Motor and vehicle

Abstract

A motor and a vehicle are provided. The motor has a rotor having magnets arranged in a ring shape on an outer side in a radial direction of a center shaft extending in an up-down direction and rotatable about the center shaft, and a stator arranged on an inner side in the radial direction of the rotor opposite the magnets in the radial direction. The stator has a stator core having a ring-shaped core back and a plurality of teeth extending from the core back to an outer side in the radial direction, a winding arranged on the teeth, an insulating member covering an axial direction of the stator core and arranged between the teeth and the winding, and a spacer of a magnetic body arranged between the stator core and the insulating member in the axial direction. The spacer has a protruding portion arranged on an outer edge portion in the radial direction. The protruding portion extends in the axial direction to a direction away from the stator core and is opposite the magnets in the radial direction.

Description

Technical Field

[0001] This invention relates to motors and vehicles. Background Technology

[0002] Conventionally, in external rotor type motors, the stator core of the stator located radially inner and the magnet of the rotor located radially outer are arranged opposite each other in the radial direction. The stator core and the magnet have approximately the same length in the axial direction, and are radially opposite each other over their entire axial region (see, for example, Patent Document 1).

[0003] Existing technical documents

[0004] Patent Document 1: Japanese Patent Application Publication No. 2002-233122

[0005] In the existing technology, if the desired magnetic properties are to be obtained, the axial length of the stator core becomes longer, and the weight of the motor becomes greater. Summary of the Invention

[0006] In view of the above problems, the object of the present invention is to provide a technique that can reduce the weight of a motor without affecting its magnetic properties.

[0007] An example motor of the present invention comprises: a rotor having a magnet arranged in an annular shape radially outward of a central axis extending in a vertical direction, and rotatable about the central axis; and a stator arranged radially opposite the magnet on the radially inner side of the rotor. The stator comprises: a stator core having an annular core back centered on the central axis and a plurality of teeth extending radially outward from the core back and arranged circumferentially; windings disposed on the teeth; an insulating member covering the axial direction of the stator core and disposed between the teeth and the windings; and a spacer of magnetic material disposed axially between the stator core and the insulating member. The spacer has a protrusion disposed on its radially outer edge. The protrusion extends axially away from the stator core and is radially opposite the magnet.

[0008] The vehicle of the present invention has a motor with the above-described structure.

[0009] According to the present invention, the weight of the motor can be reduced without affecting the magnetic properties. Attached Figure Description

[0010] Figure 1 This is a longitudinal sectional view of a motor according to one embodiment of the present invention.

[0011] Figure 2 This is a partial cross-sectional view of the motor.

[0012] Figure 3This is a partial longitudinal sectional view of the area surrounding the stator core of the motor.

[0013] Figure 4 This is a partial longitudinal sectional view of the periphery of the stator core of the motor in Variation Example 1.

[0014] Figure 5 This is a partial longitudinal sectional view of the periphery of the stator core of the motor in Variation Example 2.

[0015] Figure 6 This is a partial longitudinal sectional view of the periphery of the stator core of the motor in Variation Example 3.

[0016] Figure 7 This is a schematic diagram of a vehicle according to one embodiment of the present invention.

[0017] In the diagram: 1—Motor, 2—Rotor, 3—Stator, 4—Shaft, 5—Stator cage, 6—Bearing, 21—Magnet, 22—Rotor yoke, 23—Rim, 24—Wheel cover, 25—Brake drum, 31—Stator core, 32—Winding, 33—Insulator (insulating component), 34—Spacer, 35—Spacer, 36—Spacer, 37—Spacer, 311—Back of core, 312—Gear, 321—Coil, 341—Protrusion, 351—Protrusion, 371—Protrusion, 400—Vehicle, 401—Vehicle body, 401a—Seat, 401b—Handle handle, 402—Front wheel, 403—Rear wheel, C—Central shaft, Dr—Radial, Dx—Axial, S1—Gap, S2—Gap, S3—Clearance. Detailed Implementation

[0018] Hereinafter, a motor according to an exemplary embodiment of the present invention will be described with reference to the accompanying drawings. Furthermore, the scope of the present invention is not limited to the following embodiments, and modifications can be made freely within the scope of the technical concept of the present invention.

