JPS6231360A - Rockable motor - Google Patents

Abstract

PURPOSE:To readily control positioning by opposing a pair of coils formed with the same inner and outer radii of curvature, thereby uniformly producing a torque. CONSTITUTION:A coil 24 mounted on a coil supporting plate 14 is formed of a pair of coils 26 formed symmetrically with a rotational shaft 12 as a center, and the inside portions 28 of the coils 26 are formed in the inside circular group that the radii R2 of curvature are equal with the shaft 12 as a center. The outside portions 30 are formed in the outside circular group that the radii R2 of curvature are equal concentrically with the inside circular arc. A permanent magnet 32 is so constructed that the radius R2 formed of the inside circular arc is equal to the central air gap and the radius R1 formed of the outside circular arc is equal to the outer periphery. Thus, a torque becomes uniform within the prescribed operating range to increase the stably operating range of a rockable motor.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a swing motor. More specifically, the present invention relates to the shape and structure of a coil of a swing motor that is configured to have uniform torque within a predetermined operating range when performing positioning control with a swing motor used for a floppy disk or the like.

(Prior art) As an example of the prior art, Fig. 4 (a), (b),
The configuration shown in (C) will be explained. A swing motor is a motor that rotates a predetermined angle, for example 180 degrees, in one direction, returns to its original position at a later angle, and always continues the same reciprocating motion.This type of motor is used in floppy disks, etc. has been done. In FIG. 4, the motor housing is composed of a side frame 2, a front yoke 4, and a rear yoke 6. A rotating shaft 12 is mounted on a pair of bearings 8 and 10 provided approximately at the center of the front yoke 4 and the rear yoke 6. A pair of annular coils 16,16'i having the same shape are mounted on one side of the support plate 14 fixed to the rotating shaft 12 so as to face each other with the rotating shaft 12 sandwiched therebetween. The portions of the coil 16 facing the rotating shaft 12 form linear portions 18, 1lc-, and the shaded portion 20 is a portion that generates an effective force in the rotational direction when excited. A permanent magnet 22 having S and N poles is provided inside the rear yoke 6 so as to face the coil 16. Further, FIG. 5 is an illustration of the actually measured waveform of the generated induced voltage, which explains the torque generation state during operation of the above-mentioned motor.

In this drawing, the torque generated due to the presence of the linear portion 18 of the coil 16 has an amorphous shape with respect to the rotation angle,
It clearly shows that it is not uniform.

(Problems to be Solved by the Invention) In an oscillating motor that employs all coils having a conventional configuration, means have been taken to correct the input current waveform in advance in order to keep the generated torque constant. Therefore, there are problems such as complicating the electronic circuit, and since the linear portion 18 of the coil used in the conventional example acts to prevent the generation of effective rotational torque, the torque is reduced. However, when the range of formation was narrowed, there were problems.

(Means and effects for solving the problem) The present invention improves the shape and configuration of the coil adopted in the conventional example.
The linear part of the conventional example is eliminated, and instead, a pair of opposing inner circular arcs are formed as the entire center of the rotation axis, and the outer circular arcs of the pair of coils are arranged circularly with this circular arc (Figure 1). .

Further, between the outer diameter of the pair of inner circular arcs and the inner diameter of the pair of outer circular arcs of the coil, the diameter formed by the inner circular arc is equal to the center gap, and the inner diameter formed by the outer circular arc? Permanent magnets formed equally around the outer periphery were used. During operation of the swing motor, the torque generated by the coil and permanent magnet having the above-described configuration is uniform within a predetermined operating range.

(Embodiment) An embodiment of the present invention will be fully described below with reference to the accompanying drawings. FIG. 1 shows a coil 24 mounted on a coil support plate 14.
FIG. The coil 24 consists of a pair of coils 26 , 26 symmetrically formed around the rotation axis 12 , and the inner portions 28 , 28 of the pair of coils that surround the rotation axis 12 are close to the rotation axis 12 . An inner circular arc group having the same radius of curvature is formed around the outer part 30.
30 forms an outer arc group that is concentric with the inner arc and has the same radius of curvature. The outer arcs each form an angle of about 1200 about the axis of rotation 12.

FIG. 2 shows a permanent magnet 32 used with the coil of the present invention.
The radius R2 of the central cavity is equal to the outer radius R2 of the inner arc, and the outer circumference thereof is the same as the inner radius R1 of the outer arc. Furthermore, the connecting portion 34 between the inner coil portion 28 and the outer portion 30 (the shaded portions are portions that generate effective force in the rotational direction) is shown in FIG. This is an actually measured waveform diagram of the induced voltage generated during operation. Comparing this waveform with the waveform diagram (Figure 5) formed by a conventional swing motor, it can be seen that the torque is uniform within a predetermined operating range. It can be seen that the stable operating range of the swing motor has been expanded.Furthermore, as mentioned above, the permanent magnet employed in the present invention has a radius of the central gap and a radius of the outer circumference. Since it is manufactured according to the shape of the coil, it can be made lighter compared to the conventional example.

(Effects of the Invention) In the present invention, by arranging a pair of coils facing each other with the same radius of curvature inside and outside, the torque within a predetermined operating range is uniform during operation of the swing motor. Therefore, positioning control can be performed easily and stably, and the weight of the permanent magnet can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a plan view of the arrangement of coils of a swing motor according to the present invention. Figure 2 shows the permanent magnet of the swing motor in Figure 1. FIG. 3 is an actually measured waveform diagram of the induced voltage generated during operation of the swing motor according to the present invention. FIG. 4(a) is a sectional view of a conventional swing motor. (b) is a plan view of the coil in (a). (c) is a plan view of the permanent magnet. FIG. 5 is an actually measured waveform diagram of the induced voltage generated during operation of the swing motor shown in FIG.

Claims (1)

[Claims] 1. In a motor having a permanent magnet provided on the outer periphery of a rotating shaft and a group of coils mounted on a supporting plate facing the permanent magnet and perpendicular to the rotating shaft, Supports a coil group formed by an inner circular arc group having the same radius of curvature and arranged opposite to each other, and an outer circular arc group having the same radius of curvature and arranged concentrically outside the inner circular arc group. A swing motor characterized by being attached to a board. 2. The swing motor according to claim 1, further comprising a permanent magnet in which the outer diameter of the inner arc group is equal to the center gap thereof, and the inner diameter of the outer arc group is equal to the outer circumference thereof.