Dynamic Model and Dynamic Response of Automobile Dual-Mass Flywheel with Bifilar-Type Centrifugal Pendulum Vibration Absorber

Compared with dual-mass flywheel (DMF) and DMF with simple-type centrifugal pendulum vibration absorber (CPVA), DMF with bifilar-type CPVA has a better damping performance in the whole speed range of engine. The related research mainly focused on local models, such as dynamic model of DMF and dynamic model of CPVA, and the effect of the curvature path of CPVA on the damping performance. The reported models and methods are not sufficient for the system of DMF coupled with bifilar CPVA. Aiming at the deficiency of local models and the limitation of bench test, an integral model for DMF with bifilar CPVA is proposed and the real vehicle test is carried out in this study. Involving the moment of inertia of the centrifugal pendulum, the model considers the nonlinearities of DMF and bifilar CPVA. Afterward, the dynamic model of the automobile power transmission system equipped with the DMF with bifilar-type CPVA is built, and the dynamic responses of the system are investigated under idling and driving conditions. According to the simulation results, DMF with bifilar-type CPVA shows better vibration reduction performance in full-speed range. Moreover, the key structural parameters R and l influencing the damping performance of DMF with bifilar CPVA are discussed. The results show that the sum of R and l is directly proportional to the damping effect. Finally, real vehicle tests under idling and driving conditions (engine speed from 750 r/min to 3400 r/min) are carried out. The test results show that the 2nd order engine speed fluctuations are attenuated by more than 80% by DMF with bifilar CPVA with engine speed lower than 2000 r/min and are attenuated by more than 90% with engine speed higher than 2000 r/min. The experimental results are basically consistent with the simulation results, which verify the validity of the model.

Evaluation of Relationship Between Shape of a Rigid Body Unifilar Centrifugal Pendulum Vibration Absorber and Vibration Suppression Performance

The torsional vibration hinders the reduction of automobile exhaust gas emitted by using engines with a reduced number of cylinders. Centrifugal pendulum vibration absorbers (CPVA) have been used in engines to suppress torsional vibration. To clarify the dynamics of CPVAs, much analysis has been conducted using the point mass CPVA as the model of rigid body bifilar CPVA. However, few attempts have been made to analyze the rigid body unifilar CPVA on vibration suppression performance in frequency response. In this study, the authors have analyzed the dynamics of the rigid body unifilar CPVA, focusing on the influence of shape parameters. The results verified that the shape parameters, which relating to moment of inertia or radius of gyration of rigid body unifilar CPVA, influence the vibration suppression performance in frequency response. Moreover, the numerical simulation results were confirmed experimentally and showed in good agreement with the experimental results, and both indicated the dependence of the vibration suppression performance on the shape parameters of the rigid body unifilar CPVA.