Oil cooled trunk piston of an internal combustion engine

摘要

Oil serving for cooling is fed under pressure to an oil-cooled trunk piston of an internal combustion engine, coupled by way of a piston pin to a connecting rod and by way of the latter to a crankshaft journal, from feed ducts of the crankshaft journal by way of ducts in the connecting rod bearing and connecting rod shank and in or around the piston pin and through a spray bore running coaxially with the connecting rod longitudinal axis. The cooling oil flow is introduced into a piston cooling chamber by way of a cooling oil passage hole, which in the admission side entry area widens like a funnel towards the small end such that the cooling oil flow emerging from the spray bore and moving to and fro due to the connecting rod motion always enters the cooling oil passage hole where it can be directed by the wall of the funnel-like entry area in the direction of the piston cooling chamber. At the same time at least those wall sections of the funnel-like entry area of the cooling oil passage hole along which the cooling oil flow passes in the direction of the piston cooling chamber have a parabolic contour.