Research on Mechanical Model and Torsional Stiffness Properties of Leaf Spring Torsional Vibration Dampers for Marine Diesel Engines

The torsional stiffness parameter significantly influences the natural frequency of a leaf spring torsional vibration damper and its proper match with a diesel engine, and the nonlinear characteristics of torsional stiffness avoid reduced reliability due to the excessive torsion angle of the damper. An efficient mechanical model for the damper with nonlinear characteristics is established by integrating the Euler–Bernoulli beam theory and accounting for the geometric nonlinearity of leaf spring deformation during operation. The model’s validity is confirmed through finite element analysis. This study then explores the influence of design parameters on the mechanical characteristics of the damper. The results reveal a gradual increase in the torsional stiffness of the damper with the expanding arc radius of the clamping groove. Simultaneously, the torsional stiffness curve exhibits more pronounced nonlinear characteristics. In contrast, an elongation of the leaf spring leads to a sharp decline in torsional stiffness, accompanied by a diminishing prominence of nonlinear traits. Thus, both the arc radius of the clamping groove and the spring length significantly impact the torsional stiffness and nonlinear features of the leaf spring torsional vibration damper. The nonlinear characteristics intensify with an enlarged arc radius of the clamping groove and a reduced leaf spring length. Additionally, the damper’s torsional stiffness is influenced by the leaf spring thickness and the red copper gasket length. Future damper designs should comprehensively consider these relevant parameters.