This invention relates to high-density discoidal brushless induction open frame motors and generators with multistacking, multiphasing and multistaging capability. These motors may be in the range from 10 hp to 25,000 hp or more and these generators may range from 10 kVA to 10 megawatts or more. Rare earth permanent magnets or wound DC field poles are arranged about a disk shaped rotor. A rectangular toroidal lamination core within the stator element serves as the mounting for numerous flat wound armature coils. The heat generated by the high flux and current densities is dissipated by a liquid cooling arrangement built into the toroidal stator element. The absence of the need to use the frame as a flux return path allows light weight aluminum to be used without a loss in efficiency. The open frame structure allows for easy cascading of multiple units along the same shaft for higher capacity.