The need to reduce weight in internal combustion (IC) engines introduces new or increased NVH challenges. In particular, gear-related noise such as rattle and whine need to be addressed.
This paper discusses a methodology aimed at simulating a novel “split gear” system designed to counteract the rattle noise typically generated in accessory drive gears on combustion engines. In particular, the focus is on the increased gear whine associated with this system.
The ‘split gear’ system is simulated as a multi-body system incorporating contact force prediction developed by Siemens. It enables efficient identification of the contact between gear teeth based on their intrinsic involute geometry, including the effects from microgeometry corrections as well as relative displacements and misalignments of the gears. The gear contact force is evaluated taking into account both compliances for the global bulk and local contact. The multi-body approach and dedicated modeling technique permitted the investigation of interaction between gears of the ‘split gear’ system and appropriate replication of the operational boundary conditions.
The activity presented in this paper consisted of two main phases, measurements of the dynamic behavior of the split gear system and multi-body simulations. The former allows gathering reference data for validation of the simulation model built in the latter phase.
The results show the potential of the new method to analyze gear systems in view of NVH performance.