- Aug 11, 2014 -
Endanger of tilting lifting of electric hoist
The electric hoist and its accessories are the main parts of the lifting mechanism of the single beam crane. When the lifting load occurs, the skew inclined crane will cause great harm to the electric hoist and its accessories. One of the operation rules of electric hoist is "no skew pulling and inclined lifting", but in actual lifting process, because of the quality or objective condition of the constructors, there is a phenomenon of skew pulling.
1. The harm to the motor
When the load is suspended from the ground to the ground, the load is bound to swing, and the swing will cause the load to produce the centripetal force and increase the load of the motor. Parallel special swinging direction and car running direction, the load will be on the electric car on a thrust and drag swing through repeated action of the motor to drive the car load when, through the current motor suddenly suddenly small, light reduced, the speed of the motor overheating, noise increases or abnormal sound, coil or fuse or may damage the motor.
2. Damage to open gear
The electric car can be inclined load on both sides of the open gear uneven force. When the electric car runs on the track, the frictional strength between the open gear and the track is not the same. After a long time, the gear mesh is not stable, and the wheel pressure asymmetry on both sides makes the wheel of the electric car appear suspended. This will reduce the service life of the electric car.
3. Damage to the rope guide
The electric hoist mostly adopts screw type upper limit device, and its screw is connected with the rope guiding device on the electric hoist. When the rope is winding to a certain number on the drum, the rope guide will push the screw to touch the limit switch to make it work. When a skew hoist occurs, a lateral extrusion force is generated between the wire rope and the guide rope. Under the action of this force, the guide rope is prone to displacement, which drives the screw of the limiter to shift correspondingly, so that the rising limit occurs in advance or behind. If the rope angle is too large, heavy load, it may damage the rope guide, with the increase of the limit will fail, in inspection work, we test the researchers found that 80% of the rising limit failure is due to damage caused by the rope guide, but stayed crooked hanging is one of the main reasons cause damage to the rope guide.
4. Damage to wire rope
Because the steel wire and the guide rope are extruded by the skew skew, the friction between the rope guide and the wire rope increases, resulting in the wear and extrusion deformation of the wire rope. When the rope guide is damaged, the wire rope is very easy to remove the grooves and reduce its service life.
5. The wear of the hook
When the load of the inclined crane is in the air, the load will inevitably swing. When the swing amplitude is large, the sling chain or sling wire rope sleeve will produce a repeated slip phenomenon at the dangerous section of the hook hook. The possibility of decoupling stayed crooked hanging, hanging hook and rope cable when the suspension load is in an inclined state, the lifting load, the rope is very easy in decoupling, decoupling, rope and hook will cause friction in the course of time, will accelerate the hook of dangerous section of wear, reduce its service life.
All the above signs indicate that the oblique pulling crane will seriously damage the electric hoist and even accidents. Therefore, when using the electric hoist, we must obey the operation rules, and strictly prohibit the occurrence of the accident.