One third of the problems of consulting vibrating screen are about abnormal vibration, among which polarization, torsional vibration, small amplitude and severe vibration are the four problems with high consulting rate. Fodamon engineers summarized the causes and solutions of these four types of vibration faults.
一、 Vibrating screen polarization
In the polarization problem, the two diagonals vibrate normally, and the other two diagonals basically have no amplitude (diagonally no vibration), which is one of the most frequently asked questions. This fault may be caused by:
(1) The four supporting points of the spring are not on the same horizontal line;
(2) Vibration exciter of vibrating screen;
(3) Whether the included angle of the counterweight on the vibrating screen motor changes;
(4) There is a problem with spring support. The spring forces are different and vary greatly. It needs to be adjusted. Check whether the spring height is consistent at rest;
(5) There may be problems with the four spring fulcrums of the shale shaker. The free length of the spring is the same, but the compression modulus is inconsistent. Check whether the fixed points are stable and balanced;
(6) There is a large gap between the motor center of the vibrating screen and the coupling center at the vibrator end under the shutdown state;
(7) Check the rigidity of the screen body and whether it is loose, including whether the screen plate is fixed properly;
(8) The angle of eccentric block of vibration motor is inconsistent. Check whether there are individual motor off-axis or faults in multiple vibration motors.
(9) If the compression amount of the spring is the same, the overall stiffness of the vibrating screen machine is not enough. You can reduce the frequency to see if the situation will be better. This kind of fault is difficult and difficult to deal with.
二、 Vibrating screen polarization
In the polarization problem, the two diagonals vibrate normally, and the other two diagonals basically have no amplitude (diagonally no vibration), which is one of the most frequently asked questions. This fault may be caused by:
(1) The four supporting points of the spring are not on the same horizontal line;
(2) Vibration exciter of vibrating screen;
(3) Whether the included angle of the counterweight on the vibrating screen motor changes;
(4) There is a problem with spring support. The spring forces are different and vary greatly. It needs to be adjusted. Check whether the spring height is consistent at rest;
(5) There may be problems with the four spring fulcrums of the shale shaker. The free length of the spring is the same, but the compression modulus is inconsistent. Check whether the fixed points are stable and balanced;
(6) There is a large gap between the motor center of the vibrating screen and the coupling center at the vibrator end under the shutdown state;
(7) Check the rigidity of the screen body and whether it is loose, including whether the screen plate is fixed properly;
(8) The angle of eccentric block of vibration motor is inconsistent. Check whether there are individual motor off-axis or faults in multiple vibration motors.
(9) If the compression amount of the spring is the same, the overall stiffness of the vibrating screen machine is not enough. You can reduce the frequency to see if the situation will be better. This kind of fault is difficult and difficult to deal with.
- Device aspect
(1) Whether the spring support of the screen machine can be installed in a unified degree, whether the current tightening amount can be the same, and the error shall not exceed 5mm.
(2) Whether the phase angles on both sides are the same when installing the universal joint device, other reasons should be further determined according to the detailed screening machine and application conditions.
三、 Small amplitude of vibrating screen
The main reasons are as follows:
- Insufficient supply voltage
If the line is not connected as required and the voltage is insufficient, the amplitude of the vibrating screen will be too small.
- Too few eccentric blocks
Try increasing the number of eccentric blocks to increase the amplitude.
- The included angle of eccentric block is too small
If the supporting motor is a vibration motor, the included angle of the eccentric blocks at both ends of the motor shaft will also affect the amplitude. The included angle becomes smaller, the exciting force becomes larger, and the amplitude becomes larger. On the contrary, the amplitude becomes smaller, so the amplitude can be adjusted by changing the included angle.
- Large feeding volume and large accumulation of materials
If the stone transported to the screen surface at one time exceeds its bearing range, there will be too much residual material or accumulated material in the funnel of the screen surface and under the screen, resulting in increased equipment load and affecting the amplitude.
- Unreasonable spring design
When designing the spring, the net variable of the spring shall be less than the height of the device, otherwise the amplitude of the vibrating screen will be small; However, if the net variable of the spring is too large, it may cause the body to disengage from the spring.
- Cause of equipment failure
For example: damage of motor or electrical components, vibrator failure, etc.
四、 Large vibration of vibrating screen
- Excessive exciting force
- Excessive hardness of damping spring
If the hardness of the damping spring is too large, it will not have a cushioning effect, and the runout problem will occur when the equipment is running.
- Installation problems
For example, the installation ground is unequal.
- Loose anchor bolts
If the screen is installed horizontally on the ground, but abnormal vibration occurs after use for a period of time, it is likely to be caused by loose anchor bolts.
- Motor steering
If the motor direction and power are different, it will also cause the screen to jump violently. (generally, the rotation direction of the vibrating motor has been adjusted when the screen machine leaves the factory.)