Diesel generator maintenance training diesel article -p71-p75 oil pump

Diesel generator maintenance training diesel article -p71-p75 oil pump

After the oil pump of the diesel generator fails, start from the most easily checked part. The specific method is as follows:

1 Check the viscosity of the oil, as shown in Figure 2-90. If the oil is too dilute or the oil enters the diesel, 2 after adding the new oil. When the oil pressure does not increase, remove the pressure regulator seal screw on the oil filter to loosen the lock nut and use a flat-head screwdriver to screw in the regulator. Normally, the oil pressure should increase.

When the oil pressure, we must observe the oil pressure gauge while adjusting, once can not be adjusted too much, as shown in Figure 2-917 if the oil pressure after pressure regulation has not increased, then the first and second cylinders should be removed The side cover is used to inspect the oil filter roughing filter. If the coarse filter is not blocked, remove the oil pump for inspection and repair.

4 Measure the gear meshing clearance by checking the feeler of the oil pump stage, generally choose 120 apart.

The three positions are measured separately and then averaged. When the value of Chad exceeds the o.65 coffee, it is necessary to replace the new gear or continue to use the gear. During the inspection, if the gear end clearance is found to be too large, the gasket between the pump cover and the pump body can be adjusted; if the active uranium and the bush are excessively worn, the material sleeve should generally be replaced.

Second, oil filter

When the diesel generator oil passes between the friction elements, it will inevitably carry away some of the metal particles that have fallen off due to friction, and may also contain dust and other contaminants in the atmosphere. If these impurities are retained in the engine oil, the wear of the moving parts of the diesel engine will be exacerbated and even the sleeve tube will be clogged. Therefore, the oil must be filtered during use. At present, diesel engine is equipped with organic oil filter, its appearance is shown in Figure 2-92.

The oil filter is divided into two types, the more filter and the finer. At present, crude oil tankers equipped on diesel engines have blade-type, wire-wound, paper-type, and mesh-type structures; oil-based fine filters generally use a centrifugal structure. The following takes the 4135 oil filter as an example to introduce the wire-wound oil tanker and the centrifugal oil planter.

Wire-wound oil crude

The wire-wound oil filter (shown in Figure 243) is a two-layer copper wire filter that filters out metal particles and other impurities in the oil that passes through the copper wire. This type of turbidizer is not easy to damage,'

However, when the diesel engine is running, the filter element must be removed and put into diesel for cleaning, and then blown with compressed air.

Centrifugal oil skimmer (see Figure 2-93) consists of cover, turn, turn on shaft, base, inlet pressure limiting valve and nozzle, etc. It mainly uses the centrifugal force generated when the rotor rotates at high speed to make the oil small Metal particles and other impurities are thrown onto the rotor wall, and the filtered oil returns to the oil sump. The sleeve fine filter is not easily damaged, but when the diesel engine is running around 250b, the oil filter must be cleaned.

The pressure limiting valve and bypass valve are mounted on the base of the oil filter. The installation position of the oil filter is shown in Figure 2-94.

Pressure limiting valve consists of adjusting screw 5J, pressure limiting spring and valve. Its role is to ensure that the oil pressure meets the specified requirements, to prevent the oil pressure from being too high and damage the normal lubrication of diesel engine parts and damage the oil pipe joints, etc., the oil pressure High or low can be achieved by adjusting the pressure limiting valve.

The bypass valve b5N is composed of a ball, a spring and a lock nut. Its role is to pass through the oil strainer and directly flow from the bypass valve to the main oil when the oil strainer is blocked to ensure the normal operation of the diesel engine.

I. Oil radiator

During the rotation of the diesel generator set's diesel engine, the engine oil absorbs certain hot stars when it flows through the friction brown surface of the moving parts. With the reciprocating circulation of the oil, its temperature will gradually increase. When the oil temperature exceeds 90°C, the viscosity of the oil will be seriously reduced, which will cause the parts to lose their lubrication effect. At the same time, the oil will also undergo oxidation and deterioration, so the diesel engine must be equipped with oil cooling. Device. The role of oil cooling device is: Forced cooling of the oil to prevent the oil temperature is too high to increase the consumption of oil, but also to prevent the engine oil oxidation deterioration.

Oil cooling device is divided into water-cooled and air-cooled two. The appearance of the water-cooled oil radiator is shown in Fig. 2.95, and its physical decomposition is shown in Fig. 2-96. It is mainly composed of a core and a shell. The core consists of brass tubes, heat sinks and spacers. The oil flows between the core and the shell sandwich. When cooling water flows inside the core, it removes some of the heat from the oil. After circulating cooling water, the oil temperature is controlled within the range of 80°Ci to 5°C. The air-cooled oil radiator consists of copper tubes and heat sinks. The oil radiator of the diesel engine adopts an air-cooled type to be installed behind the water radiator, and the cooling of the engine oil is carried away by the fan blower.

The easy-to-failure of oil heat sinks is:

1 Cores, side covers, and seals of water-cooled oil radiators are easily damaged.

2 Air-cooled oil radiator brass welding parts are prone to desoldering phenomenon.

The main cause of water-cooled oil radiator damage is the winter forgetting to let go of cooling water.

During the operation of the diesel generator set diesel engine, if the organic oil in the water radiator is found, and there is cooling water in the oil inside the oil pan, the internal core of the water-cooled oil radiator is damaged. This is because when the diesel engine is in operation, when the pressure of the oil is greater than the pressure of the cooling water, the oil will enter the cooling water through a hole in the core. As the cooling water circulates, the oil enters the water radiator. When the diesel engine stops rotating, the water level of the cooling water is higher. At this time, the pressure of the cooling water is greater than the pressure of the oil, so that the cooling water enters the engine oil through the hole in the core, and finally enters into the oil pan. The bitter operating personnel failed to detect this fault in time. With the operation of the diesel engine, the lubrication effect of the oil will be lost, and eventually the diesel engine will be burned. Specific inspection method is as follows; 1 remove the oil radiator, let go of the oil inside the radiator, and then through the outlet of the oil radiator, fill the radiator with water. Then block the inlet and use a high pressure air pump or air pump to pump air to the radiator outlet.

Note that during the pumping process, the inlet and outlet openings must be sealed to prevent water from spilling out. If there is water coming out of the oil inlet or outlet of the oil radiator, the internal core of the radiator is damaged.

2 Remove the cover of the oil radiator and remove the core. If it is found that the outer layer of the core is broken, it can be repaired by brazing.

If it is found that the inner layer of the core breaks, a new core should generally be replaced. When cracks or cracks appear on the edge, they can be used after welding with cast iron electrodes. If the gasket is damaged or deteriorated, it should be replaced. When the copper tube of the air-cooled oil radiator shows a phenomenon of desoldering, it is generally repaired with a feed welding.