Research And Application On Recirculating Ball Variable Ratio Steering Gear Pair Working Conditions Under Different Steering Conditions

As a key component of automobile steering system,steering gear plays an important role in driving safty.Steering demand of the automobile is not the same in different driving conditions,and variable ratio steering gear meets the different steering demands to a certain extent.The gear pair in variable ratio steering gear is the core component which can affect the performance of the entire steering system.When the automobile is in actual driving,the movement and force of recirculating ball variable ratio steering gear pair change instantaneously as real-time steering operation.With considering actual steering conditions,analyze the dynamic performance of variable ratio gear pair has a certain guiding significance for engineering applications.The paper research object is recirculating ball variable ratio steering gear pair.Establish a bus steering system mathematical model,and analyze recirculating ball steering gear pair working conditions under different steering conditions and apply the gear working conditions to simulation finite element analysis.The main contents are as follows.(1)Establish a bus steering system mathematical model with consideration of road wheel angle,steering resistance moment and movement and force of steering rods.Analyze recirculating ball variable ratio steering gear pair working condition theoretically.(2)Combined bus different steering conditions,according to analytical equations of recirculating ball steering gear pair working condition derived in the article,theoretically calculate variable ratio gears working conditions,and simulate in TruckSim to verify the correctness of the theoretical calculation results.(3)Based on the principle of gear virtual generating cutting,using computer boolean subtraction,establish 3D model of variable ratio gear pair.Summarize and contrast some variable ratio tooth surface reconstruction methods,and reconstruct the variable ratio gear model,which can has continuous and smooth tooth surfaces with a certain precision.(4)Apply theoretical calculation results of recirculating ball variable ratio steering gear pair working conditions,including lemniscate steering condition,snake steering condition and step steering condition,to finite element analysis of variable ratio gear pair which is used as load conditions.The tooth root bending stress,tooth surface contact stress and dynamic transmission error are considered in finite element analysis.The paper presents a theoretical analysis idea of recirculating ball variable ratio steering gears pair working conditions,and the corresponding analytical equations are given.Apply the variable ratio gear pair working conditions under different steering conditions to finite element analysis.Variable ratio gear pair working conditions are connected with the bus’ s actual steering conditions closely,which can provide more reliable load basis for simulation and test trials of variable ratio gear pair in engineering.