Electric Motor

Abstract

The electric motor includes a static elimination device having a conductive component. The conductive component contacts an area of ​​a radial outer side surface of a shaft extending in the axial direction along a rotation axis parallel to the horizontal direction, which is in any one direction of vertically upward, vertically obliquely upward, and horizontal when viewed from the axial direction. The static elimination device is arranged on one side and the other side of a direction perpendicular to the axial direction and parallel to the horizontal direction than a contact portion between the shaft and the conductive component when viewed from the axial direction, or vertically obliquely upward than the contact portion. The static elimination device is also arranged on one side and the other side of the parallel direction than the rotation axis when viewed from the axial direction, or vertically obliquely upward than the rotation axis.

Description

Technical Field

[0001] The present invention relates to an electric motor. Background Art

[0002] Conventionally, a technique for discharging current from the shaft of a rotating machine such as an electric motor using a discharge device is known. For example, the discharge device includes a contact formed from a molded carbon body. The contact is housed within a guide sleeve. The contact establishes an electrical connection with the rotor contact surface formed on the periphery of the shaft through the load generated by the coil spring. Furthermore, an electrically conductive connection is formed between the contact and the sleeve portion constituting the grounding member via the guide sleeve. (For example, see Japanese Patent Application Publication No. 2019-531679)

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application No. 2019-531679 Summary of the Invention

[0006] However, if the contactor is brought into contact with the periphery of the shaft, the rotation of the shaft causes the contactor to wear, thereby generating, for example, carbon wear powder from the contactor, which may coat the static eliminating device with the wear powder.

[0007] An object of the present invention is to suppress or prevent a static eliminating device from being covered with abrasion powder.

[0008] An exemplary electric motor according to the present invention includes a shaft, a rotor, a stator, a housing, and a static eliminator. The shaft extends axially along a rotation axis parallel to the horizontal direction. The rotor is supported by the shaft and is rotatable therewith. The stator is positioned radially outward from the rotor. The housing houses the rotor and stator. The static eliminator includes a conductive member that contacts the radially outer surface of the shaft. The conductive member contacts a region of the radially outer surface of the shaft that faces in one of the vertically upward, vertically obliquely upward, and horizontal directions when viewed axially. The static eliminator is positioned on one side, on the other side, in a direction perpendicular to the axial direction and parallel to the horizontal direction, and vertically above the contact portion between the shaft and the conductive member, when viewed axially. The static eliminator is also positioned on one side, on the other side, in the direction parallel to the rotation axis, and vertically obliquely above the rotation axis, when viewed axially.

[0009] According to the motor exemplified by the present invention, it is possible to suppress or prevent the static eliminating device from being covered with abrasion powder. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is a conceptual diagram showing a structural example of an electric motor.

[0011] Figure 2 This is a conceptual diagram showing an enlarged configuration example of a main part of a motor.

[0012] Figure 3 This is a schematic diagram showing an example of a vehicle equipped with an electric motor.

[0013] Figure 4 It is a diagram showing an example of contact between the second shaft and the static eliminating device.

[0014] Figure 5 This is a cross-sectional view of the second shaft and the static eliminator as viewed from the axial direction.

[0015] Figure 6 Another arrangement example of the conductive member is shown.

[0016] Figure 7 It is a schematic diagram showing a modified example of the housing.

[0017] (Explanation of Symbols)

[0018] 100 Electric motor; 200 Battery; 300 Vehicle; 1 Electric motor; 11 Rotor; 111 Rotor core; 1111 Rotor through-hole; 112 Magnet; 12 Stator; 121 Stator core; 122 Coil; 1221 Coil end; 2 Shafts; 201 First shaft through-hole; 202 Second shaft through-hole; 21 First shaft; 211 Hollow portion; 212 Shaft cylinder; 213 Inlet; 22 Cover; 23 Second shaft; 3 Power transmission device; 31 Speed ​​reduction device; 311 Main drive gear; 312 Intermediate driven gear ; 313 final drive gear; 314 intermediate shaft; 32 differential gear; 321 ring gear; 4 housing; 401 motor storage space; 402 gear storage space; 41 first housing cylinder; 42 side plate; 4201 side plate through hole; 4202 first output shaft through hole; 421, 422, 423, 424 bearing retaining portion; 4211 bearing; 4221 bearing; 4231 first intermediate bearing; 4241 first output bearing; 43 motor cover; 431 cover; 4311 opening; 43 12 Bearing holding portion; 4313 Sealing member; 4314 Bearing; 432 Cylinder; 433 Plate; 4331 Opening; 4332 Fixing portion; 4333 Rib; 434 Bearing holding portion; 4341 Bearing; 435 Sealing member; 44 Cover member; 440 Accommodation space; 4401 Lower space; 441 First cover portion; 442 Second cover portion; 443 Through hole; 444 Cylinder; 445 Filter; 45 Second housing cylinder; 46 Gear cover; 460 Second output shaft through hole; 461, 462 , 463 bearing retaining portion; 4611 bearing; 4621 second intermediate bearing; 4631 second output bearing; 464 receiving disc portion; 465 oil circuit; 6 liquid circulation portion; 47 adhesive member; 61 piping portion; 62 pump; 63 oil cooler; 64 motor oil storage portion; 7 static elimination device; 71 conductive member; 72 elastic member; 73 retaining member; 74 fixing member; CL lubricating fluid; P liquid storage portion; Ds output shaft; J1 first rotation axis; J2 second rotation axis; J3 third rotation axis. DETAILED DESCRIPTION

[0019] Hereinafter, exemplary embodiments will be described with reference to the accompanying drawings.

[0020] In this specification, the direction parallel to the first rotation axis J1 of the motor unit 1 is referred to as the "axial direction" of the motor 100. Figure 1As shown, 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. Furthermore, the radial direction perpendicular to the specified axis is referred to as the "radial direction," and the circumferential direction centered on the specified axis is referred to as the "circumferential direction." Furthermore, in this specification, "parallel directions" include not only completely parallel directions but also approximately parallel directions. Furthermore, "extending along" a specified direction or plane includes not only extending strictly along the specified direction but also extending along a direction inclined within a range of less than 45° relative to the strict direction.

[0021] 1. Implementation Method

[0022] Figure 1 1 is a conceptual diagram showing a configuration example of the electric motor 100 . Figure 2 This is a conceptual diagram showing an enlarged configuration example of a main portion of the electric motor 100 . Figure 3 1 is a schematic diagram showing an example of a vehicle 300 equipped with the electric motor 100. Figure 1 and Figure 2 This is just a conceptual diagram, and the configuration and size of each part are not necessarily the same as those of the actual motor 100. Figure 2 It is magnified Figure 1 The dotted line encloses the portion X of the graph. In addition, Figure 3 A vehicle 300 is conceptually illustrated.

