Diagnosing potential machinery shaft alignment issues can be difficult and time-consuming, so maintenance professionals approach it as simply as possible. They break down shaft alignment in two ways: determining the issue and finding out how best to repair it.
This article on shaft alignment will explore the most effective tools and procedures for diagnosing and maintaining rotating shafts such as pumps, motors, fans, and more.
What Is Misalignment?
Misalignment is most common in rotating machinery and occurs when two rotating shafts are either offset or separated by an angular gap. This results in performance issues and can be the root cause of machine failure.
Rotating shaft components can be hard to reach. And identifying shaft alignment issues once required a skilled technician and considerable time. However, advances in modern technology have made it easier than ever before to quickly spot and repair shaft alignment issues.
Causes of Shaft Alignment Problems
What causes rotating shaft misalignment in the first place?
- Machinery settling causes one or more feet to differ in height
- Shaft warping or twisting during startup
- Improper shaft alignment measurements from human error
- Pipe strain
- Changes in temperature causing warping or expansion
Misalignment of shaft centerlines can result in wobbling and vibration, and misalignment can severely damage or destroy machinery if not dealt with. Identifying misalignment and the underlying causes can help maximize an asset’s lifespan.
4 Types of Misalignment
There are four types of misalignment that experts generally agree on.
- Vertical offset misalignment: When two shafts have centerlines parallel to each other, but they are offset vertically
- Horizontal offset misalignment: Similar to vertical offset misalignment but in the horizontal plane
- Vertical angle misalignment: Angular misalignment of two shafts in the vertical plane
- Horizontal angle misalignment: Similar to vertical angle misalignment but in the horizontal plane
Shaft alignment issues are almost always compound — a combination of both angular and offset in both planes.
Shaft Misalignment Detection Procedures
When a machine begins displaying operational issues, the best place to start is to determine if there is a shaft misalignment. Implementing a preventive maintenance routine to verify precise shaft alignment will save money and time. Keeping shafts aligned also improves energy efficiency, increases uptime, and maximizes production output.
1. Laser Shaft Alignment Systems
A laser shaft alignment system can identify misalignment and calculates the precise measurements needed to achieve alignment.
Laser shaft alignment systems are unique in that they let users both diagnose and correct alignment issues, unlike other systems which only allow for one or the other.
Laser shaft alignment tools can be either dual- or single-laser systems. A dual-laser system is inferior to the quicker and more precise single-laser alignment system. In dual-laser systems, users find it harder to line up the laser and detector which can lead to imprecise measurements. As the measurement distance increases, aligning the tools can become even harder. Technicians must often restart measurements with no guarantee that the detector will be in range. With every repeat, process time increases and the potential for error grows.
A single-laser alignment system eliminates these issues. It effectively addresses most shaft misalignments. A single-laser system has two optical detector planes in a single sensor, eliminating the technician’s need to perform the alignment manually.
2. Vibration Analysis
Every machine has a normal vibration level, but when it increases or exceeds acceptable limits, vibration analysis can help determine if a misalignment is the cause of the issue.
With advances in modern condition monitoring technology, vibration analysis has become more common and effective than ever before. Today, there are many types of vibration sensors. Accelerometer vibration sensors, piezo vibration sensors, MEMs vibration sensors, proximity sensors, or velocity transducers are the types most often used for vibration measurement and analysis. Once these signals are acquired with a data collector and vibration sensors, a vibration analysis can further diagnose the issue.
Thermography identifies abnormally hot locations within your machinery and can often lead to early detection of misalignment. Misalignment causes an increase in friction within a machine, which can raise the temperature and even lead to damage. A thermal imager is used to measure an object’s infrared energy for visual display and easy analysis.
4. Oil analysis
Oil analysis helps detect misalignment by providing the general condition of an asset’s oil and contaminants. The process can be complicated and often requires the use of third-party companies for special analysis.
Correcting Machine Misalignment with Laser Shaft Alignment Systems
Today’s machines and their misalignment problems can vary greatly, and maintenance teams regularly face unique alignment challenges. As such, they require systems and software that can help with alignment in virtually any situation, regardless of the operator’s experience and skill.
Adaptive laser shaft alignment systems provide this flexibility. With software and other features that allow them to adapt to any situation and user experience level, laser shaft alignment systems maximize productivity and return on investment while making the process easier than ever before.
The best laser shaft alignment systems eliminate human error and deliver new levels of accuracy and speed with:
1. Single-laser Alignment Technology. A single-laser system eliminates the many frustrations and risks of inaccuracies that occur when working with two lasers firing in opposite directions. Single-laser alignment systems are faster than dual-laser ones, enable rapid completion of alignment tasks, and improve precision.
2. Intelligent Alignment Software. The right software tools provide maintenance teams with real-time, actionable intelligence by filtering out low-quality measurements. The software is situationally aware and dynamically reacts to everything involved in the alignment process. It provides predictive intelligence to allow technicians to evaluate different courses of action before embarking on the time-consuming task of moving a machine.
By leveraging these technologies, maintenance teams can deliver on the promise of adaptive alignment in all three critical areas common to every alignment task: the asset, the situation, and the maintenance team.
- Adapting to the Asset. Every organization’s machinery is different. Basic laser alignment systems are rigid and often don’t have support for your specific needs. Adaptive laser alignment systems are designed to be as flexible as possible by supporting the broadest range of machinery, eliminating manual workaround and the risk of inaccuracy.
- Adapting to the Situation. Adaptive laser alignment systems can adjust to different variables, such as rotation angle, speed, and evenness while delivering a quick and easy alignment experience. Even inexperienced technicians should have no trouble following the high-quality measurements and detail steps displayed by the software. It evaluates various factors in real-time for instantaneous feedback.
- Adapting to the Team. Technicians are human, and humans make errors. The best adaptive alignment systems obtain and utilize real-time analytics to remove false data and correct common errors made by inexperienced technicians. This ensures high-quality results regardless of an engineer’s experience level.
David Metz is an application engineer and technical sales representative for Prüftechnik, a division of Fluke Reliability. Previously, he served as a machinist/millwright with more than 30 years of technical and craft experience with Exelon Energy. For more information, visit www.pruftechnik.com