Motor

Abstract

To compatibly cool a motor using a cylindrical shaft and electrically discharge the shaft by a static eliminator.SOLUTION: A motor comprises: a shaft 21 which has: a cylindrical shaft cylinder part 212 extending axially; a rotor 11 which can rotate together with the shaft; a stator 12 which is arranged radially outside the rotor; a bearing 4314 which supports the shaft rotatably; a housing which houses the rotor, the stator and the bearing; and a static eliminator 7 which electrically connects the shaft and the housing, wherein the shaft cylinder part is supplied with a lubricating liquid flowing in from an inflow port located on the other axial end side, the shaft has a lid part 22 arranged on one axial end part, and a second shaft through hole 202 penetrating the lid part axially has a diameter smaller than the inner diameter of the shaft cylinder part.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a motor. [Background technology]

[0002] Conventionally, there is known an earthing device for earthing the output shaft of a motor. For example, an earthing member of the earthing device contacts the axial center of the end face of the output shaft from the axial direction. (See, for example, JP 2019-192491 A.) [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-192491 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, when the motor is cooled by causing the refrigerant inside the hollow output shaft to flow out of the radial through-holes due to rotation, the refrigerant is drawn into the output shaft from the other axial end due to the pressure difference by drawing air from the axial end of the output shaft. Therefore, it is difficult to cool the hollow output shaft using the above-mentioned earthing device. Furthermore, if the refrigerant is supplied into the hollow output shaft, the refrigerant will adhere to the earthing member, reducing the static electricity removal efficiency.

[0005] An object of the present invention is to achieve both cooling of a motor that uses a cylindrical shaft and discharging of the shaft by a static eliminator. [Means for solving the problem]

[0006] An exemplary motor of the present invention includes: a shaft having a cylindrical shaft portion extending in an axial direction; a rotor rotatable together with the shaft; a stator disposed radially outward of the rotor; a bearing rotatably supporting the shaft; a housing that accommodates the rotor, the stator, and the bearing; and a static eliminator that electrically connects the shaft and the housing; The static eliminator is disposed outside the shaft, The shaft cylinder portion is supplied with lubricating liquid from an inlet located at the other axial end side, and the shaft is Axial direction opposite to the inlet The shaft has a cover portion disposed at one axial end, and a diameter of a second shaft through hole passing axially through the cover portion is smaller than an inner diameter of the cylindrical shaft portion. Effect of the Invention

[0007] According to the exemplary motor of the present invention, it is possible to simultaneously cool the motor using a cylindrical shaft and discharge the shaft by the static eliminator, thereby improving static elimination efficiency. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a conceptual diagram showing an example of the configuration of a motor. [Diagram 2] FIG. 2 is an enlarged conceptual diagram showing an example of the configuration of a main part of a motor. [Diagram 3] FIG. 3 is a schematic diagram showing an example of a vehicle equipped with a motor. [Figure 4] FIG. 4 is an explanatory diagram of the cover member. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Exemplary embodiments are described below with reference to the drawings.

[0010] In this specification, the direction parallel to the first rotation axis J1 of the motor unit 1 is defined as the "axial direction" of the motor 100. As shown in FIG. 1, the motor unit 1 side is defined as one axial direction D1, and the power transmission device 3 side is defined as the other axial direction D2. A radial direction perpendicular to a predetermined axis is simply referred to as a "radial direction", and a circumferential direction centered on the predetermined axis is simply referred to as a "circumferential direction". Furthermore, in this specification, a "parallel direction" includes not only a completely parallel direction, but also a substantially parallel direction. And "extending along" a predetermined direction or plane includes a direction that is inclined within a range of less than 45° with respect to the strict direction, in addition to a direction that is strictly in the predetermined direction.

[0011] <1. Embodiment> FIG. 1 is a conceptual diagram showing an example of the configuration of a motor 100. FIG. 2 is a conceptual diagram showing an enlarged example of the configuration of a main part of the motor 100. FIG. 3 is a schematic diagram showing an example of a vehicle 300 equipped with the motor 100. Note that FIGS. 1 and 2 are merely conceptual diagrams, and the arrangement and dimensions of each part are not necessarily the same as those of the actual motor 100. Also, FIG. 2 is an enlarged view of a portion X surrounded by a dashed line in FIG. 1. Also, FIG. 3 conceptually illustrates the vehicle 300.

