A rotor of an electric motor includes a rotating shaft, a rotor core and a commutator fixed to the rotating shaft, and a first sleeve, a second sleeve and a third sleeve arranged around the rotating shaft. The first sleeve is located on a side of the rotor core away from the commutator and abuts against the rotor core, the second sleeve is located between the rotor core and the commutator, and the third sleeve is located on a side of the commutator away from the rotor core.

A carbonaceous material is fabricated by kneading of carbon powder and a binder. The carbonaceous material is granulated such that an average particle diameter of the carbonaceous material is 0.3 mm or more. A brush material is fabricated by mixing of the granulated carbonaceous material and metallic powder. A ratio of the metallic powder to a total weight of the brush material is adjusted to 1% by weight or more and 30% by weight or less. Pressure molding is performed on the fabricated brush material, and thermal processing is further performed on the brush material at a temperature at which a resin in the brush material is not carbonized.

A carbonaceous material is fabricated by kneading of carbon powder and a binder. The carbonaceous material is granulated such that an average particle diameter of the carbonaceous material is 0.3 mm or more. A brush material is fabricated by mixing of the granulated carbonaceous material and metallic powder. A ratio of the metallic powder to a total weight of the brush material is adjusted to 1% by weight or more and 30% by weight or less. Pressure molding is performed on the fabricated brush material, and thermal processing is further performed on the brush material at a temperature at which a resin in the brush material is not carbonized.

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 motor includes a rotor that has a motor shaft disposed along a central axis extending in an axial direction; a stator facing the rotor with a gap interposed therebetween in a radial direction; a motor driving inverter unit supplying electric power from a battery to the stator; a charger having a charger inverter unit that charges the battery; and a housing accommodating the stator, the motor driving inverter unit and the charger The housing has a cooling flow path through which a coolant flows, a stator accommodation unit accommodating the stator, an inverter accommodation unit positioned outside the stator accommodation unit in the radial direction, a charger accommodation unit positioned outside the stator accommodation unit in the radial direction, and an intermediate partitioning wall partitioning the inverter accommodation unit and the charger accommodation unit The cooling flow path is disposed in the intermediate partitioning wall.

A motor includes a rotor that has a motor shaft disposed along a central axis extending in an axial direction; a stator facing the rotor with a gap interposed therebetween in a radial direction; a motor driving inverter unit supplying electric power from a battery to the stator; a charger having a charger inverter unit that charges the battery; and a housing accommodating the stator, the motor driving inverter unit and the charger The housing has a cooling flow path through which a coolant flows, a stator accommodation unit accommodating the stator, an inverter accommodation unit positioned outside the stator accommodation unit in the radial direction, a charger accommodation unit positioned outside the stator accommodation unit in the radial direction, and an intermediate partitioning wall partitioning the inverter accommodation unit and the charger accommodation unit The cooling flow path is disposed in the intermediate partitioning wall.

A slip ring unit for an electric generator is provided. The slip ring unit includes a slip ring attachable to a rotor shaft of the electric generator, a plurality of sliding contacts arranged along a circumference of the slip ring, to provide an electrical connection with the slip ring, at least one temperature sensor for measuring a temperature inside the slip ring unit, a fan for providing a cooling flow in the slip ring unit, and a controller connected to the fan for controlling the cooling flow rate generated by the fan, the controller being connected to the at least one temperature sensor. The at least one temperature sensor is attached to at least a holder for supporting the sliding contacts. The controller is configured in such a way that the cooling flow rate is generated depending on the temperature measured by the at least one temperature sensor.

A voltage divider circuit is configured by a resistor having one end connected to a positive electrode of a battery configuring a power source and another end connected to a first terminal that is a motor terminal on one side of a wiper motor, and a FET having one end connected to the first terminal and another end grounded. The voltage divider circuit lowers a voltage of the battery to a test voltage that does not cause the wiper motor to rotate. A microcomputer detects a detected voltage that is a voltage output from the voltage divider circuit to a second terminal that is a motor terminal on the other side of the wiper motor via the first terminal of the wiper motor and the wiper motor, and computes a motor terminal voltage, this being a potential difference between the first terminal and the second terminal, from the detected voltage.

Disclosed embodiments relate to a windscreen wiper drive of a windscreen wiper device of a rail vehicle. The drive includes at least one electric motor, a gear, the input shaft of which being connected to an output shaft of the electric motor, wherein an output shaft of the gear is provided for driving at least one windscreen wiper arm of a windscreen wiper, which arm swings back and forth with the output shaft, a rotation angle sensor unit, which detects a rotation of at least one element of the windscreen wiper drive, and a mechanical rotation angle limitation, which mechanically limits a rotational movement of at least one element of the windscreen wiper drive. The electric motor is formed by a disc motor and the gear is formed by a planetary gear.

A bus bar engaged with each brush holder and electrically connected to positive brushes. A rotor has coils and protrusions extending in an outward direction and electrically connecting the coils to commutator segments. Each brush portion end surface faces the outward direction, the bus bar has an engagement portion with an end facing the inward direction, and the end of the engagement portion is further in the outward direction than the end surface portion. The brush has an end facing the first direction, the bus bar has an end facing a second direction, and the end of the bus bar is further in the second direction than the end of the brush facing the first direction. Each protrusion end faces the second direction, and the end of the bus bar facing the first direction is further in the second direction than the end of the protrusion facing the second direction.