motor, drive

Abstract

The shaft of the motor has a first shaft and a second shaft extending from the first shaft toward an axial direction. The housing has a de-electrification device holder holding a first de-electrification device. The de-electrification device holder has a seal holder configured at a position radially outward of the second shaft and holding a seal member. The first de-electrification device electrically connects the second shaft and the de-electrification device holder. The seal member seals between the second shaft and the seal holder and is configured at a position axially on the other side of the first de-electrification device.

Description

Technical Field

[0001] This invention relates to motors and drive devices. Background Technology

[0002] Conventionally, there are known devices for removing electricity from the shaft of a motor in a drive unit. For example, a charge diffusion assembly, which is a device for removing electricity, is disposed between the shaft and the motor housing, and grounds the shaft voltage by contacting the radial outer surface of the shaft (see, for example, Japanese Patent Application Publication No. 2005-124391).

[0003] [Existing Technical Documents]

[0004] [Patent Literature]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2005-124391 Summary of the Invention

[0006] However, when foreign matter adheres to the current collector, its efficiency in removing current from the shaft can sometimes decrease. For example, in vehicle drive systems, lubricating oil, refrigerant used to cool the motor, or other substances may adhere to the current collector. In this case, due to the reduced conductivity of the current collector, it may be difficult to maintain good electrical conduction between the shaft and the housing.

[0007] The purpose of this invention is to maintain a good electrical connection between the shaft and the housing.

[0008] An exemplary motor of the present invention includes a shaft, a rotor, a stator, a bearing, a housing, a first current-eliminating device, and a sealing member. The shaft has a first shaft extending axially along a rotation axis. The rotor is fixed to the shaft and is rotatable about the rotation axis. The stator is radially spaced from the rotor. The bearing rotatably supports the shaft. The housing houses the rotor, the stator, and the bearing. The shaft also has a second shaft extending axially from the first shaft. The housing has a bearing cage and a current-eliminating device cage. The bearing cage has an opening through which the first shaft passes and holds the bearing. The current-eliminating device cage holds the first current-eliminating device and covers at least a portion of the opening. The current-eliminating device cage has a sealing cage. The sealing cage is positioned radially outward from the second shaft and holds the sealing member. The first current-eliminating device electrically connects the second shaft to the current-eliminating device cage. The sealing member seals between the second shaft and the sealing cage and is positioned axially opposite to the first current-eliminating device.

[0009] An exemplary drive device of the present invention includes the aforementioned motor and power transmission device. The power transmission device transmits the power of the motor to the drive shaft.

[0010] According to the exemplary motor and drive device of the present invention, the electrical connection between the shaft and the housing can be maintained well. Attached Figure Description

[0011] Figure 1 This is a conceptual diagram showing an example of the structure of a drive device.

[0012] Figure 2 This is a conceptual diagram showing an enlarged view of a structural example of the main components of the drive device involved in the embodiment.

[0013] Figure 3 This is a schematic diagram showing an example of a vehicle equipped with a drive unit.

[0014] Figure 4 This is a schematic diagram showing other structural examples of the first axis.

[0015] Figure 5A This is a diagram showing an example of the contact between the second shaft and the first de-energizing device.

[0016] Figure 5B This is another example of the contact between the second shaft and the first de-energizing device.

[0017] Figure 6A The first configuration example of the second shaft through hole in the shaft cover portion is shown.

[0018] Figure 6B A second configuration example of the second shaft through hole in the shaft cover portion is shown.

[0019] Figure 6C This shows a third configuration example of the second shaft through hole in the shaft cover portion.

[0020] Figure 7 This is a schematic diagram showing other configuration examples of the first power-removing device.

[0021] Figure 8 This is a schematic diagram showing other structural examples of a sealing retainer.

[0022] Figure 9 This is a conceptual diagram showing the main structural components of the drive unit in the first modified example, enlarged.

[0023] Figure 10 This is a conceptual diagram showing an enlarged view of the main structural components of the drive device involved in the second modified example.

[0024] Figure 11 This is a conceptual diagram showing an enlarged view of the main structural components of the drive unit involved in the third modified example.

[0025] (Symbol Explanation)

[0026] 100…Drive unit, 200…Battery, 300…Vehicle, 1…Motor, 11…Rotor, 111…Rotor core, 1111…Rotor through hole, 112…Magnet, 12…Stator, 121…Stator core, 122…Coil section, 1221…Coil end, 2…Shaft, 201…First shaft through hole, 202…Second shaft through hole, 21…First shaft, 211…Shaft cylinder section, 212…Hollow section, 213…Inlet, 214…Shaft cover section, 215…Peripheral wall section, 216…Step, 2161…First opposing surface, 2162…Second opposing surface, 22…Second shaft, 3…Motor Force transmission device, 31…reduction gear, 311…main drive gear, 312…intermediate driven gear, 313…final drive gear, 314…intermediate shaft, 32…differential device, 321…gear ring, 4…housing, 401…motor storage space, 402…transmission device storage space, 403…space, 41…first housing cylindrical part, 42…side plate part, 4201…side plate through hole, 4202…first drive shaft through hole, 421, 422, 423, 424…bearing retainer, 4211…bearing, 4221…bearing, 4231…first intermediate bearing, 4241…first output shaft 43…bearing cage, 431…bearing, 432…opening, 44…static eliminator cage, 441…plate portion, 4411…opening, 4412…cage recess, 442, 442a…sealing cage, 4421…first protrusion, 4422…second protrusion, 443…sealing component, 45…cover component, 451…first cover portion, 4511…plate portion, 452…second cover portion, 453…cover recess, 454…through hole, 455…filter, 46…gear cover portion, 460…second drive shaft through hole, 461, 462, 463…bearing retainer, 4611…Bearing, 4621…Second intermediate bearing, 4631…Second output bearing, 464…Packet section, 465…Oil circuit, 5…Fluid circulation section, 51…Piping section, 52…Pump, 53…Cooler, 54…Storage container, 540…Drip hole, 6…Rotation detector, 7…First electrostatic removal device, 71…Conductive component, 72…Elastic component, 73…Retaining component, 74…Fixing component, 75…Lubricating material, 8…Second electrostatic removal device, F…Fluid, P…Fluid storage section, Ds, Ds1, Ds2…Drive shaft, J1…Rotation axis, J2…Intermediate axis, J3…Differential axis. Detailed Implementation

[0027] Exemplary embodiments will now be described with reference to the accompanying drawings.

[0028] In this specification, the direction parallel to the rotation axis J1 of the motor 1 is referred to as the "axial direction" of the drive unit 100. Regarding the axial direction, as follows... Figure 1As shown, the motor 1 side is designated as the axial side D1, and the power transmission device 3 side is designated as the axial side D2. Furthermore, the radial direction orthogonal to the specified axis is simply referred to as "radial," and the circumferential direction centered on the specified axis is simply referred to as "circumferential." In addition, in this specification, "parallel direction" includes not only perfectly parallel directions but also approximately parallel directions. Moreover, the phrase "extending along a specified direction or plane" includes not only strictly extending along the specified direction but also extending along a direction inclined at a range of less than 45° relative to the strictly specified direction.

[0029] <1. Drive unit 100>

[0030] Figure 1 This is a conceptual diagram showing a structural example of the drive device 100. Figure 2 This is a conceptual diagram showing an enlarged view of the main structural examples of the drive device 100 involved in the embodiment. Figure 3 This is a schematic diagram showing an example of a vehicle 300 equipped with a drive unit 100. Additionally, Figure 1 and Figure 2 This is just a concept drawing; the configuration and dimensions of each component are not necessarily the same as the actual drive unit 100. Furthermore, Figure 2 It is Figure 1 The enlarged view of part II enclosed by the dashed line. Additionally, Figure 3 Vehicle 300 is shown schematically.

[0031] In this embodiment, such as Figure 3 As shown, the drive unit 100 is mounted on a vehicle 300, such as a hybrid electric vehicle (HV), a plug-in hybrid electric vehicle (PHV), or an electric vehicle (EV), which uses at least an electric motor as its power source. The drive unit 100 serves as the power source for the aforementioned vehicle 300. The vehicle 300 has the drive unit 100 and a battery 200. The battery 200 stores electricity for supplying to the drive unit 100. In the example of vehicle 300, the drive unit 100 drives the left and right front wheels. Alternatively, the drive unit 100 only needs to drive at least one wheel.

