US3708244A - Bladed rotor for a gas turbine engine - Google Patents
Bladed rotor for a gas turbine engine Download PDFInfo
- Publication number
- US3708244A US3708244A US00132675A US3708244DA US3708244A US 3708244 A US3708244 A US 3708244A US 00132675 A US00132675 A US 00132675A US 3708244D A US3708244D A US 3708244DA US 3708244 A US3708244 A US 3708244A
- Authority
- US
- United States
- Prior art keywords
- blade
- blades
- tie
- ties
- bladed rotor
- 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.)
- Expired - Lifetime
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Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
- F01D5/00—Blades; Blade-carrying members; Heating, heat-insulating, cooling or antivibration means on the blades or the members
- F01D5/12—Blades
- F01D5/22—Blade-to-blade connections, e.g. for damping vibrations
Definitions
- ABSTRACT A bladed rotor for a gas-turbine engine comprising a row of blades in which each blade is tied to the next adjacent blade by a Z-shaped metal tie having a center section which is inwardly curved such that centrifugal forces acting on itself are evidenced as compressive stresses within the tie and end limbs or lugs extending from the center section in opposite directions generally chordally of the blades and each being attached to the blades by bolts spaced apart transversely of the blade, the bolts extending through the blade to also attach a similar limb or lug to the opposite blade face.
- the present invention provides a rotor having ties which are both light in weight and rigid under high centrifugal stresses. At the same time they can adjust themselves to a change in diameter due to the stretch of the assembly.
- a bladed rotor for a gas turbine engine comprises a row of blades, each blade being connected to the next adjacent blade by a tie, each tie comprising an inwardly curved metal strip attached at each end to the blades and having a substantially catenary shape so that in operation centrifugal effects on the ties cause the metal strips to be under mainly compressive stress.
- each tie has an outwardly extending lug at each end by which it is attached to the blade.
- the lug may be retained to the blade by two bolts which extend through the blade and also retain a similar lug on the opposite blade face.
- the ties may be staggered" and the lugs extend substantially along the chord of the blade from one tie to the next.
- the ties are made from single pieces of sheet metal or forgings having a Z- shape, the limbs of the Z-shape being bent up to form the lugs and the interconnection being curved inwardly to form the tie.
- FIG. I is a frontal view of the fan of a gas turbine engine in accordance with the invention:
- FIG. 2 is an enlarged section through the fan of FIG. 1 and FIG. 3 is a section on the line 33 of FIG. 2.
- FIG. 1 there is shown a fan comprising a row of rotor blades 10 driven from a hub 11 and working inside a shroud 12.
- the hub 11 is driven from the gas generator section comprising the remainder of the gas turbine engine (not shown).
- each blade is attached to its next adjacent blades by means of ties 13.
- the ties 13 are seen in greater detail in FIGS. 2 and 3.
- Each tie 13 comprises an inwardly curved center section 14 of substantially constant cross-section. This center section is arranged to lie on substantially a catenary curve. To anchor the center section to the blades at either end, each end is provided with an upstanding lug 15. Each of the lugs 15 has a considerable chordal extent, and is bolted through the blade section in two chordally separated locations 16 and 17. The bolts which fasten the lug 15 of one tie also fasten the lug to the next adjacent tie.
- the blade'section is build up at 16 and 17 i on the corresponding points on the opposite surface by pads 18 andl9.'ln the present case the pads 18 and I9 formed as continuations of the central portions of the ties and extend in one direction only from the ends of the ties, and in fact they are formed from a Z-shaped piece of sheet material.
- this bolt acts about a considerable moment arm to oppose such a tendency.
- the ties illustrated are simply manufactured from a Z-shaped piece of sheet metal. It will be seen that by drilling the bolt holes, bending up the lugs 15 and forming the center section to the required catenary shape, the complete tie may be made. It is preferable if the edges of at least the center section of the tie are rounded off both to improve the aerodynamic qualities of the tie and to reduce the possibility of stress raisers and consequent cracks.
