Engineers who design equipment with motors, transmissions, and bearings know the importance of detecting the onset of a failure and rectifying the problem quickly. Bearing failure can cause catastrophic damage to equipment. Imagine the results of a bearing failure on a railway car carrying your family.
A company called Track IQ has come up with a way to monitor acoustic signals from the bearings that support the weight of a railroad car on the outer axle of a wheelset. A wheelset comprises an axle that connects two flanged metal wheels that run on a track. The technique and system are called RailBAM (Railway Bearing Acoustic Monitor). According to Siemens, which distributes the RailBAM equipment, the monitor can detect damage to the wheelset bearings in trains sooner than other techniques, so railway operators can improve the reliability of rail transport and reduce maintenance costs.
The RailBAM system monitors the sounds of wheelset bearings as trains pass a set of sensors. It now monitors trains traveling at up to 160km/hour, though Track IQ plans to adapt the system to work with faster trains. Normally, railway operators would replace a wheelset every 1.2 million kilometers (745,000 miles). Or they would use a hot box to detect overheated bearing cases, which indicate a bearing failure. Now, though, a RailBAM system lets railroad shop workers replace wheelsets whenever the acoustic measurement data reveals the first signs of trouble.
According to Track IQ, an array of acoustic sensors improves spatial discrimination or directionality. Software uses geometric wheel measurements and acoustic characteristics to reduce crosstalk in the acoustic signals. As a result, the influence of a large fault on one axle does not diminish the reading from a small fault on an adjacent axle.
In Southampton, England, RailBAM equipment has monitored 45 trains with 9,000 wheelsets over a two-year span. As a result of this test, maintenance intervals for powered and nonpowered wheelsets increased by 10 percent and 50 percent, respectively.
Though preventive maintenance regimens often use accelerometers to detect problems in stationary rotating equipment, perhaps acoustic signatures could supplement their measurements in mechatronic systems. In a railway, all wheels have similar characteristics, and they run a fixed distance from acoustic sensors. These conditions reduce the unknowns in measurement algorithms. The variability of mechatronic devices might present a challenge to something similar to the Track IQ system, but it might still deserve a look -- or a listen.
Note: For some time, railroad cars in the US have used an automatic equipment identification system that relies on heavy-duty radio frequency tags attached to both sides of a car. A tag reader system associated with a RailBAM system would let the equipment identify the specific rail car with an out-of-spec bearing or bearings.
Another interesting railroad technology, is the application of Electronically Controlled Pneumatic (ECP) brakes.
Railroads have been using the same brake technology since the late 1800's! Here's an over simplification: Basically, there's a continuous air line that runs the lenght of the train. The locomotive generates air that charges a small resevoir under each car. When sufficient air is present in the system, the brakes on the train release. To activate the brakes, the engineer releases a small amount of air from the system, which propogates back through the train, applying the brakes an amount related to the amount of air released. With long trains, it takes a long time for this air control to pass through the train, resulting in odd train handling where brakes are applying and releasing at different times in different parts of the train. Worst of all, is that if the engineer makes too many brake applications without recharging the system, the train can lose all braking ability!
With ECP, air is still used to operate the brakes, but an electrical system is used to tell the brakes when to apply and release. With this system, the locomotive can keep charging the air line so that the train won't lose braking power. They can also apply and release the brakes with more precision, and all cars react at the same time, decreasing stopping distances. And, there are individual car brake diagnostics available.
Testing has shown it to work well, but adoption is slow due to the cost and amount of rail cars out there. It's primarily being used to "unit" trains in captive service, but I hope that the technology becomes more widespread eventually.
Back about 1987 I designed a system using spectrum analyzers designed for exacly that purpose, industrial fault detection. I coulkd set the frequency range to examine and then have ten "boxes" around the PSD (Power Spectral Density) trace, and if the amplitude went outside the "box" a TTL signal would pull low and my equipment would know that the part being tested was outside of the specification. I believe that package was produced by Spectral Dynamics, but I don't recall the model number. One of the last testers used it to check in-tank fuel pumps, and I gather that it worked quite well. What I don't know is if they are still using that device to chek pumps. IT was an easily upgradeable test stand, so it could be still checking those pumps now, 32 years later. We did build equipment to last.
It would seem that a similar system could listen for bad bearings, but the train speed would need to be quite closely controlled.
Railroad companies have special cars that grind the rails to specifications, and sparks do fly out of the grinders. A water car at the end of this type of train sprays any small fires that get started in brush. Here's a short video: http://www.youtube.com/watch?v=6pAfMlr4Pko.
Buring a trip through Evanston, Wyoming my wife saw one of these grinding trains and thought it was on fire. So sometimes sparks are intentional.
The Machinist Calc Pro computes speeds and feed rates for milling, turning, and drilling: cutting speed, spindle speed, feed rate (inches/minute), cutting feed, etc.
During a recent meeting with engineering-school faculty and alumni, Contributing Technical Editor Jon Titus talked about whether colleges should educate generalists or specialists. What do you think?
From Dell / Intel® New Paradigms in Design Work Scott Hamilton, vertical market strategist for Dell Precision workstations, 5/2/2013 3
Early in my career, I worked as a draftsman and remember the days of drawing on vellum with numbered pencils and Mylar with plastic lead. This was a fun experience in the sense that I ...
I've been using workstations for more than 10 years and love finding ways to get more performance from my system. With demanding professional applications that require more power each ...
A lasting memory from my first job as an engineer in an auto assembly plant is standing on hard concrete at six in the morning, vending-machine coffee clutched in hand, listening to ...
A quick look into the merger of two powerhouse 3D printing OEMs and the new leader in rapid prototyping solutions, Stratasys. The industrial revolution is now led by 3D printing and engineers are given the opportunity to fully maximize their design capabilities, reduce their time-to-market and functionally test prototypes cheaper, faster and easier. Bruce Bradshaw, Director of Marketing in North America, will explore the large product offering and variety of materials that will help CAD designers articulate their product design with actual, physical prototypes. This broadcast will dive deep into technical information including application specific stories from real world customers and their experiences with 3D printing. 3D Printing is
To save this item to your list of favorite Design News content so you can find it later in your Profile page, click the "Save It" button next to the item.
If you found this interesting or useful, please use the links to the services below to share it with other readers. You will need a free account with each service to share an item via that service.
Tweet This
2 
