6axis loadcell

Another type is offset mounted, or cardan-shaft-coupled machines aka universal joints. These often have some type of drive, for example rollers in a papermaking machine. Many people wrongly believe that cardan-shaft-coupled machines do not need to be aligned as accurately. But an angular error in these machines causes a non-linear motion, which causes forces and vibrations in bearings, couplings and seals. In other words, shortens the service life.

Multiaxis loadcell

The biggest issue is the human element. This means the transfer of information from what is read on the dial is many times input incorrectly into the calculation.

Using a laser-based shaft alignment system is without doubt the best method. Yes, you can use a dial indicator system, however, these systems are fraught with errors. For example:

2axis loadcell

Wikipedia describes shaft alignment as “the process of aligning two or more shafts with each other to within a tolerated margin. It is an absolute requirement for machinery before the machinery is put in service.”

The goal is for these shafts to stay aligned when in operation, at full operating temperature and under load. The sheer torque of running machines will create an offset and angular misalignment, usually a combination of both (see Figure 1).

Many use the term “coupling alignment” which is incorrect. This was an old term used to describe the straightedge and feeler gauge method of alignment. This was normally done without shaft rotation. This method of alignment can still be used as a rough-in process prior to precision alignment, but it cannot achieve the necessary tolerances needed for modern day machines.

While “shaft alignment” is the common term, the correct term would be “shaft to shaft alignment”. However, when we say shaft alignment, it is assumed that we are aligning one shaft to another. What we’re trying to accomplish is the alignment of the rotational center line of one shaft with the other shafts rotational center line. These shafts are usually being held in position by bearings attached to machines such as a pump and motor.

Singleaxis loadCell

3axis loadcell

Most importantly they can give a documented, detailed report of the installation (see Easy-Laser XT Report example in Figure 5). Because if you have to do a breakdown analysis on this machine and you don’t have this report you will only be guessing as to what was done. For motor shaft alignment tools & equipment contact us.

Laser alignment tools (see Figure 4) on the other hand are considerably easier and faster to use (although speed is not an essential factor – repeatable measurements and precise results are the goals). Laser alignment systems also:

Rotating machines are usually described according to how they are connected to each other. The most common are horizontally mounted machines, usually a pump and motor (see Figure 2). Rotating machines can also be positioned vertically on a flange-mount in some circumstances.

Often several machines are connected in line, usually called a Machine Train, for example a gearbox between engine and the driven machine.