Hydraulic oil is the "blood" of hydraulic machinery. Most hydraulic system faults can be detected, the state of hydraulic oil can be observed, the causes of faults can be found, and the troubleshooting can be carried out.
Hydraulic oil is turbid with impurities
There are three types of impurities in hydraulic oil: solid impurities (debris, solid particles, solid impurities formed by hydraulic oil deterioration), liquid impurities (mainly water, followed by viscous impurities formed by hydraulic oil deterioration) and gas impurities (mainly air).
If white turbidity occurs in hydraulic oil, solid or liquid viscous impurities can be eliminated, which may be caused by water or air. Sampling and testing of hydraulic oil. If the oil sample drops on the hot plate, if there are bubbles (water turns into steam to form bubbles at high temperature), it can be determined that there is water in the hydraulic fluid or air in the hydraulic fluid.
If the water in the hydraulic oil causes turbidity, the hydraulic oil will be stationary for a period of time, so that the water sinks to the bottom of the hydraulic tank, and then the water can be taken out. However, if the water content is too high to emulsify the hydraulic oil, it is necessary to replace the new hydraulic oil.
If air in hydraulic oil is determined to cause turbidity, check whether the pipeline of hydraulic system leaks and cut off the air mixing source.
2. Abnormal temperature rise of hydraulic oil
The basic reasons for abnormal temperature rise of hydraulic oil are as follows: because the pressure setting of a safety valve is too low, most of the hydraulic oil flows back to the tank through the relief valve, and the working efficiency of the hydraulic system is too low. If the load is too large, most of the energy will be converted into the heat of the hydraulic oil, resulting in high temperature. The second reason is the cooling system. Poor effect leads to high temperature of hydraulic oil; third, too frequent oil circulation in hydraulic oil circulation loop (often causing insufficient oil), resulting in heating difficulties and temperature rise.
Fault diagnosis should be easy to difficult. First, check the oil quantity in the hydraulic tank. If the oil quantity in the tank is insufficient, it should be timely replenished to the standard level. When using, attention should be paid to the use of the same brand of hydraulic oil, which should be filtered before using.
If the amount of oil is appropriate, check whether the oil cooling system is blocked. If oil cooling system hinders air circulation, it should be cleaned in time to ensure normal air circulation and convenient heat dissipation. Sometimes fan tape is too loose and slippery, it will also reduce fan efficiency, cooling effect is not good, so timely check and adjust, if necessary, replace new tape.
If there is no problem with oil volume, oil cooling system and fan tape, it can be determined that the pressure set by the main safety valve is below the standard value. The pressure setting of the main safety valve should be readjusted to the standard value.
3. Hydraulic oil is too dirty
Hydraulic oil is dirty, too dirty, probably because of chemical changes in the long-term use of oil, or because too many impurities have changed physically. As long as we find out the reasons for these two changes, we can take corresponding measures.
In the absence of necessary testing equipment, to determine whether the hydraulic oil is chemical or physical changes, a simple and practical method is to use filter paper detection.
Take the sample of hydraulic oil and drop it on the filter paper to observe the oil halo. If the oil ring is separated by layers (dirty in the middle and clear in the edge), it indicates that the hydraulic oil is deteriorated and new oil must be replaced. If the oil halo is evenly distributed, the impurity content in hydraulic oil is too high. Check the filter in time, change the filter element, and replace the new hydraulic oil if necessary.