FAG NU221-E-XL-M1-C4 0192419760040 CYLINDRICAL ROLLER BEARINGS

This FAG cylindrical roller bearing offers high radial load capacity with standardized dimensions. It allows free axial compensation of the shaft and is designed for use at elevated operating temperatures.

Explanation:
• NU: Outer ring with two flanges, inner ring without flange; floating (non-locating) bearing design allowing axial shaft displacement in both directions
• E: Optimized internal geometry for higher radial load capacity compared to the standard design
• XL: X-life technology; improved surface quality, up to 18 % higher dynamic load ratings and more than 70 % longer nominal service life
• M1: Two-piece brass cage, hot-riveted and roller-guided
• C4: Increased radial clearance above C3 level; suitable for press fits and applications with large thermal expansion

Features:
The NU design allows a separable inner ring. During disassembly this can remain on the shaft while the outer ring, rollers and cage stay in the housing. This simplifies maintenance and dismantling operations, since when removing the shaft no elaborate bearing extraction is required.
The E design features optimized contact profiles that distribute loads more evenly and thus increase radial load-carrying capacity with identical installation dimensions. X-life technology goes a step further: refined raceway surfaces reduce friction and heat generation. Under identical operating conditions this significantly extends bearing life.
The M1 brass cage is assembled by hot riveting and is guided on the rollers. It retains its mechanical properties even at high temperatures. The increased radial clearance C4 compensates for strong thermal expansions and tight fits that could reduce the operating internal clearance in service.

Maintenance:
As an open rolling bearing without an integrated seal, the choice of lubricant, the amount of lubricant and the maintenance intervals are crucial for operational safety. Overgreasing increases operating temperature due to churning, while insufficient lubrication accelerates wear. For high-temperature applications, synthetic-based greases or greases with complex soaps are recommended.
Operating temperature is the most important monitoring parameter. Unusual vibrations or sounds such as knocking, whistling or irregular running noises require immediate inspection. Before assembly, rolling elements and raceways should be carefully cleaned to avoid contamination. Thanks to the separable inner ring, rollers, cage and raceways can be inspected individually. If there are signs of pitting, spalling or deformation, the bearing must be replaced.

Strengths:
• Separable inner ring reduces maintenance effort and downtime
• X-life technology extends bearing life and increases maintenance intervals
• M1 brass cage offers high temperature resistance in applications where polymer cages reach their limits
• C4 radial clearance prevents excessive internal stresses in operation and increases operational safety under strong temperature gradients
• Reduced friction minimizes internal heating and relieves the lubricant

Applications:
As a floating (non-locating) bearing, this FAG cylindrical roller bearing is suitable for applications with predominantly radial loads where temperature-induced axial changes in shaft length must be compensated. In medium and high power electric motors it is often used on the non-locating side in combination with a locating bearing. The same applies to industrial gearboxes, centrifugal pumps and compressors.
The increased radial clearance C4 and the M1 brass cage are specifically designed for high operating temperatures and tight fits on large-diameter shafts. Typical application areas include the steel industry, cement industry and chemical industry, for example in rolling mills, rotary kilns, industrial fans, crushers, extruders and mixers.