FEV Shows Compact DCT for FWD Vehicles

March 5, 2015

Kevin Jost

Current production dual-clutch transmissions (DCTs) are limited by their inherent mechanical complexity, according to FEV engineers. In addition, most conventional DCTs are characterized by drivers as having sluggish launch feel. The company has developed a new generation of DCTs, called the xDCT family, that are said to offer reduced transmission mass, lower complexity/cost, and improved fuel consumption, while also improving vehicle launch characteristics. The 7-xDCT has seven forward gears and a 250 N·m (184 lb·ft) input torque capacity, and the 10-xDCT has ten forward gears and an input-torque capacity of 400 N·m (295 lb·ft). Specific benefits are improved mechanical efficiency, reduced parasitic drag, an increased ratio spread, and inherent hybridization potential. Shift quality is enhanced, the company claims, by using smaller gear steps and full powershift capabilities. The technology will be on display at the upcoming SAE 2015 World Congress. Innovative features include “gear generation” and “supported shifts.” To generate gears, a switchable connection between the two input shafts is installed that allows use of all gears inside the transmission with both clutches. Supported shifts, during which torque fill-in for an automated manual (AMT)-style gear shift, is provided by the next higher gear. The combination of these two concepts allows for effective use of all theoretically available gears.