How P&H mining equipment secures bolts to secure uptime
Mining is an unforgiving world where machinery bearing extreme loads must cope with massive vibration, and every second of downtime counts. But many attempts to help bolted joints cope with this strain, from custom bolts for mining to other apparent fixes, create problems of their own. This case study explores how P and H mining equipment solved this challenge by deploying Nord-Lock X-Series washers, reducing risks and simplifying installation.
Worth a combined value of well over one trillion dollars, mining is a major contributor to global GDP, securing minerals and other raw materials that play a pivotal role in keeping the world economy moving. In the mining industry every minute of downtime is of huge consequence therefore, and one loose fastener can cost a small fortune.
While there are many custom bolts for mining on the market that claim to provide the stability needed for this intense application, in reality, the harsh conditions leave no room for half measures. This is why Joy Global doesn’t compromise when it comes to bolt security for its P&H mining equipment.
In a world where every minute is vital, P&H mining equipment excels at uptime
At an open-cut mine, virtually no other sound is audible amongst the constant grind of large, heavy-duty machinery smashing, crushing and drilling into solid rock. With minerals buried deep underground and undisturbed for millions of years, it takes a huge amount of force to extract them. The machines and vehicles on an average mining site are exposed to some of the harshest operating conditions imaginable, including lifting extreme loads and being subjected to constant vibration. As they continue to chip away at the earth’s surface, the whole landscape is radically changed, creating a deep, man-made canyon.
To describe mining as big business is an understatement. Mining has an impact on a massive cross-section of the global economy, providing materials that are essential to a wide range of industries from electronics to renewable energy, construction and beyond. Entire nations and communities rely on the mining industry and the raw resources it provides for their livelihoods, and without the mining of minerals for batteries, there can be no electrification and shift towards renewable energy sources. In other words, in many ways the continued development and industrialization of human civilization is based on our ability to dig deep and extract resources from beneath the earth’s surface.
With so much riding on the end product, any hindrance or delay has major consequences, so it’s imperative that everything works smoothly. “Every minute is quantifiable in dollars,” Nicholas Dame, Senior Engineer at Joy Global Surface Mining, explained. P&H was part of Joy Global between 2001 and 2017, until being acquired by Komatsu where the P&H brand and its legacy lives on.
“A one-hour delay can cost thousands in lost income, so uptime is extremely important,” he added.
Where custom bolts for mining need compromise, Nord-Lock washers deliver solutions
For over 140 years P&H mining equipment has been recognized as among the most reliable and productive in the industry. It is no coincidence that around ninety percent of the world’s surface mines use P&H brand equipment. The company’s success is built on its ability to understand the excessive demands of mining and design machines that can deliver continuous production. P&H prides itself on its fastidious attention to every component, including bolts and nuts. For all their horsepower and ability, even the biggest machines are only one loose bolt away from inactivity.
For a number of years, P&H products have used Nord-Lock washers to connect the gearbox to the boom on its electric shovels – an area subjected to heavy vibration. Machinery manufacturers have tried to solve this challenge in a variety of ways in the past, ranging from custom bolts for mining applications to other cumbersome solutions, and P&H itself previously used a fastening solution with a special anti-vibration thread.
This required a unique tap, however, which in turn created its own problem. When the boom was shipped, it was necessary to fill the tapped holes with lubricant in order to prevent corrosion. Since the assemblers did not have access to the unique tap, they had to use a standard thread tap to remove the corrosion protectant, which also resulted in removal of the thread. When operational, it was not possible to see what type of thread was inside the hole.
“Nord-Lock eliminates this concern completely and allows a quick spot-check to ensure proper installation,” Nicholas Dame noted. “It is a proven, low risk solution that gives a good sense of security. It is also less cumbersome and time-consuming. We were using washers anyway, so it was easy to replace them and use a Nord-Lock washer pair instead to eliminate the risk of loosening.”
Extra protection for an extreme application: X-series washers excel in the P&H 4800XCP
The world’s largest electric mining rope shovel with a 135-ton payload, the P&H 4800XCP is a mammoth machine. Compared to its predecessor (the 120-ton 4100XPC AC) it can provide up to 20 percent increased productivity, with a five percent reduction in cost per ton.
For the P&H 4800XCP the transition was made to Nord-Lock X-series, which provides reliable locking even for joints with a short clamp length, subjected to thermal cycling or vulnerable to relaxation. “I see this as the latest version of what is already a very good product,” added Dame. “It has the same properties with the added benefit of removing relaxation out of the equation.”
In addition to Nord-Lock washers on its gearboxes, Superbolt tensioners are used in its crawlers – an area that can be prone to malfunction. Superbolt tensioners maintain preload even when subjected to a million cycles of high dynamic load at a level of 98% applied preload, making them ideal for this application. “This is another fastener that’s easy to work with,” continues Dame. “Because they’re standard bolts, field assemblers are familiar with them and can fasten them quickly. They’re easily tensioned within minutes.”
With all critical joints secured, P&H machines can do what they do best – maintain production in one of the world’s most important and demanding industries.
KEY TAKEAWAYS
Use case:
Surface mining. Nord-Lock X-series washers solve where custom bolts for mining fail.
Client:
Joy Global’s P&H mining equipment (now a part of Komatsu)
Location:
Nuremberg, Germany
Benefits gained:• Proven security – resistant to vibration and significantly reduces risk.
• Easy to install – does not require tapped holes
• Visual – easy to identify whether the bolt has been secured or not.
• Universality – replaces a more complicated custom mining bolt solution
