Valve, in particular a vacuum valve

A valve, comprising:

• a valve housing and having a valve opening, which is surrounded by a valve seat;
• a valve plate arranged in an interior space of the valve housing and fixed on a shaft, wherein the valve plate, together with the shaft is displaceable back and forth in directions parallel to a longitudinal axis of the shaft between a closed position, in which the valve plate has been pushed against the valve seat and closes the valve opening, and an intermediate position, in which the valve plate has been raised up from the valve seat and coincides with the valve opening, and the valve plate is pivotable back and forth, by rotation of the shaft about the longitudinal axis of the shaft, between the intermediate position and a fully open position, in which the valve plate completely or partially frees the valve opening;
• the shaft is sealed in relation to the valve housing by a shaft feedthrough, in which the shaft is rotatable about the longitudinal axis thereof and is displaceable in directions parallel to the longitudinal axis, and for sealing the shaft in relation to the valve housing, the shaft feedthrough has a bellows, which is expandable and is pushable back together in the directions parallel to the longitudinal axis of the shaft and is fixed on the valve housing by a first bellows end, and a shaft sealing ring is arranged at a second bellows end, the second bellows end being located opposite the first bellows end, and the shaft is mounted in the shaft-sealing ring such that the shaft is rotatable about the longitudinal axis of the shaft relative to the bellows;
• a valve drive for rotating the shaft, together with the valve plate, about the longitudinal axis of the shaft and for displacing the shaft, together with the valve plate, in the directions parallel to the longitudinal axis of the shaft;
• and
• a sealing ring arranged on the valve housing, through which the shaft is guided, and an overflow opening between the shaft and the sealing ring of the valve housing that in the closed position of the valve plate and in the fully open position of the valve plate and in all the intermediate positions of the valve plate between the closed position and the fully open position remains free between an interior space of the bellows and the interior space of the valve housing and, starting from the fully open position, the shaft is displaceable, in one of the directions parallel to the longitudinal axis of the shaft, into a service position, in which the sealing ring of the valve housing butts with sealing action against the shaft and seals the interior space of the bellows in relation to the interior space of the valve housing;
• wherein the valve drive has a longitudinal drive, a rotary drive, and a yoke, the shaft is mounted in the yoke to be rotatable about the longitudinal axis thereof by the rotary drive, the shaft is positively coupled to the yoke with respect to the directions parallel to the longitudinal axis of the shaft, and the yoke, together with the shaft, are displaceable in directions parallel to the longitudinal axis of the shaft by the longitudinal drive;
• and
• wherein the shaft has a first shaft portion and a second shaft portion, the shaft has a larger diameter in the second shaft portion than in the first shaft portion and, in the service position, the sealing ring of the valve housing butts with sealing action against the second shaft portion of the shaft.

A valve, comprising:

• a valve housing and having a valve opening, which is surrounded by a valve seat;
• a valve plate arranged in an interior space of the valve housing and fixed on a shaft, wherein the valve plate, together with the shaft is displaceable back and forth in directions parallel to a longitudinal axis of the shaft between a closed position, in which the valve plate has been pushed against the valve seat and closes the valve opening, and an intermediate position, in which the valve plate has been raised up from the valve seat and coincides with the valve opening, and the valve plate is pivotable back and forth, by rotation of the shaft about the longitudinal axis of the shaft, between the intermediate position and a fully open position, in which the valve plate completely or partially frees the valve opening;
• the shaft is sealed in relation to the valve housing by a shaft feedthrough, in which the shaft is rotatable about the longitudinal axis thereof and is displaceable in directions parallel to the longitudinal axis, and for sealing the shaft in relation to the valve housing, the shaft feedthrough has a bellows, which is expandable and is pushable back together in the directions parallel to the longitudinal axis of the shaft and is fixed on the valve housing by a first bellows end, and a shaft sealing ring is arranged at a second bellows end, the second bellows end being located opposite the first bellows end, and the shaft is mounted in the shaft-sealing ring such that the shaft is rotatable about the longitudinal axis of the shaft relative to the bellows;
• and
• a valve drive for rotating the shaft, together with the valve plate, about the longitudinal axis of the shaft and for displacing the shaft, together with the valve plate, in the directions parallel to the longitudinal axis of the shaft;
• wherein the valve drive has a longitudinal drive, a rotary drive, and a yoke, the shaft is mounted in the yoke to be rotatable about the longitudinal axis thereof by the rotary drive, the shaft is positively coupled to the yoke with respect to the directions parallel to the longitudinal axis of the shaft, and the yoke, together with the shaft, are displaceable in directions parallel to the longitudinal axis of the shaft by the longitudinal drive;
• and
• wherein the shaft-sealing ring is arranged on a seal carrier and the bellows is fixed on the seal carrier via the second bellows end, and the seal carrier is positively coupled to the shaft with respect to displacement movements of the shaft in the directions parallel to the longitudinal axis of the shaft, and for positive coupling to the shaft, the seal carrier is fixed on the yoke with respect to the displacement movements of the shaft in the directions parallel to the longitudinal axis of the shaft.