KCCaclagokk17IeS-5131693290762411.pptx

KCCaclagokk17IeS-5131693290762411.pptx

• 1.
  Internal Combustion Engines Presentedby – Manmeet Singh Assistant Professor 1
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  Purpose of Lubrication Reduce the frictional resistance Protect the engine against wear. Serve as a cooling agent by picking up heat. Remove all impurities from the lubricated region. Form a seal between piston rings and the cylinder walls to prevent blowby. 2
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  Lubrication Systems ❖ Mist lubrication ❖Dry sump lubrication system Four Stroke Engines ❖s W y e s t t e s m u m plubrication systemEngines 3 Two Stroke The wet sump system is employed in relatively small engines, such as automobile engines, While the dry sump system is used in large stationary, marine and aircraft engines.
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  Mist Lubrication Systems Intwo-stroke engines, the charge is compressed in the crankcase, and as such it is not suitable to have the lubricating oil in the sump. Therefore, such engines are lubricated by adding 3 % to 6 % oil in the fuel tank itself. The oil and fuel mixture is inducted through the carburetor. The fuel gets vaporized and the oil, in the form of mist, goes into the cylinder through the crankcase. The main advantage with this system lies in the simplicity and low cost as the system does not require any oil pump, filter etc. 4
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  WET SUMP LUBRICATIONSYSTEMS 5 In the wet sump system, the bottom of the crankcase contains an oil sump (or pan) that serves as the oil supply reservoir. Oil dripping from the cylinders and bearings gravity back into the wet sump picked up by a pump and re- through the engine lubricating flows by where it is circulated system. The types of wet sump systems used are: 1. the splash and circulating pump system 2. the splash and pressure system 3. the full force-feed system
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  SPLASH AND CIRCULATINGPUMP SYSTEMD:IDM VIDEODOWNLOADEDMPEONLINE - 18-SPLASH LUBRICATION.SWF.MP4 6 C a m s ha f t C o n n e c tin g ro d be a ri n g s M a in be a r in g m a in bea rin g O il trou g h s Lo w e r o il pan O il pum p O il S t r a iner
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  SPLASH AND PRESSURESYSTEM 7 C a m s h a ft C o n n e c tin g ro d be a rings M a in be a r in g m a in be a rin g O il pum p O il S t r a iner
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  FULL FORCE FEEDSYSTEMD:IDM VIDEODOWNLOADEDAUTOMOTIVE BASICS - HOW ENGINE LUBRICATION SYSTEM WORKS.MP4 Camshaft Oil pump Oil Strainer Header main line bearing End leakage from rod connecting rod bearing Main bearing 8
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  DRY SUMP LUBRICATINGSYSTEM 9 Oil Cooler Pressure release valve Vent Filter By-Pass Presuure relief valve Filter Scavenging pum p Strainer E ngine crankcase Oil pum p To Bearings Supply Tank D ry sump
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  Properties of LubricatingOil ❖The oil used in an engine must serve as a lubricant, a coolant and an agent for removing impurities. ❖It must be able to withstand high temperatures without breaking down. The oil must operate over a good range of temperature. ❖They must not oxidize on the chamber walls, piston crown or at the piston rings. Oil have high strength to 10 preve sn ht oulmetal-to-metal filcontact even u dnder extreme loads m .
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  PROPERTIES OF LUBRICATINGOIL 11 (a)Viscosity: The lubricating oil should have the correct viscosity so that it flows easily to all the moving parts. ❖If oil viscosity is too high, more work is required to pump it and to shear it between the moving parts. This results in greater friction work, reduced brake work and hence reduced power output. ❖Viscosity is dependent on increasing with temperature. highly temperature, decreasing ❖The fuel consumption may increase by as much as 15 %.