[0012] In this embodiment, as shown in FIG. 3, the motor 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 motor 100 is used as a power source for the vehicle 300. The vehicle 300 has the motor 100 and a battery 200. The battery 200 stores power to be supplied to the motor 100. In the case of the vehicle 300, the motor 100 drives the left and right front wheels. It is sufficient that the motor 100 drives at least one of the wheels.

[0013] As shown in Fig. 1, the motor 100 includes a motor unit 1, a shaft 2, a power transmission device 3, a housing 4, and a liquid circulation unit 6. The shaft 2 extends in the axial direction along a first rotation axis J1. The shaft 2 is rotatable about the first rotation axis J1. The housing 4 accommodates the motor unit 1, the shaft 2, and the power transmission device 3. For example, the housing 4 accommodates a rotor 11 and a stator 12 of the motor unit 1, as well as bearings 4211 and 4314, which will be described later.

[0014] Moreover, the motor 100 further includes a static eliminator 7 having a conductive member 71. The static eliminator 7 electrically connects the shaft 2 and the housing 4. The static eliminator 7 is fixed to the housing 4 and contacts the shaft 2. As shown in FIG. 2, the static eliminator 7 of this embodiment further includes a conductive member 71 and a holding member 73.

[0015] The holding member 73 is ring-shaped and houses the conductive member 71 therein. The holding member 73 holds the conductive member 71. The conductive member 71 is formed by bundling a plurality of carbon thread-like members.

[0016] A fixing member (not shown) fixes the static eliminator 7 to the housing 4. In this embodiment, the fixing member is attached to the holding member 73. At least one fixing member is fixed to a plate portion 433 (see, for example, FIG. 4A ) described later. However, this is not limiting, and at least one fixing member 74 may be fixed to a cover member 44 (described later). In other words, the fixing member fixes the holding member 73 to at least one of the plate portion 433 and the cover member 44.

[0017] Moreover, the fixing member has conductivity and is electrically connected to the conductive member 71. The fixing member 74 is fixed to the conductive plate portion 433 or the cover member 44, whereby the conductive member 71 is electrically connected to the housing 4.

[0018] <1-1.Motor section 1> Next, the motor unit 1 will be described with reference to Fig. 1 and Fig. 2. The motor unit 1 is a DC brushless motor. The motor unit 1 is the driving source of the motor 100, and is driven by power from an inverter (not shown). The motor unit 1 is an inner rotor type in which a rotor 11 is rotatably disposed inside a stator 12. As shown in Fig. 1, the motor unit 1 has a rotor 11 and a stator 12.

[0019] <1-1-1.Rotor 11> The rotor 11 is supported by the shaft 2. The motor 100 includes the rotor 11. The rotor 11 is rotatable together with the shaft 2. More specifically, the rotor 11 is supported by a first shaft 21, which will be described later. The rotor 11 rotates when power is supplied to the stator 12 from a power supply unit (not shown) of the motor 100. The rotor 11 has a rotor core 111 and a magnet 112. The rotor core 111 is formed, for example, by laminating thin electromagnetic steel plates. The rotor core 111 is a cylindrical body extending along the axial direction, and is fixed to the radial outer surface of the first shaft 21. A plurality of magnets 112 are fixed to the rotor core 111. The plurality of magnets 112 are arranged along the circumferential direction with their magnetic poles alternating.

[0020] The rotor core 111 also has a rotor through hole 1111. The rotor through hole 1111 penetrates the rotor core 111 in the axial direction and is connected to the first shaft through hole 201. The rotor through hole 1111 is used as a flow path for the lubricating liquid CL, which also functions as a coolant. When the rotor 11 rotates, the lubricating liquid CL flowing through the hollow portion 211 of the first shaft 21 can flow into the rotor through hole 1111 via the first shaft through hole 201. The lubricating liquid CL that flows into the rotor through hole 1111 can flow out from both axial ends of the rotor through hole 1111. The flowing out lubricating liquid CL flies toward the stator 12 and cools, for example, the coil portion 122 (particularly the coil end 1221) and the like. The flowing out lubricating liquid CL flies toward the bearings 4211, 4314 that rotatably support the first shaft 21, and lubricates and cools the bearings 4211, 4314.

[0021] <1-1-2. Stator 12> The stator 12 is disposed radially outward from the rotor 11. The motor 100 includes the stator 12. The stator 12 has a stator core 121 and a coil portion 122. The stator 12 is interposed between the stator core 121 and the coil portion 122. The stator 12 is held by a first housing cylindrical portion 41, which will be described later. The stator core 121 has a plurality of magnetic pole teeth (not shown) extending radially inward from the inner circumferential surface of a circular ring-shaped yoke. The coil portion 122 is formed by winding a conductor around the magnetic pole teeth via an insulator (not shown). The coil portion 122 has coil ends 1221 protruding from an axial end face of the stator core 121.

