Self-machining seal ring leakage prevention assembly for rotary vane

Abstract

A low internal leakage, rotary vane gas compressor utilizing a housing having a generally elliptical cavity, whose outer boundary is defined by an inner stator wall. A shaft mounted rotor is disposed offset from the central axis of the cavity, with an end plate secured on each end of the housing. Each end plate has a centrally mounted hole for rotatably supporting the respective side of the rotor shaft. The housing has inlet and discharge passages, each in conact with the cavity. The rotor has a plurality of radial slots in equally spaced relation about its periphery, in each of which slots a slidable vane of minimal weight is disposed. Each vane is approximately the width of the rotor, and the outer tip of each vane is in close proximity to the inner stator wall. These vanes define a plurality of chambers which undergo significant volume changes during rotation of the rotor. The vanes thus cooperate with the inner stator wall and the end plates to compress gas entering the inlet passage, such that the gas thereafter leaving through the discharge passage is at a higher pressure. Advantageously, a seal ring of particularly hard, tough steel is mounted in each end plate, and biased into contact with the respective side of the rotor to effect an essentially zero gap therewith. Each seal ring has a tapered cross section, such that the initial footprint area is small, but with rotor wear, the small contact area desirably becomes a surface contact.