Description of defects of electric hoist crane and analysis of causes of defects

When the electric hoist runs left and right, the clearance between the wheel flanges at both ends of the track meets the requirements normally, but the clearance between the wheel flanges is obviously too large when it runs to the middle section. After careful inspection of the main components such as the main beam I-beam and the electric hoist wheel, the following defects were found:

(i) The surface of the main beam I-beam is seriously corroded, the upper surface of the lower flange is seriously worn, and a pit of a certain depth is formed, as shown in Figures 1 and 2;
(ii) The main beam I-beam is within 3 meters around the mid-span, and the lower flange of the two sides of the lower flange is sunken and deformed. When the wheels of the electric hoist run to the secondary area, the wheels on both sides are in a deformed position, so that the clearance between the wheels and the lower flange of the I-beam is too large.
The main reasons for the above defects are determined by the use conditions of the crane, and the main reasons are as follows:
(i) The crane has been in use for a long time and has been in an acidic environment for a long time, which accelerates the corrosion of the main beam.
(ii) The crane is frequently used, and the crane has been manufactured according to the A3 standard with a large load capacity. High-intensity and high-frequency lifting accelerates the wear of the lower flange of the main beam, eventually causing the two sides to sink and deform.
The wear and deformation of the lower flange of the I-beam of the crane main beam causes the flange gap of the electric hoist to be too large during operation, which seriously affects the safety of the equipment and poses a major safety hazard. In order to improve the operating safety of the crane and avoid accidents, the user is ordered to stop using the equipment immediately.
Considering the complexity of maintenance, the serious rust on the equipment itself and the long service life of the equipment, the user considers scrapping the equipment.
In order to reduce similar defects in the I-beam of the crane main beam and ensure the safety of the crane, the following countermeasures are taken:
The user should select a crane of the corresponding working level according to the actual operating conditions and make appropriate reservations for the rated lifting capacity of the selected crane.
The crane operators of the user should operate strictly in accordance with the requirements of the safety operating procedures of the crane, and it is forbidden to pull or lift crookedly.
For cranes operating in corrosive environments such as pickling workshops, the user should regularly carry out anti-rust treatment to extend the service life of the equipment.
Regularly maintain the lifting equipment to ensure the reliable operation of the safety protection device and prevent overload lifting.
During normal use, the user unit should replace the corresponding wearing parts in time, check the effectiveness of the relevant safety protection devices on a daily basis, and repair problems in time.
Inspection and testing personnel should pay special attention to the wheel rim clearance of the electric hoist. Once the above defects are found, measures should be taken immediately to ensure the safety of the crane.