GKN Driveline is expanding its global electric axle (eAxle) drive partnership with the BMW Group, supplying eAxle technology for a plug-in hybrid version of the BMW X1 for the Chinese market. The system is part of the same scalable family of eAxles used in the plug-in hybrid BMW 2 Series Active Tourer 225xe (earlier post).
Early adopters of GKN’s electric axle drive used the technology to create plug-in hybrid sports cars with electric all-wheel drive that enhanced performance and efficiency. Automakers are now equipping a new generation of compact vehicles with GKN electric drive technology.
The system will be supplied from GKN’s facility in Bruneck, Italy, but application and development work for the technology was conducted by GKN’s operations in Shanghai, China.
For compact car applications, GKN’s single-speed design has a transmission ratio of 12.5:1, reducing the electric motor speed in two stages. The system generates up to 2,000 N·m (1475 lb-ft) and 70 kW of additional torque and power—enough for a vehicle’s pure electric mode to achieve speeds of up to 125 km/h (78 mph) and for an all-wheel drive (AWD) mode that accelerates faster than conventional mechanical AWD systems.
The lightweight electric axle weighs just 20.2 kg (44.5 lbs) and its compact dimensions facilitate packaging and installation in smaller vehicles. The unit has a length of 457 mm, a width of 229 mm and a height of 259 mm (18 x 9 x 10 inches).
When hybrid operation is not required, an electromechanically actuated dog clutch disconnects the e-machine from the driveline, minimizing losses at higher vehicle speeds. GKN has also optimized gear and bearing arrangements for optimum efficiency, NVH (noise, vibration and harshness) and durability.