US2926491A

US2926491A - Actuating means for variable nozzles

Info

Publication number: US2926491A
Application number: US756933A
Authority: US
Inventors: Hyde John Alan Courtney
Original assignee: Orenda Engines Ltd
Current assignee: Orenda Engines Ltd
Priority date: 1958-08-25
Filing date: 1958-08-25
Publication date: 1960-03-01
Anticipated expiration: 1977-03-01
Also published as: FR1233323A

Description

March l, 1960 J. A. c. HYDE ACTUATING MEANS FOR VARIABLE NozzLEs 3 Sheets-Sheet 1 Filed Aug. 25, 1958 AT1-owns March l, 1960 J. A. C. HYDE ACTUATING MEANS FOR VARIABLE NOZZLES 3 Sheets-Sheet 2 Filed Aug. 25, 1958 INVENTORI J. A. C. HYDE'.

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March 1 1 960 J. A. c. HYDE ACTUATING MEANS FoR VARIABLE Noz'zLEs 3 Sheets-Sheet 3 Filed Aug. 25, 1958 lNveNTof/ JACHYDL: BY

ATToRgl Evs 2,926,491 ACTUATING MEANS FR VARIABLE NOZZLES John Alan Courtney Hyde, Georgetown, Ontario, ,Canada, assignor to Orenda Engines Limited, Mahon, ntario, Canada, a corporation of Canada Application August 25, 1958, Serial No. 756,933 Claims. (Cl. 60-35.6)

This invention relates to variable area nozzles and to means for actuating variable area nozzles of the type used in aircraft in conjunction with reaction propulsion units.

Such variable nozzles usually consist of a plurality of circumferentially arranged, longitudinally extending, movableaps which dene a duct terminating in a 'nozzle opening of variable area, means being provided to move the flaps to vary the area of the nozzle opening.

A major difficulty to be overcome in designing such nozzles is the restricted space available for mounting the actuating means for moving the nozzle flaps. A further diiiiculty encountered in the design of divergent nozzles is that, although it is desirable to mount the actuating means as far to the rear as possible, the space available for the mounting of such means decreases as one moves further towards the rear. Moreover it is difficult to support the actuating means in the restricted space available in such a manner that the stresses set up in the actuating means by the gas ow through the nozzle are absorbed without distortion of the actuating means.

It is an object ofthe present invention to provide means for actuating a variable area nozzle capable of being mounted in a restricted space.

Another object of the invention is to provide means for actuating a Variable nozzle which may be located at a desired position without limiting the range of movement of the nozzle aps to the extent that known mechanisms limit such movement.

A further object of the invention is to providemeans for actuating a variable nozzle in which the circumferential stresses set up in the actuating means by the gas tlow through the nozzle are absorbed vby the actuating means itself.

A still further object of the invention is to provide a variable nozzle assembly having actuating means whichl I absorbs the circumferential or hoop stresses set up in the nozzle by the gas flow therethrough. v

The invention will now be described by way of example with reference to the accompanying drawings, in which like reference numerals indicate similar parts throughout the several views, and in which:

Figure V1 is a perspective view'of a convergent-divergent nozzle, parts of the nozzle being broken away more clearly to show the construction, the convergent portion of the nozzle being operated by one form of actuating means according to the invention and the divergent portion of the nozzle being actuated by another form of actuating means according to the invention,

Figure 2 is a part longitudinal section of the con-v vergent-divergent nozzle shown in Figure 1 with the nozzle in its fully open position,

Figure 3 is a part longitudinal section similar to Figure 2 but showing the nozzle in its fully closed position,

Figure 4 is a perspective view of part of the actuating means associated with the divergent portion of the nozzle,

Figure 5 is a transverse section on the line V-V of Figure 2,

Figure 6 is a transverse section on the line VI-VI of Figure 3,

Figure 7 is a transverse section on 'the line VII-VII of Figure 2, and

Figure 8 is a transverse section on j the une vnrvnl of Figure 3.

