When the ball mill is running, a thin oil film is needed between the bearing bush and the rotating shaft of the sliding bearing for lubrication. Once the lubrication effect is not good, there will be friction between the bearing bush and the rotating shaft to produce high temperature, resulting in tile burning.
Generally, the oil film on the bearing surface of the newly installed ball mill cannot be formed quickly at the moment of start-up, so it is necessary to spray lubricating oil on the two bearing surfaces of the ball mill in advance before debugging to prevent the bearing surfaces from being pulled.
After the trial run, clean lubricating oil needs to be replaced, mainly because some fine Babbitt particles will be produced when the bearing bush runs with the hollow journal, which will lead to abrasive wear in the lubricating oil, so it is necessary to remove impurities by replacing the lubricating oil.
During the operation of the ball mill, once it is found that the lubricating oil supply of the bearing bush is insufficient or the viscosity is low, the oil film cannot be formed, resulting in the high temperature of the bearing bush. At this time, in order to avoid burning the bearing bush, it is necessary to stop cooling and replace the lubricating oil in time.
2. The lubricating oil used for ball mill bearing is inconsistent in model and poor in quality, which leads to tile burning.
The quality of lubricating oil and the choice of oil used in each link of ball mill are very important, and the bearing bush is no exception. The quality of lubricating oil directly affects the use of bearing bush.
In the concentrator, some technicians choose oil at will, not according to the different characteristics and functions of different lubricating oils, which will lead to friction and heating of the ball mill bearing bush during operation and expansion and deformation. In addition, some mineral processing plants use waste diesel oil as lubricating oil, which not only fails to lubricate, but also accelerates the heating of bearing bush and even leads to shutdown and maintenance.
In order to ensure the normal operation of bearing bush, it is suggested that each concentrator should strictly follow the standard of ball mill lubricating oil when selecting oil. Generally, N220 medium-load industrial gear oil is selected for ball mill bearings and bearing seats.
3. The mismatch between the ball bush and the ball seat of the ball mill leads to friction heating and burning of the bush.
The spherical tile of ball mill has the function of automatically adjusting the coaxiality of hollow shaft and bearing bush. If the ball bearing of the ball mill is not matched with the ball seat, the back of the ball bearing is in poor contact with the bearing seat, resulting in a small contact area between the bearing surface and the hollow journal, a large static load and a local temperature rise at the contact edge of the bearing.
At this time, the outer spherical surface of the ball tile can be scraped and polished to keep the outer spherical surface smooth, so that the concave spherical surface of the base can rotate flexibly and play the role of automatic centering.
Note: When installing the ball bearing and the ball seat, the distance between them should be no more than 5mm, the circumferential wrap angle of the ball contact zone should be no less than 45, and the axial contact width should be less than 1/3 and more than 10 mm of the ball bearing width. ..
4. The poor sealing effect of ball mill bearings leads to bearing wear.
The seal of the main bearing of ball mill generally adopts wool felt ring, which is poor and easy to wear, causing dust to enter the main bearing through the broken washer, causing abrasive wear of spherical bearing and oil circuit blockage. In case of this problem, we can only check the wear of the seal in time during use and replace it in time. Or choose ball milling equipment with better sealing effect when purchasing.
Overheating and burning of the bearing bush of the ball mill are mostly caused by nonstandard operation or design and production errors. The former needs regular maintenance, and the latter needs to choose a ball mill with good bearing effect.
So is there a better way to solve the problem of ball mill bearing and bearing overheating?
At present, some ball mill manufacturers have upgraded ball mill bearings, such as Xinhai mining equipment. According to the different use conditions of ball mill, bearings can be made into sliding bearings, or double-row cylindrical rolling bearings can be changed to replace sliding bearings according to the needs of users. No bearing bush is needed, and the lubrication requirement is low. Oil supply does not need pressure, only intermittent oil cups can meet the requirements. Therefore, the problems of bearing bush wear and burning caused by improper lubrication, insufficient lubrication or unreasonable design are completely solved.
In addition, the power consumed by the ball mill of rolling bearing is less than that of sliding bearing, and the installation requirements of rolling bearing are lower than that of sliding bearing, so the installation and operation are more convenient.