Electric vehicle drive device

Abstract

An electric vehicle drive device (1) includes: a motor main body (5); the stator (5c) is fixed on the inner side of the motor shell (6), and one axial side of the motor shell (6) is open; a motor bracket (7) covering one axial side of the stator (5c) and the rotor (5b) and having a central through hole (7a) through which a side shaft portion (5a1) extending from the rotor (5b) to one axial side passes; and a speed reducer (4) that reduces the rotational speed of the shaft (5a) and outputs the reduced rotational speed, the motor bracket (7) has one or more outer through holes (7b) that penetrate in the axial direction on the outside in the radial direction of the center through hole (7a), and the motor housing (6) or the motor bracket (7) has a cylindrical cover part (13). The cover portion (13) covers the radial outer side of the opening portion of the axial side of all the outer through holes (7b) over the whole circumference, and the end face of the axial side of the cover portion (13) abuts against a shell component (4a) of the speed reducer (4) across a sealing component (14) over the whole circumference and is sealed.

Description

Technical Field

[0001] This application relates to an electric vehicle drive system. Background Technology

[0002] In recent years, due to concerns about environmental issues such as global warming, the replacement of vehicles powered by traditional internal combustion engines with electric vehicles powered by electric motors that do not emit carbon dioxide during operation is rapidly underway. The electric vehicle drive system consists of an electric motor, a reduction gear, and an inverter. The reduction gear slows down the electric motor and transmits the speed to the axle, while the inverter converts the DC power stored in the battery into any AC power and efficiently controls the electric motor's drive. Previously, the electric motor, reduction gear, and inverter were manufactured separately and interconnected, but a structure integrating them to achieve miniaturization has been proposed (e.g., Patent Document 1).

[0003] Patent Document 1 discloses an integrated motor and reducer configuration. In this structure, a plate-like portion is provided on the end face of the motor-side housing, on the side that contacts the reducer. Conversely, a plate-like portion is provided on the end face of the reducer side, opposite to the motor-side end face. Therefore, when the motor and reducer are combined, the mating surface becomes a double-shell structure. This double-shell structure is formed by separately manufacturing the motor unit and the reducer unit, which are already sealed to the outside, and then combining them after completing their respective inspections. Although sealing to the outside is ensured, the double-shell structure presents a problem in miniaturizing, reducing cost, and lightening the electric vehicle drive unit.

[0004] A structure for an electric vehicle drive unit that does not form a double housing has been disclosed (e.g., Patent Document 2). Patent Document 2 discloses a structure in which the end face of the reducer side is shared with the face of the reducer housing within a housing that typically houses the motor. Compared to manufacturing the motor and reducer separately and then combining them, the above-described configuration avoids the mating surface becoming double. Since the mating surface is not double, it is considered to contribute to the miniaturization, cost reduction, and weight reduction of the electric vehicle drive unit. Existing technical documents Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2020-150608 Patent Document 2: Japanese Patent No. 5900012 Summary of the Invention The technical problem that the invention aims to solve

[0006] In the aforementioned patent document 2, the mating surface can be avoided from becoming double. However, the motor can only be functionally checked after assembly, including the bearings at both ends of the rotor. If this structure is adopted, the assembly process must be advanced to the process of combining the reducer and the motor to achieve the function of a motor. Therefore, it is impossible to check the individual motor; only the performance of the system combined with the reducer can be obtained. Consequently, it is difficult to grasp the deviations of the individual motor and the reducer, thus posing a problem in ensuring the reliability of the electric vehicle drive system.

[0007] Furthermore, the motor assembly process requires high-precision shaft alignment to prevent the tiny gaps between the rotor and stator from contacting, and precision assembly using assembly fixtures and the like is employed. In Patent Document 2 mentioned above, since one side of the rotor bearing is located in the reducer housing, the assembly object becomes a large product including the reducer during the assembly process. Therefore, there are problems such as difficulties in precision assembly operations and reduced productivity of the electric vehicle drive unit.

