Abstract: Two preferred embodiments of an improved refrigerant recovery system and method for recovering refrigerant from a separate system are disclosed whereby the first embodiment utilizes a closed-loop refrigeration system employing a portable storage tank to recover refrigerant from a separate system that needs to be serviced. The first embodiment recovers refrigerant from the separate system by placing a storage tank within an evaporator that is cooled by evaporator coils and evacuated by a vacuum pump. The vacuum pump is valved off and recovered refrigerant is directed to the storage tank from the separate system. None of the recovered refrigerant contacts the compressor of the recovery system and vacuum pump. An alternative to the first embodiment provides a booster pump in-line with the storage tank and the separate system for transferring any residual refrigerants into the storage tank.

Abstract: The flow of refrigerant is controlled by a strategy that strives to seek and maintain a fluctuating superheat condition. The control system causes optimal use of the evaporator coil by ensuring that the refrigerant in the coil is in the liquid state. A temperature sensor at the evaporator coil exit senses refrigerant temperature and the control system regulates refrigerant flow so that the liquid dry out point (transition between liquid state and superheat state) occurs in the vicinity of this sensor. Thus a single sensor may be used to effect closed loop control.

Abstract: A compressor has an hermetic shell within which is located an internal pressure relief (IPR) valve. The valve is resistance welded directly to a separation plate in a scroll compressor or directly to the outside wall of the discharge muffler in a piston/cylinder compressor. The direct welding of the IPR valve eliminates unnecessary components and lowers the manufacturing costs of the compressor.

Abstract: A scroll-type machine has a motion controlling member for preventing relative rotation between a first and a second scroll member while allowing relative orbiting motion therebetween. The scroll-type machine includes a novel arrangement of a spring or other flexible member for biasing the second scroll member in a torsional direction. Biasing of the second scroll member operates to reduce the mechanical impact noise or rattle which is caused by the vibration of the machines operating components.

Abstract: A heat shield is disposed in a hermetic compressor between a discharge port and a local area on an interior surface of the outer shell toward which relatively hot compressed gas is directed. The local area of the outer shell is thereby insulated from the high temperature of the discharge gas.

Abstract: A scroll-type compressor which is particularly suited for use as a refrigerant compressor has a biasing chamber for pressure biasing the non-orbiting scroll to augment tip sealing. The biasing chamber communicates with the fluid pockets of the compressor through a biasing passage extending through the end plate of the non-orbiting scroll. The biasing passage is in fluid communication with the innermost fluid pocket during only a portion of each of the cycles of orbiting motion and in fluid communication with an intermediate fluid pocket during another portion of the cycles orbiting motion.

Abstract: The control system employs multiple, distributed architechure, processors in the indoor unit, the outdoor unit and optionally the thermostat unit. The overall system control functions are distributed across the processors, which communicate with one another over a communications link, employing a messaging system which allows sensor values to be obtained locally and transmitted to the other processors. The processors communicate to automatically refresh or update information during times when it will not degrade performance of critical functions.

Abstract: A scroll machine has a multi-functional device which is attached to either or both of the scroll members that serves the purpose of optimizing or altering the discharge port geometry to a specific compression ratio or for modulation of compression ratios for performance optimization.

Abstract: A scroll-type compressor has a liquid injection system for injecting liquid into an enclosed space defined by first and second scroll members which engage in cyclical relative orbiting motion, to reduce the temperature of the working fluid. The compressor incorporates a discharge diffuser for reducing the pressure of the working fluid in an enclosed space, so that the liquid may be injected into the enclosed space from a more centrally located injection port than one which would allow liquid injection without the discharge diffuser.

Abstract: A hermetically sealed compressor has a fan for cooling the motor of the compressor. The compressor utilizes the refrigerant vapor inside the hermetic shell to cool the motor. The fan is attached to the end of the motor rotor and crankshaft to circulate the suction gas of the compressor around and through the motor rotor and motor stator to absorb heat and then directs the suction gas against the hermetic shell in a spiralling motion for transferring heat to the shell which in turn transfers heat to the atmosphere.

Abstract: A scroll-type refrigerant compressor for use in a conventional refrigerating circuit and having liquid refrigerant compressor cooling provided by the injection of liquid refrigerant into an intermediate biasing chamber and/or specifically located bleed holes.

