JPH09275648A - Stator of magnet motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the size and weight of a magnet motor to be used in an electric car, etc. SOLUTION: A stator core 31 has large-diameter sections 32 and small- diameter sections 33. The stator 31 is pushed into a case 50 to form a stator 30. The stator core 31 is pushed into the case 50 by the minimum-diameter sections 33, so the thickness of the case 50 at the pushed sections which secures a press-fit strength when the stator core 31 is pushed into the case 50 can be made larger than that of the maximum-diameter sections of the stator 30, and a sufficient press-fit strength can be obtained. The maximum-diameter sections 32 of the stator 30 are not pushed into the case and the thickness of the case at that sections can be made small and hence the size of the entire device can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is characterized by the structure of a stator of a magnet motor, and is particularly suitable for use in an electric bicycle, which is also called an assist type bicycle, in which a human driving force is assisted by a motor driving force. And a stator of a magnet motor.

[0002]

2. Description of the Related Art Recently, both a human-powered driving unit driven by human power and an electric driving unit driven by a motor are provided, and the motor is driven according to the magnitude of the human-powered driving force, and the human-powered driving force is supplemented by the motor driving force. Electric bicycles that are popular are gaining popularity.

Conventionally, such an electric bicycle has been disclosed in Japanese Patent Laid-Open No.
As shown in JP-A-358987 (B62M23 / 02), a driving system by human power and a driving system by electric motor are provided in parallel, and the driving force of the driving system by human power is detected to control the output of the electric motor. What you have done is known.

However, in such a structure, since the driving portion is located away from the rear wheels, there is a large loss of force before the driving force is transmitted to the rear wheels, and in order to transmit power to the rear wheels, pedals and The vertical rotation of the electric motor must be converted to the horizontal rotation of the drive shaft, and must also be converted to the vertical rotation to rotate the rear wheels, which complicates the configuration and increases the size. Had problems such as failure.

In order to solve this problem, the applicant has provided an electric bicycle of the type in which the rear wheels are directly rotated by an electric motor. Hereinafter, an example of a rear wheel direct drive type electric bicycle will be described with reference to the drawings.

FIG. 3 is an overall perspective view of a rear wheel direct drive type electric bicycle, in which 1 is an electric bicycle main body.
The electric bicycle main body 1 is provided with a motor 8 which will be described later, so that the driving force of the motor 8 is changed according to the magnitude of the torque due to the human power, and the power of the human power is assisted by the power of the motor 8 to travel. Has become.

A front wheel 2, a rear wheel 3, a handlebar 13 and a saddle 21 are attached to a frame 4 of the electric bicycle body 1, and the front wheel 2 is steered by the handlebar 13. A disk-shaped casing 5 is provided on the rotation shaft of the rear wheel 3.
Is provided.

The disk-shaped casing 5 comprises a rotating side casing 6 and a fixed side casing 7 fixed to the electric bicycle main body 1, and the rotating side casing 6 rotates together with the rear wheel 3. There is.

The disk-shaped casing 5 has a built-in motor 8 which is driven when electric drive is required to rotate the rotary side casing 6 together with a manual drive unit 10 which will be described later. The driving portion including the disc-shaped casing 5 is the electric driving unit 9.

The human power drive unit 10 is provided with a pedal 11 and a chain 12, and when the user steps on the pedal 11,
The rear wheel 3 is rotated via the chain 12. In this example, the chain 12 is a transmission member of human power. However, the invention is not limited thereto, and a chain, a rotating shaft, or the like may be used instead of the chain 12.

Brake levers 14 and 15 are attached to both left and right ends of a steering wheel 13 for steering the front wheel 2, and brake devices 18 and 19 are provided to the front wheel 2 and the rear wheel 3, respectively. And braking device 18, 19
Are connected by wires 16 and 17.

By pulling the brake levers 14 and 15, the wires 16 and 17 are pulled, and the wires 16 and 17 are pulled.
The front and rear brake devices 18 and 19 are respectively operated by 17. Further, a brake switch 20 is provided in the middle of the wires 16 and 17, and the mechanism is such that energization of the motor 8 is stopped when the brake levers 14 and 15 are operated.

