the axial direction, the second flow path is arranged at a position different from the bus bar.

[0012] Effects of the Invention

[0013] According to one aspect of the present invention, it is possible to provide a driving device that can easily ensure the insulation distance between the bus bar and the case. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a conceptual diagram of a driving device according to one embodiment.

[0015] Figure 2 It is a front view of the 1st cover part of one embodiment.

[0016] Figure 3 It is a front view of the first cover part of a modified example. DETAILED DESCRIPTION

[0017] Hereinafter, a drive device according to an embodiment of the present invention will be described with reference to the drawings. In the following description, the vertical direction is defined based on the positional relationship when the drive device 1 according to the present embodiment is mounted on a vehicle (not shown) located on a horizontal road surface.

[0018] In the accompanying drawings, the XYZ coordinate system is appropriately shown as a three-dimensional orthogonal coordinate system. In the XYZ coordinate system, the Z-axis direction is the vertical direction. The +Z side is the upper side in the vertical direction, and the -Z side is the lower side in the vertical direction. In the present embodiment, the upper side in the vertical direction is referred to as the "upper side", and the lower side in the vertical direction is referred to as the "lower side". The X-axis direction is a direction perpendicular to the Z-axis direction, and is the front-to-back direction of the vehicle equipped with the drive device 1. In the present embodiment, the +X side is the front side of the vehicle, and the -X side is the rear side of the vehicle. The Y-axis direction is a direction perpendicular to both the X-axis direction and the Z-axis direction, and is the left-to-right direction of the vehicle, that is, the vehicle width direction. The Y-axis direction is equivalent to the axial direction of the first axis J1, the second axis J2, and the third axis J3 described later. The front-to-back direction and the left-to-right direction are horizontal directions perpendicular to the vertical direction.

[0019] In the present embodiment, directions perpendicular to the first axis J1 and perpendicular to each other are defined as a first direction and a second direction. In the present embodiment, the first direction is the front-rear direction of the vehicle (i.e., the X-axis direction), and the second direction is the up-down direction (i.e., the Z-axis direction). In addition, one side of the second direction is the upper side (+Z side), and the other side of the second direction is the lower side (-Z side).

[0020] The first axis J1, the second axis J2, and the third axis J3 appropriately shown in the respective figures are parallel to each other and extend along the Y-axis direction (i.e., the left-right direction of the vehicle, the direction along the horizontal plane). In the present embodiment, unless otherwise specified, the direction parallel to the first axis J1 is referred to as the "axial direction", and the -Y side is referred to as one axial side, and the +Y side is referred to as the other axial side. Furthermore, the radial direction centered on the first axis J1 is referred to as the "radial direction", and the circumferential direction centered on the first axis J1, i.e., the direction around the first axis J1, is referred to as the "circumferential direction". In addition, in the present embodiment, the "parallel direction" includes a substantially parallel direction, and the "vertical direction" includes a substantially vertical direction.

[0021] Figure 1 It is a conceptual diagram of the driving device 1 .

[0022] The drive device 1 of this embodiment is mounted on an electric vehicle (EV) and used as its power source. Alternatively, the drive device 1 may be mounted on a vehicle using a motor as a power source, such as a hybrid electric vehicle (HEV) or a plug-in hybrid electric vehicle (PHV).

[0023] The drive device 1 includes a motor 2, a rotary transformer 29, a transmission mechanism 3, an inverter 7, a bus bar 30, a housing 6, a fluid O, a pump 8, a cooler 9, a first supply pipe (first supply unit) 93A, a second supply pipe (second supply unit) 95A, and a third supply pipe 94A. The motor 2, the rotary transformer 29, the transmission mechanism 3, the inverter 7, the bus bar 30, the first supply pipe 93A, the second supply pipe 95A, and the third supply pipe 94A are arranged in the housing 6. The fluid O is stored in the housing 6. The pump 8 and the cooler 9 are fixed to the outer side surface of the housing 6.

[0024] <Motor>

[0025] The motor 2 of the present embodiment is a three-phase AC motor. The motor 2 has both the function of an electric motor and the function of a generator. The motor 2 is located on one axial side (-Y side) of the transmission mechanism 3. The motor 2 has a rotor 20 that rotates around a first axis (motor axis) J1 extending in the horizontal direction and a stator 25 located radially outside the rotor 20. The motor 2 of the present embodiment is an inner rotor type motor in which the rotor 20 is arranged on the inner side of the stator 25. The structure of the motor 2 is not limited to the present embodiment.

[0026] The rotor 20 rotates around a first axis J1 extending in the horizontal direction. The rotor 20 includes a motor shaft (shaft) 21, a rotor core 24 fixed to the outer peripheral surface of the motor shaft 21, and a rotor magnet (not shown) fixed to the rotor core.

[0027] The motor shaft 21 extends along the first axis J1. The motor shaft 21 rotates around the first axis J1. The end of the motor shaft 21 on the other axial side (+Y side) is connected to the first shaft 46 of the transmission mechanism 3. Thus, the torque of the rotor 20 is transmitted to the transmission mechanism 3. The motor shaft 21 is a hollow shaft. A hole extending radially outward from the hollow portion 21h is provided in the motor shaft 21. The motor shaft 21 is rotatably supported by the housing 6 via a bearing.

