转向驱动桥变径全空心半轴的设计及力学特性

Design of steering drive axles variable diameter hollow half shaft and its mechanical characteristics

基于材料低载强化特性,研发设计了一种新型转向驱动桥变径全空心半轴结构,建立了包含英制渐开线花键齿和合理的圆角过渡等精细特征的新型半轴三维模型,运用有限元法对新型半轴的模态振型、等效应力及疲劳寿命等力学特性进行了分析,结果表明:半轴的前10阶非零振型主要为弯曲变形,新型半轴的固有频率与实心半轴的固有频率相近,在使用过程中可有效避免共振;新型半轴等效应力最大值发生在花键末端圆角过渡部位,低于半轴材料的抗扭强度,满足强度设计要求;在扭矩为1 500N·m的交变载荷下,新型半轴疲劳寿命最小值发生在花键末端圆角过渡处,与半轴应力集中节点位置一致,实际加工制造时应采用半轴冷精锻和花键轴向冷挤成型技术,以提高新型半轴的强度和使用寿命.

Based on the characteristics of low-loading strengthening for material design,a new type of steering drive axle variable diameter hollow half shaft structure was designed,and its three-dimensional mode including imperial involute spline teeth,reasonable transition fillet and other fine features was established.The modal vibration mode,equivalent stress and fatigue life of the mechanical characteristics of the new type half shaft were analyzed by finite element methods.The results show that the first ten order non-zero mode of half shaft is mainly bending deformation,and the natural frequency of the new half shaft and the solid half shaft is similar,which can avoid resonance effectively during the half shaft using process.Maximum equivalent stress of new half shaft occurs to the end of transition fillet,and less than torsional strength of the half shaft material,which satisfies the requirements for strength design of the shaft.When the torque of the new half shaft is 1 500N·m under cyclic loading,the minimum fatigue life occurs to the end of transition fillet,which is coinciding with the half shaft stress concentration of the node position,so cold precision forging and axial cold extrusion spline molding technology should be used to improve the intensity and working life of the new type half shaft in practical production processing and manufacturing.