JP2718297B2 - Brush holder for DC motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a built-in multifunctional brush holder for a small DC motor.

[0002]

2. Description of the Related Art In general, a brush holder for a built-in small DC motor is conventionally formed by clamping a press-formed metal holder on a phenol laminate or a plastic molding table, so that a metal portion is exposed and a lead wire opening is provided. The protruding portion had a bushing, and a tie band or the like was used for retaining the bushing. or,
Usually, there is no particular prevention of the protrusion of the brush in the inner circumferential direction, and the brush is assembled by using a hire. The brush pigtail hooking method is described in JP-A-61-277340.

[0003]

In the above prior art, no consideration is given to the accumulation of brush abrasion powder, there is a problem of electrical insulation deterioration or leakage, and the incorporation of the built-in brush holder is difficult. There was a problem.

An object of the present invention is to provide a multifunctional brush holder which has improved electrical insulation properties and life, and further has an easy assemblability of the brush holder itself and an easy mountability to a motor. And

[0005]

SUMMARY OF THE INVENTION The present invention comprises a motor housing, a motor end bracket mounted on the end of the housing, and a brush retainer mounted between the housing and the end bracket. The brush holder has a brush holder mold base formed of plastic and a brush holder mold lid formed of plastic, and the brush holder mold base has a back wall portion, an outer peripheral wall portion, and an inner peripheral wall portion, A brush accommodating portion is formed so as to extend from the inner peripheral wall portion in the outer peripheral direction, a brush through hole is provided in an inner peripheral wall portion corresponding to an inner peripheral position of the brush accommodating portion, and a brush and a coil spring are inserted into the brush accommodating portion. The brush is arranged on the inner circumference side with the coil spring on the outer circumference side, and a U-shaped terminal is provided outside the brush storage section The terminal is arranged so that both ends of the terminal face the inner peripheral side, the outer peripheral side of the terminal is surrounded by a raised portion that protrudes the outer peripheral wall portion toward the outer periphery, and one end of the terminal has a pigtail connected to a brush. An end of the lead wire is fixed to the other end of the terminal, and an end of a lead wire that runs between the outer peripheral wall portion and the inner peripheral wall portion is fixed to the terminal. The brush holder is closed by a brush holder mold lid attached to the brush holder mold base.

[0006]

By closing the open side of the brush holder mold base made of plastic with a brush holder mold lid made of plastic, a brush, a coil spring,
Since the terminal, the pigtail, the fixing part of the terminal and the pigtail, and the fixing part of the terminal and the lead wire are not exposed, the insulation is excellent.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS.

In FIG. 1, the external shape of the DC motor is formed by a motor housing 6, end brackets 4, 10. A magnet 7 for a magnetic field is attached to the inner periphery of the housing 6. The ball bearing 3 is fitted in the center of the end bracket 4. A ball bearing 11 is attached to the center of the end bracket. The end bracket 4 is provided with a thrust spring 2 for pressing the ball bearing 3 in the thrust direction.

A ball bearing 3 is provided on the rotor shaft.
And the ball bearing 11 rotatably supported.
The commutator 1 and the armature core 8 are attached to the shaft 12. An armature 13 is formed by winding an armature winding 9 around the armature core 8. The brush holder 5 is attached to a metal housing 6 and a metal end bracket 4.

The brush holder 5 will be described in detail with reference to FIGS.

The brush holder 5 has a brush holder mold base 25 made of plastic and a brush holder mold lid 21 made of plastic.

The brush holder mold base 25 has a back wall 25a, an outer wall 28 provided on the outer edge on the front side of the back wall 25a, and an inner wall 28a provided on the inner edge on the front. Similarly, a brush storage section 28b is provided on the front side. The brush housing portion 28b is
It is formed so as to extend in the outer peripheral direction from a. A brush passage hole 28c is formed in an inner peripheral wall portion 28a corresponding to an inner peripheral position of the brush housing portion 28b.

