Abstract: A scroll compressor has lubricant flow which passes lubricant over a portion of a compressor pump set which will be at an elevated temperature under certain adverse conditions. If the adverse conditions are occurring, then this lubricant will reach an elevated temperature. This lubricant is returned over a motor protector such that it can cause the motor protector to trip and stop further operation of the scroll compressor. The flow of lubricant can be selective, and only occur when a predetermined temperature is reached by a sensing unit, or can be ongoing.

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 variable size is provided for a discharge port in a scroll compressor. The variable size is movable dependent on conditions within the scroll compressor to achieve a desired pressure ratio based upon operational conditions in the compressor or an associated refrigerant cycle. In one embodiment a plunger moves axially to increase or decrease the size of a discharge port. In a second embodiment, the plunger rotates about an axis and has a groove that is selectively aligned with the port to increase or decrease the effective size of the port.

Abstract: A scroll compressor is provided with a motor protector for stopping operation of its motor should conditions be indicative of a problem. The motor protector is sensitive to elevated temperature, and stops operation of the motor should a sensed temperature exceed a predetermined maximum. The motor protector is positioned in a chamber in a rear face of a base of the non-orbiting scroll. A port extends through the base of the non-orbiting scroll to connect a motor protector chamber to a suction chamber. Electric wires connect the motor protector to the motor and extend through this same port. In some embodiments, a pressure relief valve also communicates with the motor protector chamber. In one embodiment the motor protector chamber is enclosed by a cap and the pressure relief valve is mounted in that cap. In another embodiment the pressure relief valve extends through a wall of the non-orbiting scroll. In other embodiments, a pair of mating plugs connect the protector to the motor.

Abstract: A compressor diagnostic system incorporates a control which receives a plurality of data streams about various operational features of the compressor. As an example, both temperature and pressure of the suction and discharge refrigerant are taken and sent to the control. Moreover, information with regard to the power being supplied to the motor is taken and stored. All of this information is utilized at a control which compares the information to expected values and determines a fault based upon the evaluation. Moreover, in another feature of this invention, much of this data is stored, and maintained at the compressor. In the event of a compressor failure, this stored information will provide a maintenance worker with a good indication of why the compressor failed.

Abstract: Motor protectors are positioned in a location in a scroll compressor where they are cooled by suction refrigerant flow. If the volume of refrigerant flow decreases, then the cooling effect also decreases. In this way, the protector becomes more sensitive to the mass flow of refrigerant. Thus, the motor protector is more likely to trip in a loss of charge situation.

Abstract: A system includes a motor mounted within a housing and a compressor pump unit. A single-phase PSC motor includes a switch assembly which selectively connects primary or alternate windings. During normal load operation, when maximum efficiency is desired, the switch is placed in one position, then during high load operation, when maximum torque output is needed at maximum a load point, the switch is placed in the closed position. In effect, the number of main winding turns is decreased and the motor is strengthened. As the auxiliary capacitors are also now connected in parallel, the net effect is an increase in the total auxiliary capacitance, which also serves to strengthen the motor. Another embodiment provides a switch for a three-phase WYE connected motor. In yet another embodiment, a three phase delta connected motor switch is provided.

Abstract: An unloader valve for a scroll compressor to selectively communicate suction and discharge is positioned outwardly of the compressor housing. In this way, the unloader valve is ideally positioned to address several system failures. As an example, loss or charge, reverse running, fan failure, etc. are all addressed in an efficient and quick manner. The unloader valve may be the normal unloader valve controlled by a system control which also selectively controls capacity. The unloader valve control is modified such that it is also operable to open the unloader valve when a system failure is detected.

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 scroll compressor is provided that has greater control over the compressed volume by having a plurality of sequentially spaced unloader valves and associated holes. By providing the plurality of valves, a control achieves greater variation over the final compressed volume. The present invention is most preferably utilized in the type of scroll compressor having a hybrid wrap geometry to provide an increased volume of refrigerant adjacent the suction area of the compressor.

Abstract: A scroll compressor is provided with a thermostat selectively closing when predetermined temperatures are reached to deliver current to a heater associated with a motor protector switch. The thermostat is able to more quickly close in response to undesirable conditions in the compressor, than would be the case with the motor protector switch typically found at the motor. The circuit associated with the motor protector switch preferably includes at least two heaters, with the normal heater associated with the power lines leading to the motor performing its normal function. The thermostat is preferably associated with an auxiliary heater. In another feature, a heater is preferably formed with a thick film technology directly onto an insulator element within the motor protector body.

Abstract: A compressor diagnostic system incorporates a control which receives a plurality of data streams about various operational features of the compressor. As an example, both temperature and pressure of the suction and discharge refrigerant are taken and sent to the control. Moreover, information with regard to the power being supplied to the motor is taken and stored. All of this information is utilized at a control which compares the information to expected values and determines a fault based upon the evaluation. Moreover, in another feature of this invention, much of this data is stored, and maintained at the compressor. In the event of a compressor failure, this stored information will provide a maintenance worker with a good indication of why the compressor failed.

Abstract: An inventive scroll compressor has its motor protector circuit mounted on the compressor pump unit. In this way, increased temperature from reverse rotation of the orbiting scroll causes the motor protector unit to quickly stop operation of the motor. Preferably, the motor protector unit is mounted on the non-orbiting scroll.

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 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 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 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: 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.