JPH0425408B2 - - Google Patents

Description

BACKGROUND OF THE INVENTION This invention relates to turbomachines and, more particularly, to gas turbine engine blade mounting assemblies.

The present invention is particularly useful, but not limited, when utilized in conjunction with gas turbine engines having vanes such as fan exit guide vanes and stator vanes. For example, stator vanes typically each have an integral mounting platform at their radially outer end, which platform is secured to the cylindrical stator casing by a retaining ring or by a plurality of mounting bolts. The stator vanes may have roots of complex shapes, such as fir tree or dovetail shapes, which fit into complementary formed slots in the inner stator support ring. Stator vanes with integral platforms and specially shaped roots have been considered essential in the prior art for accurate alignment and secure retention of the stator vanes in the stator casing.

Additionally, as modern aircraft turbine engines are becoming shorter, spacing between fan blades, stator vanes, and frame components must be reduced.
As a result, the fan rotor blades, stator vanes such as exit guide vanes, and the fan frame are in close proximity and aerodynamic interaction occurs between them, so that the desired air passes through each row of stator blades. In order to do this, it is necessary to provide one or more types of stator blades in each blade row. For example, the individual vanes of the exit guide row may have different blade cross-sections and pitches, ie, different blade azimuths relative to the turbine radial axis, to enhance aerodynamic performance.

The aforementioned use of non-uniform blades in turbomachinery and the close proximity of the blades to adjacent engine components has traditionally resulted in relatively complex installations for the installation and removal of individual blades. Required assembly. Such mounting assemblies can include many parts and require precision manufacturing, thus increasing the complexity and expense of manufacturing and assembly. For example, to reduce weight, the attachment members of the assembly are configured to be relatively small and additional interwing shaping members are disposed between adjacent wing tips to define a substantially continuous outer flowpath surface. , thus making it possible to smooth the gas flow.

Additionally, turbomachine blades are forced to vibrate at their natural frequencies, which can result in undesirably high blade stresses. Such stress is
This becomes even more critical when the wing members are made of composite materials. More specifically, the unidirectional strength properties of the fibers in composite airfoils make it difficult to install conventional integrated shrouds at the tip or partial span locations, as has been done with homogeneous metal airfoils. Mounting the blades and allowing vibration of the blades becomes more complicated.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a new and improved assembly for mounting blade groups in a turbomachine in a manner that ensures accurate alignment and retention.

Another object of the invention is to provide a wing mounting assembly for mounting a composite wing.

Another object of the present invention is to provide a wing mounting assembly that allows selective mounting and removal of individual wings.

Another object of the present invention is to provide a wing mounting assembly that provides resilient support and vibration damping for a wing.

Another object of the invention is to provide a wing mounting assembly comprising a plurality of mounting and interwing shaping members defining a shroud having a substantially continuous flow boundary surface for smoothing gas flow. That's true.

Another object of the invention is to provide a wing mounting assembly that is lightweight and has a reduced number of parts.

According to one embodiment of the invention, a plurality of mounting fairings receive and support the ends of a plurality of circumferentially spaced radially extending airfoils.
A wing tip attachment assembly is provided. Each attachment formation includes a central boss portion having at least one radially extending recess in a radially oriented surface, the recess forming an elastomeric boot for receiving one end of one of the plurality of airfoils. can be accepted. The attachment formation further includes integral first and second flanges extending circumferentially outwardly from opposite sides of the boss portion, the first and second flanges respectively intersecting with the second and first flanges of the adjacent attachment formation. located adjacent to the flange. Also,
The first and second mounting bodies have adjacent fastening means.
A substantially continuous annular shroud is formed through the flange.

DETAILED DESCRIPTION FIG. 1 shows a portion of a fan assembly for an axial high bypass ratio gas turbine engine 10. Gas turbine or turbofan engine 10 includes a fan assembly surrounded by a substantially cylindrical stator outer casing 12 . This fan assembly is
It consists of a fan rotor blade row including a plurality of fan rotor blades 11 spaced apart in the circumferential direction and extending in the radial direction. A radially inner end of the fan rotor blade 11 is suitably connected to a rotating shaft 13 .

