During the use of the shrinking machine, due to various factors, there are often some faults. In order to ensure the normal operation of the compressor, the relevant components must be repaired. However, the current compressor repair team is more complex, some are compressor manufacturers, agent dealers full-time after-sales service personnel, some are hardware store sales staff part-time, there are compressor users enterprise equipment maintenance personnel, operators, there are also market-specific Electrical maintenance service company maintenance personnel ... Therefore, professional literacy is uneven, there have been many problems.
Tear paper dividing line
1, can not correctly judge the analysis of faults, blindly dismantle the big unloading
Some maintenance personnel are unclear about the structure and principle of the compressor, do not carefully analyze the cause of the fault, can not accurately determine the fault location, blindly dismantle the mechanical unloading with the idea of "probably, almost", the result is not only the original fault is not ruled out, and Due to poor maintenance skills and craftsmanship, new problems have arisen. Therefore, when the machine fails, it must be tested by the testing equipment. If there is no testing equipment, it can be determined by the traditional fault judgment methods and means such as “question, see, check, test”, combined with the structure and working principle of the compressor. The most likely area of failure.
When judging the compressor failure, the "exclusion method" and the "comparative method" are generally used, and the order is from simple to complex, and the internal and the first assembly are re-assembled in the order of the first and the first assembly, and it is forbidden to "disregard the indiscriminate, blindly dismantling and unloading." ".
The reason is that such people still lack the systematic learning and training of compressors and related electrical and mechanical knowledge systems, lack of awareness of the compressor operation process and relevance, and blindly take one step.
2, "replacement repair" phenomenon exists to varying degrees
It is relatively difficult to judge and eliminate the compressor failure. Some maintenance personnel have always adopted the method of replacement test. Regardless of the large and small parts, as long as it is considered that the parts that may cause the failure, the test is replaced one by one, the result is not eliminated, and Replace the parts that should not be replaced at will, increasing the user's expenses.
There are also some faulty parts that can be repaired to restore their technical performance. They can be repaired without complicated repair process. However, the maintenance personnel require the user to replace the new parts and use the “replacement repair” method to cause serious waste.
The above-mentioned blind replacement test and the practice of replacing the repairable parts have existed in some repair units to varying degrees. During maintenance, the cause and location of the fault should be carefully analyzed according to the fault phenomenon. Repair the repaired parts to restore the performance and eliminate the blind replacement of parts.
In addition, many of the replaced spare parts can be repaired after being repaired by new processes such as brush plating and spraying. In actual work, maintenance workers are generally unwilling to perform maintenance. There are many reasons why maintenance personnel are reluctant to repair damaged equipment: First, the lack of necessary maintenance tools. Equipped with suitable dedicated disassembly tools and measuring instruments; electricians must be equipped with accurate digital multimeters, regulated power supplies, testers and other tools. Without these tools, the repairman can only look down on it.
Second, there is a lack of corresponding incentives. The repairman worked hard to repair a higher-priced spare part, but did not receive any encouragement or reward. Over time, the maintenance worker gradually lost the enthusiasm for repairing and recycling the waste. Therefore, incentive measures should be taken, depending on the price of the spare parts, the value of reuse, reliability, etc., the repair of spare parts should be rewarded as a percentage of the original spare parts price, and linked to monthly and annual performance to encourage maintenance personnel. The enthusiasm for the restoration and reuse of waste parts.
3, do not check the quality of new parts, the breakdown after assembly is more common
Before replacing the parts, some maintenance personnel do not perform technical inspections on the new parts and directly install them on the compressor. This is unscientific. At present, the quality of spare parts sold on the market is mixed, some fake and shoddy accessories are mixed with fish; some accessories have changed performance due to excessive inventory time. If they are not tested, they often cause failure after assembly.
Be sure to carry out the necessary inspections and tests before replacing the new parts. The tests include appearance and performance tests to ensure that the new parts are not faulty and prevent unnecessary troubles.
4, the substitution or misuse of accessories is more common, accommodating users, inferior products
When repairing the compressor, the substitution or misuse of the accessories is still common. Some accessories are feasible for emergency use, but long-term use is harmful and affects the safety and technical performance of the machine.
