Problems with centrifugal pump installation
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Hello, specialists! During routine maintenance of centrifugal pumps, when it is necessary to replace the shaft, the radial runout at the shaft end where the impeller is located is within acceptable limits (﹤0.03mm) before the new shaft is fitted with bearings. However, after the bearings are installed, the runout at the same location increases to around ten microns; moreover, lifting the shaft also results in a runout of about 10 microns. The clearance in the bearing cover is usually set at 5 microns. What could be the reason for this? The fixed-end bearing is a back-to-back angular contact bearing, while the free end is a NU series bearing. Is it really caused by bearing clearance?
You might have overlooked one issue, which is levelness. If you don’t put in the effort, such phenomena won’t occur.
Learn how to measure it – what size of pump is needed?
What do you mean by levelness?
You’d better upload a video; it’s easier to discuss when there are visuals.
Firstly, coaxiality has little effect on shaft runout; it only increases the radial load. Any bearing installation will experience deformation due to the amount of interference, and this degree is indeed related to the clearance
The bearing heater is installed hot, so the interference deformation should be uniform, right?