motor unit

Abstract

A motor unit has 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 an axial side of the motor axis, a housing that houses the motor and the gear portion, and oil housed in the housing, the housing having a motor housing portion in which a motor chamber that houses the motor is provided inside, and a gear housing portion in which a gear chamber that houses the gear portion is provided inside, an oil passage through which the oil circulates to cool the motor being provided in the housing, a cooler that cools the oil passing through the oil passage being provided in a path of the oil passage, and a pump that supplies the oil to the motor, the cooler being fixed to an outer peripheral surface of the housing, the cooler being located radially outward of the motor.

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 title "Motor Unit". Technical Field

[0002] This invention relates to motor units. Background Technology

[0003] In Japanese Patent Application Publication No. 2016-73163, the following structure is disclosed: the refrigerant is cooled by a cooling device (cooler) installed outside the motor (rotary electric machine), and the refrigerant is supplied to the motor by a pump installed outside the motor.

[0004] Existing technical documents

[0005] Patent documents

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

[0007] The problem that the invention aims to solve

[0008] In recent years, the development of motor units for vehicles, which integrate transmission devices and other components, has been underway. However, such motor units, due to their complex shapes, are prone to dead zones when mounted in vehicles.

[0009] In view of the above-mentioned problems, one of the objectives of the present invention is to provide a motor unit that can achieve overall miniaturization.

[0010] Methods for solving problems

[0011] One embodiment of the motor unit of the present invention includes: 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; a housing housing the motor and the gear portion; and oil contained within the housing. The housing includes: a motor housing portion having a motor chamber for housing the motor internally; and a gear housing portion having a gear chamber for housing the gear portion internally. An oil passage is provided in the housing for circulating the oil to cool the motor. A cooler is provided in the path of the oil passage for cooling the oil passing through the oil passage; and a pump for supplying the oil to the motor. The cooler is fixed to the outer peripheral surface of the housing and is located radially outward of the motor.

[0012] Invention Effects

[0013] According to one aspect of the present invention, a motor unit capable of achieving overall miniaturization is provided. Attached Figure Description

[0014] Figure 1 This is a conceptual diagram of a motor unit in one implementation method.

[0015] Figure 2 This is a perspective view of a motor unit according to one implementation method.

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

[0017] Figure 4 This is an exploded view of the casing of one implementation method.

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

[0019] Figure 6 This is a bottom view of one embodiment of the motor unit. Detailed Implementation

[0020] Hereinafter, the motor unit according to an embodiment of the present invention will be described with reference to the accompanying drawings. Furthermore, the scope of the present invention is not limited to the following embodiments, and modifications can be made freely within the scope of the technical concept of the present invention.

[0021] In the following description, the direction of gravity is defined and explained based on the positional relationship of the motor unit mounted on a vehicle located on a horizontal road surface. Furthermore, in the accompanying drawings, an XYZ coordinate system is appropriately shown as a three-dimensional Cartesian coordinate system. In the XYZ coordinate system, the Z-axis direction represents the vertical direction (i.e., the up-down direction), the +Z direction is the upper side (opposite to the direction of gravity), and the -Z direction is the lower side (direction of gravity). The X-axis direction is perpendicular to the Z-axis direction and represents the front-to-back direction of the vehicle equipped with 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 perpendicular to both the X-axis and Z-axis directions and represents the width direction (left-to-right direction) of the vehicle; the +Y direction is the left side of the vehicle, and the -Y direction is the right side of the vehicle. However, if 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 vehicle's left and right direction, and the -Y direction is the other side of the vehicle's left and right direction.

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

[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 accompanying drawings.

[0024] Figure 1 This is a conceptual diagram of motor unit 1 in one implementation method. Figure 2 This is a 3D view of motor unit 1. Additionally, Figure 1 This is just a concept drawing; the configuration and dimensions of each part may not be the same as the actual product.

[0025] Motor unit 1 is installed in vehicles that use motors as a power source, such as hybrid electric vehicles (HEV), plug-in hybrid electric vehicles (PHV), and electric vehicles (EV), and is used as their power source.

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

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

[0028] <Motor>

[0029] Motor 2 is housed in motor chamber 81 of housing 6. Motor 2 has rotor 20 and stator 30 located radially outside rotor 20. Motor 2 is an internal rotor type motor having stator 30 and rotor 20 rotatably disposed inside 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 rotor magnets (not shown). The rotor 20 (i.e., the shaft 21, rotor core 24, and rotor magnets) rotates about a motor axis J2 extending in a horizontal direction. The torque of the rotor 20 is transmitted to the gear section 3.