[0023] In this embodiment, the motor 100 is as follows Figure 3 The illustrated embodiment is mounted on a vehicle 300, such as a hybrid vehicle (HV), a plug-in hybrid vehicle (PHV), or an electric vehicle (EV), that uses at least an electric motor as a power source. Electric motor 100 serves as the power source for vehicle 300. Vehicle 300 includes electric motor 100 and battery 200. Battery 200 stores electricity to supply electric motor 100. In the example of vehicle 300, electric motor 100 drives the left and right front wheels. However, electric motor 100 need only drive at least one wheel.

[0024] like Figure 1 As shown, electric motor 100 includes a motor unit 1, a shaft 2, a power transmission device 3, a housing 4, and a fluid circulation unit 6. Shaft 2 extends axially along a first rotation axis J1 parallel to the horizontal direction. Shaft 2 is rotatable about first rotation axis J1. Housing 4 houses motor unit 1, shaft 2, and power transmission device 3. For example, housing 4 houses rotor 11 and stator 12 of motor unit 1, described later, as well as bearings 4211 and 4314, described later.

[0025] Furthermore, 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 in contact with the shaft 2. Figure 2 As shown, the static eliminating device 7 of this embodiment further includes an elastic member 72 , a holding member 73 , and a fixing member 74 .

[0026] The conductive member 71 is formed of a conductive material. The distal end of the conductive member 71 contacts the second shaft 23 of the shaft 2, described later. While the conductive member 71 is a molded body in this embodiment, it is not limited to the example shown above and may also have a brush shape. The conductive member 71 is preferably made of a material with good sliding properties, and more preferably, a material with a low coefficient of friction. Examples of materials for the conductive member 71 include composite resins containing conductive fillers such as carbon fiber or metal.

[0027] The elastic member 72 is housed inside the retaining member 73 in a compressed state. Due to its elasticity, the elastic member 72 presses the conductive member 71 toward the second shaft 23 of the shaft 2. As mentioned above, the static eliminating device 7 has an elastic member 72. In addition, the second shaft 23 is an example of the "shaft" of the present invention. In this embodiment, the elastic member 72 uses a coil spring, but is not limited to the above example, and other forms of members such as leaf springs and rubber can also be used. By pressing the conductive member 71 toward the second shaft 23 of the shaft 2 by the elastic member 72, even if the conductive member 71 is worn due to sliding between the conductive member 71 and the rotating second shaft 23, the conductive member 71 can maintain contact with the second shaft 23. In other words, the electrical connection between the conductive member 71 and the second shaft 23 can be maintained.

[0028] The holding member 73 is a bottomed cylindrical structure that houses a portion of the conductive member 71 and the elastic member 72. As previously described, the static elimination device 7 includes the holding member 73. The holding member 73 holds the conductive member 71. Specifically, the holding member 73 holds the end of the conductive member 71 on the elastic member 72 side so that it can move in the direction in which the holding member 73 extends. Furthermore, the holding member 73 holds the elastic member 72 so that it can expand and contract in the direction in which the holding member 73 extends.

[0029] The fixing member 74 fixes the static eliminating device 7 to the housing 4. In this embodiment, the fixing member 74 is attached to the holding member 73. In addition, at least one fixing member 74 is fixed to the plate portion 433 described later (see the following). Figure 4However, the present invention is not limited to the above example. Alternatively, at least one fixing member 74 may be fixed to the cover member 44, described later. Specifically, the fixing member 74 fixes the retaining member 73 to at least one of the plate portion 433 and the cover member 44. The static eliminator 7 includes at least one fixing member 74. By securing the retaining member 73 with the fixing member 74, the static eliminator 7 can be secured to at least one of the plate portion 433 and the cover member 44.

[0030] 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, so that the conductive member 71 and the housing 4 are electrically connected.

[0031] <1-1. Motor 1>

[0032] Next, refer to Figure 1 and Figure 2 The motor unit 1 is described below. The motor unit 1 is a DC brushless motor. The motor unit 1 is a 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 motor unit in which the rotor 11 is rotatably arranged inside the stator 12. Figure 1 As shown, the motor unit 1 includes a rotor 11 and a stator 12 .

[0033] <1-1-1. Rotor 11>

[0034] The rotor 11 is supported on the shaft 2. The electric motor 100 includes the rotor 11. The rotor 11 can rotate together with the shaft 2. In detail, the rotor 11 is supported on the first shaft 21 described later. The rotor 11 is rotated by supplying electric power from the power supply unit (not shown) of the electric motor 100 to the stator 12. The rotor 11 has a rotor core 111 and magnets 112. The rotor core 111 is formed by stacking thin electromagnetic steel plates, for example. The rotor core 111 is a cylindrical body extending in the axial direction, which is fixed to the radial outer side of the first shaft 21. A plurality of magnets 112 are fixed to the rotor core 111. The plurality of magnets 112 are arranged so that the magnetic poles are alternately arranged in the circumferential direction.

[0035] In addition, the rotor core 111 has a rotor through-hole 1111. The rotor through-hole 1111 extends axially through the rotor core 111 and is connected to the first shaft through-hole 201. The rotor through-hole 1111 serves as a circulation path for the lubricating liquid CL, which acts as a refrigerant. 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. Furthermore, the lubricating liquid CL flowing into the rotor through-hole 1111 can flow out to the outside from both axial ends of the rotor through-hole 1111. The outflowing lubricating liquid CL flows toward the stator 12, for example, cooling the coil portion 122 (particularly the coil edge 1221). Furthermore, the outflowing lubricating liquid CL flows toward the bearings 4211 and 4314 that rotatably support the first shaft 21, lubricating and cooling the bearings 4211 and 4314.

[0036] <1-1-2. Stator 12>

[0037] The stator 12 is arranged radially outward from the rotor 11. The electric motor 100 includes a stator 12. The stator 12 has a stator core 121 and a coil portion 122. The stator 12 is sandwiched between the stator core 121 and the coil portion 122. The stator 12 is retained by the first outer shell cylinder 41 described later. The stator core 121 has a plurality of magnetic pole teeth (not shown) extending radially inward from the inner circumferential surface of the annular yoke portion. The coil portion 122 is formed by winding a conductive wire around the magnetic pole teeth via an insulator (not shown). The coil portion 122 has a coil side end 1221 protruding from the axial end face of the stator core 121.

[0038] <1-2. Axis 2>

[0039] like Figure 1 As shown, 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 rotatably support the first shaft 21.

[0040] 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. The refrigerant circulates on the inner side of the first shaft 21. The motor 100 also includes the above-mentioned refrigerant. In addition, the refrigerant is a lubricating liquid CL in this embodiment. According to the rotation of the shaft 2, the refrigerant circulating on the inner side of the first shaft 21 can be supplied to the stator 12 and the bearings 4211, 4314, etc. through the first shaft through-hole 201 described later. Therefore, the stator 12 (especially the coil side end 1221 of the coil portion 122) and the bearings 4211, 4314, etc. can be cooled by the refrigerant.

