Bearing arrangement for a piston pin

摘要

A bearing arrangement for a piston pin of a piston in an internal combustion engine, especially a two-cycle engine or crank chamber supercharging four-cycle engine has one or more grooves adapted for communicating an interior of a crankcase with a hollow interior of the piston pin. The grooves are formed on at least one of an outer peripheral surface of the piston pin and an inner peripheral surface of a pin boss defining a pin-bearing hole at a portion where the piston pin is brought into sliding contact with the pin boss. The groove may also be provided on bearing surfaces between the piston pin and a connecting rod. Furthermore, a lubricating system including said bearing arrangement is disclosed which uses the aspiration between the interior of the piston pin and a crankcase chamber for directing lubricant to sliding surfaces of said bearing arrangement. <IMAGE>