FAG NJ315-E-XL-M1-C4 0192284730040 CYLINDRICAL ROLLER BEARINGS

In applications with high temperatures and heavy loads, the choice of radial clearance is critical for the service life of the rolling bearing. This FAG version features a C4 radial clearance specifically designed for large thermal expansions and very tight fits.

Explanation:
• NJ: Two ribs on the outer ring, one rib on the inner ring; axial guidance in one direction, floating bearing function in the opposite direction
• E: Increased radial load capacity through optimized internal geometry
• XL: FAG/INA X-life designation for higher service life and increased dynamic load ratings thanks to highly precise contact surfaces
• M1: Two-piece roller-guided brass cage for improved heat dissipation
• C4: Increased internal radial clearance above C3 level, suitable for large thermal expansions and very tight fits

Features:
The NJ series is based on a separable design: the inner ring can be mounted separately from the assembly of outer ring and rolling elements. This allows both assemblies to be installed independently. The inner ring can be mounted on the shaft first, which is a significant advantage particularly for shrink fits.
The E version uses an optimized internal geometry to distribute loads more evenly over the raceways. In combination with X-life technology, the bearings benefit from an improved surface quality that reduces friction, lowers heat generation and places less stress on the lubricant. The result is higher basic dynamic load ratings and a longer nominal life compared to previous generations.
The C4 radial clearance is greater than the C3 clearance, which in turn is larger than the standard CN clearance. It was specifically developed for applications with large temperature differentials or heavy press fits. This preserves sufficient deformation allowance so that no harmful internal preload occurs at operating temperature. The M1 brass cage complements this concept by providing stable roller guidance and efficient heat removal.

Maintenance:
Temperature monitoring has the highest priority in applications with C4 radial clearance. Unusually high temperatures can indicate excessive fit stresses, aged lubricants or inadequate lubricant supply. Regular temperature checks help detect deviations early and avoid bearing damage.
The type and quantity of lubricant must be adapted to the actual operating temperatures. Although the M1 brass cage reduces internal bearing heat generation, it does not replace proper relubrication according to real operating conditions.
In addition, vibration analysis and noise checks should be part of preventive maintenance. Even small changes in the vibration spectrum should be investigated. As this is an open rolling bearing, the bearing environment must be reliably protected from particles, dust and moisture.

Strengths:
• C4 radial clearance prevents harmful internal preloads in tight fits and under large temperature fluctuations
• Higher load capacity allows accommodation of larger loads without changing the design envelope
• Separable design reduces downtime during maintenance and servicing
• M1 brass cage improves heat dissipation and is particularly suitable for high-temperature applications

Applications:
The C4 version is especially suitable for heavy industry. Rolling mills, annealing furnaces, heat treatment plants and high-pressure compressors are typical applications. These plants experience alternating heating and cooling cycles, which continuously stress the radial clearance due to thermal expansion. The C4 clearance reliably compensates for these changes without unduly stressing the bearing.
High-power gearboxes as well as drive and transmission shafts in high-temperature environments also benefit from this increased radial clearance, especially where very tight fit tolerances are used. Under these conditions, the E version reduces raceway stress through optimized load distribution, while X-life quality enables longer service intervals and extended maintenance periods.