UPPER PART OF AN ASSEMBLED 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 R_z 10 and R_z 30. The wear on the contacting surfaces of the upper piece and the lower piece of the assembled piston is thus reduced.