JPS6334451Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to an improvement for making the starter smaller and lighter.

A conventional device of this type is shown in FIG. In the figure, 1 is the starter DC motor, 2
is the front bracket, 3 is the rear bracket,
4 is an armature, and the front end 5a of the armature shaft 5 is supported by a sleeve bearing 6 fitted to the inner peripheral surface of the front end of the front bracket 2. The rear end 4b of the armature 4 has a sleeve bearing 8 fitted into the inner circumferential surface of the central cylindrical protrusion 3a of the rear bracket 3, which is fitted into a recess 7a provided on the inner circumferential surface of the commutator 7.
The rear end of the shaft 5 is supported by a washer 9 inserted between the rear bracket 3 and the end surface of the commutator 7, and a washer 10 inserted into the outer surface of the rear bracket 3. It is locked by a retaining ring 11 fitted into a groove 5b provided in the groove 5b. 12 is a brush holder that energizes the commutator 7; 13 is an overrunning clutch that is spline-engaged with the armature shaft 5; it slides forward on the shaft by rotation of the shift lever 14, and is connected to the engine (not shown); The ring gear and pinion 15 are meshed and engaged.
Reference numeral 16 denotes a magnetic switch screwed onto the front bracket 2, which attracts the plunger 17 by energizing the magnetic switch.
Further, the shift lever 14 that engages with the plunger 17 is urged to rotate.

Next, the operation of the above-mentioned component device will be explained. The key switch of the engine (not shown) is closed, the magnetic switch 16 is energized, and the plunger 1 is energized.
7 is attracted to the left, rotates the engaged shift lever 14 as described above, slides the overrunning clutch 13 engaged at the other end to the right, and the pinion 15 moves to the ring gear (not shown). meshingly engages. During the above operation, the magnetic switch 16
The DC motor 1 is energized and the armature 4 generates rotational force. This rotational force is transmitted to the overrunning clutch 13 via the spline engagement portion 5c of the armature shaft 5, and the rotational force is transmitted to the pinion 15, which is engaged in one direction, to rotationally bias the ring gear and start the engine (not shown). do. After the engine is started, the magnet switch 16 is deenergized and returns to the state shown.

When the armature shaft 5 is energized or reset, a thrust stress is generated in the front and rear directions as a reaction force, but the component of this thrust stress that is applied to the left is transmitted through the commutator 7 and the washer 9 that comes into contact with the end face of the commutator. The pressure is received by the rear bracket 3. The rightward stress component of the thrust stress is applied to the rear bracket 3 through a retaining ring 11 fitted in the groove 5b and a washer 10 in contact with the rear bracket 3 as shown in the figure. Note that the above-mentioned thrust stress is also generated in response to the vibration excitation force of the above-mentioned engine to which the armature 4 is mounted, and the above-mentioned receiving force is generated to perform a locking action on the armature 4.

Conventional small and lightweight starter locking device,
In particular, the thrust stress locking device that occurs in the armature is constructed as described above, so the rear end of the armature shaft is made to protrude from the end face of the rear bracket, a groove is provided, and a retaining ring is attached to lock the thrust stress. However, because of the functions obtained, there were drawbacks such as the device becoming somewhat more complex and larger.

This idea was made in order to eliminate the above-mentioned drawbacks of the conventional one.The forward protruding thrust stress of the armature is handled by the front end of the front bracket. The purpose of the present invention is to provide a starter which can be made small and simple in structure without causing an armature shaft to protrude from a rear bracket by receiving pressure at the end face of the bracket.

An embodiment of this invention will be described below with reference to the drawings. In FIG. 2, 18 is a DC motor, 19 is an armature, 20 is an armature shaft that constitutes this armature, and 20a is a bearing part which is stepped 20b at the front end of the armature shaft as shown in the figure. It is loosely supported by a sleeve bearing 22 fitted to the front end of the bracket 21. 23 is the above amateur shaft 20
A recess 21a cut into the inner peripheral surface of the front end of the front bracket 21 is a washer inserted from the front end 20a of the front bracket 21 so as to come into contact with the stepped part 20b.
It has a sliding contact structure. Reference numeral 24 designates a commutator constituting the armature 19, which has a recess 24a in its inner periphery, in which the cylindrical protrusion 3a of the rear bracket 3 is placed, and a washer 25 at the end. A thrust gear adjustment washer 26 is in sliding contact with the end face of the recess 24a of the commutator 24 and the stepped portion 20c of the rear end of the armature shaft 20, as shown. 20d is a helical spline rolled on the outer peripheral surface of the armature shaft 20, and the overrunning clutch 13 is engaged with the spline.
The structure is such that it slides to the right on this axis.

