Abstract: A thermodynamic system that can approximate the Ericsson or Brayton cycles and operated in reverse or forward modes to implement a cooler or engine, respectively. The thermodynamic system includes a device for compressing a first fluid stream containing a first gas-liquid mixture having a sufficient liquid content so that compression of the gas within the first gas-liquid mixture by the compressing device is nearly isothermal, and a device for expanding a second fluid stream containing a second gas-liquid mixture having a sufficient liquid content so that expansion of the gas within the second gas-liquid mixture by the expanding device is nearly isothermal. A heat sink is in thermal communication with at least the liquid of the first gas-liquid mixture for transferring heat therefrom, and a heat source is in thermal communication with at least the liquid of the second gas-liquid mixture for transferring heat thereto.

Abstract: A number of embodiments are disclosed in which scroll compressor elements are actuated upon a particular condition being sensed within the scroll compressor. Upon the condition being sensed, elements are actuated which restrict the orbit radius of the orbiting scroll. In this way, conditions such as low charge, reverse rotation, and low suction pressure are encountered with little damage to the scroll compressor.

Abstract: A vent is included into a scroll compressor for protecting a refrigerant system in the event of loss of charge. The vent selectively taps an entrapped compression chamber to a housing chamber which surrounds the motor. In the event of a low charge, the gas in the compression chamber will be at a high temperature, and will heat the motor when the vent opens. The vented heated gas will then actuate a temperature protection device on the motor, causing the motor to stop rotation. In further embodiments, the compression chamber which supplies the tapped fluid is the discharge port.

Abstract: A scroll compressor is assembled by force-fitting the pump unit and the lower bearing into the generally cylindrical outer housing. The force-fit holding strength is increased by providing both the crankcase and the bearing support with cylindrical portions. Thus, force-fit holding strength is provided over the entire periphery of the elements. The structure preferably takes the outer housing beyond its plastic yield point, also increasing the hold strength. In this way, the relatively simple method of force-fitting may be utilized to assemble the scroll compressor, while still achieving acceptable holding force.

Abstract: A scroll compressor has a valve normally closed during forward operation of the scroll compressor. Upon reverse rotation, force imbalances allow the valve to open and communicate a chamber downstream of a check valve to a chamber upstream of the check valve. By communicating these two chambers, the detrimental effects of reverse rotation are reduced or eliminated. Two valve embodiments are disclosed. One embodiment also relieves unduly high discharge pressures. In a third embodiment, a pressure relief valve is provided to prevent desirably high pressure ratios or pressure differentials.

Abstract: A scroll compressor having an apparatus for minimizing oil leakage during reverse running is provided. The compressor includes a suction tube for allowing gas to enter the compressor housing. One oil minimizing apparatus is a check valve disposed at the suction tube having a spring normally biased against the inlet suction tube so as to prevent oil from exiting the suction tube during reverse running of the motor of the compressor. An alternative oil minimizing apparatus is an oil dam extending longitudinally above the suction tube on an inner surface of the compressor housing. The oil dam bends circumferentially with the inner surface for draining oil along the inner surface away from the suction tube.

Abstract: A scroll compressor is provided with structure that causes the wraps to move out of engagement when reverse rotation occurs. An eccentric pin and slider block are constructed such that when forward rotation is occurring, flat surfaces on the pin and slider block are brought into contact to drive the slider block and hold the wraps in engagement. However, when reverse rotation occurs, the flat surfaces move out of engagement. The slider block has a pivot point which moves into contact with the eccentric pin. The slider block pivots relative to the eccentric pin, and the wraps of the scroll members are brought out of engagement.

Abstract: A scroll compressor is provided with a reverse rotation detection circuit that monitors the temperature adjacent the suction tube. An elevated temperature at the suction tube is indicative of reverse rotation, and if the temperature exceeds a predetermined maximum, then a determination is made that reverse rotation is occurring. Once this determination is made, the rotation of the motor is stopped, or corrected.

Abstract: A scroll compressor of the type having a cantilever mounted shaft is provided with a carbon crankcase bearing. Further, the bearing mounting the eccentric pin within the orbiting scroll is also formed of a carbon material. The bearing mounting the lower end of the shaft is further formed of the carbon material. The carbon bearing insures that the shaft will be quickly worn away should there be shaft misalignment.

Abstract: A scroll compressor of the type having a cantilever mounted shaft is provided with a carbon crank case bearing. The carbon bearing insures that the shaft will be quickly worn away should there be shaft misalignment.

Abstract: A number of scroll compressor designs protect the back chamber seals upon reverse rotation. In the prior art, scroll compressors are sometimes miswired and inadvertent reverse rotation results. In some applications, this has caused the seals to be crushed. The present invention ensures that upon reverse rotation, the pressure within the back chamber is maintained at suction pressure rather than the very low pressure which may be found in the compression chambers. The seals are protected. In one embodiment, a relief is formed at a seal groove to ensure suction pressure does communicate into the back chamber. In other embodiments, a valve controls the pressure in the back chamber. Upon normal operation, the valve allows pressure from the back pressure tap to communicate into the back chamber. During reverse rotation, the valve allows suction pressure to communicate to the back chamber.

Abstract: Simplified capacity control mechanisms for scroll compressors include a fork operable to open and close vents associated with a pair of scroll compression chambers. A single fork opens and closes both vents simultaneously. In the past, separate members have been utilized to open and close the two individual valves, and they have sometimes been actuated in a non-synchronous manner. A control associated With the fork is operable to move the fork between the open and closed positions by simple electronic controls. In several embodiments, the electronic controls are operated simply to stop and start the electric motor for driving the compressor. Pressure forces on and associated valve element move the fork to the desired position between the open and closed positions. No separate control wires, or separate electronic valves, need to pass into the scroll housing. In another embodiment, an electric solenoid is actuated to move the fork between open and closed positions.

Abstract: A vent is included into a scroll compressor for protecting a refrigerant system in the event of loss of charge. The vent selectively taps an entrapped compression chamber to a housing chamber which surrounds the motor. In the event of a low charge, the gas in the compression chamber will be at a high temperature, and will heat the motor when the vent opens. The vented heated gas will then actuate a temperature protection device on the motor, causing the motor to stop rotation. In further embodiments, the compression chamber which supplies the tapped fluid is the discharge port.