The fault diagnosis method of the excavator hydraulic pump can be classified as an instrument diagnostic method and artificial diagnostic method. The instrument diagnosis method is a physical test method. The artificial diagnostic method uses visual, tactile, olfactory and hearing to initially diagnose the technical state and failure of the hydraulic pump. Here are some commonly used instrument test diagnostics:
1. Fast oil analysis
The basic principle of rapid oil quality analysis is to reflect the degree of aging of oil in a variation of integrated dielectric constant. The rapid oil split instrument not only provides a rapid and simple oil testing method but also to monitor the operation of the equipment by regular detection of oil, and can monitor the operation of the equipment. Changed the traditional regular replacement mode in the equipment management to achieve scientific basis. This method can quickly detect the physicochemical performance indicators of hydraulic oil according to the site, and determine whether the hydraulic pump fault is caused by the deterioration of hydraulic oil.
2, hydraulic system tester
Since the pressure of the excavator hydraulic pump remains unchanged within the adjustment range, the flow of the hydraulic pump can be determined by the hydraulic system tester. The hydraulic tester is usually composed of a pressure gauge, a flowmeter, a speedometer, and the like, depending on the picking method in the pipeline, can be divided into a through test method and a bypass test. Install the tester by bypass method on the oil pump high pressure pipe, the oil pump is operated at the rated speed, the hydraulic oil temperature is around 60 ° C, observed and record the flow reading at the time of the tester, and then loaded with load valve, The load pressure gradually rises to the rated pressure of the system, observes and records the traffic reading at this time. If the measured traffic fell by 25%, it indicated that the hydraulic pump has failed; if the flow reading is 50%, then the fault of the hydraulic system can be determined by the hydraulic pump, which must be disinforced to repair the excavator repair.
3, noise gauge
The normal noise limit value of the excavator hydraulic pump is 105dB. If this limit is exceeded, it may be that the motor is caused different from the pump drive shaft, or it may be that air enters the internal or hydraulic pump wear.
4, thermometer
Diagnostic faults by testing the difference in excavator hydraulic pump pump case temperature and hydraulic oil temperature.
If the pump case temperature is higher than the oil temperature 5 ° C, it may be that the mechanical efficiency of the hydraulic pump is too low, the mechanical wear is large; if the temperature difference is above 10 ° C, there is no problem, the oil quality is not problematic, and may be a shaft Large gap, the hydraulic pump is serious, the volume efficiency is lowered, and the leak is increased.
5, pressure gauge
Since the excavator hydraulic pump is used constant voltage control, the pressure sizes of the excavator hydraulic pump system cannot indicate the working condition of the hydraulic pump, but can judge the oil pump failure by oscillating by the pressure gauge. If the bias of the pressure gauge is more than 20KPa or swing is very slow, it is an abnormal phenomenon.