In the invented device having the configuration shown in FIG. 2,
As shown in the conventional device shown in Fig. 1, when the armature 19 receives thrust stress (thrust load) forward or backward (rightward or leftward) due to a similar biasing action, it performs a pressure receiving action similar to that of the conventional device. . That is,
The rightward stress is received by the recess 21a of the front bracket 21 via the stepped portion 20b and the washer 23. The leftward stress is transmitted and received via the commutator 24 and the adjustment washer 26 that slides on the rear stepped portion 20c of the armature shaft 20, to the washer 25 that slides on the cylindrical protrusion 3a of the rear bracket 3. Therefore, the rear end of the armature shaft 20 does not need to protrude beyond the rear bracket 3 as in the conventional device, and the features of the rear bearing recessed starter are not impaired. In addition, since the pressure-receiving sliding contact part of the left thrust stress is implemented in the recess of the commutator 24, it is extremely unlikely to be contaminated by dust such as abrasion powder of the brush holder, and will continue to function for a long time even if lubricant is applied to the sliding contact part. Additional features are added.

In addition, in the above embodiment, the bearing that supports the rear end of the armature shaft has an open structure, but this part is exposed to the outside space and is easily soiled, so a sealed structure bearing device may be installed. , hereafter, the third
To explain with reference to the drawings, reference numeral 27 denotes a sleeve bearing assembly, in which a bottomed cylindrical member 28 is fitted into the cylindrical protrusion 3a of the rear bracket 3, and the rear end of the armature shaft 20 is connected to the cylindrical member. It is loosely supported by a sleeve bearing 29 fitted on the inner peripheral surface of 28. According to the above bearing device,
The bearing mechanism part has a completely sealed structure from the outside, which has the additional effect of providing a bearing mechanism with high reliability over a long period of time with a simple configuration.

As described above, according to this invention, in the starter with the recessed rear bearing of the armature, the thrust load of the armature is slidably received at the front end of the front bracket and the recessed end of the rear bracket bearing through the washer member, and Since the rear metal sealing structure is adopted, the overall length of the device can be shortened, and the device can be made smaller and lighter, which has the effect of providing a starter with high cost benefits.

In addition, the stepped portion 20 at the rear end of the armature shaft
Although c has been shown as an example of being provided on the shaft, it goes without saying that the same effect can be expected even if the end face of the recessed portion of the commutator 24 is used instead.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a conventional starter, Fig. 2 is a sectional view of a starter according to an embodiment of this invention, and Fig. 3 is a sectional view of a starter according to an embodiment of the invention.
The figure is a partial sectional view for explaining another embodiment. In the figure, 1 and 18 are DC motors, 2 and 21 are front brackets, 3 is a rear bracket, 3
a is a cylindrical protrusion, 4 and 19 are armatures, 5 and 20 are armature shafts, 7 and 24 are commutators, 7a and 24a are recesses, 9, 10, 2
3 and 25 are washers, 11 is a retaining ring, 20b and 20c are stepped portions, 25 is an adjustment washer, and 27 is a sleeve bearing assembly. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Scope of utility model registration request] an armature shaft with a stepped portion formed at its front end; a front bracket that supports the front end of the armature shaft via a sleeve bearing; a first washer that locks onto the inner side of the armature shaft to restrict sliding toward the front side of the armature shaft; the first washer is provided on the rear end side of the armature shaft, and the rear end side is formed as a first cylindrical portion; a rear bracket having a second cylindrical portion formed to extend within the first cylindrical portion of the commutator; an inner periphery of the second cylindrical portion of the rear bracket and a rear end portion of the armature shaft; a sleeve bearing disposed between the outer periphery and supporting the armature shaft; a stepped portion formed at the rear end of the armature shaft; or at least one of the inner wall end of the first cylindrical portion of the commutator and the rear A starter comprising a second washer provided between the end of the second cylindrical part of the bracket and locked thereto to restrict sliding of the armature shaft toward the rear side.