NTN NU310EAT2X CYLINDRICAL ROLLER BEARING

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

NTN cylindrical roller bearings of the ULTAGE™ series constitute a benchmark solution for applications with high radial loads and sustained rotational speeds. The optimized internal design of this range provides increased load capacity within the same envelope as standard series, with extended maintenance intervals as a result.

Decoding:
- NU: single-row bearing with two shoulders on the outer ring and none on the inner ring; separable inner ring.
- EA: designates NTN's ULTAGE™ series; standard envelope dimensions retained, but internal specifications optimized (increased roller diameter, length and count).
- T2X: cage in glass-fiber reinforced polyamide.

Features:
These NU-type bearings are built around an outer ring with two shoulders and no shoulder on the inner ring. This configuration allows separation of the outer ring–rollers–cage assembly from the inner ring, simplifying mounting and dismounting. Axial displacement occurs by sliding on the seating surfaces, making these bearings a natural solution for floating bearings.

The ULTAGE™ series retains the envelope dimensions of standard bearings while incorporating larger-diameter rollers in greater numbers. The roller generatrix profile is optimized to limit stress concentrations at the ends of the contact. These internal improvements result in increased dynamic load capacity and an allowable speed improved by 20% compared with the standard when lubricated with oil. ULTAGE™ type rings are not interchangeable with standard series rings due to a different inscribed circle diameter.

The glass-fiber reinforced polyamide 66 cage offers good mechanical strength, heat resistance and low wear. This material also provides some flexibility during assembly, particularly useful on constrained geometries.

Maintenance:
Open bearing: lubrication (grease or oil) must be adapted to service conditions. The ULTAGE™ series benefits from extended re-greasing intervals. Shaft/housing mounting tolerances must comply with NTN recommendations to keep the residual clearance within the acceptable range. During operation, monitor temperature, vibration and noise. The allowable misalignment is 1/500 mm/mm.

Key advantages:
- Increased radial load capacity in the same envelope, without modification of existing bore dimensions.
- Separable inner ring, facilitating mounting and replacement without full removal of the shaft.
- Free axial displacement absorbing thermal expansions without imposing stress on other assembly components.
- Extended maintenance intervals thanks to the technical improvements of the ULTAGE™ series.

Applications:
These NTN bearings are used as floating bearings, paired with a fixed bearing (type NJ or NUP) to form a complete arrangement. They are suitable for industrial drives, long-shaft gear reducers, gearboxes, electric motors and motor-pump units, wherever the shaft is subject to thermal expansion or axial displacement. The robustness of the ULTAGE™ profile and the polyamide cage also makes them relevant for equipment with variable loads or frequent starts.