USOO88695 04B1 (12) United States Patent (10) Patent No.: US 8,869,504 B1 Schwarz et al. (45) Date of Patent: Oct. 28, 2014 (54) GEAREDTURBOFAN ENGINE GEARBOX 5.431,539 A 7/1995 Carvalho ARRANGEMENT 5,443,365 A * 8/1995 Ingling et al. ............. 416, 193A 5,778,659 A 7/1998 Duesler et al. 6,464,401 B1 10/2002 Allard (71) Applicant: United Technologies Corporation, 7,144.221 B2 * 12/2006 Giffin ............................ 416,189 Hartford, CT (US) 8,137,070 B2 * 3/2012 Van Houten ... 416,189 2006.0024162 A1* 2, 2006 Giffin .......... ... 415,208.3 (72) Inventors: Frederick M. Schwarz, Glastonbury, 2007/015.1258 A1* 7/2007 Gaines et al. ................... 60,792 CT (US); William G. Sheridan, 2008/00987.17 A1* 5, 2008 Orlando et al. .... ... 60,226.1 Southington, CT (US) 2010/0218478 A1* 9/2010 Merry et al. .................... 60,205 glon, 2011/0056208 A1 3/2011 Norris et al. .................... 6Of772 2011/O123326 A1 5/2011 DiBenedetto et al. (73) Assignee: United Technologies Corporation, 2012/0110979 A1* 5, 2012 Rosenkrans et al. ......... 60,226.1 Hartford, CT (US) 2012fO251306 A1* 10/2012 Reinhardt et al. ......... 415, 1821 2012fO263579 A1* 10, 2012 Otto et al. .......... ... 415,124.2 (*) Notice: Subject to any disclaimer, the term of this 2012/0291449 A1* 11/2012 Adams et al. ................... 60,793 2012/03 15130 A1 12/2012 Hasel et al. patent is extended or adjusted under 35 2013, OO25257 A1 1/2013 Suciu et all U.S.C. 154(b) by 0 days. 2013/0025258 A1* 1/2013 Merry et al. ................. 60,226.1 2013/0192198 A1 8/2013 Brilliant et al. (21) Appl. No.: 14/087,471 OTHER PUBLICATIONS (22) Filed: Nov. 22, 2013 Jane's Aero-Engines, Edited by Bill Gunston, Issue Seven, Mar. (51) Int. Cl. 2000, pp. 510-512, United Kingdom. FO2K 3/02 (2006.01) Applicant-Admitted Prior Art: V2500 Fact Sheet, International Aero FO2K L/06 (2006.01) E". 1 tipiac comwp-conten uploadio 12/03/facts.pdf un. 1, E. (% 3.08: Applicant-Admitted Prior Art: Diagram "GE 90 Engine Airflow” http://ctr-sgil. Stanford.edu/CITS ge90.html downloaded Jun. 15, (52) U.S. Cl. 2012. CPC. F02C 7/06 (2013.01); F02K I/06 (2013.01); FOID 5/141 (2013.01) (Continued) USPC ............................................ 60/226.1; 60/792 (58) Field of Classification Search Primary Examiner — Phutthiwat Wongwian USPC .............. 60/39.162, 39.163,226.1, 786, 788, (74) Attorney, Agent, or Firm — Bachman & LaPointe, P.C. 60/792, 801, 802 See application file for complete search history. (57) ABSTRACT (56) References Cited A three-spool turbofan engine (20) has a variable fan nozzle (35). The fan blades have a peak tip radius R and an inboard U.S. PATENT DOCUMENTS leading edge radius R at an inboard boundary of the flow M path. A ratio of R to R is less than about 0.40. 