In mining and other industries, it is necessary to use vibrating screen to screen materials. When the vibrating screen is used, it has a strong exciting force, and the material is also screened because of this exciting force. After using the vibrating screen for a period of time, the screen machine may have a problem of large beating. If the beating is serious, it may cause the side plate to break. Therefore, when this phenomenon is found, it should be solved immediately, but the first thing is to analyze the cause.
The reason for the large vibration of the vibrating screen
1. The damping spring has high hardness
If the hardness of the vibration damping spring is too large, it may not be able to achieve the effect of buffering, so the vibration screen will have a problem of large beating when it is running. Because the function of the damping spring is to connect the screen base and the screen frame, and it can also play a buffering role. Therefore, the hardness of the damping spring should not be too large.
2. Bearing radial clearance problem
If the radial clearance of the vibrating screen bearing is too small or too large, the bearing system will generate large vibration, and the whole vibrating screen machine will show a large beating phenomenon. When the radial clearance is too small, it will cause high frequency vibration; when the radial clearance is too large, it will cause low frequency vibration. If the radial clearance is too large, the radial natural frequency of the bearing elastic system will be reduced, resonance will easily occur, and large low-frequency vibration will be generated.
The main reason is that a large acceleration occurs at the impact point of the rolling element and the ferrule. In the early stage of the shock, a high-frequency compression wave irrelevant to the mass of the equipment and the shape of the object is generated and transmitted to the inside of the metal; while in the later stage of the shock, a mechanical vibration with a lower frequency than the shock compression wave is generated by the mechanical force. Therefore, the radial clearance is large, which increases the vibration of the bearing in the passband.
3. Exciting force is too strong
The vibration motor of the vibrating screen provides exciting force to the equipment during operation. If the motor power and model do not match, it may cause large jump or displacement during use. In order to increase the screening output or accuracy, some customers may adjust the motor excitation force to exceed the rated range, which may also cause the vibrating screen to vibrate violently.
4. The outer ring and the supporting hole are too tight
The cooperation between the outer ring and the support hole will affect the transmission of vibration of the vibrating screen. If the fit is relatively tight, it will force the raceway to deform and increase the shape error, resulting in an increase in vibration and a large jump. A looser fit can hinder the oil film in the gap. When the material properties of the outer ring and the bearing hole of the bearing seat are quite different, especially if the rubber damping ring is placed between them, the vibration transmission will be suppressed.
5. Improper installation of screen machine
When installing the vibrating screen, if the ground is uneven or improperly installed, it may cause excessive vibration, which will cause the vibrating screen to jump greatly.
6. Motor steering is inconsistent
The vibrating screen with double vibrating motor will adjust the steering of the motor when it leaves the factory, but when the motor is worn or damaged, if the motor rotation or power is inconsistent when the user replaces the motor, it may cause the vibrating screen machine to vibrate violently.
7. Loose anchor bolts
If there is abnormal vibration caused by uneven ground, it is necessary to check whether the anchor bolts are loose. Under the action of vibration, the long-term work of the vibrating screen will loosen the anchor bolts of the fixed base, which will cause the vibrating screen to vibrate too much during operation.
The solution to the large vibration of the vibrating screen
1. Users can solve the problem caused by excessive spring hardness by choosing high-quality springs.
2. If the user wants to adjust the exciting force, it needs to be adjusted within the range that the motor can bear. You can consult the manufacturer, or ask the technicians to purchase a model that is reasonable based on the properties of the materials provided, screening requirements, and output requirements.
3. When installing the vibrating screen, it should be noted that it needs to be installed according to the steps, and preparations should be made before installation, then install the support or hanging device, connect the screen box to it, and then install the motor and triangle tape to fix the screen surface. Note that debugging work is required to enter normal operation.
4. When the motor steering is inconsistent, it is necessary to consult a technician to re-adjust and install the vibration motor steering or eccentric block.
5. If the vibration screen jumps greatly due to the loosening of the anchor bolts, it is only necessary to tighten the anchor bolts.
The above is the introduction of the reasons for the large vibration of the vibrating screen and the solutions. There are seven main reasons for the large vibration, such as high hardness of the vibration damping spring, too small or too large radial clearance of the bearing, too strong excitation force, Loose bolts, etc., need to be solved according to the cause. For example, if the anchor bolts are loose, the anchor bolts need to be tightened.