Professor Ken Mao
The Lightweight Gearbox Design using 3D Printing Polymer Composite Gears and their applications in E-Motorbikes and E-Vehicles
The ever-increasing demands for light weight and low carbon motorcycle and automotive engineering have resulted in a rapid increase in the use of polymers. In particular, polymer composite gears offer a huge potential for high-technology applications and have unique advantages over metal gears: such as low cost and weight, fast manufacture, quietness of operation, functioning without external lubrication, etc. They are now used for applications ranging from low-power, precision motion to high power transmission, even in challenging environments such as healthcare and automotive engineering. For example, the use of polymer composite gears in the power train are reported to reduce mass by 70%, reduce inertia by 80% and lower fuel consumption by up to 9%.
The research aims to establish the fundamental approach for lightweight gearbox design used in e-motorbikes and e-vehicles. This will be achieved to significantly increase the gear loading capacity (>80% increase compared to the current designs) through proper optimisation of the polymer composite gear design and manufacturing processes. Also, additive manufacture (AM) allows for polymer composite gears individually manufactured according to their specific application conditions without cost injection mould and geometry (e.g., worm and double helical gears) constraints. The individual objectives are:
1) to extensively investigate manufacturing process control for optimizing high performance AM polymer composite gears. Especially, to develop designed fibre orientation to optimise gear tooth stiffness, bending & wear resistance, and to maximise the degree of crystallinity & melting point (all affecting the strength and lifetime of the gear), whilst minimising gear mass.
2) to provide new tools for micro and macro design optimisation by establishing advanced non-linear, fully coupled thermo-mechanical contact simulations for polymer gears. Especially, to reduce the layer bonding contact concentration through surface optimisations and to optimise the whole gear geometry to further support the microstructure and microgeometry optimisations.
3) to fully develop a unique test facility for AM polymer gears, with non-stop wear rate measurement and misaligned engagement. Hence, to establish an ‘open’ testing methodology and to investigate the AM polymer gear performance and failure mechanisms both for crucial model validation.
The High Performance Polymer Composite Gears in Electrical Vehicles
Polymer gears have unique advantages over metal gears: low cost and weight, high efficiency, quietness of operation, functioning without external lubrication, etc. For example, 70% reduction in mass, 80% reduction in inertia and up to 9% consumption reduction have been reported using polymer gears instead of metal gears in automotive engineering. Polymer machine elements will enable key developments in low-cost and energy efficient personal transport for the world’s emerging economies (e.g. electrical vehicles). The research will focus on polymer composite gear failure mechanisms, especially the research will combine material science, chemistry and manufacture process control to improve the gear performance. The candidates with polymer composite material science backgrounds are preferred.
Tyre Dynamic Contact Analysis
The main objective of the project is to simulate aircraft tyre dynamic contact behaviour. The non-linear FEM (Abaqus) will be employed to carry out the research. The tyre will be simulated under internal pressure first and then its foot print will be evaluated. The next step will be to investigate the slip, brake and acceleration effects on the tyre contact behaviour, i.e. dynamic responses. The stress distributions will be used to understand the tyre contact fatigue and improve the design.
It may be noted that the fibre reinforcement will be considered, i.e. the fibre imbedded with the rubber and its orientation will be also included in the research work. Also the tyre visco-elastic behaviour will be considered. The output of the research will provide fundamental information for aircraft tyre designers.
If you have any questions or would like more information on the above, please contact Dr Ken Mao.
Note: Should your application for admission be accepted you should be aware that this does not constitute an offer of financial support. Please refer to the scholarships & funding pages.