Timken77375-3Tapered Roller Bearing Cone – 3.7500 in Bore, 1.9000 in Width, Class 3, K Factor 1.59

Product Description

What this part is

Timken 77375-3 tapered roller bearing cone. This is the inner ring with its tapered roller set and cage, the rotating half of a Timken TS single-row inch tapered roller bearing, built to Class 3 precision. Bore Diameter: 3.7500 in (3-3/4 in, 95.250 mm). Overall Width: 1.9000 in (48.260 mm) inner ring width. Item Weight: 5.30 kg (11.70 lb). Dynamic Load Rating: 403,000 N (90,500 lbf) at C1. Static Load Rating: 474,000 N (107,000 lbf). Precision Class: Class 3. Rolling Elements: Tapered Roller. Number Of Rows: 1. Bore Type: Straight. Cage Type: Pressed. Bearing Material: case-carburized alloy steel. Design Units: Imperial. Series: 77000. Base Number: 77375.

Decoding the designation

77375 — a cone number in Timken’s inch 77000 tapered roller series, fixing the 3.7500 in bore and the 1.9000 in inner ring width.

-3 — Precision Class 3, also written *3 and #3. A tighter tolerance than standard, giving lower running vibration and closer location of the shaft. The class changes tolerance only; bore, width, raceway angle and load ratings are those of the 77375.

What these specs mean in practice

K Factor: 1.59. A K factor of 1.59 is a moderate taper: the bearing is weighted toward radial load with a useful thrust reserve.

Dynamic Load Rating: 403,000 N (C1, at 1 million revolutions, ISO method) — a heavy figure for a 3.75 in bore, produced by the 1.9000 in ring width and the long roller it allows. Dynamic Radial Load Rating at 90 million revolutions (C90): 104,000 N. Dynamic Axial Rating at 90 million revolutions (Ca90): 65,600 N. Static Load Rating: 474,000 N.

Class 3 precision tightens the bore tolerance and the raceway running accuracy against a standard cone, which shows up as lower vibration at speed and closer, more repeatable shaft location.

G1 Factor: 206. G2 Factor: 37.7. Geometry Factor (Cg): 0.102, the geometry constant for the lubrication life adjustment factor a3l.

Mounting data

Maximum Shaft Fillet Radius: 0.140 in (3.600 mm) — the largest fillet the shaft shoulder may carry and still be cleared by the cone corner. Shaft Backing Shoulder Diameter, frontface (da): 4.17 in (106 mm). Shaft Backing Shoulder Diameter, backface (db): 4.45 in (113 mm). Effective Centre Location: -0.38 in (-9.7 mm), inside the cone backface. Cage Location relative to backface (Aa): 0.11 in. Cage Location relative to frontface (Ab): 0.07 in.

Quantity and configuration

Unit Quantity: 1 Pc. Cone only — inner ring, rollers and cage. The matching cups are the Timken 77675 and 77676X.

Interchange guidance

77375 is an inch tapered roller cone number on the common industry dimensional standard, so a 77375 from another inch-series maker carries the same bore, width and raceway angle. The Class 3 tolerance is a Timken execution, so a standard-tolerance 77375 matches the envelope but not the running accuracy. Cross-references: Koyo 77375, NTN 4T-77375, NSK 77375, Bower / BCA 77375, Fersa 77375.