- a bladed rotor for a gas turbine engine comprising row of blades and ties, each blade being connected to a next adjacent blade by at least one tie, each tie comprising a single Z-shaped piece of metal having limbs bent up to form lugs extending in opposite directions generally chordally of the adjacent blades and having a center section interconnecting said lugs and being curved inwardly so that operational centrifical forces on the ties cause them to be under com-pressive stress, and a plurality of bolts for retaining each lug to a particular blade, said bolts being spaced apart transversely of and extending through the particular blade and also retaining a similar lug on an opposite face of the particular blade.
- a bladed rotor as claimed in claim 1 including pads secured to each face of each blade to provide a flat bearing surface for said lugs of said ties.
- a bladed rotor as claimed in claim 2 in which said pads are made from a glass reinforced plastic material and are adhesively secured to the blade surface.
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Structures Of Non-Positive Displacement Pumps (AREA)
- Turbine Rotor Nozzle Sealing (AREA)
Abstract
A bladed rotor for a gas turbine engine comprising a row of blades in which each blade is tied to the next adjacent blade by a Z-shaped metal tie having a center section which is inwardly curved such that centrifugal forces acting on itself are evidenced as compressive stresses within the tie and end limbs or lugs extending from the center section in opposite directions generally chordally of the blades and each being attached to the blades by bolts spaced apart transversely of the blade, the bolts extending through the blade to also attach a similar limb or lug to the opposite blade face.
Description
United States Patent 1 Dawson et al.
[451 Jan. 2, 1973 541 BLADED ROTOR FOR A GAS TURBINE ENGINE [75] Inventors: Lindsay Grahame Dawson, Castle- 211 App]. No.: 132,675
[22] Filed: Apr. 9, 1971 [30] Foreign Application Priority Data April 13, I970 Great Britain ..l7,546/70 [52] US. Cl. ..416/196 [51] Int. Cl. ..F0ld 5/10, FOld 5/24 [58] Field of Search ..416/196, 194, 195
[56] References Cited UNITED STATES PATENTS 937,006 10/1909 McKee .Q ..4l 6/l96 9/1962 Mitchell ..416/196 X FOREIGN PATENTS OR APPLICATIONS 563,458 11/1932 Germany .L 2.....416/196 818,806 10/1951 Germany ..416/196 315,722 2/1930 Great Britain ..4l6/l 96 Primary ExaminerEverette A. Powell, Jr. Attorney-Cushman, Darby & Cushman [57] ABSTRACT A bladed rotor for a gas-turbine engine comprising a row of blades in which each blade is tied to the next adjacent blade by a Z-shaped metal tie having a center section which is inwardly curved such that centrifugal forces acting on itself are evidenced as compressive stresses within the tie and end limbs or lugs extending from the center section in opposite directions generally chordally of the blades and each being attached to the blades by bolts spaced apart transversely of the blade, the bolts extending through the blade to also attach a similar limb or lug to the opposite blade face.
3 Claims, 3 Drawing Figures 11/1959 Mitchell ..416/195 X BLADEI) ROTOR FOR A GAS TURBINE ENGINE This invention relates to a bladed rotor for a gas turbine engine.
In certain circumstances it is necessary to stiffen the blades of such a rotor by interconnecting the blades in each row by ties. It is difficult to design ties which are light in weight and sufficiently rigid in the high G environment of such a bladed rotor.
The present invention provides a rotor having ties which are both light in weight and rigid under high centrifugal stresses. At the same time they can adjust themselves to a change in diameter due to the stretch of the assembly.
According to the present invention a bladed rotor for a gas turbine engine comprises a row of blades, each blade being connected to the next adjacent blade by a tie, each tie comprising an inwardly curved metal strip attached at each end to the blades and having a substantially catenary shape so that in operation centrifugal effects on the ties cause the metal strips to be under mainly compressive stress.
Preferably each tie has an outwardly extending lug at each end by which it is attached to the blade.
The lug may be retained to the blade by two bolts which extend through the blade and also retain a similar lug on the opposite blade face.
Thus the ties may be staggered" and the lugs extend substantially along the chord of the blade from one tie to the next.
In a preferred embodiment the ties are made from single pieces of sheet metal or forgings having a Z- shape, the limbs of the Z-shape being bent up to form the lugs and the interconnection being curved inwardly to form the tie.
