Aircraft propulsion systems

• US 7,752,834 B2
• Filed: 10/25/2006
• Issued: 07/13/2010
• Est. Priority Date: 10/25/2006
• Status: Active Grant

• Current Assignee: Rtx Corporation
• Original Assignee: United Technologies Corporation (Rtx Corporation)
• Inventors: Addis, Mark
• Primary Examiner(s): RODRIGUEZ, WILLIAM H
• Application Number:
  US11/586,172
• Publication Number:
  US 20080098719A1
• Time in Patent Office: 1,357 Days
• Field of Search: 602/24, 602/25, 602/261, 244/60, 244/55
• US Class Current: 60/224
• CPC Class Codes: B64D 27/10 of gas-turbine type jet aircraft B64D27/16
• CPC Class Codes: F02K 3/077 the plant being of the multiple flow type, i.e. having three or more flows
• CPC Class Codes: Y02T 50/40 Weight reduction
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

Abstract

Disclosed are propulsion systems 30 providing reduced fuel burn, weight and cost. A single gas generator core 38 drives multiple bladed propulsion elements 36 with a power train 48. The core 38 has a forward compressor 56 and a rearward turbine 40 and rotates about a longitudinal core axis 62. The bladed propulsion elements 36 rotate about bladed propulsion element axes 78 that are not coaxial with the core axis 62. The bladed propulsion elements 36 discharge an ambient air stream 50 rearward as a bypass stream 52 portion and a core stream 54 portion. The core stream 54 portion is directed to the compressor 56. The propulsion systems 30 mount inside a fuselage 22 of an airframe 20 or they are suspended beneath a wing 24 via pylons 32.

Claims

1. A propulsion system comprising:

a gas generator core including a forward compressor and a rearward turbine joined by a primary shaft rotational about a longitudinal core axis, the shaft projecting forward of the compressor;

a power train having a primary gearbox and multiple secondary gearboxes, where the primary gearbox is driven by the primary shaft and driving multiple drive shafts and each secondary gearbox is driven by a drive shaft and driving a fan, where the power train is driven by said primary shaft and driving multiple bladed propulsion elements, each bladed propulsion element rotating about a bladed propulsion element axis that is not coaxial with the core axis, and each bladed propulsion element discharging an air stream rearward; and

an inlet duct for directing a portion of the discharged air streams rearward to the compressor.

2. The propulsion system of claim 1 wherein said power train further comprises a frangible means between the primary gearbox and each of the secondary gearboxes.

3. The propulsion system of claim 2, wherein each drive shaft rotates about a drive shaft axis, the drive shaft axes being at an angle to the core axis.

4. The propulsion system of claim 3, wherein the drive shaft axes are perpendicular to the core axis.

5. The propulsion system of claim 4, wherein the drive shaft axes and the core axis are coplanar.

6. The propulsion system of claim 1, wherein the bladed propulsion elements rotate in the same direction as one another.

7. The propulsion system of claim 1, wherein the bladed propulsion elements counter rotate with respect to one another.

8. A propulsion system comprising:

a gas generator core including a forward compressor, a central gearbox and an rearward turbine, said core rotationally disposed about a longitudinal core axis and driving a tower shaft from the gearbox;

a power train having a primary gearbox and multiple secondary gearboxes, where the primary gearbox is driven by the tower shaft and driving multiple drive shafts and each secondary gearbox being driven by a drive shaft and driving a fan, where the power train is driven by said tower shaft and driving multiple bladed propulsion elements, each bladed propulsion element rotating about a bladed propulsion element axis that is not coaxial with the core axis, and each bladed propulsion element discharging an ambient air stream rearward; and

an inlet duct for directing a portion of the discharged air streams rearward into the compressor.

9. The propulsion system of claim 8, wherein said power train further comprises a frangible means between the primary gearbox and each secondary gearbox.

10. The propulsion system of claim 8, wherein each drive shaft rotates about an axis, the drive shaft axes being substantially parallel with the core axis.

11. The propulsion system of claim 8, wherein the bladed propulsion elements rotate in the same direction as one another.

12. The propulsion system of claim 8, wherein the bladed propulsion elements counter rotate with respect to one another.

13. A propulsion system comprising:

a gas generator core including a compressor driven by a shaft rotating about a longitudinal core axis;

a power train driven by the core, reward of the compressor, connecting the shaft to multiple bladed propulsion elements, each bladed propulsion element rotating about a bladed propulsion element axis that is not coaxial with the core axis and each bladed propulsion element discharging an ambient air stream rearward; and

an inlet duct for directing a portion of the discharged air streams from the bladed propulsion elements into the compressor.