Drive system, vehicle

Abstract

To inhibit or prevent deterioration of discharge efficiency of a shaft.SOLUTION: A drive device includes: a shaft 1; a rotor; a stator; a bearing; a housing; a first static eliminator 6; and a seal member 8. The shaft 1 extends along a rotation axis J1 in an axial direction. The rotor is fixed to the shaft 1 and may rotate around the rotation axis J1. The stator faces the rotor while forming a gap therebetween in a radial direction. The bearing rotatably supports the shaft 1. The housing 4 houses the rotor, the stator, and the bearing. The first static eliminator 6 is disposed at one axial side relative to the bearing and electrically connects the shaft 1 with the housing 4. The seal member 8 is disposed between the bearing and the first static eliminator 6 in the axial direction.SELECTED DRAWING: Figure 2A

Description

[Technical field]

[0001] The present invention relates to a drive device and a vehicle. [Background technology]

[0002] Conventionally, there has been known a static eliminator that eliminates static electricity from a shaft of a motor unit of a drive device. For example, a charge dissipation assembly as a static eliminator contacts a radially outer surface of the shaft to earth the shaft voltage (see, for example, JP 2005-124391 A). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2005-124391 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, if foreign matter adheres to the static eliminator, the efficiency of static elimination of the shaft by the static eliminator may decrease. For example, in an in-vehicle drive unit, lubricating oil, a refrigerant for cooling the motor, and the like may adhere to the static eliminator. In this case, the conductivity of the static eliminator may decrease. Also, there is a risk of a failure in the electrical connection between the static eliminator and the shaft.

[0005] An object of the present invention is to suppress or prevent a decrease in the efficiency of static electricity removal from a shaft. [Means for solving the problem]

[0006] An exemplary driving device of the present invention includes a shaft, a rotor, a stator, a bearing, a housing, a first static eliminator, and a seal member. The shaft extends in the axial direction along a rotation axis. The rotor is fixed to the shaft and is rotatable about the rotation axis. The stator faces the rotor with a radial gap. The bearing rotatably supports the shaft. The housing accommodates the rotor, the stator, and the bearing. The first static eliminator is disposed on one side of the bearing in the axial direction and electrically connects the shaft and the housing. The seal member is disposed between the bearing and the first static eliminator in the axial direction.

[0007] An exemplary vehicle of the present invention includes the drive device described above. Effect of the Invention

[0008] According to the exemplary drive device and vehicle of the present invention, it is possible to suppress or prevent a decrease in the efficiency of static electricity removal from the shaft. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a conceptual diagram showing a configuration example of a drive device. [Figure 2A] FIG. 2A is a conceptual diagram showing an example of a shaft static elimination structure of a drive device according to an embodiment. [Figure 2B] FIG. 2B is a conceptual diagram showing another example of the shaft static elimination structure of the drive device according to the embodiment. [Diagram 3] FIG. 3 is a schematic diagram showing an example of a vehicle equipped with the drive device. [Figure 4A] FIG. 4A is a perspective view illustrating an example of a first static eliminator according to an embodiment. [Figure 4B] FIG. 4B is a perspective view showing an example of a first static eliminator according to a modified example. [Diagram 5] FIG. 5 is a conceptual diagram showing a shaft static elimination structure of a drive device according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Exemplary embodiments are described below with reference to the drawings.

[0011] In this specification, the direction parallel to the rotation axis J1 of the motor unit 2 is referred to as the "axial direction" of the drive device 100. Regarding the axial direction, the motor unit 2 side is referred to as one axial direction D1, and the gear unit 3 side is referred to as the other axial direction D2, as shown in Fig. 1. In addition, the radial direction perpendicular to a predetermined axis such as the rotation axis J1 is simply referred to as the "radial direction", and the circumferential direction centered on a predetermined axis such as the rotation axis J1 is simply referred to as the "circumferential direction".

[0012] In this specification, in the positional relationship between any one of a direction, a line, and a plane and any other, "parallel" includes not only a state in which the two do not intersect at all no matter how far they are extended, but also a state in which they are substantially parallel. Furthermore, "perpendicular" includes not only a state in which the two intersect at 90 degrees, but also a state in which they are substantially perpendicular. In other words, "parallel" and "perpendicular" each include a state in which there is an angle deviation in the positional relationship between the two that does not deviate from the gist of the present invention.

[0013] In this specification, "extending" in a predetermined direction includes not only a configuration in which the extending direction is strictly in the predetermined direction, but also a configuration in which the extending direction is substantially in the predetermined direction. In other words, "extending" in a predetermined direction includes a configuration in which the direction is deviated from the predetermined direction to an extent that does not deviate from the gist of the present invention. The same applies to "spreading" in a predetermined direction.

[0014] <1. Embodiment> FIG. 1 is a conceptual diagram showing a configuration example of the drive device 100. FIG. 2A is a conceptual diagram showing an example of a shaft static elimination structure of the drive device 100 according to the embodiment. FIG. 2B is a conceptual diagram showing another example of a shaft static elimination structure of the drive device 100 according to the embodiment. FIG. 3 is a schematic diagram showing an example of a vehicle 300 equipped with the drive device 100. Note that FIGS. 1, 2A, and 2B are merely conceptual diagrams, and the arrangement and dimensions of each part are not necessarily strictly the same as those of the actual drive device 100. Also, FIGS. 2A and 2B are enlarged views of a portion A surrounded by a dashed line in FIG. 1. Also, FIG. 3 conceptually illustrates the vehicle 300.

[0015] In this embodiment, as shown in FIG. 3, the drive device 100 is mounted on a vehicle 300 that uses at least a motor as a power source, such as a hybrid vehicle (HV), a plug-in hybrid vehicle (PHV), or an electric vehicle (EV). The drive device 100 is used as a power source for the vehicle 300. The vehicle 300 has the drive device 100. By mounting the drive device 100, the drive device 100 of the vehicle 300 that is equipped with a static elimination mechanism between the shaft 1 and the housing 4 can be made smaller. In FIG. 3, the drive device 100 drives the front wheels of the vehicle 300. Note that it is sufficient that the drive device 100 drives at least one of the wheels. The vehicle 300 further has a battery 200. The battery 200 stores power to be supplied to the drive device 100.

[0016] As shown in FIG. 1, the driving device 100 includes a shaft 1, a motor unit 2, a gear unit 3, a housing 4, a liquid circulating unit 5, a first static eliminator 6, a rotation detector 7, and a seal member 8.

[0017] <1-1. Shaft 1> The shaft 1 extends in the axial direction along the rotation axis J1. As described above, the driving device 100 includes the shaft 1. The shaft 1 is rotatable around the rotation axis J1. As shown in FIG. 1 , the shaft 1 is rotatably supported by the housing 4 via a first motor bearing 4211, a second motor bearing 4221, a third motor bearing 4311, and a fourth motor bearing 4611, which will be described later. That is, the driving device 100 includes these bearings 4211, 4221, 4311, and 4611. These bearings 4211, 4221, 4311, and 4611 support the shaft 1 rotatably.

