Special precautions for adjusting bearing clearance by SET-RIGHT method1

1. The final calculated bearing clearance range may vary widely due to differences in tapered roller bearing K-factor, equivalent axial tolerance, and number of tight-fitting components (ie, larger when inner and outer rings are tightly fitted at the same time). Timken's sales engineers can help customers select bearings with specially controlled tolerances during the design phase, and help customers optimize mounting designs to obtain the smallest high-probability interval for bearing clearance. 2. Control of bearing installation dimensions, the tolerances of bearing system installation dimensions must be consistent and stable, and in some cases these tolerances should be more strictly controlled. 3. If the high probability interval of bearing clearance cannot be obtained by controlling the tolerance, and it is impractical and unsuccessful to try to reduce the larger tolerance, consider a derivative method of SETRIGHT, the SPIN-RIGHT method. 4. Field service replacements must use bearings of the same category and code as originally produced. Derivation of SET-RIGHT method: SPIN-RIGHT method In some cases, when using the SET-RIGHT method, the bearing clearance high probability interval may be too large for practical application. To reduce this interval and still apply the laws of probability, we can use the SPIN-RIGHT method. This method can be used in applications where shim pack adjustment is facilitated (Figure 16). When using this method, simply divide the current high probability interval by 2 or 3, depending on the acceptable clearance range for the application. For example, assuming the high-probability clearance interval for the bearing in Figure 1 is calculated to be 0.018 inches, the application requires an axial clearance of 0.000 inches to 0.009 inches. The current range must be reduced by half. With the SPIN-RIGHT method, the required shim increment (using a shim between the end cap and the shaft) will be equal to 0.009 inches, the following method can be used: 1. Assemble the gearbox (no shims and rotation check, no seals), confirm whether there is axial play or preload in the bearing. During the first rotation check, if the shaft is free to rotate, then there is axial play (fig. 8) and the bearing clearance is correct. 2. If the shaft does not rotate freely and the bearing is preloaded, a 0.009 in. shim must be installed. Axial play is indicated if the assembly rotates freely during the second rotation test. 3. If the preload is the required clearance, the SPIN-RIGHT method steps in the example above should be performed in reverse order: If the shaft rotates freely, then the TIMKEN bearing has incorrect clearance and needs to be removed by 0.009 inches gasket. Typical SET-RIGHT Method Application The SET-RIGHT method has been used in a variety of applications where bearing clearance needs to be set, including tractor PTO assemblies (especially blind end or split bearing housing designs), automotive front-wheel drive wheels, gear reduction boxes Shafts, planetary gears, and sprockets and torsion hubs used in construction and mining equipment.