JPH06261528A - Stepping motor - Google Patents

Abstract

PURPOSE:To obtain an inexpensive stepping motor in which a stator can be fixed with a resin housing even when the temperature changes and which can be easily assembled and worked. CONSTITUTION:Since a stator 3 is fixed by bringing the projections of a housing 1 and a cover 6 into contact with elastic projections on an insulator 10 united with the stator 3 in one body, the stator 3 can be fixed even when the temperature changes. As a result, an inexpensive stepping motor which can be easily assembled and worked can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for fixing a stator of a stepping motor having a housing made of resin or the like.

[0002]

2. Description of the Related Art With the development of car electronics in recent years, various motors have been mounted in automobiles as actuators. Among them, hybrid type stepping motors are also being installed in order to actively and finely control various controls of automobiles.

This type of motor comprises a stator around which a coil is wound, and a rotor rotatably supported inside the stator, and a torque is generated in the rotor by energizing the coil.

Conventionally, this type of stepping motor has a structure as shown in FIGS. 3 and 4 because the gap between the stator and the rotor is very small. This will be described below.

The stepping motors shown in FIGS. 3 and 4 are
The metal sleeve 2 having the fitting portion with the inner circumference of the stator 3 and the bearing 4 holding portion of the rotor 5 integrated with the resin housing 1 is press-fitted. Each is machined and press-fitted with dimensions close to the fitting tolerance. Further, the inner peripheral dimension of the metal sleeve 2 for fixing the bearing 4 of the rotor is also processed with the same tolerance as described above. Similarly, the metal sleeve 2 is press-fitted into the resin cover 6. The sleeve 2 holds the rotor held by the housing 1 and the other end of the stator.

[0006]

The stepping motor for electrical equipment has a severe operating environment, and its performance must be guaranteed especially by deformation or vibration of each part due to temperature change. Moreover, in order to reduce the weight, there is no choice but to use a resin material or the like. For example, when the thickness is 20 mm and the temperature change is 100 ° C. The linear expansion coefficient of iron is about 11 × 10E-6, and the linear expansion coefficient of resin is about 15 × 10E-5.

Therefore, conventionally, in order to fix the stator 3, a rubber molded product such as a corrugated washer 9 or an O-ring 12 for fixing the stator 3 by insert molding or applying pressure to the stator 3 is used. It was fixed. However, these methods are costly because they require man-hours, parts costs and assembly man-hours.

The present invention solves the above-mentioned problems, and can fix the stator easily, has the same reliability as the conventional method with respect to temperature changes, and is a low-cost stepping motor. Is intended to provide.

[0009]

In order to achieve the above object, the present invention provides a structure in which a resinous insulator for insulating a stator from a coil is brought into contact with a resinous housing and a protrusion having a spring property. It was done.

[0010]

With the above-described structure, the present invention can provide a low-cost stepping motor because the stator is always securely fixed even if a gap due to temperature change occurs due to the protrusion having a spring property on the insulator, and the number of processing steps is small. .

[0011]

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

FIG. 1 is a sectional view of a hybrid stepping motor according to an embodiment of the present invention, and FIG. 2 is a perspective view of a stator assembly thereof. The cover 6 and the housing 1 are fixed by a method such as screws or welding. The inner diameter of the bearing portion of the sleeve 2 is press-fitted and fixed to the outer circumference of the bearing 4 of the rotor 5. The outer diameter is fixed by press fitting with the inner diameter of the stator 3.

The insulator 10 mounted on the stator 3 is integral with the stator 3 because a coil is wound around it. The insulator 10 is provided with a spring-like projection 11, and the projection 11 fixes the stator 3 by coming into contact with the housing 1 and the tapered projection 7 of the cover 6. Further, since the protrusion 11 of the insulator 10 has a spring property, it can absorb the gap in which the temperature change occurs and fix the stator in any environment.

Further, since the protrusions can be molded integrally with the insulator 10, the housing 1 and the cover 6 with resin, respectively, the assembly is easy and the number of assembling steps is reduced, so that a low-cost stepping motor can be provided.

It goes without saying that the same effect can be obtained even if the protrusion 11 of the insulator 10 is brought into contact with only one of the housing 1 and the cover 6.

[0016]

As is clear from the above description, the insulator is provided with the spring-like projection, and the projection is brought into contact with the tapered projection of the housing or the cover, whereby the stator is fixed and the temperature is kept constant. Even if it changes, it can be fixed by the spring property. Furthermore, a low-cost stepping motor can be provided due to the small number of processing steps.

[Brief description of drawings]

FIG. 1A is a front view of a motor according to an embodiment of the present invention. FIG. 1B is a sectional view taken along line XX ′ of FIG. 1A.

FIG. 2 is a perspective view of a stator assembly according to an embodiment of the present invention.

FIG. 3 is a sectional view of a conventional motor

FIG. 4 is a sectional view of another conventional motor.

[Explanation of symbols]

 1 Housing 2 Sleeve 3 Stator 4 Bearing 5 Rotor 6 Cover 7 Cover or Housing Protrusion 8 Coil 9 Wave Washer 10 Insulator 11 Insulator Protrusion 12 O-ring

Claims (1)

[Claims] 1. A stepping device characterized in that a spring property is provided in a part of an insulator attached to a stator, and the stator is fixed while a part of the insulator contacts a housing or a cover holding the stator. motor.