NSK22218EAE4Double-Row Spherical Roller Bearing – Straight Bore, 90 mm ID, 160 mm OD, 40 mm Width, Open, CN Clearance, W33 Lubrication Groove and Three Oil Holes.

Product Description

What this part is

NSK 22218EAE4 double-row spherical roller bearing, 90 mm straight bore, 160 mm outside diameter, 40 mm width. Open, high-capacity stamped steel cage, normal radial internal clearance, with an annular groove and three lubrication holes in the outer ring. The carton also carries 22218 EA W33 and the Caterpillar number 391-3783.

Decoding the designation

222 marks a double-row spherical roller bearing in the 22 dimension series, and the bore code 18 multiplied by five gives the 90 mm bore. EA is NSK’s high-capacity reinforced internal design. E4 is the lubrication feature: a groove machined around the outer ring with three radial feed holes, which other makers designate W33. There is no clearance suffix, so the radial internal clearance is CN.

What these specs mean in practice

The two rows of barrel-shaped rollers run on a single sphered outer raceway, so the inner ring and rollers swivel inside the outer ring and the bearing accommodates shaft misalignment and housing deflection without edge loading. Being double row, it takes thrust in both directions as well as heavy radial load: 360 kN dynamic and 395 kN static. The E4 groove and holes allow lubricant to be fed straight into the roller path through the housing, which is what makes this variant the choice for oil-circulation and central grease systems on continuously loaded machinery. Mechanical limiting speed is 5000 rpm, falling to 4000 rpm on oil and 3200 rpm on grease.

Quantity and configuration

Single bearing, straight bore, mounted directly on the shaft. 1 Pc.

Fitting notes

The shaft shoulder runs from 100 mm minimum to 108 mm maximum diameter and the housing shoulder from 141 mm minimum to 150 mm maximum, with a maximum corner fillet of 2.0 mm. Chamfer on the bearing itself is 2.0 mm minimum. The three oil holes are 3.0 mm in diameter and are indexed to the housing feed port on assembly. Mounting is by interference fit on the inner ring, with heat used to expand the ring rather than force applied through the rollers.

Interchange guidance

The equivalent 90 x 160 x 40 mm double-row spherical roller with a W33 outer ring and CN clearance from another maker substitutes directly. The same number in C2, C3, C4 or C5 clearance is a related size rather than an interchange, because running clearance sets the operating temperature and load distribution. The 22218 without the E4 or W33 feature is likewise a related size: the outer ring is plain and cannot be fed through the housing. Calculation factors for load rating work on this bearing are e = 0.24, Y2 = 4.3, Y3 = 2.9 and Y0 = 2.8.