The vibrating screen is operated by the vibration force of the vibrating motor. It is a machine that uses the destructive force. This problem has been considered in the design and manufacturing. The shock absorber spring and other designs are used to reduce the impact of vibration on the machine. Generally, it is not there will be a lot of noise, so if there is a lot of noise in the equipment during production, then there must be a problem with a certain part of the machine. If it is not solved in time, it will reduce the working environment during production on the one hand, and on the other hand, it will affects the service life of the machine, so it is very important to understand the cause of the noise of the vibrating screen and its solutions.
The vibrating screen box is composed of steel parts such as beams, side plates, reinforced plates and screen surfaces. The size of these steel parts of different types of vibrating screens is also different, so the elastic vibration is not a fixed value, very It is difficult to accurately analyze and calculate it, and noise will be generated when the elastic vibration of these parts is too large.
Source of vibration screen noise:
1. Eccentric shaft
The vibrating screen relies on the centrifugal force of the eccentric block to generate the vibration force. If the eccentric force causes the eccentric shaft to deform and bend, the inner and outer bases of the bearing will be relatively deflected, and the motion trajectory of the rolling elements will change, thus increasing vibration sound.
2. Bearing
The sound pressure level of noise is proportional to the size and speed of the bearing. This is an anharmonic vibration with a higher frequency, which has a wider frequency band distribution. The vibration produced during the operation of the bearing includes two aspects. One is the structure. The rolling elements cause a small change in the position of the shaft center and cause vibration through compound action. Secondly, in terms of manufacturing, the geometrical errors of rolling elements, cages, inner and outer rings and other rolling tables will cause vibration. Among them, waviness has the greatest influence, followed by different degrees and surface finishes, in the rolling elements and inner and outer rings. Among the three parts, the geometric shape error of the rolling body surface has the greatest impact on vibration and noise. During operation, load, speed, lubrication and working clearance all affect the vibration of the bearing to varying degrees. For example, grease-lubricated bearings are prone to pitting corrosion, which increases the vibration response of the bearing.
Measures to reduce the noise of vibrating screen
1. The choice of bearing
First of all, it is necessary to meet the conditions of bearing life, and secondly, try to use bearings with a smaller size and a higher box.
2. Selection of side plate stiffness
In the design of the structure of the screen box, the rigidity of the side plate should be considered, and the appropriate rigidity should be used to reduce the vibration, so as to reduce the medium and low frequency noise waves.
3. Multi-purpose rubber and plastic components
1) The noise level of the rubber sieve is about 10 decibels lower than that of the metal sieve.
2) When selecting metal sieve plates or stainless steel slotted sieve plates, use cushion rubber or plastic pads to connect the sieve frames to avoid noise caused by the impact of metal parts.
3) Although the coil spring has a lower natural frequency, a larger static compression and load capacity, it can withstand temperature, oil, and has stable performance, but it is easy to transmit high-frequency and medium-frequency vibrations. In order to reduce noise, a layer of rubber is adhered to the spring wire to increase resistance.
4) Rubber spring, the noise generated during work is very small, but due to the existence of its internal resistance, it is necessary to consider enough iron heat dissipation area when designing.