Voith sells high-performance drive to Voestalpine

The company’s Gearlink consists of two high-performance universal joint shafts and two curved-tooth coupling shafts and was put into operation in what Voith claims is the world’s most efficient and powerful rolling mill main drive at the end of 2013. Gearlink, claims Voith, works with very small roller diameters, allowing operators to expand their product portfolio with further deformation processes, enabling them to increase productivity while improving quality.

According to Voith, the modernisation of the rolling mill has made it possible to roll significantly tougher – and higher quality – grades of steel with a width of up to 4.2 m. The two main drive shafts each transmit torques of 7500 kNm without fatigue, based on a minimum roller diameter of 980 mm – something not previously been achieved in rolling mill construction. In contrast to conventional slipper spindles, modern universal joint crosses minimise play in the drive. Power loss as a result of friction and the environmental impact of lubricants are also kept to a minimum, claims Voith.

The development of the Gearlink concept was a result of close co-operation between
Voith, Voestalpine Grobblech and BUMA Engineering.

Voith said that the Voestalpine Grobblech mill uses universal joints with a rotational diameter of 1300mm. The fully forged CHF 1300.8 universal joint shafts are all of varying length, which results in the shafts being offset on the roller side. This means that shafts of equal size can also be used on the roller side regardless of the 980mm roller diameter.

The GearLink element (a curved-tooth coupling shaft) guarantees a connection between the offset shafts and the coupling sleeves. “This reduces the load of bending moments on the roll journals to the greatest extent possible and allows the axial Continuous Variable Crown displacement of the rollers,” said Voith, adding that the coupling shaft also provides an axial emergency outlet in case of oblique fractures of the rollers.