JPS60209665A - Starter - Google Patents

Abstract

PURPOSE:To reduce effectively the impact load in the direction of thrust of the starter by a method wherein the outer diametral side of a planetary gear is supported elastically by an elastic body consisting of a thin plate fixed to the outer frame in the starter accommodating a planetary gear reduction mechanism. CONSTITUTION:In the starter, provided with the speed reduction mechanism consisting of the planetary gears 6, a sun gear 9a and an internal gear 5a fixed irrotatably to a housing 4, the outer diametral side thereof is fixed to a yoke 1 and the housing 4, which are constituting the outer frame, while the inner diametral section supports the planetary gears 6 elastically at the end face of the pinion thereof and is provided with the elastic body 8 consisting of the thin plate, whose armature side end face is opposed to the end face of an armature 2 with a gap G1. The thrust at the position of the gears after speed reduction is received by an intermediate bracket 5 and the elastic body 8 with the gap G2 while the thrust of the armature 2 is received by an end frame and the elastic body 8.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a structure for absorbing backlash in the thrust direction that occurs during driving in a starter incorporating a planetary gear reduction mechanism.

[Prior art]

If the engine is restarted while the starter is inertly rotating, the rotating pinion meshes with the engine ring gear and an excessive impact is generated between it and the ring gear. Here, the pinion moves forward to the stopper due to the force of the helical spline of the output shaft and absorbs this impact, so no excessive thrust load is generated.

However, if there are scratches or dents on the tooth surface of the ring gear, the pinion receives an impact before it can advance to the stopper, resulting in an excessive thrust load, which is transferred to the end via the armature rotation shaft. transmitted to the frame,
This had the disadvantage of causing damage to the end frame.

Furthermore, as described in Japanese Utility Model Application Publication No. 58-136676, it has been considered to insert a spring between the armature rotating shaft and the output shaft to alleviate the impact load in the thrust direction. The impact in the thrust direction is received by the end frame from the armature rotating shaft via the spring, and the transmission of thrust force between the tooth surfaces is not prevented, so there is a drawback that sufficient impact absorption effect cannot be obtained. be.

[Purpose of the invention]

In order to solve the above-mentioned drawbacks, the present invention effectively absorbs the impact load in the thrust direction by elastically supporting the 'ii star gear with an elastic body made of a thin plate whose outer diameter side is fixed to the outer frame. The purpose is to be able to reduce the amount of dust and obtain a dustproof effect at the same time.

〔Example〕

The present invention will be described below with reference to embodiments shown in the drawings.

In FIGS. 1 and 2, 2o is a DC motor, which is composed of a yoke 1, an armature 2, a brush holder (not shown), an end frame 13, etc., and is screwed onto the housing 4 with bolts 19. There is. 12 is an electromagnetic switch mounted on the housing 4, and 11 is a lever that is cam-coupled with a plunger (not shown) in the electromagnetic switch 12 and is rotatable around a fulcrum (not shown), and is slidable on the output shaft 3. The overrunning crank 10 movably engaged with the helical spline is moved in the longitudinal direction. The clutch IO has a boss 10a having a spline that engages with the helical spline portion 3b of the output shaft 3.
1 Auc 10b, mouth/-ra lOc, spring (not shown), inner 10d.

It consists of a washer 10e, a cover 1Of, and a pinion 10g that meshes with a ring gear of an engine (not shown). One end of the output shaft 3 is rotatably supported by the housing 4 by a hair ring 4a. A stopper 18 is fixed to one end of the output shaft 3 and stops the clutch lO from protruding in the axial direction. A planetary float speed reduction mechanism is arranged at the other end of the output shaft 3. 3a is a planetary gear holding part formed at the other end of the output shaft 3, into which a pin 7 that rotatably supports the planetary gear 6 is fitted via a bearing 6a fitted to the inner circumference of the planetary gear 6. It is. Reference numeral 5 designates an intermediate bracket that is non-rotatably held between the housing 4 and the yoke 1, and has an internal gear 5a carved on its inner periphery that inscribes and meshes with the planetary gear 6. It has a bearing part 5c which is rotatably supported via a bearing 5b, and the thrust of the protruding shaft 3 in the forward direction (left direction in the figure) is received by the bearing part 5C.

Reference numeral 9 denotes a rotating shaft of the armature 2, and the tip thereof is rotatably supported via a bearing 3b in the hole at the rear end of the output shaft 3 mentioned above. , are rotatably supported via bearings 13a.

