JP2574562Y2 - Brush damper structure of small 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 brush damper for a small DC motor, and more particularly to a structure for attaching a damper to a brush spring.

[0002]

2. Description of the Related Art In a small DC motor having a brush, if the brush oscillates during rotation of the rotor, not only is the brush not in good contact with the commutator, but also the brush noise is increased. Since various problems occur, measures against vibration of the brush are taken.

FIG. 5 shows an example of a conventional small DC motor.
In FIG. 5, a brush holder 2 is press-fitted and fixed to an open end of a cup-shaped stator case 1.
The rotating shaft 6 is rotatably supported by bearings 7 and 8 attached to the brush holder 2. The rotor core 4 and the commutator 9 are fixed to the rotating shaft 6, and the drive coil 5 is wound around the rotor core 4. A stator magnet 3 is fixed to the inner periphery of the stator case 1 so as to surround the rotor core 4. A base end of a plate-shaped brush 10 is fixed to the brush holder 2. The brush 10 is shown in FIG.
As shown in FIG. 1, a slit is formed in one side of the longitudinal direction in the longitudinal direction of the brush 10, thereby
Is divided into a plurality of strips, and the tip of the one side is in sliding contact with the peripheral surface of the commutator 9. A part of the brush 10 includes a damper 1 made of rubber, paper, resin, or the like in a flat shape over a part of the slit in the longitudinal direction.
2 is fixed by an adhesive or the like, and a vibration-proof measure of the brush 10 is taken. A terminal 13 is provided at the base end of the brush 10.
Is fixed.

[0004]

In the conventional brush damper for a small DC motor, when the motor is used in a high-temperature, high-humidity environment, the damper 12 is attached to the brush 10 with an adhesive. Therefore, the adhesive strength may change and the damper 12 may be shifted from a predetermined position of the brush 10. Further, when the motor is used for a long time, the temperature inside the motor becomes high due to the heat generated by the motor itself, and the damper 12 also shifts with respect to the brush 10. By the way,
If the damper 12 is displaced in a direction perpendicular to the longitudinal direction, mechanical noise increases and the life is shortened. In addition, if the motor shifts in the longitudinal direction and reaches the portion in contact with the commutator, conduction failure may occur or the motor may stop.

The present invention has been made in order to solve such a problem, and a brush for a small DC motor which can be prevented from being displaced from a predetermined position even when a damper is attached to the brush with an adhesive. The purpose is to provide a damper.

[0006]

Means for Solving the Problems The present invention is engaged.
Fixing holes to restrict longitudinal movement of members and longitudinally shaped
With one end formed by the slit
A plate-shaped brush spring with divided sides, the fixing hole and
And a damper having a convex portion engaged with the slit,
This damper is attached to a part except the tip of the brush spring.
The convex portion engages with the fixing hole and the slit in the longitudinal direction and
Fix it in a state where its displacement in the right angle direction is prevented.
I have.

[0007]

When the projection formed on the damper is engaged with the fixing hole and the slit formed on the brush spring and attached with an adhesive, the displacement of the damper with respect to the brush spring is prevented. As a result, a stable state of sliding contact with the commutator of the small DC motor is maintained, mechanical noise is prevented from occurring, and a long life can be achieved.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a brush damper for a small DC motor according to the present invention will be described below with reference to the drawings. 1 to 3 show a first embodiment of the present invention. FIG.
2, in the plate-like brush spring 20, two longitudinal slits 21 are formed on one side in the longitudinal direction, and the one side is divided into three by this slit 21. A clad portion 20a made of a noble metal having good conductivity is formed on a partial surface on one side. Further, a fixing hole 22 having a length of one side substantially equal to the width of the slit 21 is formed on the base end side on the left side of the slit 21 in the drawing. Except for the one end and the other end, the damper 23 is attached by an adhesive.
The damper 23 covers a part of the longitudinal direction.