[0018] The shaft 1 is cylindrical and extends in the axial direction. A fluid F flows inside the shaft 1. The drive unit 100 further includes the fluid F. In this embodiment, the fluid F is a lubricating liquid that lubricates the gear unit 3 and the bearings of the drive unit 100, and is, for example, an automatic transmission fluid (ATF). The fluid F is also used as a refrigerant that cools the motor unit 2 and the like. As the shaft 1 rotates, the fluid F flowing inside the shaft 1 can be supplied to the motor unit 2, the first motor bearing 4211, the third motor bearing 4311, and the like through a first shaft through-hole 101 described later. Therefore, the fluid F can cool the stator 22 (particularly the coil end 2221 described later) and the above-mentioned bearings 4211, 4311, and the like.

[0019] In addition, the shaft 1 may be split, for example, at the middle part in the axial direction. When the shaft 1 is split, the split shafts 1 are connected, for example, by spline fitting. Alternatively, they may be connected by a screw coupling using male and female threads, or may be joined by a fixing method such as press fitting and welding. When a fixing method such as press fitting or welding is adopted, serrations that combine concave and convex parts extending in the axial direction may be used. With such a configuration, it is possible to reliably transmit rotation.

[0020] <1-1-1. Shaft cylinder portion 11 and hollow portion 12> The shaft 1 has a cylindrical shaft tube portion 11 surrounding the rotation axis J1. The shaft tube portion 11 is cylindrical and extends in the axial direction along the rotation axis J1. The shaft tube portion 11 is conductive and made of metal in this embodiment. The shaft 1 also has a hollow portion 12 and an inlet 111. The hollow portion 12 is a space surrounded by the inner circumferential surface of the shaft tube portion 11 and is disposed inside the shaft tube portion 11. The inlet 111 is the other axial end portion of the cylindrical shaft tube portion 11 and is connected to a flow path 465 of the gear cover portion 46 described later. A fluid F flows from the flow path 465 into the hollow portion 12 through the inlet 111.

[0021] <1-1-2. Shaft wall 13> Next, the shaft 1 further has a shaft wall portion 13. The shaft wall portion 13 is disposed inside the cylindrical shaft portion 11 and extends in the radial direction. The shaft wall portion 13 is disposed on one axial direction D1 side of the cylindrical shaft portion 11.

[0022] In this embodiment, as shown in FIG. 2A, the shaft wall portion 13 is disposed on one axial direction D1 from the seal member 8. However, the axial position of the shaft wall portion 13 is not limited to the example of FIG. 2A. The shaft wall portion 13 may be disposed at the same axial position as the seal member 8. For example, as viewed from the radial direction, at least a part of the shaft wall portion 13 may overlap with the seal member 8. Alternatively, as shown in FIG. 2B, the shaft wall portion 13 may be disposed on one axial direction D1 from the radial inner end of the second shaft through hole 102 and on the other axial direction D2 from the seal member 8. For example, in the latter case, the one axial end of the shaft wall portion 13 may be disposed on the other axial direction D2 from the seal member 8. In this way, the axial distance between the radial inner end of the second shaft through hole 102 and the shaft wall portion 13 can be narrowed. Therefore, for example, the fluid F flowing in one axial direction D1 inside the cylindrical shaft portion 11 is more likely to flow into the second shaft through-hole 102, and less fluid F remains between the radial inner end of the second shaft through-hole 102 and the shaft wall portion 13. Therefore, the fluid F inside the cylindrical shaft portion 11 can be supplied to the third motor bearing 4311 more smoothly.

[0023] The radial outer end of the shaft wall portion 13 is connected to the inner surface of the tubular shaft portion 11. Preferably, the shaft wall portion 13 is integral with the tubular shaft portion 11. For example, in this embodiment, the shaft wall portion 13 is a different part of the same member as the tubular shaft portion 11. By integrating the shaft wall portion 13 with the tubular shaft portion 11, the shaft 1 is easier to manufacture. Furthermore, since the number of parts of the shaft 1 can be reduced, the drive unit 100 is easier to assemble. However, this is not limiting, and the shaft wall portion 13 may be a separate member from the tubular shaft portion 11.

[0024] <1-1-3. First shaft through hole 101> A first shaft through hole 101 is arranged in the shaft tube portion 11. That is, the shaft 1 further has a first shaft through hole 101 that penetrates the shaft tube portion 11 in the radial direction. The number of the first shaft through holes 101 may be one or more. When the shaft 1 rotates, the fluid F in the shaft tube portion 11 flows out of the shaft tube portion 11 from the hollow portion 12 through the first shaft through hole 101 by centrifugal force. In this embodiment, as shown in FIG. 1, the first shaft through hole 101 is arranged on one axial side D1 of the other axial end of the rotor 21 and on the other axial side D2 of the one axial end of the rotor 21, and is connected to a rotor through hole 2111 described later. 1, the first shaft through hole 101 may be disposed on the other axial side D2 of the other axial end of the rotor 21 and on the other axial side D1 of the first motor bearing 4211, or may be disposed on the other axial side D1 of the one axial end of the rotor 21 and on the other axial side D2 of the third motor bearing 4311. That is, at least a part of the first shaft through holes 101 may be disposed at least in any one of these positions. Note that the above example does not exclude a configuration in which the first shaft through hole 101 and the rotor through hole 2111 are omitted.

[0025] <1-1-4. Second shaft through hole 102> A second shaft through hole 102 is arranged in the tubular shaft portion 11. The shaft 1 further has the second shaft through hole 102. The second shaft through hole 102 penetrates the tubular shaft portion 11 in the radial direction. Alternatively, the second shaft through hole 102 may penetrate the tubular shaft portion 11 in a direction intersecting the radial direction and the axial direction. The second shaft through hole 102 is an example of a "shaft through hole" in the present invention.

[0026] The number of the second shaft through holes 102 may be one or more. In the latter case, the second shaft through holes 102 may be arranged at equal intervals or at different intervals in the circumferential direction. Note that the above examples do not exclude a configuration in which the second shaft through holes 102 are omitted.

[0027] In this embodiment, the second shaft through hole 102 is disposed on one axial direction D1 from the first shaft through hole 101 (see FIG. 1). The radial outer end of the second shaft through hole 102 is connected between the third motor bearing 4311 and the seal member 8. In FIG. 2A and FIG. 2B, the radial outer end of the second shaft through hole 102 is connected to the third motor bearing holder 431. The radial inner end of the second shaft through hole 102 is disposed on the other axial direction D2 from the shaft wall portion 13 and is connected to the hollow portion 12. In this way, at least a part of the lubricating / cooling fluid F flowing in the shaft tube portion 11 flows between the third motor bearing 4311 and the seal member 8 through the second shaft through hole 102 by the rotation of the shaft 1, and is supplied to the third motor bearing 4311. Therefore, the fluid F in the shaft tube portion 11 can be smoothly supplied to the third motor bearing 4311.

