Principles of lubrication new

Lubrication Oil & Grease
By – Fayek Shakran

Oil Analysis
Principles of Lubrication
Oil & Grease Lubrication
Right lubricant
to the right place,
on the right machine,
in the right amount,
at the right time.
Lubricant storage and handling
Task-Lubricant selection
Course Content

Our Industrial Requirement
– Improving productivity & Minimizing waste .
– Reducing costs of Operation .
How ?

When one body slides across another a resistive force must be overcome.
Friction
Force that opposes motion between two surfaces in contact.

Friction is Caused by Micro welds
Types of friction:
a. Static (usually the greatest)
b. Sliding
c. Rolling (usually the least)
Friction

Friction
• Causes of Solid Friction
Factors Influencing Friction
Surface roughness1 Flatter areas2
It is independent of both:
- Speed
- Area of contact

The principle of supporting a sliding load on a
friction-reducing film is known as lubrication
Lubrication
• prevention of metal-to-metal contact by means of
an intervening layer of fluid
1
2
These lubricants are used to a large extent in the
lubrication of aircraft internal combustion engines
& moving parts.

Lubrication
Type of lubricants
Solid- Semisolid – Fluid

Classification of Lubricants
• Animal
• Vegetable
• Mineral
• Synthetic
These are highly stable at normal
temperatures
Animal lubricants may not be used for
internal combustion because they
produce fatty acids
Animal and vegetable oils have a lower
coefficient of friction than most mineral
oils but they rapidly wear away steel
Examples of vegetable lubricants are:
Castor oil
Olive oil
Cottonseed oil

Lubricants
All liquids will provide lubrication of a sort, but some
do it a great deal bettor than others.
– Provide high quality products, supported by successful field experience.
– Work to lower maintenance.
- Work to Lower cost of operation through value added services.
– Provide products to help Machine for long operation.
Oil Requirement :
Lubricating oils

• are improved heat dissipation from the friction point
• its excellent penetrating and wetting properties.
Lubricating oils
The advantages of a lubricating oil .
Complex design is required to keep
the oil at the friction point and
prevent the danger of leakage.
main disadvantage
Lubricating
oils are used
in
sliding bearings
chains
gears
hydraulic systems

Purpose of Oils
• Oil reduces friction between moving parts
– Lubrication – slippery surface between moving parts
– Seal – between piston rings and cylinder surface
– Cool – especially bearings (dissipate heat)
– Clean – contaminates held in suspension (wear particles)
Change oil before winter lay-up so
contaminates are removed and do not
damage the machine during storage
Different lubricants show different behavior regarding these
requirements.
Oil Lubrication

Lubricating oils
• Lubricating oils consist of a base oil and additives which
determine their performance characteristics. The additives,
however, determine its actual performance by influencing the
base oil’s.
• oxidation stability.
• anticorrosion properties.
• wear protection.
• emergency lubrication properties.
• wetting behavior.
• emulsibility.
• stick-slip behavior.
• viscosity-temperature behavior.
Main tasks, remain lubrication and protection against friction and wear.
The additives to

 Synthetic oil
 Engine oil
 Transmission fluid.
 Refrigeration oil.
 Compressor oils.
 Metalworking fluids and oils.
 Laminating oils.
 Industrial hydraulic fluid.
 Copper and aluminum wire drawing
solution.
 Electrical insulating oil.
 Industrial process oils.
 Oils used as buoyants.
 This list does not include all types of
used oil.
These lubricants
are used to a
large extent in
the lubrication.
Mineral & synthetic Oil

Mineral & synthetic Oil
Oils are generally classified as refined and synthetic.
Oils are refined from crude.
Oil while synthetic oils are manufactured.
-Synthetic lubricants are produced from chemical synthesis.
-These oils are generally superior to petroleum (mineral)
lubricants in most circumstances.
-Synthetic oils perform better than mineral oils.
Petroleum (mineral) lubricants are produced from the
refinement of existing petroleum

Synthetic Lubricants
• Because of the high
operating temperatures of
gas-turbine engines, it
became necessary to
develop lubricants which
would retain their
characteristics at
temperatures that cause
petroleum lubricants to
evaporate and break down.
Synthetic lubricants do not
break down easily and do not
produce coke or other deposits

• notable at either very low
or very high temperatures.
• Good oxidation stability
• lower coefficient of
friction permits operation
at higher temperatures.
• The better viscosity index
and lower pour points
permit operation at lower
temperatures
Synthetic Oil
The major is the initial cost,
which is approximately three
times higher than mineral-
based oils.
However, the initial premium is
usually recovered over the life
of the product, which is about
three times longer than
conventional lubricants.
The higher cost makes it
inadvisable to use synthetics in
oil systems experiencing leakage
Advantages of synthetic Oil Disadvantage to synthetic oils

Petroleum Lubricants
Petroleum lubricants stand high in metal-wetting ability, and
they possess the body, or viscosity characteristics.
oils have many additional properties that
are essential to modern lubrication, such as:
-good water resistance.
-Inherent rust-preventive characteristics.
-Natural adhesiveness.
-Relatively good thermal stability.
-Ability to transfer frictional heat away
from lubricated parts.

