A system for transferring current between a rotating element and a fixed element, comprising—a support in the general shape of a sheet (10) comprising a conductive portion (11) electrically connected to the fixed element, —a brush holder (20) mounted on the support (10) and supporting a brush (30) that is pushed into contact against the rotating element, —electrical connection means (42) for connecting the conductive portion (11) of the support to a cable (40) that is joined to the brush (30), wherein a resistive element (12) is situated between the brush (30) and the conductive portion (11) of the support (10) and prevents current from flowing directly between the conductive portion and the brush.

Example brush holder assemblies of an electric machine are disclosed. An example brush holder assembly of an electric machine includes a carbon brush including an upper surface and a lower surface opposite the upper surface. The brush holder assembly also includes one or more lead wires extending out of the carbon brush at an insertion point on the upper surface and a first cavity extending into the carbon brush from the upper surface at a location spaced away from the insertion point of the one or more lead wires and unobstructed by the one or more lead wires.

A brush holder for holding at least two brushes for a sliding contact arrangement, comprising an intermediate element and two contact elements for electrically contacting at least one of the brushes, the contact elements being arranged on two opposite sides of the intermediate element and the intermediate element having a receptacle extending through the opposite sides for a rotating shaft.

A holding apparatus for a slip ring unit includes at least two slots configured for receiving slip ring brushes respectively, with the at least two slots being arranged in spaced-apart relationship. A cooling duct is arranged between the at least two slots for cooling a side surface of the slip ring brushes. The cooling duct is configured as a third slot between the at least two slots, with the at least two slots and the cooling duct being of essentially identical shape and dimension.

The present invention is an electrical slip ring device comprised of a stator, a rotor and an independent rotationally free brush ring. The brush ring may include a multitude of slipping fingers, chevrons or other current carrying structures that extend between the rotor and the stator. These current carrying structures have a directional bias or “lay”. The rotational freedom of the brush ring enables bi-directional movement of the rotor with reduced torque and wear at the sliding interfaces because sliding always occurs in the direction of the lay.

Example brush holder assemblies of an electric machine are disclosed. An example brush holder assembly of an electric machine includes a carbon brush including an upper surface and a lower surface opposite the upper surface. The brush holder assembly also includes one or more lead wires extending out of the carbon brush at an insertion point on the upper surface and a first cavity extending into the carbon brush from the upper surface at a location spaced away from the insertion point of the one or more lead wires and unobstructed by the one or more lead wires.

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.

A brush holder apparatus includes a stationary support member having at least one groove and a fork electrical connector. A brush retainment member has a brush restraint apparatus having a plunger brush restraint configured to restrain a brush from sliding within the brush retainment member by pressing it against the brush retainment member. The brush retainment member has at least one rail configured to slide along the at least one groove, and a knife electrical connector configured to mate with the fork electrical connector. The brush retainment member is configured to be releasably affixed to the stationary support member. The stationary support member is configured for electrical connection to a collector mount, and the brush retainment member is configured to retain at least one brush.

The invention relates to a method of adjusting a brush holder (41) of a slip ring and brush assembly comprising at least one slip ring (50) with a radius of curvature R. With the method a test tool (80) is used to simulate a brush in the brush holder with the important difference that the test tool is able to indicate to the operator whether full contact between the slip ring and the contact surface of the test tool is obtained.

A brush holder apparatus includes a stationary support member having at least one groove and a fork electrical connector. A brush retainment member is configured to be releasably affixed to the stationary support member. The brush retainment member has at least one rail configured to slide along the at least one groove. The brush retainment member has a knife electrical connector configured to mate with the fork electrical connector. The stationary support member is configured for electrical connection to a collector mount and the brush retainment member is configured to retain at least one brush.