US3810360A

US3810360A - Gas generator with selectively connectible turbine system

Info

Publication number: US3810360A
Application number: US00299279A
Authority: US
Inventors: H Leibach
Original assignee: MTU Motoren und Turbinen Union Muenchen GmbH
Current assignee: MTU Aero Engines GmbH
Priority date: 1971-10-20
Filing date: 1972-10-20
Publication date: 1974-05-14
Anticipated expiration: 1991-05-14
Also published as: FR2156883A1; FR2156883B1; GB1407428A

Abstract

An engine arrangement for use with a vertical/short take-off and landing airplane having a gas generator supplying exhaust gases selectively to a turbine system and to a thrust nozzle. The turbine system is connectible to auxiliary lift devices, such as a lift rotor, for effecting vertical lift operations while the thrust nozzle is designed for normal cruising operations. The flow of exhaust gases to the turbine system and the thrust nozzle is controlled such that the total cross-sectional area, with respect to the exhaust gas flow, of both the turbine system and the thrust nozzle is maintained constant for all operations. Sliding members are arranged at the respective critical crosssections in the inlets to the turbine system and thrust nozzle for blocking the exhaust gas flow. These sliding members are interconnected to one another such that opening of one causes a corresponding similar closing of the other.

Description

ilnited States Patent 1 [111 3,810,360 Leibach May 14, 11974 GAS GENERATOR WITH SELECTIVELY CONNECTIBLE TURBINE SYSTEM [75] Inventor: Heinrich Leibach,

Grafrath-Wildenroth, Germany [73] Assignee: Motoren-Und Turbinen-Union Munchen GmbH, Munchen, Germany [22] Filed: Oct. 20, 1972 [21] Appl. N 299,279

[30] Foreign Application Priority Data Oct. 20, 1971 Germany 2152207 [52] 11.8. CI 60/229, 60/39.16, 60/39.33, 60/263, 416/171 [51] Int. Cl. F02c 7/02 [58] Field of Search 60/263,'39.l7, 39.16, 39.18, 60/229, 39.16 CR, 262, 39.33, 225; 416/171 [56] References Cited UNITED STATES PATENTS 3,678,690 7/1972 Shohet et al.....'. 60/226 3,366,350 l/l968 Hoffert 60/263 2,587,649 3/1952 Pope 60/39.l6 2,507,657 5/1950 Wiessler.... 60/39.l6 3,255,584 6/1966 Grieb 60/263 FOREIGN PATENTS OR APPLICATIONS 1,099,971 l/1968 Great Britain 60/226 R Primary Examiner-Carlton R. Croyle Assistant Examiner-Warren Olsen Attorney, Agent, or Firm-Craig & Antonelli [57] ABSTRACT An engine arrangement for use with a vertical/short takeoff and landing airplane having a.v gas generator supplying exhaust gases selectively to a turbine system and to a thrust nozzle. The turbine system is connectible to auxiliary lift devices, such as a lift rotor, for effecting vertical lift operations while the thrust nozzle is designed for normal cruising operations. The flow of exhaust gases to the turbine system and the thrust nozzle is controlled such that the total cross-sectional area, with respect to the exhaust gas flow, of both the turbine system and the' thrust nozzle is maintained constant for all operations. Sliding members are ar- 7 34 Claims, 3 Drawing Figures PATENTEBHAY 14 I974 SHEET 2 [IF 3 PATENTEDHAY 14 I974 SHEET 3 [IF 3 GAS GENERATOR WITH SELECTIVIELY CONNECTIBLE TURBINE SYSTEM BACKGROUND AND SUMMARY OF THE INVENTION The present invention relates to an engine arrangement having a gas generator, a selectively connectible turbine system chargeable with the exhaust gases of the gas generator, and a selectively connectible thrust nozzle operated by the exhaust gases. The present invention specifically relates to devices rendering the critical cross section of an opened thrust nozzle, when the turbine system is not under load, substantially identical with a critical through-flow cross section of the turbine system, when the exhaust gas load on the nozzle is released, or vice versa.

