A self-oscillation mode in a mechanical system with rolling

The feedback mechanism underlying the generation of self-oscillations during the braking of rolling wheels is determined. These self-oscillations appear to be wheel shimmy, but, in contrast to shimmy, the energy input to the vibrational system depends on changes in the braking moments at the wheels determined by lateral motion. The feedback is formed by an additional loop made up by the working fluid in the line of the wheel brake system and the elastic elements of the brakes. Under certain conditions, the feedback is positive; its efficiency noticeably increases in the case of resonance, contributing to a possible loss of stability. A mathematical model describing the feedback is presented.