The invention will now be particularly described merely by way of example with reference to the accompanying drawings in which:
FIG. I is a frontal view of the fan of a gas turbine engine in accordance with the invention:
FIG. 2 is an enlarged section through the fan of FIG. 1 and FIG. 3 is a section on the line 33 of FIG. 2.
In FIG. 1 there is shown a fan comprising a row of rotor blades 10 driven from a hub 11 and working inside a shroud 12. The hub 11 is driven from the gas generator section comprising the remainder of the gas turbine engine (not shown). In order to strengthen, and modify the vibration characteristics, of the fan blades 10, each blade is attached to its next adjacent blades by means of ties 13. The ties 13 are seen in greater detail in FIGS. 2 and 3.
Each tie 13 comprises an inwardly curved center section 14 of substantially constant cross-section. This center section is arranged to lie on substantially a catenary curve. To anchor the center section to the blades at either end, each end is provided with an upstanding lug 15. Each of the lugs 15 has a considerable chordal extent, and is bolted through the blade section in two chordally separated locations 16 and 17. The bolts which fasten the lug 15 of one tie also fasten the lug to the next adjacent tie.
In order to provide a flat location for the lugs on the blade section, the blade'section is build up at 16 and 17 i on the corresponding points on the opposite surface by pads 18 andl9.'ln the present case the pads 18 and I9 formed as continuations of the central portions of the ties and extend in one direction only from the ends of the ties, and in fact they are formed from a Z-shaped piece of sheet material. Thus any tendency for the central section to rotate is opposed by the more distant of the two bolts holding the flanges in place, this bolt acts about a considerable moment arm to oppose such a tendency. It will also be noted that due to the inwardly curved catenary shape of the center portion of the ties, this portion will be under a compressive stress when centrifugal loads act on the tie in operation. The loads transferred to each blade through the lugs 15 will be opposed to some extent by opposite loads produced by the next adjacent tie.
As briefly mentioned above, the ties illustrated are simply manufactured from a Z-shaped piece of sheet metal. It will be seen that by drilling the bolt holes, bending up the lugs 15 and forming the center section to the required catenary shape, the complete tie may be made. It is preferable if the edges of at least the center section of the tie are rounded off both to improve the aerodynamic qualities of the tie and to reduce the possibility of stress raisers and consequent cracks.
It will be appreciated that various modifications can be made to the invention as described above. Thus various methods could be used to fasten the ties to the blades, and the ties need not be made from sheet metal as described in the preferred embodiment. The standard bolts shown on FIG. 2 and 3 are for test purposes only. A preferred bolt would have a shallow domed head as shown at 20 in FIG. 3. It would be used with a sunk sleeve nut which would also serve as a dowel.
We claim: I. A bladed rotor for a gas turbine engine comprisa row of blades and ties, each blade being connected to a next adjacent blade by at least one tie, each tie comprising a single Z-shaped piece of metal having limbs bent up to form lugs extending in opposite directions generally chordally of the adjacent blades and having a center section interconnecting said lugs and being curved inwardly so that operational centrifical forces on the ties cause them to be under com-pressive stress, and a plurality of bolts for retaining each lug to a particular blade, said bolts being spaced apart transversely of and extending through the particular blade and also retaining a similar lug on an opposite face of the particular blade.
' 2. A bladed rotor as claimed in claim 1 including pads secured to each face of each blade to provide a flat bearing surface for said lugs of said ties.
3. A bladed rotor as claimed in claim 2 in which said pads are made from a glass reinforced plastic material and are adhesively secured to the blade surface.
It will be seen from FIG. 3 that the lugs 15 are
Claims (3)
1. A bladed rotor for a gas turbine engine comprising: a row of blades and ties, each blade being connected to a next adjacent blade by at least one tie, each tie comprising a single Z-shaped piece of metal having limbs bent up to form lugs extending in opposite directions generally chordally of the adjacent blades and having a center section interconnecting said lugs and being curved inwardly so that operational centrifical forces on the ties cause them to be under compressive stress, and a plurality of bolts for retaining each lug to a particular blade, said bolts being spaced apart transversely of and extending through the particular blade and also retaining a similar lug on an opposite face of the particular blade.