[0031] Shaft 21 extends around a motor axis J2 that extends horizontally along the width direction of the vehicle. Shaft 21 rotates around the motor axis J2. Shaft 21 is a hollow shaft with a hollow portion 22, which has an inner circumferential surface extending along the motor axis J2 inside.

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

[0033] The rotor core 24 is constructed by stacking silicon steel sheets. The rotor core 24 is a cylinder extending axially. Multiple rotor magnets (not shown) are fixed to the rotor core 24. The multiple rotor magnets are arranged circumferentially with alternating magnetic poles.

[0034] The stator 30 surrounds the rotor 20 radially outward. The stator 30 has a stator core 32, a coil 31, and an insulating element (not shown) between the stator core 32 and the coil 31. The stator 30 is held by a housing 6. The stator core 32 has a plurality of pole teeth (not shown) extending radially inward from the inner circumference of an annular yoke. Coil wire is wound between the pole teeth. The coil wire wound around the pole teeth constitutes the coil 31. The coil wire is connected to the inverter unit 8 via a busbar (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 beyond the end of the rotor core 24 of the rotor 20. The coil end 31a protrudes axially to both sides relative to the rotor core 24.

[0035] <Gear Section>

[0036] The gear unit 3 is housed 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 shaft J2. The gear unit 3 has a reduction gear 4 and a differential gear 5. The torque output from the motor 2 is transmitted to the differential gear 5 via the reduction gear 4.

[0037] <Speed ​​Reduction Device>

[0038] The speed reduction device 4 is connected to the rotor 20 of the motor 2. The speed reduction device 4 reduces the rotational speed of the motor 2 and has the function of increasing the torque output from the motor 2 according to the reduction ratio. The speed reduction device 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 gear ring 51 (gear) of the differential gear 5 via the motor 2 shaft 21, the first gear 41, the second gear 42, the intermediate shaft 45, and the third gear 43. The gear ratio and number of gears can be varied according to the required reduction ratio. The reduction gear 4 is a parallel-shaft gear type reducer with the shafts of each gear arranged in parallel.

[0040] The first gear 41 is disposed on the outer circumferential surface of the shaft 21 of the motor 2. The first gear 41 rotates together with the shaft 21 around the motor axis J2. The intermediate shaft 45 extends along the intermediate axis J4, which is parallel to the motor axis J2. The intermediate shaft 45 rotates around the intermediate axis J4. The second gear 42 and the third gear 43 are disposed on the outer circumferential 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 around the intermediate axis J4. The second gear 42 meshes with the first gear 41. The third gear 43 meshes with the gear ring 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 device

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

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

[0044] (Configuration of each axis)

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

[0046] The motor shaft J2, intermediate shaft J4, and differential shaft J5 extend horizontally parallel to each other. The intermediate shaft J4 and differential shaft J5 are located below the motor shaft J2. Therefore, the reduction gear 4 and differential gear 5 are located below the motor 2.

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

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

[0049] The angle α between the second line segment L2 and the third line segment L3 is 30°±5°.

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

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

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

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

[0054] <Outer Shell>

[0055] like Figure 1 As shown, the motor 2 and gear unit 3 are housed in the storage space 80 inside the housing 6. The housing 6 holds the motor 2 and gear unit 3 within 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 housed in the motor chamber 81. The gear unit 3 (i.e., the reduction gear 4 and the differential gear 5) is housed in the gear chamber 82.

[0056] An oil storage section P for storing oil O is provided in the lower region within the storage space 80. In this embodiment, the bottom 81a of the motor chamber 81 is located above the bottom 82a of the gear chamber 82. Furthermore, a partition opening 68 is provided in the partition wall 61c that divides the motor chamber 81 and the gear chamber 82. The partition opening 68 communicates between the motor chamber 81 and the gear chamber 82. The partition opening 68 allows the oil O stored in the lower region of the motor chamber 81 to move towards the gear chamber 82.

