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How to repair the piston pump?-Eddie technique

Pubdate:2021-01-05 16:45:33 View:

How to repair the hydraulic pump?  The first thing we need to make clear is what problems it has, then we can solve the problems fastly. There are some problems we usually meet in the repair of piston pump in our work.

1. The hydraulic pump outlet flow is insufficient or does not deliver oil

(1) Inadequate input. The reason is that the resistance on the suction line is too high or the oil supplement is insufficient. If the pump speed is too high, the oil level in the oil tank is too low, the oil inlet pipe is leaking and the oil filter is clogged.

(2) Leakage is too high. If the oil distribution plate is scratched by metal fragments, iron filings, etc., the oil will leak from the final surface; the sealing surface of the one-way valve in the variable mechanism is not properly fitted, and the bearing surface of the pump body and the oil distribution plate are washed or scratched, lead to the large gap and the seal is not goodThe damaged part of the pump can be evaluated by examining foreign substances mixed with the hydraulic oil in the pump housing.

(3) The tilt angle of the swash plate is too small and the displacement of the pump is small. This requires adjusting the variable piston to increase the tilt angle of the swash plate.

2. Oil removal is not zero in the neutral position

When the slope angle of the swash plate of the variable axial piston pump is zero, it is called the neutral position and the output flow of the pump should be zero at this moment. However, sometimes the midpoint deviates from the midpoint of the control mechanism and there is still an exit flow at the midpoint. This is because the controller is loose, deflected, or damaged and needs to be tighted, reset, or replaced. This phenomenon can also be caused by inadequate maintenance of the pump angle and wear of a tilt journal.

3. Jog the electrical machinery, test whether the rotation of the electrical machinery is correct.

4. Check the pipeline of hydraulic pump and joints for looseness. Rotate the hydraulic pump by hand to see whetherthe hydraulic pump is flexible.

5. Unscrew the pilot plug of the hydraulic pump body, fill the pilot water.

6. The air come into the oil:

In addition to overheating caused by air entering the oil, a considerable amount of air will be dissolved in the oil under pressure. If about 10% of the compressed volume is dissolved air, foam will form when the pressure drops. When the working hydraulic cylinder is depressurizing and returning to the oil, the oil with foam will form a "sponge" property. In addition, a lot of foam in the oil will increase the total volume and cause oil spills in the fuel tank or oil reservoir.

Sometime we can do the small things to faciliate the mprovement of the pump.

(1) Clean or replace the filter element and oil filter screen;

(2) Clean the oil reservoir and the vent, use cloth when scrubbing, not cotton yarn;

(3) Disassemble all the main assembly parts, and clean the parts with diesel (do not use gasoline, because the surface of the precision parts washed by gasoline will dry). When it cannot be disassembled, it can be cleaned with light lubricating oil or a blend of engine oil and kerosene. It is forbidden to use chemical cleaning agents to clean, because they may damage the oil seal and packing, and the residue they adhere to the surface of the part may corrode the metal and contaminate the working oil;

(4) Reassemble the washed parts, and tighten each bolt and screw according to the specified torque during assembly;

(5) Drain the oil added for the first time. This oil circulates in the newly installed system to flush out possible dirt in the system, so it should be drained. After draining the oil, clean the filter and screen again;

(6)  Let the hydraulic system run dry and circulate it 3 or 4 times to release the air.

Eddie hydraulic can help you to repair the vane pump, piston pump, motor professionally, welcome to consult us by whatsapp +86 18926478344, and email:

Eddie HydraulicHow to repair the piston pump?-Eddie technique(图1)

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