There is an outlet guide blade row downstream of the plurality of fan rotor blades 11, and the blade row includes a plurality of circumferentially spaced apart and radially extending outlet guide vanes 14. Wings 14 can be made of aluminum and other metals, but lightweight, high strength composite materials are preferred. More specifically, composite materials consist of high-strength fibers embedded in a homogeneous matrix such as plastic resin.
For example, it may be composed of boron or graphite fibers.

Each outlet guide vane 14 has a radially inner end or tip 15 and a radially outer end or root 16 . Although the exit guide vane 14 may include a complex shaped tip 15 and root 16 as seen in the prior art, an improved vane mounting assembly according to one embodiment of the present invention includes a flat end vane 14.

More specifically, each wing 14 corresponds to wing 1 of FIG.
4C, it consists of an elongated airfoil member having a simple shaped, preferably airfoil-shaped tip 15 and root 16. Alternatively, the tip 15 and root 16 may have other shapes, such as rectangular, for example. The tips 15 and roots 16 of the wings 14 are resiliently attached to the stator casing 12 and the inner support shroud 17, respectively, which are suitably secured to the engine as described below.

The stator casing 12 has an annular fan inlet 1
8 and an intermediate portion coaxially spaced around and cooperatively defining an annular bypass duct or passageway 19 . A plurality of circumferentially spaced struts or frame members 20 are mounted within the bypass duct 19 to the stator casing 12 and inner shroud 17 .

During operation, ambient air is drawn in through the fan inlet 18 at the upstream end of the stator casing 12 and accelerated by the fan rotor blades 11, with a portion of this air flowing between and around the outlet guide vanes 14 through the bypass duct 19. Pass. In order to improve the aerodynamic performance of the air flowing through the bypass duct 19, the outlet guide vane 14
are arranged at non-uniform directional angles with respect to each other.

More specifically, each engine radial axis passing through the wing 14 and the bypass duct 19
The orientation of the blades 14 relative to the streamlines of the fan air flow passing through them may vary from blade to blade. Without the benefits of the present invention, such non-uniformity in the orientation of the wings 14 would require unequal mounting assemblies for each wing 14.

Furthermore, it is desirable that each vane 14 be easily and selectively attachable to and removed from its location between the stator casing 12 and the inner shroud 17. Due to the relatively close arrangement of the fan rotor blades 11, the outlet guide blades 14, and the frame member 20, the blades can be positioned at the appropriate position.
There is less room to remove it from its position, so
It becomes increasingly difficult to create such a steerable wing configuration.

In accordance with the present invention, a wing mounting assembly is provided that meets the above requirements, and its use provides other advantages as described below.

2 and 3 illustrate in detail a wing mounting assembly according to one embodiment of the invention. The vane mounting assembly includes a plurality of circumferentially adjacent arcuate mounting formations that connect adjacent outlet guide vanes 14 and stator casing 12 .

In more detail, the attachment shaping bodies may be configured to form a complementary pair including a radially inner first attachment shaping body 21 and a radially outer second attachment shaping body 22 . The mounting formations 21, 22 each include a central boss 23 having oppositely oriented radially extending first and second ends and at least one central boss at the first radially inner end. It has an elongated recess 24. Preferably, the recess 24 extends substantially radially or vertically inwardly from the lower or inner surface of the boss 23 and substantially parallel to the engine radial axis. The recess 24 is
Extending longitudinally within a boss 23 and generally parallel to the engine longitudinal centerline and receiving the root 16 of the wing 14C, as shown in detail in connection with the attachment forming body 21 of the wing 14C. For this purpose, a well is defined that generally corresponds to the cross-sectional shape of the airfoil.

