Motor and electric bike equipped with the same

Abstract

To provide a motor capable of preventing water, dust, and like from adhering to bearings while reducing the manufacturing cost by suppressing the increase in the number of parts.SOLUTION: The motor includes: a fixed part 20 that has a shaft 21 extending along a central axis J; and a rotating part 30 that rotates relative to the fixed part. The rotating part has a tubular rim, a cover 33, and a bearing 34. The cover covers at least one of the one end face or the other end face in the axial direction of the rim. The bearing supports the cover rotatably against the shaft. The cover has a main body 331 and a holding part 332. The plate-like main body has a cylindrical portion 331a penetrating in the axial direction. The cylindrical holding part is constituted of the main body and another member and is arranged on the inner peripheral surface of the cylindrical part and holds the bearing part inside. The holding part has a protrusion 332a. The protrusion protrudes radially inward from the inner peripheral surface and covers the outer surface of the bearing portion in the axial direction. The radially inner end of the protrusion is located radially inward from the inner peripheral surface of the tube.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a motor and an electric motorcycle equipped with the same. [Background technology]

[0002] A conventional motor includes, for example, a rotating shaft, a cylindrical motor case, a front cover that covers one axial end face of the motor case, and a bearing (bearing portion) that rotatably supports the rotating shaft. The bearing is held in the front cover via a cylindrical holder. An oil seal and a dust lip are provided on the inner peripheral wall of the opening in the front cover, which is located axially outside the bearing. This prevents water, dust, and the like from adhering to the bearing (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-52145 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in conventional motors, providing a dust lip or the like increases the number of parts, which can increase manufacturing costs.

[0005] An object of the present invention is to provide a motor that can reduce manufacturing costs by suppressing an increase in the number of parts, and that can suppress adhesion of water, dust, etc. to the bearing portion. [Means for solving the problem]

[0006] An exemplary motor of the present invention comprises a fixed portion including a shaft extending along a central axis, and a rotating portion that rotates relative to the fixed portion. The rotating portion has a cylindrical rim, a cover, and a bearing portion. The cover covers at least one of one axial end face or the other axial end face of the rim. The bearing portion supports the cover rotatably relative to the shaft. The cover has a main body portion and a retaining portion. The main body portion is plate-shaped and has a cylindrical portion that penetrates in the axial direction. The retaining portion is formed as a separate member from the main body portion, is disposed on the inner circumferential surface of the cylindrical portion, and retains the bearing portion therein. The retaining portion has a protruding portion. The protruding portion protrudes radially inward from the inner circumferential surface and covers the axial outer surface of the bearing portion. The radially inner end of the protruding portion is located radially inward of the inner circumferential surface of the cylindrical portion. [Effects of the Invention]

[0007] According to the exemplary embodiment of the present invention, it is possible to provide a motor that can reduce manufacturing costs by suppressing an increase in the number of parts, and that can suppress adhesion of water, dust, etc. to the bearing portion. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram of an electric motorcycle according to an embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view taken along line AA in FIG. [Figure 3] FIG. 3 is an enlarged cross-sectional view showing a holding portion of the motor according to the embodiment of the present invention. [Figure 4] FIG. 4 is an explanatory diagram illustrating a manufacturing process of the motor cover according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. In this specification, the direction parallel to the central axis of the motor is referred to as the "axial direction," the direction perpendicular to the central axis of the motor is referred to as the "radial direction," and the direction along the arc centered on the central axis of the motor is referred to as the "circumferential direction." The central axis J of the motor mounted on a vehicle extends in the left-right direction of the vehicle.

[0010] In the present application, the term "parallel direction" includes a direction that is substantially parallel to the other, and the term "perpendicular direction" includes a direction that is substantially perpendicular to the other.

[0011] (1. Electric bike configuration) An electric motorcycle 1 according to an exemplary embodiment of the present invention will now be described. Fig. 1 is a schematic diagram of an electric motorcycle 1 according to an embodiment of the present invention.

[0012] The electric motorcycle 1 includes a front wheel 2, a rear wheel 3, a body 4, a handlebar 5, an ECU (electronic control unit) 6, a throttle 7, a battery 8, and a motor 10.

[0013] The front wheel 2 and the rear wheel 3 are a pair of wheels. The front wheel 2 and the rear wheel 3 are attached to a vehicle body 4. A handlebar 5 is attached to the front of the vehicle body 4.

[0014] The ECU 6 is disposed inside the vehicle body 4. The ECU 6 is a control device. A throttle 7 is connected to the ECU 6. The throttle 7 is a speed adjustment mechanism.

[0015] The battery 8 is disposed inside the vehicle body 4. The battery 8 is connected to the ECU 6. The battery 8 is charged by a charger 9.

[0016] The motor 10 is attached to the rear wheel 3. The motor 10 is connected to the ECU 6.

[0017] (2. Motor configuration) Fig. 2 is a cross-sectional view taken along line AA in Fig. 1. The motor 10 includes a fixed part 20 and a rotating part 30.