[0019] In this specification, the direction parallel to the motor's central axis is simply referred to as "axial," the direction orthogonal to the motor's central axis is simply referred to as "radial," and the direction along a circle centered on the motor's central axis is simply referred to as "circumferential." Furthermore, for ease of explanation, in this specification, the motor's central axis is assumed to extend in the vertical direction. Therefore, the axial direction is referred to as the "vertical direction," and... Figure 1 The vertical direction in the text refers to the vertical direction of the motor to describe the shape and positional relationship of each component. However, this definition of vertical direction does not limit the orientation and positional relationship of the motor during use. For example, when the motor is mounted on a vehicle, its axis sometimes extends along the horizontal direction of the vehicle.

[0020] Furthermore, in this specification, a section parallel to the axial direction is referred to as a "longitudinal section," and a section orthogonal to the axial direction is referred to as a "cross section." Also, the terms "parallel" and "orthogonal" used in this specification are not strictly parallel or orthogonal, but rather encompass approximately parallel or orthogonal.

[0021] <1. General Structure of a Motor>

[0022] Figure 1 This is a longitudinal sectional view of a motor 1 according to one embodiment. The motor 1, for example in this embodiment, is mounted on a vehicle wheel (see reference). Figure 7 Motor 1 has a rotor 2 and a stator 3. Motor 1 also includes a shaft 4, a stator cage 5, and a bearing 6.

[0023] The rotor 2 is disposed radially outside the stator 3. The rotor 2 has magnets 21. The magnets 21 are arranged in a ring shape radially outside the central axis C extending in the vertical direction. Specifically, in this embodiment, the rotor 2 has a plurality of magnets 21. The plurality of magnets 21 are arranged circumferentially. Alternatively, the magnets 21 may be formed as a single ring. The magnets 21 have alternating S and N poles arranged circumferentially. The magnets 21 are arranged radially opposite the stator 3. The rotor 2 is capable of rotating about the central axis C.

[0024] The rotor 2 also has a rotor yoke 22, a wheel rim 23, a wheel cover 24, and a brake drum 25.

[0025] The rotor yoke 22 is, for example, a cylindrical shape extending vertically around a central axis C, and is disposed radially outside the magnet 21. The magnet 21 is fixed to the radially inner circumference of the rotor yoke 22. The rim 23 is, for example, an annular shape extending vertically around a central axis C, and is disposed radially outside the rotor yoke 22. In this embodiment, the rim 23 and the rotor yoke 22 are integral. In other words, the rim 23 and the rotor yoke 22 are formed from a single component.

[0026] The wheel cover 24 is disposed on the axial upper side of the rotor yoke 22 and the radial inner side of the wheel rim 23. The wheel cover 24 is, for example, a circular plate extending radially outward from the central axis C. The radial center portion of the wheel cover 24 is rotatably mounted relative to the shaft 4 via a bearing 6. Furthermore, the shaft 4 axially passes through the radial center portion of the wheel cover 24. The radial outer edge of the wheel cover 24 is fixed to the axial upper side of the rotor yoke 22.

[0027] The brake drum 25 is disposed on the axially lower side of the rotor yoke 22 and the radially inner side of the wheel rim 23. The brake drum 25 is, for example, a circular plate extending radially outward from the central axis C. The radial center portion of the brake drum 25 is rotatably mounted relative to the shaft 4 via a bearing 6. Furthermore, the shaft 4 axially passes through the radial center portion of the brake drum 25. The radial outer edge of the brake drum 25 is fixed to the axially lower side of the rotor yoke 22.

[0028] The stator 3 is disposed radially inside the rotor 2. The stator 3 is annular with the central axis C as its center. The stator 3 and the magnet 21 are arranged radially opposite each other. In this embodiment, the stator 3 is disposed in the space formed radially inside the rotor yoke 22, axially below the wheel cover 24, and axially above the brake drum 25. The stator 3 is fixed to the radially outer periphery of the stator cage 5.

[0029] Shaft 4 is configured along a central axis C that extends in the vertical direction. Shaft 4 is a column extending axially.

[0030] The stator cage 5 is located radially outside the shaft 4 and radially inside the stator 3. The stator cage 5 is a bottomed cylindrical shape extending axially. The radially inner circumference of the stator cage 5 is fixed to the radially outer circumference of the shaft 4. In other words, the shaft 4 passes axially through the radial center of the stator cage 5. The radially outer circumference of the stator cage 5 is fixed to the radially inner circumference of the stator 3. Thus, the stator 3 is fixed in a way that prevents rotation relative to the shaft 4.