[0028] A resolver rotor 29a of a resolver (rotation detector) 29 is fixed to one axial end (-Y side) of the motor shaft 21. The resolver rotor 29a has a plurality of magnets arranged in the circumferential direction. The resolver rotor 29a rotates around the first axis J1 together with the motor shaft 21.

[0029] The stator 25 is held by the housing 6. The stator 25 surrounds the rotor 20 from the radially outer side. The outer peripheral surface of the stator 25 faces the inner peripheral surface of the housing 6. The stator 25 has an annular stator core 27 centered on the first axis J1 and a coil 26 attached to the stator core 27. The stator core 27 is fixed to the housing 6.

[0030] The coil 26 is mounted on each tooth portion of the stator core 27 via an insulator (not shown). The coil 26 of this embodiment is composed of a plurality of coil wires. In addition, the coil 26 can also be composed by connecting a plurality of rod-shaped conductors. The coil 26 has coil ends protruding from both axial ends of the stator core 27.

[0031] The coil wire constituting the coil 26 is led out to one axial side (-Y side) as a lead wire 26a. The coil 26 of this embodiment has three lead wires 26a corresponding to the U phase, the V phase, and the W phase. The front end of the lead wire 26a is connected to the bus bar 30. The AC current flows through the coil 26 via the bus bar 30.

[0032] <Transmission mechanism>

[0033] The transmission mechanism 3 has a plurality of gears 41, 42, 43, and 51. The transmission mechanism 3 transmits the power of the motor 2 and outputs it from the output shaft 55. The transmission mechanism 3 reduces the rotation output from the motor 2 and increases the torque output from the motor 2.

[0034] The transmission mechanism 3 includes a first shaft 46, a first gear 41, a second shaft 45, a second gear 42, a third gear 43, a differential device 5, and an output shaft 55. The first shaft 46 and the second shaft 45 are hollow shafts, respectively. The first shaft 46, the second shaft 45, and the output shaft 55 extend parallel to each other.

[0035] The first shaft 46 and the first gear 41 are arranged around the first axis J1. The first shaft 46 extends in the axial direction of the first axis J1. The first shaft 46 is connected to the motor shaft 21 at the end on one axial side (-Y side). The first gear 41 is provided on the outer peripheral surface of the first shaft 46. The first gear 41 rotates together with the first shaft 46 around the first axis J1.

[0036] The second shaft 45, the second gear 42 and the third gear 43 are arranged around the second axis J2 parallel to the first axis J1. The second shaft 45 extends axially along the second axis J2. That is, the second shaft 45 extends parallel to the first shaft 46. The second gear 42 and the third gear 43 are arranged on the outer peripheral surface of the second shaft 45 at intervals from each other in the axial direction. The second gear 42 and the third gear 43 rotate around the second axis J2 together with the second shaft 45. The second gear 42 meshes with the first gear 41. The third gear 43 meshes with the ring gear 51 of the differential device 5.

[0037] The differential device 5 has a ring gear (lower end gear) 51 and a differential mechanism 5a. The differential device 5 meshes with the third gear 43 at the ring gear 51. The ring gear 51 rotates around the third axis J3 parallel to the first axis J1. The rotation of the ring gear 51 is transmitted to the differential mechanism 5a, and then output from the output shaft 55 connected to the differential mechanism 5a. When the vehicle turns, the differential mechanism 5a absorbs the speed difference between the left and right wheels while transmitting torque to the output shafts 55 of the left and right wheels. The output shaft 55 extends along the third axis J3. A pair of output shafts 55 are respectively connected to the wheels.

[0038] The torque output from the motor 2 is transmitted to the ring gear 51 of the differential device 5 via the motor shaft 21, the first shaft 46, the first gear 41, the second gear 42, the second shaft 45, and the third gear 43, and further transmitted to the wheels via the differential mechanism 5a and the output shaft 55. In this way, the transmission mechanism 3 transmits the torque of the motor 2 to the wheels of the vehicle.

[0039] <Inverter>

[0040] The inverter 7 is located on the upper side (the second direction side, +Z side) of the motor 2. The inverter 7 converts the DC current supplied from the battery (not shown) into AC current. The inverter 7 is connected to the lead wire 26a of the stator 25 via the bus bar 30. The inverter 7 supplies power to the motor 2 via the bus bar 30 to control the motor 2.

[0041] <Bus bar>

[0042] The bus bar 30 is located on one axial side (-Y side) of the stator 25. The bus bar 30 is a plate-shaped component made of a metal material with low resistance. The drive device 1 of this embodiment is provided with three bus bars 30 corresponding to the U phase, the V phase, and the W phase. One end of the bus bar 30 is connected to the lead wire 26a extending from the coil 26, and the other end of the bus bar 30 is connected to the inverter. The bus bar 30 electrically connects the inverter 7 and the stator 25.

