Analysis of common failures of air-cooled compressors (1)

There are three common failures in the main components of air-cooled compressors: 1. Failure of the gas circuit system 2. Failure of the oil circuit system 3. Failure of the transmission mechanism. Do some system analysis below

1. Air system failure:   

The air circuit system is composed of air filter, air valve, cylinder, piston, piston ring, intercooler, regulating valve, control copper pipe, pressure fork, ejector rod, gland, ejector spring and other parts.  

1. The first level air pressure is low. Possible reasons: A. Whether the air filter is clogged, remove the air filter for observation. (Here is a special reminder to remove the air filter element after get off work every day, and use air to remove dust to prevent dust from entering the cylinder and causing early wear) B. Check the first-level air intake Check whether there are lamellas, spring fractures or carbon formation. If not, use diesel or kerosene for leakage test. C. Check if the intercooler is clogged, open the bottom of the intercooler to see if the exhaust airflow is large, or block it with your fingers, and feel the pressure is large. The intercooler is slightly blocked and can be soaked in kerosene or pine perfume for 24 hours and then reinstalled. Serious blockage can only be replaced again. (The intercooler must be discharged under pressure every day, so as to ensure the internal cleanliness of the intercooler and prevent carbon formation due to the failure to remove the oil)   

2. The first level air pressure is normal and the second level air pressure is low. Possible cause: A, secondary air intake and exhaust valve leaks, remove it for inspection. B. The pressure regulating screw is loose, and the pressure regulating valve is adjusted. First loosen the big tightening nut, tighten the big nut until the secondary pressure is about 0.6mpa, and then adjust the small nut to about 0.7mpa to make the pressure regulating valve jump .  

3. Can not jump when the pressure is adjusted. Possible reasons: A. Clean the pressure regulating valve and reinstall it. According to the above adjustment method to see if it jumps, close the small valve door. If it does not jump, disassemble the control copper pipe on the first-stage cylinder to see if there is airflow. , Prove that the pressure fork, ejector rod or gland spring is worn or broken, check the wear of each part, replace it, and reinstall it for inspection. The control copper pipe on the secondary cylinder is checked in the same way as the primary cylinder. 

  4. The breathing apparatus is relatively big. Under normal circumstances, piston rings and cylinders are worn, or there is a slight cylinder pulling phenomenon, remove the air valve, check the cylinder wear and check whether there is cylinder pulling phenomenon.  

2. Oil circuit system failure:   

The oil circuit system consists of crankcase, oil pan, coarse filter box, oil suction pipe, oil pump, fine filter, oil pump bearing seat and crankshaft connecting rod components.  

1. Low oil pressure. A. Check the oil level and coarse filter box. Tighten the oil pressure screw under normal conditions. There is a slotted M14 screw on the oil pump bearing seat to see if the pressure rises. B. Disassemble the oil pipe to the oil pressure gauge and see how the oil pipe pressure is. If there is no pressure, check the fine filter, oil pump and the adjusting spring on the oil pump bearing seat. C. All the above are normal. Finally, check the clearance between the connecting rod bush and the crankshaft, the clearance between the crankshaft head and the oil pump bearing seat, and the oil quality. 

  2. There is no oil pressure. A. In this case, the motor is generally reversed, so the electric air compressor must pay special attention to the direction of motor rotation. From the direction of the motor, the motor rotates clockwise. B. There is a crack in the pipeline or the crankcase oil passage.  

3. High oil temperature or high oil consumption. General failure A. The cooling effect of the unit is poor, and the lubricating oil is too dirty or deteriorated and needs to be replaced. Check the fan belt and intercooler drain. B. Excessive wear of the cylinder or bearing bush. This situation can generally be judged from the breathing of the respirator. C. Respirator obstruction: The main reason is that the filter effect of the respirator filter is poor for a long time. Remove it and clean it with gasoline. (This type of respirator has been changed, and this usually does not happen) If this is the case in the market, you can replace 9/7 or more respirators with the same installation holes.  

3. Transmission mechanism failure:  

  The main transmission mechanism is composed of half coupling, pin, elastic sleeve, flywheel, crankshaft, connecting rod, piston, piston pin, piston ring and air valve. The secondary transmission mechanism is composed of driving gear, oil pump gear, driving pulley and fan wheel, fan belt and fan. Transmission mechanism failure is generally abnormal noise or automatic shutdown.  

1. Stop and start the crank. If the crank is relatively easy and uniform, it is usually the air cutting or the point gap on the cylinder that produces a sound. If the crank does not move, it is generally the cylinder or the drawing. In this case, the air flow in the ventilator before stopping It's very big, and it has a burnt smell. 

  2. For abnormal noise, first determine the source of the noise. A. If it is not possible to determine, run at no load and listen to the source of the sound. At this time, the noise is generally too large or too small between the main bearing cap and the bearing, or the main bearing is damaged (main bearing damage generally increases with the load. (Will increase) B. Normal empty load, there will be noise when loading, generally due to excessive wear of the connecting rod bearing and the resonance sound of the air cutting blade and spring, just replace the bearing bush or the blade and spring.