Drive means for connecting a gas turbine engine to its accessories are so constructed as to allow the accessories to be selectively positioned to any one of several predetermined circumferential positions about the perimeter of the engine. This feature permits convenient mounting of the same engine upon vehicles demanding radically different engine mounting arrangements

Adamson, A. P.

Sargisson, D. F.

English

NASA Technical Reports Server

United States Patent 1191 
Sargisson et al. 
[111 4,068,470 
[451 Jan. 17, 1978 
[54] GAS TURBINE ENGINE WITH 
CONVERTIBLE ACCESSORIES 
[75] Inventors: 
[73] Assignee: 
[21] Appl. No.: 
[22] Filed: 
Donald F. Sargisson; Arthur P. 
Adamson, both of Cincinnati, Ohio 
The United States of America as 
represented by the Administrator of 
the National Aeronautics and Space 
Administration, Washington, D.C. 
522,109 
Nov. 8, 1974 
[51] Int. Cl.2 ........................ F02K 3/02; F16H 35/00; 
F16H 1/14 
[52] U.S. Cl. .................................... 60/226 R; 74/385; 
74/4 1 7 
[58] Field of Search ......................... 74/417, 423, 385; 
60/226 R, 39.31 
[561 References Cited 
U.S. PATENT DOCUMENTS 
2,803,943 SA951 Rainbow ......................... 60/39.31 X 
2,815,834 12/1957 Mall ................................... 74/385 X 
2,932,443 4/1960 Gunberg ................................ 74/417 
2,978,209 4/1961 
3,269,118 8/1966 
3,478,620 11/1969 
3,608,684 9/1971 
3,638,421 2/1972 
3,779,006 12/1973 
3,786,691 1/1974 
3,792,586 2/1974 
3,799,476 3/1974 
3,830,058 8/1974 
Kerry ..................................... 244/54 
Benedict et al. .................... 60/39.31 
Shimanckas ....................... 74/417 X 
Shimanckas ....................... 74/417 X 
Chilman .............................. 60/39.3 1 
Lewis et al. ........................ W39.11 
Lmdstrom ......................... 74/417 X 
Kasmarik et al. ................. 60/226 R 
Bouiller et al. .................... 24/60 X 
Ainsworth ......................... 60/226 R 
Primary Examiner-Leonard H. Gerin 
Attorney, Agent, or Firm-Norman T. Musial; Robert C. 
Lampe, Jr.; Derek P. Lawrence 
1571 ABSTRACT 
Drive means for connecting a gas turbine engine to its 
accessories are so constructed as to allow the accesso- 
ries to be selectively positioned to any one of several 
predetermined ciramferential positions about the pe- 
rimeter of the engine. This feature permits convenient 
mounting of the same engine upon vehicles demanding 
radically different engine mounting arrangements. 
5 Claims, 2 Drawing Figures 
https://ntrs.nasa.gov/search.jsp?R=19780009113 2020-03-20T12:48:07+00:00Z
U.S. Patent Jan. 17, 1978 Sheet 1 of 2 4,068,470 
U.S. Patent Jan. 17, 1978 Sheet 2 of 2 4,068,470 
7& 
74 
I 
4.068,470 
1 
GAS TURBINE ENGINE WITH CONVERTIBLE 
ACCESSORIES 
The invention described herein was made in the per- 
formance of work under a NASA contract and is sub- 
ject to the provisions of Section 305of the National 
Aeronautics and Space Act of 1958, Public Law 
85-568(72 Stat. 435; 42 USC 2457). 
BACKROUND O F  THE INVENTION 
This invention relates to gas turbine engines and, 
more particularly, to engine-driven accessories for use 
therewith. 
Jet engines for powering aircraft are provided with 
engine-driven accessories to provide essential service 
and regulatory functions. These accessories are typi- 
cally mounted upon the engine casing structure and, as 
with the remainder of the engine, are typically enclosed 
in a nacelle or other streamlined structure which enve- 
lopes the engine to reduce overall aerodynamic drag. 
However, as the complexity of accessories steadily 
increases, and the space available within the nacelle 
remains at best the same, the gas turbine engine designer 
is faced with the dilemma of where to locate the acces- 
sories so as not to increase the nacelle diameter with 
consequent drag penalties. 
