Kinematic and Dynamic Analysis of V-Twin Powertrains: Design Trade-Offs

This paper examines the influence of multiple design parameters on the kinematics and dynamics of a V-twin powertrain. Two models are presented to study the design trade-offs in order to provide an analytical tool that can be used for the top-level design of a V-twin powertrain. Shaking forces and bearing loads are evaluated to quantitatively comprehend the influence of design parameters such as banking angle, crank pin, piston off-set, etc. Furthermore, the influence of parameters associated with the use of conventional Lanchester balance shafts is also investigated as part of the analysis. These parameters include support bearing locations and balancing mass location on the balance shaft. The analysis results are compared to some of the studies on balancing of shaking forces and shaking moments in the literature. While the design trade-offs associated with parameters such as banking angle are well understood in the available literature, the analysis performed in this study shows interesting results for piston off-set and crank pin design, as well as for parameters associated with the balance shaft.