An electric motor, in particular a separately excited synchronous motor, has a rotor shaft with at least one slip ring and at least one electrically conductive contact element, in particular a carbon brush, which bears against the slip ring and is accommodated in a channel-like guide formed in a housing and extending radially with respect to the rotor shaft and which carbon brush is radially tensioned against the slip ring by means of a spring element, wherein a roller is provided which is tensioned laterally against the contact element via a further spring element and via which the contact element is tensioned against a wall of the guide.

A method of replacing a brush holder includes positioning a handle on the brush holder while the brush holder is connected to a support, rotating the handle relative to the brush holder in a first direction that is clockwise or counter-clockwise to connect the handle to the brush holder, removing the brush holder from the support by pulling the handle with the handle attached to the brush holder, rotating the handle relative to the brush holder in a second direction that is opposite to the first direction while pulling a trigger on the handle that moves a core in the handle upward in a cavity in the handle, and removing the handle from the brush holder.

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 motor includes a commutator, a brush, a first spring, a second spring, and a holder. The brush is configured to come into contact with the commutator to be electrically connected to the commutator. The first spring is configured to push the brush along the first direction toward the commutator. The second spring pushes the brush along a second direction intersecting the first direction. The holder is disposed such that the brush is located between the holder and the second spring in the second direction. The holder holds the brush between the holder and the second spring.

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 motor includes a commutator, a bracket including a conductive brush, first and second wall parts, and first and second deformable parts. The conductive brush is in contact with the commutator. The first wall part includes a first surface extending along a first surface of the conductive brush. The second wall part includes a second surface extending along a second surface of the conductive brush located on a side opposite the first surface of the conductive brush. The first deformable part is in contact with both the first surface of the conductive brush and the first surface of the first wall part, and is deformable in response to movement of the conductive brush. The second deformable part is in contact with both the second surface of the conductive brush and the second surface of the second wall part, and is deformable in response to movement of the conductive brush.

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.

The disclosed invention is a slip ring assembly that provides electrical power transfer to centrifugal turbomachinery while minimizing or eliminating the presence of wires in the flow path. The device transfers electrical power through a set of wires connected to a plurality of brushes that are held rotationally stationary, but allowed to displace axially or radially through a set of springs. The brushes make contact with conductive busbar rings, transferring electricity to the busbar rings. The busbar rings rotate with the centrifugal turbomachine with a set of wires that connect the busbar rings to the blades or other aerodynamic surfaces of the centrifugal turbomachine.

The invention relates mainly to an assembly comprising a brush cage and a spiral spring (36), the spiral spring (36) comprising an axis (Y), a wound part (37) wound about the axis (Y) and an arm (39) extending from one end of the wound part (37), the brush cage comprising at least one lateral wall provided with an opening for the passage of the arm (39) through the lateral wall so that one end of the arm (39) can press against at least part of an end face of a brush, wherein the arm (39) comprises a first portion (391) of which the width (L5) measured along the axis (Y) is different from the width (L6) of the wound part (37) measured along the axis (Y) of the spiral spring (36).

A device (i.e., a slip-ring or a homopolar motor/generator) (40, 50, 80) is adapted to provide electrical contact between a stator and a rotor (41, 83), and includes: a current-carrying brush-spring (31, 84) mounted on the stator, and having two opposite surfaces; a fibrous brush assembly (35, 69) mounted on the conductor, the brush assembly having a bundle of fibers (36, 71) arranged such that the tips of the fibers will engage the rotor for transferring electrical current between the stator and rotor; a ribbon (33, 85) of superconducting material mounted on each opposite surface of the current-carrying brush-spring and communicating with the stator and the brush assembly; and another ribbon (29, 86) of superconducting material mounted on the rotor. The device is submerged in a cryogenic fluid at a temperature below the transition temperatures of the superconducting materials such that the electrical resistivity of the device will be reduced and the current-transfer capability of the device will be increased.