Search International and National Patent Collections

1. (WO2009135894) ELECTRIC MACHINE COMPRISING AT LEAST TWO PAIRS OF CARBON BRUSHES

Pub. No.:    WO/2009/135894    International Application No.:    PCT/EP2009/055517
Publication Date: Nov 12, 2009 International Filing Date: May 7, 2009
IPC: H01R 39/38
H02K 23/02
Applicants: ROBERT BOSCH GMBH
BAYER, Michael
GERSCHWITZ, Walter
Inventors: BAYER, Michael
GERSCHWITZ, Walter
Title: ELECTRIC MACHINE COMPRISING AT LEAST TWO PAIRS OF CARBON BRUSHES
Abstract:
The invention relates to an electric machine comprising at least two pairs of carbon brushes (16) consisting of one positive and one negative carbon brush which cooperate with a commutator (15) to supply the rotor with current, the carbon brushes being mounted by means of their brush holders in a retainer on a brush plate and the retainers on said brush plate lying opposite one another at an angle of 180°. The aim of the invention is to achieve a longer service life for the machine and the smallest possible variety of parts. To achieve this, on at least one brush holder (17a) the retainer part (21b) is offset from the centre, in particular the axis of symmetry (y) of the brush holder (17a), at an angle (α) in relation to the rotor axis (x), to obtain an asymmetrical arrangement of the carbon brush, and the retainer part (21b) on the remaining brush holders is arranged on the axis of symmetry (y) of said holders.