Theoretical Research And Structure Design Of Centrifugal Pendulum Shock Absorber

The torsional vibration of automotive transmission system has always been the core and concern of technological innovation in automotive industry.With the wide applications of miniaturized engine and turbocharging technology,the output torque of engine increases,which leads to the problem of torsional vibration becoming more serious.Centrifugal Pendulum Absorber(CPA)can minimize the main vibration in the range of all engine speeds due to its centrifugal force.Overseas researches and applications in this field are relatively mature,but domestic researches and development projects on CPA are still in the exploratory stage,belonging to the frontier field.Therefore,it has great significances to study the structural design methods and isolation characteristics of centrifugal pendulum absorber.In this paper,the centrifugal pendulum absorber is installed on the flange disk of a double mass flywheel.Taking a small SUV as an example,the vibration reduction characteristics of the whole transmission system are studied.Firstly,the initial dynamic model of centrifugal pendulum absorber is established.The isolation characteristics of CPA are deduced and analyzed based on Lagrange theory.Secondly,a Simulink model is established to optimize the mass parameters of CPA according to the kinematics equation of CPA.The design method of motion hole with general path is proposed to complete the three-dimensional model of centrifugal pendulum absorber.Then,based on the multi-body dynamic analysis method,the actual motion of CPA assembly is simulated with ADAMS software.The torsional vibration simulation model of transmission system equipped with CPA solid structure is established to analyze the forced vibration.Finally,the CPA prototype is trial-produced and installed on the test vehicle for road test.The actual vibration reduction effects of centrifugal pendulum absorber in different working conditions are explored.The measured signals are processed and analyzed in the time,frequency and order domains to obtain the changes of angular velocity and angular acceleration at the front and rear ends of centrifugal pendulum dual-mass flywheel.Using comparative analysis on experimental and simulation results,it shows that the second-order main harmonic frequencies of the engine in the test are not different from those of the four-cylinder engine in theory,which verifies the validity of the processing method with experimental data.The angular velocity data in different measuring points are collected.The angular acceleration curves from the front and rear ends of CPA under idle condition are obtained by the Simulink control program,and the actual vibration reduction of centrifugal pendulum dual-mass flywheel is studied.Compared with the CPA damping rate obtained by simulation analysis,they are basically consistent.The results show that the torsional vibration model of transmission system with CPA solid structure is correct and the error analysis is carried out.