Vane type hydraulic actuator

Abstract

A vane type hydraulic actuator, wherein a chip seal,, as a seal element between the case,and the rotor,can be pressed to contact tightly with the counter surface, without using a spring,as in the prior art, when a working oil is supplied either from the oil pressure chambers for timing retard or for timing advance. Simultaneously, the locking between the rotor,and the case,can be released. The hydrodynamic resistance at the gap between the tip of the seal element (chip seal),and the counter surface of the seal element is made larger than that at the gap between the flank of the seal element,and the flank of the seal groove,which accomodates the seal element, so that the working oil of the hydraulic actuator flows between the flanks. The working oil at the bottom of the seal element urges the seal element to contact tightly with the counter surface. An oil channel,connects the bottom of the seal groove and a stopper pin holding hole,which holds a stopper pin,pressed by a spring,When a working oil is supplied from either of oil pressure chambers for timing retard or advance, the channel,opens to supply a working oil into the stopper pin holding hole,so as to displace the pin against the biasing force of the spring,to release the suppression of rotation.