圆柱滚子从动件凸轮廓面的等距曲面设计方法

Profile Design of Cam with Cylindrical Roller-Followers by Offset Surfaces Method

利用空间凸轮理论廓面的概念 ,研究了圆柱滚子从动件凸轮理论廓面与实际廓面的点映射关系 ,得出了实际廓面与理论廓面互为等距曲面的结论 ,并据此提出了凸轮廓面的等距曲面设计方法 .该方法从理论廓面是滚子轴线运动形成的直纹面入手 ,考虑理论廓面与实际廓面互为等距曲面的特性 ,建立了滚子轴线、理论廓面和实际廓面三者之间的点映射关系 ,从而由理论廓面方程直接映射得到实际廓面方程 .等距曲面综合数学模型具有普遍意义 ,满足了建立凸轮 CAD的需要 .与传统的包络法和共轭曲面法相比较 ,等距曲面法几何意义明确 ,概念清晰 ,避免了约束方程的复杂求解 ,因此综合过程简单 。

By use of the theoretical surface—— the path of the axis of the roller of space cams,the cams with cylindrical roller- followers were discussed and a conclusion that the theoretical surface and real sur- face are offsetsurfaces was derived.A simple and useful procedure used to determine the real surface was presented.This method establishes the mapping relationshipsamong the axisof roller,the theoretical sur- face and real surface,and gets the simple analytical equation of the real surface.The proposed analytical model of the synthesis of offset surface can be widely used,and can satisfy the needs of CAD of cams. Compared with the conventional methods such as envelope theory and conjugating theory,this method has the features of conceptual clarity and simplicity of computation,avoiding complex solutions of the con- strain equations.