Positive and negative values of a dial indicator
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During alignment, the dial indicator is attached to the motor coupling on the pump, while another dial indicator is used to measure the upper and lower positions of the outer surface. As it rotates from 0 degrees to 180 degrees, if the contacts of the dial indicator retract, the pointer moves clockwise; in this case, the reading should be recorded as a positive value, right? At this point, a1
Yes, the hand is compressed to a positive value.
That's how it is. When the gauge is mounted on the pump and the reading is positive, it indicates that the axis of the pump is at a higher level. In other words, the motor voltage is low
There is an example where a1 is 0.04 and a3 is 0.44; in this case, a3 has a positive value, so according to the above reasoning the motor should be lower due to the shims. Yet, the diagram provided for that example shows that the center of the motor is offset upward. It’s really confusing. I seek an expert’s help to resolve this doubt.
This post was last edited by Ianshe on 2017-9-12 22:41. The book is correct – it involves attaching the dial holder to the motor in order to transmit motion to the shaft of the driven device; using the formula: S1
This post was last edited by Ianshe on 2017-9-12 22:41; the percentage gauge contacts are located on the driven shaft
Looking more closely, it’s indeed the gauge that’s mounted on the motor – it’s really confusing
Personal advice: Beginners are advised not to use positive and negative numbers
One cannot consider only the radial height; the axial opening value, that is, s3 and s1, also needs to be taken into account. s3 > s1, which means an upward opening (in the diagram, it shows a downward opening). Taking everything into account, what the book says is correct.