FAG NJ2306-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 brass cage, rim-guided
• C4: Radial clearance greater 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 floating bearing in the opposite direction. For applications requiring axial guidance in both directions, the bearing can be converted to a fixed bearing by fitting an HJ locating ring (not included). The radial clearance C4, which is larger than C3, prevents excessive internal preload in very tight fits or under pronounced thermal load cycles. The two-piece, rim-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 on the shaft independently, while the remaining bearing part is installed separately into the housing.

Maintenance:
Monitoring vibration and noise 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 indicates lubrication problems or an unsuitable bearing clearance. The C4 clearance provides increased tolerance to thermal expansions and tight fits. Nevertheless, during commissioning it should be checked whether the selected clearance corresponds to the actual installation and temperature conditions. Lubrication can be provided with grease or oil depending on speed and temperature range. Re-lubrication intervals should be determined according to the 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 easily accessible during routine inspections. A visual inspection of the raceways and rollers allows early detection of fatigue signs, spalling or indentations before bearing function is impaired.

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

Applications:
FAG cylindrical roller bearings in C4 design are particularly intended for operating conditions with high or fluctuating temperatures and tight fits. In heavy industry, for example in the steel industry, in foundries, paper mills or cement plants, 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 there lead to dimensional changes that are accommodated by the C4 clearance without producing excessive preload. The M1A brass cage and 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 at the same time preserving the freedom of movement required for thermal expansion.