Timken36690-3Tapered Roller Bearing Cone Assembly, 5.750 in Bore x 1.125 in Wide, Class 3 Precision, Cone Only

Product Description

What this part is

This is a tapered roller bearing cone assembly: the inner ring complete with its roller set and cage. It is the 36690 cone from the 36600 inch series, 5.750 in (146.05 mm) bore, cone width 1.1250 in (28.575 mm). It runs in a 36620 cup, which is a separate component and is not included in this listing.

What the “3” means

The markings 36690-3, 36690 #3 and 36690 *3 all denote Class 3 precision. To the eye a Class 3 cone is indistinguishable from a standard one.

Timken’s inch tapered roller bearings are supplied in graded precision classes: Class 4 (standard), then Class 3, Class 0, Class 00 and finer, with each step tightening the tolerances on bore, outside diameter, width and on radial and axial runout. A Class 3 cone runs truer than a standard cone in the same envelope. It costs more, it is stocked less widely, and it is specified where shaft runout translates directly into a quality problem: machine tool spindles, printing and converting rolls, gear grinders, precision index drives, paper machine positions.

A standard 36690 fits where a 36690-3 is called for, and it does not perform the same. The specific runout limits for Class 3 are set by Timken’s precision tolerance tables.

What is and is not included

Cone assembly only: inner ring, rollers, cage. No cup. Cups and cones are separable by design and are routinely replaced independently, since the cup presses into the housing and the cone onto the shaft. A complete bearing also requires a 36620 cup.

Published dimensions and ratings

Timken publishes these figures against the 36690 cone itself. Every rating below is a per-bearing figure, not a set figure.

Bore (d): 5.7500 in / 146.050 mm. Inner Ring Width (B): 1.1250 in / 28.575 mm. Dynamic Load Rating C1, per bearing (1 million revolutions, ISO method): 44,200 lbf / 196,000 N. Dynamic Radial Load Rating C90, per bearing (90 million revolutions, Timken method): 11,400 lbf / 50,900 N. Dynamic Axial Rating Ca90, per bearing: 7,220 lbf / 32,100 N. Static Load Rating C0, per bearing: 88,600 lbf / 394,000 N. K Factor: 1.59. G1 Factor: 366. G2 Factor: 121. Geometry Factor Cg: 0.177. Mass: 10.52 lb / 4.773 kg. Precision Class: Class 3. Series: 36600 inch series. Number Of Rows: 1. Rolling Elements: tapered rollers.

Envelope of the mating half, for a stack-up: 36620 cup outside diameter 7.625 in / 193.68 mm, cup width 0.9063 in / 23.02 mm, assembly width (T) 1.125 in / 28.58 mm.

What these specs mean in practice

The K Factor of 1.59 is the ratio of radial to thrust capability set by the cup angle. At 1.59 the 36600 series sits in the middle of the tapered roller range, carrying a useful axial component alongside its radial load. That is the mix a gear-driven shaft produces, which is why the series turns up in gearbox, spindle and roll positions.

Quantity and configuration

Each piece is one cone, not a set and not a cone-and-cup pair.

Mounting data

Effective Load Centre: 0.19 in / 4.8 mm. Maximum Shaft Fillet Radius: 0.06 in / 1.5 mm. Shaft Backing Shoulder Diameter, frontface (da): 6.02 in / 153 mm; backface (db): 6.10 in / 155 mm. Cage Location relative to backface (Aa): 0.04 in / 1 mm; relative to frontface (Ab): 0.13 in / 3.3 mm.

The cone presses onto the shaft. Tapered roller bearings have no built-in internal clearance; operating endplay or preload is created at assembly by how far the cone is drawn up against the cup. In a precision position that setting is specified by the machine builder.

Interchange guidance

36690 is an industry-standard inch cone designation, so a 36690 from any maker is dimensionally interchangeable. The precision class is not part of the base number, so a plain 36690 is a Class 4 standard part and is not equivalent to this 36690-3. Cross-references for the base part: 36690, 36-690, 36690-3, 36690 #3, 36690 *3, 36690 CL3.

Same-envelope sibling cone: 36691. Mating cups: 36620, 36620D (double cup), 36620DC, 36620P, 36620-B (flanged cup). Related assemblies: 36690/36620, 36691/36620, 36690/36620D, 36690/36620DC.