FR2667737A1 - BRUSH HOLDER FOR A VEHICLE ALTERNATOR. - Google Patents

Abstract

a) Brush holder for vehicle alternator. b) Brush holder for a vehicle alternator characterized by exhaust grooves (41b) for letting a compression spring (25) escape, the exhaust grooves being provided longitudinally in the portion not comprising the lower portion of the box brush, the exhaust grooves being provided in the two respective inner walls of a square hole (41a) of the brush box, where a brush comes into contact with the inner walls of the brush box. c) The invention applies to vehicle alternators and makes it possible to reduce the wear of the brushes.

Description

BRUSH HOLDER FOR A VEHICLE ALTERNATOR.

  The present invention generally relates to brush holders for vehicle alternators and more particularly to a brush holder comprising a brush box for containing the brushes and

  compression springs to constrain

brooms.

  FIG. 5 is a sectional view of an alter-

  vehicle generator equipped with a brush holder As indicated in FIG. 5, the alternator comprises a stator 1 formed of an armature armature 2 and of an armature winding 3, a rotor 4 formed of cores

  5, 6 with alternating flux, the magnetic portions

  Toothed ticks of each other coming alternately

  protruding in the circumferential direction

  In this embodiment, an inductive winding 7 held between the magnetic cores 5, 6, a rotating shaft 8 to hold the magnetic cores 5, 6, a pair of slip rings 9 held by the rotating shaft 8, and fans 10, 11 respectively by

magnetic cores 5, 6.

  The alternator further comprises a front flange and a rear flange 12, 13 for fixing the armature armature 2 by means of a clamping bolt 14, bearings 15, 16 for supporting the rotating shaft 8, respectively on the front flange and the rear flange 12, 13, a pulley 17 fixed to the rotating shaft

  8 and used to transmit the torque to the rotating shaft.

  8 to rotate the rotor 4.

  The alternator further comprises a rectifier 18 for rectifying the AC current resulting from the AC voltage induced in the winding

of armature 3.

  The alternator further comprises a regulator

  19 to detect the voltage of the alterna-

  controller, control the excitation current and

  the terminal voltage to a predetermined value.

  The alternator further comprises a brush holder 20 fixed to the rear flange 13 and serving to constrain, in the direction of longitudinal displacement, and hold the brushes 28, and an annular partition 22 fixed to the rear flange 13 so as to protecting the alternator from hazardous materials such as atmospheric moisture, salt content and the like by covering the outer circumference of the slip rings 9 with a space provided therebetween.

  Figures 6 (a) and 6 (b) are an enlarged

  partially undressed, and a side sectional view, of a conventional brush holder mounted on the vehicle alternator described above In this case, the brush holder is in a state in which it has been removed from the vehicle. alternator The brush holder

  20 comprises a brush box 21 of synthetic resin

  with the brushes 28 inserted therein, a connector member 23, a terminal member 2 E, springs

  25 to constrain the brooms

  28, a cover 27 made of synthetic resin and connection conductors 29 from

respective brooms 28.

  The inside wall of a square hole 21a of the brush box 21 is formed as shown in FIG. 7 and FIG. 8 which are sectional views taken along the lines VII-VII and VIII-VIII, respectively. split-shaped exhaust 21b are provided longitudinally along the entire length of the inner wall of the square hole in the direction of the thickness of the blade 28 so that the compression spring 25 is not impeded. As shown in FIG. 9, the blade 28 inserted in the brush box 21 is arranged so

  such that only the contact surfaces 28 a,

  hatching in the two lateral portions of the blade, in the direction of its thickness, are provided to come into sliding contact with

  the inner walls of the broom box 21.

  In the brush holder 20 for the conventional vehicle alternator described above, the exhaust grooves 21b are provided longitudinally along the entire length of the inner wall of the square hole 21a of the brush box 21 in the direction As a result, only the narrow contact surfaces 28 located in the side portions of the blade 28 in the direction of its thickness can come into sliding contact with what remains of the inner wall of the brush box. 21 As a result, there is the serious problem that the contact surfaces 28a of the blade 28 tend to wear out more and more due to the vertical movement of the slip ring 9 caused by the vibrations, which results in poor contact with the slip ring due to the fact that the

broom is shaken and rocking.

  An object of the present invention is to solve

  the above problems by proposing, for an alter-

  vehicle, a brush holder ensuring that the respective portions of small contact area only, in the side portions of a broom, in the direction of its thickness, are prevented

  come into contact with the inner walls

  The purpose of the broom box is to reduce the wear of the side portions and to maintain smooth contact of these portions with a slip ring. the brush holder for a vehicle alternator according to the present invention comprises exhaust grooves for escaping the compression spring, the exhaust grooves not extending longitudinally to the lower portion of the brush box, the exhaust grooves being provided in the two respective inner walls of a square hole of the brush box o a broom comes into contact with

these inner walls.