In composite systems, i.e., systems wherein the gas conveyed by a gas generator is passed to a utility or working turbine driving a blower or a rotor, for vertical take-off, while the thrust nozzle provided for propulsion is closed, it is necessary and important that the transition to the fully opened position of the nozzle and correspondingly a closed position of the feed inlet to the utility turbine can be effected gradually.

ln such a system, with the utility turbine under load, the guide vanes of the turbine can constitute the critical gas cross section; when the nozzle is opened for horizontal flight, the nozzle aperture forms the critical cross section. The present invention contemplates that, for transitional operation, i.e., when an airplane changes from vertical flight to horizontal flight, with the gas load being shifted from the utility turbine to the nozzle, the sum totals of the critical cross sections should be constant, so that the gas generator, with respect to its design, can always be utilized in the optimum operating range. In such a system, the gas generator does not tolerate any too large deviations from the sum of the two critical gas cross sections for the flow of exhaust gases without impairment of the gas generator operation.

. It has been contemplated to design governor of the utility turbine as adjustable, which design permits a variation of the critical cross section in a certain range. However, this governorcontrol means doubtlessly will not be able to block the cross section entirely at the corresponding number of guide vanes,-for mechanical reasons, so that there is always a certain gas permeability. This means, in addition to thermal loads on the governor, that 'a mass flow loss will be experienced in case of a fully opened nozzle. I

The present invention contemplates eliminating the disadvantages mentioned above in connection with gas generator composite systems, and has the object of constructing such a system so that it is possible in a relatively simple manner, i.e., also by relatively simple means, .to change over from pure nozzle operation (propulsive thrust) to utility turbine operation (vertical thrust),.while ensuring that the gas outlet area of the gas generator is always maintained substantially constant in the intermediate and final shifting phases.

The devices provided according to the present invention shall furthermore make it possible, when the noz-v zle or the turbine system (utility turbine) is not under load, to establish a flawless, loss-free seal and to provide for example when the turbine system is closed and the nozzle is opened an aerodynamically favorable guidance of the gaseous stream to the nozzle. F urthermore, these'devices are to be operable by relatively minor adjusting forces.

Starting with an apparatus as heretofore described, the invention contemplates essentially, in order to solve the posed problem, to fashion the devices from rotationally symmetrically disposed slides, wherein a first slide controls the critical cross sectional area of the nozzle and a second slide controls the critical feed cross section of the turbine system.

It is further contemplated by the present invention, that the slides are to be operable by means of a common control device in such a manner that the second slide closes the critical cross sectional area of the turbine system to the same extent as the first slide opens the critical cross section of the nozzle, or vice versa.

BRIEF DESCRIPTION OF THE DRAWINGS The above-discussed and further'objects, features, and advantages of the present invention will become more apparent from the followingdetailed description FIG. 2 is a schematic longitudinal sectional view of a second embodiment of an engine arrangementin ac? cordance with a second embodiment of the present invention; and

FIG. 3 is a schematic longitudional sectional view of I a third embodiment of an engine arrangement inaccordance with a third embodiment of the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS The gas generator G illustrated in FIG. 1 comprises successively from the lefthand to the righthand side a three-stage axial-flow compressor 1, an annular combustion chamber 3 disposed coaxially to the longitudinal axis 2 of the gas generator G, and an adjoining single-stage turbine4. The rotor 5 of the turbine 4 is connected to the rotors 7, 8, 9 of the axial-flow compressor l by way of a common shaft 6.

The exhaust gases conveyed by the gas generator G pass, after having been conducted past supporting guide blades 10, into an annular collecting chamber 1 l and place a single-stage turbine system 13 under load after being conducted through an annular feed duct 12, when a first cylindrical slide 14 closes the critical cross section F of a thrust nozzle 15, i.e., when a further annular duct 16 surrounding the turbine system 13 is blocked. When nozzle 15 is closed, a critical passage cross section-F, of the turbine system 13 is opened, namely by means of a second cylindrical slide 17 (final position, shown in dashed lines) to communicate the exhaust gases to the turbine system 13.

