三叶形等距型面联接的特性分析

Performance analysis of trilobe equidistant polygon connection

为分析三叶形等距型面联接的特性,给出一套准确的有限元分析方法.通过立方样条曲线拟合廓形曲线,建立了1/3周期对称的平面有限元模型;在径向边界施加周期性约束,在轮毂内表面施加了均匀切向力载荷以等效转矩,在轮毂物外表面施加了周向固定约束.通过算例,得到三叶形等距型面联接的应力分布特点:接触应力近似呈三角形分布,接触角度范围约占整个空间的1/3.摩擦力虽然在转矩传递过程中起着重要作用,但其的影响不会改变接触应力的分布范围和规律.摩擦系数的增大导致法向接触压力减小,进而提高了型面联接的承载能力.偏心率的增大导致接触面积和法向接触力的减小和力臂的增加,但摩擦力在传递转矩中所占比重也相应减少.三叶形等距型面联接工作过程中,轮毂内表面脱离接触区域,有较大的拉应力。

An accurate finite element method was set up for analysis of characteristics of trilobe equidistant polygon connection. In this method,the profile curves were fit through cubic spline curves,and a 2D FEM model with a one third triaxial symmetry was adopted. Besides,periodic constraints were exerted on the radial boundaries,and uniform tangential force was applied on the inner surface of wheel hub to simulate the torque,while the outer surface of the hub was fixed in the circumferential direction. Through a calculation example of the trilobe equidistant connection,the stress distribution characteristics were derived as follow：the contact stress shows an approximate triangular distribution while the contact angle scope spreads about one third of the entire domain. Friction,which plays an important role in the torque transmission process,does not change the distribution and rule of the contact stress. As the friction coefficient increases,the normal contact stress decreases prominently,thereby increases the capacity of profile connection. With the increase of the eccentricity,the contact area and the arm of normal contact force increases,while the normal contact force keeps falling despite that the proportion of friction taking up in the transmission torque shrinks correspondingly. In the process of the trilobe equidistant polygon connection,the separating zone of hub inner surface shows large tensile stress,while the contacting zone of the hub and the shaft endures large compressive stress.