基于运动副磨损和原始误差影响的机构运动可靠性分析

Reliability analysis of mechanism motion based on both wear of a kinematic pair and its original error

在对现有的磨损理论和研究成果进行综合的基础上,建立运动副磨损量的计算模型δw=kpvt,通过机构的运动和受力分析计算在任意位置运动副元素的接触压力和相对运动速度,在运动副连续接触理论和各随机因素符合正态分布的假设下建立机构运动精度可靠性模型,利用编写的MATLAB计算程序对所建立的模型进行实例计算,得出随着工作时间的延长磨损对于机构运动精度的影响越来越突出的结论.利用所建的模型,可以估算机构工作一定时间后的运动精度可靠度,也可以利用该研究结论反过来推算出在给定运动精度要求时机构的工作寿命.

A model for calculating the wearing capacity of kinematic pair δw=kpvt was established on the basis of summarizing the wear theories and research results available.The contact pressure and relative velocity of the pair element in any position were calculated by analyzing kinematics and kinetics of the mechanism.The reliability model of motion accuracy for the mechanism was set up based on two assumptions that the pair elements kept continually contacting and all of the random factors obey normal distribution.An actual computation with the established model was performed by using a developed MATLAB program,so that an important conclusion was obtained that the influence of wear on the reliability of motion accuracy of a mechanism would be ever-obvious along with the service time.The reliability of motion accuracy could be estimated with the established model and,oppositely,its service life could be predicted according to a given motion accuracy of the pair after some service period by using the investigation conclusion.