交错轴变传动比齿轮副变传动比齿轮数字设计方法研究

汽车转向器的传动比是影响车辆转向轻便性和灵敏性的重要因素之一,车辆在转向时为了获得轻便性和灵敏性的统一需要采用变传动比转向器。通过综合分析机械式变传动比转向器的重要部件交错轴变传动比齿轮副的啮合特点,基于包络原理提出了一种全新的变传动比齿轮数字设计方法,此方法将交错轴变传动比齿轮副中斜齿轮看作由垂直于其轴线的无限接近的平面集合与其截交后截平面的集合,每个截平面称为"齿轮元",交错轴变传动比齿轮副的啮合传动可看作齿轮元的集合与变传动比齿轮的啮合,变传动比齿轮齿廓上每个齿廓点的高度值,是过此点且垂直于齿条运动方向及斜齿轮轴线的直线随此点一起啮合传动时,与此点啮合过程中遍历齿轮元集交点高度值中的最小值。基于上述方法,建立了交错轴变传动比齿轮副变传动比齿轮齿廓点高度值计算的数学模型,开发了求解算法,得到了变传动比齿轮的齿廓点云,并将此方法成功应用到了某型变传动比转向器的研制中,通过样件试制及测试验证了该方法的正确性。

Research on the Digital Design Method for Variable Ratio Gear of Variable Ratio Gear Pair with Alternating Axis

Automobile steering gear ratio is one of the key factors which effect vehicle steering portability and sensitiveness. In order to obtain good portability and sensitiveness at the same time, it requires the use of variable ratio steering gear. Based on envelope principle, a new digital design method of variable ratio gear was proposed in this paper by analyzing the major part characteristics of the mechanical variable ratio steering. This method considers the helical gear of the gear pair with alternating axis as a set of the intersecting planes which are obtained by using a set of some infinite close planes which are perpendicular to its axis to intersect the gear, and each section is called a "gear element ". The meshing transmission process of the gear pair can be seen as a meshing process of a collection of gear element and variable ratio gear. The height value of every tooth profile point on the variable ratio gear is the minimum value of all intersections of the traverse gear element set during the meshing process and the line which passes through this point and perpendicular to the rack movement direction and the axis of the helical gear with this point meshing transmission. Based on this method, the mathematical model for calculating the variable ratio gear tooth profile point height value of the variable ratio gear pair with alternating axis was established, the solving algorithm was developed and the 3D model of the variable ratio gear was obtained, and this method is successfully applied to the development of a certain variable ratio steering gear. Besides that, the feasibility of this method was verified by trial-producing a gear pair sample with alternating axis and testing it.