Electric machine with permanent magnets between slotted rotor poles - has constant contribution to magnetic field from symmetrical magnets of rare-earth cobalt or other alloy at opposite sides of rotor.

摘要

The machine has a laminated stator and a corresp. rotor whose body (12) has slots (14) in its periphery for the winding conductors. Each half of the rotor has two groups (16,18) of slots separated by a symmetrical permanent magnet (20) preferably of SmCo5 or Nd-Fe-B alloy having about two-thirds of the width of a pole. The rotor magnets contribute a constant fraction of the magnetic field of the machine while the remainder is derived from the current flowing through the winding conductors. The magnetic material is characterised by a remanence of 1.0 to 1.3 T and a coercive force Ho = 0.6.10 power 6 A/m.