Abstract: The microprocessor-based HVAC control system detects sensor faults by comparing thermistor readings with predetermined extreme values, indicative of sensor fault. The system automatically selects the appropriate combination of automatic/preset modes of operating key system components such as the expansion valve, the demand defrost system and the indoor fan speed control system. With a view towards minimizing any negative impact on system performance and reliability in the event of sensor malfunction.

Abstract: A blocked fan or obstructed airflow condition is detected by measuring the difference between outdoor air temperature and outdoor exchanger coil temperature. If a very high difference is detected, or if no decrease in the difference is achieved after termination of the defrost cycle, and if either of these conditions persists over a plurality of defrost cycles, then the blocked condition is declared. The diagnostic system can be integrated in an existing demand defrost cycle and is capable of detecting blocked conditions attributable to foreign matter such as leaves, paper and debris which cannot be cleared by defrosting.

Abstract: A hermetic motor compressor includes a shell, first and second scroll members and a closure member extending across a portion of the interior of the shell adjacent one end of the shell to define a discharge chamber. A discharge port in the scroll member located closest to the closure member provides fluid communication between the center of the scroll members and the discharge chamber through an opening in the closure member. A seal member located between the closure member and the scroll member places the discharge port in sealed fluid communication with the discharge chamber.

Abstract: A scroll chamfer gauge measures the chamfer between the flank surface of the scroll and the tip of the scroll. The gauge is positioned on the tip of the scroll and has a locator which positions the gauge with respect to the flank surface. A probe extends from the gauge and locates the intersection of the chamfer and the flank surface. An indicator provides a direct reading of the height of the chamfer parallel to the flank surface.

Abstract: A scroll type machine is disclosed which is designed to enable it to be fully assembled prior to being installed in a hermetic shell and incorporates an improved mounting arrangement for the non-orbiting scroll member. This design enables the compressor to be tested without the need to first install it in the outer shell. This feature in combination with the mounting arrangement greatly facilitates manufacturing, assembly, testing, effectively prevents radial displacement of the non-orbiting scroll member, and offers the advantages of axial compliance. In one embodiment, the non-orbiting scroll is axially movably secured to a bearing housing by means of a plurality of bolts or bolts and sleeves. In another embodiment a rigid annular ring serves to axially movably secure the non-orbiting scroll to the bearing housing while in a third embodiment a stamped ring is secured to both the non-orbiting scroll and the bearing housing.

Abstract: A scroll type machine is disclosed which incorporates an improved mounting arrangement for the non-orbiting scroll member which mounting arrangement greatly facilitates manufacturing and assembly, effectively prevents radial displacement of the non-orbiting scroll member, and offers the advantages of axial compliance. In one embodiment, the non-orbiting scroll is axially movably secured to a bearing housing by means of a plurality of bolts or bolts and sleeves. In another embodiment a rigid annular ring serves to axially movably secure the non-orbiting scroll to the bearing housing while in a third embodiment a stamped ring is secured to both the non-orbiting scroll and the bearing housing. In another embodiment a two piece main bearing housing includes an integral ring for radially positioning the non-orbiting scroll member and means for securing anti-rotation and axial stop means thereto.

Abstract: A scroll-type machine has a motion controlling member for preventing relative rotation between a first and a second scroll member while allowing relative orbiting motion therebetween. The scroll-type machine includes a novel arrangement of a spring or other flexible member for biasing the motion controlling member in a specific direction. The biasing of the motion controlling member operates to reduce the mechanical impact noise or rattle which is caused by the vibration of the machine's operating components.

Abstract: A lubrication system for a scroll machine which, to any extent desired, can utilize the centrifugal forces generated by the orbiting of the orbiting scroll member to influence, either positively or negatively, the flow of fluid in a portion of the lubricant system. This fluid can be either a lubricating oil fed to the thrust bearing for normal lubrication, an oil injection into the intermeshed scrolls to increase sealing and efficiency while attenuating noise, or a venting of vapor from some point in the lubrication system.

Abstract: A scroll machine utilizing working fluid under pressure to enhance axial sealing, including several embodiments of a multi-function floating seal to isolate the axial biasing fluid, and provide vacuum protection and a degree of high pressure ratio protection.