In light and small lifting solutions, chain electric hoists stand out as mainstream lifting equipment for factory assembly, equipment maintenance and warehouse material handling, thanks to their advantages of low headroom, smooth operation and flexible installation. Many purchasers and equipment managers are proficient in operating chain electric hoists, yet they lack systematic knowledge of the internal power transmission logic and operating principles of safety mechanisms. A thorough understanding of how chain electric hoists work facilitates equipment selection, standardized daily operation and the formulation of periodic maintenance plans, and helps avoid safety hazards such as overload, overwinding and brake failure.
What is a Chain Electric Hoist?
A chain electric hoist is an electric lifting device powered by electricity. It adopts high-strength alloy steel load chain as the load-bearing medium to realize vertical lifting of heavy loads. It can be fixedly suspended for independent operation, or matched with hand-pushed trolleys and electric traveling trolleys, and mounted on single girder cranes, jib cranes, KBK light crane systems and gantry frames for material hoisting and transportation.
Compared with wire rope electric hoists, chain electric hoists feature compact overall structure, light self-weight and smaller minimum headroom, delivering outstanding performance in narrow factories and low-height workshops. The chain meshing transmission offers higher positioning accuracy, making it suitable for lifting precision workpieces. Standard rated load ranges from 0.125t to 50t. Multiple configurations including single-speed, dual-speed and variable frequency drives are available, widely applicable to intermittent industrial hoisting operations.
Working Principle of Chain Electric Hoist
The chain electric hoist realizes safe and stable lifting operations through coordinated operation of the electric control system, power system, transmission system and braking system. After the equipment receives operation commands to switch on the circuit, the conical rotor brake motor is energized. Electromagnetic force releases the lock of the normally closed brake. The high-speed power output from the motor passes through a multi-stage helical gear reducer for speed reduction and torque amplification. The converted high torque driving force is transmitted to the load sprocket, which drives the engaged load chain to lift and lower the hook and load smoothly.
The unit adopts a power-off self-locking brake design. In case of loose button, power cut or circuit failure, the brake spring immediately locks the transmission structure to effectively avoid risks such as hook slipping and load dropping. Meanwhile, the hoist is equipped with a mechanical overload clutch and upper & lower travel limit devices. It can effectively prevent hazards including overload, overwinding, phase loss and reverse rotation, ensuring accurate, safe and stable lifting operations in all aspects.
Structural Composition of Chain Electric Hoist
A chain electric hoist mainly consists of five major modules: power and braking system, transmission and reduction system, load-bearing lifting system, safety protection system and electrical control system.
Conical Rotor Brake Motor
Serves as the power source of the whole unit. The motor and brake are integrally assembled. When energized, electromagnetic force pushes the rotor to move axially and release the brake; upon power failure, springs engage braking lock. It is available in single-speed and dual-speed versions. Dual-speed models enable low-speed precise positioning, ideal for assembly processes.
Multi-stage Gear Reducer
Normally adopts 2-stage or 3-stage helical gear transmission. Gears are precisely manufactured via carburizing and quenching. It reduces the high rotating speed of the motor and multiplies output torque to guarantee sufficient lifting capacity, while delivering smooth transmission and lower noise. High-end models are equipped with a built-in mechanical overload safety clutch.
High-strength Load Chain & Chain Container
Core load-bearing components. Industrial standard Grade G80 and G100 alloy steel drop-forged load chains feature high tensile strength and excellent fatigue resistance. Slack side chain is stored inside the chain container to keep the site tidy and reduce chain wear.
Hook Assembly
Both upper and lower hooks are made of high-quality forged steel. Each hook is fitted with a safety latch to prevent sling disengagement. The hook supports 360° rotation to accommodate multi-angle lifting applications.
Safety Protection Components
Upper and lower travel limit switches: Restrict the extreme lifting and lowering positions of the hook to avoid overwinding and top collision.Overload clutch: Slips and idles when the load exceeds the rated value to cut off power transmission and protect the whole mechanism.Phase loss & phase reversal protection: Prevent motor burnout caused by phase loss and hazardous reverse operation.
Electrical Control System
Composed of low-voltage pendant push-button station (standard safety control voltage: 24V/36V) and control contactors. A wireless remote control unit is optional for long-distance operation and increases the safe working distance for operators.
Operation Process of Chain Electric Hoist
Lifting Process of Loads
1. The operator presses the UP button on the control pendant to energize the control circuit.
2. The motor winding is powered on. Electromagnetic attraction pulls the rotor axially, releasing the normally closed brake.
