Diesel generator set maintenance training diesel article -p165-p170

Diesel generator set maintenance training diesel article -p165-p170

Fault 9: diesel generator diesel engine during operation, found that the cooling water overflow from the pump bearings Fault Analysis:

This failure is usually caused by damage to the water seal or uneven placement of the bottom of the newly assembled water seal.

Method of exclusion

1 Remove the water pump pulley with a bearing cable, as shown in Figure 5-27.

2 According to the method shown in Figure 2-102, flush the water pump shaft with a punch, remove the damaged water seal, replace the new water seal of the same model, and then press the disassembled position to complete the assembly. The fault can be eliminated.
Fault 10: The diesel engine diesel engine has a metal impact sound at the middle of the oil engine when starting and stopping.

When the diesel engine is running, it also has a loud noise.

The sound emitted during the normal operation of the diesel engine is continuous and uniform. This sound is mainly caused by the intake and exhaust of the diesel engine, the sound emitted by the diesel fuel injected into the combustion chamber, and the mechanical friction sound of the diesel engine's gears. When the internal wear parts of the diesel engine have excessive wear gaps, loose parts, fractures, jams, incorrect adjustments, or deterioration of the work process, abnormal sounds will be emitted.

The abnormal sounds emitted by diesel engines are varied. Often on the same diesel engine, the noises reflected by faults of different nature are similar, but on different diesel engines, the sounds reflected by faults of the same nature are not the same. When the diesel engine is working, the normal sound is mixed with the abnormal sound, and sometimes the root is difficult to distinguish.

However, different sounds generally have different laws. As long as the maintenance personnel are familiar with the sound of the normal rotation of the diesel engine, and can clearly distinguish the different sounds, and then according to the working principle and structure of the diesel engine, it can quickly and correctly diagnose the causes of the r9 fault and eliminate the fault in time. The fault of this diesel engine belongs to the internal interface rubber of the diesel engine and the generator. When the apron wears out, it will cause a metal control sound when starting and stopping.

Method of exclusion:

When checking different sounds, it is advisable to use a thin steel bar or a long screwdriver (about half a meter), and one end of the bar is ground and sharpened, and the other end is made into a spherical shape. When the diesel engine emits abnormal sound during operation, put the sharp side of the steel bar or screwdriver on the surface of the diesel engine to be inspected, and stick the other end to the ear. The abnormal noise will be transmitted through the steel bar or the screwdriver. Into the ear, it can be judged by the tone of the level, severity and size.

The diesel generator set diesel engine runs little in a long term and there are a lot of abnormal sounds, such as mechanical knocking sound, burning noise of the combustion process, knocking noise of 5k lower teeth, diesel shed. With the sound of the middle part of the generator, etc. Different sounds represent different faults, and different faults have different faults.

1 In a diesel engine housing, use iron or wooden rods to make a cross. Hang a hoist hoist on the cross. The hook below hangs on the generator hoisting ring.

2 Use a tool to remove the interface screws between the diesel engine and the generator, slowly lift the generator, push it back, and slowly lower it. After replacing the apron, slowly lift the generator. After aligning the components, slowly push the generator so that it is in tight contact with the diesel engine, and then tighten the interface screws. When the diesel engine starts and stops, the fault can be eliminated.

Fault 11: After the diesel generator set diesel engine starts, there is a “dang, when” sound inside the body, and the noise increases as the rotation speed increases. Failure Analysis:

This kind of noise usually occurs on diesel engines that have just been completed or have a long life. The abnormal sound inside the body is generally a link bearing knocking sound. The connecting rod bolt is not tightened, loosened or broken, and the connecting rod bearing bush is worn out or worn out, which increases the gap between the connecting rod bearing and the connecting rod pin. When the diesel fuel is running, a large impact load is generated between the connecting rod pin and the bearing shell and an abnormal knocking sound is generated.

Method of exclusion:

7 After the Chai Sleeve has stopped rotating, remove the body's case board, and then manually shake the middle part of the connecting rods of each cylinder. If you want to add the picture 5.9, if the individual connecting rods are big, then use a torque wrench to remove them. The team 96 removes the connecting rod to check the wear of the bearing bush. If the bearing wear is serious, the appropriate new bearing bushes should be replaced according to the cooperation between the bearings: If the bearing wear is not obvious, tighten the torque according to the specified torque.

2 If the diesel engine is an overhauled diesel engine, use a torque wrench to re-check the tightening torque of the connecting rod bolt. If the throwing torque of the prepared connecting rod bolt meets the required torque requirements, each connecting rod bolt should be removed to check if the axle purchase and assembly meets the requirements.

Fault 12: diesel generator set diesel engine in a long period of load operation, found that there is water overflow between the cylinder and the whole body failure analysis:

During long-term operation of the diesel engine, due to the high body temperature, the internal water shortage and the cylinder head cap screw; the loose wire or damage to individual diesel engine components will cause the above failure. In particular, new diesel engines or overhauled diesel engines are more prone to such failures after a period of loading and running. .

Method of exclusion:

A diesel engine is a new diesel engine or a crusher after overhaul.



