Valve device in a motor vehicle

1. A valve device for a fuel cell arrangement in a motor vehicle, the valve device comprising:

a housing;

a flow channel that extends in the housing;

a shaft mounted rotatably in the housing in a longitudinal direction, the shaft having an outer surface and, a screw bore extending inwardly from the outer surface, the screw bore having an interior shoulder arranged inwardly from the outer surface of the shaft;

a flap fastened to the shaft, the flap being configured to influence a flow cross section in the flow channel;

a screw having a head having a peripheral portion thereof having, at the peripheral portion of the head, a first collar, and, arranged inwardly of the first collar, a second collar arranged below the head, the screw being configured to fixedly attach the flap to the shaft by threadingly engaging with the screw bore of the shaft;

a drive configured to drive the flap via the shaft; and

a valve seat arranged in the flow channel, the valve seating having a seal arranged on a radially circumferential edge of the flap, the seal being in contact with the valve seat in a closed position of the flap such that the shaft penetrates the flap at an angle,

wherein the screw and the shaft are structured and arranged such that when the screw is tightened in the screw bore of the shaft, the first collar of the screw contacts, and is arranged radially outside of, an outer surface of the flap, and the second collar of the screw bears against the interior shoulder of the screw bore of the shaft such that a transmission of force from the second collar of the screw to the shaft takes place via the interior shoulder of the screw bore.

2. The valve device as claimed in claim 1 , wherein a depth x to the interior shoulder of the screw bore is smaller than a shaft radius r.

3. The valve device as claimed in claim 2 , wherein the depth x of the interior shoulder is 0.2 to 0.5 times the shaft radius r.