Drives for crane manufacturing: gearboxes, motors, brakes, couplings and power supply systems
Lifting equipment — overhead bridge, gantry, tower, portal, port and jib cranes — operates in short-cycle duty with a high number of starts and reversals per hour. Each crane runs three to four drives in parallel (hoist, bridge or gantry travel, trolley travel, slewing), and the hoist drive additionally requires two independent brakes and a backstop. Outdoor installations add specific tasks: storm brakes, conductor bars along the crane runway and speed control via crane VFDs.
Industry-typical tasks
- Hoist drives for overhead bridge and gantry cranes with 5–500 t capacity, 5–40 m/min lifting speed and 1.75–2.5 braking torque safety factor
- Bridge travel drives (main end trucks) and gantry travel drives at 30–120 m/min with VFD-based soft start
- Trolley travel drives along the bridge — compact gear motors 1.1–22 kW with frequent reversals (up to 360 cycles per hour)
- Slewing, luffing and boom hoist drives for tower construction cranes and portal harbour cranes
- Dual-brake configuration for foundry, charging and metallurgical-shop cranes — service plus emergency brake with 2.0 safety factor and response time of 0.2 s or less
- Storm brakes and rail clamps for portal, gantry and tower cranes on outdoor sites
- Crane runway power supply — busbar trolley systems and festoon cable trolleys for spans of 30–500 m
- Crane speed control via dedicated VFDs with crane mode (S-curve, ESP, anti-sway, load-torque control)
Gearboxes and gear motors
Three types of gearbox solutions are used on cranes: general-purpose gear motors for travel and trolley mechanisms (K and HB series), compact hoist gearboxes with an integrated brake and a built-in mounting seat for the rope drum, and heavy parallel-shaft gearboxes for portal and shipbuilding cranes with torques up to 250 kN·m. The key feature of crane-duty gearboxes is a high service factor (SF ≥ 1.6) for starting shocks and a dedicated mounting for a gear coupling with brake drum on the high-speed shaft.
Gear motors for bridge and trolley travel
Helical-bevel (K series) and parallel-shaft (F series) gear motors are mounted on the wheel sets of the bridge and trolley. Heavy-capacity overhead bridge cranes use two to four gear motors per bridge — one per running wheel — to ensure travel synchronisation and reduce loads on the wheel bearings. Outdoor cranes require IP55 minimum; hot-shop applications need heat-resistant VG 220 oil and Pt100 thermal sensors.
- — K series (helical-bevel) for the horizontal wheel shaft
- — Gear ratio 25–125
- — Drive power 1.1–22 kW (trolley) and 5.5–55 kW (bridge)
- — Service factor of at least 1.6 for S4–S5 duty
- — Mounting interface for a motor with integrated brake
Hoist gearboxes for overhead bridge and gantry cranes
Two- or three-stage parallel-shaft gearboxes with a herringbone output stage and an integrated rope drum. The high-speed shaft accepts a gear coupling with brake drum; the low-speed shaft mates with the drum or an open gear stage. Critical hoists (foundry and charging cranes) use two independent gearboxes with split kinematics for fault tolerance.
- — Gear ratio 16–63
- — Output torque 10–250 kN·m
- — Service factor of 2.0 or above for metallurgical cranes
- — Compatibility with the YONGJING GIICL gear coupling and brake drum
- — Splash or forced lubrication with filter and magnetic plug
Slewing and luffing gearboxes for tower and harbour cranes
Helical-planetary units with high reduction ratios and an integrated emergency brake. The tower crane slewing drive works under wind loads on the boom, so the gearbox is selected with a safety margin on output-shaft radial load and is mandatorily equipped with a holding brake that locks the boom on power loss.
- — Gear ratio 80–315 (slewing) and 40–125 (luffing)
- — Torque holding on power loss (integrated brake)
- — Allowable output-shaft radial load including wind component
- — Seals rated for outdoor installation, IP65
Heavy gearboxes for harbour and shipbuilding cranes
Harbour ship-to-shore, quay and shipbuilding cranes from 100 t capacity use heavy parallel-shaft CGC H/B/K series gearboxes with torques up to 1 MN·m and a service factor of 2.5 or above. They operate in marine air with elevated corrosion load — C5-M coating and a desiccant breather are required.
