JP2023035182A - Motor, and electric bike including the same - Google Patents

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

The present invention relates to a motor and an electric motorcycle equipped with the same.

A conventional motor has, 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 that rotatably supports the rotating shaft. The bearing is held by the front cover via a cylindrical holding portion. An oil seal and a dust lip are provided on the opening inner peripheral wall of the front cover arranged axially outside the bearing. As a result, it is possible to prevent water, dust, and the like from adhering to the bearing (see, for example, Patent Document 1).

JP-A-2003-52145

However, in the conventional motor, the provision of the dust lip or the like increases the number of parts, which may increase the manufacturing cost.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a motor capable of suppressing an increase in the number of parts, reducing manufacturing costs, and suppressing adhesion of water, dust, and the like to bearing portions.

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 part has a tubular rim, a cover and a bearing. The cover covers at least one of one axial end surface and the other axial end surface of the rim. The bearing rotatably supports the cover with respect to the shaft. The cover has a body portion and a holding portion. The main body portion has a cylindrical portion that penetrates in the axial direction, and has a plate shape. The holding portion is formed of a member separate from the main body portion, is arranged on the inner peripheral surface of the tubular portion, holds the bearing portion inside, and has a tubular shape. The holding part has a protrusion. The protruding portion protrudes radially inward from the inner peripheral surface and covers the axial outer surface of the bearing portion. A radially inner end of the protruding portion is located radially inward of the inner peripheral surface of the cylindrical portion.

According to the present exemplary embodiment, it is possible to provide a motor capable of suppressing an increase in the number of parts, reducing manufacturing costs, and suppressing adhesion of water, dust, and the like to bearing portions.

FIG. 1 is a schematic diagram of an electric motorcycle according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line AA of FIG. FIG. 3 is a cross-sectional view showing an enlarged holding portion of the motor according to the embodiment of the present invention. FIG. 4 is an explanatory view explaining the manufacturing process of the motor cover according to the embodiment of the present invention.

Exemplary embodiments of the invention are described in detail below with reference to the drawings. In this specification, the direction parallel to the central axis of the motor is referred to as "axial direction," the direction orthogonal to the central axis of the motor is referred to as "radial direction," and the direction along an arc around the central axis of the motor is referred to as "circumferential direction." direction”, respectively. A central axis J of the motor mounted on the vehicle extends in the left-right direction of the vehicle.

Further, in the present application, the term “parallel direction” includes substantially parallel directions. In addition, in the present application, the term “perpendicular direction” includes a substantially perpendicular direction.

(1. Configuration of electric motorcycle)
An electric motorcycle 1 according to an exemplary embodiment of the invention will be described. FIG. 1 is a schematic diagram of an electric motorcycle 1 according to an embodiment of the present invention.

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

The front wheel 2 and rear wheel 3 are a pair of wheels. A front wheel 2 and a rear wheel 3 are attached to the vehicle body 4 . A handle 5 is attached to the front portion of the vehicle body 4 .

The ECU 6 is arranged 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 adjusting mechanism.

The battery 8 is arranged inside the vehicle body 4 . Battery 8 is connected to ECU 6 . Battery 8 is charged by charger 9 .

A motor 10 is attached to the rear wheel 3 . The motor 10 is connected to the ECU6.

(2. Configuration of motor)
FIG. 2 is a cross-sectional view taken along line AA in FIG. The motor 10 has a fixed portion 20 and a rotating portion 30 .

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

The stator 22 has an annular shape. The center of the stator 22 coincides with the central axis J of the motor 10 . The stator 22 has a stator core 221 , insulators (not shown), and coils 223 .

The stator core 221 is configured by laminating magnetic steel plates in the axial direction, for example. 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 surrounds the central axis J and is formed in an annular shape. The teeth 221b extend radially outward from the radial outer surface of the core back 221a and are arranged at regular intervals in the circumferential direction.

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 and coil 223 . An insulator is attached to each tooth 221b.

