Cam drive system tensioner

摘要

A cam drive assembly for an automotive engine comprises a crankshaft sprocket mounted for rotation with a crankshaft, a camshaft sprocket mounted for rotation with a camshaft, and a chain rotatably operable between the crankshaft sprocket and the camshaft sprocket. A chain tensioner provides tension to the chain and is supported only by an engine block side wall. The chain tensioner is comprised of a stationary portion and a flexible spring portion supported thereto, and a nylon shoe fixed to the flexible spring portion to provide a contact surface for the chain. The stationary portion has a geometrical interlocking feature to mate with a complementary geometric feature in the engine block side wall to restrict upper and lower movement of the chain tensioner. The geometrical interlocking feature of the chain tensioner may be a concave retention portion, which fits over a complementary convex nub in the engine block side wall to restrict movement of the chain tensioner by part interference.