Patent ID: 9581157
Date: 2017-02-28
CPC Classifications: F01C,F04C,F05C

Claim:
1. A pump, comprising: a housing including a fluid inlet and a fluid outlet, the housing having an interior with an interior surface that extends longitudinally and is circular in cross-section; a rotor capable of rotating in the housing about an axis when received in the housing, the rotor including a housing-engaging surface that cooperates with the interior surface of the housing to form a sealing interface therebetween, the rotor also including at least first and second shaped surfaces disposed radially inwardly of the housing engaging surface with each of the first and second shaped surfaces forming a respective chamber with the interior surface of the housing for conveying fluid from the fluid inlet to the fluid outlet on rotation of the rotor; and a seal provided between the fluid outlet and the fluid inlet to engage the first and second shaped surfaces to prevent fluid passing from the fluid outlet to the fluid inlet as each of the first and second shaped surfaces travels from the fluid outlet to the fluid inlet, and wherein the housing-engaging surface of the rotor includes a portion extending axially and circumferentially between an edge of the first shaped surface and an edge of the second shaped surface, and wherein a curvature of the portion of the housing-engaging surface is, in all planes normal to the axis of the rotor, greater than a curvature of the interior surface of the housing.