Variable hydraulic drive especially for the inlet valve of an IC engine has the slave cylinder fitted with a limiting aperture to control the fluid flow past a retarding extension to the slave piston which also has cross slots

摘要

A variable hydraulic drive, e.g. for the inlet valve of an IC engine, with less dependence on the viscocity of the hydraulic fluid, has the slave cylinder (1) fitted with a thin aperture disc (15) positioned into the stepped bore of the cylinder and through which the retarding extension (7) of the slave piston moves. The retarding extension has a cross slot (11) to provide additional flow in the initial phase of the braking action. The aperture disc has an abrupt action on the flow restriction without an undue long flow path.