Motor

Abstract

To achieve both cooling of a motor through use of a tubular shaft and discharging of the shaft by an electrical discharging device.SOLUTION: A shaft 2 of a motor 100 includes: a first shaft 21 having a tubular shape extending in an axial direction; a lid portion 22 disposed in one axial end portion of the first shaft 21; a second shaft 23 extending on one axial side from the lid portion 22; a first shaft through hole 201 penetrating the first shaft 21 in a radial direction; and a second shaft through hole 202 communicating with an inside of the first shaft 21 and an external space of the shaft 2. The lid portion 22 and the second shaft 23 have conductivity. The second shaft through hole 202 is disposed on one axial side with respect to the first shaft through hole 201. The second shaft 23 is in contact with an electrical discharging device 7 that electrically connects the shaft 2 and a housing 4 of the motor 100.SELECTED DRAWING: Figure 1

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 cooling a motor by causing the coolant inside the hollow output shaft to flow out of a radial through hole due to rotation, the coolant 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 use the above-mentioned earth device for cooling using a hollow output shaft.

[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] The exemplary motor of the present invention includes a shaft, a rotor, a stator, a bearing, a housing, and a static eliminator. The shaft includes a first shaft that is cylindrical and extends in an axial direction. The rotor is supported by the first shaft and is rotatable together with the shaft. The stator is disposed radially outward from the rotor. The bearing rotatably supports the first shaft. The housing accommodates the rotor, the stator, and the bearing. The static eliminator electrically connects the shaft and the housing. The shaft further includes a lid portion, a second shaft, a first shaft through hole, and a second shaft through hole. The lid portion is disposed at one axial end of the first shaft. The second shaft extends from the lid portion in one axial direction. The first shaft through hole penetrates the first shaft in a radial direction. The second shaft through hole communicates with the interior of the first shaft and an external space of the shaft. The lid portion and the second shaft are electrically conductive. The second shaft through hole is disposed on one side in the axial direction of the first shaft through hole. The second shaft is in contact with the static eliminator. 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 using a static eliminator. [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 4A] FIG. 4A is a diagram showing an example of contact between the second shaft and the static eliminator. [Figure 4B] FIG. 4B is a diagram showing a first modified example of contact between the second shaft and the static eliminator. [Figure 4C] FIG. 4C is a diagram showing a second modified example of contact between the second shaft and the static eliminator. [Diagram 5] FIG. 5 is a diagram showing another example of the arrangement of the first shaft through-holes. [Figure 6A] FIG. 6A shows a first arrangement example of the second shaft through-holes in the lid portion. [Figure 6B] FIG. 6B shows a second example arrangement of the second shaft through-holes in the lid portion. [Figure 6C] FIG. 6C shows a third example arrangement of the second shaft through-holes in the lid portion. [Figure 7] FIG. 7 shows an example of a second shaft through hole disposed in a first shaft. [Figure 8] FIG. 8 shows a first modified example of the lid portion. [Figure 9] FIG. 9 shows a second modified example of the lid portion. [Figure 10] FIG. 10 shows a third modified example of the lid portion. [Figure 11] FIG. 11 shows a fourth modified example of the lid portion. [Figure 12] FIG. 12 shows a first modified example of the shaft. [Figure 13] FIG. 13 shows a second modified shaft. [Figure 14] FIG. 14 shows a third modified shaft. 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 an elastic member 72, a holding member 73, and a fixing member 74.

[0015] The conductive member 71 is formed using a material having electrical conductivity. The tip of the conductive member 71 contacts the second shaft 23 of the shaft 2, which will be described later. The conductive member 71 is a molded body in this embodiment, but is not limited to this example and may be in a brush shape. The conductive member 71 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 71 can be made of a composite resin containing a conductive filler such as carbon fiber or metal, for example.

[0016] The elastic member 72 is housed in a compressed state inside the holding member 73. Due to its elasticity, the elastic member 72 pushes the conductive member 71 toward the second shaft 23. In this embodiment, a spring coil is used as the elastic member 72, but the present invention is not limited to this example, and other types of members such as a leaf spring, rubber, etc. may be used.

[0017] The holding member 73 is tubular with a bottom, and accommodates a part of the conductive member 71 and the elastic member 72 therein. The holding member 73 holds the conductive member 71. In detail, the holding member 73 holds the end of the conductive member 71 on the elastic member 72 side so as to be movable in the direction in which the holding member 73 extends. The holding member 73 also holds the elastic member 72 so as to be expandable and contractable in the direction in which the holding member 73 extends.

