AC synchronous motor having an axially laminated rotor

Claim 1

In an ac synchronous reluctance motor provided with a rotor having a central shaft along its axis of rotation and having a plurality of even-numbered rotor poles with each rotor pole having a pole center, wherein the pull-in torque, pull-out torque, power factor and efficiency of the motor are related to the ratio of direct axis reactance to the quadrature axis reactance of the motor, said ratio being predetermined for each such motor, the improvement comprising: (a) a plurality of rotor segments with each rotor segment extending axially parallel to said axis of rotation and extending angularly from a pole center to an adjacent center and adjacent portions of adjacent rotor segments comprising one-half of a rotor pole; (b) each of said rotor segments comprised of (i) a plurality of magnetic sub-segments, and (ii) a plurality of electrically conductive sub-segments interspersed with said magnetic sub-segments; (c) each of said magnetic sub-segments comprised of (i) a plurality of laminations of soft magnetic material extending axially parallel to the axis of said shaft, and (ii) non-magnetic material extending axially parallel to the axis of said shaft and positioned intermediate the laminations of soft magnetic material, (d) said laminations of soft magnetic material of said magnetic sub-segments providing decreased direct axis reluctance thereby increasing the direct axis reactance and said non-magnetic material of said magnetic sub-segments providing increased quadrature reluctance thereby decreasing quadrature axis reactance whereby the ratio of direct axis reactance to quadrature axis reactance is increased and the pull-in torque, pull-out torque, power factor and efficiency of the ac synchronous reluctance motor are improved.