Output (loose)-

Mass flow-

Wheel power-

Limited by-

Track pressure-

Slew speed-

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Bucket-Wheel Excavator Blender 5.2

One of the largest land machines: an 18-bucket wheel on a 76 m boom feeding a four-belt conveyor chain. Drag to orbit, wheel or pinch to zoom, right-drag to pan. The wheel, belts and power run in real time; the digging progress is time-compressed.

Presets

Material and cutting

Ground

Bucket wheel and drive

Conveyor system

Belt cross-section-

Belt capacity-

Belt utilisation-

Transit wheel to ground belt-

Live output and power

Loose output-

Bank (in-situ) output-

Mass flow-

Per 24 h (loose)-

Bucket interval-

Bank volume per bucket-

Cutting force F = P/v-

Wheel torque-

Specific energy-

Pass / phase-

Excavated (sim)-

Energy used (sim)-

cutting k·Q lifting ρ g h Q idling spare

Output (orange, left axis, m³/h loose) and electrical wheel power (blue, right axis, MW) against sim time. Dips are swing reversals and the step-in to the next slice; power spikes come from lumps in the ground when "Lumpy ground" is on.

What limits the machine? Capacity map

Output against specific cutting resistance: slew demand, bucket capacity and conveyor are flat; the wheel power limit falls as 1/(k + ρ g h). The thick line is the minimum; the dot is the present ground.

Machine, ground pressure and turning

Floor

Machine weight-

Mean pressure W/A-

Maximum (track edge)-

Minimum-

Bearing safety-

Tilt safety-

Load eccentricity-

Slew angle-

Turning radius-

Track speeds (out / in)-

Turn needs ΔF-

Travel power-

Plan of the 12 crawler tracks coloured by ground pressure (green low, red high). The cross is the centre of the load, the circle the slew axis, the arrow the boom direction.

Auto dig

Experiment: maximum output against digging resistance

Question: how hard can the ground be before the wheel drive, not the buckets, limits the output? The governor is simulated step by step for 24 resistance values and compared with the closed-form minimum.

Press a button. The 3D machine keeps working while the sweep is computed.

Independent numerical checks

View and time

Labels Lumpy ground Dust

The science

What the machine does

A bucket-wheel excavator cuts a bench with a slowly turning wheel (here Ø 21.6 m, 18 buckets of 6.6 m³, 2.6 rpm). The wheel boom slews across the face; each pass takes a slice of thickness t from a bench of height H. Material is lifted to the top of the wheel, falls through a chute onto the boom belt, passes the gallery over the machine house, the discharge boom and a belt wagon, and ends on the ground conveyor.

Throughput

Bucket-limited loose output is Q_b = n_b V_b (rpm/60) φ with fill factor φ; the in-situ (bank) volume is Q_b/s where s is the swell factor (loose volume / bank volume, 1.1 to 1.4). The slewing demand is Q_k = v_s t H (swing speed x slice thickness x bench height). The conveyor carries Q_c = v A λ with A the cross-section of a three-roll troughed belt (35°) heaped with a 20° surcharge, A ≈ 0.162 (0.9B − 0.05)² for equal rolls, and λ the loading.

Digging force and power

The specific cutting resistance k_s (kN/m² = kPa) is the energy needed per m³ of bank material, so the cutting power is P_cut = k_s Q and the tangential force on the cutting edge F = P_cut / v_t with the peripheral speed v_t = π D rpm / 60. Lifting adds P_lift = ρ g h_L Q with h_L ≈ 0.65 D, plus idling losses P₀. With a shaft power η P_w available, the power-limited output is Q_P = (η P_w − P₀)/(k_s + ρ g h_L). The real output is the smallest of the four capacities, and above the knee k_s* it falls like 1/(k_s + ρ g h_L). The governor in the model slows the slewing when the drive is overloaded, as the real automation does.

Ground pressure, tilting and turning

Mean pressure is W/A over the contact area of all tracks. The load of boom, counterweight, discharge boom and digging reaction is eccentric, so the pressure under a rigid footing is linear: p(x,z) = W/A + W e_x x / I_x + W e_z z / I_z; if the minimum drops below zero a track would lift. Tilt safety is the distance to the edge divided by the eccentricity. Turning makes the tracks skid sideways: the lateral resistance moment is about μ_t W x̄ (x̄ the mean distance of the track area from the slew axis), supplied by a thrust difference between outer and inner tracks at the gauge B_g.

What is simplified

The wheel is a continuous cutter at a constant mean fill (the pulsed discharge of single buckets is drawn but not modelled in the power); k_s is constant for a given ground and does not depend on chip thickness, tooth wear or moisture; the tracks are rigid on a linear pressure distribution without sinkage; the stability model uses static masses. Values are of the order of the largest machines, not the data of one machine. No company or product is depicted.