JPH03207259A - Torque motor - Google Patents

Abstract

PURPOSE:To get large torque by arranging a fixed armature, a disc, and a rotary armature inside a cylindrical case, and providing an electrode tooth in each, and generating magnetic attraction between each electrode tooth of each one so as to perform the rocking rotation of the disc and the rotations of the rotary armature and an output shaft. CONSTITUTION:By generating magnetic attraction in order between each pole tooth of a fixed armature 2 and each pole tooth on one side of a disc 11 opposed to this and between each pole tooth on the opposite side of the disc 11 and each pole tooth of the rotary armature 3 opposed to this, the rocking rotation of the disc 11 and the rotation of the rotary armature 2, i.e., a rotary shaft 4, are performed. At this time, even if the positions are dislocated from the minimum gaps respectively between the fixed armature 2 and the disc 11, and the disc 11 and the rotary armature, the widths of the gaps change slowly. Hereby, it becomes hard for saturation of magnetic flux to occur, and a large current can be let flow, and great electromotive force arises.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention uses a torque motor, especially for robots and machine tools that require high-precision positioning, so it is necessary to have high torque rotation characteristics at low speeds. It relates to a torque motor that is said to be

[Conventional technology]

Conventionally, two types of torque motors of this type are known.

One of these types is called a variable gap motor, and as shown in Figs. Two ring-shaped stators 22: inner and outer. The stator 23 is also provided. The rotor 21 has a large number of pole teeth on its outer peripheral surface, and an output shaft 2 at its center.
6, and is rotatably supported in the case 20 by a bearing 24. On the other hand, the two stators 22.
Among the stators 23, the inner stator 22 closer to the rotor 21
has a slightly larger diameter than the outer diameter of the rotor 21, and its inner peripheral surface is provided with a large number of pole teeth, the number of which is different from the number of pole teeth of the rotor 21. The rotor 21 is supported in the same manner as the Oldham joint through the
The point of closest approach to can be moved sequentially in the circumferential direction. A coil 25 is wound around each pole tooth of the inner stator 22, and is connected to a control circuit via a constant current circuit.

In such a configuration, a control circuit sequentially supplies current to each coil 25 wound around each pole tooth of the inner stator 22, and by sequentially exciting each coil 25, each pole of the inner stator 22 and rotor 21 is A magnetic attraction force is generated sequentially between the teeth, and the rotor 21 and the inner stator 22
The inner stator 22 rotates by the difference in the number of pole teeth between the inner stator 22 and
revolves relative to the rotor 21.

The rotation of the rotor 21 is transmitted to the outside by the output shaft 23.

The other type is the Epicycle Motor (trade name) shown in the daily magazine "Automation", Vol. 11, No. 7, page 88. This is an application of cycloid motion, and the rotor is attracted by the magnetic attraction force generated in the stator, and as the position of this attraction force changes, the rotor moves along the inner circumference of the stator, resulting in rotation. Torque is transmitted to the output shaft via a universal joint provided on the rotor.

[Problem to be solved by the invention] Among the conventional examples, the former variable gap motor has the following problems:
Unlike the latter Ebisiku motor, which does not require contact between the rotor and stator, it is advantageous in terms of durability and noise prevention, but as the gap between the rotor and stator deviates from the smallest gap, As the gap widens rapidly, the magnetic flux passes through only a small portion of the smallest gap.

As a result, the magnetic flux saturates quickly, making it impossible to generate a large magnetomotive force even when a large current is passed, making it difficult to obtain large torque from the motor.

The present invention aims to solve the above problems in a first type of torque motor that has the advantage that the rotor and stator do not come into contact with each other.

[Means and operations for solving the problem] In the present invention, in a torque motor, a fixed armature, a disk, and a rotating armature are arranged in a cylindrical case, and each pole tooth is provided on each of them. By sequentially generating a magnetic attraction force between each pole tooth, the oscillating rotation of the disk and the rotation of the rotary armature and output shaft are performed.

At this time, by creating a structure in which the area through which the magnetic flux passes is expanded between each opposing pole tooth, saturation of the magnetic flux does not occur, and large torque can be obtained by the magnetomotive force caused by the large current. We are making it possible to do so.

〔Example〕

・Configuration of Embodiment An embodiment of the torque motor according to the present invention will be explained using the first factor.

