Adaptive Alignment Next-Generation Technology for Solving every Shaft Alignment Challenge
The invention of laser shaft alignment revolutionized the industry by delivering measurements more precise by orders of magnitude than traditional methods. Because laser systems have moved from being “state-of-the-art” years ago to “state-of-the-business” today, one might be tempted to think that all laser measurement systems are the same, and that there is nothing left to innovate in this important technology. But that view is mistaken. It is true that some systems have remained the same, but others have continued to evolve.
This article introduces the latest advance: adaptive alignment. It is a combination of software and hardware innovations, enabling maintenance teams to address any type of shaft alignment task, from the standard, daily and simple alignment jobs through to the more complex and challenging tasks such as the alignment of cardan shafts, vertical flanged machines with right-angle gearboxes, or extensive machine trains with gearboxes.
Adaptive alignment eliminates human error while delivering new levels of accuracy and speed. This next generation in laser shaft alignment is made possible by two must-have underlying innovations: Single-Laser Technology and Active Situational Intelligence.
Systems outfitted with these technologies deliver new levels of flexibility in three key areas:
• Adapting to the Asset
• Adapting to the Situation
• Adapting to the Maintenance Team
In this article we will introduce the first two key areas. Part 2 of the article will be published in Maintworld 3/2020.
With a single-laser system, users have just one sensor and one laser to set up. Not only is this faster, it eliminates the many frustrations and risk of inaccuracies that happen when working with two lasers firing in opposite directions.
Dual laser systems are challenging to coordinate through the entire measurement process. In particular, they suffer from a “divergence” phenomenon that happens when line-over-length between the laser and sensor is out of range …
and contact between the laser and detectors is lost.
Dual laser systems struggle with angular alignment in particular. Technicians cannot easily maintain the line to the detector – a fundamental problem that is magnified as the measurement distance increases, such as measuring across a spacer shaft.
Technicians have to restart measurements, which means stopping, loosening the feet, moving the machine, retightening the feet, and then hoping the detectors are now within range. This process may need to be repeated multiple times. Every one of these episodes adds significant time to the process and increases the potential for errors.
Basic laser alignment systems can’t adapt. They recommend doing a “pre-alignment” before taking the first measurement. But this involves moving the machine from its as-found state – thus being unable to document it – and is really nothing more than a visual educated guess. In addition, only horizontal parallel movement is practically performed, overlooking the very real possibility of angular misalignment.
Single-Laser alignment systems eliminate all of these problems. Leveraging two optical detector planes in a single sensor, technicians never need to stop, loosen and retighten feet, or take multiple sets of measurements. Used in conjunction with Freeze Frame Measurement (explained below), long distances can be measured without any chance of the laser losing the target sensor.
Single-Laser Technology delivers rapid completion of alignment tasks while improving precision at the same time. Systems outfitted with this technology include a “Live Move” capability that enables technicians to literally see corrections in real time. They see updated results in vertical and horizontal planes simultaneously across the full range of the sensor detection surfaces. This overcomes the limitations inherent to non-adaptive, dual-laser systems that have the line-over-length divergence problem.
Active Situational Intelligence
Active Situational Intelligence (ASI) is software that provides real time, “in the moment” feedback and guidance. For instance, quality of measurement is tracked and displayed to the technician during a continuous sweep. Certain factors that can compromise measurement quality in non-adaptive systems, such as errors induced by coupling backlash or environmental vibration, are automatically detected and filtered out on the fly, enabling highly precise measurements even in challenging circumstances.
ASI is real time, actionable intelligence. It is situationally aware and delivered as work is being done. It dynamically reacts to everything involved in the alignment process. ASI also has predictive intelligence, enabling technicians to evaluate different possible courses of action before embarking on the time-consuming task of moving a machine.
With these two breakthroughs, advanced systems 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
Basic laser alignment systems are not engineered to support a broad range of critical rotating asset types. They are very difficult to use with certain asset types. This becomes a costly and time-consuming problem for plants that rely on those assets or on certain specialized but common asset configurations. Capabilities for adapting to the asset include:
Simultaneous Machine Train Alignment
Adaptive alignment quickly and easily handles machine trains, measuring multiple machine couplings simultaneouslyvia a unique multi-coupling measurement capability. Machine trains are common with gearboxes, and are among the most challenging of all alignment scenarios. As soon as you get to 3 machines the combinations of angles and offsets become almost exponential, and far beyond the capabilities of dual laser systems without ASI.
With basic systems, a lot of trial-and-error happens with machine trains, and they often resort to mathematical projections in place of actual measurements. Because they use only one set of heads in this scenario, they only physically measure and monitor the live adjustment of one coupling at a time. But the movement of the gearbox affects simultaneously both couplings and all shaft positions. Only if both couplings are monitored in real-time can actual, not theoretical, changes be tracked.
As work progresses sequentially on the train using a basic system, wrong moves can easily be made early in the process but not discovered until later. Assets can become bolt-bound or base-bound, and technicians cannot move them any further in the desired direction. When this happens, they must change the fixing point and start over.
With no situational intelligence, rework becomes the order of the day. Adaptive alignment systems can measure a machine train in one go. Unique ‘under-constrained’ and ‘over-constrained’ asset support enables the system to operate accurately with no fixed feet, one fixed foot, or two or more fixed feet – so technicians can get the optimum alignment incorporating real-world machine constraints.
