Daimler Chrysler Ag

Gerald Bolz

Kai Lehmann

Reinhard Orthmann

Timo Schmidt

Christian Haser

Michael J&uuml;rging

A camshaft adjuster for an internal combustion engine having hydraulic medium guides. The adjuster can include a setting unit that can be controlled by a control unit using these guides in the adjuster, wherein the setting unit is for adjusting an angle of a camshaft. This setting unit has an inner body coupled to the camshaft so as to rotate with it, and an outer body that is mounted to rotate relative to the camshaft via a drive connection which runs from a crankshaft to the camshaft. The camshaft has at least one insert part permanently inserted camshaft wherein these two components together form at least one hydraulic medium guide at least in partial regions over its axial length. This design is to create a camshaft adjuster which is in interaction with a camshaft having an insert part so that there is a simple and reliable supply of hydraulic medium to the camshaft adjuster and in particular to its control device.

Camshaft adjuster for an internal combustion engine having hydraulic medium guides

An electrohydraulic pressure supply unit involving the joint operation of two energy converters, which can be adjusted independent of each other, including an electric motor with speed control that drives a variable displacement pump with a variable displacement volume. The electric motor converts electrical output (loss-encumbered), into mechanical output, meaning into speed n and torque T. The pump then converts this mechanical output (also loss-encumbered) into hydraulic output. The hydraulic output is determined by the pressure difference &Dgr;p across the pump and the volume flow Q. The pressure difference &Dgr;p generally is impressed by the consumer or load on the system. The volume flow Q is the result of the displacement volume V and the motor speed n. The torque T, which must be generated by the motor, is derived from the displacement volume V and the pressure differential &Dgr;p. During the conversion from hydraulic output to mechanical output, the displacement volume V determines the distribution of the output to the speed n of the motor and the torque T. The current I flowing through the electric motor is primarily determined by the torque T while the voltage U is primarily influenced by the motor speed n. The volume flow supplied by the electrohydraulic pressure supply unit is essentially adjusted by controlling the speed adjustment of the electric motor. The speed of the electric drive motor in this case can essentially be adjusted independent of the displacement volume of the variable displacement pump.

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Berlin, Germany

Gerald Bolz