A Report on

Lubricating Oils

By
1. 302D049 :- Pavan patil
2. 302D050 :- mohit pilane
3. 302D059 :- Atish shinde

Guide
Prof. Aravind.R. Tole

Department of Mechanical Engineering

Sinhgad College of Engineering (2022-2023)
 Lubricating Oils

CONTENTS

 Introduction

 Lubricating Oils

 Manufacturing Process

 Function of Lubricants

 Properties of Lubricating oil

 Additives

 Trends in Lubricants additives

 Selection of Lubricating oil

 Advantages of GD & T

 Reference

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1. INTRODUCTION

 Lubricants:- Lubricants are those substances, which are used to reduce the
force of friction between two sliding surfaces.

 Lubrication:- Lubrication is the process, or technique employed to reduce

wear on surfaces in close proximity and moving relative to each other

What are types of lubricating oil?

 Lubricating oils may also be divided into categories according to

the
type of services and applications, such as motor oil, transmission oil,
hydraulic fluid, crankcase oil, cutting oil, turbine oil, heat-transfer oil,
electrical oil, and many others.

 However, there are two main groups of lubricating oils by applications: (1)
oils used in intermittent service, such as motor and aviation oils, and (2) oils
designed for continuous service, such as turbine oils.

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2. Lubricating Oils
Lubricating oils are produced from the finishing (deasphaltening,
hydrotreatment, solvent extraction, and dewaxing) of heavy vacuum gas oils.
The resulting family of base oils are blended to yield different types of
lubricating and hydraulic oils that meet various physical- and performance-
based properties. A series of GC/FIDs for different base oils. The chemical
compositions of the base oils are complex, owing in part to the overwhelming
predominance of hydrocarbons and polar compounds that cannot be resolved by
conventional GC methods. As such, the predominant feature of the
GC/FID chemical fingerprints of lubricating oils is the shape of the UCM. (New
analytical techniques, however, are revealing greater details of lubricants; Li
et al., 2014). However, that some base oils contain n-alkanes and biomarkers,
the latter of which sometimes can appear as the only resolved peaks in some
lubricating oils. The biomarker distributions in lubricating oils will largely
reflect those inherited from the crude oil feedstock and thereby provide a high
degree of specificity in the characterization of spilled lubricating oils.

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3. Manufacturing Process
 Lube oil is extracted from crude oil, which undergoes a preliminary
purification process (sedimentation) before it is pumped into fractionating
towers.

 A typical high-efficiency fractionating tower, 25 to 35 feet (7.6 to 10.6

meters) in diameter and up to 400 feet (122 meters) tall, is constructed of
high grade steels to resist the corrosive compounds present in crude oils;
inside, it is fitted with an ascending series of condensate collecting trays.

 Within a tower, the thousands of hydrocarbons in crude oil are separated

from each other by a process called fractional distillation.

 As the vapors rise up through the tower, the various fractions cool,
condense, and return to liquid form at different rates determined by their
respective boiling points (the lower the boiling point of the fraction, the
higher it rises before condensing).

 Natural gas reaches its boiling point first, followed by gasoline, kerosene,
fuel oil, lubricants, and tars.

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4. Function of Lubricants
Lubricants provide three major functions within your engine: cooling, cleaning
and reducing friction.

1. Controlling Corrosion and Acids:- Engine corrosion occurs when acids

builds up in the lubricant. Acids can cause major damage and a reduction in
performance. If your engine parts start to corrode from acids, it could lead to
engine failure
2. Handling Contaminants:- Soot and sludge are byproducts of combustion.
If the lubricant is untreated, both soot and sludge can build grow and
accumulate in the oil block oil passage and collect onto essential engine
components.
3. Maintaining Cleanliness:- Heat and oxidation can cause lubricants to
breakdown. When oil breaks down in an engine, large deposits can form on
the surface pistons and oil passages which can prevent engine parts from
functioning as intended
4. Reducing Engine Wear:- There’s no way to completely eliminate engine
friction–we have to manage it. Unmanaged friction causes a heat buildup
and engine wear. The additive solution is an anti-wear agent that forms a
solid film on metal surfaces.
5. Minimizing Oxidation:- Friction and combustion naturally cause heat.
Heat can damage parts, and reduce the ability of the other additive
components to work properly. One way that heat negatively affects the
engine lubricant is through increased oxidation.
6. Managing Viscosity:- Keeping the lubricant’s viscosity consistent is key to
making sure that all the components work together. Shear stability is a
measure of how well the oil maintains its original viscosity.
7. Decreasing Aeration:- When air gets into the lubricant, it can cause loss of
power and loss of pressure in the sump. Foam in a lubricant will not allow
the fluid to do its job of protecting critical moving

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5. Properties of Lubricating Oil

1. Viscosity: A lubricant’s “internal resistance to flow.” Higher viscosity
lubricants are thick and don’t flow, while lower viscosity lubricants
have a closer consistency to water and do flow. The image below
demonstrates the viscosity of four different oils.
2. Viscosity Index: The rate of change in viscosity with changes in

temperature. In other words, how much viscosity changes as temperature

changes
3. Pour Point: The lowest temperature at which a lubricant will flow
or pour like a liquid. This can differ depending on test conditions.

4. Oxidation Stability: Oxidation is a reaction that occurs when oxygen is

combined with lubricating oil. Variables such as high temperatures,

water and acids will accelerate the rate of oxidation

5. Flash Point: The temperature at which a lubricant will ignite when

heated and mixed with air, but a flame is not sustained

6. Thermal stability:- Thermal stability refers to the ability of lubricants to

resist breakdown at high temperatures. Poor thermal stability can result in
sludge, deposits and increased viscosity.

7. Demulsibility:- Demulsibility is another important property of

lubricating oils. It is the ability of an oil to separate from water.

8. Fire point:- Fire point is determined in a manner similar to flash point.

Oil is heated until vapours form; a flame is then passed over the oil. The
fire point is the temperature at which the oil sparks and the flame is
sustained. The fire point for lubricating oils is typically 371°C (700°F) or
above.
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6. Additives
 Why we need additives in Lubricant?

:- The primary function of Lubricant additives is to improve the properties of the base
stock under different operating conditions and the high performance requirements of
any machinery. Lubricant additives are chemical components that need to blend well

Types of Additives

1. Anti Oxidants:- Oxidation is the general attack of the weakest components

of the base oil by oxygen in the air. It occurs at all temperatures all of the
time but is accelerated at higher temperatures and by the presence of water,
wear metals and other contaminants.
2. Foam Depressants:- Prevent foam from forming, thereby maintaining a
lubricating film based on oil not air bubbles, resulting in the ability of the oil
to be pumped effectively at the required rate. The viscosity of a lubricant and
surface tension determine the stability of the foam.
3. Corrosion Inhibitors:- These additives reduce or eliminate internal rust and
corrosion by neutralizing acids and forming a chemical protective barrier to
repel moisture from metal surfaces. Some of these inhibitors are specific to
protecting certain metals. Therefore, an oil may contain several corrosion
inhibitors
4. Detergents:- Detergents perform two functions. They help to keep hot metal
components free of deposits (clean) and neutralize acids that form in the
oil. Detergents are primarily used in engine oils and are alkaline or basic in
nature. They form the basis of the reserve alkalinity of engine oils, which is
referred to as the base numbers (BN).

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5. Friction Modifiers:- Friction Modifiers are typically used in engine oils and
automatic transmission fluids to alter the friction between engine and
transmission components. In engines, the emphasis is on lowering friction to
improve fuel economy. In transmissions, the focus is on improving the
engagement of the clutch materials. Friction modifiers can be thought of as
anti-wear additives for lower loads that are not activated by contact
temperatures.
6. Viscosity index improvers:- Viscosity of oils sharply decreases at high
temperatures. Low viscosity causes decrease of the oil lubrication ability.
Viscosity index improvers keep the viscosity at acceptable levels, which
provide stable oil film even at increased temperatures. Viscosity improvers
are widely used in multigrade oils, viscosity of which is specified at both
high and low temperature.

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7. Trends in Lubricants Additives

 Increasing Demand from Automotive and Other Transportation
Industry.

1. Automotive and other transportation media, such as aircraft and marine, are
the largest markets for lubricants.
2. Engine designs have been continually improved to enhance performance, increase
efficiency, and meet environmental emission regulations.
3. Engine oils, gear oils, transmission oils, greases, and compressor oils are the most
widely used lubricants in all kinds of automobiles. Lubricants have a good share
in the aftermarket and among OEMs.
4. Medium-duty and high-performance lubricants are used extensively in vehicle
components, such as gears, transmission systems, and engines, which are
subjected to high loads and rapid rubbing.

