JPH1070862A - Brush holding device and method of assembling into DC motor - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To ensure safety by disabling the use of brushes beyond the brush life of a DC motor and to reduce the cost by improving the workability of assembling the brush holding device. A brush holder (3) has a projection (3b) near the entrance of a U-groove (3a) through which the pigtail (2) of the brush (1) passes.
And the minimum groove width of the projection 3b is smaller than the diameter of the pigtail 2. The brush 1 is pushed by the coil spring 4, and the pigtail 2 hits the projection 3b. It is not pushed out of the brush holder 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brush holding device for a brushed DC motor.

[0002]

2. Description of the Related Art FIG. 4 shows the structure of a conventional brush holding device, in which 11 is a brush, 12 is a pigtail, 13 is a brush holder, 14 is a coil spring, 15 is a lead wire, and 16 is an insulating plate. The brush holder 13 has a U-shaped groove having a width through which the pigtail 12 can easily pass.

[0003]

In this brush holding device, there is a demand for safety at the end of life due to brush wear of the DC motor and low cost.

SUMMARY OF THE INVENTION An object of the present invention is to make the use of the brush beyond the life of the brush impossible, to ensure safety, and to reduce the cost by improving the workability of assembling the brush holding device.

[0005]

SUMMARY OF THE INVENTION In order to solve this problem, the present invention is directed to preventing the brush pigtail from hitting the protrusion of the brush holder and pushing the brush out of the brush holder by the pressure of the coil spring. This is a configuration that prevents such a situation.

Thus, the operation of the brush can be stopped at the end of life due to the brush wear of the DC motor.

Further, in a completed brush holder in which the brush and the coil spring are assembled in the brush holder, since the brush is held in the brush holder, the work of assembling the DC motor with a simple jig is performed. Can be easily done.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to solve the above-mentioned problems, the present invention provides a brush having a pigtail and made of carbon or the like, a coil spring for pressing the brush toward a commutator, a brush and a coil spring. In a brush holding device having a U-groove for accommodating and passing a pigtail, and a brush holding device including an insulating plate for fixing the brush holder, the U-groove is provided with a protrusion near the entrance where the pigtail does not return. A brush holding device characterized in that:

The brush holding device according to claim 1, wherein the opening of the pigtail is formed into a step from the surface of the brush.

Further, a brush having a pigtail and a coil spring for pressing the brush toward the commutator are housed in a brush holder provided with a protrusion near the entrance of the U-groove where the pigtail does not return. The first step is to complete the brush retainer, and the armature shaft or bearing is covered with a conical simple jig having the same diameter as the commutator outer diameter. A method for assembling a completed brush holder into a DC motor, comprising a second step of inserting a product and bringing the brush into contact with the commutator.

[0011] In this way, the protrusion provided with the pigtail where the pigtail does not return near the entrance of the U groove can prevent the pigtail of the brush from hitting the protrusion by the pressure of the coil spring and being pushed out of the brush holder. Therefore, even if the brush wear of the DC motor progresses, the pigtail of the brush hits the projection by the pressure of the coil spring, and the operation of the brush can be stopped at the end of life.

Further, in the case where the opening of the pigtail is formed so as to be one paragraph from the surface of the brush, the pigtail is easily deformed when passing through the projection near the entrance of the U-groove, and the assembling work is facilitated.

Further, since the finished brush holder is in a state where the brush is held in the brush holder, the work of assembling the DC motor with a simple jig can be easily performed.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, 1 is a brush, 2 is a pigtail, 3 is a brush holder, 4 is a coil spring, 5 is a lead wire,
Reference numeral 6 denotes an insulating plate which differs from the conventional one in the shape of the U-shaped groove of the brush holder.

The brush 1 is a square pillar carbon brush made of copper and carbon, and a pigtail 2 is drawn out of the brush body. The pigtail 2 is formed of a stranded wire of an electric soft copper wire, and an end of the pigtail 2 is fixed by welding to a brush holder 3 formed of a conductor such as brass.

The brush holder 3 is provided with a U through which the pigtail 2 passes.
The protrusion 3b is provided near the entrance of the groove 3a. The width of the U groove 3a through which the pigtail 2 passes is wider than the diameter of the pigtail 2, and the minimum groove width of the protrusion 3b is narrower than the diameter of the pigtail 2. Consists of dimensions.