[0032] like Figure 1 As shown, the drive unit 100 includes a motor 1 and a power transmission device 3. The power transmission device 3 transmits power from the motor 1 to the drive shaft Ds. According to the structure of the drive unit 100 described below, the electrical connection between the shaft 2 of the motor 1 and the housing 4 can be maintained reliably. Therefore, electrolytic corrosion caused by current generated due to potential fluctuations within the shaft 2 of the motor 1 can be stably suppressed or prevented.

[0033] <2. Motor 1>

[0034] Motor 1 is a DC brushless motor. Motor 1 is the drive source for drive unit 100, driven by electricity from an inverter (not shown). Figure 1 As shown, the motor 1 includes a rotor 11, a stator 12, a shaft 2, a housing 4, a fluid circulation unit 5, a rotation detector 6, and a first electrostatic discharge device 7. Details of the housing 4 will be described later.

[0035] <2-1. Rotor 11>

[0036] The rotor 11 is fixed to the shaft 2 and is capable of rotating about the rotation axis J1. Specifically, the rotor 11 is fixed to the radial outer surface of the first shaft 21, which will be described later. The rotor 11 rotates by supplying power to the stator 12 from the power supply unit (not shown) of the drive unit 100.

[0037] The rotor 11 has a rotor core 111 and magnets 112. The rotor core 111 is formed, for example, by stacking thin sheet-like electromagnetic steel plates. The rotor core 111 is an axially extending cylinder fixed to the radially outer surface of the first shaft 21. A plurality of magnets 112 are fixed to the rotor core 111. The magnetic poles of the plurality of magnets 112 are arranged alternately circumferentially.

[0038] Furthermore, the rotor core 111 has a rotor through-hole 1111. The rotor through-hole 1111 extends axially through the rotor core 111 and is connected to the first shaft through-hole 201. The rotor through-hole 1111 serves as a flow path for the fluid F. In this embodiment, the fluid F is a lubricant used to lubricate the various bearings and power transmission devices 3 of the drive unit 100, such as oil like ATF (automatic transmission fluid). The drive unit 100 includes the fluid F. Additionally, the fluid F is also used as a refrigerant to cool the stator 12 and the bearings 4211, 431, etc., described later.

[0039] When the rotor 11 rotates, the fluid F flowing through the hollow portion 212 of the first shaft 21 can flow into the rotor through-hole 1111 through the first shaft through-hole 201. Furthermore, the fluid F flowing into the rotor through-hole 1111 can flow out from both axial ends of the rotor through-hole 1111 towards the outside of the rotor core 111. The outflowing fluid F disperses towards the stator 12, for example, cooling the coil portion 122 (particularly its coil end 1221), which will be described later. Additionally, the outflowing fluid F disperses towards the bearings 4211, 431, etc., which rotatably support the first shaft 21, lubricating and cooling the bearings 4211, 431.

[0040] <2-2. Stator 12>

[0041] The stator 12 and the rotor 11 are positioned radially apart. The stator 12 is located radially outward from the rotor 11 and drives the rotor 11 to rotate. The motor 1 is an inner rotor type with the rotor 11 rotatably arranged radially inside the stator 12.

[0042] The stator 12 has a stator core 121 and a coil portion 122. The stator 12 is held by a first housing cylinder portion 41, described later. The stator core 121 has a plurality of magnetic pole teeth (not shown) extending radially inward from the inner circumference of the annular magnetic yoke. The coil portion 122 is formed by winding a wire around the magnetic pole teeth through an insulator (not shown). The coil portion 122 has a coil end 1221 protruding from the axial end face of the stator core 121.

[0043] <2-3. Axis 2>

[0044] Shaft 2 extends axially along the rotation axis J1. Shaft 2 supports rotor 11 and is rotatable about the rotation axis J1. Shaft 2 is rotatably supported by housing 4 by bearings 4211, 4221, 431, and 4611, described later. In this embodiment, each bearing 4211, 4221, 431, and 4611 is a ball bearing. However, the types of bearings 4211, 4221, 431, and 4611 are not limited to this example. For example, up to three of them may not be ball bearings (e.g., sliding bearings, etc.).

[0045] Shaft 2 has a first shaft 21, a second shaft 22, a first shaft through hole 201, and a second shaft through hole 202. The first shaft 21 and the second shaft 22 are conductive and are made of metal in this embodiment.

[0046] <2-3-1. First Axis 21>

[0047] The first shaft 21 is a cylindrical shape extending axially along the rotation axis J1. As described above, the shaft 2 has the first shaft 21. Fluid F flows inside the first shaft 21. The fluid F is supplied to the stator 12 and bearings 4211, 431, etc. through the first shaft through-hole 201 according to the rotation of the shaft 2, and is able to cool them.

[0048] Alternatively, the first shaft 21 can be split in the middle of its axial direction. When the first shaft 21 can be split, the split first shafts 21 can be connected, for example, by spline engagement. Alternatively, the split first shafts 21 can be connected by a threaded coupling using male and female threads, or by pressing, welding, or other fixing methods. When using pressing, welding, or other fixing methods, a serrated structure combining axially extending concave and convex portions can also be used. By employing this structure, rotation can be reliably transmitted between the split first shafts 21.

[0049] The first shaft 21 has a shaft sleeve portion 211. The shaft sleeve portion 211 extends axially and surrounds the rotation axis J1. In addition, the first shaft 21 also has a hollow portion 212 and an inlet 213. The hollow portion 212 is a space surrounded by the inner circumferential surface of the shaft sleeve portion 211 and is disposed inside the shaft sleeve portion 211. The inlet 213 is an opening at the end of the shaft sleeve portion 211 on the other axial side D2, and is connected to the oil passage 465 of the gear cover portion 46 described later. Fluid F flows into the hollow portion 212 from the oil passage 465 via the inlet 213.

[0050] Additionally, the first shaft 21 also has a shaft cover portion 214. The shaft cover portion 214 is disposed on one axial side D1 of the first shaft 21. The shaft cover portion 214 extends radially outward from the rotation axis J1. In this embodiment, as... Figure 2 As shown, the shaft cover 214 is separate from the first shaft 21. However, it is not limited to this example; the shaft cover 214 may also be integral with the first shaft 21 (see Figure 21). Figure 4 ).

[0051] Furthermore, the first shaft 21 preferably has a cylindrical peripheral wall portion 215. The peripheral wall portion 215 protrudes from the end of the shaft cylindrical portion 211 on one axial side (D1 side) toward the axial side (D1 side). The front end of the sealing retainer 442, described later, is inserted into the peripheral wall portion 215.

[0052] Preferably, the first shaft 21 has a step 216. A shaft cover portion 214 is embedded in the step 216. The end of the step 216 on one axial side (D1) of the first shaft 21 is disposed on the inner circumferential surface of the first shaft 21. The step 216 includes a first opposing surface 2161 and a second opposing surface 2162. The first opposing surface 2161 is axially opposed to the end of the shaft cover portion 214 on the other axial side (D2). The second opposing surface 2162 extends radially outward from the radially outer end of the first opposing surface 2161 toward one axial side (D1), and is radially opposed to the radially outer end of the shaft cover portion 214. In this embodiment, the first opposing surface 2161 extends radially outward from the inner circumferential surface of the shaft sleeve portion 211. The second opposing surface 2162 is part of the inner circumferential surface of the peripheral wall portion 215. However, this example is not limited to this one; the second opposing surface 2162 may not be part of the inner circumferential surface of the peripheral wall portion 215, for example, it may be part of the inner circumferential surface of the shaft sleeve portion 211. In this way, when assembling the shaft 2, the shaft cover portion 214, which is separate from the first shaft 21, can be positioned relative to the first shaft 21 by abutting against the first opposing surface 2161. Therefore, the ease of assembling the shaft 2 can be improved.

[0053] Furthermore, the above examples do not preclude the possibility that the first shaft 21 may not have at least one of the peripheral wall portion 215 and the step 216.