- — Output torque up to 1 MN·m
- — C5-M anti-corrosion coating (marine environment)
- — Forced circulation lubrication with oil cooler
- — Bearing vibration and temperature monitoring
- — Breather with desiccant filter
Gear motors for jib and pillar cranes
Compact gear motors with an integrated electromagnetic brake for the slewing mechanism of jib and pillar cranes. They operate in short-start duty with a 180–360° slewing angle, typically with variable speed through a VFD for smooth positioning.
- — Worm or helical-bevel gear motors
- — Integrated electromagnetic brake
- — VFD compatibility for slewing speed control
- — Power 0.55–7.5 kW
Crane-duty electric motors
A crane-duty induction motor differs from a general-purpose unit by elevated starting torque (1.8–2.8 of rated), higher slip (5–8 %) and thermal headroom for intermittent duty S3–S5 with 25 %, 40 % or 60 % cyclic duration factor. Modern cranes pair crane-duty motors with VFDs — this lowers inrush currents on the grid and provides smooth acceleration without load sway.
Crane motors for the hoist mechanism
WOLONG YZR/YZP series — crane-duty induction motors with wound or squirrel-cage rotor, 1.5–250 kW, class H insulation, S3–S5 duty (40 % CDF). Used with INVT/INOVANCE crane-series VFDs in torque-control mode. For occasional-use cranes (standby, maintenance), squirrel-cage motors with direct-on-line starting via contactor are used.
- — Starting torque of 2.0 or above of rated
- — Class H insulation, S3–S5 duty at 40 % CDF
- — Integrated electromagnetic brake or mounting for external brake
- — IP54 (indoor shop) to IP55 (outdoor site) ingress protection
- — Encoder for closed-loop speed control
Motors for travel mechanisms
Bridge and trolley travel motors operate under frequent starting and reversing (up to 360 cycles per hour), requiring elevated starting torque and a sound thermal balance. Heavy-capacity overhead bridge cranes use up to four motors synchronously — synchronisation is provided by a crane VFD in master/slave mode.
- — S4 duty at 40 % CDF with up to 360 starts per hour
- — Starting torque of 1.8 or above of rated
- — Compatibility with crane VFDs (NEMA MG1 Part 31 insulation)
- — Integrated or flange-mounted brake with electrohydraulic thruster
General-purpose motors on auxiliary drives
Hydraulic-pump, cooling-fan and maintenance-platform winch motors are general-purpose units of the HUALI YE3/YE4 and WOLONG YE series. Crane-duty rating is not required here; IP55 and IE3 efficiency class are the priorities.
- — IE3 efficiency class (IE4 optional)
- — Continuous S1 duty
- — IP55, class F insulation
- — Standard IM1001/IM3001 mounting
Motors for tower and portal construction cranes
On tower cranes the hoist motor operates at 60 % CDF or above, so reinforced cooling (IC411 with forced ventilation) and thermal sensors on windings and bearings are added to the standard crane-duty design. Slewing motors are two-speed induction units or single-speed with VFDs for smooth ramp-up to rated speed and precise boom positioning.
- — S3 duty at 60 % CDF (tower-crane hoist)
- — Two-speed windings 4/24, 8/32 (slewing) or VFD control
- — Condensation protection (anti-condensation heaters)
- — IP55 ingress protection, class H insulation
Service, emergency and storm brakes
A crane braking system has three circuits: service brakes on every drive (hoist, travel, slewing), an emergency brake on the hoist drum for critical loads, and storm protection against runaway along the rails. Metallurgical-shop cranes handling pouring ladles use a dual-brake configuration — two independent service brakes, each rated to hold the full load with a 1.75–2.0 safety factor. Tower and portal cranes add automatic rail clamps that engage on storm-force wind or power loss.
