Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS2933234 A
Publication typeGrant
Publication dateApr 19, 1960
Filing dateDec 28, 1954
Priority dateDec 28, 1954
Publication numberUS 2933234 A, US 2933234A, US-A-2933234, US2933234 A, US2933234A
InventorsNeumann Gerhard
Original AssigneeGen Electric
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Compressor stator assembly
US 2933234 A
Abstract  available in
Images(2)
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

April 1960 c. NEUMANN 2,933,234

COMPRESSOR STATOR ASSEMBLY Filed Dec. 28. 1954 2 Sheets-Sheet 1 INVENTOR. 6264459 WfVA/i/V/V #44 Mama-7 April 1960 G. NEUMANN 2,933,234

COMPRESSOR STATOR ASSEMBLY Filed Dec. 28, 1954 2 Sheets-Sheet 2 1E4 L I INVENTOR. 6564450 A fMI/i/V/Y apd $7.

///J Irraawymum speed.

COP/ERESSOR STATOR ASSEMBLY Gerhard Neumann, Cincinnati, Ohio, assignor to General Electric Company, a corporation of New York Application December 28, 1954, Serial No. 478,100

6 Claims. (Cl. 230-114) This invention relates to stator vanes in a compressor for a gas turbine engine or the like, and, in particular, to a means for varying the position of the stator vanes in the compressor.

Wherever high pressure ratio compressors of the axial flow type are used, aerodynamic stall conditions exist at some period when going from zero speed to maxi- It has been found that the higher the pressure ratio, the more pronounced the stall conditions become. This stall condition exists as a result of the flow failing to match the aerodynamic design of the blading itself. In other words, the angle of attack is too high. Therefore, in order to correct for these stall conditions, the positions of the stator vanes are varied by changing the angle of attack to meet the flow conditions over a wide range of operating conditions. 7

It is well known that stator vanes are attached to the compressor casing at one end thereof, and, therefore act as cantilever beams. These stator vanes are subjected to extremely heavy loads and vibratory forces. It is, therefore, an object of this invention to provide a wide base support that is capable of maintaining a stator vane in a firm condition and still be easily rotatable. For this invention, a wide base support or shoulder is intended to cover a base which is relatively large in diameter with respect to the chord of the vane.

The compressor casing is often made of a relatively thin construction to hold its outside diameter to a minimum. In order to provide a support for the vanes the casing must be built up, thereby increasing the weight of the engine and reducing the advantages of the variable stator vane engine. Accordingly, it is a further object of this invention to make a light weight, shallow support that is capable of maintaining the blade in a firm condition without affecting its rotatability.

In order to make the stator blades of a compressor variable, the bases of the blades are actuated by levers which in turn are actuated by a circumferential band extending about the circumference of the compressor. Since the levers pivot in a plane tangential to the circumference of the actuator band, a problem arises as to how to connect the actuator band to the levers. It is therefore a specific object of this invention to provide a connection between the actuator band and levers which will permit them to turn in different planes, with the actuator band being constrained in an axial direction.

One of the most sought for features in a jet engine is lightness of parts. It is therefore another specific object of tlL's invention to provide fabricated lightweight levers and bases for the stator vanes with a runner mounted on the actuator bands and a sector on the compressor casing provided with anti-friction material to support the runner and for supporting the levers so as to maintain the vibratory forces at a minimum.

It is a more specific object of this invention to provide the compressor of a jet engine ith a variable stator mechanism by having the base of the stator vanes rotatable in a flat bearing in the compressor casing, the

base of the blades being fabricated for lightness.

Fabricated lever arms are connected to the bases 'of the blades so as to be rotatable therewith, the levers being pivotally connected to actuator bands through a ball and socket joint, the levers having rod ends slidably positioned in the ball. The actuator bands are supported on the casing and constrained axially and actuated by hydaulically actuated bellcranks having their fulcrums on the casing.

It is a still more specific object of this invention to provide a lightweight variable stator blade assembly and lightweight lever for actuating the blade, the blade being fabricated so as to have a fiat base and the lever being fabricated in a manner so as to be fixed to the fabricated base and carried by an actuator band, the blade assembly having a portion fixed to the casing and the blade having a portion rotatable with respect to the casing.