[0008] Therefore, the purpose of this application is to obtain an electric vehicle drive device that ensures reliability and improves productivity while miniaturizing, reducing cost and lightening weight. Technical solutions adopted to solve technical problems

[0009] The electric vehicle drive device disclosed in this application includes: a motor body having a shaft, a rotor rotating integrally with the shaft, and a stator surrounding the rotor from the radially outer side; a motor housing having the stator fixed to the inner side of the motor housing, and the motor housing having an opening on one axial side; a motor bracket covering the stator and one axial side of the rotor, and having a central through hole through which a side shaft portion extending from the rotor to the axial side passes; and a reducer connected to the side shaft portion and outputting a reduction in the rotational speed of the shaft, the motor bracket having one or more axially penetrating outer through holes on the radially outer side of the central through hole, the motor housing or the motor bracket having a cylindrical cover covering the radially outer side of the openings on the axial side of all the outer through holes throughout the entire circumference, and the end face of the axial side of the cover being sealed by abutting against the housing member of the reducer throughout the entire circumference through a sealing member. Invention Effects

[0010] The electric vehicle drive device disclosed in this application includes: a motor body having a shaft, a rotor, and a stator; a motor housing with the stator fixed to the inside and 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 a side shaft portion extending from the rotor to the axial side passes; and a reducer connected to the side shaft portion and outputting a reduction in the rotational speed of the shaft. The motor bracket has one or more outer through holes radially outside the central through hole. The motor housing or motor bracket has a cylindrical cover that covers the radially outer side of the openings on the axial side of all the outer through holes throughout the entire circumference. The end face on the axial side of the cover is sealed by a sealing member abutting against the housing member of the reducer throughout the entire circumference. Therefore, compared with Patent Document 2, it is possible to assemble the motor unit onto the reducer, thereby improving the assemblability and manufacturability of the electric vehicle drive device. Furthermore, it is possible to inspect the individual motor units, thus enabling the identification of deviations in the individual motor units and improving motor quality. This improved motor quality ensures the reliability of the electric vehicle drive device. Furthermore, compared to Patent Document 1, by providing an external through-hole on the motor bracket, the material cost of the electric vehicle drive unit can be reduced, and the electric vehicle drive unit can be made lighter. In addition, since the structure is assembled without sealing the motor and reducer separately, but rather sealing is performed during assembly, the sealing structure is simple, thus enabling miniaturization of the electric vehicle drive unit. Attached Figure Description

[0011] Figure 1 This is a cross-sectional view showing an outline of the electric vehicle drive system according to Embodiment 1. Figure 2 This is a top view showing an outline of the motor bracket of the electric vehicle drive unit according to Embodiment 1. Figure 3 This is a cross-sectional view showing an outline of another electric vehicle drive system according to Embodiment 1. Figure 4 This is a cross-sectional view showing an outline of the electric vehicle drive system of Embodiment 2. Detailed Implementation

[0012] Hereinafter, an electric vehicle drive device according to an embodiment of the present application will be described based on the accompanying drawings. Furthermore, in each drawing, the same or equivalent components and parts will be labeled with the same symbols for explanation.

[0013] Implementation method 1. Figure 1 This is a cross-sectional view showing an outline of the electric vehicle drive unit 1 according to Embodiment 1, and the view is shown in a manner that omits details of the internal structure. Figure 2This is a top view of the motor bracket 7 of the electric vehicle drive unit 1, viewed from the axial side. The electric vehicle drive unit 1, installed in the electric vehicle, is a device that transmits the rotation of the motor 2, controlled by an inverter 3 connected to an external DC power supply, to the wheel axle of the electric vehicle via a reducer 4.

[0014] <Electric Vehicle Drive System 1> like Figure 1 As shown, the electric vehicle drive unit 1 includes: a motor body 5 having a shaft 5a, a rotor 5b rotating integrally with the shaft 5a, and a stator 5c surrounding the rotor 5b radially outward; a motor housing 6, with the stator 5c fixed to the inner side of the motor housing 6, and the motor housing 6 having an opening on one axial side; a motor bracket 7 covering the stator 5c and the rotor 5b on one axial side, and having a central through hole 7a through which a side shaft portion 5a1 extending from the rotor 5b to one axial side passes; and a reducer 4 connected to the side shaft portion 5a1, which reduces the rotational speed of the shaft 5a before outputting the speed. The motor 2 is composed of the motor body 5, the motor housing 6, and the motor bracket 7. The axial side refers to the right side of the motor 2 relative to the reducer 4 in the figure. The direction of the opening of the motor housing 6 and the direction of extension of the shaft 5a of the rotor 5b fitted to the reducer 4 (the extension direction of the side shaft portion 5a1) are both on one axial side and aligned.

