Ball mill is an important grinding machine, widely used in cement, slag, electric power, chemical industry and other industries. Regardless of the type of ball mill, the perimeter gear is always a key component. The perimeter gear has a large shape and is difficult to process or install. If it is not properly maintained, it will be easily worn out during the operation of the ball mill, resulting in a lower service life than expected.
Next, we will analyze the factors that affect the service life of gear teeth from multiple angles, and summarize the methods to reduce the wear rate of gear teeth, so as to improve the operation stability of the ball mill system, reduce the failure rate, and reduce the economic loss caused by downtime.
Analysis of Wear of Ball Mill Girth Gear
The wear rate of ball mill gears during operation is mainly affected by three factors. The first is the lubrication of the gear; the second is the sealing performance of the ball mill gear; the third is the hardness of the ball mill gear. This paper mainly elaborates and analyzes these three issues in detail.
Use of Gear Lubricant
Choosing the right lubricating oil and properly lubricating the gears are important means to ensure the normal operation of the ball mill. Well-lubricated gears can not only effectively reduce running noise, but also reduce the wear rate during operation. If we do not pay enough attention to gear lubrication, if we do not have a detailed understanding of the differences between the performance and functions of each lubricant when selecting lubricants, the selected lubricant does not meet the operating requirements of the ball mill, or the lubrication method used is incorrect, It is easy to cause problems with the gears during operation.
Once the lubricating viscosity of the gear is insufficient, the gear will not form a proper oil film during operation, and the gear will wear out. Some use waste engine oil instead of lubricating oil, and impurities in waste engine oil may cause more serious gear wear. In order to effectively reduce the wear phenomenon of ball mill gears during operation, lubricating oil and lubrication methods should be selected scientifically and reasonably.
Gear sealing performance
The size of the transmission gear of the ball mill will have a certain margin in the design to ensure its normal installation, debugging and use. At present, the processing method of the internal gear of the ball mill is mostly end face pressure processing. Although this process has many advantages, it cannot effectively guarantee the sealing performance of the gear.
After the ball mill has been running for a period of time, there will be felt extrusion on the end face of the gear. Also, over time, the felt gradually loses its application elasticity and eventually fails, causing gear wear. At the same time, due to insufficient sealing performance, the gears will have dry friction, which seriously affects the work of the gears and increases the degree of wear. The sealing performance of the gear not only affects its service life, but also relates to the overall maintenance frequency of the entire ball mill system.
Material of Girth Gears
The hardness of the ball mill girth gear should be above HB300, and the hardness of the ball mill pinions should be above HRC45. If the hardness of the gear is not up to standard, it is easy to wear during operation. At present, the main material used by many gear manufacturers is ZG45 high manganese steel, which cannot be quenched. The normalized hardness of the material with the size of 100mm specified in the standard should be kept at HB160-217, but it is difficult to exceed HB170 in fact. The combined transmission of the pinion with the surface hardness of HRC45-50 will reduce the service life.