Mounting of a flap valve shaft

1. A bearing system of a flap valve, comprising:

a valve shaft with a valve shaft pivot for a valve flap, a bearing body, and a valve housing wall which has a shaft bearing in the form of a depression, the bearing body being guided at least indirectly in the depression and being rotatable about the valve shaft pivot, said bearing body being adapted to bear at least indirectly against the shaft bearing in an axial direction A with respect to the valve shaft pivot, the bearing body having a recess, into which a bearing piece is inserted, the bearing piece bearing against the shaft bearing, with the result that the bearing body is guided such that it bears indirectly via the bearing piece against the shaft bearing and is rotatable about the valve shaft pivot, wherein the bearing body is fastened on an end side to the valve shaft, the bearing body and the bearing piece are formed from different materials, wherein the bearing body and the valve shaft are connected permanently by brazing or welding.

2. Bearing system according to claim 1 , wherein the bearing piece is mounted within the recess of the bearing body and moveable in the axial direction A with respect to the valve shaft pivot, a prestressing element being provided within the recess, the bearing piece being prestressed relative to the bearing body in the axial direction A with respect to the valve shaft pivot via the prestressing element.

3. Bearing system according to claim 1 , wherein the bearing piece is fixed within the recess of the bearing body in the axial direction A with respect to the valve shaft pivot.

4. Bearing system according to claim 1 , wherein the bearing piece and the bearing body have a positively locking connection which acts in the axial direction A with respect to the valve shaft pivot, the positively locking connection

a) being configured as a one-sided stop, against which the bearing piece bears, or

b) fixing the bearing piece in the axial direction A with respect to the valve shaft pivot in both directions.

5. Bearing system according to claim 4 , wherein the one-sided positively locking connection is configured as a shoulder.

6. Bearing system according to claim 1 , wherein at least at operating temperature, the bearing piece being moveable in a circumferential direction U with respect to the valve shaft pivot relative to the bearing body or has a slight play in the radial direction.

7. Bearing system according to claim 1 , wherein a cavity is provided within the recess, between the bearing piece and the bearing body, in which cavity lubricant stored.

8. Bearing system according to claim 1 , wherein the recess has a beaded edge which forms an undercut and a positively locking connection with the bearing piece in the axial direction A, the bearing piece having a region B 1 with a diameter d 1 and a region B 2 with a diameter d 2 , where d 1 >d 2 , the region B 1 bearing against the beaded edge within the recess for the purpose of the formation of the positively locking connection.

9. Bearing system according to claim 7 , wherein the bearing piece is of spherical configuration and has a diameter d 1 , or in that the bearing piece is of pin-shaped configuration and has a shoulder which is arranged within the recess, has the diameter d 1 , and bears against the edge.

10. Flap valve having a valve housing for connecting to an exhaust gas system and a valve flap with a bearing system according to claim 1 .