JPH0847226A - Rotating magnetic field motor - Google Patents

Abstract

PURPOSE:To make fast driving easier by providing a 2-pole magnetized rotor with a notched part for forming pseudo 4-pole, and providing each three stator plates with a recessed part for forming six stator magnetic pole parts, so that hunting when a rotor stops quickly converges. CONSTITUTION:On the periphery of a 2-pole magnetized rotor 1 consisting of a permanent magnet, the first notched parts 1a and 1b, and the second notched parts 1c and 1a are provided 2 so that, a pseudo 4-pole wherein there are two magnetic flux density on each N-pole side and S-pole side is formed. Meanwhile, relating to a stator 2, three stator plates 21, 22 and 23 are provided with recessed parts 21a, 22a and 23a, so that pairs of stator magnetic pole parts 21b and 21c, 22b and 22c, 23b and 23c are formed. Further, among adjoining stator plates 21, 22 and 23, recessed parts 2b, 2e and 2h and notched parts 2c, 2f and 2i are provided, so that, narrow connection parts 2a, 2d and 2g are formed. Thus, when the rotor 1 steps, the magnetic flux direction of rotor 1 and stator 2 are matched, in parallel, in narrow range, for strong control force.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating magnetic field type motor using a permanent magnet rotor.

[0002]

2. Description of the Related Art Stepping motors, DC brushless motors and the like are well known as rotating field type motors using a permanent magnet rotor.

As one of the prior arts, the Japanese Utility Model Publication No. 2-372
As disclosed in Japanese Patent Publication No. 67,67, a cylindrical magnet magnetized with two radial poles is used as a rotor, three stators are evenly opposed to the rotor, and the excitation order of the three stators is changed to positive. There is a reverse rotation motor.

Further, as disclosed in Japanese Patent Application Laid-Open No. 4-75499, there is a motor configured to rotate in a reverse direction by changing the input pattern, timing, etc. of an input pulse.

[0005]

In the former case, the magnetizing pattern is sinusoidal in order to magnetize two poles in the radial direction while keeping the rotor in a cylindrical shape. When operating as a stepper motor, one pole of the north pole or south pole is located opposite one of the enclosed stators when the rotor attempts to converge the movement by one step,
The magnetic flux peak portion of the other pole faces the joint portion of the two stators, and the convergence of the rotor rotational movement becomes poor. Therefore, when the rotor is stopped, the rotor vibrates and stops, so-called hunting occurs. When the pointer is rotationally driven by the rotor, the above-mentioned hunting is transmitted to the pointer, and minute vibration of the pointer occurs, which is unsightly. Further, since the next drive signal is supplied after the hunting operation is stopped and completely stopped, there is a problem that the speed of the fast-forward motion cannot be increased.

The latter type uses the step-out region of the step motor and has a small inertia load. Therefore, there is a problem that it is unsuitable for a movement for equipment clocks to which various hands are attached.

An object of the present invention is to improve the above-mentioned problems and to make the hunting quickly stop when the rotor is stopped, thereby facilitating high-speed driving, and having a simple structure excellent in mass productivity and economical efficiency. To provide a rotating magnetic field type motor.

[0008]

In order to achieve the above object, a rotating magnetic field type motor of the present invention is a two-pole magnetized rotor composed of a permanent magnet and three stators surrounding the rotor with an equal angular width. The rotor includes a plate and three coils for exciting each stator plate to generate a rotating magnetic field, and the rotor has a substantially oval shape having first cutout portions on opposite side surfaces in a direction parallel to the magnetization direction. In addition to the first cutout portion, the second cutout portion having a smaller cutout amount than the first cutout portion is formed to face each other on the side surface in the direction orthogonal to the magnetization direction.
Due to the presence of the cutout portion and the second cutout portion, the rotor is a pseudo four pole having two magnetic flux density peaks on each of the N pole side and the S pole side. In addition, each of the stator plates has a pair of arc-shaped stator magnetic pole portions formed on both sides of the concave portion provided at the respective angular center positions, and six stator magnetic pole portions are arranged around the rotor. They are angularly spaced and evenly spaced.

