A rotor is provided with: a rotor core which rotates integrally with a shaft and has a plurality of radially extending teeth; windings including coil portions wound around the teeth; a commutator that is attached to the rotor core and integrally rotates with the shaft, the commutator including metal commutator segments having contact portions with which precious metal brushes make sliding contact, and a plurality of terminals to which the windings are bonded; elements which include capacitors and respectively electrically connecting terminals to which both ends of the coil portions of the same phase are connected; and a coating layer formed of an oil applied to the contact portions. A motor includes this rotor.

A sliding brush assembly for a slipring includes a sliding brush and an absorbing device containing absorbing material attached to the sliding brush, such that the at least one sliding brush is enclosed by the absorbing material. The absorbing device includes a housing with two (optionally identical) housing parts (each having an elongated base with a snap arm at one side and at the opposing side an opening, into which the snap-arm fits). The housing may easily be closed around a sliding brush by snapping two housing parts together.

A sliding brush assembly for a slipring includes a sliding brush and an absorbing device containing absorbing material attached to the sliding brush, such that the at least one sliding brush is enclosed by the absorbing material. The absorbing device includes a housing with two (optionally identical) housing parts (each having an elongated base with a snap arm at one side and at the opposing side an opening, into which the snap-arm fits). The housing may easily be closed around a sliding brush by snapping two housing parts together.

A slip ring includes a first dielectric carrier body and a second dielectric carrier body, each carrier body having at least one shoulder extending circumferentially along a circle line. In addition, the slip ring includes conductor elements, which have an annular and closed configuration with respect to an axis, at least one conductor element, which is fixed in place on the shoulder of the first dielectric carrier body, and at least one conductor element, which is fixed in place on the shoulder of the second dielectric carrier body. The first dielectric carrier body is arranged at an offset from the second dielectric carrier body in the direction of the axis, so that the shoulder having the at least one conductor element of the first dielectric carrier body and the shoulder having the at least one conductor element of the second dielectric carrier body are located axially across from each other.

A safety electrical power connector can include a first connector body having a first electrical contact and an outer surface, and a second connector body that engages the first connector body in an axial direction. The second connector body can have a second electrical contact and an inner surface configured to slide relative to the outer surface of the first connector body in the axial direction during engagement of the first and second connector bodies. The outer surface and the inner surface can define a gap therebetween sufficient to establish an isolation enclosure that isolates a volume containing the first and second electrical contacts therein. The gap can be formed prior to electrical communication of the first and second electrical contacts thereby preventing an explosion due to arcing between the first and second electrical contacts.

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.

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.

An electrical contact device includes a high electric potential-side contact and a low electric potential-side contact having a lower electric potential than the high electric potential-side contact. The high electric potential-side contact and the low electric potential-side contact are configured to be brought into and out of contact with each other. At least one of the high electric potential-side contact and the low electric potential-side contact is formed of a low-boiling point material whose boiling point is lower than 2562 C. or a mixed material that contains the low-boiling point material.

An electrical contact device includes a high electric potential-side contact and a low electric potential-side contact having a lower electric potential than the high electric potential-side contact. The high electric potential-side contact and the low electric potential-side contact are configured to be brought into and out of contact with each other. At least one of the high electric potential-side contact and the low electric potential-side contact is formed of a low-boiling point material whose boiling point is lower than 2562 C. or a mixed material that contains the low-boiling point material.

An electrical connector for providing power between a nacelle and a hub of a wind turbine. The electrical connector includes a first electrical connector part for connection to one of the nacelle or the hub, and a second electrical connector part for connection to the other of the nacelle or the hub. The electrical connector further includes an actuator for moving the first or second electrical connector parts in a first direction between an extended position in which the first and second connector parts are in contact and form an electrical connection between the nacelle and the hub, and a retracted position in which the first and second electrical connector parts are spaced apart and do not form an electrical connection. The first and/or second electrical connector parts include one or more magnets arranged to secure the first and second parts together when the respective parts are in contact.