Electric vehicle drive device

Abstract

An electric vehicle drive device (1) comprises: a motor body part (5); a motor housing (6) that has a stator (5c) fixed to the inside thereof and is open on one axial side; a motor bracket (7) that covers one axial side of the stator (5c) and a rotor (5b) and has a central through-hole (7a) through which passes a shaft portion (5a1) on one side, extending from the rotor (5b) to one axial side; and a speed reducer (4) that reduces the rotational speed of the shaft (5a) and outputs the reduced rotational speed, wherein the motor bracket (7) has one or more outer through-holes (7b) positioned radially outer side of the central through-hole (7a) and axially penetrating the motor bracket (7), the motor housing (6) or the motor bracket (7) has a cylindrical cover section (13) that covers the radially outer side of the openings of the outer through-holes (7b) on one axial side over the entire circumference of the openings, and the end surface of the cover section (13) on one axial side is sealed over the entire circumference by abutting a case member (4a) of the speed reducer (4) with a seal member (14) therebetween.

Description

Electric vehicle drive unit

[0001] The present application relates to an electric vehicle drive device.

[0002] In recent years, due to concerns about environmental issues such as global warming, there has been a rapid shift from conventional internal combustion engine-powered vehicles to electrified vehicles powered by electric motors that do not emit carbon dioxide during operation. An electric vehicle drive system that drives an electric vehicle is composed of an electric motor, a reduction mechanism that reduces the speed of the electric motor and transmits the reduced speed to the axle, and an inverter that converts DC power stored in a battery into AC power to efficiently drive and control the electric motor. Conventionally, the electric motor, the reduction mechanism, and the inverter were manufactured separately and connected to each other, but a configuration has been proposed in which these are integrated to achieve greater miniaturization (for example, see Patent Document 1).

[0003] Patent Document 1 discloses a configuration in which a motor and a reducer are integrated. In this configuration, the motor housing has a plate-like portion on the end surface that contacts the reducer. On the other hand, the reducer housing has a plate-like portion on the portion facing the end surface of the motor. Therefore, when the motor and reducer are combined, the mating surfaces form a double case. Thus, if a motor and a reducer are manufactured separately and inspected separately, and then combined, this double case configuration results. Although the electric vehicle drive device is sealed from the outside, the double case configuration poses a challenge in that it is difficult to reduce the size, cost, and weight of the electric vehicle drive device.

[0004] The configuration of an electric vehicle drive device that does not require a double case has been disclosed (for example, Patent Document 2). Patent Document 2 discloses a configuration in which the end face portion of the case that normally houses the motor, which is on the side of the reducer, is shared with the surface of the reducer case. Compared to a case in which the motor and reducer are manufactured separately and then assembled, this configuration makes it possible to avoid having double mating surfaces. The lack of double mating surfaces is thought to contribute to the miniaturization, cost reduction, and weight reduction of the electric vehicle drive device.

[0005] JP 2020-150608 A Patent No. 5900012 A

[0006] In the above-mentioned Patent Document 2, it is possible to avoid double mating surfaces. However, functional testing of a motor is only possible once assembly is complete, including the bearings at both ends of the rotor. With this configuration, the motor's functionality is only demonstrated once the assembly process has progressed to the step of combining the reducer and the motor. This means that the motor cannot be tested alone, and only the performance of the system combined with the reducer can be obtained. Therefore, it is difficult to grasp the variation in the motor alone and the variation in the reducer alone, which has led to the issue of making it difficult to ensure the reliability of the electric vehicle drive device.

[0007] Furthermore, in the assembly work of the motor, precise assembly is performed using an assembly jig or the like while precisely aligning the axes so that the slight gap between the rotor and stator does not come into contact. In the above-mentioned Patent Document 2, one of the rotor bearings is provided in the reducer case, and therefore the object to be assembled during the assembly process is a large item including the reducer, making precise assembly work difficult and reducing the productivity of the electric vehicle drive device.

[0008] Therefore, an object of the present application is to provide an electric vehicle drive device that is compact, low-cost, and lightweight, while ensuring reliability and improving productivity.