It is preferable that the angular width between the adjacent stator plates, the angular width of the stator magnetic pole portion and the angular width of the recess are substantially equal to each other.

Further, the angular width of the second cutout portion of the rotor and the angular width of the rotor magnetic pole portions on both sides thereof are formed to be equal to each other, and the angular width between the adjacent stator plates or the angular width of the stator magnetic pole portion or the concave portion of the stator magnetic pole portion. It is preferably formed to have the same width as the angular width.

Further, it is preferable that the adjacent stator plates are connected to each other via a narrow connecting portion having a large magnetic resistance, and the three stator plates are one component.

Further, it is preferable that the radial projection portion corresponding to the second cutout portion of the rotor is made of a non-magnetic material.

[0013]

An embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, a stator 2 formed of a thin plate of a magnetic material is arranged around a rotor 1 having a two-pole magnetization formed of a permanent magnet. As shown in FIG. 2 (a), the rotor 1 is formed by cutting a side surface in a direction parallel to the magnetizing direction from a circular plate made of a thick permanent magnet by a central angle of 90 degrees to form a first cutout portion 1 a, 1b are provided so as to face each other, and are formed in a substantially flat oval shape. Further, on the side surface in the direction orthogonal to the magnetizing direction, second cutouts 1c, 1d are formed facing each other by cutting by a central angle of 30 degrees having a cutout smaller than the first cutouts 1a, 1b. .

Therefore, the outer peripheral surface has first notches 1a and 1b having a central angle of 90 degrees shown in FIG. 2B and second notches 1c having a central angle of 30 degrees shown in FIG. 2C. , 1d,
The rotor magnetic pole portions 1e, 1f, 1g, and 1h, which are four circular arc surfaces of concentric circles with a central angle of 30 degrees, are alternately connected to each other. Therefore, as shown in FIG. Pseudo 4 with two magnetic flux density peaks on each S pole side
It is a pole. Further, the rotor shaft (not shown) is arranged so that the magnetic flux densities of the same pole and the different poles change abruptly.
The size of the shaft hole 1i into which is fitted is selected, and the shape as described above is determined.

A specific shape of the stator 2 will be described. As shown in FIGS. 4 and 5, the three stator plates 21, 22, and 23 surround the rotor 1 with an equal angular width,
In each of the stator plates, a pair of arc-shaped stator magnetic pole portions 21b, 21c, 22 are provided on both sides of the concave portions 21a, 22a, 23a provided at the respective angular center positions.
b, 22c and 23b, 23c are formed. Between the adjacent stator plates 21 and 22, 22 and 23, and 23 and 21, the recess 2b and the notch 2c, the recess 2e and the notch 2f,
The recessed portion 2h and the cutout portion 2i serve as narrow-width connecting portions 2a, 2d, and 2g having large magnetic resistance (small cross-sectional area). The recesses 21a, 22a, 23a and the stator magnetic pole portion 2
Each of the concave portions 1b, 21c, 22b, 22c, 23b, 23c and the concave portions 2b, 2e, 2h is formed with an angle width of a central angle of 30 degrees.

As shown in FIG. 1, the stator plates 21, 2 are
The coil cores 31 and 3 are attached to the outer ends extending from the coils 2 and 23.
One end of 2, 33 is fixed. Coil core 31,3
A yoke (yoke) 4 is fixed to the other end of each of the wires 2, 33. Each coil core 31, 32, 33 has a coil 31a,
32a and 33a are wound respectively. As a result, a magnetic circuit is configured as a whole, and the six stator magnetic pole portions 21b, 21c, 22b, 22c, 23b, 23c.
Are located around the rotor 1 at equal angular widths and at equal intervals.

