Because of its simple operation and high efficiency, vertical mills have been widely used in cement, electric power, metallurgy, chemical, non-metallic mining and other industries in recent years. As we all know, the price of a vertical mill is not cheap, and the cost of its grinding roller bearings is also quite high, sometimes up to hundreds of thousands of replacements once, and whether the grinding roller can operate normally will seriously affect the operation of the entire mill. Therefore, understanding the causes of bearing damage and mastering certain preventive measures are of great significance to the stable production of the entire system.
Causes of damage to roller bearings
1. Poor bearing quality
After the grinding is started, the vibration of the poor quality bearing is obviously too large, and the feeding amount is low, which can easily cause the bearing to be damaged.
In order to reduce the interruption of the entire vertical grinding system after the bearing is damaged, the bearing of good quality must be used to reduce the process. The cumbersomeness affects the work process.
2, the amount of lubricating oil for the grinding roller is insufficient
Compare the amount of oil in the lubricating oil when the bearing is damaged several times, and then observe that the amount of oil is also related to the temperature, and the two interact, which will affect the work of the roller. Insufficient amount of lubricating oil will cause serious running-in between the grinding roller and the bearing, generate a lot of heat, and can not be dissipated in time, and the poor lubrication effect will affect the operation of the machine and reduce its service life.
3, the category of lubricating oil is poor, and the quality is inferior
The lubricating oil is of poor category and poor lubrication effect, which prevents the formation of a good oil film between the bearing and the slide, and the quality of the oil is poor. When the temperature rises, its color will become black, and the viscosity will decrease, resulting in a better lubrication effect. Poor, it will also cause the bearing temperature to be high, which will seriously reduce the service life.
4. Uneven distribution of materials entering the mill
Through the daily analysis of the thickness of the grinding material, after comparative research, it can be found that when the material has more layers, the work of the grinding roller will increase, and the corresponding wear will be more serious, and it will also cause the accumulation of materials; the material is easy to be ground after grinding. Deviation from the center of the grinding disc will cause long-term high-load operation of the grinding roller bearing, resulting in damage to the bearing.
7 preventive measures
1. The roller assembly should not be too tight or too loose
Before installing the bearing, be sure to check it to see if the quality is good. The use of high-quality bearings is conducive to the smooth deployment of vertical milling technology, and is also conducive to subsequent work, reducing intermediate losses, and during installation. It should not be too tight or too loose. If it is too tight, it will cause faster wear and reduce the gap between the raceways, resulting in increased temperature and reduced service life. At the same time, when the bearing is damaged, it is too tight to be difficult to remove from the grinding roller, which brings further difficulties to the vertical grinding work.
If the seal is too loose, the gap between the grinding channels will increase, and the grinding roller and the bearing cannot be closely connected. When the grinding roller rotates, the phenomenon of seizure often occurs. The two bite each other, and the bearing cannot be removed from the grinding roller again, which may damage the grinding roller.
2, adopt the correct assembly method
When assembling, the first thing that should be tested is the size of the bearing. After the test, you must pay attention to check whether it is correct and make sure that it is completely correct before you can prepare for the next operation; then you must perform certain protective treatments to ensure that dust and water will not enter. Contaminants such as stains.
In the assembly process, always pay attention to the time and temperature. Different grinding rollers require different time and temperature. The oxide cortex produced by heating must be cleaned. After the assembly is completed, the inspection should be continued to prevent the gap between the inner bearing and the outer diameter from increasing, which would seriously affect the grinding roller.
3, the amount of lubricating oil should be sufficient, and the category should be good
The lubricating oil is of excellent category and cost-effective to achieve certain benefits. It is best to use industrial oil with high viscosity and good stability. At the same time, it is necessary to reduce the temperature of the bearing, adjust to a suitable temperature and increase the oil pressure, increase the oil volume, reduce the running-in between the grinding roller and the bearing, and prevent the damage of the bearing.
4. Ensure the tightness of the grinding roller
The sealing performance of the grinding roller also has a great influence on the bearing. Be sure to use a special rotating oil for sealing, which can not only lubricate, but also prevent dust, water stains and wind dust from entering it.
If the sealing effect is poor, gas will enter the sealing area from it, and then into the bearing area, causing unnecessary damage to the bearing, reducing the lubrication effect, and even causing the surface of the raceway to fall off, increasing the number of maintenance of the grinding roller.
5. Collect materials effectively
With the progress of the times and the development of high technology, new material cleaning devices can be adopted, the working principle of belt conveyors, and a good drive system can be used to collect materials that are missed by the machine during operation and prevent it from contaminating the equipment. .
6. Regularly clean the cleaning device
For the roller grinding device, it is necessary not only to adopt a good configuration, but also to do a good job of maintenance work in order to reduce the occurrence of its problems. When the mill device is used for a long time, there must be a lot of dust and dirt on the parts on the corresponding grinding roller, and even a little iron filings, which must be cleaned by regular staff.
After all the parts are cleaned, they can be scrubbed with diesel oil to ensure the quality of the parts. For the oil holes, be sure to use compressed air for blowing to ensure that the previously used oil is completely blown out, and then inject new dry oil and repeat the operation. When cleaning the parts, pay attention to the order of cleaning, to be orderly and not to miss, and to keep the daily parts clean and tidy.
7. Strengthen the management of construction staff
Regular training for the staff, real-time guarantee of staff technical updates. It is necessary to hire highly skilled and qualified staff to carry out the construction. If there are unqualified and technically unqualified personnel, they should be ordered to stop work immediately to ensure the stability of the personnel during the entire construction process to ensure the smooth progress of the entire project.