These and other objects will become more apparent when read in the light of the accompanying drawings and specification wherein like parts have the same num bers and wherein the terms used for the individual parts are intended to be as generic in their application as the prior art will permit, and wherein:

Figure 1 shows generally a gas turbine engine in which a variable stator vane construction is employed;

Figure 2 is a fragmentary plan view showing actuating means for moving the actuating ring and brackets for rotating the vanes;

Figure 3 is a plan view, partly in section, showing the ball and socket joint;

Figure 4 is a cross-sectional view taken on lines 4-4 ofFigure 2;

Figure 5 is a cross-sectional view taken on lines 5-5 ofFigure 2 showing the ring supporting means;

Figure 6 is a cross-sectional view taken on lines 6-6 of Figure 5.

Referring to the drawings, and in particular to Figures 1-4, the numeral it generally designates a gas turbine engine provided with a compressor section 12, combustor section 14, turbine section 16, and an exhaust nozzle section 18. A compressor casing 20 is provided with a plurality of stator vanes rotatably mounted in the casing as will hereinafter be described. Attached to the compressor casing 20 by rivets or the like 24 are a plurality of sectors 22. The sectors 22 are spaced circumferentially about the compressor casing 20. Fixedly mounted in each sector 22 is a grooved member 23 made of a bearing material, such'as Teflon which is well known in the art and well adapted for this pur pose since it has good heat resistant and lubrication properties. A V-shaped runner 28 made of similar bearing material is adapted to slide in the corresponding groove 26 in the member 23. This runner 28 is mounted in an actuator band 30 by means of pins 29.

The actuator band 30, of which there is one for each stage of stator vanes, is adapted to be moved in either direction by a hydraulic piston and cylinder arrangement 32 fixed to the compressor casing 26. Fixed to the piston of this cylinder is a longitudinally extending bellcrank rod 34 which carries a plurality of bellcranks 36 pivotally mounted on the bellcrank rod 34. The bellcranks are fixed at their fulcrum to the compressor casing as shown at 38 equi-distant from the bellcrank rod 34. The bellcranks 36 are pivotally connected to the actuator bands 30 but the arms of the bellcranks' are at varying distances for each stage, as is readily apparent by referring to Figure 2, according to a predetermined schedule. The actuator bands 3i) are provided with openings 40 which extend through the sides thereof for the purpose which will be hereinafter explained. The actuator band 30, being of inverted U-shape is provided with a ball and socket arrangement as shown at 4-2. The ball contains an opening 44 therethrough for receiving a rod 46 which is fixedly attached to a lever arm or bracket 48. The bracket 48 is attached to the compressor blade assembly 4-7 and blade 50 by dowel pins 4g and screw 51 so as to rotate the blade.

The compressor-casing 24 is provided with a plurality of openings 52 for receiving the compressor blade assembly 47. Fixed to the openings in the compressor casing 20 is a sleeve 54 that may be either threaded or press fitted into the opening 52. The compressor blade 50 is welded or brazed to the base or support 56. The base 56 is fabricated for lightness as shown in Figure 4. The base is formed by a cup-shaped member '3 with a cover 55 also welded or brazed thereto. The cup-shaped member 53 and cover 55 form a flat shoulder -50. The sleeve 54 has a flat bearing seat 57. The base or support 56 is mounted in a flat bearing 58 of anti-friction material, such as Teflon. This material completely surrounds the base 56 above and below the shoulder 60. The bean'ngis held in place by a lock ring 6-2 fixed in the sleeve 54. Therefore the flat shoulder or seat 60 is embedded between two flat sheets of bearing material 58 and one cylindrical along the side of the flat shoulder, which bearing material is held between the abutments formed by the lock ring 62 and the seat 57. It is noted that the three portions of beariug material can be made integral in the form of a U-shaped ring.

