The Research And Design On Motion Characteristics Of Main Drive System For PET Bottle Cap Screwing Machine

Following the development of packaging machinery, the requirement for its high-speed and reliability have been increasing recent years, and mean while many problems have been raised with the improvement of efficiency of packaging machinery. The collision and impact produced by high speed components caused not only vibration and noise, but also failure and intensified wear, which will seriously influence the stability of mechanical system. In this paper, thorough study and analysis have been made to find and improve the key point.Firstly, the mechanism composition and working principle were introduced, and the planets wheel and cam mechanism of main transmission mechanism had been designed. The number of gear and transmission had been designed according to technological requirements of the capping process, a wheel gear had been added in order to adjusting the turning direction of planets wheel. The length and pressure angle of the curve motion for cam mechanism had been carried on preliminary calculation according to travel requirements for the headset, and movement curve of cam along the bus had been draw out which provide a certain foundation for the following theory analysis.Secondly, the geometric model of cam mechanism have been built and then simulation analysis have been carried on for cam mechanism, the change for force of gear meshing when planets wheel works at high speed has been found through the simulation calculation. In order to reduce the force between gear mesh, optimization design has been made according to the objective function and constraints established for the cam mechanism, and the best speed of main drive system and reasonable structure layout have been finally confirmed.Finally, the model of main drive system was completed and motion characteristics have been carried on study and analysis. Greater flexibility flange cam had been chosen for cam structure. The right contour curve and math function have been found and established through comparison with all kinds of characteristics of motion. In order to get smooth and stable process of movement of the capping headset, modified computing for the curve has been made. The motion characteristics of main drive system have been researched through the following simulation analysis.