NEARLY TWO YEARS AGO, US company All Energy Management (AEM) began developing retrofits and training com-panies that service a fleet of 1,000 wind turbines in the UK, the US, Canada and Italy.
When embarking on repair work, it was found that the pins attaching the turbine blades to the rotor were wearing prematurely, along with the rotor holes. Line boring and welding when up on the turbine tower was not possible due to weight and space constraints. The only solution was to replace the rotor and pins, which took roughly 10 working days and cost USD 15,000.
Subsequently, AEM began discussions with Expander about developing a solution that would increase speed, improve efficiency and maintenance safety, and ultimately reduce costs. AEM developed a system to bore the holes out before installing the pins to ensure a reliable connection. Sets of three pivot pins and three different oversized sleeve options were supplied by Expander, which fitted perfectly into the holes depending on the degree of wear.
Fewer parts meant faster and simpler installation, while the Expander System also provided a perfect fit into the borehole, eliminating further movement causing wear. AEM has now been using the solution for over a year and is delighted with the results. “Instead of taking three days with four workers onsite to repair a turbine, it now takes us less than a day with only two workers required,” says Ian Sleger, Operations Manager. “The guys at Expander are really accommodating and the solution has freed us up to concentrate on other matters.”
The 2018 March issue of Bolted magazine is available now! As with every edition we have filled the magazine with interesting cases and insights from the world of bolting.
In this issue of Bolted, we take a closer look at what goes into the manufacturing process of traditional bolts – from raw steel to tailor-made applications.
We ask expert Filemon Schöffer about the potentials with 3D-printing, and we meet German company “MMG” who is a world leader in production of propellers for large container ships.
And of course a lot more.
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First published in Bolted #2 2017.
As prices continue to be down in the steel and metals industries, developing a successful partnership with a major customer can go a long way to securing profitability for a small business. The Danish company Viggo Bendz is based in Høng, on the west coast of Sjælland, the largest and easternmost of Denmark’s islands. The company employs eight people and delivers solutions and equipment for crushing, demolition and sorting. Poul Erik Jakobsen is owner and CEO. He took over the running of the business in 2006, just three years after it was formed. “When I started,” he says, “we were mainly dealing with excavators. Then one day I had a realization that the company would not survive in the future if we only sold certain kinds of bolts. We needed to expand our range in order to compete.”
The ability to anticipate change has been important to Viggo Bendz from the outset. Currently, one half of their business is parts for excavators such as teeth, buckets, cutting edges, hydraulic hammers and grabs. However, the other 50 per cent of their turnover comes from machines and complete plants for the environment and recycling business. Contractors are the main users of the Expander System bolts that they distribute, yet they have been well aware of Expander System’s potential in the recycling business, where Stena Recycling is one of the main players.
Located in five markets – Sweden, Denmark, Norway, Finland and Poland – Stena Recycling is committed to sustainability in their business practice. The two companies have had a long relationship, with Viggo Bendz supplying standard bolts for over a decade. However, they recently offered Stena Recycling the Expander System to test on their so-called ‘orange peel grabs’ (see picture). With this kind of machinery subject to wear and tear through constant and prolonged use, Stena Recycling have now taken the opportunity to employ a solution that will reduce the need for maintenance and will increase the safety and machine life cycle, Jakobsen believes. He says that, “By introducing the Expander System, Stena Recycling is saving money. Because of the quality, it represents a long-term investment for them. The industry is tough at the moment, due to the market price for steel and metals. Longer machine life obviously means both greater sustainability and profitability.”
The importance of supplying a sustainable solution to today’s market is something that Viggo Bendz knows well. The waste recycling business is one segment that is at the forefront of sustainable work practices, as companies increasingly focus on resource management and turning waste into new raw materials. More organizations are looking toward employing technology that enables this process and fits in with their sustainability strategy. Being able to supply a pivot solution that improves the durability and longevity of moving mechanical parts, means contributing something vital to the business of customers and to the environment as a whole.
As for being a smaller independent company in the current business climate, there are significant advantages according to Jakobsen. “We are focusing on quality products, which means that it is not always the cheapest solution for the customer. It is vital to us that we provide excellent service. Because of our size, we can be flexible and change direction quickly to help our customers and our own business if we need to.”
