A sliding surface of at least one of sliding members sliding with respect to each other in a sliding direction comprises a protrusion extending along a direction intersecting the sliding direction and fine dimples provided on a surface of the protrusion. I...

The piston (1) has a gudgeon pin boring (5) which is set back on both sides to form an increased-diameter recess (13) relative to the external surface (17) of the piston. The grooves for the gudgeon pin securing rings are in these recesses. The gudgeon pin...