汽车专业英语 教学课件 黄星 刘春波 黄汽驰 8.ppt

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1、Unit8AutomotiveSteeringSystemPart ITechnicalandPracticalReadingPassageATypesofSteeringSystemThesteeringsystemisamajorpartofthecar.Agoodsteeringsystemmakesdrivingmuchmorepleasurable,comfortableandsafer.Thesteeringsystem,includingsteeringwheel,steering

2、gears,linkagesandothercomponents,isusedtocontrolthedirectionofacar’smotion.Today,therearetwobasictypesofsteeringsystems:(1)recirculatingballsteeringand(2)rackandpinionsteering.Therecirculatingballsteeringcanbeeitherpower-assistedornon-power.Rackandpi

3、nionisalmostalwayspower-assisted.Seefigure8-1.Figure8-1RecirulatingBallSteeringRecirculatingballsteeringisusedonmanytrucksandSUVstoday.Thelargerandheaviertheautomobileis,themoredifficultitistosteer.Mostlargeautomobilesareequippedwitharecirculatingbal

4、lsteeringgear.Thistypeofsteeringgearisverylowinfrictionandprovidesagoodmechanicaladvantageforaheavyvehicle.Therecirculatingballsteeringusesaseriesoflinksandarmstoensurebothwheelsturninginthesamedirectionatthesametime.Seefigure8-2.Figure8-2Therecircul

5、atingballsteeringsystemconsistsofsteeringwheel,steeringshaft(column),wormgearandsectorgearinasteeringgearbox,pitmanarm,trackrod,tierodandsteeringarm.Seefigure8-3.Figure8-3Thesteeringwheelisconnectedtothesteeringboxthroughthesteeringshaft.Ontheendofth

6、esteeringshaftisawormgearinthesteeringbox.Andaballnutridesonthewormgearandalsoengageswiththesectorgearonthepitmanshaft.Apitmanshaftismountedintheboxinaposition90ºtothewormgear.Seefigure8-4.Figure8-4Thepitmanarmisconnectedtooneendofthetrackrod.Intheot

7、herendofthetrackrodisanidlerarm.Betweentheidlerandpitmanarms,thetrackrodissupportedintheproperpositiontokeeptheleftandrightwheelsworkingtogether.Theinnertierodendsareattachedtoeitherendofthetrackrodandprovidepivotpointsforthesteeringgear.Fromtherethe

8、ygototheoutertierodendsthroughanadjustmentsleeve.Thissleevejoinstheinnerandoutertierodendstogetherandallowsforadjustmentwhenthefrontwheelsarealigned.Theoutertierodendsareconnectedtothesteeringknucklearmsthatactuallyturnthefrontwheels.Seefigure8-5.Rac