[0009] The electric vehicle drive device disclosed in the present application comprises a motor main body having a shaft, a rotor that rotates integrally with the shaft, and a stator that surrounds the rotor from the radial outside; a motor housing to which the stator is fixed and which is open on one axial side; a motor bracket that covers one axial side of the stator and the rotor and has a central through hole through which one side of the shaft portion extending from the rotor to one side in the axial direction passes; and a reducer that is connected to the one side of the shaft portion and reduces the rotational speed of the shaft to output it, wherein the motor bracket has one or more outer through holes that pass through in the axial direction radially outside the central through hole, and the motor housing or the motor bracket has a cylindrical cover portion that covers the radially outer side of the openings on one axial side of all of the outer through holes over the entire circumference, and the one axial end face of the cover portion abuts against a case member of the reducer via a sealing member and is sealed over the entire circumference.

[0010] The electric vehicle drive device disclosed in the present application includes a motor main body having a shaft, a rotor, and a stator, a motor housing to which the stator is fixed and which is open on one axial side, a motor bracket covering one axial side of the stator and rotor and having a central through hole through which one axial portion of the shaft extending from the rotor passes, and a reducer connected to the one axial portion of the shaft and configured to reduce the rotational speed of the shaft and output the reduced power. The motor bracket has one or more outer through holes extending axially radially outward from the central through hole, and the motor housing or the motor bracket has a cylindrical cover portion covering the radially outer circumferential ends of the openings on one axial side of all the outer through holes. The one axial end face of the cover portion is abutted against a case member of the reducer via a sealing member and sealed around the entire periphery. This allows the motor to be assembled to the reducer as a standalone unit, thereby improving the ease of assembly and productivity of the electric vehicle drive device. Furthermore, since the motor can be inspected as a standalone unit, it is possible to identify variations within the motor, thereby improving the quality of the motor. Since the quality of the motor is improved, the reliability of the electric vehicle drive device can be ensured. Furthermore, compared to Patent Document 1, by providing an outer through hole in the motor bracket, the material cost of the electric vehicle drive device can be reduced and the weight of the electric vehicle drive device can be reduced. Furthermore, since the motor and reducer are not sealed and then assembled, the seal structure is simple and the electric vehicle drive device can be made smaller.

[0011] Fig. 1 is a cross-sectional view showing an outline of an electric vehicle drive device according to embodiment 1. Fig. 2 is a plan view showing an outline of a motor bracket of the electric vehicle drive device according to embodiment 1. Fig. 3 is a cross-sectional view showing an outline of another electric vehicle drive device according to embodiment 1. Fig. 4 is a cross-sectional view showing an outline of an electric vehicle drive device according to embodiment 2.

[0012] Hereinafter, an electric vehicle drive device according to an embodiment of the present invention will be described with reference to the drawings. Note that the same or equivalent members and parts in each drawing will be denoted by the same reference numerals.

[0013] Embodiment 1. Figure 1 is a cross-sectional view showing an outline of an electric vehicle drive device 1 according to embodiment 1, with details of the internal configuration omitted, and Figure 2 is a plan view showing an outline of a motor bracket 7 of the electric vehicle drive device 1, as seen from one axial side. The electric vehicle drive device 1 mounted on an electric vehicle is a device that transmits the rotation of a motor 2 controlled by an inverter 3 connected to an external DC power source to the wheel axle of the electric vehicle via a speed reducer 4.

[0014] 1 , the electric vehicle drive device 1 includes a motor main body 5 having a shaft 5a, a rotor 5b that rotates integrally with the shaft 5a, and a stator 5c that radially surrounds the rotor 5b; a motor housing 6 to which the stator 5c is fixed and which is open on one axial side; a motor bracket 7 that covers one axial side of the stator 5c and the rotor 5b and has a central through-hole 7a through which one axial portion 5a1 extending from the rotor 5b on one axial side passes; and a reducer 4 that is connected to the one axial portion 5a1 and reduces the rotational speed of the shaft 5a for output. The motor main body 5, the motor housing 6, and the motor bracket 7 constitute a motor 2. The one axial side is the right side of the motor 2 in the drawing, where the reducer 4 is disposed. The direction in which the motor housing 6 opens and the direction in which the shaft 5a of the rotor 5b fitted to the reducer 4 extends (the direction in which the shaft portion 5a1 on one side extends) are both on one side of the axial direction and are consistent.

[0015] The electric vehicle drive device 1 further includes an inverter 3 that converts DC power and AC power. The inverter 3 performs DC / AC conversion between a DC power source (not shown) and the multi-phase coils 5c2. In this embodiment, the inverter 3 is provided inside the case member 4a of the speed reducer 4. The portion of the case member 4a where the inverter 3 is located is sealed by an inverter lid portion 3b via a seal member 14. By providing the inverter 3 inside the case member 4a, the electric vehicle drive device 1 can be made more compact.

[0016] In this embodiment, the inverter 3 is housed in an inverter case 3a, which is integrated with the case member 4a of the reducer 4. This configuration reduces the number of case components. The reduced number of components contributes to lower costs for the electric vehicle drive device 1. Housed in a metal inverter case 3a, the inverter 3 can suppress noise leakage from the inverter 3 to the outside and noise intrusion from the outside into the inverter case 3a. Furthermore, if the case member 4a and the inverter case 3a are separate components, assembling the case member 4a and the inverter case 3a can result in variations in the arrangement between the case member 4a and the inverter case 3a. However, by integrating the inverter case 3a with the case member 4a of the reducer 4, this variation in arrangement can be suppressed. The configuration is not limited to the one in which the inverter case 3a is integrated with the case member 4a. As shown in FIG. 3 , the inverter 3 may be housed inside the case member 4a of the reducer 4 without the inverter case 3a. 3 is a cross-sectional view showing an outline of another electric vehicle drive device 1 according to embodiment 1. When the inverter case 3 a is not provided, the periphery of the inverter 3 may be sealed with gel or the like to protect the inverter 3 from oil of the reducer 4 or the like.

[0017] As shown in FIG. 1 , the stator 5c has a cylindrical core 5c1, a coil 5c2 wound around the core 5c1, and two coil ends 5c3 (only one is shown in the figure) of the coil 5c2 protruding from the core 5c1. The end of the coil end 5c3, located on one axial side of the core 5c1, has a terminal 8 to which phase power is supplied from the inverter 3. The shaft 5a is rotatably supported by bearings 9 and 10. The bearing 9 supports one shaft portion 5a1 extending axially from the rotor 5b and is provided adjacent to the central through-hole 7a of the motor bracket 7. The bearing 10 supports the other shaft portion 5a2 extending axially from the rotor 5b and is provided in the motor housing 6. A shaft grounding member 11 is provided on the other shaft portion 5a2 protruding axially from the motor housing 6 to ground the shaft 5a. The shaft grounding member 11 is installed as a countermeasure against shaft voltage. The shaft grounding member 11 slides between the shaft 5a and the grounded motor housing 6, establishing electrical continuity between them. The shaft grounding member 11 is covered by an earth cover 15. An oil seal 18 is provided in the through-hole of the motor housing 6 through which the other shaft portion 5a2 passes.

[0018] The reducer 4 has, as a speed reduction mechanism, multiple gears, multiple gear shafts that are parallel to the axial direction of the motor 2 and integrated with the gears, which are shafts of the reducer 4, and bearings that support the gear shafts. The reducer 4 converts the rotation of the motor 2 and transmits it to the wheel axle. In this embodiment, the reducer 4 has three gear shafts 4b, 4c, and 4d. Shaft 5a and gear shaft 4b are located at the same axial position. Shaft 5a and gear shaft 4b are connected by engagement and transmit power between them (the form of engagement is not shown). Gear shaft 4c is a shaft that rotates at a different position from gear shaft 4b and transmits power at a reduced speed compared to gear shaft 4b due to gear meshing. Gear shaft 4d is a shaft that rotates at an even different position from gear shaft 4c and transmits power at a reduced speed compared to gear shaft 4c due to gear meshing.

[0019] A differential mechanism 12 is attached to the gear shaft 4d. The differential mechanism 12 branches the output shaft and provides the function of absorbing the difference in rotation speed between the left and right wheels when the vehicle is driven, allowing the reduction mechanism to absorb the difference in rotation speed between the left and right wheels. The reduction mechanism is housed in a case member 4a of the reducer 4. In this embodiment, the case member 4a is composed of a housing portion 4a1 that is open on one axial side and a lid portion 4a2 that covers the opening of the housing portion 4a1. The lid portion 4a2 abuts against an end of the housing portion 4a1 that is disposed substantially parallel to the rotation plane of the gears. The gear shafts 4b, 4c, and 4d are sandwiched between the housing portion 4a1 and the lid portion 4a2 and rotatably supported by a bearing 19 provided at the bottom of the housing portion 4a1 and a bearing 20 provided in the lid portion 4a2. An oil seal 18 is provided in the through hole of the case member 4a through which the gear shaft 4d passes.

