Spindle synchronous motor with wide speed regulation range for lathe

The invention provides a spindle synchronous motor with a wide speed regulation range for a lathe. The spindle synchronous motor comprises a stator core, three-phase windings in stator grooves, a rotor core and permanent magnets which are embedded into the rotor core and are in special structures, wherein the stator core and the rotor core are formed by laminating silicon steel sheets and fixed by rivets; conductors in the stator grooves are the three-phase symmetrical windings; the permanent magnets are in layered and segmented structures; slender and nonuniform-width hollow holes are reserved into a rotor structure to form double-layer magnetic barriers; the hollow holes are symmetrically distributed on the two sides, close to the bottom of a rotating shaft, of each concave permanent magnet, and transversely arranged into quadrature axis magnetic circuits; a chamfered angle close to a stator side is larger; and a chamfered angle close to a rotating shaft side is smaller. According to the spindle synchronous motor, a new method of selecting the number of the stator conductors is provided, the magnetic potential of an armature reaction is improved by a novel rotor structure, the main magnetic flux is reduced, the output characteristic of the motor is optimized, and effects of improving the weak magnetism and increasing the maximum rotating speed are achieved, so that the speed regulation range of the spindle synchronous motor is greatly widened.