US2984454A

US2984454A - Stator units

Info

Publication number: US2984454A
Application number: US679623A
Authority: US
Inventors: Bruno M Fiori
Original assignee: United Aircraft Corp
Current assignee: Raytheon Technologies Corp
Priority date: 1957-08-22
Filing date: 1957-08-22
Publication date: 1961-05-16
Anticipated expiration: 1978-05-16
Also published as: DE1114364B; NL99435C; NL230456A; BE570533A; CH362269A; FR1211581A; GB893579A

Description

May 16, 1961 B. M. FIORI STATOR UNITS 2 Sheets-Sheet 1 Filed Aug. 22, 1957 F IG I INVENTOF? BRUNO M F-"IOFU Evy/www ATTORNEY B. M. FIORI STATOR UNITS May 16, 1961 2 ,Sheets-Sheet 2 Filed Aug. 22, 1957 INVENTQR BRUNO M F-.QRI

United States PaferlfOf m M m m 2,984,454 m M e Y sTAToR i Bruno M,`Fiori, East Hartford,vConn., assignor to United .AircraftjCorporatiom East Hartford, Conn., a corpora- 'ltpn of Delaware i Filed Aug. 22, 1957, Ser. No. 679,623

f 1on1-rms. (Cl. 25a-77s) mit stator vane removal, once vthe `Powerplant rcombus# tion chambers have been removed, thru an access path axially" forward or upstream of the vanes as `taught in application Serial No. 637,492, led January 31, 1957, now Patent No. 2,916,874, inthe name of John Worobel. While this lis a definite improvement over the fabrications Which preceded it, it `was necessary touse a rig or fixture to maintain all stator vanes in place while the damaged vane was removed and replaced.

It is an important object of this invention to teach a stator construction in which each vane is individually supported within the stator, independent of all other vanes.

It is afurther object of this invention to teach a stator construction in which both the inner vane support and the outer vane support are one-piece units. i

It is still a further object of this invention to teachl a stator construction in which the individual 'vanes maybe locked in their particular position by a mechanism which, l if it' should break loose, would not enter the powerplant` gas Y:stream and further, in which the statorjunit fabrication is such that .gas loading would tend to maintain the component parts of the stator assembled, should the lock y mechanism disengage.

It isstill a further object of this inventionto provide'ajstator unit which will permit release and removal of a' `particular stator vane thru an access path entirely on one side of the stator unit and preferably `upstream thereof,

without disturbing the other stator vanes.

It is aFfurther object of this invention toprovide Aa stator unit in which anti-erosion and thrust strips madef ofhard metals may `be'placed against the' downstream inner surface of the vane support where it 'will be subjected to the vane thrust load and to the erosion effect of theho't gases. Further, coolingair may be passed adjacent this thrust strip.

`It is still a further object of this invention to permit turbine rotor bladeinspectionr and removal by baring the rotor blades thru removal of the vanes ofthe adjacent stator unit. y

Other objects and advantages will be apparent from the following speciiication and the attached drawing in which:

Fig. 1 is a cross-sectional showing of my stator unit.

\Fi`g`.,2 is a viewtaken along line 2,-2 of Fig.` 1.

Figs. 3 and 4 show alternate connecting and locking means which maybe used to fasten the vane inner end tothe vane inner support.

Patented May 16, 196,1,

Patent No. 2,770,946, atmospheric air is introduced into` the compressor of a modern aircraft turbojet yengine and passed in compressed form into the combustion chamber for heating. The heated and compressed air is their` passed thru the turbine which performs a power extrae#1 tion function to drive the compressor and possibly a propeller, and after passing thru the turbine Vthe engine gases are discharged to atmosphere thru an exhaust out;A4

let, thereby performing a propulsion function. j

Both the axial flow compressor and the axial ow tur? bine consist basically Aof alternate rows of stationary vanes and moveable vanes, sometimes called blades. The stationary vanes are supported in position as part of a` stator unit while the moveable blades rotate with a re-` volving disc. The stator unit andthe vanes thereon perform the function of turning the Powerplant gas such that itis directed against the rotating blades immediately .'downstream thereof at the proper angle.

