Patent ID: 6557514
Filing Date: 2003-05-06
Classification: F01M,F02F,F16J

Abstract:
A monobloc piston assembly comprising:a piston head having a combustion bowl formed in an upper surface thereof and a ring belt formed with a plurality of ring grooves in an outer surface of said ring belt; a plurality of piston rings disposed in said ring grooves; an oil cooling gallery formed in said piston head adjacent said combustion bowl and said ring belt; a pair of pin bosses extending from said piston head formed with axially aligned pin bores and having axially oppositely facing outer surfaces; a piston skirt formed as one immovable piece with said pin bosses and united at an upper end thereof to said ring belt; and an oil drainage groove formed in said piston head at a location below said ring grooves, said oil drainage groove being free of any piston rings and being open to said outer surfaces of said pin bosses, said oil drainage groove including a bottom wall that extends substantially circumferentially continuously between said pin bosses and which is interrupted by said outer surfaces of said pin bosses.