It is not uncommon for cylindrical roller bearings to require modifications to meet the demands of a particular application. Heavy loads, high speeds, poor lubrication parameters, dissimilar housing/shaft materials and unique mounting conditions all may require modifications or adjustments.
When bearings are installed into a housing of one material onto the shaft made from a different material, the bearing’s design may require specific internal radial clearance for proper functionality based on its operating temperature range. These specific clearance ranges are achieved by sizing and tolerancing race and roller diameters.
Some applications are designed for another component of the application – like a gear bore – to act as the outer race. Or, to save space, the rolling elements of the bearing will actually “ride” on a hardened shaft. This situation may require a unique "under" or "over" roller diameter to achieve proper function. Once race diameters are determined, the bearing design is altered by adjusting the roller/race diameters for correct fit and operation.
When bearing lubrication is “less than ideal” due to the type of fluid used, certain characteristics can be modified to improve lubrication and smooth operation. The most common modification involves a special grinding process to give the race and roller contacts a smoother surface (super finishing). These superfinished surfaces accommodate a better lubrication film between the rollers and races.
Some applications have specific preferred load and speed conditions to maximize operation. Once these conditions are determined, the bearing loading and resultant material stresses are analyzed. Based on this analysis, the bearing can be modified to achieve maximum performance for a specific application.
Cylindrical roller bearings are not true cylinders. The race contact surfaces have a slight curvature known as the “roller crown.” The degree of this curvature can be adjusted to accommodate loads specific to the application to ensure maximal operational life. However, these modifications must be done correctly and specific to the application.
Rexnord has the ability and experience to determine when specific modifications are required, and we routinely work closely with OEMs, distributors and end users to meet their specific needs.
If you have questions about this topic or any other bearing-related issues, call (317)273-5781 or email firstname.lastname@example.org. For additional videos and demos, visit our YouTube channel.