[0041] The first shaft 21 has a hollow portion 211, a shaft cylinder portion 212, and an inlet 213. The shaft cylinder portion 212 extends axially along the first rotation axis J1. The hollow portion 211 is disposed within the shaft cylinder portion 212. The inlet 213 is disposed on the other axial side D2 of the shaft cylinder portion 212 and is connected to the oil passage 465 of the gear cover portion 46, described later. The lubricating fluid CL, described later, flows from the oil passage 465 into the hollow portion 211 via the inlet 213.

[0042] In addition, the first shaft 21 can be split at the middle portion in the axial direction. When the first shaft 21 is split, the split first shaft 21 can, for example, adopt a threaded coupling structure using external and internal threads. In addition, it is also possible to join by fixing methods such as press-fitting and welding. When using fixing methods such as press-fitting and welding, a serration structure (serration) combining concave and convex parts extending in the axial direction can also be used. By setting it to the above structure, rotation can be reliably transmitted.

[0043] The shaft 2 also includes a cover 22, a second shaft 23, a first shaft through-hole 201, and a second shaft through-hole 202. The cover 22 is disposed at one axial end of the first shaft 21. The second shaft 23 extends from the cover 22 in an axial direction D1. The first shaft through-hole 201 radially penetrates the first shaft 21. The second shaft through-hole 202 connects the interior of the first shaft 21 with the external space of the shaft 2. The second shaft through-hole 202 is disposed closer to the axial direction D1 than the first shaft through-hole 201. The first shaft 21, the cover 22, and the second shaft 23 are electrically conductive and, in this embodiment, are made of metal. The second shaft 23 is in contact with the static elimination device 7.

[0044] <1-2-1. Second axis 23>

[0045] 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 that of the first shaft 21 .

[0046] The static eliminating device 7 is in contact with the second shaft 23 . Figure 4 It is a diagram showing an example of contact between the second shaft 23 and the static eliminating device 7 . Figure 5 This is a cross-sectional view of the second shaft 23 and the static eliminating device 7 as viewed from the axial direction. Figure 4 In order to facilitate viewing of the configuration of the second shaft 23 and the static eliminating device 7, the cover member 44 described later is transparently displayed. Figure 5 The cross-sectional structure obtained by cutting the second shaft 23 , the static eliminating device 7 , and the cover member 44 along a virtual plane perpendicular to the axial direction is shown. Figure 5 The up and down direction is the vertical direction Dv. In the vertical direction Dv, Figure 5 The direction from the lower side to the upper side is above the vertical direction Dv. Figure 5 The direction from the upper side to the lower side is below the vertical direction Dv. Figure 5 The left-right direction is the horizontal direction Dh. The vertical direction Dv is perpendicular to the axial direction, and the horizontal direction Dh is perpendicular to both the axial direction and the vertical direction Dv.

[0047] like Figure 4 and Figure 5 As shown, the conductive member 71 of the static elimination device 7 contacts the radially outer side surface of the second shaft 23. The conductive member 71 contacts the area of ​​the radially outer side surface of the second shaft 23 that is vertically above the first circumferential angular position Pa on one side facing the horizontal direction Dh and the third circumferential angular position Pc on the other side facing the horizontal direction Dh. In other words, the conductive member 71 contacts the area of ​​the radially outer side surface of the second shaft 23 that is perpendicular to the first circumferential angular position Pa on the one side facing the horizontal direction Dh and the third circumferential angular position Pc on the other side facing the horizontal direction Dh. Figure 4 The first circumferential angular position Pa on the left side of the second shaft 23 is around the vertical upper side until Figure 4 The third circumferential angular position Pc on the right side contacts an area within a circumferential range of 180°.

[0048] The conductive member 71 contacts an area of ​​the radially outer surface of the second shaft 23 of the shaft 2 that faces upward in the vertical direction Dv, obliquely upward in the vertical direction, or in the horizontal direction Dh when viewed axially. The obliquely upward direction, when viewed axially, refers to a direction that has both an upward component in the vertical direction Dv and a horizontal component in the horizontal direction Dh. In other words, the conductive member 71 can contact an area in the upper half of the radially outer surface of the second shaft 23.

[0049] In other words, the conductive member 71 contacts the radially outer side surface of the second shaft 23 over a circumferential range θr of 180° from the first circumferential angular position Pa through the second circumferential angular position Pb to the third circumferential angular position Pc when viewed from the axial direction (see FIG. Figure 5 The first circumferential angular position Pa is one side of the radially outer side surface of the second shaft 23 that faces the horizontal direction Dh when viewed from the axial direction (for example, from Figure 5 The second circumferential angular position Pb is a circumferential angular position in the radially outer side surface of the second shaft 23 that is upward in the vertical direction Dv when viewed from the axial direction. The third circumferential angular position Pc is a circumferential angular position in the radially outer side surface of the second shaft 23 that is upward in the vertical direction Dv when viewed from the axial direction. Figure 5 The circumferential range θr includes a first circumferential angular position Pa, a second circumferential angular position Pb, a third circumferential angular position Pc, and a circumferential angular position that is obliquely upward when viewed from the axial direction.

[0050] In addition, Figure 4 and Figure 5In the embodiment, the conductive member 71 extends radially from the outer side of the second shaft 23 toward the first rotation axis J1 when viewed from the axial direction. However, the present invention is not limited to the above example, and the extension direction of the conductive member 71 may be offset or tilted relative to the radial direction from the outer side of the second shaft 23 toward the first rotation axis J1 when viewed from the axial direction (see FIG. Figure 6 ).

[0051] Furthermore, in this embodiment, the static eliminator 7 is positioned vertically and obliquely above the contact portion between the second shaft 23 and the conductive member 71 when viewed axially. However, this is not limited to the above example. The static eliminator 7 may be positioned directly above the contact portion when viewed axially, or may be positioned to one side or the other side of the contact portion in the horizontal direction Dh when viewed axially. In other words, the static eliminator 7 may be positioned to one side, to the other side, or vertically above the contact portion between the second shaft 23 and the conductive member 71 when viewed axially, in a direction perpendicular to the axial direction and parallel to the horizontal direction.

[0052] Furthermore, in this embodiment, the static eliminator 7 is also positioned vertically and obliquely above the first rotation axis J1 of the second shaft 23 when viewed axially. However, this is not limiting to the above example; the static eliminator 7 may also be positioned on one side or the other side of the first rotation axis J1 in the horizontal direction Dh when viewed axially. In other words, the static eliminator 7 only needs to be positioned on one side or the other side of the first rotation axis J1 in the aforementioned parallel direction (i.e., the horizontal direction Dh) when viewed axially, or vertically and obliquely above the first rotation axis J1.

[0053] By placing the conductive member 71 in contact with the upper half of the radially outer surface of the second shaft 23 and positioning the static eliminator 7 relative to the contact portion, wear powder from the conductive member 71 generated at the contact portion between the second shaft 23 and the conductive member 71 is less likely to fall onto the conductive member 71 itself. Furthermore, by positioning the static eliminator 7 relative to the first rotational axis J1, wear powder is less likely to fall onto portions of the static eliminator 7 other than the conductive member 71. Consequently, the static eliminator 7 is prevented from being coated with wear powder from the conductive member 71, allowing the wear powder to more easily fall vertically below the second shaft 23.

