The life evaluation of coal mine mechanical gear transmission system involves many aspects such as personnel, equipment and environment. The scientific and reasonable life evaluation index system will directly affect the accuracy and effectiveness of life evaluation results. The index system of coal mine mechanical gear transmission system is composed of many specific factors, which affect each other on the evaluation results. Therefore, when establishing the index system, it is necessary to clarify the index structure and determine the relationship and importance of each index. The establishment of index system will help decision-makers to find out the key factors from many factors that affect the life of gear transmission, which is the basis of life evaluation. Therefore, in order to ensure the scientific and complete index system, the following basic principles must be followed:
1) Purpose principle: for the life evaluation of coal mine mechanical gear transmission system, only the factors affecting its life need to be analyzed, and other ambiguous or far fetched factors need not be included in the research scope.
2) Scientific principle: in the life evaluation of coal mine mechanical gear transmission system, the determination of its index and index data should be based on objective basis. Only under the guidance of scientific basis, can the objectivity and reliability of the index system be ensured, so as to ensure the accuracy of the evaluation results.
3) Systematic principle: the life influencing factors of the coal mine mechanical gear transmission system are very complex, and the influence of each factor on its life is superposed or offset. Therefore, the structure of the index system must be clear and the complex relationship of each influencing factor can be expressed clearly, which is the key to accurately evaluate its life state.
4) The principle of comprehensiveness: the gear transmission system of coal mine machinery is very complex, any influencing factor may lead to its failure, thus affecting the working life. Therefore, the selection of indicators in the evaluation index system must comprehensively consider the influencing factors on their life span to ensure that the main factors affecting their life span are all in their system, so that the evaluation results are more representative.
5) Principle of practicability: the establishment of life evaluation index system of coal mine mechanical gear transmission system must consider the characteristics of its work and operation, and the collection and processing of its index data need to consider the existing level of science and technology. Practicability is the key to the index system, and the index system without practical value has no research significance for life evaluation.
6) Principle of comparability: for the qualitative evaluation indexes in the life evaluation of coal mine mechanical gear transmission system, there must be a quantitative method to deal with them, so as to compare the impact of each index on the life of coal mine mechanical gear transmission system, which is more conducive to the comprehensive and quantitative evaluation of the actual life state of coal mine mechanical gear transmission system.
7) Independence principle: when the life evaluation system of coal mine mechanical gear transmission system meets the comprehensiveness, the overlap and obvious inclusion relationship between indicators should be eliminated by appropriate methods to avoid the impact on the evaluation results.
8) Sensitivity principle: when the index data in the life evaluation index system of the gear transmission system of the coal mine machinery changes, the corresponding obvious change should also occur in the state of the coal mine machinery, so that the evaluation results are more effective and accurate.