[0028] The radial outer end of the second shaft through hole 102 is disposed on one axial direction D1 from the third motor bearing 4311. Preferably, the radial outer end of the second shaft through hole 102 is disposed on the other axial direction D2 from the one axial end of an opening 4312 of the housing cover 43, which will be described later. More preferably, the radial outer end of the second shaft through hole 102 is disposed on the other axial direction D2 from the seal member 8. Here, as described above, the radial outer end of the second shaft through hole 102 is connected to the inside of the third motor bearing holder 431. Therefore, compared to a configuration in which the radial outer end of the second shaft through hole 102 is disposed on one axial direction D1 from the one axial end of the opening 4312 (i.e., a configuration in which the radial outer end of the second shaft through hole 102 is connected to the outside of the third motor bearing holder 431), the fluid F is less likely to enter the space 403, which will be described later, in which the other axial end of the shaft tube portion 11 is disposed. This makes it possible to prevent the fluid F from getting on the first static eliminator 6 in the shaft tube portion 11. Note that the above example does not exclude a configuration in which the radially outer end of the second shaft through-hole 102 is disposed on one axial direction D1 further than one axial direction end of the opening 4312, nor does it exclude a configuration in which the radially outer end is disposed on one axial direction D1 further than the seal member 8.

[0029] <1-2. Motor section 2> The motor unit 2 is a DC brushless motor. The motor unit 2 is a drive source of the drive device 100, and is driven by power from an inverter (not shown). The motor unit 2 is an inner rotor type in which a rotor 21 is rotatably disposed inside a stator 22. As shown in FIG. 1, the motor unit 2 has a rotor 21 and a stator 22.

[0030] <1-2-1.Rotor 21> The rotor 21 is supported by the shaft 1. The driving device 100 includes the rotor 21. The rotor 21 is fixed to the shaft 1 and is rotatable about a rotation axis J1. The rotor 21 rotates when power is supplied to a stator 22 from a power supply unit (not shown) of the driving device 100. The rotor 21 has a rotor core 211 and a magnet 212. The rotor core 211 is formed, for example, by laminating thin electromagnetic steel plates. The rotor core 211 is a cylindrical body extending along the axial direction, and is fixed to the radial outer surface of the shaft 1. A plurality of magnets 212 are fixed to the rotor core 211. The plurality of magnets 212 are arranged along the circumferential direction with their magnetic poles alternating.

[0031] The rotor core 211 also has a rotor through hole 2111. The rotor through hole 2111 penetrates the rotor core 211 in the axial direction and is connected to the first shaft through hole 101. The rotor through hole 2111 is used as a flow path for a fluid F that also functions as a coolant. When the rotor 21 rotates, the fluid F flowing through the hollow portion 12 of the shaft 1 can flow into the rotor through hole 2111 via the first shaft through hole 101. The fluid F that flows into the rotor through hole 2111 can flow out from both axial ends of the rotor through hole 2111 to the outside. The outflowing fluid F flies toward the stator 22 and cools, for example, the coil portion 222 (particularly the coil end 2221). The outflowing fluid F flies toward the first motor bearing 4211 and the third motor bearing 4311 that rotatably support the shaft 1, and lubricates and cools these bearings 4211 and 4311.

[0032] <1-2-2. Stator 22> The stator 22 faces the rotor 21 with a radial gap therebetween. The drive device 100 includes the stator 22. The stator 22 is disposed radially outward from the rotor 21. The stator 22 has a stator core 221 and a coil portion 222. The stator 22 is held in a first housing cylindrical portion 41, which will be described later. The stator core 221 has a plurality of magnetic pole teeth (not shown) extending radially inward from the inner circumferential surface of the annular yoke. The coil portion 222 is formed by winding a conductor around the magnetic pole teeth via an insulator (not shown). The coil portion 222 has coil ends 2221 protruding from an axial end face of the stator core 221.

[0033] <1-3. Gear section 3> Next, the gear unit 3 is a power transmission device that transmits the power of the motor unit 2 to a drive shaft Ds (to be described later). The gear unit 3 has a reduction gear 31 and a differential gear 32.

[0034] <1-3-1. Reduction device 31> The reduction gear 31 is connected to the shaft 1. The reduction gear 31 has a function of reducing the rotation speed of the motor unit 2 and increasing the torque output from the motor unit 2 in accordance with a reduction ratio. The reduction gear 31 transmits the torque output from the motor unit 2 to the differential gear 32. That is, the gear unit 3 is connected to one axial direction D1 side of the shaft 1 that rotates about a rotation axis J1 extending along the horizontal direction.

[0035] 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. Torque output from the motor unit 2 is transmitted to a ring gear 321 of the differential gear 32 via the shaft 1, the main drive gear 311, the intermediate driven gear 312, the intermediate shaft 314, and the final drive gear 313.

[0036] The main drive gear 311 is disposed on the outer circumferential surface of the shaft 1. The main drive gear 311 may be the same member as the shaft 1, or may be a separate member that is firmly fixed thereto. The main drive gear 311 rotates together with the shaft 1 about the rotation axis J1.

[0037] The intermediate shaft 314 extends along an intermediate axis J2 parallel to the rotation axis J1. Both ends of the intermediate shaft 314 are supported by a first intermediate bearing 4231 and a second intermediate bearing 4621 so as to be rotatable about the intermediate axis J2. The intermediate driven gear 312 and the final drive gear 313 are disposed on the outer circumferential surface of the intermediate shaft 314. The intermediate driven gear 312 may be the same member as the intermediate shaft 314, or may be a separate member that is firmly fixed.

[0038] The intermediate driven gear 312 and the final drive gear 313 rotate integrally with the intermediate shaft 314 about the intermediate axis J2. The intermediate driven gear 312 meshes with the main drive gear 311. The final drive gear 313 meshes with a ring gear 321 of the differential device 32.

[0039] The torque of the shaft 1 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. The torque is further transmitted from the final drive gear 313 to the ring gear 321.

[0040] <1-3-2. Differential device 32> The differential gear 32 is attached to the drive shaft Ds. The differential gear 32 has a ring gear 321. The ring gear 321 transmits the torque transmitted from the reduction gear 31 to the drive shaft Ds. The drive shaft Ds is attached to one axial direction D1 and the other axial direction D2 of the differential gear 32. The drive shaft Ds1 on the one axial direction D1 side is rotatably supported by a first output bearing 4241 described later. The drive shaft Ds2 on the other axial direction D2 side is rotatably supported by a second output bearing 4631 described later. For example, when the vehicle turns, the differential gear 32 transmits torque to the drive shafts Ds1 and Ds2 on both axial sides while absorbing the difference in rotation speed between the drive shafts Ds1 and Ds2 on both axial sides.

