Electric motor and magnetic gear

摘要

An electric motor that can be used in driving a compressor and that incorporates a magnetic gear. The motor has high and low speed stators mounted within a motor casing side-by-side that drive coaxial low and high speed rotors also mounted within the motor casing for rotation and within the high and low speed stators. The high and low speed stators produce rotating magnetic fields that rotate in opposite directions to drive the rotors under application of a multiphase alternating current. The low speed rotor has a set of ferrous pieces, rotating with the low speed rotor and mounted thereon between the high speed rotor and the high speed stator. The ferrous pieces produce a magnetic gearing effect to drive the high speed rotor at a higher speed than the low speed rotor and in an opposite direction to the low speed rotor.

主权项

1. An electric motor comprising:
a motor casing; a high speed stator and a low speed stator mounted within the motor casing side-by-side; the high speed stator and the low speed stator each including winding systems having separate windings and electrical connections between the separate windings configured such that the separate windings are able to be separately exited by out-of-phase electrical currents generated by a multiphase alternating current source and thereby to produce magnetic fields emanating from stator pole pairs of the separate windings rotating around each of the high speed stator and the low speed stator in opposite directions when the windings are connected to the multiphase alternating current source; a low speed rotor mounted within the motor casing for rotation, coaxial to and surrounded by the high speed stator and the low speed stator, the low speed rotor having a first set of pole pieces mounted at one end thereof and opposite to the low speed stator such that the magnetic fields produced by the low speed stator are able to induce a rotation of the low speed rotor in a rotation direction of the of the magnetic fields produced by the low speed stator and a set of ferrous pieces mounted at the other end and opposite to the high speed stator and separated from one another by non-ferrous regions of the low speed stator so as to be able to conduct the magnetic fields produced by the high speed stator; a high speed rotor mounted within the motor casing for rotation coaxial to the low speed rotor and telescoped within the low speed rotor, the high speed rotor having a second set of pole pieces opposite to the ferrous pieces of the low speed rotor and the high speed stator; and the set of ferrous pieces of the low speed rotor present in a number equal to a sum of the stator pole pairs of the high speed stator and rotor pole pairs provided by the pole pieces of the high speed rotor so that motion of the ferrous pieces produced by the rotation of the low speed rotor in turn produces a gearing effect in which the high speed rotor rotates at a higher speed than the magnetic fields produced by the high speed stator and in an opposite direction thereto.