Pumps

摘要

A pump comprises a housing (10) and a rotor (11) that rotates in the housing. The housing (10) has a fluid inlet (14) and a fluid outlet (15). The rotor (11) includes two shaped surface (21, 22; 50a, 50b, 50c) radially inwardly of the housing (10) and forming with the interior surface of the housing respective chambers (23, 24; 51a, 51b, 51c) for conveying fluid from the inlet (14) to the outlet (15) on rotation of the rotor (11). A seal (12; 56) is provided between the outlet (15) and the inlet to engage the shaped surfaces (23, 24; 50a, 50b, 50c)) to prevent the passage of fluid from the outlet (15) to the inlet (14) as each shaped surface (23, 24; 50a, 50b, 50c) travels from the outlet (15) to the inlet (14). The shape of the surfaces (21, 22; 50a, 50b, 50c) provides an optimised volume for the chambers (23, 24; 51a, 51b, 51c) and the seal (12; 56) is urged into contact with the rotor (11) by spring arrangements (13, 39, 41, 59) that provide an even force along the axial length of surfaces (21, 22).

主权项

1. A pump comprising a housing and a rotor rotatably received in the housing, the housing including a fluid inlet and a fluid outlet, the rotor including a housing-engaging surface co-operating with an interior surface of the housing to form a seal therebetween and also including at least first and second shaped surfaces radially inwardly of the housing engaging surface and each forming with the interior surface of the housing respective chambers for conveying fluid from the inlet to the outlet on rotation of the rotor, a seal being provided between the outlet and the inlet to engage the first and second shaped surfaces to prevent the passage of fluid from the outlet to the inlet as each shaped surface travels from the outlet to the inlet the housing-engaging surface of the rotor including a portion extending axially and circumferentially between an edge of the first shaped surface and an edge of the second shaped surface and having in planes normal to the axis of the rotor a curvature greater than the curvature of the interior surface of the housing in corresponding planes.