Following up on last week’s blog post about inspecting motor bases, this week we take a look at shims. Just like machine bases, shims are also a key part in the foundation of the reliability of an asset. While walking around the facility have you noticed more than 4 shims on a piece of equipment? Did you know that more than 4 shims can cause a sponginess, or a type of accordion effect that could possibly introduce soft foot in your asset? This week’s video shows how to inspect and consolidate shims.
This week on the Reliability Tribe blog we are going to begin discussing some simple inspections that can be done on a machine base. All Reliability programs need to be built on a solid foundation (which we will discuss later). Just like a Reliability program your machines need to also be built on a solid foundation. Machine bases deteriorate so slowly that often we assume they are good. Every now and then we need to take a look at the machine base to inspect what’s supporting your Reliability. The video below gives some examples of machine base inspections.
In keeping with last week’s theme on the use of strobe lights, this week we have an example of how you can use a strobe light to identify belt slip. Did you know a 15% belt slip on a 100hp piece of machinery is not only reducing the motor 15 horsepower it could also potentially cost you at least $7,000.00 per year (depending on power cost) in energy consumption? Watch the video to see a simple belt slip calculation formula to identify your percentage of belt slip.
In keeping with the focus of Reliable Manufacturing®, this week we are going to start with a tool that can be used to do a simple check on machinery to assess the asset. The strobe light is a simple, inexpensive and easy to handle tool, a Strobe light, can be used for performing preliminary inspections on a variety of rotating machinery. These inspections are easy to conduct and do not take much time. The inspections will provide vital signs of possible failures of the machinery and their root causes. The strobe light can be used on mechanically coupled machines, belt driven machines, motor cooling fans, stopped yet vibrating machines, mechanical seal failures and much more. We have included a short clip from the Reliability Solutions App that shows how to use a strobelight.
Why Precision Maintenance®? Did you know according to the Nowlan and Heap study 89% of all failures occur in a random nature. Looking within the famous “6 patterns of machinery failure” you’ll notice that 68% of machinery failures follow “Pattern F”. Within pattern F the majority of failures are due to infant mortality. This means that by eliminating these premature failures better we can prevent the majority of equipment failures. If you begin to consider what causes a machine to be at such risk, the answer typically comes back as human induced errors. Discipline and documentation are key to success in lowering Pattern F failures.
We must gear people up to be better decision makers. They either have to do the work correctly or know what was done wrong. In order to do the work correctly people must understand what correctly means. The majority of these premature failures come from 3 things…Misalignment, Unbalance, and Assembly Errors. Precision Maintenance® provides some techniques to eliminate these failures! So, the question becomes; How can we make people better decision makers? Follow the Reliability Tribe blog to get weekly tips about Reliable Manufacturing® and begin creating those better decision makers!
As we start a new decade and reflect on the past decade one of the hottest reliability subjects is the Industrial Internet of Things (IIOT). Organizations are investing huge amounts in (if the marketing literature is to be believed) the ultimate answer to everything. While big data and increasing connectivity certainly brings new opportunities to us in the reliability world, one has to question where the true value lies? Is it really automating the equipment diagnosis and performance evaluation processes? We currently struggle to repair and eliminate problems we already know about. Unless we have skilled, knowledgeable, technicians and crafts people who are executing the work in an effective and efficient way, it is hard to see the promised quantum leaps in reliability happening. Remember just because it is technically feasible, does not mean it is always worth doing. What are your plans to manage the work generated by the IIOT?
Want to discuss further? Let us help you prepare www.reliabilitysolutions.net
Does your facility suffer from SCL and maybe you don’t know about it? It’s an insidious failure mode that might be causing you grief and you may not know about it or maybe you have just come to accept it as part of doing business.
We were working with a brewery and we asked the students in the reliability class what their most common failure mode was. The answer from the crew of mechanics … “SCL”. We had never heard the acronym before, but were intrigued, and of course since they had given this failure mode an acronym, we knew that it had to be real. So, what is SCL? Answer: Stuff Comes Loose… just the students used a different “s” word, one that is a little more descriptive and emphatic, but you get the idea.
When it comes to threaded fasteners, we should not accept that stuff coming loose is normal. Nor should we go and get the Loctite, split washers and a different grade of bolts. SCL is an indication that there is both a gap in knowledge and in procedures on how to correctly and consistently tighten threaded fasteners. There is a lot of science involved in correctly designing a bolted joint, and it would be pretty straight forward if not for the friction we have to overcome between the threads and between the head of the bolt and the washer. Eighty five percent of the force used to tighten a bolt is lost due to overcoming the friction forces and only fifteen percent of the force goes to actually stretching the bolt which provides the clamping force.
Check out this video on some bolt tightening ideas and don’t forget to check out the app stores for the free Reliability Solutions App that has access to over fifty practical and applicable reliability how to video
If not, why not? Bearing failures are a very common form of mechanical breakdown. Apart from identifying that the failure is occurring using a variety of techniques and tools, we rarely take the steps necessary to understanding and prevent the failure from happening again in the future. We can learn a lot about why a bearing failed by simply looking at the bearing and observing the failure patterns.
You do not need a massive investment in fancy technical gear either. A $15 jeweler’s loupe or a $20 lens kit for your smart phone and some decent light (all available from amazon) is all you really need. Couple that with good disassembly techniques (to preserve evidence) and a knowledge of what to look for and you are well on your way to understanding 80% of your failures. Take a look here for some ideas on bearing forensics and don’t forget to check out the app stores for the free Reliability Solutions App that has access to over fifty reliability how to videos. https://kvgo.com/Example/brg-forensics
Hello All and thanks for the responses to last weeks Brain Teaser. The correct answer was water marks caused by water intrusion followed by the motor then sitting for a period of time. The brown staining noticed by some was likely tarnish deposits cause by breakdown of the lubricant presumably due to the same water ingress.
So why did this bearing Fail?
It is a cylindrical roller bearing from the drive end bearing of a 3 phase Induction Motor on a VFD.
Clues in the video here
First correct answer wins a gift from Myles’ desk