초록 ▼

An integral member is disposed internal of a refrigeration screw compressor which, upon compressor shutdown, shuts off the flow of oil injected into the compressor\s working chamber as well as the oil directed to the compressor rotor bearings and which, at compressor startup, opens oil flow to those

An integral member is disposed internal of a refrigeration screw compressor which, upon compressor shutdown, shuts off the flow of oil injected into the compressor\s working chamber as well as the oil directed to the compressor rotor bearings and which, at compressor startup, opens oil flow to those locations by the use of ambient internal compressor conditions that inherently exist at those respective times. The operation of the apparatus is therefore “fail safe”and the need for external oil flow cutoff valving and the need to monitor and/or prove oil flow within the compressor is eliminated.

대표청구항 ▼

A refrigerant gas compressor of the screw type comprising: a housing defining a working chamber, said housing further defining a suction port, a discharge port and an oil supply passage, all in flow communication with said working chamber, said housing still further defining an oil flow cutoff passa

A refrigerant gas compressor of the screw type comprising: a housing defining a working chamber, said housing further defining a suction port, a discharge port and an oil supply passage, all in flow communication with said working chamber, said housing still further defining an oil flow cutoff passage in flow communication with said oil supply passage; a pair of screw rotors meshingly disposed for rotation in said working chamber; and integral valve means disposed within said compressor and positionable (i) to simultaneously occlude said oil supply passage to prevent the flow of oil therethrough and to stop the backflow of previously compressed gas back to the compressor\s working chamber at compressor shutdown and (ii) to simultaneously open said oil passage to permit the flow of oil therethrough and permit the discharge of compressed gas from said compressor immediately subsequent to compressor startup, all in direct response to ambient conditions in said compressor, downstream of said discharge port, which inherently exist at compressor shutdown and startup respectively.