With the nozzle 15 being fully opened, the first cylindrical slide 14 is shifted into the position shown in full lines, so that the critical cross section F: of the nozzle I5 is essentially formed approximately between a terminal edge 18 of the slide 14 and a terminal edge'19 of an annular jacket 20 surrounding the turbine system 13. When nozzle 15 isfully opened, the critical crosssectional area F, of the turbine system 13 is blocked, this area F, being formed between a terminal edge 21 of the second slide 17 and a divergent wall section 22 of an inner central element (the position of the second slide 17 shown in full lines).

The first slide 14 and the second slide 17 are operable, via a common steering unit '23, in such a manner that the sum of the openings at the critical cross sections F, plus F remains constant. That is, the critical cross sectional area F, of the turbine system 13 is opened to the same extent as the critical cross section F, of the nozzle is blocked, or vice versa.

It can furthermore be seen from FIG. 1 that the crosssectional widening from F, to F provided by the guide mechanism or diffuser 24 of the turbine system 13 and any power loss resulting therefrom do not play any appreciable role, especially when the useful output to be derived from the turbine system 13 is to be made available, for example, for driving a lift rotor which is not further illustrated in the drawings. For this purpose, the shaft 25 of the turbine system 13 is in power connection with a drive shaft 27 leading to the lift rotor via a miter gear 26.

By means of the control device 23, the respective relative motion of the first and second slides 14, 17 can be picked up via levers 28, 29 and connected linkages 30, 3l, by means of commonly driven shafts and cams attached thereto (not shown). The control device 23 can be driven pneumatically, i.e., by an air motor fed, for example, with air tapped from the compressor 1 of the gas generator G.

The embodiment of FIG. 2 deviates from that of FIG. I essentially in that the critical cross-sectional area F, of the turbine system 13' is formed between the outer wall section 32 ofa feed duct 33 and a terminal section 34 of the second slide 35.

In a further modification as compared to FIG. 1, the second slide 35 in FIG. 2 is shaped in the form ofa central element provided with a curved wall section 36 in order to conduct the gases in an aerodynamically favorable manner to the turbine system 13' or the nozzle 15.

Other than as indicated above, the embodiment of FIG. 2 is identical to that of FIG. 1 with respect to its mode of operation, so that the explanations set forth in connection with FIG. 1 apply in this respect, including the reference numerals.

In the embodiment of FIG. 3, the turbine system 37, inclusive of the devices (inter alia, second slide 38) for controlling the critical cross-sectional area F, thereof, is disposed in a plane spatially offset with respect to the plane of the gas generator G and the nozzle 39. In this example, the critical through-flow cross section F, of the turbine system 37 is set essentially between a terminal edge 40 of the second slide 38 and a wall 42 externally defining the feed duct 41 or an inner sealing strip 43 pertaining to this wall.

The critical cross section F, of the nozzle .39 is adjusted essentially between the convergent wall 44 of a mushroom-shaped first slide 45 shaped in a divergentconvergent manner, and the outer jacket 46 and/or a sealing strip 46 of a nozzle duct 47.

The actuation of the

slides

45, 38 of FIG. 3 lows:

A drive motor 48 drives the central shaft 51 via a shaft 49 and a bevel gear 50, and thus the first slide 45, engaging this shaft 51 by means of a spindle 52 thereof,

is as folwhich slide is, in turn, axially displaceably mounted to an inner central element 53, can be brought, for example, into the position shown in dashed lines to block the nozzle 39. Simultaneously during this above-described shifting phase of the first slide 45, the central shaft 51 produces, via a further bevel gear 54, a rotational movement of the shaft 55 oriented to the turbine system 37; the spindle 56 of this shaft causes the second slide 38 engaging this spindle to move from the position shown in dashed lines into the position illustrated in full lines, whereby the critical cross-sectional area F, is made available.

The turbine system 37 which is thereby under the load of exhaust gases of the gas generator G (see also FIGS. 1 and 2) can, for example, drive a lifting jet (not illustrated) via shaft 57 and/or the gases exiting from the turbine system 37 can be fed to a pivotably mounted elbow-shaped auxiliary nozzle 58, for example in order to produce differential lateral thrust components for controlling the airplane.