The problem is compounded when gas turbine de- 
signers are also faced with having to configure their 
engines for various unique applications demanding radi- 
cally different engine mounting arrangements. For ex- 
ample, in the aeronautics field it is contemplated that 
the same basic aircraft engine will find application in 
aircraft having conventional under-the-wing (UTW) 
pylon mounting, and yet also be required for adaptation 
to aircraft having over-the-wing (OTW) engine mount- 
ing. The latter configuration appears extremely attrac- 
tive for short take-off and landing (STOL) aircraft 
where the gas turbine engine exhaust will be used to 
provide aircraft wing lift augmentation by the Coanda 
effect of blowing across the upper surface of a wing and 
connected flap system. 
Since essential aircraft accessories are powered by 
the gas turbine engine, it is common to locate the air- 
craft and engine accessories in close relative proximity 
to be driven by a common engine power shaft. On ad- 
vanced engines such as the General Electric CF6-50 
engine, all engine-driven accessories are mounted on a 
gearbox located on the engine fan casing at the bottom 
of the engine, within the nacelle. However, such an 
arrangement necessitates relatively complex plumbing 
to operatively connect the accessories to the aircraft, 
since the accessories are located on the bottom of the 
engine while the engine is typically suspended from the 
aircraft wing by a structure known as a pylon, the point 
of attachment being at the top of the engine. 
It can be appreciated, therefore, that in order to ob- 
tain highly streamlined nacelles such as taught in co- 
pending application Ser. No. 592,108, filed Nov. 8, 
1974, Adamson et ai, entitled “An Integrated Gas Tur- 
bine Engine-Nacelle,’’ assigned to the same assignee as 
the present invention, and yet maintain flexibility in 
engine mounting configurations, it would be advanta- 
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since this would preclude switching from a UTW air- 
craft to an OTW aircraft without engine tear-down and 
reassembly to replace incompatible hardware. It is con- 
ceivable, as attested by the current trend of airlines to 
standardize their fleets, that an engine could be used on 
more than one type of aircraft application. The problem 
facing the engine manufacturer, therefore, is to provide 
an accessory arrangement which will permit engine 
adaptation to various aircraft configurations, and addi- 
tionally provide for nacelle steamlining. Although this 
invention is directed particularly to aircraft propulsion 
systems, it will become apparent that the invention is 
equally applicable to all vehicles utilizing gas turbine 
engine propulsion. 
SUMMARY O F  THE INVENTION 
The object of the present invention, therefore, is to 
provide a convertible accessory drive arrangement, 
preferably external to the gas turbine engine nacelle, 
which offers flexibility for varying mounting configura- 
tions. This and other objects and advantages will be 
more clearly understood from the following detailed 
description, drawings and specific examples, all of 
which are intended to be typical of rather than in any 
way limiting to the scope of the present invention. 
Briefly stated, the above object is attained by locating 
the engine accessory package external to the nacelle 
structure such that it fits within a pocket formed within 
the aircraft or its pylon. A drive shaft extends from the 
accessory package, through a hollow strut, into engage- 
ment with the main core engine shaft drivingly connect- 
ing the compressor and turbine portions. At least one 
other hollow strut is provided so that, if it is desirable to 
relocate the accessories, they may be removed and the 
drive shaft withdrawn from the first strut. Subse- 
quently, the drive shaft may be reinstalled within the 
second hollow strut, thus re-engaging in driving con- 
nection the core engine shaft and the accessories. 
DESCRIPTION OF THE DRAWING 
FIG. 1 is a composite schematic representation of a 
gas turbine engine incorporating the subject invention, 
the engine being mounted in either of two different 
configurations; and 
FIG. 2 is an enlarged composite schematic represent- 
ing one embodiment of the subject invention. 