[0057] A portion of the differential 5 is immersed in the oil reservoir P. The oil O stored in the oil reservoir P is lifted by the operation of the differential 5, with a portion supplied to the first oil passage 91 and a portion diffused within the gear chamber 82. The oil O diffused in the gear chamber 82 is supplied to each gear of the reduction gear 4 and the differential 5 within the gear chamber 82, ensuring that the oil O covers the tooth surfaces of the gears. Oil O used in the reduction gear 4 and the differential 5 drips and is collected by the oil reservoir P located on the lower side of the gear chamber 82. The capacity of the oil reservoir P in the storage space 80 is such that a portion of the bearing of the differential 5 is immersed in oil O when the motor unit 1 stops.

[0058] like Figure 2 As shown, the housing 6 has a first housing component 61, a second housing component 62, and a closure 63. The second housing component 62 is located on one axial side of the first housing component 61. The closure 63 is located on the other axial side of the first housing component 61. The housing may also be composed of three or more components.

[0059] Figure 4 This is an exploded view of shell 6.

[0060] The first housing component 61 has: a cylindrical peripheral wall portion 61a that surrounds the motor 2 radially outward; and a side plate portion 61b located on one axial side of the peripheral wall portion 61a. The space inside the peripheral wall portion 61a forms the motor chamber 81. The side plate portion 61b has a partition wall 61c and a protruding plate portion 61d. The partition wall 61c covers the opening on one axial side of the peripheral wall portion 61a. In addition to the partition wall opening 68 described above, the partition wall 61c also has a through insertion hole 61f for the shaft 21 of the motor 2 to be inserted through. The side plate portion 61b has 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 has a first axle passage hole 61e for a drive shaft (not shown) supporting the wheel to pass through.

[0061] The closure 63 is fixed to the peripheral wall 61a of the first outer casing member 61. The closure 63 closes the opening of the cylindrical first outer casing member 61. The closure 63 has a closure body 63a and a cover member 63b. A window 63c extending axially is provided in the closure body 63a. The cover member 63b closes the window 63c from the outside of the storage space 80.

[0062] The second housing component 62 is fixed to the side plate portion 61b of the first housing component 61. The second housing component 62 is concave in shape, opening towards the side plate portion 61b. The opening of the second housing component 62 is covered by the side plate portion 61b. The space between the second housing component 62 and the side plate portion 61b forms a gear chamber 82 for housing the gear portion 3. A second axle passage hole 62e is provided in the second housing component 62. The second axle passage hole 62e overlaps with the first axle passage hole 61e when viewed axially.

[0063] The peripheral wall portion 61a and the enclosure portion 63 of the first outer casing component 61 constitute a motor chamber 81, surrounding and housing the motor 2. That is, the peripheral wall portion 61a and the enclosure portion 63 constitute... Figure 1 The motor storage section 6a 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, surrounding and housing the gear portion 3. That is, the side plate portion 61b and the second housing member 62 constitute... Figure 1 The gear storage section 6b shown.

[0065] Thus, the outer casing 6 has: a motor housing 6a, which has a motor chamber 81 for housing the motor 2 inside; and a gear housing 6b, which has a gear chamber 82 for housing the gear 3 inside.

[0066] Figure 5 This is a side view of motor unit 1. Additionally, Figure 6 This is a bottom view of motor unit 1. Additionally, in Figure 5 and Figure 6 The diagram of inverter unit 8 is omitted in the text.

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

[0068] <Oil>

[0069] like Figure 1 As shown, oil O circulates within the oil passage 90 provided in the housing 6. The oil passage 90 is the path that supplies 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] Oil O is used for lubrication of the reduction gear 4 and the differential gear 5. Additionally, oil O is used for cooling the motor 2. Oil O accumulates in the lower region (i.e., oil reservoir P) within the gear chamber 82. Preferably, oil of the same viscosity as automatic transmission fluid (ATF) is used as oil O to achieve both lubrication and cooling functions.

[0071] <Oil Circuit>

[0072] like Figure 1 As shown, an oil passage 90 is provided in the housing 6. The oil passage 90 is located in the storage space 80 inside the housing 6. The oil passage 90 is configured to span the motor chamber 81 and the gear chamber 82 of the storage space 80. The oil passage 90 is a path that allows oil O to pass from the oil reservoir P on the lower side of the motor 2 (i.e., the lower region within the storage space 80) through the motor 2 and then back to the oil reservoir P on the lower side of the motor 2.