Referring to Fig. 1, we see a partial showing of axial flow turbine 10 having an axis or centerline `and rotor unit'12 which comprises a plurality of radially extendi ing blades 14 attached torand equally spaced circumferentially about the periphery of disc 16 for rotation u therewith. Stator unit 18` comprises a plurality of stationary vanes 20 which are `individually supported at their inner end by vane inner support 22 and at their outer end by vane outer support 24. Vane outer support 24 comprises axially directed ring l2.6 Iwhich forms acircle about turbine and powerplant axis or centerline (not- A shown) and which is supported by and may be integral Ring 26 carriesv with one-piece outer turbine case l28. axially extending and radially spaced lips 30 and32 at its forward end which form forwardly openingA lll-shaped channelV 34. Ring 126 includes a` plurality ofradiallydirectedlholes 36 lwhich are spaced' equally circumfer" entially' thereabout to receive, in positive fashionr'suclias" apnCh-t, or interlocking threads, radially directed outer vane support fpins or lugs 38. Ring26 `further comprises?v radiallydirected rflange 40 against which anti-erosion andfthrust strip 42 bears. Connecting means 44 attaches strip 42 to ring 2'6 and may be in the form of a`rivet. "Coo1` ing air from passage 46 is directed thru line 48 'and intot engine gas path 50 to perform the function of cooling@ stripi42. JThe" 'afterfor axially downstream end or sur-A` face 52 of vane platform `54 bears against strip 42andj transmits: athrust load thereto, caused by the flowoff hot exhaust gases across vane 20. j

the axially downstream flange 64. Flange 62 has a plurality-.of axially directed apertures 7i) passingA therethruy'to receivein positive fashion, such as a pinch-t or interi locking thread, axially extending inner vane support pin' or lug 72.

, A plurality lof stationaryvanes 20 areradiallydirectedl'f and equally ,spaced `circumferentiallybet-Ween vane"V innerf support 22 and` vane outer support 24 and each vanec20-` is positively positioned in stator unit 18, both` at -its inner,` end 74 and at its outer end 76, independently of all other; `vanes 20.`` lt will be noted that inner endr74. of vallei.`

stator unit illustratingl 3 2.0 .tamarins 'twg axially. flanges or lugs 78 and 80 which are joined by member 82 and which are fabricated such that the inner surface 84 ofitheaxiallynforward flange `7 8, is of greater height and of'lesser radial ldistance from theiturbine axis than is,-

inner. surface `86 csf-axially doWIlSiream llange 80. It will further be noted that surface 68 of support flange 64`eng`ages right angle` notch .88 of yflangel) in Suplportingfashion. r*In `assembled position, see Fig. 1, vane flange 78 is juxtapositioned to support flange 62, while vaneY flange l80 is juxtapositioned to support flange l64 so'zthat the gas loading tends to seat vanes 20, Withvane 20 so positioned, inner pin or rivet 72, which is Vfirmly, lixed. `in axially forwardsupport vilange 62 passes thru aperture 90 of vane flange 78 and extends axially forward thereof and carries the necessary hole therethru to permit locking the parts in this position by the use of lock wire 92 such that the lock wire passes thru the two adjacent pins or rivets 72, as best shown in Fig. 2.V

Figs. 3 and 4 show alternate vane inner end attaching and locking means. Fig. 3 shows bolt 94 passing thru vane flange 84 and support flange 62', into which it is lixedly threaded. Aperture 96 is provided to permit locking bolt 94 in position by lock wire (not shown). Fig, 4 shows bolt.98 projecting thru vane flange 84" and support flange 6'2 and threadedlyengaging insert 100 which is attached in any convenient fashion to support flange 62". Aperture 102 is provided to permit the locking of bolt 98 in position by means ofV lock wirer (not shown).y A

By referring to Fig. l, it will be noted that vane inner. end 74 is axially positioned by

support flanges

62 and 64 and is crcumferentially and radially fixed by rivet, lug or pin 72. vAt the outer end 76 of vane 20, axially extending platform 54 is received loosely by pin or lug 38 to axially Aand circumferentially position outer end 76 of vane 20 and a substantial radial distance exists .between vane platform 54 and ring 26 of vane outer support 24, thereby permitting relative radial movement therebetween. Lug 38 preferably passes thru platform 54 in a location to be substantially equidistant between the side walls of vane L20.

As shown in Fig. 1, transition duct 104 is located immediately upstream or axially forward of stator unit 18 and engages outer vane support 24 in sealing relation by seal 106 and engages inner vane flange 78 in sealing relation by seal'i108. Surface 109 of seal 108 is positioned to provide axial support to the vane inner end thru flange 78 in case of back pressure or backfire. Reverse axial loading goes from ange 78 to seal 108, to transition duct i104 and to support member 126. Transition duct 104 and combustion chamber support 110 may be removed by disengaging connecting

means

112 and 114 after the combustion chamber (not shown) has been removed. This bares lock wire 92 for removal, which will permit the removal of

bolts

94 and 98 in Figs. 3 and 4, respectively, to free the inner ends 74 of vane 20 in the conligurations shown in Figs. 1, 3 and 4, thereby permitting same to be moved radially inward, if desired, and then pivoted axially forward about pin 38 or merely pivoted axially forward about pin 38 due to the loose lit existing between 'pin 38 and platform 54, thereby releasing the outer end 76 of vane 20 to free the vane for removal from stator unit 18.

