JP2000175412A - Motor brush device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain vibration due to the sliding of a brush and provide stable brush pressure. SOLUTION: Under a rotor assembly condition, a jointing part 23 between the first spring part 22 and the second spring part is brought into contact with a vibration control member 40. While a motor is rotating, the generated vibration of the brush 30 due to sliding the movement between the brush 30 and a commutator 18 is dampened by a jointing part 23 to the second spring part through the first spring part 22. Vibration transmission to a mounting part 28 and an end bracket is restrained, thus it is possible to restrain vibration or noise of the motor as a whole.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brush device for a motor, and more particularly to a brush device capable of preventing vibration caused by sliding of a brush during rotation of a motor.

[0002]

2. Description of the Related Art Conventionally, in a brush device of a motor having a brush and a brush spring, it is desired that the brush is urged toward a commutator with a predetermined pressing force as a function of the brush spring. In the case of a small motor, the number of parts and the number of assembling steps of the brush device are reduced by integrally forming the brush spring and an attachment portion attached to the motor end bracket.

In a brush device in which a brush spring and a mounting portion are integrally formed, vibration generated by sliding of the brush and the commutator during rotation of the motor is transmitted to the end bracket via the brush spring and the mounting portion. This may cause vibration or noise of the entire motor. Therefore, conventionally, a technique is known in which a vibration isolating member is provided in a part of the brush device to suppress the vibration generated by the brush.

As shown in FIGS. 9 and 10, in a conventional brush device 50, a brush portion 52 is formed at one end of a flat brush spring 54, and the other end is attached to an end bracket 70 by a holding portion 72. The brush portion 52 is slidably pressed against the outer periphery of the commutator 60 by the elastic force of the brush spring 54 while holding the brush portion 52. Then, an anti-vibration member (projection) 74 is formed on a part of the holding part 72, and a part of the brush spring 54 is brought into contact with the anti-vibration member 74 in a state where the brush part 52 is in contact with the commutator 60. Thus, the vibration generated from the brush portion 52 during rotation of the motor is suppressed.

[0005]

However, in the above-mentioned prior art, the brush spring 54 is provided with the vibration isolating member 7.
4, the brush spring 54 directly receives the elastic repulsion of the vibration isolating member 74. Therefore, there is a problem that the pressing force of the brush portion 52 against the commutator 60 is increased to a predetermined value or more due to the elastic repulsion, and the brush wear is accelerated. Further, the elastic repulsive force of the vibration isolating member 74 may cause the bending deformation of the brush spring 54 with time, and the brush pressing force may become unstable.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above problems, and has as its object to provide a brush device for a motor that can suppress vibration caused by brush sliding and that can obtain a stable brush pressing force. I have.

[0007]

In order to solve the above-mentioned problems, a first aspect of the present invention is a motor end bracket,
A metal plate-shaped brush spring that is provided on the end bracket and supports a brush that abuts a commutator, and that applies a pressing force to the commutator side to the brush; , A second spring portion having one end connected to the other end of the first spring portion, and one end connected to the other end of the second spring portion and having the other end A third spring portion formed with an attachment portion to the end bracket, wherein the first, second, and third spring portions are formed substantially in parallel and integrally with each other; A vibration isolating member is provided on the mounting portion side, and the first spring portion and the second spring portion are connected in a state where the brush is in contact with the commutator. Is characterized in that a is brought into contact with the vibration isolating member.

According to a second aspect of the present invention, the vibration isolator is a wall integrally formed with the end bracket.

According to the first aspect of the present invention, the brush spring includes a first spring portion provided with a brush at one end, and a second spring portion having one end connected to the other end of the first spring portion. A third spring portion having one end connected to the other end of the second spring portion and the other end formed with a mounting portion to the end bracket;
The spring portions are formed substantially parallel and integrally with each other.
That is, the brush spring is formed in a substantially Z shape. Then, with the brush in contact with the commutator,
A connecting portion between the first spring portion and the second spring portion is in contact with the vibration isolating member. Accordingly, when the motor rotates, the vibration generated by the brush due to the sliding between the brush and the commutator is attenuated at the connection portion with the second spring portion via the first spring portion. Therefore, the transmission of vibration to the mounting portion and the end bracket formed on the other end side of the third spring portion is suppressed, and as a result, vibration or noise of the entire motor can be suppressed or prevented.

Further, since the pressing force of the brush against the commutator is applied by the third spring portion which does not always contact the vibration isolating member, the brush pressing force does not directly receive the elastic repulsive force of the vibration isolating member. Thus, a stable pressing force can be obtained, and the bending deformation of the brush spring over time can be prevented.

