Patent ID: 8878409

Claim:
A rotor comprising: a rotor body for rotation about a shaft; a plurality of permanent magnets spaced circumferentially about said rotor body; a containment band positioned radially outwardly of said permanent magnets, said containment band having a containment band coefficient of thermal expansion, and said permanent magnets having a permanent magnet coefficient of thermal expansion, taken parallel to a magnetic alignment, and a ratio of said containment band coefficient of thermal expansion to the permanent magnet coefficient of thermal expansion is between 0.9 and 1.15; a thickness of said containment band taken in a radial direction, and a ratio of said thickness to a diameter of said rotor is between 0.00375 and 0.040, and said rotor for use in a machine operating at a speed range of between 12,000 and 30,000 RPM; and said containment band material is a stainless steel.