BEARINGS FOR CORRUGATING ROLL SUPPORTS: A TECHNICAL INSIGHT
The performance of machinery depends heavily on the components that ensure smooth and precise operation. FARO BEARINGS has developed solutions that combine advanced materials, precision engineering, and thermal resilience to meet the rigorous requirements of corrugating rolls. This technical overview highlights the innovations and considerations that make these bearings essential for highperformance production lines.
FARO BEARINGS includes among its flagship products the full range of bearings designed for the most well-known models of machines that produce corrugated board.
Corrugating rolls are essential components within corrugated board production lines, a material widely used in the packaging and box industry.
To ensure efficient, high-quality production with smooth and precise rotation, FARO BEARINGS’ support bearings for corrugating rolls are characterized by:
•Longer service life. The bearing rings are made of high-quality steel combined with a fully machined centrifugally cast bronze cage.
•High Load Capacity. The bearings are designed to withstand heavy radial and axial loads generated by the corrugation process.
•Precision and Reliability. Accuracy is key to maintaining the uniformity of the flutes produced. Any defect in roll movement can lead to imperfections in the board.
•Special radial clearance. FARO BEARINGS has developed a balanced radial clearance that absorbs the natural expansion of the inner rings during machine start-up, while maintaining the correct value once operating temperature is reached.
•Heat Resistance. During the corrugating process, bearings are exposed to temperatures exceeding 200 °C. FARO BEARINGS has therefore applied a special heat treatment to the bearing rings, ensuring optimal performance under such conditions.
The proper choice of materials for the bearings, along with an efficient lubrication system, are key aspects to ensure long service life and optimal operating efficiency, avoiding costly downtime and excessive maintenance.
The Bearings
The traditional bearing application used on corrugating rolls requires the use of either two spherical roller bearings or two cylindrical roller bearings (one fixed / one floating).
The spherical roller bearing offers an extremely high load capacity relative to the d/D ratio (the series normally used is ISO 240 . . . K30-AH). Furthermore, its self-aligning property compensates for inevitable misalignments.
Problems may arise with the “floating end” bearing lubricated with grease due to the potential risk of blocking or seizing within its housing. To avoid this, a practical solution is the “mixed application” of a spherical roller bearing on the “fixed side” and a cylindrical roller bearing on the “floating side.” Since the cylindrical roller bearing is designed to allow sliding between the inner raceway and the rolling elements, this solution compensates for the axial expansion of the corrugating roll.
The required self-aligning capability can also be ensured through a spherical outer ring surface combined with a matching aligning housing ring. In most cases, the same diameter/dimensions of the spherical roller bearing can be maintained.
Thermal Insulation
With the steam temperatures currently used in modern machines and the adoption of grease lubrication, bearing operating conditions have become extremely demanding, almost at their limits.
Currently, only a few high-performance greases are available on the market that can withstand the extreme temperatures, loads, vibrations, and stability levels required by the application.
FARO BEARINGS suggests that an alternative is to improve bearing operating conditions by thermally insulating the roll’s inner bore. In principle, the method involves passing steam through a steel tube running along the length of the roll, creating an air gap between the tube and the shaft. Further improvements can be achieved by effectively insulating the steam joint from the shaft’s end face.
Conclusion
In conclusion, the efficiency of corrugating rolls in corrugated board production lines depends significantly on the quality and reliability of the bearings — the core elements that reaffirm FARO BEARINGS’ corporate mission.
For more information please visit:
www.faro-bearings.it