[0043] As described above, the inverter 7 is located on the upper side of the motor 2. Therefore, the bus bar 30 is arranged on the upper side (the second direction side, +Z side) with respect to the first axis J1. That is, the bus bar 30 is arranged in the same direction as the inverter 7 with respect to the motor axis J1. According to the present embodiment, the stator 25 and the inverter 7 can be connected at the shortest distance via the bus bar 30, and the power loss associated with the resistance of the bus bar 30 can be reduced.

[0044] <Housing>

[0045] The housing 6 is provided with a motor chamber 6A for accommodating the motor 2, the rotary transformer 29 and the bus bar 30, a gear chamber 6B for accommodating the transmission mechanism 3 and an inverter chamber 6C for accommodating the inverter 7. The gear chamber 6B is located on the other axial side (+Y side) of the motor chamber 6A. In addition, the inverter chamber 6C is located on the upper side (+Y side) of the motor chamber 6A.

[0046] The housing 6 is constructed by combining a plurality of components. The housing 6 has: a housing body 61; a first cover portion (cover portion) 63, which is located on one axial side (-Y side) of the housing body 61; a second cover portion 62, which is located on the other axial side (+Y side) of the housing body 61; and an inverter cover 64, which is located on the upper side (+Z side) of the housing body 61. The housing body 61, the first cover portion 63, the second cover portion 62, and the inverter cover 64 are, for example, made of aluminum die casting. The housing body 61 and the first cover portion 63 surround the motor chamber 6A. On the other hand, the housing body 61 and the second cover portion 62 surround the gear chamber 6B. The housing body 61 and the inverter cover 64 surround the inverter chamber 6C.

[0047] The housing body 61 has a first circumferential wall portion 61a, a second circumferential wall portion 61b, and a partition wall 65. That is, the housing 6 has a first circumferential wall portion 61a, a second circumferential wall portion 61b, and a partition wall 65. The first circumferential wall portion 61a is in the shape of a tube that surrounds the motor 2 from the radially outer side of the first axis J1. On the other hand, the second circumferential wall portion 61b surrounds the transmission mechanism 3 from the radially outer side. The partition wall 65 is provided at the end of the other axial side (+Y side) of the first circumferential wall portion 61a. In addition, the partition wall 65 is provided at the end of the axially one side (-Y side) of the second circumferential wall portion 61b. The partition wall 65 divides the motor chamber 6A and the gear chamber 6B. The partition wall 65 extends along a plane perpendicular to the first axis J1. The partition wall 65 supports the shafts of the motor 2 and the transmission mechanism 3 via bearings.

[0048] The partition wall 65 is provided with a connecting passage 66, a through hole 65b, and a shaft insertion hole 65c. The connecting passage 66, the through hole 65b, and the shaft insertion hole 65c connect the motor chamber 6A and the gear chamber 6B so that they are connected to each other. The shaft insertion hole 65c is circular with the first axis J1 as the center. A pair of bearings for holding the motor shaft 21 and the first shaft 46 are arranged in the shaft insertion hole 65c. The motor shaft 21 and the first shaft 46 are connected to each other inside the shaft insertion hole 65c. The through hole 65b and the connecting passage 66 extend in the axial direction and penetrate the partition wall 65. The through hole 65b and the connecting passage 66 are arranged at a position lower than the shaft insertion hole 65c.

[0049] The first cover portion 63 is in the shape of a plate extending along a plane perpendicular to the first axis J1. The first cover portion 63 is fixed to the end portion of the first peripheral wall portion 61a on one axial side (-Y side). The first cover portion 63 covers the opening of the first peripheral wall portion 61a on one axial side (-Y side).

[0050] The first cover portion 63 has an inner side surface 63a facing the other axial side (+Y side) and an outer side surface 63f facing the one axial side (-Y side). The inner side surface 63a faces the motor chamber 6A side and is opposite to the motor 2. In addition, the inner side surface 63a faces the bus bar 30. The bus bar 30 is located between the stator 25 and the first cover portion 63 in the axial direction.

[0051] The first cover portion 63 includes a retaining tube portion 63b protruding from an inner side surface 63a toward one axial side (-Y side). The retaining tube portion 63b is cylindrical with the first axis J1 as the center. The retaining tube portion 63b retains the bearing 81. The bearing 81 supports the end portion of the motor shaft 21 at one axial side (-Y side).

[0052] The resolver stator 29b is fixed to the first cover portion 63. The resolver stator 29b surrounds the resolver rotor 29a from the radially outer side. The resolver stator 29b has a coil excited by a change in magnetic flux accompanying the rotation of the resolver rotor 29a. The resolver 29 measures the rotation speed of the rotor 20 based on the excited magnetic flux change.

[0053] The second cover portion 62 is fixed to the end portion of the second peripheral wall portion 61b on the other axial side (+Y side). The second cover portion 62 covers the opening of the second peripheral wall portion 61b on the other axial side (+Y side).

[0054] The fluid O is stored in the lower region of the internal space of the housing 6. That is, the fluid O is stored in the lower region of the housing 6. Hereinafter, the lower region of the housing 6 where the fluid O is stored is referred to as a reservoir P. The reservoir P of the present embodiment is provided across the lower region of the motor chamber 6A, the lower region of the housing 6, the through hole 65b connecting them, and the communication path 66.

