The damage to lever chain hoists (chain hoists) is often related to improper operation, lack of maintenance, or environmental factors. The following three scenarios are high-risk damage points that need to be prevented:

1. Overloading use and dynamic impact load

Damage mechanism:

The core components such as chains, hooks, and gears are designed with clear rated loads (such as 5 tons and 10 tons). When overloaded by more than 10%, the gap between the chain rollers and the inner sleeve increases due to compression deformation, leading to a significant increase in the risk of chain link fracture; Overloading of the hook may result in plastic deformation or even fracture; The gear meshing surface experiences pitting and tooth breakage due to overload, accelerating wear.

Dynamic impact loads (such as sudden chain pulling or heavy object falling) can cause an instantaneous torque surge, exceeding the bearing limit of the braking system (such as friction plates, ratchet wheels), resulting in brake failure, chain slippage, or breakage. For example, if the braking sliding distance exceeds the standard in the 1.25 times static load test, it indicates that the braking system has been damaged.

Consequences: Heavy object falling, equipment damage, personnel injury or death; Long term overloading will shorten the service life of gourds and increase maintenance costs.

Prevention: Strictly adhere to the rated load and prohibit diagonal pulling and hanging; Install safety ropes when heavy objects are stationary; After new installation or major repairs, the braking performance needs to be verified through a 1.25 times static load test.

2. Brake system failure and lubrication contamination

Damage mechanism:

If the brake friction pad is contaminated with oil (such as lubricating oil leakage), the friction coefficient will decrease, leading to self-locking failure and the sliding of heavy objects; Insufficient pressure of the brake spring or fatigue fracture of the spring can weaken the braking force and cause the risk of "slipping hook".

If dust and iron filings enter the ratchet and pawl mechanism, it may cause the pawl to jam and the ratchet teeth to wear, affecting the locking function; Gears and bearings that have not been lubricated for a long time will overheat due to dry friction, accelerating wear.

Consequence: Brake failure leading to loss of control of heavy objects; Damage to gears and bearings can cause chain jamming, abnormal noise, and even paralysis of the transmission system.

Prevention: Regularly check the cleanliness of the brake surface to avoid lubricating oil contamination; Every six months to one year, a professional organization will test the pressure of the brake spring and the thickness of the friction plate; Gears and bearings should be regularly lubricated with specialized lubricating oil (such as lithium grease) to avoid the use of acidic or alkaline lubricants; The ratchet mechanism needs to be kept clean and regularly coated with anti rust oil.

3. Chain wear and maintenance deficiencies

Damage mechanism:

Long term storage of chains in humid and corrosive environments (such as chemical workshops and beaches) can cause the surface galvanized or coated layer to peel off, leading to rusting; Poor meshing between the chain and sprocket (such as sprocket wear, chain twisting) can exacerbate chain wear, causing fatigue fracture of the inner and outer chain plates and pin shafts of the chain links.

Improper tightness of the chain (too loose can easily cause the chain to fall off, too tight can increase transmission resistance), and if the distance between the two sprockets exceeds 2% -3% when lifting in the middle, it needs to be adjusted; The gap between the chain rollers and the inner sleeve that have not been lubricated for a long time has increased, resulting in transmission lag and abnormal noise.

Consequence: Chain breakage causing heavy objects to fall; Chain jamming or dropping can cause interruption of operation, and even damage to sprockets and gears; Corrosion accelerates chain fatigue and shortens service life.

Prevention: Regularly check for chain wear (replace if it exceeds 15%) to avoid mixing old and new chains; Store the chain in a dry and ventilated place, and apply anti rust oil; Adjust the tightness of the chain to a reasonable range; Lubricate the chain (special chain oil) every 200 times or once a month, and avoid using ordinary engine oil (which can easily adsorb dust).

The main equipment produced by Hebei Makita: stage electric hoist, electric chian hoist, wire rope electric hoist，Hand chain hoist, lever hoist, pneumatic hoist and other lifting equipment