Rotorestator

Rotorestator is a term used in some engineering discussions to describe a family of electromechanical devices in which aspects of a rotor and stator are combined within a compact or coaxial arrangement. The concept arises from attempts to improve torque density and packaging by reducing the axial length or by integrating magnetic components into a single rotating assembly. In rotorestator designs, one may have a rotor that carries either windings or magnets while the stator is fixed, or a shared assembly where rotating and stationary magnetic elements are integrated in a common housing. Both permanent-magnet and wound-field variants have been proposed.

Advantages cited for rotorestator approaches include higher power density, shorter machine length, and potential simplifications in cooling or electrical connections for small or specialized devices. Limitations include increased manufacturing complexity, tighter tolerances, heat management challenges, and potential issues with magnetic flux leakage and acoustic noise unless carefully engineered. Because the term is not standardized and the designs vary, rotorestator configurations are most commonly found in niche or research contexts rather than as a conventional category of electric machines.

In usage, some researchers describe rotorestator concepts as alternatives to conventional rotor-stator machines for compact electric motors, generators, or hybrid systems. Etymology derives from the two primary components, rotor and stator.