[0055] The fluid O functions as a refrigerant for cooling the motor 2 and as a lubricant for the transmission mechanism 3. In order for the fluid O to function as lubricating oil and cooling oil, it is preferable to use an oil similar to automatic transmission lubricating oil (ATF) having a relatively low viscosity.

[0056] The ring gear 51 is immersed in the fluid O in the reservoir P. The ring gear 51 lifts the fluid O in the reservoir P and spreads it into the gear chamber 6B as it rotates about the third axis J3. The fluid O lifted by the ring gear 51 is supplied to the gears in the gear chamber 6B and is used to lubricate the gear tooth surfaces.

[0057] In addition, the fluid O in the reservoir P is delivered to the upper region of the motor chamber 6A and the upper region of the gear chamber 6B through the flow path 90. The fluid O delivered to the upper region of the motor chamber 6A cools the motor 2 along the surface of the motor 2, and then drips to the reservoir P in the lower region of the motor chamber 6A. In addition, the fluid O delivered to the upper region of the gear chamber 6B lubricates the gears of the transmission mechanism 3 and the bearings supporting the transmission mechanism 3, and then drips to the reservoir P in the lower region of the gear chamber 6B.

[0058] <Flow path>

[0059] The flow path 90 is a circulation path for the fluid O to flow. The flow path 90 is a path for the fluid O to supply the fluid O from the reservoir P to the motor 2 and the transmission mechanism 3. In the present specification, the "flow path" is a concept that includes not only a path for stably forming the flow of the fluid O in one direction, but also a path for temporarily retaining the fluid O and a path for the fluid O to drip.

[0060] The flow path 90 is provided with the pump 8 , the cooler 9 , the first supply pipe 93A, the second supply pipe 95A, and the third supply pipe 94A.

[0061] The pump 8 pressurizes the fluid O in the flow path 90. Thus, the pump 8 supplies the fluid O to the motor 2. The pump 8 of this embodiment is an electric pump driven by electricity. However, the pump 8 can also be a mechanical pump that operates as the transmission mechanism 3 is driven. In the case where the pump 8 is a mechanical pump, the pump 8 is connected to any axis of the transmission mechanism 3 and driven by the power of the motor 2.

[0062] The cooler 9 cools the fluid O in the flow path 90. A refrigerant (not shown) flows inside the cooler 9. The cooler 9 is a heat exchanger that transfers heat of the fluid O to the refrigerant.

[0063] The first supply pipe 93A and the second supply pipe 95A are arranged in the motor chamber 6A. The first supply pipe 93A and the second supply pipe 95A extend in the axial direction respectively. The end of the first supply pipe 93A and the second supply pipe 95A on the other axial side (+Y side) is supported by the partition wall 65. The end of the first supply pipe 93A and the second supply pipe 95A on one axial side (-Y side) is supported by the first cover portion 63. A plurality of injection holes opening toward the stator 25 are provided in the first supply pipe 93A and the second supply pipe 95A. The first supply pipe 93A and the second supply pipe 95A supply the fluid O to the motor 2 via the ejection holes. The first supply pipe 93A and the second supply pipe 95A are both arranged on the upper side of the motor 2. In addition, at Figure 1 In FIG. 1 , the second supply pipe 95A is shown below the motor 2 , but this is schematic and does not represent the actual arrangement.

[0064] The 3rd supply pipe 94A is arranged in the gear chamber 6B. The 3rd supply pipe 94A extends in the axial direction. The end of the other axial side (+Y side) of the 3rd supply pipe 94A is supported by the second cover part 62. The end of the one axial side (-Y side) of the 3rd supply pipe 94A is supported by the partition wall 65. The 3rd supply pipe 94A of this embodiment is coaxially arranged with the 1st supply pipe 93A. The 1st supply pipe 93A and the 3rd supply pipe 94A are opposite to each other and connected in the hole portion provided in the partition wall 65. A plurality of injection holes opening toward the transmission mechanism 3 are provided in the 3rd supply pipe 94A. The 3rd supply pipe 94A supplies the fluid O to the transmission mechanism 3 via the ejection hole.

[0065] The flow path 90 of the present embodiment includes a first flow path 91, a second flow path 92, a third flow path 93, a fourth flow path 94, a fifth flow path 95, and a sixth flow path 96. The first flow path 91 and the second flow path 92 are holes provided in the housing 6. The first flow path 91, the second flow path 92, and the sixth flow path 96 are formed by drilling the wall of the housing 6 with a drill. That is, the first flow path 91, the second flow path 92, and the sixth flow path 96 are provided in the housing 6. On the other hand, the third flow path 93, the fourth flow path 94, and the fifth flow path 95 are flow paths passing through the inside of the supply pipes 93A, 94A, and 95A, respectively.

[0066] The first flow path 91 is provided in the shell body 61. The first flow path 91 extends from the storage portion P to the first cover portion 63. The first flow path 91 has an intake flow path 91a, a first discharge flow path 91b, and a second discharge flow path 91c. The intake flow path 91a connects the storage portion P and the intake port 8c of the pump 8. The end portion on the upstream side of the intake flow path 91a opens on the inner side surface of the connecting passage 66. The intake flow path 91a guides the fluid O in the storage portion P to the pump 8. The first discharge flow path 91b connects the discharge port 8b of the pump 8 and the inlet port of the cooler 9. The second discharge flow path 91c connects the outlet port of the cooler 9 and the first cover portion 63. The first flow path 91 is connected to the second flow path 92.

