Piston assembly for use in a free piston internal combustion engine

摘要

A piston assembly, particularly suitable for use in a free piston internal combustion engine, is provided with a piston including at least one oil coolant passage therein. The plunger shaft is substantially rigidly attached to the piston and axially extends from the piston. The plunger shaft includes at least one oil supply passage fluidly connected with at least one oil coolant passage.