The first mounting formation 21 further incorporates a first projection or flange 25 and a second projection or flange 26, both flanges substantially forming the radially inner facing or lower portion of the boss 23. Extending circumferentially outward from both sides. Flanges 25, 26
and boss 23 define a lateral profile generally resembling an inverted T when viewed along the engine longitudinal centerline, and flanges 25 and 26 each define one element of an overlap joint pair. First flange 25 , second flange 26 and boss 23 together define a preferably arcuate mounting formation having a continuous radially inwardly directed lower or inner concave surface 27 . However, any suitable non-arc shaped attachment formation may be used.

The flanges 25, 26 of the mounting formation 21 are relatively thin in radial or transverse dimensions to reduce the weight of the mounting formation. A plurality of integral reinforcing gussets 28 extend from the upper surfaces of the first and second flanges 25, 26 from opposite sides of the boss 23 to provide adequate structural strength. The gussets 28 define a plurality of substantially triangular weight reduction pockets 29 therebetween.

First and second flanges 2 are provided on both sides of the boss 23.
Fixing bosses 30 and 3 integrated with each of 5 and 26
1 are symmetrically arranged and adapted to receive mounting bolts. The fixing bosses 30, 31 have laterally or radially extending internal bores which may contain suitable bushings and which receive mounting bolts in such a way that the bolt heads are recessed therein.
The holes in the bosses 30, 31 each have an axis, which axes preferably intersect at a common point along the radial axis of the recess 24 substantially along the longitudinal centerline of the engine. Fixation bosses 30, 31 are disposed laterally on flanges 25, 26 and extend from first mounting form 21 by about one-half the lateral thickness of boss 23, as shown in more detail in FIG. may extend upwardly from the lower surface of the .

The second attachment formation 22 is generally similar in construction to the first attachment formation 21, but includes a first projection or flange 32 and a second projection or flange 33, both flanges being substantially It extends circumferentially outwardly from both sides of the radially outwardly facing portion, ie, the upper portion, of the boss 23. The first and second flanges 32, 33 and boss 23 define a lateral profile that generally resembles an inverted T when viewed along the longitudinal centerline of the engine. The first and second flanges 32, 33 radially overlap the second and first flanges 26, 25, respectively, of the adjacent first attachment formation 21 and define the second element of the lap joint pair. The first flange 32, the second flange 33 and the boss 23 together define a preferably arcuate mounting formation;
The mounting formation has a radially inwardly directed inner or lower concave surface 34. However, non-arc shaped attachment formations may be used where appropriate. Flanges 32, 33
They are also relatively thin in radial or transverse dimensions to reduce the weight of the mounting orthopedics.
A plurality of integral reinforcing gussets 35 extend from the upper surfaces of the first and second flanges 32, 33 and from opposite sides of the boss 23. The gussets 35 define a plurality of substantially triangular weight reduction pockets 36 therebetween.

First and second flanges 3 are provided on both sides of the boss 23.
Fixing bosses 37 and 3 integrated with each of 2 and 33
8 are symmetrically arranged and adapted to receive mounting bolts. The fixing bosses 37, 38 have laterally or radially extending internal bores which may also incorporate suitable bushings for receiving mounting bolts, and each have an axis, which axis preferably intersect with the radial axis of the recess 24 at a common point substantially along the engine longitudinal centerline. The fixing bosses 37, 38 are arranged laterally on the flanges 32, 33, and the third
As shown in more detail in the figures, about one-half the lateral thickness of the boss 23 may extend downwardly from the upper or radially outer surface of the second attachment formation 22.

The roots 16 of the wings 14 can be fixed directly in the recesses 24 of the attachment shapings 21, 22, but the attachment shapings 21, 22 can also be fitted into the depressions 24 to elastically support the roots 16 of the wings 14. It is preferred to include an elastomeric receiving means such as a closed elastomeric boot or insert 39. In this way, the mounting orthopedics can be designed to have a rigid structure to withstand any generated loads received from the wing 14 and the elastomeric boot 39
serves as a structurally flexible resilient support that can further dampen the vibrations of the wing 14.

