Patent ID: 7607907

Claim:
A roller vane pump for fluid, the pump including a carrier which is rotatable in a housing about an axis of rotation, the carrier carrying a plurality of roller vanes which are each received in a respective slot which extends inwardly of a periphery of the carrier and permits the roller vane to move inwardly and outwardly in use, the housing surrounding the carrier, pumping chambers being formed between the roller vanes, the carrier and the housing, the roller vanes engaging with the housing and moving inwardly and outwardly of their respective slots as the carrier rotates, in response to the configuration of the housing so that the pumping chambers change in volume as the carrier rotates, to effect pumping of the fluid, from an inlet to the outlet of the pump, and wherein in each of the slots in which the roller vanes are received, there is provided a restrictor element which restricts movement of the roller inwardly of its respective slot, each restrictor element occupying part only of an axial depth of its respective slot such that each restrictor element has a width substantially equal to the diameter of its respective roller vane and extending across the entire span of its respective slot, so that a space is always preserved between the bottom of the slot and its respective roller vane.