JP3583859B2 - Magnet motor stator - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a stator of a magnet motor, which is characterized by a structure of a stator of the magnet motor, and is particularly suitable for use in an electric bicycle, which is also called an assist-type bicycle, in which human-powered driving force is assisted by the driving force of the motor.
[0002]
[Prior art]
2. Description of the Related Art Recently, electric bicycles, which have both a human-powered driving unit and a motor-driven electric driving unit, drive a motor according to the magnitude of the human-powered driving force, and assist the human-powered driving force with the motor driving force, have become popular. Is calling.
[0003]
Conventionally, such an electric bicycle is provided with a drive system using human power and a drive system using an electric motor in parallel, as disclosed in Japanese Patent Application Laid-Open No. 4-35887 (B62M 23/02), and the driving force of the drive system using human power is provided. There is known a device in which the output of the electric motor is detected to detect the output of the electric motor.
[0004]
However, in such a configuration, since the driving portion is located at a position away from the rear wheel, the loss of power is large before the driving force is transmitted to the rear wheel, or the pedal and the electric motor are used to transmit power to the rear wheel. The rotation in the vertical direction must be converted to the rotation in the horizontal direction of the drive shaft, and further to the rotation in the vertical direction in order to rotate the rear wheel. There was a problem that it was likely to occur.
[0005]
Therefore, in order to solve this problem, the present applicant has provided an electric bicycle of a type in which the rear wheel is directly rotated by an electric motor.
Hereinafter, an example of an electric bicycle of a rear wheel direct drive type will be described with reference to the drawings.
[0006]
FIG. 3 is an overall perspective view of a rear-wheel direct drive type electric bicycle, in which 1 denotes an electric bicycle main body. The electric bicycle body 1 is provided with a motor 8 to be described later. The driving force of the motor 8 is changed in accordance with the magnitude of the torque generated by human power, and the motor 8 is driven by assisting the power generated by human power. Has become.
[0007]
A front wheel 2, a rear wheel 3, a handle 13 and a saddle 21 are attached to a frame 4 of the electric bicycle main body 1, and the front wheel 2 is steered by the handle 13. A disk-shaped casing 5 is provided on the rotation shaft of the rear wheel 3.
[0008]
The disc-shaped casing 5 includes a rotating casing 6 and a fixed casing 7 fixed to the electric bicycle main body 1. The rotating casing 6 rotates integrally with the rear wheel 3.
[0009]
Further, a motor 8 is built in the board-shaped casing 5, and is driven when electric driving is required, and rotates the rotation-side casing 6 together with a human-powered driving unit 10 described later. The driving portion including the disc-shaped casing 5 is the electric driving unit 9.
[0010]
The human-powered drive unit 10 includes a pedal 11 and a chain 12. 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 present invention is not limited to this.
[0011]
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 for the front wheel 2 and the rear wheel 3. 18 and 19 are connected by wires 16 and 17.
[0012]
The wires 16, 17 are pulled by pulling the brake levers 14, 15, and the front and rear brake devices 18, 19 are operated by the wires 16, 17 respectively. A brake switch 20 is provided in the middle of the wires 16 and 17, and the mechanism is such that when the brake levers 14 and 15 are operated, the power supply to the motor 8 is stopped.
[0013]
A battery section 22 serving as a power supply for the motor 8 is attached to the frame 4 on the rear wheel 3. The battery section 22 is composed of a battery case 23 slidably attached to the frame 4 and a single rechargeable battery housed in the battery case 23. The power supply voltage is approximately 24 volts.
[0014]
Next, the board-shaped casing 5 will be described with reference to FIGS.
FIG. 4 is a front view showing the configuration of the board-like casing 5 shown in FIG. 3, and in the drawing, reference numeral 7 denotes a fixed casing fixed to the electric bicycle body.
[0015]
The fixed casing 7 includes a control unit (not shown) including a control board and a radiator plate, a motor 8, a first pulley for transmitting an output of an output shaft 24 of the motor 8, a pulley set 25 of a second pulley, and a final-stage pulley. A speed reduction mechanism 26 composed of three pulley groups 28 and a transmission belt 27 that connects between the pulleys of the speed reduction mechanism 26 and the final stage pulley 28 are arranged.
[0016]
The last stage pulley 28 is fixed to the rotating casing 6. When the motor 8 rotates, the portion from the output shaft 24 of the motor 8 to the last stage pulley 28 is rotated by the transmission belt 27, and the speed is reduced and the final stage pulley 28 is rotated. The rotating casing 6 rotates.
[0017]
In addition, a one-way clutch (not shown) is interposed in the smaller one of the second pulleys connected to the final-stage pulley 28, 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.
[0018]
FIG. 5 is a front view showing an arrangement state of the motor 8 in the board-shaped casing 5, wherein 30 is a stator, 40 is a magnet, and 60 is an armature.
[0019]
However, the size and weight of the electric drive unit 9 including the disk-shaped casing 5 is considerable, and it has been desired that the electric drive unit 9 be lightweight and small in size for use in bicycles. Another problem was to reduce the size of the drive motor in order to reduce the weight and size.
[0020]
[Problems to be solved by the invention]
In order to reduce the size of a motor using a permanent magnet as a field, it is effective to use a magnet having a large BH product and increase the magnetic flux. In recent years, rare earth magnets such as neodymium magnets made of neodymium, iron, and boron and samarium-cobalt-based magnets are known as magnets having a large BH product.
[0021]
For example, a neodymium magnet has a BH product of 30 MGOe, which is about ten times that of a ferrite magnet, but is about 30 times as expensive per unit weight and is expensive. Thus, neodymium magnets are generally used in motors for the field of the rotor of brushless motors.
