Bearings are widely used in construction machinery, however, many people do not follow the correct methods to mount and remove bearing from a shaft which caused many problems.
For example, some time ago, when the factory staff disassembled the shaft end bearing of the motor, the inner ring of the bearing and the motor shaft were stuck together due to bearing damage. The worker wanted to press the bearing with a homemade press, but during the pressing process, The outer casing of the bearing and the inner sleeve are relatively slid, the bearing cage is broken, and the debris hits the worker's lower jaw, which caused a minor injury.
That is to say, how to remove the sleeve and bearing from a shaft is very significant to mechanical normal operation and bearing maintenance. Therefore the below content is all ways about how to remove the bearing from a shaft correctly
When we remove a smaller bearing, use a suitable punch to gently tap the side of the bearing ring to remove it from the shaft. A better method is to use a mechanical puller (Figure 1). Pulling acts on the inner ring or adjacent parts. If there is a groove between a shaft shoulder and bearing housing bore shoulders for the puller. This way simplifies the disassembly process. In addition, make some threaded holes on the bore shoulders to allow the bolts to push the bearings out (Figure 2).
Large and medium-sized bearings typically require more force than mechanical tools provide. Therefore, it is recommended to use hydraulic power tools or oil injection methods, or both. This means that the shaft needs to have oil holes and oil grooves. (Fig. 3).
When removing the inner ring of needle roller bearings or NU, NJ, and NUP cylindrical roller bearings, it is suitable to use the thermal disassembly method. Two commonly heating tools: heating rings and adjustable induction heaters.
Use the heating ring to install and remove the inner ring of a small and medium-sized bearing of the same size. The heating ring is better to choose a light-alloy ring. The heating ring has a radial slot and is equipped with an electrically insulated handle (Figure 4).
Debuggable induction heaters are recommended if the inner rings of different diameters are frequently removed. These heaters (Figure 5) can heat the inner ring quickly without heating the shaft. When disassembling the inner ring of a large cylindrical roller bearing, some special fixed induction heaters can be used.
Remove small bearing by pulling the inner ring with a mechanical or hydraulic assist puller. Some pullers have a spring-operated arm. Using this self-centering puller simplifies the procedure and avoids damage to the journal. If the puller jaws have no use for the inner ring, we can remove the bearing via the outer ring or with a puller in combination with the pull tab (Figure 6).
When using the oil filling method, the disassembly of medium and large bearings is safer and simpler. This method injects hydraulic oil between two conical mating faces through an oil hole and an oil sump under high pressure. Reduce the friction between the two surfaces and generate an axial force that separates the bearing from the shaft diameter.
For small bearings on a tight-fitting straight shaft, we can use a hammer to strike a small steel block that acts evenly on the end face of the bearing inner ring (Figure 7). Prior to this, lose the adapter sleeve locknut several times.
For the tightly fitted stepped shaft bearing, remove the bearing by tapping the small end face of the adapter sleeve lock nut with a special sleeve (Fig. 8). Prior to this, lose the adapter sleeve locknut several times.
For the tightly fitted stepped shafts bearing, the use of hydraulic nuts makes bearing removal easier. For this purpose, it is necessary to install a suitable stop (Fig. 9) in close proximity to the hydraulic nut piston. The oil filling method is an easier method, but we need to use an adapter sleeve with oil holes and oil grooves.
When removing the bearing on the withdrawal sleeve, we must remove the locking device. (such as lock nut, end plate, etc.)
For small and medium-sized bearings, we are better to use a lock nut, hook wrench, or impact wrench for disassembly (Figure 10).
For medium and large bearings on the withdrawal sleeve, it is easy to remove bearing with a hydraulic nut. It is recommended to install a stop behind the hydraulic nut on the shaft end (Figure 11). The stop device prevents the withdrawal sleeve and the hydraulic nut from flying out of the shaft when the withdrawal sleeve is suddenly separated from the engaged position.
To sum up, after you read our content about effective ways on how to remove the sleeve and bearing from a shaft you may reduce a lot of trouble when removing the bearing