Gas turbine engine with internal electromechanical device

• US 8,829,702 B1
• Filed: 03/11/2013
• Issued: 09/09/2014
• Est. Priority Date: 03/11/2013
• Status: Active Grant

• Current Assignee: Pratt & Whitney Canada Corporation (Rtx Corporation)
• Original Assignee: Pratt & Whitney Canada Corporation (Rtx Corporation)
• Inventors: Menheere, David, Eleftheriou, Andreas, Kostka, Richard
• Primary Examiner(s): Ponomarenko, Nicholas
• Application Number:
  US13/792,739
• Publication Number:
  US 20140252769A1
• Time in Patent Office: 547 Days
• Field of Search: 290/52, 290/47, 60/392.3
• US Class Current: 290/52
• CPC Class Codes: F02C 7/275 Mechanical drives
• 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 2220/766 via a direct connection, i.e. a gearless transmission
• CPC Class Codes: H02K 15/14 Casings; Enclosures; Supports
• CPC Class Codes: H02K 23/52 Motors acting also as generators, e.g. starting motors used as generators for ignition or lighting
• CPC Class Codes: H02K 7/1823 structurally associated with turbines or similar engines
• CPC Class Codes: Y10T 29/49009 Dynamoelectric machine

Abstract

A gas turbine engine including high and low pressure shafts, an electromechanical device having a rotor and a stator coupled such that the rotor is rotatable with respect to the stator, the rotor having a device gear secured thereto, the device being secured to a support structure in a bearing housing forming part of a bearing assembly supporting a portion of the low pressure shaft extending in proximity of the high pressure shaft and of the shaft gear, and a coupling idle gear secured for rotation about a stationary gear support mounted in the bearing housing, the idle gear being in toothed engagement with the shaft gear and with the device gear. An electromechanical device assembly for a gas turbine engine and a method of operating an electromechanical device are also provided.

Claims

1. A gas turbine engine comprising:

a rotatable high pressure shaft in driving engagement with at least one high pressure rotor of the engine and having a shaft gear secured thereto;

a low pressure shaft in driving engagement with at least one low pressure rotor of the engine and rotatable independently of the high pressure shaft;

an electromechanical device having a rotor and a stator coupled such that the rotor is rotatable with respect to the stator, the rotor having a device gear secured thereto, the device being secured to a support structure in a bearing housing, the bearing housing forming part of a bearing assembly supporting a portion of the low pressure shaft extending in proximity of the high pressure shaft and of the shaft gear; and

a coupling idle gear secured for rotation about a stationary gear support mounted in the bearing housing, the idle gear being in toothed engagement with the shaft gear and with the device gear.

2. The gas turbine engine as defined in claim 1, wherein the shaft gear, device gear and idle gear are bevel gears.

3. The gas turbine engine as defined in claim 1, wherein the device is operable as a generator to generate electrical power when the rotor is rotated.

4. The gas turbine engine as defined in claim 1, wherein the device is operable as a starter to rotate the rotor when the device is electrically powered.

5. The gas turbine engine as defined in claim 1, wherein the portion of the low pressure shaft is supported by first and second bearing assemblies with the second bearing assembly being located closer to the high pressure shaft than the first bearing assembly, the device being secured between the first and second bearing assemblies.

6. The gas turbine engine as defined in claim 5, wherein the stator is secured to the support structure of the second bearing assembly and the rotor is rotationally supported by the support structure of the second bearing assembly.

7. The gas turbine engine as defined in claim 5, wherein the device is enclosed in a housing of the first bearing assembly.

8. The gas turbine engine as defined in claim 1, wherein the low and high pressure shafts are concentric with the low pressure shaft extending through the high pressure shaft, the portion of the low pressure shaft supported by the bearing assembly extending beyond the high pressure shaft.

9. The gas turbine engine as defined in claim 1, wherein the gear support is connected to the support structure.

10. An electromechanical device assembly for a gas turbine engine, said assembly comprising:

a rotor mounted on a rotor support, the rotor support having a device gear secured thereto;

a stator mounted on a stator support, the rotor and stator supports being coupled such that the rotor is rotatable about the stator to generate at least one of electrical and mechanical power, the stator support being secured to a bearing support adapted to be part of a bearing assembly of a low pressure shaft of the engine;

a shaft gear adapted to be secured to a high pressure shaft of said engine; and

a coupling idle gear in toothed engagement with the device gear and with the shaft gear, the coupling gear being adapted to be rotationally supported by a stationary gear support in a bearing housing of the bearing assembly.

11. The assembly as defined in claim 10, wherein the coupling idle gear is a disc gear having circumferential bevelled gear teeth, the device gear and the shaft gear also having circumferential bevelled gear teeth.

12. The assembly as defined in claim 10, wherein the device is operable as a generator to generate electrical power when the rotor is rotated.

13. The assembly as defined in claim 10, wherein the device is operable as a starter to rotate the rotor when the device is electrically powered.

14. A method of operating an electromechanical device of a gas turbine engine, the method comprising:

mounting the device in a bearing housing about a low pressure shaft of the engine with a rotor of said device having a device gear connected thereto;

securing a shaft gear to a high pressure shaft of the engine; and

coupling the device and shaft gears through direct engagement with a coupling idle gear rotationally supported on a stationary gear support mounted in the bearing housing.

15. The method as defined in claim 14, wherein the device is mounted in the bearing housing between first and second bearing assemblies supporting a portion of the low pressure shaft protruding from the high pressure shaft.

16. The method as defined in claim 15, wherein the second bearing assembly is closer to the high pressure shaft than the first bearing assembly, and mounting the device includes securing the device to a bearing support of the second bearing assembly.

17. The method as defined in claim 16, wherein mounting the device further includes enclosing the device in a bearing housing of the first bearing assembly.

18. The method as defined in claim 14, wherein mounting the device includes securing a stator of the device to a bearing support of a bearing assembly supporting the low pressure shaft, securing the rotor to a rotor support having the device gear integrally formed therewith, and rotationally mounting the rotor support to the bearing support for rotational displacement around the low pressure shaft.