Bearing specialist NKE Austria GmbH has supplied a special cylindrical roller bearing with an outer diameter of 3.3 m for the application in a three-roller planetary rolling mill.
The German company ESW Röhrenwerke manufactures seamless steel pipes that are used worldwide as structural tubes in machinery, steel constructions, in the automotive industry, as boiler tubes and as pipelines and supply lines for combustible liquids, gases and oil worldwide. 70,000 tonnes of steel pipes are produced each year in the three-roller planetary rolling mill process. This high-reduction technology at the world's unique planetary rolling mill has made ESW one of the leading producers of seamless hot rolled steel pipes in particularly high qualities. The steel pipes are available in outer diameters of 70 mm to 244.5 mm and with a wall thickness of between 7.1 mm and 60 mm. Depending on the application and customer requirements, grades ranging from plain carbon steel to high alloy steel are processed.
To manufacture the pipes, up to 2 m long steel billets are heated up to rolling temperature in a rotary hearth furnace. After an initial hot rolling stage in the hollow block cross rolling mill, the hollow blocks are transported to the three-roller planetary rolling mill for the second stage of the forming process. Three rollers form the hollow block into a tube using a mandrel bar. While each roller rotates around its own axis, all three rollers also circulate around the rolled steel like planets. In the third stage of forming, the steel is then rolled out into finished pipes. The subsequent manufacturing steps are slow cooling, the subdivision into cooling bed lengths and adjustment of the pipes to ensure they are straight.
An essential component for the three-roller planetary rolling mill process is a large bearing that acts as the front support for the rolling head assembly. As ESW Röhrenwerke owns only one rolling mill, failure of the bearing presents a particularly high risk. Therefore a regular replacement of the bearing is required. When it became necessary to replace the bearing recently, ESW Röhrenwerke opted for a special bearing from NKE. The special cylindrical roller bearing with a solid steel cage has an outer diameter of 3.3 m and weighs 2.2 tonnes. The large bearing will be loaded with a supporting force of 76.3 tonnes and operates at a speed of 125 rpm; the supported rotating mass is around 200 tonnes. The oil lubrication is very low at 10 l/min. The special bearing has a service life of between six and eight years.
ESW Röhrenwerke already had very good experience in the past with NKE in terms of product quality. The critical factor in the decision to go with NKE was the fast availability of the large-size bearing. "NKE is a competent and reliable partner in bearing technology. The short lead times in the production of large-size bearings for our planetary inclined rolling mill was a major factor behind our decision on this project," explains Lothar Schmitz, Head of Maintenance and Engineering at ESW.
Alongside large bearings for the rolling mill industry, NKE also develops customised special bearings for other high end applications. Examples include bearings for use in tidal current power stations, wind turbines and mining machinery.
About NKE Austria:
NKE Austria GmbH is a bearing manufacturer headquartered in Steyr, Austria. Founded in 1996 by a group of senior staff members of former company Steyr Wälzlager, NKE produces standard and special bearings for all industrial applications. NKE's core functions - engineering, product development, final processing of components, assembly, quality assurance, logistics, and sales and marketing - are centralised at its Steyr headquarters. The factory in Steyr is certified to ISO 9001:2008, ISO 14001:2004 and OHSAS 18001. Its wide range of standard bearings are either available from stock or on short production lead-times. NKE also provides tailored products and solutions. In addition to product development and application engineering NKE provides a full range of technical services, consulting, documentation and training. NKE's products are distributed through 17 international representative offices and more than 240 distribution outlets in 60 countries.
Contact in the USA:
NKE AUSTRIA GmbH, US representative office
Mr. Dick Scott
20 Barney Road, P.O. Box 5255
Clifton Park, New York 12065
Tel: 518 371 5759
NKE AUSTRIA GmbH
Janet Mo, Marketing
Im Stadtgut C4
A-4407 Steyr, Austria
Tel: +43 7252 86667 345
Fax: +43 7252 86667 59
PO Box 11 40
D-82133 Olching, Germany
Tel: +49 (0)8142 44 82 301
Fax: +49 (0)8142 44 82 302