A battery portion 22 serving as a power source of the motor 8 is attached to the frame 4 on the rear wheel 3. The battery section 22 includes a battery case 23 slidably attached to the frame 4 and a single-type rechargeable battery housed in the battery case 23. The power supply voltage is approximately 24 volts.

Next, the board casing 5 will be described with reference to FIGS. 4 and 5. FIG. 4 is a front view showing the configuration of the disk-shaped casing 5 shown in FIG. 3, and in the figure, 7 is a stationary casing fixed to the main body of the electric bicycle.

A control unit (not shown) including a control board and a heat sink, a motor 8, a first pulley for transmitting the output of the output shaft 24 of the motor 8, and a pulley set 25 of a second pulley are provided in the stationary casing 7. A reduction gear mechanism 26 including three pulley groups of a final stage pulley 28, a transmission belt 27 that connects between the respective pulleys of the reduction gear mechanism 26 and the final stage pulley 28 are arranged.

The final stage pulley 28 is fixed to the rotating side casing 6, and when the motor 8 rotates, the output belt 24 of the motor 8 to the final stage pulley 28 is rotated by the transmission belt 27 and is decelerated to the final stage. The rotating casing 6 rotates together with the pulley 28.

The second stage connected to the final stage pulley 28
A one-way clutch (not shown) is interposed in the smaller pulley so that the motor 8 is not turned when a force from the pedal is applied, that is, the pedal is light. 29 is a rear wheel axle.

FIG. 5 shows a motor 8 in the disk-shaped casing 5.
It is a front view which shows the arrangement state of a stator, 30 is a stator, 40
Is a magnet and 60 is an armature.

However, the size and weight of the electric drive unit 9 provided with the board-like casing 5 is considerable, and it has been desired to reduce its weight and size for use in a bicycle. In addition, downsizing of the drive motor was also an issue in order to reduce the weight and size.

[0020]

In order to downsize a motor having a permanent magnet as a field, a magnet having a large BH product is used.
It is effective to take a large magnetic flux. As magnets having a large BH product, neodymium magnets made of neodymium, ferrite, iron, and boron, and rare earth magnets such as samarium-cobalt magnets have been known in recent years.

For example, the neodymium magnet has a BH product of 3 mega gauss, which is about 10 times that of a ferrite magnet, but the price is about 30 times per unit weight, which is expensive. Therefore, neodymium magnets are commonly used in the field of rotors of brushless motors in motors.

Therefore, it is an option to employ a brushless motor using a rare earth magnet such as a neodymium magnet in order to miniaturize the motor, but it is difficult in terms of complexity of the circuit structure and cost.

Therefore, it is more effective to employ a magnet motor which is a direct current motor having a mechanical brush while using a rare earth magnet for the stator to achieve miniaturization while having a mechanical brush. The present invention is intended to reduce the size and weight of a magnet motor used in an electric bicycle or the like.

[0024]

A stator of a magnet motor according to claim 1 of the present invention is a magnet motor in which an outer shape of a stator core has a large diameter portion and a small diameter portion, and the stator core is press-fitted and set in a case.
The press-fitting part of the stator core into the case is the smallest part of the outer diameter of the stator core.

As a result, the wall thickness of the case for ensuring the press-fit strength for press-fitting the stator core into the case can be made larger than the wall thickness of the portion having the maximum stator outer diameter value, so that the press-fit strength can be sufficiently obtained. Further, since the portion having the maximum outer diameter of the stator is not press-fitted into the case, the wall thickness of the case can be reduced, and the entire set can be downsized.

In the stator of the magnet motor according to the second aspect of the present invention, the outer shape of the stator core has a large diameter portion and a small diameter portion, and in the magnet motor in which the stator core is press-fitted into the case, the stator core is press-fitted into the case. Is the smallest portion of the outer diameter of the stator core, and the press-fitted portion into the case is the center of the magnet magnetic pole. As a result, it is possible to reduce the size and weight of the motor by cutting away unnecessary parts due to the motor characteristics.

