Motor axial vibration
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There is a 45KW, class 2 motor used to drive a gas conveyor. The vibration levels at the impeller end and the bearing housing are normal, but the axial vibration peak of the motor reaches 200um, while the vibrations in other directions are less than 100um. Could you please tell me the reason for this?
Reply to 1# pzhzjq: “It’s a 45KW motor of grade 2;... the peak axial vibration of the motor reaches 200um, while the vibrations in other directions are less than 100um.” The radial vibration of the motor also exceeds the allowable value, which should be 50um； 2 If the axial vibration of the fan is low, it is recommended to check the coupling to see if the elastic ring or claw-type coupling (six-star gear) is excessively worn.
Check whether the foundation strength is sufficient; this is just my personal suggestion for reference only.
Reply to 2# hcwang12345: The coupling has been replaced, and the motor bearings have also been replaced
After checking the couplings and bearings, you should also recheck the alignment to ensure that none of the motor foot bolts are loose； If that still doesn’t work, check whether the foundation is in good condition, and also examine whether the motor base is deformed.
Should the bearings be replaced before or after the vibration occurs? If it is after the vibration, it may be necessary to check the quality of the bearings, as well as whether they are installed in the correct position; also, it’s important to check whether shims of different sizes have been used in the gland
First, recheck the alignment; if that doesn’t work, perform on-site dynamic balancing!
Reply to 6# Gui Yunfei: There has been no significant change in vibration after the bearings were replaced
Reply to 4# pzhzjq: If the coupling has been replaced and axial vibration of the motor increases after that replacement, I assume the original poster has already determined the cause; it’s necessary to check whether there are any issues with the manufacturing of the coupling! What type of coupling are you using?
Reply to 9# hcwang12345: Elastically cancellable coupling
Reply to 10# pzhzjq: If it is a flexible pin coupling, is there any wear in the pin holes, and are the pin holes machined out of alignment?