The horizontal vibration of the impeller-side bearing housing in a centrifugal fan is high; how should this be addressed?
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For the centrifugal exhaust fan, the horizontal vibration of the turbine-side bearing housing is 13 mm/s, while the vertical vibration is 5 mm/s; the horizontal vibration of the drive section is 4.2 mm/s, with a vertical vibration of 2.0 mm/s. It uses a belt drive. The higher the frequency, the greater the vibration; before replacing the bearings, the maximum vibration on the impeller side reached 22 mm/s. What should be done in this situation? Thank you!
Hello, based on the data, the following analysis can be conducted: First, check whether the bearing clearance meets the standards and whether there is any damage. Second, after replacing the new impeller, the rotor should be rebalanced. If the bearings are fine, then there is an imbalance in the rotor, which is why vibrations occur.
So, check whether the bearing clearance is appropriate!
Check the fan foundation, levelness, impeller dynamic balance, and bearing clearance
Equipment vibration is related to the clearance precision of the bearings, as well as the equipment foundation, the levelness of the equipment, and whether there is sufficient air flow at the inlets and outlets. Check them one by one
There are steps to follow when carrying out maintenance; first, it is necessary to determine whether the problem developed gradually or suddenly. It’s still a phenomenon that occurs during normal maintenance. Next is to find the cause; first, manually rotate the rotor and use touch to check whether there are any issues with the bearings ； Perform dynamic balancing after discharge ； After all this is done, the basic links need to be checked. These are the main issues. Then there are the process-related issues, such as surge and oil circuit problems. . . . .
The thrust bearing is worn or the back cap is loose; also check the parallelism of the two pulleys.
It’s a standard centrifugal fan without thrust bearings; the pulley has been checked and is fine.
If it is only the horizontal vibration on the impeller side that is high, I would lean towards a problem with the bearing assembly clearance. If the vibration level was 22 before replacement and still 13 after replacement, check for any wear at the fitting area of the outer ring of the bearings in the bearing housing; another possibility is an issue with the impeller’s dynamic balance