G.Edwin Burks Lecture 1977 770531 TheIndustrial Hydraulic Torque Converter Wilbur F.Shurts Twin Disc, Inc. Earthmoving Industry Conference Central Illinois Section Peoria, Illinois April18-20,1977 Downloaded from SAE International by University of Edinburgh, Monday, August 27, 2018Copyright ©Society ofAutomotive Engineers, Inc.1977 Allrights reserved. Downloaded from SAE International by University of Edinburgh, Monday, August 27, 2018770531 TheIndustrial Hydraulic Torque Converter Wilbur F.Shurts Twin Disc, Inc. THE FIRST RECORD ofaproduction hydraulic torque converter was theFoettinger transformer designed asareduction gear forsteam turbine ship propulsion. Itwas designed tooperate at atorque ratio of5.0:1.0 ataspeed ratio of slightly less than 0.2. The development of precision gear manufacturing techniques in England resulted inhighly efficient propeller drives andstopped development ofthehydraulic torque converter. There was, thus, little hydraulic torque converter development between 1910 and1930. About thatlatter date, Alf Lysholm ofSweden developed alocomotive steam turbine forWestinghouse with radial flow blading ascontrasted tothemore normal axial flow blading arrangement. The steam turbine locomotive didnotbecome practical because thediesel electric was then coming into thepicture. Mr. Lysholm then conceived the idea ofcombining hisradial flow turbine with animpeller, andusing alight oilastheworking fluid, which resulted inthedesign anddevelop ment ofthethree-stage hydraulic torque con verter. The impeller andfirst turbine were radial outward flow, thefirst reactor was an axial flow stage, andtheremaining three stages were radial inward flow. Inlooking foran application forthisnewtransmission, heteamed up with aMr.Smith, whowasanEngineer with Leyland Motors inEngland. Smith took theLysholm circuit and combined itwith clutches andfree wheels tomake abustransmission tostart in hydraulic drive anddonormal running with the converter locked out. Aturbine driven freewheel permitted thecircuit tocome torest when inlockout condition. This three-stage, stationary housing, hydraulic torque converter became known astheLysholm-Smith system. The Allis Chalmers-Springfield Works, now Fiat-Allis Construction Machinery Inc., putthe first torque converter inacrawler tractor. This was thethree-stage stationary housing type. This crawler tractor plus wartime applications tothePearl Harbor salvage winches, landing craft kedge anchor winches, tanks, andartillery tractors brought this automatically infinitely variable transmission system totheattention of theconstruction andindustrial machinery engi neers oftheworld. Rapid development followed thereafter. Within thenext thirteen years, the torque converter became standard equipment forboth wheel andtrack type tractors, tractor scrapers, off-highway trucks, cranes, winches, andhoists ofalltypes. Over theyears, many excellent technical presentations have been published onthedesign andapplication ofthehydraulic torque converter toconstruction andindustrial machinery. The references appended tothispaper arenotcomplete, butthose papers have been selected which will give interested people areasonably complete understanding ofthesubject. The minimum number ofbladed elements necessary tobuild atorque converter isthree: an impeller, aturbine, andareactor, which acts as thefulcrum forthelever inorder togettorque multiplication. Multiple stage units may be designed togetspecific desired performance ABSTRACT The hydraulic torque converter hasgained wide acceptance inthepower transmission system ofconstruction andindustrial machinery.Thelosses involved inthis automatically and infinitely variable transmission areexamined. Means ofcontrolling theinput andoutput power oftheconverter are described. Downloaded from SAE International by University of Edinburgh, Monday, August 27, 20182 characteristics buttheadded cost, friction losses, andleakage losses associated with the multiple stages become difficult