JPS60173366A - Starter - Google Patents

Abstract

PURPOSE:To reduce any and every number of manufacturing processes, part items and assembling stages of work as well as to make them inexpensive in cost, by forming a stopper being opposed to a side wall of each planetary gear at the side of a sun gear formed in an armature shaft. CONSTITUTION:Plural pieces of a support pin 7 whose one end is locked to a flange part 3b of the sidepiece at the motor side of an output shaft 3 are set up on the circumference of a circle on the flange part 3b at regular intervals, while plural pieces of a planetary gear 6 are installed therein in a manner conformable to these support pins 7, and each gear 6 is rotatably supported on each of support pins 7, then engaged with each internal gear 5. The tip of a motor armature shaft 9 is rotatably coupled with an output shaft 3a via a bearing 3c, while there is provided a sun gear 9b engaging each of these planetary gears 6. At a spot proximate to the motor side end part, likewise there is provided a groove 9a in which a washer 8 is built and each planetary gear 6 is inset between the flange part 3b of the output shaft 3 and the washer 8 whereby these planetary gears are made so as to prevent them from slipping off, owing to the support pin 7.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a star with a planetary gear reduction mechanism used for starting an engine.

[Prior art]

Conventionally, this kind of device increases the shaft diameter of the motor side end of each support pin that supports each planet gear, and inserts it between the output shaft and the large diameter part of each support pin to provide support for each planet gear. The pin is prevented from being removed.

However, in the above-mentioned conventional device, each support pin must be formed with a large diameter portion and a small diameter portion, which has the drawback of requiring a large number of machining steps and a complicated grinding process.

Therefore, conventionally, as described in Japanese Utility Model Publication No. 56-4849, annular grooves are formed at the motor-side end of each support pin, and snap rings are fitted into these grooves to connect each planetary gear. It has been considered to prevent each support pin from being pulled out, but this requires a snap ring to be fitted into the groove of each pin, which requires a large number of parts and requires a lot of assembly man-hours (which increases costs). It has the disadvantage of becoming

[Purpose of the invention]

In order to eliminate the above-mentioned drawbacks, the present invention reduces the number of processing steps, number of parts, and assembly steps by forming a stopper facing the side wall of each planetary gear on the side of the sun gear formed on the armature shaft. The aim is to be able to do this at low cost.

〔Example〕

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

In the first embodiment shown in FIG. 1, 1 is a motor housing, 2 is a motor armature, 3 is an output shaft, and a helical spline 3a is formed on the outer periphery of the output shaft, and an overrunning clutch (not shown) is formed on the outer periphery of this spline 3a. A pinion for engine starting is connected via the . 4
is assembled to the tip of the motor housing 1 with an end cover. , 5 is a bowl-shaped center bracket held between the end cover 4 and the housing 1, and its center rotatably supports the output shaft 3 via a bearing 5a. Further, an internal gear 5b is formed on the inner circumference of the bracket 5. Reference numeral 66 is a planetary gear, and reference numeral 7 is a support pin whose one end is fixed to the flange 3b formed on the end surface of the output shaft 3 on the motor side.
A plurality of pins 7 (2
~4 pieces are preferred) are arranged. A plurality of planetary gears 6 are provided corresponding to each support pin 7, and each of these gears 6 is rotatably supported by each support pin via each bearing 6a, and connected to the internal gear 5. It meshes with the. , 9 is an armature shaft of the motor, the tip of which is rotatably connected to the output shaft 3 via a bearing 3c, and a sun gear 9b that meshes with each planetary gear 6.
is formed.

Further, an annular groove 9 is provided near the motor side end of this gear 9b.
A washer 8 is assembled into this groove 9a, and the side wall of this washer 8 faces the side wall of each planetary gear 6 with a slight gap therebetween. As a result, each planetary gear 6 is sandwiched between the flange portion 3b of the output shaft 3 and the one-shaft 8, and each planetary gear 6 is prevented from coming off from each support pin 7.