[0054] <2-3-2. Second Axis 22>

[0055] The second shaft 22 extends from the first shaft 21 toward one axial direction, D1. In this embodiment, the second shaft 22 extends from the shaft cover portion 214 along the rotation axis J1 toward one axial direction, D1. The outer diameter of the second shaft 22 is smaller than the outer diameter of the first shaft 21 (shaft cylinder portion 211), for example, smaller than the inner diameter of the shaft cylinder portion 211.

[0056] The first de-energizing device 7 is in contact with the second shaft 22. Figure 5A This is a diagram showing an example of the contact between the second shaft 22 and the first de-energizing device 7. Figure 5B This is another example of the contact between the second shaft 22 and the first de-energizing device 7. Preferably, as... Figure 5A As shown, the first current-eliminating device 7 contacts at least a portion of the circumferential region of the radially outer surface of the second shaft 22. Thus, compared to a structure where, for example, the first current-eliminating device 7 contacts the end of the second shaft 22 on one axial side (D1), it is not necessary to ensure space for arranging the first current-eliminating device 7 on one axial side (D1) of the second shaft 22. Therefore, it is possible to suppress the increase in the axial dimension of the motor 1, thereby contributing to the miniaturization of the motor 1 and the drive device 100.

[0057] In addition, such as Figure 5A As shown, when the first de-energizing device 7 contacts a portion of the circumferential region of the radially outer surface of the second shaft 22, the sliding area of ​​the first de-energizing device 7 relative to the second shaft 22 during shaft 2 rotation can be further reduced. Therefore, even if the first de-energizing device 7 wears due to sliding, its wear amount can be reduced, and the amount of wear dust generated can also be reduced.

[0058] In addition, such as Figure 5B As shown, when the first current-eliminating device 7 is in contact with all circumferential regions of the radially outer surface of the second shaft 22, the contact area of ​​the first current-eliminating device 7 with respect to the second shaft 22 can be further increased. Therefore, the resistance between the two can be further reduced, and thus the current-eliminating efficiency of the first current-eliminating device 7 can be further improved.

[0059] <2-3-3. First shaft through hole 201>

[0060] The first shaft through-hole 201 extends radially through the first shaft 21. As described above, the shaft 2 has the first shaft through-hole 201. Specifically, the first shaft through-hole 201 is disposed on the shaft sleeve portion 211 and extends radially through the shaft sleeve portion 211. When the shaft 2 rotates, the fluid F inside the first shaft 21 flows out through the first shaft through-hole 201 from the hollow portion 212 to the outside of the first shaft 21 due to centrifugal force.

[0061] In this embodiment, such as Figure 1As shown, the first shaft through hole 201 is located at a position that is closer to the other side of the axial direction D2 than the end of the rotor 11 on the axial direction D1 side and closer to the other side of the axial direction D2 than the end of the rotor 11 on the axial direction D1 side, and is connected to the rotor through hole 1111 as described above.

[0062] However, it is not limited to Figure 1 For example, at least one first shaft through hole 201 may be positioned on the axial side D1 of the bearing 4211 and on the axial side D2 of the rotor 11. Alternatively, at least one first shaft through hole 201 may be positioned on the axial side D1 of the rotor 11 and on the axial side D2 of the shaft cover portion 214. In this way, the refrigerant (i.e., fluid F) flowing inside the shaft sleeve portion 211 can flow directly out to the stator 12, bearings 4211, 431, etc. through at least one first shaft through hole 201.

[0063] <2-3-4. Second shaft through hole 202>

[0064] The second shaft through-hole 202 communicates with the outside of the shaft 2 through the space surrounded by the shaft cylinder portion 211 and the shaft cover portion 214. As described above, the shaft 2 has a second shaft through-hole 202. For example, this space is located further axially to the opposite side D2 than the shaft cover portion 214 in the hollow portion 212. The second shaft through-hole 202 is positioned further axially to the opposite side D1 than the first shaft through-hole 201 and radially outward than the second shaft 22. Thus, when the shaft 2 rotates, for example by drawing air from the second shaft through-hole 202, fluid F can be introduced into the interior from the opposite side D2 of the first shaft 21 using the pressure difference. Therefore, fluid F inside the cylindrical first shaft 21 can flow out through the first shaft through-hole 201, thereby cooling the stator 12 (especially its coil portion 122).

[0065] The second through hole 202 can be single or multiple. In the latter case, at least a portion of the second through hole 202 can be arranged at equal or different intervals in the circumferential direction (e.g., see below). Figures 6A to 6C In this embodiment, at least a portion of the second shaft through hole 202 is disposed on the shaft cover portion 214 and extends through the shaft cover portion 214 axially.

[0066] Figure 6A A first configuration example of the second shaft through hole 202 in the shaft cover portion 214 is shown. Figure 6B A second configuration example of the second shaft through hole 202 in the shaft cover portion 214 is shown. Figure 6CA third configuration example of the second shaft through hole 202 in the shaft cover portion 214 is shown. At least a portion of the second shaft through hole 202 may also be radially disposed between the radially outer end of the shaft cover portion 214 and the second shaft 22 (see, for example, reference). Figure 6A Additionally, at least a portion of the second shaft through hole 202 may also be configured along the radially outer side surface of the second shaft 22 (e.g., see reference). Figure 6B Additionally, at least a portion of the second shaft through hole 202 may also be configured along the radially outer end of the shaft cover portion 214 (see, for example, reference). Figure 6C Furthermore, the second shaft through hole 202 disposed along the radially outer end of the shaft cover portion 214 may also be composed of a cut formed at the radially outer end of the shaft cover portion 214 and a cut formed at the end of the first shaft 21 on one of the axial sides D1.

[0067] By arranging at least a portion of the second shaft through hole 202 on the shaft cover portion 214, air is more easily drawn into the interior of the first shaft 21 compared to the case where the second shaft through hole 202 is arranged on the first shaft 21. Furthermore, if multiple second shaft through holes 202 function as air intakes are provided, the amount of air drawn into the first shaft 21 and the flow of the drawn-in airflow can be appropriately adjusted according to the number and arrangement of the second shaft through holes 202.

[0068] Alternatively, the fluid F flowing through the second shaft through-hole 202 to the outside of the shaft cover portion 214 can be supplied from the inside of the first shaft 21 to the outside, and supplied to the sealing member 443 described later. Here, if the sealing member 443 is made of synthetic rubber or the like, if the surface dries, it may harden and crack. Therefore, by supplying fluid F to the sealing member 443, it is possible to prevent its surface from drying and suppress cracks caused by hardening. Thus, the lifespan of the sealing member 443 can be extended.

[0069] However, not limited to the above example, the second shaft through hole 202 can also be configured on the first shaft 21, penetrating the first shaft 21 radially.

[0070] <2-4. Power Transmission Device 3>

[0071] Next, refer to Figure 1 The power transmission device 3 will be described in detail. The power transmission device 3 is housed in the transmission device housing space 402, which will be described later in the description of the housing 4. The power transmission device 3 has a reduction gear 31 and a differential gear 32.

[0072] <2-4-1. Speed ​​Reduction Device 31>

[0073] The reduction gear 31 is connected to the other side D2 of the first shaft 21 along its axial direction. The reduction gear 31 has the function of reducing the rotational speed of the motor 1, thereby increasing the torque output from the motor 1 and the reduction ratio accordingly. The reduction gear 31 transmits the torque output from the motor 1 to the drive shaft Ds.

[0074] The reduction gear 31 has a main drive gear 311, an intermediate driven gear 312, a final drive gear 313, and an intermediate shaft 314. The torque output from the motor 1 is transmitted to the gear ring 321 of the drive shaft Ds via the shaft 2, the main drive gear 311, the intermediate driven gear 312, the intermediate shaft 314, and the final drive gear 313.

[0075] The main drive gear 311 is disposed on the outer circumferential surface of the shaft 2. The main drive gear 311 can be the same component as the shaft 2, or it can be a different component that is securely fixed. The main drive gear 311 rotates together with the shaft 2 around the rotation axis J1.

[0076] The intermediate shaft 314 extends along an intermediate axis J2 parallel to the rotation axis J1. The two ends of the intermediate shaft 314 are supported by a first intermediate bearing 4231 and a second intermediate bearing 4621, enabling it to rotate about the intermediate axis J2. An intermediate driven gear 312 and a final drive gear 313 are disposed on the outer circumferential surface of the intermediate shaft 314. The intermediate driven gear 312 can be the same component as the intermediate shaft 314, or it can be a different component that is securely fixed.

