TORRINGTON22218KW33C4Double Row Spherical Roller Bearing, Tapered 1:12 Bore, 90 x 160 x 40 mm, W33 Lubrication, C4 Clearance

Product Description

What this part is

A Torrington double row spherical roller bearing at the 22200 envelope: 90 mm bore, 160 mm outside diameter, 40 mm wide. Two rows of barrel-shaped rollers run in a single spherical outer raceway. Because that raceway is a section of a sphere, the inner ring and roller set can swivel inside it — the bearing self-aligns. It is the bearing you specify when the shaft will not stay straight: long unsupported spans, fabricated rather than machined housings, deflection under load, thermal growth pulling the two ends out of line.

The other reason to choose it is raw capacity. Two rows of rollers in line contact give this size a dynamic rating in the region of a quarter of a meganewton, which is far beyond what a ball bearing of the same bore could carry. Screens, crushers, conveyor pulleys, fans, gearbox output shafts and paper-machine rolls are its natural home.

Decoding the designation

22218: double row spherical roller bearing, 222 dimension series, bore code 18 (90 mm).

K: tapered bore, 1:12 taper. This is the most consequential letter on the part, and it is what distinguishes this bearing from a cylindrical-bore one.

W33: a lubrication groove machined around the outer ring with three radial feed holes through it, so grease or oil can be delivered directly into the rolling elements from the housing.

C4: internal radial clearance greater than C3, which is itself greater than normal. Extra loose.

F4: a Torrington internal design and clearance code carried on this part, reproduced exactly as marked. It appears in the title and cross-references because it is the number on the ring.

90SD22-F4: Torrington’s own legacy part number for this bearing. SD denotes the spherical double-row family. Retained because plant parts lists and old drawings still carry it.

Why the tapered bore and C4 clearance belong in the same sentence:
A tapered-bore spherical roller bearing is not pushed onto a shaft to a position; it is driven up a taper — either a tapered shaft seat or a withdrawal/adapter sleeve — until the interference fit is achieved. Driving it up expands the inner ring. Expanding the inner ring consumes internal clearance. The amount consumed is substantial, and it is the drive-up distance that determines it.

That is exactly why the bearing is supplied at C4. The extra-loose initial clearance is not slack to be tolerated — it is the allowance that gets used up during mounting. Mount a C4 tapered-bore bearing correctly and it ends up at roughly normal running clearance. Mount a normal-clearance tapered-bore bearing the same way and you finish with a preloaded bearing that runs hot, loses more clearance as it heats, and seizes.

Published ratings for this envelope

The figures below are SKF’s published values for the equivalent 22218 K W33 bearing at the same 90 × 160 × 40 mm envelope, given as an envelope-level guide.

Bore (d): 90 mm, tapered 1:12.

Outside diameter (D): 160 mm.

Width (B): 40 mm.

Dynamic radial load rating C: 253 kN / approx. 56,900 lbf.

Static radial load rating C0: 340 kN / approx. 76,400 lbf.

Limiting speed: 5,300 rpm.

Internal clearance: C4 (extra loose, as supplied).

Lubrication: W33 groove and three holes in the outer ring; grease or oil.

Number of rows: 2.

Rolling elements: barrel rollers, two rows.

What the W33 groove is actually for

It changes the maintenance regime, and it is a genuine reason to prefer this bearing over a plain one. Without the groove, grease pumped into a housing has to find its way past the bearing faces. With W33, the housing’s grease fitting feeds an annular groove around the outer ring and three holes deliver lubricant into the middle of the roller path, between the two rows — the exact place it is needed and the hardest place to reach from outside. On a large, slow, heavily loaded bearing that is regreased on a schedule, W33 is the difference between relubrication that works and relubrication that mostly pushes old grease around the housing.

Mounting data

Bore taper: 1:12, on diameter.

Mounting method: taper drive-up onto a tapered shaft seat or onto an adapter or withdrawal sleeve.

Control method for the fit: reduction in radial internal clearance, or axial drive-up distance.

Quantity and configuration

One complete bearing: both rings, both rows of rollers, the cage and the W33 outer ring. A tapered-bore bearing mounted on a straight shaft is fitted with an adapter or withdrawal sleeve, which is a separate part sized to the shaft diameter. Where the shaft seat is already tapered, the bearing mounts directly onto it.

Interchange guidance

Search forms include 22218KW33C4, 22218-K-W33-C4, 22218 K W33 C4, 22218KW33, 22218K, 22218-K-W33-F4/C4, 90SD22, 90SD22-F4. Same-envelope equivalents at 90 × 160 × 40 mm with a tapered bore and W33 lubrication: SKF 22218 EK/C4, 22218 EK/C3, 22218 CCK/W33 and 22218 CCK/C3W33; FAG 22218-E1-K; Timken 22218 KEJW33; NSK and NTN 22218K. Match the clearance class — C3 and C4 are not interchangeable on a tapered-bore mounting for the reasons set out above. Torrington’s bearing line went to Timken, so a machine originally built with Torrington 90SD-series bearings is supported by Timken part numbers today.