A conical fixed armature 2 is fixed to one axial side of a cylindrical case 1, and a conical rotating armature 3 is rotatably supported on the other axial side via a bearing 7. The central output shaft 4 protrudes outside the case 1. These two armatures have their conical surfaces facing each other, and the disk 5 is disposed between the facing armatures. This disk 5 is supported by a bearing 10 on the outer periphery of a small disk 11 that is fixed diagonally to the shaft 6, which is supported by a bearing 8 and a bearing 9 arranged on two armatures. is rotatably supported at an angle equal to the angle of inclination of the conical surfaces of the two armatures. The conical surface of the fixed armature 2 and the conical surface of the rotating armature 3 are each provided with a large number of pole teeth, while the front and back surfaces of the disc 50 are provided with a large number of pole teeth. A plurality of pole teeth are provided, the number of which is different from the number of each pole tooth provided. These fixed armatures 2
, the disk 5 and the rotating armature 3 are supported so that their respective pole teeth do not come into contact with each other. Furthermore, the fixed armature 2 and the rotating armature 3 are internally divided into twelve equal parts, each having a coil 12 wound thereon and connected to a control circuit.

- Effects of the embodiment In such a configuration, a control circuit sequentially supplies current to each coil 12 inside the fixed armature 2, and each coil 1
2 are sequentially excited. Further, current is sequentially supplied to each coil 12 inside the rotary armature 3 by the control circuit via the brush 13, and the coils 12 are sequentially excited. At this time, the fixed armature 2 and the rotating armature 3 are excited with a 180' phase shift. As a result, a magnetic attraction force is generated between the fixed armature 2 and the disk 5, and they try to approach each other so that the distance is minimized. , a magnetic attraction force is also generated between the rotating armature 3 and the disk 5, and they try to approach each other so that the distance between them is minimized. At this time, since the numbers of pole teeth of the fixed armature 2, disc 5, and rotating armature 3 are different, there are gaps between the fixed armature 2 and the disc 5, and between the disc 5 and the rotating armature 3, respectively. A lateral force will be applied, but since the fixed armature 3 is fixed, the disk 5 will move laterally, and the rotating armature 3 will move laterally with respect to this disk 5. A relationship is established. Therefore, by sequentially energizing each coil 12, the above-mentioned effects work in sequence, causing the rotary armature to rotate, and rotation is extracted from its output shaft 4.

The rotation speed N of the output shaft 4 is determined by the excitation rotation speed (rotation speed of the shaft 6) being No, the number of pole teeth of the fixed armature 2 being 21, the number of pole teeth of the rotating armature 3 being 22, and the number of pole teeth of the rotating armature 3 being No. If the number of pole teeth of 5 is 23, then N=NOX (Z3 Zl)/Z3
2)/Z3.

Moreover, the output torque T is the torque of the shaft 6.

Then, T-7Qxz3 / (Zs Z,)XZs / (Z
3 Z 2 ).

Here, the torque To of the shaft 6 is: magnetic attraction force is F, distance from the center of rotation to the magnetic pole is r2, inclination angle of the disk 5 is α, position angle of the magnetic pole with respect to the attracted position is θ, and magnetic flux density is μ.
If the o1 magnetic flux area is 81 and the number of coil turns is Ni, then T 0-FII tan α 11 sin
θF−uo −8−Ni2/ 2 (r −tan a
-(1-cos θ)) Therefore, To-uo -8-Ni2 s1n θ / 2・'
tan a ·(1-cosθ)2.

〔Effect of the invention〕

According to the present invention, between each pole tooth of the stationary armature and each pole tooth on one side of the disk opposite thereto, and between each pole tooth on the opposite side of the disk and each pole of the rotating armature opposite thereto, By sequentially generating magnetic attraction between the teeth, the oscillating rotation of the disk and the rotation of the rotating armature, that is, the output shaft, are performed.

At this time, between the fixed armature and the disk, and between the disk and the rotating armature, even if the position deviates from the minimum gap, the width of the gap changes gradually, and the minimum gap is between the two electric Since the structure is expanded to a length close to the radius of the child and the disk, the area through which the magnetic flux passes is also expanded. This makes saturation of the magnetic flux less likely to occur, allowing a large current to flow, generating a large magnetomotive force, and obtaining a large torque.

On the other hand, since there is no contact portion between the respective pole teeth, there is no frictional force, which prevents a decrease in durability due to wear and reduces problems such as noise and vibration.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of an embodiment of a torque motor according to the present invention, FIG. 2 is a sectional view taken along line A-A in FIG. 1, FIG. 3 is a longitudinal sectional view of a conventional torque motor, and FIG. FIG. 4 is a sectional view taken along line BB in the conventional example of FIG. 3; In the figure, numbers 1 and 2o are the case, 2 is the fixed armature, 3 is the rotating armature, 4 and 26 are the output shafts, 5 is the disk, 6 is the shaft, 7,
8, 9, 10.24 are bearings, 11 is a small disk, 12.25
is a coil, 13 is a brush, 21 is a rotor, 22 is an inner stator, and 23 is an outer stator.

Claims (1)

[Claims] A rotatable shaft is arranged between a fixed armature and a rotary armature, which have conical parts with pole teeth on the surface and a coil arranged inside facing each other, and on this shaft, A torque motor characterized in that a disc having pole teeth is rotatably supported at an inclination angle of the conical part.