Design, Simulation and Testing of Novel Compact and Robust Geared Powertrain

Common issues of geared powertrain systems are discussed in this work such as gear misalignment in conventional gearboxes and reliability issues of typical planetary gears. An extensive literature review was performed for each topic. For the misalignment issue, multiple solutions were proposed including misalignment insensitive gearing integrated with Rzeppa or constant velocity ball joint and spur gears with the modified web with thin flexible rim topology. All proposed models, and a benchmark model in the form of regular spur gears and flank modified gears were compared in terms of misalignment insensitivity. According to results, a novel gears with kinematical joint display the most superior performance in terms of gear mesh stress, with the compromise being increased stress results in internal interfaces. On the other hand, compliant web gears show moderate effectiveness against the issue and flank modification could mitigate misalignment to some extent. In terms of transmission error (TE), the gear with the Rzeppa joint demonstrates complete insensitivity to misalignment, despite experiencing high TE, whereas the conventional gears suffer from misalignment significantly, with TE amplitude increasing rapidly as misalignment angle becomes bigger. For the case of planetary gears, a planetary gearbox with novel topology and the floating carrier was presented. The key feature of the design was the elimination of bearing interface existing in the generic layout of the planetary gear set. Bearings of planets’ carriers tend to fail frequently, leading to misalignment and vibrations. The novel planetary gears were simulated using FEA and MBD to evaluate the viability of the concept. Despite replacing the bearing contact with robust geared connection, simulations results show that the novel bearingless planetary gearbox with floating carrier still suffers from common issues such as non-equal load distribution and misalignment