1. During the operation of the centrifugal pump, if there is vibration, impact or sudden increase of torque, the shaft of the pipeline centrifugal pump will be bent or broken. For certain dimensions on the pump shaft (such as the journal size at the point of engagement with the impeller, rolling bearing, and coupling), the micrometer should be used for dimensional accuracy measurements.
2. The measurement of the straightness deviation of the pump shaft of the centrifugal pump is also carried out in order to grasp the correct data of the straightness deviation of the pump shaft. First, place the pump shaft between the two tips of the lathe, set two dial gauges at appropriate places on the pump shaft, divide the outer circumference of the journal into four equal parts, and mark them separately, ie 1, 2 3, 4 four points. Slowly turn the pump shaft by hand, record the readings of the dial gauge at the four points in the table, and then calculate the straightness deviation of the pump shaft.
3. The calculation of the straightness deviation value is: half of the difference between the two dial gauges in the diameter direction. For example, the straightness deviation in the 0° and 180° directions of the I measurement point is (0.36-0.20)/2=0.08 mm. The linear deviation in the 90° and 270° directions is (0.28-0.27)/2=0.05 mm. Using these values to select a certain ratio on the graph, the bending amount and bending direction of the maximum bending point on the pump shaft can be approximated by a graphical method.
4. Check the key connection. The two ends of the pump shaft are respectively matched with the impeller and the coupling, and the two sides of the flat key should have a small interference fit with the side of the keyway on the chest shaft, and the two sides of the keyway of the impeller hole and the key hole of the coupling are Transitional cooperation. When checking, you can use the vernier caliper or micrometer to measure the size. If there is a gap between the width of the flat key and the width of the keyway on the shaft, regardless of the gap value, you can assume that the flat key has lost its useful value. Therefore, according to the actual width of the keyway, re-align the flattening key according to the tolerance. The two sides of the keyway should be perpendicular to the bottom surface of the keyway. If there is any inclination or unevenness, repair it in time.
