Loopers are normally used to control the tension of the metal strip between roll stands. The rotational angle of the looper is measured by a feedback encoder designed to meet the special demands to which it is exposed. The setting angle of approx. only 45° results in a partial load on the encoder bearings in conjunction with insufficient bearing lubrication. The encoder is subject to high levels of shock and temperature loads as well as oil/cooling emulsions/water at the place of installation. The standard encoders deployed to date by the customer have been unable to achieve the required service life.
For this application Johannes Hübner Giessen developed a special looper encoder, which boasts a considerably longer service life thanks to especially designed-in features. It has oversized bearings with the dynamic load rating increased by 40 % as well as a special radial shaft sealing ring with additional protective lip. To guarantee the best-possible signal quality the bearings are not primarily designed for high speeds, but more for high shock loads up to 450 g. The min. degree of protection is IP66 / IP67 with an operating temperature range of up to 100 °C.