[0073] Furthermore, in this specification, "oil path" refers to the path through which oil O circulates in the storage space 80. Therefore, "oil path" is a concept that includes not only the "flow path" that forms a stable flow of oil in one direction, but also paths that allow oil to temporarily stagnate (e.g., storage tanks) and paths that allow oil to drip.

[0074] Oil passage 90 has a first oil passage 91 that passes through the interior of motor 2; and a second oil passage 92 that passes through the exterior of motor 2. Oil O in the first oil passage 91 and the second oil passage 92 cools motor 2 from the interior and exterior.

[0075] Both the first oil passage 91 and the second oil passage 92 are paths that supply oil O from the oil storage section P to the motor 2 and then return it to the oil storage section P. In the first oil passage 91 and the second oil passage 92, oil O drips from the motor 2 and accumulates in the lower region of the motor chamber 81. The oil O accumulated in the lower region of the motor chamber 81 moves through the partition opening 68 to the lower region of the gear chamber 82 (i.e., the oil storage section P). That is, the first oil passage 91 and the second oil passage 92 include paths that allow oil O to move from the lower region of the motor chamber 81 to the lower region of the gear chamber 82.

[0076] (First oil line)

[0077] like Figure 1 As shown, in the first oil passage 91, oil O is lifted from the oil reservoir P by the differential device 5 and guided into the interior of the rotor 20. Inside the rotor 20, a centrifugal force based on the rotation of the rotor 20 is applied to the oil O. As a result, the oil O diffuses evenly toward the stator 30 that surrounds the rotor 20 radially outward, cooling the stator 30.

[0078] The first oil passage 91 has a lifting path 91a, a shaft supply path 91b, an internal shaft path 91c, and an internal rotor path 91d. Additionally, a first storage tank 93 is provided within the path of the first oil passage 91. The first storage tank 93 is located in the gear chamber 82.

[0079] The lifting path 91a is a path in which oil O is lifted from the oil storage section P by the rotation of the gear ring 51 of the differential device 5, and then received by the first storage tank 93. For example... Figure 3 As shown, the first storage tank 93 is positioned between the intermediate axis J4 and the differential axis J5. The first storage tank 93 opens upwards. The first storage tank 93 receives oil O lifted by the gear ring 51. In addition, when the oil level in the oil reservoir P is high, such as immediately after driving the motor 2, the first storage tank 93 receives oil O lifted by the gear ring 51, as well as oil O lifted by the second gear 42 and the third gear 43.

[0080] The shaft provides a path 91b that guides oil O from the first storage tank 93 to the motor 2. The shaft provides a path 91b formed by a hole 94 provided in the second housing component 62. The shaft internal path 91c is the path through which oil O passes through the hollow portion 22 of the shaft 21. The rotor internal path 91d is the path through which oil O splashes from the connecting hole 23 of the shaft 21 through the interior of the rotor core 24 onto the stator 30.

[0081] In the shaft path 91c, a centrifugal force based on 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 drawn into the interior of the rotor 20, causing the oil O to fill the path inside the rotor 20.

[0082] The oil O that reaches the stator 30 takes heat from the stator 30. After cooling the stator 30, the oil O drips downwards 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 wall 61c.

[0083] (Second oil line)

[0084] like Figure 1As shown, in the second oil passage 92, 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 on the outer peripheral surface of the stator 30 and absorbs heat from the stator 30 to cool the motor 2. The oil O transferred on the outer peripheral surface of the stator 30 drips downward and accumulates in the lower region of the motor chamber 81. The oil O from the second oil passage 92 and the oil O from the first oil passage 91 merge in the lower region of the motor chamber 81. The oil O accumulated in the lower region of the motor chamber 81 moves through the partition opening 68 to the lower region of the gear chamber 82 (i.e., the oil reservoir P).

[0085] The second oil passage 92 has a first flow path 92a, a second flow path 92b, and a third flow path 92c. A pump 96, a cooler 97, and a second storage tank 98 are provided along the path of the second oil passage 92. The pump 96 supplies oil O to the motor 2. The cooler 97 cools the oil O passing through the second oil passage 92. In the second oil passage 92, oil O passes through the first flow path 92a, pump 96, second flow path 92b, cooler 97, third flow path 92c, and second storage tank 98 in that order 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 of the outer casing 6 surrounding the receiving 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 receiving space 80.

