JPH0443861A - Starter for internal combustion engine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a starter for starting an internal combustion engine such as an automobile, and particularly to a bearing structure suitable for reducing shaft vibration of the starter.

[Conventional technology]

Conventionally, ball bearings or metal bearings (oil-less bearings) have been used as bearing devices for the armature rotating shaft and output rotating shaft of starters, as described in Japanese Patent Publication No. 63-44944. . In particular, metal bearings allow for smaller bearing devices.

It is superior in terms of cost and productivity, and in the starter, as shown in the example shown in FIG. 2, the armature rotating shaft 1a is rotatably supported by a cylindrical bearing 7 held by press-fitting or the like in a rear bracket 6. Therefore, the bearing support part 1 of the armature rotating shaft 1a
The clearance between the outer diameter of b and the inner diameter of bearing 7 is maintained at a certain value in order to prevent problems such as seizure.
It remains cluttered.

[Problem to be solved by the invention]

In the above conventional technology, as shown in FIG.
There is a problem in that the central axes of both parts are tilted due to the play between the outer diameter of the bearing support part 1b and the inner diameter of the bearing 7. For example, in order to make the product itself thinner and lighter, the rigidity of the bearing support part may be reduced, or if the shaft swings around due to armature imbalance or gear mesh reaction force during actual operation, etc. If there is significant misalignment due to variations in the processing and assembly accuracy of each part, it is expected that the shaft and bearing will be in uneven contact as shown in the figure. Therefore, it becomes a cause of noise due to shaft vibration and causes problems such as uneven wear and seizure of the bearing.

An object of the present invention is to provide a bearing structure that maintains a flexible relationship between the shaft and the bearing even in response to these factors.

[Means to solve the problem]

The above object is achieved by providing a bearing structure in which a ring-shaped outer diameter spherical convex portion is provided on the outer periphery or end of the shaft, and an inner diameter spherical groove is provided in the bearing, which is a concave portion that fits into the ring-shaped convex portion. As shown in FIG. 4, a bearing support part 1b with an outer diameter spherical surface attached to the end of the armature rotation shaft 1a, a bearing 7 with an inner diameter spherical groove held on the rear bracket 6, and a bearing support part 1b It is composed of a thrust spring 9 that presses in the thrust direction.

[Operation] By fitting the shaft and the bearing with the engagement between the outer diameter spherical convex part and the inner diameter spherical concave part, like a universal joint, the fifth
As shown in the figure, since the bearing support part 1b and the bearing 7 of the armature rotation @la have a relative degree of freedom, the rear bracket 6 may be deformed or the armature rotating shaft 1a may whirl around and cause vibration. Even if the center of the bearing shifts, the bearing support part 1b rotates inside the bearing to absorb the shift, and the bearing support part 1b is always pressed against the inner spherical surface of the bearing 7 by the thrust spring 9. The gap between the shaft and bearing is maintained at zero, and a good positional relationship can be maintained.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure is a longitudinal sectional view of a starter for starting an internal combustion engine according to an embodiment of the present invention.

In Fig. 1, the rotational output of motor 1 is
From the sun gear 1c formed at the end of the sun gear 1c, an internal gear 2 installed on this gear via an annular space and a plurality of planetary gears arranged at equally divided positions on the circumference of the annular space. 3. The planetary gear 3 is rotatably supported by a planetary gear shaft 4, and the planetary gear shaft 4 is held by a planetary carrier 5a that is integral with a pinion shaft 5, which is an output shaft. The rotation of each planetary gear 3 is transmitted to the pinion shaft 5 by meshing with the internal gear 2, causing the planetary gear 3 to revolve. The armature rotating shaft 1a includes a bearing 7 held by a rear bracket 6 and a pinion shaft 5.
It is rotatably supported by a bearing 8 disposed inside.

Conventional armature bearing devices are based on a general cylindrical shaft and a cylindrical bearing fitted together, and require clearance between the outer diameter of the shaft and the inner diameter of the bearing, resulting in backlash. Therefore, there is a mode in which the shaft and bearing make partial contact due to deformation of the casing that holds the bearing, whirling vibration of the shaft, etc.

This caused uneven bearing wear and noise.

In contrast, in the present invention shown in FIG.
The bearing support portions 1b and Ld of a are made into a spherical outer diameter shape, and the bearings 7 and 8 that fit therein are made into a spherical inner diameter groove shape, and a bearing device is constructed by the engagement of both. The advantage of this structure is that when the armature rotating shaft 1a is tilted, the bearing supports 1b at both ends,
ld can rotate and slide within the inner spherical surface of the bearing 7°8, and performs an alignment action between the shaft and the bearing, and at the same time, the bearing support portion 1b is always pressed against the thrust direction of the inner spherical surface of the bearing 7 by the thrust spring 9. Therefore, the gap between the shaft and bearing becomes zero. Therefore, since bearing performance is maintained well, a flexible rotation support system can be provided.

〔Effect of the invention〕

According to the present invention, due to the alignment effect of the bearing structure itself, uneven contact of the bearing part that occurs due to deformation of the casing, whirling of the shaft, misalignment during assembly, etc. can be prevented.
Uneven bearing wear and noise can be reduced.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of essential parts of a starter for starting an internal combustion engine, which is an embodiment of the present invention, and FIG. 2 is a cross-sectional view of a conventional bearing part.
3 is an enlarged sectional view of the main part of FIG. 2, FIG. 4 is a sectional view of the bearing portion of the present invention, and FIG. 5 is an enlarged sectional view of the main part of FIG. 4. 1a... Armature rotating shaft, lb, ld... Bearing support portion, 1c... Sun gear, 2... Internal gear, 3... Planetary gear, 4... Planetary gear shaft, 5 ... Pinion shaft, 5a... Planet carrier, 6... Rear bracket, 7, 8... Bearing, 9... Thrust spring.

Claims (1)

[Claims] 1. In a starter equipped with a planetary gear reducer, a ring-shaped outer diameter spherical convex part is attached to the bearing support part of the armature rotating shaft or output rotating shaft of the starter, and a concave part that fits into the ring-shaped outer diameter spherical convex part is attached. 1. A starter for starting an internal combustion engine, characterized in that an inner diameter spherical groove is provided in the bearing part, and a bearing device is formed by engagement of the concave and convex parts of both sides, thereby providing an alignment effect between the shaft and the bearing.