~.eTheEngineering Society~ ForAdvancing Mobility........,... LandSeaAirandSpace® 400COMMONWEALTH DRIVE,WARRENDALE, PA15096·0001 U.S.A. hni ~rlr 891783 StudyaboutTransient ThermalAnalysis for Transmission DiskClutches atEngage ON/OFF NoboruSunayama, Takehiko Iizuka,andYoshiaki Kato Komatsu Ltd. Reprinted fromP-224-SmallEngineTechnology Conference Proceedings SmallEngineTechnology Conference Milwaukee, Wisconsin September 11·13, 1989Downloaded from SAE International by Purdue University, Monday, August 20, 2018SAEGLOBAL MOBILITY DATABASE Nopartofthispublication maybereproduced inanyform,in anelectronic retrievalsystemorotherwise, w~houttheprior writtenpermission ofthepublisher. ISSN0148-7191 Copyright 1989SocietyofAutomotive Engineers, Inc.ThepapersmClvaed'"Ih,svalvm\! areaOlltaCled anamaexea'"tl1e SAEGIOOillMoOllify DalilOiJSe Positions andopinionsadvanced inthispaperarethoseofthe author(s) andnotnecessarily thoseofSAE.Theauthoris solelyresponsible forthecontentofthepaper.Aprocessis available bywhichdiscussions willbeprintedwiththepaper ifitispublished inSAETransactions. Forpermission to pUblishthispaperinfullorinpart,contacttheSAEPublica­ tionsDivision.Personswishingtosubmitpaperstobeconsidered forpres­ entationorpublication throughSAEshouldsendthemanu­ scriptora300wordabstractofaproposed manuscript to: Secretary, Engineering ActivityBoard,SAE. PrintedinU.S.A.Downloaded from SAE International by Purdue University, Monday, August 20, 2018891783 StudyaboutTransient ThermalAnalysis for Transmission DiskClutches atEngage ON/OFF NoboruSunayama, Takehiko lizuka,andYoshiakiKato Komatsu Ltd. ABSTRACT Torqflow transmission. whichiscOIiPosed of planetarY gearmechanism, multiple diskclutches and ahydraulic control unit,hasbeenadaptedfor Construction Machine because itallows aneasy selection ofspeeds(forward orreverse), Recently a rubberfacingmaterial withhighcoefficient friction hasbeenuseddiskclutch's facingparts forcompact design. MeanwhiIe.it'5heatconduction isinferior tometalicdisktobeusuallyused,soat engagetimetemperature ofrubberfacingdiskis higherthanmetalic andit'sablasive wearratio, whichisverified tohaveinfluence onfacing temperature byexperiments.isincreased farlore thanbefore,Therefore ,prediction offacingtempera­ turehasbeenmoreimportant thanbefore. Now.in thisreport. studyontransient thermalanalysis is introduced because it'saccuracy hascometo practical level INTROOUCTI ON Dynamic intorqflow transmission (Fig.I)was studied bylizukaetal( I).,inwhichthermal generation (0)andthermal generation rateper unitarea(q)wereproposed forevaluation of diskclucth's durability asamacrodesign characteristic value(Fig.2,3).RecentlY arubber facingmaterial withhighcoeffient friction (about 1.5timesformetalicfacingmaterial) hasbeen usedtodiskclutch's facingpartsforcOIiPactdesi­ gn.Meanwhile. it'sheatconduction isinferior to metalicfacingdisk(about1/45times),soatengage timetemperature ofrubberfacingdisk( 2 , 3 ) is whichisverified tohaveinfluence oncontact surface temperature byexperiments, isincreased farmorethanbefore(metalic disk). Bytheway.although measurement forcontact surfacetemperature ofdiskclutches hasbeendone, highaccurate measuring methods havenotbeen founded. Inotherbrakedisk,non-contact measuring wasstudied(4).However. non-contact measuring methodcanbedifficult becausediskclutches are assembled intransmission. 281Sothermalprediction oncontactsurface of diskclutches isdetermined bysimulation model, whichboundary conditions aretheoretically determi­ ned;Boundary conditions (TableI )forthismodel arecomposed ofmanydifferent contents/design parameters (Fig.4).Itisshowedthatthe resultsofnumerical calculation (FEA:Fig.5) by thesetheoretical boundary conditions havegood agreement withexperiments (Fig.13). Bytheway,inAutomotive DiskBrakes,transient thermal performance hadbeenstudied( 5 ) , butitisnotsosufficiently studied about ContactCoefficient andHeatTransfer Coefficient ofLubricant thatAutomotive DiskBrakesare notusedtomultiple disksan