[0015] The electric vehicle drive unit 1 also includes an inverter 3 that converts DC power to AC power. The inverter 3 performs DC-AC conversion between a DC power supply (not shown) and multi-phase coils 5c2. In this embodiment, the inverter 3 is disposed inside the housing member 4a of the reducer 4. The portion of the housing member 4a in which the inverter 3 is disposed is sealed by the inverter cover 3b and, through the sealing member 14. By placing the inverter 3 inside the housing member 4a, the electric vehicle drive unit 1 can be miniaturized.

[0016] Furthermore, in this embodiment, the inverter 3 is housed in an inverter housing 3a, and the inverter housing 3a is integrated with the housing member 4a of the reducer 4. This structure reduces the number of components constituting the housing. Due to the reduced number of components, the cost of the electric vehicle drive unit 1 can be reduced. By housing the inverter 3 in an inverter housing 3a made of metal, noise leakage from the inverter 3 to the outside can be suppressed, as can noise intrusion into the inverter housing 3a from the outside. Furthermore, when the housing member 4a and the inverter housing 3a are separate, configuration deviations may occur between them during assembly. However, by integrating the inverter housing 3a with the housing member 4a of the reducer 4, configuration deviations can be suppressed. The structure of integrating the inverter housing 3a with the housing member 4a is not limited to this; other structures may also be used. Figure 3 As shown, the inverter 3 can also be placed inside the housing component 4a of the reducer 4 without the inverter housing 3a. Figure 3 This is a cross-sectional view showing an outline of another electric vehicle drive device according to Embodiment 1. Without providing an inverter housing 3a, the area around the inverter 3 can be sealed with gel or the like to protect the inverter 3 from the oil or other contaminants from the gearbox 4.

[0017] like Figure 1 As shown, 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) protruding from the core 5c1 as the ends of the coil 5c2. 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 supported by bearings 9 and 10 to allow free rotation. The bearing 9 supporting one side of the shaft portion 5a1 extending axially from the rotor 5b is positioned adjacent to the central through-hole 7a of the motor bracket 7. The bearing 10 supporting the other side of the shaft portion 5a2 extending axially from the rotor 5b is located in the motor housing 6. On the other side of the shaft portion 5a2 protruding axially from the motor housing 6, a shaft grounding member 11 is provided to ground the shaft 5a. The shaft grounding member 11 is a member provided as a countermeasure against shaft voltage. The shaft grounding member 11 slides between the shaft 5a and the grounded motor housing 6, making them electrically connected. The shaft grounding member 11 is covered by a grounding cover 15. An oil seal 18 is provided at the through hole of the motor housing 6 through which the shaft portion 5a2 passes on the other side.

[0018] The reducer 4, as a speed reduction mechanism, has multiple gears, multiple gear shafts (i.e., gear shafts) that are parallel to the axis of the motor 2 and integrated with the gears, and bearings supporting 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 arranged in the same axial position. Shaft 5a and gear shaft 4b are connected by a meshing connection and transmit power between them (the meshing configuration is not shown). Gear shaft 4c is a shaft that rotates at a different position than gear shaft 4b, and transmits power at a reduced speed compared to gear shaft 4b through gear meshing. Gear shaft 4d is a shaft that rotates further at a different position than gear shaft 4c, and transmits power at a reduced speed compared to gear shaft 4c through gear meshing.

[0019] A differential mechanism 12 is mounted on the gear shaft 4d. The differential mechanism 12 enables the output shaft to branch and absorb the difference in rotational speed between them, thereby allowing the reduction mechanism to absorb the difference in rotational speed between the left and right wheels during vehicle operation. The reduction mechanism is housed in the housing member 4a of the reducer 4. In this embodiment, the housing member 4a consists of a receiving portion 4a1 with an axial opening and a cover portion 4a2 covering the opening of the receiving portion 4a1. The cover portion 4a2 abuts against the end of the receiving portion 4a1, which is positioned approximately parallel to the rotational plane of the gear. The gear shafts 4b, 4c, and 4d are held between the receiving portion 4a1 and the cover portion 4a2, and are supported by a bearing 19 located at the bottom of the receiving portion 4a1 and a bearing 20 located at the cover portion 4a2, allowing them to rotate freely. An oil seal 18 is provided at the through hole through which the gear shaft 4d passes in the housing member 4a.

