Name: Mining Dump Truck Piston Accumulator - Korea Mining Dump Truck Piston Accumulator Manufacturers, Suppliers - hydraulic cylinders price
SKU: c192e1d76973

Mining dump truck with piston accumulator equalising axle loads

Mining Dump Truck · 5th of 5 · Final

Mining Dump Truck Piston Accumulator

Not a cylinder. A hydraulic balance beam. When one axle hits a bump and the other drops into a dip, the piston accumulator transfers oil between the two suspension circuits — keeping both axles equally loaded. Without it, one axle would carry twice its share while the other lifts off the ground.

27.5 MPaMax Pressure

PistonType

N₂ + OilMedia

#31Final Product

Not a Cylinder, Not an Actuator — A Hydraulic Equaliser Between Two Axles

Every other product in this 31-product catalogue is a hydraulic cylinder — a device that converts hydraulic pressure into linear motion. The piston accumulator is different: it has no rod, no external motion, and produces no work. It is a sealed vessel with a free-floating piston inside — nitrogen gas on one side, hydraulic oil on the other. Its purpose is to store and release energy, equalising pressure between two connected hydraulic circuits.

On a tandem-rear-axle mining truck, the piston accumulator sits between the middle-axle and rear-axle suspension circuits. When the middle axle hits a bump (its suspension compresses, displacing oil), the accumulator absorbs the excess oil — preventing a pressure spike that would overload the middle axle. Simultaneously, the nitrogen gas on the other side of the piston pushes oil into the rear-axle circuit — compensating for the rear axle's extension as it enters the dip behind the bump. The result: both axles carry equal load at all times, regardless of the haul-road surface profile.

Korea Ever-Power manufactures the piston accumulator as the final component of the five-product mining dump truck hydraulic system — the equaliser that ties the suspension cylinders (#29, #30) into a balanced whole.

Technical Specifications

Parameter	Specification
Product	Mining Dump Truck Piston Accumulator
Function	Equalise load distribution between middle and rear axles in real time
Type	Piston accumulator (free-floating piston, N₂ gas / hydraulic oil)
Working Pressure	Maximum 27.5 MPa
Application	Mining Dump Truck (tandem rear axle load balancing)
Certification	ISO 9001 · 100% pressure tested · gas pre-charge certified

How the Piston Accumulator Balances Two Axles in Real Time

Middle axle hits bump → accumulator absorbs

The middle-axle suspension compresses, displacing oil from the suspension cylinders. This oil flows into the piston accumulator, pushing the free piston against the nitrogen gas. The gas compresses, absorbing the volume of oil — preventing a pressure spike that would overload the middle axle tyres and transmit a harsh jolt through the chassis.

Rear axle enters dip → accumulator supplies

A fraction of a second later, the rear axle reaches the same bump (or a different surface irregularity). As its suspension extends into a dip, it demands more oil. The nitrogen gas in the accumulator pushes the piston back, supplying oil to the rear-axle circuit — keeping the rear axle loaded and in contact with the ground.

Continuous equalisation — passive, instant, zero-delay

The piston accumulator operates passively — no valves, no electronics, no control system. It responds purely to pressure differentials between the two axle circuits. The response is instantaneous (limited only by oil flow speed and piston inertia), providing real-time load equalisation over every bump, rut, and grade change on the haul road. Contact the Korea Ever-Power engineering team for accumulator sizing.

Mining dump truck axle load equalisation

Piston Type vs Bladder Type — Why Mining Trucks Use a Free-Floating Piston

Accumulators come in three types: bladder (a rubber bag inside a steel shell), diaphragm (a rubber disc), and piston (a metal piston sliding inside a cylinder bore). Mining trucks use the piston type exclusively because of the operating conditions:

The temperature range (-40 °C to +100 °C) exceeds the service limits of most bladder rubber compounds. The continuous high-frequency cycling on haul roads (5–30 cycles per second, millions per year) would fatigue a rubber bladder within months. The high oil flow rate during impact loading (when the excavator drops a bucket load) requires a flow cross-section that a bladder's squeeze-neck cannot provide. The piston accumulator has none of these limitations: the metal piston withstands any temperature, any cycle count, and any flow rate that the bore diameter permits.

The piston slides inside a precision-honed bore, sealed by the same polyurethane seals used on the suspension cylinders (#29, #30) — and manufactured on the same production line. Korea Ever-Power applies its cylinder-manufacturing precision (bore honing, seal technology, gas sealing) directly to the piston accumulator, ensuring the same quality standard across the entire mining dump truck hydraulic system.

Manufacturing Process

The accumulator bore is honed to Ra 0.2–0.4 µm — identical to the suspension cylinder bore finish, because the piston accumulator IS effectively a short-stroke, rodless cylinder with a gas-side end cap instead of a rod gland. The free-floating piston is machined from a single steel billet with integrated seal grooves. Piston seal and gas seal are polyurethane, rated for -40 °C to +100 °C and 27.5 MPa.

Every piston accumulator is pressure tested at 1.5× rated pressure on both the oil side and the gas side independently, then gas-charged with dry nitrogen to the specified pre-charge pressure — verified with a calibrated gauge and certified. The gas charge determines the accumulator's stiffness (how much pressure change is needed to move a given volume of oil) and must match the truck OEM's specification to within ±1 bar.

OEM & ODM

What You Provide

Truck model, suspension system schematic, required oil volume displacement, gas pre-charge pressure, maximum working pressure, piston bore diameter, temperature range, mounting envelope, port size and location, and the suspension circuit hydraulic diagram showing how the accumulator connects to the middle and rear axle circuits.

What the Factory Delivers

Piston accumulator with engineering drawing, bore, piston travel, gas volume, gas pre-charge certificate (±1 bar), -40/+100 °C seal specification, port detail, and mounting dimensions. Pressure test (oil side + gas side) + gas-charge certificate. Seal kits. Browse the mobile machinery hydraulic cylinder family and the Korea Ever-Power catalogue.

Korea Ever-Power accumulator manufacturing workshop

FAQ

Do all mining trucks use a piston accumulator?

Only tandem-rear-axle trucks (those with a middle axle and a rear axle sharing the payload). Single-rear-axle trucks do not need an inter-axle equaliser because there is only one rear axle. Most ultra-class mining trucks (150+ tonnes payload) use tandem rear axles and therefore require piston accumulators.

What happens if the accumulator loses its gas charge?

Without gas charge, the piston cannot move — the accumulator becomes a rigid, non-functioning plug. The middle and rear axles lose their hydraulic connection, and each operates independently. On uneven ground, this causes one axle to carry significantly more than its share — accelerating tyre wear, increasing structural fatigue, and reducing ride comfort. Mine maintenance programs check accumulator gas pressure during scheduled services.

Can Korea Ever-Power supply the complete 5-product mining truck hydraulic set?

Yes — lifting cylinder (#27), steering cylinder (#28), front suspension (#29), rear suspension (#30), and piston accumulator (#31) are available as a complete, matched system for the same truck model. Single-source supply from Korea Ever-Power ensures system-wide pressure compatibility, seal standardisation, temperature-range matching, and coordinated delivery. Browse telescopic cylinders and industrial engineering cylinders.