Since the rotor 1 and the stator 2 each have the above-described shape, when the stator 1 is not excited and the rotor 1 is in a stationary state, the rotor 1 and the stator 4 are simulated.
The pole rotor magnetic pole portions 1e, 1f, 1g, 1h are magnetically coupled to four of the six stator magnetic pole portions. In the state of FIG. 4, the rotor magnetic pole portions 1e, 1f,
1g and 1h are stator magnetic pole portions 21b, 21c, 22c,
23b, which is magnetically coupled to each other at a position substantially corresponding to the pseudo four poles of the magnetic flux density of the rotor 1 described in FIG.

The operation of the motor in such a structure is as follows.
The output signal of the drive circuit or the like (not shown) is transferred to the coil 31.
When applied to a, 32a, 33a, a magnetic field is generated in the stator plates 21, 22, 23, and the rotor 1 is rotated by the flow of the magnetic flux.

FIG. 6 shows a stationary stable position of the rotor 1 when the coils 31a, 32a, 33a are sequentially excited. The stable position of the rotor 1 is determined by the steps 1 to 6
The stator plate 21 in each step 1 to 6,
The symbols N and S in 22 and 23 represent the excitation directions in which the stator plate is excited by the corresponding coils. Step 1
Then, the rotor magnetic pole portions 1e, 1f, 1g, 1h face the stator magnetic pole portions 21b, 21c, 22c, 23b. In step 2, the rotor magnetic pole portions 1e, 1f, 1g,
1h is the stator magnetic pole portions 23c, 21b, 22b, 22
It faces c. In step 3, the rotor magnetic pole portion 1
e, 1f, 1g, 1h are the stator magnetic pole portions 23b, 23
It faces c, 21c, and 22b. In step 4,
The rotor magnetic pole portions 1e, 1f, 1g, 1h face the stator magnetic pole portions 22c, 23b, 21b, 21c. In step 5, the rotor magnetic pole portions 1e, 1f, 1g, 1h
Faces the stator magnetic pole portions 22b, 22c, 23c, 21b. In step 6, the rotor magnetic pole portions 1e, 1
f, 1g, 1h are the stator magnetic pole portions 21c, 22b, 2
It faces 3b and 23c.

FIG. 7 shows the flow of magnetic flux at the moment when the excitation is switched from step 1 to step 2. That is, in step 1, as shown in FIG.
The pole and the stator plates 22 and 23 were excited by the S pole,
When the excitation is switched to step 2, the stator plate 21 becomes N
The pole, the stator plate 22 is switched to the S pole and the stator plate 23 is switched to the N pole, and the flow of the magnetic flux changes from the stator plate 23 to the magnetic pole portion 2.
3b, 1h, 1g, 22c and flows to the stator plate 22, and at the same time from the stator plate 21 to the magnetic pole portions 21c, 1
f, 22b and flows to the stator plate 22, and the rotor 1 starts to rotate due to the flow of this magnetic flux. As shown in FIG. 8, the magnetic flux flows from the stator pole 23 to the magnetic pole portions 23c,
At the same time as passing through 1e, 1h, 22c and flowing to the stator plate 22, the stator plate 21 causes the magnetic pole portions 21b, 1f, 1
g, 22b, and flows to the stator plate 22. At a position rotated clockwise by a central angle of 60 degrees so that the magnetic flux direction of the rotor 1 is parallel to the magnetic flux flow in a narrow range. Stop. This position (FIG. 8) is the position of step 2 in FIG. Similarly, the coils 31a, 32a,
33a are sequentially excited, the flow of magnetic flux is sequentially changed, and the rotor 1 is rotated stepwise in the clockwise direction by the central angle of 60 degrees, so that each step returns to the original step 1 and makes one rotation.

