Misalignment Costs Time and Money

Shaft misalignment is responsible for up to 50% of all costs related to rotating machinery breakdowns. These breakdowns increase unplanned machinery downtime, resulting in higher maintenance costs and loss of production. Additionally, misaligned shafts can increase vibration levels and friction, which can significantly increase energy consumption and can cause premature bearing failures.

Traditional Shaft Alignment Methods

Traditional alignment methods, although very common, do not often produce the exacting degree of accuracy required by today's precision machinery. The rough alignment methods still used nowadays, such as using a straight edge and feeler gauge, may be quick, but they can be inaccurate. Another traditional method employing dial indicators offers a higher degree of accuracy, but it requires specialist operators and can be time consuming.

Straight edge and feeler gauge method

Dial indicator method

Laser Shaft Alignment Methods

Laser alignment methods are a marked improvement on traditional ones. A laser shaft alignment tool facilitates a quicker and more accurate alignment than traditional methods. Since shaft misalignment has a direct, negative, impact on bearing service life, SKF offers a range of high precision, easy-to-use laser shaft alignment tools. The tools, the TMEA Series, combine simplicity with a high degree of accuracy. They feature a three-step process for correcting alignment: measuring, aligning, and documenting.

Parallel misalignment (or offset)

Angular misalignment

Correct alignment

Accurate shaft alignment can help you:

Increase bearing life.
Reduce stress on couplings and thereby the risk of overheating and breakage.
Reduce wear on seals, helping to prevent contamination and lubricant leakage.
Reduce friction and thereby energy consumption.
Reduce noise and vibration.
Increase machinery uptime, efficiency and productivity.
Reduce costs of replacing components and machinery downtime.

Belt Misalignment

One of the common reasons for unplanned downtime of belt–driven machinery is pulley misalignment. Pulley misalignment can increase wear on pulleys and belts as well as increasing the noise and vibration levels, which can result in unplanned machinery downtime. Another side effect of increased vibration is premature bearing failure. This too can cause unplanned machinery downtime.

Measuring parallel and angular misalignment using a straight edge or a piece of string

Traditional Belt Alignment Methods

These methods, which are the most widely used, involve either using visual judgement alone or visual judgement in combination with a straight edge and/or length of string. The advantage of these traditional methods is the perceived short time needed for adjustment, although the use of a straight edge takes more time than visual judgement alone. The major disadvantage is the lack of accuracy. Some belt manufacturers recommend a maximum horizontal angle misalignment of 0,5° or even 0,25°, which is impossible to accomplish by using naked eye.

Correct alignment means that the grooves of the pulleys are aligned

Laser Belt Alignment Methods

A laser belt alignment tool facilitates alignment with far more speed and accuracy than with traditional methods. Belt alignment tools available on the market can be categorised according to the way the tools can be attached to the pulley and the way they align. In general there are two groups; one aligns the face of the pulleys and the other aligns the grooves of the pulleys.

The major disadvantage of the tools, which use the face or side of the pulley as a reference for aligning the pulleys and belts, is that only the face of the pulley is used as a reference.

This means that only the faces of the pulleys are aligned with each other and not necessarily the grooves in which the belt runs.

This method results in varying degrees of accuracy when the pulleys are of different thickness, brands or kinds.

The tools, which align the grooves of the pulley allow for alignment where it counts most in the grooves of the pulley, substantially increasing accuracy irrespective of the thickness, brand or type of pulleys.

Accurate pulley and belt alignment can help you: