薄壁柔性轴承-椭圆凸轮波发生器的接触力学特性

Contact Mechanical Properties of Thin-Walled Flexible Bearing-Elliptical Cam Wave Generator

计及椭圆凸轮作用下薄壁套圈滚道的结构弹性大变形,运用Hertz接触理论计算钢球与椭圆套圈的精确接触刚度的变化趋势。结合三维Timoshenko梁单元和六维连接力,运用ADAMS建立了描述薄壁套圈结构弹性大变形的三维双半圆柔性套圈等效力学模型和柔性轴承-椭圆凸轮波发生器的多体接触力学模型。计算分析椭圆凸轮作用下谐波位移和径向间隙等设计参数对柔性轴承套圈变形特征及内部载荷分布的影响规律。结果表明,套圈结构弹性大变形影响下,钢球与椭圆内、外套圈的接触刚度呈现波峰波谷的双峰分布规律。由于钢球总数目为奇数,在椭圆长轴方向上呈现出两个非对称的奇、偶支承载荷区的分布规律,且谐波位移越大接触力越大。随着径向间隙增加,两个载荷内承载钢球数目均减少、接触力增加,套圈变形位移与谐波变形量设计值的差值增加。

Taking into account the large deformation of the structural elasticity of the raceway of the thin-walled collar under the action of elliptical cams,the Hertz contact theory is applied to calculate the trend of the exact contact stiffness between the steel ball and the elliptical collar.Combining the three-dimensional Timoshenko beam unit and the six-dimensional connection force,a three-dimensional double semicircular flexible collar equivalent mechanical model describing the elastic large deformation of the thin-walled collar structure and a multi-body contact mechanical model of the flexible bearing-elliptical cam-wave generator were established by using ADAMS.Calculate and analyze the influence of design parameters such as harmonic displacement and radial clearance on the deformation characteristics and internal load distribution of flexible bearing rings under the action of elliptical cams.The results show that under the influence of large elastic deformation of the collar structure,the contact stiffness between the steel ball and the elliptical inner and outer collar shows a bimodal distribution law of wave peaks and troughs.Due to the total number of steel balls is odd,in the direction of the long axis of the ellipse presents two asymmetric odd and even support load zone distribution law,and the larger the harmonic displacement the greater the contact force.As the radial clearance increases,the number of loaded balls in both loads decreases,the contact force increases,and the difference between the collar deformation displacement and the design value of the harmonic deformation increases.