Abstract: A rotary compressor is provided that has a housing including a bore, bearings, a low pressure end having a low pressure inlet and a high pressure end having a high pressure outlet. A rotor is rotatably mounted by the bearings in the bore and has an end face subject to a variable axial thrust force; and a plurality of compression chambers having a low pressure, a high pressure and intermediate pressures. A piston is provided for exerting a counterbalancing force on the rotor in opposition to the axial thrust force at the high pressure end of the compressor. An intermediate pressure port is provided in communication with the intermediate pressure chamber. A conduit is connected between the piston and the intermediate pressure port which varies according to suction pressure to cause the piston to apply a variable counterbalance force on the rotor through the output range of the compressor.

Abstract: A variable capacity rotary screw compressor having a rotor housing including a bore, an inlet, an outlet, a slide valve recess and rotors. Passive and active slide valves are mounted in the recess. Individual passive and active slide valve balancing units are connected to the passive and active slide valves respectively. A prime mover is connected to selectively regulate the position of the active slide valve. A first conduit is connected between the housing inlet and the passive and active slide valve balancing units and includes a first valve operable to either open or close the first conduit. A second conduit is connected in fluid communication between the outlet and the passive and active slide valve balancing units and includes a second valve operable to either open or close the second conduit. A first sensor provides a first signal proportional to suction pressure. A second sensor provides a second signal proportional to discharge pressure.

Abstract: A bearing and seal assembly for supporting a rotor for rotation about an axis in a rotor receiving bore of a rotating machine which is concentric to the axis of rotation. The bearing and seal assembly includes a nonrotatable bearing support member dimensioned to loosely fit inside the rotor bore so as to be radially movable relative to the axis of rotation. A bearing receiving portion is provided on the bearing support that holds a bearing which mounts the rotor on the bearing support member. A seal is nonrotatably mounted on the bearing support and has an outer peripheral portion dimensioned to have a close tolerance nonrotating fit with an inner peripheral surface of the rotor bore; an inner peripheral portion; and an nonrotating sealing surface dimensioned to have a close tolerance sealing relationship with a rotating sealing surface on the rotor.

Abstract: An evaporative condenser cools and condenses fluid, such as refrigerants in a refrigeration system, by circulating the fluid through a condensing coil, continuously and completely spraying the condensing coil from above with cooling water, and simultaneously blowing air from below the condensing coil upwardly and counter to the cooling water. Heat is transferred from the fluid to the cooling water, and heat is transferred by evaporation from the cooling water to the air and is discharged to the atmosphere. A fogging nozzle sprays a fine water mist into the air blowing into and through the condenser, which will increase the rate of evaporation and therefore increase the rate of heat transfer, thus increasing the cooling efficiency of the condenser.

Abstract: In a check valve or stop/check valve comprising a housing having an inlet port, an outlet port and a valve seat between the two ports, a valve disc moves axially within a valve housing between open and closed positions, so that fluid flow applies pressure against the valve disc to automatically open the valve, but when the fluid stops or reverses, the valve automatically closes to prevent backwash. Under conditions of pulsating, low-volume fluid flow, a ridge on the valve seat and a deflector ring on the valve disc deflects the flow of fluid, thereby using the velocity of fluid to increase pressure against the valve disc so as to smoothly and gently move the valve disc, reduce vibration of the valve disc and prevent it from striking the valve seat.

Abstract: In a disc-type stop valve, a valve disc located at the lower end of a rotatable valve stem takes the form of a solid cylindrical metal member having an annular groove formed around the periphery of its lower surface in which an annular resiliently deformable plastic seal ring is disposed. The seal ring is held in place by a smaller-diameter circular metal retainer plate which is secured by bolts against the lower surface of the valve disc and against the underside of seal ring. When the valve is closed, a circumferential lower edge of the seal ring bears against a conically-shaped annular metal valve seat surface in the valve body. A large-diameter resilient compressible conventional O-ring is disposed in an annular space defined by the rear side of the retainer plate, the annular inner edge of the seal ring and a chamfered edge along the intersection of the lower surface and the side edge of the valve disc.

Abstract: An oil separator operates to remove oil entrained in a refrigerant being circulated in a refrigeration system, especially a system using a screw-type compressor. The oil separator generally comprises a vessel having a chamber therein and a perforated plate on which oil coalescing elements are mounted divides the chamber into a lower primary oil separator section and an upper secondary oil separator section. A mixture inlet pipe extends through a side of the tank into the lower section for admitting a pressurized mixture of refrigerant and oil. A refrigerant gas outlet port is provided in the upper section for expelling refrigerant from which the oil has been separated. An oil outlet port is provided in the lower section for expelling oil collected in an oil sump at the bottom of the lower section.

