Cause and maintenance plan of bearing bush heating and cylinder crack of ball millDate: 2019-07-12 Views:
Ball mill is very common in industrial application. It is an important equipment to ensure the stability and order of industrial production. It is necessary to repair and maintain the ball mill in the daily maintenance work in order to ensure the normal stability of production. In this paper, the causes and solutions of ball mill faults are shared.
1. The temperature of bearing bush is too high.
The bearing bush is a key part of the ball mill, and the temperature is too high to cause the performance to be abnormal. In general, there are several following conditions:
1) The clearance between the hollow shaft and the shaft in the inlet end of the raw material is small
In the ball mill, about 90%of the required abrasive will be converted into thermal energy, and the temperature of abrasive material itself. The action of the abrasive material will cause thermal deformation in the axial direction of the drum, which will cause thermal expansion and cold contraction caused by shutdown.
These factors can cause the bearing bush to produce the heating condition because of the axial force, based on this, in the process of installation, it is necessary to consider from the whole, the reasonable control expansion quantity, cannot be too large or too small.
2) the scraping and grinding accuracy of bearing is insufficient.
According to the actual production requirements, the scraping range of the hollow shaft bearing of the ball mill in the smelter should be controlled below 35 °of the contact package angle.
The gap between the two sides of the bus needs to be scraped, and the distribution of contact spots should be evenly distributed along the full length of the bus, without excessive imbalance, and the spacing of spots should also have corresponding data requirements.
There is an oil tank in the contact bag angle scraping, but it should be noted that the oil tank can not be scraped through.
3)Correct selection and use of lubricating oil.
The lubricating oil is essential to the normal operation of the bearing bush. Therefore, the proper and high-quality lubricating oil can be selected according to the actual requirements of the manufacturer as much as possible, and the actual production requirements can be met.
According to the actual summary of most mining production, most of the lubricating oil taken by the bearing seat of the ball mill is determined according to its actual conditions.
4) Poor connection between the spherical surface and the spherical seat
Different from other structures, spherical bearing has the function of automatically adjusting the coaxiality of hollow shaft and bearing. Generally speaking, after the assembly of the spherical seat and the spherical tile, it is necessary to ensure the continuous and uniform distribution of the contact spots, and the spacing should be set reasonably and properly.
If the contact between the spherical tile back and the tile seat is not very good, it will directly lead to the contact between the tile surface and the small area of the hollow journal, the static load variable is large, and the edge of the bearing foundation will also have a local high temperature condition.
In order to avoid this situation, the spherical surface of the spherical tile should be polished and scraped repeatedly in the process of installation, which is to ensure that the surface of the outer spherical surface is smooth and not rough, and can also play a flexible role in the concave sphere of the base, so as to effectively play the role of automatic centring, so as to ensure the strict and reasonable connection between the spherical tile and the spherical seat.
5) sealing treatment
in the past traditional ball mill structure, the main bearing is sealed with a fine wool felt ring, is easy to wear, and the dust particles enter into the main bearing by the crack between the wool felt ring and the hollow shaft after the abrasion occurs, The abrasive wear and the oil passage of the spherical bearing bush are very easy to be caused.
Therefore, in order to check the wear of sealing ring in time, if the degree is serious, it is necessary to update and replace, and many manufacturers have also carried out improvement and optimization on this basis. In order to prevent oil leakage, the main bearing part of the seal should adopt the most advanced piston seal.
2.Fault maintenance of cylinder crack
1) Cracks in the welding process of the cylinder
If the quality is not qualified in this link, it will directly lead to the fracture of welding seam, and if the treatment time is delayed, the welding stress will be too large, which will lead to the emergence of cracks.
According to the analysis of the bending stress and shear stress of the cylinder, it can be found that its maximum force is at both ends of the cylinder, and the welding work should be done. The angular contact formed by the two is a right-angle presentation, which can easily lead to the stress concentration and the fracture crack problem.
2) Cracks in working condition
When the cylinder body is in the normal working process, once the bolt of the cylinder is loose or the lining plate is off, the cylinder body is updated and replaced at the first time, if the treatment measures are not timely, cracks of the cylinder body can be caused, and after the crack is generated, the adopted measures are clean and clean, Make sure that the position of the cylinder is correct and start the next step.
after the process of the outer welding link is finished, the root of the welding seam needs to be cleaned in the mill, the welding is carried out at the same time, the specific welding number is about three times, and for the welding personnel, during the welding process, the welding seam needs to be knocked, The number of knocking is more than four times, so that the existence of stress can be effectively eliminated, and the welding work is ensured to be good.
In the course of ball mill operation, many factors are affected, and a lot of faults can occur, and if the treatment is not solved in time, the production is difficult to proceed smoothly. For different fault phenomena, the cause of the analysis is analyzed, and the correct and reasonable solution is taken to ensure that the performance of the ball mill is normal. Welcome to the message that you've encountered.