Piston pump FAQ
First, the reasons for the excessive noise of the plunger pump and the elimination method
(1) There is air in the oil pump. This fault usually occurs when a new pump is installed. When a new pump is started, oil should be added to the pump to lubricate the pump bearing, plunger and cylinder.
Treatment method: Open the oil pump filler port when the pump is running, so that the air in the pump is discharged from the fuel filler.
(2) The oil level of the fuel tank is too low, and the suction pipe is clogged, so that the pump suction resistance becomes large, causing the pump to be sucked or the inlet pipe section to leak air, and the pump sucks in air.
Treatment method: add enough oil according to the regulations; clean the filter, dredge the intake pipe; check and tighten the connecting screw of the inlet pipe section.
(3) Improper installation of the oil pump and motor, that is to say, the concentricity of the pump shaft and the motor shaft are inconsistent, so that the oil pump bearing is subjected to radial force to generate noise.
Treatment: Check the adjustment of the concentricity of the oil pump and motor installation.
(4) The viscosity of the hydraulic oil is too large, so that the pump's self-priming ability is reduced and the volumetric efficiency is lowered.
Treatment method: Select the hydraulic oil of appropriate viscosity. If the oil temperature is too low, turn on the heater.
Second, the cause of the instability of the pressure gauge pointer when the axial piston pump is working and its elimination
(1) The oil pan and the cylinder or the plunger and the cylinder are seriously worn, causing excessive leakage and external leakage.
Treatment method: check and repair the mating surface of the oil distribution plate and the cylinder; replace the plunger with a single cylinder; tighten the screws at each joint 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, causing the flow to be too small and the internal leakage to increase relatively. Therefore, the oil cannot be continuously supplied and the pressure is unstable.
Treatment method: Appropriately increase the variable angle of the variable mechanism and eliminate internal leakage.
(3) The oil inlet pipe is blocked, the oil absorption resistance becomes large, and the air leakage may cause the pressure gauge pointer to be unstable.
Treatment method: the oil inlet pipe is blocked, the flow resistance is large, the oil pipeline can be drained and the filter is cleaned, and the connecting screw of the oil pipe section is inspected and tightened to eliminate the air leakage.
Third, the reason for the insufficient flow of the axial piston pump and its elimination
The performance of the actuator is slow and the pressure does not go up.
(1) The oil level of the fuel tank is too low, the oil pipe and oil filter are blocked or the resistance is too large and air leakage.
Treatment method: Check the oil level of the fuel tank. Should be added when it is insufficient. Tubing and filter plugging should be dredged and cleaned. Check and tighten the screws at each joint to remove air leaks.
(2) The oil pump is not filled with oil before running, leaving air.
Treatment method: fill the oil return port from the oil pump to remove the air in the oil pump.
(3) The spring of the oil pump is broken, so that the plunger cannot be returned, and the cylinder and the oil distribution plate are poorly sealed.
Treatment method: The spring of the oil pump spring is insufficient or broken.
(4) Improper connection of the oil pump causes the pump bearing to be subjected to axial force, resulting in a gap between the cylinder block and the oil distribution plate, and high and low oil chamber collusion.
Treatment method: change the connection method and eliminate the axial force.
(5) If it is a variable axial piston pump, it may be that the variable angle is too small.
Treatment method: If the variable axial piston pump variable angle is too small, it should be adjusted appropriately.
(6) The hydraulic oil is not clean, and the cylinder block and the oil distribution plate or the cylinder block and the plunger are worn out, so that the oil leakage is excessive.
Treatment method: Check the wear of the cylinder block and the oil distribution plate and the plunger, repair it as necessary, and replace the plunger.
(7) The oil temperature is too low, the viscosity of the oil drops, causing the internal leakage of the pump to increase, and the pump is accompanied by symptoms of fever.
Treatment method: According to the temperature rise of the oil pump, select the hydraulic oil of suitable viscosity. Find out why the oil temperature is too high or too low and eliminate it in time.
Fourth, the axial piston pump oil leakage serious causes and troubleshooting
(1) The joints of the oil pump are poorly sealed, such as the seal ring is damaged.
Treatment method: Check the seal of each joint of the oil pump and replace the seal.
(2) Excessive wear between the oil distribution plate and the cylinder block or the plunger and the contracted work body, causing an increase in leakage outside the oil return pipe, and also the internal leakage between the oil pump and the low pressure oil chamber.
Treatment method: grinding the contact surface of the oil distribution plate and the cylinder; researching the cylinder block and the plunger pair.
According to experience, the failure of the pump is generally caused by the damage of the pump caused by the unclean system oil. The air entering the pump is also one of the reasons for the decrease of the service life of the pump. It is necessary to maintain the oil.
Axial piston pump working principle and performance characteristics