Hydraulic pump is the power element of the hydraulic system, but also the heart of the hydraulic system, once the pump failure system can not work normally, at this time, hydraulic pump maintenance is important.Most of our hydraulic system USES plunger pump, so it is necessary to master the fault of plunger pump.Plunger pump failure in the form of the following:


1. the plunger pump work noise too much reason and elimination method

(1) there is air in the pump memory.This fault is generally installed when a new pump, in the opening of a new pump, should first add oil to the pump, the bearing of the pump, plunger and cylinder block lubrication.

Treatment: open the oil pump refueling port when the pump is running, so that the air inside the pump is discharged from the refueling port.

(2) the oil surface of the oil tank is too low, and the suction pipe blockage increases the oil suction resistance of the pump, resulting in the suction of the pump or air leakage in the inlet pipe section, and the pump inhales air.

Treatment: add enough oil;Clean the filter, dredge the air inlet pipe;Check and tighten connection screws for oil inlet section.

(3) improper installation of oil pump and motor, that is to say, the concentricity of pump shaft and motor shaft is inconsistent, which makes the oil pump bearing subject to radial force produce noise.

Processing method: check and adjust the concentricity of oil pump and motor installation.

(4) the viscosity of hydraulic oil is too large, which reduces the self-priming capacity of the pump and the volume efficiency.Treatment: choose the appropriate viscosity of the hydraulic oil, if the oil temperature is too low should be heater.

 

2.the axial plunger pump work pressure gauge pointer is not stable reason and eliminate

(1) severe wear between oil distribution pan and cylinder block or plunger and cylinder block, resulting in excessive internal and external leakage.

Treatment methods: check and repair the matching surface of oil distribution tray and cylinder body;Single cylinder matching, replacement plunger;Tighten the screws at all joints to eliminate leakage.

(2) if it is an axial piston variable pump, it may be because the variable Angle of the variable mechanism is too small, resulting in too small flow rate and relatively large internal leakage.Therefore, the pressure is unstable due to the failure of continuous oil supply.

Treatment method: appropriately increase the variable Angle of the variable mechanism and eliminate internal leakage.

(3) blockage of the oil inlet pipe, large oil absorption resistance and air leakage may cause the indicator of the pressure gauge to be unstable.

Treatment method: the oil inlet pipe is blocked, the liquid flow resistance is large, can dredge the oil pipe to wash the inlet filter, check and tighten the connection screw of the oil inlet pipe section, the inclined shaft plunger motor to eliminate air leakage.

3.axial plunger pump insufficient flow reasons and elimination methods

Performance for the slow action of the executive component, pressure is not up.

(1) the oil surface of the oil tank is too low, the oil pipe and filter are blocked, or the resistance is too large, and air leakage, etc.

Treatment: check oil level of oil tank.Should add when insufficient.Pipe, filter plug should be dredged and cleaned.Check and tighten screws at joints to eliminate air leakage.

(2) the oil pump is not filled with oil before operation, leaving air.

Treatment: fill the oil from the return port of the oil pump to remove the air in the pump.

(3) the spring in the center of the oil pump breaks, so that the plunger cannot return, and the cylinder block and oil distribution plate are not sealed well.

Treatment: oil pump center spring spring insufficient spring force or broken.

(4) improper connection of the oil pump causes axial force on the pump bearing, resulting in a gap between the cylinder block and the oil distribution plate, and high and low oil cavities.

Solution: change connection method to eliminate axial force.

(5) if the variable axial piston pump, it may be the variable Angle is too small.

Treatment: if the variable axial piston pump variable Angle is too small, should be appropriately larger.

(6) hydraulic oil is not clean, cylinder block and oil distribution plate or cylinder block and plunger wear, causing excessive oil leakage.

Treatment: check the wear condition of cylinder block, oil distribution plate and plunger, repair and replace plunger according to the situation.

(7) if the oil temperature is too low, the oil viscosity decreases, resulting in increased internal leakage of the pump, which is accompanied by the symptom of heat.

Treatment: according to the temperature rise of the oil pump, choose the right viscosity of hydraulic oil.Find out the cause of too high or too low oil temperature, and eliminate it in time.

 

4.Causes and elimination methods of serious oil leakage in axial piston pump

(1) the joints of the oil pump are not well sealed, such as the sealing ring is damaged.

Treatment: check the sealing of each joint of oil pump and replace the sealing ring.

(2) excessive wear between the oil distribution tray and the cylinder block or between the plunger and the contract work body will increase the external leakage of the return pipe and increase the internal leakage between the oil pump and the low-pressure oil cavity.

Treatment method: grind the contact surface of oil disc and cylinder body;Research and match cylinder block and plunger pair.

According to the 15-year experience of Hans of A&S Hydraulic Co.,Ltd w maintenance department, the pump failures are usually caused by the damage of the pump caused by the unclean oil of the system, which makes the Hydraulic pump maintenance become frequent.In addition, the pump into the air is also caused by the pump service life of one of the reasons.Therefore, in order to ensure the service life and efficiency of hydraulic pump, we have to do a good job in hydraulic fluid.