[0041] The lower end of the ring gear 321 is disposed inside a liquid storage section P (described later) in which the fluid F stored in the lower part of the gear unit accommodating space 402 accumulates (see FIG. 1). Therefore, when the ring gear 321 rotates, the fluid F is scooped up by the gear teeth of the ring gear 321. The fluid F scooped up by the ring gear 321 lubricates or cools each gear and bearing of the gear unit 3. In addition, a portion of the scooped up fluid F is stored in a receiver section 464 (described later) and is also used to cool the motor unit 2 via the shaft 1.

[0042] <1-4. Housing 4> The housing 4 accommodates the shaft 1, the motor section 2, and the gear section 3. The housing 4 has a first housing tubular section 41, a side plate section 42, a housing lid section 43, a cover member 44, a second housing tubular section 45, and a gear lid section 46. The first housing tubular section 41, the side plate section 42, the housing lid section 43, the cover member 44, the second housing tubular section 45, and the gear lid section 46 are formed, for example, using a conductive material, and in this embodiment, are formed using a metal material such as iron, aluminum, or an alloy thereof. In addition, in order to suppress bimetallic corrosion at the contact portion, these are preferably formed using the same material. However, this is not limited to the example, and these may be formed using a material other than a metal material, or at least some of these may be formed using a different material.

[0043] Furthermore, the housing 4 accommodates the rotor 21, the stator 22, the third motor bearing 4311, etc. As described above, the drive device 100 includes the housing 4. In detail, the housing 4 has a motor accommodating space 401. The motor accommodating space 401 is a space surrounded by the first housing cylindrical portion 41, the side plate portion 42, and the housing lid portion 43, and accommodates the rotor 21, the stator 22, the first motor bearing 4211, the third motor bearing 4311, etc.

[0044] As described above, the housing 4 accommodates the gear portion 3. More specifically, the housing 4 has a gear portion accommodating space 402. The gear portion accommodating space 402 is a space surrounded by the side plate portion 42, the second housing cylindrical portion 45, and the gear cover portion 46, and accommodates the reduction gear 31, the differential gear 32, etc.

[0045] A liquid reservoir P in which the fluid F accumulates is disposed in the lower portion of the gear portion accommodating space 402. A part of the differential gear 32 is immersed in the liquid reservoir P. The fluid F accumulated in the liquid reservoir P is scooped up by the operation of the differential gear 32 and supplied to the inside of the gear portion accommodating space 402. For example, the fluid F is scooped up by the tooth surface of the ring gear 321 when the ring gear 321 of the differential gear 32 rotates. A part of the scooped up fluid F is supplied to each gear and each bearing of the reduction gear 31 and the differential gear 32 in the gear portion accommodating space 402 and used for lubrication. Another part of the scooped up fluid F is supplied to the inside of the shaft 1 and supplied to the rotor 21 and the stator 22 of the motor unit 2 and each bearing in the gear portion accommodating space 402 and used for cooling and lubrication.

[0046] <1-4-1. First housing cylindrical portion 41> The first housing cylindrical portion 41 has a cylindrical shape extending in the axial direction. The motor portion 2, a fluid reservoir 54 (described later), and the like are disposed inside the first housing cylindrical portion 41. In addition, a stator core 221 is fixed to the inner surface of the first housing cylindrical portion 41.

[0047] <1-4-2. Side plate part 42> The side plate portion 42 covers the other axial end of the first housing tubular portion 41 and covers one axial end of the second housing tubular portion 45. The side plate portion 42 extends in a direction intersecting the rotation axis J1, and divides the first housing tubular portion 41 and the second housing tubular portion 45. In this embodiment, the first housing tubular portion 41 and the side plate portion 42 are different parts of a single member. By forming them integrally, the rigidity of these can be increased. However, this is not limited to an example, and the two may be separate members.

[0048] The side plate portion 42 has a side plate through hole 4201 through which the shaft 1 is inserted, and a first drive shaft through hole 4202. The side plate through hole 4201 and the first drive shaft through hole 4202 penetrate the side plate portion 42 in the axial direction. The center of the side plate through hole 4201 coincides with the rotation axis J1. The shaft 1 is inserted into the side plate through hole 4201. The center of the first drive shaft through hole 4202 coincides with the drive axis J3. The drive shaft Ds1 on one axial side D1 is inserted into the first drive shaft through hole 4202. An oil seal (not shown) is arranged in the gap between the drive shaft Ds1 and the first drive shaft through hole 4202 to seal the gap between them.

[0049] The side plate portion 42 further includes a first motor bearing holder 421, a second motor bearing holder 422, a first intermediate bearing holder 423, and a first output bearing holder 424. The first motor bearing holder 421 is disposed on one axial direction D1 side of the side plate through hole 4201 in the side plate portion 42, and holds a first motor bearing 4211. The second motor bearing holder 422 is disposed along an outer edge of the other axial end of the side plate through hole 4201, and holds a second motor bearing 4221. The first intermediate bearing holder 423 is disposed on the other axial end surface of the side plate portion 42, and holds a first intermediate bearing 4231. The first output bearing holder 424 is disposed along an outer edge of the other axial end of the first drive shaft through hole 4202 in the side plate portion 42, and holds a first output bearing 4241. The first motor bearing 4211, the second motor bearing 4221, the first intermediate bearing 4231, and the first output bearing 4241 are ball bearings in this embodiment.

[0050] <1-4-3. Housing lid 43> The housing lid 43 spreads in a direction intersecting the rotation axis J1 and covers one axial end of the first housing tubular portion 41. The housing lid 43 is attached to one axial end of the first housing tubular portion 41. The housing lid 43 can be fixed to the first housing tubular portion 41 by, for example, a screw, but is not limited to this, and any method that can firmly fix the housing lid 43 to the first housing tubular portion 41, such as screwing or press fitting, can be widely used. This allows the housing lid 43 to be tightly attached to one axial end of the first housing tubular portion 41. Note that the tight attachment refers to a sealability that prevents the fluid F inside the member from leaking to the outside and prevents foreign matter such as water, dirt, and dust from entering from the outside. The same applies to the tight attachment hereinafter.

[0051] Further, the housing lid portion 43 has a third motor bearing holder 431. The third motor bearing holder 431 is disposed on the other axial end surface of the housing lid portion 43. The motor includes a third motor bearing holder 431. The third motor bearing holder 431 holds a third motor bearing 4311. The third motor bearing holder 431 is an example of a "bearing holder" in the present invention. That is, the drive device 100 includes a third motor bearing 4311. The third motor bearing 4311 rotatably supports the shaft 1. The third motor bearing 4311 is an example of a "bearing" in the present invention, and is a ball bearing in this embodiment.

[0052] The third motor bearing holder 431 has an opening 4312 through which the shaft 1 is inserted. The opening 4312 passes through the housing lid portion 43 in the axial direction, and surrounds the rotation axis J1 when viewed in the axial direction.

