摘要 |
There is described a torque tool comprising a synchronous reluctance motor. The torque tool comprises an electrical machine drive system, an electronic controller and a gear system. The drive system comprises a rotor and a stator arranged around the rotor. The rotor is attached to a motor shaft and comprises a pattern of regions of relatively high magnetic permeability interspersed with regions of relatively low magnetic permeability extending generally parallel to the motor shaft such that there is a plurality of magnetic poles distributed circumferentially around the motor shaft. The stator comprises electrical windings dispersed in slots disposed around an inner surface of the stator, the slots extending generally parallel to the motor shaft such that, when current flows in the windings, a stator magnetic field generated by the current has the same number of magnetic poles as the rotor. The electronic controller is configured to control the current flow in the stator windings to cause the stator poles to rotate in synchronism with rotation of the motor. The gear system is mechanically coupled to the motor shaft and configured to apply torque to a mechanical |