[0018] The fixing member 74 fixes the static eliminator 7 to the housing 4. In this embodiment, the fixing member 74 is attached to the holding member 73. At least one of the fixing members 74 is fixed to a plate portion 433 described later (see, for example, FIG. 4A described later). However, this is not limiting, and at least one of the fixing members 74 may be fixed to a cover member 44 described later. In other words, the fixing member 74 fixes the holding member 73 to at least one of the plate portion 433 and the cover member 44.

[0019] Moreover, the fixing member 74 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.

[0020] <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.

[0021] <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.

[0022] 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.

[0023] <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.

[0024] <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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] The shaft 2 further includes a lid portion 22, a second shaft 23, a first shaft through hole 201, and a second shaft through hole 202. The lid portion 22 is disposed at one axial end of the first shaft 21. The second shaft 23 extends from the lid portion 22 in one axial direction D1. The first shaft through hole 201 penetrates the first shaft 21 in the radial direction. The second shaft through hole 202 communicates with the inside of the first shaft 21 and the external space of the shaft 2. The second shaft through hole 202 is disposed on one axial direction D1 from the first shaft through hole 201. The first shaft 21, the lid 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.

[0029] 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 drawing 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 second shaft 23. 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.

[0030] <1-2-1. Second shaft 23> The second shaft 23 extends in the axial direction along the first rotation axis J1. The outer diameter of the second shaft 23 is smaller than the outer diameter of the first shaft 21.

[0031] As described above, the static eliminator 7 contacts the second shaft 23. FIG. 4A is a diagram showing an example of contact between the second shaft 23 and the static eliminator 7. FIG. 4B is a diagram showing a first modified example of the contact between the second shaft 23 and the static eliminator 7. FIG. 4C is a diagram showing a second modified example of the contact between the second shaft 23 and the static eliminator 7. Preferably, as in FIGS. 4A and 4B, the static eliminator 7 contacts at least a part of the circumferential area of ​​the radial outer surface of the second shaft 23. For example, in this embodiment, as in FIG. 4A, the static eliminator 7 contacts a part of the circumferential area of ​​the radial outer surface of the second shaft. On the other hand, as in FIG. 4B, the conductive member 71 of the static eliminator 7 may contact the entire circumferential area of ​​the outer surface of the second shaft 23. The static eliminator 7 contacts at least a partial region in the circumferential direction of the radially outer surface of the second shaft 23, which has an outer diameter smaller than that of the first shaft 21, thereby making it possible to reduce the sliding area of ​​the static eliminator 7 against the second shaft 23 per rotation of the shaft 2. This makes it possible to reduce wear powder generated at the contact portion between the static eliminator 7 and the shaft 2. Note that, without being limited to this example, the static eliminator 7 may be in axial contact with one axial end of the second shaft as shown in FIG. 4C.

[0032] <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.

[0033] 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.

[0034] <1-2-3. Second shaft through hole 202> The second shaft through-hole 202 is disposed in at least one of the lid portion 22 and the shaft tube portion 212. 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 providing a plurality of second shaft through-holes 202 functioning as air intakes, the amount of air drawn into the first shaft 21 and the flow of the drawn airflow can be appropriately adjusted depending on the number and arrangement of the second shaft through-holes 202.

[0035] FIG. 6A shows a first arrangement example of the second shaft through holes 202 in the lid portion 22. FIG. 6B shows a second arrangement example of the second shaft through holes 202 in the lid portion 22. FIG. 6C shows a third arrangement example of the second shaft through holes 202 in the lid portion 22. At least some of the second shaft through holes 202 may be arranged between the radial outer end of the lid portion 22 and the second shaft 23 in the radial direction (see, for example, FIG. 6A). At least some of the second shaft through holes 202 may be arranged along the radial outer side surface of the second shaft 23 (see, for example, FIG. 6B). At least some of the second shaft through holes 202 may be arranged along the radial outer end of the lid portion 22 (see, for example, FIG. 6C). Furthermore, the second shaft through holes 202 arranged along the radial outer end of the lid portion 22 may be composed of a notch formed in the radial outer end of the lid portion 22 and a notch formed in one axial end of the first shaft 21.

