JPS6125338Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to the armature of an engine starting motor, and particularly relates to an improvement in the means for attaching the commutator to the shaft.

First, this type of conventional device will be explained with reference to FIGS. 1 and 2. That is, in FIGS. 1 and 2, 1
is a shaft, and an engine drive pinion (not shown) is connected to one end of the shaft via an overrun clutch (not shown). Reference numeral 2 denotes a laminated iron core fixed to this shaft, and a plurality of coil insertion holes 2a are formed on the outer periphery. 3 is a coil inserted into the insertion hole 2a of this iron core, 4 is an insulating sheet for insulating between these coils, and 5 is the coil 3
A bind wire 6 is wound around the end of the coil, and 6 is a commutator, which is formed with a metal annular bushing 7 having a diameter slightly smaller than that of the shaft 1, and a resin molded integrally with this bushing. The current collector ring 9 is formed integrally with the annular body and the bush 7 to supply power to the coil 3. Reference numeral 10 denotes a power supply brush that is always in sliding contact with the current collecting ring; 11 a washer that is loosely fitted to the shaft 1 so as to come into contact with the end face of the commutator 6; and 12, the shaft 1 is rotatable via a bearing 13. This is the rear bracket that supports it.

Next, the operation of this conventional device will be explained.

That is, in the conventional device, when manufacturing it, first the laminated iron core 2 with the coil 3 inserted into the shaft 1.
to fix. Next, insert the commutator 6 into the other end of the shaft 1, press fit the bush 7 of the commutator 6 into the shaft 1, and remove the commutator 6.
Fix it to shaft 1. Further, the end of the current collecting ring 9 of the commutator 6 and the end of the coil 3 are joined by welding or the like. After that, after loosely fitting the washer 11 onto the shaft 1 and installing the overrunning clutch, pinion, etc. on the shaft 1, the rear bracket 1 is attached.
2. Complete the production by rotatably attaching it to a housing consisting of a yoke and a front bracket (not shown).

By the way, in the above starter motor, when it is not operating, that is, when the pinion and the engine ring gear are not engaged, the armature is always moved in the left direction in the figure by the pinion shift lever and spring (not shown). A pressing force is applied, and the washer 11 is pressed against the rear bracket 12. Further, the starting motor is provided adjacent to the vehicle engine, and after the engine is started, it receives engine vibrations and vehicle vibrations, and the vibrations act on the armature as axial vibrations through the shaft 1. The commutator 6 repeatedly moves into and out of contact with the rear bracket 12 via the washer 11, and a force acts on the commutator 6 to try to pull it out of the shaft 1. Conventionally, in order to prevent the commutator 6 from coming off the shaft 1, the inner diameter of the bush 7 is set slightly larger than the outer diameter of the shaft 1, so that the bush 7 can be inserted into the shaft 1 in a press-fit state. Therefore, the pressure force of the inner peripheral surface of the bush 7 prevents the commutator 6 from coming off.

However, the conventional commutator 6 requires a metal bush 7, and the bush 7 and the current collecting ring 9 must be integrally molded with resin to manufacture the commutator 6. The positioning of the bush 7 required a lot of effort during molding, resulting in extremely poor workability. In addition, in order to eliminate these problems, metal bushings 7
The inner diameter of the resin annular body 8 can be adjusted to the shaft 1 without using
It is conceivable that the outer diameter of the commutator 6 is set slightly smaller than the outer diameter of the resin annular body 8 to prevent the commutator 6 from coming off due to the pressure applied to the inner circumferential surface of the resin annular body 8; There was a problem in which the annular body 8 was destroyed.

This invention provides an excellent armature for an engine starting motor that eliminates the above-mentioned problems.

An embodiment of this invention shown in FIGS. 3 and 4 will be described below.

That is, in FIGS. 3 and 4, 1a denotes a radial protrusion 14 integrally formed on the shaft 1.
is a resin annular body having an inner diameter formed to be approximately the same as the outer diameter of the shaft 1, and its right end surface is engaged with the radial protrusion 1a, and its left end surface is engaged with the washer 11. There is.

In the commutator 6 in this embodiment, only the current collecting ring 9 is molded with resin, and the inner diameter of the resin annular body 14 is set to be approximately the same as the outer diameter of the shaft 1. Further, since the shaft 1 is formed with the protrusion 1a, when the commutator 6 is inserted into the shaft 1, the commutator 6
The right end surface of is pressed to the left side surface of the protrusion 1a. Thereafter, the shaft 1 is supported on the rear bracket 12 so that the washer 11 is pressed against the left end surface of the commutator 6.

That is, in the commutator 6 of this embodiment, the protrusion 1a formed on the shaft 1 prevents the shaft 1 from coming off, and the pressing force of the inner circumferential surface of the commutator 6 against the shaft 1 is almost negligible. It can be set so that it does not work.

Therefore, the commutator 6 can be sufficiently prevented from coming off without using the conventional metal bush 7, and the commutator 6 will not be destroyed.

In the above description, the radial protrusion 1a is referred to as the shaft 1.
Although the example is shown in which the parts are formed integrally with the parts, it is of course possible to form them separately.

As mentioned above, this invention includes a washer that is loosely fitted on the shaft between the commutator and the brush,
In the armature of the engine starting motor, the armature of the engine starting motor is configured such that when the pinion transfer lever is not in operation, a pressing force is applied to the shaft by the pinion transfer lever and a spring that presses the lever toward the bracket, The resin annular body of the commutator is directly press-fitted into the shaft, and the shaft is provided with a radial protrusion that can lock the side surface of the core of the resin annular body, so that the starting motor receives vibrations from a locomotive, etc. Even if axial vibration acts on the commutator, the commutator is positioned by the radial protrusion of the shaft, so it is possible to prevent the commutator from coming off from the shaft with an extremely simple configuration. This eliminates the need for a bushing, which eliminates the work of forming the bushing and positioning the bushing when molding the bushing with resin, improving work efficiency. Since it is not necessary to prevent the commutator from coming off by applying pressure on the inner circumferential surface of the resin annular body, the resin annular body can be formed without breaking.

[Brief description of the drawings]

Figure 1 is a sectional view showing a conventional device, and Figure 2 is a cross-sectional view of a conventional device.
Figure 3 is a cross-sectional view showing an assembled state of the conventional device, Figure 3 is a cross-sectional view showing one embodiment of this invention, and Figure 4 is the third
FIG. 3 is a sectional view showing an assembled state of the embodiment shown in the figures. In the figure, 1 is a shaft, 1a is a radial protrusion, and 2
is an iron core, 3 is a coil, 6 is a commutator, 7 is a bush, 8 and 14 are resin annular bodies, 9 is a current collector ring, 1
0 is a brush, 11 is a washer, and 12 is a rear bracket. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] A shaft supported by a bracket and capable of driving an engine, an iron core fitted to the shaft, a coil attached to the iron core, a resin annular body secured to the shaft adjacent to the iron core, and A commutator having a current collecting ring fixed to the outer periphery of the resin annular body and connected to the coil, and a washer loosely fitted to the shaft between the commutator and the bracket, and the pinion transfer lever is prevented from operating. At times, in an armature of an engine starting motor configured such that a pressing force is applied to the shaft by the pinion transfer lever and a spring that presses the lever toward the bracket side, the resin annular body of the commutator An armature for an engine starting motor, characterized in that the armature is directly press-fitted into the shaft, and the shaft is provided with a radial protrusion capable of locking the iron core side of the resin annular body.