PAGE\*MERGEFORMATIII轻型汽车动力转向系统设计摘要汽车的转向系统是一套用来改变或恢复汽车行驶方向的专用机构。本文针对的是与非独立悬架相匹配的整体式两轮转向机构。利用相关汽车设计和连杆机构运动学的知识，首先对汽车总体参数进行设计，在此基础上，对转向器，转向传动机构进行选择，接着再对转向器和转向传动机构进行设计，最后，利用软件AUTOCAD完成转向梯形和转向器的设计图纸。动力转向系是在机械转向系的基础上增设一套转向加力装置，这套装置由转向动力缸、转向液压泵、转向油罐、转向控制阀、转向油管组成。本设计中主要完成了转向动力缸的设计计算及校核，其他部件的选择依照实际车辆的尺寸进行。在对转向器的设计中，选用的是循环球式齿条-齿扇转向器，包括了螺杆—钢球—螺母传动副的设计和齿条—齿扇传动副的设计，前者的设计需先确定出钢球中心距，设计出一系列的尺寸，而后者则是根据汽车前轴的载荷确定出齿扇模数，再由此设计出所有参数。本设计选用的是整体式转向梯形，在设计中借鉴同类汽车转向梯形设计的经验尺寸对转向梯形进行尺寸初选。再通过对转向内轮实际达到最大偏转角时与转向外轮理想最大偏转角度的差值的检验，判定转向梯形的设计是否符合基本要求。关键词：转向系，转向器，转向梯形，动力转向LIGHTVEHICLEPOWERSTEERINGSYSTEMDESIGNABSTRACTVehiclesteeringsystemisanexclusivemechanismtochangeorrestorethedirectionofacar.Thisarticlewasstudiedaboutthewholesteeringstructureoftwowheelmatchedtonon-independentsuspension.Basedontherelevantknowledgeaboutthevehicledesignandkinematiclinkmechanism,thecollectivityparametersofthesteeringsystemwasfirstdesigned,andthenthetypeofthesteeringgearandthetransmissionmechanismwereselectedanddesigned,andatlast,AUTOCADsoftwarewasusedtodrawandcompletethewholesteeringsystem.Powersteeringsystemisamechanicalsteeringsystembasedonthecreationofasteeringafterburnerdevice,whatbeconsistedofsteeringpowercylinder,steeringpump,steeringoiltank,steeringcontrolvalve,andsteeringhose.Thesteeringpowercylinderdesign,calculationandcheckingmustbecompletedinthisdesign,thechoiceofothercomponentsofthevehicleaccordingtotheactualdimensions.Insteeringgeardesign,selectionoftherecirculatingballtypesteeringgearrackandgearsector,includingthedesignofballscrewnuttransmissionpair--Designandrackandsectorgeartransmissionpair,mustfirstdeterminetheballcenterdistanceoftheformerdesign,designaseriesofsize,whilethelatterisdeterminethetoothfanmoduleaccordingtotheloadofautomobilefrontaxle,andthendesignallparameters.Thisdesignisawholeselectionofsteeringtrapezoid,similarsteeringtrapeziumdesignexperiencedimensionsweretheprimarysizeofsteeringtrapezoidindesign.Throughtotheactualsteeringwheelreachesthemaximumdeflectionanglewithth