[0054] <1-2-2. First Shaft Through Hole 201>

[0055] In addition, the first shaft through hole 201 is arranged in the shaft cylinder portion 212 and penetrates the shaft cylinder portion 212 in the radial direction. When the shaft 2 rotates, the lubricating fluid CL in the first shaft 21 flows out of the hollow portion 211 through the first shaft through hole 201 under the action of centrifugal force to the outside of the first shaft 21. In this embodiment, as shown in FIG. Figure 1As shown, the first shaft through hole 201 is arranged closer to the other axial direction D2 than one axial end of the rotor 11 and closer to one axial direction D1 than the other axial end of the rotor 11, and is connected to the rotor through hole 1111 as described above.

[0056] However, it is not limited to Figure 1 For example, the first shaft through hole 201 may be arranged at a position D1 closer to one axial direction than one axial end of the rotor 11, or may be arranged at a position D2 closer to the other axial direction than the other axial end of the rotor 11. In other words, at least a portion of the first shaft through hole 201 may be arranged at at least one of the above positions.

[0057] <1-2-3. Second Shaft Through Hole 202>

[0058] The second shaft through hole 202 is configured in at least one of the cover portion 22 and the shaft cylinder portion 212. In this embodiment, the second shaft through hole 202 is configured in the cover portion 22 and penetrates the cover portion 22 in the axial direction (for example, see Figure 2 ). In this way, air is more easily drawn into the interior of the first shaft 21 than when the second shaft through-hole 202 is arranged on the first shaft 21. Furthermore, if a plurality of second shaft through-holes 202 are provided, functioning as air intake ports, the amount of air flowing into the first shaft 21 and the flow of the inhaled airflow can be appropriately adjusted based on the number and arrangement of the second shaft through-holes 202. However, the present invention is not limited to the above example; the second shaft through-hole 202 may also be arranged on the first shaft 21 and radially penetrate the first shaft 21.

[0059] Furthermore, the number of the second shaft through-holes 202 may be single or multiple. In the latter case, the second shaft through-holes 202 may be arranged at equal intervals or at different intervals in the circumferential direction.

[0060] <1-2-4. Cover 22>

[0061] In this embodiment, if Figure 2 As shown, the cover portion 22 is in the shape of a plate that extends radially from the first rotation axis J1. However, the cover portion 22 is not limited to the above example and may be in a shape other than a plate, for example, in the shape of a cone that extends radially outward toward one axial direction D1 or the other axial direction D2.

[0062] <1-3. Power Transmission Device 3>

[0063] Next, refer to Figure 1 The power transmission device 3 will be described in detail. The power transmission device 3 transmits the power of the motor unit 1 to the output shaft Ds. The power transmission device 3 includes a speed reduction device 31 and a differential device 32 .

[0064] <1-3-1. Speed ​​Reducer 31>

[0065] The reduction gear 31 is connected to the shaft 2. The reduction gear 31 reduces the rotational speed of the motor unit 1 and increases the torque output from the motor unit 1 according to the reduction ratio. The reduction gear 31 transmits the torque output from the motor unit 1 to the output shaft Ds. Specifically, the power transmission device 3 is connected to the other axial direction D2 of the shaft 2, which rotates about the horizontally extending first rotation axis J1.

[0066] The reduction gear 31 includes a main drive gear 311, a counter driven gear 312, a final drive gear 313, and an intermediate shaft 314. The torque output from the motor unit 1 is transmitted to the ring gear 321 of the output shaft Ds via the shaft 2, the main drive gear 311, the counter driven gear 312, the intermediate shaft 314, and the final drive gear 313.

[0067] The main drive gear 311 is disposed on the outer peripheral surface of the shaft 2. The main drive gear 311 may be the same member as the shaft 2 or a separate member that is securely fixed thereto. The main drive gear 311 rotates together with the shaft 2 about the first rotation axis J1.

[0068] The intermediate shaft 314 extends along a second rotation axis J2, which is parallel to the first rotation axis J1. The intermediate shaft 314 is supported at both ends by a first intermediate bearing 4231 and a second intermediate bearing 4621 for rotation about the second rotation axis J2. The intermediate driven gear 312 and the final drive gear 313 are disposed on the outer circumference of the intermediate shaft 314. The intermediate driven gear 312 and the intermediate shaft 314 may be the same component or separate components that are securely fixed.

[0069] The intermediate driven gear 312 and the final drive gear 313 rotate integrally with the intermediate shaft 314 about the second rotation axis J2. The intermediate driven gear 312 meshes with the main drive gear 311. The final drive gear 313 meshes with the ring gear 321 of the output shaft Ds.

[0070] The torque of the shaft 2 is transmitted from the main drive gear 311 to the counter driven gear 312. The torque transmitted to the counter driven gear 312 is then transmitted to the final drive gear 313 via the intermediate shaft 314. The torque is then transmitted from the final drive gear 313 to the output shaft Ds.

[0071] <1-3-2. Differential Gear 32>

[0072] The differential device 32 is mounted on the output shaft Ds. The differential device 32 includes 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 includes left and right axles Ds1 and Ds2, each mounted to the differential device 32. For example, when the vehicle turns, the differential device 32 absorbs the difference in rotational speed between the left and right axles and transmits torque to the left and right axles Ds1 and Ds2.

[0073] The lower end portion of the ring gear 321 is disposed inside a liquid reservoir P, which is described later, and is used to store the lubricating liquid CL stored in the lower portion of the gear housing space 402 (see FIG. Figure 1 ). Therefore, when the ring gear 321 rotates, the lubricating liquid CL is lifted up by the gear teeth of the ring gear 321. The lubricating liquid CL lifted up by the ring gear 321 lubricates or cools the gears and bearings of the power transmission device 3. In addition, a portion of the lifted lubricating liquid CL is stored in the receiving tray portion 464 described later and is also used to cool the motor unit 1 via the shaft 2.

[0074] <1-4. Housing 4>

[0075] Next, refer to Figure 1 and Figure 2 , the details of the housing 4 will be described. The housing 4 has a first housing cylinder 41, a side plate 42, a motor cover 43, a cover member 44, a second housing cylinder 45 and a gear cover 46. In addition, the first housing cylinder 41, the side plate 42, the motor cover 43, the second housing cylinder 45 and the gear cover 46 are formed using, for example, a conductive material. In the present embodiment, they are formed using metal materials such as iron, aluminum and alloys thereof. In addition, in order to suppress contact corrosion between different types of metals at the contact portion, it is preferred that the above-mentioned components are formed using the same material. However, this is not limited to the above examples, and the above-mentioned components may be formed using materials other than metal materials, or at least a portion of the above-mentioned components may be formed using different materials.

