Abstract: The invention relates to a valve with a central guide and a check valve. The check valve and valve form an integrated component, the check valve being formed by a band which is shaped into a ring and is arranged in an internal groove.

Abstract: A camshaft adjusting system for an internal combustion engine has a camshaft adjusting device with a first hydraulic chamber and a second hydraulic chamber, wherein the first and second hydraulic chambers act in opposition to one another. A control valve group working as a 4/4-way valve system has a first connection to the first hydraulic chamber, a second connection to the second hydraulic chamber, a tank connection, and a connection for pressurization. The camshaft adjusting system in a first state of the control valve group, when starting the internal combustion engine, is pressure-relieved relative to the tank connection by simultaneously hydraulically connecting the first and second connections of the camshaft adjusting device so that the camshaft adjusting device moves into a dwell position with a single locking mechanism. The dwell position also provides a safety function in case of system failure.

Abstract: A camshaft adjusting system for an internal combustion engine has a camshaft adjusting device with a first hydraulic chamber and a second hydraulic chamber, wherein the first and second hydraulic chambers act in opposition to one another. A control valve group working as a 4/4-way valve system has a first connection to the first hydraulic chamber, a second connection to the second hydraulic chamber, a tank connection, and a connection for pressurization. The camshaft adjusting system in a first state of the control valve group, when starting the internal combustion engine, is pressure-relieved relative to the tank connection by simultaneously hydraulically connecting the first and second connections of the camshaft adjusting device so that the camshaft adjusting device moves into a dwell position with a single locking mechanism. The dwell position also provides a safety function in case of system failure.

Abstract: The invention relates to a valve with a central guide and a check valve. The check valve and valve form an integrated component, the check valve being formed by a band which is shaped into a ring and is arranged in an internal groove.

Abstract: In an electromagnet with sleeve-shaped magnet housing with integrated valve body, in particular for the actuating of valves, the pole core is developed as a separate part and is surrounded by the sleeve-shaped magnet housing. The magnet housing has inward-directed corrugations distributed uniformly over its circumference which serve as axial support for the pole core in the direction of the electric windings.

Abstract: An actuating system is provided that includes a differential hydraulic cylinder containing a piston and a piston rod connected to one side of the piston. A first or head chamber (53) is defined in the cylinder and is bounded by the one side of the piston, to which the piston rod is not connected. A second or rod chamber (54) is also defined in the cylinder and is bounded by the other side of the piston, to which the piston rod is connected. An actuatable assembly is provided that is adapted to be connected to either the hydraulic cylinder or the piston rod. Finally, a proportional control valve is provided which is adapted to actuate the hydraulic cylinder by controlling the amount of fluid supply to the first chamber, wherein the supply pressure is connected to the second chamber.

Abstract: In a process for controlling an actuator which can be adjusted by means of a proportional valve, the proportional valve is controllable by means of two control magnets with control pulses acting in opposite directions. A phase angle between the control pulses is varied as a function of at least one control variable (command variable, correction variable or difference between the amplitudes or pulse durations of the control pulses), i.e. it is reduced as the control variable increases. This measure prevents undesired vibrations of the actuator and resulting noises.