On The Dynamic Analyses And Design Of Cam Mechanisms

As an important branch of mechanism, the design and manufactureof the cam mechanism is currently in quite active stage, mainly inresearch in CAD/CAM and dynamics of the cam.Firstly, this paper introduces a kind of the harmonic motion events,which applies to intermediate-speed and high-speed cam mechanism.The formula of the motion events is characterized by multi-harmoniccomponent superimposed and making express by a mathematicalformula in a week period. The basic idea is making ideal workrequirements as a reference, and the least squares method to optimizethe displacement, velocity or acceleration, so as to determine thecoefficients of harmonic components, also using acceleration as optimalthe objective function which constraint condition is for some time thecorresponding displacement, velocity, acceleration or jerk and so on, toturn into the constrained optimization problem, then to obtain theharmonic coefficients with the optimization of the analysis software.And combined with the instance, the design of harmonic motion eventsis completed and compares with the characteristic values of the sinmotion events and modified sin motion events under the sameconditions, which reflects the small advantages of the harmonic motionevents in the maximum speed and maximum acceleration.Secondly, this subject is based on the dynamic theory ofmechanical system and analyses the dynamic response of cammechanisms, including the displacement response, velocity responseand acceleration response. According to the comparison and analysis ofresponses, the harmonic motion events are more effective in decreasingthe vibration of cam mechanisms running with high-speed. Theanalytical stages of subject include modeling, establishing differentialequation of motion and solving the differential equation of motion. The analytical solutions of differential equations of motion only can besolved in some simple cases and in general, it can only be solved byusing the numerical method. In this paper the analytical solutions ofdynamic responds are got and are compared with the ideal outputresponse in order to reflect the reliability of harmonic motion eventsused in cam mechanism.Finally, the cam mechanism was in modal analysis, the mainpurpose is to provide an objective reference data for improving thedynamic performance of the institutions and the optimization design.The corresponding frequency of different order modes correspond to thedifferent resonant frequency of component, the resonance frequency ofthe component is of concern by designers to institutional dynamicanalysis. In the paper， through the swinging follower planar CAMmechanism as an example, it first finished the design of organizationaccording to the conventional way, and in dynamic analysis by ADAMS,through the analysis, it reflected the lack of conventional methods in thedesign, inspired the vibration of the institution, so that to make thefollower motion trajectory distortion. So combining the results of themodal dynamic analysis, the harmonic order was determined, and theharmonic motion events were applied to the design of the cammechanisms, and re-measured the state of motion of the follower,reflecting the advantages and applicability of the harmonic motionevents applied to high-speed cam design.