Large Size Bearings
Characteristics: Outer Diameter up to 2000 mm; segmented cages; thru-hardened or carburized rings; often four-point contact or slewing ring type.
Advantages: Lifetime 100,000 hours in wind turbines vs. standard segmented bearings (usually fail due to Brinelling). Handles combined moment loads (tilt, radial, axial).
Technical Ceiling: Radial runout <50 µm (for 2m diameter); static safety factor S0 >1.5 for earthquake load; hardness 55-60 HRC at 25 mm depth (induction hardened). Max speed <30 rpm.
Caution: Standard bearing selection ignores tilt moment – immediate failure under wind or crane loads. Must use through-hardened not case-carburized. Installation requires heated or cooled shaft/housing fit (interference 0.2–0.5 mm). Bolting pattern critical - no standard pattern.
