1, the contactor is prone to adhesion and failure.
2, the conical brake and the motor rotor brake shaft are prone to distortion and cracking.
During the lifting and lowering of the electric hoist, there will be repeated jogging operations, the cone brake will be opened and closed frequently, and the brake will be repeatedly subjected to the starting torque and braking torque, which is prone to fatigue and cracking. After the brake shaft is cracked, the braking torque cannot be transmitted to the reel, and the heavy objects hoisted by the hoisting machinery with the electric hoist as the hoisting organization will fall under the effect of gravity.
3. When the hoisting height limiter of the hoisting machinery fails or the hoisting contactor in the control electrical cabinet is stuck and blocked, the hoisting mechanism will always run upwards, resulting in over-hoisting, and the hook group hits the reel, causing the reel to deform. . The reel is connected with the output shaft of the reducer through gear meshing, and the output shaft of the reducer is easily cracked under the impact effect. If the reel is only replaced during the repair process, and the output shaft of the reducer is not checked and the operation is resumed, the cracking of the output shaft of the reducer will cause the heavy objects to slide down.
4, it is the failure or damage of various safety protection devices of the hoisting machinery, such as the failure of the lifting height limiter, the failure of the lifting weight limiter, the failure of the travel limiter of the cart walking organization, etc.