[0077] The intermediate driven gear 312 and the final drive gear 313 rotate integrally with the intermediate shaft 314 around the intermediate axis J2. The intermediate driven gear 312 meshes with the main drive gear 311. The final drive gear 313 meshes with the gear ring 321 of the drive shaft Ds.

[0078] The torque of shaft 2 is transmitted from the main drive gear 311 to the intermediate driven gear 312. The torque transmitted to the intermediate driven gear 312 is then transmitted to the final drive gear 313 via the intermediate shaft 314. Furthermore, the torque is transmitted from the final drive gear 313 to the drive shaft Ds.

[0079] <2-4-2. Differential Device 32>

[0080] The differential 32 is mounted on the drive shaft Ds. The differential 32 has a gear ring 321. The gear ring 321 transmits the output torque of the motor 1 to the drive shaft Ds. The drive shaft Ds has drive shafts Ds1 and Ds2 respectively mounted on the left and right sides of the differential 32. For example, when the vehicle is turning, the differential 32 absorbs the speed difference between the left and right drive shafts and transmits torque to the left and right drive shafts Ds1 and Ds2.

[0081] <2-5. Shell 4>

[0082] Next, the housing 4 will be described in detail. The housing 4 includes a first housing cylinder portion 41, a side plate portion 42, a bearing cage 43, a current-eliminating device cage 44, a cover member 45, and a gear cover portion 46. Furthermore, the first housing cylinder portion 41, the side plate portion 42, the bearing cage 43, the current-eliminating device cage 44, the cover member 45, and the gear cover portion 46 are formed, for example, of a conductive material; in this embodiment, they are formed of metallic materials such as iron, aluminum, or their alloys. Additionally, to suppress dissimilar metal contact corrosion in the contact portions, they are preferably formed of the same material. However, this is not a limitation to this example; they may also be formed of materials other than metallic materials, and at least some of them may be formed of different materials.

[0083] The housing 4 houses the rotor 11, stator 12, and bearings 4211, 431, etc. More specifically, the housing 4 has a motor housing space 401 for housing them. The motor housing space 401 is the space enclosed by the first housing cylindrical portion 41, the side plate portion 42, and the bearing cage 43.

[0084] In addition, the housing 4 houses the power transmission device 3. Specifically, the housing 4 has a transmission device storage space 402. The transmission device storage space 402 is a space enclosed by the side plate portion 42 and the gear cover portion 46, and houses the reduction device 31 and the differential device 32, etc.

[0085] A fluid storage section P for storing fluid F is disposed in the lower part of the transmission device housing space 402. A portion of the differential device 32 is disposed in the fluid storage section P. The fluid F stored in the fluid storage section P is agitated by the operation of the differential device 32 and supplied to the interior of the transmission device housing space 402. For example, the lower end of the gear ring 321 is immersed in the fluid storage section P. When the gear ring 321 rotates, the fluid F is agitated by the tooth surfaces of the gear ring. A portion of the agitated fluid F is supplied to the gears and bearings of the reduction gear 31 and the differential device 32 within the transmission device housing space 402 for lubrication and cooling. In addition, another portion of the agitated fluid F is supplied to the interior of the shaft 2 and to the rotor 11 and stator 12 of the motor 1, as well as to the bearings within the transmission device housing space 402, thereby for cooling and lubrication.

[0086] <2-5-1. First Shell Cylinder 41>

[0087] The first housing cylindrical portion 41 is a cylindrical shape that extends axially. A motor 1 and a storage device 54 (described later) are disposed inside the first housing cylindrical portion 41. Furthermore, a stator core 121 is fixed to the inner surface of the first housing cylindrical portion 41.

[0088] <2-5-2. Side Panel Section 42>

[0089] The side plate portion 42 extends in a direction perpendicular to the rotation axis J1, covering the end of the first housing cylinder portion 41 on the opposite axial side D2. In this embodiment, the first housing cylinder portion 41 and the side plate portion 42 are different parts of the same component. By forming them integrally, their rigidity can be improved. However, this example is not limited to, and the first housing cylinder portion 41 and the side plate portion 42 may also be different components.

[0090] The side plate portion 42 has a side plate through hole 4201 for inserting shaft 2 and a first drive shaft through hole 4202. The side plate through hole 4201 and the first drive shaft through hole 4202 extend axially through the side plate portion 42. The first shaft 21 is inserted into the side plate through hole 4201. One drive shaft Ds1 of the drive shaft Ds is inserted into the first drive shaft through hole 4202. A sealing part such as an oil seal (not shown) is disposed in the gap between the drive shaft Ds1 and the first drive shaft through hole 4202 to seal between the two.

[0091] Furthermore, sealing refers to the degree to which different components are tightly fitted together, for example, to prevent the fluid F inside the component from leaking to the outside, and to prevent the intrusion of foreign objects such as water, dust, and dirt. The same applies to sealing below.

[0092] In addition, tightness refers to the degree to which the fluid F inside a component does not leak to the outside, and the degree to which external foreign objects such as water, dust, and dirt do not intrude. The same applies to tightness below.

[0093] Additionally, the side plate portion 42 also has bearing retaining portions 421, 422, 423, and 424. Bearing retaining portion 421 is disposed in the motor housing space 401 on the end face of the side plate portion 42 on one axial side (D1 side) and retains bearing 4211. Bearing retaining portions 422, 423, and 424 are disposed in the transmission device housing space 402 (described later) on the end face of the side plate portion 42 on the other axial side (D2 side). Bearing retaining portion 422 is disposed along the outer edge of the end portion of the side plate through hole 4201 on the other axial side (D2 side) and retains bearing 4211. Bearing retaining portion 423 retains the first intermediate bearing 4231. Bearing retaining portion 424 is disposed along the outer edge of the end portion of the first drive shaft through hole 4202 on the other axial side (D2 side) and retains the first output bearing 4241.

[0094] <2-5-3. Bearing Cage 43>

[0095] Bearing cage 43 holds bearing 431. As described above, housing 4 has bearing cage 43. Bearing 431 rotatably supports shaft 2. Motor 1 includes bearing 431.

[0096] The bearing cage 43 has an opening 432 through which the first shaft 21 is inserted. The opening 432 extends axially through the bearing cage 43. Figure 2 As shown, the bearing cage 43 extends in a direction (e.g., radial) intersecting the rotation axis J1 and covers the end of the first housing cylinder 41 on one side D1 of the axial direction.

[0097] The bearing cage 43 is mounted on the axial side (D1) end of the first housing cylindrical portion 41. The bearing cage 43 can be fixed to the first housing cylindrical portion 41, for example, by using screws. However, it is not limited to this example; various methods (screwing, pressing, etc.) can be used to securely fix the bearing cage 43 to the first housing cylindrical portion 41. Thus, the bearing cage 43 can be tightly fitted against the axial side (D1) end of the first housing cylindrical portion 41.

[0098] <2-5-4. Electrostatic Discharge Device Holder 44>

[0099] The current-eliminating device holder 44 extends in a direction intersecting the rotation axis J1 and is mounted at the end of the bearing holder 43 on one axial side (D1). As described above, the housing 4 has the current-eliminating device holder 44. The current-eliminating device holder 44 holds the first current-eliminating device 7 and covers at least a portion of the opening 432 of the bearing holder 43. In this embodiment, the first current-eliminating device 7 is disposed on one axial side (D1) of the current-eliminating device holder 44. The first current-eliminating device 7 electrically connects the second shaft 22 to the current-eliminating device holder 44. Thus, the current generated by the potential change generated in the shaft 2 can be discharged to the housing 4 via the first current-eliminating device 7.

[0100] In addition, the electrostatic discharge device holder 44 has a plate portion 441, a sealing holder 442, and a sealing component 443.

[0101] <2-5-4-1. Sheet Metal Section 441>

[0102] like Figure 2 As shown, the plate portion 441 extends in a direction (e.g., radially) intersecting the rotation axis J1. As described above, the electrostatic discharge device holder 44 has the plate portion 441. The plate portion 441 is mounted on the axial side (D1 side) of the bearing holder 43. The plate portion 441 and the bearing holder 43 together form a space 403. A portion of the shaft 2 (e.g., the axial side (D1 side) of the first shaft 21) and the rotation detector 6, etc., are disposed in this space 403.

