气缸套活塞环摩擦副上止点附近的低速润滑特性

Slow-speed Lubrication Characteristics of Cylinder Liner and Piston Ring near Top Dead Center

针对柴油机气缸套-活塞环摩擦副在上止点附近的低速润滑问题,采用往复摩擦磨损试验方法,获得不同载荷、不同润滑介质条件下,速度对润滑特性的影响规律。试验结果表明:低速区域滑动速度的微小变化带来了上止点附近润滑特性的明显改变。当载荷为10 MPa,滑动速度小于0.4 mm/s时,润滑油中的添加剂ZDDP会显著减小摩擦力;滑动速度大于0.4 mm/s时,添加剂ZDDP对减小摩擦力的影响减弱。当载荷为20 MPa时,添加剂ZDDP在试验速度范围内会一直减小摩擦力。

The lubrication problems near the top dead centre（TDC）of cylinder liner and piston ring in diesel engine were investigated in a piston ring reciprocating liner test rig,and the friction force-sliding speed characteristics of lubrica-ting film under different loads and lubricating medium conditions were analyzed.The results show that minor speed change results in the obvious variation of lubrication characteristic near TDC.When the load is 10 MPa,the friction force is re-duced by ZDDP additives at sliding speeds less than 0.4 mm/s,and as the sliding speeds is more than 0.4 mm/s,the in-fluence of ZDDP additives on the lubricating film shear characteristics becomes weakened.When the load is 20 MPa,the friction force is constantly reduced by ZDDP additives at the test sliding speed range.