Abstract: Steel roll round baler is one of the key technical equipment for straw harvesting in China. Currently, there is still a lack of basic design method for the core mechanism (steel roll round baler) of this machine. Based on the reverse engineering (RE) principles, plane geometry, material mechanics, mechanical design, test method and ANSYS analysis method, the reserve design method for the mechanism was carried out in this paper. Next, the relationship function among the four characteristic parameters, i.e, bale chamber radius, steel roll count, steel roll radius, and clearance between adjacent steel rolls, was established based on plane geometry; the contact model between the roll and the straw core was established by theoretical analysis, and the influence law of steel roll radius on contact force between them was determined by using highspeed camera observation method and probability principle. Moreover, the highspeed camera was also reutilized to determine the correlation of the occurrences of entanglement with the clearance between steel rolls and ridges on the steel roll surface. Combined with the test results and theoretical calculations, the dimensions of the feed inlet were designed. Afterward, the mechanical model of steel roll was established, and an important component of the steel roll, i.e, the longitudinal diameter, was designed. Furthermore, the stiffness and strength of the steel roll (assembly) were validated using the Workbench module in ANSYS. According to these findings, the reverse design with DN4575 round baler model as the design objective was carried out. The results of design were as follows: steel roller radius: 75 mm, number of steel rollers: 10, clearance between steel two rollers: 10 mm, width of feeder inlet: 162 mm, steel roller long axis diameter: 20 mm, number of spoke plates: 5. In conclusion, the above reverse design process provides a systematic design method for the key parameters of steelroll round balers, which has important guiding significance for the design of steelroll round balers.

Key words:  round baler, baling mechanism, reverse engineering, reverse design, structural parameter, wrapping test

摘要： 钢辊式圆捆机是我国秸秆收获的关键技术装备之一，目前尚缺乏针对该机型核心机构（钢辊式卷捆机构）的基础性设计方法。为此，基于逆向工程原理，综合运用平面几何学、材料力学、机械设计学、试验法、ANSYS分析法等，对该机构展开反求设计。运用平面几何学建立卷捆室半径、钢辊数量、钢辊半径、钢辊间隙四个特征参数间的关系函数；通过理论分析建立钢辊与累积草芯的接触模型，以此为依托运用高速摄像观测法与概率学原理确定钢辊半径对二者间接触力的影响规律；通过高速摄像观测法，确定钢辊间隙及钢辊表面凸棱与缠辊现象间的关联性；采用试验与理论计算相结合的方法实现喂入口尺寸的设计；建立钢辊的力学模型，对钢辊重要组件——长轴直径进行设计，同时利用ANSYS中的Workbench模块实现对钢辊（复合体）刚度及强度的校核。运用上述研究结果，以DN4575型圆捆机为目标机进行反求设计，设计结果如下：钢辊半径75 mm，钢辊数量10根，钢辊间隙10 mm，喂入口宽度162 mm，钢辊长轴直径20 mm，钢辊辐板数量5个。上述反求过程为钢辊式卷捆机构的关键参数提供了系统性的设计方法，该方法对钢辊式圆捆机的设计具有重要的指导意义。

关键词: 圆捆机, 卷捆机构, 逆向工程, 反求设计, 结构参数, 卷捆试验