Torsional analysis of crank mechanism and Front End Auxiliary Drive system of a P0 hybrid powertrain for light duty application

The automotive industry is currently undergoing a significant transformation due to increased attention to pollution levels. The European Commission is aiming for a zero-emission scenario by 2035, and as such, stricter EURO regulations will be implemented to achieve this goal. Light-duty vehicles and passenger vehicles are the primary focus of this process. The compliance to the latest standards is strongly affecting to the engine mechanical design with the need to introduce new configurations. The most widely adopted solution is hybridization, which involves coupling an electric machine with an internal combustion engine. This requires a substantial redesign of the transmission system to manage torque split and accommodate the new architecture. In this study, a case study from FPT Industrial involving the redesign of a light-duty engine with a new P0 hybrid engine is considered. The company’s concern is understanding if the new design is compliant with the targets. It is a strong point of discussion because the P0 configuration introduces strong torques on the front-end auxiliary drive (FEAD) system. After building a model for the crankshaft and the FEAD system, a torsional dynamic analysis will be performed to discuss whether the design is compliant to the targets. Furthermore, the introduction of two mechanical components, torsional vibrations damper and vibrations decoupler, will be discussed. The TVD and the decoupler are the widest solutions to the problems introduced by the P0 hybrid design. In the second part of the study the effect of the TVD and decoupler on company’s targets will be assessed, showing their strong contribution in limiting the vibrations helping the two systems to be compliant to the requirements.