3. The motor rotor rotates at high speed and transmits power to the reducer.
4. Power is converted into low-speed, high-torque output via multi-stage gear reduction and torque amplification, then delivered to the load sprocket.
5. The sprocket drives the load chain. The load-side chain is retracted, and the hook lifts the load steadily.
6. Once the UP button is released, the motor loses power. The brake spring compresses the brake disc to lock the transmission shaft, holding the load stationary in position.
7. When the hook rises to the upper limit position, the limit switch activates to cut off the lifting control circuit; only lowering operation is available.
Lowering Process of Loads
1. Press the DOWN button on the pendant. The motor receives reverse power supply and the brake opens.
2. The motor rotates reversely. Power passes through the reducer to the load sprocket, which rotates backward to pay out the load chain.
3. The hook and load descend steadily under motor drive. The brake continuously provides braking force to prevent uncontrolled load slipping.
4. Immediate braking and locking take place upon button release. When the hook reaches the lower limit, the lower limit switch is triggered to disconnect the lowering circuit.
Important Note：The lowering motion of a chain electric hoist does not rely on the free fall of the load by self-weight. The whole process is controllably driven by the motor and restrained jointly by the brake system. This is the core reason why it enables precise positioning during lifting operations.
Application Fields of Chain Electric Hoist
Thanks to its compact size and multiple mounting options, the chain electric hoist is widely adopted for material lifting operations across various industries.
Machining & Equipment Manufacturing
Lifting of machine tool workpieces, component assembly, disassembly and transfer of moulds.
Automotive & New Energy Production Lines
Fixed-point lifting on assembly lines for the assembly of motor housings and battery modules.
Warehousing & Logistics
Stacking of warehouse goods, loading and unloading of heavy materials on racks.
Wind Power & Construction Machinery Maintenance
Lifting for inspection and maintenance of nacelle components, main shafts and various small parts.
Steel Structure Engineering & Small Construction Sites
Installation of factory components and medium & small-sized equipment.
Shipbuilding, Water Treatment & Chemical Workshops
Corrosion-resistant hoists are selected for lifting, disassembly and installation of pumps and valves.
The hoist supports diversified installation methods. It can be fixedly suspended for independent use, or fitted with hand-pushed trolleys and electric traveling trolleys to travel along I-beam tracks. It can also be matched with jib cranes, single girder cranes and KBK light crane tracks to build a complete material handling system.
Why Choose Dafeng Chain Electric Hoists?
Dafeng Crane specializes in the R&D and manufacturing of cranes and light & small lifting equipment, with years of in-depth experience in the lifting machinery industry. Our self-developed chain electric hoists are optimally designed to meet the requirements of actual working conditions. The core advantages are listed below:
Braking System
Equipped with an integrated conical rotor brake motor as standard. It features fast braking response and stable braking torque, effectively mitigating the risk of hook slipping under long-term frequent start-stop operations.
High-strength Transmission Structure
Reducer gears are precision ground from alloy steel. The sealed housing enables long-term continuous lubrication to reduce gear wear and extend overall service life. A built-in mechanical overload protector is optional to provide multi-layer protection against overload operation.
Premium Load Chain
Grade G80 alloy steel load chain is supplied as standard, while upgraded Grade G100 high-strength chain is available as an option. The chain undergoes surface hardening treatment with outstanding tensile strength and wear resistance, suitable for continuous cyclic lifting operations.
Diversified Customization Solutions
Options include single-speed / dual-speed types, fixed suspension types / trolley-mounted types. Standard models as well as special anti-corrosion and dustproof versions are available, compatible with various voltage specifications.
Comprehensive Safety Features
The hoist is fitted with upper and lower limit devices and safety hook latches to prevent sling detachment. Low-voltage remote control and variable frequency speed regulation assemblies are optional for steady low-speed lifting, ideal for handling precision workpieces.
Full-life-cycle Technical Support
We provide customers with selection proposals and remote technical guidance for installation. All products undergo strict testing in accordance with lifting equipment standards before delivery to support smooth implementation of customer engineering projects.
Conclusion
Although the chain electric hoist appears to have a simple structure, it is a mechatronic lifting equipment with highly coordinated power, transmission, braking and electric control systems. A thorough grasp of its working principle helps enterprises select suitable models, standardize operation procedures, reduce downtime caused by failures, and mitigate safety risks of lifting operations from the source.