[0076] As previously mentioned, the housing 4 houses the rotor 11, stator 12, bearings 4211, 4314, and the like of the motor unit 1. Specifically, the housing 4 defines a motor housing space 401. The motor housing space 401 is a space enclosed by the first housing cylindrical portion 41, the side plate portion 42, and the motor cover portion 43, and houses the rotor 11, stator 12, bearings 4211, 4314, and the like.

[0077] Furthermore, the housing 4 houses the power transmission device 3. Specifically, the housing 4 has a gear unit housing space 402. The gear unit housing space 402 is a space enclosed by the side plate portion 42, the second housing cylindrical portion 45, and the gear cover portion 46, and houses the reduction gear 31, the differential device 32, and the like.

[0078] A liquid reservoir P for storing the lubricating liquid CL is arranged at a lower portion of the gear unit housing space 402 .

[0079] A portion of the differential gear 32 is immersed in the liquid reservoir P. The lubricating liquid CL accumulated in the liquid reservoir P is lifted up by the operation of the differential gear 32 and supplied to the interior of the gear unit storage space 402. For example, when the ring gear 321 of the differential gear 32 rotates, the lubricating liquid CL is lifted up by the tooth surfaces of the ring gear 321. A portion of the lifted lubricating liquid CL is supplied to the various gears and bearings of the reduction gear 31 and the differential gear 32 within the gear unit storage space 402 and used for lubrication. Furthermore, another portion of the lifted lubricating liquid CL is supplied to the interior of the shaft 2, and is supplied to the rotor 11 and stator 12 of the motor unit 1, as well as the various bearings within the gear unit storage space 402, and is used for cooling and lubrication.

[0080] <1-4-1. First Housing Tubular Portion 41>

[0081] The first outer cylindrical portion 41 is cylindrical and extends in the axial direction. The motor portion 1 and the motor oil reservoir 64 described below are arranged inside the first outer cylindrical portion 41. The stator core 121 is fixed to the inner surface of the first outer cylindrical portion 41.

[0082] <1-4-2. Side Plate 42>

[0083] The side plate portion 42 extends in a direction perpendicular to the first rotation axis J1 and covers the other axial end of the first outer shell tube portion 41. In this embodiment, the first outer shell tube portion 41 and the side plate portion 42 are distinct parts of a single component. By forming them into an integral unit, their rigidity can be improved. However, this is not limited to the above example; the first outer shell tube portion 41 and the side plate portion 42 may also be separate components.

[0084] The side plate portion 42 has: a side plate through-hole 4201 for the shaft 2 to pass through; and a first output shaft through-hole 4202. The side plate through-hole 4201 and the first output shaft through-hole 4202 extend through the side plate portion 42 in the axial direction. The first shaft 21 is inserted into the side plate through-hole 4201. An axle Ds1 of the output shaft Ds is inserted into the first output shaft through-hole 4202. An oil seal (not shown) is arranged in the gap between the output shaft Ds and the first output shaft through-hole 4202 to seal the two. In addition, the so-called sealing refers to the fact that different components are tightly attached to each other, for example, to the extent that the lubricating fluid CL inside the component does not leak to the outside, and foreign matter such as water, dust, and dirt from the outside does not enter. Regarding the sealing, the following are the same.

[0085] The side plate portion 42 also has bearing retaining portions 421, 422, 423, and 424. The bearing retaining portion 421 is arranged at one axial end surface of the side plate portion 42 in the motor housing space 401 and retains the bearing 4211. The bearing retaining portions 422, 423, and 424 are arranged at the other axial end surface of the side plate portion 42 in the gear housing space 402 described later. The bearing retaining portion 422 is arranged along the outer edge of the other axial end of the side plate through-hole 4201 and retains the bearing 4211. The bearing retaining portion 423 retains the first intermediate bearing 4231. The bearing retaining portion 424 is arranged along the outer edge of the other axial end of the first output shaft through-hole 4202 and retains the first output bearing 4241.

[0086] <1-4-3. Motor Cover 43>

[0087] The motor cover 43 is mounted on one axial end of the first housing tube 41. The motor cover 43 can be fixed to the first housing tube 41 by, for example, screws, but is not limited thereto. A wide range of methods can be used to securely fix the plate 433 to the first housing tube 41, such as screwing in or pressing in. This allows the motor cover 43 to adhere tightly to one axial end of the first housing tube 41. "Tightly adhere" means having a degree of sealing such that the lubricating fluid CL inside the component does not leak to the outside and foreign matter such as water, dust, and dirt from the outside does not enter. Regarding tight adherence, the same applies to the following.

[0088] like Figure 2 As shown, the motor cover 43 includes a cover portion 431 , a cylinder portion 432 , a plate portion 433 , and a bearing holding portion 434 . In other words, the housing 4 includes the cover portion 431 , the cylinder portion 432 , and the plate portion 433 .

[0089] <1-4-3-1. Cover 431>

[0090] The cover portion 431 extends in a direction intersecting the first rotation axis J1 and covers one axial end portion of the first housing cylinder portion 41. The cover portion 431 has an opening portion 4311 for inserting the shaft 2. The opening portion 4311 extends through the cover portion 431 in the axial direction. The first shaft 21 is inserted into the opening portion 4311. In addition, the cover portion 431 also has a bearing retaining portion 4312 and a sealing member 4313. The bearing retaining portion 4312 is arranged on the other axial end surface of the cover portion 431 in the motor housing space 401. The bearing retaining portion 4312 is arranged along the outer edge portion of the other axial end portion of the opening portion 4311 and retains the bearing 4314. The sealing member 4313 is arranged between the first shaft 21 and the cover portion 431 in the opening portion 4311 and seals the space between the two. Sealing the opening 4311 with the sealing member 4313 can prevent foreign matter such as abrasion powder generated in the static eliminator 7 from entering the motor housing space 401 housing the stator 12 and the like through the opening 4311 .

[0091] <1-4-3-2. Cylinder 432>

[0092] The cylindrical portion 432 has a cylindrical shape surrounding the first rotation axis J1 and extends from one axial end surface of the cover portion 431 toward the axial direction D1 .

[0093] <1-4-3-3. Plate 433>

[0094] The plate portion 433 extends in a direction intersecting the first rotation axis J1 and is mounted on the other axial end portion of the cylinder portion 432. As described above, the housing 4 has a plate portion 433. In the present embodiment, the plate portion 433 is conductive and extends in the radial direction. The plate portion 433 is arranged closer to the axial side D1 than the stator 12 and the bearing 4341 described later. An opening portion 4331 for inserting the second shaft 23 of the shaft 2 is arranged in the plate portion 433. In other words, the plate portion 433 has an opening portion 4331. The opening portion 4331 penetrates the plate portion 433 in the axial direction. In addition, a static eliminating device 7 is arranged at one axial end portion of the plate portion 433.

