JPH04138051A - Brush holder of ac generator for vehicle - Google Patents

Abstract

PURPOSE:To eliminate contact by only a partial small contact surface of a brush so as to obtain a brush holder, which maintains smooth contact of the brush with a slip ring, of an AC generator for a vehicle by providing a relief groove, which allows a compression spring of the brush to escape, in a height direction upward with a lower part left in a brush box. CONSTITUTION:A split circular relief groove 41b, which allows a compression spring 25 to escape, is provided in an upper side in an extension range of the compression spring 25, when wearing of a brush 28 reaches its wearing limit, in both internal surfaces relating to a thickness direction of the brush 28 of internal surfaces of a brush box 41. On the other hand, no relief groove 41b is provided in a lower part internal surface of the brush box 41 so as to bring the brush 28 into sliding contact in its total side surface. Since the brush 28 is brought into full surface contact in this part of the brush box 41, a sliding contact surface relating to the thickness direction of the brush is increased larger than that in the past to reduce wearing of the brush side surface, and smooth contact with a slip ring is maintained by suppressing looseness and tilting in the brush box.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a brush holder for a vehicle alternator, in which brushes are inserted into a brush box and compressed by a compression spring.

[Conventional technology]

FIG. 5 shows a cross-sectional view of a vehicle alternator equipped with a brush holder. In the figure, 1 is a stator, and stator core 2
and a stator coil 3. 4 is a rotor, and 05 and 6 are magnetic pole cores of different polarity, which are configured as follows.
Both magnetic pole tooth portions are arranged alternately in the circumferential direction.

7 is an excitation coil held between both magnetic pole iron cores 5.6;
8 is a rotating shaft to which the magnetic pole cores 5 and 6 are fixed; 9 is a pair of slip rings fixed to the rotating shaft 8; and 10 and 11 are fans fixed to the magnetic pole cores 5 and 6.

Next, reference numerals 12 and 13 denote a front bracket and a rear bracket, which are tightened to fix the stator core 2 with bolts 14. Bearings 15 and 16 support the rotating shaft 8 on the front bracket 12 and rear bracket 13, and 17 is a pulley fixed to the rotating shaft 8, which transmits engine rotation to the rotating shaft 8 and rotates the rotor 4.

18 is a rectifier that rectifies the alternating current caused by the alternating current voltage induced in the stator coil 3 into direct current.

A voltage regulator 19 detects the generator voltage, controls the excitation current, and adjusts the terminal voltage to a predetermined value.

20 is a brush holder fixed to the rear bracket 13;
The brush 28 is pressed and held so that it can move up and down. A partition 22 is fixed to the rear bracket 13, surrounds the outer circumference of the slip ring 9 with a gap, and blocks harmful substances such as moisture and salt in the outside air from entering.

A conventional brush holder attached to the vehicle alternator is shown in FIGS. 6(a) and 6(b) in a partial front view and side sectional view. The figure shows the state removed from the alternator. The brush holder 1520 is configured as follows. 21 is a brush box made of synthetic resin material,
I have inserted a brush for 2 days. 23 is a connector portion, 24 is a terminal portion, 25 is a compression spring that presses the brush 28, 27 is a cover made of a synthetic resin material, and 29 is a connection lead extending from the brush 28.

The inner surface of the square hole 21a of the brush box 21 is shown in FIGS. 7 and 8.
It is formed as shown in the cross-sectional view taken along the line ■--■ and the line ■--■ in FIG. 6(a). In order not to restrict the compression spring 25, a split circular cutout groove 21b is provided on the inner surface of the brush 28 in the thickness direction over the entire length in the vertical direction.

As shown in FIG. 9, the brush 28 inserted into the brush box 21 comes into contact with the inner surface of the brush box 21 only at the contact surface 28a shown by hunting on the side surface in the thickness direction.

[Problem to be solved by the invention]

Brush holder 2 of a conventional vehicle alternator as described above
0, a slot 21b is provided on the inner surface of the square hole 21a of the brush box 210 in the thickness direction of the brush 28 over the entire length in the height direction. The side surface in the horizontal direction becomes a joint that comes into close contact with the small contact surface 28a. For this reason, the brush 28 suffers a large amount of wear on the contact surface 28a due to the vertical movement caused by the vibration of the slip ring 9, and the brush 28 becomes unstable with the slip ring 9 due to large rattling and tilting inside the brush box 21. There was a problem of poor contact. This invention was made to solve this problem. This eliminates contact with the slip ring, reduces wear on that part, and maintains smooth contact with the slip ring.
The purpose is to obtain a brush holder for a vehicle alternator.

