1. US20110209480 - Rotary compressor-expander systems and associated methods of use and manufacture

The present technology is directed generally to rotary displacement systems and associated methods of use and manufacture. The systems can be used to compress and/or expand compressible fluids. In some embodiments, the rotary displacement systems include a chamber housing having a pressure-modifying chamber with a first port and a second port, a first passageway in fluid communication with the chamber via the first port, and a second passageway in fluid communication with the chamber via the second port. The systems can further include a shaft positioned within the chamber housing and rotatable relative to the chamber housing about a rotational axis, and a rotor comprising no more than two lobes. The rotor can be carried by and rotatable relative to the shaft, and can be alternately operable in a first mode in which flow is provided from the first passageway to the second passageway via the chamber and in a second mode in which flow is provided from the second passageway to the first passageway via the chamber.