JPS633541B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an insulation structure between a rotor core of a small motor and a coil wound around the rotor core.

Conventionally, insulation by electrostatic coating has been used as a means of insulating the rotor core of a small motor, but the equipment is expensive, unsuitable for small-lot production, requires a large number of steps, and the insulation treatment is expensive. Furthermore, in electrostatic devices, since the outer peripheral surface of the rotor core is also coated, a large air gap with the stator must be maintained, which tends to reduce the efficiency of the motor.

Another insulation method is to attach resin-molded end insulators to both end faces of the rotor core, but since this is resin-molded, the thickness and overall area of the end insulators cannot be increased. This results in poor efficiency as a motor, and the use of molded products increases costs.

As another insulating method, some insulating paper such as fibers is attached only to both end faces of the rotor core in accordance with the shape of the end faces, and the slots of the rotor core are not insulated, but this is because the insulation is not sufficient. ,
This method cannot be applied to rotor cores with a large thickness or a large capacity.

The present invention aims to improve the above-mentioned conventional drawbacks, and aims to provide a small and efficient motor. The present invention will be explained below with reference to the drawings showing one embodiment thereof.

Reference numeral 1 designates a rotor core made of laminated steel plates, the slots 1a of which are covered with an insulating thin film 2 of plastic sheets for insulation, and coils 3 are wound around the poles 1b of this rotor core. 4 is a shaft. The insulating thin film 2 is made by punching out a plastic sheet with a thickness of 0.01 to 0.25 mm into the shape shown in Figure 3.
It is bent as shown in the figure.

That is, the shape of the insulating thin film 2 of the plastic sheet consists of a central part 6 having a hole 5 through which the shaft 4 passes, and leaf parts 7 extending radially from the central part 6 by the number of slots 1a. in,
U-shaped notches 8 are provided at both end edges of the leaf portion 7 at the connecting portions with the central portion 6.

Then, as shown in FIG.
bend this leaf part 7 at right angles to the slot 1a.
The central part 6 is brought into contact with the end surface of the rotor core 1, the leaf part 7 is inserted into the slot 1a, and both ends of the leaf part 7 are inserted into the rotor core. The coil is wound by folding it back toward the end face of the coil. Note that the notch 8 functions to facilitate bending of the leaf portion 7. Additionally, both end faces of the rotor core are coated with an insulating coating.

As is clear from the above embodiments, the rotor of the small motor of the present invention is made of a plastic sheet having a shape in which the same number of leaves as the number of slots are arranged radially from the center, and both ends of the leaves are arranged in a radial manner. The edge is equipped with an insulating thin film with a notch for folding the leaf part, and the center part is brought into contact with the end face of the rotor core, which has insulation coating on both end faces, and the leaf part is bent at right angles to the center part. The coil is inserted into the slot, curved along the inner surface of the slot, both edges of the leaf are folded back along the end surface of the rotor core, and the coil is wound around the rotor core through the leaf. Electrical insulation between the rotor core and the coils, particularly at the corners of the rotor core, is sufficient, and since the insulating thin film of the plastic sheet is used, the volume of the coil is small, making the motor compact and efficient.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of the rotor of a small motor showing an embodiment of the present invention in a state where no coil is wound, Fig. 2 is a partial sectional view of the rotor, and Fig. 3 is a diagram of the insulating thin film of the rotor. The developed view and FIG. 4 are perspective views of the same insulating thin film. 1...Rotor core, 1a...Slot, 1b...
...Pole, 2...Insulating thin film, 3...Coil, 6...Center, 7...Leaf, 8...Notch.

Claims (1)

[Claims] 1. It is made of a plastic sheet having a shape in which the same number of leaves as the number of slots are arranged radially from the center, and is provided with an insulating thin film with notches for folding the leaves on both edges of the leaves, The central part is brought into contact with the end face of the rotor core, which has an insulating coating on both end faces, and the leaf part is bent at right angles to the central part, inserted into the slot, and curved along the inner surface of the slot. A rotor for a small motor, characterized in that both end edges of the leaf portion are folded back along the end face of the rotor core, and a coil is wound around the rotor core via the leaf portion.