Development of ULTAGE Large Size Tapered Roller Bearing

NTN Corporation has developed the “ULTAGE*1 Large Size Tapered Roller Bearing” that delivers the world’s highest standard of high-load capacity and high rotational precision with optimizations made to the internal bearing design.

NTNLargeTRBBearings used in various plant equipment for steel and wind turbines, general industrial machinery such as construction and mining machinery are subjected to harsh environments during operation, including vibrations and shocks, and thus require a high load capacity. High-speed shafts of gearboxes and reducers are increasing in output and efficiency, and require high rotational precision.

The newly developed “ULTAGE Large Size Tapered Roller Bearing” has an optimized internal design compared to conventional tapered roller bearings*2 and reviews made to the crowning shape*3 of the roller in particular allows the bearing to maintain a uniform contact pressure between the rolling element and raceway, even when subjected to high loads. This gives the bearing a high-load capacity that is 1.3-times or higher than the conventional product, and improves the rated life of the bearing 3-times or more and the load resistance 2-times or more. Sliding contact sections between the rollers and inner ring have an optimum shape to control increases in the rotational torque and temperature increases, which raises the permitted rotational speed by approximately 10% to offer the world’s highest load capacity and high rotational precision.

The developed product also features special heat resisting treatment on the bearing steel to limit the rate of dimensional change of the bearing over time during use to less than 1/10 that of conventional bearings using bearing steel (less than 1/4 for case hardened steel), which maintains high performance when used over long periods of time.

With the “ULTAGE Large Size Tapered Roller Bearing,” NTN meets demands for “long operating life,” “load resistance” and “high rotational precision” required for general industrial machinery, and will also increase the large series lineup with bearing outer diameter of 270 mm or more while expanding global sales activities.

*1) ULTAGE is the name for NTN’s new generation of the world’s highest standard of bearing series, and expresses the “ULTIMATE” performance on any type of “STAGE.”
*2) NTN catalog: CAT.No.2250/J “Large tapered roller bearing”
*3) Cylindrical shape where the diameter of rollers gradually becomes smaller on a micron scale in the direction of the edges

Features Compared to conventional products (large tapered roller bearing)

(1) Bearing rated life: 3-times or more (1.3-times or more high load capacity)
(2) Load resistance: 2-times or more
(3) Permitted rotational speed: approximately 10% improvement
(4) Rate of dimensional change: 1/10 or less (bearing steel), 1/4 or less (case hardened steel)


Steel production equipment, wind turbines, general industrial machinery such as construction and mining machinery