JP2001275312A - Vibration-proofing construction for brush of direct current motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration-proofing construction for the brushes of a DC motor, which reduces noise and is manufacturable at a lower cost by absorbing vibration near the vibration generating sources of the brushes, and by reducing the size of cushioning materials. SOLUTION: Brush holders 3, which support brushes 4 in a freely slidable way are arranged confronting each other on both sides of the shaft insertion hole 1 of a brush base 2, with the hole 1 in-between. A cushioning material 17 is interposed between each of these brush holders 3 and a brush support portion 13, 13 arranged on the brush base 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art As shown in FIG.
On one surface of a ring-shaped brush base 2 opened around the shaft insertion hole 1, square cylindrical brush holders 3 are mounted on both sides of the shaft insertion hole 1 with the shaft insertion hole 1 interposed therebetween. A prism-shaped brush 4 is inserted into the brush holder 3, and the tip end of the brush 4 is in sliding contact with a commutator of a shaft (not shown) inserted through the shaft insertion hole 1, and the back side is slidably supported by a spring 5. Have been.

As shown in FIG. 9, cushion material mounting grooves 7 project from the periphery of the ring-shaped brush base 2, and an arc-shaped cushion material 8 formed of an elastic material such as rubber. , 8 are fitted, and projecting portions 9, 9 protruding on the outer peripheral side thereof are fitted into fitting grooves 11 formed in the cylindrical frame 10, and the brush base 2 is It has a structure supported by.

In this structure, the brush 4 comes into sliding contact with the commutator of the rotating shaft, and the vibration generated at this time is transmitted to the brush base 2, and the cushion member interposed between the brush base 2 and the cylindrical frame 10. 8 absorbs vibration.

However, in the conventional brush vibration isolating structure, since the arc-shaped cushion member 8 is interposed between the brush base 2 and the cylindrical frame 10, the volume of the cushion member 8 is large and the cost is increased. . Further, since the cushion material 8 is attached to a place away from the brush 4 which is a vibration source, the vibration absorbing effect is not sufficient.
In addition, since vibration is transmitted to the brush base 2, there is a problem that the effect of reducing noise is small.

[0006]

SUMMARY OF THE INVENTION The present invention eliminates the above-mentioned problems, reduces noise by absorbing vibration near the vibration source of the brush, and reduces the manufacturing cost by reducing the size of the cushion material. An object of the present invention is to provide a brush vibration isolating structure for a DC motor.

[0007]

According to a first aspect of the present invention, there is provided a brush vibration damping structure for a DC motor, wherein a brush holder for slidably supporting a brush is provided on both sides of a shaft insertion hole of a brush base. A cushioning material is interposed between the brush holder and a holder support provided on the brush base.

According to a second aspect of the present invention, there is provided a brush vibration isolating structure for a DC motor, wherein a rectangular cylindrical cushioning material is attached to an outer surface of a brush holder, and the cushioning material is provided between holder supporting portions projecting from a brush base. Is inserted.

According to a third aspect of the present invention, there is provided a brush vibration isolating structure for a DC motor, wherein a support pin is provided on the outer surface of the brush holder, a cylindrical cushion member is attached to the support pin, and the brush base is provided on the brush base. The cushion member is inserted into a support portion.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention is shown in FIG.
This will be described with reference to FIG. On one surface of the ring-shaped brush base 2 opened around the shaft insertion hole 1, holder support portions 13 are provided on both sides of the shaft insertion hole 1 with the shaft insertion hole 1 interposed therebetween. This holder support 13
Is formed integrally with the brush base 2 as shown in FIG.
Two support plates 15, 15 provided with a locking portion 14 at the upper part are protruded at intervals. Further, triangular prism-shaped holding portions 16 are protrudingly provided on the front and rear sides of the support plate 15.

A rectangular cylindrical cushion member 17 made of an elastic material such as rubber is attached to the outside of the brush holder 3 in which the brush 4 is inserted. Reference numeral 18 denotes a coil spring, and 19 denotes a spring retainer. The coil retainer 18 is supported by a spring retainer 19 attached to the back of the brush holder 3 to press the back of the brush 4.

The brush holder 3 with the brush 4 inserted therein.
The cushion member 17 is provided outside the brush unit 20 including the coil spring 18 and the spring retainer 19.
And is inserted between the holder supporting portions 13 protruding from the brush base 2 as shown in FIG. The support plate 15 forming the holder support 13 has a locking portion 14
The upper part of the quadrangular cylindrical cushioning material 17 is locked here, and the front and rear of the cushioning material 17 are supported by triangular prism-shaped pressing parts 16, 16.

In the brush vibration isolating structure of the DC motor having the above structure, the brush 4 slides on the commutator of the rotating shaft. At this time, the generated vibration is absorbed by the cylindrical cushion member 17 provided in the vicinity thereof. The noise is not transmitted to the brush base 2 or the cylindrical frame 10 and can be reduced. Since the cushion member 17 is provided in the vicinity of the source of vibration as described above, the vibration absorbing effect is excellent, and the cushion member 17 can be reduced in size, so that the manufacturing cost can be reduced.

