Hybrid induction motor with self aligning permanent magnet inner rotor
OwnerLouis J. Finkleinventor
Life of this patent
Estimating the term…
Abstract
A hybrid induction motor includes an inductive rotor and an independently rotating permanent magnet rotor. The inductive rotor is a squirrel cage type rotor for induction motor operation at startup. The permanent magnet rotor is axially displaced and variably coupled to the inductive rotor (or to a motor load) through a clutch and is allowed to rotate independently of the inductive rotor at startup. The independently rotating permanent magnet rotor quickly reaches synchronous RPM at startup. As the inductive rotor approaches or reaches synchronous RPM, the coupling between the inductive rotor and the permanent magnet rotor increases until the two rotors are coupled the synchronous RPM and the motor transitions to efficient synchronous operation.
Claims20
A hybrid permanent magnet/induction motor, starting as an induction motor and transitioning to synchronous operation, the motor comprising:
- a motor shaft;
- a fixed stator creating a rotating stator magnetic field;
- a rotating rotor comprising:
- an inductive rotor co-axially fixed to the motor shaft and including a squirrel cage to induce current;
- and
- a permanent magnet rotor residing coaxially with the motor shaft and axially displaced from the inductive rotor and variably rotationally coupled to the motor shaft allowing the permanent magnet rotor to rotate independently of the motor shaft at startup and low speed and increasing coupling with the motor shaft as the permanent magnet rotor approaches synchronous speed, the permanent magnet rotor and inductive rotor residing sequentially end to end on the motor shaft, not overlapping;
- wherein the stator magnetic field cooperates with the squirrel cage to induce current in the inductive rotor whenever the rotation of the inductive rotor is not in sync with the rotation of the stator magnetic field and the stator magnetic field cooperates with the permanent magnet rotor to accelerate the rotation of the permanent magnet rotor to be in sync with the rotation of the stator magnetic field.
A hybrid permanent magnet/induction motor, starting as an induction motor and transitioning to synchronous operation, the motor comprising:
- a motor shaft;
- a fixed stator creating a rotating stator magnetic field;
- a rotating rotor comprising:
- an inductive rotor co-axially fixed to the motor shaft and including a squirrel cage to induce current;
- and
- a permanent magnet rotor coaxially with the motor shaft and axially displaced from the inductive rotor and variably rotationally coupled to the motor shaft allowing the permanent magnet rotor to rotate independently of the motor shaft when the inductive rotor is rotating at low RPM and to increasingly couple the permanent magnet rotor to the motor shaft as the inductive rotor approaches synchronous RPM,
- wherein the stator magnetic field cooperates with the squirrel cage to induce current in the inductive rotor whenever the rotation of the inductive rotor is not in sync with the rotation of the stator magnetic field and the stator magnetic field cooperates with the permanent magnet rotor to accelerate the rotation of the permanent magnet rotor to be in sync with the rotation of the stator magnetic field.
A hybrid permanent magnet/induction motor, starting as an induction motor and transitioning to synchronous operation, the motor comprising:
- a motor shaft;
- a fixed stator creating a rotating stator magnetic field;
- a rotating rotor coaxial with the motor shaft and comprising:
- an inductive rotor fixed to the motor shaft and including a squirrel cage to induce current;
- and
- a permanent magnet rotor coaxially with and axially displaced from the inductive rotor and variably rotationally coupled to the inductive rotor through a centrifugal clutch allowing the permanent magnet rotor to rotate independently of the inductive rotor when the inductive rotor is rotating at low RPM and to increasingly couple the permanent magnet rotor to the inductive rotor as the inductive rotor approaches synchronous RPM at startup and low speed and increasing coupling with the motor shaft as the permanent magnet rotor approaches synchronous speed, the permanent magnet rotor and inductive rotor residing sequentially end to end on the motor shaft, not overlapping,
- wherein the stator magnetic field cooperates with the squirrel cage to induce current in the inductive rotor whenever the rotation of the inductive rotor is not in sync with the rotation of the stator magnetic field, and the stator magnetic field cooperates with the permanent magnet rotor to accelerate the rotation of the permanent magnet rotor to be in sync with the rotation of the stator magnetic field.
Dependencies are inferred from the claim text.