Solving pivot pin wear issues in mining with the Expander System
Breaker boom systems are a key part of mining, delivering the power needed to remove obstacles and clear blockages. But with every blow sending energy back through the boom, pivot wear is a constant concern. This case study explores how switching from a traditional pivot pin to the Expander System unlocked improved performance, saved time and reduced costs for mining machinery manufacturer Rambooms (now Normet).
Why pivot pins wear out
Finland-based Rambooms (known since 2023 as Normet) is a global supplier of breaker boom systems to crusher manufacturers and mines. As these products are used to break oversized rocks, pivot wear in their applications is common, and must be solved to minimize costly machine downtime.
This occurs because standard straight pivot pins must be slightly smaller than the lug hole they are mounted into, meaning the movement of the axle will wear down the lug hole through repeated use over time. As the wear grows, precision and control of the machine reduce, and maintenance becomes an acute need.
Rambooms previously used their own basic conical locking solution to try and resolve this issue, but it came with its own challenges. These pins arrived at the Rambooms factory in pieces rather than pre-assembled, which meant extra repacking work for personnel before they could send the pins on as spare parts.
A better alternative to traditional pivot pins
In 2009 Rambooms decided to test the Expander System instead. It addresses lug wear by expanding upon installation to conform to the pattern of the lug it is inserted into, distributing pressure more evenly than traditional pivot pins and preventing further deformation.
Consisting of a tapered pin with conical ends, two expansion sleeves, washers and fasteners, the Expander System is also pre-assembled, and arrives ready to be mounted.
More than a pivot pin: gaining simplified installation and a mark of quality
The Expander System is straightforward to apply even for these heavy-duty machines: inserted into the pivots of the breaker boom, it is then locked by tightening the fasteners. The system’s double-sided locking increases safety and stability, while dismantling is equally simple as fitting, and is achieved by reversing the installation process.
With no pivot wear issues since, Rambooms considered the change a success:
“Our customers recognize the fact that the Expander System technology means good quality. This reflects well on us and our business,” Samppa Varhomaa, Product Manager at Rambooms Oy concluded.
Faster assembly and reduced downtime thanks to the Expander System
Rambooms achieved several positive outcomes from the change. As the Expander System arrives fully assembled, switching meant significant time and cost savings in a competitive industry. Their technicians also found fitting and locking much easier than they did with the previous traditional pivot pin solution.
On top of this, a marked improvement in delivery times was also noted, with Expander stock always available, ready to ship. These various improvements in downtime add up to a more efficient solution that keeps machines in operation for longer.
Key take-aways
Use case:
Improving pivot pin performance in breaker boom systems
Customer:
Rambooms (known since 2003 as Normet)
Location:
Finland for global distribution
Benefits gained:
- Simplified installation
- Eliminated need for pre-assembly
- Improved delivery time
- Proven performance with no wear issues
- Cost and time savings
