WO2001054251A1

WO2001054251A1 - Brush apparatus of motor

Info

Publication number: WO2001054251A1
Application number: PCT/KR2000/001450
Authority: WO
Inventors: Tae Hee Lee
Original assignee: Tae Hee Lee
Priority date: 1999-12-31
Filing date: 2000-12-13
Publication date: 2001-07-26
Also published as: AU2028701A; KR200185282Y1

Abstract

The present invention relates to a brush assembly of a motor, wherein a rectifier is assembled in the configuration of a roller, which enables the rolling-contact between the rectifier and the brush connected thereto, and more particularly to the brush supplying the current to the rectifier of a rotator mounted in a motor case is disposed at a terminal part on a motor cover, which closes a motor case, the motor case includes the brush configured of the rectifier and a cylindrical roller being rolling contacted to the rectifier, a brush shaft installed on the center of the brush, and a bearing installed on the front end of the terminal part that supports the brush shaft.

Description

BRUSH APPARATUS OF MOTOR

Technical Field

:, The present invention relates to a brush apparatus of a motor, and more particularh . to the brush apparatus of the motor that carries out rolling contact between a brush supplying a current to a commutator rotating at a high speed and the commutator, whereby an amount of generation of sparks and noises due to the friction between the brush and the commutator can be reduced and long life of the l i ' brush can be achieved.

Background Art

A direct current motor is generally composed of a stator using a permanent

1 ^~ magnet and a rotator on which a coil is wound. If a current is supplied to the rotator, the repulsion and absorption of the magnetic force is generated betw een the rotator and the stator. At this time, the rotator turns at a high speed. Recently, such the direct current motor inclusive of an industrial motor, a model car motor, a wireless control toy motor and the like is widely used in various kinds of fields.

20 The direct current motor exhibits a rotation characteristic proportional in a straight line to the voltage applied, an output torque proportional in a straight line to input current and a good output efficiency.

However, the direct current motor has a serious disadvantage that there is a mechanical contact point between the brush and the commutator, from the 7) view point of the construction thereof. This causes sparks, noises caused upon rotation and the reduction of the life of the brush. The generation of friction between the commutator rotating and the brush fixed renders the brush substantially worn out. thereby reducing the life of the brush. In addition, the noises and sparks due to the friction between the commutator and the brush are generated. 0 In case of controlling a microcomputer, etc.. noises between the commutator and the brush can be generated. In order to reduce the noises, a ceramic condenser is attached between a brush terminal and a motor case, such that the sparks produced from the commutator can be absorbed.

Disclosure of Invention

It is an object of the present invention to provide a brush assembly of a motor that provides a brush that takes a roller shape, such that the brush can be in rolling-contact with a commutator, whereby the abrasion ofthe brush caused due to the friction against the commutator is suppressed.

It is another object of the present invention to provide the brush assembly of a motor that provides a bearing structure supporting a brush on a terminal part, for the purpose of rotating a brush and a commutator in engaged relation to each other. such that the noises caused upon the rotation of the brush can be reduced and the sparks generated during the rotation can be prevented.

To accomplish the above objects of the present invention, there is provided a brush assembly of a motor wherein a brush that supplies a current to a commutator of a rotator provided in a motor case is disposed at a terminal part on a motor cover closing the motor case, which includes: the brush taking a shape of a substantially cylindrical roller, thus to be rolling-contact with the commutator: a brush shaft provided on the center of the brush; and a shaft base for supporting the brush shaft on the front end ofthe terminal part.

Brief Description of the Drawings

Further objects and advantages of the invention can be more fully understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a separated perspective view of a motor with a brush assembly constructed according to the present invention: FIG. 2 is a sectional view ofthe motor with the brush assembly according to the present invention;

FIG. 3 is a sectional view illustrating a brush assembly according to an embodiment ofthe present invention: and FIG. 4 is a sectional view illustrating a brush assembly according to another embodiment ofthe present invention.

Best mode for Carrying Out the Invention

FIG. 1 is a separated perspective view of a motor with a brush assembly constructed according to the present invention, and FIG. 2 is a sectional view of the motor with the brush assembly according to the present invention. The motor of the present invention includes a motor case 10 provided with a stator 1 1. a rotator 20 provided in the interior of the motor case 10 and a brush 50 supplying a current to the rotator 20. The motor case 10 takes a generally cylindrical shape having one side opened and has the stator 11 that is divided in three directions on the inner peripheral surface thereof. The stator 1 1 is formed of a permanent magnet, and the rotator 20 is provided in the interior of the motor case 10 in such a manner as to be separated from the stator 1 1. The rotator 20 takes a generally cylindrical shape having a plurality of substantially circular iron pieces piled up and has a coil 21 wound in the three directions on the outer peripheral surface thereof. Also, the rotator 20 is provided with a rotary shaft 22, on the center thereof, which is protruded to the both sides of the rotator 20. The side of the motor case 10 that is not opened is provided with a bearing 12. on the center thereof, into which the rotary shaft 22 of the rotator 20 is inserted. The bearing 12 is a metal bearing and in some cases, may be a ball bearing.

The side of the motor case 10 that is opened is provided with a motor cover 30 for closing the motor case 10. On the center of the motor cover 30. there is provided a bearing 31 that is adapted to support the rotary shaft 22 of the rotator 20. Further, the brush 50, which supplies the current to the commutator 23 of the rotator 20. is disposed on the inside surface of the motor cover 30.

The brush 50 takes a pair shape and thus, the pair of brushes is provided on the front end of each terminal part 40 supported on the motor cover 30. Each of the terminal parts 40 is connected to power outside via a terminal 42 protruded to the outside of the motor cover 30, and the brush 50 provided on each of the terminal parts 40 is embodied as the cylindrical roller, such that it can be rolling-contact with the commutator 23. The brush 50 is provided with a brush shaft 51 passing through the center thereof, and each of the terminal parts 40 is provided with a shaft base 41 for supporting the brush shaft 51 on the front end thereof.

FIG. 3 is a sectional view illustrating a brush assembly according to an embodiment of the present invention. The brush 50 is provided with a hole 52 passing through the center thereof, into which a pair of sleeves 53 is tightly fitted. The pair of sleeves 53 serves as a brass metal bearing, which is fitted to the hole 52 at the both sides of the brush 50 and then met at the center of the hole 52. such that the brush 50 is divided into two parts. At each of the outer ends of the divided tw o brush parts 50. there is provided a flange 54 that is adapted to cover the side of the brush 50.

The brush shaft 51 is loosely fitted to the inner peripheral surface of the pair of sleeves 53 and is coupled to the shaft base 41 of the front end of the terminal part 40 on the both ends thereof. Also, the brush shaft 51 is not rotated with the shaft base 41. The pair of sleeves 53 is rotated along the outer periphery of the brush shaft 51 with the brush 50.

Under the above construction, an explanation of the assembling process of the motor according to the present invention will be discussed. First, the stator 1 1 is fixedly fitted in three directions to the inner periphery of the motor case 10 and then, the rotator 20 is fitted to the interior of the motor case 10. with a result that a predetermined gap is generated between the rotator 20 and the inner periphery of the stator 11. The rotator 20 is coupled to the bearing 12 on the side of the motor case 10 at the one end of the rotary shaft 22 on the center thereof, and the brush 50 is coupled to the front end of each terminal part 40 of the motor cover 30.

The pair of sleeves 53 is tightly fitted to the hole 52 formed on the center of the brush 50 at the both sides thereof, and the brush shaft 51 is loosely fitted to the inner periphery ofthe pair of sleeves 53. The shaft base 41 formed on the front end of each of the terminal parts 40 is coupled to each end portion of the brush shaft 51. in order not to rotate the brush shaft 51. The shaft base 41 is rolled during the assembling process, such that it surrounds the outer periphery of the brush shaft 51. or it is previously manufactured when the terminal part 40 is made, such that the brush shaft 51 is tightly fitted to the shaft base 41.

