NACHI NUP228E Cylindrical Roller Bearing

NACHI NUP228E Cylindrical Roller Bearing

The NACHI NUP228E is a precision cylindrical roller bearing (NUP – Inner Ring One Integral Rib + Loose Rib) designed for high radial load capacity at moderate to high speeds. With a bore diameter of 140 mm, outer diameter of 250 mm, and a width of 42 mm, this bearing conforms to ISO dimension standards and is a direct interchange for equivalent cylindrical roller bearings from other manufacturers.

Design & Construction

Manufactured by NACHI – one of Japan’s leading bearing producers – the NUP228E is precision-ground from high-carbon chromium bearing steel (AISI 52100 / JIS SUJ2), heat-treated to achieve optimum hardness and fatigue resistance. The line contact between rollers and raceways provides a much larger contact area than ball bearings of the same size, resulting in substantially higher radial load capacity. The NUP design features an inner ring with one integral rib and one loose (removable) rib, combined with an outer ring with two ribs. This configuration can carry radial loads and limited axial loads in both directions, while the loose rib simplifies mounting. This is an enhanced capacity (E) variant featuring an optimised roller complement and modified internal geometry, providing significantly higher dynamic and static load ratings compared to the standard version. As a double-row cylindrical roller bearing, it provides substantially higher radial load capacity and increased rigidity compared to single-row designs, making it particularly suitable for heavy-duty applications.

Performance

Rated for a basic dynamic load capacity of 395.0 kN and a static load capacity of 515.0 kN, this bearing delivers exceptional radial load-carrying ability and long calculated service life under correct operating conditions. Permissible speeds reach 2,200 rpm with grease lubrication and 2,600 rpm with oil lubrication. Cylindrical roller bearings are inherently separable – the inner ring with roller and cage assembly can be mounted independently from the outer ring, simplifying installation and maintenance in many applications.

Typical Applications

• Electric motors and generators
• Gearboxes, reducers, and transmission assemblies
• Pumps, compressors, and turbines
• Machine tool spindles and precision equipment
• Rolling mill and heavy industrial machinery
• Wind turbine drivetrain components
• Railway axlebox and traction motor bearings
• Mining, quarrying, and construction equipment
• Paper and steel mill processing equipment
• General industrial and workshop machinery