[0018] (2-1. Fixed part) The fixed portion 20 includes a shaft 21, a stator 22, and a holder 23. The shaft 21 extends along a central axis J. The shaft 21 is made of, for example, metal.

[0019] The stator 22 is annular in shape. The center of the stator 22 coincides with the central axis J of the motor 10. The stator 22 includes a stator core 221, an insulator (not shown), and a coil 223.

[0020] The stator core 221 is formed, for example, by stacking magnetic steel plates in the axial direction. The stator core 221 has a core back 221a and teeth 221b. The core back 221a and the teeth 221b are integrally formed. The core back 221a is formed in an annular shape surrounding the central axis J. The teeth 221b extend radially outward from the radial outer surface of the core back 221a and are arranged at equal intervals in the circumferential direction.

[0021] An insulator (not shown) covers at least a portion of stator core 221. The insulator is an insulating member that electrically insulates stator core 221 from coil 223. The insulator is attached to each tooth 221b.

[0022] The coils 223 excite the stator core 221. The coils 223 are formed by winding a conductive wire (not shown) around each tooth 221b via an insulator. A plurality of the coils 223 are arranged in the circumferential direction.

[0023] The holder 23 is a disk-shaped pressed product, and the stator 22 is fixed to the outer periphery of the holder 23. The holder 23 has a holder through-hole 23a that penetrates along the central axis J. For example, the shaft 21 is press-fitted into the holder through-hole 23a, and the holder 23 and the shaft 21 are fixed together. In this way, the stator 22 is fixed to the shaft 21 via the holder 23.

[0024] (2-2. Rotating part) The rotating part 30 rotates relative to the fixed part 20. The rotating part 30 rotates around a central axis J. The rotating part 30 has a cylindrical rim 31, a magnet 32, a cover 33, and a pair of bearing parts 34.

[0025] The rim 31 is a cylindrical casting. The rim 31 has a rim main body portion 31a and a rim flange portion 31b. The rim main body portion 31a is formed in a cylindrical shape, with a magnet 32 ​​arranged on its inner circumferential surface. The tire 3a is arranged on the outer circumferential surface of the rim main body portion 31a. The rim flange portion 31b branches off in the axial direction from the circumferential surface of the rim main body portion 31a and extends radially outward. The rim flange portion 31b holds the tire 3a by clamping it in the axial direction.

[0026] A plurality of magnets 32 are arranged with gaps between them on the radially outer side of the stator 22. A plurality of magnets 32 are arranged on the inner peripheral surface of the rim 31 so that north poles and south poles are alternately arranged in the circumferential direction. The magnets 32 are, for example, made of rectangular parallelepiped permanent magnets.

[0027] The cover 33 covers at least one of one end face or the other end face in the axial direction of the rim 31. The cover 33 of this embodiment covers both end faces in the axial direction of the rim 31. The cover 33 is, for example, a wheel cover.

[0028] The cover 33 has a cover main body (main body) 331 and a holding portion 332. The cover main body 331 is disk-shaped and has a cylindrical portion 331a. The cylindrical portion 331a surrounds the central axis J and penetrates in the axial direction.

[0029] The holding portion 332 is cylindrical and is made of a separate member from the cover main body (main body) 331. The holding portion 332 is disposed on the inner circumferential surface of the cylindrical portion 331a and holds the bearing portion 34 therein. The bearing portion 34 supports the cover 33 rotatably with respect to the shaft 21.

[0030] (3. Structure of the holding part) FIG. 3 is an enlarged cross-sectional view of the retaining portion 332. The retaining portion 332 has a protrusion 332a. The protrusion 332a protrudes radially inward from the inner circumferential surface of the retaining portion 332 and covers the axially outer surface of the bearing portion 34. The radially inner end of the protrusion 332a is located radially inward of the inner circumferential surface of the cylindrical portion 331a. This allows at least a portion of the axially outer surface of the bearing portion 34 to be covered by the protrusion 332a. This prevents water, dust, and the like from entering the interior through the axially outer open end of the cylindrical portion 331a and adhering to the axially outer surface of the bearing portion 34. Furthermore, providing the protrusion 332a on the retaining portion 332 that retains the bearing portion 34 prevents an increase in the number of parts, thereby reducing the manufacturing cost of the motor 10.

[0031] Furthermore, the protrusion 332a comes into contact with the axial outer surface of the bearing portion 34. In this embodiment, the axial outer surface of the bearing portion 34 is the outer surface of the bearing portion 34 located on the opposite side from the stator 22 in the axial direction.

[0032] This further prevents water, dust, and the like from entering between the protruding portion 332a and the bearing portion 34 and adhering to the bearing portion 34. Furthermore, the protruding portion 332a comes into contact with the axial outer surface of the bearing portion 34, thereby preventing the bearing portion 34 from moving axially outward within the holding portion 332. In this embodiment, the axial outer side refers to the side that moves away from the stator 22 in the axial direction. In other words, even if the bearing portion 34 moves axially, the surface of the protruding portion 332a that faces the bearing portion 34 in the axial direction comes into contact with the axial outer surface of the bearing portion 34, preventing the bearing portion 34 from moving axially.

