Research On Vibration Characteristics Of DMF With Centrifugal Pendulum Vibration Absorber

DMF is a new kind torsional vibration damper,which has lower torsional stiffness and performs better than CTD at low engine speed.However,its effect becomes worse at high engine speed.CPVA’s natural frequency changes with engine speed,using this characteristic and combine CPVA with DMF,a new type torsional vibration damper—DMF with CPVA is formed.In theory,it performs well in any engine speed.In this paper,the working principle of DMF with CPVA was analyzed,the dynamic model of the driveline was built,and the parameters of DMF with CPVA was matched with the driveline.The main contents are:Firstly,different types of CPVA were introduced,their working principles were analyzed.Two typical type—DMF with simple type CPVA and DMF with Bifilar type CPVA were researched,and their dynamic models were built.Based on the working principle,the preliminary design method of DMF with CPVA was analyzed.Secondly,a commercial vehicle was taken as the research object,preliminarily designed a DMF with CPVA for it.By experimental measurement,inquiry,FEA and CAD calculation,the dynamic parameters of the vehicle were determined.Then,the driveline’s dynamic models using DMF,DMF with simple type CPVA,DMF with Bifilar type CPVA under different conditions were built.Thirdly,the differential equations of motion were established,numerically solved and simulated by Matlab.By plotting the angular acceleration of the primary flywheel and the primary shaft of the transmission,the damping effect of traditional DMF,DMF with simple type CPVA,DMF with Bifilar type CPVA were compared.Finally,the parameter optimization model of DMF with CPVA was built.The preliminarily designed DMF with CPVA was optimized,and its damping effect was compared with the effect before optimization by simulation.Then,a real vehicle test under idling condition and first speed condition was conducted.The result suggested that the matching method of DMF-CPVA with driveline was effective.