[0087] In this embodiment, the first flow path 92a, the second flow path 92b, and the third flow path 92c pass through the interior of the wall of the outer casing 6 surrounding the storage space 80. Therefore, no additional tubing is required, which helps to reduce the number of components.

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

[0089] like Figure 6 As shown, the pump 96 includes a pump mechanism 96p, a pump motor 96m, an inlet 96a, and an outlet 96b. In this embodiment, the pump mechanism 96p is a cycloidal pump that rotates by the meshing of 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 connects to the inlet 96a and the outlet 96b.

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

[0091] The pump motor 96m rotates the internal gear of the pump mechanism 96p. The rotation axis J6 of the pump motor 96m is parallel to the motor axis J2. The pump 96, which has the pump motor 96m, is easily elongated in the direction of the rotation axis J6. According to this 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, the pump 96 can easily overlap with the protrusion 6d of the housing 6 when viewed from the axial direction. As a result, the axial projected area of ​​the motor unit 1 is suppressed from increasing, and a structure that easily miniaturizes the motor unit 1 can be achieved.

[0092] Pump 96 is located on the lower side of motor chamber 81. Pump 96 is also fixed to the side of the protrusion 6d facing the motor housing 6a. The suction port 96a of pump 96 is positioned opposite the protrusion 6d. A first flow path 92a, connected to the suction port 96a of pump 96, extends axially through the wall of the protrusion 6d and opens into the lower region within the gear chamber 82. That is, a first flow path 92a is provided in the protrusion 6d, extending axially and connecting to pump 96 from the lower region within the gear chamber 82 (i.e., the oil storage section P).

[0093] According to this embodiment, the pump 96 is disposed on the lower side of the motor chamber 81, thus facilitating the placement of the suction inlet 96a near the oil reservoir P. As a result, the first flow path 92a connecting the oil reservoir P and the suction inlet 96a can be shortened. Furthermore, the closer distance between the oil reservoir P and the suction inlet 96a allows the first flow path 92a to be a straight flow path. By making the first flow path 92a a straight and shorter flow path, pressure loss along the path from the oil reservoir P to the pump 96 can be reduced, enabling efficient oil O circulation.

[0094] like Figure 1 As shown, a first flow path 92a and a second flow path 92b are connected to the cooler 97. The first flow path 92a and the second flow path 92b are connected via internal flow paths of the cooler 97. A cooling water pipe 97j is connected to the cooler 97 for the cooling water cooled by the radiator (not shown). Cooling is achieved through heat exchange between the oil O passing through the interior of the cooler 97 and the cooling water passing through the cooling water pipe 97j. In addition, an 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 radially outward outer peripheral surface of the motor housing 6a on the lower side of the motor chamber 81. Figure 1 As shown, the oil O supplied to the motor 2, after temporarily accumulating in the lower region of the motor chamber 81, moves through the partition opening 68 to the lower region of the gear chamber 82. According to this embodiment, the cooler 97 is fixed to the outer peripheral surface of the motor housing 6a on the lower side of the motor chamber 81, so that the oil O stored in the lower region of the motor chamber 81 from the mounting surface of the cooler 97 through the wall area of ​​the motor housing 6a can be cooled.

[0096] like Figure 5 As shown, at least a portion of the cooler 97 and pump 96 overlap with the protrusion 6d of the gear housing 6b when viewed axially. A gear unit 3 is housed inside the protrusion 6d. The axial projected area of ​​the protrusion 6d is determined by the size of each gear in the gear unit 3. The size of each gear constituting the gear unit 3 is set to satisfy a desired gear ratio. Therefore, it is difficult to reduce the axial projected area of ​​the protrusion 6d. According to this embodiment, by arranging the cooler 97 and pump 96 overlapping with the protrusion 6d in the axial direction, it is possible to suppress the increase in the axial projected area of ​​the motor unit 1 caused by the cooler 97 and pump 96. Thus, by suppressing the increase in the axial projected area of ​​the motor unit 1, the motor unit 1 can be miniaturized.

[0097] According to this embodiment, when viewed axially, at least a portion of the cooler 97 and pump 96 overlaps with the second gear 42 of the gear section 3. Therefore, even when the projected area viewed axially from the protrusion 6d is minimized along the outline of each gear of the gear section 3, a structure in which the cooler 97 and pump 96 overlap with the protrusion 6d when viewed axially can be achieved. As a result, the axial projected area of ​​the motor unit 1 is suppressed from increasing, and the motor unit 1 can be miniaturized.

