TRIBOLOGY BEHAVIOR OF A COPPER-BASED COMPOSITE FOR HEAVILY-LOADED WET CLUTCH

摘要

Wet clutches are often used to transmit torque, bring about gear changes and prevent motion in vehicle drivetrains. For heavy-duty equipment applications such as tanks, wet clutches are always under high energy density friction conditions and are required to possess excellent friction and wear characteristics, smooth engagement (anti-shudder), high reliability and a long operating life. As critical components in the clutch system, friction materials strongly affect the force transmission, energy loss and lifetime of clutches, and they ultimately influence the dynamic behaviors of an entire vehicle. Therefore, friction materials should possess an adequate friction coefficient and moderately low wear rate over a broad range of contact pressures and sliding velocities under oil lubrication [1, 2]. Copper-based friction materials manufactured by powder metallurgy have been widely applied to heavily-loaded wet clutches because of their excellent mechanical, thermal and tribological properties. These materials can also withstand higher stresses and temperatures compared with paper-based materials and are fairly cheap to manufacture when compared with carbon-fiber materials in wet clutch applications [3～5].