1. Hydraulic oil malfunction
According to statistics, 70% of hydraulic device failures are related to hydraulic oil, and about 90% of these 70% are caused by impurities. The inspection of hydraulic oil mainly includes the following points: cleanliness, color, viscosity, and consistency of hydraulic oil; In addition, there is also an odor. When hydraulic oil flows from the high-pressure side to the low-pressure side without performing mechanical work, heat is generated in the hydraulic system. Excessive temperature of hydraulic oil can cause expensive seals to deteriorate and the oil to oxidize and fail, leading to corrosion and the formation of deposits, which can block damping holes and accelerate valve wear. Excessive temperature can cause valves and pumps to jam, and high temperatures can also pose safety issues. By checking the oil temperature inside the fuel tank, system failures can sometimes be eliminated before serious harm occurs. In most systems, the overflow valve is the main heat source, and the excessive flow through the pressure reducing valve is another major cause of heat generation. Due to the correlation between low efficiency and energy loss, checking the operating temperature can determine whether there is a problem of low efficiency. For hydraulic systems, controlling pollutants in the oil is a major task, and the sources of pollutants mainly include the following aspects:
Entered with new oil.
During the assembly process, the internal components of the system.
Entered with the surrounding air.
Caused by internal wear of hydraulic components.
Entered through leaking or damaged seals.
It was brought in during maintenance.
The removal and control of pollutants require the use of filters, and hydraulic systems may be equipped with good filters with suitable installation locations. However, if not maintained carefully and in a timely manner, the filters cannot play their due role, wasting the cost spent. So the following tasks should be done well:
Develop a maintenance schedule for filters and strictly implement it.
Check the replaced filter element from the system to identify signs of system failure and potential issues.
Do not pour any leaked oil back into the system.
2. Malfunctions of pumps and valves
If the pump is installed and used correctly, the hydraulic pump can be used continuously for many years without maintenance. Once a problem is discovered, the cause should be identified and eliminated as soon as possible. Using hydraulic diagrams to diagnose system faults is much simpler. The manufacturing accuracy of hydraulic valves is high. As long as they are properly assembled and maintained in good working condition, they generally have little leakage and can accurately control the oil pressure, direction, and flow in the system. The pollutants in the oil are the main cause of valve failure, and small amounts of fibers, dirt, oxides, or sludge can cause malfunctions or damage to the valve. If products from trustworthy manufacturers are used, the possibility of improper design is very small. The main reasons for pump and valve failures are as follows:
2.1 External conditions
a. Loosening of fastening bolts, deformation and damage caused by excessive tightening.
b. Sudden changes in load.
c. Vibration and impact.
d. Errors in assembly, disassembly, and repair operations and sequences, the quality of tools, damage, deformation, scars, and loss of parts.
e. Deformation and damage caused by piping distortion, or piping errors, etc.
2.2 Hydraulic oil conditions
a. Mixing impurities, water, air, and deterioration.
b. Is the viscosity and temperature appropriate.
c. Lubrication.
d. Whether the inhalation conditions are good (preventing air pockets, excessive positive or negative pressure).
e. Abnormal high pressure and pressure fluctuations.
2.3 The quality of the components themselves
a. Structure and strength.
b. Quality of components (bearings, oil seals, bolts, shafts).
c. Wear, scratches, and sticking of sliding parts.
d. Wear, scratches, deformation, and deterioration of components.
e. Oil leakage (internal leakage, external leakage).
To ensure the safety and reliability of valve maintenance work, the following principles should be followed:
a. Before disassembling the hydraulic valve, cut off the power supply to prevent the system from accidentally starting or causing the tool to fly out.
b. Before disassembling the hydraulic valve, move the valve handle in all directions to release the pressure inside the system.
c. Before disassembling the hydraulic valve, all working mechanisms of the hydraulic transmission should be locked or placed in a lower position.
3. Fault of accumulator
An accumulator is a device that stores high-pressure oil. When the pump is in a normal no-load or idle state, the accumulator can be filled with oil. The high-pressure oil stored in the accumulator can be released when needed to supplement the flow of the pump or supply oil to the system when the pump is stopped. The energy storage devices we currently use are mostly diaphragm type and airbag type; Accumulators rely on compressing inert gas to store energy, usually using nitrogen gas. The actual inflation pressure should not exceed the critical value. In most cases, the inflation pressure value should be within the range of 1/3 to 1/2 of the highest system pressure value, which is the most effective and results in minimal changes in the working characteristics of the circuit. It is particularly emphasized not to use oxygen or mixed gases containing oxygen.
In short, by gaining a deeper understanding and mastery of hydraulic systems, continuously improving technical and operational capabilities, we can better solve the main problems faced by hydraulic equipment users and manage hydraulic systems effectively. When the system encounters problems, the real cause of the system failure can be identified. More work begins with daily inspections, paying attention to the details of equipment inspection and maintenance work. Various factors that cause failures are eliminated in the early stages of the failure. Through continuous improvement and enhancement of the work cycle, the predictive maintenance work can be further improved in the constantly changing working environment, ensuring that the equipment plays a greater role and achieving the goal of zero equipment accidents.
2024 December 4th Week VAFEM Product Recommendation:
Water pump bearings are double row bearings and, in contrast to conventional double row bearings, do not have an inner ring but raceways machined directly into the surface of the shaft.
As a precious high quality water pump bearings manufacturer and supplier in China, VAFEM can guarantee the quality and precision of the products through complete testing technology and advanced equipment. Please come to buy water pump bearings at the best price and quality from VAFEM. Please contact us for any questions!
https://www.vafem.com/products/Water-Pump-bearings/847.html
As a precious high quality wheel hub bearings manufacturer and supplier in China, VAFEM can guarantee the quality and precision of the products through complete testing technology and advanced equipment. Please come to buy wheel hub bearings at the best price and quality from VAFEM. Please contact us for any questions!
2025-01-02