Abstract: A rotary device has a first rotor having a recess and a second rotor counter-rotatable to the first rotor and having a radial lobe. A housing in which the rotors are enclosed has a first arcuate recess, an edge of the recess of the first rotor forming a sliding seal with the first arcuate recess during a portion of the rotation of the first rotor. The housing has a second arcuate recess, the lobe of the second rotor forming a sliding seal with the second arcuate recess during a portion of the rotation of the first rotor. Thus, for a portion of the rotation of the rotors, there is defined between the first and second rotors and the arcuate recesses of the housing a transient chamber of volume which progressively decreases on rotation of the rotors. The maximum volume of the transient chamber can be varied.

Abstract: A rotary device (11) has a first rotor (12) rotatable about a first axis and having at its periphery a recess (14). A second rotor (13) is counter-rotatable to said first rotor (12) about a second axis, parallel to said first axis, and has a radial lobe (15). The first and second rotors (12,13) are coupled for rotation and are intermeshed such that, for a portion of the rotation of the rotors (12,13), there is defined between the first and second rotors (12,13) a transient chamber of volume which progressively decreases on rotation of the rotors (12,13). Means (27,28) are provided for monitoring the clearance between the rotors (12,13). Means for adjusting the clearance between the rotors (12,13) are provided.