Axis Alignment Measurement with Fuji Prescale: The Easiest and Simplest Defect-Detection Mechanism

High-rotation assemblies, like industrial air compressors or high pressure oil pumps are finely balanced machines that are very sensitive to load and alignment discrepancies. Even the slightest deviation in loads can cause catastrophic failures and even larger loss of productivity. Here is a case study of how the Fuji Prescale high-pressure films can be used to quickly and accurately detect any discrepancies between the axis and the machine body.

Pressure Measurement as axis alignment testing

Axis alignment testing is crucial for the longevity and balanced work of the machine. This is especially true for high-rotation machines, including internal combustion engines, pumps and compressors.

If the axis deviates even minutely from its desired alignment with the engine body, the machine will be loaded with strong vibrations and will work below its optimal efficiency. These loads and efficiency losses grow as the rotation speed and mass of the rotating elements grow. So for heavier machines, axis alignment is even more important.

In order to avoid any design flaws, during the prototyping phase, constructors need to measure the axis alignment. Also, when a high-rotation machine is in for inspection or repair, measuring the axis alignment is crucial to the ongoing reliability and efficiency of the machine.

Fuji Prescale film as alignment tester

Measuring actual tactile pressure between two curved surfaces is very easy to achieve with the flexible and thin pressure sensitive Fuji Prescale films.

When it comes to measuring pressure, the Fuji pressure sensitive films can help you measure both load distribution and axis alignment.

If the axis is off-specs, when rotating, it will induce more pressure at one side of the ball-bearing, and reduce pressure on the opposite, 180-degrees end. This kind of pressure spiking is cyclical, and the faster the axis rotates, the stronger vibrations it creates.

Measuring axis alignment

To measure the alignment of the axis with the engine body, you can use the Fuji Prescale high-pressure sensitive films (series 4 to 8 from the Fuji Prescale sensitivity scale). Knowing how well the axis is balanced will help you know how durable and stable the machine will be. Even slight deviations on high-rotation machines will eventually cause the machine to fail, so during the construction or repair procedure, fine-tuning the axis alignment is crucial.

Here is how you can measure axis alignment:

1. Remove the axis with ball bearings still attached on the axis
2. Place pressure sensitive films on both ball-bearing sleeves on the chassis
3. Place the axis back to its position without rotating it. Tighten the bolts, and mark the axis and prescale
4. Tighten the bolts to specified tightening force

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Once you remove the developed pressure sensitive film, inspect the pressure distribution. If the pressure distribution is noticeably greater on one side of the axis, this may be indicative of an axis misalignment.

To verify the misalignment, go through Steps 1-4 but now rotate the axis for 180 degrees before tightening the bolts.

Then compare the two developed films. If the pressure discrepancy overlaps, namely, when the axis was on a zero-rotation angle and you noticed a decreased pressure in the middle of the film, and this pressure minimum corresponds to the pressure maximum when the axis rotation was 180 degrees, this is a clear indicator that the axis is damaged.

Thanks to this very simple diagnostics procedure, you can avoid catastrophic failures of the machine. This kind of testing

• Takes very little time
• Is cost-effective
• Gives you a graphic representation of where the problem lies