[0067] The second flow path 92 is provided in the first cover portion 63. That is, the second flow path 92 passes through the inside of the first cover portion 63. The second flow path 92 has a first end 92a as an end on the upstream side and a second end 92b as an end on the downstream side. The second flow path 92 is connected to the first flow path 91 at the first end 92a, and is connected to the third flow path 93 at the second end 92b. That is, the second flow path 92 has a first end 92a connected to the first flow path 91 and a second end 92b connected to the first supply pipe 93A. In addition, the second flow path 92 is connected to the fifth flow path 95 at a connection portion 92c located between the first end 92a and the second end 92b. That is, the second flow path 92 has a connection portion 92c connected to the second supply pipe 95A. In addition, the second flow path 92 has a branch flow path 92d opened inside the retaining cylinder 63b. The branch flow path 92d supplies the fluid O to the inside of the holding cylinder 63b. A portion of the fluid O supplied to the holding cylinder 63b is supplied to the bearing 81 supporting the motor shaft 21 to lubricate the bearing 81. In addition, a portion of the fluid O supplied to the holding cylinder 63b intrudes into the hollow portion 21h of the motor shaft 21 and is supplied to the stator 25 through the hole provided in the motor shaft 21.

[0068] In addition, the second flow path 92 will be described in more detail later.

[0069] The third flow path 93 is provided inside the first supply pipe 93A. A part of the fluid O flowing into the third flow path 93 is supplied to the motor 2 through the discharge hole provided in the first supply pipe 93A. The downstream end of the third flow path 93 is connected to the fourth flow path 94 .

[0070] The fourth flow path 94 is provided inside the third supply pipe 94A. A part of the fluid O flowing into the fourth flow path 94 is supplied to the transmission mechanism 3 through the discharge hole provided in the third supply pipe 94A. The downstream end of the fourth flow path 94 is connected to the sixth flow path 96 .

[0071] The fifth flow path 95 is provided inside the second supply pipe 95A. The fluid O having flowed into the fifth flow path 95 is supplied to the motor 2 via the discharge hole provided in the second supply pipe 95A.

[0072] The sixth flow path 96 is provided in the second cover portion 62. That is, the sixth flow path 96 passes through the interior of the second cover portion 62. The fluid O that has flowed into the sixth flow path 96 is supplied to the interior of the second shaft 45 and the first shaft 46 and the bearings that support them.

[0073] Figure 2 It is a front view of the first cover portion 63 of the drive device 1 .

[0074] Here, according to Figure 2The first cover portion 63 and the second flow path 92 of the present embodiment will be described in more detail.

[0075] The first cover portion 63 is provided with a first linear convex portion 63 p , a second linear convex portion 63 q , a concave portion 63 d , a convex portion 63 e , and a window portion 63 w in addition to the second flow path 92 .

[0076] The second flow path 92 has a first straight portion 92p and a second straight portion 92q. The first straight portion 92p and the second straight portion 92q are straight holes formed by machining the first cover portion 63 with a drill.

[0077] The first straight portion 92p and the second straight portion 92q extend along the surface direction of the first cover portion 63 (i.e., along the direction of the plane perpendicular to the axial direction). The first straight portion 92p and the second straight portion 92q extend in different directions. The first straight portion 92p and the second straight portion 92q intersect each other at the intersection 92r. That is, the first straight portion 92p and the second straight portion 92q are connected at the intersection 92r.

[0078] As described above, the second flow path 92 has the first end 92a as the end on the upstream side and the second end 92b as the end on the downstream side. The first straight portion 92p extends linearly from the first end 92a and opens on the motor chamber 6A side. On the other hand, the second straight portion 92q extends linearly from the second end 92b to the intersection 92r with the first straight portion 92p.

[0079] The first straight portion 92p opens to the inner side surface of the holding tube 63b at the end opposite to the first end 92a. In the first straight portion 92p, the region from the intersection 92r to the holding tube 63b constitutes a branch flow path 92d of the second flow path 92.

[0080] The second flow path 92 of this embodiment is formed by connecting the first straight portion 92p and the second straight portion 92q at the intersection 92r to form a flow path connected from the first end 92a to the second end 92b. According to this embodiment, by combining the straight hole portions (the first straight portion 92p and the second straight portion 92q), the second flow path 92 bent at the intersection 92r is formed.

