THREE PIECE TYPE OIL CONTROL RING

摘要

A spacer expander (1) of a three piece type oil control ring, comprises an outer side (7); protrusions (4) axially protruded from the outer side (7) to support the side rails (2, 3); an inner side (8); and lugs (5) axially protruded from the inner side (8) to radially outwardly push the side rails (2, 3). Since the lugs (5) are formed on the inner segments every other corrugation or every three or more corrugations, the distance between the adjacent lugs (5) is longer than that of a prior art spacer expander, resulting in reduction of the rigidity. Accordingly, each lug (5) is easy to perform the independent movement with less dynamic influence by adjacent lugs (5) so that the lugs (5) can certainly push the side rails (2, 3) on cylinder bore surface (13).