Drive device

Abstract

The drive device comprises: a motor having a motor shaft that rotates around a motor axis extending in a horizontal direction; a gear portion that is connected to the motor shaft on one axial side of the motor axis; a housing having a motor housing and a gear housing, the gear portion having a reduction gear and a differential device, the reduction gear having a first gear that rotates around the motor axis and a second gear, a third gear and an intermediate shaft that rotate around an intermediate axis, the torque output from the motor is transmitted to the ring gear of the differential device that rotates around the differential axis via the motor shaft, the first gear, the second gear, the intermediate shaft and the third gear of the motor, the motor axis, the intermediate axis and the differential axis extend parallel to each other, an inverter unit that supplies power to the motor is located on the outer peripheral surface of the motor housing facing radially outward of the housing, and at least a portion of the inverter unit overlaps with the ring gear when viewed from the axial direction.

Description

[0001] This application is a divisional application of the invention patent application with application number 201880084227.5 (international application number PCT / JP2018 / 047081), application date December 20, 2018, and invention name “Motor Unit”. Technical Field

[0002] The present invention relates to a drive device. Background Art

[0003] Japanese Patent Application Publication No. 2016-73163 discloses a structure in which a refrigerant is cooled by a cooling device (cooler) provided outside a motor (rotating electric machine), and a pump provided outside the motor is used to supply the refrigerant to the motor.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Publication: Japanese Patent Application Publication No. 2016-73163 Summary of the invention

[0007] Problems to be solved by the invention

[0008] In recent years, development of motor units for vehicles in which a transmission device etc. is mounted on a motor has been progressing. Such motor units have a complex outer shape, and therefore have a problem of easily generating a dead zone when mounted on a vehicle.

[0009] One aspect of the present invention has been made in view of the above-mentioned problems, and one object of the present invention is to provide a driving device that can achieve overall miniaturization.

[0010] Means for solving problems

[0011] One embodiment of the drive device of the present invention comprises: a motor having a motor shaft that rotates around a motor axis extending in a horizontal direction; a gear portion that is connected to the motor shaft on one axial side of the motor axis; and a housing having a motor housing portion and a gear housing portion, the motor housing portion having a motor chamber that accommodates the motor inside, the gear housing portion having a gear chamber that accommodates the gear portion inside, the gear portion having a reduction gear and a differential device, the reduction gear having a first gear that rotates around the motor axis and a gear that rotates around an intermediate axis. The second gear, the third gear and the intermediate shaft rotate, and the torque output from the motor is transmitted to the ring gear of the differential device rotating around the differential axis via the motor shaft of the motor, the first gear, the second gear, the intermediate shaft and the third gear. The motor axis, the intermediate axis and the differential axis extend parallel to each other. The inverter unit that provides power to the motor is located on the outer peripheral surface of the motor housing portion of the housing facing radially outward, and at least a portion of the inverter unit overlaps with the ring gear when viewed from the axial direction.

[0012] Effects of the Invention

[0013] According to one aspect of the present invention, there is provided a driving device capable of achieving overall miniaturization. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0015] Figure 2 It is a perspective view of a motor unit according to one embodiment.

[0016] Figure 3 is a schematic side view of a motor unit according to an embodiment.

[0017] Figure 4 is an exploded view of a housing of one embodiment.

[0018] Figure 5 is a side view of a motor unit according to one embodiment.

[0019] Figure 6 This is a bottom view of the motor unit according to one embodiment as seen from below. DETAILED DESCRIPTION

[0020] Hereinafter, a motor unit according to an embodiment of the present invention will be described with reference to the drawings. Note that the scope of the present invention is not limited to the following embodiment, and can be arbitrarily modified within the scope of the technical concept of the present invention.

[0021] In the following description, the gravity direction is defined and described according to the positional relationship of the motor unit mounted on a vehicle located on a horizontal road surface. In addition, in the accompanying drawings, an XYZ coordinate system is appropriately shown as a three-dimensional rectangular coordinate system. In the XYZ coordinate system, the Z-axis direction shows the vertical direction (i.e., the up and down direction), the +Z direction is the upper side (the opposite side of the gravity direction), and the -Z direction is the lower side (gravity direction). In addition, the X-axis direction is a direction perpendicular to the Z-axis direction, showing the front and rear direction of the vehicle equipped with the motor unit 1, the +X direction is the front of the vehicle, and the -X direction is the rear of the vehicle. However, it is also possible that the +X direction is the rear of the vehicle and the -X direction is the front of the vehicle. The Y-axis direction is a direction perpendicular to both the X-axis direction and the Z-axis direction, showing the width direction of the vehicle (left and right direction), the +Y direction is the left side of the vehicle, and the -Y direction is the right side of the vehicle. However, in the case where the +X direction is the rear of the vehicle, it is also possible that the +Y direction is the right side of the vehicle and the -Y direction is the left side of the vehicle. That is, regardless of the direction of the X-axis, the +Y direction is one side of the left-right direction of the vehicle, and the -Y direction is the other side of the left-right direction of the vehicle.