Referring now to the drawings,the rear portion of a nacelle, in which is mounted a reaction propulsion unit (not shown), is indicated at '10, and concentrically mounted within the nacelle is the rear portionl of the jet pipe 11 of the propulsion unit. The'jet pipe 11 has a convergent portion 12 terminating in a ring 13 which is provided with a circumferential groove 14 in which are mounted a plurality of flaps 15. Each ap 15 has a hinge portion 16 which is received within the groove 14 and a gas tight connection is made between the hinge portions 16 and the groove 14 by means of wire braid inserted into the groove in known manner.

lThe aps 15 are circumferentially arranged around the jet pipe and define a duct which terminates in a nozzle opening of variable area, the area of the nozzle opening being altered by pivoting the aps 15 about the hinge portions 16 in the groove 14. Upstanding from the exterior surface of the ring'13 are a plurality circumferentially spaced lugs 17 to each of which is pivotally mounted, at 18, an elongated kconnecting member 19, Athe number of connecting members being equal to the number of flaps and each connecting member 19 being associated with a flap 15. Each connecting member 19 is formed adjacent to the end remote from the pivot 18, with a depending slotted portion 20 in the slot of which is received a. bar 21 held in spaced relation from, but secured to, the Hap V15A associated with the member 19 Each connecting member 19 is also formed with half'a bearing housing indicated at 22, the bearing housing being completed by a cap 23 secured in position on the half housing 22 by pins 24.

Mounted in each bearing housing 22, '23 is a supporting member 25 o'f generally recurved form, in the embodiment shown each supporting member 25 is generally U-shaped. The supporting members 25 each comprise a pair of arms 26, one at each end of an axle 27, the axle being received in the bearing

housing

22, 23 von the connecting member. One of the arms 26 of each supporting member 25 is slotted as indicated at 28 in Figure 3, while the other of the arms is provided with a reduced portion 29 arranged to be received in the slot 28 in an arm of an adjacent supporting member.

Referring now to Figure 5, it will be seen that the supporting members 25 carried `in the bearing housings of adjacent connecting members 19 have the ends of their arms 26 connected together through part-spherical bear ings. In each slot 28 in an arm 26 is mounted a partspherical elementV 30 held in position by a pin 31 and each reduced portion 29 is provided with a part-spherical aperture which embraces the part-spherical element 30. As will be clearly seen from Figure l, the supporting members 25 are pivotally `interconnected adjacent to the ends of the arms 26 to form a closed chain around the duct formed by the flaps 15.

Each supporting member 25 is rotatable about a,-

straight line axis, the straight line axes of adjacent supporting members intersecting in points which lie on a circle common to all the supporting members of the chain. Referring to Figure 5, the supporting member indicated at 25a is rotatable about a straight line axis indicated in chain dotted lines at 32. Similarly, the supporting member 25b is. rotatable about a straight line axis indicated in chain dotted lines at 33. The

axes

32, 33 intersect at a point 34 and the points of intersection of the rotation axes of each pair of adjacent supporting members intersect in points similar to the point 34, all the points lying on an imaginary circle common to all the members 25 in the chain, the circle is indicated, in Figure 5 at 35. It follows that the axes of rotation of the supporting member are chords of the circle 35 and intersect in points lying Von the circle.

Each supporting member 25 is provided, intermediate the ends of its axle 27, with an arm 36 which projects through aslot 37 provided in each bearing housing cap 23 Vfor that purpose. As shown in Figures l, 2 and 3, each arm 36 is pivotally attached at 38 to' an associated connecting rod 39, all the rods 39, at their other ends, being pivotally attached, at `40, to a box section unison ring 41. The unison ring 41 is in turn pivotally connected at 42 tothe piston rods 43 of a plurality of hydraulic actuators, one of which is shown at The actuators are circumferentially spaced around the jet pipe 11 and are secured to the inner wall of the nacelle by standards 45 to which the actuators are pivotally connected at 46. Y

