GB2420162A - A seal arrangement for sealing between turbine blades - Google Patents

A seal arrangement for sealing between turbine blades Download PDF

Info

Publication number
GB2420162A
GB2420162A GB0425187A GB0425187A GB2420162A GB 2420162 A GB2420162 A GB 2420162A GB 0425187 A GB0425187 A GB 0425187A GB 0425187 A GB0425187 A GB 0425187A GB 2420162 A GB2420162 A GB 2420162A
Authority
GB
United Kingdom
Prior art keywords
seals
filler
arrangement
seal
sealing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
GB0425187A
Other versions
GB0425187D0 (en
Inventor
Rodney Alan Cross
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Cross Manufacturing Co 1938 Ltd
Original Assignee
Cross Manufacturing Co 1938 Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Cross Manufacturing Co 1938 Ltd filed Critical Cross Manufacturing Co 1938 Ltd
Priority to GB0425187A priority Critical patent/GB2420162A/en
Publication of GB0425187D0 publication Critical patent/GB0425187D0/en
Publication of GB2420162A publication Critical patent/GB2420162A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01DNON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D11/00Preventing or minimising internal leakage of working-fluid, e.g. between stages
    • F01D11/005Sealing means between non relatively rotating elements
    • F01D11/006Sealing the gap between rotor blades or blades and rotor
    • F01D11/008Sealing the gap between rotor blades or blades and rotor by spacer elements between the blades, e.g. independent interblade platforms
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01DNON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D11/00Preventing or minimising internal leakage of working-fluid, e.g. between stages
    • F01D11/005Sealing means between non relatively rotating elements
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01DNON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D5/00Blades; Blade-carrying members; Heating, heat-insulating, cooling or antivibration means on the blades or the members
    • F01D5/12Blades
    • F01D5/22Blade-to-blade connections, e.g. for damping vibrations
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16JPISTONS; CYLINDERS; SEALINGS
    • F16J15/00Sealings
    • F16J15/02Sealings between relatively-stationary surfaces
    • F16J15/021Sealings between relatively-stationary surfaces with elastic packing
    • F16J15/028Sealings between relatively-stationary surfaces with elastic packing the packing being mechanically expanded against the sealing surface
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16JPISTONS; CYLINDERS; SEALINGS
    • F16J15/00Sealings
    • F16J15/16Sealings between relatively-moving surfaces
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16JPISTONS; CYLINDERS; SEALINGS
    • F16J15/00Sealings
    • F16J15/16Sealings between relatively-moving surfaces
    • F16J15/164Sealings between relatively-moving surfaces the sealing action depending on movements; pressure difference, temperature or presence of leaking fluid
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05DINDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
    • F05D2250/00Geometry
    • F05D2250/20Three-dimensional
    • F05D2250/23Three-dimensional prismatic
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02TCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T50/00Aeronautics or air transport
    • Y02T50/60Efficient propulsion technologies, e.g. for aircraft

Abstract

A seal arrangement for sealing between turbine blades 1, 2 comprising a filler subassembly 3 which spans the space between adjacent turbine blades 1, 2 in order to isolate the annular gas intake area 4 from the central machinery space 5. The filler subassembly comprises a filler member 7 and seal members 10, 11 located in slots at either end of the filler member. Each of the seals 10, 11 engages a respective blade 2, 1. The seal members 10, 11 and slots have cooperating inclined surfaces 12, 8 whereby when the turbine rotates in use, an upward force is generated on the seal members 10, 11 as a result of the cooperation of the surfaces 12, 8, so that they move upwardly to close the respective gap 13 between the respective edge of the filler member 7 and the associated blade 1, 2.

