Abstract: A refrigerant cycle is provided with an expansion device that is movable between a normal mode of operation and a low charge mode of operation. In the low charge mode of operation, the expansion device does not lower the pressure of the refrigerant as much as it does in its normal mode of operation. In this way, the relatively high pressure ratios that are experienced by a compressor during a low charge operation will not be experienced. Instead, the pressure ratio across the compressor is reduced during low charge operation, and the compressor will be better protected.

Abstract: A scroll compressor is provided with a clutch to minimize or eliminate the detrimental effects of reverse rotation. Generally, the clutch prevents rotation of the shaft during both powered and unpowered reverse rotation. The clutch could be subject to damage during powered reverse rotation, and thus a clutch protection mechanism is incorporated that will prevent the clutch from moving to an actuated position if powered reverse rotation occurs.

Abstract: A low cost protective clutch member is positioned adjacent an end of the drive shaft in a scroll compressor. The device is a thin washer having a tab which is selectively driven against the housing stop when the compressor is driven in a forward direction, but is movable into a notch in the shaft when the shaft is driven in a reverse direction. The tab prevents rotation of the shaft when in the notch.

Abstract: A two stage reciprocating compressor and associated HVAC systems and methods are disclosed. The reciprocating compressor includes a crankshaft having an eccentric crankpin, a reversible motor for rotating the crankshaft in a forward and a reverse direction, and an eccentric, two position cam rotatably mounted over the crankpin. The crankshaft and cam combine to cause the piston to have a first stroke when the motor operates in the forward direction and a second stroke when the motor operates in the reverse direction. The cam and crankpin also include stabilization means to restrict the relative rotation of the cam about the crankpin. A lubrication system is provided to lubricate the engaging surfaces of the crankshaft and cam and between the cam and the bearing surface of the connecting rod. There is also provided a control for selectively operating the motor either in the forward direction at a first power load or in the reverse direction at a reduced second power load.

Abstract: A scroll compressor is provided with a clutch to minimize or eliminate the detrimental effects of reverse rotation. Generally, the clutch prevents rotation of the shaft during both powered and unpowered reverse rotation. The clutch could be subject to damage during powered reverse rotation, and thus a clutch protection mechanism is incorporated that will prevent the clutch from moving to an actuated position if powered reverse rotation occurs.

Abstract: A number of improvements increase the flow of lubricant within a scroll compressor. A centrifugal oil separator is mounted on the discharge port to remove oil from the refrigerant. The oil is returned through a leak path such that the oil can easily return back to a suction pressure chamber. The leak path is preferably upstream of a check valve. Thus, at shutdown, the leak path will not allow upstream components to also equalize in pressure with the suction pressure chamber of the compressor. Further, a number of embodiments include ways of resisting flow of refrigerant through the leak path, while still allowing oil flow. A number of valve elements are described which perform this function. Alternatively, labyrinth flow paths, or positioning of the return paths such that it will be closed when the compressor is shut down are disclosed.

Abstract: A scroll compressor assembly includes a first linear drive for driving a first scroll along a first linear axis and a second linear drive for driving the first or second scroll along a second linear axis which is non-parallel to the first linear axis. Relative orbital movement between the first and second scrolls is obtained by controlling the frequency of oscillations of the first linear motor along a first linear axis and the second linear motor along the second linear axis. Further, capacity control is achieved by varying the movement of the first and second linear motors.

Abstract: A two-stage reciprocating compressor is provided. The compressor includes a block with a single cylinder and associated single compression chamber and single piston. The compressor further includes a crankshaft. The crankshaft has an eccentric crankpin that is operatively connected to the piston. A reversible motor is provided to rotate the crankshaft in a forward direction and in a reverse direction. An eccentric cam is rotatably mounted on the eccentric crankpin. The eccentric cam is held stationary with respect to the crankpin when the crankshaft is rotating in the forward direction. When rotating in the forward direction, the crankshaft drives the piston at a full stroke between a bottom position and a top dead center position. The eccentric cam rotates with respect to the crankpin when the crankshaft is rotating in the reverse direction. When rotating in the reverse direction, the crankshaft drives the piston at a reduced stroke between an intermediate position and the top dead center position.

Abstract: An improved motor protection switch incorporates a parallel feedback component mounted in parallel to a heater in a motor protection circuit. The parallel feedback component senses the temperature of a compressor component. If tie temperature increases then the current flow through the heater increases. This causes a motor protector switch to open. In this way, the feedback component provides feedback from the compressor pump unit to the motor protection circuit more quickly than in the prior art.

Abstract: A simplified drive arrangement is provided to allow a scroll compressor to be operated at two capacity levels by a reversible electric motor. A pair of one-way clutches are positioned on a pair of parallel shafts. When the motor is driven in a forward direction drive passes through one of the one-way clutches and directly to the orbiting scroll. However, when the motor is driven in a reverse direction, drive passes through a countershaft, which in turn passes through a second one-way clutch. The drive passing through the second one-way clutch will result in the orbiting scroll being driven at a distinct speed then when the motor is driven in a reverse direction. In this way, capacity modulation is achieved with a very simple mechanism.