Some maintenance personnel have little understanding of the mechanical structure and principle, and many spare parts models do not match, but they believe that as long as they can be installed, it is not considered whether the technical performance of the equipment can be exerted. Therefore, when repairing the compressor, the original type of accessories should be used as much as possible, and other types of accessories should not be used instead, and it should not be misused.
In order to meet the low price requirements of customers and win orders, some people often use inferior goods. Counterfeit and inferior goods are really cheap, but they are not worth the loss for the users. For example, air compressor oil, long-term use of inferior air compressor oil will cause early wear on the surface layer and parts of the rotor, and will increase fuel consumption, reducing the efficiency and performance of the air compressor. Inferior air compressor oil is not in conformity with the standard, and it is easy to cause oil filter and oil blockage. If you want to make the inferior oil core achieve the original filtration effect, you must increase the filtration area, but this will easily increase the compressor energy consumption. The poor quality oil core is also prone to explosion accidents due to poor conductivity. The oil filter with poor filtration effect can't filter out the dust and impurities in the air. The dust will follow the lubricating oil into the rotor, causing bearing wear and reducing efficiency. The inferior oil filter can easily cause the filter to burst during work due to quality problems.
5, the maintenance method is not formal, "the symptoms are not cured" is still the usual means
When repairing the compressor, some maintenance personnel do not take the correct maintenance method, and think that the emergency measures are omnipotent. There are still many phenomena of “emergency” generation “maintenance” and “treatment of the standard without a cure”.
Dealing with over-temperature shutdown is just to clean the cooler and change the oil. This method is very effective for the new machine. But for the old machine of more than two years, it is a temporary solution. Often just after cleaning up, there is an over-temperature shutdown. In this case, we always suspect that the cooler is not clean enough. But is the real reason like this? In fact, it is not the case that the cooler is not completely cleaned. There is a huge over-temperature hazard in the oil system of the machine. Most of today's screw air compressors use mineral oil or mineral oil-based semi-synthetic oil, and the service life is generally between 2000-4000 hours. This kind of oil usually runs for about two years, and there will be coking, even if it is normal oil change, because it is impossible to discharge 100% of the oil every time the oil is changed. The remaining oil is deposited at the low point of the oil circuit such as the bottom of the gear box, and then participates in the oil circuit cycle along with the new oil. Running for a certain period of time will cause oil quality deterioration and coking. Green or blue effluent will be discharged from the drain of the air compressor. When the oil is changed, the viscosity of the oil is large, and the asphalt-like hard block is discharged. If you continue to operate, there will be difficulty in cold start of the machine and the motor will often be overloaded. In the worst case, the host will not be able to rotate, resulting in a false lock.
The air cooling inside the air compressor is water-cooled. At the initial stage of operation, the cooling water that is connected is tap water. After a period of operation, the gas cooling effect will decrease. The main reason is fouling or blockage of the wall of the cooling water system. Flushing in the forward and reverse directions with high pressure water has a certain effect, but it is still not ideal. After repeated washing with the detergent, the effect is very good. However, the descaling agent has a strong acidity, which will corrode the wall of the cold water system. Frequent washing will make the wall thinner, affecting the pressure resistance and service life of the tube, and thus the treatment will not cure the problem. The most effective method is to deal with the cause of scaling and blockage. Since tap water is prone to fouling, the cooling water is changed to soft water that is not easily fouled, and a filter is installed at the cooling water inlet to clean the filter regularly. This makes maintenance easy and convenient, while reducing equipment failure rate and extending system life.
Often encountered in the "repair by welding", is also an example, some parts can be repaired, but some maintenance personnel to save trouble, but often use the "weld death" method. When the piston pin is installed, the piston pin is directly driven into the pin hole without heating the piston, resulting in an increase in the amount of deformation of the piston and an increase in ellipticity; when the motor is repaired, the bearing pad is excessively scraped, and the friction reducing alloy layer on the surface of the bearing pad is scraped off, resulting in scraping The bearing steel and the crankshaft directly rub against the crankshaft for early wear; when the interference fit parts such as bearings and pulleys are disassembled, the tension device is not used, and the hard knocking is hard, which may cause deformation or damage of the components; enable the new piston, cylinder liner and injector assembly. When the parts such as the plunger assembly are used, the oil or wax sealed on the surface of the fired parts is used to change the performance of the parts, which is not conducive to the use of the parts. When the pressure of the pipe end or pneumatic equipment is found to be insufficient, the cause of the failure is not checked, and the working pressure of the system is blindly increased, resulting in excessive system pressure, easy damage to valves, pipelines, etc.; diesel-shifted compressors, in order to make the diesel engine "powerful", Artificially increase the fuel supply of the fuel injection pump and increase the fuel injection pressure of the injector.
