Explosion-proof electric hoist fault how to check

Introduction: We often encounter the phenomenon that the explosion-proof hoist can not work. After all, under what kind of circumstances the explosion-proof hoist can not work, the following is a simple analysis given by divine force:

First, check if the power supply has electricity. The most common way is to use the electric pen. One side will know it. This is the first step, if it is normal.

The second part of the test is to check the circuit of the explosion-proof hoist, whether there is any bad contact, etc. If there is a disconnection or poor contact, etc., it shall be promptly sent for inspection and repair to avoid the motor burned out due to the lack of power supply.

The final step: look at the voltage situation, if the voltage is too low, certainly not bring, certainly not work properly, if the voltage is normal, you should check the motor has been said in the front, there is to look at the explosion-proof hoist itself maintenance The problem is that repair can not be repaired, there is an external reason that it can not be overloaded, overload can also cause the gourd can not work properly.

The main body of the electric hoist is a wire rope reel central, one end is a motor, through the middle of the rotating shaft, the power is transmitted to the other end of the reducer, the reducer drives the reel (or ring chain) wire rope lifting.

The electric hoist is a small-sized lifting device that integrates an electric motor, a speed reducer and a wire rope reel (or chain), and most of them also have a walking trolley, which is combined with a single-girder bridge or gantry crane to form a complete lifting machine. .

Electric motors of electric hoists now use cone-rotor motors, which are capable of self-braking in the event of a power failure.

1. Please read the instructions and the information on the nameplate before you read it.

2. Please adjust the stop block of the upper and lower limit before lifting the object.

3. Before using the electric hoist, check whether the brake condition is reliable.

4. If you find any abnormalities in the wire rope before using the electric hoist, never operate it.

Explosion-proof wire rope electric hoist is a light and small lifting equipment product, compact structure, light weight, small size, large lifting capacity, when the plant is filled with flammable and explosive mixtures, explosion-proof wire rope electric hoist under the premise of ensuring safety It is an advantageous tool to improve working conditions and increase labor productivity.

When selecting chain hoists or electric hoists, whether or not they need to be used for explosion-proof, explosion-proof, anti-corrosion, dust-proof, flammable, and common types of hoists, the first thing to do depends on the type of environment where the environment is used. Occasionally, it is used in hazardous situations. If it is accompanied by danger, it belongs to any dangerous place.

Use place environment selection methods such as (flammable, explosive, corrosion-prone) chemical, high temperature, steam, and other places to consider which type of explosion-proof wire rope electric hoist. What is the temperature, humidity, and whether the hoist can work normally?

Explosion-proof gourd can be applied to high-risk, with flammable, explosive place and ordinary gourd can only be used in general places.

This is also the difference between explosion-proof and ordinary electric hoists and chain hoists.

I. Why can't I use the electric hoist after it is turned on?

Mainly because the electric hoist did not switch on the rated working voltage, and it can not work, there are generally 3 kinds of situations:

1: Electric hoist motor terminal voltage is lower than the rated voltage by more than 10%, the motor starting torque is too small, so that the electric hoist can not lift the goods and can not work. When checking, use a multimeter or voltmeter to measure the voltage of the motor input terminal. If the voltage is too low and the motor cannot be started, wait until the system voltage returns to normal before using the electric hoist. Sometimes, the voltage of the electric hoist motor is normal, and the electric hoist is not working. This needs to consider other reasons.

E.g:

The motor is burned and the motor must be replaced during inspections.

Electric hoist used for a long time, poor maintenance and other reasons to make the brake wheel and the end cover rusted, the brake wheel can not be opened when starting, the motor only issued a "click" sound, can not rotate, electric hoist can not work. At this time, the brake wheel should be removed to clean the rusted surface and then retested;

If the motor is severely broomed, the motor will not rotate. If this condition is found, it should be stopped and the motor must be overhauled or replaced to ensure that the electric hoist works normally.

2: Whether the power supply system sends power to the power of the electric hoist. Generally, it is tested with a test pencil. If no power is supplied, it will work after sending the power.

3: electric hoist main, control circuit damage to electrical appliances, disconnected lines or poor contact, but also make the electric hoist motor can not be energized, this happens, need to repair the main, control loop, maintenance, in order to prevent the main, control loop to send If the power supply to the three-phase motor is lost and the motor is burned out, or the electric motor of the hoist is suddenly operated, causing a hazard, the electric hoist motor must be disconnected from the power supply line, and only the main and control loops should be powered, and then the starting point should be started. And stop the switch, check and analyze the control of electrical and circuit work, repair or replace the problem of electrical or line, when you confirm that the main and control circuit is not faulty, before re-testing;

In addition, it is forbidden to overload the electric hoist in production. When the goods are overloaded, the electric hoist will not move the goods, and the electric motor will only send a “buzz” noise, and will not operate. If it is serious, it will burn the motor or even cause an accident. It should immediately Shut down, lighten goods, make electric hoist work under rated power.

The mechanism of the noise generated by the wire rope electric hoist gear is relatively complex, and summed up in the following two aspects:

1. The pulsation of the node impacts a pair of gears in the meshing process. The relative speed at the node is zero, there is no relative sliding, and at each point outside the node, the meshing tooth surface has a relative sliding, generates a sliding friction force, and changes from the node. The magnitude and direction of the friction force, the greater the distance from the node, the greater the friction, and the largest at the beginning and end of meshing. Since the magnitude and direction of the friction force during gear transmission are changed, the pulsation impulse of force occurs on the node, that is, the maximum is 0, which is referred to as the node pulsation, the transmission force and the friction coefficient of the tooth surface when the size is in mesh with the gear. The magnitude of the sliding speed is related, and the relative sliding speed of the tooth surface is proportional to the rotating speed of the gear. Therefore, when the power transmitted by the gear is larger, the higher the rotating speed, the worse the roughness of the tooth surface, the larger the pulsation of the node. Since this is caused by the gear transmission characteristics, even if a pair of ideal gears are processed and installed, the pulsation shock generated during the meshing process is also difficult to avoid.

2. Engagement of gears When the gears are meshed, they are subjected to force, and the meshing teeth will inevitably produce a certain amount of elastic deformation. The electric hoist lifting gear unit is driven by a helical gear. The total meshing coefficient (overlapping coefficient) is generally around 2, and the meshing teeth are at the same time. There are 2 to 3 pairs. Whenever a pair of teeth starts to mesh, the load of the 1 to 2 pair of meshing teeth is relatively reduced, and the deformation is slightly restored, giving a tangential acceleration to the gear body, and thus generating an impact. In addition, the elastic deformation of the original meshing teeth, together with the machining error of the gears, causes the teeth that are just to be meshed to fail to get the smooth contact of the theoretical tooth profile and collide. All of these form a gear meshing impact force.

Second, leading to the main reason for the electric hoist skid

After a long period of use or improper use, electric hoists can cause slippage. If they are not dealt with in time, they will cause failures. What are the reasons for this phenomenon? Today, Hebei Shenli reveals the reasons why electric hoists slip.

1. The brake of the motor is loose. After a long period of use, the device may cause the motor brake to loosen.

2. Friction plate problems. Long-term use or poor quality electric hoists are very common. In order to save costs, ordinary workshops use unqualified friction plates. Therefore, electric hoists will soon slip.

3, motor spline wear, long-term use results.

4, the transmission parts wear and other reasons.

5, wire rope electric hoist on the row of wire rope device has worn.

6、Is there a problem with the travel switch?

All of the above can lead to skidding when the electric hoist is in use. Watch for slippage and check the problem in time to avoid accidents.

Source: Hebei Shenli Rigging Group Co., Ltd.