Used in conjunction with the Virtual Move Simulator (described below), Simultaneous Machine Train Alignment enables technicians to test a range of tolerances and proposed movements on the complete machine train, eliminating the trial-and-error and consequent rework common to basic laser alignment systems.
Total Thermal Coverage
In operating condition, most assets change their relative position due to increased temperatures and therefore need special presets during alignment. Since alignment can only be done when the machine is stopped, it’s essential to fully anticipate and account for real operating temperatures.
Basic systems only measure the coupling changes. Unfortunately, this is only half of the thermal picture, ignoring machine feet measurement changes. By not calculating and displaying the feet, maintenance technicians using these systems do not have complete information, and thermal impact becomes a matter of guesswork.
Some systems attempt to compensate by enabling entry of one set of presets and attempt to derive the others. But this does not give technicians the full range of adaptability and control they want.
Adaptive alignment systems deliver total thermal coverage that includes dynamic changes at both the coupling and the feet. This enables the maintenance team to enter thermal presets at both the coupling and/or machine feet.
In-Situ Cardan Shaft Alignment
Not every industry has cardan shafts, but those that do face extreme alignment challenges. Standard practice for these assets is to take the cardan shaft out in order to accomplish alignment. This means dismantling and removing the cardan shaft, which may require a hoist or crane just to undertake an alignment measurement check.
Adaptive alignment includes breakthrough technology that enables measurement with the cardan shaft in place – so no removal is needed. For critical assets that have rollers, In-Situ Cardan Shaft Alignment is an innovation that saves tremendous amounts of time and money – while delivering a high-precision result.
When laser alignment supports the widest range of assets and configurations, it is a more complete solution that eliminates the manual workarounds and accuracy problems common to basic laser alignment systems.
Although alignment seems to be a simple process – measure ? move ? remeasure, maintenance technicians know it is deceptively simple. They have to deal with many variables that come into play: asset type, asset location, installation or maintenance project, measurement setup, movement options, etc.
Perhaps the strongest attribute of adaptive alignment is Active Situational Intelligence – its ability to adjust to these many different variables while delivering a smooth, rapid, and accurate alignment experience. The concept of adaptive alignment applies throughout the process and is driven by ASI. Here are a few of the innovations that come into play:
Uncoupled Shaft Awareness
When installing machines, the alignment should commence with uncoupled shafts, to remove any residual forces in the machine train. But basic systems don’t have optimized measurement procedures for uncoupled shafts. Technicians have to manually hold shafts to make sure both are at the same relative angle, then manually take the point, then manually move them. This greatly increases the risk of errors.
With adaptive alignment, uncoupled shafts can be in any position; the laser just needs to hit the detector. During the measurement, shafts can be freely moving while the adaptive system works out the angles and obtains the measurement.
This capability delivers high ROI when teams are installing an asset, because accurate results and required machine movements are obtained in the fastest possible time.
Laser alignment systems, when confronted with a big initial misalignment, will come to the end of the detector range before completing the shaft rotation. The alignment cone is so big that the laser exceeds the measurement range, and a complete measurement is not possible.
In cases like this, and because they lack adaptability, the standard advice for basic systems is to do a “pre-alignment” or “rough align” so that subsequently the laser and detector can operate within their limited range. Of course, this pre-alignment is done without any measurement help – technicians don’t know how much shimming or horizontal movement to do. They are estimating without knowing what the underlying problem is. Plus, in a practical sense these systems only show visual indications of horizontal position. Although some acknowledgement of the need for vertical positioning is made, no practical process for obtaining vertical position, such as shim correction amounts, are given – so technicians operate in the dark.
Adaptive alignment solves the problem with Freeze-Frame Measurement. It handles any misalignment, no matter how big, over any practical distance. Technicians are automatically alerted when getting towards the detector edge during a continuous sweep measurement, and can freeze the measurement, reposition the laser, and continue with the continuous sweep. Built-in algorithms connect the sectors when the measurement is
finished, “stitching” them together. The result is complete knowledge and documentation of the misalignment: where the problem actually is, and therefore what to do about it, without resorting to guesswork.
Automatic Multi-Factored Quality Enhancement
An advanced innovation built into Active Situational Intelligence is the ability to detect and compensate for many factors that might negatively influence a measurement. ASI applies these quality enhancement factors in real time, during the continuous sweep. Technicians get immediate feedback, and in cases where automated corrections are not enough to produce a highly precise result, the technician is told exactly what to pay attention to when doing a new continuous sweep.
This means that even less experienced technicians can take high-quality measurements by just following the steps and tips displayed on the screen.
ASI evaluates many quality factors simultaneously in real time, such as rotation angle, speed, and evenness, providing instantaneous feedback. Included among those factors are these common issues:
• Instant Coupling Backlash Filtering
Basic laser alignment systems advise and/or warn users to “eliminate coupling backlash to obtain accurate measurement.” That’s easy for the vendor to say but not so easy for the technician to do.
In contrast, ASI assumes that coupling backlash is going to happen. Built-in intelligence automatically detects backlash during the continuous sweep and filters it out. By recognizing coupling backlash and eliminating the appropriate measurement data, ASI delivers a clean measurement even when coupling backlash is present.
• Environmental vibration
Another automatic adjustment happening in the background during the measurement is the filtering out of the low-quality measurement points induced by environmental vibration – which commonly happens when a nearby machine is operating and producing such vibrations.
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