Reduced Fuel Consumption With Ball Screw Drives in Electromechanical Steering System
Modern, electromechanical steering systems offer drivers optimized steering feel and save up to three percent in fuel compared with conventional hydraulic systems. Schaeffler KG has developed a high-precision ball screw drive, whose performance density is exactly matched to the high demands of this type of steering system. With this product, the company is expanding its range by a subassembly that has since recently been in use in the new Tiguan from Volkswagen AG.
Schaeffler KG delivers the ball screw drive as well as a toothed rack that is partly designed as a spindle on which the drive is located. Ball screw drives are used to transform rotary motion into linear motion through a direct coupling between drive element and output element. In the Tiguan, the ball nut is driven by a servomotor that is linked with the screw drive via a belt. In contrast to hydraulic systems, where a pump must constantly supply pressure to provide steering motion, the electric motor becomes active only the moment when steering motion is initiated. Pump and feeds are no longer necessary, which reduces the space required for operating the electromechanical steering system.
With the new steering system in the Tiguan, Volkswagen is offering one of the most powerful steering gears in the market. The demands placed on the ball screw drive are therefore especially high. It can support high dynamic loads thanks to appropriate spindle dimensions and high material strengths. Due to the low internal friction of the ball screw drive, the driver can directly feel the low-frequency changes on the wheel when driving on asphalt that are important for the drive feel.
For applications in other vehicles, the ball screw drive can be modified in such a way that the steering characteristics and steering feel for the driver vary depending on the customer
Product Model | Inside Diameter | Outside Diameter | Thickness |
BR395 bearing | |||
BR385 bearing |