[0103] The plate portion 441 has an opening 4411 and a retainer recess 4412. The opening 4411 extends axially through the plate portion 441. The second shaft 22 is inserted through the opening 4411. The retainer recess 4412 is disposed at the end of the retainer 44 (particularly the plate portion 441) on one axial side (D1). That is, the retainer 44 has a retainer recess 4412. The retainer recess 4412 is recessed towards the other axial side (D2). At least a portion of the first electric shock device 7 is housed in the retainer recess 4412. By disposing of at least a portion of the first electric shock device 7 in the retainer recess 4412 disposed on one axial side (D1) of the retainer 44, the first electric shock device 7 can be further disposed on the other axial side (D2). Therefore, the axial dimension of the motor 1 can be reduced, and the motor 1 and the drive device 100 can be further miniaturized.

[0104] In addition, in this embodiment, such as Figure 2 As shown, the first de-energizing device 7 is located away from the inner surface of the retainer recess 4412 facing radially inward. However, the configuration of the first de-energizing device 7 is not limited to this example. For example, as... Figure 7 As shown, the first current-eliminating device 7 (particularly its radially outer end) can also contact the radially inward-facing inner surface of the retainer recess 4412. This allows for a larger contact area between the first current-eliminating device 7 and the current-eliminating device retainer 44. Therefore, the electrical conductivity between them can be improved. Alternatively, the first current-eliminating device 7 can be embedded and fixed between the shaft 2 and the inner surface of the retainer recess 4412.

[0105] <2-5-4-2. Sealing retainer 442>

[0106] A sealing retainer 442 is disposed radially outside the second shaft 22 to retain the sealing member 443. As described above, the electrostatic eliminator retainer 44 has a sealing retainer 442. In this embodiment, the sealing retainer 442 is cylindrical and extends from the end of the plate portion 441 on the axially opposite side D2 to the axially opposite side D2. Viewed axially, an opening 4411 is disposed radially inside the sealing retainer 442.

[0107] Preferably, the end of the sealing retainer 442 on the opposite axial side (D2) is housed inside the first shaft 21. This allows the electrostatic eliminator retainer 44 to be closer to the end of the first shaft 21 on the opposite axial side (D1). Therefore, the axial dimensions of the motor 1 and the drive unit 100 can be reduced. Furthermore, the fluid F must flow between the first shaft 21 and the sealing retainer 442 before entering between the second shaft 22 and the sealing retainer 442. That is, because the flow distance of the fluid F can be longer, it is more difficult for the fluid F to flow to the first electrostatic eliminator 7.

[0108] Furthermore, the peripheral wall portion 215 is preferably positioned radially outward from the sealing retainer 442. In this case, the sealing retainer 442 is radially opposed to the peripheral wall portion 215 and axially opposed to the end of the shaft sleeve portion 211 on one side (D1). This allows for a longer path from the inside of the shaft sleeve portion 211 to the outside of the shaft 2 between the sealing retainer 442 and the first shaft 21. Therefore, even if fluid F leaks from the second shaft through-hole 202 disposed on the shaft cover portion 214, the fluid F is less likely to leak to the outside of the shaft 2 through the aforementioned path.

[0109] However, the above examples do not preclude a structure in which the end of the sealing retainer 442 on the other axial side (D2) is not housed within the first shaft 21. For example, the end of the sealing retainer 442 on the other axial side (D2) may also be located away from the end of the first shaft 21 on one axial side (D1).

[0110] Preferably, the sealing retainer 442 has a first protrusion 4421 and a second protrusion 4422. The first protrusion 4421 protrudes from the end of the plate portion 441 on the axially opposite side (D2 side) toward the axially opposite side (D2 side). The second protrusion 4422 protrudes from the end of the first protrusion 4421 on the axially opposite side (D2 side) toward the axially opposite side (D2 side). In this embodiment, the first protrusion 4421 and the second protrusion 4422 are both cylindrical in shape extending axially. The radially outer surface of the second protrusion 4422 is positioned radially inward than the radially outer surface of the first protrusion 4421. At least the end of the second protrusion 4422 on the axially opposite side (D2 side) is inserted into the end of the first shaft 21 on the axially opposite side (D1 side). That is, the second protrusion 4422 is positioned radially inward than the end of the first shaft 21 on the axially opposite side (D1 side). The end of the first shaft 21 on one axial side (D1) is axially opposed to the first protrusion 4421 and radially opposed to the second protrusion 4422. This allows for a longer path from the inside of the first shaft 21 to the outside of the shaft 2 between the sealing retainer 442 and the first shaft 21. Therefore, even if fluid F leaks from the second shaft through-hole 202 disposed on the shaft cover portion 214, it is difficult for fluid F to leak to the outside of the shaft 2 through the aforementioned path.

[0111] However, the above examples do not preclude a structure in which the sealing retainer 442 does not have the second protrusion 4422. For example, as Figure 8 As shown, the sealing retainer 442 may have only a first protrusion 4421. In this case, the first protrusion 4421 is positioned radially inward from the end on the axial side D1 of the first shaft 21. The first protrusion 4421 is axially opposed to the end on the axial side D1 of the shaft sleeve portion 211 and radially opposed to the peripheral wall portion 215.

[0112] <2-5-4-3. Sealing component 443>

[0113] A sealing member 443 is disposed on the opposite side (D2) of the axial direction of the electrostatic eliminator cage 44, isolating the space where the first electrostatic eliminator 7 is disposed from the fluid F. The motor 1 has a sealing member 443. The sealing member 443 seals between the second shaft 22 and the sealing cage 442, and is disposed on the opposite side (D2) of the axial direction of the first electrostatic eliminator 7. Thus, by sealing the space between the second shaft 22 and the sealing cage 442 with the sealing member 443, fluids that lubricate and cool the stator 12 and bearings 431 are unlikely to flow to the first electrostatic eliminator 7. For example, a mist-like fluid F may sometimes leak from between the inner and outer rings of the ball bearing 431 or from between the bearing 431 and the second shaft 22 through the opening 432 of the bearing cage 43 into the space 403 on the opposite side (D1) of the axial direction of the bearing cage 43, and intrude between the second shaft 22 and the sealing cage 442. The sealing member 443, by sealing the space between the second shaft 22 and the sealing retainer 442, can suppress or prevent the flow of fluid F. That is, fluid F is less likely to flow towards the axial direction D1 compared to the sealing member 443. Furthermore, for example, fluid F is less likely to leak towards the axial direction D1 compared to the retainer 44. Therefore, it is possible to suppress or prevent fluid F from flowing onto the first electrostatic eliminator 7. Thus, the motor 1 and the drive unit 100 can reliably maintain the electrical connection between the second shaft 22 and the housing 4.

[0114] The sealing component 443 may, for example, use an oil slinger ring. For instance, the sealing component 443 has a fixing portion (not shown) and a flange portion (not shown). The fixing portion is fixed to the radially outer surface of the second shaft 22. The flange portion extends radially outward from the fixing portion. Alternatively, the fixing portion may also be fixed to the radially inner surface of the sealing retainer 442. In this case, the flange portion extends radially inward from the fixing portion. The flange portion seals the gap between the second shaft 22 and the sealing retainer 442. However, the sealing component 443 is not limited to this example. The sealing component 443 may also use an oil seal, mechanical seal, gasket, etc.

[0115] <2-5-5. Cover Component 45>

[0116] The cover member 45 is disposed at one axial D1 side end of the current-eliminating device holder 44. As described above, the housing 4 has the cover member 45. The cover member 45 covers the opening 432 of the current-eliminating device holder 44 and the first current-eliminating device 7. The cover member 45 can be installed in the current-eliminating device holder 44 by means of threaded fastening, but is not limited thereto.