  According to the present invention, the side walls of the blade, in the direction of its thickness, come into sliding contact with a portion not comprising the exhaust grooves provided in the upper portion of the respective inner walls of the brush box: is therefore the entire surface of the side portions of the brush which comes into sliding contact with the inner walls of the brush box, thereby preventing the side portions of the brush from wearing down and preventing the brush

  to be shaken and to switch in the broom box.

  Figures 1 (a) and 1 (b) are a schematic

  partially undressed, and a side sectional view, of a brush holder for a vehicle alternator embodying the present invention; Figure 2 is a sectional view taken along line II-II of Figure 1 (a); Figure 3 is a sectional view taken along the line III-III of Figure l (a); Figure 4 is a sectional view of another brush holder embodying the present invention and corresponding to what is shown in Figure 2; Figure 5 is a vertical sectional view of a vehicle alternator;

  Figures 6 (a) and 6 (b) are views in

  partially undressed, and a side sectional view of a conventional brush holder for a vehicle alternator; Figure 7 is a sectional view taken along the line VII-VII of Figure 6 (a); Figure 8 is a sectional view taken along line VIII-VIII of Figure 6 (a); and FIG. 9 is an elevational view of the surfaces

  side contact of the blade of Figure 6 (a).

  Figures 1 (a) and 1 (b) are elevational views, partially undressed, and a view

  in side section, a brush holder for a genera-

  vehicle driver embodying the present invention,

  the brush holder being mounted on the alternator

  5 as shown in the drawings, a brush holder 40 is formed in one piece with a brush box 41 made of synthetic resin and with an annular partition 42, the brush holder having a connector member 43 and a terminal member 44 A terminal metal plate 45 has one end of the connecting conductor 29 of a brush 28 which is connected thereto and is attached to the brush box 41 The terminal metal plate 45 also functions as

  stop for the compression springs 25

  vercle 46 is mounted on the upper part of the

  brush box 41 and serves as protection.

  The inner wall of the square hole 41a of the brush box 41 is shaped so that its upper portion has, in the vertical direction, in section, the configuration taken along line II-II of FIG. 1 (a) as shown in FIG. 2 exhaust grooves 41b, in the form of a doorway, which allows the compression spring 25 to escape,

  are provided in the two inner walls

  in the direction of the thickness of the blade 28, in

  remaining on the extension range of the mainspring

  pressure 25 when the blade 28 reaches the wear limit, the inner walls being provided in the upper portion of the inner wall of the

broom box 41.

  The lower inner walls of the square hole 41a of the brush box 41 are formed so that the square hole has, in section, the configuration taken along line III-III of FIG. 1 (a) as

  shown in Figure 3 No escape grooves

  41b is not provided in the lower inner wall.

  the upper part of the brush box 41 and it is the entire lateral portion of the brush 28 which can come into sliding contact with the inner walls of the square hole Because it is the entire surface of the brush 28 which can come in contact with the inner walls of the square hole of the brush box 41, it is thus possible to prevent local wear

the side portion of the broom.

  FIG. 4 represents another embodiment of the present invention in which trapezoidal exhaust grooves 41c are provided according to

  a sectional view corresponding to what is

shown in Figure 2.

  As indicated above, the escape grooves

  in order to escape the compression spring of the blade, are provided in the two inner walls of the square hole of the brush box of the brush holder, in the direction of the thickness of the brush, the exhaust grooves n ' being provided that in the upper portion of the brush box The contact surface in which the brush comes into sliding contact, in the direction of its thickness, increases in comparison with the conventional brush holder It follows that the brush is prevented from be shaken and tilt into the broom box to ensure it maintains a smooth contact with the slip ring.

Claims (3)

  A brush holder for a vehicle alternator, comprising a compression spring (25) for pushing a broom; and a brush box (41) having a square hole (41a) for holding a brush, said square hole being defined by two pairs of inner walls of said brush   broom box, a pair of said surfaces   opposing edges, in the direction of the thickness of a blade, being provided with exhaust grooves (41b, 41c) to allow said compression spring to escape, characterized in that said exhaust grooves are provided longitudinally in a portion excluding the lower portion of said brush box o is not the compression spring, said brush (28) coming into sliding contact with said walls inside the broom box.   Brush holder as claimed in claim   cation 1, characterized in that said grooves   exhaust have the shape of a portion of a circle.   3 Brush holder as claimed in the present invention   1, characterized in that said grooves   exhaust are trapezoidal.