FIGS. 4 and 5 show another embodiment of the present invention, in which cylindrical support pins 22 project from left and right side surfaces and a bottom surface of the brush holder 3. As shown in FIG. 4, the holder supporting portions 13 provided on the brush base 2 have keyhole-shaped grooves 2 having upper portions opened on opposite sides thereof.
3 is formed, and a circular fitting hole 2 is formed in the brush base 2.
4 are provided.

A cylindrical cushion member 17 is attached to each of the support pins 22 of the brush unit 21 having the brush holder 3 having the support pins 22 projecting therefrom. Next, as shown in FIG. 5, the holder supporting portions 13, 13 protruding from the brush base 2 are provided.
And the cushion member 17 projecting downward is inserted into the fitting hole 24 to support the brush unit 21.

In the brush vibration isolating structure of the DC motor having the above structure, the vibration generated from the brush 4 causes the cylindrical cushion members 17 attached to the support pins 22 of the brush holder 3.
And the noise is not transmitted to the brush base 2 or the cylindrical frame 10 to reduce noise.

FIGS. 6 and 7 show another embodiment of the present invention, in which inverted L-shaped support pins 22 are protruded from the left and right side surfaces of the brush holder 3. A cylindrical cushion member 17 is attached to the inverted L-shaped support pins 22 and 22, and is inserted from above into keyhole-shaped grooves 23 of the holder support portions 13 and 13 projecting from the brush base 2 as shown in FIG. Thus, the brush unit 21 is supported.

In the brush vibration isolating structure of the DC motor having the above structure, the vibration generated from the brush 4 is absorbed by the cylindrical cushion members 17 attached to the inverted L-shaped support pins 22. The noise can be reduced without being transmitted to the cylindrical frame 10.

[0019]

As described above, claim 1 according to the present invention.
According to the brush vibration isolating structure of the DC motor described above, the cushion material is interposed between the brush holder and the holder supporting portion provided on the brush base, so that the vibration is absorbed near the vibration source of the brush. Noise can be reduced, and the cost can be reduced by reducing the size of the cushion material.

Further, according to the brush vibration isolating structure of the DC motor according to the second aspect, a rectangular cylindrical cushioning material is attached to the outer surface of the brush holder, and the cushioning material is provided between the holder supporting portions projecting from the brush base. , The assembly work is easy.

According to a third aspect of the present invention, the brush vibration isolating structure of the DC motor has a support pin protruding from the outer surface of the brush holder, a cylindrical cushioning material attached to the support pin, and a protrusion protruding from the brush base. Since the cushion material is inserted into the holder supporting portion, the size of the cushion material can be further reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a brush vibration isolating structure of a DC motor according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view showing the brush anti-vibration structure of FIG. 1;

FIG. 3 is a sectional view showing the brush vibration isolating structure of FIG. 1;

FIG. 4 is an exploded perspective view showing a brush vibration isolating structure of a DC motor according to another embodiment of the present invention.

FIG. 5 is a sectional view showing the brush vibration isolating structure of FIG.

FIG. 6 is an exploded perspective view showing a brush vibration isolating structure of a DC motor according to another embodiment of the present invention.

FIG. 7 is a sectional view showing the brush vibration isolating structure of FIG. 6;

FIG. 8 is a perspective view showing a brush vibration isolating structure of a conventional DC motor.

FIG. 9 is a cross-sectional view of the conventional brush vibration isolation structure shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Shaft insertion hole 2 Brush base 3 Brush holder 4 Brush 5 Spring 7 Cushion mounting groove 8 Cushion material 9 Projection part 10 Frame 11 Fitting groove 13 Holder support part 14 Locking part 15 Support plate 16 Holding part 17 Cushion material 18 Coil Spring 19 Spring retainer 21 Brush unit 22 Support pin 23 Keyhole-like groove 24 Fitting hole

Claims (3)

[Claims] 1. A brush holder for slidably supporting a brush is provided on both sides of a shaft insertion hole of a brush base so as to oppose each other, and a brush holder and a holder supporting portion provided on the brush base are provided. A brush vibration isolating structure for a DC motor, characterized by interposing a cushion material between the brushes. 2. The direct current according to claim 1, wherein a rectangular cylindrical cushioning material is attached to the outer surface of the brush holder, and the cushioning material is inserted between holder supporting portions protruding from the brush base. Motor brush vibration isolation structure. 3. A support pin is projected from an outer surface of the brush holder, and a cylindrical cushion material is attached to the support pin.
2. A brush vibration isolating structure for a DC motor according to claim 1, wherein said cushion material is inserted into a holder supporting portion projecting from a brush base.