Abstract: A housing of a reciprocating gas compressor comprises a partition member separating an upper suction chamber through which gas passes and a lower crankcase chamber in which a crankshaft rotates and which has an oil sump at the bottom. The partition member is imperforate except for sealed openings through which cylinder sleeves and hydraulic fluid lines extend between the chambers. A conduit located on the housing exterior and connected between the chambers performs three functions, namely: enables gas flow in either direction to effect pressure equalization; enables oil to flow by gravity from low points in the upper chamber into the sump; and enables oil mist in the gas flow through the conduit to coalesce on the inner walls of the conduit and flow by gravity into the sump.

Abstract: A liquid level control in a refrigeration system operates a solenoid valve to maintain the level of liquid refrigerant in a vessel within a range defined by predetermined lower and upper liquid levels, sounds an alarm if the upper level is exceeded and stops a pump if the lower level is violated. The control comprises a float assembly and a switching assembly. The float assembly comprises a float chamber connected to the vessel, a float ball therein, a vertically extending float rod connected to the float ball and movable along a vertical path, and a pair of spaced apart stop members on the float rod disposed within the switching assembly. The switching assembly comprises a switch actuator permanent magnet, having magnet poles at opposite ends, slidably mounted on the float rod between the stop members and movable thereby along the said path.

Abstract: A large manually operated leak-proof corrosion-proof low-cost shut-off or stop valve for handling high pressure refrigerant liquid and/or gases is disclosed. The valve comprises a valve body formed of two sheet metal hemispheres electron-welded to the periphery of a circular metal valve plate which has an aperture therethrough. Hollow cylindrical metal tubes entend into circular holes formed in the hemispheres and are electron-welded to the hemispheres along the edge of the circular holes. One tube on each hemisphere serves for fluid flow. Another internally and externally threaded tube on one hemisphere serves as valve sleeve through which a manually rotatable and axially shiftable externally threaded valve spindle extends. The inner end of the valve spindle is secured to a valve disc which cooperates with the aperture in the valve plate. In the method, components to be welded together are assembled and rotated with respect to a stationary electron welding beam.

Abstract: A method is disclosed for operating a large motor-driven refrigeration gas compressor which has independently movable suction and discharge slide valves to prevent undesirable, possibly damaging hydraulic pressure build-up caused by sealing oil remaining in the gas compression chambers during compressor start-up. While the compressor is started and brought up to full speed, the suction slide valve is disposed in fully unloaded position to fully open the gas suction port and the discharge slide valve is disposed in position to fully open the gas discharge port to enable excess oil in the gas compression chambers to exit freely through the compressor gas discharge port before oil pressure build-up can occur. When the compressor is at full speed, the suction slide valve is positioned to maintain a desired gas suction pressure and the discharge slide valve is positioned to equalize gas pressure between the gas compression chambers and the compressor gas discharge port.

Abstract: A manually operated valve is usable as a shut-off and stop/check valve for handling refrigerant fluids in a system subject to reverse fluid flow. The valve comprises a hollow valve body having fluid inlet and outlet ports, a valve plate within the body with a fluid flow passage therethrough, an annular valve seat on the valve plate around the passage, a hollow internally threaded valve stem sleeve attached to the valve body, a rotatable and axially shiftable externally threaded valve stem extending through the valve stem sleeve into the valve body, and a valve disc which is rotatably and axially shiftably mounted on the inner end of the valve stem and releasably engageable with the valve seat to open and close the valve. Rotation and axial shifting of the valve stem effects axial shifting of the valve disc to open and close the valve to enable it to function as a shut-off valve.

Abstract: A reciprocating type gas compressor comprises a hollow frame or housing having spaced apart end walls, a motor-driven crankshaft disposed within the housing and rotatably mounted on bearing assemblies on the end walls and connecting rods connected to crank pins on the crankshaft for driving pistons located within the housing. The crankshaft comprises a drive shaft at one end and a pump shaft the other end, both extending along a common axis of rotation. The crankshaft also comprises a pair of axially spaced apart counterweights located between the two shafts and a crank arm or link located between the counterweights. A crank pin extends from each counterweight to the link along a pin axis which is parallel to and spaced apart from the common axis of rotation. Each bearing assembly has a hollow cylindrical inner race which is friction-fitted on a shaft at an end of the crankshaft and abutts the side of one counterweight.

Abstract: A rotary screw gas compressor for a refrigeration system comprises a motor-driven single main rotor having helical grooves and mounted for rotation in a rotor bore in the compressor housing and a pair of star-shaped gate rotors rotatably mounted in the housing and engageable with the helical grooves to define a plurality of compression chambers. A suction slide valve member is slidably positionable (between full load and unload positions) to control where low pressure uncompressed refrigerant gas from a suction port is admitted to the compression chambers to thereby function as a suction bypass to control compressor capacity. A discharge slide valve member is slidably positionable (between minimum and adjusted volume ratio positions) to control where high pressure compressed refrigerant gas is expelled from the compression chambers to a discharge port to thereby control the volume ratio and thereby the input power to the compressor.

