JPH04168947A - Thrust bearing structure for starter - Google Patents

Abstract

PURPOSE:To protect the end part against abrasion and to suppress noise due to contact by placing solid state lubricant between the end of a tubular fixed frame and the stepped part of shaft and the end of a bush. CONSTITUTION:A commutator is integrally molded 20 of phenol resin between commutator bars 19 and between the commutator bar 19 and a metallic or nonmetallic bush 21. A tubular part 20b is formed in the rear of the molded part 20 and lubricant, e.g. grease or oil, is placed in a space 22 defined by the tubular part 20b, the stepped part 12a of shaft, the tubular part 17a of the fixed frame and the end part 17b. Furthermore, a packing such as a rubber or a felt is applied on the inner peripheral surface 20b at the tubular part of the molded part 20 and the outer peripheral surface at the tubular part 17a of the fixed frame. According to the constitution, the end part can be protected against abrasion, noise due to contact can be suppressed, abnormal abrasion of the commutator bar and a carbon due to oil leakage can be prevented, and abnormal abrasion of a bearing 24 due to intrusion of carbon powder can also be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thrust receiving structure for a starter that starts an engine, and particularly to prevention of wear between a rotating part and an end face of a fixed frame and prevention of leakage of lubricant.

[Conventional technology]

As described in Japanese Utility Model Publication No. 63-34451, the conventional device includes a second washer between the stepped portion at the rear end of the armature shaft and the end of the second cylindrical portion of the rear bracket. It was designed to restrict the shaft from sliding toward the rear.

[Problem to be solved by the invention]

The above-mentioned conventional technology does not take into account the fact that the second washer wears out, and there are problems such as abrasion powder having an adverse effect on the adjacent sleeve bearing and commutator. Also the second
There were also problems such as the vibration of the washer causing abnormal noise.

The present invention aims to suppress wear as much as possible and prevent the occurrence of abnormal noise.

[Means to solve the problem]

In order to achieve the above purpose, the second washer is removed and sliding towards the rear is restricted at least between the stepped part of the motor shaft or the bush end face of the commutator inner circumferential part and the end face of the rear bracket cylindrical part. , with a lubricant such as grease or oil interposed between the inner circumferential surface of the first cylindrical part of the commutator, and
A seal made of rubber, felt, etc. is provided between the rear bracket and the outer peripheral surface of the cylindrical part to prevent oil leakage.

[Effect]

First, when current flows through the mag switch 2, the plunger 3 moves to the left, and the shift lever 4 rotates counterclockwise about the fulcrum 4a. As a result, clutch 5. The pinion gear 6 is moved to the right and meshes with the ring gear 7 directly connected to the engine. At the same time as they mesh, brush 8. Current flows through the commibar 9° coil 10 and the fixed coil 11, and the shaft 12 is supported by the front bearing 23 and rear bearing 24 and begins to rotate. A spline groove 13 is provided on the front portion of the shaft 12 and meshes with a spline 14 on the inner peripheral portion of the clutch 5, so that the clutch 5. The pinion gear 6 rotates, causing the pinion gear 7 to rotate and starting the engine. When the engine is started, the electric current of the mag switch 2 is cut off, the plunger 3 returns to the right, the pinion gear 6 and ring gear 7 are separated, and the shaft 1
2 also rotates and stops. The ring gear 7 continues to be rotated by the engine. The above is the general operation of the starter. Here, when the pinion gear 6 and ring gear 7 mesh, the shaft 12 also receives a thrust load in the front direction (right direction),
By the end surface 16a of the front frame 16 and the stopper 15,
Regulate sliding.

On the other hand, when the pinion gear 16 returns to the left, the shaft 12
receives a thrust load to the left, the tip 17b of the cylindrical portion 17a of the fixed frame 17 and the stepped shaft portion 12a come into contact, and the shaft 12 is restricted from sliding. This shaft 1
The sliding distance 2 is adjusted by the thickness and number of washers 18. The snap ring 19 is fixed to the shaft 12,
This prevents the washer 18 from falling off. There is a method of regulating sliding between the end surface 20a of the mold part 20 and the inner wall of the fixed frame 17, but bringing the mold made of resin into contact may cause abnormal wear of the mold end surface 20a.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. A plurality of commi bars 19 are arranged in the circumferential direction.
A mold part 20 made of a phenolic resin molding material is integrally molded between the bushings 21 made of metal or non-metal.

This commutator is press-fitted into the shaft 12 and rotates and slides together with the shaft 12. A cylindrical portion 20b is formed at the rear of the molded portion 20, and this and the stepped shaft portion 12
a and the cylindrical portion 17a of the fixed frame 17.

A lubricant such as grease or oil is interposed in the space 22 surrounded by the tip 17b to prevent wear and noise when the tip 17b and the stepped portion 12a come into contact and slide. In addition, the inner peripheral surface 20b of the cylindrical part of the mold part 20 and the fixed frame cylindrical part 17
A packing 2 made of rubber, felt, etc. is placed between the outer peripheral surface of a.
5 to prevent leakage of lubricants such as grease and oil,
Prevents abnormal wear due to lack of oil. Further, the tip of the bushing 21 may be flush with or protrude from the stepped shaft portion 12a, and may come into contact with and slide on the tip portion 17b.

〔Effect of the invention〕

According to the present invention, the presence of a lubricant can prevent wear of the tip and prevent noise from coming into contact. Further, by providing the packing, it is possible to prevent abnormal wear of the commibar and carbon due to oil leakage, and conversely, it is also possible to prevent abnormal wear of the bearing 24 due to intrusion of carbon powder. On the other hand, it also has the effect of preventing wear of the tip due to lack of oil.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a starter according to an embodiment of the present invention, and FIG. 2 is a partial sectional view of the main part of FIG.

Claims (1)

[Scope of Claims] 1. In a starter in which a cylindrical fixed frame extends within a cylindrical part of a rotatable commutator, and a motor shaft passes through an inner peripheral part of the cylindrical fixed frame, the cylindrical The structure is such that the tip of the fixed frame can come into contact with at least the stepped portion of the shaft or the end surface of the bush on the inner circumference of the commutator, and the tip of the cylindrical fixing frame, the stepped portion of the shaft, and the end surface of the bush A starter thrust receiving structure characterized by having a solid oil lubricant interposed between the starter and the starter. 2. In claim 1, a packing made of felt or rubber is provided between the outer circumference of the cylindrical fixed frame and the inner circumference of the cylindrical part of the commutator to prevent lubricant from leaking to the outside. The thrust receiving structure of the starter is characterized by: