JPS63309767A - Starter motor for automobile - Google Patents

Abstract

PURPOSE:To surely regulate the thrust of an armature by a holding washer in simple ways by forming a circumferential groove onto a bracket for supporting one edge of an armature shaft through bearings and inserting the holding washer into the circumferential groove. CONSTITUTION:The armature 2 of a motor 1 is constituted of a shaft 3 arranged at the center part and a commutator 5 having a brush 4 contacting the outer periphery. The both edges of the shaft 3 are supported by a bracket 7 and a gear case 9 through bearings 6 and 8. The holding plate 13 of a holder 12 for accommodating the brush 4 is fixed by a screw 14 onto the bracket 7. With such constitution, a circumferential groove 11 is formed between the commutator 5 fixed onto the shaft 3 and one edge 10 of the shaft 3 supported by the bearing 6. A holding washer 15 is inserted into the circumferential groove 11. Therefore, the shift of the armature 2 in the axial direction is regulated by the holding washer 15.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a starter motor for an automobile, and particularly to a thrust mechanism of an armature of a starter motor that has a simple structure and does not require thrust adjustment.

[Conventional technology]

Conventional starter devices for automobiles are, for example,
As described in Publication No. 8056, etc., the thrust of the armature of the DC motor (starting motor) opens the protruding tip of the bearing part of the bracket (supporting cover), and the armature shaft protrudes from this open part. (drive shaft) and a circumferential groove and insert a retaining ring.This creates a mechanism that holds the armature in the axial direction with the commutator (commutator) and retaining shaft on the bracket, and furthermore, the protrusion of the bracket is released. The amount of thrust of the armature was adjusted by covering the area with a cover and inserting washers into the retaining ring and the open end of the bracket protrusion.

[Problem that the invention seeks to solve]

However, the above-mentioned conventional technology has the problem that the number of parts increases due to its configuration, the shaft length becomes long, and the number of assembly steps also increases because it is necessary to insert the washer for thrust adjustment. .

In view of the problems in the prior art described above, an object of the present invention is to
It is an object of the present invention to provide a starter motor for an automobile that has a thrust mechanism that reduces the axial length of the starter motor and is also easy to assemble.

[Means for solving problems]

The object of the present invention is to provide a structure in which a circumferential groove is provided inside the bracket near the end of the armature shaft of a starter motor, a retaining washer is fixed to the bracket, and the retaining washer is inserted into the circumferential groove of the shaft. This is achieved by a starter motor with a mechanism to the thrust 1.

[Effect]

Due to the thrust mechanism described above, the motor armature moves smoothly in the rotational direction, but its axial movement is regulated by the washer, making it possible to assemble the motor with high precision without adjusting the armature thrust amount. .

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

In Fig. 1, 2 is a DC motor 1 of an automobile starter.
Armature with armature shaft located in the center 3. It consists of a commutator 5 with a braai 4 in contact with the outer periphery, and both ends of the armature shaft 3 are supported by a gear case 9 via a bearing 6, a bracket 7, and a bearing 8. A circumferential groove 1 is formed between a commutator 5 integrally fixed to the armature shaft 3 and a shaft end 10 supported by a bearing 6.
1 is installed, a brush holder holding plate 13 of a brush holder 12 that houses the bracket 7 and the brush 4 is fixed with a set screw 14, and a holding washer 15 held between the two is inserted.

As shown in FIG. 2, this holding washer 15 has a hollow portion in the center of a substantially disk shape for supporting the shaft, and further has a substantially U-shape for inserting the circumferential groove 11 of the shaft from the side. It has a notch 30 with a narrow entrance and a wide groove in the center. Also, retaining washer 1
5 is a circumferential groove 11 of the armature shaft 3 shown in FIG.
The width of this groove is slightly larger than the thickness of the holding washer 15, so that it can rotate smoothly in the rotational direction, but can be held with a small amount of thrust with a small gap in the axial direction. Since the holding washer 15 is fixed to the bracket 7, the movement of the armature 2 in the axial direction is due to the difference between the groove width of the circumferential groove 11 and the thickness of the holding washer 15.