2. A bladed rotor as claimed in claim 1 including pads secured to each face of each blade to provide a flat bearing surface for said lugs of said ties.
3. A bladed rotor as claimed in claim 2 in which said pads are made from a glass reinforced plastic material and are adhesively secured to the blade surface.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB1754670 | 1970-04-13 |
Publications (1)
Publication Number | Publication Date |
---|---|
US3708244A true US3708244A (en) | 1973-01-02 |
Family
ID=10097090
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US00132675A Expired - Lifetime US3708244A (en) | 1970-04-13 | 1971-04-09 | Bladed rotor for a gas turbine engine |
Country Status (5)
Country | Link |
---|---|
US (1) | US3708244A (en) |
DE (1) | DE2117387A1 (en) |
FR (1) | FR2089567A5 (en) |
GB (1) | GB1335553A (en) |
IT (1) | IT942542B (en) |
Cited By (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4407634A (en) * | 1981-09-08 | 1983-10-04 | Northern Engineering Industries Plc | Axial-flow steam turbine wheel |
US4734010A (en) * | 1985-05-31 | 1988-03-29 | Bbc Brown, Boveri & Company, Limited | Damping element for independent turbomachine blades |
US4798519A (en) * | 1987-08-24 | 1989-01-17 | United Technologies Corporation | Compressor part span shroud |
US5783330A (en) * | 1995-09-28 | 1998-07-21 | Yazaki Corporation | Electrode material and secondary battery |
US5984638A (en) * | 1994-08-12 | 1999-11-16 | Elliott Turbomachinery Co., Inc. | Turbomachine radial impeller vibration constraining and damping mechanism |
GB2441543A (en) * | 2006-09-07 | 2008-03-12 | Rolls Royce Plc | A bridging element for reducing vibrations in an array of elongate components |
US20110064570A1 (en) * | 2009-09-16 | 2011-03-17 | O'connor John F | High Efficiency Low-Profile Centrifugal Fan |
US20110142650A1 (en) * | 2009-12-14 | 2011-06-16 | Beeck Alexander R | Turbine Blade Damping Device with Controlled Loading |
US20110142654A1 (en) * | 2009-12-14 | 2011-06-16 | Marra John J | Turbine Blade Damping Device With Controlled Loading |
US20120244008A1 (en) * | 2011-03-25 | 2012-09-27 | Shun-Chen Chang | Impeller structure |
USRE45690E1 (en) | 2009-12-14 | 2015-09-29 | Siemens Energy, Inc. | Turbine blade damping device with controlled loading |
US20160040537A1 (en) * | 2014-08-07 | 2016-02-11 | General Electric Company | Turbine blade mid-span shroud assembly |
US20230258092A1 (en) * | 2022-02-14 | 2023-08-17 | General Electric Company | Part-span shrouds for pitch controlled aircrafts |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2251897B (en) * | 1991-01-15 | 1994-11-30 | Rolls Royce Plc | A rotor |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US937006A (en) * | 1906-03-03 | 1909-10-12 | Allis Chalmers | Steam-turbine. |
GB315722A (en) * | 1928-07-16 | 1930-02-27 | The British Thomson-Houston Company Limited | |
DE563458C (en) * | 1929-02-10 | 1932-11-05 | Siemens Schuckertwerke Akt Ges | Stiffening of steam turbine blades |
DE818806C (en) * | 1949-02-17 | 1951-10-29 | Escher Wyss Ag | Blading on rotors of axially flowed through, strongly twisted blades having centrifugal machines, in particular steam, gas turbines and compressors |
US2914299A (en) * | 1954-02-05 | 1959-11-24 | Gen Electric Co Ltd | Steam turbines |
US3055634A (en) * | 1959-12-07 | 1962-09-25 | Gen Electric Co Ltd | Steam turbines |
-
1971
- 1971-04-08 DE DE19712117387 patent/DE2117387A1/en active Pending
- 1971-04-09 US US00132675A patent/US3708244A/en not_active Expired - Lifetime
- 1971-04-13 FR FR7112951A patent/FR2089567A5/fr not_active Expired