[0020] The motor housing 6, motor bracket 7, and housing component 4a are manufactured, for example, by aluminum die casting. In this embodiment, the motor housing 6 is formed as a bottomed cylindrical shape with an opening on one axial side. With the configuration described above, the motor housing 6 can be mass-produced inexpensively by means of aluminum die casting or the like. In addition, compared to a structure where the motor housing 6 is divided on the other axial side, the number of parts can be reduced. Furthermore, the components of the motor body 5 can be inserted into the inside of the motor housing 6 through the opening, thereby facilitating the assembly of the motor 2. Therefore, the assemblability and manufacturability of the electric vehicle drive unit 1 can be improved.

[0021] <Sealing Structure> The sealing structure, which is a major part of this application, will be described. For example... Figure 2 As shown, the motor bracket 7 has one or more axially penetrating outer through holes 7b radially outside the central through hole 7a. In this embodiment, the motor bracket 7 has four outer through holes 7b, but the number of outer through holes 7b is not limited to four. Figure 1As shown, the motor housing 6 or motor bracket 7 has a cylindrical cover 13 that covers the radially outer side of the openings on the axial side of all the outer through holes 7b throughout the entire circumference. The end face on the axial side of the cover 13 is sealed by abutting against the housing member 4a of the reducer 4 through the sealing member 14 throughout the entire circumference. In this embodiment, the motor bracket 7 abuts against the housing member 4a, and the motor bracket 7 is fixed to the housing member 4a.

[0022] The sealing member 14 may be a rubber component such as a liquid gasket, a metal gasket, or an O-ring, but is not limited to these, and may also be other components. In the structure of this application, the sealing member 14 is not limited at all.

[0023] With the configuration described above, compared to Patent Document 2, the motor 2 can be assembled onto the reducer 4 as a single unit, thus improving the assemblability and manufacturability of the electric vehicle drive unit 1. Furthermore, the individual motor 2 units can be inspected, allowing for the identification of deviations, thereby improving the quality of the motor 2 and reducing inspection costs. This improved quality of the motor 2 ensures the reliability of the electric vehicle drive unit 1. Moreover, compared to Patent Document 1, the material cost of the electric vehicle drive unit 1 can be reduced and its weight reduced by providing an outer through-hole 7b on the motor bracket 7. Additionally, since the motor 2 and reducer 4 are sealed during assembly rather than after separate sealing, the sealing structure is simplified, enabling miniaturization of the electric vehicle drive unit 1.

[0024] The sealing structure in this embodiment will be described in detail. The motor bracket 7 covers the opening on one axial side of the motor housing 6. The motor bracket 7 has a cylindrical bracket-side extension 7c that extends axially from the portion having a central through hole 7a and an outer through hole 7b, and this bracket-side extension 7c is a cover portion 13. With the configuration described above, the motor housing 6 can be made into a simple bottomed cylindrical shape. Due to the simple shape of the motor housing 6, the cost of the motor housing 6 can be reduced.

[0025] In this embodiment, the opening on the axial side of the motor housing 6 is sealed to the motor bracket 7 by a sealing member 14. The motor housing 6 is fixed to the motor bracket 7. With the configuration described above, the inner side of the motor housing 6 can be easily protected from external influences. Furthermore, in the portion of the housing member 4a of the reducer 4 surrounded by the cover portion 13, a housing through hole 4a3 is provided through which a side shaft portion 5a1 or the shaft of the reducer 4 connected to the side shaft portion 5a1, i.e., the gear shaft 4b, can pass. With the configuration described above, the side shaft portion 5a1 and the gear shaft 4b can be easily connected via the housing through hole 4a3. Furthermore, since the housing through hole 4a3 is surrounded by the cover portion 13, the housing through hole 4a3 can be sealed from the outside. In addition, in this embodiment, since the inverter housing 3a and the housing member 4a of the reducer 4 are integrated, the flatness accuracy of the portion of the housing member 4a that abuts against the motor bracket 7 can be improved, thereby improving the sealing performance.

[0026] <Wiring Structure> The wiring structure of this application will be described. In the portion of the housing member 4a of the reducer 4 surrounded by the cover portion 13, an inverter through-hole 4a4 extending axially is provided. The inverter 3 and the motor body 5 are connected via the outer through-hole 7b and the inverter through-hole 4a4. The motor body 5 has multiple locations for connection to the inverter 3. Therefore, various connecting wires, such as phase power lines 3c and sensor signal lines 3d, are arranged between the motor body 5 and the inverter 3. With the configuration described above, various connecting wires can be easily connected to the motor body 5 and the inverter 3 via the outer through-hole 7b and the inverter through-hole 4a4. Furthermore, since the end face of the cover portion 13 abuts against the housing member 4a of the reducer 4 through the sealing 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. Since no additional sealing structure is required, the productivity of the electric vehicle drive unit 1 can be improved.

