Rotary sliding vane compressor with hydrostatic bearings

Claim 1

A rotary sliding vane compressor comprising: a casing defining a closed cylindrical chamber having a cylindrical wall and spaced first and second parallel end walls; a slotted rotor rotatably mounted eccentrically in said cylindrical chamber to provide, with said cylindrical wall and said end walls, a crescent-shaped compression chamber and having first and second rotor faces adjacent and parallel to said first and second end walls respectively, said rotor subject to a relatively small amount of axial movement between said end walls; suction and discharge ports communicating with said compression chamber; a plurality of vanes slidably mounted in the slots of said rotor for engaging said cylindrical wall to compress a gaseous fluid introduced through said suction port and to discharge that fluid through said discharge port at a higher pressure; a source of pressurized lubricating oil; and first and second parallel and independent oil flow paths each coupled from said oil source to said compression chamber, said first flow path including in series a first flow control orifice, a first hydrostatic bearing cavity defined between said first rotor face and first end wall, and a first restrictive clearance between said first face and first wall and located radially outward from said first bearing cavity, and said second flow path including in series a second flow control orifice, a second hydrostatic bearing cavity defined between said second rotor face and second end wall, and a second restrictive clearance between said second face and second wall and located radially outward from said second bearing cavity; the oil pressure in each of said first and second bearing cavities varying inversely with changes in said first and second clearances respectively, which occur when said rotor shifts axially, thereby to effect automatic centering of said rotor between said end walls.