- 1971-04-13 IT IT23101/71A patent/IT942542B/en active
- 1971-04-19 GB GB1754670A patent/GB1335553A/en not_active Expired
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US937006A (en) * | 1906-03-03 | 1909-10-12 | Allis Chalmers | Steam-turbine. |
GB315722A (en) * | 1928-07-16 | 1930-02-27 | The British Thomson-Houston Company Limited | |
DE563458C (en) * | 1929-02-10 | 1932-11-05 | Siemens Schuckertwerke Akt Ges | Stiffening of steam turbine blades |
DE818806C (en) * | 1949-02-17 | 1951-10-29 | Escher Wyss Ag | Blading on rotors of axially flowed through, strongly twisted blades having centrifugal machines, in particular steam, gas turbines and compressors |
US2914299A (en) * | 1954-02-05 | 1959-11-24 | Gen Electric Co Ltd | Steam turbines |
US3055634A (en) * | 1959-12-07 | 1962-09-25 | Gen Electric Co Ltd | Steam turbines |
Cited By (20)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4407634A (en) * | 1981-09-08 | 1983-10-04 | Northern Engineering Industries Plc | Axial-flow steam turbine wheel |
US4734010A (en) * | 1985-05-31 | 1988-03-29 | Bbc Brown, Boveri & Company, Limited | Damping element for independent turbomachine blades |
US4798519A (en) * | 1987-08-24 | 1989-01-17 | United Technologies Corporation | Compressor part span shroud |
US5984638A (en) * | 1994-08-12 | 1999-11-16 | Elliott Turbomachinery Co., Inc. | Turbomachine radial impeller vibration constraining and damping mechanism |
US5783330A (en) * | 1995-09-28 | 1998-07-21 | Yazaki Corporation | Electrode material and secondary battery |
GB2441543A (en) * | 2006-09-07 | 2008-03-12 | Rolls Royce Plc | A bridging element for reducing vibrations in an array of elongate components |
US20080063522A1 (en) * | 2006-09-07 | 2008-03-13 | Rolls-Royce Plc | Array of components |
GB2441543B (en) * | 2006-09-07 | 2008-07-23 | Rolls Royce Plc | An array of components |
US8647051B2 (en) | 2009-09-16 | 2014-02-11 | The Bergquist Torrington Company | High efficiency low-profile centrifugal fan |
US20110064570A1 (en) * | 2009-09-16 | 2011-03-17 | O'connor John F | High Efficiency Low-Profile Centrifugal Fan |
US20110142650A1 (en) * | 2009-12-14 | 2011-06-16 | Beeck Alexander R | Turbine Blade Damping Device with Controlled Loading |
US20110142654A1 (en) * | 2009-12-14 | 2011-06-16 | Marra John J | Turbine Blade Damping Device With Controlled Loading |
WO2011081761A1 (en) * | 2009-12-14 | 2011-07-07 | Siemens Energy, Inc. | Turbine blade damping device with controlled loading |
US8540488B2 (en) | 2009-12-14 | 2013-09-24 | Siemens Energy, Inc. | Turbine blade damping device with controlled loading |
US8616848B2 (en) | 2009-12-14 | 2013-12-31 | Siemens Energy, Inc. | Turbine blade damping device with controlled loading |
USRE45690E1 (en) | 2009-12-14 | 2015-09-29 | Siemens Energy, Inc. | Turbine blade damping device with controlled loading |
US20120244008A1 (en) * | 2011-03-25 | 2012-09-27 | Shun-Chen Chang | Impeller structure |
US20160040537A1 (en) * | 2014-08-07 | 2016-02-11 | General Electric Company | Turbine blade mid-span shroud assembly |
US20230258092A1 (en) * | 2022-02-14 | 2023-08-17 | General Electric Company | Part-span shrouds for pitch controlled aircrafts |
US11913355B2 (en) * | 2022-02-14 | 2024-02-27 | General Electric Company | Part-span shrouds for pitch controlled aircrafts |
Also Published As
Publication number | Publication date |
---|---|
DE2117387A1 (en) | 1971-11-04 |
IT942542B (en) | 1973-04-02 |
GB1335553A (en) | 1973-10-31 |
FR2089567A5 (en) | 1972-01-07 |
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