[0022] In the following description, unless otherwise specified, the direction parallel to the motor axis J2 of the motor 2 (Y-axis direction) is referred to as the "axial direction", the radial direction centered on the motor axis J2 is referred to as the "radial direction", and the circumferential direction centered on the motor axis J2 (i.e., the direction around the motor axis J2) is referred to as the "circumferential direction". However, the above-mentioned "parallel direction" also includes a substantially parallel direction.

[0023] Hereinafter, a motor unit (electric drive device) 1 according to an exemplary embodiment of the present invention will be described with reference to the drawings.

[0024] Figure 1 This is a conceptual diagram of a motor unit 1 according to one embodiment. Figure 2 is a perspective view of the motor unit 1. In addition, Figure 1 This is just a concept image. The configuration and size of each part may not be the same as the actual one.

[0025] The motor unit 1 is mounted on a vehicle using a motor as a power source, such as a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHV), or an electric vehicle (EV), and is used as the power source of the vehicle.

[0026] like Figure 1 As shown, the motor unit 1 includes a motor (main motor) 2 , a gear portion 3 , a housing 6 , oil O accommodated in the housing 6 , an inverter unit 8 , and a parking mechanism 7 .

[0027] like Figure 1As shown, the motor 2 has a rotor 20 that rotates around a motor axis J2 extending in the horizontal direction, and a stator 30 that is located radially outside the rotor 20. A storage space 80 for storing the motor 2 and the gear unit 3 is provided inside the housing 6. The storage space 80 is divided into a motor chamber 81 for storing the motor 2 and a gear chamber 82 for storing the gear unit 3.

[0028] <Motor>

[0029] The motor 2 is accommodated in the motor chamber 81 of the housing 6. The motor 2 includes a rotor 20 and a stator 30 located radially outside the rotor 20. The motor 2 is an inner rotor type motor including the stator 30 and the rotor 20 rotatably disposed inside the stator 30.

[0030] The rotor 20 is rotated by supplying power to the stator 30 from a battery (not shown). The rotor 20 has a shaft (motor shaft) 21, a rotor core 24, and a rotor magnet (not shown). The rotor 20 (i.e., the shaft 21, the rotor core 24, and the rotor magnet) rotates around the motor axis J2 extending in the horizontal direction. The torque of the rotor 20 is transmitted to the gear unit 3.

[0031] The shaft 21 extends around the motor axis J2 extending horizontally in the width direction of the vehicle. The shaft 21 rotates around the motor axis J2. The shaft 21 is a hollow shaft provided with a hollow portion 22 having an inner peripheral surface extending along the motor axis J2.

[0032] The shaft 21 extends across the motor chamber 81 and the gear chamber 82 of the housing 6. One end of the shaft 21 protrudes toward the gear chamber 82. The first gear 41 is fixed to the end of the shaft 21 protruding toward the gear chamber 82.

[0033] The rotor core 24 is formed by laminating silicon steel sheets. The rotor core 24 is a cylindrical body extending in the axial direction. A plurality of rotor magnets (not shown) are fixed to the rotor core 24. The plurality of rotor magnets are arranged in the circumferential direction so that the magnetic poles are alternated.

[0034] The stator 30 surrounds the rotor 20 from the radial outside. The stator 30 has a stator core 32, a coil 31, and an insulator (not shown) between the stator core 32 and the coil 31. The stator 30 is held by the housing 6. The stator core 32 has a plurality of magnetic pole teeth (not shown) extending radially inward from the inner circumference of the annular yoke. The coil wire is wound between the magnetic pole teeth. The coil wire wound around the magnetic pole teeth constitutes the coil 31. The coil wire is connected to the inverter unit 8 via a bus bar (not shown). The coil 31 has a coil end 31a protruding from the axial end face of the stator core 32. The coil end 31a protrudes axially from the end of the rotor core 24 of the rotor 20. The coil end 31a protrudes axially on both sides relative to the rotor core 24.

[0035] <Gear Department>

[0036] The gear unit 3 is accommodated in the gear chamber 82 of the housing 6. The gear unit 3 is connected to the shaft 21 on one axial side of the motor axis J2. The gear unit 3 includes a reduction gear 4 and a differential device 5. The torque output from the motor 2 is transmitted to the differential device 5 via the reduction gear 4.

[0037] <Reduction gear>

[0038] The reduction gear 4 is connected to the rotor 20 of the motor 2. The reduction gear 4 reduces the rotation speed of the motor 2 and has a function of increasing the torque output from the motor 2 according to the reduction ratio. The reduction gear 4 transmits the torque output from the motor 2 to the differential device 5.

[0039] The reduction gear 4 includes a first gear (intermediate drive gear) 41, a second gear (intermediate gear) 42, a third gear (final drive gear) 43, and an intermediate shaft 45. The torque output from the motor 2 is transmitted to the ring gear 51 (gear) of the differential device 5 via the motor 2 shaft 21, the first gear 41, the second gear 42, the intermediate shaft 45, and the third gear 43. The gear ratio of each gear and the number of gears can be variously changed according to the necessary reduction ratio. The reduction gear 4 is a parallel axis gear type reducer in which the axis cores of each gear are arranged in parallel.

