Product Description
Timken - Taper Roller Cup - 3.125" O.D.
Timken® Precision Taper Roller Bearing — 9 Variants
Timken taper roller bearing cups are the outer race of a taper roller bearing set — the component that seats in the housing bore and provides the outer raceway surface for the tapered rollers. Every Timken cup is precision-ground from premium bearing steel with surface finishes measured in micro-inches, ensuring full contact across the roller length for maximum load distribution and service life.
The cup is always paired with a matching Timken cone (inner race assembly). Together, they form a taper roller bearing set capable of handling combined radial and thrust loads in a single compact unit. Timken’s proprietary steel chemistry and heat treatment process produces cups with exceptional hardness uniformity and dimensional stability, even under heavy loads and elevated temperatures.
This product includes 9 cup variants grouped by outside diameter. The matching cone number for each cup is listed in the specifications table. Always replace cups and cones as matched sets.
- Timken Premium Bearing Steel — proprietary chemistry for hardness, toughness, and fatigue resistance
- Precision Ground — races and rollers ground to micro-inch surface finishes
- Combined Load Capacity — handles radial and thrust loads simultaneously
- Dimensional Stability — heat treatment ensures consistent fit under load and temperature
- ABMA/ISO Standards — manufactured to industry dimensional and tolerance standards
| Cup No. | O.D. (mm / in.) | Cone Bore (mm / in.) | Width (mm / in.) | Dynamic Load (N / lbf) |
|---|---|---|---|---|
| Taper Roller Cup - 3.125" O.D. (9) | ||||
| 17830 | 79.375 / 3.1250 | 42.987 / 1.6924 | 20.638 / 0.8125 | 68900 / 15500 |
| 18620 | 79.375 / 3.1250 | 44.450 / 1.7500 | 17.462 / 0.6875 | 52000 / 11700 |
| 26822 | 79.375 / 3.1250 | 35.000 / 1.3780 | 23.812 / 0.9375 | 91100 / 20500 |
| 26822A | 79.375 / 3.1250 | 39.687 / 1.5625 | 23.812 / 0.9375 | 91100 / 20500 |
| 2731 | 79.375 / 3.1250 | 36.487 / 1.4365 | 23.812 / 0.9375 | 86900 / 19500 |
| 2734 | 79.375 / 3.1250 | 38.100 / 1.5000 | 25.400 / 1.0000 | 86900 / 19500 |
| 3420 | 79.375 / 3.1250 | 31.750 / 1.2500 | 29.370 / 1.1563 | 105000 / 23500 |
| 43312 | 79.375 / 3.1250 | 24.384 / 0.9600 | 25.400 / 1.0000 | 92000 / 20700 |
Where Timken Taper Roller Bearings Work
- Automotive & Fleet — wheel hubs, differential carriers, transmission shafts, pinion bearings, and steering gear
- Agricultural Equipment — disc harrow spindles, combine rotor shafts, planter drives, and wheel bearings on implements and trailers
- Industrial Machinery — gearbox shafts, conveyor rollers, machine tool spindles, and pump drives
- Mining & Aggregate — crusher main shafts, screen deck bearings, and conveyor idler rolls
- Oil & Gas — mud pump crankshafts, rotary table bearings, and drawworks shafts
- Rail & Heavy Transport — axle bearings, traction motor bearings, and journal box assemblies
Selection Tip: Always match cone and cup part numbers from the Timken catalog. Dynamic load ratings in the spec table help you estimate bearing life using the L10 formula: L10 = (C/P)^(10/3) million revolutions, where C is the dynamic load rating and P is the equivalent radial load.
1 All dimensions follow the Lambear tri-format: Imperial fraction – Decimal inches – Metric (mm).
2 Dynamic load ratings are catalog values for L10 life calculation. Contact us for application-specific bearing selection.