JPH0130618Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a starter motor, particularly to an improvement in its dust-proof structure.

As an example of this type of starting motor that is conventionally known, a front nose type starting motor is the first one.
This will be explained using figures. In the figure, 1 is a fixed member (not shown) of an internal combustion engine (not shown, the same applies hereinafter), etc.
With the front bracket fixed to the protrusion 1a
It has a shaft bearing part 1b near the tip. 2 is a cylindrical yoke having one end fixed to the front bracket 1;
The electric motor housing is constructed in cooperation with the electric motor housing. Reference numeral 3 denotes a rotating shaft of an electric motor whose one end is rotatably supported by the shaft bearing portion 1b, and 4 is slidably fitted in a helical spline (not shown) formed near one end of the rotating shaft 3 in the axial direction. The engaged overrunning clutch 5 is a pinion that is integrally provided with the overrunning clutch 4, so that it can mesh with a ring gear 6 fixed to the rotating shaft (not shown, the same applies hereinafter) of the internal combustion engine. It is located in 7 is an annular stopper fixed to one end of the rotating shaft 3;
8 is an electric motor fixed to the rotating shaft 3;
9 is the field coil fixed to the yoke 2;
10 is a shift lever whose one end is engaged with the overrunning clutch 4; 11 is a holder that pivots around the center of the lever; 12 is a spring that presses the holder 11 to the right in FIG. 1;
3 is a grommet supporting one end of the spring 12, and 14 is an electromagnetic switch fixed to the front bracket 1, which controls the axial movement of the plunger 14a engaged with the other end of the shift lever 10.

In the engine configured as described above, when the internal combustion engine is started, the electromagnetic switch 14 first moves the plunger 14a to the left. Therefore,
The shift lever 10 is rotated counterclockwise around the holder 11, and the overrunning clutch 4 and pinion 5 slide rightward along the helical spline on the shaft 3 until the pinion 5 contacts the stopper 7. The pinion 5 meshes with the ring gear 6. Next, the armature 8 and the field coil 9 are energized to generate rotational force in the armature 8, and the ring gear 6 is rotated via the rotary shaft 3, helical spline, overrunning clutch 4, and pinion 5, and the internal combustion engine is started. After the engine starts, the pinion 5 is forced to over-rotate due to the rotation of the ring gear 6, but due to the unidirectional transmission function of the overrunning clutch 4, the rotating shaft 3 is not over-rotated and rotates freely without load. are doing. Next, the electromagnetic switch 14 returns the plunger 14a to the right, the overrunning clutch 4 and pinion 5 are moved to the left via the shift lever 10, and the field coil 9 and armature 8 are de-energized. It is then cut off and stops in the state shown in FIG.

Incidentally, in order for the pinion 5 to mesh with the ring gear 6, an opening was provided in the front bracket 1. For this reason, there has been a drawback that dust enters the motor housing formed by the front bracket 1 and the yoke 2 from outside the housing and adversely affects the movable parts.

This invention was made in order to eliminate the above-mentioned drawbacks of the conventional device, and its purpose is to provide a starter motor with excellent dust resistance.

An embodiment of this invention will be described below with reference to FIGS. 2 to 4. In the figure, 15 is the pinion 5
is a disc-shaped plate having a protrusion 15a protruding between the teeth of the pinion 5, and even when the pinion 5 is in the state shown in FIG.
Even in the state shown in FIG. 4 in which the protrusion 15a is in contact with the tooth, the protrusion 15a is arranged so as to protrude between the teeth.

The protrusion 15a faces the pinion 5 with a slight gap therebetween, and the pinion 5 moves in the axial direction while slidingly contacting the protrusion 15a. Reference numeral 16 denotes a holding member that rotatably holds the plate 15, and includes a first annular holding part 16a fixed to the front bracket 1 near the outer periphery, and a first holding part 16a fixed to the first holding part. and a second holding part 16b that holds the plate 15 in cooperation with the holding part. Descriptions of other symbols are omitted as they are the same as those of the conventional device.

In the structure configured as described above, when the engine is started, the overrunning clutch 4 and pinion 5 are moved relative to the rotating shaft 3 and the plate 15 by the plunger 14 via the shift lever 10, as in the conventional device. The fourth
It meshes with the ring gear 6 as shown in the figure. next,
Although the pinion 5 is rotated via the rotating shaft 3 and the overrunning clutch 4 as in the conventional device,
At this time, since the protrusion 15a protrudes between the teeth of the pinion 5, the plate 15 is similarly rotated.
After the engine is started, the system returns to the state shown in FIG. 2 in the same manner as the conventional system. In any case, the protrusion 15a protruding between the teeth of the pinion 5 can provide a sufficient dustproof effect.

Note that if the plate 15 and the holding member 16 are made of a wear-resistant metal such as phosphor bronze, or a nylon resin material, there is an effect that wear is reduced and durability is improved.

As described above, this invention provides a plate near the opening of the casing that has a protrusion that protrudes between the teeth of the pinion, so it has the effect of greatly improving the dust-proofing properties of the starter motor.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view showing a conventional device, and FIGS. 2 to 4 are partial sectional views showing an embodiment of this invention. In the figure, 1 is a front bracket, 2 is a yoke, 3 is a rotating shaft, 5 is a pinion, 8 is an electric element,
15 is a plate, 15a is a protrusion, and 16 is a holding member. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] A housing, a rotor supported within the housing, a pinion movable in the axial direction of the rotor near the opening of the housing, and a protrusion protruding between the teeth of the pinion. A starter motor comprising: a plate that rotates together with the pinion; and a holding member fixed to the housing so as to rotatably hold the plate.