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

The holder 23 is a disk-shaped pressed product, and the stator 22 is fixed to the outer peripheral portion of the holder 23 . The holder 23 has a holder through hole 23a passing through along the central axis J. As shown in FIG. For example, the shaft 21 is press-fitted into the holder through-hole 23a, and the holder 23 and the shaft 21 are fixed. Thereby, the stator 22 is fixed to the shaft 21 via the holder 23 .

(2-2. Rotating part)
The rotating portion 30 rotates relative to the fixed portion 20 . The rotating part 30 rotates about the central axis J. As shown in FIG. The rotating portion 30 has a tubular rim 31 , a magnet 32 , a cover 33 and a pair of bearings 34 .

The rim 31 is a tubular casting. The rim 31 has a rim body portion 31a and a rim flange portion 31b. The rim main body portion 31a is formed in a cylindrical shape, and a magnet 32 is arranged on the inner peripheral surface thereof. The tire 3a is arranged on the outer peripheral surface of the rim body portion 31a. The rim flange portion 31b branches axially from the peripheral surface of the rim body portion 31a and extends radially outward. The rim flange portion 31b axially sandwiches and holds the tire 3a.

A plurality of magnets 32 are arranged radially outward of the stator 22 with gaps therebetween. A plurality of magnets 32 are arranged on the inner peripheral surface of the rim 31 such that N poles and S poles are alternately arranged in the circumferential direction. The magnet 32 is configured by, for example, a rectangular parallelepiped permanent magnet.

The cover 33 covers at least one of one axial end surface and the other axial end surface of the rim 31 . The cover 33 of the present embodiment covers both end surfaces of the rim 31 in the axial direction. The cover 33 is, for example, a wheel cover.

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

The holding portion 332 is formed of a separate member from the cover main body portion (main body portion) 331 and has a tubular shape. The holding portion 332 is arranged on the inner peripheral surface of the cylindrical portion 331a and holds the bearing portion 34 inside. The bearing portion 34 rotatably supports the cover 33 with respect to the shaft 21 .

(3. Structure of holding part)
FIG. 3 is a cross-sectional view showing the holding portion 332 in an enlarged manner. The holding portion 332 has a projecting portion 332a. The protruding portion 332 a protrudes radially inward from the inner peripheral surface of the holding portion 332 and covers the axial outer surface of the bearing portion 34 . A radially inner end of the projecting portion 332a is positioned radially inward of the inner peripheral surface of the cylindrical portion 331a. As a result, at least a portion of the axial outer surface of the bearing portion 34 is covered with the projecting portion 332a. Therefore, it is possible to prevent water, dust, and the like from entering the cylindrical portion 331 a from the axially outer open end and adhering to the axially outer surface of the bearing portion 34 . Further, by providing the protrusion 332a on the holding portion 332 that holds the bearing portion 34, an increase in the number of parts can be suppressed and the manufacturing cost of the motor 10 can be reduced.

In addition, the projecting portion 332 a contacts 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 of the stator 22 in the axial direction.

As a result, it is possible to further prevent water, dust, and the like from entering between the projecting portion 332 a and the bearing portion 34 and adhering to the bearing portion 34 . In addition, the bearing portion 34 can be prevented from moving outward in the axial direction within the holding portion 332 by the protrusion portion 332 a coming into contact with the axial outer surface of the bearing portion 34 . In this embodiment, the axially outer side is the side away from the stator 22 in the axial direction. That is, even if the bearing portion 34 moves in the axial direction, the surface of the protruding portion 332a that faces the bearing portion 34 in the axial direction contacts the axial outer surface of the bearing portion 34. can be prevented.

Moreover, the projecting portion 332 a is formed in an annular shape and surrounds the shaft 21 . In addition, the radially inner end of the projecting portion 332 a is located radially inward of the outer ring 34 a of the bearing portion 34 . As a result, the bearing portion 34 has a wider area covered by the protruding portion 332a, and the attachment of water, dust, and the like to the bearing portion 34 can be further suppressed.

