Drives for Mining & Mineral Processing: Mine Hoists, Mills, Conveyors, Crushers
Mining and mineral processing places a combination of demands on drive equipment rarely seen together in other sectors: heavy low-speed mill drives with torques of tens of mega-newton-metres, shaft hoists with redundant braking systems, multi-kilometre belt conveyors with starting fluid couplings and backstops, crushers exposed to peak impact loads from oversize feed, and slurry pumps handling abrasive pulp. General-purpose industrial product lines fail quickly here — what is required are solutions engineered specifically for mining duty.
Industry-typical tasks
- Main shaft mine hoist drives — gearboxes 1,000–4,000 kW, service and emergency brakes, 6/10 kV HV motors
- Drives for trunk and open-pit belt conveyors 1–5 km long — K-series gear motors 75–1,600 kW, starting fluid couplings, backstops and anti-runback devices
- Main drives for ball, rod and SAG mills at processing plants — low-speed gearboxes and HV motors 1,500–15,000 kW
- Drives for jaw, cone and hammer crushers — heavy starts under load, fluid couplings, jam protection
- Drives for vibrating screens, feeders, thickeners and slurry pumps — general-industrial gear motors and pumps for abrasive media
- Hydraulic power units for surface blasthole drill rigs and underground heading machines — 200–500 bar pumps, oil coolers
- Personnel and freight cage hoists and skip hoists — current collectors, emergency catch brakes
- Mobile open-pit conveyors and stackers on overburden dumps — reversible drives with high dust resistance
Gearboxes
Three classes of gearboxes are used in mining and mineral processing: heavy-duty specialised units (main mill drives, mine hoist gearboxes), industrial gear motors (conveyors, feeders, screens) and planetary units (rotary kilns, thickeners, low-speed slurry handling drives). The key selection criterion is the rated service factor with allowance for shock overloads (no less than 2.0 for crushing and grinding equipment) together with a thermal-rating check for conveyors with frequent fully-loaded starts.
Main mine hoist gearbox
Two-stage parallel-shaft gearboxes with a herringbone output stage transmit torque from the HV motor to the drum or Koepe friction sheave shaft. They run reversibly through long cycles of cage or skip hoisting and lowering, and require high housing rigidity to limit deformation under the weight of the drum and rope. CGC ZSY/MBY series with parallel power split deliver up to 4,000 kW per case at a service factor of 1.8–2.0.
- — Gear ratio 12.5–50
- — Output torque 100–800 kN·m
- — Service factor not less than 1.8 (including emergency braking)
- — Forced circulation lubrication with filter and oil cooler
- — Online bearing temperature and vibration monitoring
Main drive for ball and SAG mills
Low-speed two- or three-stage gearboxes with a high reduction ratio transmit power from the HV motor to the girth gear surrounding the mill shell. The output peripheral speed is low (1–5 m/s) but the torque reaches 5 MN·m. CGC MBY/JDX series are rated for continuous S1 duty and come with an oil supply unit including main and standby pumps, oil cooler and fine filter. On large mills (Ø 5 m and above) a dual-drive arrangement is used — two identical gearboxes driving one girth gear with PLC-based torque balancing.
- — Gear ratio 25–100
- — Output torque 500 kN·m – 5 MN·m
- — Service factor not less than 2.0
- — Oil supply unit with redundant pumps
- — Capability to operate as dual drive on a single girth gear
Gear motors for trunk conveyors
All-purpose helical-bevel gear motors of the Boneng K-series and HB-series are the backbone of conveyor drives at open-pit mines and processing plants. A heavy fully-loaded belt start requires a service factor of at least 1.5 and mandatory thermal verification — long mining conveyors often run in S4 duty with 6–12 starts per hour. Inclined conveyors lifting load are equipped with a backstop on the drive to prevent belt runback at shutdown.
