In a recent conversation with Andrew Lechner of R+W, we discussed IoT functionality in a new line of couplings from the component manufacturer motion components. Here’s what Lechner had to say.
Lechner • R+W: 15 or so years ago, we experimented with bellows couplings capable of measuring misalignment. couplings that can provide information about shaft misalignment and torque. In fact, for a couple decades other coupling manufacturers have supplied couplings integrating torque meters … but these are no different from standard torque meters — and they require a static component in addition to the rotating coupling.
R+W actually leads in IIoT innovation, and has made significant progress on such technology through our R&D department … which includes a team of engineers 100% dedicated to the development of smart couplings. What’s changed is that suddenly our industry is very interested in the IIoT … so now machine builders are asking: “How do your components connect? What’s your part in all of this?”
Now we’ve released an informative coupling that goes beyond torque measurements to monitor other characteristics in the driveline — and address current technologies’ deficiencies in accurately recording downstream performance characteristics.
There are problems associated with both of the dominant technologies currently used.
• Readings done at the motor drive are often too insensitive to what’s happening at the furthest reaches of the axis, as such readings are too far upstream and can fail to account for driveline inertia.
• Torque sensors and vibration monitors peppered over a machine at strategic locations can be expensive and typically require static base stations to be nearby.
The third option we offer with our informative coupling packages the sensing into a rotating component farther down the driveline and outputs signals wirelessly — for a more effective and economical solution overall.
Lisa Eitel • Design World: What industries will these products serve?
Lechner • R+W: Much of the interest has been from our industrial equipment customers — so people in the process industry designing extruder, pumping, and heavier manufacturing applications. Here, a flywheel effect can greatly influence driveline components downstream without much effect at all on the motor. So the first models of these informative couplings are for application torques of 350 to 2,500 Nm.
Do you think we’ll see informative couplings for smaller applications?
Lechner • R+W: I hope we will. Of course, smaller motor drives can be somewhat more sensitive than larger drives … but we’ve observed that even small servos can fail to detect the downstream results of impact loads and abrupt stops. Of course, it’s a design objective to make all industrial rotating equipment compact. The sensor package on current informative-coupling models is about 75 mm long … of course, the larger the transmission, the less impact this size has on the overall design footprint.
What was behind the decision to use a battery to power the sensors?
Lechner • R+W: Batteries are robust and easy to implement. We extend sensor operation by allowing two modes — a high-resolution mode to allow three days of data collection and a lower-resolution mode for a couple weeks of data collection.
Of course, many engineers want this design to have constant power sans need for recharging. That’s why we’re currently developing an informative-coupling variation with energy harvesters to allow 24/7 high-resolution monitoring.
Would you be at liberty to discuss the exact sensor technologies inside?
Lechner • R+W: Torque and axial strain are measured with strain gauges. Then accelerometers measure vibration. A gyroscope tracks speed. These devices are similar to those you’d find in your phone.
It’s Moore’s law at work.
Lechner • R+W: Indeed. Traditional methods of developing and bringing such a coupling to market are obsolete; now we need to build the car while we’re driving it. So the informative couplings we are selling now are prototype-level one-offs — and we’re perfecting the design in partnership with OEMs. We aim to sell informative couplings as standard catalog product toward the end of 2020. In fact, engineers who want to share their thoughts on this company are invited to review the R+W information we’ve published on this offering and fill out a survey we’ve setup.
We’ll be sure to post that questionnaire. Moving on to integrating these couplings … what output signals does this informative coupling generate?
Lechner • R+W: We keep the design simple so end users can easily get their data. There’s wireless transmission to the R+W Android app. We’re also developing a gateway with USB, RS232, and analog output. End users can also emulate a serial connection using third-party software. Soon, R+W informative couplings could have IO-Link connectivity as well.
Here is the questionnaire mentioned: R+W Customer Survey for Integral Sensor Coupling
Is the R+W app for this readily available — or is that still in development?
Lechner • R+W: In Germany it’s on Google Play as an Android app. Once proven, it’ll release in the U.S. … most likely in July.
Is this technology primarily to support predictive maintenance?
Lechner • R+W: There’s far more to it than that. Predictive maintenance is the first function, as that affords lets end users know when tools are worn or axes are exhibiting misalignment or lubrication loss.
In addition, the informative coupling supports condition monitoring. Case in point: Process engineers involved in everything from food to plastics to oil (such as drilling mud in the oil industry) must monitor viscosity variations along with other properties of the material being processed. Measuring torque required by a mixer, extruder, or pump to stir or push through that substance at the coupling yields accurate information about viscosity.
For example, the start of an extrusion process needing more torque than usual may indicate that the vat of plastic is too cold — and requires more warming. Here, our informative coupling can help optimize such processes.
Lisa Eitel • Design World: It reminds me of my senior project in college, which focused on the prevention of breakouts on continuous-casting steel operations. Here sudden spikes in the shaker’s inertia indicated an issue.
Engineers looking for more information on this coupling can visit www.ai-coupling.com.