Considering Clearance Slot Wheel Mechanism Of Bond Graph Modeling And Simulation

The Geneva mechanism is widely adopted by automatic mechanism because the advantage of simple structure, high transmission efficiency, steady performance, design and manufacturing is convenient, and can be smoothly, intermittently for inversion. But the scope of application is limited because when Geneva mechanism on working, with shock, cause impact. Research shows that the cause for the vibration of the Geneva mechanism includes two aspects:For one thing is the flexible impact when cylindrical pin pass in or out the slot of the Geneva mechanism, for another thing is the contact and collision clearance exists in kinematics pair of clearance. At present, the study about kinematics pair of clearance contact and collision of Geneva mechanism is also relatively few, at home or abroad, So, I think on this subject very practical significance.The key is to solve the problem of modeling and calculation about kinematics pair of clearance contact and collision of Geneva mechanism, when we want to make dynamics research more close to its real process, in order to achieve the purpose of improved design, reduce cost, reducing vibration and noise. This thesis research launches under the theory of elastic collision, based on the modeling theory of switched bond graph and simulation software of20-sim, and the dynamic characteristics of Geneva mechanism are analyzed, Compared with the ideal state and kinematics pair of clearance contact and collision, illustrate the clearance of kinematics pair largely influences the Geneva mechanism’s motion characteristics, produces deviation between ideal and practical movement, and movement between kinematics pair of clearance caused the vibration, causing noise, accelerate the wear and reduce work efficiency.This research manifests that use of the theory of elastic collision of spring-damping model solve the problem of kinematics pair of clearance contact and collision about Geneva mechanism, close to the actual motions. And switched bond graph theory in the dynamic characteristics study of the Geneva mechanism, made working process into discretization modeling method is simple. Finally, the result of these simulations demonstrates that the system dynamics model is correct and effective, when we using the simulation software of20-sim which based on switched bond graph theory. Compared the dynamic analysis method with traditional, this model is correct and more concise, more suitable for computer simulation calculation, for the study of dynamic characteristics of Geneva mechanism provides a new method and the way.