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How to make in-situ Cardan shaft alignment less cumbersome

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Cardan Shaft

Among the most challenging machinery alignment tasks you might face is aligning a Cardan shaft—named after 16th-century Italian polymath Gerolamo Cardano, who invented it along with other machine mechanisms.

Cardan shafts are essentially couplings. Their purpose is to accommodate a horizontal or vertical offset between a driven shaft and a driving shaft—most commonly a motor and a gearbox.

The Cardan shaft is the input shaft to the gearbox—versus the slower output shaft of the gearbox. Together, the rotational speed of both shafts connecting the motor to the gearbox via the Cardan shaft is the same.

Angular misalignment can increase the strain on joints and bearings and lead to a Cardan shaft becoming damaged or destroyed. Angular misalignment also often leads to increased vibration, which can cause uneven rotation during operation and, ultimately, shortened asset life.

Fortunately, with adaptive alignment systems from PRUFTECHNIK, it is quick and easy to measure the parallelism of two shafts connected to a Cardan shaft.

No removal is required, and measurements are much easier

The usual method of aligning these assets is to take the Cardan shaft out to align it, which requires dismantling and removing the Cardan shaft. This process can be cumbersome and time-consuming, and sometimes even requires a hoist or a crane.

But with adaptive alignment, it is possible to perform measurements with the Cardan shaft in place by using a specially designed rotating arm bracket fixture. This innovation is called in-situ Cardan shaft alignment. With no removal required, measurements are obtained much more easily and without the need for lengthy downtime.

Cardan shafts often exist in tight spaces, which can be challenging to navigate when using standard alignment procedures. But with adaptive alignment in-situ shaft measurement, tight spaces are no problem at all.

Two specific features of adaptive alignment, single-laser technology and Active Situational Intelligence (ASI), make it easier to handle difficult alignment situations, such as tight spaces, while also increasing both measurement speed and accuracy.

Measurements are reliable and precise—accurate to a hundredth of a millimeter. Successfully aligning a Cardan shaft requires a level of precision most easily achieved using single laser technology. Determining the parallelism of two shafts connected by a Cardan shaft is much quicker and easier, thanks to adaptive alignment.

How adaptive alignment tools adapt to a range of situations and challenges

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Machinery alignment scenarios are rarely the same. Using an easy shaft alignment tool that works for some simple jobs can introduce new errors on more complex projects. This unnecessarily complicates the alignment process, frustrating technicians, and driving up operational costs. Frequently, what maintenance leaders save with a cheaper system they lose in manual efforts and rework.

Enter adaptive alignment, a signature feature of PRUFTECHNIK laser shaft alignment systems.

This combination of software and hardware innovations enables maintenance teams to address any shaft alignment task, from the standard, daily, and straightforward alignment jobs to more complex and challenging tasks – such as aligning Cardan shafts, vertical flanged machines with right-angle gearboxes, or extensive machine trains with gearboxes.

Adaptive alignment systems contain Active Situational Intelligence (ASI), a software innovation with capabilities that enable the solutions to take on from the standard to complex and challenging tasks and complete them faster and with more accuracy than the many more basic solutions on the market.

Here are some of the adaptive alignment enhancements:

Multi-Factor Quality Enhancement

With this feature, the software detects and compensates for many factors that might negatively influence a measurement. It provides technicians with immediate feedback and allows even less experienced technicians to fetch high-quality measurements just by following the steps and tips displayed on the screen.

Uncoupled Shaft Awareness

When installing machines, the alignment should begin 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 must manually hold shafts to make sure both are at the same relative angle, then manually take the point, then manually move them. This method dramatically increases the risk of errors.

With adaptive alignment, uncoupled shafts can be in any position—the laser only 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 you get accurate results and required machine movements in the fastest possible time.

Virtual Move Simulator

Moving the machine is often the costliest part of alignment—and carries with it the risk of additional cost and time if it turns out to be the wrong move. Virtual Move Simulator (VMS) has saved technicians thousands of hours across many industries around the world by enabling them to model different options for a move, see the results, and refine choices before actually doing the physical movement. Read this separate blog post for more on VMS.