[Failure to solve the problem]

The brush holder for a vehicle alternator according to the present invention includes:
On the inner surface of the square hole of the brush box, on the surface in contact with the thickness direction of the brush, a clearance groove for letting the compression spring escape is provided in the upper part of the brush box, leaving the lower part inside, in the height direction.

[Effect]

In this invention, the side surface of the brush in the thickness direction is in sliding contact with the upper part of the inner surface of the brush box except for the undercut groove, but in sliding contact with the entire lower part of the inner surface of the brush box, Wear on the sides of the brush is reduced, and rattling and tilting within the brush box are suppressed.

〔Example〕

FIGS. 1(a) and 1(b) are a partially sectional front view and a sectional side view of a brush holder of a vehicle alternator according to an embodiment of the present invention, and FIG. mounted on the machine. In the figure, reference numeral 40 denotes a brush holder, in which a brush box 41 made of synthetic resin and a partition sill 42 are integrally formed, and a connector portion 43 and a terminal portion 44 are provided. 45 is a metal terminal plate to which the ends of the connection leads 29 of the brushes 28 are connected, which is fixed to the brush box 41 and receives the compression spring 25. O46 is a cover that is fitted over the top of the brush box 41 to close it off. .

The inner surface of the square hole 41a of the brush box 41 has an upper side in the height direction as shown in FIG. 2, which is a sectional view taken along line 1-1 in FIG. 1(a). On both inner surfaces of the brush box 41 in the thickness direction of the brush 2, there are cut circular grooves 41t for letting the compression spring 25 escape. It is located on the upper side of the range.

The lower inner surface of the square hole 41a of the brush box 410 is shown in FIG. 1(a).
A cross-sectional view taken along line I-1 is shown in FIG. The lower inner surface of the brush box 41 is not provided with an undercut groove 411), so that the brush 28 comes into sliding contact with all sides. In this part of the brush box 41, the brushes 2 and 41 are in full contact with each other to prevent local wear on the sides.

FIG. 4 shows another embodiment of the present invention, and is a sectional view corresponding to FIG. 2, in which a trapezoidal undercut groove 41c is provided.

〔Effect of the invention〕

As described above, according to the present invention, on both sides of the inner surface of the rectangular hole of the brush box of the brush holder, grooves for releasing the compression springs of the brushes in the brush thickness direction are provided in the upper part, leaving the lower part. Therefore, the sliding contact surface of the surface in the thickness direction of the brush is increased compared to the conventional one, reducing wear on the side of the brush, suppressing rattling and tilting in the brush box, and improving the slip ring. Smooth contact is maintained with the

[Brief explanation of drawings]

FIGS. 1(a) and (b) are a partially sectional front view and side sectional view of a brush holder for a vehicle alternator according to an embodiment of the present invention, and FIG. 3 is a sectional view taken along line 1-1, FIG. 3 is a sectional view taken along line T in FIG. 1(a), and FIG. 4 is a sectional view corresponding to FIG. 2 of a brush box showing another embodiment of the present invention. , FIG. 5 is a vertical cross-sectional view of a vehicle alternator, FIGS. 6(a) and (b) are a partially sectional front view and side cross-sectional view of a brush holder of a conventional vehicle alternator, and FIG. Figure 7 is a cross-sectional view taken along the line ■-■ in Figure 6(a);
Figure 8 is a sectional view taken along the line ■-■ in Figure 6(a);
The figure is a front view showing the side contact surface of the brush of FIG. 6(,). 28... Brush, 29... Compression spring, 40... Brush holder, 41... Brush box, 41a... Square hole, 41b, 41c... Undercut groove. Note that the same symbols in the drawings Indicates the same or equivalent part.

Claims (1)

[Claims] Of the inner surface of the square hole into which the brush of the brush box is inserted, an undercut groove is provided on the surface facing the thickness direction of the brush to allow the compression spring for the brush to escape, leaving the lower part in the height direction of the brush box on the upper side. A brush holder for a vehicle alternator, characterized by: