The function of a hydraulic system is to increase the force by altering pressure. A complete hydraulic system consists of five components: power elements, actuating elements, control elements, auxiliary elements (accessories), and hydraulic oil. Hydraulic systems can be divided into two categories: hydraulic drive systems and hydraulic control systems. The primary function of a hydraulic drive system is to transmit power and motion. A hydraulic control system is designed to ensure that the output of the hydraulic system meets specific performance requirements (especially dynamic performance). When we refer to a hydraulic system, we generally mean a hydraulic drive system.
Maintenance:
The quality of a hydraulic system depends not only on the rationality of the system design and the performance of its components, but also on the system's protection against and treatment of contamination. System contamination directly affects the reliability of the hydraulic system's operation and the lifespan of its components. Statistics show that about 70% of hydraulic system failures globally are caused by contamination.
Fault Diagnosis:
Hydraulic drive systems have gained increasingly widespread applications across various fields due to their unique advantages, such as broad process adaptability, excellent control performance, and low cost. However, due to the unstable quality of components and accessories objectively, as well as subjective misuse and inadequate maintenance, and because the system's components and working fluids operate within a closed oil circuit, unlike machinery and equipment which are more直观, or electrical equipment that can be conveniently measured with various detection instruments, hydraulic systems rely solely on a limited number of pressure gauges, flowmeters, and other indicators to display working parameters of certain parts of the system. Other parameters are difficult to measure, and the root causes of general malfunctions have many possibilities, making fault diagnosis of hydraulic systems somewhat challenging.
On the production floor, due to constraints imposed by production schedules and technical conditions, it is required that fault diagnosis personnel accurately and simply identify hydraulic equipment failures; maintenance personnel are to utilize existing information and on-site technical conditions to minimize disassembly work, saving repair time and costs. Using straightforward technical methods, they should pinpoint the fault location and its cause as quickly as possible, repair it, restore the system to normal operation, and strive to prevent recurrence of similar failures in the future.
System Maintenance:
A system typically undergoes flushing before being officially put into use. The purpose of flushing is to remove pollutants, metal shavings, fiber compounds, iron cores, and other debris from within the system. During the initial two hours of operation, even without completely damaging the system, it can cause a series of malfunctions. Therefore, the following steps should be followed to clean the system's oil circuit:
1) Clean the oil tank with a quick-drying solvent, then remove any residue with filtered air.
2) Clean all piping in the system; in some cases, it may be necessary to soak the piping and joints.
3) Install oil filters in the pipeline to protect the valve's fuel and pressure lines.
4) Install a flushing plate on the manifold instead of a precision valve, such as an electro-hydraulic servo valve.
5) Verify all pipeline sizes are appropriate and connections are correct.
If the system utilizes electro-hydraulic servo valves, I'll elaborate a bit further. The flushing plate of the servo valve must allow oil to flow from the supply pipeline to the accumulator and then directly back to the oil tank, enabling the oil to circulate repeatedly for system flushing. This allows the oil filter to remove solid particles. During the flushing process, check the oil filter every 1 to 2 hours to prevent blockage by contaminants. Do not open the bypass; if you notice the oil filter starting to clog, replace it immediately.
The cycle for flushing is determined by the system's construction and the level of system contamination. If the sample of the filter medium lacks or has very few foreign contaminants, install a new oil filter, remove the flushing plate, and set the valve to work!
Scheduled Maintenance: Establish a regular maintenance system for the hydraulic system
