Electric machine with a transformer having a rotating component
AssigneeColeman Powermate, Inc.
InventorsHarold C. Scott, Gary W. Johnson
Life of this patent
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Abstract
An electric machine according to various aspects of the invention includes a transformer having a rotating component for transmitting power from a stationary portion of the machine to a rotating portion of the machine, or vice versa. Both the rotating component and a stationary component of the transformer includes a winding, wherein the windings are disposed to be magnetically coupled. Current provided to the winding of the stationary component generates a magnetic field, which induces current in the winding of the rotating component.
Claims30
An electric machine, comprising:
- a rotating portion including a rotor winding;
- a stationary portion;
- means juxtaposing said rotating portion with said stator portion for mutual rotation such that magnetic coupling therebetween defines a rotational frequency;
- a transformer with first and second windings, said first winding attached to said stationary portion and said second winding attached to said rotating portion and magnetically coupled to said first winding, such that current flowing in one of said windings induces current in the other of said windings;
- and
- a variable power source connected to said first winding to provide variable power to said second winding;
- and
- means electrically coupling said second winding to said rotor winding.
A brushless electric machine comprising:
- a rotatable assembly including a rotor winding disposed thereon;
- a stator including a main winding and an excitation winding disposed such that rotation of said rotatable assembly causes magnetic fields generated by said rotor winding to induce current in said stator main winding and said stator excitation winding;
- a rotating transformer winding disposed to rotate with said rotatable assembly and connected to provide current to said rotor winding;
- a stationary transformer winding magnetically coupled to said rotating transformer winding so that current through said stationary transformer winding generates a magnetic field to induce current in said rotating transformer winding to supply current to said rotor winding;
- and
- a variable power source coupled intermediate said stator excitation winding and said stationary transformer winding to regulate the current through said stationary transformer winding.
A brushless portable generator comprising:
- an engine having a rotating shaft;
- a rotor assembly coupled at a proximal end to said engine shaft, said rotor assembly including a rotor excitor winding;
- a stator including a main winding and an excitation winding, said stator disposed with respect to said rotor assembly such that rotation of said rotor assembly causes magnetic fields generated by said rotor excitor winding to induce current in said main winding and said excitation winding at an electrical rotational frequency dependent upon the rate of rotation of said rotor assembly;
- a transformer having a stationary portion with a primary winding electrically coupled to said stator excitation winding and a rotating portion with a secondary winding electrically coupled to said rotor excitor winding, where
- said rotating portion is disposed at said distal end of said rotor assembly;
- and
- said stationary portion is disposed adjacent to and axially aligned with said rotating portion, with said primary winding magnetically coupled to said secondary winding such that current flowing in said primary winding induces current in said secondary winding.
The portable generator of claim of 24 further including a sensor for generating a feedback signal indicative of an output voltage across said main stator winding, where said feedback signal is applied to said inverter to control modulation of said AC signal at said transformer primary winding.
Dependencies are inferred from the claim text.