- — K-series (15°/45° bevel) or HB-series (heavy industrial)
- — Power 75–1,600 kW per drive
- — Service factor not less than 1.5
- — Mounting interface for a backstop on the low-speed shaft
- — Dust protection — IP65 labyrinth seals
Gearboxes for crushing and screening equipment
Jaw, cone and hammer crushers use industrial parallel-shaft or helical-bevel gearboxes with an elevated service factor (SF 2.0–2.5) to absorb shock loads from oversize feed. The drive is typically arranged as “motor + Jiaohua YOX fluid coupling + gearbox” — the fluid coupling provides a soft start and protects the gearbox from peak torques during chamber jamming.
- — Service factor 2.0–2.5
- — Compatibility with a hydrodynamic coupling (flange interface)
- — Reinforced bearings for high radial loads
- — Shear pin or fusible plug as overload protection
- — Lubrication access without disassembly
Drives for rotary kilns and thickeners
Low-speed multi-stage gearboxes with reduction ratios of 200–500 are mounted on the kiln girth gear or on the central column of a thickener. Continuous duty (S1, 24/7), low rotational speed (0.1–4 rpm) and high radial loads from the equipment self-weight are typical. Thickener drives must be redundant — once stopped, slurry sediment hardens within 4–6 hours and a restart becomes impossible.
- — Gear ratio 200–500
- — Continuous S1 duty 24/7
- — Redundant lubrication system
- — Resistance torque monitoring (rake jam protection)
- — Corrosion-resistant design for slurry service
High-power electric motors
Main drives for mine hoists, mills, dust-extraction fans and compressors at mining sites fall into the domain of HV asynchronous and synchronous motors with ratings from 800 kW to 15 MW at 6 or 10 kV. Beyond raw ratings, specific requirements apply: capability to operate with an HV variable-frequency drive, high starting torque for crushers and mills, protection of bearings against shaft currents, and thermal margin for the frequent starts and reversals of mine hoists.
Main motor for the mine hoist
Synchronous or asynchronous 6/10 kV HV motors rated 800–4,000 kW operating with a four-quadrant HV inverter. The hoist duty cycle includes acceleration, travel at full speed, deceleration and emergency braking — the motor must withstand 60–120 starts per shift with a peak torque of 2.0–2.5 of nominal. Wolong YHTM and WD3000 series cover the full power range with an efficiency above 96 % at rated load.
- — Power 800–4,000 kW, voltage 6/10 kV
- — Insulated bearing on the non-drive end
- — Forced cooling IC81W or IC611
- — Encoder with at least 4,096 ppr
- — Thermal margin for 60–120 starts per shift
Motors for main mill drives
HV asynchronous motors rated 1,500–15,000 kW at 6/10 kV operate in continuous S1 duty, started through a fluid coupling or an HV inverter. Direct-on-line starting is unacceptable for large mills — the inrush current is 5–7 times nominal, which is unacceptable for mine substations. The combination “Wolong YHTM motor + Jiaohua YOX fluid coupling + CGC MBY gearbox” is the standard arrangement for ball mills at processing plants.
- — Power 1,500–15,000 kW, voltage 6/10 kV
- — Compatibility with a starting fluid coupling
- — Insulation class F with class B thermal margin
- — Vibration monitoring per ISO 10816-3 (zone B)
- — Bearing protection against shaft currents (insulated bearing)
Slurry pump and pulp delivery motors
Kingda KSM/KSL slurry pumps for abrasive pulp are driven by HV motors of 200–1,600 kW. Continuous S1 duty with a minimum number of starts but high reliability requirements — a slurry pipeline standstill exceeding 2 hours leads to solids settling and pipeline blockage. Motors are specified with tropicalised winding insulation and reinforced bearings to handle the radial load from the pump coupling.
- — Power 200–1,600 kW, voltage 0.4/6/10 kV
- — IP55, tropicalised winding insulation
- — Reinforced bearings for high radial loads
- — Redundancy of critical drives (1+1)
- — Compatibility with a variable-frequency drive
Motors for crushing equipment
Jaw and cone crushers are driven by asynchronous motors of 132–1,250 kW at 6/10 kV or 0.4 kV. The heavy start under load requires a starting torque of at least 1.8 of nominal. The standard arrangement is motor through a fluid coupling driving the crusher flywheel; the flywheel stores energy and smooths peak loads from oversize feed. For frequent reversing during jam clearing, motors with rotor resistance starting are used.