[0095] The plate portion 433 also includes a fixing portion 4332 that projects in the axial direction. The fixing portion 4332 projects in one axial direction D1 from the plate portion 433. The fixing member 74 of the static elimination device 7 is fixed to the fixing portion 4332.

[0096] In addition, the plate portion 433 further includes a rib 4333 protruding in the axial direction. The rib 4333 extends in a direction away from the fixing portion of the plate portion 433 to which the fixing member 74 of the static elimination device 7 is fixed. For example, in this embodiment, Figure 4As shown, a plurality of ribs 4333 protrude from the plate portion 433 in the axial direction D1. The plurality of ribs 4333 extend radially from the fixing portion 4332 relative to each fixing portion 4332. In addition, the end portion of each rib 4333 on the fixing portion 4332 side is connected to the outer side surface of the fixing portion 4332. Figure 4 In the example, three ribs 4333 are arranged relative to each fixing portion 4332. However, the number of ribs 4333 relative to each fixing portion 4332 is not limited to the example above and can be one or more than three. The arrangement of ribs 4333 reinforces the portion of the plate portion 433 where the fixing member 74 of the static eliminator 7 is fixed. Furthermore, axial vibration of the plate portion 433 caused by the vibration of the static eliminator 7 due to sliding with the rotating shaft 2 can be suppressed.

[0097] Furthermore, when at least a portion of the fixing member 74 of the static eliminator 7 is fixed to the cover member 44, the fixing portion 4332 and ribs 4333 for the fixing member 74 may also be disposed on the cover member 44. In this manner, the placement of the ribs 4333 reinforces the portion of the cover member 44 to which the fixing member 74 of the static eliminator 7 is fixed. Furthermore, axial vibration of the cover member 44 caused by vibration of the static eliminator 7 due to sliding movement with the rotating shaft 2 can be suppressed.

[0098] <1-4-3-4. Bearing holding portion 434>

[0099] The bearing holding portion 434 is arranged along the outer edge of one axial end portion of the opening portion 4331 on the other axial end surface of the plate portion 433 , and holds the bearing 4341 .

[0100] <1-4-3-5. Sealing member 435>

[0101] The sealing member 435 is disposed in the opening 4331 of the plate portion 433. The electric motor 100 includes an annular sealing member 435. The sealing member 435 is disposed between the second shaft 23 and the plate portion 433 in the opening 4331, and seals the space between them. The radially inner end of the plate portion 433, along the outer edge of the opening 4331, contacts the radially outer side surface of the second shaft 23 of the shaft 2 via the sealing member 435. The radially outer end of the sealing member 435 contacts the radially inner inner circumferential surface of the opening 4331. The radially inner end of the sealing member 435 contacts the radially outer side surface of the second shaft 23. By sealing the opening 4331 with the sealing member 435, wear powder generated by the static eliminator 7 disposed on one axial end surface of the plate portion 433 is prevented from entering the axially opposite side of the plate portion 433 through the opening 4331. Therefore, wear powder is prevented from entering the interior of the housing 4 that houses the stator 12 and other components. For example, wear powder can be prevented from entering the hollow portion 211 of the first shaft 21 through the second shaft through-hole 202. Therefore, wear powder can be prevented from entering the motor housing space 401 along with the flow of lubricating fluid CL in the hollow portion 211.

[0102] <1-4-4. Cover member 44>

[0103] The cover member 44 is disposed on one axial end surface of the plate portion 433. As previously described, the housing 4 includes the cover member 44. The cover member 44 covers the opening 4331 and the static eliminator 7. Specifically, the static eliminator 7 is housed within the storage space 440 defined by the plate portion 433 and the cover member 44. Wear powder from the conductive member 71 generated at the contact portion between the second shaft 23 of the shaft 2 and the conductive member 71 is contained within the storage space 440. This prevents the wear powder from scattering outside the storage space 440.

[0104] Furthermore, storage space 440 includes a lower space 4401 of a predetermined size. Lower space 4401 is positioned vertically below opening 4331 of plate 433. This allows wear powder generated at the contact point between second shaft 23 and static eliminator 7 to be stored in lower space 4401. By providing sufficient size for lower space 4401, wear powder accumulated in the lower portion of storage space 440 can be prevented from overflowing into the space between second shaft 23 and plate 433 in opening 4331.

[0105] The cover member 44 can be attached to the plate portion 433 by, for example, screw fastening, but is not limited thereto. In this embodiment, the cover member 44 and the plate portion 433 together form a storage space 440. The storage space 440 is a space enclosed by the cover member 44 and the plate portion 433, and houses the opening 4331 and the static elimination device 7.

[0106] The cover member 44 includes 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 arranged radially outward from the first cover portion 441. Specifically, the first cover portion 441 and the second cover portion 442 extend in a direction intersecting the first rotation axis J1. The first cover portion 441 is arranged axially on one side D1 relative to the opening portion 4331 and the static eliminator 7. Furthermore, the second cover portion 442 is arranged axially on the other side D2 relative to the first cover portion 441. The radially inner end of the second cover portion 442 is connected to the radially outer end of the first cover portion 441, and the radially outer end of the second cover portion 442 is connected to one axial end surface of the plate portion 433. The lower space 4401 is arranged between the plate portion 433 and the second cover portion 442. Thus, the second cover portion 442 is arranged axially on the other side D2 relative to the first cover portion 441, thereby saving space in the housing 4 in the axial direction. Furthermore, a portion of the space between the plate portion 433 and the second cover portion 442 can be used as a lower space 4401 for accumulation of wear powder.

[0107] Furthermore, the cover member 44 has a through hole 443, a cylindrical portion 444, and a filter 445. The through hole 443 connects the storage space 440 to the outside. Figure 1 However, the configuration of the through hole 443 is not limited to Figure 1 443 can be provided in at least one of the first cover portion 441 and the second cover portion 442. The cylindrical portion 444 extends axially from the outer edge of the cylindrical portion 444. The interior of the cylindrical portion 444 communicates with the through-hole 443. The filter 445 is mounted on the front end of the cylindrical portion 444. The storage space 440 communicates with the exterior via the through-hole 443 and the filter 445.

[0108] <1-4-5. Second Housing Cylinder 45>

[0109] The second outer cylindrical portion 45 is cylindrical and extends in the axial direction. The power transmission device 3 is arranged inside the second outer cylindrical portion 45. One axial end of the second outer cylindrical portion 45 is connected to the side plate portion 42 and covered by the side plate portion 42.

[0110] <1-4-6. Gear Cover 46>

[0111] The gear cover portion 46 extends in a direction intersecting the first rotation axis J1 and can be detachably mounted on the other axial end portion of the second outer shell cylinder portion 45. In the present embodiment, the second outer shell cylinder portion 45 and the gear cover portion 46 are different parts of a component. However, this is not limited to the above example, and the second outer shell cylinder portion 45 and the gear cover portion 46 can also be different components. In addition, the installation of the gear cover portion 46 to the second outer shell cylinder portion 45 can be, for example, fixed by screws, but it is not limited to this, and methods such as screwing in and pressing in can be widely used to firmly fix the gear cover portion 46 to the second outer shell cylinder portion 45. As a result, the gear cover portion 46 can be in close contact with the other axial end portion of the second outer shell cylinder portion 45.

