JPH0147099B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing 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,
BACKGROUND ART A stator core having windings has been molded into a resin mold by means such as injection molding or injection molding to produce an integrally molded stator.

However, with the conventional winding storage method in which the windings are stored in the slots of the stator core as described above, the windings are washed away by the injection pressure during resin molding, causing deformation and damage. Additionally, there is a risk that the windings may be exposed on the surface of the molding resin. In order to prevent this, it is possible to lower the injection pressure of the resin material used as the molding material, but in this case, depending on the viscosity of the resin material, the resin material may not flow sufficiently into the slots etc. inside the stator core. A resin material with a very high viscosity cannot be used because it will cause problems.

In particular, the synthetic resin material used for this resin mold is generally a mixture of thermosetting resins such as polyester and epoxy with glass fiber and various fillers, and is usually quite viscous. The injection pressure cannot be lowered too much, and the problems described above are likely to occur.

In view of the above, the present invention aims to reduce the size and weight of induction motors and shorten the manufacturing process.The present invention aims to reduce the size and weight of induction motors and shorten the manufacturing process. It is an object of the present invention to provide a method for manufacturing a stator that can be reliably molded without fear of flowing or being damaged, and that also allows the use of a relatively high viscosity resin material.

In other words, the method of manufacturing a stator for an induction motor according to the present invention involves winding a yoke around each slot of a stator core having a large number of slots spaced apart by teeth on the inner periphery. It is characterized in that the winding is applied and resin molding is carried out so that the winding is embedded, leaving at least the inner circumferential end surface of the tooth portion that forms the surface facing the rotor.

Next, embodiments of the present invention will be described based on FIGS. 1 to 6.

FIG. 1 shows a stator manufactured according to the present invention, and FIG. 6 schematically shows an induction motor using the stator. In the figure, 1 is a stator, 2 is a rotor, 3, 3 is a bearing that supports the shaft 4 of the rotor 2, and 5 is a rotor.
indicates the frame part.

In manufacturing the stator 1, first, as shown in FIG. To the stator core 10, a toroidal winding 15 is provided for each slot 12, around which a yoke 14 is wound through an insulating means. In this case, in addition to directly winding the annular stator core 10 in which the tooth portion 13 and the yoke portion 14 are integrally formed using a toroidal winding device, the stator core 10 may be divided into two, etc. It is also possible to form the divided core in a plurality of directions, and after winding each slot of the divided core via an insulating means, the divided cores can be joined together. It is more efficient to wind the wire around the split core than to wind the wire around the annular stator core 10.

The insulation means 16 between the winding 15 and the stator core 10 may be formed by painting an insulating material on at least a portion of the stator core 10 or split cores to which the winding 15 is applied, or may be formed of a synthetic material. Split-shaped insulators 16a and 16b having shapes as shown in FIGS. 5a and 5b, which approximately correspond to the core shapes of the tooth portion 13 and the yoke portion 14, are adhered from both sides using an insulating material such as resin. , especially the insulators 16a, 16
b can be provided with a flange 16c that improves the winding condition, and furthermore, a conductive member for the lead wire can be provided on the flange 16c.

Even in the case where the insulators 16a and 16b are attached to the stator core 10, the insulator 1
6a and 16b are tightened inward and tightly adhered to the stator core 10, and as a result, the windings 15 and stator core 10 can be tightly wound without creating any voids between them. .

Next, the stator core 10 having the windings 15 applied thereto as described above is molded using a well-known resin molding method, so that at least the inner circumferential end surface of the toothed portion 13, which forms the surface facing the rotor 2, of the stator core 10 is molded using a well-known resin molding method. A molding material 18 made of a synthetic resin material is injected to the outside so as to embed the remaining winding wire 15, and the whole is molded and integrated. That is, as shown in FIG. 3, the stator core 10 with the winding 15 is set in a mold 20, a resin material as the mold material 18 is press-fitted into the mold 20, and the outside of the stator core 10 is set in a mold 20. The stator 1 is covered with a resin material and fixed by molding, thereby obtaining the stator 1 shown in FIGS. 1 and 4. Note that the frame portion 5 of the electric motor is also integrally formed with this resin mold.

As the resin molding method, for example,
As seen in JP-A No. 52-98909 and JP-A No. 53-107605, well-known molding methods such as injection molding may be used, and this type of synthetic resin can also be used as the molding material 18. Synthetic resin materials commonly used in electric motors, etc.
For example, a synthetic resin material is used, which is a mixture of polyester-based or epoxy-based thermosetting resin with glass fiber, various fillers, and the like. The injection pressure of the molding material 18 is usually set to about 10 kg/cm ² although it varies depending on the viscosity of the molding material.

However, during the resin molding, the winding 1
5 is wound in a toroidal manner around the yoke portion 14 of each slot 12 of the stator core 10, and the stator core 1
0, even if the mold material 18 is made of a relatively high viscosity resin material or the injection pressure is relatively high. Therefore, defects such as the winding 15 being washed away by the molding material 18 or being scratched do not occur. In addition, the winding 15 wound in a toroidal shape is compactly wound around the stator core 10 via an insulating means, so that no air space is created between the winding and the core, and the winding 15 is wound in a radial direction or outward direction of the core. Since the protrusion dimension is smaller, even if the thickness of the mold resin portion is reduced, there is no risk of the winding being exposed to the mold resin surface, and molding can be performed with a correspondingly smaller amount of mold resin material.

As described above, the present invention provides a toroidal winding around which a yoke is wound in each slot of the stator core, leaving at least the inner circumferential end surface of the tooth portion facing the rotor. Since we decided to mold the resin from the outside so as to embed the winding, the injection pressure during resin molding can be increased and the winding can be molded without the risk of deforming or damaging it.
To obtain a compact induction motor that can securely cover and protect the windings without exposing them with a small amount of molding resin material, and has a stator with a compact external shape and a frame part integrally molded. Can be done.

Moreover, by increasing the injection pressure as mentioned above, the time required for injection molding can be shortened, and together with the fact that the windings are tightened to the stator core, it is possible to use a resin material with high viscosity. This makes it possible to obtain a motor with high mold resin strength.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a stator manufactured according to the present invention, FIG. 2 is a schematic front view showing the winding structure of the stator, FIG. 3 is a longitudinal sectional view showing a molded state, and FIG.
The figure is a partially cutaway perspective view of the manufactured stator, FIGS. 5a and 5b are partial perspective views illustrating an insulating fitting, and FIG. 6 is a longitudinal sectional view showing an induction motor according to the present invention. be. 1... Stator, 2... Rotor, 10... Stator core, 11, 11... Split core, 12... Slot, 13... Teeth, 14... Yoke, 15... Winding , 18...Mold material, 20...Mold type.

Claims (1)

[Claims] 1. A stator core has a large number of slots spaced apart by teeth on the inner periphery. A toroidal winding is provided around each slot of the stator core, and a yoke is wound around each slot so that the stator core is at least facing the rotor. A method for manufacturing a stator for an induction motor, characterized in that resin molding is performed to embed the windings while leaving the inner peripheral end surfaces of the tooth portions forming a surface.