There is noise from the three-screw pump in the light oil station
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This post was last edited by Frozen Desert on 2019-2-16 at 15:54. There was noise coming from the motor bearings yesterday; after replacing those bearings this morning, noise was heard again one minute after the pump started running. What could be the cause? Is the gap at both ends of the rotor larger?
Low temperature, oil solidification/impurities present, high stress on the screw – unusual noises?
It’s because the medium has solidified. Keep running and observe
The other backup unit makes no sound when connected; I plan to take it apart to check it today
This post was last edited by Frozen Desert on 2019-2-17 09:41. The main screw is a bit rusty, and the upper part of the secondary screw is slightly worn
There’s no space in areas where there’s no clearance
How to measure the screw clearance? I didn’t find anything
After disassembling it yesterday and swapping the auxiliary screw, there was still noise when reinstalling it; no signs of wear were detected, and the noise remained the same. Is the axial clearance too large? The axial clearance was not measured
The secondary screw is worn; it is not possible to determine whether the balance sleeve is worn, but the diameter clearance can be measured. When investigating external causes, 1. First, determine if there is an installation issue – is the coupling aligned? Reasons related to the pump: 2. If there is excessive vibration and loud noise only when the pump is started, it is due to dry friction between the screw and the rubber sleeve ； Remember, screw pumps must not be operated dry! Check whether the inlet of the pipeline is too narrow; a low material temperature results in slow flow into the pump chamber, causing the pump to not receive enough fluid. 3. In the event of prolonged vibration, check the screw and the screw sleeve, as well as whether there are any impurities inside the pump and if the sleeve is severely worn.
The vibration isn’t much; it’s mainly the noise that’s loud. There are no rubber covers – everything is made of metal. Only the machine seal area hasn’t been removed; everything else has been taken apart
Your auxiliary rod is worn; this wear is caused by wear on both the main and auxiliary components. The other cylinder liners show no signs of wear. Is the medium dirty? It’s not a problem with the mechanical seal. It makes noise after running for a while as well, right? If there are no sounds of friction or collision, then it’s not a big problem.