Patent ID: 6453858
Filing Date: 2002-09-24
Classification: F01L

Abstract:
A hydraulic camshaft adjusting device of a rotary piston type for varying valve timing of gas exchange valve in an internal combustion engine, said device comprising:a drive pinion connected in driving relationship to a crankshaft of the internal combustion engine and a winged wheel connected rotationally fast to a camshaft of the internal combustion engine, said drive pinion comprising a hollow space formed by a hollow cylindrical circumferential wall and two side walls, at least one hydraulic working chamber being formed in the hollow space by at least two radial limiting walls, at least one wing arranged on an outer periphery of a wheel hub of the winged wheel extending radially into the at least one working chamber and dividing this working chamber into two oppositely acting hydraulic pressure chambers, by a selective or simultaneous pressurizing by a hydraulic pressure medium, the pressure chambers effect a pivoting or a fixing of the winged wheel relative to the drive pinion, and thus, of the camshaft relative to the crankshaft, on switching-off of the internal combustion engine, an auxiliary energy acting between the winged wheel and the drive pinion rotates the camshaft into a preferred basic position for starting the internal combustion engine, in the basic position of the camshaft, the winged wheel can be mechanically coupled to the drive pinion by a lock that can be hydraulically unlocked again upon renewed pressurizing of the device, whereinthe lock for mechanically coupling the winged wheel to the drive pinion is formed by at least one cage-guided free-wheel arranged between the winged wheel and the drive pinion, said lock comprises at least one clamping body that blocks a direction of rotation of the winged wheel opposed to the basic position of the camshaft, and at least parts of a surface of a cage of the free-wheel are configured as a pressure application surface for the hydraulic pressure medium for a hydraulic unlocking of the free-wheel.