新型媒介点啮合弧面凸轮分度机构设计与分析

Design and analysis of new globoidal cam indexing mechanism withmedia point engagement

采用圆锥滚子轮齿创成弧面分度凸轮廓面,与球形滚子齿实现点接触共轭,构建一种新型的点啮合式弧面凸轮分度机构装置,文中给出了该机构的技术实施方案,通过改变球形滚子齿的球体半径来实现可控点啮合,能够提高此机构对制造和安装误差的适应性。运用媒介共轭的原理与方法,分析了此种间歇运动机构的啮合原理,运用给出的媒介曲面(圆锥滚子轮齿廓面)方程获取其创成的分度凸轮廓面方程的基础上,利用圆锥滚子轮齿廓面与球形滚子轮齿廓面间的线接触关系,推导出分度凸轮廓面与球形滚子廓面间的点啮合条件下的接触迹方程及其诱导曲率方程,以此来确定获取此种高副机构最佳点啮合性能情况下共轭轮齿的运动几何参数。

In this article,the conical roller tooth is used to create a globoidal indexing cam profile and realize point-contact conjugation with the spherical roller tooth.Thus,a new globoidal cam indexing mechanism with point engagement is developed.The technical implementation scheme is presented for this globoidal cam indexing mechanism with point engagement.The point engagement can be controlled by changing the radius of the spherical roller teeth,and the mechanism’s adaptability to manufacturing and installation errors can be improved.With the help of media conjugation,the engagement principle of this intermittent motion mechanism is analyzed.The equation of the media surface(the conical roller tooth profile)is used to work out the equation of the indexing cam profile;the line-contact relationship between the conical roller tooth profile and the spherical roller tooth profile is used to derive the contact-trajectory equation and its induced curvature equation under the point-engagement condition between the indexing cam profile and the spherical roller profile,in order to determine the kinematic geometric parameters of the conjugate tooth with the optimal point-engagement performance of this high-pair mechanism.