JPS6139838A - Permanent magnet type motor - Google Patents

Abstract

PURPOSE:To prevent a permanent magnet from scattering by winding a glass cloth impregnated with resin on the magnet. CONSTITUTION:A glass cloth 4 impregnated with B-stagelike epoxy resin is wound several times on the outer periphery of a permanent magnet 3, and thermally cured. Thus, even if the magnet 3 is cracked or collapsed, it is not scattered to the outer periphery. Even if the cloth 4 is formed in width wider than the magnet 3 to cut out the cloth 4 projected from the magnet 3, and bent to the inner periphery to protect the side of the magnet 3, the same effect as above can be obtained.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention is applicable to intermittent operation, etc., where the starting frequency is high, and the start-up of the motor,
The present invention relates to a permanent magnet motor that has a short fall time and is used in industrial sewing machine drive motors, industrial robot motors, and the like.

Conventional Structures and Problems Permanent magnet electric motors have good start-up and fall characteristics, so they are beginning to be used in industrial sewing machines, industrial robots, etc. that frequently start and stop. However, since permanent magnets with low mechanical strength, such as ferrite magnets, are used, there is a possibility that the permanent magnets may scatter due to sudden changes in rotational speed or high-speed rotation. Therefore, in order to prevent the above-mentioned problem, as shown in FIG. 6, thread-like glass fibers 11 are wound many times so as to cover the outer periphery of the permanent magnets 12 constituting the rotor. As described above, in the conventional method, it is necessary to wrap the permanent magnet many times to cover the entire permanent magnet, the thickness is uneven, the glass fiber ends tend to unravel, and it is impossible to protect the side surfaces of the magnet. In addition, since the Gaos fibers are wound only in the circumferential direction (hereinafter referred to as the vertical direction), there is no glass fiber running in the direction perpendicular to the circumference (hereinafter referred to as the horizontal direction), resulting in a problem of low strength. There was a point.

OBJECTS OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks of the conventional art, and it is an object of the present invention to provide a method of preventing scattering of permanent magnets at low cost with a simple structure.

Structure of the Invention The present invention involves winding a glass cloth impregnated with a B-stage resin, such as an epoxy resin, several times around the outer peripheral surface of a permanent magnet that is adhesively fixed to the shaft or yoke of a rotor. After application, the resin is cured.

DESCRIPTION OF THE EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 to 6.

FIG. 1 is a rotor of a permanent magnet type electric motor showing an embodiment of the present invention, and FIG. 2 is a sectional view taken along line A-A in FIG. As shown in the figure, a rotor yoke 2 is press-fitted and fixed to a shaft 1, and four permanent magnets 3 are bonded to the rotor yoke 2.
The permanent magnets 3 are magnetized alternately with north and south poles and are assembled into an electric motor.

The permanent magnet 3 is a ferrite magnet with low mechanical strength.
Since cracks and chips are likely to occur, it is highly likely that centrifugal force during rotation, acceleration, and deceleration forces will cause them to fly out to the outer periphery and come into contact with the stator, making it impossible to operate.

Therefore, a glass cloth 4 impregnated with B-stage epoxy resin is placed around the outer periphery of the permanent magnet 3 to prevent it from popping out to the outer periphery even if the permanent magnet 3 is cracked or chipped. As shown in Figure 3, it is wrapped several times and hardened by heating.

In FIG. 4, the width of the glass cloth 4 is made wider than the width of the permanent magnet 30, a cut is made in the glass cloth 4 that protrudes beyond the permanent magnet 3, and the side surface of the permanent magnet 3 is bent inward. It is also protected.

In FIG. 6, the ring-shaped glass cloth 5 is fixed to the side surface of the permanent magnet 3 to protect both the outer periphery and the side surface of the permanent magnet 3.

Effects of the Invention: 1% As is clear from the present invention, by wrapping a resin-impregnated glass cloth around a permanent magnet, the number of times the reinforcing material is wrapped can be greatly reduced and the manufacturing process can be simplified. can be converted into In addition, since the glass fibers run both vertically and horizontally, it has strength both vertically and horizontally, and is effective in preventing cracks and chatter in all directions. Furthermore, since glass cloth is used, there is little variation in thickness depending on location, and it is possible to finish the product with a uniform thickness, thereby preventing accidents such as contact with the stator.

Further, since the end portion of the winding of the glass cloth is continuous in the vertical and horizontal directions, it will not come off even if the end portion is not specially fixed, and there is no need to perform special end treatment.

As described above, the permanent magnet scattering prevention structure is strong in both the vertical and horizontal directions, has a uniform thickness, is easy to manufacture, and can be provided at low cost, and its practical effects are great. There is something.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a rotor of a permanent magnet type electric motor according to an embodiment of the present invention, Fig. 2 is a sectional view taken along line A-A in Fig. 1, and Fig. 3 is a manufacturing process diagram of the rotor of the present invention. 4 and 6 are cross-sectional views showing other embodiments of the present invention, and FIG. 6 is a diagram showing the manufacturing process of a conventional rotor. 1... shaft, 2... rotor yoke, 3...
...Permanent magnet, 4...Glass cloth. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure C @ Figure 2, Figure 9 Figure 3 M4

Claims (3)

[Claims] (1) After fixing a permanent magnet to the outer circumference of the rotor shaft or yoke, and wrapping a glass cloth made of warp and weft impregnated with B-stage resin around the outer circumference of the permanent magnet,
A permanent magnet type electric motor including a rotor made of a hardened resin. (2) Make the width of the glass cloth wider than the width of the permanent magnet,
2. The permanent magnet electric motor according to claim 1, further comprising a rotor that includes the permanent magnet side surface by bending an end of the glass cloth. (3) A permanent magnet electric motor according to claim 1, comprising a rotor formed by fixing a ring-shaped glass cloth to a side surface of a permanent magnet.