DESCRIPTION O F  THE PREFERRED 
EMBODIMENT 
Referring to the drawings wherein like numerals 
correspond to like elements throughout, reference is 
first directed to FIG. 1 wherein an engine depicted 
generally at 10 and embodying the present invention is 
diagrammatically shown. This engine may be consid- 
ered as comprising generally a core engine 12, a fan 
assembly 14 including a stage of fan blades 15, and a fan 
turbine 16 which is interconnected to the fan assembly 
14 by shaft 18. The core engine 12 includes an axial flow 
compressor 20 having a rotor 22. Air enters inlet 24 and 
60 is initially compresse;d by fan assembly 14. A first por- 
tion of this compressed air enters the fan bypass duct 26 
defined, in part, by core engine 12 and a circumscribing 
fan nacelle 28 and discharges through a fan nozzle 30. A 
I Y 
geous to have the engine-driven accessories external of second portion of the compressed air enters inlet 32, is 
the nacelle and located at the optimum circumferential 65 further compressed by the axial flow compressor 20 and 
location consistent with particular aircraft mounting. then is discharged to a combustor 34 where fuel is 
Ideally, any one particular engine should not be limited burned to provide high energy combustion gases which 
to one circumferential location for its driven accessories drive a turbine 36. The turbine 36, in turn, drives the 
4,068,470 
3 4 
rotor 22 through a shaft 38 in the usual manner of a gas cated further aft in this configuration as a result of spe- 
turbine engine. The hot gases of combustion then pass cial consideration and are driven by shaft 78. 
to and drive the fan turbine 16 which, in turn, drives the As clearly shown in phantom in FIG. 2, the meshing 
fan assembly 14. A propulsive force is thus obtained by of bevel gears 60 and 62' occurs at 64', but by virtue of 
the action of the fan assembly 14 discharging air from 5 bevel gears 68' and 70', the direction of rotation of 
the fan bypass duct 26 through the fan nozzle 30 and by accessory drive shaft 6 6  remains unchanged as depicted 
the discharge of combustion gases from a core engine by the rotational arrows. This ensures proper operation 
nozzle 40 defined, in part, by plug 42. The above de- of all accessory components without the necessity of 
scription is typical of many present-day gas turbine modification. 
engines and is not meant to be limiting, as it will become 10 In operation, when it is desired to switch the engine 
readily apparent from the following descriptions that from a UTW configuration to an OTW configuration, 
the present invention is capable of application to any the operator merely has to disconnect the engine acces- 
gas turbine engine and is not necessarily restricted to sories 52 from the aircraft accessories 50, pull the engine 
gas turbine engines of the turbofan variety. The forego- accessories and drive shaft 56 from strut 58 and engage- 
ing description of the operation of the engine depicted 15 ment with core shaft 38, and reinsert the assembly into 
in FIG. 1 is, therefore, merely meant to be illustrative of another hollow strut 58' whereupon engagement with 
one type of application. core shaft 38 is re-established. Alternatively, a plurali! y 
Continuing with the description of the embodiment of drive shafts, such as 56 and 56,  could remain operd- 
of the invention as depicted in the upper portion of tively connected to the core shaft 38 with the point of 
FIG. 1, it is shown therein that engine 10 is suspended 
from a pylon depicted generally at 44 which, in turn, is 
suspended from and integral with an aircraft wing 46 by 
means of truss structure 48. The aircraft propulsion 
mounting system herein discussed is provided as an 
example of possible uses for the subject invention as it 
will become apparent that the invention is equally appli- 
cable to all vehicles utilizing gas turbine propulsion. 
This configuration is representative of under-the-wing 
(UTW) engine mounting. Pylon 44 is shown to include, 
and have disposed within, aircraft accessories depicted 
generally at 50. Critical engine accessories depicted 
generally at 52 are located within a pocket 54 of the 
pylon 44 although they are an integral part of the engine 
hardware. Appropriate disconnects are provided, as at 
55 and 57, to allow separation of the engine from the 
pylon and aircraft accessories. The engine accessories 
are drivingly connected to the core engine 12 through a 
driving means, such as a drive shaft 56, which is routed 
through one of a plurality of struts 58 spanning the fan 
bypass duct 26. 
Referring now to FIG. 2, there is schematically de- 
picted in greater detail the accessory drive arrangement 
of FIG. 1. The upper half of FIG. 2 is consistent with 
the OTW mounting arrangement hereinbefore dis- 
cussed. The core engine shaft 38 is shown to have inte- 
gral therewith a first gear means, such as bevel gear 60. 
Drive shaft 56 includes a second gear means such as 
bevel gear 62, which drivingly engages bevel gear 60 as 
at 64. Drive shaft 56 is operatively connected to an 
engine accessories drive shaft 66 by known geared en- 
gagement means such as bevel gears 68 and 70, the 
accessory drive shaft 66 being an integral portion of the 
engine accessories denoted generally at 52. The aircraft 
accessories, generally denoted at 50, are drivingly con- 
nected to the drive shaft 56 as by cooperating bevel 
gears 72 and 74, and shaft 76. 
