A slip ring unit for an electrical machine is provided for accommodating a carbon brush system. The slip ring unit includes at least one insulating segment having shaped sections for cooling parts of the electrical machine. The insulating segment having the shaped sections is shaped from the insulating segment as a fanwheel, wherein the insulating segment having the shaped sections forms a fan to distribute a cooling air flow to the parts of the electrical machine to be cooled. The slip ring unit has boreholes on the sides of supports of the slip rings for passage of cooling air.

A slip ring unit for an electrical machine is provided for accommodating a carbon brush system. The slip ring unit includes at least one insulating segment having shaped sections for cooling parts of the electrical machine. The insulating segment having the shaped sections is shaped from the insulating segment as a fanwheel, wherein the insulating segment having the shaped sections forms a fan to distribute a cooling air flow to the parts of the electrical machine to be cooled. The slip ring unit has boreholes on the sides of supports of the slip rings for passage of cooling air.

A method for measuring a state of wear of a consumable friction element, a measuring device and a friction element, in particular a brush or the like. The measuring device includes a sensing device having a sensor. A magnetic field can be produced by means of the sensor, and the friction element can be moved in the magnetic field relative to the sensor. The measuring device comprises an indicator that can be attached to the friction element. The indicator comprises a ferromagnetic, antiferromagnetic and/or ferrimagnetic substance, and a change in the magnetic field can be detected by means of the sensing device as a result of a change in the position of the indicator relative to the sensor.

A method for measuring a state of wear of a consumable friction element, a measuring device and a friction element, in particular a brush or the like. The measuring device includes a sensing device having a sensor. A magnetic field can be produced by means of the sensor, and the friction element can be moved in the magnetic field relative to the sensor. The measuring device comprises an indicator that can be attached to the friction element. The indicator comprises a ferromagnetic, antiferromagnetic and/or ferrimagnetic substance, and a change in the magnetic field can be detected by means of the sensing device as a result of a change in the position of the indicator relative to the sensor.

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 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.

A brush device includes: a first and a second flange disposed side by side, each flange extending radially between a rubbing face intended to rub against a moveable element and a flange head intended to be connected electrically to another moveable element, a first plate rigidly fixed to the first flange only and extending tangentially above the head of the second flange, in such a way as to transmit, when this first plate is loaded by pressure unit, pressure forces on the second flange, a second plate, distinct from the first plate, rigidly fixed to the second flange only and extending tangentially above the head of the first flange in such a way as to bear on the first flange in the event of relative motion of the second flange with respect to the first flange towards the first moveable element.

A brush device includes: a first and a second flange disposed side by side, each flange extending radially between a rubbing face intended to rub against a moveable element and a flange head intended to be connected electrically to another moveable element, a first plate rigidly fixed to the first flange only and extending tangentially above the head of the second flange, in such a way as to transmit, when this first plate is loaded by pressure unit, pressure forces on the second flange, a second plate, distinct from the first plate, rigidly fixed to the second flange only and extending tangentially above the head of the first flange in such a way as to bear on the first flange in the event of relative motion of the second flange with respect to the first flange towards the first moveable element.

A brush used to contact with a commutator, includes a brush body which includes two opposite axial end faces and a protruding portion projecting from the brush body toward the commutator. The protruding portion includes a first surface, a second surface and at least two teeth. The first surface and the second surface are respectively adjacent to the two axial end faces. Angles formed between the first surface and the second surface and corresponding adjacent axial end faces are obtuse. The teeth is located between the first surface and the second surface, and extends generally along a circumferential direction of the commutator. The ratio of a total width of the at least two teeth in an axial direction of the brush to an axial height of the brush body is in the range of 0.25-0.75. An electric motor including the brush is also provided.

A brush used to contact with a commutator, includes a brush body which includes two opposite axial end faces and a protruding portion projecting from the brush body toward the commutator. The protruding portion includes a first surface, a second surface and at least two teeth. The first surface and the second surface are respectively adjacent to the two axial end faces. Angles formed between the first surface and the second surface and corresponding adjacent axial end faces are obtuse. The teeth is located between the first surface and the second surface, and extends generally along a circumferential direction of the commutator. The ratio of a total width of the at least two teeth in an axial direction of the brush to an axial height of the brush body is in the range of 0.25-0.75. An electric motor including the brush is also provided.