The damper 23 is made of rubber, paper, resin, or the like, is formed in a strip shape, and is provided at the longitudinal end of the brush spring 20 at a position corresponding to the slit 21 and the fixing hole 22.
4 are formed. As shown in FIG. 3, the convex portion 24 has a width at the end of the damper 23,
Is formed on the lower surface of the damper 23 by forming a tongue piece 24a substantially equal to or slightly smaller in width than the width of the tongue piece 24a and bending the tongue piece 24a toward the back surface. And the convex part 24
Is engaged with the slit 21 and the fixing hole 22 as shown in FIG. 2, and the flat portion 23a of the damper 23 and the brush spring 20 are attached with an adhesive.

As described above, the protrusion 2 formed on the damper 23
4 is engaged with the slit 21 and the fixing hole 22 of the brush spring 20 so that the protrusion 24 engaged with the fixing hole 22 prevents displacement of the brush spring 20 in the longitudinal direction and the direction perpendicular thereto. In addition, the protrusion 24 engaged with the slit 21 is prevented from shifting in the direction perpendicular to the longitudinal direction of the brush spring 20.

FIG. 4 shows a second embodiment of the present invention. In FIG. 4, the projection 25 of the damper 23 is formed by a dowel. In this case, the material of the damper 23 is desirably resin, and the protruding projection 25 is engaged with the slit 21 and the fixing hole 22 of the brush spring 20. According to this configuration, the brush spring 2 is also provided similarly to the above-described example.
The displacement in the longitudinal direction and its perpendicular direction to 0 is prevented. FIG. 7 shows a third embodiment of the present invention, in which a slit 2 is provided.
1 in that the fixing hole 22 is integrated with the other embodiments.
However, the longitudinal direction of the brush spring 20 is
Is prevented from moving in the longitudinal direction by the slit 21.
Prevention of movement at right angles to the other
Same as the example.

The brush spring 20 configured as described above is
For example, the terminal 1 whose base end is described with reference to FIG.
3 and can be used in a state where the clad portion 20a at the tip end divided by the slit 21 is slidably contacted with the commutator 9.

Note that the convex portion 2 described in the above embodiment is used.
As 4, a cut may be formed in the damper 23, and the tongue piece may be bent in a tapered shape on the back side to engage with the slit 21 of the brush spring 20.
Various changes can be made without departing from the scope of the present invention, as long as it has a function of engaging with the first and fixing holes 22.

[0014]

As is clear from the above description, the brush damper structure of the small DC motor of the present invention is attached by engaging the convex portion formed on the damper with the fixing hole and the slit formed on the brush spring. The displacement of the damper with respect to the brush spring in the longitudinal direction and the direction perpendicular thereto can be prevented . Therefore, it is possible to maintain a stable sliding contact state with the commutator of the small DC motor, prevent mechanical noise from occurring, and extend the life.

[0015]

[Brief description of the drawings]

FIG. 1 is a plan view showing a first embodiment of a brush damper according to the present invention.

FIG. 2 is a sectional view of the embodiment.

FIG. 3 is a perspective view showing a part of a manufacturing process of the embodiment.

FIG. 4 is a plan view showing a second embodiment of the brush damper according to the present invention.

FIG. 5 is a sectional view showing a conventional small motor.

FIG. 6 is a sectional view showing a conventional brush damper.

FIG. 7 is a plan view and a sectional view showing a third embodiment of the brush damper according to the present invention.

[Explanation of symbols]

 Reference Signs List 20 brush spring 21 slit 22 fixing hole 23 damper 24 convex part

Claims (1)

(57) [Scope of request for utility model registration] 1. A longitudinal movement of an engaged member is restricted.
Having a fixing hole and a slit formed in the longitudinal direction.
A plate-shaped brush whose one end is divided by the slit
A spring and a convex portion that engages with the fixing hole and the slit.
And a damper having the brush spring.
The protrusions are partially formed on the fixing hole and the slot except for the tip of the fixing hole.
To prevent displacement in the longitudinal direction and its perpendicular direction
Brush of a small DC motor
Damper structure.