[0027] In this embodiment, the end of the coil edge 5c3 located on one axial side of the core 5c1 has a terminal 8 for supplying phase power from the inverter 3. The terminal 8 is connected to the inverter 3 via an outer through-hole 7b and an inverter through-hole 4a4. The inverter 3 has a phase power line 3c for supplying 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 the configuration described above, the terminal 8 and the inverter 3 can be connected via the outer through-hole 7b and the inverter through-hole 4a4 through the phase power line 3c, thus facilitating easy connection between the terminal 8 and the inverter 3. Furthermore, the length of the wiring connecting the terminal 8 and the inverter 3, i.e., the phase power line 3c, can be shortened. Since the length of the phase power line 3c is shortened, the impact of noise can be reduced.

[0028] In this embodiment, the motor 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 uses the temperature information measured by the temperature sensor 16 to control the operation of the motor 2. The temperature sensor 16 is mounted on the coil end 5c3 located on the axial side of the core 5c1, and the temperature sensor 16 is connected to the inverter 3 via an outer through-hole 7b and an inverter through-hole 4a4. The inverter 3 has a sensor signal line 3d that connects the inverter 3 and the temperature sensor 16. The sensor signal line 3d passes through the outer through-hole 7b and the inverter through-hole 4a4. With the configuration described above, the temperature sensor 16 and the inverter 3 can be connected via the outer through-hole 7b and the inverter through-hole 4a4 through the sensor signal line 3d. Therefore, the temperature sensor 16 and the inverter 3 can be easily connected without being affected by other components. In addition, the length of the wiring connecting the temperature sensor 16 and the inverter 3, i.e., the sensor signal line 3d, can be shortened. Because the length of the sensor signal line 3d is shortened, the impact of noise can be reduced.

[0029] In this embodiment, the motor body 5 has a rotation sensor 17. The rotation sensor 17 detects the rotation (rotation angle and rotation speed) of the motor body 5. The inverter 3 uses the rotation information of the motor body 5 measured by the rotation sensor 17 to control the operation of the motor 2. The rotation sensor 17 is, for example, a resolver. The rotation sensor 17 is not limited to a resolver, but may also be a magnetic sensor using a magnetoelectric conversion element such as a Hall element. The rotation sensor 17 is mounted in part of the motor bracket 7 inside the cover 13. The rotation sensor 17 is connected to the inverter 3 via an inverter through-hole 4a4. The inverter 3 has a sensor signal line 3d that connects the inverter 3 and the rotation sensor 17. The sensor signal line 3d passes through the inverter through-hole 4a4. With the configuration described above, the rotation sensor 17 and the inverter 3 can be connected via the inverter through-hole 4a4 and the sensor signal line 3d, so that the rotation sensor 17 and the inverter 3 can be easily connected without being affected by other components. Furthermore, the length of the wiring connecting the rotation sensor 17 and the inverter 3, i.e., the sensor signal line 3d, can be shortened. Because the length of the sensor signal line 3d is shortened, the impact of noise can be reduced.

[0030] In this embodiment, the rotation sensor 17 is disposed on one axial side of the motor bracket 7, which is made of metal. The material of the motor bracket 7 is, for example, aluminum. The motor bracket 7 is grounded. With the configuration described above, since a conductive motor bracket 7 is sandwiched between the stator 5c and the rotation sensor 17, the adverse effects of leakage flux generated from the stator 5c mixing into the rotation sensor 17 and forming noise can be reduced. In this embodiment, an example of disposing of the rotation sensor 17 on one axial side of the motor bracket 7 is shown, but the configuration of the rotation sensor 17 is not limited to this; it can also be disposed on the other axial side of the motor bracket 7. When the rotation sensor 17 is disposed on the other axial side of the motor bracket 7, the rotation sensor 17 and the inverter 3 are connected via the outer through-hole 7b and the inverter through-hole 4a4 through the sensor signal line 3d. When the rotation sensor 17 is disposed on the other axial side of the motor bracket 7, it is desirable to cover the area around the rotation sensor 17 with a magnetic shield.

[0031] As described above, the electric vehicle drive unit 1 of Embodiment 1 includes: a motor body 5 having a shaft 5a, a rotor 5b, and a stator 5c; a motor housing 6 with the stator 5c fixed to the inside and open on one axial side; a motor bracket 7 covering the stator 5c and the axial side of the rotor 5b, and having a central through hole 7a through which a side shaft portion 5a1 extending from the rotor 5b to the axial side passes; and a reducer 4 connected to the side shaft portion 5a1, which reduces the rotational speed of the shaft 5a and outputs the speed. The motor bracket 7 has a central through hole 7a. The motor housing 6 or motor bracket 7 has one or more outer through holes 7b on its radial outer side. The motor housing 6 or motor bracket 7 has a cylindrical cover 13 that covers the radial outer side of the openings on the axial side of all the outer through holes 7b throughout its entire circumference. The end face on the axial side of the cover 13 is sealed by abutting against the housing member 4a of the reducer 4 through a sealing member 14 throughout its entire circumference. Therefore, compared to Patent Document 2, the motor 2 can be assembled onto the reducer 4 as a single unit, thereby improving the assemblability and manufacturability of the electric vehicle drive unit 1. Furthermore, the individual motor 2 can be inspected, thus allowing for the identification of deviations in the individual motor 2, thereby improving the quality of the motor 2. Due to the improved quality of the motor 2, the reliability of the electric vehicle drive unit 1 can be ensured.

[0032] Furthermore, compared to Patent Document 1, by providing an outer through hole 7b on the motor bracket 7, the material cost of the electric vehicle drive unit 1 can be reduced, and the electric vehicle drive unit 1 can be made lighter. In addition, since the sealing structure is not performed after sealing the motor 2 and the reducer 4 separately, but during assembly, the sealing structure is simple, and therefore, the electric vehicle drive unit 1 can be miniaturized.

[0033] The motor bracket 7 covers the opening on one axial side of the motor housing 6. The motor bracket 7 has a cylindrical bracket-side extension 7c that extends axially from the portion having a central through hole 7a and an outer through hole 7b. When the bracket-side extension 7c is a cover 13, the motor housing 6 can be made into a simple bottomed cylindrical shape. Due to the simple shape of the motor housing 6, its cost can be reduced. Furthermore, when the opening on one axial side of the motor housing 6 is sealed to the motor bracket 7 by a sealing member, the inner side of the motor housing 6 can be easily protected from external influences.

[0034] When the housing member 4a of the reducer 4, which is surrounded by the cover portion 13, has a housing through hole 4a3, a side shaft portion 5a1 and a gear shaft 4b can be easily connected through the housing through hole 4a3. The housing through hole 4a3 allows either the side shaft portion 5a1 or the shaft of the reducer 4 connected to the side shaft portion 5a1, i.e., the gear shaft 4b, to pass through. Furthermore, since the housing through hole 4a3 is surrounded by the cover portion 13, it can be sealed from the outside.

[0035] The electric vehicle drive unit 1 includes an inverter 3 that converts DC power to AC power. The inverter 3 is located inside the housing member 4a of the reducer 4. An axially penetrating inverter through-hole 4a4 is provided in the portion of the housing member 4a surrounded by the cover 13. When the inverter 3 is connected to the motor body 5 via the outer through-hole 7b and the inverter through-hole 4a4, various connecting lines such as phase power lines 3c and sensor signal lines 3d can be easily connected via the outer through-hole 7b and the inverter through-hole 4a4. Furthermore, since the end face of the cover 13 abuts against the housing member 4a of the reducer 4 through a sealing member 14, and the inverter through-hole 4a4 is covered by the cover 13, the inverter through-hole 4a4 can be sealed without the need for an additional sealing structure. This elimination of the need for an additional sealing structure improves the productivity of the electric vehicle drive unit 1.

[0036] When the inverter 3 is housed within the inverter housing 3a, and the inverter housing 3a is integrated with the housing member 4a of the reducer 4, the number of components constituting the housing can be reduced. This reduction in the number of components allows for cost reduction of the electric vehicle drive unit 1. Furthermore, when the housing member 4a and the inverter housing 3a are separate units, configuration discrepancies may occur between them during assembly. However, by integrating the inverter housing 3a with the housing member 4a of the reducer 4, configuration discrepancies can be suppressed.

