As of December 2011 Johannes Hübner GmbH, based in Gießen, Germany, will be introducing a worldwide first to the market in the form of its looper encoder ALS 40 K. Thanks to unique design characteristics this special encoder offers twice to three times the length of service life usual to date.
In hot rolling mills loopers have two tasks to fulfil: they measure and compensate for any imbalance in the rolling process by altering the loop length. And, in addition, they measure the strip tension and keep it as constant as possible. From the point of view of productivity and product quality these are extremely important processes.
The rotational angle of the looper is measured by an encoder. However, because the maximum angle of the looper is 45 degrees the encoder bearings are subjected to one-sided loads, which results in insufficient lubrication of the bearings. In addition, the encoder is subject to high levels of shock and temperature loads, causing wear as a result. The standard encoders deployed to date have never been able to guarantee the length of service life demanded by customers. Unplanned stoppages of the complete mill train repeatedly led to losses in production.
What does the new looper encoder ALS 40 K have to offer?
With its ALS 40 K Johannes Hübner GmbH has developed a special loop encoder, which offers a significantly longer service life. It boasts specially dimensioned bearings with a 40% higher dynamic rating and a special radial shaft sealing ring with an additional protective lip. To guarantee a long service life the bearings were not primarily designed for high speeds, but rather to withstand high shock loads up to 450 g. In addition, the encoders are equipped with a strengthened shaft made of high-tensile, stainless steel. They are designed with IP66/IP67 degree of protection and have an approved operating temperature range of up to 100 degrees Celsius. The new encoder delivers a guaranteed high quality signal and high levels of availability while operating under the typically high temperature and shock loads to which loopers are subject.
Market demand is already huge according to Thomas Brandenburger, a member of the Hübner management. "Since presenting the ALS 40 K at the International Metallurgical Technology Trade Fair in Düsseldorf at the end of June, we have received a growing number of enquiries wishing to know when the encoder will be available for delivery. That will be the case as of December 2011."
More key data about the Looper encoder ALS 40 K
- Weight: approx. 3.5 kg
- Design: flange (B5) or flange/foot (B35)
- Shaft diameter: 11 or 14 mm
- Supply voltage 12 V to 30 V DC
- Resolution: 13 bit single turn (8192 steps per revolution)
- Connection technology: terminal strip, plug or cable
- Interfaces: SSI (others on request)
- Standard colour: RAL 7030 (stone grey)
The bearings of a classic encoder in comparison with the new ALS 40 K from Johannes Huebner GmbH. The Hübner solution has a 40% higher dynamic rating and is shock resistant up to 450 g.