[0117] The cover component 45 has a first cover portion 451 and a second cover portion 452. The first cover portion 451 is positioned further axially towards the D1 side than the opening 432 and the first electrostatic eliminator 7, covering the opening 432 and the first electrostatic eliminator 7. The first cover portion 451 has a plate portion 4511. In other words, the cover component 45 has a plate portion 4511. The plate portion 4511 extends in a direction intersecting the rotation axis J1. The second cover portion 452 is positioned radially outward towards the D2 side, opposite to the first cover portion 451. The radially inner end of the second cover portion 452 is connected to the radially outer end of the first cover portion 451, and the radially outer end of the second cover portion 452 is connected to the end face of the electrostatic eliminator holder 44 on the D1 side of the axial direction.

[0118] In addition, the cover component 45 also has a cover recess 453. The cover recess 453 is recessed from the plate portion 4511 toward the other side D2 in the axial direction.

[0119] Additionally, the cover component 45 also has a through hole 454. The through hole 454 connects the space surrounded by the power-dissipating device holder 44 and the cover component 45 to its exterior. Figure 2 As shown, the through hole 454 can be single or multiple. Figure 2 In this configuration, a through hole 454 is provided in the first cover portion 451. However, the configuration of the through hole 454 is not limited to... Figure 2 Example. A through hole 454 may be provided on at least one of the first cover portion 451 and the second cover portion 452. Alternatively, the through hole 454 may also be provided on the current-eliminating device holder 44. That is, the through hole 454 may be provided on at least one of the current-eliminating device holder 44 and the cover member 45. In this way, the space between the current-eliminating device holder 44 and the cover member 45 can communicate with the outside of the space via the through hole 454. Therefore, changes in the internal pressure of the space caused by temperature changes, etc., can be prevented, and the pressure difference between the inside and outside of the space can be eliminated. For example, since the generation of a pressure difference between the axial side D1 and the axial side D2 of the sealing member 443 can be prevented, fluid F can be prevented from entering the space between the current-eliminating device holder 44 and the cover member 45 by depressurization.

[0120] Additionally, the cover component 45 also has a filter 455. The filter 455 covers the through hole 454. The housing 4 has the filter 455. The space between the electrostatic eliminator holder 44 and the cover component 45 is connected to the outside through the through hole 454 and the filter 455. Preferably, at least one through hole 454 is provided in the cover recess 453. By covering the through hole 454 with the filter 455, even if abrasive powder is generated in the first electrostatic eliminator 7, it is possible to prevent the abrasive powder from flying out to the outside through the through hole 454. More preferably, the filter 455 covering the through hole 454 of the cover recess 453 is arranged at a position on the axially opposite side D2 of the plate portion 4511. In this way, it is not necessary to ensure space for arranging the filter 455 on the axially opposite side D1 of the plate portion 4511. Therefore, it is possible to prevent an increase in the axial dimension of the motor 1 and the drive device 100 caused by the arrangement of the filter 455.

[0121] In this embodiment, viewed axially, a first current-eliminating device 7 is disposed between the through hole 454 and the filter 455 and the second shaft 22. The through hole 454 and the filter 455 are disposed radially outward from the first current-eliminating device 7. The second shaft 22 is disposed radially inward from the first current-eliminating device 7. That is, the through hole 454 and the filter 455 are disposed on the opposite side of the second shaft 22, separated by the first current-eliminating device 7. In other words, viewed radially, at least a portion of the filter 455 overlaps with the first current-eliminating device 7. This allows the filter 455 and the plate portion 4511 of the cover member 45 to be further disposed on the other axial side D2. Therefore, the axial dimensions of the motor 1 and the drive device 100 can be further reduced.

[0122] However, the configuration of the through hole 454 and the filter 455 is not limited to this example. Additionally, viewed radially, at least a portion of the filter 455 may not overlap with the first current-eliminating device 7. Viewed axially, the through hole 454 and the filter 455 may also be configured on the opposite side of the first current-eliminating device 7, separated by the second axis 22 (e.g., see reference 1). Figure 7 ).

[0123] <2-5-6. Gear cover 46>

[0124] The gear cover 46 is mounted on the axial side D2 of the side plate portion 42. In this embodiment, the gear cover 46 has a plate portion (not shown) and a cylindrical portion (not shown). The plate portion extends in a direction intersecting the rotation axis J1. The cylindrical portion is a cylindrical shape extending from the end of the plate portion on the axial side D1 towards the axial side D1. The end of the cylindrical portion on the axial side D1 is connected to and covered by the side plate portion 42. The plate portion and the cylindrical portion together with the side plate portion 42 form a transmission device storage space 402 for arranging the power transmission device 3. The gear cover 46 can be mounted to the side plate portion 42, for example, by fixing with screws. However, it is not limited to this example, and methods such as screwing or pressing can be widely used to firmly fix the gear cover 46 to the side plate portion 42. Thus, the gear cover 46 can be tightly attached to the end of the side plate portion 42 on the axial side D1.

[0125] The gear cover portion 46 has a second drive shaft through hole 460. The center of the second drive shaft through hole 460 coincides with the differential axis J3, which is parallel to the rotation axis J1. The other drive shaft Ds2 is inserted into the second drive shaft through hole 460. A sealing part such as an oil seal (not shown) is arranged in the gap between the drive shaft Ds2 and the second drive shaft through hole 460.

[0126] Additionally, the gear cover portion 46 also has bearing retaining portions 461, 462, and 463. The bearing retaining portions 461, 462, and 463 are disposed in the transmission device housing space 402 on the end face of the gear cover portion 46 on the axial opposite side (D2). Bearing retaining portion 461 retains bearing 4611. Bearing retaining portion 462 retains the second intermediate bearing 4621. Bearing retaining portion 463 is disposed along the outer edge of the end portion on the axial opposite side (D2) of the second drive shaft through hole 460, retaining the second output bearing 4631.

[0127] Additionally, the gear cover portion 46 has a tray portion 464 and an oil passage 465. The tray portion 464 is disposed on the end face of the gear cover portion 46 on one axial side (D1 side) and has a recessed portion that is recessed vertically downward. The tray portion 464 can store the fluid F stirred up by the gear ring 321. The oil passage 465 is the passage for the fluid F and connects the tray portion 464 to the inlet 213 of the shaft 2. The fluid F stored in the tray portion 464 is supplied to the oil passage 465 and flows into the hollow portion 212 from the inlet 213 at the end of the shaft 2 on the other axial side (D2 side).

[0128] <2-7. Fluid Circulation Section 5>

[0129] The fluid circulation unit 5 supplies fluid F contained in the housing 4 to the stator 12 and bearings 4211, 431, etc. The fluid circulation unit 5 includes a piping unit 51, a pump 52, a cooler 53, and a reservoir 54.

[0130] Piping 51 connects pump 52 and reservoir 54, supplying fluid F to reservoir 54. Pump 52 draws in fluid F stored in the lower region of the transfer device receiving space 402. Pump 52 is an electric pump, but is not limited to this. For example, it may be a structure driven by a portion of the power of shaft 2 of drive unit 100.

[0131] A cooler 53 is disposed between the pump 52 and the reservoir 54 in the piping section 51. That is, the fluid F drawn by the pump 52 is transported to the reservoir 54 after passing through the cooler 53 via the piping section 51. A refrigerant, such as water supplied from the outside, is provided to the cooler 53. The cooler 53 performs heat exchange between the refrigerant and the fluid F to reduce the temperature of the fluid F.

[0132] The reservoir 54 is a tray capable of storing fluid F and is housed in the motor housing 401, described later, within the housing 4. Inside the motor housing 401, the reservoir 54 is positioned vertically above the stator 12. A drip hole 540 is formed at the bottom of the reservoir 54, through which fluid F is dripped to cool the motor 1. The drip hole 540 is formed, for example, above the coil end 1221 of the coil portion 122 of the stator 12, which is cooled by the fluid F.

[0133] <2-8. Rotation Detector 6>

[0134] Additionally, the rotation detector 6 detects the rotation angle of the shaft 2. In this embodiment, the rotation detector 6 is a resolver having a resolver rotor and a resolver stator. The rotation detector 6 has a resolver rotor (not shown) fixed to the shaft 2 and a resolver stator (not shown) fixed to one axial side of the bearing cage 43 of the housing 4. The resolver rotor and resolver stator are annular. The inner circumferential surface of the resolver stator is radially opposed to the outer circumferential surface of the resolver rotor. The resolver stator periodically detects the rotation angle position of the resolver rotor as the rotor 11 rotates. Thus, the rotation detector 6 obtains information about the rotation angle position of the rotor 11. Furthermore, not limited to the example of this embodiment, the rotation detector 6 may not be a resolver; for example, it may be a rotary encoder.

