By replacing a solid spherical roller bearing on an exhaust gas fan with a split spherical roller bearing, a chemical plant has saved €220,000.
The solid spherical roller bearing, which had an outside diameter of 230mm, needed replacing urgently. In the past, if the bearings were worn or damaged, the customer replaced these with similar solid (unsplit) spherical roller bearings. However, every time a bearing replacement took place, this resulted in 14 hours of downtime, which cost around €280,000. This figure not only included the cost of production downtime, but also the additional costs relating to labour, alignment of the shaft, crane hire and the costs of an additional replacement bearing.
By replacing the solid spherical roller bearing with a split spherical roller bearing from Schaeffler, the chemical plant reduced downtime to just three hours, with overall costs of €60,000. The costs of additional alignment, crane hire and a replacement bearing were not required this time. The customer therefore saved around €220,000 by using split spherical roller bearings.
Replacing damaged or worn parts on heavy machinery that requires regular servicing or maintenance can be a costly problem, particularly for companies in heavy industries such as mining, quarrying, oil and gas, paper, and steel production, where the value of capital equipment and production machinery is high.
The use of split spherical roller bearings reduces the time it takes to replace bearings, particularly in areas that are difficult to access such as shafts with multiple supports. In a split bearing, the inner ring, outer ring and roller-and-cage assembly are split into two halves that are clamped together using screws. A cylindrical bore provides direct mounting onto the shaft, which means the bearings typically offer high thrust loads and dynamically compensate for any misalignment. Also, by using a split version of the bearing, many stages of the mounting and dismounting process are omitted. This means that downtimes – and any associated costs – are reduced significantly.
As the dimensions of Schaeffler’s solid and split spherical roller bearings are identical, the split versions can be mounted in the same space as their solid counterparts (including the adapter sleeve). Typical applications include belt drives, paper machines, mixing and stirring plant, conveying equipment, roll mills, converters, crushers, rotary kilns, fans, ventilators, drive and transmission shafts.
In many applications, the spherical roller bearing is mounted to the shaft in such a complex arrangement that when the bearing needs to be replaced, it is also necessary to remove all the adjacent components. This results in increased downtime and complex additional tasks such as the removal of gears, clutches and other drive units.
Schaeffler offers split spherical roller bearings for shaft diameters from 55mm up to 630mm. In most cases, the outside diameter, outer ring width and diameter of the shaft seat, match the dimensions of the standard solid spherical roller bearings, including the adapter sleeve. This means that the bearings are easily interchangeable.
For more information, www.schaeffler.co.uk