Proper maintenance of lever chain hoists requires systematic implementation from four aspects: daily inspection, regular maintenance, standardized operation, and safety protection. The specific points are as follows:

1、 Pre use inspection (critical safety barrier)

Component integrity check

Hook: No cracks or deformations, the pin is firmly fixed; Chain: No severe rusting, slipping, twisting, or breakage (must be replaced if worn to 15% or more); Gears/sprockets: No wear or deformation, no damage to the wheel shaft, and intact split pins.

Braking system: The self-locking function of the friction plate, disc, and ratchet ring is normal, the brake ring is free of oil stains (oil stains can reduce the friction coefficient and cause slipping), and the pressure of the brake spring is moderate (if the sliding distance exceeds the standard, it needs to be adjusted or replaced).

Empty load and functional testing

Pull the chain without load and check if the transmission is flexible, without any jamming, sliding or falling chains; After tightening, test whether the self-locking device (friction plate, ratchet) is reliable to ensure there is no risk of "slipping hook".

After new installation or major repairs, a static test at 1.25 times the rated load for 10 minutes and a dynamic test at 1.1 times the rated load are required to verify the braking performance and structural stability.

2、 Operating standards during use

Load and operational requirements

Overloading is strictly prohibited, and the number of zippers should be allocated based on the lifting capacity of the hoist (1 person for less than 5 tons and 2 people for more than 5 tons); The direction of the zipper should be consistent with the direction of the sprocket, and the force should be evenly applied to avoid sudden pulling or acceleration.

When the suspended object needs to stop halfway, the hand zipper must be tied to the lifting chain and a safety rope must be installed to prevent self-locking failure; It is prohibited to use gourds for storing heavy objects or equipment at heights.

Environment and Safety Protection

It is strictly prohibited to stand below during operation, and avoid using in damp, high temperature, and corrosive environments (protective measures should be taken if necessary); The chain must not be mixed with a new chain to avoid transmission impact.

3、 Regular maintenance and upkeep

Chain and gear maintenance

Chain tightness adjustment: When lifting or pressing down in the middle, it is advisable to have a distance of 2% -3% between the two chain wheels; Even numbered chain links can be removed when they are too long (with the locking plate opening facing in the opposite direction of rotation), and welding broken chains is strictly prohibited.

Lubrication requirements: Special lubricating oil should be regularly added to the gap between the chain roller and the inner sleeve, as well as the gear meshing area (to prevent lubricating oil from seeping into the brake friction pad and causing self-locking failure); When used frequently, check the lubrication condition monthly. If left idle for a long time, clean and apply rust proof oil, and store in a dry and ventilated place.

Braking and transmission system

When the wear of the brake ring exceeds the limit or the contact is poor, it needs to be replaced or repaired; When the sprocket is severely worn, it is necessary to replace both the sprocket and the chain simultaneously (to avoid poor meshing caused by separate replacement); The sprocket installation is not skewed, and the deviation of the two wheel end faces is ≤ 1-2mm (1mm below 0.5m and 2mm above).

The reducer needs to be regularly lubricated to avoid excessive wear of gears/bearings due to lack of oil; Abnormal motor noise (such as "buzzing" sound, bearing "clanging" sound) should be immediately stopped for maintenance.

Regular testing cycle

Daily inspection: once a month, focusing on checking chain wear, braking performance, and hook integrity; Professional testing: Load testing, material analysis, fatigue testing, etc. are conducted by authoritative institutions (such as CMA/CNAS certified laboratories) every six months to one year to ensure compliance with safety standards.

4、 Fault handling and safety precautions

Chain handling: After placing heavy objects, conduct maintenance and prohibit forced pulling; Brake failure: Check the brake surface for oil stains, spring pressure, and coupling status, and replace parts if necessary.

Electrical malfunction: Check the power supply, control circuit, and voltage stability when the motor cannot start (voltage fluctuations exceeding 10% need to be repaired before use); Abnormal noise: Based on the sound source (control circuit, motor, reducer), locate faults such as contactor failure, bearing damage, etc., which require professional maintenance.

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