Cascaded rotary electric motors having axial and radial air gaps

A cascaded rotary electric motor comprising:

• a rotor comprising a plurality of annular rings configured about an axis of rotation and axially adjacent each other, each ring having disposed therein a plurality of permanent magnets;
• and
• a stator comprising a plurality of annular rings, each in concentric alignment with, and at least partially surrounded by, a respective one of the rotor rings, each stator ring comprising separated electromagnet core segments disposed coaxially about the axis of rotation;
• wherein
• two axial air gaps are formed between each stator ring and its respective rotor ring;
• each rotor annular ring has a U-shaped cross section with two ferromagnetic side walls connected by a cross wall, an inner surface of each of the side walls having permanent magnets mounted thereon, the mounted permanent magnets having surfaces facing one of the axial air gaps;
• and
• wherein the axially adjacent rotor annular rings are in contact with each other and share a common side wall.