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  Selecting right viscosity-Rating of Lubricating Oil ❖ Lubricatin oil generally rated using a ❖The oil with lower viscosity grades is less viscous and is used in cold-weather operation. Modern high temperature, high speed, close 12 e t o n l g e i r n a e n s c e u s ehigh viscosity grades oil. visgcosity scale e istablished by the SAE . Commonly usedsviscosity grades are: SAE 5 SAE 10 SAE 20 SAE 30 SAE 40 SAE 45 SAE 50
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  13 RATING OF LUBRICATINGOIL – VISCOSITY INDEX ❖When certain polymers are added to oil, the temperature dependency of oil viscosity is reduced. These oils have low viscosity grades when they are cold and higher as they become hot. ❖As for example, SAE 10W-30 means that the oil has a grade 10 when it is cold (W stands for winter) and 30 when it is hot. ❖Commonly used oils in this category are: SAE 5W-20 SAE 10W -40 SAE 5W-30 SAE 10W -50 SAE 5W-40 SAE 15W -40 SAE 5W-50 SAE 15W -50 SAE 10W -30 SAE 20W-50
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  Rating of LubricatingOil (b)Specific Gravity: This property is of little importance except as an indicator of weight and volume. The specific gravity of oil varies from 0.85 to 0.96. (c)Pour Point: It indicates the temperature below which the lubricating oil loses its fluidity and will not flow or circulate in the system. This characteristics of the oil is important at low temperature. 14
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  lubricating oil shouldhave low Rating of Lubricating Oil (d)Oxidation Stability: Oxidation stability of an oil is its resistance to oxidation. Due to oxidation, oil forms deposits on the piston rings, and thereby loses its lubricating property. Some inhibitors are used to counteract these tendencies. (e) Acidity and Neutralization Number: Th neutralization number is a measure eofaacciiddiitcy .or alkaline contents of oil.(TAN NumbeTr)he (f) Oiliness: Oiliness is responsible for the boundary layer of molecules that can adhere or cling to a metal surface and provide lubrication after most of the oil gets displaced or squeezed 15 out.
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  CLASSIFICATION OF LUBRICANTS 16 • Animal •Vegetable • Mineral • Synthetic
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  Types of LubricatingOil Q Vegetable oils have been used in the past, especially for racing car engines. The main advantages of these oils are their high film strength, and they have a good lubricity. 17 Q Later, specially formulated have replaced their use mineral oil in s high performance engines. Mineral oils are most readily available and cost effective. They additives, and can be readily respond to produced in a wide range of viscosities. The main disadvantage lies with its wax content that affects cold performance and can clog filters.
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  ANIMAL LUBRICANTS 18 at normal •Lubricants with animal origin: – Tallow – Tallow oil – Lard oil – Neat’s foot oil – Porpoise oil • These are highly stable temperatures not be used because thf e o y r • Animal may internal lub cr o ic m ab nu t stion p sroduce fatty acids.
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  VEGETABLE LUBRICANTS 19 of mineral –Solid, Semisolid, Fluid • Examples of vegetable lubricants are: – Castor oil, Olive oil, Cottonseed oil • Animal and vegetable oils have a lower coefficient of friction than most mineral oils but they rapidly wear away steel. Mineral Lubricants • These lubricants are used to a large extent in the lubrication of aircraft internal combustion engines. • There are three classifications lubricants:
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  SYNTHETIC LUBRICANTS 20 • Because ofthe high operating temperatures of gas-turbine engines, it became necessary to develop lubricants which would retain characteristics at tempert a h te ui rr es that cause petroleum lubricants to evaporate and break down. • Synthetic lubricants do not break down easily and do not produce coke or other deposits.
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  Additives ❖ Corrosion andRust Inhibitors ❖ Anti-foam Agents ❖ Detergent-Dispersants ❖ Pour Point Improvers ❖ Oiliness and Film-strength Agents 21
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  Conclusions 22 In order tominimize friction between the moving parts and hence wear, lubrication system in an engine plays a significant role. The lubrication system is designed to deliver clean oil at the correct temperature and pressure to every part of the engine. Lubricatin oil can be supplied to g the various engine components by a splash system or by a pressurized system or a by a combination of both. In two-stroke engines, oil is mixed with the fuel itself.