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.

The disclosure describes an apparatus for sealing a rotating machine, such as an electric machine or gas turbine engine. The apparatus includes a brush seal. The brush seal includes a plurality of first filaments and a plurality of electrically conductive filaments. The first filaments are configured to seal a lubricant within a bearing chamber or sump of the rotating machine. The plurality of electrically conductive filaments is configured to contact a shaft of the rotating machine and discharge a shaft voltage-induced current from the shaft to an external ground of the rotating machine.

An intraoperative monitoring module (IMM) for assessing strength of screw attachments to bone and detecting breaches includes a torque sensor on a rotatable tool receptacle and a variable-output current source. The IMM provides concurrent monitoring of rotational torque applied to a screw and stimulus current passing through the screw into bone for evoked electromyography. A motor housing configured to drive in rotation a tool receptacle on the IMM, a screw driver modified for carrying the stimulus current, and a screw attached to the screw driver are optionally included. Cooperative anti-rotation features on the motor housing and IMM support accurate torque measurements and prevent the outer housing of the IMM from rotating with the tool receptacle while a screw is being driven. The motor housing optionally provides electrical power to the IMM.

An electrically conductive assembly is for a bearing disposed about a shaft and disposed within a housing. The conductive assembly includes an annular retainer coupleable with a bearing outer ring or with the bearing housing and having a centerline and an open inner end defining an annular groove. At least two and preferably several conductors each have a radially outer end disposed within the retainer groove and a radially inner end contactable with the shaft. Each conductor is formed of a plurality of conductive fibers arranged to extend radially inwardly from the retainer inner end. The at least two conductors are spaced apart circumferentially about the centerline so as to define at least two axial passages between the retainer and the shaft. Preferably, the conductors are separated by spacers formed of conductive fibers each having a length shorter than the length of the fibers of the conductors.

A motor includes an armature including a commutator, a bracket including a conductive brush and a first wall part, and a first deformable part. The conductive brush is in contact with the commutator. The first wall part includes a first surface extending along a first surface of the conductive brush. The first deformable part is in contact with both the first surface of the conductive brush and the first surface of the first wall part. The first deformable part is deformable in response to movement of the conductive brush.

A motor includes an armature including a commutator, a bracket including a conductive brush and a first wall part, and a first deformable part. The conductive brush is in contact with the commutator. The first wall part includes a first surface extending along a first surface of the conductive brush. The first deformable part is in contact with both the first surface of the conductive brush and the first surface of the first wall part. The first deformable part is deformable in response to movement of the conductive brush.

An intraoperative monitoring module (IMM) for assessing strength of screw attachments to bone and detecting breaches includes a torque sensor on a rotatable tool receptacle and a variable-output current source. The IMM provides concurrent monitoring of rotational torque applied to a screw and stimulus current passing through the screw into bone for evoked electromyography. A motor housing configured to drive in rotation a tool receptacle on the IMM, a screw driver modified for carrying the stimulus current, and a screw attached to the screw driver are optionally included. Cooperative anti-rotation features on the motor housing and IMM support accurate torque measurements and prevent the outer housing of the IMM from rotating with the tool receptacle while a screw is being driven. The motor housing optionally provides electrical power to the IMM.

A grounding brush assembly includes a plurality of conductive fibers extending from at least one support, a mounting plate having a first side and a second side and an opening configured to surround a rotatable motor shaft having an axis of rotation, and a plurality of tabs disposed in a circle around the periphery. Each of the tabs extends axially from the first side of the mounting plate and radially toward or away from the axis of rotation to define with an adjacent portion of the first side of the mounting plate a U-shaped bracket. The at least one support is secured against the first side of the mounting plate by the plurality of tabs.

An electric machine having a field coil and a rotatable armature coil. A rotatable commutator is conductively coupled with the armature coil and has a plurality of contacts. A plurality of brushes are conductively engageable with the plurality of contacts wherein rotation of commutator about the rotational axis causes the plurality of contacts to sequentially engage the plurality of brushes as the plurality of contacts rotate about the rotational axis. The plurality of brushes includes at least one positive brush and at least one negative brush, the at least one positive brush being a multi-layer brush and the negative brush being a single layer block brush. The multi-layer brush may include a high-copper layer and a low-copper layer with the low-copper layer forming the trailing edge of the brush. The single layer brush may have a copper content greater than the high-copper layer of the multi-layer brush.

An intraoperative monitoring module (IMM) for assessing strength of screw attachments to bone and detecting breaches includes a torque sensor on a rotatable tool receptacle and a variable-output current source. The IMM provides concurrent monitoring of rotational torque applied to a screw and stimulus current passing through the screw into bone for evoked electromyography. A motor housing configured to drive in rotation a tool receptacle on the IMM, a screw driver modified for carrying the stimulus current, and a screw attached to the screw driver are optionally included. Cooperative anti-rotation features on the motor housing and IMM support accurate torque measurements and prevent the outer housing of the IMM from rotating with the tool receptacle while a screw is being driven. The motor housing optionally provides electrical power to the IMM.