1. Side wear of I-beam of electric hoist: ① The large deviation of the wheel diameter of the electric hoist causes the trolley to run on the I-beam at an angle. ②The deviation of the parallelism of the driving wheel holes of the trolley causes the trolley to run unbalanced. ③ The deviation between the egocentricity of the driving wheel and the driven wheel of the trolley causing the trolley to run erratically. Solution: (1) If this mentioned problem occurs, we should first replace the electric hoist trolley that meets the standards, and check that the trolley is stable and free of swing when installed. (2) Measure the damaged I-beam,if the wear of the flange width is not greater than 5% of the original size, repair may not be performed, but the lateral clearance between the wheel flange and the track must be readjusted according to the standard requirements. . (3) When the amount of wear on the side of the flange is greater than 5% and less than 10 mm of the original size, repair the reinforcing plate by welding under the I-beam. 2. I-beam wear of electric hoist: ① Wear caused by prolonged use. ② Irregular use, such as oblique pulling or a reaction force in the running direction, make the trolley idling at the local position of the track. ③ When lifting a large object, if the brake of trolley is adjusted too tight, it will cause the trolley to slip when the workpiece shakes, resulting in track wear. ④ The rusty environment of open-air operation will accelerate the wear of the I-beam. Solutions: (1) Check and measure the worn I-beam. When the tread wear is less than 10% of the original size and no other damage is found, repair may not be performed, but the cause of wear should be found out and strengthen supervision during use. (2) If the measured amount of tread wear reaches or exceeds 10% of the original size, the load capacity of the flange has not reached the original design load capacity, so it needs to be repaired.