An important factor in the embodiment of FIG. 3, just as in FIGS. 1 and 2, is that the change-over phases from one through-flow cross section, e.g., F to another, e.g., F,, or vice versa, can be executed continuously or gradually. This factor, just as the permanent maintenance of a constant total exit cross section of the gases, formed from the sum of F, and F is of special importance for any transitional phases of an airplane operation, i.e., from horizontal flight to vertical flight, or vice versa.

While I have shown and described several embodiments in accordance with the present invention, it is understood that the same is not limited thereto but is susceptible of numerous changes and modifications as known to a person skilled in the art, and I therefore do not wishto be limited to the details shown and described herein but intend to cover all such changes and modifications as are within the scope of those skilled in the art.

I claim: 1. An engine arrangement comprising: gas generator means for supplying exhuastgases,

a turbine system arranged downstream of said gas generator means, said turbine system having a first inlet for accepting said exhaust gases to drive said turbine system, said first inlet having a first critical cross-section corresponding to optimum driving of said turbine system by said exhaust gases,

a thrust nozzle arranged downstream of said gas generator means, said thrust nozzle having a second inlet for accepting said exhaust gases, said second inlet having a second critical cross-section corresponding to optimum operation of said thrust nozzle by said exhaust gases,

first inlet blocking means for selectively varying the inlet opening at said first critical cross-section,

second inlet blocking means for selectively varying the inlet opening at said second critical crosssection,

and control means interconnecting said first and second inlet blocking means such that opening of said first critical cross-section results in simultaneous closing of said second critical cross-section and a closing of said first critical cross-section results in simultaneous opening of said second critical crosssection,

wherein said first and second critical cross sections are annular shaped, and wherein said first and second inlet blocking means are constructed as respective rotationally symmetrical first and second slide members. 2. An arrangement according to claim 1, wherein said first inlet blocking means includes means for varying the opening at said first critical cross section from an extreme open position corresponding to optimum operation of said turbine system utilizing all of said exhaust gases to an extreme closed position corresponding to complete shutdown of said turbine system utilizing none of said exhaust gases, wherein said second inlet blocking means includes means for varying the opening at said second critical cross section from an extreme open position corresponding to optimum operation of said thrust nozzle utilizing all of said exhaust gases to an extreme closed position corresponding to a complete shutdown of said thrust nozzle utilizing none of said exhaust gases, and wherein said control means includes means for placing said first inlet blocking means in said closed position when said second inlet blocking means is in said open position and for placing said first inlet blocking means'in said open position when said second inlet blocking means is in said closed position.

3. An arrangement according to claim 1, wherein said first critical cross section has the same size as said second critical crosssection.

4'. An arrangement according to claim 2, wherein said first critical cross section has the same size as said second critical cross section.

5. An arrangement according to claim 4, wherein said control means includes a common control device for moving said slide members in such a manner that closing movement of one of said slide members is accompanied by a similar opening movement of the other of said slide members, whereby the total cross sectional area at said first and second cross sections remains constant for all operating conditions of the turbine system and thrust nozzle.

6. An arrangement according to claim 5, wherein said common control device includes pneumatic means for moving said. slide members. 1

7. An arrangement according. to claim 5, wherein said second critical cross section is formed between a terminal edge of said second slide member and a terminal edgeof an annular jacket surrounding'the turbine system.

8. An arrangement according to claim 7, wherein said first critical cross section is formed between a di- .vergent wall section of an inner central element of the turbine system and a terminal edge of said first slide member.

9. An arrangement according to claim 8, wherein said first critical cross section is formed. between an outer wall section of said first inletand a terminal 'section of said first slide member.

10. An arrangement according to claim 9, wherein said first slide member is shaped inthe form of a central element provided with a curved wall section for aerodynamically guiding said exhaust gases to one of said turbine system and thrust nozzle.

11. An arrangement according to claim 10, wherein said gas generator means and said thrust nozzle are disposed in a common plane, and wherein said turbine system and said first inlet blocking means are disposed in a plane spatially ofi'set with respect to said common plane.