Service brakes for travel mechanisms and trolleys
HUAWU TKT/TKK shoe brakes with Ed-30 to Ed-201 electrohydraulic thrusters are mounted on the brake drum of the high-speed-shaft gear coupling. The brake engages by spring force on power loss and is released by the thruster. Response time is 0.1–0.3 s. Modern VFD-driven cranes often use HUAWU YPZ2/YWZ5 disc brakes — more compact and with tighter response timing.
- — Braking torque safety factor of 1.5–1.75 of rated
- — Response time on power loss of 0.2 s or less
- — Ed-30 to Ed-201 electrohydraulic thruster
- — Limit switch for lining wear monitoring
- — Manual release capability
Dual-brake configuration for foundry and charging-crane hoists
Cranes carrying pouring ladles and charging buckets use a dual-brake configuration: two independent HUAWU YPZ2 (disc) or YWZ5 (shoe with electrohydraulic thruster) brakes on a single rope hoist. Each brake has a 1.75 torque safety factor of rated — that is, either one alone can hold the full load. Engagement on power loss is 0.15 s or less. Certified to GOST 31303 for metallurgical cranes.
- — Braking torque safety factor of 1.75 or above per brake
- — Two independent control and power circuits
- — Response time of 0.15 s or less
- — IP55 ingress protection, ambient temperature up to +60 °C
- — GOST 31303 certification
Storm brakes and rail clamps for portal, gantry and tower cranes
Storm-brake rail clamps — JINGU CWZ or ZHONGHAI SB — are mounted on portal- and gantry-crane end trucks and lock the crane to the runway rails when wind exceeds the set point. They engage automatically by anemometer signal (typically at 15 m/s and above in service and 20 m/s and above out of service) or on power loss. They hold the design crane against gusts up to 35 m/s.
- — Holding against wind up to 35 m/s
- — Automatic actuation on anemometer signal
- — UPS backup power for emergency engagement
- — Pneumatic or hydraulic release
- — CE certification and compatibility with the crane PLC system
Explosion-proof brakes and brakes for aggressive environments
Cranes in chemical, petrochemical and mining facilities are equipped with ZHONGHAI explosion-proof brakes rated Ex d IIB T4. The electrohydraulic thruster and coil are housed in an enclosure that contains an internal explosion without transmitting it to the surrounding atmosphere. Lining wear monitoring is routed to the PLC through intrinsically safe circuits.
- — Ex d IIB T4 marking (or higher per project)
- — IP66 for thruster and coil enclosures
- — Intrinsically safe circuits for wear and position monitoring
- — Compatibility with Zone 1 and Zone 2 per GOST R 51330
Backstop overrunning clutches for hoist drives
TIANIU backstops are installed between the motor and the hoist gearbox of inclined conveyor cranes or belt lifts, preventing uncontrolled load reversal on power loss or brake failure. They act as a backup to the service and emergency brakes.
- — Rated torque with a safety factor of 1.5 or above
- — Compatibility with the gearbox shaft diameter and key
- — Low overrunning torque in the free direction
- — Service life of 20,000 reversal cycles or above
Couplings and power supply systems
Gear-type drum couplings with brake drum form the backbone of crane drive kinematics: they simultaneously compensate for shaft misalignment after installation and thermal expansion, and serve as the mounting seat for the service brake. Travel mechanisms often use flexible pin couplings with brake drum to damp shock loads. A separate part of the crane package is the runway power supply and the trolley festoon system.
Gear couplings with brake drum
YONGJING GIICL and LONGXUAN WGZ drum gear couplings with integrated brake drum are mounted between the motor and the hoist gearbox. The gear ring compensates for radial, axial and angular shaft misalignment up to 1.5°, while the brake drum accepts the service brake. One component covers two functions — this saves space in the confined envelope of the hoist drive train.
- — Torque 5–125 kN·m
- — Angular misalignment compensation up to 1.5°
- — Brake drum diameter 200–800 mm
- — G6.3 balancing at peripheral speeds above 15 m/s
- — Grease lubrication via grease nipple at 6-month intervals
Flexible pin couplings with brake drum
LONGXUAN LX/LMC flexible pin couplings with brake drum are used on crane travel and trolley mechanisms. Elastomeric bushings damp starting shocks and compensate for small radial misalignment; the brake drum accepts a TKT/TKK shoe brake with electrohydraulic thruster.
