The new Mercedes-Benz SLK: Passion meets efficiency - Daimler

The increase in driving dynamics is also aided by an increased yaw rate(steering response) at low to medium speeds, as this augments the effect of thesteering movement. At high speeds this increase in yaw rate is small, whichmeans that the car responds safely and predictably to steering movements.Page 37Despite its remarkable effect, the key component of the Direct-Steer system issimply a steering rack. Its secret lies in the teeth cut into it. In the mid-areathese are slightly wave-shaped, with varying flank profiles. To both sides theteeth are spaced at varying distances apart. The change in steering ratio istherefore produced by purely mechanical means. With this solution, Mercedesengineers have been able to dispense with the complex actuators and sensorsystems used by other variable steering systems. The advantages include verylow susceptibility to faults and low weight. Moreover, the system alwaysresponds predictably and in the same way, while other variable steeringsystems sometimes require rapid adaptation by the driver in rapidly changingsituations.ECO steering servo pump lowers fuel consumptionDriving straight ahead in the new SLK also means saving fuel. This is ensuredby an ECO steering servo pump as standard in all SLK models. Its centrepieceis an electrically actuated proportional solenoid valve which variably opens abypass aperture at the pressure connection to feed the steering gear with justthe right amount of fluid. As the steering has a lower energy requirement whendriving straight ahead, the throughflow pressure in the steering system can beminimised. Less energy is therefore consumed.Daimler Communications, 70546 Stuttgart/GermanyMercedes-Benz – A Daimler Brand