BRUSH MODULE AND ASSEMBLY METHOD

Abstract

The invention relates to a brush module (10) for an electric machine and to a method for mounting such a brush module, the brush module having a brush (13) for forming an electric contact with a slip ring, the brush module having an mounting device (12) and a brush holder (11) for accommodating and holding the brush, the mounting device being realized as a U-shaped sheet-metal bracket (17) which engages over the brush holder, the sheet-metal bracket having laterally protruding fastening tabs (18) for fastening the brush holder to an mounting surface (19), an access opening (25) being formed in the brush holder, a retaining tab, which is formed on a fastening tab of the sheet-metal bracket, engaging in the access opening and holding the brush in the brush holder in a retaining position (24) in a form-fitting manner, the fastening tab having the retaining tab being inclined at an angle α relative to the mounting surface of the brush holder.

Claims

1. A brush module (10) for an electric machine, in particular an electric motor, the brush module having at least a brush (13) for forming an electric contact with a slip ring of the machine, the brush module having an mounting device (12) and a brush holder (11) for accommodating and holding the brush, the mounting device being realized as a U-shaped sheet-metal bracket (17) which engages over the brush holder, the sheet-metal bracket having laterally protruding fastening tabs (18) for fastening the brush holder to an mounting surface (19), wherein an access opening (25) is formed in the brush holder, a retaining tab (26), which is formed on a fastening tab of the sheet-metal bracket, engaging in the access opening and holding the brush in the brush holder in a retaining position (24) in a form-fitting manner, the fastening tab having the retaining tab being inclined at an angle α relative to the mounting surface of the brush holder.

2. The brush module according to claim 1, wherein the fastening tab (18) is inclinable at angle α for coming into contact with the mounting surface (19), the retaining tab (26) releasing the brush (13) and the brush being moveable into a contact position (31) at an inclination of angle α.

3. The brush module according to claim 1, wherein the angle α is 5° to 50°.

4. The brush module according to claim 1, wherein passages (21) for a screw are formed in each of the fastening tabs (18).

5. The brush module according to claim 1, wherein the fastening tab (18) having the retaining tab (26) is connected to the U-shaped sheet-metal bracket (17) via a bendable hinge.

6. The brush module according to claim 5, wherein the hinge is realized by a material weakening in a bending edge (34) on the sheet-metal bracket (17).

7. The brush module according to claim 1, wherein the brush holder (11) has a receiving sleeve (14), in which the brush (13) is held so as to be displaceable in the longitudinal direction, and a spring device (15), the spring device being realized such that it exerts a contact pressure on the brush in the direction of a longitudinal axis (16) of the receiving sleeve, the access opening (25) being formed in the receiving sleeve.

8. The brush module according to claim 1, wherein the brush (13) is realized having a groove (27) which extends in the direction of a longitudinal axis (16) of the brush and in which the retaining tab (26) engages, the groove forming a step (29) on a proximal end (28) of the brush, the retaining tab and the step together forming a rear stop for the brush.

9. The brush module according to claim 8, wherein a guiding tab (33) which engages in the groove (27) is formed on a distal end (32) of the brush holder (11), the guiding tab and the step (29) together forming a front stop for the brush (13).

10. The brush module according to claim 1, wherein the brush holder (11) has a positioning recess in which a positioning tab (36) formed by the sheet-metal bracket engages.

11. The brush module according to claim 10, wherein the positioning recess is realized by the access opening (25).

12. The brush module according to claim 1, wherein the sheet-metal bracket (17) has laterally protruding positioning tabs (22), which are disposed parallel to each other, for fastening the brush holder on parallel lateral surfaces (23) of a carrier (20) realizing the mounting surface (19).

13. The brush module according to claim 1, wherein the brush holder (11) is made of sheet metal.

14. An electric machine, wherein the electric machine has a brush module (10) according to claim 1.

15. A method for mounting a brush module (10) on an electric machine, at least a brush (13) of the brush module forming an electric contact with a slip ring of the machine, the brush being accommodated and holding in a brush holder (11) of the brush module, an mounting device (12) of the brush module being realized as a U-shaped sheet-metal bracket (17) which engages over the brush holder, the sheet-metal bracket being realized having laterally protruding fastening tabs (18), the brush holder being fastened to a mounting surface (19) by means of the fastening tabs, wherein an access opening (25) is formed in the brush holder, a retaining tab (26), which is formed on a fastening tab of the sheet-metal bracket, engaging in the access opening and holding the brush in the brush holder in a retaining position (24) in a form-fitting manner, the fastening tab having the retaining tab being inclined at an angle α relative to the mounting surface of the brush holder.