[0053] The housing lid 43 further includes a detector holder 432 and a recess 433. In this embodiment, the detector holder 432 and the recess 433 are steps arranged on one axial direction D1 side of the housing lid 43. These steps are annular surrounding the rotation axis J1. The detector holder 432 holds the rotation detector 7. The recess 433 is arranged on one axial direction D1 side of the housing lid 43 and recessed toward the other axial direction D2. An opening 4312 communicates with the detector holder 432 and the recess 433.

[0054] <1-4-4. Cover member 44> The cover member 44 is attached to one axial end surface of the housing lid portion 43. The cover member 44 can be attached to the housing lid portion 43 by, for example, screwing, but is not limited to this, and any method that can firmly fix the cover member 44 to the housing lid portion 43, such as screwing or press fitting, can be widely used. In this embodiment, the cover member 44 forms a space 403 together with the housing lid portion 43. The space 403 is a space surrounded by the housing lid portion 43 and the cover member 44, and accommodates one axial end portion of the shaft 1, the rotation detector 7, the seal member 8, etc.

[0055] The cover member 44 has a plate portion 441 and a plate recess 442. The plate portion 441 is a plate-like member that extends in a direction intersecting the rotation axis J1, and in this embodiment, extends in a radial direction from the rotation axis J1. The plate portion 441 is disposed on one axial direction D1 from one axial end of the shaft 1, and covers the opening 4312 and one axial end of the shaft 1. The plate recess 442 is disposed on the other axial direction D2 side of the plate portion 441, and is recessed in one axial direction D1 around the rotation axis J1. The plate recess 442 accommodates one axial end of the shaft tube portion 11 and the first static eliminator 6.

[0056] <1-4-5. Second housing cylindrical portion 45> The second housing tubular portion 45 is cylindrical and surrounds the rotation axis J1, and extends in the axial direction. One axial end of the second housing tubular portion 45 is connected to and covered by the side plate portion 42. In this embodiment, the second housing tubular portion 45 is detachably attached to the other axial end of the side plate portion 42. The second housing tubular portion 45 can be attached to the side plate portion 42 by, for example, fixing with a screw, but is not limited to this, and any method that can firmly fix the second housing tubular portion 45 to the side plate portion 42, such as screwing or press fitting, can be widely used. This allows the second housing tubular portion 45 to be in close contact with the other axial end of the side plate portion 42.

[0057] <1-4-6. Gear cover part 46> The gear lid portion 46 extends in a direction intersecting with the rotation axis J1. The gear portion 3 is disposed inside the second housing tubular portion 45 and the gear lid portion 46. In this embodiment, the second housing tubular portion 45 and the gear lid portion 46 are different parts of a single member. However, this is not limiting, and the second housing tubular portion 45 and the gear lid portion 46 may be separate members.

[0058] 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 drive axis J3. The drive shaft Ds is inserted through the second drive shaft through hole 460. An oil seal (not shown) is arranged in the gap between the drive shaft Ds2 on the other axial side D2 and the second drive shaft through hole 460.

[0059] The gear cover 46 further includes a fourth motor bearing holder 461, a second intermediate bearing holder 462, and a second output bearing holder 463. These bearing holders 461, 462, and 463 are disposed on one axial end surface of the gear cover 46 in the gear portion accommodating space 402. The fourth motor bearing holder 461 and the second intermediate bearing holder 462 are disposed on one axial end surface of the gear cover 46. The fourth motor bearing holder 461 holds a fourth motor bearing 4611. The second intermediate bearing holder 462 holds a second intermediate bearing 4621. The second output bearing holder 463 is disposed along the outer edge of one axial end of the second drive shaft through hole 460 in the gear cover 46, and holds a second output bearing 4631. The fourth motor bearing 4611, the second intermediate bearing 4621, and the second output bearing 4631 are ball bearings in this embodiment.

[0060] The gear lid portion 46 also has a tray portion 464 and a flow path 465. The tray portion 464 is disposed on one axial end surface of the gear lid portion 46, and has a recess that is recessed vertically downward. The tray portion 464 can store the fluid F scooped up by the ring gear 321. The flow path 465 is a passage for the fluid F, and connects the tray portion 464 and the inlet 111 of the shaft 1. The fluid F stored in the tray portion 464 is supplied to the flow path 465 and flows into the hollow portion 12 from the inlet 111 at the other axial end of the shaft 1.

[0061] <1-5.Liquid circulation section 5> Next, a description will be given of the liquid circulation section 5. The liquid circulation section 5 has a piping section 51, a pump 52, a cooler unit 53, and a fluid reservoir .

[0062] The piping section 51 connects the pump 52 to a fluid reservoir 54 disposed inside the first housing cylindrical section 41, and supplies the fluid F to the fluid reservoir 54. The pump 52 sucks the fluid F stored in a lower region of the gear portion accommodating space 402. The pump 52 is an electric pump, but is not limited to this. For example, the pump 52 may be configured to be driven by utilizing part of the power of the shaft 1 of the drive unit 100.

[0063] The cooler unit 53 is disposed between the pump 52 and the fluid reservoir 54 in the piping section 51. That is, the fluid F sucked by the pump 52 passes through the cooler unit 53 via the piping section 51, and is then sent to the fluid reservoir 54. A refrigerant such as water supplied from the outside is supplied to the cooler unit 53. The cooler unit 53 exchanges heat between the refrigerant and the fluid F to lower the temperature of the fluid F.

[0064] The fluid reservoir 54 is a tray disposed vertically above the stator 22 inside the motor accommodating space 401. A drip hole (reference number omitted) is formed in the bottom of the fluid reservoir 54, and the motor section 2 is cooled by dripping the fluid F from the drip hole. The drip hole is formed, for example, above the coil end 2221 of the coil section 222 of the stator 22, and the coil section 222 is cooled by the fluid F.

[0065] <1-6. 1st static eliminator 6> Next, the first static eliminator 6 will be described with reference to Fig. 2A and Fig. 2B and Fig. 4A and Fig. 4B. Fig. 4A is a perspective view showing an example of the first static eliminator 6 according to an embodiment. Fig. 4B is a perspective view showing a modified example of the first static eliminator 6.

[0066] The first static eliminator 6 is disposed radially outward from the shaft tube portion 11. The first static eliminator 6 is disposed on one axial side D1 from the third motor bearing 4311, and electrically connects the shaft 1 and the housing 4. As described above, the drive device 100 includes the first static eliminator 6. Since it is not necessary to dispose the first static eliminator 6 between the shaft wall portion 13 and the cover member 44 in the axial direction, an increase in the axial size of the drive device 100 can be suppressed.