[0135] The rotary detector 6 is disposed in the space 403 surrounded by the bearing cage 43 and the electrostatic eliminator cage 44. This eliminates the need to ensure sufficient space for the rotary detector 6 to be disposed on the axial side D1 of the electrostatic eliminator cage 44. Therefore, it is possible to suppress the increase in the axial dimension of the motor 1 and the drive unit 100.

[0136] <2-9. First Electrostatic Discharge Device 7>

[0137] Next, refer to Figure 5A and Figure 5BThe structure of the first static eliminator 7 is described below. The first static eliminator 7 is fixed to the housing 4 and contacts the shaft 2. The first static eliminator 7 electrically connects the shaft 2 to the housing 4. In this embodiment, the first static eliminator 7 is disposed on the axial side D1 of the static eliminator holder 44 and contacts the radially outer surface of the second shaft 22.

[0138] like Figure 5A (and Figure 2 As shown in the figure, the first power removal device 7 of this embodiment has a conductive component 71, an elastic component 72, a retaining component 73, and a fixing component 74.

[0139] The conductive component 71 is formed using a conductive material. The front end of the conductive component 71 contacts the second shaft 22. In this embodiment, the conductive component 71 is a molded body, but it is not limited to this example; it could also be a brush shape formed by bundling carbon fibers or the like. The material of the conductive component 71 is preferably a material with good sliding properties, and more preferably a material with a low coefficient of friction. For example, carbon fibers or composite resins containing conductive fillers such as metals can be used as materials for the conductive component 71.

[0140] The elastic member 72 is housed inside the retaining member 73 in a compressed state. Due to its elasticity, the elastic member 72 pushes the conductive member 71 toward the second shaft 22. In this embodiment, the elastic member 72 is a spring coil, but it is not limited to this example; other components such as leaf springs and rubber may also be used.

[0141] The retaining member 73 is a bottomed cylindrical shape, housing a portion of the conductive member 71 and the elastic member 72 inside. The retaining member 73 holds the conductive member 71. Specifically, the retaining member 73 holds the end of the conductive member 71 on the side of the elastic member 72 so that it can move along the direction in which the retaining member 73 extends. In addition, the retaining member 73 telescopically holds the elastic member 72 in the direction in which the retaining member 73 extends.

[0142] The fixing member 74 secures the first static eliminator 7 to the housing 4. In this embodiment, the fixing member 74 secures the first static eliminator 7 to the static eliminator holder 44 (see, for example, reference...). Figure 5A However, not limited to this example, the fixing member 74 can also fix the first power-eliminating device 7 to the cover member 45. That is, the fixing member 74 can fix the first power-eliminating device 7 to at least one of the power-eliminating device holder 44 and the cover member 45.

[0143] In addition, the fixing member 74 is conductive and is electrically connected to the conductive member 71. By fixing the fixing member 74 to the conductive current-eliminating device holder 44 or the cover member 45, the conductive member 71 is electrically connected to the housing 4.

[0144] In this embodiment, such as Figure 5A As shown, the first current-eliminating device 7 (its conductive component 71) contacts a portion of the circumferential region of the radially outer surface of the second shaft. However, this is not limited to this example; the first current-eliminating device 7 (its conductive component 71) may also be... Figure 5B As shown, it can also contact the entire circumferential region of the outer surface of the second shaft 22. That is, the first current-eliminating device 7 (the conductive component 71) only needs to contact at least a portion of the circumferential region of the radially outer surface of the second shaft 22. By making the first current-eliminating device 7 contact at least a portion of the circumferential region of the radially outer surface of the second shaft 22, which has an outer diameter smaller than the first shaft 21, the sliding area of ​​the first current-eliminating device 7 relative to the second shaft 22 per revolution of the shaft 2 can be further reduced. Therefore, the wear dust generated at the contact portion between the first current-eliminating device 7 and the shaft 2 can be reduced.

[0145] <3. Variations>

[0146] Next, refer to Figures 9 to 11 The first to third modifications of the implementation method are described below. Figure 9 This is a conceptual diagram showing an enlarged view of the structure of the main part of the drive device 100 in the first modified example. Figure 10 This is a conceptual diagram showing an enlarged view of the main structural components of the drive unit 100 in the second modified example. Figure 11 This is a conceptual diagram showing an enlarged view of the main structural components of the drive unit 100 involved in the third modified example. Additionally, Figures 9 to 11 This is just a concept drawing; the configuration and dimensions of each component are not necessarily the same as the actual drive unit 100. Furthermore, Figures 9 to 11 Corresponding to Figure 1 Enlarged view of part II enclosed by the dashed line.

[0147] Furthermore, the above-described embodiments and the first to third modifications can be appropriately combined and implemented as long as there is no particular contradiction.

[0148] <3-1. First Variation>

[0149] Reference Figure 9 The first modified example will be described. Furthermore, the following description will focus on structures in the first modified example that differ from the embodiments described above. Additionally, components identical to those in the embodiments described above will be labeled with the same symbols, and their descriptions will be omitted.

[0150] In the first modification, the motor 1 further includes a second current-eliminating device 8. The second current-eliminating device 8 electrically connects the first shaft 21 to the housing 4. In this way, the current generated by the potential change in the shaft 2 can be discharged to the housing 4 via the second current-eliminating device 8. Therefore, the current-eliminating efficiency of the shaft 2 can be further improved.

[0151] The second de-energizer 8 is fixed to one axial side (D1) of the bearing cage 43. The second de-energizer 8 is positioned further along the other axial side (D2) than the end of the first shaft 21 on the D1 axial side. The second de-energizer 8... Figure 9 The second electrostatic discharge device 8 contacts a portion of the circumferential region on the radially outer surface of the first shaft 21. However, not limited to this example, the second electrostatic discharge device 8 may also contact all circumferential regions on the radially outer surface of the first shaft 21. This eliminates the need to ensure space for the second electrostatic discharge device 8 on the axial side D1 of the first shaft 21. Therefore, it is possible to suppress the increase in the axial dimensions of the motor 1 and the drive unit 100. This contributes to the miniaturization of the motor 1 and the drive unit 100.

[0152] The structure of the second de-energizing device 8 is the same as that of the first de-energizing device 7 in this embodiment, but it is not limited to this example and may also be different from the first de-energizing device 7.

[0153] <3-2. Second Variation>

[0154] Next, refer to Figure 10 The second modification will be described below. Furthermore, the structure that differs from the above-described embodiment and the first modification will be described in the second modification. Additionally, the same reference numerals are used for the same constituent elements as in the above-described embodiment and the first modification, and their descriptions are omitted.

[0155] In the second variation, the sealing retainer 442a is a recess located on the axially opposite side D2 of the current-eliminating device retainer 44, recessed in one direction. Furthermore, the sealing retainer 442a extends axially from the end of the first shaft 21 on the axially opposite side D1. The sealing member 443 is disposed on the radially inward-facing inner surface of the sealing retainer 442a.

[0156] Therefore, the first shaft 21 does not have a peripheral wall portion 215, and the end of the shaft sleeve portion 211 on one axial side (D1 side) becomes the end of the first shaft 21 on one axial side (D1 side). In addition, the shaft cover portion 214 is disposed at the end of the first shaft 21 on one axial side (D1 side).

[0157] According to the second modification, the axial distance between the end of the first shaft 21 on the D1 side and the retainer 44 can be narrowed. Therefore, the axial dimensions of the motor 1 and the drive device 100 can be further reduced.

[0158] <3-3. Third Variation>

[0159] Next, refer to Figure 11The third modification will be described below. Furthermore, the structure that differs from the above-described embodiments, the first modification, and the second modification will be described in the third modification. Additionally, the same reference numerals are used for the same constituent elements as in the above-described embodiments, the first modification, and the second modification, and their descriptions are omitted.

[0160] In the third variation, the first de-energizing device 7 is positioned between the second shaft 22 and the sealing retainer 442 on the axial side D1 side of the sealing member 443. Even so, it is possible to more reliably suppress or prevent fluid F from flowing to the first de-energizing device 7.

