Oil cooling apparatus for refrigeration screw compressor

Refrigeration apparatus comprising a screw compressor which is cooled and lubricated by the circulation of oil therethrough and from which a mixture of compressed refrigerant and oil issues to an oil separator through a discharge duct, oil recirculating means comprising an oil pump having an inlet communicated with the oil separator and an outlet from which pressurized oil is conducted to the screw compressor, a receiver to which refrigerant flows from the oil separator through a condenser and in which liquid refrigerant is held for circulation through an evaporator, and delivery means comprising a motor and a refrigerant pump which is driven by said motor and whereby liquid refrigerant is drawn from said receiver and delivered to said discharge duct to cool said mixture, said apparatus being characterized by:

• A. said delivery means comprising
• (1) a sealed housing having therein
• (a) a pair of cavities, one near each of its opposite ends,
• (b) at least one bore connecting said cavities, and
• (c) an inlet port and an outlet port for each of said cavities, each opening from its cavity to the exterior of the housing,
• (2) rotary means in each of said cavities, the rotary means in one cavity comprising a hydraulic motor and the rotary means in the other cavity being of substantially the same kind but comprising said refrigerant pump, and
• (3) at least one shaft in said housing journaled in said at least one bore and drivingly connecting the rotary means in said one cavity with the rotary means in said other cavity;
• B. oil duct means connecting said inlet port for said one cavity with said outlet of the oil pump for delivery to the hydraulic motor of a portion of the pressurized oil issuing from said outlet;
• and
• C. other oil duct means connecting said outlet port for said one cavity with said discharge duct for delivery to the latter of exhaust oil from said hydraulic motor.