The leakage of any of the motive fluid from the compressor will decrease the efficiency and result in poor performance of the engine. maintained between the blade assembly and compressor casing by providing a flat bearing seat 63 surrounding the opening 52 and a mating flat bearing seat 64 on the fixed slseve 54. It is noted that this arrangement provides for ease of assembly of the blade assembly in the compressor cassing. Also, the Teflon surrounding the shoulder 69 on the wide base 56 also acts as a seal to prevent leakage from the compressor.

In order to operate the stator vanes the piston and cylinder arrangement 32 is operated so as to move the bellcrank rod 34 which in turn operates the bellcranks 36. Since the throw of the bell cranks for each stage is different, the actuator bands 30' are moved by a different pie-determined amount. Movement of the actuator band 3%} results in the movement of the lever arms 48. It is noted that the rod 46 is slidably mounted in the ball and socket arrangement 42 to permit'the turning of the bracket 48 without twisting even though the actuator band 3%) and levers 48 turn in different planes. Since the bracket ts is fixed to the root of the blade 50 through the dowel pins 49 and screw 51, the blade 50 will turn a pre-determined amount. Further, since the lever arms 48- are of lightweight material, they are too flexible to operate without a support on their outer ends. Therefore, the actuator bands 30 support thelever arms Therefore, a close fit is at the rod portions 46 by having the actuator bands good sealing and lubricating properties as well as temperature qualities. Further, the connection between the lever arms and actuator band is such thatthey can move in difierent planes. Also, sections of runners are provided on the casing for carrying theactuator bands which support the lever arms.

It is apparent that the above description has been given by way of explanation and not by way 'of limitation and that many modifications, improvements and changes may be made to the above structures without departing from the spirit and intent of this invention. All of such modifications and improvements are intended to be included within the scope of this invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In a compressor for a turbomachine comprising a casing, at least one stage of stator vanes rotatably mounted in the casing, lever arms fixed to the base of said stator vanes so as to turn therewith, an actuator band. slidably mounted on said casing adjacent each stage of rotatable stator vanes, ball and socket arrangemeans in said actuator bands openingsin the ball portions, said lever arms having rod ends extending axially of the arms through the openings in said ball portions, the actuator bands having a runner and the casing having a sector thereon for supporting the runner and actuator bands, anti-friction material on the runner and sector constraining the actuator band in an axial direc-' tion while permitting the band to be actuated in a circumferential direction, and means for actuating the bands.

2. In a compressor for a turbomachine comprising a casing, at least one stage of stator vanes rotatably mounted in the casing, the bases of said stator vanes each having a rotatable portion with a flat bearing surface, sleeves mounted in said casing for receiving said bases, each sleeve having a flat bearing seat surface, layer of anti-friction material positioned between the seat surface and the flat bearing surface of the associated blade, lever arms fastened to the rotatable portion of the bases to as to turn therewith, actuator bands extending about the casing, balls rotatably mounted in the actuator bands, the lever arms having rod ends thereon extending through the balls, said bands being actuated so as to turn said stator vanes.

3. In a turbomachine, a'casing, openings in the easing, a blade assembly fixed in each opening, the blade assembly including a sleeve having a fixed seat and a removable seat, a blade provided with a base having a flat shoulder which is located between the seats, and flat bearing material positioned between each seat and the flat shoulder to permit the blade to rotate with respect to, the sleeve, and means for simultaneously rotating the blades.- I

4. Ina turbomachine, a casing, openings in the casing, a'blade assembly-fixed in each opening, said blade assembly including a sleeve having a fixed seat and a removable seat, a blade provided with a base having a flat shoulderwhich'is' located between the seats, andfiat bearing material positioned between each seat and the flat shoulder to permit the blade to rotate with respect to the sleeve, alever arm fixed to each blade base so as to rotate therewith, actuator bands slidably mounted on the casing, ball and socket joints in the actuator bands, said actuator bands being connected to the lever arms through the ball and socketjoint to permit the band to rotate in an arc of a circle and the lever arm to rotate in a plane tangent to the arc of the circle.

