Show notes
We interview with Cory Mittleider of Malloy Wind, a company specializing in providing bearing solutions for wind turbine applications. Cory shares insights into common pitch bearing failure modes, how Malloy Wind analyzes failed bearings to develop improved designs, and the importance of factors like grease and manufacturing processes in bearing longevity. Visit https://www.malloywind.com/ for more info!
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Allen Hall: Welcome to the special edition of the Uptime Wind Energy Podcast. I'm your host, Allen Hall, and I'm here with my co host, Joel Saxum. If you were an owner, operator, or technician in wind, you have come across pitch bearing problems. And those pitch bearing problems can get really hard to detect early. But once you see them, they're expensive to repair.
So Joel and I thought it was time to bring on an expert. In bearings to the podcast. So our guest today is Cory Mittleider of Malloy Wind. And Cory has an extensive background in wind bearings. Now, Malloy, if you're not familiar, is based in Sioux Falls, South Dakota, which is in the middle of the United States.
And Malloy Wind specializes in providing solutions for wind turbine. applications. So they're a total wind focus organization. They offer a variety of services, including upgrading gearbox bearings, blade bearings, main shaft bearings, pitch motor renewals, and generator bearings. Cory, welcome to the program.
Cory Mittleider: Hey guys, thanks for having me.
Allen Hall: So there's so many questions about pitch bearings and just having been down in San Diego at the ACP OMNS one of the complaints is, Oh, I got a huge bearing replacement program going on this summer. And my first thought was of you were thinking, wow, you guys must be really busy because Bearings are probably after lightning, it's lightning and then bearings were one and two of the problems for wind turbines at the moment.
Cory Mittleider: Yeah, it's been it's been a busy couple of years. There's certainly standout platforms that are having their own platform specific failure modes that we're discovering as we work with operators.
Joel Saxum: Yeah we talked a little bit off air about some of that thing. Okay, so we're in lightning space.
We know if someone calls and says, I have this turbine with these blades, you go, Ooh, you got problems. So I know that it's the same thing in the Bering world, generators, like you know the ones that are going to happen. So when you guys initially talk with someone, What are some of the points that you asked them right away?
Okay. They've called, what are we looking at?
Cory Mittleider: Sure. Sure. So to your point, it's a lot of platform specific. We know platform X has this history of problems. Platform Y has a different set of history and platform Z is a pretty stable, pretty robust platform, for example. So we start to, to investigate, is it one of those platforms that we already know has some issues that we either maybe have something developed for, or are currently working on.
We talk about how soon are they experiencing their first failures or how are they detecting them? And most importantly, I think is how long do they plan to run the site? Are they two thirds of the way through the life of the site? Then, we probably propose a different solution to them than we do to some of the worst case scenarios where they're having failures in the three year ballpark and they're trying to get to 25.
Joel Saxum: Yeah, no. One of the things that we talked about was, hey, you're on platform A. With bearings, but you have bearings B and C, same design. But different manufacturers, and sometimes you run into issues there as well.
Cory Mittleider: Yeah. It's really interesting when it comes down to it. There's only four parts in a blade bearing.
There's the rings, the rollers, the seals, and the cage or the spacers, depending on the configuration. It sounds easy, right? But there are a lot of process controls quality checks, things like that. That can be done to ensure. The best long life operation. We actually got a call about three years ago from an operator in our neighborhood that said we have platform a and we have two bearing manufacturers installed across our fleet, all from original build.
The site was about 10 years old. They said, why are all of brand X failing and none of Brand Y. So we worked with them. We investigated that a little bit and we found exactly that, that the bearings are the same dimensions, from a raceway load capacity point of view they should have been the same, but what we found is it was some subtle manufacturing differences from the way the the races were hardened. control point of view. And corrosion protection of the bolt holes, for example, that were leading to that. So very small details, right? That lead to larger implications a decade later.
Allen Hall: And just seeing some of the pictures. That Malloy Wind has on its website and there's some great technical information about bearings. So if you want to know anything about bearings, go to the Malloy Wind's website and start looking at the technical explanation, because it's written in English for in simple terms that even I can understand for me.
Yeah. For people like me that don't know a lot about bearings, that was really helpful because I'm a picture person, right? I want to see how, what the, how these things break down. The pictures of these pitch bearings coming apart was fascinating because essentially, from what I could tell, it starts to degrade internally and it starts to blow out the seal.
So it starts spitting out metal parts that. Once that begins, it's bad stuff. You really can't fix it from there. That's my understanding of it.
Cory Mittleider: Yeah, then maybe I'll dive into that, right? Yeah, to your point and you mentioned right at the top that blade bearings are almost impossible to get a health assessment on.
It's not like a high speed gearbox bearing where you've got vibration and temperature because it's running fast and at full revolutions. But Blade bearings are they don't ever go full revolution and they go so incredibly slow. So you really can't apply any of the traditional bearing monitoring tools.
That we're used to, right? So health assessment is incredibly difficult. Even when you look at the construction of the traditional two row four point bearing type that's used as a blade bearing it actually stops you for the most part, for most part from even trying to bore scope them.
Joel Saxum: But you can't access them by design.
Cory Mittleider: Yeah. Yeah, you really can't access it. To your point Allen a lot of the times what what leaves people to look at them or operators to look at them is pitch faults. For example, especially electric pitch turbines, you'll start to see an increase in pitch faults, asymmetry type stuff or overload over current on electric pitch.
Or I think you mentioned the seals come out, and grease leaks all over, you'll get dirty blade ruts, and that's a signal you can see from further away. But you may have some blade bearing health issues. What we do we and we support in the field. We don't climb. We don't do the installation removal, but as the bearing distributors, the bearing experts supporting these operators we'll get pictures from the field.
We'll get a call. What am I looking at? If they're not used to navigating that kind of external inspection, we help that way. But when we get I say a new platform with a new failure mode. We haven't heard of, we'll have them replace it. We bring it back to our shop in Sioux Falls, South Dakota, and we'll dismantle it.
And I think there's a couple of those pictures, those dismantling pictures on the website that you talked about. It's it's a terrible job. It's dirty. That grease is really sticky, especially electric pitch turbines. That tooth the open gear grease is really sticky stuff. But you work through it, you dismantle it.
Sometimes they've been locked up such that we had to cut the bearing in half. To get inside to see it. Other times we're able to remove the filling plugs, pull the balls out and rotate the inner ring around. And that still takes half a day to do. So it's a really dirty process. Then you got to clean everything after you get it dismantled.
But then we put all that diligent diligence and effort into we're inspecting the rolling elements that came out, inspecting the raceway, looking for signs of wear. Or electrification or, what they're called micro pitting or spalling of the raceways, things like that, that help inform the updated designs that we are offering to operators that have had these premature failure problems.
Joel Saxum: One thing you talked about offshore, and this is just a funny note when you were talking about an extreme cases. We're like, how do they know when it fails? When does the seal go bad? When does it get enough holes in it? And you're like, yeah, sometimes you have water that runs into the hub from the outside, or you got to put, you got to make sure you got your hard hat on when you get out of the truck, because you might have pieces of bearing falling down from the top.
Cory Mittleider: So to that point, one of the common problems in the last five or eight years has been cage failures.