- — Torque 1.6–25 kN·m
- — Radial misalignment compensation 0.2–0.5 mm
- — Brake drum 100–500 mm
- — Elastomeric element service life of 30,000 h or above
Busbar trolley systems along crane runways
Seamless ANNENG AN series busbar trolley systems are the standard power-supply method for overhead bridge and gantry cranes over spans of 30–500 m. An insulated conductor in a protective housing carries the current; a current collector on a carriage runs along the busbar. The power channel handles 100–1,250 A plus 4 signal lines. Compatible with crane control systems over Profibus or Modbus.
- — Current rating 100–1,250 A (depending on crane power)
- — Span length 30–500 m (with expansion joints)
- — IP23 (indoor shop) or IP55 (outdoor, under canopy)
- — Reserve of 4 signal lines for control and communication
- — TR CU 004/2011 certification
Festoon cable trolleys and cable reels for crane trolleys
Power to the crane trolley along the bridge and to the operator cabin is supplied through ANNENG festoon cable trolleys running along a C-track profile or round cable. For long spans and large-stroke gantry cranes, motor-driven cable reels with spring-tensioned winding are used.
- — Trolley load capacity 5–50 kg (per cable bundle)
- — Travel speed up to 120 m/min
- — Compatibility with C-track profile or round cable 6–12 mm
- — Provision for separate routing of power and control cables
Gear couplings for heavy harbour cranes
On portal harbour, shipbuilding and container cranes, oversized YONGJING GIICL drum gear couplings rated at 100–500 kN·m with double-ring design are mounted between the motor and hoist gearbox to compensate for large angular misalignment. Seals are marine-grade with salt-mist protection.
- — Torque 100–500 kN·m
- — Double-ring design (angular misalignment compensation up to 1.5°)
- — Salt-mist-resistant seals
- — Grease lubrication at 3-month intervals (marine environment)
- — Compatibility with brake drum and emergency brake
Applications gallery
Our solutions for this industry
SDS portfolio brands that cover typical applications in this industry.
- BONENGK and HB gear motors for bridge travel, trolley travel and jib-crane slewing mechanisms; industrial gearboxes with integrated brake
- CGCHeavy H/B/K series gearboxes for portal, harbour and shipbuilding cranes with torques up to 1 MN·m, C5-M anti-corrosion design
- WOLONGYZR/YZP crane-duty motors with starting torque of 2.0 or above for hoist and travel mechanisms, general-purpose YE3 motors for auxiliary drives
- HUALIGeneral-purpose IE3/IE4 motors for hydraulic pumps, cooling fans and auxiliary crane winches
- HUAWUYPZ2/YWZ5 service and emergency brakes for the dual-brake configuration on foundry and charging cranes, Ed-30 to Ed-201 electrohydraulic thrusters
- JINGUCWZ storm-brake rail clamps for portal and gantry cranes, disc-type service brakes for hoist mechanisms
- ZHONGHAIEx d IIB T4 explosion-proof brakes and SB storm brakes for cranes in chemical facilities and outdoor sites
- YONGJINGGIICL drum gear couplings with brake drum — the backbone of crane hoist drive kinematics
- LONGXUANLX/LMC flexible pin couplings and WGZ gear couplings with brake drums for bridge and trolley travel mechanisms
- TIANIUBackstop overrunning clutches for hoist drives on inclined conveyor cranes and protection against load reversal
- ANNENGSeamless AN busbar trolley systems rated at 100–1,250 A and festoon cable trolleys for power supply along runways and crane trolleys
- INVTGD300-Crane series VFDs with anti-sway, S-curve and load-torque modes for hoist and travel mechanisms
- INOVANCEMD500-Crane VFDs with dual-processor control and integrated braking transistor for S3–S5 duty
Image credits: Rolf Obermaier (Public domain) · G-13114 (CC0) · W.carter (Public domain) · Thakerus (CC0) · Sclaferriere (CC BY-SA 4.0)