[0081] The first linear protrusion 63p and the second linear protrusion 63q protrude from the outer side surface 63f to one axial side (-Y side). The first linear protrusion 63p and the second linear protrusion 63q extend linearly along the surface direction of the first cover portion 63 (i.e., along the direction of the plane perpendicular to the axial direction). The cross-sectional shape of the first linear protrusion 63p and the second linear protrusion 63q is semicircular. The first linear protrusion 63p and the second linear protrusion 63q intersect each other. When viewed from the axial direction, the first linear protrusion 63p overlaps with a portion of the first linear portion 92p. When viewed from the axial direction, the second linear protrusion 63q overlaps with the entirety of the second linear portion 92q. A portion of the first linear portion 92p is arranged inside the first linear protrusion 63p. On the other hand, a portion of the second linear portion 92q is arranged inside the second linear protrusion 63q. According to the present embodiment, by providing the first linear protrusion 63p and the second linear protrusion 63q on the first cover portion 63, the first cover portion 63 can be made thinner in the portion other than the first linear protrusion 63p and the second linear protrusion 63q. Thus, the weight of the drive device 1 can be reduced.

[0082] The recess 63d is provided on the inner side surface 63a of the first cover portion 63 and is open on the other axial side (+Y side). The recess 63d overlaps with the bus bar 30 when viewed from the axial direction. The three bus bars 30 of the present embodiment are arranged as a whole in the area inside the recess 63d when viewed from the axial direction. According to the present embodiment, the insulation distance between the first cover portion 63 and the bus bar 30 can be ensured in the axial direction.

[0083] The convex portion 63e is provided on the outer side surface 63f of the first cover portion 63. The convex portion 63e protrudes from the outer side surface toward one axial side (-Y side). When viewed from the axial direction, the convex portion 63e overlaps with the concave portion 63d. By providing the convex portion 63e overlapping with the concave portion 63d when viewed from the axial direction on the outer side surface 63f, it is possible to suppress the local thinning of the first cover portion 63 and ensure the rigidity of the first cover portion 63.

[0084] The window portion 63w penetrates the first cover portion 63 in the axial direction. The window portion 63w exposes the connector portion 29c provided on the rotary transformer stator 29b. That is, the window portion 63w exposes at least a portion of the rotary transformer 29. A plurality of wires 29e are connected to the connector portion 29c. The wires 29e connect the rotary transformer stator 29b and the inverter 7. The plurality of wires 29e supply power from the inverter 7 to the rotary transformer stator 29b, and output the measurement result of the rotary transformer 29 to the rotation angle of the rotor 20 to the inverter 7. The operator performs maintenance of the rotary transformer 29 or assembly processes such as connecting the wires 29e to the connector portion 29c through the window portion 63w.

[0085] like Figure 2As shown in FIG. 1 , when the first cover portion 63 is observed from the axial direction, an imaginary line L is assumed as a line segment connecting the first end portion 92a and the second end portion 92b. In the present embodiment, the bus bar 30 is arranged on the imaginary line L when observed from the axial direction. That is, the bus bar 30 is arranged between the first end portion 92a and the second end portion 92b when observed from the axial direction. In addition, when observed from the axial direction, the second flow path 92 is arranged at a position different from the bus bar 30.

[0086] The inverter 7 is arranged on the upper side of the motor 2 in consideration of maintainability, etc. In addition, the first supply pipe 93A is arranged on the upper side of the motor 2 in order to supply fluid to the motor 2 as a whole by utilizing gravity. That is, the inverter 7 and the first supply pipe 93A of the present embodiment are both arranged on the upper side (the second direction side, +Z side) of the motor 2. In this way, when the inverter 7 and the first supply pipe 93A are arranged in the same direction relative to the motor 2, the bus bar 30 connected to the inverter 7 and the second flow path 92 connected to the first supply pipe 93A are easily arranged in a concentrated manner.

[0087] The second flow path 92 of the present embodiment passes through a path that is bent at the intersection 92r, thereby bypassing the area overlapping with the bus bar 30 when viewed from the axial direction. A high voltage current flows through the bus bar 30. In addition, the first cover portion 63 is made of a metal material in order to ensure sufficient rigidity. Therefore, it is preferred that the bus bar 30 and the first cover portion 63 are configured to be sufficiently separated to ensure the insulation distance. According to the present embodiment, when viewed from the axial direction, the second flow path 92 does not overlap with the bus bar 30, so by providing a recess 63d on the inner side surface 63a of the first cover portion 63, etc., it is easy to ensure the insulation distance between the bus bar 30 and the first cover portion 63. In addition, the thickness dimension of the first cover portion 63 is likely to be larger in the portion where the second flow path 92 is provided compared to other portions. According to the present embodiment, the second flow path 92 and the bus bar 30 do not overlap when viewed from the axial direction. Therefore, even if the first cover portion 63 is thickened in the portion overlapping the second flow path 92 , it is easy to ensure the insulation distance between the bus bar 30 and the first cover portion 63 .

[0088] like Figure 2 As shown, in the second flow path 92 of the present embodiment, the first end 92a is located on one side (-X side) in the front-rear direction (first direction) relative to the first axis J1, and the second end 92b is located on the other side (+X side) in the front-rear direction (first direction) relative to the first axis J1. According to the present embodiment, when the second flow path 92 extends in the front-rear direction of the vehicle, it is possible to suppress the bus bar 30 and the second flow path 92 from being overlapped when viewed from the axial direction.

