Rencol to exhibit at USA Vehicle Dynamics Expo 2007

Electric power-assisted steering (EPAS), which is fast becoming the preferred method of power assisted steering in Europe and Japan, is a typical application for tolerance rings. They are designed-in to allow slip between the gear wheel and drive shaft at a pre-determined torque level. This functionality protects the gear teeth and motor from damage during back-driven shock loads, such as when the wheel accidentally hits the edge of a curb.

Chris Needes, Automotive Product Manager at Rencol, says: "Rencol's tolerance rings are used on both rack- and column-mounted electric power steering systems in production line models for manufacturers including Audi, BMW, Citroen, Honda, Mitsubishi, Seat, Toyota and Volkswagen."

The European automotive industry is also experiencing growing demand for convenience and safety functions, such as ABS, ESP or ACC. These sophisticated automotive systems require the detection of rotational movement, where discrete angular positions are essential. The detection of steering angle, pedal and gear lever detection and positions of valves in motor management and climate control units have high demands on the sensor devices, and frequently incorporate magnets manufactured from powdered metal.

Needes explains: "When the magnet assembly is fitted with a tolerance ring, the fitting force can be accurately determined by the design of the ring. The arrangement no longer depends heavily on component tolerances, which eliminates the risk of damage and, thanks to the resilient nature of Rencol's tolerance rings, provides the magnet sensors with a useful degree of protection against vibration and shock. Another key benefit of using a tolerance ring is that the poles of the magnet can be aligned after assembly."

During the show, visitors to the Rencol/USA Tolerance Rings stand will have the opportunity to see first-hand an impressive array of automotive applications already employing tolerance rings, as well as speaking to engineers about their project needs.