Variable volume rotary vane pump-motor units

In a variable volume rotary vane device wherein a plurality of vanes are sequentially brought into sealing engagement with a surface of an outer sleeve,

• the improvement comprising, providing an enlarged head on said vanes and vane caps on the head of each of said vanes and applying a fluid force to each of said head and vane caps to urge the head and vane caps into sealing contact with the outer sleeve.

In a variable volume rotary vane device which includes a shaft mounted, eccentric, rotor rotatable within a cylindrical sleeve including a plurality of radially mounted vanes mounted in bores in the rotor so as to define a plurality of chambers between said rotor, said vanes and said sleeve, the improvement comprising,

• providing said vanes with a head and shaft in the general shape of a T or Y with the head of each vane positioned proximate the sleeve and providing on the head of each of said vanes at least two grooves each adapted to receive a seal means wherein the seal means are mounted on the head of the vanes so as to circumscribe a surface area on the head of the vanes proximate said cylindrical sleeve, wherein the head of the vane is sized and shaped such that the surface area of the head adjacent said shaft is greater than the surface area of the head adjacent said cylindrical sleeve lying outside said circumscribed surface area, which seal means together with said head of the vanes within said circumscribed surface area and the cylindrical sleeve define a closed space, and a conduit for placing each of said grooves in fluid communication with at least one of said chambers.