Abstract: A scroll machine has an intermediate pressure cavity which is operable to open and close a leakage path between the discharge zone and the suction zone of the scroll machine. The leakage path is closed when intermediate pressurized fluid is supplied to the cavity and the leakage path is open when the cavity is open to the suction zone of the compressor. A valve (102) which can be mechanical or electrical is used to open and close a passageway extending between the cavity and the suction zone of the machine. A high pressure relief valve is incorporated into the design of the compressor to prevent slugging. The high pressure relief valve will release the intermediate pressurized fluid to suction and/or discharge when the pressure within the intermediate pressure cavity exceeds a predetermined value.

Abstract: A scroll compressor includes a discharge valve assembly for blocking compressed refrigerant flow from the discharge chamber through the scroll members. This blocking of flow results in the elimination of reverse rotation at shut down. The discharge valve assembly includes a leakage path which allows a limited amount of refrigerant flow past the discharge valve to eliminate the forming of a vacuum during powered reverse rotation. In one embodiment, a valve located in the leakage path provides a time delay to optimize the performance of the discharge valve assembly.

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: There is disclosed a scroll-type machine particularly suited for use as a refrigerant compressor and incorporating a lubrication system for supplying lubricant from a sump to a thrust surface on which the orbiting scroll member is supported. The lubrication system utilizes passages provided in the driving crankshaft and the bearing housing which housing defines the thrust surface.

Abstract: An air treating system filters and dehumidifies contaminated air within an industrial plant. The air treating system includes a prefilter, a filter, a blower and an evaporator. A self-contained filtering unit directly communicates with a flume which receives fluid carrying contaminated particles from a machining center. Multiple self-contained filter and dehumidifier units are coupled with a single air conditioning compressor and condenser unit.

Abstract: A scroll compressor has a wedge camming device operable between the orbiting scroll of the scroll compressor and a fixed wall forming part of the compressor, for the purposes of automatically engaging the wall and the orbiting scroll upon reverse operation of the compressor to thereby separate the wraps of orbiting and non-orbiting scroll during such reverse operation. Damage to the compressor in the event of powered reverse is also prevented.

Abstract: A plastic terminal box is secured to a shell of a working machine. The plastic terminal box includes a plastic body which is secure to the shell and a plastic cover which is sealingly and releasably secured to the plastic body. The plastic body defines an aperture into which is inserted an electrical terminal of the working machine. A seal is located around the terminal and between the shell and the plastic body. The terminal and its associated electrical connections are thus isolated by the plastic terminal box due to the seal between the body and the shell and by the seal between the cover and the body.

Abstract: A system for making a gray cast iron scrolls using a high performance inoculant.

Abstract: A lost foam casting method for the manufacture of scrolls.

Abstract: A method of making a scroll-type machine particularly suited for use as a refrigerant compressor and incorporating an improved suspension system for the non-orbiting scroll whereby the latter may be pressure biased for the purpose of augmenting tip sealing. The machine also has a modified wrap tip and end plate profile in order to enhance performance, as well as an improved lubrication system for the drive and a baffle arrangement to provide a directed suction inlet. The machine also has an Oldham coupling utilizing a novel ring element which is non-circular and provides for increased thrust-bearing size, or reduced machine size.

Abstract: A scroll-type machine is disclosed which is particularly well suited for use as a compressor in refrigeration and air conditioning systems and incorporates a unique arrangement for modulating the capacity thereof. In one group of embodiments the capacity of the scroll-type machine is modulated by relative axial movement between the scroll members so as to form a leakage path across the wrap tips and opposed end plates. In another group of embodiments, modulation is achieved by reducing the orbital radius of one of the scroll members to thereby form a leakage path across the flank surfaces of the wraps. Both types of scroll separation may be accomplished in a time pulsed manner to thereby enable a full range of modulation with the duration of the loading and unloading periods being selected to maximize the efficiency of the overall system.

Abstract: A thermally responsive valve assembly for scroll motor-compressor high temperature protection, which causes a high-side to low-side leak when excessive discharge gas temperatures are encountered, thereby causing the motor protector to trip and de-energize the motor. The valve assembly includes means for ducting the excessive temperature discharge gas to the lower portion of the motor/compressor shell to the motor to circulate the high temperature gas throughout the motor cavity. The excessive temperature discharge gas heats the motor stator and windings which will in turn cause the motor protector to trip and de-energize the motor. A secondary flow passage increases the flow rate or the discharge gas to lower the cycle time of the compressor.

Abstract: Compressor discharge temperature, ambient outdoor air temperature and thermal load are used as control parameters for controlling the expansion valve setting and indoor fan speed. Diagnostics monitor a feedback signal from the fan motor to detect fan over-speed and increased speed due to decreased air flow caused by a dirty indoor air filter. Discharge pressure of the compressor is monitored to detect a blocked outdoor fan. The difference between actual and optimum compressor discharge temperatures and suction pressure of the compressor are monitored to detect a stuck-closed expansion valve or low refrigerant charge. Compressor "short-cycling" is limited to prevent reduced reliability of the compressor. The difference between compressor discharge temperature and outdoor coil temperature is measured before and after startup to detect compressor failure.

Abstract: A scroll-type refrigeration compressor is disclosed which incorporates an efficient, reliable, low cost modulation system employing a single actuator to effect switching between full and reduced capacity operation. The modulation system of the present invention includes an annular valving ring rotationally supported on the non-orbiting scroll which operates to ensure simultaneous opening and closing one or more unloading passages thus avoiding the possibility of even transient pressure imbalances between opposed compression pockets during operation of the compressor or in one of the alternative embodiments, providing a controlled imbalance to provide a noise reducing torsional loading on the Oldham coupling. Further, the modulation system of the present invention provides for reduced capacity at both start up and shut down thus enabling the use of more efficient lower starting torque motors and reducing the potential for noise generating reverse rotation on shut down.

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 machine has a muffler which is located between a discharge port located in the scroll assembly and a discharge chamber located in a hermetic shell. The muffler has a top cap which is attached to a partition which defines the discharge chamber. A muffler is attached to the top cap and extends towards the scroll assembly through an opening in the partition. The muffler has a generally cylindrical body with two end caps having a spherical surface. The cylindrical body and the end caps define a plurality of perforations which comprise a specific percentage of the total area of these components.

Abstract: A cover for an outside air conditioning system includes a hood molded from a single piece of plastic and a metal grill secured to the cover and the air conditioning system. The molding of the cover allows for the addition of colored dyes to be added to the virgin material during the molding process for producing covers of various colors. The design of the cover permits nesting of the covers during shipment in order to reduce the costs associated with transporting the covers.

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 and the noise and vibrations that are often associated with hot gas impinging on the shell.

Abstract: A scroll compressor includes a liquid injection system. The liquid injection system receives liquid refrigerant from the refrigeration system at a point between the condenser and the evaporator. This liquid refrigerant is then injected into at least one enclosed space defined by the scrolls of the scroll compressor. The liquid injection system includes a valve which selectively controls the flow of liquid refrigerant to the enclosed space. The valve is responsive to the discharge pressure of the compressor.

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.