The motor operates with significant vibration, and the gauge shaft fluctuates by about 0.13 mm
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630KW three-phase asynchronous motor, speed of 994 r/min; bearings MU234+6234, at the shaft extension end. It is a single-unit motor. The vibration levels are 1.0 in the vertical direction, 3.9 in the horizontal direction, and 1.0 in the axial direction when the motor is started. When the motor shaft is rotated using a dial indicator, the pointer moves by 0.13 mm. Is this caused by excessive bending? I’ve encountered situations where the gauge needle jumps by 0.3 mm, but the vibration isn’t that strong when it’s in operation.
This post was last edited by byh_XDNmY on 2022-12-6 08:22. When machining the outer surface of a coupling, factors such as the surface finish of that outer surface and the precision of the machining process need to be taken into account, right? Personally, I think it should be the machined surface; in addition, axial runout and dynamic balance also need to be considered. Additionally, the quality of the bearings also directly affects the vibration levels.
What was said upstairs makes sense. The reading you have, with paint on the surface, is probably not very accurate; the fluctuation values should be within a reasonable range. If possible, measure the spectral data to determine whether it’s a problem with the bearings or with the dynamic balance
Use a dial indicator to check whether the bottom corners of the motor are under load at 3 points with 1 point hanging in the air. After turning the machine on, loosen the bolts one by one to check the motor vibration, then tighten them, and proceed to check the next one, repeating this process. If there are no problems, check the sound of the bearings while the motor is running; it’s useful to have a comparison. If that’s not possible, consider the previous operating conditions or disassemble the rotor to check its dynamic balance. If everything is fine, replace the bearings and pay attention to the clearance of the bearing caps as well as the fit between the outer and inner circles
Is this how you time it? Shouldn’t they be together?