非对称运动曲线对凸轮机构接触应力之影响

Abstract

藉由应用非对称的运动规律，从动件之运动特性得以改善。本文同时探讨非对称的运动规律对凸轮与从动件之工作表面间的接触应力的影响。根据本文所归纳出的结果，当减速区所占的凸轮旋转角大于加速区所占的凸轮旋转角时，可降低减速度的极值，同时可降低减速区时弹簧力与惯性力所造成的负载。然而，加速区与减速区所占的凸轮旋转角必需适当的分配，以避免过度减少加速区所占的凸轮旋转角，使得加速区的惯性力剧增，进而导致相应增加的接触应力对凸轮轮廓产生严重的破坏。 By applying the asymmetrical motion curve, the kinematic characteristics of the follower motion of the cam mechanism can be improved. This paper also investigates the effects of asymmetrical motion curve on the induced con-tact stress of the mechanism. The results show that the follower motion will have lower maximum deceleration when the cam angle of the deceleration interval is larger than that of the acceleration interval, and in such condition, it may lead to a smaller extreme resulting load caused by the spring force and inertia forces. The asymmetrical ratio of motion curve must be properly specified so as to obtain optimum benefits of the contact stress.