SELF-CLEANING SINGLE LOOP MIST TYPE LUBRICATION SYSTEM FOR SCREW COMPRESSORS

摘要

SELF-CLEANING SINGLE LOOP MIST TYPELUBRICATION SYSTEM FOR SCREW COMPRESSORSABSTRACT OF THE DISCLOSUREIntermeshed helical screw rotors are mounted forrotation by anti-friction bearings surrounding inte-gral shafts extending axially outward of the ends ofthe intermeshed screw rotors and within respectivehigh pressure outlet and low pressure inlet bearinghousings, sealed to the exterior. Oil from a separa-tor/sump at or near compressor discharge pressurefeeds via a closed passage to annular cavities sur-rounding the rotor shafts upstream of the outlethousing bearings. Oil seeps through very narrowannular gaps functioning as self-cleaning upstreamcapillaries to the outlet bearing cavities with thepressure reduction causing oil mist lubrication of theconfined bearings within the outlet bearing housing.Further passages fluid connect the outlet bearinghousing cavities to similar cavities within the inletbearing housing where mist lubrication of the inletbearings occurs. Further, oil passage means connectthe inlet bearing housing cavities to an oil injectionport via a downstream capillary with the oil injectionport opening to the working chamber first closedthread. The upstream and downstream capillariesinsure proper pressure reduction through the singleloop lubrication system and the downstream capillaryfunctions to maintain 2 pressure differential betweenthe inlet bearing housing and the suction side of theintermeshed screws when the slide valve shifts to fullunloaded position such that the oil injection port isopen directly to the suction port of the compressor.