[0020] The motor housing 6, motor bracket 7, and case member 4a are manufactured by, for example, aluminum die-casting. In this embodiment, the motor housing 6 is formed into a cylindrical shape with one axial end open and a bottom. This configuration allows the motor housing 6 to be mass-produced inexpensively by aluminum die-casting or the like. Furthermore, the number of parts can be reduced compared to a configuration in which the other axial end of the motor housing 6 is divided. Furthermore, the motor 2 can be easily assembled by inserting the parts of the motor main body 5 into the motor housing 6 through the opening in the motor housing 6, thereby improving the ease of assembly and productivity of the electric vehicle drive device 1.

[0021] <Sealing Structure> The sealing structure, which is a key feature of the present application, will now be described. As shown in FIG. 2 , the motor bracket 7 has one or more outer through-holes 7 b that penetrate the motor bracket 7 in the axial direction, radially outward of the central through-hole 7 a. In this embodiment, the motor bracket 7 has four outer through-holes 7 b, but the number of outer through-holes 7 b is not limited to four. As shown in FIG. 1 , the motor housing 6 or the motor bracket 7 has a cylindrical cover portion 13 that covers the entire radially outer side of the openings on one axial side of all of the outer through-holes 7 b. One axial end face of the cover portion 13 abuts against the case member 4 a of the reducer 4 via a seal member 14, thereby being sealed. In this embodiment, the motor bracket 7 abuts against the case member 4 a and is fixed to the case member 4 a.

[0022] The sealing member 14 is, for example, a liquid gasket, a metal gasket, or a rubber member such as an O-ring, but is not limited to these and may be other members. In the configuration of the present application, the sealing member 14 is not limited in any way.

[0023] With this configuration, compared to Patent Document 2, the motor 2 can be assembled to the reducer 4 as a standalone unit, thereby improving the ease of assembly and productivity of the electric vehicle drive device 1. Furthermore, since the motor 2 can be inspected as a standalone unit, variations in the motor 2 can be identified, improving the quality of the motor 2 and reducing the cost of inspecting the motor 2. The improved quality of the motor 2 ensures the reliability of the electric vehicle drive device 1. Furthermore, compared to Patent Document 1, providing the outer through-hole 7b in the motor bracket 7 reduces the material cost of the electric vehicle drive device 1 and reduces the weight of the electric vehicle drive device 1. Furthermore, since the motor 2 and the reducer 4 are sealed during assembly rather than being assembled after sealing each of them, the seal structure is simple, allowing the electric vehicle drive device 1 to be made smaller.

[0024] The seal structure of this embodiment will now be described in detail. The motor bracket 7 covers an opening on one axial side of the motor housing 6. The motor bracket 7 has a cylindrical bracket one-side extension portion 7c that extends to one axial side from a portion where the central through-hole 7a and the outer through-hole 7b are provided, and the bracket one-side extension portion 7c is the cover portion 13. This configuration allows the motor housing 6 to be manufactured in a simple, bottomed cylindrical shape. Because the shape of the motor housing 6 is simple, the cost of the motor housing 6 can be reduced.

[0025] In this embodiment, a seal member 14 seals the gap between the opening on one axial side of the motor housing 6 and the motor bracket 7. The motor housing 6 is fixed to the motor bracket 7. This configuration easily protects the inside of the motor housing 6 from the outside. Furthermore, a case through-hole 4a3 is provided in the portion of the case member 4a of the reducer 4 surrounded by the cover portion 13, through which the shaft portion 5a1 on one side or the gear shaft 4b, which is the shaft of the reducer 4 to which the shaft portion 5a1 on one side is connected, passes. This configuration easily connects the shaft portion 5a1 on one side to the gear shaft 4b via the case through-hole 4a3. Furthermore, because the case through-hole 4a3 is covered by the cover portion 13, the case through-hole 4a3 can be sealed from the outside. Furthermore, in this embodiment, the inverter case 3a is integrated with the case member 4a of the reducer 4, improving the flatness of the portion of the case member 4a that abuts the motor bracket 7, thereby improving sealing performance.

[0026] <Wiring Structure> The wiring structure of the present application will be described. An inverter through-hole 4a4 is provided axially through the portion of the case member 4a of the reducer 4 surrounded by the cover portion 13. The inverter 3 and the motor main body 5 are connected via the outer through-hole 7b and the inverter through-hole 4a4. The motor main body 5 has multiple locations for connection to the inverter 3. Therefore, various connection lines, such as the phase power lines 3c and the sensor signal lines 3d, are arranged between the motor main body 5 and the inverter 3. This configuration allows the various connection lines to be easily connected to the motor main body 5 and the inverter 3 via the outer through-hole 7b and the inverter through-hole 4a4. Furthermore, the end face of the cover portion 13 abuts against the case member 4a of the reducer 4 via the seal member 14, and the inverter through-hole 4a4 is covered by the cover portion 13. This allows the inverter through-hole 4a4 to be sealed without the need for an additional seal structure. Since an additional seal structure is not required, the productivity of the electric vehicle drive device 1 can be improved.