[0027]

1 is a block diagram of a stator of a magnet motor according to claim 1 of the present invention. FIG. 1 is a front view of a stator of a magnet motor.

In the figure, 30 is a stator of a magnet motor, 31 is a stator core of a magnet motor formed by laminating iron plates (silicon steel plates), 40a, 40b, 41.
Reference characters a, 41b, 42a, 42b, 43a and 43b are flat magnets, which are inserted and retained in the magnet insertion holes formed in the stator core 31. The magnet is a strong magnet type of rare earth magnet such as neodymium magnet, and two magnets form one magnetic pole. In this example, a 4-pole stator is configured.

The stator core 31 has a portion 32 having a large outer diameter and a portion 33 having a small outer diameter, and the stator core 31 is press-fitted into the case 50 to form the stator 30.

In the stator of the magnet motor according to the first aspect of the present invention, the press-fitting portion of the stator core 31 into the case 50 is the smallest portion 33 of the outer diameter of the stator core. In the case of this embodiment, since the minimum portion 33 of the outer diameter of the stator core is at four places, there are also four places where the stator core 31 is press fit into the case 50.

With such a structure, the thickness of the case for ensuring the press-fitting strength for press-fitting the stator core 31 into the case 50 can be made larger than the wall thickness of the portion having the maximum stator outer diameter, so that the press-fitting strength is increased. Can be taken sufficiently. Further, since the portion 32 having the maximum outer diameter of the stator is not press-fitted into the case, the wall thickness of the case can be reduced, so that the stator 30 can be downsized as a whole set.

FIG. 2 is a block diagram of a stator of a magnet motor according to claim 2 of the present invention. FIG. 2A is a front view of the stator of the magnet motor, and FIG. 2B is a side view of the stator.

In the figure, the same components as those in FIG. 1 are designated by the same reference numerals. Reference numeral 30 denotes a magnet motor stator, 31 denotes a magnet motor stator core formed by laminating iron plates (silicon steel plates), and 40a and 40a.
b, 41a, 41b, 42a, 42b, 43a, 43b
Is a flat magnet, and is adhered and held on the inner surface side of the stator core 31. The magnet is a strong magnet type of rare earth magnet such as neodymium magnet, and two magnets form one magnetic pole. In this example, a 4-pole stator is configured.

The stator core 31 has a portion 32 having a large outer diameter and a portion 33 having a small outer diameter, and the stator core 31 is press-fitted into the case 50 to form the stator 30.

In the stator of the magnet motor according to the second aspect of the present invention, the press-fitting portion of the stator core 31 into the case 50 is the smallest portion of the outer diameter of the stator core, and the press-fitting portion into the case is the magnetic poles 40a, 40b. 41
a, 41b, 42a, 42b, 43a, 43b center,
For example, the magnetic poles 40a and 40b are configured so as to be at the center point 40p.

In the case of this embodiment, the center of the magnet magnetic pole is four in the smallest portion of the outer diameter of the stator core, so that there are four press-fitting portions of the stator core 31 into the case 50.

Since the center of the magnet magnetic pole is not important for the magnetic circuit, the wall thickness of the case can be reduced by cutting away the wall thickness of the case which is not necessary for the motor characteristics.
The size of the motor can be reduced, and the size and weight of the motor can be reduced.

[0038]

As described above, according to the present invention, the thickness of the case for ensuring the press-fitting strength for press-fitting the stator core into the case can be made thicker than the thickness of the portion having the maximum stator outer diameter. Can be taken sufficiently. In addition, since the thickness of the case can be reduced by cutting off the thick part of the case that is not necessary for the motor characteristics, the stator as a whole can be made smaller, and the motor can be made smaller and lighter. it can.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a stator of a magnet motor according to claim 1 of the present invention.

FIG. 2 is a configuration diagram of a stator of a magnet motor according to claim 2 of the present invention.

FIG. 3 is an overall perspective view of an electric bicycle.

FIG. 4 is a front view and a side view showing a configuration of a board-shaped casing.

FIG. 5 is a layout view of motors on a board casing.