Reference numeral 9a denotes a sun gear formed on the rotating shaft 9, which meshes with the planetary gear 6 described above to form a speed reduction mechanism. 1
6 is a thrust washer inserted between the rotating shaft 9 and the end frame 13.

Reference numeral 8 denotes an elastic body made of a disc-shaped thin plate, the outer diameter side of which is fixed and fixed in a non-rotatable manner between the yoke l and the intermediate bracket 5, and a cylindrical part 8c with a corrugated cross section whose tip 8b extends toward the armature 2 side. is integrally formed on the inner diameter side. A small gap G2 is formed between the bearing part 5C of the intermediate bracket 5 and the holding part 3a of the output shaft 3 via a thrust washer 3c, and the force of the return spring in the electromagnetic switch 12 is transferred to the lever 1.
1. By receiving through the clutch 10 and output shaft 3,
exists, and due to the force that balances the elastic body 8, the inner diameter convex portion 8a
This presses the end face of the planetary gear 6. Further, the tip 8b of the cylindrical portion 8C extending in the axial direction faces the end surface of the armature 2, and is closer to the gap G3 between the output shaft 3 and the armature-side rotating shaft 9 and the gap G4 between the end surface of the planetary gear 6 and the end surface of the sun gear 9a. The armature 2 also has a small gap Gl, which restricts movement of the armature 2 in the forward direction (to the left in the figure). Further, the inner periphery of the cylindrical portion 8C of the elastic body 8 faces the rotating shaft 9 with a small gap therebetween. Further, the gap G2 is also smaller than the gaps G3 and G4.

Now, when the rotational torque of the motor 20 is applied to the pinion lOg while the forward movement of the pinion 10 is stopped by the ring gear, the helical spline 3b connecting the clutch 10 and the output shaft 3 causes the clutch 10 to move forward. There is also a thrust force (reaction force) f on the output shaft 3 that causes it to move backward.
aJ<.

In the conventional device, the thrust force is transmitted to the armature 2 through the end face of the output shaft 3, the end face of the armature rotating shaft 9, and the tooth surfaces of the planetary gear 6 and the sun gear 9a, but according to the present embodiment, only the latter is transmitted. In response to the thrust force of the planetary gear 6, the elastic body 8 deflects between the outer diameter portion and the inner diameter convex portion 8a, and also simultaneously deflects between the inner diameter convex portion 8a and the tip 8b while applying a thrust force to the armature 2. is transmitted. In this way, the thrust force becomes indirect, and phenomena such as destruction of the end frame 13 are eliminated, making it possible to provide a highly reliable starter.

Additionally, as an additional effect, if the elastic body 8 is annular and has a small inner diameter (one of which has a small gap with the outer diameter of the armature rotating shaft (2), a large dustproof effect can be obtained.

〔Effect of the invention〕

As described above, in the present invention, the planetary gear is elastically supported on the pinion side end face of the inner diameter part of the elastic body made of a thin plate fixed to the outer diameter side or the outer frame, and the armature side end face of the elastic body is The part faces the end face of the armature with a gap of Gl, and the thrust of the part after deceleration is received by the intermediate bracket and the elastic body, and the thrust of the armature is received by the end frame and the elastic body. The impact load can be effectively reduced by using the plate-shaped elastic body, and the elastic body also provides a dust-proofing effect for the M star deceleration mechanism portion.

[Brief explanation of the drawing]

FIG. 1 is a partially sectional front view showing an embodiment of the starter of the present invention, and FIG. 2 is an enlarged vertical sectional view of the essential parts of the above embodiment. 1.4...Yoke and housing that make up the outer frame. 2... Armature, 3... Output shaft, 5... Intermediate bracket, 5a... Internal gear float, 6... Planetary gear, 8
...Elastic body. 8a... Inner diameter convex part, Bb... Tip, 3c... Cylindrical part, 9... Rotating shaft, 9a... Sun gear, 10g...
・Pinion. 13...End” frame. Patent attorney Takashi Okabe

Claims (1)

[Claims] In the starter, the starter has an internal reduction mechanism composed of a planetary gear, a sun gear, and an internal gear, and the internal gear is fixed to the outer frame in a non-rotatable manner, and the outer diameter side is fixed to the outer frame. , in the inner diameter part, the end face on the pinion side elastically supports the planetary gear, and the end face on the armature side has an elastic body made of a thin plate facing the armature end face with a gap Gl, and the thrust of the part after deceleration is The intermediate bracket
A starter in which the throat and the elastic body receive the thrust with a gap G2, and the thrust of the armature is received by the end frame and the elastic body.