Synchronous motor

Claim 1

In a synchronous motor, a pair of circular permanent magnet means respectively having equal diameters and respectively surrounding a common axis while being situated adjacent each other respectively on opposite sides of a plane normal to said axis, each of said permanent magnet means having a series of N and S poles alternating with each other and circumferentially distributed about said axis and the number of N and S poles of one of said permanent magnet means equalling the number of N and S poles of the other of said permanent magnet means while being angularly offset with respect thereto to provide a predetermined out-of-phase relationship between the poles of said pair of permanent magnet means, a pair of circular coil means which have equal diameters respectively surrounding and spaced from said pair of permanent magnet means and also situated adjacent each other on opposite sides of said plane for respectively receiving alternating currents of the same frequency which have with respect to each other the same out-of-phase relationship as the poles of said pair of permanent magnet means, a circular magnetic plate situated in said plane between said pair of coil means for separating the latter from each other, said plate having an inner circumferential edge defining a circle whose center is in said axis and whose diameter is larger than the diameter of each of said permanent magnet means, said plate, said pair of coil means, and said pair of permanent magnet means all being stationary and forming part of a stator of the motor, a single rotor interacting with both permanent magnet means and both coil means, and support means supporting said rotor for rotary movement around said axis, said rotor having a cylindrical wall coaxially surrounding said axis and situated between said pair of permanent magent means, and said pair of coil means and plate, with said cylindrical wall of said rotor having an inner surface directed toward said pair of permanent magent means and an outer surface directed toward said pair of coil means and said plate therebetween, said cylindrical wall having a plurality of axially extending elongated cutouts circumferentially distributed about said axis and separated from each other by elongated portions of said cylindrical wall which extend substantially pArallel to said axis, the number of poles of each of said permanent magnet means being an even multiple of the number of said elongated portions of said cylindrical wall and the latter elongated portions of said cylindrical wall being uniformly distributed circumferentially around said axis.