[0022]
Therefore, adopting a brushless motor using a rare earth magnet such as a neodymium magnet for downsizing of the motor is one option, but there is a problem in terms of complexity of the circuit configuration and cost.
[0023]
Therefore, it is more useful to employ a magnet motor which is a DC motor having a mechanical brush while having a mechanical brush while reducing the size by using a rare earth magnet for the stator. The present invention aims at reducing the size and weight of a magnet motor used for an electric bicycle or the like.
[0024]
[Means for Solving the Problems]
[0025]
Magnet motor stator of the present invention, there is a large portion and a small portion of the outer shape of the stator core diameter, the minimum in the magnet motor stator is press set into the case, the press-fit portion of the stator core of the case within the stator core outer diameter And is formed at a position that is the center of the magnet magnetic pole .
[0026]
Further, by cutting off unnecessary parts in terms of motor characteristics, the size and weight of the motor can be reduced.
[0027]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 shows a configuration diagram of a stator of a magnet motor according to claim 1 of the present invention. FIG. 1 is a front view of the stator of the magnet motor.
[0028]
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, 41a, 41b, 42a, 42b, 43a, 43b are plate magnets, It is inserted and held in a magnet insertion hole formed in the stator core 31. The magnet is a strong magnet type of a rare earth magnet such as a neodymium magnet, and one magnet is formed by two magnets. In this example, a four-pole stator is configured.
[0029]
The stator core 31 has a portion 32 having a large outer diameter and a portion 33 having a small diameter. The stator core 31 is press-fitted into a case 50 to constitute the stator 30.
[0030]
In the stator of the magnet motor according to claim 1 of the present invention, the press-fit 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 four, the number of press-fitting points of the stator core 31 into the case 50 is also four.
[0031]
By adopting such a configuration, the thickness of the case for securing the press-fitting strength for press-fitting the stator core 31 into the case 50 can be made thicker than the thickness of the portion of the maximum value of the stator outer diameter. I can take it. Further, since the portion 32 having the maximum value of the outer diameter of the stator is not press-fitted into the case, the thickness of the case can be reduced, so that the stator 30 can be downsized as a whole set.
[0032]
FIG. 2 shows a configuration diagram of a stator of a magnet motor according to claim 2 of the present invention. FIG. 2A is a front view of a stator of the magnet motor, and FIG. 2B is a side view of the stator.
[0033]
In the figure, the same components as those in FIG. 1 are denoted by the same reference numerals.
Reference numeral 30 denotes a stator of a magnet motor, 31 denotes a stator core of a magnet motor formed by laminating iron plates (silicon steel plates), and 40a, 40b, 41a, 41b, 42a, 42b, 43a, 43b denote flat plate magnets. It is adhesively held on the inner surface side. The magnet is a strong magnet type of a rare earth magnet such as a neodymium magnet, and one magnet is formed by two magnets. In this example, a four-pole stator is configured.
[0034]
The stator core 31 has a portion 32 having a large outer diameter and a portion 33 having a small diameter. The stator core 31 is press-fitted into a case 50 to constitute the stator 30.
[0035]
In the magnet motor stator according to claim 2 of the present invention, the press-fit 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-fit portion into the case is the magnet magnetic poles 40a, 40b, 41a, 41b. , 42a, 42b, 43a, 43b, for example, the center point 40p with the magnetic poles 40a, 40b.
[0036]
In the case of this embodiment, since the center of the magnet pole is four at the smallest part of the outer diameter of the stator core, the stator core 31 is also pressed into the case 50 at four places.
[0037]
As a result, the magnetic flux of the magnet pole is divided in the left and right direction from the center of the magnet pole, and the magnetic flux density is reduced at the center of the pole. . Therefore, a portion unnecessary for the motor characteristics of the stator is cut off, and the portion is used as a press-fit portion into the case 50. Therefore, the stator 30 can be reduced in size, and the entire set can be reduced in size, and the motor can be reduced in size and weight. It is planned.
[0038]
【The invention's effect】
As described above, according to the present invention, the thickness of the case for securing the press-fitting strength for press-fitting the stator core into the case can be made larger than the thickness of the portion having the maximum outer diameter of the stator, so that the press-fitting strength can be sufficiently obtained. Also, by reducing the thickness of the case, which is not necessary for the motor characteristics, the thickness of the case can be reduced, so that the stator can be downsized as a whole set, and the motor can be reduced in size and weight. it can.
[Brief description of the 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 the 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 a motor on a board-shaped casing.
[Explanation of symbols]
1 Electric bicycle body 2 Front wheel 3
Reference Signs List 3 rear wheel 4 frame 5 disc-shaped casing 6 rotating casing 7 fixed casing 8 motor 9 electric drive unit 10 manual drive unit 11 pedal 12 chain 13 handle 14, 15 brake lever 16, 17, wire 18, 19 brake device 20, brake switch DESCRIPTION OF SYMBOLS 21 Saddle 22 Battery part 23 Battery case 24 Motor output shaft 25 Pulley set 26 Reduction mechanism 27 Transmission belt 28 Last stage pulley 29 Rear wheel axle 30 Stator 31 Stator core 32 Stator core outer diameter maximum portion 33 Stator core outer diameter minimum portion 40 to 43 Magnet 50-53 Magnet insertion hole 60 Case

Claims (1)

In a magnet motor in which the outer diameter of the stator core has a large diameter portion and a small diameter portion, and the stator core is press-fitted into the case, the press-fit portion of the stator core into the case is the smallest portion of the outer diameter of the stator core and the center of the magnet pole. A stator for a magnet motor, wherein the stator is formed at the following position .

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