牵引式山地果园运输机驱动绳轮摩擦磨损

为探究牵引式山地果园运输机驱动绳轮系统的摩擦磨损机理,该研究首先利用Adams软件建立绳轮系统模型,在各因素水平允许范围内进行单因素试验,再进行台架试验分析不同因素对绳轮接触处摩擦磨损的影响。仿真模型计算结果表明,从连接负载端开始,各完整缠绕圈所在槽道受到的摩擦力沿钢丝绳方向呈现逐渐减小趋势,与多槽轮的磨损形貌分析结果一致,且槽道上容易发生的失效形式为塑性变形和微动磨损。单因素试验结果显示,圈数从2/3增加到4/5,受力最大处摩擦力减小48.66%,各槽道受力标准差由102.97 N减小到46.53 N,受力更加均衡;多槽轮中心距越小或轮径越大,各完整缠绕圈的槽道受力越均衡;同一多槽轮上的槽距和槽壁角度对摩擦的影响很小。台架正交试验的多槽轮磨损率分析结果表明,较大的中心距,较小的预紧力,较多的圈数可以缓解磨损。研究结果可为后续对驱动绳轮系统的优化提供参考。

Friction and wear behaviors of driving rope wheel system in the traction type mountain orchard transporter

Abstract: A system of driving rope wheel is the main driving part of a traction-type transporter for mountainous orchards. Specifically, a steel wire rope is winded alternately on two fixed multi groove wheels in turn, and then the rope is tensioned after connecting into a closed loop in the system of driving rope wheel for the traction-type transporter. One multi groove wheel is connected with the power source, and another is fixed independently to the bodies which define the frame of a transporter. As such, the system of driving rope wheel can provide the driving force for the orchard transporter, with large working load, long working time, and serious wear. In this study, a systematic investigation was made to analyze the influence of variable factors on the tribological behavior at the dual contact region between a wire rope and pulley, in order to explore the friction and wear mechanism of a driving rope wheel system. A dynamic contact model of a rope and friction pulley was established using an ADAMS platform, where a series of comparative models were obtained by tailoring the parameters of each factor. A bench test was also carried out to verify the effectiveness of the mathematical model and numerical simulation of a driving rope wheel system. A tension sensor, electronic balance, and three-dimensional microscope system were used to quantify the force of steel wire rope, the wear amount, and wear morphology of multi groove wheels. The simulation results showed that the complete winding can bear most of the friction force during contacting. Starting from the load end of the connection, the friction force on the grooves at each complete winding ring decreased along the steel wire rope direction. The wear morphology of multi groove wheels showed that the friction force of each groove also decreased along the direction of steel wire rope, where the failure mode of the groove was plastic deformation and wear mode. The number of winding turns increased from 2/3 to 4/5, compared with the calculation of the model. The friction force at the maximum stress decreased by 48.66%, and the mean square deviation of forces on each channel was reduced from 102.97 N to 46.53 N, indicating the force was more balanced in the system of driving rope wheel. The larger the center distance or the smaller the diameter of the two grooved wheels was, the more balanced the stress on the grooves of each complete winding ring was. There was very small influence of slot distance and dip angle of slot wall on friction behavior. The wear rate analysis of multi groove wheels showed that the larger center distance, smaller preload and more turns can effectively alleviate the wear of the wire rope and friction pulley. The findings can provide a promising reference for the subsequent optimization of the driving rope wheel system in a traction-type transporter for mountainous orchards.