A self adjusting hydraulic tappet for a heat engine particularly a heat engine having valves controlled by means of rockers

摘要

A self adjusting hydraulic tappet for an overhead or side valve push rod engine comprises a cup-shape body (6) having an end wall (13) contacting a cam (7) of a cam shaft (1) and a side wall (14) slidable in a bore (15) in the engine block, and an inner body (16) slidable within the cup-shape body (6) and defining with it a chamber (17) which can be filled with fluid under pressure notably the engine lubrication oil, via passages (19, 20, 20a) in the two bodies (6, 16). The passages (19) in the inner body (16) each include a check valve comprising a ball (23) housed in a conical valve seat (22) formed at the entrance to the passage (19) where it opens into the chamber (17). The ball valves are positioned to remain open under the action of gravity and to close when the pressure in the chamber (17) exceeds a predetermined value. The balls (23) are retained in their valve seats (22) by a stop member (27) fixed to the inner body (16). IMAGE