[0067] The first static eliminator 6 is in contact with the shaft 1 and the cover member 44 and is electrically connected to both. For example, the first static eliminator 6 is housed in the plate recess 442 of the cover member 44. This can further suppress an increase in the axial size of the drive device 100. In this embodiment, as shown in FIG. 2A and FIG. 2B, the radial inner end of the first static eliminator 6 is in contact with the outer circumferential surface of the shaft tube portion 11. In addition, the radial outer end of the first static eliminator 6 is in contact with the cover member 44. In this embodiment, the radial outer end of the first static eliminator 6 is in contact with the inner circumferential surface of the plate recess 442 facing radially inward, and one axial end of the first static eliminator 6 is in contact with the inner bottom surface of the plate recess 442 facing the other axial direction D2. The first static eliminator 6 is in contact with both the inner circumferential surface and the inner bottom surface of the plate recess 442, so that the contact area between the first static eliminator 6 and the cover member 44 can be made larger. Therefore, the electrical conductivity between them can be further increased, thereby improving the effect of eliminating static electricity from the shaft 1 by the first static eliminator 6. However, without being limited to the examples shown in Figures 2A and 2B, the first static eliminator 6 may be in contact with only one of the inner circumferential surface and the inner bottom surface of the plate recess 442.

[0068] In this embodiment, the first static eliminator 6 has a conductive member 61 and a conductive holding member 62. The holding member 62 holds the conductive member 61.

[0069] The conductive member 61 may be, for example, in the form of a brush including a plurality of fibers extending in the radial direction, or may be a molded body. The conductive member 61 is formed using a material having electrical conductivity. The conductive member 61 is preferably made of a material having good sliding properties, and more preferably of a material having a low coefficient of friction. The conductive member 61 may be made of, for example, a composite resin including a conductive filler such as carbon fiber or metal. The holding member 62 is, for example, made of metal, and houses a part of the conductive member 61 therein.

[0070] In this embodiment, the tip (i.e., the radially inner end) of the conductive member 61 contacts the outer circumferential surface of the tubular shaft portion 11. The holding member 62 is fixed to the cover member 44 (the inner circumferential surface and / or the inner bottom surface of the plate recess 442). However, without being limited to the example of this embodiment, the tip (i.e., the radially outer end) of the conductive member 61 may contact the cover member 44 (for example, the inner circumferential surface and / or the inner bottom surface of the plate recess 442) and the holding member 62 may be fixed to the outer circumferential surface of the tubular shaft portion 11.

[0071] In this embodiment, the first static eliminator 6 is annular and surrounds the rotation axis J1, and is fitted into the inner circumferential surface of the plate recess 442. In this manner, the annular first static eliminator 6 can be fitted into the inner circumferential surface of the plate recess 442, so that the first static eliminator 6 can be stably fixed inside the shaft cylindrical portion 11.

[0072] 4A, the conductive member 61 and the holding member 62 are annular about the rotation axis J1. The radially outer side of the conductive member 61 is held by the radially inner end of the holding member 62. The radially inner side of the conductive member 61 extends radially inward from the radially inner end of the holding member 62. The radially outer end of the holding member 62 fits into the inner circumferential surface of the shaft tube portion 11.

[0073] 4A, the radially outer end of the conductive member 61 may be fitted into the inner circumferential surface of the shaft tube portion 11. In this case, the radially inner side of the conductive member 61 is held by the radially outer end of the holding member 62, and the radially outer side of the conductive member 61 spreads outward in the radial direction from the radially outer end of the holding member 62.

[0074] Also, without being limited to the example of FIG. 4A, the first static eliminator 6 may not be annular. For example, the first static eliminator 6 may be a rectangular parallelepiped as shown in FIG. 4B, or may be an arc extending in the circumferential direction centered on the rotation axis J1. For example, the conductive member 61 may contact the outer circumferential surface of the tubular shaft portion 11 in a partial circumferential region, and the holding member 62 may be fixed to the cover member 44. Alternatively, conversely, the conductive member 61 may contact the cover member 44 in a partial circumferential region, and the holding member 62 may be fixed to the outer circumferential surface of the tubular shaft portion 11. By the conductive member 61 contacting the outer circumferential surface of the tubular shaft portion 11 or the cover member 44 in a partial circumferential region, the sliding area of ​​the conductive member 61 per one rotation of the shaft 1 can be made smaller. Therefore, the wear powder generated at the contact portion between the conductive member 61 and the tubular shaft portion 11 or the cover member 44 can be reduced.

[0075] The first static eliminator 6 may further include an elastic member 63 (see FIG. 4B). The elastic member 63 is accommodated inside the holding member 62 in a compressed state. Due to its elasticity, the elastic member 63 presses the conductive member 61 toward the shaft 1 or the cover member 44 (the inner peripheral surface of the plate recess 442). The elastic member 63 may be a spring coil, a leaf spring, rubber, or the like. Although the elastic member 63 is not illustrated in FIG. 4A, the first static eliminator 6 in FIG. 4A may include the elastic member 63 as in FIG. 4B. However, these examples do not exclude a configuration in which the first static eliminator 6 does not include the elastic member 63.

[0076] <1-7. Rotation detector 7> The rotation detector 7 is attached to one axial direction D1 side of the housing lid portion 43. As described above, the drive device 100 is provided with the rotation detector 7. The rotation detector 7 detects the rotation angle of the shaft 1. The rotation detector 7 is disposed between the third motor bearing holder 431 and the first static eliminator 6 in the axial direction. In this way, the rotation detector 7 disposed between the third motor bearing 4311 and the first static eliminator 6 can detect the rotation angle of the shaft 1.

[0077] Preferably, the rotation detector 7 is disposed on one axial direction D1 from the seal member 8 (see FIGS. 2A and 2B). In this way, the rotation detector 7 such as a resolver can be disposed in a space partitioned from the third motor bearing 4311 by the seal member 8. For example, the rotation detector 7 can be disposed in the space 403 in which the first static eliminator 6 is disposed. This makes it possible to suppress or prevent the fluid F that lubricates the third motor bearing 4311 from coming into contact with the rotation detector 7. However, this example does not exclude a configuration in which the rotation detector 7 is disposed on the other axial direction D2 from the seal member 8.

[0078] In this embodiment, the rotation detector 7 is a resolver having a resolver rotor and a resolver stator. The rotation detector 7 has a resolver rotor (not shown) fixed to the shaft 1, and a resolver stator (not shown) fixed to the housing lid portion 43 of the housing 4. The resolver rotor and the resolver stator are annular. The inner peripheral surface of the resolver stator faces the outer peripheral surface of the resolver rotor in the radial direction. The resolver stator periodically detects the rotation angle position of the resolver rotor when the rotor 21 rotates. In this way, the rotation detector 7 obtains information on the rotation angle position of the rotor 21. Note that the present embodiment is not limited to the example, and the rotation detector 7 does not have to be a resolver, and may be, for example, a rotary encoder.