3,775,023 A 11, 1973 Davis et al. 4,704,862 A 11, 1987 Dennison et al. 29 Claims, 6 Drawing Sheets US 8,869,504 B1 Page 2 (56) References Cited Jane's Aero-Engines, Aviadvigatel D-1 10, IHS Global Limited, Coulsdon, United Kingdom. OTHER PUBLICATIONS Jane's Aero-Engines, Honeywell LF502, IHS Global Limited, Coulsdon, United Kingdom. Jane's Aero-Engines, Honeywell LF507, IHS Global Limited, Applicant-Admitted Prior Art: TFE731-20 PR Sheet, http://design. Coulsdon, United Kingdom. ae.utexas.edu/subjet? work TFE731 4.jpg downloaded Jun. 15. Jane's Aero-Engines, Honeywell TFE731, IHS Global Limited, 2012. Coulsdon, United Kingdom. Applicant-Admitted Prior Art: Rolls Royce Trent 800, cutaway view, Jane's Aero-Engines, lychenko-Progress D-727, IHS Global Lim http://www.epower-propulsion.com/epower/gallery/ABP ited, Coulsdon, United Kingdom. RR%20Trent%20800%2Ocutaway.htm downloaded Jun. 15, 2012. Jane's Aero-Engines, lychenko-Progress D-436, IHS Global Lim Applicant-admitted prior art: Rolls-Royce Trent cutaway view from ited, Coulsdon, United Kingdom. http://web.mit.edu/aeroastro/labs/gtl/early GT history.html Applicant-Admitted Prior Art: Flight International, Avco Lycoming downloaded Jun. 15, 2012. ALF502F-2 Cutaway, 2007. http://www.flightglobal.com/airspace? Applicant-admitted prior art: Garrett TFE731-3 sectional view from mediafaeroenginesjetcutawayStavco-lycoming-alfS02r-2-cutaway http://perso.ovh.net/-caeaxtke/fr/coll/falcon50 5.html downloaded 5582.aspx. Jun. 15, 2012. Applicant-Admitted Prior Art: Flight International, Lycoming Applicant-admitted prior art: Rolls-Royce Trent 1000 cutaway view LF507F Cutaway, 2007. http://www.flightglobal.com/airspace/me from http://hackedgadgets.com/2011/08/02/how-to-build-a-rolls diafaeroenginesjetcutawayStavco-lycoming-alfS02r-2-cutaway royce-trent-1000-jet-engine-used-in-the-boeing-787, downloaded 5582.aspx. Jun. 15, 2012. Applicant-Admitted Prior Art: Flight International, Garrett TFE531 Applicant-admitted prior art: Rolls-Royce Trent cutaway view from Cutaway, 2007.http://www.flightglobal.com/airspace/media/ http://www.warandtactics.com/smfplanet-earth-the-Serious-stuff aeroenginesjetcutawayStavco-lycoming-alfS02r-2-cutaway-5582. non-mil-news/a-380-emergency-landinglf downloaded Jun. 15, aspX. 2012. NASA Conference Publication 2077, “Quiet, Powered-Lift Propul Michael Cusick, "Avco Lycoming's ALF 502 High Bypass Fan sion'. Conference held at Lewis Research Center, Cleveland, Ohio, Engine.” SAE Technical Paper 810618, 1981, doi:10.4271/810618, Nov. 14-15, 1978, pp. 79-81. Society of Automotive Engineers, Inc., Warrendale, PA. Eric S. Hendricks and Michael T. Tong, “Performance and Weight Karl R. Fledderjohn, “The TFE731-5: Evolution of a Decade of Estimates for an Advanced Open Rotor Engine', 48th Joint Propul Business Jet Service.” SAE Technical Paper 830756, 1983, doi:10. sion Conference and Exhibit, Jul. 30, 2012, NASA/TM-2012 4271/830756, Society of Automotive Engineers, Inc., Warrendale, 217710, AIAA-2012-3911, NASA Glenn Research Center, Cleve PA. land, Ohio. T. A. Dickey, and E.R. Dobak, “The Evolution and Development General Electric F101, Jane's Aero-Engines, dated Oct. 11, 2012, Status of the ALF 502 Turbofan Engine.” SAE Technical Paper IHS Global Limited, Coulsdon, United Kingdom. 