Installation and maintenance of bearings
The main elements that affect the normal operation and life of turntable bearings:
1. Manufacturing quality 2. Lubrication and maintenance 3. Rigidity of support base structure 4. Accuracy of mounting plane of support base
5. Mass of bolt pair 6. Pre-tightening force for bolt installation 7. Installation quality 8. Overload work
Mounting plane
The turntable bearing is a large thin-walled ring component, which must be rigidly connected to the support seat. If the mounting plane of the car is uneven, the turntable bearing will warp with the shape of the mounting plane after the installation. Deformation
Installation requirements
Bearing installation should meet the following requirements:
● Before installation, do not open the inner and outer packaging at will to prevent moisture, dirt, etc. from entering. After the packaging is removed, install and soften the bearing in a short time.
● Before installation, clean the mounting plane of the support seat to remove oil, burrs, and debris (see Figure 8)
● Before installation, check the appearance and rotation of the bearing, such as: rotation accuracy, clearance (see Figure 9), turning flexibility, whether the seal is installed in place, lubricant filling, etc.
● During installation, the points marked with "S" (hardened soft band) on the end face of the turntable bearing should be placed in the non-load area or the area where the load is not frequently used (the filling plug is always located at the soft band of the ferrule) Figure ten)
● After the bearing is placed on the support seat, a feeler gauge should be used to check the fit between the bearing mating surface and the mounting plane of the support seat. If there is a gap, the mounting plane should be re-processed. When it cannot be processed, it can be filled with high-strength special plastic or appropriate gaskets to prevent the bearing from deforming after the bolts are tightened.
● The axis of the mounting hole on the mounting plane should be as coincident as possible with the axis of the bearing mounting hole. For oil-lubricated bearings, pay attention to the location of the lubrication hole.
● The bolts should be evenly tightened, such as sequential tightening or M-shaped tightening, and ensure that the pre-tightening force meets the specified requirements
● Welding operations are not allowed on bearings. When welding operations are performed on adjacent parts, heat transfer to the bearings should be avoided to avoid bearing deformation or hardness changes.
● For bearings with a ring gear, in order to ensure the smoothness and meshing performance of the bearing transmission, the gears should be checked for meshing accuracy, contact length, backlash, etc. before the bolts are fully tightened.
● After installation, the rotation of the bearing must be checked to prevent jamming points and abnormal sounds. If there are jamming points, readjust them.
● Check the gap between the bearing and the seating surface. If there is a supporting gap, it must be eliminated.
● Increase rain protection measures for bearings that are often operated in the open air
● Anticorrosive measures should be taken for bearings operating in corrosive environments. The surface anti-corrosion treatment of the turntable bearing includes metal spraying such as aluminum spraying, zinc spraying, paint spraying, and phosphating treatment.
maintenance
Proper maintenance of the turntable bearings can ensure the effective performance of the bearings and prolong the service life of the bearings. Maintenance is generally divided into two phases, one is the maintenance of new bearings after installation and "run-in" operation for a period of time, and the second is the daily maintenance after entering normal work.
The first stage of maintenance is generally performed within 100 hours of new bearing use. The focus of maintenance is to clean the dirt (oil) on the tooth surface and the bearing seal, check the accuracy of the meshing, and re-tighten the bolts once. The second phase of maintenance is divided into daily maintenance and regular maintenance:
● Routine maintenance is performed after each equipment startup. Check the bearings for abnormal sounds, vibrations, host current changes or sudden power increases. If there is an abnormality, stop the machine for inspection.
● Regular maintenance is generally performed every 500 hours according to the workload of the host and environmental conditions. Before the regular maintenance, the bearing should be inspected. The inspection is limited to the appearance and running state. The bearing must not be disassembled. The main inspection contents and countermeasures can be found.