12. An arrangement according to claim 10, wherein said gas generator means includes a turbine and compressor unit mounted for rotation on a gas generator shaft, wherein said turbine system includes a turbine wheel mounted for rotation on a turbine system shaft, and wherein said turbine system shaft and said gas generator shaft extend along a common axis.

13. An arrangement according to claim 12, wherein said thrust nozzle is symmetrically arranged about said common axis.

14. An arrangement according to claim 10, wherein said thrust nozzle is symmetrically arranged about an axis extending in the longitudinal direction of said gas generator shaft.

15'. An arrangement according to claim 5, wherein said first critical-cross section is formed between an outer wall section of said first inlet and a terminal section of said first slide member.

16. An arrangement according to claim 5, wherein said gas generator means and said thrust nozzle are disposed in a common plane, and wherein said turbine system and said first inlet blocking means are disposed in a plane spatially offset with respect to said common plane.

17. An arrangement according to claim 5, wherein said first critical cross section is formed between a divergent wall section of an inner central element of the. turbine system and a terminal edge of said first slide member.

18. An arrangement according to claim 4, wherein said second critical cross section is formed between a terminal edge of said second slide member and a terminal edge of an annular jacket surrounding the turbine system.

19. An arrangement according to claim 4, wherein said first critical cross section is formed between a divergent wall section of an inner central element of the turbine system and a terminal edge of 'said first slide member.

20. An arrangement according to claim 4, wherein said first critical cross section is formed between an outer wall section of said first inlet and a terminal section of said first slide member. I

21. An arrangement according to claim 20, wherein said first slide member is shaped in the form of a central element provided with a curved wall section for aerodynamically guiding said exhaust gases to one of said turbine system and thrust nozzle.

22. An arrangement according to claim 4., wherein said gas generator means and said thrust nozzle are disposed in a common plane, and wherein said turbine system and said first inlet blocking means are disposed in a plane spatially offset with respect to said common plane.

23. An arrangement according to claim 4, wherein said gas generator means includes a turbine and compressor unit mounted for rotation on a gas generator shaft, wherein said turbine system includes a turbine wheel mounted for rotation on a turbine system shaft, and wherein said turbine system shaft and said gas generator shaft extend along a common axis.

24. An arrangement according to claim 23, wherein said thrust nozzle is symmetrically arranged about said common axis.

25. An arrangement according to claim 23, wherein said slide members are constrained to move only in a direction parallel to said common axis.

26. An arrangement according to claim 4, wherein said gas generator means includes a turbine and compressor unit mounted for rotation on a gas generator shaft, wherein said turbine system includes a turbine wheel mounted for rotation on a turbine system shaft, and wherein said turbine system shaft is angularly disposed with respect to said gas generator shaft.

27. An arrangement according to claim 26, wherein said control means includes a common drive motor drivingly connected to said first and second slide members by way of shafts and spindles.

28. An arrangement according to claim 26, wherein said first slide member is constrained to move only in a direction parallel to said turbine system shaft, and wherein said second slide member is constrained to move only in a direction parallel to said gas generator shaft.

29. An arrangement according to claim 4, wherein said control means includes a common drive motor drivingly connected to said first and second slide members by way of shafts and spindles.

30. An arrangement according to claim 29, wherein said turbine system includes means for driving a lift rotor or lifting jet of an airplane, and wherein said thrust nozzle is operatively arranged for providing cruising thrust to said airplane.

31. An arrangement according to claim 4, wherein said turbine system includes means for driving a lift rotor or lifting jet of an airplane, and wherein said thrust nozzle is operatively arranged for providing cruising thrust to said airplane.

32. Anarrangement according to claim 3, wherein said second critical cross section is formed between a terminal edge of said second slide member and a terminal edge of an annular jacket surrounding the turbine system.

33. An arrangement according to claim 3, wherein said first critical cross section is formed between a divergent wall section of an inner central element of the turbine system and a terminal edge of said first slide member.

