SYSTEM AND METHOD FOR MODIFYING A GAS TURBINE ENGINE IN THE FIELD

• US 20130305508A1
• Filed: 05/16/2012
• Published: 11/21/2013
• Est. Priority Date: 05/16/2012
• Status: Active Grant

• Current Assignee: Solar Turbines Incorporated (Caterpillar Incorporated)
• Original Assignee: Solar Turbines Incorporated (Caterpillar Incorporated)
• Inventors: Sachacht, Thomas C., Rodriguez, David
• Granted Patent: US 8,979,442 B2
• Time in Patent Office: Days
• US Class Current: 29/402.18
• CPC Class Codes: B23P 2700/06 Cooling passages of turbine components, e.g. unblocking or preventing blocking of cooling passages of turbine components
• CPC Class Codes: B23P 6/002 Repairing turbine components, e.g. moving or stationary blades, rotors, B23P6/045 takes precedence
• CPC Class Codes: F01D 25/285 Temporary support structures, e.g. for testing, assembling, installing, repairing; Assembly methods using such structures
• CPC Class Codes: F01D 5/005 Repairing methods or devices
• CPC Class Codes: F01D 5/186 Film cooling F01D5/187 takes precedence
• CPC Class Codes: Y10T 29/49318 Repairing or disassembling
• CPC Class Codes: Y10T 29/49718 Repairing
• CPC Class Codes: Y10T 29/49746 by applying fluent material, e.g., coating, casting
• CPC Class Codes: Y10T 29/49998 Work holding
• CPC Class Codes: Y10T 29/5105 Drill press
• CPC Class Codes: Y10T 408/56245 including tool-guide [or bushing]
• CPC Class Codes: Y10T 408/567 Adjustable, tool-guiding jig
• CPC Class Codes: Y10T 409/301624 Duplicating means
• CPC Class Codes: Y10T 409/302576 with means to support templet above or under work

Abstract

A system and method for modifying a gas turbine engine in the field to drill a series of cooling holes in a turbine rotor disk made of a superalloy. A portable field repair system includes a stand configured to receive, support, and position a turbine rotor disk, a drill having a self-feeding spindle and configured to automatically drill a predetermined depth through a superalloy and to automatically stop upon completion, a drill guide configured to coordinate the drill with a plurality of radial axes associated with a precise hole pattern to be cut and a drill mount configured to mechanically couple the drill to the drill guide and to position the drill during the modification of the gas turbine engine turbine rotor disk.

Claims

1. A system for modifying a gas turbine engine in the field, the system comprising:

a base configured to receive, support, and position a turbine rotor disk removed from the gas turbine engine, the turbine rotor disk made from a superalloy;

a drill having a single drill axis;

a drill guide configured to coordinate the single drill axis with a plurality of radial axes associated with the turbine rotor disk such that the single drill axis is prevented from departing one of the plurality of radial axes beyond design tolerances associated with a modification to be performed when drilling has been initiated; and

,

a drill mount configured to mechanically couple the drill to the drill guide and to position the drill during drilling operations.

2. The system of claim 1, wherein the drill has a self-feeding spindle and is configured to automatically drill a predetermined depth through the superalloy along the single drill axis upon initiation, and to automatically stop upon completion;

3. The system of claim 1, further comprising a compressed air subsystem including a compressed air receptacle, an air tank, and a drill interface, the air supply subsystem configured to supply compressed air to the drill from both the compressed air receptacle and the air tank.

4. The system of claim 1, further comprising a nose piece alignment bushing and wherein the drill guide includes a plurality of radial access holes configured to receive the nose piece alignment bushing.

5. The system of claim 1, further comprising:

an enclosure configured to enclose the system during transport and to permit operational access to the system upon deployment; and

,

a lubricant drip receptacle configured collect used lubricant.

6. The system of claim 1, wherein the drill includes an internally cooled carbide drill bit that is lubricated and cooled internally by the integrated cutter lubricant subsystem.

7. The system of claim 1, wherein the drill guide further comprises a plurality of radial access holes configured to receive the nose piece alignment bushing.

