Self-Aligning Ball B. SKF 1318 K/C3

The SKF 1318 K/C3 double-row self-aligning ball bearing features a 90 mm bore diameter, a 190 mm outer diameter, a tapered bore and an increased C3 clearance.

This 1318 K/C3 self-aligning ball bearing is a double-row rolling bearing with a common hollow-ball raceway in the outer ring. The bearing is manufactured by SKF and is made from 100Cr6 bearing steel to standard tolerance P0/PN. Thanks to the movable arrangement of the two rows of balls, the design automatically compensates for misalignment and shaft deflection during operation. The open design allows for a flexible choice of lubricant and facilitates inspection as part of industrial maintenance.

In which installation situations does the 1318 K/C3 self-aligning ball bearing compensate for misalignment?

By design, this type is primarily suitable for bearing arrangements with long shafts or separate housings, where misalignment may occur between the bearing positions. Typical applications include shaft arrangements prone to deflection or elastic deformation under operating conditions. The self-aligning bearing primarily absorbs radial forces, guides the shaft and, in doing so, accommodates misalignments between the inner and outer rings. The sheet steel cage keeps the rolling elements evenly aligned, even under dynamic loads.

Why is the combination of a tapered bore and C3 clearance important?

The suffix ‘K’ denotes the tapered bore with a ratio of 1:12, allowing you to mount the bearing directly onto tapered shaft seats or using adapter sleeves. When the bearing is axially pushed onto the taper, the inner ring expands, which reduces the radial bearing clearance. The factory-set increased C3 bearing clearance compensates for this expansion as well as for operational temperature differences between the inner and outer rings. As a result, once the bearing has been fitted correctly, the required operating clearance is maintained to ensure smooth running across the entire temperature range from -30 to +150 degrees.