Abstract: A rotary screw gas compressor for a refrigeration system comprises a motor-driven single main rotor having helical grooves and mounted for rotation in a rotor bore in the compressor housing and a pair of star-shaped gate rotors rotatably mounted in the housing and engageable with the helical grooves to define a plurality of compression chambers. A suction slide valve member is slidably positionable (between full load and unload positions) to control where low pressure uncompressed refrigerant gas from a suction port is admitted to the compression chambers to thereby function as a suction bypass to control compressor capacity. A discharge slide valve member is slidably positionable (between minimum and adjusted volume ratio positions) to control where high pressure compressed refrigerant gas is expelled from the compression chambers to a discharge port to thereby control the volume ratio and thereby the input power to the compressor.

Abstract: A gas compressor has cylinders in which gas is compressed by pistons. Each cylinder has a suction valve and an exhaust valve to admit uncompressed gas and expel compressed gas. The suction valve includes a suction valve plate which repeatedly moves toward and away from the top end of the cylinder between closed and open positions, respectively. Apparatus to control compressor capacity includes an unloader mechanism to selectively prevent the suction valve plate moving to fully closed position to thereby unload the cylinder and reduce compressor capacity. The unloader mechanism comprises an unloader piston movable in an unloader cylinder in response to system conditions to move a linkage which determines the closure position of the suction valve plate. The linkage includes a pivotable lift arm biased toward a position which allows full closure of the suction valve plate and is movable by the unloader piston to another position which prevents full closure of the suction valve plate.

Abstract: A refrigeration system comprises a compressor, a condenser, a receiver, an evaporator, and an adjustably controllable expansion valve connected in the refrigerant supply line from the receiver to the evaporator. An electronic control system adjustably controls the expansion valve so as to maintain the maximum amount of liquid refrigerant in the evaporator while preventing flow of liquid refrigerant to the compressor. The electronic control system measures both the actual refrigerant temperature and refrigerant vapor pressure at a common point near the evaporator outlet port, converts the measured vapor pressure to a saturation temperature, determines the differential between the two temperatures and adjusts the expansion valve in accordance therewith, i.e., closing or opening in response to differentials below or above a set point, respectively.

Abstract: A refrigeration gas compressor comprises a piston reciprocably movable to effect gas compression, a motor-driven rotatable crank shaft, and a connecting rod between a crank shaft, crank pin and a piston wrist pin. A crank pin receiving hole and a wrist pin receiving hole in the connecting rod are connected by an oil passage. The crank pin has two lubricating oil supply ports at opposite sides of its outer surface through which lubricating oil is pumped. A bearing assembly comprising semi-circular upper and lower bearing sections is disposed around the crank pin. The upper bearing section has wedge-shaped oil well recesses at opposite ends of its inner surface which receive oil from the oil supply ports. The upper bearing section also has two oil feed holes therethrough for supplying oil from the wells to a groove in the crank pin hole side wall adjacent the upper bearing section.

Abstract: A refrigeration system comprises an evaporator which feeds uncompressed vapor to a first (low) stage compressor, a second (high) stage compressor which receives low compression vapor from the first stage and feeds high compression vapor to a condenser, and a receiver which receives liquid from the condenser and ultimately feeds it to the evaporator. Desuperheater apparatus, comprising a pressure vessel (subcooler) and a heat exchanger, is provided to remove excess heat (superheat) from the compressed vapor fed by the first stage to the second stage to thereby improve thermal efficiency of the system and to reduce the mass of refrigerant to be handled by the second stage thereby enabling use of a smaller, more economical second stage compressor. The pressure vessel contains a bath of liquid which is supplied from the receiver and then fed to the evaporator.

Abstract: A refrigeration system includes a latent heat storage tank having an evaporator coil or tube submerged in water and on which a layer of ice forms in response to circulation therethrough of refrigerant from a motor-driven compressor. Apparatus is provided to measure, indicate and regulate the thickness of the ice layer. The apparatus comprises an ice sensing device which provides an electric signal proportional to ice layer thickness to an electrical control circuit which then operates a meter to indicate thickness and operates a motor controller to stop or start the compressor motor. The ice sensing device comprises a probe which is periodically movable back and forth in a short arc in one cycle to detect ice by a timer-actuated electric motor and a potentiometer which moves in response to probe movement to provide a signal porportional to ice thickness to the abovementioned electrical control circuit.