自动装盒机椭圆-圆齿轮行星轮系取盒机构轨迹分析与设计

Elliptical-circular Planetary Gear Train Box-taking Mechanism Design and Trajectory Analysis for Automatic Cartoning Machines

自动装盒机连续旋转式行星轮系取盒机构与间歇式往复摆杆取盒机构相比,机构振动小,速率更高。基于行星轮系取盒机构输出末端内摆线运动特性要求和非圆齿轮传动比可变的特点,提出一种椭圆-圆齿轮行星轮系代替现有的圆齿轮行星系取盒机构,使输出末端运动轨迹和特性得到优化。建立圆齿轮行星系取盒机构和椭圆-圆齿轮行星轮系取盒机构的运动学模型,分析两种机构的工作原理和运动特性,对机构进行轨迹仿真和运动特性求解,分析出机构主要参数对机构运动轨迹和特性的影响。利用人机交互的方法,对椭圆-圆齿轮行星轮系取盒机构的参数优化,得到一组较优的结构参数,并建立三维仿真模型。参数优化后的椭圆-圆齿轮行星轮系取盒机构运动特性与圆齿轮行星系取盒机构对比,在取盒和放盒工位的速度变化减小14.3%,最大加速度减小9.9%。上述研究可为行星轮系高速吸盒机构的设计提供理论依据。

A planetary gear train box-taking mechanism continuously rotates in automatic cartoning machines and shows a better performance than the pendulum box-taking mechanism due to its smaller trajectory and higher speed. Based on the movement requirements of hypocycloid trajectory and variable transmission ratio character of a non-circular gear train, a new type of box-taking mechanism of planetary gears using elliptical-circular gear is developed instead of circular planetary gears. The extremity movement trajectory of the box taking is also optimised. Thereafter, the kinematic models of circular and elliptical-circular planetary gears are established, and the work principle and movement characteristics of the two mechanisms are analysed. Moreover, the simulated trajectory and movement characteristics of the mechanisms are solved, and the influence of the main parameters on movement trajectory and characteristics are analysed. Using the man-machine interactive optimisation method, the parameters of the elliptical-circular planetary gear train box-taking machine are optimised, and a group of superior structural parameters is identified. In addition, a three-dimensional simulation model is developed using the main structural parameters. Finally, the movement characteristics of the elliptical-circular gear are compared with those of the circular planetary gear. The change in velocity reduced by 14.3% at the box-taking and box-putting stations, while the maximum acceleration decreased by 9.9%. This study can provide a theoretical basis for the design of planetary gear train box-taking mechanism.