Views: 86 Author: Site Editor Publish Time: 2020-11-03 Origin: Site
Like other engine lubricating systems, the function of the lubricating system of 4stroke turbocharger diesel engine is to send a certain amount of clean and temperature appropriate lubricating oil to each friction surface for lubrication, so as to reduce the wear of moving parts, clean and cool the friction surface, improve the sealing performance of sealing moving parts and play a role of rust prevention for all moving parts.
According to the way that oil is delivered to the friction surface of moving parts, the engine can be divided into three lubrication modes: splash type, pressure type and compound type.
(1) Splash lubrication is also called splash lubrication. For the friction parts with small load, such as cylinder wall, cam and tappet of valve mechanism, the oil squeezed from the clearance between crankshaft main bearing and connecting rod bearing splashes to the friction surface for lubrication. Of course, the oil droplets or oil mist formed by the oil splashing in the oil bottom from the lower part of the big end of the connecting rod can also be used for lubrication. The structure of this lubrication method is simple, but the lubrication is not reliable, oil consumption is large, easy to oxidize and easy to pollute.
(2) For the friction surfaces with large load and high relative motion speed, such as main bearing, connecting rod bearing, camshaft bearing and other parts, pressure lubrication is a way of using the pressure of oil pump to send oil from oil pan to friction surface of all moving parts through oil passage and oil pipe for lubrication. Pressure lubrication is reliable, effective, easy to clean and has a good cooling effect.
(3) The compound lubrication uses the oil supply method of pressure lubrication and splash lubrication to lubricate the friction surfaces of the engine. This lubrication method is widely used in modern high speed multi cylinder diesel engines because it not only works reliably but also simplifies the structure of the whole lubrication system.
Because the lubricating systems of various engines are basically the same, they can be divided into dry cycle system and wet cycle system according to the different ways of lubricating oil storage of some large-sized and medium-sized powerful 12cylinder diesel engines.
l Dry cycle system: the system in which the oil is stored separately in the oil tank outside the engine is called dry cycle system. The oil recycled from each lubricating part is collected by the oil pan on the engine and then sent to the oil tank for storage through the oil suction pump. The oil in the oil tank is sent to each friction surface through the pressure oil pump. This system is suitable for mobile large and medium low speed 4 stroke 6cylinder diesel engines.
l Wet cycle system: the system in which oil is stored directly in the oil bottom is called wet cycle system. It is characterized in that oil circulation can be realized without oil suction pump and only two pressure pumps. This cycle system is used in both medium and small engines.
The composition of the lubrication system is determined according to the specific needs of the engine. The lubrication system of modern high speed 6cylinder diesel engine generator consists of the following basic parts:
(1) The oil storage and delivery device include an oil pump, an oil delivery pipeline and an oil pan, which circulates the oil in the engine.
(2) The oil filtering device has a primary oil filter and a fine oil filter, which are used to filter various impurities contained in the oil.
(3) The oil cooling device has an oil cooler or oil radiator to cool the oil, which can prevent the high oil temperature from affecting the normal operation of the engine.
(4) The safety protection device includes various alarm devices such as safety valve, pressure limiting valve, high-power engine and automatic stop device for low oil pressure.
(5) The indicating device includes an oil temperature gauge and an oil pressure gauge for monitoring the operation of the lubrication system.