Feeder breakers are built to take punishment, but their reliability is never accidental. Learn how to optimise performance with McLanahan.
By breaking down both the engineering principles and the maintenance steps behind reliable performance, McLanahan is helping operators turn everyday upkeep into measurable gains in machine life and production uptime.
Speaking during a recent webinar, McLanahan global product engineering specialist Dave Imler guided miners through the inner workings of feeder breakers, sharing insights that could save downtime and extend machine life.
“Feeder breakers might look straightforward, but these machines are far more complex than they might seem,” Imler said.
“Their performance, reliability and longevity all hinge on operators’ understanding the engineering behind them and applying disciplined maintenance practices.”
Feeder breakers are used to break down large lumps of ore or coal and feed them into the processing plant at a controlled rate. And at the heart of every feeder breaker is the chain and flight bar system.
Operators may encounter slip-fit bars, bolted bars, or a combination of both, while most installations rely on engineering-class push-link chains designed to withstand constant impact.
Chain tension is one of the simplest yet most important factors in preventing failures: too tight and shafts, sprockets and bearings are overstressed; too loose and the chain can skip teeth or even drop flight bars.
For ideal chain tension, a slight droop under the head shaft on the return side should be visible through inspection ports, giving operators a clear guide to proper tension.
Adjusting tension is straightforward when done correctly, according to McLanahan. Most machines use hydraulic cylinders and shim packs at the tail shaft, allowing controlled adjustments.
Symmetry is essential. Both sides must be evenly set to prevent misalignment, which can quickly lead to costly damage. Planning for chain replacement is equally important.
Sites that keep full chain and flight assemblies on hand can proactively schedule change-outs, turning what could be a drawn-out downtime event into a controlled, one-day task.
Imler suggests using the right tools that are designed to make the job easier, but stresses the importance of safety.
“Hydraulic jigs and custom fixtures can simplify the process, but safety is paramount,” he said. “Locking out and tagging out before the adjustments keeps operators clear of high-force areas and careful preparation prevents injuries during high-pressure maintenance tasks.”
The drives that power feeder breakers are another critical area requiring attention.
These machines typically use one of three coupling types: safety couplings that shear under extreme torque to instantly decouple the drive; fluid couplings that transmit torque through hydraulic oil like a car’s torque converter; and friction-plate clutches that rely on spring tension and pad condition, slipping when overloaded.
Each system behaves differently under stress and requires specific maintenance routines to maintain reliability.
Hydraulic conveyor drives introduce another layer of engineering. Variable-displacement axial-piston pumps control conveyor speed by adjusting the swash plate, while charge pumps maintain system pressure and cooling.
Operators who understand normal pressure ranges, oil flow and temperature – ideally around 120°F (49°C) – can detect emerging issues before they become major problems.
Mechanical connections also demand careful attention.
Shrink-disc locks, taper-bushing connections and bearings all require precise installation and regular inspection to prevent wear, misalignment or premature failure.
Daily and weekly checks, such as verifying chain tension, monitoring bearings for heat and cleaning dust from critical areas, help maintain efficiency and prevent small issues from escalating.
Over time, predictable wear appears on breaker bits, liners around the roll shaft, top-deck plates and chain transition zones. Annual inspections allow teams to plan component replacements before failures interrupt production, turning maintenance from a reactive task into a proactive strategy.
Imler said audits and proactive inspections help to save production and reduce costs.
“We know these machines inside and out,” he said. “Mines should identify emerging wear patterns before they turn into critical problems.”
The feeder breaker, often operating quietly in the background, is a decisive piece of machinery in mining operations.
With the right understanding, regular maintenance and careful planning, these machines can deliver years of reliable performance, even in the harshest conditions.
This feature appears in the February issue of Australian Mining magazine.