A positive displacement expander with an operating fluid chamber of expansive volume regulated by a shifting head. The shifting head may enhance rotation of a housing utilized to rotate a shaft for providing work to any of a variety of power retrieval devices. Additional efficiencies may also be realized through unique hydraulic layouts for circulating of the operating fluid from a heat exchanger, through the rotary device and to a cold exchanger for continuous operating of the rotary device.

A positive displacement expander with an operating fluid chamber of expansive volume regulated by a shifting head. The shifting head may enhance rotation of a housing utilized to rotate a shaft for providing work to any of a variety of power retrieval devices. Additional efficiencies may also be realized through unique hydraulic layouts for circulating of the operating fluid from a heat exchanger, through the rotary device and to a cold exchanger for continuous operating of the rotary device.

The disclosed invention provides an unmodified scroll compressor with enhanced oil management system that enables the compressor system to compress helium. The compressor system includes a standard scroll compressor, oil separator, and an adsorber. The compressor includes a housing containing an orbiting scroll and a stationary scroll, a motor, and an oil sump in a bottom of the housing. The stationary scroll has one or more injection ports, and the housing contains a single discharge port, a return port, and a single injection port connected to the injection ports of the stationary scroll. The oil separator receives a mixture of helium and oil from the discharge port. The compressor system further includes a line bringing a first fraction of oil from the oil separator to the injection port, one or more lines bringing a second fraction of oil to the return port along with helium. The adsorber retains a third fraction of oil.

The disclosed invention provides an unmodified scroll compressor with enhanced oil management system that enables the compressor system to compress helium. The compressor system includes a standard scroll compressor, oil separator, and an adsorber. The compressor includes a housing containing an orbiting scroll and a stationary scroll, a motor, and an oil sump in a bottom of the housing. The stationary scroll has one or more injection ports, and the housing contains a single discharge port, a return port, and a single injection port connected to the injection ports of the stationary scroll. The oil separator receives a mixture of helium and oil from the discharge port. The compressor system further includes a line bringing a first fraction of oil from the oil separator to the injection port, one or more lines bringing a second fraction of oil to the return port along with helium. The adsorber retains a third fraction of oil.

This invention provides a means to start an oil lubricated air cooled helium compressor at ambient air temperatures in the range from 30 C. to 0 C. by heating the oil in the sump and opening one or more by-pass valves that allows oil to flow to the oil injection port of the compressor without passing through all of the after-cooler.