Spherical roller bearings are a special class of roller bearing, counted on in the most difficult and demanding applications. Increasingly, engineers and equipment operators look to spherical designs to deliver special advantages, particularly in markets where machinery is pushed to its limits.
These self-aligning, double-row radial bearings have an inner and outer ring and “barrel”-shaped rollers separated by a cage, allowing for greater load-carrying capacity and dynamic misalignment ability, compared to other common bearing types, including tapered and cylindrical.
Most bearings are intended to carry either a radial load or axial (thrust) load. Spherical roller bearings, however, must tolerate combined loads where moderate to high radial and axial forces are encountered.
These bearings are also used where contamination, shock and vibration are constant challenges. Their robust design and higher tolerance for misalignment are especially suited to heavy machines, industrial equipment and large gearboxes.
Higher performance bearings
The constant aim of heavy industry is to find roller bearings that offer greater reliability at higher operating temperatures, loading capacities and speeds. As oil producers move farther from shore, as mills commission bigger and faster machines, and as mining operations grow more rigorous, the importance of bearing performance and durability is amplified.
Today, companies seek new operational efficiencies―measurable gains in productivity and profitability tied to improvements of existing assets. In response, “high-performance” bearings are a continual focus for most bearing manufacturers.
High performance, relative to roller bearings, can be described as an increase in service life, which allows the potential to downsize other part selections while maintaining system performance. High performance also is described as a reduction in heat generation―bearings that function at lower temperatures create the potential for increased efficiency and speeds of operation.
Recent improvements
While the basic functionality of today’s spherical roller bearings remains fundamentally similar to that introduced in the 1950s, the escalating needs of the industry continue to drive improvement efforts. These activities often include optimizing internal geometries to maximize roller length and dynamic capacity, improving surface finishes to support higher ratings and increased lubrication lambda ratios, strengthening cage design to reduce wear, enhancing lubrication flow to rolling contact surfaces, and improving heat dissipation.
The common goal for manufacturers is to deliver a class of higher-performing spherical roller bearings that provide greater load-carrying capability, reduced operating temperature and extended service life. Significantly, a 5°C decrease in machine operating temperature can equal a 9% increase in bearing life. It is this consistently cooler performance that can mean a lower cost of machine ownership to a company.
If you haven’t yet considered a spherical roller bearing for your demanding application or difficult environment, take another look at all the improvements—and advantages—the industry has to offer.
Timken
www.timken.com/spherical