Being a distributor for the Expander System suits Viggo Bendz’ business model. They have a market presence all over Denmark, covering industries such as construction, mineral and scrap recycling. Currently Expander System accounts for around 200,000 euros of their annual turnover. Like almost every modern business, raising the company’s profile nationally has meant increasing their online presence. “We are focusing a lot on social media now,” continues Jakobsen. “Once a week we try to upload a case story to Facebook. Every time we upload an Expander System case, we get a couple of new customers. This is something that we must continue to use to our advantage.”
With pricing being crucial to compete succesfully in the market for the foreseeable future, Viggo Bendz is both positive and pragmatic about its current position. “Yes, it is all about price,” Jakobsen says. “However, with Expander System we do not have so many direct competitors. Being able to offer reliable, long-term solutions gives us the chance to target customers in waste recycling and other sustainable businesses. Even travelling around locally, you see how many grabs and different machinery are in operation. This potential is exciting for us.”
FACTS: THE SOLUTION
CLIENT: Viggo Bendz.
END CUSTOMER: Stena Recycling.
PROJECT: To provide solution for pivot wear on grab machinery.
NORD-LOCK GROUP PRODUCT: The Expander System.
The Expander System: cost-effective and sustainable
With its focus on sustainability and cost-efficiency, the waste recycling industry is tailor-made for long-term bolting solutions. Grab machines work constantly and repetitively, collecting, sorting and distributing waste of all kinds. Naturally, they develop pivot wear over time. Standard bolt fittings and joints become worn, leading to enforced machine reparations, which in turn lead to downtime.
The difference with the Expander System is that it is installed directly into the existing mounting on the machines, and involves a simple process which avoids welding and line boring. As well as being cost-effective in terms of longer machine life and increased uptime, it also adheres to sustainability principles, requiring less equipment and repeated repairs. By prolonging the lifetime on cylinder rod ends and moving mechanical parts, Expander System contributes to the increased safety and productivity of hard-working grab machinery.
The Expander System is installed on over 10,000 types of machines, covering more than 80,000 different pivot applications so far. The most common industries where they are being used are construction, manufacturing, oil & gas, mining, marine and agriculture.
Within waste recycling, The Expander System is not the only Nord-Lock Group solution to be hard at work. Several companies currently employ Nord-Lock Group products, including large UK waste services company Biffa. They have been using the wheel nuts on all their Mercedes trucks since 2012, having found them safer, more reliable and cheaper to source than standard locking wheel nuts.
First published in Bolted #2 2017.
Any machine with moving pivots will eventually experience lug wear. The most common are applications subjected to heavy loads and vibrations, such as mining and construction equipment. Other common applications include industrial presses, wind turbines and moveable bridges. Any moving pivot in just about any application will experience lug wear at some point – the higher the demands, the faster the onset. When it happens, it will lead to a loss of precision and control.
There are three main reasons why lug wear is inevitable when using conventional straight pins:
The most common solution to lug wear is to repair the lugs with welding and line boring. The first step of this is to unload the pivot and dismount the pin. Then the line boring equipment needs to be lined up and “mounted” to the equipment. The worn lugs are rebored, filled up with weld, and finally rebored with a fine cut to the original diameter and tolerance. After removing the line boring equipment and repainting the lugs, a new replacement pin is installed. This whole process can take anywhere from a few hours to a few days, depending on the size and complexity of the installation. During this time, the machine is inoperable.
Despite the time and costs, this method is generally accepted as unavoidable. “It’s just something everybody does because everybody else does it, and they’re not even aware that there is another way,” says Jonny Wiberg, development & research engineer, Expander System. “Repairs are just accepted, and people don’t even look for another solution.”
Over the years, engineers have searched for better solutions to the lug wear problem. None of the previous attempts has proven universally effective. One option is to use a pin that fits as tightly as possible into the lug’s holes, practically eliminating the play between the two, and ensuring the best possible pressure distribution for a straight pin. Not only does this make the pivot expensive and the pin difficult to mount; over time, the lug hole will expand anyway.
Using the temperature method, the pin is frozen and then allowed to get warmer and expand once installed, creating a perfect press fit in the lugs. Tolerances of both pin and lugs need to be exceptionally tight – down to some hundredth of a millimetre, or tolerance grade 6. This significantly increases the cost of the pivot. Pivots with frozen axles are often considered maintenance-free, but they are impossible to maintain, as the axle can’t be removed.
