Control piston i.e. cylindrical body, for 4/3-way central valve utilized in camshaft adjusting device for actuating camshaft of petrol engine for automobile, has air- and oil-permeable separation structure arranged in cavity filled with oil

摘要

The piston (14) has an oil cavity (16) filled with oil. An air- and oil-permeable separation structure (30) e.g. sintered metal filter and metal foil, is arranged in the cavity. A front end (26) of the piston forms a support surface for a re-setting element i.e. return spring. The separation structure is secured at the front end, and forms a wall of the cavity. The separation structure is formed as a single- or two-piece component and a flat component. The metal foil comprises passage apertures in a micrometer range.