To Study the Basics of Crane

2)The circle number of the left steel rope of the  bridge crane and the mobile crane should not be less than two and three.
3)The new hook of the crane should be marked with the certification and the casting hooks are not allowed to use.
4)Under the influence of the eccentric force, the single hooks are usually used in the crane with the lifting capacity under 80t.
5)The lifting hook should bear 2 times load of test without falling off.
6)The steel rope turns the rotational movement of the motor to the lifting movement of the hook. It is also one of the important parts that bearing all the extra load.
7)The wear of the friction washer of the crane brake reaches 50% of the original size should be scrapped.
8)The friction wear of the roll wall reaches 20% of the original thickness, should be scrapped.
Due to lack of lubrication,  frequent work and play, anti-car, etc., the teeth of the tooth couplings fall off to cause the drop of the  heavy objects.
1)The ends of the steel rope of gantry crane should be fixed with the pressing plate, which should not be less than 2. (T)
2)If there are cracks on the pulley, or there are damage on the edge of the pulley, they should be replaced. (T)
3)If there are cracks on the roll, they can be welded and rubbed with grinding wheel. Then they can be put into used again. (F)
4)The brake of the operating mechanism is used to dissipate the kinetic energy of moving parts, and can cause the mechanism to stop in a decreased speed. (T)
5)To avoid the objects falling off the drive system of the lifting mechanism, some brakes are installed on the high-speed shaft or the rolls. (F)
6)Two connected steel ropes can be used in the lifting mechanism. (F)
The electric motor is used in the usual environment with the highest temperature 40℃. (T)