[0022] <1-2. Shaft 2> 1, the shaft 2 is rotatably supported by the housing 4 via bearings 4211, 4221, 4314, and 4611 (described later). That is, the motor 100 includes bearings 4211, 4221, 4314, and 4611. The bearings 4211, 4221, 4314, and 4611 support the first shaft 21 for rotation.

[0023] The shaft 2 has a first shaft 21. As described above, the motor 100 includes the shaft 2. The first shaft 21 is cylindrical and extends in the axial direction. A coolant flows inside the first shaft 21. The motor 100 further includes this coolant. In this embodiment, the coolant is a lubricating liquid CL. As the shaft 2 rotates, the coolant flowing inside the first shaft 21 can be supplied to the stator 12 and the bearings 4211, 4314 through a first shaft through hole 201, which will be described later. Therefore, the stator 12 (particularly the coil end 1221 of the coil portion 122) and the bearings 4211, 4314 can be cooled by the coolant.

[0024] The first shaft 21 has a hollow portion 211, a shaft tube portion 212, and an inlet 213. The shaft tube portion 212 extends axially along the first rotation axis J1. The hollow portion 211 is disposed inside the shaft tube portion 212. The inlet 213 is disposed on the other axial direction D2 side of the shaft tube portion 212, and is connected to an oil passage 465 of the gear cover portion 46, which will be described later. Lubricating liquid CL, which will be described later, flows into the hollow portion 211 from the oil passage 465 via the inlet 213.

[0025] The first shaft 21 may be split at the axial middle. When the first shaft 21 is split, the split first shaft 21 may be joined by a screw coupling using, for example, a male screw and a female screw. The first shaft 21 may also be joined by a fixing method such as press fitting or welding. When a fixing method such as press fitting or welding is used, serrations combining a concave portion and a convex portion extending in the axial direction may be used. With this configuration, rotation can be transmitted reliably.

[0026] The shaft 2 further includes a cover portion 22, a first shaft 21, a first shaft through hole 201, and a second shaft through hole 202. The cover portion 22 is disposed at one axial end of the first shaft 21. The first shaft through hole 201 penetrates the first shaft 21 in the radial direction. The first shaft 21, the cover portion 22, and the second shaft 23 are conductive and made of metal in this embodiment. The second shaft 23 contacts the static eliminator 7.

[0027] Since the second shaft through hole 202 arranged on one axial direction D1 from the first shaft through hole 201 is provided in the shaft 2, the lubricating liquid CL serving as a refrigerant can be drawn from the other axial direction D2 side of the first shaft 21 into the inside by the pressure difference by sucking air from the second shaft through hole 202. Therefore, the lubricating liquid CL inside the cylindrical first shaft 21 can be caused to flow out of the first shaft through hole 201 by rotation, and the motor section 1 (particularly the coil section 122 of the stator 12) can be cooled. Furthermore, the shaft 2 is electrically connected to the housing 4 by the contact of the static eliminator 7 with the first shaft 21. Therefore, the current generated by the potential fluctuation occurring in the shaft 2 can be discharged to the housing 4 via the static eliminator 7. Therefore, it is possible to simultaneously cool the motor section 1 by the refrigerant (the lubricating liquid CL in this embodiment) inside the cylindrical first shaft 21 and discharge the shaft 2 by the static eliminator 7.

[0028] <1-2-2. First shaft through hole 201> Further, the first shaft through hole 201 is disposed in the shaft cylindrical portion 212 and penetrates the shaft cylindrical portion 212 in the radial direction. When the shaft 2 rotates, the lubricating liquid CL in the first shaft 21 flows out of the first shaft 21 from the hollow portion 211 through the first shaft through hole 201 due to centrifugal force. In this embodiment, as shown in Fig. 1, the first shaft through hole 201 is disposed on the other axial direction D2 of one axial end of the rotor 11 and on the one axial direction D1 of the other axial end of the rotor 11, and is connected to the rotor through hole 1111 as described above.

