As a configuration of carrying out a turning operation of a brushless synchronous power generation apparatus, there are provided a synchronous generator, an AC exciter, a rotary rectifier attached to an armature of the AC exciter, and short-circuiting means which three-phase short-circuits armature windings of the AC exciter, wherein the armature windings of the AC exciter are short-circuited, causing the AC exciter to operate as an induction motor, thus rotating the rotor shaft of the synchronous generator.

A marking system for knowing precisely at which location on an electrical device a used brush and associated brush holder assembly were positioned to evaluate whether abnormal brush wear, abnormal operation or other anomaly is occurring and performing maintenance and/or replacement of components as needed.

A marking system for knowing precisely at which location on an electrical device a used brush and associated brush holder assembly were positioned to evaluate whether abnormal brush wear, abnormal operation or other anomaly is occurring and performing maintenance and/or replacement of components as needed.

A brush motor including a rotor having a core with a winding wound thereon and a commutator electrically connected to the winding, a brush configured to contact the commutator to cause a current to be supplied to the rotor, and a movable permanent magnet arranged to oppose the core with a gap therebetween and to be movable in a circumferential direction of the rotor within an angle range. The angle range includes a retarded angle position and an advanced angle position, in which the movable permanent magnet is displaced respectively in a retarded angle direction and an advanced angle direction relative to the brush, to thereby respectively cause a first torque and a second torque higher than the first torque. The movable permanent magnet is movable in the retarded or advanced angle direction within the angle range at least within a period in which a current is supplied to the rotor.

A starter motor for starting up an engine mounted to a straddled vehicle. The starter motor includes a rotor, a brush in contact with the rotor to cause a current supplied thereto, and a movable permanent magnet arranged to oppose a core of the rotor with a gap therebetween and to be movable in a circumferential direction of the rotor within an angle range. The angle range includes a retarded angle position and an advanced angle position in which the movable permanent magnet is displaced respectively in a retarded and advanced angle direction relative to the brush. The movable permanent magnet is located in the advanced angle position when the rotor starts to rotate upon a supply of the current to the rotor, and to be moved in the retarded angle direction to the retarded angle position within a period in which the rotor is rotating with the current supplied to the rotor.

A motor driving assembly includes a motor. The motor includes an outer housing, and a rotor and a brush holder received in the outer housing. The rotor includes a rotary shaft extending out of the outer housing. A commutator is fixed on a shaft portion of the rotary shaft within the outer housing. Brushes for contacting the commutator are disposed on the brush holder. A visible identification mark fixed relative to the rotary shaft is disposed outside the outer housing of the motor, such that a relative position between the brushes and the commutator in a rotational direction of the rotary shaft is identifiable by reference to a position of the visible identification mark relative to the outer housing in the rotational direction of the rotary shaft. As such, the commutator can be prevented from stalling at a position where arcing noise may be easily generated.

A motor driving assembly includes a motor. The motor includes an outer housing, and a rotor and a brush holder received in the outer housing. The rotor includes a rotary shaft extending out of the outer housing. A commutator is fixed on a shaft portion of the rotary shaft within the outer housing. Brushes for contacting the commutator are disposed on the brush holder. A visible identification mark fixed relative to the rotary shaft is disposed outside the outer housing of the motor, such that a relative position between the brushes and the commutator in a rotational direction of the rotary shaft is identifiable by reference to a position of the visible identification mark relative to the outer housing in the rotational direction of the rotary shaft. As such, the commutator can be prevented from stalling at a position where arcing noise may be easily generated.

The present disclosure relates to a conductive slip ring for logging while drilling (LWD) instrument. The present disclosure utilizes a mechanical conductive slip ring to solve the problems of transmission of electric power and signals between two structures that have relative rotation, and the conductive slip ring has a simple structure, doesn't involve any complex circuit, and has low cost and high reliability. With the conductive slip ring in the present disclosure, there is no power transmission efficiency problem or signal transmission error rate problem. The conductive slip ring has high temperature-resistant, pressure-proof, and vibration-roof abilities, and can be applied widely.

The invention relates to an electrical machine, such as a motor vehicle that includes a rotor connected to a hollow shaft mounted such that it can rotate about an axis of rotation. The electric machine also includes a rotary transformer that includes a first slip ring and a first brush adjacent thereto. The first slip ring may be arranged inside the hollow shaft and is connected thereto. The invention also relates to a motor vehicle that includes a drive wheel that is operatively connected to the electrical machine.

Electric motors and machines including such electric motors, the electric motors having improved impact resistance. Features of the electric motors minimize axial shifting of the motor shaft and other components of the electric motor, and/or minimize damage to components caused by such axial shifting occasioned by an impact force on the motor.