The rotor dynamic balancing machine equipment is secondarily corrected. It is a rotor that does not meet the rotor dynamic balance level, the unbalance amount is greater than the rotor dynamic balance standard, and the rotor is re-placed in the dynamic balancing machine.

In the usual rotor correction work, we use more of the imbalance after the rotor is recalibrated and the unbalanced quantity does not meet the standard. That is, each time the rotor is dynamically balanced, the unbalanced quantity after retesting is still not in accordance with the standard rotor. Secondary correction.

1, 180 ° two test plus mass method
(1) Start the unit at a steady working speed, measure the amplitude of each bearing (which can only measure the bearing closest to the rotor and measure the bearing in the future) in three directions (refer to the double amplitude).
(2) Determine the test mass based on the amplitude, rotor mass, speed, and the radius at which the counterweight is mounted. The calculation formula for the test plus quality is 2 3000) 1.5WAR(n P(12-7)
In the formula:
A - the original maximum amplitude, silk;
W - the mass of the rotor being balanced, kg;
R —— test the mass installation radius, mm;
n - rotor operating speed, r / min.
The above formula is an empirical formula, and the test quality can be increased or decreased according to the situation. However, the centrifugal force generated by this mass should not be greater than 10% to 15% of the rotor mass. (According to the experience of dynamic balance calibration, the quality of the mass can be tested. Add 20% to 30% based on the calculated result value for reference).
(3) Mount the test mass on the rotor as the mark 1 (according to the actual experience, it is generally installed at the outer circumference of the top of the vertical line passing through the center of the shaft after the rotor is naturally stopped), then start the unit and measure the bearing. The amplitude A 1 is stopped after the amplitude is measured in stable operation.
(4) Remove the test mass, move it 180 °, install it and mark it 2, then start the unit for the third time, measure the amplitude A 2 of the bearing, and stop the machine after measuring the amplitude in stable operation.

2. Drawing and calculation.
(1) Make a triangle ODM such that OM : OD : DM = A 0 : ? A 1 :? A 2 .
(2) Extend MD to C, make CD=MD, and connect OC.
(3) With O as the center and OC as the radius for a circle.
(4) Extend the intersection of CO and circle at B, and extend the intersection of MO and circle at S.
(5) Determination of balance quality: The balance quality is calculated according to the following formula, namely OC OM P G where: P —— test quality, mg.
(6) Determination of the balance mass position.
If the angle of the COS is α, the balance mass should be added at the counterclockwise turning α angle of the first trial plus mass position 1 or clockwise to the α angle. Here is the ∠MOC as an angle between the unbalanced mass and the test mass, which can be proved by the graph method. Since the disturbance power is proportional to the amplitude, the phase difference between the vibration and the disturbance power does not change at a certain speed, so the vibration vector can be used to represent the force. O represents the center of rotation of the shaft, and OM represents the original unbalanced centrifugal force.
Extend OD to N to make DN=OD

For many newcomers, due to the lack of skill in the process of rotor dynamic balance, the correction of the rotor is not ideal, and it needs to be corrected by secondary correction.