HAWE piston pump maintenance correct method and failure analysis

I believe that users who know the HAWE piston pump are very clear, HAWE piston pump is currently the most common HAWE piston pump, placed in the cyLinder outside of the plunger through the sliding shoe to take the swash plate contact, when the drive shaft drives the cylinder to twist, the swash plate will be the plunger from the cylinder outside of the pull or push back to complete the process of suction and discharge of oil. 

The oil in the working cavity formed by the plunger and the cylinder hole is connected to the suction and discharge cavities of the pump through the oil distribution disk. 

The variable mechanism is used to change the inclination of the swash plate, by scheduling the inclination of the swash plate can change the displacement of the pump. 

So what is the correct maintenance method and fault analysis of HAWE piston pump? 

Today, the technician of Curran will tell you the correct maintenance method and failure analysis of HAWE piston pump as follows:

One, maintenance and failure of HAWE plunger pumps

1、Swash plate type HAWE piston pump generally adopts the form of cylinder body dynamic elasticity and end face flow distribution. Cylinder end face set without a friction vice by the bimetallic plate to take the steel oil distribution disk, and most of them are the use of plane flow distribution example, so the maintenance is more convenient. The oil distribution plate is one of the parts of the HAWE piston pump, when the pump is working, on the one hand, the High Pressure oil in the working chamber pushes the cylinder body to the oil distribution plate, on the other hand, the oil distribution plate and the cylinder body between the oil film pressure on the cylinder body to form a hydraulic counter-thrust so that the cylinder body back away from the oil distribution plate. The hydraulic compression force fn of the cylinder to the distributor plate is slightly larger than the hydraulic thrust ff of the distributor plate to the cylinder, i.e. fn/ff=1.05~1.1, 

so that the pump can work generally and connect with high volumetric efficiency.

Two, the output pressure is too low

1, in reality, because of the oil pollution, often make the oil distribution disk to take the cylinder body between the light wear. Especially when high pressure, even slight wear and tear may make the hydraulic counter-thrust ff deletion, thus destroying fn three, common malpractice disposal and so on. Harvey piston pump principle of operation variable piston pump maintenance and troubleshooting, a, working principle such as the pump shaft and motor shaft is not centered or top dead, torsion shaft bearings, coupling damage, elastic cushion damage and disAssembly bolts loosening will occur noise. For high-speed operation or transmission of large energy pumps, to check on a regular basis, record the amplitude of the components, frequency and noise. If the pump's dynamic frequency of pressure valve solid frequency is not the same, will cause resonance, can change the speed of the pump to eliminate resonance.

2, hydraulic pump excessive fever without two causes, one is mechanical friction heat. Because of the hook profile in dry friction or semi-dry friction form, the hook parts with each other friction heat. Second, the liquid friction heat. High-pressure oil leaks through all kinds of cracks to the low-pressure chamber, a large amount of hydraulic energy loss into heat. So the accurate selection of the gap between the hook parts, tank volume and cooler, may be able to put an end to the pump's excessive fever and high oil temperature phenomenon. In addition, the return oil filter cLogging to form the return oil back pressure is too high, will also cause the oil temperature is too high and the pump body overheating.

3, variable Harvey piston pump swash plate inclination angle of zero is called the outer position, the output flow of the pump at this time when zero. However, there will be times when the outer position deviates from the phenomenon of regulating the component structure of the outer point, there is still no flow output at the outer point. The cause is the position of the regulator deviation, loose or damaged, need to be adjusted from scratch, fastening or replacement. Pump angle to maintain the force is not enough, tilt angle trunnion wear will also occur that kind of phenomenon.

Third, the output pressure is too high

1, for the molding machine Hydraulic System using more cylinders, and the load of each station is not the same, so the use of variable pumps outside the system is very meaningful. Into the oil pipeline is too thin, into the oil filter flow capacity is too small or clogged, into the oil pipe into the air, oil exemption is too high, the oil level is too low suction is not enough and high pressure pipeline outside the liquid shock, etc., will occur noise. Therefore, it is necessary to accurately envision the oil tank, accurately select the oil filter, oil pipe and target valve. Pump output pressure is determined by the load, and the input torque is approximately inversely proportional. Output pressure is very no two types of disadvantages.

Fourth, the hydraulic pump output flow is not enough or do not output oil piston pump oil leakage is secondary to the following causes:

(1) from the shaft oil seal damage or shaft without defects, scratches; (2) internal leakage is too large, the formation of oil seals at the pressure deletion, and the oil seals will be destroyed or flushed out; (3) drain pipe exhaustive length, so that the seal leakage; (4) the pump's external oil pipe loosening, pipe joints damage, gasket aging or cracks; (5) variable scheduling mechanism bolts loosening, sealing breakage; (6) the cast iron pump casing without sand holes or poor welding.