TORRINGTON22228KC4W33Spherical Roller Bearing 140x250x68 mm, Double Row, 1:12 Tapered Bore, C4 Internal Clearance, W33 Oil Groove — Self-Aligning

Product Description

What this part is

A double-row spherical roller bearing, 140 mm bore, 250 mm outside diameter, 68 mm width. The outer ring has a single spherical raceway, which lets the whole roller-and-inner-ring assembly swivel inside it — the defining feature of the type. Torrington’s bearing business became part of The Timken Company, and the 22228K envelope remains in current Timken production.

Decoding the designation

222 — ISO 222 dimension series: the wider, higher-capacity of the two common spherical series (against the shallower 223 and the narrower 213).
28 — ISO bore code 28, giving a 140 mm bore.
K — tapered bore, 1:12 taper. This is the single most important suffix on the part: it changes how the bearing is mounted entirely.
C4 — internal radial clearance greater than normal, and greater than C3.
W33 — an annular oil groove machined around the outer ring with three radial lubrication holes through to the raceway.

The alternative designation 140SD022 K F4 W33 recorded against this item is Torrington’s own legacy numbering for the same bearing.

What these specs mean in practice

The self-aligning geometry is the reason you would choose this type: it accommodates several tenths of a degree of misalignment between shaft and housing without generating edge loading. That makes it the standard bearing for long shafts that deflect under load, for split or separately-machined housings, and for anything mounted on a structure that moves — conveyors, fans, crushers, mill drives, screens.

The tapered bore and the C4 clearance work together and must not be considered separately. A K-bore bearing is mounted by driving it up a tapered shaft seat or an adapter sleeve, which expands the inner ring and consumes internal clearance as you go. The amount of clearance you start with therefore determines how far you can drive it before the bearing binds. C4 exists to give that mounting process enough headroom. Fit a C3 bearing where a C4 was specified and you can run out of clearance before reaching the correct drive-up; fit C4 where C3 was intended and the mounted bearing may be left too loose. Clearance mismatch fails in both directions.

W33 matters wherever the bearing is oil-lubricated or relubricated in service. The groove and holes feed lubricant directly into the loaded zone through the outer ring, rather than relying on it migrating in from the sides — essential in a housed unit with a grease line, and the reason W33 is near-universal on larger spherical bearings.

Published ratings and mounting data

Timken publishes the following for the current-production 22228KEJW33, the steel-cage bearing occupying this same 22228K envelope. These are Timken’s own catalogue figures for that designation, offered here as the best available reference for the envelope rather than as a certified rating for this specific legacy Torrington part:

Bore (d): 140 mm; outside diameter (D): 250 mm; width (B): 68 mm
Dynamic radial load rating (C1): 863,000 N (194,000 lbf)
Static radial load rating (C0): 1,060,000 N (237,000 lbf)
Thermal reference speed, oil: 2,600 rpm; grease: 2,200 rpm
e factor: 0.25; static factor Y0: 2.61
Dynamic equivalent radial load factors: Y = 2.67 when Fa/Fr ≤ e (X = 0.67); Y = 3.98 when Fa/Fr > e (X = 1)
Maximum shaft fillet radius: 2.5 mm (0.100 in)
Shaft backing shoulder diameter: 167 mm (6.600 in)
Housing backing shoulder diameter: 228 mm (9.000 in)

Note that the static rating correctly exceeds the dynamic rating here, as it should on a spherical roller bearing. The cage on this Torrington item may differ from the current EJ steel cage, which would affect speed capability rather than the load ratings.

Fitting notes

This is a tapered-bore bearing and cannot simply be pressed onto a parallel shaft. It requires either a matching 1:12 tapered shaft seat or an adapter sleeve with a lock nut and locking device. Mounting is done by controlled drive-up, measured either as radial clearance reduction (feeler gauge across the unloaded top roller, before and after) or as axial advance up the taper. Follow the manufacturer’s drive-up figure for the bore size and clearance class — guessing it is the most common way these bearings are destroyed on installation.

If your shaft is parallel and you have no adapter sleeve, you need the straight-bore 22228 without the K, not this bearing. Adapter sleeves are sold separately; ask and we will check stock.

Interchange guidance

ISO base number 22228K. The full modern Timken equivalent is 22228KEJW33. Equivalents from other makers in the same envelope carry their own cage and clearance suffixes — always match the bore type (K or straight), the clearance class (C3, C4) and the W33 groove, not just the 22228 root.