Rotor 1 rotates about fixed axis A and has seven vanes 2 sliding in radial slots of the rotor. When rotor 1 rotates, vanes 2 are held against the internal surface of cylindrical housing 3, located eccentrically with respect to centre A of rotor 1. The suction and discharge chambers are formed between vanes 2, rotor 1 and housing 3. Housing 3 is mounted in ball bearings d in yoke member 4. Turning yoke member 4 about shaft 5 increases or reduces the eccentricity of housing 3 with respect to rotor 1. This increases or reduces the delivery of liquid. Channels a and b in the rotor shaft are for the suction and discharge of the liquid.
$3803$LHP,RP$