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8. Selection of Lubricating Oil

 Key Factors for Lubricant Selection

1. Function: What Does the Lubricant Do?

:-Lubricants have a wide range of functions that include controlling the following:

 Friction (lubricants reduce heat generation and energy consumption)

 Wear (lubricants can reduce mechanical and corrosive wear)
 Corrosion (quality lubricants protect surfaces from corrosive substances)
 Contamination (lubricants transport particles and other contaminants to filters and
separators)
 Temperature (lubricants can absorb and transfer heat)
 Sometimes, in the case of hydraulics, lubricants also provide power transmission

2. Ingredients: What’s in the Lubricant?

 You may not think of lubricants as having many ingredients, but in fact there are
lots of different additions to the base oil. These ingredients are deliberately chosen
based on how the lubricant will be used. This is true of greases as well as oils.
Many people are unaware that greases are actually oils with thickeners added. The
type of thickener matters a great deal. The thickener typically is composed of
fibrous particles that act like a sponge, holding the oil in place to give it a more
viscous quality. Each thickener type confers different advantages and
disadvantages, specifically having to do with shear stability, pumpability, heat
resistance and water resistance.

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3. Terminology: What Do These Things Mean?

 To make correct lubrication choices, you must have an understanding of the

terminology involved. Commonly used terms include the following:

 Viscosity — This describes how thick or resistant to flow the oil or grease is.
Higher viscosity means higher flow resistance.
 Kinematic viscosity — A simple pour test can be used to offer a visual illustration
of viscosity. Lube technicians can provide a demonstration of kinematic viscosity
on the shop floor, because it’s easy to do and takes very little time.
 Weight — This also relates to how viscous an oil is or how easily it flows at a
specific temperature.
 NLGI consistency — The consistency indicates how hard or soft a grease is. The
numbers range from 000 (like cooking oil) to 6 (like cheddar cheese).

4. Ease of Use:-

 Not all oils are applied the same way. The method of application will depend on
your particular equipment. For some situations, such as an easy-to-reach hinge, an
aerosol lubricant may suffice. A grease may be easily applied by hand to an
accessible gearbox. However, for hard-to-reach locations, an automatic dispenser
that only needs to be refilled every six months can be a great option. For chains
that require regular lubing, a continuous dispenser might be best. If you are
purchasing lubricants from a reputable vendor, consult with one of their specialists
to determine what method will be most beneficial.

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5. Longevity:-

Lubricants have an optimal lifespan, and once it’s over, they need to be replaced.
Failure to do so can result in runout, metal-on-metal contact, destroyed bearings and
other issues leading to downtime and higher expenses. The problem is that it’s not
always obvious when this is about to occur.

 One important way to track a lubricant’s lifespan is by monitoring the operating

temperature of your equipment. Excess heat destroys lubricants. Every rise in
temperature of 10 degrees C (18 degrees F) above 65 degrees C (150 degrees F)
will
cut the lubricant’s service life in half. This means a lubricant that would normally
last one month at 150 degrees F will last only two weeks at 168 degrees F, one
week at 186 degrees F, and just three or four days at 204 degrees F before needing
to be replaced or rejuvenated. After that, it will cease to do its job, essentially
offering little or no protection even if lubricant levels appear high.

6. Cost:-

 As with most things in life, you get what you pay for. A food-processing plant may
opt to use mineral oil on transport chains because it’s cheap and food-safe.
However,
plain mineral oil has a number of disadvantages that outweigh the low cost. For
instance, this particular oil may have poor runout characteristics, attract
contaminants to form an abrasive paste or drip to create an unsafe working
environment. Managers who choose this option will soon discover that their
savings are wiped out by the cost of downtime resulting from using inferior-
quality lubricants, not to mention the potential of workplace accidents.

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9. Applications
 Lubricants are primarily used to reduce friction stress between surfaces.
They have the following uses:

 As antiwear, antioxidants, and antifoaming agents.

 As demulsifying and emulsifying agents.
 As rust and corrosion inhibitors.
 In machinery as engine oils, compressor oils, gear oils, and piston oils.
 As hydraulic, brake, and gear box fluids.
 Used in the soap and paint industries.
 Some specific uses of certain variants of lubricants are:
 Synthetic lubricants are used in turbines, vacuum pumps, and
semiconductor devices.

 Molybdenum is used as a paint pigment and as a catalyst.

 Liquid lubricants are used in medicines.

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10.References
1. https://www.sciencedirect.com/topics/earth-and-planetary-
sciences/lubricating-oil
2. https://360.lubrizol.com/2015/Vital-Functions-of-an-Engine-
Lubricant
3. https://www.globalspec.com/reference/38787/203279/Applicati
ons-of-Lubricants

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