[0040] The first gear 41 is provided on the outer peripheral surface of the shaft 21 of the motor 2. The first gear 41 rotates together with the shaft 21 about the motor axis J2. The intermediate shaft 45 extends along the intermediate axis J4 parallel to the motor axis J2. The intermediate shaft 45 rotates about the intermediate axis J4. The second gear 42 and the third gear 43 are provided on the outer peripheral surface of the intermediate shaft 45. The second gear 42 and the third gear 43 are connected via the intermediate shaft 45. The second gear 42 and the third gear 43 rotate about the intermediate axis J4. The second gear 42 meshes with the first gear 41. The third gear 43 meshes with the ring gear 51 of the differential device 5. The third gear 43 is located on the side of the partition wall 61c relative to the second gear 42.

[0041] <Differential gear>

[0042] The differential device 5 is connected to the motor 2 via the speed reduction device 4. The differential device 5 is a device for transmitting the torque output from the motor 2 to the wheels of the vehicle. The differential device 5 has a function of absorbing the speed difference between the left and right wheels when the vehicle turns and transmitting the same torque to the axles 55 of the left and right wheels. The differential device 5 has a ring gear 51, a gear housing (not shown), a pair of pinion gears (not shown), a pinion shaft (not shown), and a pair of side gears (not shown).

[0043] The ring gear 51 rotates around a differential axis J5 parallel to the motor axis J2. The torque output from the motor 2 is transmitted to the ring gear 51 via the reduction gear 4. That is, the ring gear 51 is connected to the motor 2 via other gears.

[0044] (Configuration of each axis)

[0045] Figure 3 is a schematic side view of the motor unit 1.

[0046] The motor axis J2 , the intermediate axis J4 , and the differential axis J5 extend in parallel with each other in the horizontal direction. The intermediate axis J4 and the differential axis J5 are located below the motor axis J2 . Therefore, the reduction gear 4 and the differential gear 5 are located below the motor 2 .

[0047] When observing from the axial direction of the motor axis J2, the line segment that imaginarily connects the motor axis J2 and the intermediate axis J4 is set as the first line segment L1, the line segment that imaginarily connects the intermediate axis J4 and the differential axis J5 is set as the second line segment L2, and the line segment that imaginarily connects the motor axis J2 and the differential axis J5 is set as the third line segment L3.

[0048] The second line segment L2 extends substantially in the horizontal direction. That is, the intermediate axis J4 and the differential axis J5 are substantially aligned in the horizontal direction. In addition, in the present embodiment, the substantially horizontal direction in which the second line segment L2 extends refers to a direction within ±10° relative to the horizontal direction.

[0049] An angle α formed by the second line segment L2 and the third line segment L3 is 30°±5°.

[0050] The first line segment L1 extends substantially in the vertical direction. That is, the motor axis J2 and the intermediate axis J4 are arranged substantially in the vertical direction. In the present embodiment, the substantially vertical direction in which the first line segment L1 extends refers to a direction within ±10° relative to the vertical direction.

[0051] The length L1 of the first line segment, the length L2 of the second line segment, and the length L3 of the third line segment satisfy the following relationship.

[0052] L1:L2:L3=1:1.4~1.7:1.8~2.0

[0053] In addition, the reduction ratio of the reduction mechanism from the motor 2 to the differential device 5 is greater than 8 and less than 11. According to this embodiment, the positional relationship between the motor axis J2, the intermediate axis J4 and the differential axis J5 as described above can be maintained, and the desired gear ratio (greater than 8 and less than 11) can be achieved.

[0054] <Casing>

[0055] like Figure 1As shown, the motor 2 and the gear unit 3 are stored in the storage space 80 provided inside the housing 6. The housing 6 holds the motor 2 and the gear unit 3 in the storage space 80. The housing 6 has a partition wall 61c. The storage space 80 of the housing 6 is divided into a motor chamber 81 and a gear chamber 82 by the partition wall 61c. The motor 2 is stored in the motor chamber 81. The gear unit 3 (that is, the reduction gear 4 and the differential gear 5) is stored in the gear chamber 82.

[0056] An oil reservoir P for storing oil O is provided in the lower region of the storage space 80. In the present embodiment, the bottom 81a of the motor chamber 81 is located above the bottom 82a of the gear chamber 82. In addition, a partition wall opening 68 is provided in the partition wall 61c that divides the motor chamber 81 and the gear chamber 82. The partition wall opening 68 allows the motor chamber 81 to communicate with the gear chamber 82. The partition wall opening 68 allows the oil O stored in the lower region of the motor chamber 81 to move to the gear chamber 82.

[0057] A portion of the differential device 5 is immersed in the oil reservoir P. The oil O accumulated in the oil reservoir P is lifted by the action of the differential device 5, a portion of which is provided to the first oil passage 91, and a portion of which is diffused in the gear chamber 82. The oil O diffused in the gear chamber 82 is provided to each gear of the reduction device 4 and the differential device 5 in the gear chamber 82, so that the oil O spreads over the tooth surfaces of the gears. The oil O used for the reduction device 4 and the differential device 5 is dripped and recovered by the oil reservoir P located at the lower side of the gear chamber 82. The capacity of the oil reservoir P of the storage space 80 is such that a portion of the bearing of the differential device 5 is immersed in the oil O when the motor unit 1 stops.

