KoyoDouble-Row Spherical Roller Bearing – 1:12 Tapered Bore, 60 mm ID, 110 mm OD, 28 mm Width, Open, W33 Lubrication Groove, Pressed Steel Cage, C3 Clearance, H312 Sleeve Mount

Product Description

What this part is

Koyo 22212RHKW33C3 double-row spherical roller bearing, 222 series, 60 mm bore x 110 mm outside diameter x 28 mm width. Bore: 60 mm. Outside Diameter: 110 mm. Overall Width: 28 mm. Bore Type: Tapered, 1:12 taper. Number Of Rows: 2. Rolling Elements: Convex symmetric spherical rollers. Closure Type: Open. Cage Material: Pressed steel. Cage Type: Pressed. Internal Clearance: C3, greater than standard. Precision Class: ABEC 1, ISO normal. Permissible Misalignment: 2°. Relubrication Feature: W33, a lubrication groove and lubrication holes in the outer ring outside surface. Design Units: Metric. Material: Chrome steel. Country of Origin: Japan.

Decoding the designation

222: the double-row spherical roller series. 12: the bore code, giving 60 mm. RH: Koyo’s internal design with convex symmetric rollers and a pressed cage, running a centre guide ring in place of an inner-ring rib. K: tapered inner-ring bore, 1:12 taper. W33: a lubrication hole and lubrication groove on the spherical roller bearing outer ring outside surface. C3: clearance greater than standard. Searchable variants: 22212-RH-K-W33-C3, 22212 RH K W33 C3, 22212RHKW33, 22212CK, 22212CCK, 22212CKJ.

What these specs mean in practice

Two rows of barrel-shaped rollers run in a common spherical outer raceway, so the inner ring, rollers and cage swivel as an assembly relative to the outer ring. Koyo states that the self-alignment feature accommodates up to 2° of misalignment, which makes the bearing tolerant of shaft deflection and housing bore misalignment. Because both rows are angled, a double-row spherical roller bearing carries thrust in either direction as well as heavy radial load. Koyo’s RH design uses two rows of longer symmetrical rollers with a centre guide ring instead of a rib, which raises load capacity over the earlier asymmetric R design. The 1:12 tapered bore lets the bearing be driven up a matching taper, so radial internal clearance is set by drive-up distance rather than by shaft interference fit. The W33 groove distributes lubricant circumferentially around the outer ring and its radial holes carry it inward to the rolling elements; the same passages take grease or oil, so the feature suits a grease gun, a single-point lubricator or a circulating-oil system equally. Internal Clearance: C3, which leaves more room than standard once mounted. Lubricant: grease or oil.

Quantity and configuration

Unit Quantity: 1 Pc. Tapered-bore execution. It mounts on an H312 adapter sleeve, which has a 55 mm cylindrical shaft seat and a 60 mm tapered outside diameter matching this bore, together with a KM12 locknut and an MB12 lockwasher. It also mounts directly on a shaft journal machined to a 1:12 taper, and comes off with a withdrawal sleeve.

Interchange guidance

Same-envelope tapered-bore designations at the same clearance class with a lubrication groove: Timken 22212KEJW33C3 and NSK 22212CDKE4C3. SKF 22212 EK/C3 and FAG 22212-E1-XL-K-C3 share the envelope, taper and clearance without the lubrication groove. Related part in the same series: the 22212RHW33C3, which shares the 60 x 110 x 28 mm envelope with a straight cylindrical bore.