Mechanicsanalysis And Parametrical System Development For Recirculating Ball Variable Ratio Steering Gear

Steering gear is an important actuators in the automobile steering system whichcan maintain to change running direction of automobile, plays an important role inreducing the number of traffic accidents and protecting the drive’s safety, at the sametime make a certain effect on adjusting the steering gear ratio characteristics. Thevariable ratio steering gear can solve the conflict between “portability” and“sensitiveness” in a certain extent, the design and development of the variable rackand pinion which is the key parts has the direct impact on the development andinnovation of steering gear.Take the enterprise commissioned projects as a support, steering gear variableratio’s rack and pinion is parametric designed, analyzed and its finite element systemdeveloped using the parametric theory, finite element technology and modulardevelopment theory. The paper’s main researches include the following:（1）Through the technology research and analysis, combined with the structureof the variable ratio steering gear and rack the variable rack and pinion is modeled byEnveloping Principle Simulation Method based on Solidworks.（2）Based on the studying of the mathematical model of the vehicle steeringsystem, deduces the stress mathematical model of variable rack and pinion, andsimulation the tooth surface stress state in the process of the whole by Matlab. Thevariable rack and pinion model is analyzed by ANSYS in tooth surface contact stressand tooth root bending stress of the maximum stress state.（3）Based on the variable rack and pinion modeling，suited with the Size JointDriving Method and Program Driving Method, combined with VB and Solidworksparameterized human-computer interaction interface, design the parametricdevelopment module of the variable rack and pinion, which can realized theparametric of the rack and gear and the variable transmission ratio. Establish theinfluence of different gear parameters、variable transmission ratio parameters、finiteelement analysis parameters on the contact analysis of the variable rack and pinion intooth surface contact stress and put forward some optimization improvement opinion.（4）Establish the analysis module of variable rack and pinion in tooth surface contact stress and tooth root bending stress,and embed them into the main menu ofANSYS by studying the analysis modular development with APDL and UIDL ofANSYS, which achieve the operation programing and modular.The research of this paper shows the general flow of the variable ratio rack andpinion’s parameterized modeling and modular analysis system, and the methods hastheoretical guidance meaning and practical engineering application value to thedesign and development of variable ratio steering gear.