After the mounting has been completed, a running test should be conducted to confirm that the bearings have been mounted correctly.
Turning by Hand and Test Operation
For small machines and in cases where the shaft can be rotated easily, turn the bearing manually to confirm that it rotates smoothly. If there appear to be no problems like uneven or irregular rotation, make a test operation under power.
For large machines, start it under no load and let it coast by immediate switch-off. After confirming that there are no problems such as vibration or noise, make a test operation under power.
Powered operation should be started under no load, and its speed and load should be gradually increased. The temperature of the bearing would rise slowly and come to a constant temperature after one or two hours. If there is a problem of the bearing or its mounting, the temperature would keep rising abnormally and excessively.
Abnormal Bearing Operation Causes and Countermeasures
|
Operation Status
|
Causes
|
Countermeasures
|
|
|---|---|---|---|
| Noise | Loud Metallic Sound | Abnormal load | ●Correct the fit ●Check the clearance ●Adjust the position of housing shoulder, etc. ●Adjust the preload |
| Improper mounting | ●Improve machining accuracy of shaft and housing ●Improve the accuracy when mounting bearings |
||
| Insufficient or improper lubricant | ●Replenish lubricant ●Replace with proper lubricant |
||
| Contact of rotating parts | ●Correct contact where rubbing occurs | ||
| Loud Regular Sound | Flaws and scratches on raceway | ●Replace bearing | |
| Flaking on raceway | ●Replace bearing | ||
| Irregular Sound | Excessive clearance | ●Replace bearing with appropriate clearance ●Readjust the clearance |
|
| Penetration of foreign particles | ●Clean or replace bearing ●Clean related parts ●Improve seal or shield ●Replace lubricant with clean one |
||
| Flaws or flaking on balls | ●Replace bearing | ||
| Abnormal Temperature Rise | Excessive amount of lubricant | ●Reduce the amount of lubricant | |
| Insufficient or improper lubricant | ●Replenish lubricant ●Replace with proper lubricant |
||
| Abnormal load | ●Correct the fit ●Check the clearance ●Adjust the position of housing shoulder, etc. ●Adjust the preload |
||
| Improper mounting | ●Improve machining accuracy of shaft and housing ●Improve accuracy when mounting bearings |
||
| Creep on fitted surface Excessive seal friction | ●Replace bearing ●Review the fit ●Improve the seal |
||
| Excessive Vibration | Indentation or flaking on raceway | ●Replace bearing | |
| Improper mounting | ●Correct perpendicularity of the shoulder of shaft or housing and squareness of side face of spacer ●Improve accuracy when mounting bearings |
||
| Penetration of foreign particles | ●Clean or replace bearing ●Clean related parts ●Improve seal or shield ●Replace lubricant with clean one |
||