Self-supporting amortisseur cage for high-speed synchronous machine solid rotor

Claim 1

In a high-speed solid rotor machine wherein the rotor comprises: a cylindrical nonmagnetic hub; a plurality of circumferentially-spaced longitudinally-extending pole pieces affixed to the outer surface of said hub; a plurality of permanent magnets disposed between said pole pieces; a shrink ring surrounding and retaining said pole pieces and permanent magnets; said shrink ring maintaining said hub, pole pieces and magnets in a state of compression over the total operating speed range of the machine, the improvement comprising: a cylindrical amortisseur cage fabricated of electrically conductive sheet, fitting tightly about and radially-outward of said shrink ring, said cage including circular end portions joined by a plurality of spaced ribs disposed about the circumference of said shrink ring; and means exhibiting high tensile strength wound circumferentially under tension about said cage for retaining said cage in contact with said shrink ring against centrifugal force when said machine is operating.