HIGH END LOW SPOOL ACCESSORY GEARBOX DRIVE

• US 20180291817A1
• Filed: 04/11/2017
• Published: 10/11/2018
• Est. Priority Date: 04/11/2017
• Status: Active Grant

• Current Assignee: Rtx Corporation
• Original Assignee: United Technologies Corporation (Rtx Corporation)
• Inventors: Suciu, Gabriel L., Duong, Hung, Zimmitti, Jonathan F., Sheridan, William G., McCune, Michael E., Merry, Brian
• Granted Patent: US 10,358,981 B2
• Time in Patent Office: Days
• CPC Class Codes: F02C 7/185 Cooling means for reducing the temperature of the cooling air or gas
• CPC Class Codes: F02C 7/32 Arrangement, mounting, or driving, of auxiliaries
• 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 2220/764 of the alternating current (A.C.) type
• CPC Class Codes: F05D 2220/768 equipped with permanent magnets
• CPC Class Codes: F05D 2270/023 of different spools or shafts

Abstract

A gas turbine engine comprises a low speed spool and a high speed spool, with each of the spools including a turbine to drive a respective one of the spools. The high speed spool rotates at a higher speed than the low speed spool. A high speed power takeoff is driven to rotate by the high speed spool, and a low speed power takeoff is driven to rotate by the low speed spool. The high speed power takeoff drives a starter generator and a permanent magnet alternator. The low speed power takeoff drives a variable frequency generator.

Claims

1. A gas turbine engine comprising:

a low speed spool and a high speed spool, with each of said spools including a turbine to drive a respective one of said spools;

said high speed spool rotating at a higher speed than said low speed spool;

a high speed power takeoff driven to rotate by said high speed spool, and a low speed power takeoff driven to rotate by said low speed spool;

said high speed power takeoff driving a starter generator and a permanent magnet alternator; and

said low speed power takeoff driving a variable frequency generator.

2. The gas turbine engine as set forth in claim 1, wherein a first transmission is driven by said low speed or power takeoff, and said first transmission driving said variable frequency generator at a plurality of speeds.

3. The gas turbine engine as set forth in claim 2, wherein said first transmission also driving a hydraulic pump at one of a plurality of distinct speeds relative to an input speed from said low speed power takeoff.

4. The gas turbine engine as set forth in claim 3, wherein a controller controls said first transmission to achieve a desired input speed for said variable frequency generator.

5. The gas turbine engine as set forth in claim 4, wherein said controller also controls said first transmission to drive a hydraulic pump at a desired speed.

6. The gas turbine engine as set forth in claim 5, wherein said low speed power takeoff also driving an oil pump.

7. The gas turbine engine as set forth in claim 6, wherein cooling air is tapped from a location in a compressor section which is upstream of a most downstream location in said compressor section and said tapped air being passed through a heat exchanger and through a cooling air compressor.

8. The gas turbine engine as set forth in claim 7, wherein said low speed spool power takeoff driving said cooling air compressor.

9. The gas turbine engine as set forth in claim 8, wherein a second transmission is driven by said low power takeoff to drive said cooling air compressor at a desired speed.

10. The gas turbine engine as set forth in claim 9, wherein said second transmission is a three-speed transmission.

11. The gas turbine engine as set forth in claim 10, wherein said controller controlling said second transmission to achieve a desired speed for said cooling air compressor.

12. The gas turbine engine as set forth in claim 2, wherein cooling air is tapped from a location in a compressor section which is upstream of a most downstream location in said compressor section and said tapped air being passed through a heat exchanger and through a cooling air compressor.

13. The gas turbine engine as set forth in claim 12, wherein said low speed spool power takeoff driving said cooling air compressor.

14. The gas turbine engine as set forth in claim 13, wherein a second transmission is driven by said low power takeoff to drive said cooling air compressor at a desired speed.

15. The gas turbine engine as set forth in claim 14, wherein said second transmission is a three-speed transmission.

16. The gas turbine engine as set forth in claim 15, wherein said controller controlling said second transmission to achieve a desired speed for said cooling air compressor.

17. The gas turbine engine as set forth in claim 2, wherein a controller controls said first transmission to achieve a desired input speed tor said variable frequency generator.

18. The gas turbine engine as set forth in claim 17, wherein said controller also controls said first transmission to drive a hydraulic pump at a desired speed.

19. The gas turbine engine as set forth in claim 17, wherein cooling air is tapped from a location in a compressor section which is upstream of a most downstream location in said compressor section and said tapped air being passed through a heat exchanger and through a cooling air compressor.

20. The gas turbine engine as set forth in claim 19, wherein a second transmission is driven by said low power takeoff to drive said cooling air compressor at a desired speed.