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In a vertical hermetic compressor, an inner cylindrical housing coaxially mounted within a sealed outer enclosure, sealably carries at its lower end, paired helical screw rotors defining with the inner housing a screw compressor compression chamber and supports coaxially with one of the screw rotors

In a vertical hermetic compressor, an inner cylindrical housing coaxially mounted within a sealed outer enclosure, sealably carries at its lower end, paired helical screw rotors defining with the inner housing a screw compressor compression chamber and supports coaxially with one of the screw rotors and constituting an axial extension thereof the compressor electrical drive motor by longitudinally spaced tapered roller bearings. Oil is bled from the sump and fed to the suction inlet tube to the compressor upstream of the working gas filter. Compressed working fluid is discharged axially downwardly with the lower tapered roller bearing assembly providing a minimal high pressure gap between the screw rotor ends and the stationary end plates. Entrained oil from the discharge passage which extends through the electric motor rotor seeks the suction side of the compressor through the upper of the two tapered roller bearing pack assemblies for controlled continuous lubrication of the upper bearing assembly. The compressed working fluid discharges axially through the center of the sealed outer enclosure at its upper end free of oil which is separated by impact with a curved plate deflector overlying the upper end of the electric motor and by centrifugal force provided by the electric motor rotor rotation. The upper bearing pack assembly for the screw rotors may employ needle bearings instead of tapered roller bearings and the lower bearing pack assemblies may incorporate radially extending needle bearings for thrust take up in lieu of one set of tapered roller bearings, with the needle bearings carried by a spherical, self-aligning mounting assembly. A capillary line passing through the compressor inlet passage carries oil from the sump to an injection port opening to a closed thread just after suction cut off for lubricating and sealing of the screw rotors.

대표청구항 ▼

A vertical axis hermetic rotary helical screw compressor comprising: a closed vertical, cylindrical outer enclosure, an inner cylindrical casing of a diameter less than that of the outer enclosure, means for concentrically, fixedly mounting said inner cylindrical casing within said outer enclosure,

A vertical axis hermetic rotary helical screw compressor comprising: a closed vertical, cylindrical outer enclosure, an inner cylindrical casing of a diameter less than that of the outer enclosure, means for concentrically, fixedly mounting said inner cylindrical casing within said outer enclosure, said inner cylindrical casing including transverse wall means separating said cylindrical casing into upper and lower chambers, rotor means including intermeshed helical screw rotors, vertical shaft means for at least one of said helical screw rotors and coaxially fixed to said at least one helical screw rotor intermediate of the ends of said vertical shaft means, a casing end plate fixed to the lower end of said inner cylindrical casing, a vertical bore means formed within said casing for mounting said at least one helical screw rotor and partially forming therewith a compressor working chamber, an upper roller bearing pack assembly carried by said casing means at said transverse wall means for supporting the upper end of said vertical shaft means, and a lower roller bearing pack assembly carried by said casing end plate for supporting the lower end of said vertical shaft means, said lower roller bearing pack assembly including at least one tapered roller bearing for absorbing compressor developed thrust force, an inlet tube opening to said casing bore means and said compressor chamber at the upper end of said at least one helical screw rotor for supplying working fluid to said compressor, an electrical drive motor, said motor including a stator and a rotor, said motor rotor being coaxially mounted to the upper end of said vertical shaft means above said upper roller bearing pack assembly, said stator being fixedly mounted to said inner casing, concentrically about said motor rotor and spaced radially therefrom, said end plate underlying the lower end face of said at least one helical screw rotor and including a horizontal compresssor discharge passage for receiving the compressed working fluid, said casing further comprising a vertical compressor discharge passage means extending from said casing end plate to said transverse wall means and opening to the upper chamber housing said drive motor at one end and said horizontal compressor discharge passage at the other end, an axial gas discharge outlet within the top of said vertical cylindrical outer enclosure, the upper end face of said at least one helical screw rotor being open to the upper roller bearing pack assembly, seal means carried by said upper roller bearing pack assembly for sealing said upper chamber from said at least one helical screw rotor upper end face, said seal means including a rotatable seal element fixed to said shaft means and rotatable therewith, and passage means carried by said electric drive motor for permitting said compressed working fluid to pass into said cylindrical outer enclosure at the upper end of said motor, such that during compressor operation, compressor discharge pressure acting on the upper end of said shaft means and on said at least one rotatable seal element and the weight of said motor rotor and said screw rotor partially balances the developed thrust forces acting on said at least one helical screw rotor, while said upper and lower roller bearing pack assemblies absorb the remaining developed thrust force and any radial force acting on said shaft means.