Failsafe air valve arrangement

1. An air valve arrangement for a motor vehicle, comprising:

a frame comprising an air passage opening having a passage opening area;

an air valve provided on said frame so as to be rotatable thereto about an axis in opposing directions of relative rotation, provided in such a way on the frame that it is rotatable between a shut-off position and a passage position, the air valve in the shut-off position reducing the passage opening area of the air passage opening from in the passage position; and

a drive, which is designed to drive the air valve in at least one first direction of the relative rotation about the axis;

wherein the air valve is coupled to a preloading device, which preloads the air valve toward the passage position in a direction of relative rotation;

wherein the preloading device comprises an at least two-part housing, with a first housing part non-rotatable relative to the frame and with a second housing part non-rotatable relative to the air valve;

wherein a preloading means is accommodated in the interior of the housing;

wherein the first and the second housing parts are coupled to one another in a torque-transmitting manner via the preloading means.

2. An air valve arrangement according to claim 1 , wherein the preloading device is provided in the torque transmission path between drive and air valve.

3. An air valve arrangement according to claim 1 ,

wherein the second housing part is connected detachably to the air valve for common relative movement about the axis.

4. An air valve arrangement according to claim 1 , wherein the first and second housing parts are secured against axial displacement relative to one another along the axis.

5. An air valve arrangement according to claim 1 , Wherein the first and the second housing parts are coupled to one another via a preloading spring.

6. An air valve arrangement according to claim 5 , wherein the preloading spring is supported at one end on the first housing part and at the other end on the second housing part.

7. An air valve arrangement according to claim 1 , wherein the air valve is directly connected to an output shaft, which extends from the drive.

8. An air valve arrangement according to claim 1 , wherein the air valve is directly connected to an output shaft which extends from the drive, wherein the output shaft passes through at least the first housing part.

9. An air valve arrangement according to claim 5 , wherein the air valve is directly connected to an output shaft which extends from the drive, wherein the output shaft passes through at least the first housing part, and passes at least partially through the preloading-spring.

10. An air valve arrangement according to claim 1 , wherein the drive comprises a motor and a transmission being provided between motor and air valve.

11. An air valve arrangement according to claim 1 , wherein the preloading device preloads the air valve towards the passage position with a preloading action which increases as the distance from the passage position increases.

12. The air valve arrangement according to claim 1 , wherein the two housing parts of the two-part housing are sealed relative to one another, in order to prevent fluid from penetrating into the two-part housing.

13. The air valve arrangement according to claim 3 , wherein the second housing part is connected to the air valve by a polygonal geometry surrounding the axis.

14. The air valve arrangement according to claim 4 , wherein the first and second housing parts are secured by an interlocking bayonet connection.

15. The air valve arrangement according to claim 7 , wherein the air valve is detachably connected to the output shaft.

16. The air valve arrangement according to claim 8 , wherein the output shaft passes also through the second housing part.

17. The air valve arrangement according to claim 9 , wherein the preloading spring is helical at least in places.