Determination of the hydraulic system condition evaluation criteria
To determine the condition evaluation criteria for a hydraulic system, the first step is to identify which parameters characterize the faults and to evaluate their relative importance. The second step is to establish quantitative boundaries for fault evaluation parameters. The initial determination of these parameter boundaries can be based on: hydraulic component manufacturing standards, guidelines in hydraulic equipment operation and maintenance manuals, data provided in hydraulic repair publications, allowable variations in equipment performance parameters as permitted by production processes, and empirical data accumulated by on-site technical personnel. Sometimes, the required LED display data may be difficult to obtain initially; in such cases, similar hydraulic systems' data can be referenced with appropriate adjustments made according to different situations, or certain assumptions can be made based on relevant materials and experience. It is essential to continuously test and revise fault evaluation criteria during application to make them more precise.
With quantitative fault evaluation criteria established, fault analysis personnel can assess the specific condition of the hydraulic system, determining whether there are any faults and how severe they are. To ensure more accurate results, it is important to analyze each situation specifically rather than rigidly applying the standards. First, attention should be paid to the working environment of the subject under examination, such as seasonal changes that cause variations in ambient temperature and cooling water temperature, thereby affecting the temperature of the hydraulic system. After equipment repairs or component replacements, some performances may change. Variations in work tasks lead to changes in load conditions. Different equipment maintenance management methods also have close relationships with the state of the equipment. Random factors affecting electric lubrication pump hydraulic systems do not follow regular patterns, such as fluctuations in grid voltage, changes in cooling water pressure, variations in hydraulic oil condition, and operational errors, all of which cause irregular changes in relevant information. When observing and testing hydraulic systems, it is crucial to maintain consistent environmental conditions before and after testing and ensure the system is in a relatively stable state to improve the accuracy and comparability of test data.
Secondly, fault evaluation criteria may involve multiple characteristic parameters, but the most important ones should serve as the primary basis for evaluation. For example, when assessing the condition of an axial piston hydraulic motor, the main criteria are the decrease in rotational speed under a specific load resistance torque and the corresponding leakage amount (which can be measured within the leakage pipe). Thirdly, based on the site conditions, data should be collected through relatively simple means, extracting relevant information. If there is insufficient testing equipment for manual lubrication pumps, preliminary information about the hydraulic system can be obtained indirectly and processed appropriately. For instance, without a flowmeter, if it is impossible to measure the flow rate delivered by the hydraulic pump to the hydraulic cylinder directly, the flow value can be calculated indirectly using the hydraulic cylinder's operating speed and piston area.
In conclusion, establishing a clear and reliable evaluation criterion for hydraulic systems allows for better diagnosis of their health status, enabling timely maintenance actions and prolonging the service life of the equipment.