5. In a compressor for a gas turbine engine, comprising a casing, openings in the casing, bearing seats in said casing each surrounding an opening therein, a plurality of stator vanes mounted on said seats and extending through said'openings, the openings containing a'removable seat spaced from the seat in the casing, the base of each of the vanes forming a substantially wide shoulder, flat bearing material positioned between the spaced seats and wide shoulder on the base of each of the vanes, lever arms fixed to the stator vanes so as to rotate therewith, the lever arms being suificiently light so as to be flexible, band actuators slidably mounted on the casing, said band actuators carrying the lever arms, means on the band actuators to permit movement of the lever arms without twisting, and means for actuating the bands.

- 2,933,234 5 t 6. In a compressor for a gas turbine engine comprising References Cited in the file of this patent a casing, a plurality of openings in the casing, spaced UNITED STATES PATENTS bearing seats in each opening, a plurality of stator vanes each having a substantially wide shoulder, the Wide shoul- 22,05 311 lePdrasslk 1942 der being positioned between the bearing seats, fiat bear- 5 9 W1,1de 1952 ing material interposed between and bearing against the L29 2 Fellden Sept 1953 seats and the wide shoulder, lever arms fixed to the vanes, L496 Buckland Sept 1953 actuator bands slidably mounted on the casing, ball and 2671634 Morley 1954 socket joints mounted in the actuator bands, the actuator FOREIGN PATENTS bands being connected to the lever arms through the ball 10 500 965 Great Britain Feb 20 1939 and socket joints to permit the actuator bands and lever 1 Great Britain h 1949 arms move dlfierent Planes- 701,576 Great Britain Dec. 30, 1953 1,022,629 France Dec. 17, 1952 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No, 2333 234: April 19 1960 Gerhard Neumann It is hereby certified that error appears in the-printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 4 lines 13 and M for "arrangemeans" read arrangements Signed and sealed this 29th day of November 1960.,

( SEA L) Attest:

