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US 9,431,884 B2Granted
Dual rotor switched reluctance machine
AssigneeCaterpillar Inc.
InventorKrishnakumar D. Ramamoorthy
Life of this patent
Estimating the term…
Abstract
A dual rotor switched reluctance machine with a fixed stator and separate input and output rotors on either side of the fixed stator is used to transmit power between a power source such as an gas engine and a mechanical drive unit such as wheels or tracks. A switched reluctance motor configuration, such as a 6/4 motor can be combined with a with a higher pole count switched reluctance generator to allow simultaneous operation of the dual rotor machine as both a generator and a motor. Because the fixed stator has the only set of windings the control electronics are greatly simplified over separate motor-generator configurations.
Claims18
An energy conversion machine comprising:
- the energy conversion machine comprising a dual rotor switched reluctance machine including a stator, an input rotor, an output rotor, and a single converter;
- the stator having a cylindrical shape with an inner circumference and an outer circumference, the stator fixedly mounted and having poles, each pole having an electrical winding and extending radially from the inner circumference of the cylindrical shape of the stator to the outer circumference of the cylindrical shape of the stator;
- the input rotor rotatably mounted adjacent to one circumference of the stator, the input rotor free of both windings and permanent magnets and coupled to a first driveshaft configured to transmit power between the input rotor and a power source;
- the output rotor rotatably mounted adjacent to the other circumference of the stator, the output rotor free of both windings and permanent magnets and coupled to a second driveshaft configured to transmit torque between a mechanical load and the output rotor;
- the single converter including control electronics coupled to the electrical winding of each pole and a controller, the control electronics including a transistor pair for each stator phase that captures electrical energy generated by the input rotor and delivers electrical energy to the output rotor, each stator phase including two stator poles;
- and
- wherein the controller selectively energizes the stator electrical windings of one or more stator poles extending between the input rotor and the output rotor to transfer electrical energy and torque developed between the input rotor and the stator directly to the output rotor without externally storing or converting electrical energy separate from the single converter.
4 more elements
A method of converting energy from a power source to a mechanical load comprising:
- providing a switched reluctance machine with a first rotor free of both windings and permanent magnets, a second rotor free of both windings and permanent magnets, a single converter, and a stator, the stator fixedly mounted with respect to the first rotor and the second rotor and the stator having a cylindrical shape and poles extending from an inner circumference of the cylindrical shape of the stator to an outer circumference of the cylindrical shape of the stator, each stator pole having an electrical winding and electrically energized with a corresponding, axially opposite stator pole;
- providing the first rotor and the second rotor overlapping the stator, and mounting the first rotor adjacent to one of the inner circumference and the outer circumference of the stator, and mounting the second rotor adjacent to the other of the inner circumference and the outer circumference of the stator;
- providing the stator with a plurality of phases, each phase including two stator poles;
- providing the single converter, the single converter including control electronics coupled to the electrical winding of each stator pole and a controller, the control electronics including a transistor pair for each stator phase that captures electrical energy generated by the first rotor and delivers electrical energy to the second rotor;
- receiving power from the power source at the first rotor via a first driveshaft coupled to the first rotor;
- energizing, via the controller, the electrical windings of a first stator pole extending between the input rotor and the output rotor during a stoke angle of the second rotor;
- concurrent with the energizing of the first stator pole, the controller energizing the electrical windings of a second stator pole extending between the input rotor and the output rotor once for each pole of the first rotor that passes the second stator pole, the second stator pole adjacent to the first stator pole;
- and
- transferring electrical energy and torque developed between the first rotor and the stator directly to the second rotor without externally storing or converting electrical energy separate from the single converter;
- and
- transmitting torque transferred to the second rotor to the mechanical load via a second driveshaft coupled to the second rotor.
8 more elements
A system for propelling a vehicle comprising:
- an engine;
- an energy conversion machine, the energy conversion machine comprising a dual rotor switched reluctance machine having an input rotor coupled to the engine, an output rotor, a stator, and a single converter;
- the stator having a cylindrical shape with an inner circumference and an outer circumference, the stator fixedly mounted and having stator poles, each stator pole having an electrical winding and extending radially from the inner circumference of the cylindrical shape of the stator to the outer circumference of the cylindrical shape of the stator;
- the input rotor rotatably mounted radially adjacent to one circumference of the stator, the input rotor free of windings and permanent magnets, the input rotor coupled to a first driveshaft configured to transmit power between the input rotor and the engine;
- the output rotor rotatably mounted radially adjacent to the other circumference of the stator, the output rotor free of windings and permanent magnets;
- the single converter including control electronics coupled to the electrical winding of each stator pole and a controller, the control electronics including a transistor pair for each stator phase that captures electrical energy generated by the input rotor and delivers electrical energy to the output rotor, each stator phase including two stator poles;
- wherein the controller selectively energizes the stator electrical windings of one or more stator poles extending between the input rotor and the output rotor to transfer electrical energy and torque developed between the input rotor and the stator directly to the output rotor without externally storing or converting electrical energy separate from the single converter;
- a second driveshaft coupled to the output rotor;
- and
- a propulsion device that converts torque from the output rotor received via the second driveshaft to propel the vehicle.
7 more elements
Dependencies are inferred from the claim text.