避免加速度倍频激励共振的凸轮从动件运动规律设计  

Design of resonance-avoiding cam-follower motion curves based on the spectral characteristics of periodical excitation

作　　者：王东菱 马勋勋 王永兴[1] 王生泽[1,2] WANG Dong-ling;MA Xun-xun;WANG Yong-xing;WANG Sheng-ze(School of Mechanical Engineering,Donghua University,Shanghai 201620;Engineering Research Center of Advanced Textile Machinery,Ministry of Education,Donghua University,Shanghai 201620)

机构地区：[1]东华大学机械工程学院,上海201620 [2]东华大学纺织装备教育部工程研究中心,上海201620

出　　处：《机械设计》2020年第4期16-21,共6页Journal of Machine Design

摘　　要：提出了一种运用有限傅里叶级数进行凸轮从动件运动规律设计的方法,运用该方法可有效减小或避免凸轮机构运动产生的某倍频激励恰与所作用对象的固有频率相近或相等而产生较大的倍频振动或共振。凸轮从动件运动规律依据工艺运动要求设计,常用有高次多项式等,通过对其周期运动进行频谱分析,可得其加速度幅值频谱;结合考虑激励对象的动态特性,在满足凸轮从动件运动规律工艺运动要求的条件下,选择去掉该凸轮从动件运动规律加速度幅值频谱中那些易引起倍频激励共振的项,得到改进设计后的运动规律,进而达到通过改变激励源频谱特性来减小激励对象振动的目的。进一步通过对改进后的凸轮从动运动规律的有限傅里叶级数的项数及系数进行优化,可使其能更好地满足给定工艺运动要求。In this article,a design method for the cam-follower motion curves by means of the finite Fourier series is proposed. The cam can effectively reduce vibration or avoid resonance,which takes place when the frequency and the octave of the cam motion is close or equal to the natural frequency of the cam-follower system in the design process. To better illustrate the problem,the displacement curve is worked out with the aid of the polynomial curve-fitting method,and then resonance occurs in the cam-follower system based on the dynamic analysis. Therefore,to avoid resonance,the displacement curve is redesigned via the finite Fourier series based on the excitation characteristic of the motion curves and the dynamic characteristics of the camfollower system,and the offending frequency component is removed from the amplitude spectrum of the motion curves to identify the improved motion curves. By changing the excitation source of the cam motion,efforts are made for vibration reduction of the cam-follower system. Finally,it’s found that the equation of follower displacement ensures better performance of the cam-follower motion curves,with the optimized coefficients of the chopped finite Fourier series.

关 键 词：周期激励 频谱分析 倍频共振 有限傅里叶级数 凸轮从动件 

分 类 号：TH113[机械工程—机械设计及理论]