According to claim 2 of the present invention, the vibration isolating member is
The wall is formed integrally with the end bracket.
Therefore, the number of parts and the number of assembling steps are reduced, and the manufacturing cost of the motor can be reduced.

[0012]

Next, a first embodiment according to the present invention will be described with reference to the drawings. FIG. 1 is an explanatory diagram showing a basic configuration of a motor 10 provided with a brush device 1. The motor 10 is, for example, a relatively small motor used as an actuator for a side mirror or an air conditioner of an automobile. The motor 10 mainly includes a yoke 12, an end bracket 14, and a rotor 16.
The motor shaft 17 is rotatably supported by bearings 13 and 15 provided on the yoke 12 and the end bracket 14, respectively. An excitation magnet 19 is provided in the yoke 12.

The end bracket 14 is made of resin, and is fixed to the yoke 12 by press fitting, caulking or the like.
The brush device 1 for supplying power to the commutator 18 fixed to the rotor 16 is disposed on the surface facing the yoke 12. 2 and 3 (view A in FIG. 2)
As shown in FIG. 1, the brush device 1 includes a brush 30 made of carbon, a brush spring 20 for applying a pressing force to the brush 30 toward the commutator 18, and an attachment for attaching the brush spring 20 to the end bracket 14. And a section 28. The mounting portion 28 has a substantially U
A power supply terminal portion 29 (FIG. 2) formed in a character shape is integrally connected.

The brush spring 20 is in the form of a thin metal plate. As shown in FIG. 2, the brush spring 20 has a first spring portion 22 to which the brush 30 is fixed at one end and a first spring portion at one end. A second spring portion 24 connected to the other end of the second spring portion 22; and a third spring portion 26 having one end connected to the other end of the second spring portion 24 and an attachment portion 28 formed at the other end. I have. The first, second, and third spring portions 22, 24, and 26 are formed substantially parallel and integrally with each other in a direction intersecting with the axial direction of the motor shaft 17 (the X direction in FIG. 3). And the terminal part 29 are integrally formed. That is, the brush spring 20 includes the connecting portion 23 and the second spring portion 24 between the first spring portion 22 and the second spring portion 24.
The connecting portion 25 is provided between the first spring portion 26 and the third spring portion 26, and the overall shape of the brush spring 20 is formed in a substantially Z-shape.

On the other hand, as shown in FIG. 4 and FIG.
Are integrally formed at two places.
Each holding portion 15 has holding walls 15a and 15b, respectively, and the mounting portion 28 is held between the holding walls 15a and 15b. When the brush spring 20 is held, the terminal portion 29 is housed in a terminal housing hole 14a formed in the end bracket 14 and connected to an external connector terminal (not shown).

Further, each holding portion 1 of the end bracket 14
The vibration isolating member 40 is disposed at a position sandwiched between the vibration damping members 5. The anti-vibration member 40 is a rubber material formed in a block shape, and is provided with a predetermined interval between the sandwiching portions 15 by an adhesive, a press fit, or the like. The brush spring 20 (the third spring portion 26) protrudes toward the brush 30 from the gap between the holding portion 15 and the vibration isolating member 40.

As shown in FIG. 4, in the brush device having the above structure, the brush spring 20 does not contact the vibration isolating member 40 before the rotor is assembled. When the rotor 16 is assembled to the yoke 12 and the end bracket 14 from this state, and as shown in FIG. The first spring part 22 and the second spring part 24
Is in contact with the side surface 40 a of the vibration isolating member 40.

Next, the brush device 1 according to the present embodiment will be described.
The operation of will be described. According to the present embodiment, the brush spring 20 includes the first spring portion 22 to which the brush 30 is fixed, the second spring portion 24 having one end connected to the other end of the first spring portion 22, and one end having A third spring portion 2 connected to the other end of the second spring portion 24 and having a mounting portion 28 for attaching to the end bracket 14 on the other end side;
And a connecting portion 23 between the first spring portion 22 and the second spring portion 24 in the rotor assembled state.
Are brought into contact with the vibration isolating member 40. Therefore, when the motor rotates, the vibration generated by the brush 30 due to the sliding between the brush 30 and the commutator 18 is attenuated by the connection portion 23 with the second spring portion 24 via the first spring portion 22.
Therefore, the transmission of vibration to the mounting portion 28 and the end bracket 14 formed on the other end side of the third spring portion 26 is suppressed, and as a result, vibration or noise of the entire motor 10 can be suppressed or prevented.

