Patent ID: 7845921

Claim:
A positive displacement supercharger comprising: a rotor housing including a rotor cavity formed with a pair of parallel cylindrical bores overlapping to define a longitudinal cavity with a peripheral inner wall having a necked-down cross-sectional shape where the bores overlap similar to a figure 8; a pair of positive displacement rotors rotatable on parallel longitudinal axes within the rotor cavity, the rotors having interleaved lobes with outer tips rotatably facing opposed portions of the peripheral inner wall and cooperating valleys in the associated rotors operative to carry air longitudinally from an inlet end to an outlet end of the cavity, the lobes having lengthwise grooves extending along their outer edges and receiving flexible tip seals engaging the peripheral wall of the cavity and the cooperating recesses in the rotors to seal the rotor chambers and improve pumping efficiency; an air inlet opening in the housing adjacent the inlet end of the cavity for admitting air into the rotor chambers; an air outlet opening in the housing through the peripheral wall adjacent the outlet end of the cavity for discharging compressed air from the cavity, the outlet opening extending across a necked-down portion of the cavity near the outlet end of the cavity; and support bars extending laterally across the outlet opening at longitudinally spaced intervals and having inner surfaces conforming with the shapes of the associated bore surfaces, the bars supporting the seals as they rotate with the rotors across the periphery of the outlet opening surfaces formed by the bars to reduce outward movement and flutter of the seals as they move across the opening.