Rotor assembly in vane machine with pressure balance devices

Claim 1

A ROTARY FLUID HANDLING MACHINE COMPRISING, IN COMBINATION, AT LEAST ONE ANNULAR CASING MEANS HAVING AN INTERNAL SPACE AND HAVING ANNULAR END FACE MEANS AT THE OPPOSITE AXIAL ENDS THEREOF, SAID ANNULAR END FACE MEANS HAVING AN INNER EDGE; AT LEAST ONE ROTOR MEANS RECEIVED IN SAID SPACE AND HAVING AN AXIS OF ROTATION, SAID ROTOR MEANS FORMED WITH A PLURALITY OF SUBSTANTIALLY RADIALLY INWARDLY EXTENDING SLOT MEANS; AT LEAST TWO SIDE WALL MEANS EACH HAVING AN OUTER ANNULAR FACE, RESPECTIVELY CONFRONTING AND BEING LOCATED CLOSELY ADJACENT TO ONE OF SAID ANNULAR END FACE MEANS AND COVERING AT LEAST AN ANNULAR REGION OF THE SAME ALONG SAID INNER EDGE THEREOF; VANE MEANS RECIPROCABLY RECEIVED IN SAID SLOT MEANS SO AS TO DIVIDE SAID SPACE INTO A PLURALITY OF FLUID RECEIVING WORKING CHAMBERS, SAID VANE MEANS SLIDABLY ENGAGEABLE WITH SAID CASING MEANS; MEANS FOR ADMITTING A WORKING FLUID TO SAID WORKING CHAMBER; COVER MEANS OUTWARDLY ADJACENT TO AT LEAST ONE OF SAID SIDE WALL MEANS AND DEFINING WITH SAID ONE SIDE WALL MEANS AT LEAST ONE PRESSURE COMPARTMENT; MEANS FOR CONNECTING SAID ROTOR MEANS, SAID SIDE WALL MEANS AND SAID COVER MEANS SO THAT SAID ROTOR MEANS, SAID SIDE WALL MEANS AND SAID COVER MEANS ROTATE IN UNISON AND FOR LIMITING AXIAL MOVEMENT OF SAID COVER MEANS SO THAT SAID SIDE WALL MEANS HAVE LIMITED FREEDOM OF AXIAL MOVEMENT WITH RESPECT TO SAID COVER MEANS AND SAID CASING MEANS; AND MEANS FOR ADMITTING A PRESSURE FLUID TO SAID PRESSURE COMPARTMENT SO THAT THE PRESSURE FLUID MAY COUNTERACT THE FLUID PRESSURES DEVELOPING IN SAID WORKING CHAMBERS AND THAT THE PRESSURE FLUID MAY MAINTAIN SAID SIDE WALL MEANS IN CLOSE PROXIMITY OF SAID ANNULAR REGION OF THE END FACE MEANS OF SAID CASING MEANS.