[0031] The bearings 6 are arranged in a pair, one above the other in the axial direction. In this embodiment, the bearings 6 are, for example, ball bearings. The axially upper bearing 6 is located on the axially upper side of the stator 3 and the stator cage 5. The axially upper bearing 6 is radially disposed between the shaft 4 and the wheel cover 24, supporting the wheel cover 24 so that it can rotate relative to the shaft 4. The axially lower bearing 6 is located on the axially lower side of the stator 3 and the stator cage 5. The axially lower bearing 6 is radially disposed between the shaft 4 and the brake drum 25, supporting the brake drum 25 so that it can rotate relative to the shaft 4.

[0032] In the motor 1 with the above structure, when a drive current is supplied to the coil 321 of the stator 3 (described later), a radial magnetic flux is generated in the stator 3. The magnetic field generated by the magnetic flux of the stator 3 and the magnetic field generated by the magnet 21 interact to generate a torque in the circumferential direction of the rotor 2. Through this torque, the rotor 2 rotates about the central axis C.

[0033] <2. Detailed Structure of the Stator>

[0034] Figure 2 This is a partial cross-sectional view of motor 1. Figure 3 This is a partial longitudinal sectional view of the periphery of the stator core 31 of motor 1. Figure 3 In the diagram, "Dx" represents the axial direction of motor 1, and "Dr" represents the radial direction of motor 1. The stator 3 has a stator core 31, windings 32, insulators (insulating components) 33, and spacers 34. Additionally, in... Figure 3 The description of winding 32 is omitted in the text.

[0035] The stator core 31 has a core back 311 and a plurality of teeth 312. The core back 311 is annular about a central axis C. The plurality of teeth 312 extend radially outward from the core back 311 and are arranged circumferentially. Specifically, the plurality of teeth 312 extend radially outward from the radially outer periphery of the core back 311 and are arranged at predetermined intervals in the circumferential direction. The stator core 31 is constructed, for example, by bending strip-shaped steel plates along the plate surface and stacking them into a spiral shape. The stator core 31 may also be constructed, for example, by stacking multiple steel plates of the same shape axially.

[0036] Winding 32 is disposed on teeth 312. In each of the plurality of teeth 312, a coil 321 based on winding 32 is formed. In other words, in each of the plurality of teeth 312, coil 321 is constituted by winding 32 wound around insulator 33. The plurality of coils 321 are arranged at predetermined intervals in the circumferential direction.

[0037] An insulator 33 is disposed on the stator core 31, covering the axial direction of the stator core 31. The insulator 33 is configured to surround the outer surface of the tooth 312. The insulator 33 is disposed between the tooth 312 and the winding 32. The insulator 33 is made of an insulating component such as synthetic resin. Through the insulator 33, the tooth 312 and the winding 32 are electrically insulated from each other. In addition, the radial outer circumferential surface of the tooth 312, i.e., the opposing portion opposite to the magnet 21, is exposed from the insulator 33.

[0038] The spacer 34 is axially disposed between the stator core 31 and the insulator 33. In this embodiment, the spacer 34 is disposed on the axially upper side of the stator core 31. For example, the spacer 34 extends from the radially inner edge of the back surface 311 of the core to the radially outer edge of the tooth 312. The spacer 34 is a magnetic body and is separate from the stator core 31. The spacer 34 has a protrusion 341.

[0039] A protrusion 341 is disposed on the radially outer edge of the spacer 34. The protrusion 341 extends axially away from the stator core 31. That is, in this embodiment, the protrusion 341 extends axially upward relative to the stator core 31. The protrusion 341 is radially opposed to the magnet 21. Specifically, the radially outer periphery of the protrusion 341 is radially opposed to the radially inner periphery of the magnet 21.

[0040] By providing a protrusion 341 to the spacer 34, the area of ​​the stator core 31 opposite the magnet 21 can be increased axially. This ensures optimal magnetic characteristics in the motor 1. Furthermore, the axial length of the protrusion 341 can be shortened by the amount of the axial length of the stator core 31. This reduces the number of steel plates that constitute the stator core 31 and are stacked axially, thus reducing the weight of the stator core 31. Therefore, according to the above structure, the weight of the motor 1 can be reduced without affecting the magnetic characteristics.

[0041] Furthermore, the upper axial end of the protrusion 341 is located lower than the upper axial end of the magnet 21. In other words, the protrusion 341 extends axially to one side relative to the stator core 31, and the front end of the protrusion 341 is located further axially to the other side than the end of the magnet 21 on the axial side. This allows magnetic flux to pass easily between the stator core 31 and the magnet 21. Therefore, in the motor 1, preferred magnetic characteristics can be ensured, and weight can be reduced.

