Electric power steering system has nylon resin worm wheel.(Automotive Materials)

Automotive systems maker ZF Lenksysteme of Germany is the first company to use a plastic gear wheel in electric power steering units now being fitted to medium-sized passenger cars such as the new Golf, Touran by Volkswagen, and the Audi A3. A plastic worm wheel driven by a power-assistance servo-motor is made from Ultramid A4H, a nylon resin from BASF Corp., Mount Olive, N.J. The plastic must retain good tribological properties at extremes of temperature and in contact with a wide variety of lubricants. [ILLUSTRATION OMITTED] Electric power steering is expected to eventually ...