[0112] The gear cover 46 has a second output shaft through-hole 460. The center of the second output shaft through-hole 460 is aligned 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 output shaft Ds and the second output shaft through-hole 460.

[0113] The gear cover 46 also includes bearing retaining portions 461, 462, and 463. These bearing retaining portions 461, 462, and 463 are located on one axial end surface of the gear cover 46 within the gear housing space 402. Bearing retaining portion 461 retains bearing 4611. Bearing retaining portion 462 retains second intermediate bearing 4621. Bearing retaining portion 463 is located along the outer edge of one axial end of the second output shaft through hole 460 and retains second output bearing 4631.

[0114] The gear cover 46 also includes a receiving tray 464 and an oil passage 465. The receiving tray 464 is located on one axial end surface of the gear cover 46 and has a recessed portion that is recessed vertically downward. Lubricating fluid CL lifted by the ring gear 321 is stored in the receiving tray 464. The oil passage 465 is a pathway for the lubricating fluid CL, connecting the receiving tray 464 with the inlet 213 of the shaft 2. The lubricating fluid CL stored in the receiving tray 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.

[0115] <1-4-7. Modification of the housing 4>

[0116] Next, refer to Figure 7 Modifications of the housing 4 will be described. Figure 7 Schematic diagram showing a modified example of the housing 4. Figure 7 This is just a conceptual diagram, and the configuration and size of each part are not necessarily the same as those of the actual motor 100. Figure 7 and Figure 2 The dotted line portion Y in FIG.

[0117] like Figure 7 As shown, the housing 4 may also have an adhesive member 47 with adhesive properties. In the present embodiment, the adhesive member 47 is in the form of a sheet, which is adhered to the surface of one axial end face of the plate portion 433 and the surface of the other axial side D2 of the cover member 44 in the storage space 440. However, it is not limited to the above example, and the adhesive member 47 may also be adhered to one of the surfaces of one axial end face of the plate portion 433 and the surface of the other axial side D2 of the cover member 44 in the storage space 440. That is, the adhesive member 47 only needs to be arranged between the plate portion 433 and the cover member 44 on at least one of the plate portion 433 and the cover member 44. In addition, it is preferred that the adhesive member 47 is arranged in at least the lower space 4401. In this way, by making the wear powder adhere to the adhesive member 47, the wear powder can be suppressed or prevented from floating in the storage space 440 between the plate portion 433 and the cover member 44. Therefore, the static elimination device 7 can be suppressed or prevented from being covered with wear powder. In addition, Figure 7 The example does not exclude a structure in which the adhesive member 47 is not arranged in the storage space 440.

[0118] <1-5. Liquid Circulation Unit 6>

[0119] Next, the liquid circulation unit 6 will be described. The liquid circulation unit 6 includes a piping unit 61 , a pump 62 , an oil cooler 63 , and a motor oil reservoir 64 .

[0120] The piping section 61 connects the pump 62 to the motor oil reservoir 64 located within the first housing cylindrical portion 41, supplying lubricating fluid CL to the motor oil reservoir 64. The pump 62 draws the lubricating fluid CL stored in the lower region of the gear unit housing space 402. The pump 62 is an electric pump, but is not limited thereto. For example, it may be driven by a portion of the power of the shaft 2 of the motor 100.

[0121] The oil cooler 63 is disposed between the pump 62 of the piping section 61 and the motor oil reservoir 64. Specifically, the lubricating fluid CL pumped by the pump 62 passes through the piping section 61, through the oil cooler 63, and then to the motor oil reservoir 64. For example, a refrigerant such as water supplied from an external source is supplied to the oil cooler 63. The oil cooler 63 exchanges heat between the refrigerant and the lubricating fluid CL to reduce the temperature of the lubricating fluid CL.

[0122] The motor oil reservoir 64 is a tray located vertically above the stator 12 within the motor housing space 401. A drip hole is formed at the bottom of the motor oil reservoir 64, through which lubricating liquid CL drips, cooling the motor 1. The drip hole is formed, for example, above the coil end 1221 of the coil portion 122 of the stator 12, allowing the coil portion 122 to be cooled by the lubricating liquid CL.

[0123] <2. Other>

[0124] The above describes the embodiments of the present invention. The scope of the present invention is not limited by the above embodiments. The present invention can be implemented with various modifications to the above embodiments without departing from the spirit of the invention. Furthermore, the matters described in the above embodiments can be appropriately combined in any manner without causing any contradiction.

[0125] Industrial applicability

[0126] The present invention is useful in devices for grounding a shaft.

Claims

1. An electric motor, comprising: a shaft extending in an axial direction along a rotation axis parallel to the horizontal direction; a rotor supported by the shaft and rotatable together with the shaft; a stator, the stator being arranged radially outward of the rotor; a housing for housing the rotor and the stator; as well as a static eliminator having a conductive member in contact with a radially outer side surface of the shaft, The conductive member contacts a region of the radially outer side surface of the shaft that faces in any one of the vertically upward direction, the vertically obliquely upward direction, and the horizontal direction when viewed from the axial direction. When viewed from the axial direction, the static eliminating device is arranged on one side and the other side of the contact portion between the shaft and the conductive member in a direction perpendicular to the axial direction and parallel to the horizontal direction, and on the vertically upper side of the contact portion. When viewed from the axial direction, the static eliminating device is further arranged at one of the side and the other side of the rotation axis in the parallel direction and at a position vertically obliquely above the rotation axis. The first circumferential angular position is a circumferential angular position of the radially outer side surface of the shaft that faces the horizontal direction in a horizontal plane passing through the rotation axis when viewed from the axial direction. The second circumferential angular position is a circumferential angular position on the radially outer side surface of the shaft that faces vertically upward when viewed from the axial direction. The third circumferential angular position is a circumferential angular position of the radially outer side surface of the shaft that is in the horizontal plane passing through the rotation axis when viewed from the axial direction and that faces the other side of the horizontal direction. The conductive member contacts a region of the radially outer side surface of the shaft over a circumferential range of 180° from the first circumferential angular position through the second circumferential angular position to the third circumferential angular position when viewed in the axial direction.

2. The electric motor according to claim 1, wherein: The housing also has: a plate portion having electrical conductivity and extending in a radial direction; and a cover member, the cover member being arranged on one axial end surface of the plate portion, The plate portion is provided with an opening portion through which the shaft is inserted. The static eliminating device is accommodated in an accommodation space surrounded by the plate portion and the cover member.

3. The electric motor according to claim 2, wherein: The plate portion is arranged at an axially closer position than the stator. The storage space includes a lower space of a predetermined size arranged vertically below the opening.

