230/850YMB Spherical Roller Bearing (850x1220x295mm)

About This Type

Spherical roller bearings carry very high radial loads together with axial loads in both directions, and their spherical outer-ring raceway accommodates shaft misalignment and housing deflection. Typical applications include vibrating screens, conveyors, mining and cement machinery, paper machines, industrial gearboxes and wind-turbine main shafts.

The self-aligning capability makes this type the default where the housing cannot be aligned precisely or the shaft deflects under load. For a given bore size, the 222 and 223 series provide higher load ratings at the expense of envelope size; the 230 and 239 series are narrow, light designs for arrangements where radial space or speed is critical; and the 240 and 241 series are wider light-series designs that raise load ratings where the diameter is limited but axial width is available. Because these bearings often run hot and under heavy load, C3 or C4 clearance is commonly specified; the catalogue limits for the axial-to-radial load ratio should be observed, since a very light radial load combined with a high axial load can cause roller skidding.

Most spherical roller bearings are available with a cylindrical or tapered bore (suffix K or K30); tapered-bore versions are mounted on adapter or withdrawal sleeves, or directly on a tapered shaft seat. Mounting a tapered-bore bearing is carried out by the drive-up method: the clearance reduction or axial displacement is measured — typically the clearance with a feeler gauge — rather than relying on nut torque alone. The initial clearance must be selected so that sufficient residual clearance remains after interference fitting and at operating temperature.

Series note: The 230 series is a light design that combines a narrow section with relatively high speed capability.