[0058] like Figure 2 As shown, the housing 6 includes a first housing member 61, a second housing member 62, and a closing portion 63. The second housing member 62 is located on one axial side of the first housing member 61. The closing portion 63 is located on the other axial side of the first housing member 61. The housing may be composed of three or more members.

[0059] Figure 4 It is an exploded view of the housing 6.

[0060] The first housing member 61 includes: a cylindrical peripheral wall portion 61a that surrounds the motor 2 from the radially outer side; and a side plate portion 61b that is located on one axial side of the peripheral wall portion 61a. The space inside the peripheral wall portion 61a constitutes the motor chamber 81. The side plate portion 61b includes a partition wall 61c and a protruding plate portion 61d. The partition wall 61c covers the opening on one axial side of the peripheral wall portion 61a. In addition to the partition wall opening 68 described above, the partition wall 61c is also provided with a through-hole 61f through which the shaft 21 of the motor 2 is inserted. The side plate portion 61b includes a partition wall 61c and a protruding plate portion 61d that protrudes radially outward relative to the peripheral wall portion 61a. The protruding plate portion 61d is provided with a first axle through hole 61e through which a drive shaft (not shown) that supports a wheel passes.

[0061] The closing portion 63 is fixed to the peripheral wall portion 61a of the first housing member 61. The closing portion 63 closes the opening of the cylindrical first housing member 61. The closing portion 63 includes a closing portion body 63a and a cover member 63b. The closing portion body 63a is provided with a window portion 63c penetrating in the axial direction. The cover member 63b closes the window portion 63c from the outside of the storage space 80.

[0062] The second housing member 62 is fixed to the side plate portion 61b of the first housing member 61. The second housing member 62 is in a concave shape that opens toward the side plate portion 61b. The opening of the second housing member 62 is covered by the side plate portion 61b. The space between the second housing member 62 and the side plate portion 61b constitutes a gear chamber 82 that accommodates the gear portion 3. The second housing member 62 is provided with a second axle through hole 62e. The second axle through hole 62e overlaps with the first axle through hole 61e when viewed from the axial direction.

[0063] The peripheral wall portion 61a and the sealing portion 63 of the first housing member 61 constitute a motor chamber 81, which surrounds the motor 2 and accommodates the motor 2. That is, the peripheral wall portion 61a and the sealing portion 63 constitute Figure 1 The motor housing portion 6a is shown.

[0064] Similarly, the side plate portion 61b of the first housing member 61 and the second housing member 62 constitute a gear chamber 82 that surrounds the gear portion 3 and accommodates the gear portion 3. That is, the side plate portion 61b and the second housing member 62 constitute Figure 1 The gear housing portion 6b is shown.

[0065] Thus, the housing 6 includes the motor housing portion 6 a having the motor chamber 81 for housing the motor 2 therein, and the gear housing portion 6 b having the gear chamber 82 for housing the gear portion 3 therein.

[0066] Figure 5 is a side view of the motor unit 1. In addition, Figure 6 This is a bottom view of the motor unit 1 as viewed from the bottom. Figure 5 and Figure 6 In the figure, the inverter unit 8 is omitted.

[0067] like Figure 5 and Figure 6 As shown, the gear housing portion 6b has an extension portion 6d that extends radially relative to the motor housing portion 6a when viewed from the axial direction. In the present embodiment, the extension portion 6d extends toward the rear side and the lower side of the vehicle relative to the motor housing portion 6a. The extension portion 6d accommodates a portion of the gear portion 3. More specifically, a portion of the second gear 42 and a portion of the ring gear 51 are accommodated inside the extension portion 6d.

[0068] <Oil>

[0069] like Figure 1 As shown, the oil O circulates in an oil passage 90 provided in the housing 6 . The oil passage 90 is a path for supplying the oil O from the oil reservoir P to the motor 2 . The oil passage 90 circulates the oil O to cool the motor 2 .

[0070] The oil O is used for lubrication of the reduction gear 4 and the differential gear 5. In addition, the oil O is used for cooling the motor 2. The oil O is stored in the lower area (i.e., the oil storage portion P) in the gear chamber 82. As the oil O, it is preferable to use an oil equivalent to an automatic transmission lubricating oil (ATF: Automatic Transmission Fluid) having a relatively low viscosity so as to realize the functions of lubricating oil and cooling oil.

[0071] <Oil circuit>

[0072] like Figure 1 As shown, the oil passage 90 is provided in the housing 6. The oil passage 90 is located in the housing space 80 in the housing 6. The oil passage 90 is configured to span the motor chamber 81 and the gear chamber 82 of the housing space 80. The oil passage 90 is a path for the oil O to flow from the oil reservoir P on the lower side of the motor 2 (i.e., the lower area in the housing space 80) through the motor 2 and then be directed to the oil O in the oil reservoir P on the lower side of the motor 2 again.

[0073] In addition, in this specification, the "oil path" refers to the path of the oil O that circulates in the storage space 80. Therefore, the "oil path" is a concept that not only forms a "flow path" that allows the oil to always flow stably in one direction, but also includes a path where the oil temporarily stays (such as a storage tank) and a path where the oil drips.

