Abstract: An impeller has a plurality of rotating passageways which can be defined between adjacent blades, the blades having a curved root portion and able to pivot across a part spherical hub to maintain a fine line contact. The passageways have a convergence to improve the efficiency of the impeller. The hub can be split into two relatively rotating portions, with the blades attached to each portion to provide an efficient means to vary the pitch of the blades.

Abstract: A pressure boost impeller configured for compressing fluids, such as gases and liquids. Such impeller has a front intake area and a rear discharge area, and a hub containing the rotational axis of the impeller. Several blades extend about the hub, with some of the blades being in an overlapping relationship to define a passageway between adjacent blades. The passageway has an inlet communicating with the front intake area and an outlet communicating with the rear discharge area. The inlet is greater in area than the outlet, thus defining a step down in volume of fluid passing through the passageway.