The inspection of gears and hooks is a crucial part of the annual inspection of electric hoists. The following are the annual inspection requirements for electric hoist gears and hooks:

Annual inspection requirements for gears

Wear and tear inspection:

Lifting mechanism gear: The wear of the first stage gear should be less than 10% of the original gear, and the wear of other gears should be less than 20%. This standard helps ensure that gears remain efficient and stable when transmitting power.

Operating mechanism gears: For the operating mechanism, the wear of the first gear should be less than 15% of the original gear, and the wear of other gears should be less than 25%. For open gears, the wear amount should be less than 40% of the original tooth thickness (note: there may be slight differences from different sources, such as some regulations of 30%, but the overall principle is similar).

Tooth surface inspection:

The tooth surface of the gear must not have serious defects such as cracks or broken teeth.

The area of pitting damage on the tooth surface shall not exceed 30% of the meshing surface, and the depth shall not exceed 10% of the original tooth thickness. These requirements help prevent abnormal noise and vibration during gear meshing, ensuring smooth transmission.

Other checks:

The wear of the gear shaft is also an important inspection item, and its wear should not exceed 1% of the original shaft neck. This helps to maintain the stability and load-bearing capacity of the gear shaft.

Annual inspection requirements for lifting hooks

Appearance inspection:

The surface of the hook shall not have cracks, and the threaded part, dangerous section, and neck shall not have any form of plastic deformation or damage.

The opening degree of the hook shall not exceed 10% of the original size to prevent accidental detachment during lifting.

Wear and tear inspection:

The wear of the dangerous section of the hook shall not exceed 5% of the original size to ensure that the load-bearing capacity of the hook is not affected.

The torsional deformation of the hook shall not exceed a certain limit (the specific value may vary depending on different standards, but generally should be controlled within a smaller range).

Other checks:

The pulley of the hook should rotate flexibly without any jamming phenomenon.

The stop nut of the hook should be effective in preventing loosening and preventing the hook from falling off during use.

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