SNR21318VMBC3Double Row Spherical Roller Bearing 90x190x43 mm Straight Bore Brass Cage C3 Clearance Self-Aligning

Product Description

What this part is

A double-row spherical roller bearing with a straight bore and a machined brass cage. Bore 90 mm, outside diameter 190 mm, width 43 mm.

Decoding the designation

213xx — double-row spherical roller series, a lower cross-section than the 223xx series of the same bore.
MB — machined brass cage.
C3 — greater than normal radial internal clearance. The J30 code in the same designation is the SNR notation for that same C3 clearance.
No K suffix, so the bore is cylindrical rather than tapered.

What these specs mean in practice

Two rows of barrel rollers running in a common spherical outer raceway make this bearing self-aligning: it accommodates shaft deflection and housing misalignment without generating edge loading. Because the two rows are opposed, a double-row spherical roller carries thrust in both directions as well as heavy radial load. C3 clearance leaves more room than the normal grade, which suits an interference fit on the shaft, a hot running temperature, or both, since the operating clearance closes up once the bearing is mounted and warm. A machined brass cage tolerates higher temperature and shock loading than a pressed steel cage and raises the load rating relative to one.

Quantity and configuration

1 Pc. Straight bore, so the bearing mounts directly on the shaft seat with no adapter sleeve.

Fitting notes

With a cylindrical bore the inner ring is drawn or heated onto the shaft to its interference fit, and the C3 clearance is consumed by that fit and by thermal expansion in service. Radial internal clearance is checked before mounting, not adjusted afterwards.

Interchange guidance

The tapered-bore counterpart of this bearing is the 21318 K, which requires an adapter sleeve and is a related size rather than an interchange. A 22318 is the heavier 223xx cross-section on the same 90 mm bore, and variants at CN, C2 or C4 clearance, or with a pressed steel cage, differ in a spec that governs fit and capacity — all related sizes.