Analysis of Wet Clutch Dynamics for Enhanced Control and Shift Quality of Light Speed Transmission

Sammanfattning

In the ever-evolving backdrop of automotive powertrains, development in the field of automatic transmissions has been flourishing ever since its invention and at its heart lies the wet clutch. Optimizing the wet clutch based on its performance parameters has been a critical topic which determines the overall performance of the transmission. Koenigsegg’s Light Speed Transmission is at the pinnacle of current powertrain technologies. The Master thesis topic “Analysis of Wet Clutch Dynamics for Enhanced Control and Shift Quality of Light Speed Transmission” highlights the intricacies associated with wet clutch optimization.The topic is chosen due to its difficulties in understanding the complex adversaries between the frictional characteristics, thermal dynamics and lubrication regimes which impact the overall performance of the vehicle. Existing research has focused on general clutch systems with lower performance vehicles, leaving a gap for further analysis in the hypercar segment.To analyse this problem, a comprehensive experimental approach was employed, with a gearbox dynamometer and the Light Speed Transmission attached with the vehicle thermal management system. Experiments were designed to measure the friction coefficient of the clutch along with the thermal dynamics under various operating conditions similar to real world scenarios. The thermal data was collected through temperature probes and analysed to understand the effect of temperature, pressure and slip speeds on clutch performance.The study concludes by stressing the importance of rotational speed, pressure, operating temperature of both clutch and oil and the cooling strategies which impact the overall performance and durability of the transmission. The findings of this thesis provide an insight for optimizing wet clutch systems in hypercars, leading to improved shift quality and performance. Future work can build upon these results to further refine clutch designs, advance the cooling system and build models to predict clutch wear and improve life of the clutch for long term reliability.