Common faults and troubleshooting of the vacuum pu

Common faults and troubleshooting of the vacuum pumping device system of offset printing machine

the vacuum pumping device of offset printing machine is composed of high-speed direct connected vacuum pump and three-phase motor. In addition, there are rubber pipes, solenoid valves, air valves, pressure gauges, electronic universal testing machine, which is powered by electromechanical and other accessories

the vacuum pump of offset printing machine is composed of stator, rotor and rotary blade. The rotor is eccentrically installed in the cylinder, and two rotating pieces are installed in the rotor slot, which are close to the cylinder wall due to the elastic force of the spring. Therefore, the inlet and outlet of the stator are separated into two parts by the rotor and the rotor. When the rotor rotates in the cylinder, the volume of the air inlet will be gradually expanded and the gas will be sucked in periodically. At the same time, the volume of the exhaust port will be gradually reduced, and the inhaled gas will be compressed and discharged from the exhaust valve, so as to achieve the purpose of air extraction

there are two common faults in the vacuum pumping device of offset printing machine: first, the vacuum degree of the vacuum pump of the printing machine decreases; Second, the vacuum pump leaks oil

1. The vacuum pump of the plate printer is insufficient, and the vacuum degree is reduced, which is often easy to cause the drug film surface of the film or the positive image output by the laser printer. The absorption between the sulfuric acid paper and the PS plate is not tight and solid, and the quality of the PS plate can not be guaranteed, and the words, lines, images and dots can not meet the requirements when they are dried on the printing plate

to test the quality of the offset vacuum printer mainly depends on two factors: first, whether the drug film surface of the photosensitive film is closely matched with the photosensitive film of the PS plate, without any gap, which requires the vacuum pump to operate normally, and the pumping rate is about 2 ~ 4 L/sec; Second, when the PS version is exposed, whether the blue violet illumination on the whole glass surface around, at the edge and in the middle is uniform is the standard to measure the performance of the offset printing machine

the vacuum pump of the plate printer is insufficient, and the reasons for the decrease of vacuum degree are:

(1) the rubber pipe for gas transmission leaks due to rat bite, aging and rupture

(2) aging, cracking and air leakage of the elastic rubber sealing cloth pad of the printing frame of the printing machine

(3) the rubber pipe for gas transmission is too long, and the gas circuit consumption affects the vacuum flow

(4) insufficient oil in the vacuum pump

(5) there are too many impurities in the direct air oil in the vacuum pump

(6) the vacuum pump seal is worn and leaks air and oil

(7) the oil delivery hole in the pump is blocked or the oil supply is insufficient

(8) exhaust valve plate is worn and damaged

(9) broken leaf spring, etc

accordingly, the methods to eliminate these faults are:

(1) replace the damaged rubber pipe

(2) stick the air leakage place of the elastic rubber sealing cloth of the drying frame with adhesive tape and tape, pay attention to maintenance every week, wipe and moisten the rubber frame with glycerin once to prevent aging, maintain the elasticity of the rubber frame, and reduce the air leakage problem of the frame

(3) the length of rubber pipeline for gas transmission shall not exceed 2 meters to avoid gas consumption on the pipeline

(4) add new vacuum oil to the center line of the oil standard

(5) Replace Fresh vacuum oil

(6) replace with new seals, or readjust the assembly

(7) clean the oil inlet hole

(8) replace the exhaust valve disc with a new one

(9) replace with a new leaf spring

in addition, the air path should be kept clean, and the inner wall of the pipeline should be free of dust or any foreign matter. Often use a thin iron wire to poke it clean, so as to keep the rubber hose pipeline smooth

at the same time, pay attention to the positive and negative rotation of the three-phase motor of the vacuum pump. If the phase circuit of the motor is installed incorrectly, it will reverse, and the vacuum pump gas pipe may blow. At this time, be sure to change the phase at the motor wiring to make the vacuum pump inhale

2. Oil leakage from the vacuum pump of offset printing machine is a common problem. The main reason is that the pump shaft and oil seal device accessories of the vacuum pump have been used for many years, resulting in the wear of the sealing ring. When the oil leakage was serious, the vacuum oil just injected leaked out a large pool of oil after a while, which not only polluted the environment, but also affected the normal operation of the vacuum pump. During maintenance, the spring coil should be reduced or the oil seal device should be replaced. During disassembly, assembly and repair, the sealing gasket shall be coated with sealant to prevent oil and air leakage. In addition, the sealing gasket at the connection of the vacuum pump oil tank is damaged, which will also cause oil leakage. The solution is to replace the sealing gasket. When filling the vacuum pump oil, do not add too much oil, and align it with the oil level line. If the vacuum oil is added too much, the vacuum pump will splash and throw oil stains during operation

keep the function of the air extraction system intact in daily work. As the manufacturer of such instruments, Jinan Shijin vacuum pump is also committed to breaking through many difficulties. The oil level should always be aligned with the oil level line, and the vacuum oil must be replaced after working for a year

generally, the vacuum pump and motor are installed in the corner of the back of the plate printer. The surrounding environment of the vacuum pump and motor should be kept clean to reduce dust and debris sticking to the pump body and motor. At the same time, it should be able to ventilate and dissipate heat. The vacuum pump must be disassembled and repaired regularly every year

the rubber hose from the suction hole of the printing frame under the printing machine to the suction nozzle of the vacuum pump is easy to be shrunk and damaged after a long working time, so it should be replaced in time to prevent air leakage

the surface and back of the glass plate table must be kept clean. When wiping, first clean it with a soft brush, and then wipe it with absorbent cotton or gauze dipped in absolute alcohol

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