Piston assembly with cooling lubricant reservoir defining member engaged to piston pin mounting bosses

摘要

A piston assembly for an internal combustion engine is made up from a piston main body and a lubricant reservoir defining member. The piston main body has a cup-shaped structure including a crown portion and a hollow cylindrical wall portion joining thereto, two piston pin bosses being formed at opposite sides of the wall portion. The lubricant reservoir defining member is made from a shelf plate main body portion which provides a central lubricant reservoir and two openings on its opposite sides, and two major legs extending from the shelf plate main body portion and each formed with a hole surrounded by an annular portion. Each of the annular portions is engaged with an inner end portion of a corresponding one of the bosses and surrounds the piston pin hole thereof. Thus the lubricant reservoir defining member is securely mounted within the cup shaped piston main body by a reliable and simple construction, with the shelf plate portion generally parallel to and opposing the piston crown and thereby providing a central lubricant reservoir for aiding with the flow of cooling lubricant flowing in and out through the two openings to flow along the underneath of the piston crown.