Referring now to Figure 5, the clearances between the longitudinal edges of the aps are sealed by sealing strips 47 which are supported between the flaps 1S in any convenient conventional manner. Y j Referring now to Figures 3, 4 and 7, the nacelle is reinforced at its downstream termination by a box-section ring 48 to which are pivotally attached, as at 49, a plurality of circumferentially arranged, longitudinally extending aps indicated generally at 50.l The flaps 50 serve the dual purpose of forming a continuation of the nacelle as a cowl and connecting the aps of the divergent portion of the nozzle to the actuating means. Each fiap or connecting member 50 is provided with a depending ange 51 in which is formed a half bearing housing S2, the housing being slotted at 53 (see Figure 7)to one lside of the flange 51 and being completed by a slotted bearing cap 54. Received in each bearing housing is a supporting member 55 of generally recurved shape, and consisting of a central axle 56 and a pair of arms 57 at the ends of the axle. Eachsupporting member 55 is generally U-shaped, with the limbs of the U being formed by the arms 57. Fixedly mounted intermediate the ends of the axle 56 on each supporting member 55 is a pinion 58 which 'is embraced by a trunnion member 59 rotatably mounted on the axle 56. The pinion 58 and the trunnion member 59 project through the slot 53 of their associated half bearing housing 52 and also through the slot in the bearing cap 54.

Associated with each pinion 58 is a rack 60 toothed to engage with the pinion and being retained in engagement with the pinion by means of one of the trunnion members 59. Each rack 60 is integral with a connecting rod 61 which is pivoted at its other end, as at 62, to a box section unison ring 63. The unison ring in turn is pivotally connected at 64 tothe piston rods 65 ofra plurality of circumferentially spaced hydraulic actuators, one of which is indicated at 66. Each actuator is pivotally mounted at 67 to a standard 68 secured to the inner wall of the nacelle 10.

n Referring now to Figure 7, the arms 57 of adjacent supporting members 55 are connected together by double hemispherical joints indicatedY generally at 69, the supporting members providing a closed chain around the j divergent duct hereinafter described. Each joint consists of Va. shouldered pin 70 having secured to itsends a pair of hemispherical bearing members 71. The members 71 are secured to the pins 70 by nut and washer assemblies 72 and are received in hemispherical seatings 73 in the ends of the arms 57. The pins 70 pass through tapered apertures 73a in the arms 57.

Each supporting member 55 pivots abouta straight line axis,'thus the member 55a in Figure '7 pivots about an'axis shown inchain dotted lines at 74, while the supporting member 55b rotates about a straight line axis indicatedv at 75.

The'axes

74, 75 intersect at a point 76 which-lies on an imaginary circleindicated at 77. The rotational -axes ofV adjacent supporting members intersect in points on the circle 77 which is common to all the supporting members 55, the axes being chords of the circle.

Secured to the ring 48 are a plurality of longitudinali)l Q extending support bars 78, one for each tiap 50, each bar 78 being formed with a sleeve 79 at its downstream end (see Figures 2, 3 and 4). Slidable in each sleeve is a cylindrical bar 80 having a iiattened apertured end 80a through the aperturefof which passes a pin 7) of one of the double hemispherical joints 69 between the arms 57 of an adjacent pair of supporting members 55 (see Figure 7).

The clearances between the longitudinal edges of adjacent flaps 59 are closed by sealing strips 81, each of which is Welded along one edge to a iiap 50. Also mounted on the flaps are a plurality of longitudinally extending, circumferentially arranged nozzle tiaps 83 which dene a diverging duct. As shown in Figures l and 7, each flap 83 has an upstanding ange member 812 which extends along substantially the whole length of the iiap. The upstream end of each member 84 is pivotally connected as at 85 to one of the connecting members 19. Adjacent to the downstream end of each member 84 is pivotally mounted a link 86, the other end ot the link being pivoted to a flange 51 of a ilap 5G. Sealing strips 87 extend between adjacent flaps 83 to seal the clearances between the longitudinal edges thereof and are supported -by` retaining bars 88, sec Figure l, in known manner.

The operation of the actuating means and nozzle will now be described. The flaps 15 define a duct which forms the convergent portion of the nozzle while the aps S3 define a duct which constitutes the divergent portion of the nozzle and -the setting of the convergent portion may be altered by operating the actuators 44 while the setting of the divergent portion of the nozzle may be adjusted by operating the hydraulic actuators 66. Assuming that the nozzle is in its fully open position as shown in Figure 2 and that it is desired to close down the divergent portion, the actuators 66 are operated to move the unison ring 63 in a downstream direction. As the unison ring 63 moves in a downstream direction, the connecting rods 61 and racks 60 also move in a downstream direction thus turning the pinions 58 mounted on eachflap 50. As the pinions 58 turn, the supporting members are caused to rotate about their straight line axes of rotation, which are fixed in radial position and, therefore, as the pinions rotate in a clockwise direction in Figures 2 and 3 the axles 56 of the supporting members 55 will all move inwardly, and, if the operation is continued, will ultimately assume the positions shown in Figures 3 and 8. The unison ring 63 synchronizcs the movementsy of the supporting members 55.

Similarly, if itl is desired to close down the convergent portion of the nozzle, the actuators 44 are operated to move the unison ring 41 in an upstream direction thereby pivoting in synchronism, by means of the connecting rods 39 and the arms 36, the supporting members 25 about their axes of rotation and, if the ring moves suiiiciently far, the parts will ultimately assume the positions shown in Figures 3 and 6. The unison ring 41 serves to synchronize movements of the supporting members 25.

The positions of the tiaps 83 which form the divergent portion of the nozzle will depend on the relative positions of the connecting membersr19 and the flaps 50 since one end of each flap 83 is pivotally connected at 85 to a connecting member 19 and the other end of the ap is connected through a link 86 to a iiap 50.

l During movement of the aps 50 and the flaps 83 from the positions shown in Figure 2 to the positions shown in Figure 3, the supporting members 55 move in an upstream direction during rotation due to the fact that they are mounted on the flanges 51 of the connecting members 50 which, in turn, are pivoted at 49 to a fixed ring 48. The purpose of the support bars 78, sleeves 79 and bars is to guide the supporting members during their axial movement consequent upon their pivotal mounting. However, due to the fact that the supporting members are pivotally interconnected into a closed chain,

any hoop stress set up in the chain due tothe flow of gases through the nozzle is absorbed by the supporting members themselves so that it is unnecessary to provide undesirably massive structure at the rear end of the nacelle where weight is best kept at a minimum.

Similarly, since the flaps and connecting members 19 are not pivoted about a common point, there is relative axial movement during their pivotal movement. This relative axial movement is accommodated by the sliding of the bars 21 in the slots of the depending slotted mem-I bers 20.

Due to -the generally recurved shape of the supporting

members

25, 55 and to the fact that they are connected together to form a closed chain around the respective ducts, it will be seen that the

aps

15, 83 may come very near to the

imaginary circles

35, 77 about chords of which the supporting members pivot, this is shown particularly in Figures 5 and 8 the radial distances being indicated at A and B respectively. It is thus possible, by means of the invention, to have a closed chain of supporting members which will absorb the hoop stress induced by the reaction of the gas flow through the nozzle but which will, due to the recurved shape of the supporting members have as it were, circumferential discontinuities in which the means connecting the llaps to the supporting members may enter so that the actuating means may be mounted in a restricted space. Moreover, this arrangement permits a greater range of movement of the flaps than with known actuating mechanisms having unison rings surrounding the flaps. In such known mechanisms the structure supporting the vanes may not pass through the circle whereas in the construction which has been described the structure can, as it were, pass through the discontinuities in the circle and thereby give extended movement to the aps. advantage of the invention.

It will be seen that the invention also provides actuating means in which the points of action of the forces applied to the nozzle flaps are remote from their hinge mountings so that good leverage is obtained and the bending moments set up in the flaps reduced.

Although the invention has been described as applied to a convergent-divergent nozzle, actuating means according to the invention may also be applied to variable convergent nozzles or Variable divergent nozzles separately.

It will be understood that the form of the invention herewith shown and described is a preferred example and various modifications can be carried out without departing from the spirit of the invention or the scope of the appended claims.

What I claim as my invention is:

1. Means for actuating a variable nozzle which includes a plurality of circumferentially arranged, longitudinally extending, movable flaps defining a duct terminating in a nozzle opening of variable area, said means comprising a plurality of supporting members circumferentially disposed about the duct, each supporting member having an intermediate portion extending in generally recurved form between the ends of the member, bearing means interposed between the ends of adjacent members and pivotally interconnecting the members to form a closed chain around the duct capable of withstanding hoop stress, each member being rotatable in said bearing means about a straight line axis passing through the bearing means associated with the member to swing the intermediate portion of the member in arcs about said axis, said axes of adjacent members intersecting in points lying on a circle of fixed radius common to all the members, means connecting the members intermediate their ends to the flaps, means synchronising rotation of the members about their respective axes and means to rotate the members about said axes to vary the area of the nozzle opening by swinging said intermediate portions to move the aps.