[0036] However, without being limited to the above example, the second shaft through hole 202 may be disposed in the first shaft 21 and may penetrate the first shaft 21 in the radial direction. FIG. 7 shows an example of the second shaft through hole 202 disposed in the first shaft 21. As shown in FIG. 7, the second shaft through hole 202 may be disposed in the shaft tube portion 212 and may penetrate the shaft tube portion 212 in the radial direction. In this way, the amount of air taken into the first shaft 21 can be increased. In addition, if there are a plurality of second shaft through holes 202 functioning as an intake port, the amount of air taken into the first shaft 21 and the flow of the taken airflow can be appropriately adjusted according to the number and arrangement of the second shaft through holes 202.

[0037] Furthermore, the number of the second shaft through-holes 202 may be one or more. In the latter case, the second shaft through-holes 202 may be arranged at equal intervals or at different intervals in the circumferential direction (see, for example, FIGS. 6A to 6C).

[0038] <1-2-4. Lid part 22> Next, the lid portion 22 will be described with reference to Figures 2 and 8 to 11. Figures 8 to 11 show first to fourth modified examples of the lid portion 22, respectively.

[0039] In this embodiment, the lid portion 22 is in the form of a plate expanding radially from the first rotation axis J1 as shown in Fig. 2. However, the lid portion 22 is not limited to this example. Fig. 8 shows another shape of the lid portion 22. The shape of the lid portion 22 may be a shape other than a plate, and may be, for example, a cone shape expanding radially outward toward one axial direction D1 or the other axial direction D2 as shown in Fig. 8.

[0040] Preferably, the lid portion 22 is integral with the first shaft 21. Alternatively, the lid portion 22 is integral with the second shaft 23. For example, the lid portion 22 is a different part of the same member as the second shaft 23 in this embodiment (see FIG. 2), but may be a different part of the same member as the first shaft 21 (see FIG. 9). By integrating the lid portion 22 with the first shaft 21 or the second shaft 23, the shaft 2 becomes easier to manufacture. In addition, the number of parts of the shaft 2 can be reduced, so that the motor 100 becomes easier to assemble. However, this example does not exclude a configuration in which the lid portion 22 is a separate member from both the first shaft 21 and the second shaft 23.

[0041] Furthermore, when the lid portion 22 is a separate member from the second shaft 23, the lid portion 22 may have a hole 221 (see FIG. 10). The hole 221 is disposed at one axial end of the lid portion 22 and extends in the other axial direction D2. The hole 221 may be a through hole that passes through the lid portion 22 in the axial direction as shown in FIG. 10, or may be a recess that is recessed from one axial end face of the lid portion 22 in the other axial direction D2. A portion of the second shaft 23 on the other axial direction D2 side fits into the hole 221. This allows the second shaft 23 to be easily attached to the lid portion 22.

[0042] When the second shaft 23 fits into the hole 221, the shaft 2 preferably further includes a first fixing portion 222. The first fixing portion 222 fixes the second shaft 23 to the lid portion 22 (see FIG. 10). 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 second shaft 23 to the lid portion 22 in the hole 221 may be brazing, bonding using an adhesive, or welding. In this way, the second shaft 23 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 second shaft 23 may be fixed to the lid portion 22 by screwing a male screw portion formed on the radially outer surface of the second shaft 23 into a female screw portion formed on the inner surface of the hole 221. However, this example does not exclude a configuration in which the shaft 2 does not include the first fixing portion 222.

[0043] In this embodiment, as shown in FIG. 2, the lid portion 22 is connected to one axial end of the tubular shaft portion 212 and covers the opening of the one axial end of the tubular shaft portion 212. However, the lid portion 22 is not limited to this example. For example, the lid portion 22 may be disposed radially on one side of the first shaft through-hole 201 and disposed inside the tubular shaft portion 212 in a portion on the one axial direction D1 side of the tubular shaft portion 212 (see FIG. 11). In other words, the lid portion 22 may be fitted to one axial end of the first shaft 21. The second shaft 23 can be attached to the first shaft 21 by fitting the lid portion 22 to the first shaft 21. Therefore, the axial length of the shaft 2 can be adjusted.