Live Move

Single-laser technology delivers rapid completion of alignment tasks while improving precision. Systems outfitted with this technology let technicians see corrections in real-time. They can view updated live results in both vertical and horizontal planes simultaneously across the full range of the sensor detection surfaces. With this capability, you avoid the limitations inherent to non-adaptive, dual-laser systems that have a line-over-length divergence problem.

Adaptive alignment can save time, improve accuracy, and offer numerous other advantages. Learn more about the adaptive alignment concept and feature set in PRUFTECHNIK systems by visiting our website.

Active Situational Intelligence provides real-time measurement guidance

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Active Situational Intelligence

Misaligned machinery is costly for a number of reasons, from increased energy consumption to more frequent repairs and failures to shorter asset life cycles. Precisely aligned machines use up to 10 percent less energy than misaligned ones.

Correct alignment is important not just at commissioning, but as part of regular, ongoing maintenance. Laser alignment is an accurate, efficient way to make sure assets are precisely aligned. To ensure the most effective alignment, you need a tool that pairs the right hardware with the right software. Alignment may seem simple on the surface, but in reality, the process is full of variables.

Adaptive alignment tools are designed to save time and money, enabling maintenance teams to solve alignment challenges from the simple to the complex, and for almost any asset or situation.

Active Situational Intelligence, or ASI, is a Pruftechnik innovation that makes an adaptive alignment tool accessible for users of any skill or experience level. The software provides instant—and specific—feedback to the user as they are performing a continuous sweep and lets them know exactly what they need to do differently to improve the accuracy of a measurement. For instance, a notification will pop up on a tool’s screen to say “rotate slower” or “direction reversed” so the technician can make the necessary corrections in the moment.

In addition to this real-time guidance, ASI automatically detects and filters out errors such as environmental vibration or coupling backlash. In non-adaptive alignment systems, these factors can compromise measurement quality. With ASI, a quality measurement is ensured—even in the most challenging situations. Over time, technicians with the least training and experience can learn how to improve on subsequent measurements and ultimately obtain the same quality of results as more experienced technicians.

By eliminating errors and guesswork, ASI allows maintenance teams to unlock their full potential and capacity—and to do the same for their assets.

PRUFTECHNIK expands Fluke Reliability condition monitoring offerings

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Connected maintenance

Now that PRUFTECHNIK has joined Fluke Reliability, customers have access to an even more comprehensive range of tools from one source. Some may already be familiar with PRUFTECHNIK from their industry-leading systems for machinery alignment. They also specialize in test and analysis tools for condition-based maintenance, including vibration analysis, ultrasonic testing, and lubricant particle counting.

Condition monitoring is a maintenance strategy where you gather data on the condition of an asset while it is operating, and base maintenance actions on that condition rather than on what a calendar says an asset needs. Data on an asset’s condition can be tracked continuously through sensors, or at intervals using measurement tools for spot checks.

With condition monitoring, assets are repaired or replaced only when failures are detected. The length of time between the detection of an issue and the failure of an asset depends on the type and frequency of testing. Technologies and methods used to test assets include:

  • Ultrasonic testing
  • Oil analysis
  • Vibration analysis
  • Motor testing
  • Infrared imaging

Ultrasonic testing to find leaks in pressurized pipes is an effective method for detecting potential failures early. Compressed air is expensive, and leaking compressed air is one of the largest sources of energy waste in manufacturing—when leaks exist, assets require more energy to compensate for them. Ultrasound can also be used for electrical and insulation inspections and to monitor bearing lubrication.

The SONOCHEK from PRUFTECHNIK is an easy-to-use, high-performance leak tester with a bandwidth of 20-100 kHz. Humans cannot hear these frequencies. The SONOCHECK translates them into an intuitive graphic display, identifies leaks, and specifies and evaluates the total amount of loss. With the optional parabolic long-range sensor, the SONOCHEK can discover leaks from up to 25 meters (82 feet).

By providing and supporting an array of methodologies, Fluke Reliability helps your team maximize your asset uptime. With the addition of PRUFTECHNIK, Fluke Reliability is a one-stop shop for all the tools maintenance teams need.

