The ball mill is a very important equipment in the selection plant, and it also accounts for a large proportion of the investment in the entire selection plant. In order to ensure the service life of the ball mill during use, it is necessary to first ensure the service life of the ball mill gears, because the ball mill gears are mechanical components that achieve the transmission of operation and power of the ball mill. Once the gear of the ball mill is damaged, the wait for the ball mill is to stop production and repair.

1. Improper selection and use of lubricating oil can cause gear wear in the ball mill
The selection of lubricating oil and lubrication method is an important means to ensure the normal operation of ball mill gears, as well as a necessary condition for noise reduction and wear reduction.

In the beneficiation plant, technical personnel have a relatively arbitrary choice of lubrication for the gear of the ball mill, and have not completely selected and used different lubricating oils according to their different characteristics and effects, nor have they correctly selected lubricating oils according to the actual use situation on site. This will result in insufficient viscosity of the lubricating oil during the operation of the ball mill gears, which cannot effectively form a protective oil film, leading to wear of the ball mill gears.

In addition, there are also a few selection factories that use substandard lubricating oil as a substitute, using discarded diesel as lubricating oil. This not only fails to provide lubrication, but also accelerates the wear of the ball mill.

2. Poor sealing performance of transmission gear section
The transmission gear size of a ball mill is generally relatively large. According to relevant national design standards, there is a certain numerical error allowed on the gear surface. Therefore, a sealing device is needed to ensure the sealing performance between the gears of the ball mill.

However, in the existing processing technology, many ball mill gear cross-sections are processed using the end face pressurization method. The gears produced by this process have good performance in the early stage of use and have good sealing performance. However, after running for a period of time, the felt on the end face is compressed, which will cause the elasticity of the felt to lose its effectiveness, leading to the failure of the sealing performance of the gears.

A failed sealing device will allow more dust and impurities to enter the gear. Under long-term operation, it will cause severe wear on the gear surface, greatly reducing its service life and affecting subsequent maintenance and installation operations.

To ensure the sealing of the ball mill gears, the precision and hardness of the gears can only be strengthened during the production and processing of the ball mill gears. However, at present, the accuracy of ball mill gears in China is generally 9-8-8DC and 9-9-8DC, with a tooth surface roughness of 3.2 μ m. This accuracy and roughness are difficult to meet long-term operations, so daily inspection, regular maintenance, or the use of more precise ball mill gears are necessary.

3. Wear caused by substandard hardness of ball mill gears
According to relevant national standards, the hardness of the large gear of the ball mill should reach HB300 or even higher, and the tooth surface hardness of the small gear should also be HRC45 or even higher. But some production units cannot meet the above hardness requirements in actual production.

In addition, the key is that some manufacturers have omitted the internal stress treatment process of gears in order to save equipment maintenance time, making it difficult for gears to meet the hardness requirements in actual production, thereby reducing the wear resistance of ball mill gears. To improve the hardness of the ball mill gears, this is necessary.
Firstly, when purchasing a ball mill, it is important to choose a manufacturer with good quality.
Secondly, when installing the gears of the ball mill, it is necessary to strictly follow the national regulations to ensure that the top clearance, runout, contact, etc. of the large and small gears meet the specified requirements.

Thirdly, during the subsequent operation of the gear, it is necessary to regularly inspect the working status of the gear. When the wear reaches the upper limit, it should be repaired or replaced in a timely manner. If the surface of the small gear is found to be rough, manual polishing can be carried out to reduce the roughness of the gear surface; If the large gear is severely worn, due to its high cost, it can be repaired or flipped over for continued use, which can not only extend the service life but also reduce the investment of the large gear.