[0079] <1-8. Sealing material 8> The seal member 8 is disposed between the third motor bearing 4311 and the first static eliminator 6 in the axial direction. As described above, the drive device 100 further includes the seal member 8. The seal member 8 divides the third motor bearing holder 431 from the space 403 in which the rotation detector 7 is disposed. In detail, the seal member 8 is annular and surrounds the rotation axis J1, and covers the gap between the shaft 1 and the housing cover 43 (in other words, the inner circumferential surface of the opening 4312). In this way, the seal member 8 disposed between the third motor bearing 4311 and the first static eliminator 6 can isolate the first static eliminator 6 from the third motor bearing 4311. Therefore, it is possible to suppress or prevent the fluid F that lubricates the third motor bearing 4311 from coming into contact with the first static eliminator 6. Therefore, the first static eliminator 6 can maintain a good electrical connection with the shaft 1. In other words, it is possible to suppress or prevent a decrease in the static elimination efficiency of the shaft 1. Furthermore, the seal member 8 can suppress or prevent the fluid F that lubricates the third motor bearing 4311 from getting onto the rotation detector 7.

[0080] In this embodiment, the seal member 8 is disposed outside one axial end of the opening 4312. However, the arrangement of the seal member 8 is not limited to the example of this embodiment. For example, the seal member 8 may be disposed inside the opening 4312. Also, preferably, the seal member 8 is disposed on one axial side D1 of the radial outer end of the second shaft through hole 102. In this way, it is possible to suppress or prevent the fluid F flowing out from the second shaft through hole 102 from getting onto the rotation detector 7. However, this example does not exclude a configuration in which the seal member 8 is disposed on the other axial side D2 of the radial outer end of the second shaft through hole 102.

[0081] In this embodiment, a so-called slinger is used for the seal member 8. For example, the seal member 8 has a fixed portion 81. The fixed portion 81 is fixed to the radial outer surface of the shaft 1. The fixed portion 81 is cylindrical and extends in the axial direction. The seal member 8 further has a flange portion 82. The flange portion 82 spreads outward in the radial direction from the fixed portion 81 to cover the gap between the opening 4312 (the inner peripheral surface of the opening 4312) and the shaft 1. By covering the gap between the opening 4312 and the shaft 1 with the flange portion 82 spreading outward in the radial direction from the fixed portion 81, the fluid F that lubricates the third motor bearing 4311 is less likely to enter the space 403 in which the first static eliminator 6 is disposed from the third motor bearing holder 431.

[0082] However, the sealing member 8 is not limited to this example. The sealing member 8 may be an oil seal, a mechanical seal, a packing, or the like. Alternatively, the sealing member 8 may be a part of the third motor bearing 4311. That is, the third motor bearing 4311 may be a sealed ball bearing including the sealing member 8. Alternatively, the sealing member 8 may be a part of the first static eliminator 6. For example, the sealing member 8 may be a coating film that covers the surface of the first static eliminator 6 to seal it from the space 403.

[0083] <2. Modifications> Next, a modified example of the embodiment will be described with reference to FIG. 5. FIG. 5 is a conceptual diagram showing a shaft static elimination structure according to the modified example. Note that FIG. 5 is merely a conceptual diagram, and the arrangement and dimensions of each part are not necessarily strictly the same as those of the actual driving device 100. Also, FIG. 5 corresponds to part A surrounded by a dashed line in FIG. 1. Below, the modified example will be described in terms of a configuration different from the above-described embodiment. Also, the same reference numerals will be used to designate the same components as those in the above-described embodiment, and the description thereof may be omitted.

[0084] In the modified example, the drive device 100 further includes a second static eliminator 9. The second static eliminator 9 is disposed between the third motor bearing 4311 and the first static eliminator 6 in the axial direction, and electrically connects the shaft 1 and the housing 4. For example, as shown in FIG. 5, the second static eliminator 9 is disposed between the housing lid portion 43 and the shaft tube portion 11 in the radial direction. By further disposing the second static eliminator 9 in addition to the first static eliminator 6, the shaft 1 can be more reliably electrically connected to the housing 4. Therefore, the static elimination effect of the shaft 1 can be improved.

[0085] Preferably, the second static eliminator 9 is disposed on one axial direction D1 from the seal member 8. The second static eliminator 9 contacts the shaft 1 and the housing lid 43 and is electrically connected to both. As shown in FIG. 5, the second static eliminator 9 is fixed to one of the housing lid 43 (the inner circumferential surface of the opening 4312) and the shaft tube 11, and contacts the other of the housing lid 43 (the inner circumferential surface of the opening 4312) and the shaft tube 11. In this way, the second static eliminator 9 can be disposed in a space partitioned from the third motor bearing 4311 by the seal member 8. For example, the second static eliminator 9 can be disposed in the space 403 in which the second static eliminator 9 is disposed. Therefore, it is possible to suppress or prevent the fluid F that lubricates the third motor bearing 4311 from coming into contact with the second static eliminator 9.

[0086] In this embodiment, as shown in Fig. 5, the second static eliminator 9 is disposed between the rotation detector 7 and the seal member 8 in the axial direction. That is, the second static eliminator 9 is disposed on the other axial direction D2 than the rotation detector 7. However, without being limited to the example shown in Fig. 5, the second static eliminator 9 may be disposed, for example, between the first static eliminator 6 and the rotation detector 7 in the axial direction.

[0087] Furthermore, without being limited to the above example, the second static eliminator 9 may be disposed on the other axial side D2 of the seal member 8. For example, the second static eliminator 9 may be disposed between the third motor bearing 4311 and the seal member 8 in the axial direction. The second static eliminator 9 may be disposed within the opening 4312.

[0088] The second static eliminator 9 has a conductive member 91 and a conductive holding member 92. The holding member 92 holds the conductive member 91. The second static eliminator 9 may have the same configuration as the first static eliminator 6, or may have a different configuration from the first static eliminator 6.

[0089] The conductive member 91 may be, for example, in the form of a brush including a plurality of fibers extending in the radial direction, or may be a molded body. The conductive member 91 is formed using a material having electrical conductivity. The conductive member 91 is preferably made of a material having good sliding properties, and more preferably of a material having a low coefficient of friction. The conductive member 91 may be made of, for example, a composite resin including a conductive filler such as carbon fiber or metal. The holding member 92 is, for example, made of metal, and houses a part of the conductive member 91 therein.

[0090] 5, the tip (i.e., radially inner end) of the conductive member 91 contacts the outer peripheral surface of the cylindrical shaft portion 11. The holding member 92 is fixed to the housing lid portion 43 (the inner peripheral surface of the opening 4312). However, without being limited to the example of FIG. 5, the tip (i.e., radially outer end) of the conductive member 91 may contact the housing lid portion 43 (the inner peripheral surface of the opening 4312) and the holding member 92 may be fixed to the outer peripheral surface of the cylindrical shaft portion 11.

[0091] 5, the second static eliminator 9 is annular and surrounds the rotation axis J1, and is fitted into the inner circumferential surface of the recess 433 of the housing lid portion 43. By fitting the second static eliminator 9 into the recess 433, the second static eliminator 9 can be stably fixed to the housing lid portion 43.