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

[0099] The cooler 97 and pump 96 are located on the lower vertical side of the motor chamber 81. The motor unit 1 is, for example, disposed inside the hood of a vehicle. Furthermore, in the motor unit 1, the cooler 97 and pump 96 are protrusions protruding relative to the housing 6. According to this embodiment, by distributing the cooler 97 and pump 96 on the lower vertical side of the motor chamber 81, even in the event of a collision between the vehicle and an object due to an accident, it is possible to prevent the cooler 97 and pump 96, as protrusions, from penetrating the object.

[0100] According to this embodiment, the pump 96 and the cooler 97 are fixed to the outer peripheral surface of the housing 6. Therefore, compared to a structure where the pump 96 and the cooler 97 are fixed to the outside of the housing 6, it is possible to reduce the size of the motor unit 1. Furthermore, by fixing the pump 96 and the cooler 97 to the outer peripheral surface of the housing 6, a flow path connecting the housing space 80 to the pump 96 and the cooler 97 can be formed using the first flow path 92a, the second flow path 92b, and the third flow path 92c through the wall of the housing 6.

[0101] like Figure 6 As shown, according to this embodiment, the axial positions of the pump 96 and the cooler 97 overlap. The cooler 97 and the pump 96 are connected via a second flow path 92b. That is, a second flow path 92b connecting the pump 96 and the cooler 97 is provided in the second oil passage 92. According to this embodiment, by making the axial positions of the pump 96 and the cooler 97 overlap, a structure in which the second flow path 92b extends linearly in a direction perpendicular to the axial direction can be achieved. That is, the second flow path 92b can be made straight and shorter, reducing pressure loss along the path from the pump 96 to the cooler 97, and enabling efficient oil circulation.

[0102] like Figure 1 As 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 above the motor. The second storage tank 98 stores oil O supplied to the motor chamber 81 via the third flow path 92c. The second storage tank 98 has multiple outlets 98a. The oil O accumulated in the second storage tank 98 is supplied to the motor 2 from each outlet 98a. The oil O flowing out of the outlets 98a of the second storage tank 98 flows from top to bottom along the outer peripheral surface of the motor 2, absorbing heat from the motor 2. Thus, the entire motor 2 can be cooled.

[0103] The second storage tank 98 extends axially. Furthermore, outlets 98a of the second storage tank 98 are located at both axial ends of the second storage tank 98. The outlets 98a are situated above the coil ends 31a. This allows oil O to be poured onto the coil ends 31a located at both axial ends of the stator 30, directly cooling the coil 31a.

[0104] After the coil 31 is cooled, the oil O drips downwards 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 this embodiment, a cooler 97 for cooling oil O is provided in the path of the second oil passage 92. The oil O cooled by the cooler 97 after passing through the second oil passage 92 merges with the oil O that has passed through the first oil passage 91 in the oil storage section P. In the oil storage section P, the oil O passing through the first oil passage 91 and the second oil passage 92 mix and exchange heat. Therefore, the cooling effect of the cooler 97 arranged in the path of the second oil passage 92 can also affect the oil O passing through the first oil passage 91.

[0106] <Inverter Unit>

[0107] Inverter unit 8 is electrically connected to motor 2. Inverter unit 8 controls the current supplied to 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 radially outward outer peripheral surface of the motor housing 6a.

[0108] When viewed axially, at least a portion of the inverter unit 8 overlaps with the protrusion 6d of the gear housing portion 6b. According to this embodiment, by arranging the inverter unit 8 and the protrusion 6d in an overlapping configuration when viewed axially, it is possible to suppress the increase in the axial projected area of ​​the motor unit 1 caused by the inverter unit 8. Therefore, by suppressing the increase in the axial projected area of ​​the motor unit 1, it is possible to miniaturize the motor unit 1.

[0109] According to this embodiment, at least a portion of the inverter unit 8 overlaps with the gear ring 51 of the gear section 3 when viewed from the axial direction. Therefore, even when the projected area of ​​the protrusion 6d viewed from the axial direction is minimized along the outline of each gear of the gear section 3, a structure in which the inverter unit 8 overlaps with the protrusion 6d in the axial direction can be achieved. As a result, the axial projected area of ​​the motor unit 1 is suppressed from increasing, and the motor unit 1 can be miniaturized.