[0029] However, without being limited to the example of FIG. 1, the first shaft through hole 201 may be disposed on the axial one side D1 of the rotor 11, or may be disposed on the axial other side D2 of the rotor 11. That is, at least a part of the first shaft through holes 201 may be disposed at least in any one of these positions. FIG. 5 is a diagram showing another arrangement example of the first shaft through hole 201. For example, as shown in FIG. 5, at least a part of the first shaft through holes 201 may be disposed on the axial one side D1 of the rotor 11 and on the axial other side D2 of the bearing 4314. Also, at least a part of the first shaft through holes 201 may be disposed on the axial other side D2 of the rotor 11 and on the axial one side D1 of the bearing 4211. In this way, the refrigerant (i.e., the lubricating liquid CL) flowing inside the shaft tube portion 212 can be directly discharged toward the stator 12 and the bearings 4211 and 4314 through the first shaft through hole 201 disposed on the axial one side D1 or on the axial other side D2 of the rotor 11.

[0030] <1-2-3. Second shaft through hole 202> The second shaft through hole 202 is formed in the lid portion 22. In this embodiment, the second shaft through hole 202 is disposed in the lid portion 22 and penetrates the lid portion 22 in the axial direction (see FIG. 2, for example). This makes it easier to draw air into the first shaft 21 than when the second shaft through hole 202 is disposed in the first shaft 21. Furthermore, by changing the diameter of the second shaft through hole 202 that functions as an intake port, the amount of air drawn into the first shaft 21 and the flow of the drawn airflow can be appropriately adjusted.

[0031] <1-2-4. Lid part 22> Next, the lid portion 22 will be described with reference to FIGS.

[0032] As shown in FIG. 2, in this embodiment, the cover portion 22 is in the form of a plate extending radially from the first rotation axis J1.

[0033] The lid portion 22 is a separate member from the first shaft 21, and the lid portion 22 is fitted to the end portion of the first shaft 21 on one axial direction D1 side.

[0034] The lid portion 22 further has a first fixing portion 222. The first fixing portion 222 fixes the first shaft 21 to the lid portion 22. The first fixing portion 222 may be, for example, a brazing material (such as silver solder), an adhesive, or a welded mark. That is, the means for fixing the first shaft 23 to the lid portion 22 in the hole portion 221 may be brazing, bonding using an adhesive, or welding. In this way, the first shaft 21 can be more reliably held in the lid portion 22. Note that the first fixing portion 222 is not limited to these examples. For example, the first shaft 21 may be fixed to the lid portion 222 by screwing a male screw portion formed on the radial outer surface of the first shaft 21 into a female screw portion formed on the inner surface of the hole portion 221. However, this example does not exclude a configuration in which the shaft 2 does not have the first fixing portion 222.

[0035] 2, in this embodiment, the cover portion 22 is connected to one axial end of the cylindrical shaft portion 212 and covers the opening at one axial end of the cylindrical shaft portion 212. This opening is located at the position farthest from an inlet 213 of the shaft 2, which will be described later.

[0036] The second shaft through hole 202 of the lid portion 22 is smaller than the inner diameter of the hole portion 221. That is, the inner diameter of the hole portion 221 is the same as the inner diameter of the shaft tube portion 212. That is, the diameter of the second shaft through hole 202 of the lid portion 22 is smaller than the inner diameter of the shaft tube portion 212. The lid portion 22 also has a recess 223. The recess 223 is provided so as to face one axial side. This can reduce the amount of lubricating liquid CL inside the first shaft 21 that splashes into the static eliminator accommodating space 71 in which the static eliminator 7 described later is accommodated. Therefore, the amount of lubricating liquid CL that splashes into the static eliminator accommodating space 403 can be reduced, and static elimination efficiency can be improved.

[0037] In addition, when the lid portion 22 is fitted to the first shaft 21, the lid portion 22 preferably further has a first chamfered portion 224. The first chamfered portion 224 is disposed at the radially outer end of the other axial end of the lid portion 22. For example, at the other axial end of the lid portion 22, a corner formed by the other axial end face of the lid portion 22 and the radially outer side surface of the lid portion 22 is subjected to so-called R chamfering (round chamfering) that forms a curved surface between the two, or so-called C chamfering (beveling) that cuts off the corner obliquely, over the circumferential direction. The arrangement of the first chamfered portion 224 makes it even easier for the lid portion 22 to be fitted to the one axial end of the first shaft 21. Therefore, the first shaft 21 and the lid portion 22 can be attached to the one axial end of the first shaft 21 even more easily. However, this example does not exclude a configuration in which the lid portion 22 does not have the first chamfered portion 224. <1-3. Power transmission device 3> Next, the power transmission device 3 will be described in detail with reference to Fig. 1. The power transmission device 3 transmits the power of the motor unit 1 to the output shaft Ds. The power transmission device 3 has a reduction gear 31 and a differential gear 32.

