A pump assembly comprises an inlet, an outlet and a housing having an inlet aperture in fluid connection with the inlet, and an outlet aperture in fluid connection with the outlet. A rotor located within the housing is shaped to form with an interior surface of the housing a chamber. On rotation of the rotor, the chamber conveys fluid from the inlet aperture to the outlet aperture. The housing carries a seal located in the inlet and urged into contact with the rotor to prevent the passage of fluid past the rotor from the outlet to the inlet. Center lines of the inlet and the outlet are parallel to one another. The outlet can be formed by linear movement of a mold core.

A pump includes a housings and a rotor capable of rotating within the housing. The rotor engages an interior surface of the housing in use, with at least two radially-inward shaped surfaces on the rotor forming respective chambers with the interior surface. In use, the chambers transport fluid from an inlet in the housing to an outlet in the housing as the rotor rotates. A seal provided between the inlet and the outlet will engage each of the shaped surfaces to prevent fluid passing from the outlet to the inlet as each shaped surface travels from the outlet to the inlet. The rotor includes a surface portion extending axially and circumferentially between respective edges of the shaped surfaces. On planes normal to an axis of rotation of the rotor, the surface portion of the rotor has a greater curvature than that of the interior surface of the housing.

A pump includes a housings and a rotor capable of rotating within the housing. The rotor engages an interior surface of the housing in use, with at least two radially-inward shaped surfaces on the rotor forming respective chambers with the interior surface. In use, the chambers transport fluid from an inlet in the housing to an outlet in the housing as the rotor rotates. A seal provided between the inlet and the outlet will engage each of the shaped surfaces to prevent fluid passing from the outlet to the inlet as each shaped surface travels from the outlet to the inlet. The rotor includes a surface portion extending axially and circumferentially between respective edges of the shaped surfaces. On planes normal to an axis of rotation of the rotor, the surface portion of the rotor has a greater curvature than that of the interior surface of the housing.