[0074] The oil passage 90 includes a first oil passage 91 passing through the inside of the motor 2 and a second oil passage 92 (oil passage) passing through the outside of the motor 2. The oil O in the first oil passage 91 and the second oil passage 92 cools the motor 2 from the inside and the outside.

[0075] The first oil passage 91 and the second oil passage 92 are both paths for supplying the oil O from the oil reservoir P to the motor 2 and recovering the oil in the oil reservoir P again. In the first oil passage 91 and the second oil passage 92, the oil O drips from the motor 2 and is accumulated in the lower area of ​​the motor chamber 81. The oil O accumulated in the lower area of ​​the motor chamber 81 moves to the lower area (i.e., the oil reservoir P) in the gear chamber 82 via the partition wall opening 68. That is, the first oil passage 91 and the second oil passage 92 include paths for moving the oil O from the lower area in the motor chamber 81 to the lower area in the gear chamber 82.

[0076] (1st oil circuit)

[0077] like Figure 1 As shown, in the first oil passage 91, the oil O is lifted from the oil reservoir P by the differential device 5 and guided to the inside of the rotor 20. Inside the rotor 20, the centrifugal force due to the rotation of the rotor 20 is applied to the oil O. As a result, the oil O is evenly diffused toward the stator 30 surrounding the rotor 20 from the radial outside, thereby cooling the stator 30.

[0078] The first oil passage 91 includes a lifting path 91a, a shaft supply path 91b, an inner shaft path 91c, and an inner rotor path 91d. In addition, a first reservoir tank 93 is provided in the first oil passage 91. The first reservoir tank 93 is provided in the gear chamber 82.

[0079] The lifting path 91a is a path for lifting the oil O from the oil reservoir P by utilizing the rotation of the ring gear 51 of the differential device 5, and receiving the oil O by utilizing the first storage tank 93. Figure 3 As shown, the first storage tank 93 is arranged between the intermediate axis J4 and the differential axis J5. The first storage tank 93 is opened upward. The first storage tank 93 receives the oil O lifted by the ring gear 51. In addition, when the liquid level of the oil reservoir P is high, such as just after the motor 2 is driven, the first storage tank 93 receives the oil O lifted by the second gear 42 and the third gear 43 in addition to the oil lifted by the ring gear 51.

[0080] The shaft supply path 91b guides the oil O from the first storage tank 93 to the motor 2. The shaft supply path 91b is formed by a hole portion 94 provided in the second housing member 62. The shaft inner path 91c is a path for the oil O to pass through the hollow portion 22 of the shaft 21. The rotor inner path 91d is a path for the oil O to pass from the communication hole 23 of the shaft 21 through the inside of the rotor core 24 and splash toward the stator 30.

[0081] In the shaft path 91c, centrifugal force due to the rotation of the rotor 20 is applied to the oil O inside the rotor 20. As a result, the oil O continuously splashes radially outward from the rotor 20. In addition, as the oil O splashes, the path inside the rotor 20 becomes negative pressure, and the oil O accumulated in the first storage tank 93 is sucked into the inside of the rotor 20, so that the oil O fills the path inside the rotor 20.

[0082] The oil O reaching the stator 30 removes heat from the stator 30. The oil O cooling the stator 30 drips downward and accumulates in the lower region of the motor chamber 81. The oil O accumulated in the lower region of the motor chamber 81 moves to the gear chamber 82 via the partition opening 68 provided in the partition 61c.

[0083] (Oil circuit No. 2)

[0084] like Figure 1 As shown, in the second oil passage 92, the oil O is lifted from the oil reservoir P to the upper side of the motor 2 and supplied to the motor 2. The oil O supplied to the motor 2 is transferred to the outer peripheral surface of the stator 30, and heat is taken away from the stator 30 to cool the motor 2. The oil O transferred to the outer peripheral surface of the stator 30 drips downward and is stored in the lower area of ​​the motor chamber 81. The oil O of the second oil passage 92 merges with the oil O of the first oil passage 91 in the lower area of ​​the motor chamber 81. The oil O stored in the lower area of ​​the motor chamber 81 moves to the lower area (i.e., the oil reservoir P) in the gear chamber 82 via the partition wall opening 68.

[0085] The second oil passage 92 includes a first flow passage 92a, a second flow passage 92b, and a third flow passage 92c. A pump 96, a cooler 97, and a second storage tank 98 are provided in the path of the second oil passage 92. The pump 96 supplies the oil O to the motor 2. In addition, the cooler 97 cools the oil O passing through the second oil passage 92. In the second oil passage 92, the oil O passes through each part in the order of the first flow passage 92a, the pump 96, the second flow passage 92b, the cooler 97, the third flow passage 92c, and the second storage tank 98, and is supplied to the motor 2.

[0086] The first flow path 92a, the second flow path 92b, and the third flow path 92c pass through the wall portion of the housing 6 surrounding the storage space 80. The first flow path 92a connects the oil reservoir P and the pump 96. The second flow path 92b connects the pump 96 and the cooler 97. The third flow path 92c connects the cooler 97 and the storage space 80.

