TransPower’s Automated Manual Transmission (AMT) Image Credit TransPower
TransPower’s Automated Manual Transmission (AMT) is a key new technology that enables the ElecTruck™ Main Propulsion System (MPS) to achieve superior road performance and efficiency, while enhancing drivability. The AMT provides improved road performance at both high and low speeds, while enabling the use of a more efficient manual transmission, which reduces energy consumption and increases operating range. Shifting is accomplished smoothly and automatically, resulting in a favorable driver experience.
The AMT is built around Eaton’s Road Ranger® manual transmission, versions of which have been in production for 60 years. Shifting is mechanically accomplished with an “X-Y shifter” employed by Eaton for the past 15 years to enable manual transmissions to shift automatically, using special software developed by Eaton for trucks using conventional internal combustion engines. TransPower has adapted the Eaton transmission and shifter to electric trucks by developing its own proprietary AMT software that regulates shifting based on continuous calculations of electric motor speed and vehicle torque requirements. TransPower offers AMT solutions based on both Eaton’s 6-speed and 10-speed Road Ranger® transmissions. The 6-speed version is generally used with a single Fisker drive motor for vehicles requiring power levels up to about 200 horsepower, and the 10-speed version is typically used with TransPower’s dual motor configuration for power levels up to 400 horsepower.
As compared with electric vehicles using direct drive motors, the AMT provides higher starting torque without compromising efficiency at higher operating speeds. As compared with electric vehicles using automatic transmissions, the AMT eliminates losses associated with torque converters. Maintaining high efficiency across the vehicle speed range and eliminating parasitic losses such as those created by torque converters are important because these factors directly affect the operating range a vehicle can achieve on a single battery charge.