16. The method according to claim 15, wherein the fastening tab (18) is inclined at angle α and comes into contact with the mounting surface (19), the retaining tab (26) releasing the brush (13) and the brush being moved into a contact position (31) at an inclination of angle α.

Description

[0028] In the figures:

[0029] FIG. 1 shows a perspective view of a brush module;

[0030] FIG. 2 shows a front view of the brush module before a mounting of the brush module;

[0031] FIG. 3 shows the front view of the brush module after the mounting of the brush module:

[0032] FIG. 4 shows a perspective view of the brush module after the mounting of the brush module.

[0033] A combined view of FIGS. 1 to 4 shows a brush module 10 in different views. Brush module 10 serves to form an electrical contact with a slip ring of an electric machine (not illustrated) and comprises a brush holder 11, a mounting device 12 and a brush 13. Brush 13 is essentially made of a carbon material and is inserted into brush holder 11 and held therein so as to be moveable longitudinally. Brush holder 11 realizes a receiving sleeve 14 for brush 13 and comprises a spring 15 which exerts a contact pressure on brush 13 in the direction of a longitudinal axis 16 of receiving sleeve 14, such that brush 13 can be pressed against the slip ring (not illustrated) by means of the contact pressure.

[0034] Mounting device 12 is realized as a U-shaped sheet-metal bracket 17 which engages over brush holder 11 and which has laterally protruding fastening tabs 18 for fastening brush holder 11 on a mounting surface 19 (only schematically illustrated). Mounting surface 19 is realized on the electric machine (not illustrated) by a carrier 20. Carrier 20 is positioned such that brush module 10 can be mounted on the slip ring in a desired position. Passage openings 21 are formed in each fastening tab 18, screws (not illustrated) being insertable through each passage opening 21 and being able to be screwed into carrier 20 for mounting the brush holder on carrier 20. Furthermore, laterally protruding positioning tabs 22 which serve for fastening brush holder 11 on parallel lateral surfaces 23 of carrier 20 are realized on sheet-metal bracket 17. Positioning tabs 22 are realized parallel to each other and are distanced so far from each other that a clamping force can be exerted on lateral surfaces 23 of carrier 20 between positioning tabs 22. It is thus possible to pre-position brush module 10 on carrier 20.

[0035] FIGS. 1 and 2 show brush module 10 before a final mounting on carrier 20, brush 13 being disposed in a retaining position 24 in brush holder 11 in this case. In particular, an access opening 25, in which a retaining tab 26 formed on a fastening tab 18 engages, is formed in brush holder 11. In this case, retaining tab 26 holds brush 13 in retaining position 24 in a form-fitting manner, fastening tab 18 having retaining tab 26 being inclined at an angle α relative to mounting surface 19. A groove 27 is formed in brush 13, said groove 27 forming a step 29 on a proximal end 28 of brush 13. Retaining tab 26 engages in groove 27 and, by means of establishing contact on step 29, prevents brush 13 from being pushed out of receiving sleeve 14 via spring 15.

[0036] FIGS. 3 and 4 show brush module 10 after a mounting of brush module 10 on carrier 20 by means of being screwed onto carrier 20. In this case, fastening tabs 18 are disposed in a shared mounting plane 30 with mounting surface 19. During screwing, fastening tabs 18 are bent or approximated by respective angles α and β in the direction of mounting plane 30 or mounting surface 19 until they abut flatly on mounting surface 19. In particular during pivoting of fastening tab 18 having retaining tab 26, retaining tab 26 is moved so far out of groove 27 that step 29 is released. By means of spring 15, brush 13 can now be moved into contact position 31 (shown in FIG. 4) or into the position reached on the worn end of brush 13. To prevent brush 13 from falling out of receiving sleeve 14, a guiding tab 33 is formed on a distal end 32 of receiving sleeve 14, said guiding tab 33 engaging in groove 27 and being able to come into contact with step 29. The guiding tab essentially prevents brush 13 from falling out of receiving sleeve 14.

[0037] To ensure a pivoting of fastening tab 18 having retaining tab 26 by angle α in the desired manner, an oblong hole 35 is formed in a bending edge 34 on sheet-metal bracket 17, such that a defined pivoting movement on bending edge 34 becomes possible. Furthermore, access opening 25 in receiving sleeve 14 serves to exactly position brush holder 11 in sheet-metal bracket 17. Thus, a positioning tab 36 which engages in access opening 25 without coming into contact with brush 13 is formed on sheet-metal bracket 17. In this manner, positioning tab 36 determines a position of brush holder 11 in the direction of longitudinal axis 16 relative to sheet-metal bracket 17.