Suitable materials for boot 39 may include, for example, polyester urethane. Fluoroelastomers, for example "Viton" (EIdupont)
A commercially available product under the trademark de Nemours & Co.) is suitable. This is because its material properties hardly deteriorate at the high temperatures encountered during operation.

The attachment forms 21, 22 may be made of metal such as aluminum or pressure formed using polysulfone or polyamideimide, such as a commercially available product under the trademark "Torlon" (Amoco Chemicals Corp.). . However, molded and mounted orthopedics made of graphite fiber reinforced nylon are preferred. This is because it provides light weight and relatively high structural strength.

The bushings within the fixing bosses 30, 31, 37, 38 may be constructed of a hard or soft material to rigidly or elastically support the mounting fairings 21, 22, respectively. However, the mounting orthopedic body 2 made of a non-metallic material such as graphite fiber piece reinforced nylon
1 and 22 are preferably metal bushings made of aluminum, for example.

The recess 24 can be formed large enough to accommodate a set of blade roots 16 having various cross-sections and orientations.
In this way, the first and second mounting shaping bodies 21,
22 can each be manufactured to be of uniform construction, and only the boots 39 need be individually formed to fit the various blade roots 16. The boot 39 can easily be individually molded to accommodate the various roots 16 within the recess 24 of the mounting orthosis.

Each attachment forming 21 or 22 and its corresponding boot 39 and wing 14 form an assembly unit that can be assembled, and when the boot 39 is glued to the root 16 of the wing 14 using an adhesive such as epoxy, the recess 24 Alternatively, the wing 14 may be glued within the wing 14.
The root portion 16 of the corresponding attachment shaping body 21 or 2
2 and the boot 39 can be molded in place and cured, with the boot 3
9 acts as an adhesive that joins the boot 39 to the root 16 of the wing 14 and the wall of the recess 24.

To assemble the outlet guide vane 14 into the turbofan engine 10, the roots 16 of the vane 14 are assembled to corresponding first and second mounting fairings, as previously described. Shown in more detail in FIG. 2 and wing 14C
As shown in the exploded view of FIG.
Place within 0. Boot 40 is similar in structure and configuration to boot 39 and has a recess. This recess is shaped complementary to the tip 15 so as to tightly receive it. Each boot 40 is suitably secured within one of a plurality of radially extending slots 41 in the inner shroud 17. The wing 14 with the second attachment shaping 22 secured to the root 16, ie, the wing 14d shown in the intermediate position between the attached and detached positions, is then attached to the tip 15.
into the boot 40 (not shown) in the slot 41 of the inner shroud 17.
Place it inside.

As shown in FIGS. 2 and 3, the annular spacer 4
2 is disposed between the upper surface of the second mounting shaped body 22 and the stator casing 12, and passes through the holes of the fixing bosses 37 and 38 of the first and second flanges 32 and 33, respectively, and the stator casing 12. Preferably, the spacers and holes are all aligned along their respective common radial axes.

The first mounting shaping body 21 is replaced by the second mounting shaping body 22.
The first and second flanges of adjacent mounting formations are brought into contact with each other in the radial direction. To explain in more detail, the first mounting orthopedic body 21
The outer surfaces of the bosses 30, 31 are adjacent to the second and first flanges 33, 3 of the second mounting orthopedic body 22, respectively.
2 to form a lap joint.

The mounting bolts 44 pass through corresponding first and second flanges of adjacent mounting forms, further pass through the spacer 42 and the holes 43 in the stator casing 12, and are suitably secured to the stator casing 12, for example by nuts. Ru. The heads of the bolts 44 are appropriately embedded in the inner surfaces of the bosses 30 and 31 of the first mounting forming body 21. Each mounting fairing is held in place by two bolts, which also support adjacent mounting fairings, resulting in an efficient design where only one bolt per mounting fairing is required. A good mounting assembly is obtained.