Description

* çIS * * *. S ** SI I S S * S S S S S S * I _Il_. S I III * S I S I I I
S.. S 511 us S S
IMPROVEMENTS TO SEALS
Field of the Invention
The invention relates to axial compressor assemblies where there is a requirement to isolate the annular shaped gas intake spaces through which the compressor fan blades are rotating from the central cylindrical spaces containing the rotor bearings and other precision machinery parts of the engine. The invention is of particular, but not exclusive benefit) to large aircraft gas turbine engines where the initial stages of the compressor occupy relatively large intake diameters.
Background to the Invention
In the case of modest size axial compressors, the annular isolation feature required to separate the gas intake path from the central machinery space can be obtained by arranging for the adjacent fan blade root fixtures to abut each other on a boundary line which is in a plane approximately mid way between adjacent fan blades.
However, on large axial compressors, particularly on those employed in aircraft gas turbine engines, the spacing between adjacent fan blades on the initial two or thee stages is too large to enable the blade root fixtures to abut and the current 3D practice is to fit lightly constructed annulus sealing membranes or fillers" to seal up and isolate, as far as possible, the central machinery spaces from the gas being compressed by the rotating fan blades. In a typical installation the gas pressure generated by the initial stages may be for example 4 or 5 bars (60 to 75 p.s.1.) above the pressure existing in ti-is central machinery core of the engine.
The high stresses due mainly to centrifugal forc2s set up in the rotating fan blades and the expansion and consequent distortion * 4*S * 4 4 I4 4 *S I. * S * S * S S I S S * S S S S I 151 * S j S 4 I I *5* * b4V i.e, . of metal alloy components due to varying temperature rises results in a situation where it is not possible to use close fitting mating components in the regions between adjacent fan blade rootg. Because of this situation the annulus sealing fillers have to be provided with a significant working clearance where the boundaries of the fillers are adjacent to the blade profile. A further reason for maintaining a boundary gap is to prevent metal to metal contact resulting In fretting on the fan blade surfaces at radial distances from the turning centre where the stresses due to centrifugal force are at or near their maximum values. In practice, working gaps up to 4 to 6 millimetres (0.16 to 0.24 inches) can be present on large by-pass flow gas turbines.
The present method of sealing the gaps between the fan blade profiles and the filler and to prevent metal to metal fretting is to provide substantially rectangular section flexible strip polymer seals located in rectangular section grooves along the edges of the fillers which are adjacent to the fan blade profiles The vor)cing life of these seals Is at present significantly less than the normal service life of the adjacent metal alloy components.
Summary of the Invention
The improvements which are the subject of this invention are to replace the flexible polymer sealing strips with semi-rigid sealing strips made of polymer material, or made of a combination of materials and to so shape the seals and the seal locating grooves in the filler that centrifugal force acting on the mass of each sealing strip holds the strip in contact with one surface of the filler whilst simultaneously providing opposing forces in substantially circumferential directions which hold the said sealing strips in contact with the fan blade profiles; the said combination of substantially radial and circumferential forces being sufficient to hold the sealing strips in contact with the cooperating sealing surfaces against the forces generated by the gas pressure acting on the exposed surface areas of the striDs.
* IS* * * I I. * ** I. * I I * * * I S t S S * * _3_ S S iii * S I S S S S I.. S *** III 5 0 Where a combination of materials is used for making the sealing strips this may be in the form of a central relatively heavy core to provide both semi-regidity and mass, the latter required to generate sufficient centrifugal force, the core being surrounded by a flexible polymer coating to provide the gas sealing surfaces and to prevent the metal to metal contact on the highly stressed regions of the fan blades.
Brief Description of the Drawings
Figure 1 is a view looking on the air entry end of an aircraft gas turbine in which the entry stage fan assembly has been partially removed through two fan blades to show a cross section of a filler sub-assembly provided with a typical current design of polymer sealing strips.
Figure 2 is an enlarged cross section of the same two blades as shown in Figure 1 but with the modified design of filler and sealing strips the subject of this invention.
Figure 3 shows a view of a further embodiment of the sealing strip having a metal core section with a surrounding polymer coating.
Description of the Preferred Ebodiments
Figure 1 shows a simplified view of the ihtake area of an aircraft gas turbine of current design. Two of the first stage fan blades 1 and 2 have been partially sectioned near the blade root fixings to illustrate the filler sub-assembly 3 which spans the space between the adjacent fan blades 1 and 2 in order to isolate the annular gas intake area 4 from the central machinery space 5. The polymer seal 6 which limits the gas leakage between these two spaces is of rectangular cross section form and is contained within rectangular shaped slots in the filler with one free surface abutting the fan blade profile.
* ... I * * I
II I SI IS S S
* I S * I q I * * I I I I I III * 1 *A I I I * le. . . * Figure 2 shows an enlarged view of the sectioned area in Figure 1 with the filler sub-assembly 3 replaced by the new design of filler 7 and seals 10 and 11, the subject of this invention. The former rectangular slots have now been replaced by slotsjln which the former outer slot surface, which was in a direction substantially parallel tO the filler outer surface has now been replaced by a slot surface 8 which is inclined as illustrated.
The central inward directed protrusion 9 is an anchor extension which holds the filler sub-assembly on to the rotor shaft (not illustrated in Figure 2). The slot surface B inclination angle, related to a radial plane lying in the axis of rotation of the compressor and passing through the centre of gravity of the seals 10 and 11 contained within the slots, is typically 45 degrees. The cross sections of the seal strips 10 arid 11 are so shaped that, along the seal strip lengths, the seals have surfaces 12 which cooperate with the inclined surfaces 8 in the filler 7 slots.
As the compressor rotation accelerates from rest, the radial centrifugal forces acting on the seal strips, increase overcoming the gravitational forces and causing each seal to exert a force on the inclined surface 8 in the filler slot.
Because of the inclination of the surfaces 8 and 12 on each side of the filler two opposed outward directed forces are generated by these radial centrifugal forces acting on the seals. Provided that the surfaces inclination angles are sufficiently small relative to the aforementioned plane the outward directed forces will overcome the restraining forces due to the cooperating surfaces friction coefficient and each seal will slide upwards as drawn along the inclined outer slot surfaces causing the seals to span the clearance gap 13 between the edge of the filler and each fan blade profile. This arrangement, therefore, ensures that substantial sealing contact pressures can be generated on both the fan blade profiles and the filler inclined slot surfaces when the compressor is rotating at its normal running speeds.
Figure 3 shows a sealing strip 14 removed from the filler slot.
In order to increase the stiffness of the seal when dealing with * I** * * * * * w at a. . V * S * * I I S S I S I S I a III S a I S * as. * *d. a.. * * wide and varying gaps 13 it may be necessary to provide a metal alloy reinforcing wire or tube core 15 moulded, or otherwise located, in the centre of the seal section. A further enthodiment, when dealing with high rotor speeds and high gas pressure differences across the gaps 13 can be to use a met- al core section which is a similar shape but smaller than the required seal section and to make up the dimensional difference with a polymer coating which surrounds, or partly surrounds, the core at substantially constant thickness.
The core section may also be used to modify the mass of the seal, for example, a solid metal core using an iron based alloy can have a density of between five to seven times the density of the polymer seal material. This facility will enable the sealing pressures to be modified for any given rotor speed because these pressures will be in a linear relationship to the centrifugal forces which, in turn, are proportional to the mass of each composite material seal,

