摘要 |
A synchronous motor which has a ring-shaped stator with a radially magnetized ring-shaped permanent magnet and an external housing of a material of high permeability to complete the magnetic circuit. At the inner side of this ring-shaped stator lies a rotor having a central core provided at its ends with pole rings of a material of high permeability. The coil of the motor is provided in the center of the stator and mounted between the pole rings. This construction gives rise to a high magnetic flux in the permanent magnet in the region of the poles of the rotor, which in turn, provides a high driving torque; while the rotor is made exclusively of material of high permeability, having a low weight and a low moment of inertia. Such motors, even when constructed to operate at relatively high power, are thus assured of positive starting. |