Mixed Lubrication and Friction Power Loss of Piston Ring Pack

With consideration of asperity contact, the minimum oil film thickness and friction power loss are calculated by simultaneous solution of the dynamics, blow-by and lubrication of piston ring pack. Take the piston ring pack in the first cylinder from the free end of a six-cylinder diesel engine for example, results show that the asperity contact takes place at all of the compression rings and oil ring; the minimum oil film thickness is 1.04 mu m at the top ring; the total friction loss power is 0.94kW, the top ring accounts for 37.2%, the second ring accounts for 33.0%, the oil ring accounts for 29.8%.