JPH0837750A - Stator holding structure - Google Patents

Abstract

PURPOSE:To surely stop the movement of a stator so as to improve the insertability of the stator into a case by providing a projecting section outside a frame and recessed section inside the case correspondingly to it so that the former can become larger than the latter at a normal temperature and the former can become smaller than the latter at a temperature which is the sum of the highest operating temperature and an operation temperature rise. CONSTITUTION:A projecting section 2a is provided outside a frame 2 and a recessed section 1a is provided inside a case 1. In addition, a plurality of small projecting sections 2b are provided outside the frame 2. The outside diameter of the frame 2 is set so that the diameter can become larger than the inside diameter of the case 1 at a normal temperature and, when the case 1 is preheated to the highest operating temperature of a stator, the outside diameter of the frame 2 can become smaller than the inside diameter of the case 1 and the outside diameter of the small projecting sections 2b can become larger than the inside diameter of the case 1. Therefore, a sufficiently strong retaining force can be obtained to fix the stator and case 1 even when the stator is operated at the worst operating temperature, because the movement of the stator in both the rotational and axial directions can be prevented. At the time of inserting the stator into the case 1, in addition, the stator can be smoothly inserted into the case 1, because the preheating temperature of the case 1 is set within a relatively low temperature range.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stator holding structure which contributes to weight reduction of a motor by using a resin case in the demand for weight reduction of the motor in all fields.

[0002]

2. Description of the Related Art In recent years, demands for weight reduction of motors, particularly in the field of automobiles, have become strict, and the use of resin for the motor case has been extensively studied.

The above-mentioned conventional stator holding structure will be described below with reference to FIGS. 4 and 5.

As shown in FIG. 4, a frame 2 and a case 1
To prevent the movement of the stator, inject the adhesive 5 into the gap of the frame to fix the frame 2 and the case 1 or insert the stator into the case 1 as shown in FIG. 5 and then fix the cover 6 via the preload spring 7. Was there.

[0005]

As described above, in the conventional motor case, when an adhesive is used, workability, quantity control, securing the coaxiality of the case and the stator inner diameter with respect to the case, heat resistance of the adhesive, It has a difficulty in cold resistance, and when the preload spring is used, it is difficult to secure the coaxiality and to use the preload spring itself as an extra material.

The present invention has been made to solve the above-mentioned problems, and provides a stator holding structure for improving the insertability of the stator into the case by ensuring the movement of the stator by devising the shapes of the frame and the case. .

[0007]

In order to achieve the above object, the present invention provides a frame outer diameter with, for example, one convex portion,
The concave portion corresponding to the convex portion is made of resin (for example, PBT, PE
T) A plurality of (for example, 3 to 6) minute convex portions are provided on the outer circumference of the case, and the outer diameter of the frame is set to be larger than the inner diameter of the case at room temperature of the motor in the highest environment in which the motor is used. When the case is preheated at a temperature plus a temperature increase due to motor operation, the frame outer diameter is smaller than the case inner diameter, and the plurality of minute convex portion outer diameters of the frame outer circumference are larger than the case inner diameter. It is configured so that

[0008]

With the above-described structure, the present invention prevents the movement of the stator in the case by using the frame outer diameter and the case inner diameter in the usage state including the environmental temperature of the motor without using any additional parts, It is possible to prevent motor lock, vibration, and noise due to the movement of the stator.

Also, the insertability of the stator into the case can be easily made by preheating the case in a relatively low temperature range.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

As shown in the figure, the outer diameter of the frame 2 is 1
A convex portion 2a is provided, a concave portion 1a corresponding to the convex portion 2a of the frame 2 is provided on the inner diameter of the case 1, and a plurality of (for example, 3 to 6) minute convex portions 2b are provided on the outer periphery of the frame 2. It is provided.

A coil 3 and a yoke 4 are provided on the frame 2.
Are housed to form a stator.

The outer diameter of the frame 2 is larger than the inner diameter of the case 1 when the motor is at room temperature, and when the case 1 is preheated at a temperature including the maximum operating temperature environment and the temperature rise caused by the motor operation, the outer diameter of the frame 2 is It is set to be smaller than the inner diameter of the case 1 and larger than the outer diameter of the minute convex portion 2b of the frame 2.

As described above, according to the stator holding structure of the embodiment of the present invention, it is possible to prevent the stator from moving in any direction in the case 1 even when the motor is used at the worst environmental temperature.

[0015]

As is apparent from the above embodiments, according to the present invention, the concave portion of the case and the convex portion of the frame can prevent movement in the rotational direction, and the minute convex portions on the outer periphery of the frame prevent movement in the axial direction. Even if the motor is operated at the worst operating environment temperature, the stator and the case can be fixed without the use of an adhesive or a preload spring, and the occurrence of problems such as motor locking, vibration, and noise due to movement can be prevented. In addition, a necessary and sufficient stator holding force can be obtained without applying an excessive stress to the resin (for example, PBT or PET) case. Further, even when the stator is inserted, the case can be preheated in a relatively low temperature region, and the stator can be smoothly inserted.

[Brief description of drawings]

FIG. 1 is a perspective view showing a case which is an embodiment of the present invention.

FIG. 2 is a perspective view showing a frame which is an embodiment of the present invention.

FIG. 3 is a cross-sectional view when a stator according to an embodiment of the present invention is inserted into a case.

FIG. 4 is a sectional view showing a state in which a stator is inserted in a conventional case.

FIG. 5 is a sectional view of a conventional motor

[Explanation of symbols]

 1 case 1a concave part of case 2 frame 2a convex part of frame 2b minute convex part of frame 3 coil 4 yoke 5 adhesive 6 cover 7 preload spring

Claims (1)

[Claims] 1. A convex portion is provided on an outer diameter of a frame for housing a coil and a yoke, a concave portion corresponding to the convex portion is provided on an inner diameter of a resin case, and a plurality of minute convex portions is provided on an outer circumference of the frame. The diameter is set to be larger than the inner diameter of the case at room temperature of the motor, and when the case is preheated at a temperature including a maximum environmental temperature in which the motor is used and a temperature increase due to motor operation, the outer diameter of the frame is The stator holding structure is characterized in that it is set to be smaller than the case inner diameter, and the outer diameters of the plurality of minute convex portions on the outer periphery of the frame are set to be larger than the case inner diameter.