Abstract: A rotary positive displacement pump comprises a housing rotationally supporting first and second parallel and axially extending drive shafts having constantly meshing gears such that the drive shafts rotate in opposite directions. A rotor casing is connected to a front side of the housing and has axial rear and front walls and a circumferential side wall jointly defining a pumping cavity. The casing houses first and second rotors drivingly connected to the first and second drive shafts respectively. The rotors rotate in opposite directions and mutually interact to provide a positive pumping effect on fluid product entering the cavity. First and second sealing arrangements prevent leakage of fluid product from the cavity towards the rear side of the casing along the first/second drive shafts. A heating device is detachably fastened to the rear casing wall to heat the casing, the first/second sealing arrangements and/or any fluid product within the casing.

Abstract: A rotary positive displacement pump comprises a transmission housing having front and rear walls and rotationally supporting first and second drive shafts having constantly meshing gears such that the drive shafts rotate in opposite directions. A rotor casing connected to a front side of the housing has rear and front walls and a circumferential side wall defining an interior pumping cavity. The casing houses first and second rotors drivingly connected to the first and second drive shafts to provide a positive pumping effect on fluid product entering the cavity. The front and rear walls of the housing define an intermediate space through which the drive shafts extend. A first guard is located in the intermediate space and surrounds the drive shafts, or first and second guards are located in the intermediate space and surround the first and second drive shafts respectively, for protecting a person from contacting the drive shafts.

Abstract: A rotary positive displacement pump includes a main body rotationally supporting two parallel, axially extending, shafts with gears in constant mesh condition, such that the shafts rotate in opposite directions. A rotor case body is connected to a front side of the main body and has a stationary interior pumping cavity, fluid product inlet and outlet openings, and two cylindrical rotor case hubs each receiving internally one of the shafts. A pair of rotors each have a rotor wing and a rotor drive element that is mounted torque proof on a rotor seat at an end region of one of the shafts. Each rotor seat pair has an axial abutment surface and a mounting surface. The pump also includes fasteners each engaging a mating section of one of the shafts and exerting an axial clamping force on one of the rotor drive elements against one of the axial abutment surfaces.