[0110] According to this embodiment, when viewed vertically, the inverter unit 8 is located on the opposite side of the cooler 97, across the motor axis J2. Therefore, when viewed axially, by effectively utilizing the area overlapping with the protrusion 6d, the horizontal dimension of the motor unit 1 can be reduced, and miniaturization of the motor unit 1 can be achieved.

[0111] like Figure 1 As shown, a cooling water pipe 97j extending from a heat sink (not shown) is connected to the inverter unit 8. This allows for efficient cooling of the inverter unit 8. Furthermore, the cooling water flowing through the cooling water pipe 97j also cools the motor housing 6a, which is in contact with the housing, via the inverter unit 8's housing.

[0112] Parking facilities

[0113] In electric vehicles, apart from the side brakes, there is no braking mechanism in the vehicle to apply the brakes, so a 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 an intermediate shaft 45 and rotating together with the intermediate shaft 45 about an intermediate axis J4; a rotation-stopping part 72 that moves between the teeth of the parking gear 71 to prevent the parking gear 71 from rotating; and a parking motor 73 that drives the rotation-stopping part 72. When the motor 2 is activated, the rotation-stopping part 72 retracts from the parking gear 71. On the other hand, when the gear lever is in the parking position, the parking motor 73 moves the rotation-stopping part 72 between the teeth of the parking gear 71 to prevent the parking gear 71 from rotating.

[0115] The embodiments and variations of the present invention have been described above. However, the structures and combinations thereof in the embodiments are merely examples, and structural additions, omissions, substitutions, and other changes can be made without departing from the spirit of the present invention. Furthermore, the present invention is not limited to the embodiments.

[0116] Label Explanation

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

Claims

1. A motor unit comprising: A motor having a motor shaft that rotates about a motor axis extending in a horizontal direction; A gear section, which is connected to the motor shaft on one axial side of the motor axis; A housing that houses the motor and the gear assembly; and The oil is contained within the outer casing. The outer casing has: A motor housing, which has a motor chamber inside for housing the motor; and The gear storage section has a gear chamber inside for storing the gear section. The housing is provided with an oil passage for circulating the oil to cool the motor. The oil circuit path includes: A cooler that cools the oil passing through the oil passage; and A pump that supplies the oil to the motor. The cooler is fixed to the outer peripheral surface of the outer casing. The cooler is located radially outside the motor. The oil circuit has a first oil circuit passing through the interior of the motor and a second oil circuit passing through the exterior of the motor. The cooler and the pump are located in the second oil circuit. In the second oil circuit, oil is supplied to the motor via the cooler.

2. The motor unit according to claim 1, wherein, The cooler and the pump are located on the vertically lower side of the motor chamber.

3. The motor unit according to claim 1 or 2, wherein, The position of the pump along the axial direction of the motor shaft overlaps with the position of the cooler.

4. The motor unit according to claim 1 or 2, wherein, The cooler is fixed to the outer peripheral surface of the motor housing on the lower vertical side of the motor chamber.

5. The motor unit according to claim 1 or 2, wherein, The pump has a pump motor. The rotation axis of the pump motor is parallel to the motor axis.

6. The motor unit according to claim 1 or 2, wherein, The oil passage includes a path that allows the oil to move from the lower region of the motor chamber to the lower region of the gear chamber.

7. The motor unit according to claim 1 or 2, wherein, The motor unit has an inverter unit that controls the current supplied to the motor. The inverter unit is fixed to the outer peripheral surface of the motor housing.

8. The motor unit according to claim 1 or 2, wherein, When viewed from the axial direction, the pump and the cooler are arranged circumferentially.

9. The motor unit according to claim 1 or 2, wherein, The motor unit has an inverter unit that controls the current supplied to the motor. When viewed from the axial direction, the inverter unit and the cooler are arranged circumferentially.

10. The motor unit according to claim 9, wherein, When viewed from the axial direction, the inverter unit, the cooler, and the pump are arranged circumferentially.

11. The motor unit according to claim 1 or 2, wherein, The motor unit has an inverter unit that controls the current supplied to the motor. The inverter unit is located on the opposite side of the cooler, separated from the motor axis.

12. The motor unit according to claim 1 or 2, wherein, In the second oil circuit, oil is lifted to the top of the motor via the cooler and supplied to the motor.

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