NTN NU2309EAT2X CYLINDRICAL ROLLER BEARING

Suited to high radial loads and to use as a floating 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.

NTN cylindrical roller bearings of the ULTAGE™ series represent 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, along 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: designation for NTN's ULTAGE™ series; standard envelope dimensions retained, but internal specifications optimized (increased roller diameter, length and number).
- T2X: glass-fiber reinforced polyamide cage.

Features:
These NU-type bearings are built around an outer ring with two shoulders and an inner ring without shoulders. This configuration allows the outer ring–rollers–cage assembly to be separated from the inner ring, simplifying mounting and disassembly. Axial displacement is accommodated by sliding on the seats, making these bearings a natural choice for floating bearings.

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

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

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

Key advantages:
- Increased radial load capacity within the same envelope, without modifying existing bore dimensions.
- Separable inner ring, facilitating mounting and replacement without complete shaft removal.
- Free axial movement 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 the floating bearing, combined 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.