- — Starting torque not less than 1.8 of nominal
- — Compatibility with a fluid coupling and flywheel
- — IP55 minimum
- — Thermal protection for frequent starts (S4–S6)
- — Dust-tight terminal box
Industrial brakes
Mine and processing plant safety depends directly on braking systems. A mine hoist must have both a service brake and an emergency brake, each rated to hold the full conveyance load with a margin of 1.5–2.0 — a requirement of the Russian Mine Safety Rules. Brakes are also installed on inclined conveyors to prevent belt runback, on skip hoists, and on winches of drilling and tunnelling equipment.
Mine hoist disc brakes — service and emergency
Huawu YPZ2/YWZ5 series — hydraulic disc brakes with spring-applied force. On a mine hoist they are arranged in sets of 4–16 brake modules around the perimeter of the brake disc fixed to the winding drum. The service brake is controlled by a pressure regulator and provides smooth braking under normal operation; the emergency brake closes by spring force on loss of pressure or an alarm signal within 0.15–0.30 s. A dual system is mandatory under the Russian Mine Safety Rules for personnel hoists.
- — Braking torque with a 1.5–2.0 margin over loaded conveyance weight
- — Closing time on tripping not exceeding 0.3 s
- — Electronic monitoring of pressure and pad position
- — Dual set (service + emergency)
- — Certification per PB 03-553-03 (mine hoisting installations)
Inclined conveyor brakes and backstops
Inclined and horizontal conveyors with long belts use TKT/TKK electrohydraulic shoe brakes mounted on the brake drum of the gearbox shaft. They hold the conveyor at shutdown and prevent belt runback under the weight of ore. On intermediate drives of trunk conveyors, Tianiu backstops are installed in parallel — a mechanical protection independent of electrical power.
- — Electrohydraulic thruster Ed-50 to Ed-301
- — Compatibility with a brake drum coupling
- — Manual release for maintenance
- — Pad wear monitoring (limit switch)
- — Mining-grade design for underground conveyors (Ex db)
Explosion-proof brakes for underground duty
For conveyors, hoists and winches in coal mines with high gas hazard, Zhonghai brakes in mining flameproof design with Ex db I Mb marking are used. The thruster housing and electrical components are certified per GOST 31610.0/31610.1 and approved for atmospheres containing methane and coal dust.
- — Ex db I Mb marking (mining flameproof)
- — Conformity certificate to TR CU 012/2011
- — Light-alloy or non-sparking steel housing
- — IP65 minimum, coal dust protection
- — Full set of supporting documentation in Russian
Wind-storm brakes for open-pit stackers and reclaimers
On rail-mounted mobile open-pit machines — stackers, reclaimers and mobile conveyors — Jingu CWZ or Zhonghai SB rail clamps are installed. They hold the machine on its rails against gusts of up to 35 m/s during idle periods. Activation is automatic on an anemometer signal or on power loss.
- — Holding capability up to 35 m/s wind
- — Automatic activation on anemometer signal
- — UPS backup or self-contained power source
- — Pneumatic release for start-up
- — CE certification and operation across −40 to +60 °C
Couplings
Mining drives use four types of couplings: hydrodynamic for starting under load (trunk conveyors, mills, crushers), gear-type drum couplings for heavy main drives (mine hoists, mills), flexible pin-and-bush couplings on general-industrial drives (feeders, screens, pumps) and backstops on inclined conveyors. Couplings are sized for torque with a 1.5–2.0 margin, with mandatory verification of starting duty and fluid-coupling thermal load under heavy starting cycles.
Starting fluid couplings for conveyors and mills
Jiaohua YOX/YOXII/COX series provide a soft start under full load through slip between the pump and turbine wheels via the working fluid (typically hydraulic oil). The motor accelerates almost unloaded and gradually picks up the load — this reduces grid current peaks and protects the gearbox from torque spikes. A nominal slip of 2–4 % protects the motor against overload during belt or mill rotor jam.
