eDCT: 4 speed seamless-shift technology for electric vehicles

For electric vehicles there is a fundamental shift in the philosophy of the electric powertrain. This manifests itself as a move away from single speed transmissions to multiple speed transmissions. For the comfort to the driver, the multispeed transmission must be achieved with seamless-shift technology. The eDCT is a novel design concept for electric vehicles that takes inspiration from DCT (Dual Clutch Transmission) technology, from which the eDCT takes all the benefits but with a reduction in terms of weight, size, power loss and cost. The solution is an ingenious mechanical design that is controlled by a reduced set of transmission control software, when compared to alternative automated transmission technology, giving performance and efficiency improvements that can translate into a greater vehicle range or a smaller battery pack. The latest generation of eDCT design has allowed the opportunity to introduce flexibility into the design in terms of motor location, through modularity of design, allowing opposing motor or parallel motor installation, further increasing the desirability of the design for different applications. The opposing motor design has been integrated into a demonstrator vehicle, a Mercedes Vito Minibus. The cost and efficiency benefits of the eDCT in this application are detailed together with the first results of the testing on this vehicle.