The lead wire 5 is welded and fixed to the brush holder 3, and thereafter, the brush holder 3 is caulked and fixed to the insulating plate 6 to obtain a finished brush holder. The lead wire 5, the brush holder 3, and the pigtail are supplied from an external power source. 2. A current is supplied to the commutator (not shown) via the brush 1.

With the above configuration, when the coil spring 4 and the brush 1 are stored in the brush holder 3, the pigtail 2 is deformed in the radial direction when passing through the projection 3b, and after passing through the projection 3b, the diameter of the pigtail 2 is reduced. Restore. Thereby, the brush 1 is pressed by the pressure of the coil spring 4, and the pigtail 2 pulled out from the brush 1 hits the end of the projection 3 b and can be prevented from being pushed out of the brush holder 3.

Further, the effective length of the brush 1 can be freely set by the size of the position where the pigtail 2 is exposed and the position of the projection 3b.

In FIG. 2, reference numeral 1a designates a brush in which the protruding portion of the pigtail is formed as one paragraph from the surface of the brush.

The leading end 2a of the pigtail 2 of the brush 1a is formed in a U-shape as one paragraph from the surface. When the pigtail 2 passes through the protrusion 3b of the brush holder 3, the brush 1
Since the pigtail 2 can be deformed in the direction of the gap formed as one paragraph from the surface of a, the pigtail 2 can more easily pass through the protrusion 3b,
Installation work can be further improved.

In FIG. 3, 7 is a bearing, 8 is a commutator, 9
Denotes a simple jig, and 10 denotes a finished brush holder.

Hereinafter, the work of assembling into the DC motor will be described. The conical simple jig 9 having the same diameter as the outer diameter of the commutator 8 is put on the armature bearing 7, and the finished brush holder 10 is placed on the simple jig 9 and inserted to the position of the commutator 8. At this time, the brush 1 held along the outer diameter of the simple jig 9 compresses the coil spring 4 and enters the brush holder 3, and the brush 1
If the simple jig 9 is extracted at a regular contact position between the brush holder and the commutator 8, the completed brush holder product 10 can be assembled into a DC motor.

When the outer diameter of the bearing 7 is larger than the outer diameter of the commutator 8, a simple jig 9 is put on the shaft, the brush holder finished product 10 is assembled first, and the bearing 7 is later mounted on the shaft. Just attach it.

[0026]

As is clear from the description of the above embodiment,
According to the first aspect of the present invention, by applying a pigtail to the projection of the brush holder, the brush can be prevented from being pushed out of the brush holder by the pressure of the coil spring, and the life end due to brush wear of the DC motor can be prevented. Sometimes the operation of the brush can be stopped. Further, in the case where the opening of the pigtail is formed as one paragraph from the surface of the brush, the pigtail is more easily deformed when passing through the projection, and the workability can be further improved.

According to the third aspect of the present invention, there is a feature that the completed brush holder can be assembled into a DC motor using a simple jig.

[Brief description of the drawings]

FIG. 1 is a view showing a brush holding device according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a main part showing another embodiment of the present invention.

FIG. 3 is an explanatory view of a method of assembling into a DC motor showing an embodiment of the present invention.

FIG. 4 is a diagram showing a conventional brush holding device.

[Explanation of symbols]

 1, 1a brush 2 pigtail 2a outlet 3 brush holder 3a U groove 3b projection 4 coil spring 6 insulating plate 7 bearing 8 commutator 9 simple jig 10 brush holder completed product

Claims (3)

[Claims] 1. A brush holder having a pigtail, a columnar brush made of carbon or the like, a coil spring for pressing the brush toward a commutator, and a U-shaped groove for accommodating the brush and the coil spring and allowing the pigtail to pass therethrough. And a brush holding device provided with an insulating plate for fixing the brush holder, wherein the U-groove is provided with a protrusion near the entrance where the pigtail does not return. 2. The brush holding device according to claim 1, wherein the outlet portion of the pigtail is formed into a step from the surface of the brush. 3. A brush in which a brush retainer is fixed to an insulating plate, and a brush having a pigtail and a coil spring for pressing the brush toward a commutator are provided with a projection near the entrance of the U-groove so that the pigtail does not return. A first step of applying a pigtail to the protrusion after storing in the retainer to make a brush retainer finished product,
The conical simple jig having the same diameter as the commutator outer diameter is put on the armature shaft or bearing, and the brush holder completed product is inserted into the simple jig to bring the brush and the commutator into contact with each other. A method of incorporating the finished brush retainer into a DC motor, comprising the steps of: