Timken47688-3Tapered Roller Bearing Cone 3-9/32″ Bore, Class 3 Precision, Inch TS Series, Cone Only

Product Description

What this part is

A Timken 47688 single-row tapered roller bearing cone: the inner ring with its tapered rollers and cage retained as one unit, in Timken precision Class 3. Inch (imperial) series, TS single-row configuration. Cone only. The matching cup is the Timken 47620.

Decoding the designation

47688 is the cone number and 47620 is the separate cup number; the two written together as 47688/47620 form the assembly designation. The trailing -3, also written *3 or #3, is Timken’s precision Class 3 mark, a tighter bore and outside-diameter tolerance grade than the standard Class 4 / Class K used on general-purpose inch tapered bearings.

Specifications

Manufacturer: The Timken Company. Part Number: 47688-3. Base Number: 47688. Cone Part Number: 47688. Cup Part Number: 47620. Bearing Type: tapered roller bearing cone, single row, inch TS series. Series: 47600 inch tapered, TS single row. Bore (d): 3.2813 in / 83.345 mm. Cone Width (B): 1.3125 in / 33.338 mm. Number of Rows: 1. Precision Class: Timken Class 3. Bearing Class: Class 3. Rolling Elements: tapered rollers. Cage Type: stamped one-piece roller cage. Cage Material: steel. Bearing Material: case-carburized alloy steel. Closure Type: open. Design Units: inch (imperial). Harmonization Code: 8482.20.00. Country of Origin: United States.

Assembly data, 47688 cone with 47620 cup

Timken publishes the following for the complete 47688/47620 assembly. Assembly Envelope: 3.2813 x 5.250 x 1.3125 in / 83.345 x 133.35 x 33.338 mm. Outside Diameter (D): 5.250 in / 133.35 mm. Assembly Width (T): 1.3125 in / 33.338 mm. Cup Width (C): 1.0313 in / 26.195 mm. Dynamic Radial Load Rating, 1M revs (C1): 48,100 lbf / 214,000 N. Dynamic Radial Load Rating, 90M revs (C90): 12,500 lbf / 55,500 N. Dynamic Axial Rating, 90M revs (Ca90): 8,640 lbf / 38,400 N. Static Radial Load Rating (C0): 58,900 lbf / 262,000 N. e Factor: 0.4. K Factor: 1.44. Y Factor: 1.48. Geometry Factor (Cg): 0.127. Assembly Weight: 3.7 lb / 1.70 kg. Effective Center Location: -0.17 in / -4.3 mm, inside the cone backface. 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): 3.58 in / 91 mm. Shaft Backing Shoulder Diameter, backface (db): 3.82 in / 97 mm. Housing Backing Shoulder Diameter, frontface (Da): 5.08 in / 129.00 mm. Housing Backing Shoulder Diameter, backface (Db): 4.69 in / 119.13 mm. Cage Location Relative to Backface (Aa): 0.08 in / 2 mm. Cage Location Relative to Frontface (Ab): 0.12 in / 3 mm.

What these specifications mean in practice

Class 3 tightens the tolerance band on the cone bore and width, which holds shaft position more consistently across a batch of assemblies; that is why it appears on machine-tool spindles, precision gearboxes and aircraft wheel ends rather than on general industrial shafting. The tapered geometry carries heavy radial load together with thrust in one direction through a single raceway, and the K factor of 1.44 is the ratio Timken publishes for resolving that combined load.

Quantity and configuration

Unit Quantity: 1 Pc. One cone assembly: inner ring, tapered rollers and cage. The 47620 cup is a separate part number.

Interchange guidance

47688 is the industry cone number and is used unchanged across the inch tapered interchange. Cones 47679, 47680, 47686 and 47687 also run against the 47620 cup, differing in bore, width or precision grade. The 47688 also appears in the 47688/20629 assembly. A plain Timken 47688 is the same cone in the standard Class 4 / K tolerance grade.