NTN NU309EAT2X CYLINDRICAL ROLLER BEARING

Suited to high radial loads and for use as a non-locating or locating bearing, cylindrical roller bearings offer low friction and good rigidity. They are available in a wide range of models and variants tailored to specific contexts: temperature, axial displacement, operating noise, speed, capacity, etc.

NTN cylindrical roller bearings of the ULTAGE™ series represent a reference 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, together with extended maintenance intervals.

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

Features:
These NU-type bearings are built around an outer ring with two shoulders and an inner ring without shoulders. This configuration allows separation of the outer ring–rollers–cage assembly from the inner ring, simplifying mounting and dismounting. Axial displacement is accommodated by sliding on the seating surfaces, making these bearings a natural solution for non-locating bearings.

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

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

Maintenance:
Open bearing: lubrication (grease or oil) must be adapted to service conditions. The ULTAGE™ series benefits from extended relubrication intervals. Shaft/housing mounting tolerances must meet NTN recommendations to maintain the residual clearance within the admissible range. In operation, monitor temperature, vibrations and noise. Permissible misalignment is 1/500 mm/mm.

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

Applications:
These NTN bearings are used as non-locating bearings, paired with a locating bearing (type NJ or NUP) to form a complete arrangement. They are suitable for industrial drives, long-shaft 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 make them relevant for equipment with variable loads or frequent starts.