Ventilanordnung

摘要

This invention relates to a valve assembly for granular and/or abrasive materials. The valves comprises a housing having an inlet and an outlet wherein the ratio of the outlet diameter to inlet diameter is no less than 1:1 for unrestricted flow of materials through the valve assembly. Also provided is a spherical closure member within the housing; a valve seat within the housing with which the closure member matably engages in a first position in closing relationship with the outlet; and an elongated shaft drivably connected to the closure member for rotating the closure member about the shaft axis between a second position in an open relationship with the outlet and the first position to facilitate a flow of material therethrough from the inlet to the outlet of the valve assembly by rotation of the shaft to move the closure member between the first and second positions. There is an annular recess in the housing adjacent the valve seat containing a resilient inflatable sealing ring, the ring being dimensioned so as to sealably contact the closure member when the closure member is in the first position upon inflation of the ring. A fluid inlet supplies a fluid under pressure to the sealing ring to inflate the sealing ring. A shaft channel in the housing contains a shaft seal and a shaft bearing, the shaft seal and shaft bearing having apertures therein for receiving the shaft therethrough in the shaft channel in order to provide sealed rotation of the shaft about the shaft axis with respect to the housing. An outer end of the shaft projects from the shaft channel and contains an external hub disposed on the outer end of the shaft which hub is dimensioned and arranged so as to engage the housing to restrict longitudinal movement of the shaft in the channel. The hub is connected to the outer end of the shaft by axial connection means which engages the hub and shaft together so as to restrict axial movement of one with respect to the other in a manner which limits the imposition of any radially directed impact forces upon the shaft associated with connection of the hub to the shaft.