[0042] The radially outer periphery of the protrusion 341 and the radially inner periphery of the magnet 21 have a predetermined radial distance S1. Furthermore, the radial distance S1 between the radially outer periphery of the protrusion 341 and the radially inner periphery of the magnet 21 is constant in the axial direction. Therefore, for example, when the protrusion 341 is inclined towards the magnet 21 in an upward axial direction, contact between the protrusion 341 and the magnet 21 can be suppressed. Additionally, for example, when the protrusion 341 is inclined away from the magnet 21 in an upward axial direction, the influence of the magnetism of the magnet 21 can be suppressed. Therefore, the magnetic characteristics of the motor 1 can be stabilized.

[0043] The outer radial periphery of the stator core 31 and the inner radial periphery of the magnet 21 are radially spaced by a predetermined distance S2. Furthermore, the radial distance S1 between the outer radial periphery of the protrusion 341 and the inner radial periphery of the magnet 21 is the same as the radial distance S2 between the outer radial periphery of the stator core 31 and the inner radial periphery of the magnet 21. This improves the stability of the magnetic characteristics of the motor 1.

[0044] The protrusion 341 is located radially outward of the insulator 33. In other words, the protrusion 341 and the insulator 33 are radially opposed. Furthermore, the protrusion 341 and the insulator 33 are radially separated. Specifically, the radially outer periphery of the insulator 33 and the radially inner periphery of the protrusion 341 have a radial gap S3.

[0045] For example, when the radially outer periphery of the insulator 33 is located radially outer compared to the radially inner periphery of the protrusion 341, it is difficult to position the insulator 33 radially inner compared to the protrusion 341. However, according to the structure of this embodiment, the protrusion 341 is located radially outer of the insulator 33 and away from the insulator 33, so that when the insulator 33 is installed on the axially upper side of the spacer 34, the radially outer periphery of the insulator 33 can be prevented from getting stuck in the radially inner periphery of the protrusion 341. Therefore, the workability when assembling the motor 1 can be improved.

[0046] <3. Variations of Motors>

[0047] Next, a modified example of motor 1 will be described. Furthermore, the basic structure and use of the modified example will be explained. Figures 1 to 3The embodiments described above are the same; therefore, common structural elements are labeled with the same reference numerals or names as described above, and their descriptions are sometimes omitted. Furthermore, depictions of structural elements other than feature parts are omitted from the figures.

[0048] <3.1 Variation Example 1>

[0049] Figure 4 This is a partial longitudinal sectional view of the periphery of the stator core 31 of the motor 1 in Modified Example 1. The stator 3 of the motor 1 in Modified Example 1 has a spacer 35. The spacer 35 has a protrusion 351.

[0050] A protrusion 351 is disposed on the radial outer edge of the spacer 35. The protrusion 351 extends axially away from the stator core 31, i.e., axially upward. The axially upward end of the protrusion 351 is located at the same position as the axially upward end of the magnet 21. In other words, the protrusion 351 extends axially relative to the stator core 31. The front end of the protrusion 351 is located at the same position as the axially side end of the magnet 21.

[0051] According to the above structure, a minimum magnetic flux channel can be ensured between the stator core 31 and the magnet 21, and the axial length of the magnet 21 can be shortened as much as possible. Therefore, in the motor 1, the weight can be reduced without affecting the magnetic properties.

[0052] <3.2 Variation Example 2>

[0053] Figure 5 This is a partial longitudinal sectional view of the periphery of the stator core 31 of the motor 1 in Modified Example 2. The stator 3 of the motor 1 in Modified Example 2 has a spacer 36. The spacer 36 has a protrusion 361.

[0054] The spacer 36 and the stator core 31 are formed from a single component. In other words, the spacer 36 and the stator core 31 are constructed from the same component. Furthermore, in other words, the spacer 36 and the stator core 31 are formed as a single unit. As a result, the materials of the stator core 31 and the spacer 36 can be unified, which can stabilize the magnetic characteristics of the motor 1.

[0055] In this embodiment, the stator core 31 is formed by stacking multiple steel plates axially. In an exemplary embodiment, the spacer 36 is formed from the outermost steel plate axially. Furthermore, the spacer 36 can be formed from a single steel plate or from two or more steel plates.

[0056] <3.3 Variation Example 3>

[0057] Figure 6This is a partial longitudinal sectional view of the periphery of the stator core 31 of the motor 1 in Modified Example 3. The stator 3 of the motor 1 in Modified Example 3 has spacers 34 and 37. The spacers 34 and 37 are axially disposed between the stator core 31 and the insulator 33. The spacer 34 is disposed on the axially upper side of the stator core 31. The spacer 37 is disposed on the axially lower side of the stator core 31.