The brush 3 for the commutator 18
Since the pressing force of 0 is always applied by the third spring portion 26 that does not contact the vibration isolating member 40, the pressing force of the brush 30 does not directly receive the elastic repulsive force of the vibration isolating member 40. Therefore, a stable pressing force can be obtained, and the bending deformation of the brush spring 20 with time does not occur.

Next, a second embodiment according to the present invention will be described with reference to the drawings. The same members as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

At a position between the holding portions 15 of the end bracket 14, a vibration isolating member 4 made of a rubber material as a separate component is provided.
The second embodiment of the present invention is characterized in that the anti-vibration member itself is formed integrally with the end bracket 14 in contrast to the first embodiment in which 0 is disposed. That is, at the time of forming the end bracket 14, the holding portions 15 are formed at two places, and the wall 42 is formed at a position between the holding portions 15 as shown in FIG. The connecting part 23 of the first spring part 22 and the second spring part 24 is in contact with each other.

As a result, when the motor rotates, the vibration generated by the brush 30 due to the sliding between the brush 30 and the commutator 18 is transmitted to the second spring portion 2 via the first spring portion 22.
4 at the connection 23. Therefore, the transmission of vibration to the mounting portion 28 and the end bracket 14 formed on the other end side of the third spring portion 26 is suppressed, and as a result, vibration or noise of the entire motor 10 can be suppressed or prevented.

The brush 3 for the commutator 18
Since the pressing force of 0 is always applied by the third spring portion 26 that does not contact the wall 42, the pressing force of the brush 30 does not directly receive the elastic repulsive force of the wall 42. Therefore, a stable pressing force can be obtained, and the bending deformation of the brush spring 20 with time does not occur.

Further, it is not necessary to provide a vibration isolating member as a separate component as in the first embodiment, and the number of components and the number of assembling steps are reduced, so that the manufacturing cost of the motor can be reduced.

In the above embodiment, the brush 30 made of carbon is provided at one end of the first spring portion 22 of the brush spring 20 and is brought into contact with the commutator 18. However, the present invention is not limited to this, and as shown in FIG. Brush spring 20
Three sliding pieces 21 are attached to one end of the (first spring portion 22).
May be integrally formed, and the sliding piece 21 may be brought into contact (sliding contact) with the outer peripheral surface of the commutator 18. With this configuration, the number of parts and the number of assembling steps are reduced, and the manufacturing cost of the motor can be further reduced. The number of the sliding pieces 21 is not limited to three, but may be two or four.

As described above, the brush device for a motor according to the present invention has an excellent effect that vibration due to brush sliding can be suppressed and a stable brush pressing force can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a motor according to the present invention.

FIG. 2 is a plan view showing a brush and a brush spring according to the first embodiment of the present invention.

FIG. 3 is a diagram viewed from the arrow A in FIG. 2;

FIG. 4 is a plan view showing a state before the rotor assembly of the brush device according to the first embodiment of the present invention.

FIG. 5 is a perspective view of the brush device corresponding to FIG. 4;

FIG. 6 is a plan view showing a state after the rotor is assembled in the brush device according to the first embodiment of the present invention.

FIG. 7 is a plan view showing a brush device according to a second embodiment of the present invention.

FIG. 8 is a front view showing a modification of the brush.

FIG. 9 is a plan view showing a conventional brush device.

FIG. 10 is a plan view showing a conventional brush device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Motor, 14 ... End bracket, 18 ... Commutator, 20 ... Brush spring, 21 ... Sliding piece (brush), 22 ... 1st spring part, 24 ... 2nd spring part, 26 ... 3rd spring part, 28 ... Attachment part, 30: brush, 40: anti-vibration member, 42: wall (anti-vibration member)

Claims (2)

[Claims] An end bracket of a motor, and a brush provided on the end bracket and supporting a brush abutting on a commutator, and applying a pressing force to the brush toward the commutator side. The brush spring includes a first spring portion provided with the brush at one end, a second spring portion connected at one end to the other end of the first spring portion, and a second spring portion provided at one end. A third spring portion connected to the other end side and having an attachment portion to the end bracket formed on the other end side, wherein the first, second, and third spring portions are formed substantially parallel and integrally with each other; The end bracket has a vibration isolating member on the side of the mounting portion of the brush spring, and the first bracket is provided with the brush in contact with the commutator. Motor brush device, characterized in that the connecting portion is brought into contact with the damping member of the pulling portion and the second spring portion. 2. The apparatus according to claim 1, wherein the vibration isolating member is a wall integrally formed with the end bracket.
A brush device for the motor according to the above.