[0027] In this embodiment, the end of the coil end 5c3 located on one axial side of the core 5c1 has a terminal 8 to which phase power is supplied from the inverter 3, and the terminal 8 and the inverter 3 are connected via the outer through-hole 7b and the inverter through-hole 4a4. The inverter 3 has a phase power line 3c that supplies phase power from the inverter 3 to the terminal 8. The phase power line 3c passes through the outer through-hole 7b and the inverter through-hole 4a4. With this configuration, the terminal 8 and the inverter 3 can be connected by the phase power line 3c via the outer through-hole 7b and the inverter through-hole 4a4, making it easy to connect the terminal 8 and the inverter 3. Furthermore, the length of the phase power line 3c, which is the wiring connecting the terminal 8 and the inverter 3, can be shortened. Because the length of the phase power line 3c is shortened, the effects of noise can be reduced.

[0028] In this embodiment, the motor main body 5 includes a temperature sensor 16. The temperature sensor 16 measures the temperature of the coil 5c2. The temperature sensor 16 is, for example, a thermistor. The inverter 3 controls the operation of the motor 2 using the temperature information measured by the temperature sensor 16. The temperature sensor 16 is attached to a coil end 5c3 located on one axial side of the core 5c1, and the temperature sensor 16 and the inverter 3 are connected via the outer through-hole 7b and the inverter through-hole 4a4. The inverter 3 includes a sensor signal line 3d connecting the inverter 3 to the temperature sensor 16. The sensor signal line 3d passes through the outer through-hole 7b and the inverter through-hole 4a4. This configuration allows the temperature sensor 16 and the inverter 3 to be connected by the sensor signal line 3d via the outer through-hole 7b and the inverter through-hole 4a4, making it easy to connect the temperature sensor 16 and the inverter 3 without being affected by other components. Furthermore, the length of the sensor signal line 3d, which is the wiring connecting the temperature sensor 16 and the inverter 3, can be shortened. Since the length of the sensor signal line 3d is shortened, the influence of noise can be reduced.

[0029] In this embodiment, the motor main body 5 includes a rotation sensor 17. The rotation sensor 17 detects the rotation (rotation angle and rotation speed) of the motor main body 5. The inverter 3 controls the operation of the motor 2 using information about the rotation of the motor main body 5 measured by the rotation sensor 17. The rotation sensor 17 is, for example, a resolver. The rotation sensor 17 is not limited to a resolver and may be a magnetic sensor using a magnetoelectric conversion element such as a Hall element. The rotation sensor 17 is attached to the motor bracket 7 inside the cover 13. The rotation sensor 17 and the inverter 3 are connected via the inverter through-hole 4a4. The inverter 3 includes a sensor signal line 3d connecting the inverter 3 and the rotation sensor 17. The sensor signal line 3d passes through the inverter through-hole 4a4. With this configuration, the rotation sensor 17 and the inverter 3 can be connected by the sensor signal line 3d via the inverter through-hole 4a4, making it easy to connect the rotation sensor 17 and the inverter 3 without being affected by other components. Furthermore, it is possible to shorten the length of the sensor signal line 3d, which is the wiring connecting the rotation sensor 17 and the inverter 3. Since the length of the sensor signal line 3d is shortened, it is possible to reduce the influence of noise.

[0030] In this embodiment, the rotation sensor 17 is provided on one axial side of the motor bracket 7, and the motor bracket 7 is made of metal. The motor bracket 7 is made of, for example, aluminum. The motor bracket 7 is grounded. With this configuration, the electrically conductive motor bracket 7 is interposed between the stator 5c and the rotation sensor 17, thereby reducing the adverse effect of leakage magnetic flux from the stator 5c entering the rotation sensor 17 and causing noise. In this embodiment, the rotation sensor 17 is provided on one axial side of the motor bracket 7. However, the location of the rotation sensor 17 is not limited thereto, and the rotation sensor 17 may also be provided on the other axial side of the motor bracket 7. When the rotation sensor 17 is provided on the other axial side of the motor bracket 7, the rotation sensor 17 and the inverter 3 are connected by a sensor signal line 3d via the outer through-hole 7b and the inverter through-hole 4a4. When the rotation sensor 17 is provided on the other axial side of the motor bracket 7, it is desirable to cover the periphery of the rotation sensor 17 with a magnetic shield.

