Patent ID: 6397801
Filing Date: 2002-06-04
Classification: F01L

Abstract:
Apparatus for adjusting a rotational relation between a camshaft and a crankshaft of an internal combustion engine, comprising:a drive wheel configured as outer rotor in driving relation with the crankshaft and defining a center axis, said drive wheel including a cylindrical peripheral wall and two sidewalls for formation of a hollow space which defines at least one hydraulic working chamber demarcated by two boundary walls extending inwardly from an inner wall surface of the peripheral wall in the direction of the center axis; a rotatable impeller configured as inner rotor and mounted in fixed rotative engagement with the camshaft, said impeller fitted in the hollow space of the drive wheel and having a wheel hub and at least one vane extending radially out from the wheel hub into the working chamber of the drive wheel to thereby subdivide the working chamber in two hydraulic pressure compartments acting in opposition to one another through selective or simultaneous admission of hydraulic fluid to thereby effect a rotation or fixation of the impeller with respect to the drive wheel and thus of the camshaft relative to the crankshaft; and a seal, positioned between a free end face of the vane of the impeller and the inner wall surface of the peripheral wall of the drive wheel, for fluidly sealing the pressure compartments from one another, said seal being formed by a roller-type sealing member spring-mounted in radial direction in an axial groove, with the inner wall surface forming for the sealing member a slanted ramp surface which extends radially outwards in a rotation direction of the impeller, so that a torque is transmittable onto the impeller by a tangential force component resulting from a combination of the slanted ramp surface of the drive wheel and a radial spring force of the sealing member applied upon the impeller, thereby matching adjustment speeds of the apparatus in both rotation directions during operation of the internal combustion engine and automatically rotating the impeller into a desired starting position of the camshaft, when shutting down the internal combustion engine, thereby mechanically coupling the impeller and the drive wheel, when the camshaft is in the starting position.