Aligning new shaft bearings for the feed water pump
Thread Content
When replacing the new bearing shells, lifting the shaft can help determine whether it is aligned properly. I would like to ask whether the center of gravity is adjusted using the adjustment bolts shown in the diagram, or by some other method – and how exactly is this adjustment carried out?
It must be positioned using bolts, but to find the center, the shaft needs to be lifted and a dial indicator is used
The one on the left is the horizontal adjustment bolt (there’s another one in the opposite direction on the other side; they form a pair). The one in the middle is likely the temperature sensor. I don’t see anything in the upper circle, but the vertical adjustment bolt wouldn’t be here either; it should be near the horizontal adjustment bolt – give it a try. Additionally, such adjustment bolts are located near the fixing bolts around the bearing housing; they can’t be elsewhere, unless some kind of transmission mechanism is used, but obviously the designers aren’t that lazy:lol
Since new bearings are being installed, it is necessary to check the alignment as well as the interference and clearance of the bearings
Do you want to check the rotor runout? When replacing the bearing shells, just take the rotor off as well and place it on a lathe to check for runout.
Adjusting the shaft involves using the adjustment bolts shown in the diagram to move it up, down, left, and right. There should be 3 such bolts: two for left and right movement, and one for up and down movement; this last bolt is located below the bearing housing. A dial indicator is needed to locate it. In applications with high temperature and pressure like yours, the value is usually around 40, and since the bearing caps are not under pressure at either end, the shaft can be rotated by hand
Bearing housings are usually positioned using set screws; if the bearing shells are standard, you only need to check the alignment of the shaft assembly again!
Use a dial indicator to determine the center of a circular axis