[0037] The stator 5c has a cylindrical core 5c1, a coil 5c2 wound around the core 5c1, and two coil ends 5c3 protruding from the core 5c1 as the ends of the coil 5c2. The end of the coil end 5c3 located on the axial side of the core 5c1 has a terminal 8 for supplying phase power from the inverter 3. When the terminal 8 is connected to the inverter 3 through the outer through hole 7b and the inverter through hole 4a4, the terminal 8 and the inverter 3 can be connected through the outer through hole 7b and the inverter through hole 4a4 via the phase power line 3c. Therefore, the terminal 8 and the inverter 3 can be easily connected. In addition, the length of the wiring connecting the terminal 8 and the inverter 3, i.e., the phase power line 3c, can be shortened.

[0038] With the temperature sensor 16 mounted on the coil end 5c3 located on the axial side of the core 5c1, and the temperature sensor 16 connected to the inverter 3 via the outer through-hole 7b and the inverter through-hole 4a4, the temperature sensor 16 and the inverter 3 can be connected via the sensor signal line 3d through the outer through-hole 7b and the inverter through-hole 4a4. Therefore, the temperature sensor 16 and the inverter 3 can be easily connected without being affected by other components. In addition, the length of the wiring connecting the temperature sensor 16 and the inverter 3, i.e., the sensor signal line 3d, can be shortened.

[0039] In the portion where the rotation sensor 17, which detects the rotation of the motor body 5, is mounted on the motor bracket 7 inside the cover 13, and the rotation sensor 17 is connected to the inverter 3 via the inverter through-hole 4a4, the rotation sensor 17 and the inverter 3 can be connected via the sensor signal line 3d through the inverter through-hole 4a4. Therefore, the rotation sensor 17 and the inverter 3 can be easily connected without being affected by other components. In addition, the length of the wiring connecting the rotation sensor 17 and the inverter 3, i.e., the sensor signal line 3d, can be shortened.

[0040] When the rotation sensor is located on the axial side of the motor bracket 7, and the motor bracket 7 is made of metal, the presence of a conductive motor bracket 7 between the stator 5c and the rotation sensor 17 reduces the adverse effects of leakage flux generated from the stator 5c mixing into the rotation sensor 17 and causing noise. Furthermore, when the motor housing 6 is formed as a bottomed cylindrical shape with an opening on one axial side, the motor housing 6 can be mass-produced inexpensively using methods such as aluminum die casting. Moreover, components of the motor body 5 can be inserted into the inside of the motor housing 6 through the opening, facilitating the assembly of the motor 2. Therefore, the assemblability and manufacturability of the electric vehicle drive unit 1 can be improved.

[0041] Implementation method 2. The electric vehicle drive device 1 of Embodiment 2 will be described. Figure 4This is a cross-sectional view showing an outline of the electric vehicle drive unit 1 according to Embodiment 2, shown in a way that omits details of the internal structure. In the electric vehicle drive unit 1 of Embodiment 2, the motor housing 6 abuts against the housing member 4a via the sealing member 14, and the motor housing 6 is fixed to the housing member 4a.

[0042] In this embodiment, the motor housing 6 has a cylindrical housing-side extension 6a that extends radially outward and axially towards the motor bracket 7. The motor bracket 7 is disposed inside the housing-side extension 6a, and the portion of the housing-side extension 6a that is further axially towards the motor bracket 7 is a cover portion 13.

[0043] With the configuration described above, since a sealing member is not required between the motor bracket 7 and the motor housing 6, the assemblability and manufacturability of the electric vehicle drive unit 1 can be improved. Furthermore, the cost of the electric vehicle drive unit 1 can be reduced.

[0044] Furthermore, the diagram of motor 2 shown in this application is illustrated with a commonly used internal rotor-radial clearance type configuration. The structure of motor 2 is not limited to this and may be of other forms, such as external rotor-radial clearance type, axial clearance type, or other motor types. The structure of this application is also applicable to motors with other structures and is not intended to limit the structure of the motor.