When assembling the mounting shaping bodies 21 and 22 to each other,
The lap joint configuration of the first and second flanges is effective in providing a substantially continuous segmented cylindrical outer shroud joining the airfoils 14. Further, the inner surfaces 27, 34 of each of the first and second mounting fairings 21, 22 are circumferentially aligned at a common radius from the longitudinal center of the engine and are substantially continuous and aerodynamically smooth straight cylinders. Define a shaped channel or shaping surface. Such shaped surfaces may reduce radially outward airflow leakage between the blades 14 and smooth axial gas flow.

As shown in more detail in FIG. 2, individual removal of any vane 14 from the exit guide vane row involves removing two bolts 44 through the appropriate mounting fairings and tilting the vane assembly. This can easily be achieved by taking it out. More specifically, when removing the first mounting fairing/wing unit, for example the wing 14C, the tip 15 of the wing 14 can slide radially in the recess 41 of the inner shroud 17, thus removing the unit from its position. Can be lowered radially. 2nd mounting orthopedic body/wing unit,
For example, the wing 14d unit can be removed individually after the spacer 42 has been removed so that the fairing and wing unit can be first rotated axially and secondly radially or lifted to remove the exit guide vane row. It can be removed from the

The elastomeric boots 39, 40 are used as resilient attachment means to support the outer ends of the wing 14, i.e., tip and root, in a substantially simple but non-rigid manner. This simply supported configuration reduces aerodynamically induced wing stresses at both supported outer ends of the wing. Stress reduction at the supported outer end of the airfoil 14 is a primary consideration for the preferred installation of composite airfoils of the type described above. Also, the use of elastomeric boots 39, 40 inherently provides effective damping of possible vibrations of the airfoil 14. Additionally, resilient attachment of the wings 14 may reduce foreign object damage to the wings 14 that might otherwise occur.

Another embodiment of the invention is shown in FIG. A plurality of attachment fairings 45 secure the radially outer ends of the blades 14 to the stator casing 12. Each mounting orthopedic body 4
5 is generally similar in construction and materials to the first attachment form 21 as shown in FIGS. 2 and 3. However, in this embodiment all attachment formations 45 have substantially the same dimensions and are adjacent to each other without radial overlap of adjacent flanges. As in the first embodiment, the boot 39 may be individually molded to accommodate uneven orientation of the wings 14 within the recess 24.

Since there is no overlap of adjacent mounting forming bodies as shown, two bolts 44 for each mounting forming body are required to attach the airfoils 14 to the stator casing 12. This is different from using one bolt per wing as in the first embodiment. However, apart from this point, all the advantages of the invention as described for the first embodiment can be realized.

Although preferred embodiments of the invention have been described above, it will be appreciated that various other modifications are possible within the scope of the invention. For example, the mounting fairings 21, 22 may each have one or more bosses 23 having a plurality of circumferentially spaced recesses 24 for receiving a plurality of blade roots. In this way,
The blades 14 can be mounted and assembled in groups, thus simplifying assembly and disassembly and increasing the vibration characteristics of the blade group by increasing the natural frequency.

The attachment shaping may alternatively be attached to the wing 1 as desired.
It can be designed to mount the radially inner end of 4.

Boots 39, 40 may alternatively be open-ended bushings glued into recesses 24, 41, respectively. Note that the recesses 24 and 41 may be formed as holes penetrating the boss 23 and the shroud 17, respectively. Also,
The first and second flanges of the mounting orthopedics may be flanges arranged axially side by side to provide overlapping joints in the axial plane and to suitably join.

Although the vane mounting assembly described above is for mounting an outlet guide vane in a gas turbine engine, this configuration may be used to mount any stator vane to the stator casing in a gas turbine engine.

The wing attachment assembly may consist of a rotatable outer shroud for interconnecting the tips of the rotor blades in the engine. In this embodiment, the mounting bolts 44 need only connect the first or forward end flange and the second or aft end flange of adjacent mounting fairings and need not be attached to the stator outer casing 12. This allows the rotor wheel and rotor blades to rotate freely.