[0089] The second flow path 92 of this embodiment is connected to the second supply pipe 95A at the connection portion 92c. According to this embodiment, the flow path 90 can supply the fluid O to the stator 25 not only in the first supply pipe 93A but also in the second supply pipe 95A, so that the entire stator 25 can be cooled more uniformly.

[0090] In the second flow path 92 of the present embodiment, the connection portion 92c is located on one side (-X side) of the front-to-back direction (first direction) relative to the first axis J1, and the second end portion 92b is located on the other side (+X side) of the front-to-back direction (first direction) relative to the first axis J1. Furthermore, the connection portion 92c and the second end portion 92b are located at a position higher than the first axis J1 (one side of the second direction, +Z side). Therefore, the first supply pipe 93A and the second supply pipe 95A are both arranged at a position higher than the first axis J1, and are arranged on opposite sides of the front-to-back direction relative to the first axis J1. According to the present embodiment, by discharging fluid from the first supply pipe 93A and the second supply pipe 95A to the outer side of the stator 25, respectively, the fluid O can be provided to the entire stator 25, and the stator 25 can be evenly cooled.

[0091] In the present embodiment, the connector portion 29c of the rotary transformer 29 is arranged to be biased toward the upper side of the inverter 7 in order to shorten the path of the electric wire 29e. Therefore, the window portion 63w that exposes the connector portion 29c is also arranged to be biased toward the upper side than the first axis J1. In the present embodiment, the bus bar 30, the second flow path 92 and the window portion 63w are respectively concentrated in the first cover portion 63 at a position that is higher than the first axis J1 (on the second direction side). In the present embodiment, the second straight portion 92q of the second flow path 92 is located between the bus bar 30 and the window portion 63w. That is, when viewed from the axial direction, the second flow path 92 is provided between the bus bar 30 and the window portion 63w. Therefore, the bus bar 30, the second flow path 92 and the window portion 63w can be concentrated on the upper side of the first axis J1 (on the second direction side) and arranged at different positions.

[0092] The second flow path 92 of the present embodiment is composed of a linear first straight portion 92p and a second straight portion 92q. According to the present embodiment, the second flow path 92 that bypasses the bus bar 30 can be formed by easy processing, and the manufacturing cost of the drive device 1 can be reduced. Here, the angle formed by the first straight portion 92p and the second straight portion 92q is called the intersection angle α. The intersection angle α is an angle greater than 0° and less than 180°.

[0093] In the present embodiment, the intersection angle α is an obtuse angle. By making the intersection angle α an obtuse angle, the flow path length of the second flow path 92 can be prevented from becoming too long, and the pressure loss of the fluid O in the second flow path 92 can be suppressed. In addition, by making the intersection angle α an obtuse angle, the flow direction of the fluid O in the intersection 92r can be changed smoothly, and the pressure loss of the fluid O in the second flow path 92 can be further suppressed.

[0094] In addition, if Figure 3 As shown as a modified example in , the intersection angle α can also be an acute angle. The second flow path 192 of this modified example has a first straight portion 192p and a second straight portion 192q. The first straight portion 192p and the second straight portion 192q intersect and communicate with each other at the intersection. The intersection angle α of the first straight portion 192p and the second straight portion 192q of this modified example is an acute angle. When the intersection angle α is an acute angle, it is possible to ensure that the area between the first straight portion 192p and the second straight portion 192q is large enough, and it is easy to fully ensure the distance between the bus bar 30 and the second flow path 192. In addition, according to this modified example, it is easy to configure other components in the area between the first straight portion 192p and the second straight portion 192q.

[0095] The embodiments of the present invention and their variations are described above, but the various structures and their combinations in the embodiments and variations are examples, and addition, omission, substitution and other changes of the structures can be made without departing from the scope of the present invention. In addition, the present invention is not limited to the embodiments.

[0096] For example, in the above-mentioned embodiment, the supply part for supplying fluid to the motor or the transmission mechanism is a tubular supply pipe. However, the structure of the supply part is not limited to this embodiment, and the supply part may be, for example, a groove-shaped one.

[0097] In addition, the structure of each shaft of the transmission mechanism in the above embodiment is an example. The shafts constituting the transmission mechanism are not limited to three. In addition, two of the multiple shafts may be coaxially arranged in a manner such that one passes through the hollow portion of the other.

[0098] In addition, the present technology can adopt the following structures.

[0099] (1) A drive device comprising: a motor having a rotor rotating about a motor axis and a stator surrounding the rotor; a housing having a cylindrical peripheral wall portion surrounding the motor from the radially outer side of the motor axis and a cover portion covering an opening on one axial side of the peripheral wall portion; a fluid stored in a storage portion in the housing; a first supply portion disposed in the housing and supplying the fluid to the motor; an inverter supplying electric power to the motor; and a bus bar axially located between the stator and the motor. The inverter is electrically connected to the stator between the stator and the cover, and the housing is provided with: a first flow path extending from the storage portion to the cover; and a second flow path passing through the interior of the cover, the second flow path having: a first end connected to the first flow path; and a second end connected to the first supply portion, when viewed axially, the bus bar is arranged between the first end and the second end, and when viewed axially, the second flow path is arranged at a position different from the bus bar.