[0087] In the present embodiment, the first flow path 92a, the second flow path 92b, and the third flow path 92c pass through the interior of the wall portion of the housing 6 surrounding the storage space 80. Therefore, it is not necessary to prepare a pipe separately, which can contribute to a reduction in the number of components.

[0088] The pump 96 is an electrically driven electric pump and sucks up oil O from the oil reservoir P via the first flow path 92 a and supplies the oil to the motor 2 via the second flow path 92 b , the cooler 97 , the third flow path 92 c , and the second reservoir tank 98 .

[0089] like Figure 6 As shown, the pump 96 has a pump mechanism 96p, a pump motor 96m, a suction port 96a and a discharge port 96b. In the present embodiment, the pump mechanism 96p is a trochoidal pump that rotates by meshing an external gear and an internal gear (not shown). The pump motor 96m rotates the internal gear of the pump mechanism 96p. The gap between the internal gear and the external gear of the pump mechanism 96p is connected to the suction port 96a and the discharge port 96b.

[0090] The suction port 96a of the pump 96 is connected to the first flow path 92a. In addition, the discharge port 96b of the pump 96 is connected to the second flow path 92b. The pump 96 sucks up the oil O from the oil reservoir P via the first flow path 92a, and supplies the oil to the motor 2 via the second flow path 92b, the cooler 97, the third flow path 92c, and the second storage tank 98.

[0091] The pump motor 96m rotates the internal gear of the pump mechanism portion 96p. The rotation axis J6 of the pump motor 96m is parallel to the motor axis J2. The pump 96 having the pump motor 96m is likely to be in a shape that is long in the direction of the rotation axis J6. According to the present embodiment, by making the rotation axis J6 of the pump motor 96m parallel to the motor axis J2, the radial dimension of the motor unit 1 can be miniaturized. In addition, by miniaturizing the radial dimension of the motor unit 1, it is easy to overlap the pump 96 with the extension portion 6d of the housing 6 when viewed from the axial direction. As a result, the axial projection area of ​​the motor unit 1 is suppressed from becoming larger, and a structure that easily miniaturizes the motor unit 1 can be achieved.

[0092] The pump 96 is located on the lower side of the motor chamber 81. In addition, the pump 96 is fixed to the surface of the extension portion 6d facing the motor housing portion 6a. The suction port 96a of the pump 96 is arranged opposite to the extension portion 6d. The first flow path 92a connected to the suction port 96a of the pump 96 passes through the wall surface of the extension portion 6d in a straight line along the axial direction and opens to the lower area in the gear chamber 82. That is, the first flow path 92a is provided in the extension portion 6d, and the first flow path 92a extends in the axial direction and is connected to the pump 96 from the lower area in the gear chamber 82 (that is, the oil storage portion P).

[0093] According to the present embodiment, the pump 96 is arranged at the lower side of the motor chamber 81, so it is easy to arrange the suction port 96a near the oil reservoir P. As a result, the first flow path 92a connecting the oil reservoir P and the suction port 96a can be shortened. In addition, the distance between the oil reservoir P and the suction port 96a is relatively close, so the first flow path 92a can be a straight flow path. By making the first flow path 92a a straight and short flow path, the pressure loss of the path from the oil reservoir P to the pump 96 can be reduced, and efficient circulation of the oil O can be achieved.

[0094] like Figure 1 As shown, the first flow path 92a and the second flow path 92b are connected to the cooler 97. The first flow path 92a and the second flow path 92b are connected via the internal flow path of the cooler 97. The cooler 97 is connected to a cooling water pipe 97j through which cooling water cooled by a radiator (not shown) passes. The oil O passing through the cooler 97 is cooled by heat exchange with the cooling water passing through the cooling water pipe 97j. In addition, the inverter unit 8 is provided in the path of the cooling water pipe 97j. The inverter unit 8 is cooled by the cooling water passing through the cooling water pipe 97j.

[0095] like Figure 5 As shown, the cooler 97 is fixed to the outer peripheral surface of the motor housing portion 6a facing radially outward at the lower side of the motor chamber 81. Figure 1 As shown, the oil O supplied to the motor 2 is temporarily accumulated in the lower area of ​​the motor chamber 81, and then moves to the lower area of ​​the gear chamber 82 through the partition wall opening 68. According to the present embodiment, the cooler 97 is fixed to the outer peripheral surface of the motor housing portion 6a at the lower side of the motor chamber 81, so that the oil O in the lower area of ​​the motor chamber 81 can be cooled from the installation surface of the cooler 97 through the wall area of ​​the motor housing portion 6a.

[0096] like Figure 5 As shown, the cooler 97 and the pump 96 at least partially overlap with the extension 6d of the gear housing portion 6b when viewed from the axial direction. The gear unit 3 is housed inside the extension 6d. The axial projection area of ​​the extension 6d is determined according to the size of each gear of the gear unit 3. The size of each gear constituting the gear unit 3 is set to satisfy the desired gear ratio. Therefore, it is difficult to reduce the axial projection area of ​​the extension 6d. According to this embodiment, in the axial direction, by arranging the cooler 97 and the pump 96 to overlap with the extension 6d, it is possible to prevent the cooler 97 and the pump 96 from increasing the axial projection area of ​​the motor unit 1. Thus, the axial projection area of ​​the motor unit 1 is prevented from increasing, and the motor unit 1 can be miniaturized.

