Causes & Counter Measures of Gear Wear of Ball Mill Mining

As mill grinding machines widely used in mining, metallurgy and cement production, ball mill machine are known for their practicality. However, due to the simple mechanical structure, gears, which are the main internal components, have frequently received attention. Generally speaking, the gear life is between 6 and 10 years. As long as the gear works in the machine, it will inevitably wear out. Therefore, how to reduce the wear of the gear surface to a large extent during the operation of the machine during the same operation time has become a problem that needs to be explored. Based on these problems, a more practical solution is proposed. We are one of the top industrial grinding mill manufacturers.

Reasons for Ball Mill Girth Gear of Mineral Grinding Mill

During the use of the mining ball mill, the ball mill girth gear will wear out to a certain extent, which is a normal phenomenon. However, serious wear and tear in a short period of time are often determined by the problem of human operation and the irreversible situation caused by the rapid wear and tear of the machine itself. In addition, the mechanical structure of the ball mill itself is relatively simple, resulting in relatively low manufacturing costs, so the requirements for installation accuracy are not high.

The figure below is a schematic diagram of the appearance of the dry ball mill.

Ball Mill

Despite this, the wear and tear of mining ball mills and maintenance costs remain high, mainly due to the short service life of the large and small gears. Based on previous maintenance experience, every two ball mill overhaul cycles, the large ring gears and small gears must be replaced.

This article will analyze several main reasons that affect the service life of the overflow ball mill and wet grid ball mill, and propose countermeasures.

1.1 Material hardness affects ball mill girth gear life

The hardness of the gear material of the ball mill is closely related to the material of the gear produced. According to the national standard, the hardness standard of the large gear of the mining ball mill must be maintained above HB300, and the standard of the small gear must be above HRC45. In other words, if the gear is produced in accordance with national standards, it can be maintained until the next maintenance cycle. However, judging from the current speed of overhaul and replacement of ball mill gears, the hardness of large and small gears produced by many manufacturers is below the standard. Moreover, in the process of actual use of the ball mill, the user will often check and repair the gears of the machine in a fast and time-saving manner. It will not deal with the internal stress of the gears in the early stages of machine use and before changing the gears. Such gears whose hardness is lower than the standard and the subsequent use processing procedures are also improper, naturally do not have a long service life.

1.2 The tightness of the gear surface of the ball mill girth gear is not strong

In addition to the material used in the production process of the gear, it directly determines the service life of the gear. When the section of each gear that fits during operation is not well sealed, it will directly cause serious wear on the large gear surface of the ball mill. This is because when designing the large gear of the ball mill, some margin is generally reserved in advance so that it can be better installed and debugged before it is put into use. And if you refer to the relevant national standards, the gear faces of the big gear are allowed to have a certain degree of numerical error. Combined with the analysis of the existing gear processing technology, it can be found that most gear processing will use the end face pressure process, which has obvious advantages in itself. The ball mill girth gear in CIC girth gear manufacturer can ensure the sealing performance of the gear faces at the initial stage of use. However, after the ball mill has been used for a period of time, the self-contained felt on the end face of the internal gear will weaken its elasticity due to being squeezed, which will eventually cause the gear to gradually lose its original tightness. With the weakening of the sealing performance of the felt failure, the gap between the gears will increase. In addition, dust and other impurities will inevitably appear during the operation of the ball mill mining. Once these dust and impurities enter the gap caused by the poor sealing of the gears, it will produce more serious wear, directly affect the life of the gear, but also damage the machine, and bring difficulties to the follow-up inspection and maintenance work.

1.3 The selection of gear lubricants affects ball mill girth gear life

The selection of lubricating oil and the way of lubrication also determine the life of the gear to a large extent. The large and small gears are installed on the corresponding positions of the ball mill, and subsequent oiling and lubrication work is required. This is because the continuous friction of the two meshing gears during operation will generate heat, which will further cause irreversible losses to the gears. From this point of view, applying lubricating oil between gears is not only to cool the temperature caused by friction but also to effectively reduce friction and delay the speed of gear wear. Therefore, we have to mention the selection of gear lubricants, which directly affect gear life. However, in the process of actual use of the ball mill, the selection of gear lubricants is often very random. Many operators do not carefully understand and select lubricants with different parameters. The selected lubricants may not be suitable for lubricating the gears of the ball mill, or even for save costs, and choose some low-quality lubricants. Once the mining grinding mill is added with lubricating oil that is not suitable for the machine itself or of inferior quality, not only the lubricating effect is greatly reduced, but also the sealing degree of the lubricating oil is not enough after the film is formed, it will accelerate the wear of the gear and the corrosion of other metal parts of the ball mill.

Countermeasures to Prevent Ball mill Girth Gear of Mining Ball Mill

2.1 Strict gear production and processing standards to improve ball mill girth gear hardness

In view of the problem of gear wear in mining ball mills, the focus should be on improving the precision of gear production and processing, grinding mill design, and the hardness of the materials used in the production of gears. As we all know, the rougher the surface of an object, the greater the friction generated after contact. It can be seen that when the gear surface processing accuracy is not enough, it will quickly wear and passivation after being put into use. In addition, ZG45 materials are often used in the production of such gears in my country. Because this material is difficult to quench, there is still a certain gap between the wear resistance of the gear and the expected wear resistance after it is put into use. Therefore, the technology of fine gear processing and the materials used for controlling gear processing is extremely important.

2.2 Do the ball mill girth gear maintenance work before putting it into use

Before the mining ball mill is put into use, in addition to the inspection of other metal components, a more detailed inspection of the gear is required. After the gear is put into use, the state of the gear surface can be easily observed by the naked eye. This requires maintenance and repair personnel to find out in time, and grasp the status of the two gears from the beginning of the installation of the gears into the ball mill. Before the gear is officially put into use, check all possible vulnerabilities during installation, and timely add lubricating oil that meets the gear lubrication standard to protect the ball mill and gear, so as to better avoid the two gears that may occur during the later use of the machine problem.

2.3 Scientifically and reasonably select ball mill girth gear lubricants

During the operation of the ball mill, it is inseparable from the use of lubricating oil. This can play a role in cooling and lubricating the machine, and ultimately directly affect the wear of the gear. The scientific and reasonable selection of gear lubricating oil for ball mills is one of the important means to restrain gear wear. At present, there are a wide variety of lubricating products of various forms and brands, which are mainly divided into three categories: lubricants, greases and solid lubricants. Compared with lubricating oil, greases and solid lubricants have the advantages of strong adhesion, good shock resistance and strong bearing capacity. However, due to the poor boundary strength and poor fluidity of the film formed after use, the advantages of lubricating oil are more obvious on the whole. And because lubricating oil is also specifically divided into mechanical oil and gear oil, the gear oil has a higher viscosity and better oiliness, and the oil body contains more polar substances, and the gear is more likely to form a highly closed oil film during the rotation process. Therefore, in the gear lubrication work of the ball mill, it is best to use professional gear oil to extend the service life of the machine components and gears, reduce losses and reduce costs.

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