[0161] In the third variation, the first de-energizing device 7 is disposed on the opposite axial side D2 of the de-energizing device holder 44. Therefore, the end of the second shaft 22 on the opposite axial side D1 can be disposed closer to the opposite axial side D2 than the plate portion 441. Furthermore, as... Figure 11 As shown, the opening 4411 and the retainer recess 4412 may not be provided on the plate portion 441 of the current-eliminating device holder 44. Furthermore, by omitting the opening 4411, the cover member 45 can also be omitted. This reduces the number of components in the housing 4 and allows for a simpler structure for the current-eliminating device holder 44. Additionally, since the components on the axial side D1 of the current-eliminating device holder 44 can be omitted, the axial dimensions of the motor 1 and the drive unit 100 can be reduced.

[0162] In addition, in the third variation, the first static eliminator 7 is a conductive bearing lubricated by a lubricating material 75 with a higher conductivity than the fluid F. In this embodiment, the lubricating material 75 is a conductive grease. Conductive materials such as copper powder and carbon powder are added to the grease or other lubricating oil. The first static eliminator 7 can electrically connect the second shaft 22 to the static eliminator cage 44 via the lubricating material 75. Figure 11 In this configuration, the first de-energizing device 7 is a ball bearing lubricated with lubricating material 75. The inner ring of the first de-energizing device 7 is fixed to the radially outer surface of the second shaft 22, and the outer ring of the first de-energizing device 7 is fixed to the radially inner surface of the sealing retainer 442. In this configuration, since the inner and outer rings of the first de-energizing device 7 are electrically connected via the lubricating material 75, the second shaft 22 is electrically connected to the sealing retainer 442 of the de-energizing device retainer 44.

[0163] Furthermore, the first static eliminator 7 is coaxially configured with the bearing 431. For example, they are arranged in a ring around the same axis (i.e., the axis of rotation J1). In this way, the first static eliminator 7, together with the bearing 431, can more stably support the shaft 2 for rotation.

[0164] in addition, Figure 11The example does not preclude the first current-eliminating device 7 from being a conductive bearing structure. Furthermore, in the third variation, the first current-eliminating device 7 contacts the entire circumferential region of the radially outer surface of the second shaft 22, but is not limited to this example; it may also contact a portion of the circumferential region of the radially outer surface of the second shaft 22. Additionally, the first current-eliminating device 7 may be fixed to either the second shaft 22 or the sealing retainer 442, or it may contact the other. For example, the first current-eliminating device 7 may also be... Figure 5A or Figure 5B That kind of structure.

[0165] <4. Other>

[0166] The embodiments of the present invention have been described above. However, the scope of the present invention is not limited to the embodiments described above. The present invention can be implemented with various modifications to the above embodiments without departing from the spirit of the invention. Furthermore, the matters described in the above embodiments can be appropriately combined arbitrarily without causing contradictions.

[0167] This invention can be used in devices for grounding shafts.

Claims

1. A motor, characterized in that, include: A shaft having a first shaft extending axially along the axis of rotation; A rotor fixed to the shaft and capable of rotating about the axis of rotation; A stator that is radially spaced apart from the rotor; A bearing capable of rotatably supporting the shaft; A housing that houses the rotor, the stator, and the bearing; First electrostatic removal device; as well as Sealing components, The shaft also has a second shaft extending axially from one of the first axes. The housing has: A bearing cage having an opening for insertion of the first shaft and holding the bearing; and A retainer for the electrostatic eliminator, the retainer holding the first electrostatic eliminator and covering at least a portion of the opening. The electrostatic discharge device holder has a sealed holder, which is positioned radially outward from the second shaft and holds the sealing component. The first electrostatic removal device electrically connects the second shaft to the electrostatic removal device cage. The sealing component seals the space between the second shaft and the sealing cage, and is positioned on the opposite side of the axial direction compared to the first de-energizer. The first shaft has: A cylindrical shaft portion extending axially and surrounding the axis of rotation; and The shaft cover portion is disposed on one axial side of the shaft cylinder portion. The shaft also has: A first through hole extending radially through the first shaft; and A second shaft through hole connects the space enclosed by the shaft sleeve and the shaft cover to the outside of the shaft. The second shaft through hole is axially opposite to the sealing component. Fluid can flow inside the shaft cylinder and in the second shaft through hole.

2. The motor according to claim 1, characterized in that, The first electrostatic removal device is disposed on either the axial side of the electrostatic removal device holder or at a position between the second shaft and the sealing holder that is axially closer to the sealing member.

3. The motor according to claim 1 or 2, characterized in that, The outer diameter of the second shaft is smaller than the outer diameter of the first shaft. The first power-removing device is in contact with at least a portion of the circumferential region of the radially outer surface of the second shaft.

4. The motor according to claim 1 or 2, characterized in that, The holder of the electrostatic discharge device also has a plate portion that extends in a direction intersecting the axis of rotation. The sealing retainer also has: A first protrusion protruding from the other axial end of the plate portion in the opposite axial direction; and A second protrusion protrudes from the other axial end of the first protrusion in the opposite axial direction. The second protrusion is positioned radially inward from one end of the first shaft along its axial direction. One axial end of the first shaft is axially opposed to the first protrusion and radially opposed to the second protrusion.

5. The motor according to claim 1 or 2, characterized in that, The other axial end of the sealing retainer is housed inside the first shaft.

6. The motor according to claim 1 or 2, characterized in that, The second shaft through hole is located axially to the side of the first shaft through hole and radially outward from the second shaft.

7. The motor according to claim 1 or 2, characterized in that, The second shaft extends axially from the shaft cover portion. At least a portion of the second shaft through hole extends through the shaft cover portion.

8. The motor according to claim 7, characterized in that, The first shaft also has a peripheral wall portion that protrudes axially from one axial end of the shaft sleeve portion. The peripheral wall portion is positioned radially outward compared to the sealing retainer. The sealing retainer is radially opposed to the peripheral wall portion and axially opposed to one axial end of the shaft cylinder portion.

9. The motor according to claim 1 or 2, characterized in that, The first shaft also has a step for the shaft cover portion to be inserted. The steps include: A first opposing surface, which is axially opposed to the other axial end of the shaft cover portion; and The second opposing surface extends axially from the radially outer end of the first opposing surface and is radially opposed to the radially outer end of the shaft cover portion.

10. The motor according to claim 1 or 2, characterized in that, It also includes a rotation detector for detecting the rotation angle of the shaft. The rotary detector is configured within the space enclosed by the bearing cage and the electrostatic removal device cage.

11. The motor according to claim 1 or 2, characterized in that, It also includes a second de-energizing device that electrically connects the first shaft to the housing.

12. The motor according to claim 11, characterized in that, The second electrostatic removal device is positioned on the opposite side of the axial direction from one end of the first shaft.

13. The motor according to claim 1 or 2, characterized in that, The first electrostatic removal device is disposed on one axial side of the electrostatic removal device holder. The retainer of the power removal device also has a retainer recess that is recessed in the opposite axial direction. At least a portion of the first power-removing device is housed in the cage recess.

14. The motor according to claim 13, characterized in that, The radially outer end of the first power-removing device contacts the radially inward-facing inner surface of the retainer recess.

15. The motor according to claim 1 or 2, characterized in that, The housing also has a cover component disposed at one axial end of the retainer of the electrostatic eliminator and covering the first electrostatic eliminator and the opening. At least one of the current removal device holder and the cover component is provided with a through hole.

16. The motor according to claim 15, characterized in that, The housing also includes a filter that covers the through-hole. The space between the electrostatic discharge device holder and the cover component is connected to the outside via the through hole and the filter. The cover component has: A plate portion extending in a direction intersecting the axis of rotation; and A recessed portion of the cover that is recessed in the opposite axial direction from the plate portion. At least one of the through holes is disposed in the cover recess. The filter covering the through hole of the cover recess is positioned axially opposite to the plate portion.

17. The motor according to claim 16, characterized in that, The first electrostatic removal device is disposed on one axial side of the electrostatic removal device holder. Viewed radially, at least a portion of the filter overlaps with the first electrostatic removal device.

18. A driving device, characterized in that, include: The motor according to any one of claims 1 to 17; as well as A power transmission device that transmits the power of the motor to the drive shaft.

Images