[0038] <1-3-1. Reduction device 31> The reduction gear 31 is connected to the shaft 2. The reduction gear 31 has a function of reducing the rotational speed of the motor unit 1 and increasing the torque output from the motor unit 1 in accordance with a reduction ratio. The reduction gear 31 transmits the torque output from the motor unit 1 to the output shaft Ds. That is, the power transmission device 3 is connected to the other axial side D2 of the shaft 2 that rotates about a first rotation axis J1 extending along the horizontal direction.

[0039] 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 1 is transmitted to a ring gear 321 of the output 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.

[0040] The main drive gear 311 is disposed on the outer circumferential surface of the shaft 2. The main drive gear 311 may be the same member as the shaft 2, or may be a separate member that is firmly fixed to the shaft 2. The main drive gear 311 rotates together with the shaft 2 about the first rotation axis J1.

[0041] The intermediate shaft 314 extends along a second rotation axis J2 parallel to the first 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 second rotation 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.

[0042] The intermediate driven gear 312 and the final drive gear 313 rotate about the second rotation axis J2 integrally with the intermediate shaft 314. 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 output shaft Ds.

[0043] The torque of the 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 output shaft Ds.

[0044] <1-3-2. Differential device 32> The differential 32 is attached to the output shaft Ds. The differential 32 has a ring gear 321. The ring gear 321 transmits the output torque of the motor unit 1 to the output shaft Ds. The output shaft Ds has axles Ds1, Ds2 attached to the left and right sides of the differential 32, respectively. The differential 32 transmits torque to the left and right axles Ds1, Ds2 while absorbing the difference in rotational speed between the left and right axles when the vehicle turns, for example.

[0045] A lower end of the ring gear 321 is disposed inside a liquid reservoir P (described later) in which lubricating oil CL and the like stored in the lower portion of the gear portion accommodating space 402 accumulates (see FIG. 1). Therefore, when the first gear 331 rotates, the gear teeth of the ring gear 321 scoop up the lubricating liquid CL. The gears and bearings of the power transmission device 3 are lubricated or cooled by the lubricating liquid CL scooped up by the ring gear 321. A portion of the scooped up lubricating liquid CL is also stored in a receiver portion 464 (described later) and is used to cool the motor portion 1 via the shaft 2.

[0046] <1-4. Housing 4> Next, the details of the housing 4 will be described with reference to Figs. 1 and 2. The housing 4 has a first housing tubular portion 41, a side plate portion 42, a motor lid portion 43, a cover member 44, a second housing tubular portion 45, and a gear lid portion 46. The first housing tubular portion 41, the side plate portion 42, the motor lid portion 43, the second housing tubular portion 45, and the gear lid portion 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 this 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.

[0047] As described above, the housing 4 accommodates the rotor 11, the stator 12, the bearings 4211, 4314, etc. of the motor unit 1. 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 motor cover portion 43, and accommodates the rotor 11, the stator 12, the bearings 4211, 4314, etc.

[0048] The housing 4 also accommodates the power transmission device 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.

[0049] A liquid reservoir P in which the lubricating liquid CL is stored 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 lubricating liquid CL stored 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 lubricating liquid CL 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 lubricating liquid CL 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. In addition, another part of the scooped up lubricating liquid CL is supplied to the inside of the shaft 2 and is supplied to the rotor 11 and the stator 12 of the motor unit 1 and each bearing in the gear portion accommodating space 402 and used for cooling and lubrication.

[0050] <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 1, a motor oil reservoir 64 (described later), and the like are disposed inside the first housing cylindrical portion 41. In addition, a stator core 121 is fixed to the inner surface of the first housing cylindrical portion 41.

[0051] <1-4-2. Side plate part 42> The side plate portion 42 extends in a direction perpendicular to the first rotation axis J1 and covers the other axial end portion of the first housing cylindrical portion 41. In this embodiment, the first housing cylindrical portion 41 and the side plate portion 42 are different parts of a single member. By forming the two integrally, the rigidity of these can be increased. However, this is not intended to be limiting, and the first housing cylindrical portion 41 and the side plate portion 42 may be separate members.