1 Remove valve cover and swing wall seat.


2 Disassemble the shaker assembly as shown in Figure 5-19.

2 According to the method shown in Figure 2-14, use the torque wrench to tighten the cylinder head nut in the order of the torque from the inside to the outside.

4 Assemble the rocker assembly as required and re-adjust the valve clearance. After the diesel engine starts, there is no water overflow and the fault can be eliminated.

If the diesel engine is a diesel engine with a long service life or a long-term full-load operation, the troubleshooting method for water-related problems is:

1 Remove the cylinder head nut in the order from the outside to the inside in the diagonal direction. Remove the cylinder head and the 5 is damaged. The location of the cylinder head water block is shown in Figure 2-10(b).

2 Remove the cylinder gasket and check the overall quality of the cylinder head gasket and cylinder head gasket. Replace new parts of the same model.

2 If no fault site is found after the above inspection, the shape is caused.

Then the failure may be due to a change in the cylinder head or body.

Fault 13; Diesel generator set diesel engine at rated speed, the speed suddenly dropped to idle, and the speed instability Analysis of the failure:

This kind of failure is generally caused by the plugging phenomenon of the oil pump inlet filter.

Method of exclusion:

When troubleshooting such failures, first check whether the low-pressure oil path of the diesel engine has oil leakage and whether the oil return screw is loose. If there is no oil leakage in the tubing or if there is no loosening of the oil return screw, the fault is generally caused by the plugging of the oil pump inlet strainer. The filter should be disassembled for cleaning.

Fault 14: When the diesel generator set is running at rated speed, the oil pressure is too low. Fault Analysis:

During the operation of the diesel engine, all moving parts must maintain sufficient lubrication, which is an essential condition for the normal operation of the diesel engine. The oil pressure is an important indicator of whether the diesel engine can be adequately lubricated during operation. Different types of diesel engines are in operation, and have certain requirements and requirements for the oil pressure during normal lubrication. At the same time, they also specify the minimum oil pressure limit requirements for diesel engines during operation. Therefore, the change of the oil pressure must be closely watched during the use of the diesel engine. Caused by the diesel engine oil pressure is too low: diesel oil or water into the oil, or too little oil, so that the viscosity of the oil is too low: the internal gear of the oil pump is seriously worn or the assembly does not meet the requirements, the oil pump is not working properly; Large clearances on the lubrication surfaces of large bearings, connecting rod bearings, etc., cause increased oil leakage and lower oil pressure: oil pressure gauges are inaccurate, sensors are defective, oil oil suction filter screens are blocked or radiators are blocked, and internal heat is emitted. Without going out, the oil temperature is high; improper regulation of the pressure regulating valve leads to serious oil leakage; the oil filter is blocked by dirt and causes the oil circulation resistance to be too large; the newly assembled oil filter does not meet the quality requirements.

Method of exclusion

When troubleshooting this type of failure, the maintenance personnel or the operator should understand Joe's oil flow, the working principle, and the composition of each part. The methods to eliminate such failures include observation and comparison methods.

1 Pull out the oil gauge in the oil pan and check whether the oil in diesel oil makes the viscosity of the oil too low (The diesel engine with a long service life is prone to faults in the injector oil and cylinder pressure, and these faults are particularly easy to make The oil enters the diesel, so the injector should be calibrated periodically at the professional pump center). If the viscosity of the oil is too low, replace the oil with a higher viscosity or adjust the pressure of the oil.

2 The oil pressure adjustment method is: After the diesel engine starts, use a spanner or an open end wrench to unscrew the oil seal nut on the pressure regulator valve, loosen the lock nut, and then use a flat-head screwdriver to screw in the adjustment bolt (see Figure 2-91). ) At this time, the oil pressure should be able to rise. If the oil pressure cannot be improved by this adjustment method, remove the oil filter screen of the oil pump suction plate and check it. 2 After the diesel engine stops rotating, release the oil in the oil pan, and then use the tool to remove the first, The two-cylinder body side cover plate, and then hand extended to the bottom of the oil pan (as shown in Figure 5-28), open the lock spring of the plenum pan filter cover, remove the suction pan filter and remove the adsorption in the filter Miscellaneous items on the internet. In cold regions, the operation of some diesel vehicles or diesel generators is often mistakenly using the blowtorch to bake the bottom of the oil pan, so that the viscosity of the oil is reduced to reduce the starting resistance, so as to achieve a smooth start of the diesel engine. The mistake of this kind of practice is to make the engine oil of the oil pan by the blowtorch easy to be degraded. After starting the diesel engine, the plastic block will be adsorbed on the oil suction disc filter screen, causing the filter screen to clog, causing the oil pressure to decrease. All the plugging of the filter screen caused the diesel engine to "hold the tile" accident, causing undue economic losses.

4 Remove the oil pump and check the gap between the internal gear oil pump.

(6) If a diesel engine with a long service life is used, if the oil pressure after overhauling is still too low, check whether the gap between the main bearing and the connecting rod bearing in the lubrication area is too large.

(6) If the newly assembled diesel engine is under low oil pressure, check the oil pump assembly for any errors.