[0033] Furthermore, the protruding portion 332a is formed in an annular shape and surrounds the shaft 21. Furthermore, the radially inner end of the protruding portion 332a is located radially inward of the outer ring 34a of the bearing portion 34. This increases the area of ​​the bearing portion 34 that is covered by the protruding portion 332a, thereby further preventing water, dust, and the like from adhering to the bearing portion 34.

[0034] The cylindrical portion 331a also has a protrusion 331b. The protrusion 331b protrudes radially inward from the inner circumferential surface of the cylindrical portion 331a and comes into contact with the axial outer surface of the protrusion 332a. This narrows the interior of the cylindrical portion 331a, further preventing water, dust, and the like from entering the bearing portion 34. This also prevents the bearing portion 34, together with the holding portion 332, from moving outward in the axial direction.

[0035] Furthermore, the seal member 40 is disposed axially outside the protrusion 332a, and the inside of the cylindrical portion 331a is covered with the seal member 40. The seal member 40 is, for example, an annular rubber cap, and is fixed inside the cylindrical portion 331a. The inner peripheral edge of the seal member 40 slides on the outer peripheral surface of the shaft 21. By providing the seal member 40, it is possible to further prevent water, dust, etc. that has entered the inside from the axial opening end of the cylindrical portion 331a from entering the bearing portion 34 side.

[0036] 4 is an explanatory diagram illustrating the manufacturing process of the cover 33. In this embodiment, the cover main body (main body) 331 is made of a die-cast member, and the holding portion 332 is made of a metal member such as iron. The cover 33 is an insert-molded product, and the cover main body (main body) 331 and the holding portion 332 are molded integrally by pouring a die-cast member into a mold (not shown) that holds the holding portion 332.

[0037] At this time, the radially inner end of the protruding portion 332a is located radially inward of the inner circumferential surface of the cylindrical portion 331a, so that inside the cylindrical portion 331a, the pin P can press the protruding portion 332a in the axial direction (the direction of the arrow in the figure) to press the holding portion 332 against the mold. This makes it possible to prevent the holding portion 332 from being molded axially misaligned with respect to the cover main body portion (main body portion) 331 during insert molding.

[0038] (5. Other) The above-described embodiment is merely an example of the present invention. The configuration of the embodiment may be appropriately modified without departing from the technical spirit of the present invention. Furthermore, the embodiments may be combined as far as possible. In this embodiment, the protrusion 332a is formed in an annular shape, but is not limited to an annular shape. For example, the protrusion 332a may partially protrude radially inward from the inner circumferential surface of the holding portion 332. [Industrial Applicability]

[0039] The motor of the present invention can be used in, for example, an electric motorcycle. [Explanation of symbols]

[0040] 1. Electric motorcycle 2 front wheels 3 rear wheels 3a tires 4. Body 5 Handle 6 ECU(electronic control unit) 7. Throttle 8 Battery 9 charger 10 Motor 20 Fixed part 21 Shaft 22 Stator 23 Holder 23a Holder through hole 30 Rotating part 31 rims 31a Rim body 31b Rim flange 32 Magnet 33 Cover 34 Bearing section 34a outer ring 40 sealing material 221 Stator Core 221a Coreback 221b Teeth 223 Coil 331 Cover body 331a Cylinder part 331b Protrusion 332 Maintenance Department 332a protrusion J Center axis P ピン

Claims

1. a fixed portion including a shaft extending along a central axis; a rotating portion that rotates relative to the fixed portion, The rotating part is A cylindrical rim and a cover that covers at least one of one end surface or the other end surface in the axial direction of the rim; a bearing portion that rotatably supports the cover relative to the shaft, The cover is a plate-shaped main body portion having a cylindrical portion penetrating therethrough in the axial direction; a cylindrical holding portion that is a separate member from the main body portion and is disposed on an inner circumferential surface of the cylindrical portion to hold the bearing portion therein; the retaining portion has a protruding portion that protrudes radially inward from an inner peripheral surface and covers an axially outer surface of the bearing portion, a radially inner end of the protruding portion positioned radially inward of an inner circumferential surface of the cylindrical portion;

2. The motor according to claim 1 , wherein the protrusion contacts an axially outer surface of the bearing portion.

3. The motor according to claim 1 or 2, wherein the protrusion is formed in an annular shape and surrounds the shaft.

4. 4. The motor according to claim 1, wherein a radially inner end of the protrusion is positioned radially inward of an outer ring of the bearing portion.

5. 5. The motor according to claim 1, wherein the cylindrical portion has a protrusion that protrudes radially inward from an inner peripheral surface and that comes into contact with an axially outer surface of the protrusion.

6. The motor according to any one of claims 1 to 5, wherein the inside of the cylindrical portion is covered with a seal member disposed axially outside the protruding portion.

7. The motor according to any one of claims 1 to 6, wherein the main body is made of a die-cast member.

Images