34. An arrangement according to claim 1, wherein said turbine system includes means for driving a lift rotor or lifting jet of an airplane, and wherein said thrust nozzle is operatively arranged for providing cruising thrust to said airplane.

Claims

1. An engine arrangement comprising: gas generator means for supplying exhuast gases, a turbine system arranged downstream of said gas generator means, said turbine system having a first inlet for accepting said exhaust gases to drive said turbine system, said first inlet having a first critical cross-section corresponding to optimum driving of said turbine system by said exhaust gases, a thrust nozzle arranged downstream of said gas generator means, said thrust nozzle having a second inlet for accepting said exhaust gases, said second inlet having a second critical cross-section corresponding to optimum operation of said thrust nozzle by said exhaust gases, first inlet blocking means for selectively varying the inlet opening at said first critical cross-section, second inlet blocking means for selectively varying the inlet opening at said second critical cross-section, and control means interconnecting said first and second inlet blocking means such that opening of said first critical crosssection results in simultaneous closing of said second critical cross-section and a closing of said first critical crosssection results in simultaneous opening of said second critical cross-section, wherein said first and second critical cross sections are annular shaped, and wherein said first and second inlet blocking means are constructed as respective rotationally symmetrical first and second slide members.

2. An arrangement according to claim 1, wherein said first inlet blocking means includes means for varying the opening at said first critical cross section from an extreme open position corresponding to optimum operation of said turbine system utilizing all of said exhaust gases to an extreme closed position corresponding to complete shutdown of said turbine system utilizing none of said exhaust gases, wherein said second inlet blocking means includes means for varying the opening at said second critical cross section from an extreme open position corresponding to optimum operation of said thrust nozzle utilizing all of said exhaust gases to an extreme closed position corresponding to a complete shutdown of said thrust nozzle utilizing none of said exhaust gases, and wherein said control means includes means for placing said first inlet blocking means in said closed position when said second inlet blocking means is in said open position and for placing said first inlet blocking means in said open position when said second inlet blocking means is in said closed position.

3. An arrangement according to claim 1, wherein said first critical cross section has the same size as said second critical cross section.

4. An arrangement according to claim 2, wherein said first critical cross section has the same size as said second critical cross section.

6. An arrangement according to claim 5, wherein said common control device includes pneumatic means for moving said slide members.

7. An arrangement according to claim 5, wherein said second critical cross section is formed between a terminal edge of said second slide member and a terminal edge of an annular jacket surrounding the turbine system.

8. An arrangement according to claim 7, wherein said first critical cross section is formed between a divergent wall section of an inner central element of the turbine system and a terminal edge of said first slide member.

9. An arrangement according to claim 8, wherein said first critical cross section is formed between an outer wall section of said first inlet and a terminal section of said first slide member.

10. An arrangement according to claim 9, wherein said first slide member is shaped in the form of a central element provided with a curved wall section for aerodynamically guiding said exhaust gases to one of said turbine system and thrust nozzle.

11. An arrangement according to claim 10, wherein said gas generator means and said thrust nozzle are disposed in a common plane, and wherein said turbine system and said first inlet blocking means are disposed in a plane spatially offset with respect to said common plane.

15. An arrangement according to claim 5, wherein said first critical cross section is formed between an outer wall section of said first inlet and a terminal section of said first slide member.

17. An arrangement according to claim 5, wherein said first critical cross section is formed between a divergent wall section of an inner central element of the turbine system and a terminal edge of said first slide member.

19. An arrangement according to claim 4, wherein said first critical cross section is formed Between a divergent wall section of an inner central element of the turbine system and a terminal edge of said first slide member.

20. An arrangement according to claim 4, wherein said first critical cross section is formed between an outer wall section of said first inlet and a terminal section of said first slide member.

22. An arrangement according to claim 4, wherein said gas generator means and said thrust nozzle are disposed in a common plane, and wherein said turbine system and said first inlet blocking means are disposed in a plane spatially offset with respect to said common plane.

32. An arrangement according to claim 3, wherein said second critical cross section is formed between a terminal edge of said second slide member and a terminal edge of an annular jacket surrounding the turbine system.