Timken74556/74845Tapered Roller Bearing, Single Row – 5.5108 in Bore, 8.4636 in Outside Diameter, 1.875 in Width, Case-Carburized Steel

Product Description

What this part is:

Timken 74556/74845 single-row inch tapered roller bearing, cone and cup. Bore Diameter: 5.5108 in (139.974 mm). Outside Diameter: 8.4636 in (214.975 mm). Overall Width: 1.875 in (47.625 mm). Rolling Elements: Tapered Roller. Number Of Rows: 1. Closure Type: Open. Bearing Material: Case-carburized steel. Unit Quantity: 2 Pcs.

Decoding the designation:

74556 — Cone part number: the inner ring, roller and cage assembly, 5.5108 in bore, inner ring width 1.875 in.

74845 — Cup part number: the outer ring, 8.4636 in outside diameter, outer ring width 1.375 in.

74000 — Series: the Timken inch tapered roller family covering this raceway angle and envelope.

What these specs mean in practice:

Dynamic Load Rating: 354,000 N (79,500 lbf) at 1 million revolutions. Static Load Rating: 614,000 N (138,000 lbf). Dynamic radial rating at 90 million revolutions (C90): 91,700 N (20,600 lbf). Dynamic axial rating at 90 million revolutions (Ca90): 76,500 N (17,200 lbf).

e Factor: 0.49. K Factor: 1.2. Y Factor: 1.23. Geometry Factor (Cg): 0.134. G1 Factor: 362.9. G2 Factor: 68.5. The e factor is the thrust-to-radial ratio above which thrust governs life; K and Y convert a combined load into the equivalent radial load the ratings are quoted against. A tapered roller bearing carries radial and one-direction thrust together, which is why these factors matter more here than on a radial ball bearing.

Mounting data:

Inner Ring Width (B): 1.875 in (47.625 mm). Outer Ring Width (C): 1.375 in (34.925 mm). Effective Center Location: 0.09 in (2.3 mm). Max Shaft Fillet Radius: 0.140 in (3.600 mm). Max Housing Fillet Radius: 0.130 in (3.30 mm). Shaft Backing Shoulder Diameter, frontface (da): 5.98 in (152 mm). Shaft Backing Shoulder Diameter, backface (db): 6.22 in (158 mm). Housing Backing Shoulder Diameter, frontface (Da): 8.23 in (209.00 mm). Housing Backing Shoulder Diameter, backface (Db): 7.72 in (196.09 mm). Cage Location Relative to Backface (Aa): 0.18 in (4.6 mm). Cage Location Relative to Frontface (Ab): 0.1 in (2.5 mm). The fillet figures are the largest shaft and housing corner radii the bearing corners will clear.

Tapered roller bearings of this type are mounted in opposing pairs so that each bearing takes thrust in one direction and the pair locates the shaft.

Quantity and configuration:

Cone and cup. Unit Quantity: 2 Pcs — one 74556 cone and one 74845 cup. The 74845 cup also mates with the 74500 and 74550 cones.

Interchange guidance:

74556/74845 is an industry-standard inch tapered roller designation, carried under the same cone and cup numbers by SKF, NTN, Koyo, NSK, FAG, Bower/BCA and Fersa. Timken 74550/74845 uses the same cup against the 74550 cone, and Timken 74550/74856 runs the same taper against the larger 8.5625 in 74856 cup; both are related builds on a different cone or housing bore.