Design of high performance hybrid transmissions—Dorsch, 2019
This thesis examines transmission systems for high-performance hybrid (ICE and electric motor) automobiles. Traditional hybrid designs fell into two groups. Everyday road vehicles use hybridization to boost drivetrain efficiency, including low-speed electric driving and regenerative braking. Performance cars use electric motors to boost performance. Advanced hybrid architectures that allow for great efficiency and higher performance are described utilizing a novel framework for studying propulsion system elements and functions. Two-motor clutchless hybrid gearbox idea. An investigation of high-performance vehicle operating modes increases drivetrain performance and efficiency. The benefits and downsides of a dual-shaft, single-motor, clutchless transmission are contrasted to a two-motor architecture and a typical ICE only transmission. The final portion of this thesis proposes a two-speed electric motor system that might be implemented into an ICE AMT. This system uses custom sensors to track the synchronizer's dogteeth. Electric motor control is utilized to synchronize motor speed during a shift event, as friction synchronization alone is insufficient. This technique removes the tradeoff for optimal shift actuator design (bigger pistons result in quicker speed synchronization but slower actuation motion during other shift phases) and resulting in faster gearshifts. Dogtooth tracking ensures no dogtooth collisions and faster shifter motion than with a standard synchronizer. Shift performance was experimentally characterized. Using speed matching and dogtooth tracking to make entire gearshifts validates the suggested shift control method and allows for frictionless synchronizer designs. This work will lead to a new generation of high-performance hybrid automobiles.
Dorsch, D. S., Carrus, J., Xu, Z., Xu, D., Winter, A. G., Wallach, M., Dokras, N., & Marquart, T. (2018). Experimental setup to characterize shift time for high performance hybrid transmissions. Volume 3: 20th International Conference on Advanced Vehicle Technologies; 15th International Conference on Design Education. https://doi.org/10.1115/detc2018-85617
