Key characteristics of vibration spectrum: rotor unbalance is usually the core of high rotating frequency vibration, and its rotating frequency vibration component usually exceeds or corresponds to about 80% of its pass frequency vibration.
The unbalanced force has the necessary directionality, the centrifugal force is uniform on the radial foundation, and the motion track of the shaft and the supporting bearing is similar to that of a circle. Obviously, since the vertical bearing stiffness of the bearing seat exceeds the horizontal direction, the normal motion track of the shaft and the supporting bearing is elliptical, i.e. the horizontal vibration is 1.5 to 2 times larger than the vertical vibration under normal conditions. If this standard is exceeded, other problems will exist. Very likely there will be resonance problems.
In comparison with axial vibration, when imbalance is at the core, the radial vibration (horizontal and vertical) is smaller than the axial vibration (except for the cantilever rotor).
This article was originally edited by Shenman Balancing Machine Factory www.shshenman.com. It can not be reproduced without permission!
The unbalanced force has the necessary directionality, the centrifugal force is uniform on the radial foundation, and the motion track of the shaft and the supporting bearing is similar to that of a circle. Obviously, since the vertical bearing stiffness of the bearing seat exceeds the horizontal direction, the normal motion track of the shaft and the supporting bearing is elliptical, i.e. the horizontal vibration is 1.5 to 2 times larger than the vertical vibration under normal conditions. If this standard is exceeded, other problems will exist. Very likely there will be resonance problems.
In comparison with axial vibration, when imbalance is at the core, the radial vibration (horizontal and vertical) is smaller than the axial vibration (except for the cantilever rotor).
Direction of unbalance problem of cantilever rotor. Generally speaking, both radial and axial vibration are large. This is the existence of static unbalance and force couple unbalance together. Therefore, balancing correction needs to be carried out in two planes generally.
Rotors with unbalanced vibration problems have smooth and identical vibration phases. The imbalance problem promotes the amplification of the resonance amplitude. If the operating speed of the rotor is close to the resonance point at the system's natural frequency, a small amount of imbalance vibration will expand by 10 to 50 times.
The phase performance of rotor imbalance problem is the same as that of rotor input and output bearings in horizontal direction (+/-30 degrees). Otherwise, the key problem is not dynamic balance. For example, if the vibration phase difference detected at the horizontal direction of the bearing at the input and output sides of a motor is 30 degrees and the similarity of the vibration phase difference detected at the vertical direction of the bearing at the input and output sides is 150 degrees, the technician attempts to balance the rotor dynamically as if it were a waste of time.This article was originally edited by Shenman Balancing Machine Factory www.shshenman.com. It can not be reproduced without permission!
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