[Brief explanation of drawings]

FIG. 1 is a partial sectional view of a fan assembly and outlet guide vane of a gas turbine engine using the present invention, and FIG. 2 is a partial perspective view of a blade mounting assembly constructed according to an embodiment of the present invention. 3 is a partial cross-sectional view taken generally along line 3--3 in FIG. 1, and FIG. 4 is a partial cross-sectional view taken generally along line 3--3 in FIG. The attached wing mounting assembly is shown. 12... Stator casing, 14... Outlet guide vane, 17... Inner shroud, 21, 22, 4
5... Mounting shaped body, 23... Boss, 24... Recess, 25... First flange, 26... Second flange, 27... Lower surface, (inner surface), 30, 31... Fixing boss, 32 ...First flange, 33... Second flange, 34... Lower surface (inner surface), 37, 38...
Fixing boss, 39, 40...Elastomer boot, 41...Slot, 44...Mounting bolt.

Claims (1)

[Scope of Claims] 1. A mounting body for positioning a wing, comprising: a central boss portion; a recess disposed in the boss portion for receiving one end of the wing; and a recess extending outwardly from both sides of the boss portion. first and second flanges extending and cooperating with the boss to form a substantially continuous flow boundary surface to smooth gas flow past the airfoil and the fairing; The first and second flanges each have an aperture for receiving a mounting bolt, and each aperture and the boss recess have a radial axis that intersects at a substantially common point. 2. An assembly for mounting a plurality of circumferentially spaced and radially extending blades within an annular casing, each blade having a radially extending first and second end. comprising a plurality of circumferentially arranged attachment fairings and fastening means, each said attachment shaping for receiving a first end of a corresponding one of said plurality of wings. a central boss having a radially extending recess in a radially oriented surface and first and second flanges extending circumferentially outwardly from opposite sides of the boss integrally therewith; flanges are disposed adjacent, respectively, second and first flanges of adjacent mounting forms, and the fastening means connects the first and second flanges to the casing to form a substantially continuous annular member. Wing mounting assembly for connection. 3. The assembly of claim 2, wherein the radially facing surface of the boss is a radially inner surface and the first end of a corresponding one of the plurality of wings is a radially outer end. . 4. The assembly of claim 2, wherein the first and second flanges of adjacent mounting forms radially overlap each other. 5. Each of the attachment shapes further includes receiving means disposed within the recess of the boss, the receiving means having an opening for receiving the first end of a corresponding one of the plurality of wings. , an assembly according to claim 2. 6. The assembly of claim 5, wherein said receiving means is made of an elastomer and serves for resilient support of said first end and vibration damping of a corresponding one of said plurality of wings. 7. The assembly of claim 5, wherein said receiving means comprises a boot adhered within said recess of said boss. 8. In an axial flow turbomachine having a cylindrical stator casing, the stator assembly includes an annular inner shroud having a plurality of circumferentially spaced indentations and a plurality of circumferentially spaced and radially extending stator vanes. , a plurality of mounting formations and fastening means, each stator vane having a flat inner end and a flat outer end, the inner end of the stator vane being secured within a respective recess of the inner shroud; Each mounting shaping includes a central boss having a radially extending recess provided in an inner surface for receiving a corresponding outer end of one of the stator vanes, and a central boss having a central boss having a radially extending recess provided in an inner surface for receiving a corresponding outer end of one of the stator vanes; the first and second
flanges, the first and second flanges being disposed adjacent to the second and first flanges, respectively, of adjacent attachment orthopedics, and the fastening means being arranged adjacent to the first flanges of adjacent attachment orthopedics.
and a stator assembly coupling a second flange to the stator casing. 9. The invention of claim 9, further comprising elastomeric receiving means bonded within the recess of the inner shroud and within the recess of the mounting formation for receiving and resiliently supporting each end of the stator vane. A stator assembly according to range 8.