Self-starting miniature synchronous motors

Claim 1

A self-starting miniature synchronous motor comprising a rotor provided with a plurality of equally spaced poles of alternate polarities; the number of the pole pairs n being equal to or larger than 5, where n represents an odd integer, a pair of first and second stators having opposed semicircular portions each of the same diameter and both stator diameters being greater than the diameter of the rotor and arranged to surround the rotor; a single exciting coil for exciting said pair of stators; the centers of the semicircular portions of said pair of stators being located at points displaced from the axis of rotation of said rotor such that said semicircular portions will be point symmetrical with respect to the axis of rotation of the rotor, the semicircular portions of the first and second stators being respectively formed with main pole pieces at the adjacent portions thereof, notches at other portions, and interpole pieces adjacent the main pole pieces which are located closest to said rotor, the radial spacing of said interpole pieces from said rotor being greater than the spacing of said main pole pieces located closest to said rotor and less than the spacing of the other main pole pieces from said rotor such that a large torque is applied to the rotor irrespective of the angular position thereof thus positively self-starting the rotor without a dead center condition.