[0044] In addition, when the lid portion 22 is fitted to the first shaft 21, the shaft 2 preferably further includes a second fixing portion 223, as shown in FIG. 11 for example. The second fixing portion 223 fixes the lid portion 22 to the first shaft 21. The second fixing portion 223 may be, for example, a brazing material (such as silver solder), an adhesive, or a welded mark. That is, the means for fixing the lid portion 22 to the first shaft 21 on the one axial direction D1 side in the shaft tube portion 212 may be brazing, bonding using an adhesive, or welding. In this way, the first shaft 21 can hold the lid portion 22 more reliably. Note that the second fixing portion 223 is not limited to these examples. For example, the two may be fixed by screwing a male screw portion formed on the radial outer surface of the second shaft 23 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 include the second fixing portion 223.

[0045] 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 (see FIG. 11). 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 of 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.

[0046] <1-2-5. Other Modifications of Shaft 2> Next, other modified examples of the shaft 2 will be described with reference to Figures 12 to 14. Figures 12 to 14 show first to third modified examples of the shaft 2, respectively.

[0047] As shown in Figs. 12 to 14, the shaft 2 may further have a cylindrical lid tube portion 24. The lid tube portion 24 extends from the other axial end of the lid portion 22 in the other axial direction D2. The outer peripheral surface of the lid tube portion 24 contacts the inner peripheral surface of the one axial end of the first shaft 21. For example, as shown in Fig. 12, the lid tube portion 24 may extend in the other axial direction D2 from the lid portion 22 that closes the one axial end of the shaft tube portion 212. Also, as shown in Fig. 13, the lid tube portion 24 may extend in the other axial direction D2 from the lid portion 22 that fits on the one axial direction D1 side of the shaft tube portion 212. As shown in Fig. 14, for example, the lid tube portion 24 may extend in the other axial direction D2 from the conical lid portion 22 that expands radially outward as it approaches the one axial direction D1 or the other axial direction D2. When the lid portion 22 is attached to the first shaft 21, the lid cylinder portion 24 makes it difficult for the lid portion 22 to tilt in the axial direction, so that the attachment accuracy of the lid portion 22 and the second shaft 23 to the first shaft 21 can be improved. Therefore, for example, it is possible to suppress or prevent misalignment between the center of rotation of the second shaft 23 and the center of rotation of the first shaft 21. Furthermore, when a refrigerant such as the lubricating liquid CL flows inside the first shaft 21, the lid cylinder portion 24 can prevent the refrigerant flowing along the inner circumferential surface of the first shaft 21 due to the rotation of the shaft 2 from reaching one axial end of the first shaft 21. Therefore, the refrigerant is less likely to leak from one axial end of the first shaft 21.

[0048] Preferably, the lid cylinder 24 has a second chamfered portion 241. The second chamfered portion 241 is disposed at the other axial end of the outer circumferential surface of the lid cylinder 24 (see Figs. 12 to 14). For example, at the other axial end of the lid cylinder 24, a corner formed by the outer circumferential surface of the lid cylinder 24 and the other axial end face of the lid cylinder 24 is subjected to so-called R chamfering, which forms a curved surface between the two, or so-called C chamfering, which cuts off the corner obliquely, over the circumferential direction. The arrangement of the second chamfered portion 241 makes it easier to fit the lid cylinder 24 to one axial end of the first shaft 21. Therefore, the lid portion 22 can be easily attached to one axial end of the first shaft 21. However, this example does not exclude a configuration in which the lid portion 22 does not have the second chamfered portion 241.

[0049] In addition, the first shaft 21 may further have a third chamfered portion 214. The third chamfered portion 214 is disposed at one axial end of the inner circumferential surface of the first shaft 21. This configuration is particularly effective for a configuration in which the cover portion 22 fits into the first shaft 21 (see, for example, Figs. 11 and 13 to 14) and a configuration in which the shaft 2 has a cover cylinder portion 24 (see, for example, Figs. 11 and 14). For example, at one axial end of the first shaft 21, a corner formed by the inner circumferential surface and one axial end face of the first shaft 21 is subjected to so-called R chamfering, which forms a curved surface between the two, or so-called C chamfering, which cuts off the corner obliquely, over the circumferential direction. The arrangement of the third chamfered portion 214 makes it easier to fit a member into one axial end of the first shaft 21. For example, the lid portion 22 or the cylindrical lid portion 24 described later can be more easily fitted to one axial end portion of the first shaft 21 (see Figs. 11 to 14 described later). Therefore, members such as the lid portion 22 and the cylindrical lid portion 24 can be easily attached to one axial end portion of the first shaft 21. However, this example does not exclude a configuration in which the first shaft 21 does not have the third chamfered portion 214.

