Nonlinear dynamics of torsichrone CPVA with synchroringed form closure constraint

Centrifugal pendulum vibration absorbers (CPVA) are order-tuned torsional dampers, increasingly employed in modern powertrains to reduce torque disturbance even at low engine speed. In this paper, an advanced architecture of such devices, herein termed synchroringed CPVA (SR-CPVA), is analyzed from kinematic and dynamic point of view. Its novelty is represented by a form closure constraint element, able to synchronize the absorbers motion (the synchro ring). This mechanical connection ensures the avoidance of bifurcation phenomena, which affect the absorbers previous designs, without decay of their vibration attenuation effectiveness. Intrinsic geometry and higher-path curvature kinematics differential tools provide the theoretical framework for this investigation. Furthermore, perturbation methods are applied to solve SR-CPVA nonlinear dynamics. To improve vibration isolation performance, a peculiar design condition, named torsichronism, is also deduced. A numerical comparison with parallel and trapezoidal architectures is assessed, to evidence strengths and drawbacks of each respective dynamic behavior. In conclusion, the proposed analytical model is validated through a multibody dynamics simulation.