Pump having a housing and a rotor capable of rotating in the housing

A pump, comprising:

• a housing including a fluid inlet and a fluid outlet;
• 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 an 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 each of the first and second shaped surfaces has first and second circumferentially spaced side edges and a convex curvature in all planes normal to the axis of the rotor, and
• wherein a depth of each of the first and second shaped surfaces, as measured radially inwardly from the housing-engaging surface, varies non-uniformly in a circumferential direction from the first circumferentially spaced side edge of the shaped surface to the second circumferentially spaced side edge of the shaped surface.

A pump, comprising:

• a housing including a fluid inlet and a fluid outlet;
• 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 an 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 each of the first and second shaped surfaces is convexly curved in at least some planes normal to the axis of the rotor and concavely curved in planes that include the axis of the rotor.