FAG NJ2311-E-XL-M1A-C4 CYLINDRICAL ROLLER BEARING

This FAG cylindrical roller bearing with radial internal clearance C4 has been designed for applications with strong 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 longer service life
• M1A: Two-piece brass cage, flange-guided
• C4: Radial internal clearance greater than C3, suitable for strong 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 provides reliable axial guidance in one direction while allowing use as a non-locating bearing in the opposite direction. For applications requiring axial guidance in both directions, the bearing can be converted into a locating bearing by fitting an HJ angle ring (not included). The radial clearance C4, which is larger than C3, prevents excessive internal preload with very tight fits or pronounced thermal load cycles. The two-piece, flange-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 uniform load distribution on the raceways. The separable design facilitates assembly and maintenance. The inner ring can be mounted independently onto the shaft, while the remaining part of the bearing is inserted separately into the housing.

Maintenance:
Monitoring vibrations and noise emission is an important indicator of bearing condition. Unusual changes can indicate raceway damage or lubricant contamination. Bearing temperature should also be regularly monitored. A temperature rise that cannot be explained by the operating conditions often indicates lubrication problems or an inappropriate bearing clearance. The C4 clearance provides increased tolerance to thermal expansions and tight fits. Nevertheless, during commissioning it should be verified whether the chosen bearing clearance corresponds to the actual mounting and temperature conditions. Lubrication can be with grease or oil depending on speed and temperature range. Relubrication intervals should be defined according to actual loads and operating conditions. As this bearing is open, appropriate measures to protect against dust and abrasive particles must be taken during all maintenance work. Because the inner ring is separable, the rolling elements are more accessible during routine inspections. A visual inspection of the raceways and rollers enables early detection of signs of fatigue, spalling or indentations before the bearing's function is impaired.

Strengths:
• The C4 bearing clearance compensates for strong thermal expansions and is suitable for very tight fits.
• The separability of the inner ring reduces downtime during maintenance.
• The increased dynamic load capacity provided by the X-life design 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 plants, such bearings are frequently used in gearboxes, rolling mills and rotating equipment that are exposed to strong temperature gradients. Industrial compressors and high-power drive systems are also typical application areas. Cold starts and load changes there lead to dimensional changes that are absorbed by the C4 clearance without causing excessive preload. The M1A brass cage and the X-life technology ensure consistently high performance even under recurring thermal loads. In mechanical drivetrains 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.