[0050] <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.

[0051] <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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] <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.

[0058] 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.

[0059] <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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] <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.

[0064] <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.

[0065] 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.

[0066] 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.

[0067] <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".

[0068] 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.

[0069] <1-4-3-1. Lid section 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.

[0070] <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.

[0071] <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.

[0072] <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 .

[0073] <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.

[0074] <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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] <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.

[0079] <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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] <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.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] <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]

[0088] The present invention is useful in devices for grounding shafts. [Explanation of symbols]

[0089] 100 motor, 200 battery, 300 vehicle, 1 motor section, 11 rotor, 111 rotor core, 1111 rotor through hole, 112 magnet, 12 stator, 121 stator core, 122 coil section, 1221 coil end, 2 shaft, 201 first shaft through hole, 202 second shaft through hole, 21 first shaft, 211 hollow section, 212 shaft cylinder section, 213 inlet, 214...third chamfered portion, 22...lid portion, 221...hole portion, 222...first fixing portion, 223...second fixing portion, 224...first chamfered portion, 23...second shaft, 24...tubular cover portion, 241...second chamfered portion, 3...power transmission device, 31...reduction gear, 311...main drive gear, 312...intermediate driven gear, 313...final drive gear, 314...intermediate shaft, 32...differential device, 321...ring gear, 4...housing, 401... Motor accommodating space, 402...gear portion accommodating space, 41...first housing cylindrical portion, 42...side plate portion, 4201...side plate through hole, 4202...first output shaft through hole, 421, 422, 423, 424...bearing holder, 4211...bearing, 4221...bearing, 4231...first intermediate bearing, 4241...first output bearing, 43...motor cover, 431...cover, 4311...opening, 4312...bearing holder, 4313... 435·sealing member, 4314·bearing, 432·cylindrical portion, 433·plate portion, 4331·opening portion, 434·bearing retaining portion, 4341·bearing, 435·sealing member, 44·cover member, 440·accommodating space, 441·first cover portion, 442·second cover portion, 443·through hole, 444·cylindrical portion, 445·filter, 45·second housing cylindrical portion, 46·gear cover portion, 460·second output shaft through hole, 461, 462,463···Bearing retaining portion, 4611···Bearing, 4621···Second intermediate bearing, 4631···Second output bearing, 464···Receiver portion, 465···Oil passage, 6···Liquid circulation portion, 61···Pipe portion, 62···Pump, 63···Oil cooler, 64···Motor oil reservoir, 7···Static charge eliminator, 71···Conductive member, 72···Elastic member, 73···Retaining member, 74···Fixing member, CL···Lubricant, P···Liquid storage portion, Ds···Output shaft, J1···First rotating shaft, J2···Second rotating shaft, J3···Third rotating shaft,

Claims

1. A shaft having a first shaft that is cylindrical and extends in an axial direction; a rotor supported by the first shaft and rotatable together with the shaft; a stator disposed radially outward from the rotor; a bearing that rotatably supports the first shaft; a housing that accommodates the rotor, the stator, and the bearing; a static eliminator that electrically connects the shaft and the housing; Equipped with The shaft is A cover portion disposed at one axial end of the first shaft; A second shaft extending in one axial direction from the cover portion; a first shaft through hole that penetrates the first shaft in a radial direction; a second shaft through hole communicating with an interior of the first shaft and an exterior space of the shaft; and the lid portion and the second shaft are electrically conductive, the second shaft through hole is disposed axially to one side of the first shaft through hole, the second shaft is in contact with the static eliminator, At least a part of one axial end of the cover portion is located on the other axial side of the one axial end of the first shaft, A motor, wherein an inner circumferential surface of the first shaft and an outer circumferential surface of the second shaft face each other in a radial direction.

2. A shaft having a first shaft that is cylindrical and extends in an axial direction through which a refrigerant can flow; a rotor supported by the first shaft and rotatable together with the shaft; a stator disposed radially outward from the rotor; a first bearing that rotatably supports the first shaft; a housing that accommodates the rotor, the stator, and the bearing; a static eliminator that electrically connects the shaft and the housing; Equipped with The shaft is A cover portion disposed at one axial end of the first shaft; A second shaft extending in one axial direction from the cover portion; a first shaft through hole that penetrates the first shaft in a radial direction; a second shaft through hole communicating with an interior of the first shaft and an exterior space of the shaft; and the lid portion and the second shaft are electrically conductive, the second shaft through hole is disposed axially to one side of the first shaft through hole, the second shaft is in contact with the static eliminator, A second bearing is further provided to rotatably support the second shaft. At least a portion of the second shaft through hole faces the second bearing in the axial direction.

