Thermoelastic effects on slipring surface leading to brush vibrations

A novel interpretation of the brush vibration phenomenon is presented for current collection systems consisting of carbon brushes and steel sliprings. For the investigation of this phenomenon, a mechanical model with a rigid brush was used, and the thermal deformation of the slipring surface due to the losses generated by the vibrating brush was taken into consideration. The calculations show that at certain parameter configurations the brush vibration reinforces the thermal deformation and the closed-loop system becomes unstable, leading to pronounced brush vibration referred to as regenerative brush chatter. Measurements of the slipring surface temperature confirm this theory