'It will be noted that a single vane 20 may be released, removed and replaced thru access from the upstream or axially forward side of stator unit 18 only, without disturbingthe .other vanes in any way.

As best shown in Fig. 5, it is possible to assemble and disassemble any number of vanes '20 or an individual vane 20 without disturbing any of the remaining vanes. In assembling the entire unit, rotor 16, outer case 28 and inner case 60 are fastened inV position. Each vane will be assembled in'turn' by utilizing the access hole'defined between

cases

28 and 60 on the forwardfside of Spaedand radially directed rotor 1 6 by introducing the vane toouteryane support 24 with the vane inner end 74 axially forward of the vane outer end 76, in tilted fashion, such that a preliminary connection may be made between lug 38 and platform 54, whereupon vane 20 will be pivoted clockwise about pin 38 into the position shown in Fig. l in which vane flange 78 engages lugY 72. This assembly is possible since pin 72 is heldin position by a tight it in llange 62 and extends loosely through aperture 90 in ange 94 whilein like manner pin 83 passesrloosely through the aperture in vane platforml 54. l Lock Wire 92 will then be fastened in position as shown in Fig. 2 and the transition duct 104, the burner after support and the combustion chambers will be assembled. It will be noted that lock wire 92 is confined within chamber 116 such that if a rupture should occur therein and a piece break loose therefrom during operation, the piece would not fall into .gas passage 50. ASeal `118 is carried by cylindrical support 120 and performs the function ofpreventing air flow between gas passage 50 and chamber 1,22. Support 120 is fastened to vane inner support `22 by any convenient means such as welding or brazing, and.

vane inner support 22 isy attached to structural members 126 of turbine 10 byconnecting means 124. In known fashion, the engine case or combustion chamber case, may then be placed in position to envelop the series of,

combustion chambers.

To replace a singlevane 20, it is merely necessary to remove the combustion chamber case (not shown), to. remove the combustion chamber and transition duct,104 and thereby gain access to vanes'20 from the axially forward side thereof. Lockwire 94 is then removed, whereupon vane 20 may be tilted forwardly in itsinner end to pivot slightly about pin 38. This pivot action frees the inner end of thevane from ange 64, whereupon the vane may bey moved radially inwardly to clearpin 38 and then moved axially forwardly in complete freedom.

.Although the preferred embodiments have been shown and described, it will be apparent that various changes and modifications may be made in the construction and arrangement of the various parts without departing from the scope of this novel concept.

I claim:

1. A stator unit of circular cross-section for use in a powerplant having an axis comprising a plurality of vanes, each having a hole in one end thereof, means for supporting each of said vanes in its operative position to be substantially radially extending and substantially van equal radial distance from and equally spaced in a circle.l about said axis, means providing access to one side of.'

said vanes and support means, and said support means including a Aplurality of substantially radially extending pins each received loosely in one of said holes in said vanes and a plurality of readily releasable means each accessible from .said one side and each fully supporting the other end of one of said vanes thereby permitting the removal and replacement of any vane in said plurality from said oneside while maintaining all other vanes in Y operative position.

2. A .stator unit of circular cross-section for use in a powerplant having an axis comprising a plurality of vanes, each having a hole in the outer end thereof, means to4 support said vanes to be substantially radially extending and substantially an equal radial distance from and equally spaced in a circle aboutY said axis including first means supporting the outer end of each of said .vanes individually and independently of all other vanes and second means independent of said first means supporting the inner end of each of said vanes individually and inden pendently of all other vanes Vsaid rst means including a ring enveloping said vanes and having a plurality of substantially radially inwardly directed pins each received loosely in one of said holes in said vanesV and said second,

means including a plurality of readily releasable means porting each of said vanes in its operative position to be substantially radially extending and substantially an equal radial distance from and equally spaced in a circle about said axis, and means providing access to said side of said vanes and support means.

4. A stator unit comprising a vane outer support cornprising a ring, a vane inner support comprising at least one radially extending circular flange, a plurality of vanes each having an axially extending platform at its outer end and at least one radially extending ilange at its inner end and with said vanes extending radially between and spaced circumferentially about said vane supports and each located with respect thereto such that said radially extending flanges are juxtapositioned and further such that said vane outer support ring and each of said vane platforms is spaced a preselected distance apart radially, a plurality of radially directed lugs each connected to said vane outer support ring and projecting loosely thru one of said vane platforms to position the vane outer end, a plurality of axially directed lugs each connected to said vane inner support flange and projecting thru the inner end flange of one of said vanes and projecting therebeyond to position said vane inner end, and means removable from one side of said stator unit locking each of said vane anges in position individually against said support flange and on one of said axial lugs thereby permitting one of said vanes to be released, removed and replaced thru access from one Side of said stator unit only while all other vanes are maintained in position.