Claims (6)

* *1* * a a ENID.21 GB - claims.doc * , * a * * a a a ass * s a a a a a as. a as. as. a CLAIMS
1. A seal arrangement for sealing between turbine blades comprising a filler section for extending between the blades and defining oppositely facing slots at its edges and a respective seal member located in each slot for engaging its respective blade characterised in that the seal members and the slots have cooperating inclined surfaces whereby when the turbine rotates in use an upward force is generated on the seals as a result of the cooperation of the surfaces, so that the move upwardly to close the respective gap between the respective edge of the filler section and the associated blade.
2. An arrangement as claimed in claim 1 wherein the filler section includes an anchor for anchoring the filler section relative to the blades.
3. An arrangement as claimed in claim 2 wherein the seals retained by the blades and the filler section.
4. An arrangement as claimed in any one of the preceding claims wherein the seals are substantially trapezoidal in section.
5. An arrangement as claimed in any one of the preceding claims wherein the seals are semi-rigid.
6. An arrangement as claimed in claim 5 wherein the seals have a central rigid core covered with a flexible coating.
GB0425187A 2004-11-16 2004-11-16 A seal arrangement for sealing between turbine blades Withdrawn GB2420162A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB0425187A GB2420162A (en) 2004-11-16 2004-11-16 A seal arrangement for sealing between turbine blades

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB0425187A GB2420162A (en) 2004-11-16 2004-11-16 A seal arrangement for sealing between turbine blades

Publications (2)

Publication Number Publication Date
GB0425187D0 GB0425187D0 (en) 2004-12-15
GB2420162A true GB2420162A (en) 2006-05-17

Family

ID=33523759

Family Applications (1)

Application Number Title Priority Date Filing Date
GB0425187A Withdrawn GB2420162A (en) 2004-11-16 2004-11-16 A seal arrangement for sealing between turbine blades

Country Status (1)

Country Link
GB (1) GB2420162A (en)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008286197A (en) * 2007-05-15 2008-11-27 General Electric Co <Ge> Turbine rotor blade assembly and method of fabricating the same
EP2108786A2 (en) 2008-04-07 2009-10-14 Rolls-Royce plc Aeroengine fan assembly
EP2295727A3 (en) * 2009-08-14 2014-05-07 Rolls-Royce plc A sealing assembly
CN104145087A (en) * 2012-02-22 2014-11-12 斯奈克玛 Linear seal of an inter-blade platform
ITCO20130051A1 (en) * 2013-10-23 2015-04-24 Nuovo Pignone Srl METHOD FOR THE PRODUCTION OF A STAGE OF A STEAM TURBINE
US9228444B2 (en) 2011-11-15 2016-01-05 Rolls-Royce Plc Annulus filler
FR3081501A1 (en) * 2018-05-23 2019-11-29 Safran Aircraft Engines SHUTTER FOR A TURBOREACTOR HAVING AN ABSENT RECTIFIER BLADE

