Rotary vane machines with anti-friction positive bi-axial vane motion

Abstract

A fluid displacement machine of the vane type which can be operated as a compressor or motor utilizes a cylindrical rotor equipped with one or more tethered sliding vanes wherein the rotor and vane set is rotatably located eccentrically inside an internal conforming casing profile between opposing endplates to define enclosed variable volume compartments. [Each vane is fitted on opposite sides eith tethers which are pivotally-mounted remotely from the vane tips. The tethers engage, through anti-friction means, circular annuli located within the endplates which are eccentric with the hollow casing profile.] Anti-friction tether-to-annuli means are used, one in the form of freely-rotating caged roller bearings interposed between the tethers and the respective internal annuli, and another in the form of tethers equipped with trunnioned bearings which directly engage these internal annular surfaces. [Combinations of these anti-friction vane tethering means are also disclosed, including a compressor with a twin roller tether arrangement and one with a variable speed roller bearing retainer. The vane tethers engage both internal peripheries of the endplate annuli for the purpose of providing positive bi-axial radial vane motion control, and the profile of the casing is defined such that the tips of the positive motion-controlled vanes remain in an exceedingly close yet substantially frictionless sealing relationship with the conforming hollow casing.] A circular casing interior profile is achieved by placing the center of the vane tip radius at the exact coincidence with the glider axle center and making the tip radius equal to the difference in the radii of the stator and the radius of the path of the glider axle centerline less the rotor offset from the stator center. A compressor can be provided with an oil separator in the discharge line or with a discharge valve to reduce noise and increase operating efficiency over a larger temperature range. Alternatively, a volunteer oiling system can be employed to circulate lubricant continuously. For lower costs machines, low friction sliding surfaces can be ussed in lieu of the ball bearings or a semi-lubricated ring can be substituted to provide a permanent lubricant change.