8. The system of claim 1, wherein the drill mount is further configured to mechanically couple to at least one of the base and the drill guide.

9. The system of claim 1, wherein the drill guide comprises a ring keyed to the turbine rotor disk, the ring having a plurality of radial access holes configured to interface with the nose piece alignment bushing and align with the plurality of radial axes.

10. The system of claim 1, wherein the turbine rotor disk includes a cooling arm;

and,

wherein the base is further configured to position the cooling arm below the balance of the turbine rotor disk when drilling has been initiated.

11. The system of claim 1, wherein the system weighs less than 700 lbs.

12. A method for modifying a gas turbine engine in the field, the method comprising

assembling a system for modifying the gas turbine engine in the field, the system including a base, a drill mount, a drill, and a drill guide;

removing a turbine rotor disk from the gas turbine engine;

aligning the turbine rotor disk with the drill guide such that each single drill axis will be coordinated with one of a plurality of radial axes associated with cooling holes to be made in the turbine rotor disk;

securing the turbine rotor disk in the base;

interfacing and securing the drill with the drill guide via the drill mount, such that the single drill axis is aligned with a first radial axis of the turbine rotor disk;

drilling a first hole in the turbine rotor disk to a predetermined distance in the turbine rotor disk along the single drill axis coordinated with the first radial axis;

interfacing and securing the drill with the drill guide via the drill mount, such that the single drill axis is aligned with a second radial axis of the turbine rotor disk;

drilling a second hole in the turbine rotor disk to the predetermined distance in the turbine rotor disk along the single drill axis coordinated with the second radial axis;

removing the turbine rotor disk from the base; and

,

reinstalling the turbine rotor disk to the gas turbine engine.

13. The method of claim 12, further comprising:

initiating the drill to automatically drill a first hole in the turbine rotor disk; and

,

initiating the drill to automatically drill a second hole in the turbine rotor disk; and

,

wherein the drilling the first hole in the turbine rotor disk to the predetermined distance in the turbine rotor disk comprises automatically drilling to the predetermined distance in the turbine rotor disk responsive to the initiating the drill to automatically drill the first hole in the turbine rotor disk; and

,

wherein, the drilling second hole in the turbine rotor disk to the predetermined distance in the turbine rotor disk along the single drill axis coordinated with the second radial axis comprises automatically.

14. The method of claim 12, wherein the drill is pneumatically powered, the method further comprising:

coupling the system for modifying the gas turbine engine to a shop air hose; and

,

decoupling the system for modifying the gas turbine engine from shop air hose after the modification is performed.

15. The method of claim 12, further comprising:

unpacking the system for modifying the gas turbine engine from an enclosure; and

,

repacking the system for modifying the gas turbine engine in the enclosure after the removing the gas turbine engine disk from the base.

16. The method of claim 12, wherein the drill includes an integrated cutter lubricant subsystem, the method further comprising lubricating and cooling an internally cooled carbide drill bit internally with the integrated cutter lubricant subsystem when automatically drilling to the predetermined distance.

17. A system for modifying a turbine rotor disk, made of a superalloy, in the field, the system comprising:

a stand configured to receive, support, and position the turbine rotor disk;

a drill having a self-feeding spindle, a nose piece alignment bushing, and an integrated cutter lubricant subsystem, the drill configured to automatically drill a predetermined depth through the superalloy along a single drill axis upon initiation and to automatically stop upon completion; and

a drill guide having a plurality of radial access holes configured to receive the nose piece alignment bushing, each of the plurality of radial access holes associated with a radial axis associated with a cooling hole to be machined in the turbine rotor disk.

18. The system of claim 17, further comprising a drill mount configured to mechanically couple the drill to the drill guide when the nose piece alignment bushing is fully engaged with one of the plurality of radial access holes.

19. The system of claim 17, further comprising a compressed air subsystem including a compressed air receptacle, an air tank, and a drill interface, the air supply subsystem configured to supply compressed air to the drill from both the compressed air receptacle and the air tank.

20. The system of claim 17, further comprising:

an enclosure configured to enclose the system during transport and to permit operational access to the system upon deployment; and

,

a lubricant drip receptacle configured collect used lubricant.