Three abnormal conditions in which hydraulic oil is most prone to occur

Update:20-07-2018
Summary:

Three abnormal conditions in which hydraulic oil is mos […]

Three abnormal conditions in which hydraulic oil is most prone to occur

Hydraulic oil can be described as the "blood" of hydraulic machinery. The failure of most hydraulic systems can be solved by detecting and observing the condition of the hydraulic oil to find the cause of the fault, thus eliminating the fault.

1. The hydraulic oil has impurities that are turbid

There are 3 types of impurities in hydraulic oil, namely solid impurities (debris, solid particles, solid impurities formed by the deterioration of hydraulic oil, etc.), liquid impurities (mainly water, viscous impurities formed by the deterioration of hydraulic oil) and gaseous impurities. (mainly air).

If the hydraulic oil is white turbid, it can eliminate the possibility of solid impurities and liquid viscous impurities, which can only be caused by air. Sampling and testing hydraulic oil. Aerobic drops are dropped on the hot iron plate. If bubbles appear (water becomes water vapor or bubbles at high temperatures), it can be judged to be water in the hydraulic oil; otherwise, the hydraulic oil contains air.

If it is determined that the hydraulic oil is mixed with moisture and causes turbidity, after the hydraulic oil is allowed to stand for a while, the water is allowed to sink to the bottom of the hydraulic tank, and then the water is removed. However, if the moisture content is too high and the hydraulic oil is emulsified, a new hydraulic oil needs to be replaced.

If it is determined that the air is mixed with air, causing turbidity, check the hydraulic system piping for leaks and cut off the air from the source.

2. The hydraulic oil temperature rises abnormally

The reason why the temperature of the hydraulic oil and oil rises abnormally has the following three aspects: First, because the set value of the safety valve pressure is too low, most of the hydraulic oil flows back to the fuel tank through the safety valve, so that the work efficiency of the hydraulic system is too low, such as If the load is too large, most of the energy will be converted into the thermal energy of the hydraulic oil, resulting in high temperature: second, due to the poor cooling effect of the cooling system, the hydraulic oil temperature is too high; third, the hydraulic oil circulates too frequently in the oil circuit (often It is caused by insufficient oil), which causes heat dissipation and temperature rise.

The fault diagnosis should be from easy to difficult. First check the amount of oil in the hydraulic tank. If the oil in the tank is insufficient, it should be added to the standard level in time. When filling, please pay attention to the use of the same hydraulic oil, should also be filtered before use.

If the oil quantity is right, check whether the oil cooling system is blocked. If it is found that the oil cooling system hinders air circulation, it should be cleaned in time to ensure normal air circulation and facilitate heat dissipation. Sometimes the fan tape is too loose and slippery, which will cause the fan efficiency to decrease, and the cooling effect is not good. It should be checked and adjusted in time, and if necessary, replace the new tape.

If there is no problem with the oil quantity, the oil cooling system, and the fan tape, it can be determined that the main relief valve setting pressure is lower than the standard value. The pressure setting of the main relief valve should be adjusted again to the standard value.

3 hydraulic oil is dirty

Hydraulic oil is dirty and dirty, which may result in chemical changes in the oil due to long-term use; it may also be that too many impurities have undergone physical changes. As long as you find the cause of these two changes, you can take appropriate measures.

In the absence of the necessary testing equipment and equipment, it is judged whether the hydraulic oil is chemically changed or physically changed. A relatively simple and practical method is to use filter paper to detect.

Sampling the hydraulic oil, dripping the oil onto the filter paper, observing the oil faint formed by it, if the stratification and splitting phenomenon of the oil faint is obvious (the middle is dirty, the more the edge is clearer), indicating that the hydraulic oil has deteriorated, it must be Replace the new oil; if the oil mist spreads evenly, it means that the impurity content of the hydraulic oil is too much. Check the oil filter in time, replace the filter element, and replace the new hydraulic oil if necessary.