Push rod valve mechanism for IC engine - has clearance between bottom of push rod and cam follower maintained by spring

摘要

A valve (13) of the engine is opened by a rocker arm (18) which is moved by a push rod (22) through a tappet (24). All these parts are in close contact at all times without clearance. The end of the push rod sits inside a cylindrical recess in a cam follower (27). The follower is always in contact with the cam (21a). The only clearance is between the bottom (26) of the push rod and the bottom of the recess in the follower. The clearance is maintained by a spring (28) between a collet (29) on the push rod and the bottom of the recess in the follower.