On the opposite side of the armature shaft 3 to the commutator 5 is a ring gear 16 that is directly connected to the engine crankshaft (not shown).
A pinion 17 that moves in the axial direction and engages with the armature shaft 3 is disposed, and the pinion 17 is fixed to the armature shaft 3 in the rotational direction and is integrally formed with a one-way clutch 18 that moves in the axial direction.

A washer 20 is fixed to the sleeve 19 of the one-way clutch 18, and one end 22 of the shift lever 21 is inserted into the outer circumference of the sleeve 19 between the one-way clutch 18 and the washer 20. The fulcrum 24 of the shift lever 21 is pressed against the pushing spring 25 of the gear case 9, and the other end 23 is inserted into the engagement hole 28 of the plunger 27 of the shift solenoid switch 26.

Numeral 29 is a through bolt that integrally fixes the field 31° bracket 7 of the DC motor 1 and the gear case 29.

In the above configuration, when the shift solenoid switch 26 is operated, the plunger 27 moves in the axial direction, and the shift lever 21 inserted into the engagement hole 28 rotates to the left about the fulcrum 24. The one-sided clutch 18 and pinion 17 engaged with the other end 22 move to the right, and the pinion 17 meshes with the ring gear 16. On the other hand, the DC motor 1 is energized via the shift solenoid switch 26, and the armature 2 rotates. As the armature 2 rotates, the armature shaft 3 that is integrally formed also rotates, and the one-sided clutch 18 that is fixed to the armature shaft 3 in the rotational direction. The pinion 17 also rotates, turning the ring gear 16 and starting the engine.

In such an operation, the armature 2 is fixed with a small gap in the axial direction by the holding washer 15 inserted into the circumferential groove 11 installed in the armature shaft 3, so that the armature 2 exhibits a stable state during rotation.

Furthermore, since the diameter of the armature shaft 3 that contacts the holding washer 15 at this time is small, friction loss is small and the performance of the DC motor 1 can be improved.

According to this embodiment, the thrust of the armature 2 is reliably and accurately ensured with a simple structure in which the holding washer 15 held between the bracket 7 and the brush holder holding plate is inserted into the circumferential groove 11 of the armature shaft 3. There is an effect that can be done.

〔Effect of the invention〕

According to the present invention, the structure is as simple as inserting the holding washer 15 into the circumferential groove 11 installed in the armature shaft 3 inside the bracket 7, and the number of parts is small, the shaft length can be shortened, and friction loss is reduced. This has the effect of making it more efficient with less.

[Brief explanation of drawings]

1 is a longitudinal cross-sectional view showing one embodiment of the present invention, FIG. 2 is a perspective view of the holding washer shown in FIG. 1, and FIG. 3 is a perspective view showing the shaft end portion of FIG. 1.

Claims (1)

[Scope of Claims] 1. An armature of a starter DC motor, a field magnet that together with the armature constitutes the DC motor, a bracket that includes a bearing that supports the shaft end of the armature, and a brush holder held in the bracket. In a starter motor for an automobile comprising a brush fixed through a plate, a circumferential groove is provided inside the bracket near one end of the armature shaft, and a retaining washer is fixed to the end of the bracket, and the circumferential groove A starter motor for an automobile, characterized in that a thrust of the armature is defined by inserting the holding washer into the starter motor. 2. The starter motor for an automobile according to claim 1, wherein the holding washer inserted into the circumferential groove of the armature shaft that regulates the thrust of the armature is U-shaped. 3. The starter motor for an automobile according to claim 1, wherein the holding washer is held between the bracket and the brush holder holding plate. 4. The starter motor for an automobile according to claim 2, wherein the U-shaped holding washer has a narrow groove at its entrance and a wide groove at its center.