4. The electric motor according to claim 3, wherein: The cover member has: a first cover portion, the first cover portion covering the static elimination device; and a second cover portion, the second cover portion being arranged radially outward of the first cover portion, The second cover portion is arranged at the other side of the axial direction than the first cover portion. The lower space is disposed between the plate portion and the second cover portion.

5. The electric motor according to claim 2, wherein: Also includes an annular sealing member, A radially inner end portion of the plate portion along an outer edge portion of the opening portion is in contact with a radially outer side surface of the shaft via the sealing member.

6. The electric motor according to claim 2, wherein: The housing also has an adhesive member having adhesive properties. The adhesive member is disposed between the plate portion and the cover member on at least one of the plate portion and the cover member.

7. The electric motor according to claim 2, wherein: The static elimination device also has: a holding member that holds the conductive member; and At least one fixing member that fixes the holding member to at least one of the plate portion and the cover member.

8. The electric motor according to claim 7, wherein: At least one of the fixing members is fixed to the plate portion, The plate portion also has ribs protruding along the axial direction. The rib extends in a direction away from a fixing portion of the plate portion to which the fixing member is fixed.

9. The electric motor according to any one of claims 1 to 8, wherein: The static eliminating device further includes an elastic member that presses the conductive member toward the shaft.

10. An electric motor, comprising: a shaft extending in an axial direction along a rotation axis parallel to the horizontal direction; a rotor supported by the shaft and rotatable together with the shaft; a stator, the stator being arranged radially outward of the rotor; a housing for housing the rotor and the stator; as well as a static eliminator having a conductive member in contact with a radially outer side surface of the shaft, The conductive member contacts a region of the radially outer side surface of the shaft that faces in any one of the vertically upward direction, the vertically obliquely upward direction, and the horizontal direction when viewed from the axial direction. When viewed from the axial direction, the static eliminating device is arranged on one side and the other side of the contact portion between the shaft and the conductive member in a direction perpendicular to the axial direction and parallel to the horizontal direction, and on the vertically upper side of the contact portion. When viewed from the axial direction, the static eliminating device is further arranged at one of the side and the other side of the rotation axis in the parallel direction and at a position vertically obliquely above the rotation axis. The housing also has: a plate portion having electrical conductivity and extending in a radial direction; and a cover member, the cover member being arranged on one axial end surface of the plate portion, The plate portion is provided with an opening portion through which the shaft is inserted. The static elimination device is accommodated in an accommodation space surrounded by the plate portion and the cover member. The plate portion is arranged at an axially closer position than the stator. The storage space includes a lower space of a predetermined size arranged vertically below the opening. The cover member has: a first cover portion, the first cover portion covering the static elimination device; and a second cover portion, the second cover portion being arranged radially outward of the first cover portion, The second cover portion is arranged at the other side of the axial direction than the first cover portion. The lower space is disposed between the plate portion and the second cover portion.

11. The electric motor according to claim 10, wherein Also includes an annular sealing member, A radially inner end portion of the plate portion along an outer edge portion of the opening portion is in contact with a radially outer side surface of the shaft via the sealing member.

12. The electric motor according to claim 10, wherein: The static elimination device also has: a holding member that holds the conductive member; and At least one fixing member that fixes the holding member to at least one of the plate portion and the cover member.

13. The electric motor according to claim 10, wherein: The static eliminating device further includes an elastic member that presses the conductive member toward the shaft.

14. An electric motor, comprising: a shaft extending in an axial direction along a rotation axis parallel to the horizontal direction; a rotor supported by the shaft and rotatable together with the shaft; a stator, the stator being arranged radially outward of the rotor; a housing for housing the rotor and the stator; as well as a static eliminator having a conductive member in contact with a radially outer side surface of the shaft, The conductive member contacts a region of the radially outer side surface of the shaft that faces in any one of the vertically upward direction, the vertically obliquely upward direction, and the horizontal direction when viewed from the axial direction. When viewed from the axial direction, the static eliminating device is arranged on one side and the other side of the contact portion between the shaft and the conductive member in a direction perpendicular to the axial direction and parallel to the horizontal direction, and on the vertically upper side of the contact portion. When viewed from the axial direction, the static eliminating device is further arranged at one of the side and the other side of the rotation axis in the parallel direction and at a position vertically obliquely above the rotation axis. The housing also has: a plate portion having electrical conductivity and extending in a radial direction; and a cover member, the cover member being arranged on one axial end surface of the plate portion, The plate portion is provided with an opening portion through which the shaft is inserted. The static elimination device is accommodated in an accommodation space surrounded by the plate portion and the cover member. The housing also has an adhesive member having adhesive properties. The adhesive member is disposed between the plate portion and the cover member on at least one of the plate portion and the cover member.

15. The electric motor according to claim 14, wherein Also includes an annular sealing member, A radially inner end portion of the plate portion along an outer edge portion of the opening portion is in contact with a radially outer side surface of the shaft via the sealing member.

16. The electric motor according to claim 14, wherein The static elimination device also has: a holding member that holds the conductive member; and At least one fixing member that fixes the holding member to at least one of the plate portion and the cover member.

17. The electric motor according to claim 14, wherein: The static eliminating device further includes an elastic member that presses the conductive member toward the shaft.

18. An electric motor, comprising: a shaft extending in an axial direction along a rotation axis parallel to the horizontal direction; a rotor supported by the shaft and rotatable together with the shaft; a stator, the stator being arranged radially outward of the rotor; a housing for housing the rotor and the stator; as well as a static eliminator having a conductive member in contact with a radially outer side surface of the shaft, The conductive member contacts a region of the radially outer side surface of the shaft that faces in any one of the vertically upward direction, the vertically obliquely upward direction, and the horizontal direction when viewed from the axial direction. When viewed from the axial direction, the static eliminating device is arranged on one side and the other side of the contact portion between the shaft and the conductive member in a direction perpendicular to the axial direction and parallel to the horizontal direction, and on the vertically upper side of the contact portion. When viewed from the axial direction, the static eliminating device is further arranged at one of the side and the other side of the rotation axis in the parallel direction and at a position vertically obliquely above the rotation axis. The housing also has: a plate portion having electrical conductivity and extending in a radial direction; and a cover member, the cover member being arranged on one axial end surface of the plate portion, The plate portion is provided with an opening portion through which the shaft is inserted. The static elimination device is accommodated in an accommodation space surrounded by the plate portion and the cover member. The static elimination device also has: a holding member that holds the conductive member; and at least one fixing member that fixes the holding member to at least one of the plate portion and the cover member, At least one of the fixing members is fixed to the plate portion, The plate portion also has ribs protruding along the axial direction. The rib extends in a direction away from a fixing portion of the plate portion to which the fixing member is fixed.

19. The electric motor according to claim 18, wherein Also includes an annular sealing member, A radially inner end portion of the plate portion along an outer edge portion of the opening portion is in contact with a radially outer side surface of the shaft via the sealing member.

20. The electric motor of claim 18, wherein: The static eliminating device further includes an elastic member that presses the conductive member toward the shaft.

Images