JPH0147100B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a stator for an induction motor.

Conventionally, the stator of an induction motor usually has windings housed in slots formed on the side of the stator core facing the rotor, and the so-called coil is the transition part from slot to slot. The end portions protrude from both sides of the stator core.

In addition, in recent years, with the aim of making electric motors smaller and lighter and shortening the manufacturing process, in this type of electric motor,
An integrated stator has been manufactured by molding a stator core with windings into a resin mold by means such as injection molding or injection molding.

By the way, in this type of stator, it is necessary to insulate between the stator core and the wires, and in the conventional winding storage method in which the windings are stored in the slots of the stator core, the inner peripheral shape of the slots However, if resin molding is used as described above, the injection pressure during molding will cause the winding inside the slot to The wires and insulators move easily, making it difficult to maintain the windings in close contact with the stator core through the insulators, which may result in poor insulation or the windings and insulators being exposed to the molded resin surface. There is.

Therefore, in order to reduce the size and weight of an induction motor and shorten the manufacturing process, the present invention provides an insulating means between the stator core and the windings when the stator core with windings is resin molded. As,
An insulating layer made of a well-known pre-molded synthetic resin or the like is formed on the surface of the stator core, and a toroidal winding is applied to the outside of this insulating layer. By tightening from the outside, the stator core can be securely held in close contact with the stator core without fear of lifting, and the windings can be wrapped tightly and without any looseness and molded with resin, providing excellent integrity and durability. This provides a stable stator.

That is, the present invention has a stator core having a large number of slots spaced apart by teeth on the inner periphery, and a pre-molded insulating layer on the surface of the stator core except for at least the inner periphery of the teeth. At the same time, a toroidal winding is applied to wind the yoke part for each slot of the stator core through this insulating layer, and the winding is embedded leaving at least the inner peripheral end surface of the tooth part of the stator core. It is characterized by being molded with resin.

Next, embodiments of the present invention will be described based on the drawings.

1 and 2 show a stator according to the present invention, and FIG. 3 schematically shows an induction motor configured with the stator of the present invention. In the figure, 1 is a stator;
2 is a rotor, 3 and 3 are bearings that support the shaft 4 of the rotor, and 5 is a frame portion.

The stator 1 has the following configuration.

11 is a stator core having an annular or cylindrical shape, and has a large number of axial slots 1 on the inner peripheral side.
2 and a yoke 14 on the outer periphery thereof.

As shown in the figure, an insulating layer 20 is formed on the surface of the stator core 11 by pre-molding means such as a well-known synthetic resin, except for at least the inner circumferential end of the toothed portion 13. In particular, this insulating layer 20 can be integrally formed with a flange 20a that improves the winding condition.

A toroidal winding 15 for winding the yoke 14 is provided in each slot of the stator core 11 via the insulating layer 20. As a means for applying this winding 15, the stator core 1 has an annular shape in which the tooth portion 13 and the yoke portion 14 are integrally formed.
In addition to directly winding the stator core 11 by holding the toroidal winding device with the insulator 20 fitted onto the stator core 11, the stator core 11 is divided into a plurality of parts such as two parts, and each slot of the divided core is After each core is wound with an insulator 20 in between, the split cores can be joined together. In this case, the insulating layer 20 may also be formed for each divided core in correspondence with the divided core. It is more efficient to wind the wire around the split core than to wind the wire around the annular stator core.

Furthermore, the stator core 11 with the winding 15 as described above is molded by a well-known resin molding method so as to embed the winding 15 leaving at least the inner circumferential end surface of the toothed portion 13 that faces the rotor 2. Fixed. 16 indicates a mold resin portion. If the frame portion 5 is also integrally formed with the resin mold as shown in FIG. 3, the stator 1 and the frame portion 5 will have excellent integrity and the winding 15 will be protected effectively.

Therefore, the stator 1 of the present invention described above has an insulating layer 20 formed by pre-molding on the surface of the stator core 11.
is formed, and a toroidal winding 15 is applied to each slot 12 via this insulating layer 20, which not only ensures reliable insulation between the stator core 11 and the winding 15. The winding 15 itself is tightly wound toward the inner center due to the winding pressure, resulting in the minimum size, and there is no chance of the winding 15 loosening and protruding, which will prevent it from being washed away or exposed on the surface during resin molding. There is no risk of such.

In particular, the winding pressure of the toroidal winding 15 causes the insulation layer 2 formed on the surface of the stator core 11 to
0 is strongly tightened from the outside, and is securely held in close contact with the stator core 11 without causing distortion.
It is also possible to prevent deformation such as floating due to heat generation during use.

In other words, although the insulating layer made of pre-molded synthetic resin is layered on the stator core surface, the adhesion strength to the core is not very strong, and it is susceptible to peeling and deformation due to lifting, etc., especially due to the heat generation effect when the electric motor is used. However, according to the present invention,
The winding pressure of the winding itself wound on the outside of the insulating layer improves the adhesion of the insulating layer to the stator core, and the above-mentioned problem does not occur.

Therefore, it can be easily and reliably molded by increasing the injection pressure during resin molding or by using a resin material with high viscosity, and the entire stator has excellent strength and integrity, and the outside of the molded resin part When a mechanical impact is received from the stator, the impact is dispersed toward the inner center, resulting in a strong stator with excellent durability.
Further, as described above, the winding can be tightly wound around the stator core with the insulator interposed therebetween, without any gaps, so the winding efficiency can be increased and the quality can be stabilized.

Therefore, according to the present invention, a durable stator with excellent integrity can be provided easily and at low cost, and it greatly contributes to reducing the size and weight of induction motors by resin molding.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway perspective view of a stator showing an embodiment of the present invention, FIG. 2 is a longitudinal cross-sectional view of the same, and FIG. 3 is a longitudinal cross-sectional view showing an induction motor using the stator of the present invention. . DESCRIPTION OF SYMBOLS 1... Stator, 2... Rotor, 11... Stator core, 12... Slot, 13... Teeth, 14...
... Yoke part, 15 ... Winding wire, 16 ... Molding resin, 20 ... Insulating layer.

Claims (1)

[Claims] 1. The stator core has a number of slots spaced apart by teeth on the inner periphery, and an insulating layer is formed by pre-molding on the surface of the stator core except for at least the inner periphery of the teeth, A toroidal winding is applied in which the yoke is wound around each slot of the stator core through this insulating layer, and resin molding is performed to embed the winding, leaving at least the inner peripheral end surface of the teeth of the stator core. A stator for an induction motor, characterized by: