3 Common Problems in Maintenance Material and Parts of Diesel Generators

Previously, we analyzed the problems in the maintenance methods of diesel generators. This article will continue to study the problems in repair materials and parts of diesel generator.

1. Without checking the quality of new parts, the problem of failure after assembly is relatively common.

Take the 4 stroke turbocharger diesel engine as an example. Before replacing its parts, some maintenance personnel do not perform technical inspection on the new parts and install them directly on the equipment after they are taken. This is unscientific. At present, the quality of spare parts sold on the market is uneven, and some fake and inferior parts are mixed in the fish head; some parts have changed their performance due to the long inventory time. If they are not tested, they often cause failures after assembly. Therefore, be sure to carry out the necessary inspection tests before replacing new parts. The inspection includes appearance and performance tests to ensure that the new accessories are free of trouble and to eliminate unnecessary troubles caused by them.

2. No attention is paid to the type of accessories, and the substitution or misuse of accessories is more common.

When maintaining diesel generators, the substitution or misuse of accessories is still relatively common. There are many types of diesel generators, and emergency replacement of some accessories is feasible, but long-term use is harmful and unhelpful, affecting the safety and technical performance of the equipment. For example, 12 cylinder 420KW power generator diesel engine and 441KW 6 cylinder water cooled diesel engine generator set, some maintenance personnel have little understanding of the mechanical structure and principle of the two, and many parts and accessories do not match, but they think that as long as they can be installed. They do not consider whether the technical performance of the machine can be brought into full play; replacing defective products with defective products, replacing cotter pins with iron wires and nails, and using steel bars, etc. The quality cannot be guaranteed, and long-term use is never allowed.

Therefore, when repairing different types of diesel engine generator set, the original model parts should be used as much as possible, and other types of parts can not be used as substitutes, not to mention misuse. It is not uncommon to replace components in pairs or in sets. There are many components on the equipment, such as the plunger pair of the diesel generator fuel system, the fuel outlet valve pair, and the injector needle valve assembly. These matching components are specially processed at the factory and are ground in pairs. They are used in pairs throughout the life of the use and are not interchangeable. Some components that cooperate with each other, such as the piston and the cylinder liner, the bush and the journal, etc., after a period of running-in use, the relative cooperation is better. When repairing, you should also pay attention to the assembly in pairs and do not get tangled. These machines use a set of accessories at the same time. If they are damaged, they must be replaced in a complete set. Otherwise, due to the large differences in the quality of the accessories, the different levels of old and new, and the length and size, the equipment will be unstable and the replacement parts will be damaged early.

3. The use of the gasket is not standardized, and the phenomenon of random use still exists.

There are many types of gaskets used between the mating surfaces of diesel generator parts. Commonly used gaskets are asbestos pads, rubber pads, cardboard pads, cork pads, felt pads, spring pads, flat pads, etc. Some are used to prevent oil leakage, water leakage, air leakage, and electric leakage between the mating surfaces of parts; some play the role of fastening and preventing loosening. There are different regulations and requirements for the timing and occasion of each type of gasket.

In the maintenance of equipment, the phenomenon of irregular or even inadvertent use of gaskets is relatively serious, resulting in frequent leakage between the mating surfaces and the loosening of bolts and nuts, which affects the normal use of the equipment. If the generator cylinder gasket is too thick, the compression ratio is reduced, and the engine is difficult to start; copper gaskets should be used between the injector and the cylinder head mating surface. If replaced with asbestos gasket, it is easy to cause ablation of the injector's poor heat dissipation. Therefore, when repairing the high speed 6 cylinder diesel engine, the maintenance personnel must remember that "the gasket is small and useful."