KoyoDouble-Row Spherical Roller Bearing, 80 x 140 x 33 mm, Straight Bore, Machined Brass Cage, W33 Lubrication, C4 Clearance

Product Description

What this part is

A Koyo 22216R double-row spherical roller bearing measuring 80 mm bore x 140 mm outside diameter x 33 mm wide. Straight (cylindrical) bore, open, machined brass cage, W33 relubrication features in the outer ring, C4 radial internal clearance. Spherical roller bearings carry very high radial load plus axial load in both directions, and the spherical outer raceway lets the inner-ring assembly swivel so the bearing self-aligns to shaft deflection or housing misalignment. Sold as 1 Pc.

Decoding the designation

222 — double-row spherical roller bearing, ISO dimension series 22.
16 — bore code; 16 x 5 = 80 mm bore.
R — Koyo internal design. Two rows of convex asymmetrical rollers separated by a central rib on the inner ring, held in a machined copper-alloy (brass) prong-type cage. Koyo rates the R design as its best spherical roller type for high-speed running.
W33 — circumferential lubrication groove around the outer ring outside diameter plus three radial lubrication holes through to the raceway, so the bearing can be regreased in service through the housing.
C4 — radial internal clearance greater than C3, which is itself greater than normal.
No K in the designation — straight cylindrical bore. No adapter sleeve is involved.

What these specs mean in practice

The brass cage is the reason to buy this variant. A machined brass prong cage runs cooler and tolerates higher speed, shock and marginal lubrication than a pressed steel cage, and it is the standard choice where the bearing sees vibration or repeated start-stop duty. It is also heavier and costs more, which is why steel-caged versions exist at all.

The trade-off in the R design is roller geometry. Asymmetrical rollers running against a central inner-ring rib give excellent speed capability, but the rib takes up axial space that a guide-ring design (Koyo RH) uses for longer rollers and higher load capacity. Pick R for speed and cage robustness, RH for maximum load in the same envelope.

W33 only earns its keep if the housing has a matching grease feed. Line the housing feed hole up with the outer ring groove and the fresh grease is pushed straight into the middle of both roller rows — that symmetrical feed is why relubrication intervals get longer. Feed a W33 bearing from the side instead and the groove does nothing.

C4 is chosen deliberately, not as an upgrade. Extra clearance absorbs a heavy interference fit, a large inner-to-outer ring temperature difference, or thermal growth in the housing, all of which eat clearance once the machine is hot. Fitting C4 where normal clearance was specified leaves a lightly loaded bearing able to skid its rollers rather than roll them.

Published mounting data for the 80 x 140 x 33 envelope

Bore d: 80 mm
Outside diameter D: 140 mm
Width B: 33 mm
Chamfer r min: 2 mm; fillet ra max: 2 mm
Shaft abutment da min: 91 mm
Housing abutment Da max: 129 mm
Permissible angular misalignment: 1.5°
Mass: approx. 2.1 kg
Number of rows: 2
Precision: ISO normal class (ABEC 1 / P0)

Quantity and configuration

One bearing per sale — 1 Pc. Complete non-separable bearing: inner ring with central rib, two rows of asymmetrical rollers, machined brass cage and outer ring with the W33 groove and holes. No adapter sleeve, no locknut and no housing are included.

Fitting notes

Straight-bore spherical roller bearings mount with an interference fit on the shaft. Heat the bearing or use a hydraulic fit-up tool; drive against the inner ring only, never through the outer ring, because the outer ring can swivel and will cock the rollers. Confirm the housing grease port aligns with the outer ring groove before final assembly. Grease fill is typically 30–50% of free space — overpacking a spherical roller bearing is a common cause of an early temperature rise.

Part number forms and nearby parts

The 80 x 140 x 33 mm 222-series envelope is industry-standard, so a 22216 in another brand’s nomenclature fits the same seat. 22216MB is carried on this listing because MB is the FAG code for a machined brass cage guided on the inner ring — the closest cage match to Koyo’s R design — so buyers searching that number land here; verify the clearance and W33 features, which vary by suffix. SKF calls its machined-brass-cage spherical roller design CA or CAC; NSK calls it CAM; NTN and NTN-SNR use EM; Timken uses EM or EMB. 53516 is the GOST designation for the same envelope. A version without W33 has no groove or holes in the outer ring and cannot be regreased through the housing.