ENERGY TRANSFER MACHINE FOR CORROSIVE FLUIDS

An internal gear pump or motor includes inner and outer rotors that mesh together. An internal electric motor or generator may include a stator supported by a support element that passes through bearings of the outer rotor and the inner rotor may act as a rotor of the electric motor or generator. With or without the stator, the support element may support bearings of the inner rotor. The support element may be, for example, an eccentric shaft. Fluids may be supplied via the support element, if present, for cooling, lubrication or to flush a working fluid out of portions of the pump or motor, such as bearings. Flushing may also occur via channels in the housing with or without the presence of the support element. Axial faces of one of a pair of adjacent elements, for example the inner rotor and the outer rotor, may include portions for improved axial sealing and wearing in of the other of the pair. Fluid may enter and exit chambers between the inner and outer rotors by radial ports