PUMP, ESPECIALLY FOR CONVEYING CONSTRUCTION MATERIALS

摘要

A pump is comprised of a housing within which a rotary piston is rotatably mounted, to define therebetween an annular conveying channel between an inlet port and an outlet port. Annular sealing rings between the piston and housing seal the conveying channel at the periphery of the piston. A stopper extends into the conveying channel in the back flow path, and sealing elements are provided to seal the entire cross section of the back flow paths. Radially movable slides on the piston are resiliently urged into the conveying channel, the radial position thereof being controlled by a cam surface in the housing. The slides are urged radially outwardly by springs, and seals are provided on the piston for sealingly guiding the piston in the radial direction.