NSKDouble-Row Spherical Roller Bearing 90 x 160 x 40 mm, Straight Bore, W33 Lube Groove, C3 Clearance

Product Description

What this part is

An NSK 22218EAE4C3 double-row spherical roller bearing in the 222 series, 90 mm bore x 160 mm outside diameter x 40 mm width (3.5433 x 6.2992 x 1.5748 in). The bore is straight. Two rows of barrel-profile rollers run on a common spherical raceway in the outer ring, so the inner ring, rollers and cage assembly swivel relative to the outer ring and the bearing is self-aligning. Approximate mass 3.3 kg (7.3 lb).

Decoding the designation

222 — double-row spherical roller bearing, dimension series 22 (the wider-section 222 family).
18 — bore code, 90 mm bore.
EA — NSK’s reinforced high-capacity internal design with a pressed-steel cage.
E4 — NSK’s code for the W33 execution: an annular lubrication groove around the outer ring plus three radial lubrication holes through it.
C3 — radial internal clearance greater than ISO normal.
No K in the designation, so the bore is cylindrical and seats directly on a straight shaft journal.

What these specs mean in practice

The spherical outer raceway is the point of the type. It absorbs shaft-to-housing misalignment and shaft deflection that would edge-load a cylindrical or tapered roller bearing, which is why the type dominates conveyor pulleys, crusher shafts, fans, gearbox output shafts and vibrating screens. Two symmetric roller rows carry thrust in both directions in addition to heavy radial load.

The E4 groove-and-holes execution puts fresh grease or oil directly into the roller path from the outer ring, so the bearing can be relubricated in service through a housing with a matching lube port. The plain execution without the groove has to be fed from the sides.

C3 clearance runs looser cold than normal clearance. That buys tolerance for a heavier interference fit on the shaft, for thermal growth of the inner ring relative to the outer, and for a temperature gradient across the bearing — the standard combination in a hot, heavily loaded, press-fit installation. The cost is more radial play and more noise at light load and low temperature than a CN bearing gives.

The pressed-steel cage of the EA design is lighter and cheaper than machined brass and tolerates the same 200 °C stabilisation ceiling, with lower speed and shock-load headroom than a brass-caged CA-type execution.

Published ratings and mounting data

Basic dynamic load rating Cr: 360,000 N (360 kN / 80,930 lbf)
Basic static load rating C0r: 395,000 N (395 kN / 88,800 lbf)
Limiting speed, grease lubrication: 3,200 rpm
Limiting speed, oil-bath lubrication: 4,000 rpm
Thermal speed rating, oil bath (ISO 15312): 3,800 rpm
Mechanical speed limit, forced-circulation oil: 5,000 rpm
Chamfer dimension r (min): 2 mm
Shaft abutment diameter da: 100 – 108 mm
Housing abutment diameter Da: 142 – 150 mm
Shaft or housing fillet radius ra (max): 2 mm
Calculation factors: e = 0.24, Y2 = 4.3, Y3 = 2.9, Y0 = 2.8

Quantity and configuration

Bearing only. One piece per sale unit. Open on both faces, no seals or shields.

Fitting notes

The cylindrical bore seats directly on a straight shaft journal, normally with an interference fit and drawn up with a nut or pressed. The housing bore and shaft shoulders follow the abutment diameters listed above so the ring faces are supported without fouling the chamfer. Where the housing carries a lubrication port, aligning it with the outer-ring groove feeds the roller path through the three radial holes.

Interchange guidance

The ISO base number is 22218. Genuine same-spec equivalents in other schemes are the SKF 22218 E/C3 with W33 groove execution, the FAG 22218-E1-XL-K-C3 family’s straight-bore sibling 22218-E1-XL-C3 with the S or AS groove suffix, the NTN 22218EAD1C3 and the Timken 22218EJW33C3. Related sizes rather than interchanges: the 22218EAKE4C3 is the same envelope with a 1:12 tapered bore, and the 21318 and 22318 carry the same 90 mm bore in different section heights.