[0092] The conductive member 91 and the holding member 92 in FIG. 5 are annular about the rotation axis J1, similar to the first static eliminator 6 in FIG. 4A. However, the second static eliminator 9 is not limited to this example, and may not be annular. For example, the second static eliminator 9 may be rectangular like the first static eliminator 6 in FIG. 4B, or may be arc-shaped extending in the circumferential direction about the rotation axis J1. In this way, the conductive member 91 contacts the shaft tube portion 11 or the housing lid portion 43 in a part of the circumferential area. Therefore, the sliding area of ​​the conductive member 91 per one rotation of the shaft 1 can be made smaller. Therefore, the wear powder generated at the contact portion between the conductive member 91 and the shaft 1 or the housing lid portion 43 can be reduced.

[0093] 4B, the second static eliminator 9 may further include an elastic member (not shown). The elastic member is housed in the holding member 92 in a compressed state. Due to its elasticity, the elastic member presses the conductive member 91 toward the shaft 1 or the housing lid 43 (the inner circumferential surface of the opening 4312).

[0094] <3.Other> The embodiments of the present invention have been described above. Note that the scope of the present invention is not limited to the above-described embodiments. The present invention can be implemented by adding various modifications to the above-described embodiments without departing from the spirit of the invention. Furthermore, the matters described in the above-described embodiments can be appropriately combined in any manner as long as no contradiction occurs.

[0095] In the present embodiment and the modified example, the present invention is applied to an in-vehicle drive device 100. However, the present invention is not limited to this example, and can also be applied to drive devices used for purposes other than in-vehicle use. [Industrial Applicability]

[0096] The present invention is useful for a device for grounding a rotatable shaft. The present invention is also useful for a drive device mounted on a vehicle, but is also useful for a drive device used for purposes other than a vehicle. [Explanation of symbols]

[0097] 100 Drive device, 200 Battery, 300 Vehicle, 1 Shaft, 101 First shaft through hole, 102 Second shaft through hole, 11 Shaft cylinder portion, 111 Inlet, 12 Hollow portion, 13 Shaft wall portion, 2 Motor portion, 21 Rotor, 211 Rotor core, 2111 Rotor through hole, 212 Magnet, 22 Stator, 221 Stator core, 222 Coil portion, 2221 Coil end, 3 Gear portion, 31 Reduction gear, 311 Main driver a drive shaft through hole, 421...first motor bearing holder, 4211...first motor bearing holder, 4222...second motor bearing holder, 4223...second motor bearing holder, 4224...second motor bearing holder, 4225...second motor bearing holder, 4226...second motor bearing holder, 4227...second motor bearing holder, 4228...second motor bearing holder, 4229...second motor bearing holder, 4230...second motor bearing holder, 4231...second motor bearing holder, 4232...second motor bearing holder, 4233...second motor bearing holder, 4234...second motor bearing holder, 4235...second motor bearing holder, 4236...second motor bearing holder, 4237...second motor bearing holder, 4238...second motor bearing holder, 4239...second motor bearing holder, 4240...second motor bearing holder, 4241...second motor bearing holder, 4242...second motor bearing holder, 4243...second motor bearing holder, 4244...second motor bearing holder, 4245...second motor bearing holder, 4246...second motor bearing holder, 4247...second motor bearing holder, 4248...second motor bearing holder, 4249...second motor bearing holder, 4250...second motor bearing holder, 4251...second motor bearing holder, 4252...second motor bearing holder, 4253...second motor bearing holder, 4254...second motor bearing holder, 4255...second motor bearing holder, 4256...second motor bearing holder, 4257...second motor bearing holder, 4258...second motor bearing holder, 4259...second motor bearing holder, 4260...second motor bearing holder, 4261...second motor bearing holder, 4262...second motor bearing holder, 4263...second motor bearing holder, 4264...second motor bearing holder, 4265...second motor bearing holder, motor bearing, 423...first intermediate bearing holder, 4231...first intermediate bearing, 424...first output bearing holder, 4241...first output bearing, 43...housing lid portion, 431...third motor bearing holder, 4311...third motor bearing, 4312...opening, 432...detector holder, 433...recess, 44...cover member, 441...plate portion, 442...plate recess, 45...second housing cylindrical portion, 46...gear lid portion, 460...second drive shaft through hole, 461... ·Fourth motor bearing holder, 4611···Fourth motor bearing, 462···Second intermediate bearing holder, 4621···Second intermediate bearing, 463···Second output bearing holder, 4631···Second output bearing, 464···Receiver portion, 465···Flow path, 5···Liquid circulation portion, 51···Pipe portion, 52···Pump, 53···Cooler unit, 54···Fluid reservoir, 6···First static eliminator, 61···Conductive member, 62···Holding member, 63···Elastic member, 7···Rotation detector, 8···Sealing member, 9···Second static eliminator,91 conductive member, 92 holding member, F fluid, P liquid storage section, Ds, Ds1, Ds2 drive shaft, J1 rotating shaft, J2 intermediate shaft, J3 drive shaft,

Claims

1. A shaft extending axially along a rotation axis; a rotor fixed to the shaft and rotatable about the rotation axis; a stator facing the rotor with a radial gap therebetween; A bearing that rotatably supports the shaft; a housing that accommodates the rotor, the stator, and the bearing; a first static eliminator disposed on one side of the bearing in the axial direction and electrically connecting the shaft and the housing; a seal member disposed between the bearing and the first static eliminator in an axial direction; Equipped with The shaft is A cylindrical shaft portion surrounding the rotation shaft; a shaft through hole penetrating the shaft tube portion in a radial direction or in a direction obliquely intersecting the radial direction and the axial direction; having The housing has a bearing holder that holds the bearing, the bearing holder has an opening through which the shaft is inserted, A drive device, wherein a radially outer end of the shaft through hole is connected to a gap between one axial end of the bearing and the seal member within the opening.

2. The bearing, the seal member, and the first static elimination device are overlapped in the axial direction, The drive unit according to claim 1 , wherein the first static eliminator is disposed on an axially other side of the one axial end of the shaft and in contact with an outer circumferential surface of the shaft.

3. The shaft further includes a shaft wall portion disposed inside the shaft tube portion and extending in a radial direction, 3. The drive device according to claim 1, wherein the shaft wall portion is disposed at the same axial position as the seal member, or on one axial side of a radial inner end of the shaft through hole and on the other axial side of the seal member.

4. The sealing member is A fixing portion fixed to a radially outer surface of the shaft; a flange portion that extends radially outward from the fixing portion and covers the opening and the gap between the shaft; The drive device according to claim 1 , further comprising:

5. A rotation detector for detecting a rotation angle of the shaft is further provided. The drive device according to claim 1 , wherein the rotation detector is disposed between the bearing and the first static eliminator in the axial direction.

6. The drive unit according to claim 5 , wherein the rotation detector is disposed axially to one side of the seal member.

7. The drive device according to claim 1 , further comprising a second static eliminator arranged between the bearing and the first static eliminator in the axial direction and electrically connecting the shaft and the housing.

8. The drive unit according to claim 7 , wherein the second static eliminator is disposed on one side of the seal member in the axial direction.

9. A vehicle comprising the drive device according to any one of claims 1 to 8.

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