Nonlinear Vibrations of Carbon Brushes Sustained by Thermoelastic Effects of the Slipring

Summary

For the investigation of the brush vibrations a mechanical model with a rigid brush sliding on a predeformed slip ring surface is adopted. The rotation of the predeformed slip ring leads to brush vibrations causing a particular distribution of friction losses resulting then in a thermally induced deformation of the slip ring surface. At certain parameter configurations the thermal deformation reinforces the predeformation and the system becomes unstable. Due to a nonlinear contact geometry a strong sensitivity to small parameter variation exists. The model allows new explanations for measured phenomena.

In addition chaotic motion has also been observed in the mathematical model. This motion occurs at higher predeformation levels of the slip ring surface.