As automakers pursue higher fuel efficiency, one method, such as in plug-in hybrid electric vehicles, is to reduce powertrain power output and weight.
At the same time, however, drivers have a hard time adapting to less-powerful powertrains, so plug-in hybrid automakers are trying to squeeze every last bit of power out of smaller and lighter components. Typically, this is a recipe for disaster. For example, you might think of the relatively small engines that power race cars. Turbocharged, supercharged, they generate tons of power, but they’re also rebuilt after every race, so they’re not very practical in production automobiles.
Building a simpler, lighter plug-in hybrid transmission that is also powerful, robust, and reliable, is a complicated task. FEV, a world leader in powertrain development, took to the task, and the newly-revealed two-speed plug-in hybrid transmission is a marvel of simplicity. Starting from a clean slate, FEV developed a two-speed transmission that doesn’t include anything extraneous, a single planetary gearset (I’m guessing) for two-speed operation, a single electric motor / generator, and no torque converter. The new transmission is 10% smaller and lighter than similar dual-clutch performance transmissions.
In spite of its simplicity, the FEV two-speed plug-in hybrid transmission is still versatile. In electric-vehicle mode, two gear ratios are available for efficient power transfer. In hybrid mode, the transmission delivers full parallel hybrid electric vehicle functionality, including electric boost, regenerative braking, and power split mode while cruising. Additionally, because only two gear ratios are utilized, even sporty applications of the plug-in hybrid powertrain would benefit from solid engagement and powerful launch capability. FEV hasn’t revealed exactly who is testing their new transmission, but has hinted that it’s being tested on the world-renowned Nürburgring endurance racing circuit in Nürburg, Rhineland-Palatinate, Germany.
Image © FEV