[0052] The side plate portion 42 has a side plate through hole 4201 through which the shaft 2 is inserted, and a first output shaft through hole 4202. The side plate through hole 4201 and the first output shaft through hole 4202 penetrate the side plate portion 42 in the axial direction. The first shaft 21 is inserted through the side plate through hole 4201. One axle Ds1 of the output shaft Ds is inserted through the first output shaft through hole 4202. An oil seal (not shown) that seals the gap between the output shaft Ds and the first output shaft through hole 4202 is disposed. Note that the term "seal" refers to the adhesion between different members to such an extent that, for example, lubricating liquid CL inside the members does not leak to the outside, and foreign matter such as water, dirt, and dust from the outside does not enter. The same applies hereinafter to the seal.

[0053] The side plate portion 42 further includes bearing holding portions 421, 422, 423, and 424. The bearing holding portion 421 is disposed on one axial end surface of the side plate portion 42 in the motor accommodating space 401, and holds a bearing 4211. The bearing holding portions 422, 423, and 424 are disposed on the other axial end surface of the side plate portion 42 in the gear portion accommodating space 402, which will be described later. The bearing holding portion 422 is disposed along an outer edge of the other axial end surface of the side plate through hole 4201, and holds the bearing 4211. The bearing holding portion 423 holds a first intermediate bearing 4231. The bearing holding portion 424 is disposed along an outer edge of the other axial end surface of the first output shaft through hole 4202, and holds a first output bearing 4241.

[0054] <1-4-3. Motor cover part 43> The motor lid part 43 is attached to one axial end of the first housing tubular part 41. The motor lid part 43 can be fixed to the first housing tubular part 41 by, for example, screws, but is not limited to this, and any method that can firmly fix the plate part 433 to the first housing tubular part 41, such as screwing or press fitting, can be widely used. This allows the motor lid part 43 to be tightly fitted to one axial end of the first housing tubular part 41. Note that the term "fitted" refers to a level of sealing that prevents the lubricating liquid CL 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 hereinafter to the term "fitted".

[0055] 2, the motor cover portion 43 has a cover portion 431, a cylindrical portion 432, a plate portion 433, and a bearing holding portion 434. In other words, the housing 4 has the cover portion 431, the cylindrical portion 432, and the plate portion 433.

[0056] <1-4-3-1. Lid part 431> The lid portion 431 expands in a direction intersecting the first rotation axis J1 and covers one axial end of the first housing cylindrical portion 41. The lid portion 431 has an opening 4311 through which the shaft 2 is inserted. The opening 4311 penetrates the lid portion 431 in the axial direction. The first shaft 21 is inserted into the opening 4311. The lid portion 431 further has a bearing holding portion 4312 and a seal member 4313. The bearing holding portion 4312 is disposed on the other axial end surface of the lid portion 431 in the motor accommodating space 401. The bearing holding portion 4312 is disposed along the outer edge of the other axial end of the opening 4311 and holds a bearing 4314. The seal member 4313 is disposed between the first shaft 21 and the lid portion 431 in the opening 4311 and seals between them. By sealing the opening 4311 with the sealing member 4313, it is possible to prevent foreign matter such as wear powder generated by the static elimination device 7 from entering the motor accommodating space 401 in which the stator 12 and the like are housed through the opening 4311.

[0057] <1-4-3-2.Cylinder part 432> The cylindrical portion 432 is cylindrical and surrounds the first rotation axis J1, and extends from one axial end face of the cover portion 431 in one axial direction D1.

[0058] <1-4-3-3. Plate part 433> The plate portion 433 extends in a direction intersecting the first rotation axis J1, and is attached to the other axial end of the tube portion 432. The plate portion 433 is conductive. As described above, the housing 4 has the plate portion 433. In this embodiment, the plate portion 433 is disposed on one axial side D1 of the stator 12 and a bearing 4341 described later, and extends in the radial direction. The plate portion 433 has an opening 4331 through which the second shaft 23 is inserted. In other words, the plate portion 433 has an opening 4331. The opening 4331 penetrates the plate portion 433 in the axial direction. In addition, the static eliminator 7 is disposed at one axial end of the plate portion 433.

[0059] <1-4-3-4. Bearing holder 434> The bearing holder 434 is disposed along the outer edge of one axial end of the opening 4331 on the other axial end face of the plate portion 433 , and holds a bearing 4341 .

