Abstract:
What is described is: an electric machine (1), in particular for a motor vehicle, with an electrical contact pair, which comprises a first stationary, substantially fixedly arranged current-transfer apparatus, preferably in the form of brushes (4), and a second current-transfer apparatus arranged so as to enable rotary movement, each of said current-transfer apparatuses having functional faces (9, 49) which come into contact with one another during a rotation of the second apparatus for a sliding contact for current transfer, and the surfaces of the functional faces (9, 49) being formed with a defined roughness (Rh). In order to achieve a longer life of an electric machine, and in a manner which is as inexpensive as possible, the surface at least of one functional face of the first and/or second current-transfer apparatus is formed with local, geometrically defined, regular irregularities (20x) in each case in one dimension greater than the defined roughness (Rh) of the local surface of at least one functional face.
Abstract:
A method is proposed for establishing an electrically conductive and mechanically secure connection (28, 29) between the conductors (23, 26) of a rotor winding and a commutator segment of a commutator (13), wherein the conductors (23, 26) are arranged in such a manner that one of the conductors (23) is arranged between the other conductor (26) and the commutator segment (20), and thereafter a region of the surface of the one conductor (23) is bonded to the commutator segment (20), wherein the conductor (23) that is intended to be bonded to the commutator segment (20) is first pressed onto a stamping core (32), wherein the conductor (23) is shaped in the process and thereby the region of the surface is adapted at least to a section of the outer contour (43) of the stamping core (32) and thereafter the stamping core (32) is removed and is replaced by the commutator (13) and then the conductor (23) having the adapted surface is placed onto a commutator segment and bonded to said commutator segment.