Vibrating screen main beam fracture
Writer： admin Time：2020-10-22 16:16 Browse：℃
The main beam of the vibrating screen refers to the beam that supports the vibrator on the upper part of the screen frame, also called the main beam. Normally, the vibrating screen of the box vibrator has a very compact main beam, and its working condition is very important to the service life of the screen. However, the vibrating screen often encounters the main beam falling off, and it is not easy to repair after falling off, which seriously affects production. So what caused the main beam to break? Today, the polyurethane screen manufacturers will explain to you:
It cannot be completely concluded that it is a product quality problem or a fault problem. Sometimes it is related to the design of the main beam part of the vibrating screen. If the main beam is not designed or manufactured, it is often prone to breakage, and it is not easy to make up for the breakage. Cause the entire sieve to be scrapped. Seriously affect production.
One. Design issues:
The main beam is to support the vibrator and transmit the exciting force. The main beam is a very complicated structure.
The force of the main beam includes:
1. Gravity: Including the gravity of the vibrator and the gravity of the main beam itself.
2. Exciting force: all the exciting force generated by the vibrator is borne by the main beam.
3. Inertial force: the inertial force generated by the vibrator and the main beam during the vibration of the screen.
In addition to gravity, the exciting force and inertial force are alternating loads, and the exciting force is also a concentrated force.
Therefore, the design of the main girder not only needs to calculate the strength, but also consider the reasonable force in the structure to reduce the weight as much as possible.
Therefore, the design of main beams by means of surveying, mapping and imitation is often prone to problems, knowing the reason and not knowing the reason. Because although you can map the main beam, it is not easy for you to map the vibrator, and the vibrator you use may be different from the surveying product in weight and exciting force, and the inertial force is also different. Of course, the force of the beam may be very different. If you don't pass calculations, it is difficult to judge how much this difference in force is. Therefore, the design will often go wrong based on the feeling.
Because the force of the main beam is very complicated, many people cannot grasp the calculation method of the main beam force. Therefore, the main beam is designed by means of surveying, mapping and imitation. Even if it is calculated, the establishment of the force model does not specifically conform to the actual situation. This is the main reason why many people in China do not design the main beam well.
If there is a problem with the design, no matter how good it is, it is useless. Therefore, the quality problems of any product are mostly caused by design problems.
Therefore, understanding the force of the main girder and establishing a realistic force model is the key to the design of the girder.
In addition, both ends of the main beam and the side plates of the screen frame are connected by high-strength bolts, so the size and quantity of bolts must be calculated correctly.
The design of the main beam should also consider other factors, which should be clearly marked on the drawings, such as the perpendicularity tolerance of the main beam and the side plate of the screen frame, the flatness tolerance of the connecting part of the main beam and the vibrator, the weld form and heat treatment And so on.
Therefore, the main beam seems to be uncomplicated in structure, but it is not easy to design a successful beam. It is difficult to design successfully without specific experience accumulation.
If there is a problem in the design of the girder, it will be difficult to handle on site, and the entire screen may be scrapped.
2. Operation and use factors
According to production experience, the main reasons for the main beam termination in use are:
1) Bolt softening
If the bolts are loose, the movement of the two vibration exciters will destroy the cycle of inertial force of the main beam. This will inevitably cause the excitation force generated by the vibrator to violently impact the main beam, causing the main beam to be subjected to abnormal impact force, causing the main beam to fall off and break.
2) Deposited materials
Excite the beam, and material accumulation often occurs. If it is not cleaned immediately, it will cause serious local wear of the main beam and cause the main beam to break.
3) Overload or load start
Overload or load lifting mainly causes great losses to the spring and motor of the screening machine. Frequent overload lifting will destroy the overall force balance of the sand screening machine. The sand screening machine will have different amplitudes before and after, and the movement trajectory of the material will change. , The impact on the screen frame and the screen will increase, causing cracking.
4) Improper feeding
Improper feeding of the production system, the impact of the material will not only partially wear the screen of the sand screen, but also destroy the overall force balance of the screen. Therefore, improper feeding has a particularly serious impact on the life of the sand screener.
5) Abnormal driving of the excitation motor
The abnormal operation of the excitation motor will directly cause the main beam to break. Before a similar situation occurs, there will be very unusual noises. Some errors in routine maintenance methods can easily cause such accidents. For example, when the exciter is at a high temperature, using water to cool down has a great impact on the life of the exciter and the screen beam.
6) Excessive excitation force
Excessive vibration force causes a greater load on the sand screener, which seriously affects the service life of the sand screener beam.
Three, manufacturing factors
The production must be in accordance with the requirements of the drawings. Pay attention to the marked technical requirements. If there is a slight negligence in the manufacturing process, the main beam is prone to problems.
Pay attention to the following points during production:
1) Welding: Use the specified welding rod, no welding defects are allowed, and the welding process should ensure that the welding deformation is small.
2) Use reasonable technology to ensure the geometric tolerance of the main beam.
3) Carry out heat treatment as suggested in the drawing.
The above is the reason why the main beam of the vibrating screen is easy to break as introduced by Chaishang Trading Co., Ltd. For other questions, please refer to other content on this site or call for detailed inquiries.