Timken938-90091Two-Row TDO Tapered Roller Bearing Assembly, 4.5000 in Bore, 8.3750 in OD, 5.6249 in Overall Width, Case-Carburized Steel, Matched Cone Spacer

Product Description

What this part is

Timken 938-90091 two-row TDO tapered roller bearing assembly. Bore Diameter: 4.5000 in (114.300 mm). Outside Diameter: 8.3750 in (212.725 mm). Overall Width: 5.6249 in (142.872 mm). Number Of Rows: 2. Rolling Elements: Tapered Roller. Bore Type: Straight. Bearing Material: Case-Carburized Steel. Cage Type: Stamped. Cage Material: Steel. Closure Type: Open. Item Weight: 20.113 kg (44.34 lb). GTIN: 053893101286. Country of Origin: United States. The build is two 938 cones, one 932CD double cup and one X1S-938 cone spacer.

Decoding the designation

938 — the cone number, the inner ring and roller assembly.

932 — the cup number, the outer race.

CD — a one-piece double cup carrying two raceways, so one 932CD seats both cones.

X1S — a cone spacer, ground to set the axial spacing between the two cones.

-90091 — a Timken assembly number, which fixes the complete factory-matched build and names the cup and the spacer that accompany the cones.

What these specs mean in practice

Dynamic Load Rating: 996,000 N (224,000 lbf) at 1 million revolutions. Static Load Rating: 786,000 N (177,000 lbf). Dynamic Radial Rating, 2-Row at 90M Revolutions (C90-2row): 258,000 N (58,000 lbf). Dynamic Axial Rating at 90M Revolutions (Ca90): 82,700 N (18,600 lbf). Those figures place the assembly in rolling-mill and heavy shafting service.

e Factor: 0.33. K Factor: 1.79. Y1 Factor: 2.07. Y2 Factor: 3.09. Geometry Factor (Cg): 0.115. The e and K factors set the thrust-to-radial load split used in Timken life calculations, and Y1 and Y2 convert an applied thrust into an equivalent radial load.

A TDO assembly carries radial load together with thrust in both directions, and the spread between the two roller paths gives it moment capacity, which holds shaft alignment under overhung loading. The matched cone spacer fixes the internal setting at manufacture, so the assembly goes in at a known running clearance. Bearing Material: Case-Carburized Steel — a hard raceway over a tough core, which suits shock and heavy intermittent loading.

Mounting data

Outer Ring Width (C): 4.625 in (117.475 mm). Shaft Backing Shoulder Diameter, Backface (db): 5.55 in (141 mm). Housing Backing Shoulder Diameter, Frontface (Da): 7.61 in (193.04 mm). Maximum Shaft Fillet Radius: 0.280 in (7.100 mm). Maximum Housing Fillet Radius: 0.06 in (1.5 mm). The two fillet figures are the largest radii the shaft and the housing may carry for the bearing corners to clear them. Cone Inner Ring Width (B): 2.6250 in (66.675 mm). Cone Effective Center Location: -0.78 in (-19.8 mm), inside the cone backface. Cone Shaft Backing Shoulder Diameter, Frontface (da): 5.04 in (128 mm).

Quantity and configuration

Unit Quantity: 4 Pcs — one complete assembly built from two 938 cones, one 932CD double cup and one X1S-938 cone spacer. Number Of Rows: 2. Arrangement: TDO, tapered double outer, with both cones seated inside a single common cup.

Interchange guidance

Component replacement inside this assembly runs on the industry-standard inch tapered roller numbers: cone 938 and cup 932. Equivalents by maker — SKF 938 and 932, Koyo 938 and 932, NTN 4T-938 and 4T-932, BCA/Bower 938 and 932, Fersa 938 and 932. Searchable designation variants: 938-90091, 938 90091, 93890091, 938/932CD, 938-932CD, 932-CD, X1S-938, X1S938. GTIN: 053893101286.