JPH08298740A - Molded motor - Google Patents

Abstract

PURPOSE: To provide a molded motor which can enhance the accuracy of the inside diameter of a bearing housing without requiring a special mold and a special working method, in the nearly same number of processes as in prior art cases and by using low-cost components, which reduces a noise and a vibration and whose accuracy can be enhanced. CONSTITUTION: A cylindrical component 10 which is composed of a metal for contraction prevention is inserted integrally into a bearing housing 6 which is molded integrally by a molding resin. Consequently, the dimensional accuracy of the inside diameter of the bearing housing 6 which is molded integrally with a winding and 1 by a molding resin can be increased easily, and it is possible to realize a molded motor which reduces a noise and a vibration and whose reliability is high.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molded motor in which a winding complete and a bearing housing are integrally molded with resin.

[0002]

2. Description of the Related Art Conventionally, in a molded motor in which a winding is completely sealed, a bearing housing is manufactured in advance by metal press parts, etc., and is inserted into a molding die at the time of molding and is integrally molded. A molding method, a housing press-fitting method in which the bearing housing is press-fitted and fixed to a molded finished product that seals the winding complete when assembling the motor, or a method in which the bearing housing is mechanically attached to the completed mold with screws etc. there were.

However, in each of the above methods, the number of precision molds for manufacturing the bearing housing, the number of facilities, and the number of man-hours for insert molding or press fitting, screwing, etc. have increased. Further, in a method in which the bearing housing is press-fitted or fixed mechanically at the time of assembling the motor, the concentricity of the stator core and the bearing portion tends to be deviated.

In order to improve these problems, in recent years,
When sealing one end of the bearing housing with resin,
At the same time, the method of integrally molding has come to be widely used. As this method, in order to guarantee the concentricity of the bearing housing part and the stator core inner diameter, a mold incorporating a mold called a center shaft in which the bearing housing part and the stator core inner diameter part are integrally processed by a method such as cylindrical polishing. The bearing housing was integrally molded at the same time that the winding was molded by using, and the inner diameter accuracy and the concentricity with the inner diameter portion of the stator core were secured.

FIG. 2 is a cross-sectional view of a conventional molded motor of the integral bearing type. The bearing housing 6 includes an upper die forming an upper portion 6a of the bearing housing and a bearing housing inner diameter 7
It is formed by a mold composed of a center shaft that forms the. The upper mold is combined with the lower mold that forms the hinge portion 2 of the motor, and gates 3 for injecting resin are provided at both ends of the lower mold. Generally, in such a configuration, the inner diameter 7 of the bearing housing contracts in the direction of the gate 3 and the number 1 in the direction perpendicular to the direction
It is known that there is a tendency for the size to decrease by about 0 μ.

[0006]

A motor in which one bearing housing is integrally molded with resin is rational because the number of parts can be reduced, and the man-hours during molding resin molding and motor assembly are extremely small. It was However, in order to manufacture motors with low noise and high reliability that are required more and more, it has been indispensable to further improve the accuracy of the bearing housing inner diameter. Not only the physical properties, but also the surroundings of the bearing housing, the shape of the end of the winding, the preheating temperature of the end of the winding, and the temperature of the mold are also greatly affected. Although it is known that the bearing housing has a close relationship, it was extremely difficult to mold the bearing housing in accordance with the dimensional accuracy (especially the roundness) of the original die called the center shaft. That is, the inner diameter of the bearing housing after molding tends not to be a perfect circle, no matter how accurately the mold is processed into a perfect circle due to the shrinkage of the resin.

The present invention solves the above problems and requires substantially the same number of man-hours as the present, without requiring a special mold and a processing method.
Another object of the present invention is to provide a molded motor that can improve the accuracy of the bearing housing inner diameter with inexpensive parts, reduce noise and vibration, and improve reliability.

[0008]

In order to achieve the above-mentioned object, the molded motor of the present invention is configured such that a cylindrical component for preventing shrinkage is inserted into a bearing housing integrally molded with a molding resin.

[0009]

According to the present invention, with the above-described structure, it is possible to easily improve the inner diameter dimension accuracy of the bearing housing integrally formed with the molding resin so that the winding is completed, reduce noise and vibration, and manufacture a highly reliable molded motor. You can

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1A is a partial perspective view of a molded motor according to an embodiment of the present invention, and FIG. 1B is a sectional view of the molded motor. As described above, in the conventional molded motor shown in FIG. 2, the inner diameter of the bearing housing shrinks in the direction of the gate, and tends to decrease by several tens of μ in the direction perpendicular to the direction. Therefore, in the present embodiment, FIG.
As shown in (b), the bearing housing 6 includes an upper die forming the bearing housing upper portion 6a and a bearing housing inner diameter 7
It is formed by a mold composed of a center shaft that forms the. The upper mold is combined with the lower mold that forms the hinge portion 2 of the motor, and both ends thereof are provided with gates for injecting resin. Generally, in such a configuration, the inner diameter 7 of the bearing housing shrinks in the direction of the gate, and a few tens of degrees in the direction perpendicular to the direction
It is known that there is a tendency to decrease by about μ. In order to eliminate the deviation from the line of the perfect circle due to the contraction,
By inserting and molding the metallic cylindrical part 10 into the bearing housing 6, the inner diameter dimension after molding shrinkage is secured. For this cylindrical part 10, an inexpensive iron material having a linear expansion coefficient equivalent to that of the molding resin used for molding is selected. The inner diameter 11 is 10 to 10 of the inner diameter 7 of the bearing housing.
30% increase, outer diameter 12 is 5 of bearing housing outer diameter 14
Reduce by 10%. The thickness 13 is 50 to 80% of the bearing housing depth 15.

This cylindrical part 10 is mounted on the center shaft 16 at the time of molding, and the winding 1 and integral molding are performed.
Even when mounted on the center shaft 16, it is possible to easily mount it because there is no need for fine dimensional regulation, and it is possible to process with less man-hours than the conventional method in which the bearing housing part is manufactured in advance by a separate part and insert-molded. is there.

By inserting and molding the cylindrical part 10, the inner diameter 7 of the bearing housing hardly shrinks even when heat shrinks due to cooling after the molding, and the original size of the mold called the center shaft is maintained. A molded product will be obtained,
It is possible to manufacture a molded motor with extremely high dimensional accuracy.

[0013]

As described above, according to the present invention, a molded motor having extremely high dimensional accuracy can be manufactured at a low cost and easily processed, and the man-hours can be manufactured at the same level as before, and noise and vibration can be reduced. A highly reliable molded motor can be realized.

[Brief description of drawings]

FIG. 1A is a partial perspective view of a molded motor according to an embodiment of the present invention. FIG. 1B is a sectional view of a molded motor according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a conventional molded motor of a bearing integral molding type.

[Explanation of symbols]

 1 Winding complete 6 Bearing housing 7 Bearing housing inner diameter 10 Cylindrical part

Claims (1)

[Claims] Claims: 1. A molded motor in which the winding is completely sealed with resin, one bearing housing is integrally molded with the same resin, and a cylindrical part for preventing shrinkage is formed in the bearing housing. Molded motor characterized by being inserted.