[0060] <1-4-3-5. Sealing material 435> The seal member 435 is disposed in the opening 4331 of the plate portion 433. The motor 100 includes an annular seal member 435. The seal member 435 is disposed between the second shaft 23 and the plate portion 433 in the opening 4331, and seals between them. The radial outer end of the seal member 435 contacts the inner circumferential surface of the opening 4331 facing inward in the radial direction. The radial inner end of the seal member 435 contacts the radial outer surface of the second shaft 23. By sealing the opening 4331 with the seal member 435, it is possible to prevent wear powder generated from the static eliminator 7 disposed on one axial end face of the plate portion 433 from entering the other axial side of the plate portion 433 through the opening 4331. Therefore, it is possible to prevent wear powder from entering the inside of the housing 4 in which the stator 12 and the like are accommodated. For example, it is also possible to prevent wear powder from entering the hollow portion 211 of the first shaft 21 through the second shaft through hole 202. Therefore, the wear powder can be prevented from entering the motor accommodating space 401 along with the flow of the lubricating liquid CL in the hollow portion 211.

[0061] <1-4-4. Cover member 44> The cover member 44 is disposed on one axial end face of the plate portion 433. The cover member 44 covers the opening 4331 and the static eliminator 7.

[0062] The cover member 44 can be attached to the plate portion 433 by, for example, but not limited to, screw fastening. In this embodiment, the cover member 44 forms an accommodation space 440 together with the plate portion 433. The accommodation space 440 is a space surrounded by the cover member 44 and the plate portion 433, and accommodates the opening 4331 and the static eliminator 7.

[0063] The cover member 44 has a first cover portion 441 and a second cover portion 442. The first cover portion 441 covers the static eliminator 7. The second cover portion 442 is disposed radially outward from the first cover portion 441. In detail, the first cover portion 441 and the second cover portion 442 extend in a direction intersecting with the first rotation axis J1. The first cover portion 441 is disposed on one axial direction D1 from the opening 4331 and the static eliminator 7. The second cover portion 442 is disposed on the other axial direction D2 from the first cover portion 441. A radial inner end portion of the second cover portion 442 is connected to a radial outer end portion of the first cover portion 441, and a radial outer end portion of the second cover portion 442 is connected to one axial end face of the plate portion 433.

[0064] Further, the cover member 44 has a through hole 443, a cylindrical portion 444, and a filter 445. The through hole 443 connects the accommodation space 440 to the outside. The through hole 443 is disposed in the first cover portion 441 in FIG. 1. However, the arrangement of the through hole 443 is not limited to the example of FIG. 1. The through hole 443 can be disposed in at least one of the first cover portion 441 and the second cover portion 442. The cylindrical portion 444 extends in the axial direction from the outer edge portion of the through hole 443. The inside of the cylindrical portion 444 is connected to the through hole 443. The filter 445 is attached to the tip of the cylindrical portion 444. The accommodation space 440 is connected to the outside via the through hole 443 and the filter 445.

[0065] <1-4-5. Second housing cylindrical portion 45> The second housing cylindrical portion 45 has a cylindrical shape extending in the axial direction. The power transmission device 3 is disposed inside the second housing cylindrical portion 45. One axial end of the second housing cylindrical portion 45 is connected to and covered by the side plate portion 42.

[0066] <1-4-6. Gear cover part 46> The gear lid portion 46 spreads in a direction intersecting with the first rotation axis J1, and is detachably attached to one axial end of the second housing tubular portion 45. In this embodiment, the second housing tubular portion 45 and the gear lid portion 46 are different parts of a single member. However, the present invention is not limited to this example, and the second housing tubular portion 45 and the gear lid portion 46 may be separate members. In addition, the gear lid portion 46 can be attached to the second housing tubular portion 45 by, for example, fixing with a screw, but is not limited thereto, and any method capable of firmly fixing the gear lid portion 46 to the second housing tubular portion 45, such as screwing or press-fitting, can be widely adopted. This allows the gear lid portion 46 to be in close contact with one axial end of the second housing tubular portion 45.

[0067] The gear cover portion 46 has a second output shaft through hole 460. The center of the second output shaft through hole 460 coincides with the third rotation axis J3. The output shaft Ds is inserted through the second output shaft through hole 460. An oil seal (not shown) is disposed in the gap between the other output shaft Ds and the second output shaft through hole 460.

[0068] The gear lid portion 46 further has bearing retaining portions 461, 462, and 463. The bearing retaining portions 461, 462, and 463 are arranged on the other axial end surface of the gear lid portion 46 in the gear portion accommodating space 402. The bearing retaining portion 461 retains a bearing 4611. The bearing retaining portion 462 retains a second intermediate bearing 4621. The bearing retaining portion 463 is arranged along the outer edge portion of the other axial end portion of the second output shaft through hole 460, and retains a second output bearing 4631.