Virtual Move Simulator helps you make all the right moves

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One of the biggest challenges in aligning large or high-speed machines is determining precisely how much the asset must undergo a move to achieve optimal alignment. This determination has long been a manual and tedious process. You calculate the amount and direction of the movement based on the degree of misalignment. Then you move the asset and remeasure, and perhaps move it again, remeasure, and repeat and repeat until you finally achieve alignment.

When you’re dealing with substantial assets that weigh several hundred tons, this process can take considerable time, require numerous resources, and keep the asset out of service for a lengthy period. It can be a hassle – one that is often further complicated by dealing with a machine that is bolt-bound, base-bound, or has limited movement in specific directions. You may delay or even have to reschedule the alignment.

Using adaptive alignment systems with Active Situational Intelligence (ASI) technologies such as Virtual Move Simulator (also known as Move Simulator) can take the frustration and headaches out of this process. You can get not only a precise readout of shaft misalignment but also a preview of the necessary adjustments to align the asset, before actually moving it.

Adaptive alignment systems contain a unique combination of hardware and software that enable users to adapt to virtually any situation in the field, as well as their own experience and skill levels.

How Virtual Move Simulator works

Virtual Move Simulator (VMS), included in the PRUFTECHNIK ROTALIGN touch laser alignment system, simulates horizontal and vertical moves to calculate the precise movement necessary to align shaft couplings. After measuring the alignment of assets, a millwright can enter the estimated amount of change or shimming into VMS and view the results on the screen.

If those virtual moves align the couplings precisely, the screen shows a “smiley” face. If the result is not a smiley face, the technician makes additional adjustments until the smiling face appears. An “OK” is also acceptable in cases where the asset cannot be moved further due to an obstruction.

VMS shows its most significant benefit when used for multi-coupling alignment. Instead of aligning each coupling separately and having to remeasure and adjust each one back and forth, you can simulate the alignment of multiple couplings in one process.

The graphic below shows how this might work in aligning a motor/gearbox/pump setup. You can mount one laser to the left of the coupling between the motor and gearbox and the sensor for that laser to the right of that coupling.

Similarly, you can mount the second laser to the left of the coupling between the gearbox and the pump and the sensor for that laser to the right of that coupling. You can then measure the alignment between the motor and the gearbox and the gearbox and the pump simultaneously as the ROTALIGN touch yields alignment values for the whole machine train (this is known as “Simultaneous Machine Train Alignment”).

After taking the alignment measurement, click on the Virtual Move Simulator button and start the virtual alignment:

  1. View the results for the gearbox-to-pump coupling. Make the adjustments necessary to bring those two couplings into virtual alignment by selecting the V (vertical) or H (horizontal) direction and, using the arrow keys, add or subtract movement. Watch the virtual-simulated alignment change in real time.Gearbox-to-pump coupling result
  2. Success is confirmed when the smiley face appears on the screen (plus blue correction arrows and colored shaft centerlines).Gearbox-to-pump coupling result after adjustment
  3. View the results for the motor-to-gearbox coupling and continue to adjust as necessary, as described in Step 1, to achieve alignment between those two assets.Motor-to-gearbox result
  4. Simulated alignment between the motor and gearbox is determined complete as indicated by the smiley face shown below.Motor-to-gearbox adjustment
  5. When a simulated alignment of each pair of assets is complete, you can see the moves recommended to align all three machine shafts in one virtual-simulated “Live Move.”Live move graph

With ROTALIGN touch single-laser technology, you can keep the laser and sensors in place and switch from Virtual Move Simulator to Live Move mode. This action enables you to see the values change in real time as the complete machine train is simultaneously physically moved to match the values provided by VMS.

Virtual Move Simulator is just one of many features included in the Active Situational Intelligence software featured in PRUFTECHNIK adaptive alignment systems. This software provides real-time predictive intelligence that is situationally aware to filter out error-causing conditions such as coupling backlash or environmental vibration to increase alignment precision and speed.

