Daily inspection of hydraulic system

Daily inspection, that is, with day vision, hearing and hand touch and other simple methods for visual inspection, inspection should check the local, but also pay attention to the overall equipment. If abnormal conditions are found in the inspection, emergency treatment shall be taken to prevent the continued work of the hydraulic equipment; the other shall be carefully observed and recorded, and shall be resolved at regular maintenance. Before and after the start of the pump and check before parking, the most likely to find the problem: pump start operation must be very careful, in cold areas such as low-temperature starting and long-term parking after starting more careful.

1. check before starting of pump

1) to check the oil level gauge oil quantity. Often from the gas port to check the oil level gauge indicates whether there is error. Keep the liquid level near the limit mark.

2) check the oil temperature of the tank from the oil temperature meter. Such as the use of N15O turbine oil or a considerable amount of oil, its oil temperature below 10 degrees, attention should be paid to the start of the hydraulic pump, starting after no-load operation more than 20min. Operating at O degrees Celsius is dangerous.

3) understand the room temperature from a thermometer. That is, the fuel tank temperature is higher, the pipeline temperature is still close to room temperature. Therefore, when the temperature is low in winter, attention should be paid to pump starting.

4) when parking, the indicator of the pressure gauge is at OMPa, to observe whether it is abnormal or not.

5) relief valve set pressure at OMPa, the starting pump load is very small, in a state of unloading; small equipment, in addition to temperature, but also pay attention to relief valve set pressure, and then start.

2. starting and starting inspection of pump

(1) pump starting should be inching, for winter hydraulic oil viscosity high (300mm2/s above) and relief valve in the setting pressure status of the start, be particularly careful.

1) from the point to the continuous operation should be carried out according to the following ways: move start running 3s- parking (repeat 3~4 times); move the start (5S operation) - parking (3~4 times); move the starting (running 10s) a parking (repeat 2~3 times); continuous running without load (each part pre heat) -10~20min; continuous operation.

2) in the point of movement, from the sound changes in the pump and pressure gauge slightly rise to determine the flow of the pump, a pump in the state without flow operation, more than 1min, there will be the risk of death.

3) operate the overflow valve, make the pressure rise and fall times, prove the action is reliable, the pressure can be adjusted, and then adjust to the required pressure.

4) when operating the above 3 items, check that the noise of the pump varies with the pressure, and that there is an abnormal sound. If there is a continuous sound of "Grignard", the air is sucked at the side of the suction pipe or at the transmission shaft. If high pressure, especially large noise, should check the suction screen, stop valve and other resistance.

5) check the oil filter screen, whether or not there is a blockage after the pump starts, which can be judged by the noise of the pump.

6) according to the online oil filter indicator to understand the resistance or blockage, the effect in the oil pump start, and clarify the action indicator.

7) according to the operation of the relief valve, the on-off of the unloading circuit and the operation of the reversing valve, make sure the pressure rise and fall. According to the action of the pressure gauge and the expansion of the hydraulic cylinder, the response performance is clarified. Make hydraulic cylinder, hydraulic motor action more than 2 times, to prove their action and the action of the valve (vibration, impact size) are good.

The inspection sequence before and after starting is shown in table 12-1. The inspection of serial number 1~5 is before the pump starts, and the check of 1~12 is after the starting of the pump.

(2) the sports and parking for inspection are simple. Yao inspection, a clear understanding of wear, leakage, internal leakage, the change of oil temperature rise, pump and control valve. The main points of the examination are as follows:

1) color bubbles, visual inspection of oil in the tank (in white and black) etc.. If there are more bubbles or white oil on the surface, to study its reason.

2) determine the oil temperature with a thermometer and touch the side of the tank to determine whether the oil temperature is constant (usually below 60 degrees Celsius).

3) turn on the pressure gauge switch and check the needle swing at high pressure. A condition of great vibration is an anomaly. The normal condition of the needle swing should be within 0.3Mpa.

4) according to the hearing to judge the pump situation, the noise is big, the needle is big, the oil temperature is too high, possibly is the pump produces the attrition.

5) according to 4) point, contrast pump shell temperature and tank temperature, such as before and after the two temperature difference is higher than 5 degrees, you can think that the efficiency of the pump is very low, this point can be touched to determine.

6) check oil level indication, Zhao, a side side cover leaks.

7) check the pump shaft, connections and other places of oil spills. Oil spills are most likely to occur at high temperatures and pressures.

8) check the stopping state and working speed of the hydraulic cylinder when it stops. In addition, check whether there is oil leakage at the piston rod at high temperature and high pressure.

9) understanding hydraulic motor movement, noise, leakage and so on.

10) check the voice of the solenoid valve, reversing any abnormalities, and touch the temperature of the solenoid valve shell, 300 degrees higher than the room temperature, it is normal to bite.

11) according to the hearing and check overflow valve pressure gauge sound size and vibration.

12) observe the pipeline (flange, joints, clamping sleeve) and valve oil leakage, or hand inspection; keep the bottom of the pipeline clean, so that a simple observation can be found oil spills. Oil spills are most likely to be found at high temperatures and pressures.

13) check the vibration of pipes, valves and hydraulic cylinders, and check if the mounting bolts are loose.

Table 2-2 shows the check order for running and stopping.