[0058] Spacer 34 has a protrusion 341. The protrusion 341 protrudes upward in the axial direction and extends therein. Spacer 37 has a protrusion 371. The protrusion 371 protrudes downward in the axial direction and extends therein. That is, the protrusions are respectively disposed on both sides of the stator core 31 in the axial direction.

[0059] By providing spacers 34 and 37 on the upper and lower sides of the stator core 31 respectively, the axial length of the stator core 31 can be further shortened. This allows for a further reduction in the weight of the motor 1 without affecting its magnetic properties.

[0060] <4. Vehicle Structure>

[0061] Figure 7 This is a schematic diagram of a vehicle 400 according to an embodiment of the present invention. The vehicle 400 includes a motor 1. In this embodiment, the motor 1 is a so-called in-wheel motor, mounted on the vehicle 400. The vehicle 400 is, for example, an electric motorcycle. The vehicle 400 has a vehicle body 401, a front wheel 402, and a rear wheel 403.

[0062] The vehicle body 401 has a seat 401a and a handle 401b. The seat 401a is located, for example, at the rear of the vehicle body 401 in the direction of travel. The handle 401b is positioned at the front of the vehicle body 401 in the direction of travel. The driver sits in the seat 401a and holds the handle 401b to operate the vehicle 400. The handle 401b is equipped with a throttle valve, brake, etc. (not shown).

[0063] The front wheels 402 are positioned in front of the vehicle body 401 in the direction of travel and are in contact with the road surface. The rear wheels 403 are positioned behind the vehicle body 401 in the direction of travel and are in contact with the road surface. The vehicle 400 can move relative to the road surface by rotating the front wheels 402 and the rear wheels 403. A motor 1 is, for example, mounted on the rear wheels 403. The vehicle 400 controls the drive of the motor 1 according to throttle operation performed by the driver, causing the rear wheels 403 to rotate and move.

[0064] According to the above structure, the weight of vehicle 400 can be reduced without affecting the magnetic characteristics of motor 1.

[0065] In this embodiment, the motor 1 is mounted on the rear wheel 403 of the vehicle 400, but it can also be mounted on the front wheel 402. Furthermore, in this embodiment, the vehicle 400 is a two-wheeled vehicle, but it can also be a three-wheeled or four-wheeled vehicle.

[0066] <5. Others>

[0067] The embodiments of the present invention have been described above, but the scope of the present invention is not limited thereto. Without departing from the spirit of the present invention, various modifications, omissions, substitutions and other changes to the structure can be made to implement it.

[0068] The industrial availability is as follows.

[0069] This invention can be applied to motors and vehicles.

Claims

1. A motor, characterized in that, have: A rotor having magnets arranged in a ring shape radially outward of a central axis extending in a vertical direction, and capable of rotating about said central axis; and The stator is arranged radially opposite the magnet on the radially inner side of the rotor. The stator has: A stator core having an annular core back centered on the central axis and a plurality of teeth arranged circumferentially extending radially outward from the core back; The winding configured on the tooth; An insulating component that covers the axial direction of the stator core and is disposed between the teeth and the winding; and A spacer made of steel plate, which is axially disposed between the stator core and the insulating component. The spacer has a protrusion disposed on its radial outer edge. The protrusion extends axially away from the stator core and is radially opposed to the magnet.

2. The motor according to claim 1, characterized in that, The protrusion extends axially to one side relative to the stator core. The front end of the protrusion is located on the opposite side of the axial direction from the end on one side of the magnet.

3. The motor according to claim 1, characterized in that, The protrusion extends axially to one side relative to the stator core. The front end of the protrusion is located at the same position as the end on the axial side of the magnet.

4. The motor according to any one of claims 1 to 3, characterized in that, The radial distance between the radially outer periphery of the protrusion and the radially inner periphery of the magnet is constant in the axial direction.

5. The motor according to any one of claims 1 to 3, characterized in that, The radial distance between the radial outer periphery of the protrusion and the radial inner periphery of the magnet is the same as the radial distance between the radial outer periphery of the stator core and the radial inner periphery of the magnet.

6. The motor according to any one of claims 1 to 3, characterized in that, The protrusion and the insulating component are arranged opposite each other in the radial direction. The protrusion and the insulating component are separated radially.

7. The motor according to any one of claims 1 to 3, characterized in that, The spacer and the stator core are formed from a single component.

8. The motor according to any one of claims 1 to 3, characterized in that, The protrusions are respectively disposed on both sides of the stator core in the axial direction.

9. A vehicle, characterized in that, The motor having any one of claims 1 to 8.

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