In a modified configuration shown is phantom in 
FIG. 1 and 2, the engine accessory package is adapted 
for an over-the-wing engine mounting arrangement. As 
depicted in phantom in FIG. 1, it is shown therein that 
engine 10 is mounted over a wing 46' by means of coop- 
erating pylon assembly 44'. The engine accessories 52' 
are here mounted below the engine, external to the 
nacelle 28 and located within pylon 44'. Again, the 
engine accessories are drivingly connected to core en- 
gine 12 by means of drive shaft 5 6  which has now been 
inserted through a hollow strut 58' located at the bot- 
tom of the engine. The aircraft accessories 50' are lo- 
20 engine accessory disengagement occurring between 
gears 68 and 70. Appropriate blank-off plates (IS I 
shown) would serve to cover the drive shafts not being 
used. This arrangement would be applicable where it  
was desired to mount the engine accessories in the 
25 pylon structure and have them remain there when the 
engine and nacelle structure was dismounted from the 
aircraft. Such an arrangement is particularly attractive 
from an aircraft operator's point of view since he need 
maintain a supply of accessories approximately equal to 
30 his aircraft needs, independent of the number of spare 
engines on hand. Therefore, the operator may maintain 
a minimum engine build-up unit comprising the mini- 
mum required engine components, thus enhancing his 
quick-engine-change capability. Yet another alternative 
35 would include redundant drive shaft gears 62 and 
62'(FIG. 2) permanently installed in the engine, the 
remainder of the drive shaft 56 being so constructed as 
to permit a driving connection with either gear. This 
arrangement is attractive where the required size of the 
40 gear is greater than the available hole through which it 
would otherwise have to pass. 
It should be obvious to one skilled in the art that 
certain changes can be made to the above-described 
invention without departing from the broad inventive 
45 concepts thereof. for example, as previously mentioned, 
the above invention is applicable to any gas turbine 
engine and is not limited to those of the gas turbofan 
variety. Further, it is contemplated that alternative 
gearing arrangements are possible in order to achieve 
50 the broad inventive concepts of the subject invention. 
Still further, it is readily apparent that the subject inven- 
tion is not limited to over-the-wing and under-the-wing 
applications, but is applicable when accessories con- 
vertibility is desired between any two or more acces- 
55 sory mounting locations on any gas turbine engine pro- 
pelled vehicle.It is intended that the appended claims 
cover these and all similar variations of the present 
invention's broader inventive concepts. 
What is claimed is: 
1. A gas turbine engine comprising: 
a core engine including a core shaft; 
a nacelle partially circumscribing said core engine; 
first gear means within said core engine and driven by 
said core shaft; 
a plurality of circumferentially spaced hollow struts 
extending radially between said core engine and 
said nacelle and in general axial alignment with said 
first gear means; 
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4,068,470 
r: J 
convertible accessory means disposed external to said 
nacelle and in general alignment with one of said 
struts; and 
drive shaft means, one end of which is drivingly con- 
nected to said accessory means, and the other end 
of which includes a second gear means insertable 
into any of said hollow struts and into driving en- 
gagement with said first gear means, and 
wherein said first gear means and said second gear 
means may be disengaged by withdrawing said 
drive shaft means radially outwardly with respect 
to said core shaft. 
2. The gas turbine engine of claim 1 wherein said first 
gear means and said second gear means are bevel gears. 
3. The gas turbine engine of claim 2 wherein said 
drive shaft means is integral with said accessory means 
and removable from the engine therewith. 
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4. The gas turbine engine as recited in claim 1 
wherein said first gear means is disposed upon said core 
shaft. 
5. A gas turbine engine comprising: 
a core engine including a core shaft; 
a nacelle partially circumscribing said core engine; 
first gear means within said core engine and driven by 
said core shaft; 
a plurality of circumferentially spaced hollow struts 
extending radially between said core engine and 
said nacelle and in general axial alignment with said 
first gear means; 
convertible accessory means disposed external to said 
a 
nacelle and in general alignment with one of said 
struts; and 
plurality of circumferentially spaced drive shaft 
means in geared engagement with said first gear 
means, and wherein said accessory means are oper- 
atively connected to one of said drive shaft means. 
* * I * *  
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Gas turbine engine with convertible accessories

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