SHAFT ALIGNMENT TECHNIQUES

We have already discussed “Basics of shaft alignment” and “Shaft alignment terminology” in our previous post. We have also studied in our previous post about the need and advantage of successful shaft alignment for maintaining the healthiness of our equipment. As we have already discussed the various terms and terminology used in shaft alignment and also we have discussed the activities those are very important to follow before the final shaft alignment . 

I will request to all my colleague, friends and readers to read “Basics of shaft alignment”,  “Shaft alignment terminology” and "shaft alignment procedure" before reading this article to complete understanding of precision shaft alignment in step by step.

Shaft alignment plays a very crucial role to secure a healthy maintenance system, so let us start the main subject now without wasting your valuable time.

We were discussing the shaft alignment in our previous discussion “shaft alignment procedure”.  Now we need to follow the below activities to secure the final shaft alignment.

Fixing of coupling with driver and driven shaft

Now we need to install the coupling (we are considering here the gear coupling) with driver shaft and driven shaft, before installation of gear coupling we need to check the coupling bore size and shaft size and there must be tolerance as per specified by the manufacturer. 

There must not be any axial or radial play between coupling hub and shaft and driver and driven shaft should rotate freely with coupling hub fixed on the respective shaft. After successful installation of gear coupling on shaft, we need to position the driver and driven unit over the respective base plate.

Preliminary inspection of angular measurement

After positioning the pump and motor over base plate, we will measure the angular measurement between both coupling hubs with the help of feeler gauge. During inspection of angular clearance between both coupling hubs, we need to check angular clearance at four locations i.e. first at 0⁰, second at 90⁰, third at 180⁰ and fourth at 270⁰. We need to adjust the angular clearance below 0.05 mm total indicated runout at all four above locations.

Preliminary inspection of parallel measurement

Once we have adjusted the angular clearance with specified dial testing indicator reading i.e. 0.05 mm, we need to measure the parallel alignment of both coupling hubs with the help of straight gauge. First we will measure the parallel offset in horizontal axis and after that we will measure the parallel offset in vertical axis. 

We must note it down, during preliminary alignment, we will have to recheck the alignment if we are doing any changing whenever we change the position of equipment to secure the parallel/angular alignment. Suppose if you are doing any changing for parallel alignment, you need to recheck for angular alignment and vice-versa because any changing in position of equipment may change the alignment.

Piping and duct work

Once we have completed the preliminary alignment, we will have to fix the piping and duct work with the pump and we will check for any stress during connection of piping and duct work with the pump. We will remove if there is any stress whether stress is in horizontal or vertical position.

Dial indicator application to determine the total indicated runout

Once we have completed all the piping and we have also secured the angular alignment as well as parallel alignment with 0.05 total indicated runout. We will check the shaft alignment with the help of dial indicator. We will align the shaft with a target of 0.02 mm total indicated runout.

We will use rim and face indicator method of to secure the final alignment of shaft. We will also discuss Rim and face method of shaft alignment very soon.