NTN NU204EAT2X CYLINDRICAL ROLLER BEARING

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

NTN cylindrical roller bearings of the ULTAGE™ series constitute 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 dimensions as standard series, with extended maintenance intervals as a consequence.

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 are retained, but internal specifications are optimized (increased roller diameter, length and number).
- T2X: polyamide cage reinforced with glass fibers.

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, which simplifies mounting and disassembly. Axial displacement is accommodated by sliding on the seats, making these bearings a natural solution for free (floating) bearings.

The ULTAGE™ series retains the overall dimensions of standard bearings while incorporating rollers of larger diameter and in greater number. The generating profile of the rollers is optimized to limit stress concentrations at the contact ends. These internal developments result in an increased dynamic load capacity and an admissible 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 polyamide 66 cage reinforced with glass fibers 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 relubrication intervals. Shaft/housing mounting tolerances must comply with NTN recommendations to maintain the residual clearance within the permissible range. During operation, monitor temperature, vibration and noise. The allowable misalignment is 1/500 mm/mm.

Key benefits :
- Increased radial load capacity within 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 components of the assembly.
- Extended maintenance intervals thanks to the technical improvements of the ULTAGE™ series.

Applications :
These NTN bearings are used as a free bearing, paired with a fixed bearing (type NJ or NUP) to form a complete arrangement. They are suitable for industrial drive trains, reducers with long shafts, 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.