Pump alignment

DropTheHeader212

Just want to see what you guys are using for alignment of pumps and motors. I’m looking to get a dial indicator setup but unsure what to get. Thanks !

Solid_Fuel_Man

What kind of pump? A circulator? Oil pump?

Pumpguy

Are you familiar with coupling alignment procedures? Most just use a straight edge and eyeball the vertical and horizontal alignment. Using a dial indicator is a better way to go as it gives you some numbers to work with.

If you can get a copy of Audell's Mechanics and Millwrights Guide, there is an excellent chapter on how to do this without chasing your tail for hours.

First step is to get 0 - 0 @ 6 and 12 o'clock on the coupling's vertical face. This takes care of the vertical angular alignment. Then you add or subtract the same thickness of shims under all 4 motor feet to get the vertical horizontal alignment. Last step is horizontal on the horizontal plane by moving the motor side to side. For this it's nice if you can rig up some horizontal jack screws and get some precision tweaking.

Hardest part is finding or making suitable attachment fixtures to hold the indicator. I can't tell you where to find one as I've never seen them offered. I would think they are available, but don't know where.

What I did is take a short piece of angle iron, maybe 1" or so, and 1" long, fastened a 5/16" rod to the apex of the angle, and then cut a couple of slots in the sides of the angles so a hose clamp can go through and around the coupling or shaft. Then usual indicator attachment hardware can be used to contact the opposite coupling's face and OD.

One caution, be sure the motor is a rigid base type and not resilient base. I'm fighting an alignment problem now where a previous knucklehead installed resilient base motor. Alignment and overall operation is crazy. I may have to change to rigid base motor, or close coupled pumps, but that involves shim block and or piping changes.

Hope this is helpful.

Brad Notter

We mostly do straight edge for 7.5hp and below and laser from 10 to 250hp. I have done rim/face and reverse dial indicator alignments over the last 22 years, and laser is faster as it does all of the math for you and tells you exactly what you need to do at the four motor feet.
Here is a link to one of our service techs doing a straight edge alignment.


https://www.youtube.com/watch?v=95Bq9zbwO1Y

Pumpguy

While this video gives a good start on coupling alignment, it does not address angular alignment, only parallel.

To check angular alignment, a common bow caliper can be used to measure the vertical or horizontal angular alignment by measuring the width differences across the coupling faces; 6 and 12 o'clock for vertical, and 3 and 9 o'clock for horizontal. For correct angular alignment, the coupling width distances should be the same across the coupling faces. Depending on the design of the coupling, feeler gauges can be used to measure distance differences on the coupling's inside faces.

To adjust the vertical angular alignment, shim changes will need to be made to either the front 2 or the back 2 motor feet, tilting the shaft up or down.

Setting the vertical angular alignment should be the first step. Once the vertical angular alignment is set, then go ahead and change the shim thickness under all 4 motor feet by the same thickness as described in the video.

Some couplings are more tolerant to misalignment than others. I prefer a coupling that has only flexing elements, not rubbing.

Back in the early part of the 20th century, there used to be a coupling available that was simply a heavy coil spring welded to each coupling hub. These worked great so long as the spring didn't break or the weld fail.

For something available today, I would look at a Dodge Para Flex or a T B Woods Dura Flex type. These have a rubber or similar flexing element that clamps or bolts to the hubs.