Patent ID: 8602757

Claim:
A rotary device comprising: a barrier ring having: a central longitudinal axis; a tubular interior surface through which the longitudinal axis extends centrally, in spaced relation, the interior surface including one or more portions which each define a longitudinally extending, inwardly-projecting ridge; and defined therethrough, on opposite circumferential sides of each of said one or more ridges, a first port and a second port; a rotor mounted for rotation in the barrier ring about the longitudinal axis, the rotor including a rotor body; a plurality of vanes mounted to the rotor body for rotation with the rotor body about the longitudinal axis and for radial extension and retraction relative to the rotor body such that at least portions of the interior surface of the barrier ring can be swept by the vanes; a sealing structure providing a seal between the rotor and the barrier ring to permit fluid communication into and out of the rotary device substantially only via the first and second ports; and an arrangement for causing the vanes to retract and extend as the rotor body rotates such that chambers are created which decrease in volume when in communication with the first ports and such that chambers are created which increase in volume when in communication with the second ports, the arrangement including a fluid pressure mechanism for causing the vanes to retract.