[0097] According to the present embodiment, when viewed from the axial direction, at least a portion of the cooler 97 and the pump 96 overlaps with the second gear 42 of the gear unit 3. Therefore, even when the projection area viewed from the axial direction of the extension portion 6d is made as small as possible along the outer shape of each gear of the gear unit 3, it is possible to realize a structure in which the cooler 97 and the pump 96 overlap with the extension portion 6d when viewed from the axial direction. As a result, the axial projection area of ​​the motor unit 1 is suppressed from increasing, and the motor unit 1 can be miniaturized.

[0098] According to the present embodiment, the cooler 97 and the pump 96 are located above the lower end of the extension portion 6d. That is, the cooler 97 and the pump 96 do not extend further downward from the lower end of the extension portion 6d. Therefore, the motor unit 1 can be made smaller in the vertical direction.

[0099] The cooler 97 and the pump 96 are located on the lower side of the motor chamber 81 in the vertical direction. The motor unit 1 is arranged, for example, in the hood of the vehicle. In addition, in the motor unit 1, the cooler 97 and the pump 96 are protrusions protruding from the housing 6. According to the present embodiment, by arranging the cooler 97 and the pump 96 on the lower side of the motor chamber 81 in the vertical direction, even if the vehicle collides with an object due to an accident or the like, the cooler 97 and the pump 96, which are protrusions, can be prevented from piercing the object.

[0100] According to the present embodiment, the pump 96 and the cooler 97 are fixed to the outer peripheral surface of the housing 6. Therefore, compared with the case where the pump 96 and the cooler 97 are fixed to the structure outside the housing 6, it is possible to contribute to the miniaturization of the motor unit 1. In addition, by fixing the pump 96 and the cooler 97 to the outer peripheral surface of the housing 6, the first flow path 92a, the second flow path 92b, and the third flow path 92c passing through the wall portion of the housing 6 can be used to form a flow path connecting the storage space 80 with the pump 96 and the cooler 97.

[0101] like Figure 6 As shown, according to the present embodiment, the axial position of the pump 96 and the position of the cooler 97 overlap each other. The cooler 97 is connected to the pump 96 via the second flow path 92b. That is, the second flow path 92b that connects the pump 96 and the cooler 97 is provided in the second oil circuit 92. According to the present embodiment, by making the axial positions of the pump 96 and the cooler 97 overlap each other, it is possible to achieve a structure in which the second flow path 92b extends straight in a direction perpendicular to the axial direction. That is, the second flow path 92b can be made a straight and short flow path, reducing the pressure loss of the path from the pump 96 to the cooler 97, and realizing efficient oil O pair circulation.

[0102] like Figure 1As shown, the second storage tank 98 is located in the motor chamber 81 of the storage space 80. The second storage tank 98 is located on the upper side of the motor. The second storage tank 98 stores the oil O provided to the motor chamber 81 via the third flow path 92c. The second storage tank 98 has a plurality of flow outlets 98a. The oil O accumulated in the second storage tank 98 is provided to the motor 2 from each flow outlet 98a. The oil O flowing out of the flow outlet 98a of the second storage tank 98 flows along the outer peripheral surface of the motor 2 from the upper side to the lower side, taking away the heat of the motor 2. In this way, the motor 2 can be cooled as a whole.

[0103] The second storage box 98 extends in the axial direction. In addition, the outflow port 98a of the second storage box 98 is provided at both ends of the second storage box 98 in the axial direction. The outflow port 98a is located above the coil end 31a. Thus, the oil O can be poured onto the coil ends 31a located at both ends of the stator 30 in the axial direction, and the coil 31 can be directly cooled.

[0104] After cooling the coil 31, the oil O drips downward and accumulates in the lower region of the motor chamber 81. The oil O accumulated in the lower region of the motor chamber 81 moves to the gear chamber 82 through the partition opening 68 provided in the partition 61c.

[0105] According to the present embodiment, a cooler 97 for cooling the oil O is provided in the path of the second oil path 92. The oil O cooled by the cooler 97 after passing through the second oil path 92 merges with the oil O after passing through the first oil path 91 in the oil reservoir P. In the oil reservoir P, the oil O passing through the first oil path 91 and the oil O passing through the second oil path 92 are mixed with each other to perform heat exchange. Therefore, the cooling effect of the cooler 97 disposed in the path of the second oil path 92 can also be extended to the oil O passing through the first oil path 91.

[0106] <Inverter unit>

[0107] The inverter unit 8 is electrically connected to the motor 2. The inverter unit 8 controls the current supplied to the motor 2. Figure 5 As shown, the inverter unit 8 is fixed to the housing 6. More specifically, the inverter unit 8 is fixed to the outer peripheral surface of the motor housing portion 6a that faces the radial direction outward.

[0108] When viewed from the axial direction, at least a portion of the inverter unit 8 overlaps with the extension portion 6d of the gear housing portion 6b. According to the present embodiment, when viewed from the axial direction, by arranging the inverter unit 8 to overlap with the extension portion 6d, it is possible to prevent the inverter unit 8 from increasing the axial projection area of ​​the motor unit 1. Thus, the axial projection area of ​​the motor unit 1 is prevented from increasing, and the motor unit 1 can be miniaturized.