[0069] The gear lid 46 also has a saucer portion 464 and an oil passage 465. The saucer portion 464 is disposed on one axial end surface of the gear lid 46, and has a recess that is recessed vertically downward. The saucer portion 464 can store the lubricating liquid CL scooped up by the ring gear 321. The oil passage 465 is a passage for the lubricating liquid CL, and connects the saucer portion 464 and the inlet 213 of the shaft 2. The lubricating liquid CL stored in the saucer portion 464 is supplied to the oil passage 465 and flows into the hollow portion 211 from the inlet 213 at the other axial end of the shaft 2.

[0070] <1-5.Liquid circulation section 6> Next, a description will be given of the liquid circulation unit 6. The liquid circulation unit 6 has a piping unit 61, a pump 62, an oil cooler 63, and a motor oil reservoir 64.

[0071] The piping section 61 connects the pump 62 to a motor oil reservoir 64 arranged inside the first housing cylindrical section 41, and supplies the lubricating liquid CL to the motor oil reservoir 64. The pump 62 sucks the lubricating liquid CL stored in a lower region of the gear portion accommodating space 402. The pump 62 is an electric pump, but is not limited to this. For example, the pump 62 may be configured to be driven by utilizing part of the power of the shaft 2 of the motor 100.

[0072] The oil cooler 63 is disposed between the pump 62 and the motor oil reservoir 64 of the piping section 61. That is, the lubricating liquid CL sucked by the pump 62 passes through the oil cooler 63 via the piping section 61, and is then sent to the motor oil reservoir 64. A coolant such as water supplied from the outside is supplied to the oil cooler 63. The oil cooler 63 exchanges heat between the coolant and the lubricating liquid CL to lower the temperature of the lubricating liquid CL.

[0073] The motor oil reservoir 64 is a tray disposed vertically above the stator 12 inside the motor accommodating space 401. A drip hole is formed in the bottom of the motor oil reservoir 64, and the lubricating liquid CL is dripped from the drip hole to cool the motor section 1. The drip hole is formed, for example, above the coil end 1221 of the coil section 122 of the stator 12, and the coil section 122 is cooled by the lubricating liquid CL.

[0074] <2.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. [Industrial Applicability]

[0075] The present invention is useful in devices for grounding shafts. [Explanation of symbols]

[0076] 100···Motor, 200···battery, 300 vehicles, 1. Motor section, 11... rotor, 12 Stator 2... shaft, 201: First shaft through hole, 202: second shaft through hole, 21...First shaft, 211...Hollow part, 212... Shaft cylinder portion, 213...inlet, 22...Lid part, 221...Hole part, 3... Power transmission device, 31...Reduction device, 32...Differential device, 4. Housing, 401: Motor housing space, 402 Gear unit accommodation space, 403: Static electricity removal device housing space 7... Static eliminator, CL...Lubricating fluid, P: Liquid storage section, Ds...Output shaft, J1: First rotating axis J2: Second rotation axis J3: Third rotation axis

Claims

1. a shaft having a cylindrical shaft portion extending in an axial direction; a rotor rotatable with the shaft; a stator disposed radially outward from the rotor; A bearing that rotatably supports the shaft; a housing that accommodates the rotor, the stator, and the bearings, and a static eliminator that electrically connects the shaft and the housing, The static eliminator is disposed outside the shaft, The lubricating liquid is supplied to the shaft tube portion from an inlet located at the other axial end side, the shaft has a cover portion disposed at one axial end portion opposite the inlet in the axial direction, A motor, wherein a diameter of a second shaft through hole that passes axially through the cover portion is smaller than an inner diameter of the shaft tube portion.

2. The cover portion has a recess extending radially and facing one axial side, and a first fixing portion, The motor according to claim 1 , wherein the first fixing portion fixes the cover portion and the shaft.

3. The housing comprises: a cylindrical portion that surrounds the rotor and the stator from the radially outer side; a motor cover portion that extends in a radial direction and covers one axial end portion of the cylindrical portion; a plate portion extending in a radial direction and provided on one axial side of the motor lid portion; having The motor according to claim 1 , wherein the static eliminator is disposed in a space defined by the motor lid and the plate.

4. The motor cover portion has an opening through which the shaft is inserted, The motor of claim 3 , wherein a seal member is disposed at the opening between the shaft and the motor lid.

5. A motor as described in claim 4, wherein the sealing member is arranged between the rotor and the electrostatic elimination device in the axial direction.

6. A motor as described in claim 5, wherein the sealing member is arranged between the bearing and the electrostatic elimination device in the axial direction.

7. A motor as described in any one of claims 1 to 6, further comprising a power transmission device.

Images