5. A stator unit having an axis and comprising a vane outer support comprising a ring, a vane inner support comprising two axially spaced rings forming radially extending circular ilanges of different inner diameters such that the axially forward flange is of lesser diameter, a plurality of vanes each having an axially extending platform at its outer end and two axially spaced radially extending flanges at its inner end and with the axially forward vane flange of greater height and with said vanes extending radially between and spaced circumferentially about said vane supports and each located with respect thereto such that said radially extending flanges are juxtapositioned with said axially forward vane iange engaging the axially forward support flange on the axially forward side thereof and with the other flanges engaging in the same relative axial positions and further such that said vane outer support ring and each of said vane platforms is spaced a preselected distance apart radially, a plurality of radially directed lugs each connected to said vane outer support ring and projecting loosely thru one of said vane platforms to position the vane outer end, a plurality of axially directed lugs each connected to said axially forward inner support flange and projecting thru the axially forward inner end flange of one of said vanes and projecting therebeyond to position said vane inner end, and means removable from one side of said stator unit locking each of said vane flanges in position individually against said support flange and on one of said axial lugs thereby permitting one of said vanes to be released, removed and replaced thru access from one side of said stator unit only while all other vanes are maintained in position.

6. A stator unit having an axis and comprising a vane outer support comprising an axially extending ring forming a circle about said axis, an anti-erosion and thrust ring attached to said vane outer support ring, cooling gas passages in said outer support ring positioned to direct Cooling sas carer Said-,antil-emsionand thrustting, axane inner support olprisins .two axially spaced. Lfilles; termf ing radially extending circular `flanges of different imeljdiamcters such that the axially forward flange is of lesser diameter; ai pluralityaof` vanes each ,havinganfaxially extending platformat itsouter endand-twoaxially spaced radially extendirig"tlaiiges at its inne' end uand with the axia11yrorwgd vane-aange- Vof greater' height and with said vanes extending radially Vbetween and spaced circumferentially about said vane supports and each located with respect thereto such that said radially extending anges are juxtapositioned with said axially forward vane flange engaging the axially forward support flange on the axially forward side thereof yand with the other flanges engaging in the same relative axial positions and further such that said vane outer support ring and each of said vane platforms is spaced a preselected distance apart radially, and further such that the after end of said platform bears against said anti-erosion and thrust ring, a plurality of -radially directed lugs each connected to said vane outer support ring and projecting loosely thru one of said vane platforms to position the vane outer end, a plurality of axially `directed -lugs each connected to said axially -forward vane inner support flange and projecting thru the axially forward inner end flange of one of said vanes and projecting therebeyond to position said vane inner end, and means removable from one side of said stator unit locking each of said vane flanges in position individually against said support flange and on one of said axial lugs thereby permitting one of said vanes to be released, removed and replaced thru access from one side of said stator unit only while all other vanes are maintained in position.

7. A turbine or compressor unit having an axis and comprising a rotor unit and a stator unit coaxial therewith and positioned axially forward thereof,l said rotor unit comprising a plurality of removable radially extending blades attached to the periphery of a rotatable disc and equally spaced thereabout, said stator runit. comprising a vane outer support comprising an axially extending ring forming a circle about said axis, an anti-erosion and thrust ring attached to said vane outer support ring, cooling gas passages in said outer support ring positioned to direct cooling gas over said anti-erosion and thrust ring, a vane inner support comprising two axially spaced rings forming radially extending circular flanges of different inner diameters such that the axially forward flange is of lesser diameter, a plurality of vanes `aligned with said blades each having an axially extending platform at its outer end and two axially spaced radially extending flanges at its inner end and with the axially forward vane flange of greater height and with said vanes extending radially between and spaced circumferentially about said vane supports and each located with respect thereto such that said radially extending flanges are juxtapositioned with said axially forward vane flange engaging the axially yforward support flange on the axially forward side thereof and with the other flanges engaging in the same relative axial positions and further such that said vane outer support ring and each of said vane platforms is spaced a preselected distance apart radially and further such that the v after end of said platform bears against said :anti-erosion and thrust ring, a plurality of radially directed lugs each connected to said vane outer support ring and projecting loosely thru one of said vane platforms to position the vane outer end, a plurality of axially directed lugs each connected to said axially forward vane inner support flange and projecting thru the axially forward inner end flange of one of said vanes and projecting therebeyond to position said vane inner end, and means removable from one side of said stator unit locking each of said vane flanges in position individual-ly against said support flange and on one of said axial lugs thereby permitting one of said vanes to be released and removed individually and independently of Vall other vanes thru access from one side