KARL H. AXLINE ROBERT C. WATSON Commissioner of Patents Attesting Oflicer

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2305311 *Jul 5, 1938Dec 15, 1942George JendrassikGas turbine plant equipped with regulating apparatus
US2613029 *Jun 1, 1948Oct 7, 1952Rolls RoyceAxial flow compressor regulation
US2651492 *Mar 14, 1947Sep 8, 1953Power Jets Res & Dev LtdTurbine
US2651496 *Oct 10, 1951Sep 8, 1953Gen ElectricVariable area nozzle for hightemperature turbines
US2671634 *Jun 30, 1950Mar 9, 1954Rolls RoyceAdjustable stator blade and shroud ring arrangement for axial flow turbines and compressors
FR1022629A * Title not available
GB500965A * Title not available
GB621175A * Title not available
GB701576A * Title not available
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3356288 *Apr 7, 1965Dec 5, 1967Gen ElectricStator adjusting means for axial flow compressors or the like
US3376018 *Dec 21, 1966Apr 2, 1968Rolls RoyceVane operating mechanism
US3458118 *Aug 21, 1967Jul 29, 1969Gen ElectricLow profile stator adjusting mechanism
US3502260 *Sep 22, 1967Mar 24, 1970Gen ElectricStator vane linkage for axial flow compressors
US3841788 *Nov 9, 1972Oct 15, 1974Galperin JDevice for turning the stator vanes of turbo-machines
US4279568 *Oct 16, 1978Jul 21, 1981United Technologies CorporationVane angle control
US4558987 *Apr 5, 1985Dec 17, 1985Mannesmann AktiengesellschaftApparatus for regulating axial compressors
US4773821 *Dec 15, 1987Sep 27, 1988Societe Nationale D'etude Et De Construction De Moteurs D'aviation "S.N.E.C.M.A."Control mechanism for variably settable vanes of a flow straightener in a turbine plant
US4810165 *Jul 8, 1987Mar 7, 1989Mtu Motoren- Und Turbinen-Union Munchen GmbhAdjusting mechanism for guide blades of turbo-propulsion units
US4812106 *Apr 27, 1988Mar 14, 1989Rolls-Royce PlcVariable stator vane arrangement for a compressor
US4826399 *May 6, 1988May 2, 1989General Motors CorporationUnison ring mounting arrangement
US5190439 *Jul 15, 1991Mar 2, 1993United Technologies CorporationVariable vane non-linear schedule for a gas turbine engine
US6174130Jun 30, 1999Jan 16, 2001General Electric CompanyMovable shaft assembly
US6551057Nov 22, 1999Apr 22, 2003General Electric CompanyDamped torque shaft assembly
US6860717May 10, 2002Mar 1, 2005Avio S.P.A.Axial turbine for aeronautical applications
US7396203 *Jun 16, 2005Jul 8, 2008Rolls-Royce, PlcSpacer arrangement
US7588415 *Jul 20, 2005Sep 15, 2009United Technologies CorporationSynch ring variable vane synchronizing mechanism for inner diameter vane shroud
US7628579 *Jul 20, 2005Dec 8, 2009United Technologies CorporationGear train variable vane synchronizing mechanism for inner diameter vane shroud
US7690889 *Jul 20, 2005Apr 6, 2010United Technologies CorporationInner diameter variable vane actuation mechanism
US7753647 *Jul 20, 2005Jul 13, 2010United Technologies CorporationLightweight cast inner diameter vane shroud for variable stator vanes
US7802964 *Aug 9, 2006Sep 28, 2010SnecmaLink device of controllable variable length
US7901178Mar 18, 2009Mar 8, 2011United Technologies CorporationInner diameter vane shroud system having enclosed synchronizing mechanism
US8393857Oct 9, 2009Mar 12, 2013Rolls-Royce CorporationVariable vane actuation system
US8435000Mar 7, 2008May 7, 2013Rolls-Royce CorporationVariable vane actuation system
US8794910Feb 1, 2011Aug 5, 2014United Technologies CorporationGas turbine engine synchronizing ring bumper
US8864450Feb 1, 2011Oct 21, 2014United Technologies CorporationGas turbine engine synchronizing ring bumper
DE3623001C1 *Jul 9, 1986Jul 9, 1987Mtu Muenchen GmbhVerstellvorrichtung fuer schwenkbare Leitschaufeln von Turbotriebwerken
DE4102188A1 *Jan 25, 1991Aug 6, 1992Mtu Muenchen GmbhEinrichtung zur verstellung der leitschaufeln einer turbine eines gasturbinentriebwerks
DE10243103A1 *Sep 17, 2002Mar 25, 2004Rolls-Royce Deutschland Ltd & Co KgDevice for adjusting the compressor blades of a gas turbine, comprises angled levers mounted on an adjusting ring and coupled to a blade spindle
EP0274931A2 *Dec 2, 1987Jul 20, 1988Societe Nationale D'etude Et De Construction De Moteurs D'aviation, "S.N.E.C.M.A."Adjusting device for the stator vanes of a turbo machine
EP0289697A1 *Jan 13, 1988Nov 9, 1988MAN Gutehoffnungshütte AktiengesellschaftActuator for the variable guide vanes of an axial turbo machine
EP0375593A1 *Dec 19, 1989Jun 27, 1990United Technologies CorporationAdjustable spacer
EP1207272A2 *Nov 16, 2001May 22, 2002General Electric CompanyReplaceable variable stator vane for gas turbines
EP1256698A2 *May 10, 2002Nov 13, 2002FIATAVIO S.p.A.Axial turbine with a variable-geometry stator
EP2481891A2 *Jan 31, 2012Aug 1, 2012United Technologies CorporationGas turbine engine synchronizing ring bumper
EP2481892A2 *Jan 31, 2012Aug 1, 2012United Technologies CorporationGas turbine engine synchronizing ring bumper
EP2824286A1 *Jan 31, 2012Jan 14, 2015United Technologies CorporationGas turbine engine synchronizing ring bumper
Classifications
U.S. Classification415/149.4, 415/150, 415/160
International ClassificationF01D17/16
Cooperative ClassificationY02T50/671, F01D17/162
European ClassificationF01D17/16B