Variable valve timing apparatus for internal combustion engine

摘要

A variable valve timing apparatus for a combustion engine is disclosed. The apparatus includes an air intake valve and an air exhaust valve, a camshaft (11), and a crankshaft. The camshaft is operably coupled to the crankshaft. The camshaft is selectively advanced and retarded between two extreme opposite degrees with respect to the crankshaft to selectively open and close the valves with variable timing based on a running condition of the engine. The apparatus further includes a first rotating body (17) operably coupled to the crankshaft. A second rotating body (19) is operably coupled to the camshaft. A vane (24) is integrally formed with one of the rotating bodies. A cavity (26) is provided with one of the rotating bodies to receive the vane (24). The cavity (26) has an edge (26a) opposite to the vane. A member (28) is provided with the vane (24) abutting against the second edge (26a). A biasing means (29) biases the abutting member (28) to the second edge (26a). A first chamber is defined by the vane in the cavity to receive fluid in the first chamber. The fluid creates pressure to perform relative rotation of the first rotating body (17) and the second rotating body (19). The abutting member (28) slides on the edge (26a) to adjust the amount of advancing or retarding of the camshaft (11) with respect to the crankshaft. <IMAGE>