FIG. 9 shows the flow of magnetic flux at the moment when the excitation is switched from step 1 to step 3. That is, in step 1, as shown in FIG.
The pole and the stator plates 22 and 23 were excited by the S pole,
When the excitation is switched to step 3, the stator plates 21 and 2 are
2 switches to the S pole and the stator plate 23 switches to the N pole, and the flow of the magnetic flux changes from the stator plate 23 to the magnetic pole portions 23b, 1h, 1
g and 22c to the stator plate 22, and at the same time, from the stator plate 23 to the magnetic pole portions 23c, 1e and 21b to the stator plate 21, and the rotor 1 starts to rotate due to the flow of the magnetic flux. As shown in FIG. 5, the magnetic flux flows from the stator plate 23 to the magnetic pole portions 23b, 1e,
At the same time as passing through h and 22b to the stator plate 22, the stator plate 23 moves the magnetic pole portions 23c, 1f, 1g and 2
1c to flow to the stator plate 21, and the rotor 1 stops at a position rotated clockwise by a central angle of 120 degrees so that the magnetic flux direction of the rotor 1 is parallel to the magnetic flux flow in a narrow range. . This position (Fig. 10) is step 3
Position, and the fast-forwarding is twice as fast as the drive described previously in FIG. Similarly, the coils 31a, 32a, 3
3a is sequentially excited, the flow of magnetic flux is sequentially switched,
When the rotor 1 rotates in the clockwise direction by the central angle of 120 degrees, the rotor 1 returns to the original step 1 through every other step and makes one rotation.

In any of the above driving modes, when the rotation of the rotor 1 is stopped, the magnetic flux directions of the rotor 1 and the stator 2 are parallel to each other in a narrow range, so that strong braking can be performed. Further, in the above description, the rotor 1 is excited so as to rotate clockwise, but it is also easy to rotate the rotor 1 counterclockwise by changing the order of excitation of the coils. Therefore, for example, when this motor is applied to a parent-child clock, the pointer can be rotated normally and reversely, fast-forwarding hand movement at double speed is possible at the time of adjusting the hand, and the pointer stopping operation is extremely fast and the needle movement operation is crisp. It is possible.

FIG. 11 shows another embodiment of the rotor. In this rotor 10, as in the rotor 1 of FIG.
Instead of providing the cutouts 1c and 1d, the recess 1 is formed in this portion.
0c and 10d are provided. Other configurations are substantially the same as those in FIG.

FIG. 12 shows still another embodiment of the rotor. In this rotor 20, the radial projection portion 20a corresponding to the second cutouts 1c and 1d is made of a non-magnetic material like the rotor 1 of FIG. And portions 20b and 20c made of a magnetic material are attached to both sides thereof. This part 2
The configurations of 0b and 20c are substantially the same as the corresponding portions of FIG.

FIG. 13 shows another embodiment of the stator, in which the stator plates 31, 32 and 33 are separated and made up of three parts. The other structure is substantially the same as that described in FIG.

FIG. 14 shows another embodiment of the stator, in which deep recesses 40b, 40d and 40f are provided from the outer edges of the stator plates 41, 42 and 43, whereby the narrow connecting portions 40a, 40c and 40e are formed. It is provided. The other structure is substantially the same as that described in FIG.

[0027]

According to the rotating magnetic field type motor of the present invention having the above construction, the rotor has two magnetic flux density peaks on the N pole side and the S pole side due to the presence of the first notch and the second notch. Six stator magnetic pole portions of the three stator plates that surround the rotor with an equal angular width are located around the rotor with an equal angular width and at equal intervals. When the plate is excited to generate a magnetic flux flow and the rotor rotates, and when the rotation is stopped, the magnetic flux flow is parallel to the magnetic flux direction of the rotor in a narrow range, so that strong braking can be performed and the rotor When stopped, the swinging motion (hunting) can be quickly converged. Further, it is possible to easily drive the forward and reverse rotations only by changing the order of excitation of the stator plate, and it is possible to realize a simple structure which is excellent in mass productivity and economical efficiency. Further, by changing the way of exciting the stator plate, it is possible to carry out a double speed step drive. When this motor is used for a clock or the like, the feed of the hands at the time of time adjustment is accelerated to improve the time adjustment operation. The time can be shortened and the deflection of the pointer is small, so that the movement of the pointer can be sharpened.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of the present invention.

