Mechanical buckling induced thermoelastic instability in frictional clutches

A multi-disc clutch test bench was set up and sliding experiments were conducted to investigate the relationship between the friction glazed spot distribution and mechanical torsion buckling on frictional components. The buckling deformation model of a separator disc with spline teeth subjected to mechanical torsion is established to compare with the experimental observation. The buckled spline disc provides a certain perturbation frequency during the sliding period. Under this sliding condition, when the relative sliding rubbing speed in frictional clutches exceeds the thermoelastic instability (TEI) speed predicted by Barber and Lee's TEI model, mechanical buckling induces thermoelastic instability (MBTEI). The dangerous sliding speed and perturbation pressure growth rate are obtained in regard to structural parameters, temperatures, abrasion cracks and torques.