FAG NJ2313-E-XL-M1A-C4 CYLINDRICAL ROLLER BEARING

This FAG cylindrical roller bearing with radial clearance C4 has been developed for applications with large thermal expansions or very tight fits. The X-life design and the increased radial load capacity make it a suitable solution for demanding heavy-duty applications.

Explanation:
• NJ: Single-row bearing with two ribs on the outer ring and one rib on the inner ring
• E: Optimized internal geometry for increased radial load capacity
• XL: X-life designation for improved contact surfaces and extended service life
• M1A: Two-piece, rib-guided brass cage
• C4: Radial clearance larger than C3, suitable for large thermal expansions and very tight fits

Features:
The combination of an outer ring with two ribs and an inner ring with one rib defines the NJ design. It enables reliable axial guidance in one direction while functioning as a non-locating (floating) bearing in the opposite direction. For applications requiring axial location in both directions, the bearing can be converted to a locating bearing by fitting an HJ locating ring (not included). The C4 radial clearance, which is larger than C3, prevents excessive internal preload in very tight fits or under pronounced thermal load variations. The two-piece, rib-guided brass cage M1A stabilizes the rolling elements and supports heat dissipation during operation. The contact surfaces optimized by X-life manufacturing technology reduce stress peaks and ensure a more even load distribution across the raceways. The separable design simplifies assembly and maintenance. The inner ring can be mounted independently on the shaft while the remaining bearing part is inserted separately into the housing.

Maintenance:
Monitoring of vibration and noise development is an important indicator of bearing condition. Unusual changes can indicate raceway damage or lubricant contamination. Bearing temperature should also be checked regularly. A temperature rise that cannot be explained by operating conditions often points to lubrication problems or an unsuitable internal clearance. The C4 clearance provides increased tolerance to thermal expansions and tight fits. Nevertheless, during commissioning it should be verified whether the selected internal clearance matches the actual installation and temperature conditions. Lubrication can be carried out with grease or oil depending on speed and temperature range. Relubrication intervals must be defined according to the actual loads and operating conditions. As this bearing is of open design, appropriate measures to protect against dust and abrasive particles must be taken during all maintenance work. The separability of the inner ring makes the rolling elements more accessible during regular inspections. A visual inspection of the raceways and rollers enables early detection of signs of fatigue, spalling or indentations before bearing performance is impaired.

Strengths:
• The C4 internal clearance compensates for large thermal expansions and is suitable for very tight fits.
• The separability of the inner ring reduces downtime for maintenance.
• The X-life design’s increased dynamic load capacity allows an extension of the nominal service life by more than 70%.

Applications:
FAG cylindrical roller bearings in C4 design are especially intended for service areas with high or fluctuating operating temperatures and tight fits. In heavy industry—for example in the steel industry, foundries, paper mills or cement works—such bearings are frequently used in gearboxes, rolling mills and rotating equipment exposed to strong temperature gradients. Industrial compressors and high-power drive systems are also typical application areas. Cold starts and load changes lead to dimensional changes that are absorbed by the C4 clearance without creating excessive preload. The M1A brass cage and X-life technology ensure consistently high performance even under recurring thermal loads. In drive trains and gearboxes of large machines, the NJ design provides reliable axial guidance of the shaft in one direction while maintaining the freedom of movement required for thermal expansions.