Current supplying device for rotor winding of electric machine

摘要

A current supplying device comprises a slip ring mounted on a rotor shaft with an electrically insulating layer interposed therebetween, and contacting the brushes of the current collecting bus bars of the brush contact device of an electric machine. At least on one end of the slip ring a distribution ring is mounted to which a current supplying bus bar electrically connected with the rotor winding is secured and which contacts the slip ring through an additional electrically conductive layer formed of a material with a lower specific electric resistance than that of the material of the slip ring. Both the slip ring and the distribution ring are provided with through holes arranged around the circumference of these rings and having longitudinal axes parallel to longitudinal axes of these rings. Each one of the through holes of the slip ring corresponds to one of the through holes of the distribution ring and is coaxial therewith, so that they form an integral ventilating channel. In so formed ventilating channels, sleeves of the additional electrically conductive layer are disposed, which sleeves connect the distribution ring with the slip ring.