These irregular maintenance methods can only be used for emergency, but they cannot be used for a long time. The cause of the failure must be fundamentally detected. Regular maintenance methods should be used to eliminate the fault and should be brought to the attention of maintenance personnel.
6, "small pieces" are not good or bad, because "small" loss of "big" leads to increased failure
In the maintenance work, some maintenance personnel often only pay attention to the maintenance of the machine head, three filters, and the motor, but neglect the maintenance of "small pieces" of various valves, various instruments, pipes, etc. They think these "small pieces" As long as it does not affect the stable gas production, even if it is damaged, it does not matter, as long as the mechanical action is available. I don't know, it is these "small pieces" that lack maintenance, leading to early wear and tear on the machine and shortening the service life.
Such as the water temperature gauge used by the compressor, the oil temperature gauge, the oil pressure gauge, the sensor, the alarm, the fan air hood, the bolt nut, etc. These "small pieces" are essential for the normal operation and maintenance of the compressor. Extending the service life of the machine is very important. In the maintenance work, if you do not pay attention to maintenance, it will often result in a compressor failure due to “small loss”.
7, after the maintenance of taboos forget the brain, hidden faults frequently
When repairing the compressor, some maintenance personnel do not understand some problems that should be paid attention to during maintenance, which leads to “habitual” errors in disassembly and assembly, which affect the quality of maintenance.
If the hot car is disassembled, the equipment will be deformed and cracked; when the piston pin is installed, the piston pin will be directly driven into the pin hole without heating the piston, resulting in an increase in the piston deformation and an increase in the ellipticity; the crankshaft main bearing or the connecting rod back is copper. Pad or paper pad, easy to block the oil passage, causing the shaft to burn the shaft; excessively scraping the bearing bush, the friction reducing alloy layer on the surface of the bearing bush is scraped off, causing the bearing steel back and the crankshaft to directly rub the early wear; disassembling the bearing, the pulley, etc. When the parts are matched with the parts, the tensioner is not used, and the hard parts are hard to be knocked, which may cause deformation or damage of the parts. When the new parts are unsealed, the oil or wax sealed on the surface of the fired parts is used to change the performance of the parts, which is not conducive to the use of the parts. .
8, the compressor Ma Daha a lot, the details are not pay attention, maintenance remains hidden
The same problem is dealt with because of different personnel and technical capabilities, which will bring different final results, and the differences often come from some details:
Different grades of lubricating oil are mixed, which causes the lubricating oil to deteriorate. Before the air compressor starts, it does not confirm whether the motor rotates in the same direction as the specified steering, which causes the air compressor to reverse. The pressure in the pump head cannot be established. The rotor has no lubricating oil and cannot be used. The lubricating oil circulation takes away the heat generated by the friction in the pump head, and instantly accumulates heat to generate high temperature, which causes the screw and the outer casing of the main body to be deformed, and the female and male screws are engaged and locked. The end face of the rotor and the end cap are stuck together due to high temperature, causing serious wear on the end face of the rotor, and even the parts are missing, resulting in damage to the gear box and the rotor. Freely change or increase the safety and reliability of the air compressor; remove the high temperature components when the temperature is cooled to the ambient temperature; operate the air compressor when the specified pressure and the specified temperature are exceeded; The air compressor suction port was blocked during operation; after maintenance, it was not confirmed that all safety devices had been reinstalled before starting, and the tools were removed from the air compressor.
Ma Daha-type maintenance personnel are in the industry, and the details that are often forgotten are precisely the crucial links.
9, parts decontamination, cleaning is not thorough, early damage, corrosion often occurs
When repairing the compressor, it is important to properly remove the oil stains and impurities on the surface of the parts to improve the repair quality and extend the service life of the machine. Due to the inattention to the cleaning of parts, the unreasonable selection of cleaning agents, improper cleaning methods, etc., the early wear and corrosion of parts are caused by some repair units.