The brush 18 and the coil spring 17 are inserted into the brush storage section 28b. The brush 18 is disposed on the inner peripheral side, and the coil spring 17 is disposed on the outer peripheral side.

A U-shaped terminal is provided on the outer periphery of the brush housing portion 28b. The terminal 27 is arranged so that both ends face the inner peripheral side.

The outer peripheral side of the terminal 27 is surrounded by a protruding portion 28d which protrudes the outer peripheral wall portion 28 toward the outer periphery.

The pigtail 14 has one end connected to the brush 18,
The other end is fixed to one end of the terminal 27. A pigtail 14 is hooked on a hooking boss 15 formed so as to rise on the front side of the back wall portion 25a. Until the brush retainer 5 is incorporated into the motor, the pigtail 14 is hooked on the hook boss 15. This is the brush holder 5
The workability was improved in incorporating the into the motor. By hooking the pigtail 14 on the hook boss 15, the brush 18 is placed in a state of being retracted to the outer peripheral side against the coil spring 17. For this reason, when the brush retainer 5 is incorporated into the motor, the inner end of the brush 18 is located outside the outer periphery of the commutator 1, so that the workability of the assembly is good. After installation is completed, hook boss 15
By removing the pigtail 14 from the coil spring 17
As a result, the brush 18 is pushed, and the inner end of the brush 18 comes into contact with the outer periphery of the commutator 1.

The lead wire holding portion 22 is provided on a brush holder mold stand 25, and a lead groove 23 for drawing out the lead wire 20 is formed in the lead wire holding portion 22.

The brush holder mold lid 21 is provided with a lead wire pressing projection 29 for pressing the lead wire 20 fitted in the lead groove 23.

The lead wire 20 is laid between the outer peripheral wall portion 28 and the inner peripheral wall portion 28a, and the core wire 19 is fixed to the other end of the terminal 16 (the side to which the pigtail 14 is not fixed).

The brush housing 28b is closed on the back side by the back wall 25a and open on the front side, so that the brush 18 and the coil spring 17 are exposed on the front side. The terminal 16 is surrounded on the front side by the back wall part 25a and on the outer side by the outer peripheral wall part 28 or the protruding part 28d, but the front side is exposed. However, when the brush holder mold lid 21 is attached to the front side of the brush holder mold base 25 and the front side of the brush holder mold base 25 is closed, the brush 18, the coil spring 17, the terminal 16, and the pigtail 14 are exposed when viewed from the front side. Is gone.

As described above, the brush 18, the coil spring 1
The conductive metal parts such as the terminal 7, the terminal 16, the pigtail 14, and the like are not exposed even on the surface side, and are entirely covered with the brush holder mold base 25 and the brush holder mold lid 21, which are plastics of an insulating material. For this reason,
The accumulation of brush abrasion powder on the conductive metal portion is extremely small, and a decrease in insulation and deterioration can be prevented, and the distance from other metal parts can be reduced.

The lead wire 20 fitted in the lead-out groove 23 of the lead wire holding portion 22 is
Since the lead wire 20 is pressed by the one lead wire pressing protrusion 29, the lead wire 20 is prevented from coming off.

The positioning of the brush holder 5 is centered by fitting the positioning boss 24 provided on the brush holder mold base 25 into the recess of the end bracket 4.
A plurality of claws 26 are provided on the brush holder mold lid 21,
The claw 26 is engaged with the brush holder mold base 25 and the brush holder mold lid 25 is attached to the brush holder mold base 25.
By attaching 1, fastening parts such as bolts can be omitted.

