Seeking help with table alignment issues
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When aligning a single component, if the outer surface of the coupling is not centered with the shaft (or if the outer surface of the coupling is not smooth enough), it can cause errors in the measurements. How do people deal with such deviations?
Original poster, are you trying to perform alignment when the two coupling drums do not rotate at the same time? As long as the two coupling drums rotate simultaneously, then any shape errors in the outer surfaces of those drums have no impact on the alignment process.
I hope you won’t laugh at me, but I really don’t understand this. For example, if the percentage-indicating gauge is placed on the motor-side half-coupling, while the meter is located on the pump-side half-coupling, then what’s the point of taking readings at four different points when both half-couplings are rotating at the same time? I think if it rotates simultaneously, the readings on the gauge in all four directions should be the same.
How could they be the same? That’s exactly why there is an eccentricity in the eccentric wheel
Ugh, if the centers don’t align, rotating in those four directions gives different results
I somewhat understand now: it’s necessary to drive each of the two half-couplings once, with the rotation direction and angle being the same in both cases； Instead of both half-couplings rotating with each measurement, right?
Single-table alignment involves synchronous barring, which can prevent errors caused by large outer circular runout.
When aligning a single gauge and recording data, the gauge holder remains stationary while the gauge head rotates; if the axes are not aligned, the dial indicator will show this deviation based on the eccentric circle, which is easy to understand. But if both half-couplings are rotated simultaneously (that is, the side of the watch holder and the watch face are rotated at the same time), assuming the markers are a1, a2, a3, a4 and b1, b2, b3, b4 respectively, then if they are rotated together, the holder will always be in position b1 and the watch face will always be in position a1; only their orientation changes. Can the deviation still be measured?
Reply to 8# zhaoming4865: For a single table, two need to be entered. Rotor A needs to be struck once, and rotor B needs to be struck once. They all rotate at the same time. Then compare where the data differences lie.
Aligning a single watch is indeed a bit tedious, but it’s the same in this case: no matter how much the two pairs of wheels differ from each other, as long as both pairs rotate simultaneously, the watch hands will be at the same position
Reply to 8# zhaoming4865: Think carefully. The rotation center of the drive device remains unchanged, as does that of the driven device. If the drum is perfectly round, there is no difference between rotating it simultaneously or rotating one side alone. If you don’t understand, try drawing it out on a diagram. Currently, in order to avoid the impact of any shape errors in the drum, it is necessary to rotate it simultaneously, meaning that the position indicated by the dial gauge stays constant; thus, any shape errors in the drum do not affect the measurements. By rotating it simultaneously, it’s not necessary to tighten all the bolts of the coupling at once – you can first rotate one side and then the other, adjusting the gauge until it returns to its original position.