Hydraulic tappet-clearance compensating arrangement for a cam-controlled valve lifter
AssigneeVolkswagen Aktiengesellschaft
InventorHermann Kruger
Life of this patent
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Abstract
A hydraulic tappet-clearance compensating arrangement having no check valve includes an outer cylinder formed with a cup tappet and a piston axially displaceable in the outer cylinder and forming a pressure chamber therein. The outer cylinder is formed with a through-hole and a channel axially positioned so that a flow connection for the pressure medium is provided between the pressure chamber and a reservoir only during the base circle phase of the valve-operating cam and a flow connection is provided between the reservoir and a pressure medium supply only outside the base circle phase of the cam.
Claims7
A hydraulic tappet-clearance compensating arrangement for a cam-controlled valve lifter comprising an outer cylinder guided for axial displacement in response to operation of a cam, a piston axially displaceable in the outer cylinder, a transverse wall fixed in the outer cylinder forming a cup tappet and providing a hydraulic pressure chamber in conjunction with the piston, a compression spring disposed between the piston and the transverse wall, a reservoir for a hydraulic pressure medium supplied from an external pressure medium supply, a pressure medium control opening in the outer cylinder communicating with the pressure chamber and positioned to communicate with the reservoir only during the base circle phase of the cam, and a channel formed in the outer cylinder and providing communication between the reservoir and the external pressure medium supply only outside the base circle phase of the cam.
Dependencies are inferred from the claim text.