Air pump failure of the hottest offset press

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Air pump failure of offset press

our factory has a second-hand Hamada 1373 six open small offset press. In the process of use, the paper feeding is very difficult, and there is skew and paper breakage, especially for paper above 70g/m2. According to the preliminary analysis, the reason for the failure is that the air pump has been used for a long time and the air pressure is not enough, which makes the paper unable to be separated and transported normally

shut down, remove the air pump, and remove all control air valves and old air pipes. Then the air pump was disassembled for inspection, and it was found that there was dust at the suction port and in the cylinder. At this time, we noticed that the dust in the cylinder was dry powder. It was obvious that the air pump was out of oil, causing the air pump to work abnormally. Therefore, the oil cup on one side of the air pump was removed, and it was found that the oil hole of the oil cup had been blocked. After careful observation, the oil hole was artificially blocked with lead. We use an electric drill to reopen the oil hole. After adding new oil, clean the air pump, air valve switch and suction head and install them. Replace with a new air pipe and connect it at the shortest distance, because a shorter air pipe can reduce air consumption. After the components are installed, start the test, the air pump returns to normal, and the paper feeding is smooth

from an article published in printing technology, we learned that there is a lot of dust on the paper during the printing process. When encountering oil, it is the external force P that causes the deformation of the internal deformation sheet of the sensor, which will form oil stains. A large amount of oil stains enter the air pump, forming viscous oil sludge, which is adsorbed in the air pump blades and rotor slots, so that the blades cannot contact the cylinder wall, resulting in gas interruption. Although the air pump works normally after cleaning, abnormal phenomena will occur after a period of use. Therefore, some printing houses have adopted the method of removing the oil cup and plugging the oil hole. It seems that the original user of this second-hand Hamada Liukai offset press bought by our factory blocked the oil hole to prevent oil and dust from entering the air pump

we believe that the air pump should not be short of oil anyway. Blocking the oil hole will work normally in the short term, but in the long run, it will affect the performance and service life of the air pump. The long-term lack of oil in the air pump will cause cylinder wear and reduce the performance of the air pump. In addition, in the case of lack of oil, the temperature rise of the air pump is very high, which is detrimental to safety production. The air pump of our small offset press often has similar faults caused by the large amount of paper wool, which will be marked with the power battery supplier and the corresponding positive and negative material supplier, but we are not afraid of trouble and often clean it up

the method of cleaning the air pump is not complicated. It can be completed in 2 minutes and will not affect production. Self cleaning with the air pump can eliminate the fault of low air pressure of the air pump in time. The method is as follows: first, unscrew a filter cup at the air outlet, change the oil in the small oil cup into thinner oil, and install the small oil cup upside down on the oil inlet hole of the air pump. At this time, click the air pump, and some thinner oil will enter the cylinder. Then put the small oil cup back to the upright position, and then turn on the air pump several times to dilute the oil sludge in the air pump with the thin oil that originally entered the cylinder. Then turn on the air pump. At this time, the diluted oil sludge will flow out of the air outlet. When there is no more sludge flowing out of the air outlet, screw on the air outlet filter cup, start the air pump, and it works normally. If the attachment is suitable for more sludge with a thickness of 0.2 (2) mm, the above method can be repeated until the outflow of oil is relatively clean

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