Abstract: A scroll compressor is provided with structure between its slider block and its eccentric pin that allows relative movement, but limits such movement. In one embodiment, a spring biased piston resists relative movement between the slider block and the eccentric pin. In another embodiment, incrementally spaced indexed surfaces are defined. With either embodiment the amount of relative movement of the slider block is limited relative to the eccentric pin and hence between the wraps of the orbiting scrolls. This will result in quieter operation.

Abstract: A low noise scroll compressor assembly has an orbiting scroll supported for movement about an axis, and a non-orbiting scroll mounted to the crankcase housing along the axis. The non-orbiting scroll is mounted to the crankcase housing by at least one guide bushing that allows axial movement of the non-orbiting scroll relative to the orbiting scroll. A plurality of openings are arranged radially within mounting flanges projecting outward from the non-orbiting scroll. Each opening includes a guide bushing and a dampening bushing. The dampening bushing comprises a material that will absorb an impact force between the non-orbiting scroll and the guide bushing. Absorption of impact forces by the dampening bushing prevents the transmission of vibrations, thereby minimizing or preventing noise.

Abstract: An improved scroll compressor having an axially movable non-orbiting scroll eliminates the need for a separator plate. With the elimination of the separator plate, a back pressure chamber is provided to resist the discharge pressure which will be directed against a rear face of the non-orbiting scroll. In other embodiments, a seal on the rear of the non-orbiting scroll contacts the inner periphery of the end cap. Various ways of increasing the discharge pressure volume, or eliminating undesirable noise are also disclosed. Further, several ways of connecting the end cap to the center shell are also disclosed.

Abstract: A two stage reciprocating compressor and associated HVAC systems and methods are disclosed. The reciprocating compressor includes a crankshaft having an eccentric crankpin, a reversible motor for rotating the crankshaft in a forward and a reverse direction, and an eccentric, two position cam rotatably mounted over the crankpin. The crankshaft and cam combine to cause the piston to have a first stroke when the motor operates in the forward direction and a second stroke when the motor operates in the reverse direction. The cam and crankpin also include stabilization means to restrict the relative rotation of the cam about the crankpin. A lubrication system is provided to lubricate the engaging surfaces of the crankshaft and cam and between the cam and the bearing surface of the connecting rod. There is also provided a control for selectively operating the motor either in the forward direction at a first power load or in the reverse direction at a reduced second power load.

Abstract: A number of improvements increase the flow of lubricant within a scroll compressor. A centrifugal oil separator is mounted on the discharge port to remove oil from the refrigerant. The oil is returned through a leak path such that the oil can easily return back to a suction pressure chamber. The leak path is preferably upstream of a check valve. Thus, at shutdown, the leak path will not allow upstream components to also equalize in pressure with the suction pressure chamber of the compressor. Further, a number of embodiments include ways of resisting flow of refrigerant through the leak path, while still allowing oil flow. A number of valve elements are described which perform this function. Alternatively, labyrinth flow paths, or positioning of the return paths such that it will be closed when the compressor is shut down are disclosed.

Abstract: An improved scroll compressor having an axially movable non-orbiting scroll eliminates the need for a separator plate. With the elimination of the separator plate, a back pressure chamber is provided to resist the discharge pressure which will be directed against a rear face of the non-orbiting scroll. In other embodiments, a seal on the rear of the non-orbiting scroll contacts the inner periphery of the end cap. Various ways of increasing the discharge pressure volume, or eliminating undesirable noise are also disclosed. Further, several ways of connecting the end cap to the center shell are also disclosed.

Abstract: Scroll compressors having a non-orbiting scroll the type that moves axially for a limited distance are provided with an economizer fluid tube. The economizer tube is received within an opening in the non-orbiting scroll such that the non-orbiting scroll can move relative to the tube. This is an improvement over the prior art, and provides a more secure and simple connection.

Abstract: A scroll compressor includes a non-orbiting scroll wherein the base is sealed to the housing. That is, the non-orbiting scroll provides the function of the scroll member, and also the function typically provided by a separator. A heat shield is positioned between the discharge pressure chamber and the base of the non-orbiting scroll. Leakage paths are provided to allow refrigerant to communicate between the discharge pressure chamber and spaces between the heat shield and the non-orbiting scroll.

Abstract: A unique protection circuit for a sealed compressor incorporates oil structure which directs a heated oil onto a motor protection circuit. The motor protection circuit is of the type which shuts down operation of an electric motor when a predetermined temperature is sensed. The motor protection circuit is positioned adjacent to an oil return path which is opened when a high temperature is experienced in the compressor pump unit. The valve in the path opens to allow flow of the returned oil onto the motor protection switch. The motor protection switch is then actuated to stop further operation of the motor. In another embodiment, the motor protection switch is immersed in the oil sump. Again, when the oil temperature increases to a predetermined amount, the motor protection switch stops further operation of the motor.

Abstract: A scroll compressor is provided within a sealed housing. Although the invention is shown with regard to a scroll compressor, it should be understood that aspects of the invention have benefit to any type sealed compressor. A lower bearing is attached directly to a housing end cap. The lower bearing is easily and accurately attached to the end cap, and reduces the complexity and cost of assembly of a sealed compressor. In particular, the end cap is provided with upset portions spaced circumferentially by gaps. The bearing is secured to the upset portions by welding. Oil can flow through the gaps and into a space beneath the bearing such that it can reach oil passages in the shaft.