UPPER PART OF A COMPOSITE PISTON

摘要

An upper part (1) of an assembled piston is disclosed, comprising a radially directed inner contact surface (2) arranged on the underside of an annular rib (15) and a radially directed outer contact surface (3) arranged on the underside of an annular wall (25), the outer (3) and the inner contact surface (2) each having a grooved profile in the form of concentric grooves with an average depth between Rz 10 and Rz 30. The wear on the contacting surfaces of the upper piece and the lower piece of the assembled piston is thus reduced.