Patent ID: 9062676
Filing Date: 2015-06-23
Classification: F04C

Abstract:
1. A rotary positive displacement pump for pumping a fluid, the rotary positive displacement pump comprising: a gear case including a pair of shafts extending therefrom at a forward end; a pump body supported by the gear case on the forward end of the gear case, the pump body having a cover attached thereto so as to define a cavity between the pump body and the cover in which the cavity has an inlet and an outlet, the pump body having a pair of hubs that extend into the cavity in which each of the pair of hubs has an axially-extending opening through each one of which a corresponding one of the pair of shafts from the gear case is received; a pair of rotors, each of the pair of rotors having a central portion received on one of the pair of shafts inside the axially-extending opening of the hub, each rotor having wings attached to the central portion of the rotor in which the wings of the rotor are disposed radially outward of the hub when the central portion of the rotor is attached to the shaft, the rotors on the pair of shafts being rotatable in opposite directions to pump a fluid through the pump body from the inlet through the cavity to the outlet; a pair of forwardly-positioned sealing arrangements each forming a dynamic seal between the central portion of the one of the pair of rotors and a corresponding one of the pair of hubs proximate a forward end of the pair of shafts; and a pair of rearwardly-positioned selective sealing arrangements between the gear case and the pump body proximate a rearward end of the pair of shafts wherein, when the pair of rotors are secured to the pair of shafts, the pair of rearwardly-positioned selective sealing arrangements do not establish seals between the gear case and the pump body and wherein, when the pair of rotors are removed from the pair of shafts, the pair of rearwardly-positioned selective sealing arrangements establish seals between the gear case and the pump body.