[0031] As described above, the electric vehicle driving device 1 according to the first embodiment includes the motor main body 5 having the shaft 5a, the rotor 5b, and the stator 5c, the motor housing 6 to which the stator 5c is fixed and which is open on one axial side, the motor bracket 7 covering one axial side of the stator 5c and the rotor 5b and having a central through-hole 7a through which the shaft portion 5a1 on one side extending from the rotor 5b on one axial side passes, and the reducer 4 connected to the shaft portion 5a1 on one side and reducing the rotational speed of the shaft 5a for output. The motor bracket 7 has a center One or more outer through-holes 7b are formed radially outward of the core through-hole 7a, and the motor housing 6 or motor bracket 7 has a cylindrical cover portion 13 that completely covers the radially outer side of the openings on one axial side of all of the outer through-holes 7b. One axial end face of the cover portion 13 abuts and is sealed against the case member 4a of the reducer 4 via a seal member 14 along the entire circumference. This allows the motor 2 to be assembled to the reducer 4 as a standalone unit, compared to Patent Document 2, thereby improving the ease of assembly and productivity of the electric vehicle drive device 1. Furthermore, because the motor 2 can be inspected standalone, variations in the motor 2 can be identified, thereby improving the quality of the motor 2. This improved quality of the motor 2 ensures the reliability of the electric vehicle drive device 1.

[0032] Furthermore, compared to Patent Document 1, providing the outer through-hole 7b in the motor bracket 7 reduces the material costs of the electric vehicle drive device 1 and makes it possible to reduce the weight of the electric vehicle drive device 1. Furthermore, since the motor 2 and the reducer 4 are not sealed separately and then assembled, but are sealed at the time of assembly, the sealing structure is simple and the electric vehicle drive device 1 can be made smaller.

[0033] When the motor bracket 7 covers the opening on one axial side of the motor housing 6, the motor bracket 7 has a cylindrical bracket one-side extension portion 7c extending to one axial side from the portion where the central through hole 7a and the outer through hole 7b are provided, and the bracket one-side extension portion 7c is the cover portion 13, the motor housing 6 can be manufactured in a simple, bottomed, cylindrical shape. Because the shape of the motor housing 6 is simple, the cost of the motor housing 6 can be reduced. Furthermore, when the gap between the opening on one axial side of the motor housing 6 and the motor bracket 7 is sealed with a seal member, the inside of the motor housing 6 can be easily protected from the outside.

[0034] When a case through-hole 4a3 through which one shaft portion 5a1 or the gear shaft 4b, which is the shaft of the reducer 4 to which the one shaft portion 5a1 is connected, passes is provided in the portion of the case member 4a of the reducer 4 surrounded by the cover portion 13, the one shaft portion 5a1 and the gear shaft 4b can be easily connected via the case through-hole 4a3. Furthermore, since the case through-hole 4a3 is covered by the cover portion 13, the case through-hole 4a3 can be sealed from the outside.

[0035] The electric vehicle drive device 1 includes an inverter 3 that converts DC power and AC power, the inverter 3 is disposed inside the case member 4a of the reducer 4, and an inverter through-hole 4a4 that penetrates axially is provided in the portion of the case member 4a of the reducer 4 that is surrounded by the cover portion 13. When the inverter 3 and the motor main body 5 are connected via the outer through-hole 7b and the inverter through-hole 4a4, various connection lines such as the phase power lines 3c and the sensor signal lines 3d can be easily connected via the outer through-hole 7b and the inverter through-hole 4a4. Furthermore, because the end face of the cover portion 13 abuts against the case member 4a of the reducer 4 via the seal member 14 and the inverter through-hole 4a4 is covered by the cover portion 13, the inverter through-hole 4a4 can be sealed without the need for an additional sealing structure. Because an additional sealing structure is not required, the productivity of the electric vehicle drive device 1 can be improved.

[0036] When the inverter 3 is housed in an inverter case 3a and the inverter case 3a is integrated with the case member 4a of the reducer 4, it is possible to reduce the number of case components. The reduced number of components contributes to lower costs for the electric vehicle drive device 1. Furthermore, when the case member 4a and the inverter case 3a are separate bodies, assembling the case member 4a and the inverter case 3a can cause variations in arrangement between the case member 4a and the inverter case 3a, but by integrating the inverter case 3a with the case member 4a of the reducer 4, it is possible to suppress variations in arrangement.

