Research On Motion Reliability And Dynamic Reliability Of The Linkage Mechanism

Reliability refers to the ability to complete the required function within the time prescribed under the conditions and regulations. With the development of the machinery in the direction of higher-speed and more sophisticated, the demand for product reliability is ever growing. Planar linkage mechanism is common in most of the mechanical systems. However, due to its inherent structure, the processing error of the components, the inevitable joint clearance and some other reasons, the real output of the mechanism tends to have random errors. Therefore, the research on motion reliability and dynamic reliability has important theoretical and practical significance. From the perspective of mechanism dynamics, this thesis systematically studied the influence of length error and joint clearance on motion reliability and dynamic reliability of planar linkage mechanism.Considering the randomness of manufacturing error, the matrix form of motion reliability and dynamic reliability analysis model are established. This model avoids the complex on differential mathematical operation of the output expression, while its simple matrix form is suitable for computer programming calculation. This model provides a quantitative method for evaluating motion reliability and dynamic reliability of mechanism with length error.Adopt continuous contact model, combined with the second Lagrange equation, the dynamic model of planar linkage mechanism with joint clearance is established, the expression of kinetic output and dynamic output are deduced.Considering both of joint clearance and length error, combining probability statistics theory and stochastic process theory, the matrix form of motion reliability and dynamic reliability analysis model are established. In terms of analyzing the influence of joint clearance, evaluating the kinematic and dynamic accuracy of mechanism, designing the dimensional tolerance and joint clearance, and improving the motion reliability and dynamic reliability, this model is of great significance.