CONVERTIBLE COMPOSITE ENGINE

• US 3,678,690 A
• Filed: 07/10/1970
• Issued: 07/25/1972
• Est. Priority Date: 07/10/1970
• Status: Expired due to Term

• Current Assignee: Edward R. Primachuk, Herbert N. Shohet, Joseph L. Magri
• Original Assignee: Edward R. Primachuk, Herbert N. Shohet, Joseph L. Magri
• Inventors: Shohet, Herbert N., Magri, Joseph L., Primachuk, Edward R.
• Primary Examiner(s): Croyle, Carlton R.
• Assistant Examiner(s): Garrett, Robert E.
• Application Number:
  US05/053,713
• Time in Patent Office: 746 Days
• Field of Search: 60/39.16,39.17,39.33,39.25,226,39.15,236,225 415/61,68 416/125,127 417/408,409 244/7,53,6
• US Class Current: 60/226.3
• CPC Class Codes: F02C 3/10 with another turbine driving an output shaft but not driving the compressor
• CPC Class Codes: F02K 3/06 with front fan
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

Abstract

A convertible composite engine capable of either shaft horsepower or thrust generation and split-powered operation in which partial thrust and partial shaft horsepower is generated. The engine is concentric about a single centerline and includes two coaxial free turbines, one driving a load such as by-pass fan and the other a shaft horsepower take-off, such as is commonly used to drive a helicopter rotor drive shaft. A single gas generator provides compressed and heated gases to the coaxial free turbines with the total amount of gases provided determined by the total power required from the two free turbines and the split of gas flow through each free turbine determined by the position of the variable inlet guide vanes at the inlet to each turbine.

Claims

1. A convertible engine having an axis and including:

A. a gas generator comprising a compressor, a burner, and a turbine, and with said compressor and turbine mounted for rotation about said axis, B. two free turbines positioned downstream of the gas generator and mounted for independent rotation about said axis and being in parallel flow relationship with the gas generator.

2. a combustion chamber section communicating with the compressor section to receive compressed air therefrom to bE heated therein,

3. Apparatus according to claim 2 and including means to selectively control the flow of exhaust gas from the gas generator through each of the free turbines.

4. Apparatus according to claim 3 and including a fixed or variable geometry exhaust duct operatively connected to one of the free turbines and a variable area exhaust duct operatively connected to the other free turbine.

5. A convertible composite engine capable of combination shaft horsepower and direct thrust mode of operation and having an axis and including:

A. a gas generator mounted for rotation about said axis, B. two free turbines mounted for independent rotation about said axis and positioned downstream of said gas generator so as to be powered by the exhaust gases therefrom and further positioned so as to be in parallel flow relationship with one another, C. means operatively connecting one of said free turbines to a direct thrust generating device, D. means operatively connecting the other of said free turbines to a shaft horsepower driven device, E. and means operative to divide gas generator exhaust gas flow between said free turbines.

6. Apparatus according to claim 5 wherein said exhaust gas flow dividing means are variable area inlet guide vanes at the inlet of each of said free turbines and separaTe exhaust gas ducts for said free turbines.

7. A convertible composite, in-line engine extending along an axis and including:

A. a gas generator comprising a compressor, a burner, and a turbine, and with said compressor and turbine mounted for rotation about said axis, B. a first free turbine mounted for rotation about said axis and positioned downstream of the gas generator to receive exhaust gases therefrom, C. a second free turbine mounted for rotation about said axis and positioned downstream of said gas generator to receive exhaust gases therefrom and also positioned in parallel flow relationship to said first free turbine, D. a first power generating device connected to be driven by the one of said free turbines, E. a second power generating device connected to be driven by the other of said free turbines, F. and means to vary the amount of gas generator exhaust gas being passed through either of said free turbines without affecting the power developed by the other of said free turbines.

8. Apparatus according to claim 7 wherein said exhaust gas glow varying means constitute variable area inlet guide vanes operatively associated with each of said first and second free turbines.

9. Apparatus according to claim 8 wherein the blades of said second free turbine are located at a greater diameter from said axis than the blades of said first free turbine and so that the gas path flow therethrough is concentric about said axis and so that each turbine exhausts through separate exhaust ducts.

10. Apparatus according to claim 9 wherein said first power generating means is a helicopter rotor operatively connected to be driven by said second free turbine and wherein said second power generating means is a by-pass fan compressor operatively connected to be driven by said first free turbine.

11. A convertible composite, in-line, axial flow engine having an axis and including:

A. pressurized gas generating means comprising, a compressor, a burner, and a turbine, and with said compressor and turbine mounted for rotation about said axis, B. two free turbines mounted for rotation concentrically about said axis and positioned downstream of said gas generating means to receive and be driven by the gases therefrom and having turbine blade paths of different diameters and with the free turbines being in parallel flow relation, C. first power take-off means connected to be driven by one of said free turbines, D. second power take-off means connected to be driven by the other of said free turbines, E. means to regulate the amount of pressurized gas flow from said pressurized gas generating means through each of said free turbines.

12. Apparatus according to claim 11 and including engine housing means defining an annular passage between said gas generator and to and through said free turbines and with each of said free turbines exhausting through separate exhaust ducts.

13. Apparatus according to claim 12 and including a variable area exhaust outlet positioned downstream of one of said free turbines to receive gas flow therefrom for discharge therethrough to atmosphere and a fixed or variable outlet positioned downstream of the other of said free turbines to receive gas flow therefrom for discharge therethrough to atmosphere.

14. A convertible composite, in-line engine having a single centerline and including:

A. an engine case having a forward end and an after end and positioned concentrically about the centerline, B. a by-pass fan compressor consisting of at least one stage positioned forward of the engine case and mounted for rotation about the centerline, C. a gas generator positioned within the engine case at the forward portion thereof and mounted for rotation about the centerline and including;

15. Apparatus according to claim 14 and including:

A. a fixed exhaust duct positioned aft of said first free turbine and communicating therewith so that the exhaust gases passing through the first free turbine will be discharged to atmosphere through the fixed exhaust duct, and B. a variable area exhaust duct operatively connected to the second free turbine and communicating therewith so that the exhaust gases being passed through the second free turbine to power that turbine will be exhausted to atmosphere therethrough.

16. Apparatus according to claim 15 wherein said first free turbine includes at least one stage of rotatable turbine blades mounted at a selected diameter for rotation about the centerline and wherein the second free turbine includes at least one stage of turbine blades mounted for rotation about the centerline at a diameter greater than the diameter of the blades of the first free turbine and wherein the gases powering the first free turbine pass through appropriate apertures in the support disc of the second free turbine.

17. Apparatus according to claim 16 and including a fixed shroud enveloping said by-pass fan compressor and cooperating with said engine case to define an annular exhaust passage for the fan generated compressed air to effect thrust generation.