JPH01138936A - Manufacture of induction motor stator - Google Patents

Abstract

PURPOSE:To prevent the deformation and damage of a winding by resin mold forming a stator core from the outside in the manner of embedding said winding while leaving the tooth part inner peripheral end face forming an opposed face at least to a rotor. CONSTITUTION:A toroidal winding 15, which winds a yoke part 14 via an insulating means for every slot 11, is applied to a stator core 10. Then, the whole stator core 10, to which said winding 15 has been applied, is molded into an integral body by injection of a molded material 18 composed of synthetic resin material to the outside in the manner of embedding said winding 15 while leaving the tooth part 13 inner peripheral end face of the stator core 10 forming an opposed face at least to a rotor. In this manner, there is no possibility of the winding coming off or being damaged at the time of resin mold forming.

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, for the purpose of making electric motors smaller and lighter and shortening the manufacturing process, in this type of electric motor, the stator core with windings is molded in resin by means such as injection molding or injection molding. Efforts have been made to manufacture stators that are integrally molded.

However, with the conventional winding storage method in which the windings are stored in the slots of the stator core as described above, the injection pressure during resin molding can cause the windings to be washed away, deforming or damaging them, or causing the windings to become damaged. There is a risk that the wires may be exposed on the mold resin surface. 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 materials used for this resin mold are generally made by mixing thermosetting resins such as polyester and epoxy with glass fiber and various fillers, and are 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.

That is, the method for manufacturing the stator of an induction motor according to the present invention is as follows:
A stator core has a large number of slots spaced apart by teeth on the inner periphery, and a toroidal winding around which a yoke is wound is provided for each slot of the stator core, forming at least the surface facing the rotor. It is characterized by resin molding so that the winding wire is embedded leaving the inner circumferential end surface of the tooth portion.

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 the stator, (2) is the rotor, (3) (3)
indicates a bearing that supports the shaft (4) of the rotor (2), and (5) indicates a frame portion.

In manufacturing the stator (1), first the second
As shown in the figure, a tooth section (13) having a large number of axial slots (12) spaced apart on the inner peripheral side facing the rotor (2).
) and a yoke part (14), a toroidal winding (15 ). 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 a plurality of parts in the circumferential direction, such as into two parts, and after winding each slot of the divided core via an insulating means, the divided cores may be joined together.

It is more efficient to wind the wire on a split core than on the annular stator core (lO).

Further, as the insulation means (1B) between the winding (15) and the stator core (10), at least a portion of the stator core (lO) or split core where the winding (15) is applied is made of an insulating material. 5(a) and (b), which approximately corresponds to the core shape of the tooth portion (13) and the yoke portion (14). Split insulators (18a) (lBb) are applied from both sides, especially the insulators (lea) (16b).
) can be provided with a collar (lee) to improve the winding condition, and furthermore, a conductive member for the Hiji wire can be provided on the collar (lee).

Even in the case where the insulator (lea) (18b) is attached to the stator core (10) as described above, the insulator (lea) is
a) (18b) is tightened inward and firmly adheres to the stator core (10), so that no air gap is created between the winding (15) and the stator core (10); This allows for tight wrapping.

Next, the stator core (
10) by a well-known resin molding method to embed the winding (15) leaving at least the inner peripheral end surface of the toothed portion (13) forming the surface facing the rotor (2) of the stator core (lO). Then, a molding material (18) made of synthetic resin is injected to the outside to integrally mold the whole. That is, a stator core (10) with windings (15) as shown in FIG.
is set in a mold (20), a resin material (18) is press-fitted into the mold (20), and the outside is covered with this resin material and fixed by molding. Thus, a stator (1) as shown in FIGS. 1 and 4 is obtained. 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, Japanese Patent Application Laid-Open No. 52-9
As seen in JP-A No. 8909 and JP-A-53-107605, well-known molding methods such as injection molding may be used, and molding materials (
As for 8), a synthetic resin material commonly used in this type of synthetic resin electric motor, etc., such as a synthetic resin material made by mixing polyester-based or epoxy-based thermosetting resin with glass fiber, various fillers, etc., is used. . The injection pressure of the molding material (18) varies depending on the viscosity of the molding material, etc., but is usually set to about 10 kg/c-.

Therefore, during the resin molding, the winding (15) is attached to the yoke portion (
14) in a toroidal shape, and the stator core (10
), so even if the molding material (18) is made of a relatively high viscosity resin material, the injection pressure is relatively high. Even if the winding (15) is washed away or scratched by the molding material (18), no defects occur. In addition, the winding wire (15) wound in a toroidal shape is compactly wound around the stator core (10) via an insulating means, so that no gap is created between the winding wire and the core, and the winding wire (15) is wound in a radial direction of the core. Since the dimension of protrusion in the outward direction is smaller, even if the thickness of the mold resin portion is reduced, there is no risk of the winding being exposed to the surface of the mold resin, and molding can be performed with a correspondingly smaller amount of mold resin material.

As described above, the present invention provides a toroidal winding for winding the yoke 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 winding from the outside so that the winding is embedded, we can increase the injection pressure during resin molding and mold the winding without worrying about deforming or damaging it, and we can also mold the winding with a small amount of molding resin. It is possible to reliably cover the stator without exposing it, thereby providing good protection, and to obtain a compact induction motor in which the stator has a compact external shape and the frame portion is integrally molded.

Furthermore, 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 the drawing]

FIG. 1 is a longitudinal cross-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 cross-sectional view showing the molded state, and FIG. A partially cutaway perspective view of the manufactured stator, FIGS. 5(a) and 5(b) are partial perspective views illustrating an insulating fitted body, and FIG. 6 is a longitudinal sectional view showing an induction motor according to the present invention. It is. (1)...Stator, (2)...Rotor, (10)...
... Stator core, (11) (11) ... Split core, (
12) Slot, (13) Teeth, (14)
... Yoke part, (15) ... Winding wire, (18) ... Mold material, (20) ... Mold mold. Patent applicant Shibaura Seisakusho Co., Ltd. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 [Q] [b]

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, at least on the surface facing the rotor. 1. A method for manufacturing a stator for an induction motor, characterized in that resin molding is performed so as to embed the windings while leaving the inner circumferential end surface of the teeth forming the shape.