OK, even though I’m not much of a soccer fan, I’ve got to admit it was pretty exciting to be in Germany for the final games of the World Cup series. But for me, an even hotter ticket was a chance to drive some trucks with the latest technology from ZF at the Munsingen proving ground near Stuttgart.
While ZF is working on projects like heavy-duty, independent front suspension and rack-and pinion steering – they even had a North-American-spec Volvo tractor with rack and pinion – there were a couple of technologies on display and available for driving that totally blew me away.
First, part of a parallel hybrid drivetrain is the “electrodynamic starting element,” which replaces the master or starting clutch and starting motor. The system connects the engine’s output shaft to the transmission via an electric motor and planetary gearset. By spinning the motor at the same rpm as the engine, in the opposite direction, the net rpm output is zero. By varying the speed of the motor, engine power is sent through the transmission to the wheels.
Not only does the system eliminate clutch wear, it also can start and stop the engine with the vehicle, provide automatic vehicle hold when starting out on a grade, and allow a vehicle to creep, as would an automatic transmission with a torque converter. Moreover, the electric motor is used as a generator for capturing energy when braking. Also, the system takes up very little space and, according to ZF, fits within the existing bell housing of the company’s ZF-AS Tronic transmission. Field testing reportedly will begin soon.
Next, the products of ZF Lenksysteme, a 50/50 joint venture between ZF and Robert Bosch, are two electrohydraulic steering systems that can assist drivers by maintaining direction in case of strong crosswinds, highway track grooves or hard split-coefficient-of-friction (split-mu) surfaces. The Servotwin is networked with a vehicle’s sensors and electronics, and can superimpose torque via an electric servo, and counter-steer to keep a vehicle on course. With this system, the course correction is communicated to the driver through the steering wheel.
The Servoactive steering system is really wild. It uses vehicle sensors and electronics, an electric servo and a planetary gearset in the steering box, which adds or subtracts an adjustable angle in relation to the steering wheel angle. With this system, the conversion of steering wheel motion to the front axle is highly flexible, which provides a high degree of maneuverability at low speeds with fewer turns of the steering wheel.
Also, under conditions that might want to force a vehicle from the driver’s intended course, the system can make corrections via the planetary gearset. Since the output shaft turns without the input shaft, corrections are made without the driver noticing any motion at the steering wheel. The system already is in use in BMW 5-series passenger vehicles.
While these systems are still in the testing phase for commercial vehicles, they promise to reduce driving stress and improve safety – goals that should score big points in anyone’s game.