A slip ring unit for an electrical machine includes a brush holding apparatus including brush boxes configured to receive slip ring brushes. For realizing an effective cooling of the slip ring brushes, the brush holding apparatus has cooling air lines for the targeted supply of cooling air to the slip ring brushes, and cooling air ducts which each have an air inlet opening for collecting cooling air and an air outlet opening for supplying the cooling air which is collected in the cooling air ducts to the slip ring brushes via the cooling air lines which are connected to the air outlet openings.

A method for producing a bush and a bush for a rotor shaft are disclosed. The method includes: providing a flat metal strip; introducing at least one of (i) a surface structure onto one side of the flat metal strip for at least one of enlarging a heat-transferring area and directing a coolant, and (ii) at least one hole into the flat metal strip; and rolling up the flat metal strip to form the bush. The surface structure, if provided, lies on an inner surface area of the bush.

An electric machine, including a stator and a rotor shaft having a cooling device, which shaft carries at least one slip ring, which has a lateral surface, which electrically contacts a contact element fixed on the stator, and which is at least partially accommodated in a recess of the rotor shaft, wherein an extension section of the slip ring, which is at least partially accommodated in the recess, extends beyond the lateral surface in one or both axial directions of the rotor shaft.

An electric machine, including a stator and a rotor shaft having a cooling device, which shaft carries at least one slip ring, which has a lateral surface, which electrically contacts a contact element fixed on the stator, and which is at least partially accommodated in a recess of the rotor shaft, wherein an extension section of the slip ring, which is at least partially accommodated in the recess, extends beyond the lateral surface in one or both axial directions of the rotor shaft.

An assembly for the suction of dust generated by the friction of an end of a brush on a collector at a contact surface, including at least one suction device and a brush/brush holder assembly, the suction device defines an inner opening to receive the end of the assembly and allow a gaseous passage between the brush/brush holder assembly and the suction device. A gaseous chamber is defined by a tubular wall and extending according to a plane to form a closed ring, the ring defining the inner opening. A collection opening extends longitudinally over a part of the tubular wall intended to face the collector, the collection opening bordered by at least one lip extending from the gaseous chamber in the direction of the inner opening to form a narrow corridor.

A rotor shaft of an electric motor, in particular of an electrically excited synchronous machine, is composed of a shaft body and a power transmission module, the shaft body having a tubular open end that faces the power transmission module and forms a seat in which an end of the power transmission module located closer to the shaft body is interlockingly accommodated in the seat.

A rotor shaft of an electric motor, in particular of an electrically excited synchronous machine, is composed of a shaft body and a power transmission module, the shaft body having a tubular open end that faces the power transmission module and forms a seat in which an end of the power transmission module located closer to the shaft body is interlockingly accommodated in the seat.

This machine includes: a rotor; sliprings that are placed on an outer circumferential surface of an end portion of a shaft located on one end side thereof and projecting from the rotor; a brush assembly that has a cylindrical shape with an open end located near a head of the shaft, to thereby surround the sliprings; and brushes that penetrate in the brush assembly toward the sliprings from their radially outer sides and make contact with the sliprings, for supplying a current to the sliprings; wherein, on an inner circumferential surface of the brush assembly near the open end, a first wall that extends in a circumferential direction and a second wall that forms, between it and the first wall, a flow passage that leads in the circumferential direction from a region corresponding to a penetrating region of the brush, to an outside thereof, are formed.

This machine includes: a rotor; sliprings that are placed on an outer circumferential surface of an end portion of a shaft located on one end side thereof and projecting from the rotor; a brush assembly that has a cylindrical shape with an open end located near a head of the shaft, to thereby surround the sliprings; and brushes that penetrate in the brush assembly toward the sliprings from their radially outer sides and make contact with the sliprings, for supplying a current to the sliprings; wherein, on an inner circumferential surface of the brush assembly near the open end, a first wall that extends in a circumferential direction and a second wall that forms, between it and the first wall, a flow passage that leads in the circumferential direction from a region corresponding to a penetrating region of the brush, to an outside thereof, are formed.

A slip ring body for electrically contacting an asynchronous machine includes first and second slip rings rigidly connected to one another, with at least two conductor bars fastened to each of the slip rings. At least one of the slip rings has a recess for passage of the conductor bars of the other slip ring and defining around the recess a first region in which air is at least partially present and which has a magnetic conductivity that is lower than a magnetic conductivity in a second region in which the conductor bars to the one slip ring are fastened, or which second region is embodied for contacting with an energy-transmitting brush. The first and second regions are not made of copper. The recess defines an opening cross-sectional area which is greater than a cross-sectional area of the conductor bars fastened to the one slip ring.