Transient Clunk Response of a Driveline System: Laboratory Experiment and Analytical Studies

• Published in: SAE transactions 2007-01, Vol.116, p.1754-1762
• Main Authors: Gurm, Jaspreet S., Chen, Wan Joe, Keyvanmanesh, Amir, Abe, Takeshi, Crowther, Ashley R., Singh, Rajendra
• Format: Article
• Language: English
• ISSN: 0096-736X; 2577-1531

A laboratory experiment is designed to examine the clunk phenomenon. A static torque is applied to a driveline system via the mass of an overhanging torsion bar and electromagnet. Then an applied load may be varied via attached mass and released to simulate the step down (tip-out) response of the system. Shaft torques and torsional and translational accelerations are recorded at pre-defined locations. The static torque closes up the driveline clearances in the pinion/ring (crown wheel) mesh. With release of the applied load the driveline undergoes transient vibration. Further, the ratio of preload to static load is adjusted to lead to either no-impact or impact events. Test A provides a 'linear' result where the contact stiffness does not pass into clearance. This test is used for confirming transient response and studying friction and damping. Test is for mass release with sufficient applied torque to pass into clearance, allowing the study of the clunk. A set of non-linear differential equations describe the experiment and the applicable dry friction coefficients are experimentally found. Various test conditions (corresponding to no impacts, and single-sided or double-sided impacts) are successfully simulated. Numerical and experimental time histories compare well.