圆柱直齿轮滚轧成形工艺基础研究

To solve some problems of the forging process of a cylindrical spur gear instead of the cutting method, the foundations of gear rolling process are investigated. The biting condition, the calculating method of the blank dimension, the gear index uniformity condition, the design method of the gear roller, the match of roller's rotating speed with its feeding speed and rolling stage design, and equations of the rolling force and the rolling moment in the cylindrical spur gear rolling process are established based on the generating motion relationship between the gear roller and the workpiece and the metal plastic forming theory. The effect laws of blank diameter, roller's dimensions and the tooth structure and gear rolling parameters on the biting status, the gear index uniformity, tooth filling and profile precision of the gear are obtained through FEM analysis and the formation mechanism of rabbitear as a characteristic of gear rolling is revealed. Quality control methods are proposed to reduce or eliminate the rabbitear defect by designing the preform shape and to improve gear rolling precision by controlling the gear pitch of the workpiece in generating motion during gear rolling. Preforms, rolling process parameters, roller's dimensions and its tooth structure which can improve tooth forming quality are given by optimization analysis. A set of cylindrical spur gear rolling experimental device is designed and related experiments are carried out. The research work in this project has an important theory meaning and application value for enriching local loading rotary plastic forming process and technology foundation and boosting the development of gear parts rolling technology.

针对圆柱直齿轮采用锻造成形工艺取代切削加工方法遇到的若干问题，开展圆柱直齿轮滚轧成形工艺基础研究。根据滚压轮与坯料范成运动关系及金属塑性成形基础理论，建立圆柱直齿轮滚轧成形工艺的咬入条件、坯料尺寸确定方法、分齿均匀性条件、滚压轮设计方法、滚压轮旋转与送进速度匹配及滚轧工序设计方法、滚轧力与力矩表达等；通过有限元模拟分析给出坯料尺寸与滚压轮参数及其齿形结构以及滚轧成形工艺参数对咬入状况、分齿均匀程度、齿形填充及成形精度的影响规律，揭示突耳变形特征的形成机理；提出采用预成形设计方法减小或消除突耳缺陷及控制滚轧过程范成运动中的工件齿形节距提高成形精度的质量控制方法，优化给出提高齿形成形质量的预制坯及滚轧工艺参数与滚压轮参数及齿形结构；设计并加工圆柱直齿轮滚轧成形实验装置，进行实验研究。项目研究对丰富局部加载回转塑性成形工艺技术基础及推动齿轮类零件滚轧成形技术的发展具有重要的理论意义和应用价值。

项目开展了圆柱直齿轮滚轧成形工艺基础研究。建立了圆柱直齿轮滚轧成形工艺滚轧初期的咬入条件及允许打滑量、坯料尺寸确定方法、分齿均匀性评价方法及其控制措施、滚压轮转速与送进速度及坯料转速匹配关系、滚压轮齿形结构参数的设计准则、滚压轮与坯料接触弧长的解析式及其数值求解方法等滚轧工艺基础条件；研究获得了圆柱直齿轮滚轧成形工艺参数、滚压轮参数及其齿形结构对滚轧齿轮齿形成形质量的影响规律，揭示了齿轮滚轧成形过程中齿形突耳现象的形成机理；优化了齿轮滚轧工艺参数及滚压轮齿形结构及其参数，并给出了坯料预成形优化设计方法，减小了齿形突耳缺陷；提出了可有效抑制和消除齿形突耳缺陷的附加圆柱轮的齿轮滚轧工艺及采用锥形滚压轮的新型齿轮滚轧工艺，并给出了锥形滚压轮的结构设计方法；开发了一套圆柱直齿轮滚轧成形实验装置，通过伺服电机控制，可实现齿轮滚轧成形中滚压轮与坯料间精确的范成运动关系，完成了圆柱直齿轮打滑与齿形形貌的实验研究及锥形滚压轮滚轧齿轮成形及其突耳缺陷控制实验研究，实验结果与理论分析、数值模拟结果吻合较好。项目研究对丰富局部加载回转塑性成形工艺技术基础及推动齿轮类零件滚轧成形技术的发展具有重要的理论意义和应用价值。