Further, the shape of the washer 8 is as shown in FIG.
It has a center hole 8a with a tooth profile slightly smaller than the tooth profile of the sun gear 9b.
After making the shape of the washer 8 slightly larger than the tooth profile of the sun gear 9b due to thermal expansion, the washer 8 is moved in the axial direction through the outer periphery of the sun gear 9b to the annular groove 98, and then the washer 8 is cooled and contracts. It is fixed by a so-called shrink fit, in which the groove 9a is fitted into the groove 9a.

Further, as shown in FIG. 3, the shape of the washer 8 is a circular hole 3a' slightly smaller than the diameter of the tooth of the sun gear 9b.
It is also possible to fit and fix it to R9a by shrink fitting.

Furthermore, in the case of using a washer 8 having a center hole 8a with a tooth profile as shown in FIG. As shown in FIG. 4, the washer 8 is brought into contact with the raised gear 9C of the sun gear 9b.
may be assembled to the sun gear 9b. In this case, it is not necessary to provide the groove 9a in the sun gear 9b.

Furthermore, in the above explanation, the washers 8 are all ring-shaped and are moved in the axial direction to be assembled to the sun gear 9b. It is also possible to more elastically engage the grooves 9a of the sun gears 4 and 9b.

FIG. 5 shows a second embodiment of the present invention, in which a collar portion 9d forming a stopper is integrally formed on the end surface of the armature shaft 9 on the side of the sun gear 9b by extending in the radial direction by cold forging or cutting. This flange 9d prevents each planetary gear 6 from being removed from each support pin 7.

FIG. 6 shows a third embodiment of the present invention, in which a dustproof cover 1 is placed between the center bracket 5 and the motor housing 1.
The peripheral edge of the motor 0 is fixed, and the cover IO prevents brush abrasion powder from the motor side from entering the planetary gear reduction mechanism.

In each of the embodiments described above, the sun gear 9b is cut directly on the outer periphery of the armature shaft 9, but it goes without saying that a separate sun gear may be connected and fixed to the armature shaft 9. . Further, the tail portion 9d in FIG. 5 can also be formed on the sun gear 9b.

〔Effect of the invention〕

As described above, in the present invention, a stopper is formed on the sun gear side to face the side wall of each planet gear and prevent the planet gears from being pulled out from each pin. With this stopper, it is possible to effectively prevent the plurality of planetary gears from being pulled out from each support pin.
Therefore, the number of machining steps, number of parts, and assembly steps can all be reduced, and since it is not necessary to integrally assemble each planetary gear to the output shaft in advance, ease of assembly is improved9.
It has the excellent effect of being inexpensive.

[Brief explanation of the drawing]

1, 5, and 6 are longitudinal cross-sectional views of the main parts of the starter according to the invention, showing first to third embodiments, and FIGS. FIG. 4 is a plan view showing an example, and FIG. 4 is a longitudinal sectional view showing another example of the structure of the washer assembly section in the starter shown in FIG. 3... Output shaft, 5b... Internal gear, 6... Planetary gear. 7...Support pin, 8...Washer forming a stopper,
9... Armature shaft, 9b... Sun gear, 9
d...Brim portion forming a stopper. Representative Patent Attorney Takashi Okabe Figure 1 Figure 2 Figure 3N Figure 4 Figure 5 Figure 6

Claims (3)

[Claims] (1) A sun gear formed on the armature shaft of the motor, a plurality of planetary gears meshing with the sun gear, a plurality of support pins that rotatably hold each of these planetary gears, and an engine driving/use device to which each of these pins is fixed. an output shaft, an internal gear with which each of the planetary gears meshes, and an internal gear formed on the side of the sun gear and facing a side wall of each of the planetary gears to prevent each of these planetary gears from coming off from each of the pins. A starter comprising a stopper. (2) The starter according to claim 1, wherein the stopper is a washer assembled to the sun gear. (3) The starter according to claim 1, wherein the stopper comprises a flange integrally formed on the sun gear side.