Installation design and clearance setting device of tapered roller bearings
Tapered roller bearings can be installed in various forms. In different installation forms, there are many ways to set the bearing clearance to the required axial clearance or preload. In the process of back-to-back installation of the inner ring setting clearance device, usually only one inner ring is supported by a fixed shoulder, while the other inner ring is movable and supported by some kind of setting clearance device. A slotted nut can be used to obtain the required bearing clearance (Figure 20). The nut is locked by a split pin. The size of the nut and washer must provide sufficient support for the inner ring. The two split pin holes on the shaft are separated by 90 degrees, which can obtain twice the locking position in one rotation of the nut, so that a corresponding tighter bearing clearance can be obtained. A self-locking nut, knurled washer, and lock washer can be used instead of a slotted nut (Figure 21). For the use of other lock nuts, please refer to the auxiliary parts section in the Timken® Tapered Roller Bearing Catalog. The bearing clearance can be set with the standard pile nut (Figure 22), and the thin end can be knocked into the keyway to lock it. The clearance in Figure 23 is obtained by means of bolts, gaskets fixed to the shaft end and end caps. The end cap can be slotted to measure the gap of the gasket. A TDO bearing (located above the centerline, Figure 24) with an inner ring spacer and a TNA bearing (located below the centerline) are manufactured with a fixed internal clearance. As shown in the figure, the TDO bearing has an inner ring spacer, which is clamped and installed on the shaft by the end cover and the shoulder. The TNA bearing directly tightens the inner ring on the shaft through the shoulder. In each case, no additional clearance adjustment process is required. During the face-to-face installation of the outer ring clearance setting device, usually only one outer ring is supported by a fixed shoulder, and the other movable outer ring can be adjusted by a suitable clearance setting device. An outer ring bushing (Figure 25, located above the center line) and an outer ring end cover (located below the center line) use gaskets to adjust the clearance, while the bushing or end cover is fixed by bolts. The clearance can be set by selecting the outer ring spacer and using the end cover bolted to the bearing housing (Figure 26). For TDI bearings with outer ring spacer (Figure 27), the outer ring spacer can provide a specific fixed internal clearance. The bearing clamps the outer ring and the spacer ring through the outer ring end cover and the bearing seat shoulder. No additional clearance adjustment process is required. Summary Compared with other types of bearings, one of the advantages of tapered roller bearings is that the clearance can be adjusted during installation. Manually set the clearance has been accepted by many manufacturers and will continue to be used. However, due to cost and stricter performance requirements, more manufacturers tend to use the method of automatically setting the bearing clearance. It is best to choose the method of automatically setting the bearing clearance at the design stage. However, if the equipment has been designed and manufactured, one or a combination of multiple clearance setting methods can also be used to improve the reliability of clearance setting and reduce assembly time. When choosing a suitable method for automatically setting the bearing clearance, please contact Timken's bearing sales engineer for further support. The Qingdao Ruijing Electromechanical Equipment Co., Ltd. team can provide assistance in fixture design, prototype testing and production process implementation.