PISTON ASSEMBLY DESIGN FOR IMPROVED THERMAL TRIBOLOGICAL PERFORMANCE

The tribological system in the piston assembly of an internal combusti on engine includes contacts at interfaces of piston/piston ring/cylind er liner, piston shirt/cylinder wall, and piston/piston pin/connecting rod. The thermal and tribological properties of the piston, piston ri ngs, and cylinder wall are critical to the life and quality of the eng ine. Severe wear and scuffing failure, especially at the ring/ring gro ove and ring/liner interfaces, may present a major problem if the pist on temperature is too high. Temperature considerations for the piston often limit the effort to increase the engine power. A new engine pist on incorporating the heat pipe cooling technology has been developed f or reducing the piston temperature, especially in the ring land and al ong the piston wall. The current work aims at investigating the effect of reciprocating heat pipes on heat conduction in the piston, and thu s the tribological behavior of the piston assembly. Due to the high th ermal conductance of the reciprocating heat pipe, a considerably large amount of combustion heat, which is conventionally conducted through the piston, wall, is transferred through heat pipes. This new design w ill result in a lower temperature on, the piston wall and a reasonably low temperature distribution in the piston.