Authors: Andy Gale, Research Engineer; Dr Paul Langlois, Software Engineering Director and Dr Owen Harris, Director of Research
Our Gear Blank Tuning white paper builds on last year’s submission to the March/April 2019 GT issue, where Dr Owen Harris, Dr Paul Langlois, and Andy Gale explored gear blank tuning as an optimisation solution to electric vehicle whine noise. This paper builds on that and features an additional study into how further NVH optimisations can be achieved through design of gear blank holes, using existing and upcoming new functionality in MASTA.
Authors: Dr Paul Langlois; Software Engineering Director and Baydu Al; Senior Software Engineer / Analyst – Gear Specialist
Dr Paul Langlois and Baydu Al present a Loaded Tooth Contact Analysis model and explore the application of asymmetric gears within an automotive transmission. The Loaded Tooth Contact Analysis is an extension of MASTA’s world leading Advanced LTCA functionality to asymmetric gears. The model uses a hybrid Hertzian and FE based formalism that is both accurate and fast. Validation against surface to surface contact in a general FE package is presented, demonstrating excellent correlation for transmission error, contact stress and root stress. While comparable in accuracy MASTA’s calculation is orders of magnitude faster than the general FE analyses.
An automotive example is presented showing how an optimised asymmetric gear design performed in comparison to an original symmetric design Interestingly, in this study, given the constraints, an optimised high contact ratio symmetric gear design could always be found which was better than the optimised asymmetric gear design in every aspect. This indicated that although there are stated potential improvements which can be achieved with asymmetric designs, improvements are not guaranteed. This highlighted the need for an accurate and efficient tool such as MASTA to make informed design decisions.