Patent ID: 6105544
Filing Date: 2000-08-22
Classification: F01L,Y10T

Abstract:
Apparatus for changing the opening and closing times of gas exchange valves of an internal combustion engine, comprising:a drive unit in driving relationship with a crankshaft via a tension means, said driving unit including a drive wheel and a housing;a driven unit in fixed rotative engagement with an intake or exhaust camshaft;an adjusting piston for adjusting a relative rotation between the crankshaft and the camshaft, said adjusting piston being capable of reciprocating in the housing between two end positions by means of a hydraulic medium for defining two pressure compartments, said adjusting piston having two axially-spaced sections in the form of opposing oblique teeth, with one of the sections interacting with complementary teeth of the drive unit, and with the other one of the sections interacting with complementary teeth of the driven unit; anda locking means for substantially barring a displacement of the adjusting piston into an undesired adjusting direction when the pressure of hydraulic fluid in the respective one of the pressure compartments falls below a required level for realizing a displacement of the adjusting piston, and for permitting a displacement of the adjusting piston into a preferred position via an auxiliary energy.