NTN NU314EAT2XC3 CYLINDRICAL ROLLER BEARING

Suitable for high radial loads and for use as non-locating or locating bearings, cylindrical roller bearings offer low friction and good rigidity. They are available in a wide range of designs and variants addressing specific conditions: heat, axial displacement, operating noise, speed, capacity, etc.

The ULTAGE™ series from NTN groups cylindrical roller bearings whose internal specifications have been optimized to improve performance, extend service life and reduce maintenance intervals. The separability of the inner ring simplifies mounting and facilitates periodic inspections.

Explanation:
- NU: single row of rollers, outer ring with two shoulders, inner ring without shoulder. The outer ring, rollers and cage assembly is separable from the inner ring; for non-locating bearing use only.
- EA: denotes NTN's ULTAGE™ series; rollers of larger diameter and in greater number than a standard type, optimized roller generatrix profile, increased load capacity at identical envelope dimensions.
- T2X: glass fibre reinforced polyamide 66 cage; lightweight, wear-resistant, economical, promotes ease of assembly.
- C3: internal radial clearance greater than normal clearance; compensates for tight fits and thermal expansions in service.

Characteristics:
NTN NU-type cylindrical roller bearings are the reference for non-locating bearing applications. The outer ring has two shoulders that retain the rollers and the cage, while the inner ring, without shoulder, allows free axial displacement in both directions. This separability simplifies mounting on long shafts and permits thermal expansion without imposing axial constraint on the bearing.

The EA suffix identifies the ULTAGE™ series: the diameter, length and number of rollers have been increased compared with the standard type, while retaining the external envelope dimensions. The roller generatrix profile is optimized to better distribute contact stresses and limit pressure concentrations at the edges. The permissible speed increases by 20% under oil lubrication compared with equivalent standard types.

The glass fibre reinforced polyamide 66 cage (T2X) contributes to the overall lightness and tolerates common mechanical loads. It offers good resistance to heat and wear.

The C3 internal clearance, greater than normal, compensates for tight fits and temperature rises in operation, thus reducing the risk of excessive internal preload.

Maintenance:
Bearings of this NTN cylindrical roller series are supplied without grease: lubricant selection and application are the operator's responsibility. Oil lubrication is recommended for high speeds, grease lubrication being suitable for slower or less accessible applications. Extreme-pressure additives of type S or P should be avoided with the T2X polyamide cage, particularly when operating temperature is high.

As with any open bearing, this series must be protected from contamination by seals or baffles fitted in the housing. When disassembling for inspection, it is advisable to check the condition of the raceways, the roller surfaces and the integrity of the cage. Any sign of pitting, flaking or deformation requires replacement of the affected component.

Key advantages:
- Increased radial load capacity at constant envelope dimensions: replacement of a standard type without modifying the housing.
- Free axial displacement: no parasitic axial load generated on the assembly in case of thermal expansion.
- Separable inner ring: independent mounting on a long shaft without risk of damage.
- Extended maintenance intervals thanks to ULTAGE™ internal specifications, reducing stoppages on production lines.
- Permissible speed increased by 20% (oil lubrication) compared with the equivalent standard type.
- C3 clearance suited to pronounced thermal cycles and frequent starts, without risk of excessive preload.

Applications:
NTN NU-type cylindrical roller bearings are structurally intended for non-locating positions, i.e. mounting points where the shaft must be free to move axially. This requirement is systematically encountered in two-bearing arrangements, where one bearing is fixed and the other free, to absorb dimensional variations due to temperature or manufacturing tolerances.

In power transmission mechanics, they equip industrial electric motors, speed reducers and general transmission gearboxes. The ability to run at high speed with good rotational accuracy makes them suitable for the high-speed shafts of these machines. Industrial pumps and process fans are also common applications, particularly where the mounting requires managing the expansion of a long horizontal shaft.

The C3 internal clearance makes them particularly relevant for equipment subject to frequent starts or significant thermal variations, such as construction machinery, cranes or production machines operating in alternating cycles.