Electro-magnetic coupling system

• US 9,190,892 B2
• Filed: 03/20/2013
• Issued: 11/17/2015
• Est. Priority Date: 05/03/2012
• Status: Active Grant

• Current Assignee: Rolls-Royce PLC (Rolls-Royce Holdings Plc)
• Original Assignee: Rolls-Royce PLC (Rolls-Royce Holdings Plc)
• Inventors: Anthony, John Edward
• Primary Examiner(s): Nguyen, Hoang
• Application Number:
  US13/847,739
• Publication Number:
  US 20140328668A1
• Time in Patent Office: 972 Days
• Field of Search: 415/10, 415 83- 87, 415/122.1, 310/103, 310/114
• US Class Current: 1/1
• CPC Class Codes: F02C 3/107 with two or more rotors connected by power transmission
• CPC Class Codes: F02C 7/36 Power transmission arrangements between the different shafts of the gas turbine plant, or between the gas-turbine plant and the power user F02C3/107 - F02C3/13 and F02C7/32 take precedence; couplings for transmitting rotation F16D; gearing in general F16H
• CPC Class Codes: F05D 2240/00 Components
• CPC Class Codes: F05D 2260/404 through magnetic drive coupling
• CPC Class Codes: H02K 21/14 with magnets rotating within the armatures
• CPC Class Codes: H02K 21/40 with flux distributors rotating around the magnets and within the armatures
• CPC Class Codes: H02K 49/102 Magnetic gearings, i.e. assembly of gears, linear or rotary, by which motion is magnetically transferred without physical contact magnetized gearings with physical contact F16H13/12, F16H49/005
• CPC Class Codes: H02K 99/10 Generators
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

Abstract

An electro-magnetic coupling system for transferring torque between a pair of coaxial spools of a gas turbine engine is provided. The system includes a first rotor rotatable with one of the spools, a second rotor rotatable with the other of the spools, and a stator. The first and second rotors and the stator are coaxial with each other. The second rotor operably couples the first rotor and the stator. The first rotor carries a plurality of magnetic flux-producing formations which produce a first magnetic field. The stator carries a plurality of electrical winding coils which are energisable to generate a second magnetic field. The second rotor carries an arrangement of interpoles which modulate the first and second magnetic fields such that the modulated fields interact to transfer torque between the spools.

Claims

1. An electro-magnetic coupling system for transferring torque between a pair of coaxial spools of a gas turbine engine, the system including a first rotor rotatable with one of the spools, a second rotor rotatable with the other of the spools, and a stator, the first and second rotors and the stator being coaxial with each other, and the second rotor operably coupling the first rotor and the stator;

wherein;

the first rotor carries a plurality of magnetic flux-producing formations which produce a first magnetic field,

the stator carries a plurality of electrical winding coils which are energisable to generate a second magnetic field, and

the second rotor carries an arrangement of interpoles which modulate the first and second magnetic fields such that the modulated fields interact to transfer torque between the spools.

2. A system according to claim 1, wherein the electrical winding coils of the stator are de-energisable to remove the second magnetic field, and the system is configured such that, in the absence of the second magnetic field, there is no torque transfer between the spools.

3. A system according to claim 1, wherein the second rotor has a substantially constant speed ratio relative to the first rotor during predetermined operating conditions of the engine, and the number of magnetic flux-producing formations of the first rotor and the number of interpoles of the second rotor are selected such that, at the constant speed ratio, the electrical power flow through the electrical winding coils of the stator is zero.

4. A system according to claim 1, wherein the second rotor has a substantially constant speed ratio relative to the first rotor during predetermined operating conditions of the engine, and the number of magnetic flux-producing formations of the first rotor and the number of interpoles of the second rotor are selected such that, at the constant speed ratio, the electrical power flow through the electrical winding coils of the stator is minimized.

5. A system according to claim 1, wherein the magnetic flux-producing formations of the first rotor are permanent magnets.

6. A system according to claim 1, wherein the magnetic flux-producing formations of the first rotor are further electrical winding coils.

7. A system according to claim 1, wherein the first rotor is radially spaced from the stator, and the second rotor is radially located between the first rotor and the stator.

8. A system according to claim 7, wherein the stator is radially outward of the first rotor.

9. A system according to claim 1, wherein the first rotor is axially spaced from the stator, and the second rotor is axially located between the first rotor and the stator.

16. A gas turbine engine having at least two coaxial spools, the engine further having an electro-magnetic coupling system for transferring torque between the spools according to claim 1.

10. An electro-magnetic coupling system for generating electrical power from a pair of coaxial spools of a gas turbine engine, the system including a first rotor rotatable with one of the spools, a second rotor rotatable with the other of the spools, and a stator, the first and second rotors and the stator being coaxial with each other, and the second rotor operably coupling the first rotor and the stator;

wherein;

the first rotor carries a plurality of magnetic flux-producing formations which produce a magnetic field,

the second rotor carries an arrangement of interpoles which modulate the magnetic field, and

the stator carries a plurality of electrical winding coils which are arranged to transduce the modulated magnetic field into electrical energy.

11. A system according to claim 10, wherein the magnetic flux-producing formations of the first rotor are permanent magnets.

12. A system according to claim 10, wherein the magnetic flux-producing formations of the first rotor are further electrical winding coils.

13. A system according to claim 10, wherein the first rotor is radially spaced from the stator, and the second rotor is radially located between the first rotor and the stator.

14. A system according to claim 13, wherein the stator is radially outward of the first rotor.

15. A system according to claim 10, wherein the first rotor is axially spaced from the stator, and the second rotor is axially located between the first rotor and the stator.

17. A gas turbine engine having at least a two coaxial spools, the engine further having an electro-magnetic coupling system for transferring torque between the spools according to claim 10.