VIBRATION ANALYSIS, SHAPE AND DESIGN OF MOTORCYCLE MOUNTING SYSTEM SUBJECTED TO SHAKING FORCES

This article presents a study of a mounting system that is used to isolate vibrations in motorcycles. The isolating system consists of the powertrain assembly, swing-arm assembly and the mounts that are used for isolation. In addition to mounting the powertrain in place, engine mounts are used to minimize the transmitted forces from the engine to the frame. The governing equations of motion are being derived for a V-Twin engine which is generally used in motorcycle applications. The loads that need to be minimized are the loads due to the shaking force. These forces are generated in part as a result of the rotating unbalance due to eccentric masses and due to the acceleration of the moving masses that the reciprocating engine consists of. An optimization problem is first set up to determine the mount stiffness rates in all three principal directions. Then the effect of the varying engine speed on mount characteristics is studied. Shape optimization is also performed to find the geometrical mount shape due to the stiffness values in the principal direction of the mount