Time-Dependent Reliability Analysis Of Planar Linkage Mechanism With Joint Clearance

With the development of modern science and technology, machinery is increasingly developing to high-speed, lightweight, heavy-duty and high-precision. Kinematics accuracy of mechanisms has become an important factor affecting the quality of the mechanical products. Usually these factors include dimensional tolerances, joint clearance, the deformation of component by force or heart, the property of component materials and the fluctuations of motion input.This paper research on the planar Linkage Mechanism, and make analysis of the reliability of the kinematic accuracy of planar four bar mechanism with dimensional tolerances, joint clearance and structural errors. In this paper, the general theory of kinematics accuracy is given and the loop vector differential method is used to build the kinematic accuracy model of the planar linkage mechanism. Basing on the formal kinematics accuracy model of the mechanism, we adopt The First Order Second Moment method (FOSM) to analysis the point reliability and the time-dependent reliability. In order to exam the correctness of the analytical method, the results by Monte Carlo method is given as a reference. Then we deal with the reliability of the kinematic accuracy of the planar four bar linkage mechanism with structure errors, and we proposed an equivalent model which transform the mechanism with structure errors to not. This method reveals the mechanism by which the structure errors work on the reliability of the kinematic accuracy of the planar linkage mechanism.Comparing the result of the analytical method with Monte Carlo method, the stochastic model, the kinematics accuracy models and the theory of the reliability of the kinematic accuracy of the planar linkage mechanism are proved to be reasonable and effective.