This is an important' 2. Means for actuating a variable nozzle which includes a plurality of circumferentially arranged, longitudinally extending, movable aps defining a duct terminating in a nozzle opening of variable area, said means comprising a plurality of supporting members of generally recurred form circumferentially disposed about the duct, the members being pivotally interconnected adjacent to their ends to form a closed chain around the duct capable of withstanding hoop stress, each member being rotatable about a straight line axis, the rotational axes of adjacent members intersecting in points lying on a circle common to all the members, connecting members interposed between the supporting members and the aps and pivoted to standing structure, bearing housings on the connecting members for the reception of the supporting members intermediate their ends, a crank arm on each supportingmember intermediate its vends, means synchronising rotation of the supporting members, means connecting the crank arms to the synchronising means and means to rotate the supportingmembers to vary the area of the nozzle opening by moving the flaps.

3. Means for actuating a variable nozzle which includes a plurality of circumferentially arranged, longitudinally extending, movable aps defining a duct terminating in a nozzle opening of variable area, said means comprising a plurality of supporting members of generally recurved form circumferentially disposed about the duct, the members being pivotally interconnected adjacent to their ends to form a closed chain around the duct capable of withstanding hoop stress, each member being rotatable about a straight line axis, the rotational axes of adjacent members intersecting in points lying on a circle common to all the members, connecting members interposed between the supporting members and the aps and pivoted to standing structure, bearing housings on the connecting members for the reception of the supporting members intermediate their ends, a pinion on each supporting member intermediate its ends, a rack associated with each pinion, a unison ring, means connecting all said racks to the unison ring, and means to move the unison ring to vary the area of the nozzle opening by rotating the supporting members to move the aps.

4. Means for actuating a variable nozzle which includes a plurality of circumferentially arranged, longitudinally extending, movable aps defining a duct terminating in a nozzle opening of variable area, said means comprising a plurality of supporting members of generally recurved form circumferentially disposed about the duct, the members being pivotally interconnected adjacent to their ends to form a closed chain around the duct capable of withstanding hoop stress, each member being rotatable about a straight line axis, the rotational axes of adjacent members intersecting in points lying on a circle common to all the members, connecting members interposed between the supporting members and the aps and being pivoted to standing structure, bearing means on the connecting members for rotatably supporting the supporting members intermediate their ends, means synchronising rotation of 7the supporting members about their respective axes and means to rotate the supporting members to vary the area of the nozzle opening by moving the flaps.

5. Meansvfor actuating a variable nozzle which includes a plurality of circumferentially arranged, longitudinally extending, movable flaps defining a duct terminating in a nozzle opening of variable area, said means comprising a plurality of supporting members of generally recurved form circumferentially disposed about the duct, the members being pivotally interconnected adjacent to their ends to form a closed chain around the duct capable ofwthstanding hoop stress, each member being rotatable about a straight line axis, the rotational axes of adjacent members intersecting in points lying on a circle common to all the members, connecting members interposed between the supporting members i? and the flaps, bearin'ghousings on th connecting ineinbe'rs for the reception of the sp'porting members inter mediate their ends; acrank arm on each supporting m'enber intermediate its ends, means synchronising rotation of the supporting me'rnb'ers-,V means connecting the crank arms to the synchronising means and means to rotatethe supporting members to vary the area of the nozzle opening by'moving the naps: t

6. Means for actuating a variable-nozzle which in'cll'des a plurality of circumfer'entiallyI arranged, longitudinally extending, movable flaps dening a d'u'ct terminating in a nozzle opening' of variable area, said means comprising4V porting member intermediate its ends, a ns'n ring; con-` necting rods pivotally connecting all said cranks to the unison ring, and means to move ythe'unison ring to vary the nozzle opening by rotating the slpporting members to move the naps'.

