SKF, the leading knowledge engineering company, has developed a new bearing solution for the latest environmentally friendly micro-hybrid cars. Its new magnetic sensor bearing is part of Valeo's StARS (Starter Alternator Reversible System) micro-hybrid system, which enables vehicle manufacturers to reduce the fuel consumption and CO2 emissions of their cars without the need for any radical changes in the engine architecture.
The StARS system features a Stop-Start function, which cuts off the engine when the vehicle stops at a red light or slows down in congested traffic situations, and restarts it quickly and silently when the driver releases the brake or engages a gear. This enables a reduction in fuel consumption and CO2 emissions of up to 25% in dense urban traffic, typically during rush hour when vehicles are continually stopping and starting.
Integral to the StARS system is SKF’s latest magnetic sensor bearing technology, which provides a powerful magnetic field that enables the bearing to function effectively under severe running conditions, including high temperatures and speeds. Furthermore, the accurate and repeatable magnetic field makes it possible to receive data on the speed and positioning of the shaft, making the reversibility of the StARS system, which combines the alternator and starter functions, possible.
Tryggve Sthen, President of the SKF Automotive Division, commented, "This new bearing solution is a successful step in our strategy to be a partner to the automotive industry in delivering energy efficient vehicles. The Valeo StARS system is a good example of how new technology and joint development can achieve significant reductions in CO2 emissions."
The StARS Stop-Start system is currently being used in Citroen’s C2 and C3 Stop&Start models, the Smart Micro Hybrid Drive model, and the Mercedes-Benz Class A and B Blue Efficiency models.