Gas turbine engine with accessory gearbox
A gas turbine engine with an accessory gearbox. The accessory gearbox is rotatably coupled to the engine drive shaft. The gearbox has a gear shaft rotatable about a gear shaft axis. The gear shaft has a first end drivingly engaged to a first accessory and a second end drivingly engaged to a second accessory.
1. A gas turbine engine, comprising:
an engine drive shaft; and
an accessory gearbox rotatably coupled to the engine drive shaft, the gearbox having a first accessory with a first accessory shaft rotatable in a first rotational direction, and a second accessory with a second accessory shaft rotatable in a second rotational direction opposite to the first rotational direction, the gearbox having a gear shaft rotatable about a gear shaft axis, the gear shaft having a first end drivingly engaged to the first accessory shaft and a second end drivingly engaged to the second accessory shaft.
2. The gas turbine engine of claim 1 , wherein the gear shaft axis is transverse to a center axis of the gas turbine engine.
3. The gas turbine engine of claim 2 , wherein the accessory gearbox is disposed at an aft end of the gas turbine engine.
4. The gas turbine engine of claim 1 , wherein the accessory gearbox is disposed on top of a casing of the gas turbine engine, or along a side of the casing.
5. The gas turbine engine of claim 4 , wherein the gear shaft axis is parallel to a center axis of the gas turbine engine.
6. The gas turbine engine of claim 1 , wherein the accessory gearbox has first and second mounting pads spaced apart across a width of the accessory gearbox.
7. The gas turbine engine of claim 1 , wherein the first accessory shaft is rotatable at a first rotational speed and the second accessory shaft is rotatable at a second rotational speed, the first and second rotational speeds being the same.
8. The gas turbine engine of claim 7 , wherein the first accessory has a first rotational speed range and the second accessory has a second rotational speed range, the first and second rotational speeds being closer to one of an upper limit and a lower limit of the first rotational speed range, and first and second rotational speeds being closer to the other one of an upper limit and a lower limit of the second rotational speed range.
9. The gas turbine engine of claim 1 , comprising a spline rotatably coupled to one of the first and second ends of the gear shaft, and to a corresponding one of a first and second accessory shafts of the first and second accessories, the spline rotatable about the gear shaft axis.
10. The gas turbine engine of claim 9 , wherein the spline is made of a polymer material.
11. The gas turbine engine of claim 1 , wherein the first accessory is a fuel control unit (FCU) and the second accessory is a starter/generator.
12. The gas turbine engine of claim 1 , wherein the first accessory is a fluid accessory and the second accessory is an electrical accessory.
13. An accessory gearbox, comprising:
a first mounting pad and a second mounting pad;
a gear shaft having a first end mounted to the first mounting pad and a second end mounted to the second mounting pad, the gear shaft rotatable about a gear shaft axis; and
a first accessory mounted to the first mounting pad and having a first accessory shaft rotatable in a first rotational direction and rotatably coupled to the first end of the gear shaft, and a second accessory mounted to the second mounting pad and having a second accessory shaft rotatable in a second rotational direction opposite to the first rotational direction and rotatably coupled to the second end of the gear shaft.
14. The accessory gearbox of claim 13 , wherein the first accessory shaft is rotatable at a first rotational speed and the second accessory shaft is rotatable at a second rotational speed, the first and second rotational speeds being the same.
15. The accessory gearbox of claim 14 , wherein the first accessory has a first rotational speed range and the second accessory has a second rotational speed range, the first and second rotational speeds being closer to one of an upper limit and a lower limit of the first rotational speed range, and first and second rotational speeds being closer to the other one of an upper limit and a lower limit of the second rotational speed range.
16. A method of driving a first accessory and a second accessory of a gas turbine engine, the method comprising rotating a single gear shaft extending between the first accessory and the second accessory about a gear shaft axis to simultaneously drive the first accessory and the second accessory in opposite rotational directions.
17. The method of claim 16 , wherein rotating the single gear shaft includes rotating the single gear shaft to simultaneously drive the first accessory at a first rotational speed and the second accessory at a second rotational speed, the first and second rotational speeds being the same.