[0037] The stator 5c has a cylindrical core 5c1, a coil 5c2 wound around the core 5c1, and two coil ends 5c3 that are ends of the coil 5c2 and protrude from the core 5c1, and the end of the coil end 5c3 located on one axial side of the core 5c1 has a terminal 8 to which phase power is supplied from the inverter 3, and when the terminal 8 and the inverter 3 are connected via the outer through hole 7b and the inverter through hole 4a4, the terminal 8 and the inverter 3 can be connected by a phase power line 3c via the outer through hole 7b and the inverter through hole 4a4, so that the terminal 8 and the inverter 3 can be easily connected. Furthermore, the length of the phase power line 3c that connects the terminal 8 and the inverter 3 can be shortened.

[0038] When the temperature sensor 16 is attached to the coil end 5c3 located on one axial side of the core 5c1 and the temperature sensor 16 is connected to the inverter 3 via the outer through-hole 7b and the inverter through-hole 4a4, the temperature sensor 16 can be connected to the inverter 3 by the sensor signal wire 3d via the outer through-hole 7b and the inverter through-hole 4a4, so that the temperature sensor 16 can be easily connected to the inverter 3 without being affected by other components. In addition, the length of the sensor signal wire 3d that connects the temperature sensor 16 to the inverter 3 can be shortened.

[0039] When the rotation sensor 17 that detects the rotation of the motor main body 5 is attached to the motor bracket 7 inside the cover 13 and the rotation sensor 17 and the inverter 3 are connected via the inverter through-hole 4a4, the rotation sensor 17 and the inverter 3 can be connected by the sensor signal wire 3d via the inverter through-hole 4a4, so that the rotation sensor 17 and the inverter 3 can be easily connected without being affected by other components. Also, the length of the sensor signal wire 3d that connects the rotation sensor 17 and the inverter 3 can be shortened.

[0040] If the rotation sensor is provided on one axial side of the motor bracket 7 and the motor bracket 7 is made of metal, the conductive motor bracket 7 is interposed between the stator 5c and the rotation sensor 17, thereby reducing the adverse effect of leakage magnetic flux from the stator 5c entering the rotation sensor 17 and causing noise. Furthermore, if the motor housing 6 is formed in a cylindrical shape with a bottom and an opening on one axial side, the motor housing 6 can be mass-produced inexpensively using aluminum die-casting or the like. Furthermore, the motor 2 can be easily assembled by inserting the components of the motor main body 5 into the motor housing 6 through the opening, thereby improving the ease of assembly and productivity of the electric vehicle drive device 1.

[0041] Second Embodiment An electric vehicle drive device 1 according to a second embodiment will now be described. Figure 4 is a cross-sectional view showing an outline of the electric vehicle drive device 1 according to the second embodiment, with details of the internal configuration omitted. In the electric vehicle drive device 1 according to the second embodiment, the motor housing 6 abuts against the case member 4a via a seal member 14, and the motor housing 6 is fixed to the case member 4a.

[0042] In this embodiment, the motor housing 6 has a cylindrical housing one-side extension portion 6a that extends to one axial side radially outside the motor bracket 7. The motor bracket 7 is disposed inside the housing one-side extension portion 6a, and the portion of the housing one-side extension portion 6a on one axial side of the motor bracket 7 is the cover portion 13.

[0043] This configuration eliminates the need for a seal member between the motor bracket 7 and the motor housing 6, improving the ease of assembly and productivity of the electric vehicle drive device 1. In addition, the cost of the electric vehicle drive device 1 can be reduced.

[0044] The diagram of the motor 2 shown in this application is of the commonly used inner rotor radial gap type arrangement. However, the configuration of the motor 2 is not limited to this, and other forms such as outer rotor radial gap type, axial gap type, and other motor types are also possible. The configuration of this application is also applicable to motors of other configurations, and there is no intention to limit the motor configuration.

[0045] Furthermore, although various exemplary embodiments and examples are described in this application, the various features, aspects, and functions described in one or more embodiments are not limited to the application of a particular embodiment, but may be applied to the embodiments alone or in various combinations. Therefore, countless modifications not illustrated are contemplated within the scope of the technology disclosed in this specification. For example, this includes cases where at least one component is modified, added, or omitted, or where at least one component is extracted and combined with components of another embodiment.

