Bearing should be installed in a dry, dust-free area as far as possible, and away from equipment that generates metal chips and dust. When it must be installed in a complex environment, contamination should be minimized. When installing bearings, mechanical, thermal or hydraulic methods should be selected according to the type and size. ”Cylinder bore bearing installation
cold installation
When installing small bearings that are not too tight, you can pass a sleeve (picture 5, picture 6) and use a hammer method to tap lightly The sleeve holds the bearing in place. The tap should be applied as evenly as possible to the bearing ring to prevent tilting or skewing of the bearing.
Most bearings are press-fit Installation. If the inner and outer rings of the bearing are to be installed on the shaft and the bearing housing at the same time, it must be ensured that the same pressure p acts on the inner and outer rings, and must be on the same plane as the contact surface of the installation tool.
Hot Mounting
Typically, for larger bearings, mounting is not possible without heating the bearing or housing, as mounting requires The larger the force is. The temperature difference between the bearing ring and the shaft or the bearing seat required for hot mounting mainly depends on the interference and the diameter of the bearing fit. The heating temperature of the open bearing should not exceed 120 ℃. It is not recommended to put the belt Bearings with seals and dust covers are heated to above 80°C (make sure that the temperature does not exceed the allowable temperature of seals and grease).
When heating the bearing, it should be heated evenly, and there must be no partial Overheating.
Bearing induction heater
Tapered bore bearing installation
Most of the inner ring of a bearing with a tapered bore is an interference fit The way to install. The amount of interference is determined by the axial advancing distance of the inner ring on the conical shaft diameter, the adapter sleeve or the withdrawal sleeve. The larger the advancing distance on the conical mating surface, the larger the diameter of the bearing. The smaller the internal clearance, the interference can be determined by measuring the clearance reduction or the axial advance distance.
Small and medium bearings can be installed with a bearing installation tool or preferably with a locknut. Push the ring to the appropriate position on the conical shaft diameter. In the case of using an adapter sleeve, use a socket nut that can be locked with a hook wrench or impact wrench. It should be pushed into the bearing bore.
Larger bearings require more force to install, so hydraulic nuts should be used.
Hydraulic nuts allow tapered bore bearings to be mounted on tapered bores. On the shaft diameter (Figure 11), on the adapter sleeve (Figure 12), on the withdrawal sleeve (Figure 13).
oil injection method
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The working principle of the oil injection method is: the hydraulic oil is injected into the mating surface between the bearing and the shaft diameter through the oil hole and the oil groove under high pressure to form an oil film. The oil film separates the mating surfaces so that the The friction is greatly reduced. This method is usually used when the bearing is directly mounted on a conical shaft diameter. The necessary oil holes and oil grooves should be part of the overall shaft design. If the adapter sleeve and the withdrawal sleeve, have been machined Oil hole and oil groove, this method can also be used to install the bearing on an adapter or withdrawal sleeve.
Figure 14
Example of common mistakes in bearing installation
Walk the inner circle
The fit between the shaft and the inner hole of the bearing is too loose (commonly known as 'walking the inner ring')
Because the fit between the shaft and the inner hole is too loose, the sliding between the shaft and the surface of the inner hole occurs. Sliding friction will cause heat, and the bearing will be damaged due to heat.
Sliding traces between the shaft and the inner hole surface
When 'walking the inner ringThe contact surface between the end face and the shaft shoulder is very small, and its temperature e is higher. The end face of the inner ring produces thermal cracks, and the continuous extension of the thermal cracks will cause the inner ring of the bearing to break during use.
The end face of the inner ring and the shaft e generate cracks due to friction and heat.
Due to the 'running of the inner ringand produce adhesions.
The shaft and the surface of the inner hole are heated and cause adhesion.
Walking the outer ring
The fit between the housing bore and the bearing outer diameter is too loose (commonly known as 'walking' Outer ring”)
Because the selected fit of the housing bore and the bearing outer diameter is too loose (), sliding occurs between their surfaces. Sliding friction will cause heat, causing the bearing to heat up and be damaged.
The traces of sliding between the housing bore and the bearing outer diameter surface
Install the bearing with interference fit of the inner ring (or outer ring), and it is forbidden to hit it directly with a hammer The end face of the inner ring (or outer ring) of the bearing, so that it is easy to knock out the rib. The sleeve should be placed on the end face of the inner ring (or outer ring) and installed by hitting the sleeve with a hammer.
The hammer directly hits the bearing
Some users use an acetylene spray gun to heat the inner hole of the bearing, when the heating temperature exceeds 727℃ (phase transformation temperature of bearing steel), the metallographic structure inside the bearing steel will change. When the bearing cools, the bearing bore cannot return to its original size, usually larger than it was before heating.
The surface of the bearing heated by the acetylene spray gun turns black
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