FAG NJ318-E-XL-TVP2-C4 CYLINDRICAL ROLLER BEARING

These FAG cylindrical roller bearings of the X-life series were designed for applications with large thermal expansions or very tight fits. The increased load capacity, the polyamide cage and the increased radial clearance C4 meet the demands of challenging industrial operating conditions.

Explanation:
• NJ: single-row bearing, outer ring with two flanges, inner ring with one flange; high radial load capacity and accommodation of axial loads in one direction; can be combined with an HJ-locating ring for axial location in both directions
• E: increased load capacity through optimized internal geometry
• XL: X-life designation; on average 18 % higher dynamic basic load ratings and over 70 % longer nominal life
• TVP2: solid cage made of glass-fiber-reinforced PA66 polyamide; reduced weight and lower inertia; maximum operating temperature +120 °C
• C4: larger internal radial clearance than C3; suitable for large thermal expansions and very tight fits

Features:
The C4 radial clearance is larger than the C3 clearance and is designed for applications with large temperature fluctuations or very tight fits. The additional clearance reserve prevents excessive internal preload, which under demanding operating conditions could shorten the bearing life. The separable design allows the inner ring to be left on the shaft during removal and at the same time simplifies assembly, since the bearing rings can be heated and mounted separately. The NJ design provides axial guidance in one direction. High radial loads and axial loads in one direction are accommodated, while the bearing acts as a floating bearing in the opposite direction. By using an HJ-locating ring (available separately), it can be converted into a fixed bearing without modifications to the housing. X-life quality is based on optimized raceway surfaces, which reduce stress peaks and decrease internal friction. The glass-fiber-reinforced PA66 polyamide cage contributes to the reduction of rotating mass and is designed for service temperatures up to +120 °C.

Maintenance:
As there is no integrated sealing, protection against contamination depends entirely on the housing design and the configuration of the mechanical system. The lubricant must be selected according to the operating temperatures, which in applications typical for C4 clearance may be elevated (circulating oil or grease). The TVP2 cage imposes an absolute temperature limit of +120 °C and requires the use of a compatible lubricant. During operation, temperature, noise emission and vibrations should be monitored. Deviations in any of these parameters usually indicate contamination, raceway wear or lubricant deterioration. Regular monitoring of the remaining bearing clearance enables early detection of wear or excessive preload.

Strengths:
• C4 radial clearance: Prevents excessive internal preload in applications with large thermal expansions or very tight fits
• Separable design: Reduces downtime during maintenance as well as during assembly and disassembly
• Extended service life (X-life): The higher nominal life reduces total operating costs
• Increased load capacity (E): Accommodates higher loads with unchanged mounting dimensions
• TVP2 polyamide cage: Reduces rotating mass and improves responsiveness under dynamic load changes
• Modularity with HJ-locating ring: Enables conversion from a floating bearing to a fixed bearing and reduces the number of bearing references to manage

Applications:
The C4 radial clearance makes this bearing particularly suited to industries with pronounced temperature differences in operation, such as the steel industry, cement plants, the glass industry, mining as well as drying and furnace plants. High-performance electric motors with strong thermal load cycles and heavy industry installations are typical areas of application. In practice, gearboxes and mechanical drive systems operating in high-temperature environments particularly benefit from the additional clearance reserve, as it prevents shaft seizure during temperature increases. The separable design eases maintenance of rolling mill cylinders, compressors or shafts of rotary kilns, where full disassembly of the bearing would involve significant operational effort. Furthermore, the X-life properties allow extended maintenance intervals, which is particularly advantageous for hard-to-access installations or long shutdown periods.