ON THE VIBRATION IN WET FRICTION SYSTEMS WITH PAPER-BASED MATERIALS - EFFECTS OF DRIVING CONDITIONS AND DESIGN FACTORS -

摘要

The vibration caused by friction force in a wet friction system was studied in the present paper. In these systems, unexpected vibration or noise occasionally occurs during the engagement process of the input shaft to the output one. Such a vibration has been explained as self-excited vibration caused by friction force. When friction force increases with decreasing relative sliding speed, this friction characteristic is generally expressed as negative damping. In this study, a testing machine was developed to evaluate the vibration characteristics of wet friction systems with paper-based materials. The acceleration of the input shaft and the separator plate were directly measured in the engagement process together with the variation of transmitted torque. The effects of the driving conditions and design factors of wet friction systems with paper-based friction materials on the vibration and their characteristics were discussed. It is shown that the in-plane and out-of-plane vibration of the separator plate were induced by the torsional vibration of the input shaft during the engagement process of the friction plate and separator plate. While the torsional vibration of the input shaft was observed, the Torque-V slope was estimated to be negative, and its magnitude grew faster as the number of friction plates increased even under the same applied normal load condition.