Oscillation damper with adjustable damping force

1. An oscillation damper with a variable damping force, said damper comprising

a torsion spring which exerts a reaction force,

an actuator which can be rotated against the reaction force of said torsion spring, said actuator comprising an electric motor, said electric motor comprising a housing and a rotor which is rotatable relative to said housing, said torsion spring being operatively connected between said housing and said rotor, and

a valve device which can be adjusted by rotating said actuator according to a manipulated variable, said manipulated variable comprising a current for activating a driving force of the electric motor, said valve device having a position which is determined by the current and the reaction force of the torsion spring, the reaction force being in proportion to the current, wherein said current and said reaction force act in opposite rotational directions on said rotor and are always in a defined ratio.

2. An oscillation damper as in claim 1 wherein said torsion spring is a helical spring having a first winding portion fixed to said actuator and a second winding portion fixed to said rotor.

3. An oscillation damper as in claim 1 further comprising

a drive line arranged between said actuator and said valve device, and

an overload clutch arranged in said drive line.

4. An oscillation damper as in claim 3 wherein said overload clutch comprises

a torque input part,

a torque output part, and

a spring which clamps said torque input part and said torque output part against each other.

5. An oscillation damper as in claim 4 wherein said spring which clamps said torque input part and said torque against each other is a helical tension spring.

6. An oscillation damper as in claim 5 wherein said helical tension spring is operatively connected to said torque input part and said torque output part.

7. An oscillation damper as in claim 4 wherein one of said torque input part and said torque output part comprises a sleeve and the other of said torque input part and said torque output part comprises a blind opening, said sleeve being received in said blind opening to align said torque input part relative to said torque output part.

8. An oscillation damper with a variable damping force, said damper comprising

a torsion spring which exerts a reaction force,

an actuator which can be rotated against the reaction force of said torsion spring,

a valve device which can be adjusted by rotating said actuator, and

a spindle connected to said actuator for converting a rotary motion of said actuator to an axial motion of said valve device, said spindle comprising an adjusting ring which can be fixed to a component which is fixed against rotation relative to said actuator, and an anti-rotation safeguard for preventing rotation of said valve device relative to said adjusting ring.

9. An oscillation damper as in claim 8 wherein said anti-rotation safeguard comprises at least one groove in said adjusting ring and a transverse pin which engages in said at least one groove.

10. An oscillation damper as in claim 8 further comprising latching means for fixing said adjusting ring to said component.

11. An oscillation damper as in claim 10 wherein said latching means comprise at least one spring loaded latching body.

12. An oscillation damper as in claim 11 further comprising at least one expanding spring which preloads a respective said at least one spring loaded latching body.

13. An oscillation damper as in claim 11 wherein said latching means comprise at least one expanding spring, each said at least one expanding spring comprising a spring leaf segment which forms a respective said at least one spring loaded latching body.

14. An oscillation damper as in claim 11 wherein said component comprises at least one receptacle, said at least one spring loaded latching body engaging in said at least one receptacle.

15. An oscillation damper as in claim 14 further comprising a piston rod, said component being fixed with respect to said piston rod.

16. An oscillation damper as in claim 15 wherein said piston rod is a hollow piston rod and said component is a piston rod extension fixed to said hollow piston rod, said spindle being received in said hollow piston rod.

17. An oscillation damper as in claim 16 further comprising a compression spring which preloads said spindle relative to said piston rod extension.