Precautions
As rolling bearing is a precise component, we should operate carefully during the mounting and dismounting preferably with the tools. Neither strong impact nor direct hit upon the bearing nor pressure via the rolling is allowed. Keep the mounting environment clean and no material like cloth or fibre should be used to clean the bearings as they effect the bearings life & result in premature failure of bearings.
Bearing Mounting
Whether the bearing mounting is correct has the direct influence on the precision, life and the performance of bearings. The bearing should be mounted according to right and scientific operation standard. The work flow can be as follows:
- Clean up bearing & relevant components.
- Check dimension and precision of relevant components.
- Mounting Operation
- Inspect after Mounting
- Replenishment of lubricants
The mounting method of bearing varies with bearing structure, fitting and working conditions.If shaft rotates, the inner ring need to adopt interference fit. For bearings with cylindrical bore, we often use press tool for mounting or expand bearing by heating. Bearing with tapered bore is mounted directly on tapered shaft or use sleeves for mounting. Clearance fit is often applied to the housing.
Anti-corrosion measure should be taken in situations in which ice is used for the coolant in thermal contraction method because the moisture in the atmosphere adheres to bearings.
Bearing Dismounting
A bearing may be removed for periodic inspection or periodic change. When dismounting, the procedure and sequence of removal should first be studied using the machine drawing and considering the type of mounting fit in order to perform the operation properly. Dismounting of bearings with cylindrical bores & with tapered bore are to be done with the proper tools.
Maintenance of bearings
To keep the original performance, proper maintenance & inspection should be performed.Periodically according to the operation standard of target machinery. This periodic maintenance encompasses the supervision of operation conditions, the periodic inspection.
If an irregularity is found during operation, the cause should be determined and the proper corrective actions should be taken. If necessary, the bearings should be dismounted & examined in detail.
Methods of analyzing bearing failure
1. Noise Checking should be done to detect the abnormalities in bearings. Attaching hearing aids or listening rods on housings is effective for detecting bearing noise.
2.Operating temperature should be checked to detect the abnormalities in bearings. If the abnormality is there, then the temperature either increases or changes irregularly.
3.Lubrication checking enables to check the defects from the foreign elements including dirt and metallic powder. This method is used where the bearings cannot be checked by close visual inspection and for the large size bearings.