7. Means for actuating a variable nozzle which includes a plurality ofk circumferentially arranged; longitudinally extending, movable naps denninga dnct termi'- nating in a nozzle opening of variable area; said means comprising a plurality of supporting members' of generally recurved form circumferentially posed" about the duct, the members being pivotally interconnected adjacent to their ends to form a closed chain ronnd the duct capable of withstanding hoop stress; each member' being rotatable about a straight line axis; 'tlie rotational axes of adjacent members intersectingl in points lying on a circle common to al1 the members, connecting members interposed between the supporting` members and the naps, bearing housings on the connecting members for the reception of the supporting members intermediate their ends, a pinion on each supporting member inl termediate its ends, a rack associated'witli eacli pinion, a unison ring, means connecting all said racks to the unison ring; and means to move the unison' ring tovary the area of the nozzle opening byfro'ttig the; support'- ing members to movethe naps;

8. Means for actuating a variable nzzl'e which in cludes a pluralityof circumferentially arranged, 1ongitudinally extending; movable flaps pivoted' aton'e end'to standing structure toV denne a duct terminating at the other ends of theaps in a nozzle openingf Variable area, said means comprising a plurality' f supporting members of generally recurved formz circumferentially disposed about the duct, the members being? pivotally interconnected adjacent to their ends to forin a closed chain around the duct capable of 'withstanding hoop stress, each member being rotatable about a straight line axis, the rotational axes of adjacent members intersecting in points lyingon a circle common to all the members, connecting members interposed between the supporting members and the flaps, each connecting member being pivoted to the standingv structure, bearing housings on the connecting members for the reception of theV supporting members intermediate their ends, ,a crank on each recurved member intermediate its ends,y anison ring, connecting Irods piyotally connecting all of said cranks to the unison ring, and means to move: the unison ring to vary the area of the nozzle opening by rotating the members to move the flaps.

9. A variable nozzle assembly for an aircraft `including a plurality of circumferentially arranged, longitudinallyv extending, movable naps defining a dct terminating in fname naar a nozzle opening of variable area, a plurality of support'- ing members of generallyv recurved form circumferentially disposed about the duct, the members being pivotally interconnectedl adjacent to their ends to form a closed chain around the duct capable of withstanding hoop stress, each member being rotatable about a straight line axis, the rotational axes of adjacent members intersecting in points lying on a circle common to all members, a plurality of circumferentially arranged, longitudinally extending connecting members interposed between the liaps and the supporting members and pivoted to standing structure to form a shroud round the duct, bearing housings on the connecting members lfor the reception of the supporting members intermediate their ends, the naps being pivotally connected to the connecting members adjacent to one end thereof, means synchronising rotation of the supporting members about their respectiver axes, and means to rotate the supporting members to vary the area of the nozzle opening by moving the' naps. Y

10. A variable convergent-divergent nozzle for use in aircraft, including a first plurality of circumferentially arranged, longitudinally extending flaps pivoted to standing structure and defining a duct converging to terminate in a nozzle opening of variable area, a rst plurality of supporting members of generally recurved form circumferentially disposed about the first duct, the members being pivotally interconnected adjacent to their ends to form a closed chain around the du'ct capable of withstanding hoop stress, each member being rotatable about a straight line axis, the rotational axes of adjacent members intersecting in points lying on a circle common to all the members, a tirst plurality of connecting members pivoted to the standing structure, a bearing housing on eachv connecting member for the reception oi a supporting member intermediate its ends, means connecting each connecting member with a flap of the first plurality, means synchronising rotation of the supporting members about their respective axes, means to rotate the supporting members about their axes to vary the area of the nozzle opening of the first duct, a second plurality of circumferentially arranged, longitudinally extending movable aps defining-a second duct diverging to-ter'mi'nat'e in a nozzle opening of variable area downstream from the nozzle opening of the first duct, a second.

plurality of supporting-members of generally recurved form circumferentially disposed about the second duct, said supporting members being pivotally interconnected adjacent to their ends to form a closed chain around the second duct capable of withstanding hoop stress, each member being rotatable about a straight line axis, the rotational axes of adjacent members intersecting in points lying on a circle common to all the supporting members of the second plurality, a second plurality of circumferentially arranged, longitudinally extending connecting members pivotally mounted to the standing structure and forming a shroud surrounding and spaced from the second duct, each of said connecting members including a bearing housing for the reception of one of the supporting members of the second plurality, the naps of the second plurality being pivotally connected at their one ends to` the connecting members of the first plurality, and at their other end being pivotally connected to the connecting members of the second plurality, means synchronising rotation of the supporting members of the second plurality and means to rotate said supporting members to vary the area of the nozzle opening of the second duct by moving the naps. Y

References Cited in the tile of this patent' UNITED STATES PATENTS