2A and 2B show the shape of a rotor, in which FIG. 2A is an enlarged front view, FIG. 2B is a left side view, and FIG. 2C is a plan view.

FIG. 3 is a front view illustrating the magnetic flux density of the rotor.

FIG. 4 is a partially enlarged front view illustrating the shape of a stator magnetic pole portion.

FIG. 5 is a partially enlarged front view illustrating the relationship between the shapes of the rotor and the stator when the rotor is stopped.

FIG. 6 is a front view illustrating a stopped state of the rotor from step 1 to step 6 when the motor is step-driven.

FIG. 7 is a partially enlarged front view showing the flow of magnetic flux when switching the excitation from step 1 to step 2.

FIG. 8 is a partially enlarged front view showing the flow of magnetic flux when the rotor is stopped in step 2.

FIG. 9 is a partially enlarged front view showing the flow of magnetic flux when switching the excitation from step 1 to step 3.

FIG. 10 is a partially enlarged front view showing the flow of magnetic flux when the rotor is stopped in step 3.

FIG. 11 is a front view showing another embodiment of the rotor.

FIG. 12 is a front view showing still another embodiment of the rotor.

FIG. 13 is a front view showing another embodiment of the stator.

FIG. 14 is a front view showing still another embodiment of the stator.

[Explanation of symbols]

1, 10, 20 Rotor 1a, 1b First cutout portion 1c, 1d Second cutout portion 1e, 1f, 1g, 1h Rotor magnetic pole portion 10c, 10d Second cutout portion (recess) 20a Radial direction corresponding to the second cutout portion Projection portions 2a, 2d, 2g Narrow width connecting portions 21, 22, 23 Stator plates 21a, 22a, 23a Stator recesses 21b, 21c Stator magnetic pole portions 22b, 22c Stator magnetic pole portions 23b, 23c Stator magnetic pole portions 31, 32, 33 Stator Plates 40a, 40c, 40e Narrow width connecting portions 41, 42, 43 Stator plates

Claims (5)

[Claims] 1. A two-pole magnetized rotor comprising a permanent magnet,
Three stator plates that surround this rotor with equal angular width,
The rotor includes three coils for exciting each stator plate to generate a rotating magnetic field, and the rotor has a first side surface in a direction parallel to a magnetization direction thereof.
The second cutout portion is formed in a substantially oval shape having the cutout portions facing each other, and a second cutout portion having a cutout amount smaller than that of the first cutout portion is formed on a side surface in a direction orthogonal to the magnetization direction. Due to the presence of the first notch and the second notch, the rotor has a pseudo four pole having two magnetic flux density peaks on the N pole side and the S pole side, respectively. In each of the stator plates, a pair of arc-shaped stator magnetic pole portions are formed on both sides of the concave portion provided at each angular center position, and the six stator magnetic pole portions are A rotating magnetic field type motor characterized in that it is located around the rotor at equal angular widths and at equal intervals. 2. The rotating magnetic field type motor according to claim 1, wherein the angular width between adjacent stator plates, the angular width of the stator magnetic pole portion, and the angular width of the recess are substantially equal to each other. 3. The rotor according to claim 1, wherein the angular width of the second cutout portion of the rotor and the angular width of the rotor magnetic pole portions on both sides thereof are formed to be equal to each other, and the angular width between adjacent stator plates or the stator magnetic pole portion is A rotary magnetic field type motor, characterized in that it is formed to have an angular width or an angular width of a recess. 4. The stator according to claim 1, wherein adjacent stator plates are connected to each other through a narrow connecting portion having a large magnetic resistance, and the three stator plates are one component. A rotating magnetic field type motor. 5. The rotating magnetic field type motor according to claim 1, wherein a radial projection portion corresponding to the second cutout portion of the rotor is made of a non-magnetic material.