[0045] Furthermore, this application describes various exemplary embodiments and examples, but the various features, methods and functions described in one or more embodiments are not limited to the application of a specific embodiment, and can be applied to the embodiment alone or in various combinations. Therefore, numerous variations not illustrated are contemplated within the scope of the technology disclosed in this application. These include variations, additions, or omissions of at least one constituent element, as well as the extraction of at least one constituent element and its combination with constituent elements of other embodiments. Symbol Explanation

[0046] 1. Electric vehicle drive unit; 2. Motor; 3. Inverter; 3a. Inverter housing; 3b. Inverter cover; 3c. Phase power line; 3d. Sensor signal line; 4. Reducer; 4a. Housing component; 4a1. Receiving part; 4a2. Cover; 4a3. Housing through hole; 4a4. Inverter through hole; 4b, 4c, 4d. Gear shafts; 5. Motor body; 5a. Shaft; 5a1. One side shaft part; 5a2. The other side shaft part; 5b. Rotor; 5c. Stator; 5c1. Core; 5c2. Coil; 5c3. Coil end; 6. Motor housing; 6a. One side extension of housing; 7. Motor bracket; 7a. Center through hole; 7b. Outer through hole; 7c. One side extension of bracket; 8. Terminal; 9. Bearing; 10. Bearing; 11. Shaft grounding component; 12. Differential mechanism; 13. Cover; 14. Sealing component; 15. Grounding cover; 16. Temperature sensor; 17. Rotation sensor; 18. Oil seal; 19, 20. Bearings.

Claims

1. An electric vehicle drive device, characterized in that, include: The motor body has a shaft, a rotor that rotates integrally with the shaft, and a stator that surrounds the rotor from the radial outside. A motor housing, wherein the stator is fixed to the inner side of the motor housing, and the motor housing has an opening on one axial side; A motor bracket, which covers the stator and one axial side of the rotor, and has a central through hole through which a side shaft portion extending from the rotor to one axial side passes. as well as A speed reducer is connected to the shaft portion on one side, and reduces the rotational speed of the shaft before outputting the speed. The motor bracket has one or more axially penetrating outer through holes radially outside the central through hole. The motor housing or the motor bracket has a cylindrical cover that covers the radially outer side of the openings on one side of all the outer through holes throughout the entire circumference. The end face of the cover on one axial side is sealed by abutting against the housing component of the reducer across the entire circumference through the sealing member.

2. The electric vehicle drive device according to claim 1, characterized in that, The motor housing has a cylindrical housing extension on one side, which extends radially outward and axially towards the motor bracket. The motor bracket is disposed on the inner side of the extension on one side of the housing. The portion of the outer casing that is further axially from the motor bracket is the cover portion.

3. The electric vehicle drive device according to claim 1, characterized in that, The motor bracket covers the opening on one axial side of the motor housing. The motor bracket has a cylindrical bracket extension on one side, which extends axially from the portion having the central through hole and the outer through hole. The extension on one side of the bracket is the cover.

4. The electric vehicle drive device according to claim 3, characterized in that, The opening on the axial side of the motor housing is sealed to the motor bracket by a sealing member.

5. The electric vehicle drive device according to any one of claims 1 to 4, characterized in that, A housing through hole is provided in a portion of the housing member of the reducer surrounded by the cover, and the shaft portion of the reducer connected to the shaft portion of the reducer passes through the housing through hole.

6. The electric vehicle drive device according to any one of claims 1 to 5, characterized in that, The electric vehicle drive unit includes an inverter that converts DC power to AC power. The inverter is located inside the housing component of the reducer. An inverter through-hole is provided in the portion of the housing component of the reducer surrounded by the cover. The inverter is connected to the motor body via the outer through hole and the inverter through hole.

7. The electric vehicle drive device according to claim 6, characterized in that, The inverter is housed in an inverter housing. The inverter housing is integrated with the housing component of the speed reducer.

8. The electric vehicle drive device according to claim 6 or 7, characterized in that, The stator has a cylindrical core, a coil wound around the core, and two coil ends protruding from the core as ends of the coil. The end of the coil edge located on one axial side of the core has a terminal for supplying phase power from the inverter. The terminal is connected to the inverter via the outer through-hole and the inverter through-hole.

9. The electric vehicle drive device according to claim 6 or 7, characterized in that, The stator has a cylindrical core, a coil wound around the core, and two coil ends protruding from the core as ends of the coil. The temperature sensor is mounted on the coil end located on the axial side of the core. The temperature sensor is connected to the inverter via the outer through-hole and the inverter through-hole.

10. The electric vehicle drive device according to claim 6 or 7, characterized in that, A rotation sensor for detecting the rotation of the motor body is mounted on a portion of the motor bracket inside the cover. The rotary sensor is connected to the inverter via the inverter through-hole.

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

12. The electric vehicle drive device according to any one of claims 1 to 11, characterized in that, The motor housing is formed as a bottomed cylindrical shape with an opening on one side along the axial direction.

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