[Explanation of symbols]

 1 Electric Bicycle Main Body 2 Front Wheel 3 3 Rear Wheel 4 Frame 5 Panel Casing 6 Rotating Side Casing 7 Fixed Side Casing 8 Motor 9 Electric Drive 10 Human Power Drive 11 Pedal 12 Chain 13 Handle 14, 15 Brake Lever 16, 17 Wire 18 , 19 Brake device 20 Brake switch 21 Saddle 22 Battery part 23 Battery case 24 Motor output shaft 25 Pulley set 26 Reduction mechanism 27 Transmission belt 28 Final stage pulley 29 Rear wheel axle 30 Stator 31 Stator core 32 Stator core outer diameter maximum part 33 Stator core outside Diameter minimum part 40-43 Magnet 50-53 Magnet insertion hole 60 Case

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[Procedure amendment]

[Submission date] December 26, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0020

[Correction method] Change

[Correction contents]

[0020]

In order to downsize a motor having a permanent magnet as a field, a magnet having a large BH product is used.
It is effective to take a large magnetic flux. As magnets having a large BH product, rare earth magnets such as neodymium magnets made of neodymium, iron and boron and samarium cobalt magnets have been known in recent years.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0021

[Correction method] Change

[Correction contents]

For example, a neodymium magnet has a BH product of 30.
With MGOe, which is about 10 times that of a ferrite magnet,
The price is about 30 times more expensive per unit weight, which is expensive. So neodymium magnets are commonly used in the field of rotors of brushless motors in motors.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0022

[Correction method] Change

[Correction contents]

Therefore, it is an option to employ a brushless motor using a rare earth magnet such as a neodymium magnet in order to miniaturize the motor, but it is difficult in terms of complexity of the circuit structure and cost.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0028

[Correction method] Change

[Correction contents]

In the figure, 30 is a stator of a magnet motor, 31 is a stator core of a magnet motor formed by laminating iron plates (silicon steel plates), 40a, 40b, 41.
Reference characters a, 41b, 42a, 42b, 43a, 43b are flat magnets, which are inserted and held in magnet insertion holes formed in the stator core 31. The magnet is a strong magnet type of rare earth magnet such as neodymium magnet,
Two magnets form one magnetic pole. In this example, a 4-pole stator is configured.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0033

[Correction method] Change

[Correction contents]

In the figure, the same components as those in FIG. 1 are designated by the same reference numerals. Reference numeral 30 denotes a magnet motor stator, 31 denotes a magnet motor stator core formed by laminating iron plates (silicon steel plates), and 40a and 40a.
b, 41a, 41b, 42a, 42b, 43a, 43b
Is a flat magnet, and is adhered and held on the inner surface side of the stator core 31. The magnet is a strong magnet type of rare earth magnet such as a neodymium magnet, and two magnets form one magnetic pole. In this example, a 4-pole stator is configured.

[Procedure correction 6]

[Document name to be amended] Statement

[Correction target item name] 0037

[Correction method] Change

[Correction contents]

As a result, the magnetic flux of the magnetic poles of the magnet is divided in the left-right direction from the magnetic pole center of the magnet, and the magnetic flux density is low at the center of the magnetic poles. Become part.
Therefore, a portion of the stator that is not necessary for the motor characteristics is shaved and the portion is used as the press-fitting portion into the case 50.
The stator 30 can be downsized, the entire set can be downsized, and the size and weight of the motor can be reduced.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshihiro Suhara 2-5-5 Keihan Hondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Inventor Toshihiro Matsumoto 2-chome, Keihanhon-dori, Moriguchi-shi, Osaka No. 5-5 Sanyo Electric Co., Ltd.

Claims (2)

[Claims] 1. In a magnet motor in which a stator core has a portion with a large diameter and a portion with a small diameter, and the stator core is press-fitted into the case, the press-fitted portion of the stator core into the case is the smallest portion of the stator core outer diameter. The stator of a magnet motor, which is characterized in that 2. The stator of a magnet motor according to claim 1, wherein the press-fitting portion into the case is arranged to be the center of the magnet magnetic pole.