Abstract: A refrigerant compressor system utilizing a plurality of motor-compressors in a single shell in order to provide capacity modulation, wherein each motor-compressor is of the welded hermetic type having a minimum of modification, in order to take advantage of the low cost and optimized efficiency of such motor-compressors. Several related embodiments are also disclosed.

Abstract: The refrigeration control software periodically checks for overcharge and undercharge conditions by placing the expansion valve at a predetermined setting, based on measured environmental temperature. While the expansion valve is at the predetermined setting a series of compressor discharge temperature readings are taken to obtain an average reading and this average reading is compared with a reference value. An undercharge condition is declared when the average reading is greater than the reference value and an overcharged condition is declared when the average reading is less than the reference value.

Abstract: A scroll machine has a cover plate attached to the lower bearing housing which is adjacent the lower motor windings of the scroll machine. The cover plate has a plurality of grooves which work in conjunction with a lower counterweight of the scroll machine to circulate the lubricating oil located in the sump around the lower motor winding to cool the motor.

Abstract: A scroll machine has an elastomeric member placed between the drive shaft and an unloader drive bushing of the scroll machine. The elastomeric member provides limited transverse movement between the drive shaft and the orbiting scroll member which is driven by the drive bushing. The limited transverse movement permits radial compliant engagement of the scroll wraps of the scroll machine. In one embodiment, the elastomeric member is connected to the drive shaft and a bearing plate is placed between the elastomeric member and the drive bushing for driving engagement. In another embodiment, the elastomeric member is connected to the drive bushing and a bearing plate is placed between the elastomeric member and the drive shaft for driving engagement.

Abstract: A scroll compressor oil pumping system has a concentric axial bore located in the driveshaft of the compressor which serves as the primary oil pump. The driveshaft is journaled in a lower bearing housing and is located within the oil sump of the compressor. An inlet housing is attached to the lower bearing housing and creates a stepped flow path for the oil between the sump and the oil pump. The inlet housing may also be equipped with a plurality of air foil shaped vanes to impede the formation of a bottom vortex. The stepped flow path causes an annular vortex to form which operates to separate the contaminants from the lubricating oil. In order to assist in the formation of the annular vortex, the driveshaft can include an impeller. The contaminants are channelled into a holding chamber formed by the lower bearing housing and the inlet housing. A plurality of funnel shaped orifices guide the contaminants into the chamber and operate to resist blow out of the debris during liquid flashing conditions.

Abstract: A scroll compressor oil circulation system has the usual concentric bore oil pump which supplies lubricating oil to a chamber within which an impeller rotates. The rotating of the impeller within this chamber pumps lubricating oil through a passage which communicates with a control passage which injects a quantity of lubricant into the compression chambers of the scrolls for cooling and lubrication. The amount of oil injected into the compression chamber is controlled by the shape of the control passage through the orbiting scroll.

Abstract: A thermal protection system for a scroll compressor has a temperature sensor which is positioned directly within the discharge passage of the scroll compressor by being directed through an access passageway between the discharge zone and the suction zone of the compressor. The lead wires from the temperature sensor are wired in series with the normal motor temperature sensor circuit to provide the scroll discharge temperature control function as an integral part of the motor temperature control system located within the hermetic shell of the compressor. An additional embodiment of the present invention not only detects discharge gas temperatures but it also has the ability to detect the actual temperature of other selected compressor 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 machine has a shell and a muffler plate which defines a muffler chamber and a main chamber. The muffler plate has a face for engaging a seal which is disposed at an interface between the muffler chamber and the main chamber. The muffler plate has a structurally advantageous configuration incorporating a frusto-conical portion and a tubular portion, which reduces distortion of the face and thereby reduces leakage between the muffler and main chambers.

Abstract: A refrigeration compressor incorporating an improved suction muffler is disclosed. The suction muffler provides dual sound attenuating chambers within a single housing, which housing is secured to the suction inlet conduit extending between the motor cover and suction inlet for the compressor. The suction inlet conduit is increased in diameter between the motor cover and the compressor inlet to provide a stepped portion which operates to reflect pressure waves. Integrally formed openings in the sidewall of the conduit provide communication with each of the two chambers and the respective chambers may be tuned to attenuate different specific frequencies. Internal integrally formed baffles within each of the chambers serve to reduce standing waves within the chambers as well as adding stiffness to the muffler.

