Equipment maintenance "five sins", see if you have been shot?

Mistake one: do not analyze the cause of failure, blindly unload the big demolition

Some maintenance personnel due to the mechanical structure of the equipment, the principle is not clear, do not seriously analyze the causes of failure, can not accurately determine the fault parts, with "about, about" the idea of blindly to the equipment big demolition, the results not only the original fault is not eliminated, and because of poor maintenance skills and techniques, and new problems. When mechanical failure, to detect through testing equipment; such as no testing equipment, through "ask, see, check, test" and other traditional methods and means of fault determination, combined with the structure and working principle of the equipment, to determine the most likely parts of the fault. In determining equipment failure, generally used "exclusion method" and "comparison method", in accordance with the simple to complex, first after the exterior, first assembly and then parts of the order, do not "do not ask red and white, blindly dismantle the big unload Never "blindly dismantle and dismantle without asking questions". 

Mistake 2: Blindly replacing parts

Equipment fault judgment and troubleshooting is relatively difficult, some maintenance personnel consistently use the method of replacement test, regardless of large and small parts, as long as the parts that may cause the fault, one by one replacement test. The result is not only the fault is not eliminated, and should not replace the parts replaced at will, increasing the maintenance costs. In the maintenance, according to the failure phenomenon should be carefully analyzed to determine the causes and parts of the failure, the parts can be repaired to take the repair method to restore technical performance, to eliminate the practice of blindly replacing parts. 

Mistake three: do not test the parts with clearance

In diesel engine maintenance, piston and cylinder liner with clearance, piston ring "three gaps", piston top clearance, valve clearance, plunger clearance, brake shoe clearance, main and driven gear meshing clearance, bearing axial and radial clearance, valve rod and valve guide with clearance, etc., all types of models have strict requirements, must be measured during maintenance The parts that do not meet the clearance requirements should be adjusted or replaced. The actual maintenance work, do not measure the clearance and blindly assembled parts of the phenomenon of many, resulting in early bearing wear or ablation, burning oil, starting difficulties or deflagration, piston ring breakage, machine crash, oil leakage, gas leakage and other failures. Sometimes even due to parts with improper clearance, resulting in serious damage to machinery accidents. 

Mistake four: assembly parts installed in reverse

In the maintenance of equipment, some parts assembly has a strict directional requirements; only the correct installation, in order to ensure that the parts work properly. Some parts are not obvious external features, positive and negative can be installed, in the actual work from time to time there is a reverse situation, resulting in early damage to parts, machinery can not work properly, equipment damage accidents. Such as engine cylinder liner, unequal distance valve spring, engine piston, piston ring, fan blade, gear oil pump side plate, skeleton oil seal, thrust washer, thrust bearing, thrust gasket, oil ring, injection pump plunger, clutch friction disc hub, drive shaft universal joint and other parts in the installation, such as do not understand the structure and installation precautions, the easiest to install the reverse. Resulting in the assembly of the work is not normal, resulting in equipment failure. Therefore, maintenance personnel in the assembly of parts, must master the structure of the parts and installation direction requirements, do not think blindly installed. 

Mistake five: maintenance method is not formal

In the maintenance of equipment, some maintenance personnel do not take the correct maintenance method, that emergency measures are all-powerful, to "emergency" instead of "repair", "treat the symptoms but not the root cause" phenomenon is still Many. An example of this is the frequent practice of "welding instead of repairing". Some parts can be repaired, but some maintenance personnel to save trouble, but often use the "welded" method; in order to make the machine "strong", artificially adjust the injection pump's oil supply and adjust the injector injection pressure high. These irregular maintenance methods can only be emergency, but not long-term use, the root cause of the failure must be identified, to take regular maintenance methods to remove the fault, should draw the attention of maintenance personnel.