When the brush 50 is coupled to the motor cover 30. the motor cover 30 is coupled to the end portion opened of the motor case 10. At this time, the bearing 31 that is formed on the center of the motor cover 30 is fitted to the rotary shaft 22 of the rotator 20. thereby completing the assembling process ofthe motor. In the state where the motor cover 30 is coupled to the end portion of the motor case 10. each of the brushes 50 comes in rolling-contact with the outer periphery of the commutator 23 of the rotator 20. If a current is applied to each of the terminal parts 40 via the terminal 42. it is transmitted to each of the brushes 50 through the shaft base 41 of each of the terminal parts 40. the brush shaft 51 and the pair of sleeves 53. The current flowing to each of the brushes 50 is applied to the coil 21 of the rotator 20 via the commutator 23 being rolling-contact with the brush 50. Thereafter, the rotator 20 is changed into an electromagnet, such that it produces repulsive and absorbing forces against the stator 11. As a result, the rotator 20 can be rotated at a high speed. The commutator 23 is in rolling-contact with the cylindrical roller brush 50 while the rotator 20 is being rotated, with a consequence that noises and sparks caused by the friction between the commutator 23 and the brush 50 can be prevented. In addition, the rolling contact of the brush 50 with the commutator 23 enables the abrasion of the brush 50 to be reduced. The brush 50 is rotated along the outer periphery of the brush shaft 51 with the sleeve 53 serving as the metal bearing, so that the abrasion caused due to the friction between the brush 50 and the brush shaft 51 can be avoided. In addition, the formation of the flange 54 covering the side of the brush 50 on the end portion of the sleeve 53 allows the shaft base 41 to be separated from the side of the brush 50. such that the abrasion of the side of the brush 50 caused due to the friction against the shaft base 41 can be prevented.

FIG. 4 is a sectional view illustrating a brush assembly according to another embodiment of the present invention. The cylindrical roller brush 50 is provided with the hole 52 passing through the center thereof, to which the brush shaft 51 is tightly fitted. A sleeve 53 is loosely fitted to the both ends of the brush shaft 51 passing through the hole 52. respectively. The shaft base 41 of each of the terminal parts 40 is coupled at the outer periphery of the sleeve 53. The shaft base 41 is rolled during the assembling process, such that it surrounds the outer periphery of the brush shaft 51, or it is previously manufactured, such that the sleeve 53 is tightly fitted to the inner periphery of the shaft base 41.

According to the above-mentioned embodiment of the present invention, the brush shaft 51 is rotated, wherein each of the sleeves 53 is fixedly coupled to the shaft base 41 and the brush shaft 51 is loosely fitted to the inner periphery of each of the sleeves 53. Each of the sleeves 53 is formed with the flange 54 that is adapted to separate the side of the brush 50 from the shaft base 41. such that the abrasion of the side of the brush 50 by the friction against the shaft base 41 can be reduced. While the brush 50 is rotated, the brush shaft 51 is supported on the corresponding sleeve 53. with a result that the abrasion due to the friction and the rotation noises can be suppressed.

Industrial applicability

As set forth in the foregoing, a brush assembly of a motor according to the present invention provides a roller type brush that is in rolling-contact with a commutator, thereby reducing the abrasion of the brush caused due to the friction against the commutator. In addition, no sparks is produced, such that there is no need for an additional condenser for absorbing noises. Moreover, the brush is coupled to a brush shaft with a sleeve serving as a metal bearing, thereby allowing life of the brush to be further prolonged.

Claims

What Is Claimed Is:

1. A brush assembly of a motor wherein a brush that supplies a current to a commutator of a rotator provided in a motor case is disposed at a terminal part on a motor cover closing the motor case, the device comprising: the brush taking a shape of a substantially cylindrical roller, thus to be rolling-contact with the commutator; a brush shaft provided on the center ofthe brush; and a shaft base for supporting the brush shaft on the front end of the terminal part.

2. The brush assembly according to claim 1, wherein the brush is provided with a hole passing through the center thereof and a pair of sleeves tightly fitted to the hole, the pair of sleeves made of a brass material, and the brush shaft is loosely fitted to the pair of sleeves and fixedly coupled to the corresponding shaft base of the terminal part on each end thereof.

3. The brush assembly according to claim 1. wherein the brush is provided with a hole passing through the center thereof and the brush shaft tightly fitted to the hole, and a pair of sleeves made of a brass material is loosely fitted to the end portions of the both sides of the brush shaft, each of the pair of sleeves fixedly coupled to the corresponding shaft base ofthe terminal part.