High and low spool accessory gearbox drive

• US 10,605,173 B2
• Filed: 06/28/2019
• Issued: 03/31/2020
• Est. Priority Date: 04/11/2017
• Status: Active Grant

• Current Assignee: Rtx Corporation
• Original Assignee: United Technologies Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Suciu, Gabriel L., Duong, Hung, Zimmitti, Jonathan F., Sheridan, William G., McCune, Michael E., Merry, Brian
• Primary Examiner(s): English, James A
• Application Number:
  US16/456,087
• Publication Number:
  US 20190316526A1
• Time in Patent Office: 277 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;

said low speed power takeoff driving a variable frequency generator;

wherein a first transmission is driven by said low speed power takeoff, and said first transmission driving said variable frequency generator at a plurality of speeds; and

wherein a controller controls said first transmission to achieve a desired input speed for said variable frequency generator.

2. The gas turbine engine as set forth in claim 1, 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.

3. The gas turbine engine as set forth in claim 2, wherein said controller also controls said first transmission to drive a hydraulic pump at a desired speed.

4. The gas turbine engine as set forth in claim 3, wherein said low speed power takeoff also driving an oil pump.

5. The gas turbine engine as set forth in claim 1, wherein said low speed spool driving a fan rotor through a gear reduction.

6. The gas turbine engine as set forth in claim 5, 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.

7. The gas turbine engine as set forth in claim 6, wherein said controller also controls said first transmission to drive a hydraulic pump at a desired speed.

8. The gas turbine engine as set forth in claim 7, wherein said low speed power takeoff also driving an oil pump.

9. The gas turbine engine as set forth in claim 8, wherein a gear ratio of said gear reduction is greater than 2.3.

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

11. The gas turbine engine as set forth in claim 5, wherein a gear ratio of said gear reduction is greater than 2.3.

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

13. The gas turbine engine as set forth in claim 1, wherein said low speed power takeoff also driving an oil pump.

14. The gas turbine engine as set forth in claim 1, wherein said control is provided with power at start up by said permanent magnet alternator.