Abstract: A scroll machine designed to provide an unbalanced loading of the orbiting scroll and anti-rotation coupling in a direction which adds to the moment caused by contact forces between the scroll wraps during normal operation. The loading decreases the sound level of the machine and is achieved through the use of unbalanced flank gas leakage forces and flank contact forces, which are created by providing a targeted initial swing radius bias and/or a generating radius bias to either one or both of the scroll wraps. The generating radius biasing can be singular or plural on a given scroll wrap set. A number of different techniques for obtaining such biasing are disclosed.

Abstract: A scroll-type compressor is disclosed having a discharge diffuser for improving the efficiency of the compressor, especially at off-design, high pressure ratio operating conditions. The diffuser allows fluid pressure recovery and consequently results in an efficient discharge process using a relatively small discharge port. It also reduces compression losses by reducing gas transport in the reverse flow direction.

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: A suction conduit assembly mounting has a plurality of retaining tabs located at the open end of the suction conduit assembly which mates with a plurality of slots located in a motor cover of a compressor. The plurality of tabs are aligned with the plurality of slots, the suction conduit assembly is assembled to the motor cover and rotated into position. An integral annular sealing ring is located on the open end of the suction conduit assembly spaced inward from the plurality of retaining tabs. The assembly of the suction conduit assembly elastically deflects the annular sealing ring to effect a seal between the motor cover and the suction conduit assembly as well as eliminating any type of noise or rattle caused by relative movement of the two components.

Abstract: A scroll compressor has a fluid brake for resisting and impeding objectionable reverse movement of the orbiting scroll member. The brake includes a one-way clutch interconnecting a drive shaft and a paddle disposed in the compressor oil sump, and optionally a rotor shield for controlling oil flow around the lower end of the motor rotor. A two piece paddle has a rotatable paddle having blades to impart angular momentum to the lubricating oil and a stationary housing having vanes to resist the angular momentum imparted to the lubricating oil by the blades of the rotatable housing.

Abstract: A scroll-type machine is disclosed which incorporates a unique Oldham coupling for preventing relative rotation between the two scroll members while allowing relative orbital motion therebetween. The Oldham coupling is positioned below the end plate of the orbiting scroll member and includes a first pair of keys slidingly engaging slots in the orbiting scroll and a second pair of keys slidingly engaging slots in the non-orbiting scroll. An optional third key may be provided to slidingly engage a slot in the non-rotating bearing housing.

Abstract: A microprocessor based control system for controlling frost accumulation on the outdoor evaporator coil of a heat pumping system during normal heat mode operations. A demand defrost concept is implemented to increase efficiency and maximize time intervals between defrost cycles by initiating the defrost cycle only when an optimal maximum amount of frost has accumulated on the coil. The control system also facilitates monitoring of the rate of frost accumulation to make the outdoor coil conditions less favorable to frost buildup.

Abstract: Refrigerant is metered through the expansion valve based on compressor discharge temperature and ambient air temperature measurements. The microprocessor-based control system selects the appropriate stepper motor valve setting to achieve optimal performance. The temperature measurements used in the control system are decoupled from fluctuations due to shifting of the refrigerant dry out point. This allows the system to be operated at much lower superheat temperatures than heretofore attained, yielding improved performance and longer component life.

Abstract: The microprocessor-based control system optimizes efficiency of the ON/OFF cycle by shutting the expansion valve fully closed at the beginning of each OFF cycle to maintain system pressure differential. At the beginning of each ON cycle the expansion valve is opened to an initial larger than average of three openings to allow the system to quickly reach steady state operating levels. Thereafter, the valve opening is reduced to an average of the last three steady state settings. After a predetermined time, control of the valve opening is passed to an adaptive control algorithm which adjusts the valve setting for optimized performance during steady state.

Abstract: The microprocessor-based control system selects the appropriate indoor airflow (fan speed) to place the system in an optimal efficiency range. The indoor fan speed is further controlled based on humidity measurements, to produce a slower airflow when conditions are humid. This helps remove a greater amount of moisture from the air. Occupant comfort is enhanced by microprocessor control of the indoor fan speed to stay within the boundaries of the cooling mode comfort envelope.