Reasons for bearing burnout in multi-stage pumps
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I’m new to multi-stage pumps, and I’ve encountered bearing burnout. I first removed the bearing housing from the rotor impeller bearings, then measured the total translation amount of the impeller back and forth, and adjusted the position of the bearings using shims so that the impeller was in the center position. So far, after the machine has been running for a day, no heating of the bearings has been observed. Do any of you have any other simple methods to determine the center position of the impeller? Also, we’re all using deep-groove bearings – how can there be cross-talk momentum? I’m a beginner; please advise me, experts.
Install the balance discs and then measure the axial displacement again; this is known as the supplementary axial displacement. Theoretically, this supplementary axial displacement should be half of the total axial displacement of the impeller. Once this value is set correctly, the position of the impeller will be roughly in the middle between the two intermediate sections. Next, install the seal on the non-driving end, tighten the gland screws, and push the shaft toward the driving end so that the friction surfaces of the two balance discs come into contact. Install the bearing and bearing housing on the non-driving end, and tighten the bearing gland properly. Before locking it in place, place a dial indicator on the coupling surface and set it to zero. Then lock the non-driving end; as it is locked, the dial indicator will rotate counterclockwise, causing the non-driving end to move axially and separating the friction surfaces of the two balance discs. The axial distance between these friction surfaces is called the balance disc gap, and this gap should be adjusted to between 10 and 20 microns. When the pump is started, the rotor moves from the outlet to the inlet; the outlet being on the high-pressure side, this creates an axial force on the rotor that pushes it from the outlet toward the inlet. This axial force drives the rotor in motion. The balance disc, along with appropriate balance gaps and balance tubes, helps to counteract this axial force. Deep groove ball bearings are primarily designed to bear radial loads
Thank you! Very detailed; I used to work on compressors and only started working with multi-stage pumps recently after being transferred to the methanol sector. Thank you for the answer