Another solution is to improve the strength of the lugs with bushings. However, this will only prolong the onset of lug wear, and will not eliminate the problem completely, as the bushings need to be replaced several times during the equipment’s lifetime.
None of these solutions will completely remove the need for costly and time-consuming lug repairs. In contrast, the Expander System can potentially eliminate lug wear once and for all. It works by using a pin with tapered ends and expanding sleeves on each side. When it is installed, the sleeves expand radially, so that they fill the lug to create an exact press fit.
As the sleeves of the Expander System expand into the lug, they can take up unevenness or deformation, eliminating the need for welding and line boring. This significantly reduces the time needed for installation as well as the machine downtime. The most time-consuming process for installing the Expander System is the dismantling and removal of the original pin – a process that is also necessary before welding and line boring. In a recent example, the Swedish Expander System company was asked to do a cost comparison for a 70-millimetres axle. Considering the cost of the expansion bolt, the cost of pin removal and installation, plus the income loss from downtime, the total cost of the Expander System solution was calculated at around 500 euros. A conventional pin was around a third of the purchase price, while the costs of removal and installation remained the same. The time needed for line boring, in addition to the time taken for the transportation of line boring equipment, and the loss of income from significantly higher downtime, all contributed to a total cost estimation of over 2,300 euros.
Using the Expander System will not totally eliminate the need for boring, but for the welding process. It will eliminate the lug wear problem for the lifetime of that pivot. Using conventional pins, lug wear would inevitably return and the repair procedure would need to be repeated. In a typical application, this happens three to four times during a machine’s lifetime or every 3,000 or 4,000 hours. This means that the cost savings can amount to thousands of euros – for each machine.
How a rusty nail led to an award-winning innovation
In the 1950s, twin brothers Everth and Gerhard Svensson were building roads throughout Sweden, and becoming increasingly frustrated with the downtime and repairs caused by lug wear. One day, when a pivot pin was coming loose, Everth improvised and took an old rusty nail to fix the pin in the lug hole.
As a temporary solution, the rusty nail worked quite well and inspired Everth to develop the Expander System. For many years, the twin brothers used expander products as they continued to build roads. However, it wasn’t until 1986, when Everth’s son Roger realized the ingenuity of his father’s solution, that the concept was patented and the company Expander System Sweden AB was founded. In 1987, the Swedish Minister of Industry awarded the Expander System with the Innovation Development Award, in memory of Alfred Nobel. Today, the Expander System is installed in millions of machine joints globally.
Getting over 6,000 extra operating hours
Lug wear is a widespread problem for machinery pivots. It has cost users of machinery lots of money through the years – for repairs as well as for downtime. This is something that the Expander System can put an end to.
The Expander System will in most cases cost more than a traditional straight pin. But when all costs are fully calculated, including the time and costs associated with welding and line boring, and the loss of production due to downtime, the Expander System will prove to be significantly more cost-effective. The full extent of savings depends on many different variables, but it is fair to say that the higher the frequency of lug wear and the higher the costs of downtime, the greater the potential savings.
For Swedish construction machine supplier Maskinia AB, every minute of downtime for machine repairs means lost income. This is why they have been using the Expander System since 1999.
Recently, an excavator was brought in for repairs after 3,700 hours of operation. Using the Expander System, the boom mounting axle was replaced in just 6 hours. By contrast, the repair would have taken 3–4 days if it was replaced by a traditional pin, using the common method of welding and line boring.
Lars Malmén, Aftermarket Manager at Maskinia, says that, “The Expander System admittedly costs more than a traditional axle, but if you include repair time and stoppages with loss of income, the difference is clearly to the advantage of the Expander System. If you add the fact that Expander offers a 10-year function warranty, you can count on at least 10,000 problem-free operating hours – compared with the 3,700 that is regarded as normal for a traditional pin.”
The 2017 September issue of Bolted magazine is available now! As with every issue we have filled the magazine with interesting cases and insights from the world of bolting.
In this edition, our theme article focus on lug wear which is a common issue for pivot joints. But why does it occur, what solutions exist and do they solve the root cause of the problem?
You will find out more about Expander System in our customer case, where we visited Danish company Viggo Benz who delivers solutions and equipment for crushing, demolition and sorting.
Also, see how Nord-Lock washers secure containers that transport radioactive substances, where there is no room for equipment failure.
