Seal damage.
Fourth, cavitation and cavitation
????External gear pump cavitation and cavitation, it will produce pressure pulsation and pitched howling. Performance gear pump damage caused by the cavitation and cavitation
floating inside of the side surface of the ring metal flaking pieces. The inner wall of the high pressure side of the pump housing area small pieces peeling off the metal surface, even a small
cave cavernous.
????External gear pump in the suction process, the absolute pressure of the suction even lower than the atmospheric pressure. If the pump from the oil is very high. Or the oil
filter and the suction piping resistance is too large, it is easy to make the suction chamber pressure below the pressure of the air separation, forming air pockets. When the hydraulic oil into
the high-pressure side of the pump with bubbles. High pressure around the adiabatic compression of the bubble, the rapid collapse
Collapse, local can reach very high temperatures and pressure impact. On the one hand the metal fatigue, on the other hand the hydraulic oil change and chemical properties,
chemical corrosive effect on metal.
????To avoid cavitation and cavitation, suction port must maintain sufficient pressure should not be less than 0.07 a 0.8 MPa (or keep the 0.03 MPa pressure drop). Therefore, the
position of the suction port of the suction pipe resistance, the viscosity of oil and the pump speed must be mutually coordinated:
????a tank level is too low, to minimize suction height; return pipe should be inserted below the liquid level.
????b using a larger inner diameter of the suction pipe, and try to do apricot head.
????c selection of larger capacity oil filter to reduce the pipe resistance. Regularly check the filter is clogged, replace the oil filter regularly.
????d Check the seal leaks, if the leak replaced immediately.
????e for full tank of gas may take short-term parking, the bubble fully precipitated.
Gear pump generates voice sound is why!
(1) "air pockets. Phenomena and" cavitation phenomenon
????"Cavitation" phenomenon and "cavitation" phenomenon is caused by one of the main internal gear pump voice sound too high. In the flow of the liquid, due to the phenomenon of
pressure at a point lower than the pressure of the air separation bubble generation, known as "cavitation" phenomena. Inevitably separated out after the formation of the air bubbles resulting in
a large number of the original continuous fluid becomes discontinuous The state, while these bubbles with oil from the gear pump low pressure chamber into the pressure chamber. rapid burst under
the impact of pressure oil, this process is instantaneous, it will cause local hydraulic shock in the bubble condenses place , pressure and temperature will rise sharply. cause strong vibrations
and noise. When "cavitation" phenomenon, often accompanied by whistling and cause fluctuations in hydraulic pressure. resulting device may not work properly. In this case, if the suction pipe
joints and shaft seals of the seal is not good, into the oil pipeline blockage inner tank level is too low bit stool, dry oil is too high, it will cause the hydraulic gear pump inlet at the
vacuum is too high, the air permeability people have a "suction air. phenomena, when these bubbles penetrate into the gear pump high pressure chamber will have a" cavitation phenomenon, causing
vibration and noise.
???Currently measures usually taken to be:
① use a larger diameter suction pipe according to the actual flow gear pumps, piping cloth to make the most reasonable in order to reduce local resistance line, make sure that
the flow rate of oil hydraulic gear pump suction pipe 2 a 3 m / s examination blight of hydraulic oil. Replacing the hydraulic oil is too high and regular washing lines;
② Check the suction pipe joints are reliable seal at the shaft extension seal wear, deformation or else replace the seals.;
③ large-capacity suction filter, installed in the lower part of the tank and do, in order to ensure the ability to filter through the oil, regular cleaning filter!;