NTN NU206EAT2XC3 CYLINDRICAL ROLLER BEARING

Suited to high radial loads and for use as a free or fixed bearing, cylindrical roller bearings offer low friction and good stiffness. They are available in a wide range of designs and variants tailored to specific conditions: heat, axial displacement, operating noise, speed, capacity, etc.

The NTN ULTAGE™ series 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.

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

Features :
NTN NU-type cylindrical roller bearings are the reference for free bearing applications. The outer ring has two shoulders that retain the rollers and 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 same 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% in oil lubrication compared with equivalent standard references.

The polyamide 66 cage reinforced with glass fiber (T2X) contributes to the assembly's lightness and tolerates common mechanical stresses. It exhibits good resistance to heat and wear.

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

Maintenance :
Bearings of this NTN 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 lower-speed or less accessible applications. Extreme-pressure additives of type S or P should be avoided with the T2X polyamide cage, particularly at elevated operating temperatures.

As with any open bearing, this series must be protected from contamination by seals or baffles fitted in the housing. During disassembly for inspection, the condition of the raceways, the rollers' surface and the cage integrity should be checked. Any sign of pitting, spalling or deformation requires replacement of the affected component.

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

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

In power transmission, they equip industrial electric motors, speed reducers and general gearboxes. Their 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 when the assembly must manage the expansion of a long horizontal shaft.

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