[0024]

According to the present invention, there is provided a brush holder comprising: a motor housing; a motor end bracket mounted on an end of the housing; and a brush holder mounted between the housing and the end bracket. Has a brush holder mold base made of plastic and a brush holder mold lid made of plastic, and the brush holder mold base has a back wall part, an outer peripheral wall part, and an inner peripheral wall part. A brush housing portion is formed so as to extend in the outer circumferential direction from the inner surface of the brush housing portion. A brush through hole is provided in an inner peripheral wall portion corresponding to an inner circumferential position of the brush housing portion. The coil spring is located on the outer side, and a U-shaped terminal is provided outside the brush Nulls are arranged so that both ends face the inner peripheral side, the outer peripheral side of the terminal is surrounded by a protruding portion that protrudes the outer peripheral wall portion toward the outer periphery, and an end of a pigtail connected to a brush at one end of the terminal. Is fixed to the other end of the terminal, and the end of a lead wire laid between the outer peripheral wall portion and the inner peripheral wall portion is fixed, and the open side which is the front side of the back wall portion of the brush holder mold base is brushed. A brush holder for a DC motor, wherein the brush holder is closed by a brush holder mold lid attached to a holder mold base. According to this configuration, since the conductive metal parts such as the brush, the coil spring, the terminal, and the pigtail are entirely covered with the brush holder mold base and the brush holder mold lid, the brush wear powder accumulates on the conductive metal part. This is extremely low and has excellent insulating properties.

Before the brush holder mold lid is attached, the surface side of the brush holder mold base is in an open state, so that the assembly of the brushes, the coil springs, the terminals, and the pigments to the brush holder mold base can be extremely easily performed. .

[Brief description of the drawings]

FIG. 1 is a top sectional view of a motor equipped with a brush retainer of the present invention.

FIG. 2 is a front view showing an assembled state of the brush holder of the present invention.

FIG. 3 is a sectional view of the same.

FIG. 4 is a front view showing a state of attachment to an embra.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Commutator, 2 ... Thrust spring, 3 ... Ball bearing, 4 ... B end bracket, 5 ... Brush holder, 6 ...
Housing, 7: magnet, 8: armature core, 9: armature winding, 10: P end bracket, 11: ball bearing (2), 12: shaft, 13: armature, 14
... brush pigtail, 15 ... hook boss, 17 ... coil spring, 18 ... brush, 19 ... lead wire, 20 ... lead wire, 21 ... brush holder lid, 22 ... lead wire holding part,
23 ... lead wire guide groove, 24 ... positioning boss, 25 ...
Brush holder mold stand, 25a ... back wall, 26 ...
Claw, 27 ... Terminal, 28 ... Outer peripheral wall, 28a ... Inner peripheral wall, 28b ... Brush storage, 28d ... Protrusion, 29 ...
Lead wire holding projection.

Claims (2)

(57) [Claims] 1. A motor having a motor housing, a motor end bracket mounted on an end of the housing, and a brush retainer mounted between the housing and the end bracket, wherein the brush retainer is made of plastic. It has a formed brush holder mold base and a brush holder mold lid formed of plastic. The brush holder mold base has a back wall part, an outer peripheral wall part, and an inner peripheral wall part, and from the inner peripheral wall part to the outer peripheral direction. A brush accommodating portion is formed so as to extend, a brush through hole is provided on an inner peripheral wall portion corresponding to an inner peripheral position of the brush accommodating portion, and a brush and a coil spring are inserted into the brush accommodating portion, and the brush is disposed on the inner peripheral side with the coil spring. It is located on the outer peripheral side, and a U-shaped terminal is provided outside the brush storage Are arranged so as to face the inner peripheral side, the outer peripheral side of the terminal is surrounded by a protruding portion obtained by protruding the outer peripheral wall portion toward the outer periphery, and an end of a pigtail connected to a brush is fixed to one end of the terminal. The other end of the terminal is fixed to the end of a lead wire that runs between the outer peripheral wall and the inner peripheral wall, and the open side that is the front side of the back wall of the brush holder mold base is the brush holder mold base. A brush holder for a DC motor, wherein the brush holder is closed by a brush holder mold lid attached to the brush. 2. A direct current according to claim 1, wherein a hooking boss is provided on the brush holder mold base so that the pigtail can be removed after the brush retainer is incorporated into the motor. Brush retainer for electric motor.