NSK 2218C3 Self Aligning Ball Bearing, Cylindrical Bore, C3 90 x 160 x 40 mm

The NSK 2218C3 is a double row self-aligning ball bearing with a cylindrical bore and C3 radial internal clearance. It measures 90 x 160 x 40 mm (bore x outer diameter x width) and carries a basic dynamic load rating of 77,500 N and a basic static load rating of 28,700 N, with limiting speeds of 3,600 rpm on grease and 4,300 rpm on oil.

Self aligning ball bearings have a spherical outer ring raceway, so the inner ring, balls and cage can swing to take up small angular misalignment between shaft and housing. They suit long shafts, shafts that deflect under load and housings that cannot be bored in line. The C3 clearance suits interference fits and bearings that run warm.

Where this product is used

• Conveyor pulleys and idler rolls
• Fans, blowers and agricultural machinery
• Line shafting and general industrial machinery where the shaft or housing may deflect

Features

• Double row design with a spherical outer ring raceway, so the bearing tolerates small angular misalignment between shaft and housing
• Cylindrical bore for a conventional press or slip fit on a plain shaft
• C3 radial internal clearance, larger than Normal, which suits interference fits and temperature differences between the rings
• Basic dynamic load rating 77.5 kN and static load rating 28.7 kN, with limiting speeds of 3,600 rpm on grease and 4,300 rpm on oil

Key specifications

Selecting the right option

A cylindrical bore suits a plain shaft with a conventional press or slip fit, and is the simpler choice where the shaft can be machined to size.

C3 radial internal clearance is larger than Normal (CN). Choose C3 where the bearing will run with an interference fit on the shaft or in the housing, or where the inner ring will run warmer than the outer ring, because both take up clearance. Keep Normal clearance for light fits, low temperature rise and quiet running.

Fitting and use

Check the load and speed against the figures for your size before ordering and apply a suitable safety factor. Self aligning bearings carry radial load and a light axial load in either direction, and the misalignment they accept is small, so heavy axial loads and large deflections should be checked with AIMS before ordering.

Fit the bearing by pressing on the ring that is being fitted, never through the balls. On a tapered bore, drive the inner ring up the taper (or tighten the sleeve) while checking the internal clearance, and stop at the clearance reduction the application calls for.