- — Transmitted power 75–4,000 kW
- — Nominal slip 2–4 %
- — Fusible plug set at 145–160 °C (overheat protection)
- — Oil fill 70–85 % of internal volume
- — Thermal margin for 4–6 starts per hour
Gear drum couplings for main drives
Yongjing GIICL and Longxuan WGZ series are used on rigid connections such as “gearbox — mine hoist friction sheave” and “gearbox — mill girth gear”. They transmit torque up to 1.2 MN·m while compensating radial, axial and angular shaft misalignment within 0.5–1.0°. The crowned tooth profile tolerates misalignment, and the grease lubrication via a nipple is renewed every 6 months.
- — Torque 50–1,200 kN·m
- — Angular misalignment compensation 0.5–1.0°
- — Grease lubrication on a 6-month interval
- — G6.3 balancing for speeds above 15 m/s
- — Forged steel coupling halves
Conveyor backstops
Tianiu NJZ/NYD series are mounted on the low-speed shaft of an inclined conveyor gear motor. They transmit torque in one direction only — rotating freely during start-up and operation, locking instantly on any attempt at belt runback under the load weight. This is a mechanical protection independent of electrical power: even on a complete site blackout the belt remains stationary.
- — Holding torque 1.5 times the calculated runback torque
- — Mounting on the gearbox low-speed (output) shaft
- — Locking time not exceeding 0.5 s
- — Service life of at least 1 million locking cycles
- — Compatibility with the gearbox output shaft diameter
Pin-and-bush couplings with brake drum
Longxuan YOXp/YOXz and Yongjing LX/LMC series are pin-and-bush couplings with elastic sleeves, often integrated with a brake drum. They are used on conveyors, feeders and screens of medium power class where damping of starting shocks and a mounting interface for a shoe brake are required at the same time. NBR/NR elastic elements compensate small misalignments and act as a fuse — at 50 % overload the sleeves fail, interrupting power transmission.
- — Torque 5–125 kN·m
- — Brake drum integration per GOST 21424
- — Radial misalignment compensation 0.2–1.0 mm
- — Service life of elastic sleeves at least 30,000 h
- — Sleeve replacement without coupling-half removal
Applications gallery
Our solutions for this industry
SDS portfolio brands that cover typical applications in this industry.
- BONENGK-series and HB-series gear motors for trunk and open-pit belt conveyors, feeders and screens — primary supplier for conveyor drives
- CGCheavy-duty mine hoist gearboxes (ZSY/MBY) and main mill drive gearboxes (MBY/JDX) up to 5 MN·m, available in dual-drive configuration on a single girth gear
- WOLONGHV motors for mills, mine hoists and slurry pumps (YHTM, WD3000) rated 800–15,000 kW at 6/10 kV
- HUAWUYPZ2/YWZ5 mine hoist disc brakes — service and emergency systems compliant with PB 03-553-03
- JINGUwind-storm rail clamps for open-pit stackers, reclaimers and mobile conveyors on overburden dumps
- ZHONGHAIEx db I Mb explosion-proof brakes for underground conveyors, winches and hoists in coal mines
- YONGJINGGIICL gear drum couplings, LX/LMC pin-and-bush couplings and cardan shafts for friction sheaves and main drives
- JIAOHUAYOX/COX starting fluid couplings for trunk conveyors, mills and crushers — soft start under load
- LONGXUANWGZ gear couplings and pin-and-bush couplings with brake drum for conveyor and hoisting drives
- KINGDAKSM/KSL slurry pumps for abrasive pulp at processing plants and tailings handling — flagship SDS solution
- ANNENGtrolley busways and current collectors for skip and cage hoists in mine shafts
- TIANIUNJZ/NYD backstops for inclined conveyors — mechanical protection requiring no electrical power
- DONLYhydraulic power units for surface blasthole drill rigs and underground heading machines, 200–500 bar pumps and oil coolers
- INIhydraulic components — pumps, hydraulic motors and valves for drill rigs and auxiliary open-pit equipment
- HUADEhydraulic components for HPUs of drilling and tunnelling equipment — valves, pumps and directional controls
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