Special precautions for adjusting bearing clearance by SET-RIGHT method
1. Because of the difference in K factor, equivalent axial tolerance and the number of tight-fitting parts (that is, the inner ring and outer ring are tightly matched at the same time) of tapered roller bearings, the final calculated bearing clearance range may vary greatly. Timken’s sales engineers can help customers select bearings with special tolerances during the design stage, and help customers optimize the installation design, so that the bearing clearance can obtain the smallest high probability range. 2. To control the mounting dimensions of the bearing, the tolerances of the mounting dimensions of the bearing system must be kept consistent and stable. In some cases, these tolerances should be controlled more strictly. 3. If the high probability range of bearing clearance cannot be obtained by controlling the tolerance, it is impractical and unsuccessful to try to reduce the larger tolerance, then a derivative method of SETRIGHT—SPIN-RIGHT method must be considered. 4. On-site replacement parts must use bearings of the same category and code as the original production. Derivation of the SET-RIGHT method: SPIN-RIGHT method In some cases, when the SET-RIGHT method is used, the high probability interval of bearing clearance may be too large for practical applications. To reduce this interval and still apply the law of probability, we can use the SPIN-RIGHT method. This method can be used for applications that facilitate the adjustment of the gasket set (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 that the high probability clearance interval of the bearing in Figure 1 is calculated to be 0.018 inches, this 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 methods can be used: 1. Assemble the gearbox (no shim and rotation check required, no Seals), confirm whether the bearing has axial clearance or preload. In the first rotation check, if the shaft rotates freely, then there is an axial clearance (Figure 8), and the bearing clearance is correct. 2. If the shaft cannot rotate freely and the bearing is preloaded, then a 0.009 inch gasket must be installed. In the second rotation test, if the component can rotate freely, it indicates that there is an axial gap. 3. If the preload is the required clearance, then the steps of the SPIN-RIGHT method in the above example should be executed in reverse order: if the shaft can rotate freely, then the bearing clearance is incorrect, and the 0.009 inch one needs to be removed. Gasket. Typical application of SET-RIGHT method The SET-RIGHT method has been applied to a variety of applications where the bearing clearance needs to be set, including tractor PTO assembly (especially blind end or split bearing housing design), automobile front drive wheels, gear reduction boxes Shafts, planetary gears, sprockets and torque wheels used in construction and mining equipment.