Open vs Sealed Spherical Roller Bearing: Which Is Better for High Heat?

In high-temperature industrial environments, choosing the right bearing type is critical for reliability, safety, and service life. Spherical roller bearings are commonly used in heavy-duty machinery due to their high load capacity and self-aligning capability. However, when operating under high heat, engineers often face a key question: open vs. sealed spherical roller bearing— which is better for high heat?

Open spherical roller bearings are widely preferred in high-temperature applications. Their open design allows for better heat dissipation and the use of high-temperature lubricants, including circulating oil systems. Because there are no seals to degrade under extreme heat, open bearings can operate more reliably at elevated temperatures. This makes them suitable for steel mills, cement kilns, paper dryers, and other environments where sustained heat is unavoidable.

Another advantage of open spherical roller bearings in high-heat conditions is lubrication flexibility. Operators can adjust lubrication type, flow rate, and intervals based on operating temperature and load. Oil lubrication, in particular, helps remove heat from the bearing and flush out contaminants, significantly improving thermal stability and bearing life.

Sealed spherical roller bearings, by contrast, are designed primarily for protection against contamination rather than extreme temperature resistance. The integrated seals help keep grease inside and prevent dirt or moisture from entering. While this design reduces maintenance in normal environments, seals are typically made from elastomeric materials that have temperature limits. In high-heat conditions, seals may harden, crack, or lose effectiveness, leading to lubrication failure and premature bearing damage.

However, sealed spherical roller bearings can still be effective in moderately elevated temperatures where contamination is a greater concern than heat. In applications with fluctuating temperatures or intermittent heat exposure, high-temperature seals and special greases may provide acceptable performance. That said, their operating temperature range is generally more limited compared to open bearings.

From a maintenance perspective, open spherical roller bearings require more active lubrication management but offer greater adaptability in high-temperature environments. Sealed bearings offer convenience and lower routine maintenance but are less suitable for continuous high-heat operation.

In conclusion, when evaluating open vs. sealed spherical roller bearing for high heat, open spherical roller bearings are generally the better choice. Their superior heat dissipation, lubrication flexibility, and resistance to seal degradation make them the preferred solution for sustained high-temperature industrial applications.