Diagnosis and elimination methods of common faults in hydraulic systems

Hydraulic equipment is composed of mechanical, hydraulic, electrical and other devices, so the faults that occur are also diverse. A certain fault phenomenon may be caused by many factors, so analyzing hydraulic faults requires understanding the schematic diagram of the hydraulic system, having a general understanding of the functions of each component in the schematic, and then analyzing and judging based on the fault phenomenon. For the fault causes caused by many factors, it is necessary to analyze them one by one, grasp the main contradictions, and better solve and eliminate them. The flow of working fluid in components and pipelines in hydraulic systems is difficult to understand by the outside world, which brings many difficulties to analysis and diagnosis. Therefore, it requires people to have strong ability to analyze and judge faults. Identify the cause and location of faults in complex relationships between machinery, hydraulic, and electrical systems, and promptly and accurately eliminate them.

1.Simple fault diagnosis method

The simple fault diagnosis method is currently the most commonly used method. It relies on the personal experience of maintenance personnel, using simple instruments to objectively understand the working situation of the hydraulic system based on faults, using methods such as asking, seeing, listening, touching, and smelling to analyze, diagnose, and determine the cause and location of the faults. The specific methods are as follows:
1) Inquire with the equipment operator to understand the operating status of the equipment. This includes: whether the hydraulic system is working properly; Check for any abnormalities in the hydraulic pump; The time and results of hydraulic oil cleanliness testing; Cleaning and replacement of filter cartridges; Has the hydraulic component been adjusted before the malfunction occurred; Have sealing components been replaced; What abnormal phenomena have occurred in the hydraulic system before and after the malfunction; What faults have occurred in the system in the past and how they were resolved need to be understood one by one.

2) Check the actual working condition of the hydraulic system and observe whether there are any problems with the system pressure, speed, oil, leakage, vibration, etc.
3) Listen to the sound of the hydraulic system, such as impact sound; Pump noise and abnormal sounds; Determine if the hydraulic system is working properly.
4) Measure the temperature rise, vibration, crawling, and the tightness of the connection to determine whether the working status of the moving parts is normal.
In short, the simplified diagnostic method is only a simple qualitative analysis, which has a wide range of practicality for quickly diagnosing and eliminating faults.

2.Hydraulic system schematic analysis method

Analyze the faults in the hydraulic transmission system based on the schematic diagram of the hydraulic system, identify the location and cause of the faults, and propose methods for troubleshooting. The hydraulic system diagram analysis method is currently the most commonly used method by engineering and technical personnel. It requires people to have a certain foundation in hydraulic knowledge and be able to understand the names and functions of the components represented by various graphic symbols. They should also have a certain understanding of the principles, structures, and performance of the components. With such a foundation, it is easy to compare and analyze faults with the action cycle table. So studying hydraulic fundamentals seriously and mastering hydraulic schematics is the most powerful assistant for fault diagnosis and troubleshooting, as well as the foundation for other fault analysis methods. It must be carefully mastered.

3.Other analytical methods

When a hydraulic system malfunctions, it is often not possible to immediately identify the location and root cause of the malfunction. In order to avoid blindness, people must conduct logical analysis based on the principles of the hydraulic system or use causal analysis methods to eliminate each problem one by one, and finally find the location of the malfunction. This is the method of using logical analysis to find the fault. For the convenience of application, fault diagnosis experts have designed logic flow charts or other charts to make logical judgments on faults, providing convenience for fault diagnosis.