In addition, the cylindrical portion 331a has a projection portion 331b. The protruding portion 331b protrudes radially inward from the inner peripheral surface of the cylindrical portion 331a and contacts the axial outer surface of the protruding portion 332a. As a result, the inside of the cylindrical portion 331a is narrowed, and the entry of water, dust, etc. into the bearing portion 34 side can be further suppressed. Moreover, it is possible to prevent the bearing portion 34 from moving axially outward together with the holding portion 332 .

Further, the sealing member 40 is arranged axially outside the projecting portion 332a, and the inside of the cylindrical portion 331a is covered with the sealing member 40. As shown in FIG. The sealing 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 sealing member 40, it is possible to further suppress water, dust, etc., entering the inside from the open end in the axial direction of the cylindrical portion 331a from entering the bearing portion 34 side.

4A and 4B are explanatory diagrams for explaining the manufacturing process of the cover 33. FIG. 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 a die-cast member is poured into a mold (not shown) in which the holding portion 332 is held, and the cover main body portion (body portion) 331 and the holding portion 332 are integrally formed. to mold.

At this time, the radially inner end of the protruding portion 332a is positioned radially inward of the inner peripheral surface of the cylindrical portion 331a, so that the protruding portion 332a is moved axially ( The holding portion 332 can be pressed against the mold by pressing in the arrow direction). Accordingly, it is possible to prevent the holding portion 332 from being axially misaligned with respect to the cover main body portion (main body portion) 331 during insert molding.

(5. Others)
The above embodiments are merely examples of the present invention. The configuration of the embodiment may be changed as appropriate without departing from the technical idea of the present invention. Also, the embodiments may be implemented in combination within a possible range. In this embodiment, the projecting portion 332a is formed in an annular shape, but is not limited to an annular shape. For example, it may partially protrude radially inward from the inner peripheral surface of the holding portion 332 .

The motor of the present invention can be used, for example, in electric motorcycles.

REFERENCE SIGNS LIST 1 electric motorcycle 2 front wheel 3 rear wheel 3a tire 4 vehicle body 5 steering wheel 6 ECU (electronic control unit)
7 Throttle 8 Battery 9 Charger 10 Motor 20 Fixed Part 21 Shaft 22 Stator 23 Holder 23a Holder Penetration Hole 30 Rotating Part 31 Rim 31a Rim Body 31b Rim Flange 32 Magnet 33 Cover 34 Bearing 34a Outer Ring 40 Sealing Member 221 Stator Core 221a Core back 221b Teeth 223 Coil 331 Cover body 331a Cylindrical portion 331b Protruding portion 332 Holding portion 332a Protruding portion J Central axis P Pin

Claims (7)

a fixed portion including a shaft extending along a central axis;
a rotating part that rotates relative to the fixed part,
The rotating part is
a tubular rim;
a cover that covers at least one of one end surface and the other end surface of the rim in the axial direction;
a bearing portion that rotatably supports the cover with respect to the shaft;
The cover is
a plate-shaped main body having a cylindrical portion that penetrates in the axial direction;
a cylindrical holding portion which is formed of a separate member from the main body portion and which is arranged on the inner peripheral surface of the cylindrical portion and holds the bearing portion therein;
The holding portion has a protrusion that protrudes radially inward from the inner peripheral surface and covers the axial outer surface of the bearing,
The motor, wherein the radially inner end of the projecting portion is located radially inwardly of the inner peripheral surface of the cylindrical portion. 2. The motor of claim 1, wherein the protrusion contacts an axially outer surface of the bearing. 3. A motor according to claim 1 or claim 2, wherein the projection is annularly formed and surrounds the shaft. 4. The motor according to any one of claims 1 to 3, wherein the radially inner end of the projecting portion is located radially inwardly of the outer ring of the bearing portion. 5. The motor according to any one of claims 1 to 4, wherein the tubular portion has a protrusion that protrudes radially inward from an inner peripheral surface and contacts an axial outer surface of the protrusion. 6. The motor according to any one of claims 1 to 5, wherein the inside of said cylindrical portion is covered with a seal member arranged axially outside said projecting portion. 7. The motor according to any one of claims 1 to 6, wherein the body portion is made of a die-cast member.

Images