Design of a Modular Swift-shift Multi-speed Transmission with Double Dual Clutches for Electric Vehicles

In this paper a novel concept of modular swift-shift multi-speed transmission with double dual clutches is proposed, with its architecture, simulation and control strategies discussed in detail. Due to its modularity, the desired number of gear ratios can be readily realized by adding the appropriate number of modules. Further, in this design, both the underdrive and the overdrive modes are combined within one single gear train, which reduces the overall volume and weight significantly. Due to its modularity and compactness, this transmission is suitable for electric vehicles, especially commercial fleets of medium- and heavy-duty electric trucks. A proof-of-concept testbed was developed; its preliminary simulation analysis is reported here.