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2208529A (en) * 1987-08-05 1989-04-05 Gen Electric Turbine blade platform sealing and vibration damping apparatus
US6457935B1 (en) * 2000-06-15 2002-10-01 Snecma Moteurs System for ventilating a pair of juxtaposed vane platforms
GB2400144A (en) * 2003-03-19 2004-10-06 Alstom Technology Ltd Sealing between turbine blade platforms

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2208529A (en) * 1987-08-05 1989-04-05 Gen Electric Turbine blade platform sealing and vibration damping apparatus
US6457935B1 (en) * 2000-06-15 2002-10-01 Snecma Moteurs System for ventilating a pair of juxtaposed vane platforms
GB2400144A (en) * 2003-03-19 2004-10-06 Alstom Technology Ltd Sealing between turbine blade platforms

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008286197A (en) * 2007-05-15 2008-11-27 General Electric Co <Ge> Turbine rotor blade assembly and method of fabricating the same
EP1992786A3 (en) * 2007-05-15 2011-11-30 General Electric Company Rotor blade platform and corresponding bladed rotor assembly
EP2108786A2 (en) 2008-04-07 2009-10-14 Rolls-Royce plc Aeroengine fan assembly
EP2108786A3 (en) * 2008-04-07 2012-12-26 Rolls-Royce plc Aeroengine fan assembly
US8535013B2 (en) 2008-04-07 2013-09-17 Rolls-Royce Plc Aeroengine fan assembly
EP2295727A3 (en) * 2009-08-14 2014-05-07 Rolls-Royce plc A sealing assembly
US9228444B2 (en) 2011-11-15 2016-01-05 Rolls-Royce Plc Annulus filler
EP2594773A3 (en) * 2011-11-15 2017-12-20 Rolls-Royce plc Annulus filler
CN104145087A (en) * 2012-02-22 2014-11-12 斯奈克玛 Linear seal of an inter-blade platform
CN104145087B (en) * 2012-02-22 2016-03-02 斯奈克玛 For the linear liner of platform between blade
ITCO20130051A1 (en) * 2013-10-23 2015-04-24 Nuovo Pignone Srl METHOD FOR THE PRODUCTION OF A STAGE OF A STEAM TURBINE
WO2015059078A1 (en) * 2013-10-23 2015-04-30 Nuovo Pignone Srl Method for manufacturing a stage of a steam turbine
US11333029B2 (en) 2013-10-23 2022-05-17 Nuovo Pignone Srl Method for manufacturing a stage of a steam turbine
FR3081501A1 (en) * 2018-05-23 2019-11-29 Safran Aircraft Engines SHUTTER FOR A TURBOREACTOR HAVING AN ABSENT RECTIFIER BLADE
US10858941B2 (en) 2018-05-23 2020-12-08 Safran Aircraft Engines Shutter for turbine machine having an absent rectifier blade

Also Published As

Publication number Publication date
GB0425187D0 (en) 2004-12-15

Similar Documents

Publication Publication Date Title
US8113785B2 (en) Turbomachine rotor and turbomachine comprising such a rotor
EP1934474B1 (en) Combined labyrinth seal and screw-type gasket bearing sealing arrangement
US8474827B2 (en) Film riding pressure actuated leaf seal assembly
US8657573B2 (en) Circumferential sealing arrangement
US9909439B2 (en) Gas turbine rotor blade and gas turbine rotor
EP0867599A2 (en) Method and apparatus for sealing a gas turbine stator vane assembly
RU2598620C2 (en) Sealing assembly for turbine machine (versions)
EP3653843B1 (en) Air seal interface with forward engagement features and active clearance control for a gas turbine engine
US20060056963A1 (en) Retaining of centring keys for rings under variable angle stator vanes in a gas turbine engine
US8152462B1 (en) Card seal with conical flexible seal
GB2438858A (en) A sealing arrangement in a gas turbine engine
US6884027B2 (en) Sealing of turbomachinery casing segments
EP3653842B1 (en) Air seal interface with aft engagement features and active clearance control for a gas turbine engine
US9739163B2 (en) Strip for abradable in a compressor turbine
US20120315138A1 (en) Compliant plate seal assembly for a turbo machine
US7572098B1 (en) Vane ring with a damper
GB2567083A (en) Assembly forming a labyrinth seal for a turbomachine comprising an abradable material and inclined fins
GB2420162A (en) A seal arrangement for sealing between turbine blades
US10871079B2 (en) Turbine sealing assembly for turbomachinery
US9664054B2 (en) Turbomachine rotor with blade roots with adjusting protrusions
US5006043A (en) Floating annular seal with thermal compensation
US10830253B2 (en) Rotor, axial compressor, installation method
US20230106380A1 (en) Seal assembly for a rotary machine
GB2408548A (en) Finned seals for turbomachinery
RU2235919C2 (en) Gas-turbine engine compressor

Legal Events

Date Code Title Description
WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)