[0046] 1 Electric vehicle drive device, 2 Motor, 3 Inverter, 3a Inverter case, 3b Inverter cover portion, 3c Phase power line, 3d Sensor signal line, 4 Reducer, 4a Case member, 4a1 Storage portion, 4a2 Cover portion, 4a3 Case through hole, 4a4 Inverter through hole, 4b, 4c, 4d Gear shaft, 5 Motor main body portion, 5a Shaft, 5a1 One side shaft portion, 5a2 Other side shaft portion, 5b Rotor, 5c Stator, 5c1 Core, 5c2 Coil, 5c3 Coil end, 6 Motor housing, 6a Housing one side extension portion, 7 Motor bracket, 7a Central through hole, 7b Outer through hole, 7c Bracket one side extension portion, 8 Terminal, 9 Bearing, 10 Bearing, 11 Shaft earth member, 12 Differential mechanism, 13 Cover portion, 14 Seal member, 15 Earth cover, 16 Temperature sensor, 17 rotation sensor, 18 oil seal, 19, 20 bearing

Claims

1. a motor body including a shaft, a rotor that rotates integrally with the shaft, and a stator that surrounds the rotor from the radially outer side; a motor housing having the stator fixed therein and an opening on one side in the axial direction; a motor bracket covering one axial side of the stator and the rotor and having a central through hole through which one axial portion of the shaft extending from the rotor passes; a reducer connected to the shaft portion on the one side and configured to reduce the rotation speed of the shaft and output the reduced rotation speed, the motor bracket has one or more outer through holes extending axially therethrough, radially outward of the central through hole; the motor housing or the motor bracket has a cylindrical cover portion that covers the entire radial outside of openings on one axial side of all the outer through holes, An electric vehicle drive device in which an end face on one side in the axial direction of the cover portion is in contact with a case member of the reducer via a sealing member along the entire circumference, thereby being sealed.

2. the motor housing has a cylindrical housing one-side extension portion that extends radially outward from the motor bracket to one side in the axial direction, the motor bracket is disposed inside the housing one-side extension portion, The electric vehicle drive device according to claim 1 , wherein a portion of the housing one-side extension portion on one side in the axial direction of the motor bracket serves as the cover portion.

3. the motor bracket covers an opening on one side of the motor housing in the axial direction, the motor bracket has a cylindrical bracket one-side extension portion that extends to one side in the axial direction from a portion where the central through hole and the outer through hole are provided, The electric vehicle drive device according to claim 1 , wherein the bracket one-side extension portion is the cover portion.

4. The electric vehicle drive device according to claim 3, wherein a seal member seals the gap between the opening on one axial side of the motor housing and the motor bracket.

5. 5. The electric vehicle drive device according to claim 1, wherein a case through hole is provided in a portion of the case member of the reducer surrounded by the cover portion, through which the shaft portion on one side or the shaft of the reducer to which the shaft portion on one side is connected passes.

6. An inverter is provided for converting DC power and AC power, the inverter is provided inside a case member of the reducer, an inverter through-hole that penetrates in the axial direction is provided in a portion of the case member of the reducer that is surrounded by the cover portion, The electric vehicle drive device according to claim 1 , wherein the inverter and the motor main body are connected via the outer through-hole and the inverter through-hole.

7. The inverter is housed in an inverter case, The electric vehicle drive device according to claim 6, wherein the inverter case is integrated with a case member of the reducer.

8. The stator has a cylindrical core, a coil wound around the core, and two coil ends that are ends of the coil and protrude from the core, an end of the coil end arranged on one side in the axial direction of the core has a terminal to which phase power is supplied from the inverter, The electric vehicle drive device according to claim 6 , wherein the terminal and the inverter are connected via the outer through-hole and the inverter through-hole.

9. The stator has a cylindrical core, a coil wound around the core, and two coil ends that are ends of the coil and protrude from the core, a temperature sensor attached to the coil end disposed on one side of the core in the axial direction; The electric vehicle drive device according to claim 6 , wherein the temperature sensor and the inverter are connected via the outer through-hole and the inverter through-hole.

10. a rotation sensor for detecting rotation of the motor main body is attached to the motor bracket on the inside of the cover; The electric vehicle drive device according to claim 6 , wherein the rotation sensor and the inverter are connected via the inverter through-hole.

11. the rotation sensor is provided on one side of the motor bracket in the axial direction, The electric vehicle drive device according to claim 10, wherein the motor bracket is made of metal.

12. The electric vehicle drive device according to claim 1 , wherein the motor housing is formed in a cylindrical shape with a bottom and one axial side open.