[0100] (2) The drive device according to (1), wherein the cover portion has an inner side surface facing the other axial side, and a recessed portion opening toward the other axial side is provided on the inner side surface, and when viewed from the axial direction, the recessed portion overlaps with the bus bar.

[0101] (3) A drive device according to (1) or (2), wherein a direction perpendicular to the motor axis is set as a first direction, the first end is located on one side of the first direction relative to the motor axis, and the second end is located on the other side of the first direction relative to the motor axis.

[0102] (4) The drive device according to (3), wherein the drive device has a second supply portion arranged in the housing, the second supply portion supplies the fluid to the motor, and the second flow path has a connection portion connected to the second supply portion.

[0103] (5) A drive device according to any one of (1) to (4), wherein the second flow path has: a first straight portion extending in a straight line from the first end; and a second straight portion extending in a straight line from the second end, the first straight portion and the second straight portion being connected at an intersection.

[0104] (6) A drive device according to (5), wherein the rotor has a shaft extending along the motor axis, an end portion of the shaft on one axial side is supported by a bearing, the cover portion has a retaining cylinder portion for retaining the bearing, and the first straight portion opens on the inner side surface of the retaining cylinder portion at an end portion on the opposite side of the first end portion.

[0105] (7) The driving device according to (5) or (6), wherein an angle formed by the first straight line portion and the second straight line portion is an obtuse angle.

[0106] (8) The driving device according to (5) or (6), wherein an angle formed by the first straight line portion and the second straight line portion is an acute angle.

[0107] (9) A drive device according to any one of (1) to (8), wherein the drive device also has a rotation detection portion arranged in the shell, and a window portion is provided in the cover portion that penetrates along the axial direction, and the window portion exposes at least a portion of the rotation detection portion, and when viewed from the axial direction, the second flow path is provided between the bus bar and the window portion.

[0108] Description of symbols

[0109] 1: driving device; 2: motor; 6: housing; 7: inverter; 20: rotor; 21: motor shaft (shaft); 25: stator; 29: rotary transformer (rotation detection part); 30: bus bar; 63: first cover part (cover part); 63a: inner side surface; 63b: retaining cylinder part; 63d: recessed part; 63w: window part; 81: bearing; 90: flow path; 91: first flow path; 92, 192: second flow path; 92a: first end part; 92b: second end part; 92c: connecting part; 92p, 192p: first straight part; 92q, 192q: second straight part; 92r: intersection part; 93A: first supply pipe (first supply part); 95A: second supply pipe (second supply part); J1: first axis line (motor axis line); O: fluid; P: storage part.

Claims

1. A driving device, comprising: A motor having a rotor that rotates around a motor axis and a stator that surrounds the rotor; a housing having a cylindrical peripheral wall portion surrounding the motor from the radially outer side of the motor axis and a cover portion covering an opening on one axial side of the peripheral wall portion; a fluid stored in a storage portion within the housing; a first supply unit, which is disposed in the housing and supplies the fluid to the motor; an inverter that provides power to the motor; as well as a bus bar, which is located between the stator and the cover in the axial direction and electrically connects the inverter and the stator, The housing is provided with: a first flow path extending from the storage portion to the cover portion; and a second flow path passing through the interior of the cover portion, The second flow path has: a first end portion connected to the first flow path; and a second end portion connected to the first supply portion, When viewed from the axial direction, the bus bar is arranged between the first end portion and the second end portion, The second flow path is arranged at a position different from the bus bar when viewed in the axial direction.

2. The driving device according to claim 1, wherein: The cover portion has an inner side surface facing the other side in the axial direction. A recessed portion opening toward the other axial side is provided on the inner side surface. The recessed portion overlaps with the bus bar when viewed in the axial direction.

3. The driving device according to claim 1, wherein: A direction perpendicular to the motor axis is defined as a first direction. The first end portion is located on one side of the first direction relative to the motor axis. The second end portion is located on the other side of the motor axis in the first direction.

4. The driving device according to claim 3, wherein: The driving device includes a second supply unit disposed in the housing, and the second supply unit supplies the fluid to the motor. The second flow path has a connection portion connected to the second supply portion.

5. The driving device according to claim 1, wherein: The second flow path has: a first straight portion extending linearly from the first end portion; and a second straight portion extending straightly from the second end portion, The first straight line portion and the second straight line portion are connected at an intersection.

6. The driving device according to claim 5, wherein: The rotor has a shaft extending along the motor axis, The end portion of the shaft on one axial side is supported by a bearing. The cover portion has a retaining cylinder portion for retaining the bearing. The first straight portion opens to the inner side surface of the holding tube portion at an end portion opposite to the first end portion.

7. The driving device according to claim 5, wherein: An angle formed by the first straight line portion and the second straight line portion is an obtuse angle.

8. The driving device according to claim 5, wherein: An angle formed by the first straight line portion and the second straight line portion is an acute angle.

9. The driving device according to claim 1, wherein: The driving device also has a rotation detection unit disposed in the housing. The cover portion is provided with a window portion penetrating in the axial direction, and the window portion exposes at least a portion of the rotation detection portion. The second flow path is provided between the bus bar and the window portion when viewed in the axial direction.

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