尖底摆动从动件圆盘凸轮的设计及特性值分析

Design of Circular Disk Cam with Knife-Edge Oscillating Follower and Analysis of Its Characteristic Value

圆盘凸轮机构的设计方法和特性值分析目前少见,影响其设计和性能评判。详细研究了尖底摆动从动件圆盘凸轮的运动学,获得了从动件的角位移、角速度、角加速度、角跃度、角跳度、压力角以及最大无量纲角速度、最大无量纲角加速度、最大无量纲角跃度、最大无量纲转矩这4个主要的动力学特性值的精确计算式、求解方法和曲线图。根据计算结果,可判断与特性值有关的动力学性能的优劣和适用场合。给出了在满足压力角和尺寸的约束下通过求解非线性方程组来设计机构的一种方法及实例。研究结果显示:特性值只决定于各构件的相对长度;若凸轮偏心率变小,则机构性能趋好;该机构无任何冲击,可用于高速场合,值得重视和优先采用。

The methods for the design of circular disk cam mechanism and the analysis of its characteristic value are rare at present,so its design and performance evaluation are affected.This paper researches on the kinematics of the circular disk cam with knife-edge oscillating follower in detail and obtains the accurate formulas and solving methods for angular displacement,angular velocity,angular acceleration,angular jerk,angular jump,pressure angle,as well as four major dynamic characteristic values with maximum dimensionless angular velocity,maximum dimensionless angular acceleration,maximum dimensionless angular jerk and maximum dimensionless torque and their curves.According to results of the numerical calculation,the dynamic performances related to the characteristic values and the suitable application occasions can be judged.The method and example by solving the nonlinear equations to design the mechanism under the constraint condition of the pressure angle and the sizes of the mechanisms are givenout.Results above show that the characteristic values are determined only by relative lengths of each member,if cam’s eccentricity decreases,the performances of the mechanism usually become better;this mechanism has no any impact during its motion so it can be applied to high speed.It deverves extra attention and the priority is given to its use.