ACTIVeDRIVE - Electric Vehicle with Active Torque Distribution

Schaeffler is presenting its ACTIVeDRIVE concept vehicle for electric mobility. It complements the trio of demo vehicles with which Schaeffler is visualizing the spectrum of modern automobility. “These three cars are full of ideas and function as platforms for the testing of various components and systems under realistic conditions,” says Prof. Dr.-Ing. Peter Gutzmer, Member of the Executive Board and responsible for technical development at Schaeffler.

The ACTIVeDRIVE is a purely electric vehicle with four-wheel drive, based on a Skoda Octavia Scout. The three vehicles – CO2ncept-10%, Schaeffler Hybrid and ACTIVe-DRIVE – represent Schaeffler’s broad-spectrum strategy and product portfolio.

    With its CO2ncept-10% vehicle based on the Porsche Cayenne, Schaeffler is impressively demonstrating the improvement potentials that can be achieved through consistent detailed work on vehicles with internal combustion engines. In the case of the CO2ncept-10%, these optimization measures cover detailed solutions that are already available or close to series production, but do not touch the basic configuration. Moreover, the optimization of the classic drive train also includes the use of electrified components instead of the previous hydraulically actuated elements.
    Based on a compact Opel Corsa, the Schaeffler Hybrid serves as an ‘ideas’ vehicle and a practice-oriented testing laboratory for various hybrid solutions. This versatile and variable advance development project enables a practical comparison of a wide range of options in the field of electric mobility. The driving modes represented range from classic operation with internal combustion engine and operating modes as parallel and serial hybrid with range extender to fully electric driving.
    The ACTIVeDRIVE is a thoroughbred electric vehicle (BEV: Battery Electric Vehicle).

These three vehicles provide an overview of Schaeffler’s wide product portfolio which ranges from energy-efficient solutions for the classic drive train with internal combustion engine all the way through to products for hybrid vehicles and elements for purely electric vehicles.

The major innovation of the Schaeffler ACTIVeDRIVE is its active electric differential (eDifferential) which is installed both on the front and on the rear axles. This component combines the electric drive with the option of wheel-selective drive power control. This enables torque vectoring (torque distribution between the right and the left wheel), which enhances driving dynamics, driving safety and driving comfort. “The eDifferential permits active intervening in driving dynamics through well-aimed power supply – instead of braking intervention and thus power reduction, as is the case with the ESP. The active electric differential significantly improves power transmission when driving on surfaces with different friction coefficients. Moreover it assists the steering and has a clearly positive effect on driving dynamics, driving safety and driving comfort. In addition, the use of two eDifferentials enables the longitudinal distribution of drive torques,” explains Prof. Dr.-Ing. Gutzmer. The possibility of active longitudinal and lateral distribution of drive torques makes the eDifferential an ideal platform for innovative vehicle dynamics control systems. With the solution shown in the ACTIVeDRIVE, Schaeffler is a pioneer in such electric concepts for vehicle drives.

The actively controllable torque distribution enables torque vectoring, which means that the vehicle can be controlled virtually without the use of steering and braking by means of a wheel-selective flow of forces. “So the potential fields of application for the eDifferential range from sports cars with extremely high driving dynamics and vehicles of classic automobile categories to agricultural machines,” explains Dr. Tomas Smetana, Senior Manager Advance Development Power Transmission Systems at Schaeffler Automotive.

The eDifferential system integrates two water-cooled permanent magnet synchronous machines (PMSM) of different dimensions, a planetary gear, a gearbox for active torque distribution and – a central element – a Schaeffler lightweight differential. The electric machines come from Schaeffler’s brand IDAM. The larger PMSM, which delivers up to 105 kW and 170 Nm, is responsible for the drive. The second PMSM, which controls the torque distribution, must deliver merely 5 kW output to generate up to 2000 Nm of torque difference to the axle. Other innovations shown in conjunction with the ACTIVeDRIVE include an integrated electromechanical parking lock, a new forced lubrication system without oil pump for the gearbox, sheet metal planetary carriers and various high-speed and friction-optimized bearing solutions. The electronic control is supplied by AFT and thus comes from Schaeffler as well.

Due to the use of two active electric differentials, the concept car has an overall output of up to 210 kW and features four-wheel drive. Fitted in the cardan tunnel and in front of the rear axle, Li-ion batteries with a capacity of 18 kWh function as energy storage devices. Thanks to its performance and traction capacity, the 1,900-kilogram test platform accelerates from a standstill to 100 km/h in merely 8.5 seconds. There is an electronic top speed regulation at 150 km/h. The vehicle’s cruise range in this configuration amounts to up to 100 kilometers.