Check out how adaptive alignment technologies from PRUFTECHNIK can address your machinery alignment challenges.

How to diagnose and correct soft foot (part 2)

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Eliminating soft foot before attempting machinery alignment will save you time and money

In the first installment of this two-part blog series about soft foot, you learned how to identify the symptoms, effects, and types of soft foot conditions. In this second post, you’ll learn how to diagnose and correct the condition and what types of tools to use.

It’s estimated that two-thirds of all rotating machinery have soft foot conditions. Soft foot is also the root cause of most alignment issues and is considered to be the most critical thing to check before performing an alignment. So why is soft foot one of the most overlooked machinery problems?

Granted, the process of diagnosing and correcting soft foot can be frustrating, and it often takes longer to fix than the actual machine alignment. However, if you can remain calm and think critically, the effort always has a huge payoff which is preventing machine destruction.

Soft foot toolkit (Diagnosing soft foot)

Several ways exist to diagnose and measure soft foot. It’s essential to apply the following methods during every machine alignment and installation to determine if there’s a soft foot condition.

Having the right devices on hand can make detecting soft foot go smoother and faster. Here’s a list of tools to help you measure for soft foot and eliminate any debris found under and around the feet to ensure machine alignment.

  • Image 1 – Feeler gauge
    Image 1 – Feeler gauge

    Feeler gauge: A feeler gauge is used to measure gap widths or the clearance between two parts. The tool has several steel blades with different thicknesses that can measure as little as 1/1000 of an inch or up to a quarter (¼) inch.

 

  • Micrometer or digital caliper: A micrometer can also measure gap thickness. The tool is used to verify shim thickness. A caliper is used to measure shim stacks before inserting them under the feet. This verifies that the shims are the thickness as labelled and not defective.

    Image 2 – Digital caliper
    Image 2 – Digital caliper
  • Wire brush: This clears away the debris or corrosion you may come across while checking machinery feet.
  • Cleaner/degreaser: Use a heavy-duty degreaser in combination with the wire brush to clean existing shims and contact surfaces during the soft foot correction. Brake cleaner works well, but you might also have success with other well-known commercial cleaners.

 

  • Laser shaft alignment system: A laser system can be helpful when measuring for soft foot and is easy to use. This sophisticated tool walks you through the measurement process via a series of screens and includes an auto diagnosis. Although you can use either a dual or single laser shaft alignment system, a dual system can be more challenging to use.

 

Correcting soft foot with shims

Using shims to correct machine foot issues is usually very effective. However, if the frame or mount is bent, twisted, or cracked, or other overall machinery destruction has occurred, correcting the condition can be quite tricky.

In most cases, the machine you’ll be working on will already be shimmed. It’s a good practice to clean any shims that are not new and also clean the base plates and feet to eliminate any dirt and debris. If you do not remove the corrosion, paint, and grime that can accumulate over time, it’s possible to form a new condition, squishy foot, during alignment.

5 rules to avoid squishy foot

Here are some good rules of thumb to follow to better ensure that you don’t create a squishy foot condition while trying to eliminate another soft foot condition.

  1. Use shims big enough to cover at least 80% of the footprint. Shims come in many sizes, and if the machinery requires large shims, they’re usually fabricated on site.
  2. ShimApply no more than four shims under each foot. If you add too many shims, you risk producing a spring-like situation, i.e., squishy foot.
  3. Sandwich thin shims in between thick shims. It makes placement easier and eliminates the potential for shim creasing.
  4. Measure stacks with a micrometer to verify shim thickness. Use it to make sure things add up as they should because errors or defects sometimes happen during manufacturing.
    Shim rules pic
  5. Measure shims over 0.030 to verify thickness. Some sources might recommend lower or higher thicknesses, but ultimately, it’s your decision.

By following these soft foot best practices, including applying the right methods and tools to accurately diagnose and correct the condition, you set yourself up for success. Always remember to check for soft foot before aligning shafts. It will save you time, money, and headaches.

For a more in-depth look at soft foot, watch the Fluke Accelix Best Practice Webinar, “A hard look at soft foot: detecting machine frame distortion before it causes major issues.”