Engine drive train having a front gear train with improved torsional dynamics

摘要

An improved engine gear drive train arrangement is provided which effectively minimizes the crankshaft torsional vibrations at the location of the gear train, for engines with a front gear train. A flywheel is resiliently connected to the rear end portion of the crankshaft so as to resiliently connect a driven unit to the crankshaft. An extra inertial device is connected to the front end portion of the crankshaft and includes an inertia so selected as to cause a nodal point of the first torsional vibration mode of the crankshaft to be located in the vicinity of the crank gear to minimize the amplitude of torsional deflection of the crankshaft at the crank gear. Also, the device for resiliently connecting the flywheel to the rear end portion of the crankshaft may include resilient members positioned in cavities formed by engaging rings. The nodal point of the first torsional mode of the crankshaft is optimally positioned close to the crank gear by selecting an inertia for the rear mounted flywheel, an optimum inertia for the front mounted inertial device and a resilient material for the flywheel connecting device having the appropriate stiffness, so that the combination of these features achieves the desired nodal point positioning for a given engine or application.