An externally excited electric machine comprises a rotor as well as a contact device having at least one sliding contact element positioned against a contact segment of the rotor for transmitting an exciter current, wherein the sliding contact element is integrated in an electromagnetic actuator, by which it can be controlled to move between a position lying against the contact segment and a position spaced apart from it.

An externally excited electric machine comprises a rotor as well as a contact device having at least one sliding contact element positioned against a contact segment of the rotor for transmitting an exciter current, wherein the sliding contact element is integrated in an electromagnetic actuator, by which it can be controlled to move between a position lying against the contact segment and a position spaced apart from it.

Methods and systems for monitoring a brush holder assembly and/or detecting wear of a brush in a brush holder assembly are disclosed. One method includes sending data from a plurality of remote monitoring locations to a central control unit, where the data may be evaluated in order to monitor states of brushes at a plurality of remote electrical facilities. For example, multiple images of a marker tracking longitudinal movement of the brush may be acquired. A comparison of the images, for example, a comparative imaging technique, such as pixel-by-pixel comparison, may then be performed in order to evaluate a condition of the brush, such as the wear rate, wear state, or life expectancy of the brush.

Methods and systems for monitoring a brush holder assembly and/or detecting wear of a brush in a brush holder assembly are disclosed. One method includes sending data from a plurality of remote monitoring locations to a central control unit, where the data may be evaluated in order to monitor states of brushes at a plurality of remote electrical facilities. For example, multiple images of a marker tracking longitudinal movement of the brush may be acquired. A comparison of the images, for example, a comparative imaging technique, such as pixel-by-pixel comparison, may then be performed in order to evaluate a condition of the brush, such as the wear rate, wear state, or life expectancy of the brush.

Proposed is an electronic parking brake actuator assembly including: a main housing constituted by a motor mounting part and a gear mounting part integrated with each other; a motor part assembled with the motor mounting part of the main housing; a gear part assembled with the gear mounting part of the main housing and rotated in engagement with the motor part by a rotational force of the motor part; and a cover assembled with the main housing and shielding the motor part and the gear part, wherein a brush card assembly is assembled directly with the motor mounting part, a terminal constituting the brush card assembly being insert-injected into the motor mounting part.

This motor includes a yoke housing, a brush holder, a housing case and a circuit board. The brush holder holds a power supply brush and power supply terminals. The housing case has a board containing recess into which front end portions of the power supply terminals are inserted. The circuit board has terminals which are electrically connected to the power supply terminals within the board containing recess. The power supply terminals have terminal connection parts which linearly extend and are arranged in the board containing recess. The terminals are fork terminals which are electrically connected to the terminal connection parts. With respect to the terminal connection parts, portions closer to the base ends than terminal connected positions, where the terminals are connected, are covered by noise reduction member for reducing noise.

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.

A brush holder for electrical machines has a clamping piece with a first mounting part and a second clamping part, which when assembled define a clamping hole to be assembled around a spindle; and two brush holder arms pivotally mounted on the first mounting part of said clamping piece, and adapted to receive and retain a brush. The arms have an upper side which is opposite to a lower side facing a slip ring; at least one biasing spring to act upon said brush holder arms in such a way that said brush holder arms move pivotally towards and presses said brushes against the slip ring. A conductive wire connects the brush to the clamping piece. A brush holder arm locking mechanism is adapted to be inserted into a slot in the second clamping part. A brush locking pin retains the brush in said brush holder arm and provided in corresponding bores arranged in the brush holder arm and the brush. The brush locking pin has a pipe portion and a spring portion arranged inside the pipe and that protrudes from a slot in a wall of said pipe. The mounting part of said clamping piece is provided with a brush arm stop to limit a pivot movement of the brush holder arm towards a slip ring.

An angle grinder includes a housing, an output shaft, and a motor. The motor includes a stator assembly, a rotor assembly including a motor shaft configured to rotate about a first axis, a commutator, and a carbon brush. The commutator includes a bushing, configured to connect the commutator to the motor shaft, a plurality of commutator segments, sequentially distributed in a circumferential direction around the first axis and arranged around the bushing, and an insulating member, configured to bond the bushing and the plurality of commutator segments so as to constitute a whole.

A seal device (3) for a rotating shaft (1). The seal device has a shaft seal (4), a shaft grounding connection (6) and a holding feature (9) for holding the shaft seal (4) and the shaft grounding connection (6). The holding feature (9) has at least one opening (10), between the shaft seal (4) and the shaft grounding connection (6), for clearing particles away from the shaft seal (4) and the shaft grounding connection (6). An electric machine with a rotor shaft (1) that can be driven in rotation and with a seal device (3) of the above type for sealing the rotor shaft (1) and, therefore, also sealing an inside space of the electric machine. Furthermore, a drive unit for electrically driving a motor vehicle, including an electric machine of the above type for providing drive power of the drive unit.