Technical Education

What is Oil Filter Working Principle?

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The oil filter working principle depends on the gravitational force for filtration and supply of oil to the engine parts. I will discuss the oil filter types and working process in this article.   Oil Filter Working Principle An oil filter is used in most motor vehicles’ lubrication systems to …

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Petroil Lubrication System | Petroil Lubrication System Diagram.

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Petroil lubrication system is the oldest and the simplest lubricating system. It was basically used in motorbikes. In this article, I will discuss the petroil lubrication system.


Petroil Lubrication System
 

Petroil Lubrication System

This system of lubrication is generally adopted in two-stroke petrol engines, like scooters and motorcycles. It is the simplest form of the lubrication system. It does not consist of any separate part, like an oil pump, for the purpose of lubrication.
 
But the lubricating oil is mixed in the petrol itself while filling in the petrol tank of the vehicle, in a specific ratio. When the fuel goes into the crank chamber during the engine operation, the oil particles go deep into the bearing surfaces and lubricate them. The piston rings, cylinder walls, piston pins, etc. are lubricated in the same way.
 
If the engine remains unused for a considerable time, the lubricating oil separates off from petrol and less clogging of passages in the carburetor, resulting in engine trouble. This is the main disadvantage of this system. 

What is SAE Number? SAE Viscosity Number.

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What is SAE number is discussed in this article. I will cover all the SAE viscosity numbers in this article.    What is the SAE Number What is the SAE Number? The most common question in the lubrication system. The SAE number is essential for selecting the right lubricant for …

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Hydrodynamic Theory of Lubrication | Definition and Meaning.

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Hydrodynamics theory of lubrication depends on fluid mechanics. In this article, I will discuss the meaning and advantages of the hydrodynamic theory of lubrication.


 

Hydrodynamic Theory of Lubrication
 

Hydrodynamic Theory of Lubrication

Among various theories of lubrication, the hydrodynamic theory stands out as a cornerstone in understanding the mechanisms behind optimal lubricant performance.
 
The Hydrodynamic Theory of Lubrication is a fundamental concept that elucidates how lubricants work between moving surfaces to reduce friction and wear. Unlike boundary lubrication, where direct contact between surfaces is prevented by a thin film of lubricant, hydrodynamic lubrication relies on the principle of fluid dynamics.
 
Fluid dynamics play a crucial role in hydrodynamic lubrication. When two surfaces move relative to each other, a lubricating fluid, often an oil-based substance, is introduced into the gap between them. As the surfaces move, they create pressure gradients within the fluid, leading to the formation of a continuous lubricating film. This film separates the surfaces and prevents them from coming into direct contact.
 

Definition of Hydrodynamic Theory of Lubrication

Definition of Hydrodynamic Theory of Lubrication

 

When the shaft rotates in a bearing, it takes an eccentric position in the bearing, as shown in the figure. This is due to the loading of the journal W and the direction of rotation.
 
The oil film is maintained by the wedging action as the oil is forced into the wedge at the bottom by the pressure generated when the oil is carried from the wide space A and forced into the narrow space B at the bottom by rotating the journal to which the oil adheres. This is called the hydrodynamic theory of lubrication.  
 

Meaning of Hydrodynamic Theory of Lubrication.

From the above there, it is clear that the oil film is maintained only when the journal is in motion. When the journal comes to rest the oil film is squeezed out. When the engine is first started, boundary lubrication comes into play until the oil film is built up by rotating the journal.
 
The qualities of lubricant called adhesiveness and film strength, help the lubricant to enter the metal ports and cling to the surfaces of the bearing and journals keeping them wet when the journals are at rest, preventing metal contact until the film of lubricant is built up. 

What is the Function of Lubricating Oil?

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The function of Lubricating oil means why the oil is used in the engine. In this article, I will discuss the function of lubricating oil in an engine.

Function of lubrication oil.
 

The function of Lubricating Oil

There is always friction between two surfaces when they rub against each other no matter how highly polished surfaces are, such as the shaft in a bearing, or the piston in a cylinder.
 
Irregularities of the highly polished surface can be examined under a magnifying glass or microscope. The high points of one irregular surface strike the high points of another irregular surface when they are rubbed with each other. 
 
Without lubrication between two surfaces, the heat generated would bind or burn out the surfaces. Also, there would be considerable wear and power loss. If the surfaces are lubricated, like the engine bearing, the shaft would float on a film of lubricant. 
 
The grassy slippery particles of the oil film slide on each other, minimizing friction, wear, and heat generation. An adequate amount of lubricating oil must be fed continuously to the bearing so that a film of oil is maintained in the bearing under all operating conditions.

Bearing Alloys | Types and Properties with details.

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Bearing alloys, also known as bearing metals or babbitt metals, are a class of materials used in the manufacturing of bearings. In this article, I will cover all the topics related to Bearing Alloys. 


Bearing Alloys
 

Bearing Alloys

Any alloy can function as a bearing alloy, provided it possesses the required anti-frictional properties and sufficient strength and corrosion resistance as well as some desirable properties for specific conditions.
 
Common bearing materials used in sliding bearing are white material alloys, bronzes, copper-lead alloys, silver and lead aluminum alloys, and porous metal bearings. 
 
Such materials as plastics, wood, carbon-graphite, cast iron, steel, various carbides, and sintered ceramics are also used for many special applications. 
 
 
Bearings are mechanical components that support the movement of rotating or sliding shafts within machinery, reducing friction and enabling smooth motion. Bearing alloys are designed to provide low friction and wear-resistant surfaces to ensure efficient and long-lasting operation of machinery.

Overcooling of Engine | Problems Due to Overcooling the Engine.

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Overcooling of the engine means the working temperature of the machine falls down. In this article, I will discuss the overcooling of the engine and the causes and cures. 

Overcooling of Engine
 

Overcooling of Engine

Overcooling of engine is a condition in which the engine’s operating temperature drops below the optimal range. If it drops the working temperature then it causes it to run colder than intended.
 
While less common than engine overheating, overcooling can still lead to various issues and affect the performance and efficiency of the vehicle. The engine is designed to operate within a specific temperature range, typically between 195 to 220 degrees Fahrenheit (90 to 104 degrees Celsius), and overcooling occurs when it falls below this range.
 
 
If the engine’s working temperature falls then the engine starts to knock or the engine stalling happens. Let’s find out the causes-
 

Causes of Engine Overcooling

The temperature gauge on the dashboard shows abnormally low readings when the engine is overcooled. This happens when the insufficient heat output from the vehicle’s heater, especially during colder weather. The causes of engine overcooling are- 
 
1) If the thermostat valve is stuck or choked at that time the coolant flow will hamper and cause the engine to overcooling. 
 
2) If the thermostat valve allows too much coolant due to the sensor problem, the engine will cool down rapidly and cause the engine to overcool. 
 
3) A low coolant level in the cooling system can reduce the amount of heat-absorbing fluid available, leading to insufficient heat transfer and overcooling.
 
4) The coolant in the cooling system should be mixed with the anti-freeze mixture with the proper ratio and properties. If the coolant mixture is mismatched at that time the problem happens.
 
5) The cooling fan helps dissipate heat from the radiator. Failure to engage or operate at a lower speed than necessary can cause the engine to overcool.
 
6) If the weather is extremely cold, then the overcooling of the engine happens.