考虑滚动体尺寸误差和径向游隙时直线轴承的力学性能分析

Analysis on Mechanical Properties of Linear Bearings Considering Dimensional Error of Rolling Elements and Radial Clearance

以受横向载荷的滚珠直线轴承为研究对象,对直线轴承进行了力学分析,建立了直线轴承受横向载荷下的力学模型,结合赫兹接触理论和变形协调关系,构建了在考虑滚动体几何误差和轴承游隙条件下能对直线轴承的每一个滚动体受力、变形进行精确计算的力学模型。并以LM8UU型直线轴承为算例,深入研究了载荷大小和位置、径向游隙、单个滚动体出现的尺寸误差、每个滚动体都存在的尺寸误差等因素对直线轴承力学性能的影响规律。研究发现,横向载荷的大小和作用位置会改变直线轴承内部滚动体受力的大小和承载区的分布情况;单个滚动体尺寸正误差使其受力增大,负误差使其受力减小。

Taking the linear ball bearing subjected to transverse load as the research object,the relationship between the contact force and deformation of the balls was established based on mechanical analysis.Combined with the Hertz theory and deformation coordination relation,an accurate mechanical model for calculating the contact force and deformation of each ball in linear bearing was constructed,which considered the dimensional error of the balls and the clearance of the bearing.Using MATLAB software to develop the algorithm and taking the LM8UU linear bearing as an example,the factors affecting the contact force of the balls,such as the size and position of lateral load,the dimensional error and clearance between the balls,and raceways,were systematically studied.Finally,a series of regular relationship curves were obtained.The results showed that the contact force of each ball increased with the increase of transverse load.As the transverse load moved from the middle to the edge,the distribution of force on the balls started to become uneven,with more circular columns bearing the force,but less balls bearing in each column.Clearance made the contact force decrease among most of the balls,while a small part of the balls bore more with the increase of clearance.The negative dimensional error of one ball reduced its contact force and the positive one increased its contact force.When all the balls had dimensional error,the contact force exerted on each ball would be distinctly different from that without considering dimensional error.These conclusions provided a theoretical basis for further accurate calculation of the stress distribution,deformation and fatigue life of linear bearings.