[0109] According to the present embodiment, at least a portion of the inverter unit 8 overlaps with the ring gear 51 of the gear unit 3 when viewed from the axial direction. Therefore, even when the projection area of ​​the extension portion 6d viewed from the axial direction is made as small as possible along the outer shape of each gear of the gear unit 3, a structure in which the inverter unit 8 overlaps with the extension portion 6d when viewed from the axial direction can be achieved. As a result, the axial projection area of ​​the motor unit 1 is suppressed from increasing, and the motor unit 1 can be miniaturized.

[0110] According to the present embodiment, the inverter unit 8 is located on the opposite side of the cooler 97 across the motor axis J2 when viewed from the vertical direction. Therefore, when viewed from the axial direction, the area overlapping with the extension portion 6d is effectively utilized, the horizontal dimension of the motor unit 1 can be reduced, and the motor unit 1 can be miniaturized.

[0111] like Figure 1 As shown, a cooling water pipe 97j extending from a radiator (not shown) is connected to the inverter unit 8. Thus, the inverter unit 8 can be efficiently cooled. In addition, the cooling water flowing in the cooling water pipe 97j cools the motor housing portion 6a in contact with the housing portion via the housing portion of the inverter unit 8.

[0112] <Parking mechanism>

[0113] In an electric vehicle, the vehicle does not have a brake mechanism for applying brakes other than the side brakes, and therefore the parking mechanism 7 is required in the motor unit 1 .

[0114] like Figure 1 As shown, the parking mechanism 7 includes: a parking gear 71 fixed to the intermediate shaft 45 and rotating around the intermediate axis J4 together with the intermediate shaft 45; a rotation preventing portion 72 moving between the teeth of the parking gear 71 to prevent the rotation of the parking gear 71; and a parking motor 73 driving the rotation preventing portion 72. When the motor 2 is in operation, the rotation preventing portion 72 retreats from the parking gear 71. On the other hand, when the shift lever is in the parking position, the parking motor 73 moves the rotation preventing portion 72 between the teeth of the parking gear 71 to prevent the rotation of the parking gear 71.

[0115] The embodiments and modifications of the present invention have been described above, but the various structures and combinations of the embodiments are examples, and addition, omission, substitution and other changes of structures can be made within the scope of the present invention.

[0116] Description of symbols

[0117] 1: Motor unit; 2: Motor; 3: Gear part; 6: Housing; 6a: Motor housing; 6b: Gear housing; 6d: Extension part; 8: Inverter unit; 21: Shaft (motor shaft); 81: Motor chamber; 82: Gear chamber; 90: Oil circuit; 92: Second oil circuit (oil circuit); 96: Pump; 96m: Pump motor; 97: Cooler; J2: Motor axis; J6: Rotation axis; O: Oil.

Claims

1. A driving device, comprising: a motor having a motor shaft that rotates about a motor axis extending in a horizontal direction; a gear portion connected to the motor shaft on one axial side of the motor axis; and The housing has a motor housing portion and a gear housing portion, wherein the motor housing portion has a motor chamber for housing the motor, and the gear housing portion has a gear chamber for housing the gear portion. The gear unit has a speed reduction device and a differential device. The reduction gear comprises a first gear that rotates around the motor axis, and a second gear, a third gear, and an intermediate shaft that rotate around an intermediate axis. The torque output from the motor is transmitted to the ring gear of the differential device rotating around the differential axis via the motor shaft of the motor, the first gear, the second gear, the intermediate shaft, and the third gear. The motor axis, the intermediate axis and the differential axis extend parallel to each other, An inverter unit that supplies power to the motor is located on an outer peripheral surface of the motor housing portion of the housing that houses the motor and faces radially outward. At least a portion of the inverter unit overlaps with the ring gear of the differential device when viewed in the axial direction of the motor axis.

2. The driving device according to claim 1, wherein: The inverter unit is fixed to an outer peripheral surface of the motor housing portion that faces outward in the radial direction.

3. The driving device according to claim 1 or 2, wherein: The inverter unit is provided in the path of the cooling water pipe. The cooling water passing through the cooling water pipe cools the inverter unit.

4. The driving device according to claim 1 or 2, wherein: At least a portion of the inverter unit overlaps with the extended portion of the gear housing portion when viewed from the axial direction.

5. The driving device according to claim 1 or 2, wherein: The inverter unit is located on the opposite side of the cooler across the motor axis when viewed in the vertical direction.

6. The driving device according to claim 1 or 2, wherein: An oil passage for circulating oil to cool the motor is provided in the housing, and a pump for supplying the oil to the motor is provided in the oil passage. The pump has a pump motor, The rotation axis of the pump motor is parallel to the motor axis.

7. The driving device according to claim 1 or 2, wherein: An upper surface of the inverter unit is coplanar with an upper surface of the housing.

8. The driving device according to claim 1 or 2, wherein: A parking mechanism is fixed to the outer peripheral surface of the housing.

9. The driving device according to claim 8, wherein: The parking mechanism is located on the opposite side of the cooler across the motor axis when viewed in the vertical direction.

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