Last but not least, don’t miss out on how and why we now offer lifetime warranty throughout our product range.
Want to receive your complimentary copy of the Bolted magazine? Subscribe here now!
First published in Bolted #1 2017.
What is Expander’s business?
“Our patented Expander System is a state-of-the-art, cost-effective solution that permanently ends pivot wear in construction, forestry, mining and other heavy machinery. Fitted in the pivot, a double-locking expanding pivot pin assembly increases stability and safety and eliminates welding and line boring of worn-out pivot lug ears. The system has been field-tested for over 50,000 hours without failure.”
How did the company start?
“My father, Everth, and his twin brother Gerhard, did road work in the 1950s, starting out with one bulldozer. Machinery joints and pivots are prone to wear and tear, leading to expensive downtime and repairs, but they came up with a makeshift solution, knocking a rusty nail into the lughole to eliminate the gap. This worked surprisingly well, which inspired them to start developing the technology.”
When did you get involved?
“I learned about their ideas and immediately saw the potential. My father and I founded the company in 1986. At quite an early stage we got involved with computer engineers in the development of a parameter-controlled CAD system. This is an invaluable tool, as each Expander System is custom made to fit customer-specific applications.
In the 1990s we expanded geographically. North America is a huge market and in 1997 I moved there to get a business foothold. The launch was successful and in 2006 we established our own production facility in North America.”
Why did you sell the company?
“Enormous markets, such as South America, are starting to develop, but you need local presence. It was about either setting up my own network or selling to someone that already had a global subsidiary and distributor network. We already collaborated with Nord-Lock and after several discussions with Ola Ringdahl, CEO, Nord-Lock Group, I was sure that the Nord-Lock Group was a perfect fit.”
What does Expander bring to the Nord-Lock Group?
“There has been a major change in how people view repair and maintenance, which makes the market potential for the Expander System huge. We’ve only scratched the surface.
Also, we and the Nord-Lock Group have often shared customers, but solved different problems. Bringing our solutions together – and cross-fertilising them – will make our portfolio and product range so much stronger, which will benefit the customers.”
Facts: Roger Svensson
Role: Founder and former CEO, Expander System Group.
Lives: Sedona, Arizona, USA.
Background: Studied Economics/Political Science at UCLA (double major). Member of the UCLA team that won the prestigious NCAA swimming championships in 1982. Held a couple of positions with other companies before starting Expander with his father in 1986. “I have always been an entrepreneur.”
Passion: Music: sings, plays guitar and writes his own songs. Is currently working on his debut album. Also paints and likes to write.
First published in Bolted #1 2017.
Range: >40 models from 450 kg to 20 tonne
End-customers: Crusher manufacturers and mines
Product used: Expander System Pivot Technology
Applications: Breaker boom systems
Rambooms Oy is a global supplier of breaker boom systems to crusher manufacturers and mines. Based in Finland, its products are used to break oversized rocks.
Pivot wear on these applications is a natural occurrence through time and repeated use, and the company had previously been using its own solution to prevent this. This solution, with a basic conical locking, had caused some issues. Rambooms’ own pins also arrived at its factory in pieces rather than assembled, which meant extra repacking work for personnel when sending the pins on as spare parts.
In 2009, the company took the decision to test the Expander System pivot technology and has been extremely satisfied with the results. The Expander pivot pins are already fully assembled when they arrive. This represents a significant time and cost saving in a competitive industry. Technicians have found fitting and locking much easier than the company’s previous solution.
The Expander System has offered Rambooms significant peace of mind, as it has had no customer issues with pivot wear since the company employed it. A marked improvement in delivery times has also been noted, as Expander always has the stock ready to ship.
“Our customers recognise the fact that the Expander pivot technology means good quality. This reflects well on us and our business,” says Samppa Varhomaa, Product Manager at Rambooms Oy.
The Expander System is locked into the pivot on the machinery when fasteners are tightened. The double-sided locking increases safety and stability, while both fitting and dismantling is simple.
Are you getting the most out of your machinery?
Pivot wear is a common problem with all machinery. Expander pivot pins allow you to avoid costly and time-consuming repairs.
Watch Jonny, our engineer at Expander System, who explains the Expander technology that gives a permanent solution to your pivot wear challenge.
Find out what our customers have to say on how Expander System has saved time and money in industries such as construction, forestry and mining. ► Read customer cases