720840, 1972, doi:10.4271/720840, Society of Automotive Engi General Electric F101, Scramble The Aviation Magazine, Oct. 24. neers, Inc., Warrendale, PA. 2011, downloaded May 17, 2013 from http://wiki. Scramble.nl/index. Jane's Aero-Engines, lychenko-Progress Al-727M, 2011, IHS Glo php?title=General Electric F101#F101-GE-100. bal Limited, Coulsdon, United Kingdom. Stanley W. Kandebo, “Geared-Turbofan Engine Design Targets Cost, Jane's Aero-Engines, Rolls-Royce M45H, IHS Global Limited, Complexity”. Aviation Week & Space Technology, Feb. 23, 1998, Coulsdon, United Kingdom. vol. 148, p. 32. The McGraw-Hill Companies, Inc., New York, NY. Jane's Aero-Engines, Turbomeca Aubisque, IHS Global Limited, Coulsdon, United Kingdom. * cited by examiner U.S. Patent Oct. 28, 2014 Sheet 1 of 6 US 8,869,504 B1 U.S. Patent Oct. 28, 2014 Sheet 2 of 6 US 8,869,504 B1 Z |||||| ?----FEE= té++|- 99||69| ÍTE? U.S. Patent Oct. 28, 2014 Sheet 3 of 6 US 8,869,504 B1 U.S. Patent Oct. 28, 2014 Sheet 4 of 6 US 8,869,504 B1 97 97 U.S. Patent Oct. 28, 2014 Sheet 5 of 6 US 8,869,504 B1 H mrma s C O S N R g 1. CN C C - U.S. Patent Oct. 28, 2014 Sheet 6 of 6 US 8,869,504 B1 H ma s US 8,869,504 B1 1. 2 GEARED TURBOFAN ENGINE GEARBOX etry and overall engine efficiency, however, are the bearing ARRANGEMENT arrangements used to Support the various rotating structures; improvements in this area are, therefore, always of interest to BACKGROUND the turbofan engine designer. The disclosure relates to turbofan engines. SUMMARY Gas turbine engines and similar structures feature a num ber of Subassemblies mounted for rotation relative to a fixed One aspect of the disclosure involves a three-spool turbo case structure. Such engines typically have a number of main fan engine comprising a fan having a plurality of blades. A bearings reacting radial and/or thrust loads. Examples of such 10 transmission is configured to drive the fan. The fan blades bearings are rolling element bearings such as ball bearings have a peak tip radius R. The fan blades have an inboard and roller bearings. Typically such bearings all react radial leading edge radius R at an inboard boundary of the flow loads. Some such bearings also react axial (thrust) loads path. A ratio of R to R is less than about 0.40. (either unidirectionally or bidirectionally). Ball bearings A further embodiment may additionally and/or alterna typically react thrust loads bidirectionally. However, if the 15 inner race is configured to engage just one longitudinal side of tively include a three-spool turbofan engine comprising a first the balls while the outer race engages the other longitudinal spool comprising a first pressure turbine and a first shaft side, the ball bearing will react thrust unidirectionally. coupling the first pressure turbine to the transmission. A Tapered roller bearings typically react thrust unidirection second spool comprises a second pressure turbine, a first ally. Two oppositely-directed tapered roller bearings may be compressor, and a second spool shaft coupling the second paired or “duplexed to react thrust bidirectionally. An pressure turbine to the second spool compressor. A core spool example is found in the fan shaft bearings of U.S. Patent comprises a third pressure turbine, a second compressor, and Application Publication 2011/0123326A1, which is incorpo a core shaft coupling the third pressure turbine to the second rated herein by reference in its entirety and which is entitled compressor. A combustor is between the second compressor “Bellows Preload and Centering Spring for a Fan Drive Gear 25 and the third pressure turbine.