3. The outer diameter of the second shaft is smaller than the outer diameter of the first shaft, The motor according to claim 1 , wherein the static eliminator is in contact with at least a portion of a circumferential area of ​​a radially outer surface of the second shaft.

4. The motor according to claim 1 , wherein the second shaft through-hole is disposed in the first shaft and penetrates the first shaft in a radial direction.

5. The motor according to claim 1 , wherein the second shaft through hole is disposed in the lid portion and passes through the lid portion in the axial direction.

6. A shaft having a first shaft that is cylindrical and extends in an axial direction; a rotor supported by the first shaft and rotatable together with the shaft; a stator disposed radially outward from the rotor; a bearing that rotatably supports the first shaft; a housing that accommodates the rotor, the stator, and the bearing; a static eliminator that electrically connects the shaft and the housing; Equipped with The shaft is A cover portion disposed at one axial end of the first shaft; A second shaft extending in one axial direction from the cover portion; a first shaft through hole that penetrates the first shaft in a radial direction; a second shaft through hole communicating with an interior of the first shaft and an exterior space of the shaft; and the lid portion and the second shaft are electrically conductive, the second shaft through hole is disposed axially to one side of the first shaft through hole, the second shaft is in contact with the static eliminator, The cover portion is integral with the first shaft.

7. The motor according to claim 1 , wherein the cover portion is integral with the second shaft.

8. A shaft having a first shaft that is cylindrical and extends in an axial direction; a rotor supported by the first shaft and rotatable together with the shaft; a stator disposed radially outward from the rotor; a bearing that rotatably supports the first shaft; a housing that accommodates the rotor, the stator, and the bearing; a static eliminator that electrically connects the shaft and the housing; Equipped with The shaft is A cover portion disposed at one axial end of the first shaft; A second shaft extending in one axial direction from the cover portion; a first shaft through hole that penetrates the first shaft in a radial direction; a second shaft through hole communicating with an interior of the first shaft and an exterior space of the shaft; and the lid portion and the second shaft are electrically conductive, the second shaft through hole is disposed axially to one side of the first shaft through hole, the second shaft is in contact with the static eliminator, the cover portion has a hole portion disposed at one end portion in an axial direction of the cover portion and extending in the other axial direction, the second shaft is a member separate from the lid portion, A motor, wherein the other axial side portion of the second shaft is fitted into the hole portion.

9. The motor according to claim 8 , wherein the shaft further includes a first fixing portion that fixes the second shaft to the lid portion.

10. The motor according to claim 1 , wherein the cover portion is fitted onto one axial end portion of the first shaft.

11. The motor according to claim 1 , wherein the shaft further includes a second fixing portion that fixes the cover portion to the first shaft.

12. The lid portion further includes a first chamfered portion, The motor according to claim 1 , wherein the first chamfered portion is disposed at a radially outer end of the other axial end of the cover portion.

13. The shaft further includes a cylindrical cover portion extending in the other axial direction from the other axial end portion of the cover portion, The motor according to claim 1 , wherein an outer circumferential surface of the cylindrical cover portion is in contact with an inner circumferential surface of one axial end of the first shaft.

14. The tubular lid portion has a second chamfered portion, The motor according to claim 13 , wherein the second chamfered portion is disposed at the other axial end of the outer circumferential surface of the cylindrical cover portion.

15. the first shaft further includes a third chamfer; The motor according to claim 1 , wherein the third chamfered portion is disposed at one axial end of an inner circumferential surface of the first shaft.

16. Further comprising an annular seal member; The housing has a plate portion that is disposed on one side of the bearing in the axial direction and extends in a radial direction, The plate portion has an opening through which the second shaft is inserted, the seal member is disposed in the opening of the plate portion, The static eliminator is disposed at one axial end of the plate portion, A radially outer end portion of the seal member contacts an inner circumferential surface of the opening portion facing inward in the radial direction, The motor according to claim 1 , wherein a radially inner end of the seal member contacts a radially outer surface of the second shaft.

17. The motor of claim 1 , further comprising a coolant flowing inside the first shaft.

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