Characteristics of Lubricating Oils
Gravity
Flash Point
Viscosity
Cloud Point
Pour Point
Carbon-
Residue Test
Ash Test
Precipitation-
number

• The gravity of petroleum oil is a numerical value which
serves as an index of the weight of a measured volume of
this product
Gravity
Flash Point
1
3
2
Temperature which the oil give off enough vapor to form a
combustible mixture above the surface.
Viscosity
Viscosity a measure of a resistance to flow

Cloud Point4
The cloud point is the temperature at which the separation of
wax becomes visible in certain oils under prescribed testing
conditions.
Pour Point5
The pour point of an oil is the temperature at which the oil
will just flow without disturbance when chilled.
Carbon-Residue Test6
The purpose of the carbon-residue test is to study the carbon-
forming properties of a lubricating oil.

Ash Test
7
The ash test is an extension of the carbon-residue test - The
ash content is a percentage (by weight)
Precipitation number8
The precipitation number recommended by the ASTM
(American Society for Testing and Materials) is the number of
milliliters of precipitate formed when 10 mL of lubricating
oil is mixed with 90 mL of petroleum naphtha under specific
conditions and then centrifuged

Lubricant Additives
-Additives are most effective in overall performance of an oil .
-A poor oil cannot be converted into a quality oil by additives.
-There are limits to the amount of additives that can be added.
additive may function in any of the following three ways:
Protecting lubricated surfaces. Additives coat the
lubricated surfaces and prevent wear or rust
Improving performance. Viscosity index improvers
and antifoaming agents are examples.
Protecting the lubricant itself. Antioxidants reduce
the tendency of oil to oxidize and form sludge.

Viscosity
With lubricating oils, viscosity is
one of the most fundamental
properties, and much of the
story of lubrication is built
around it.
viscosity a measure of a resistance to flow
Thick fluids, like molasses, have relatively
high viscosities; they do not flow readily.
Thinner fluids, such as water, flow very
easily and have lower viscosities.
Lubricating oils are available in a wide
variety of viscosities

Typical Lubrication Systems
Oil bath lubricationOil injection lubricationCirculatory oil lubrication
Cooling
pump

Oil Lubrication Methods
Gravity LubricationSplash Feed Lubrication

Vibrating pin LubricationOil Bath Lubrication

Pressure Feed Lubrication

Wick Lubrication Ring Feed Lubrication

Boundary Lubrication
When a complete
fluid film does not
develop between
potentially rubbing
surfaces
Stribeck Curve
Mixed Film
Hydrodynamic
Lubrication

Hydrodynamic Lubrication
hydrodynamic
film occurs
when there is
sufficient
lubricant
between the
lubricated
surfaces at the
point of
loading to form
a fluid wedge
that separates
the sliding
surfaces.

Under even
heavier loads
and moderate
to high sliding
speeds, surfaces
deform
elastically and
thin oil films
are "trapped"
between them
Elastohydrodynamic

Hydrodynamic Lubrication
New device

Components of Lubrication Systems
• Plumbing for Lubrication Systems
• Temperature Regulator (Oil Cooler)
• Oil Viscosity Valve
• Oil Pressure Relief Valves
• Oil Separator
• Oil Pressure Gauge
• Oil Temperature Gauge
• Oil Pressure Pumps
• Scavenge Pumps
• Oil Dilution System

Lubricating Greases
• Lubricating greases consist of a lubricating oil, a thickening
agents and one or more additives.

Lubricating Greases
Today’s new-generation greases are expected to do much more
than lubricate. They must meet a wide range of demanding
performance requirements.
• Long, trouble-free service life, even at
high temperatures
• Rust and corrosion prevention
• Dependable, low-temperature start-up
• Resistance sling and water wash.
The function of grease is to remain in contact with and lubricate moving
surfaces without leaking out under gravity or centrifugal action, or be
squeezed out under pressure.

• Lubricating greases consist of a lubricating
oil, a thickener and one or more additives.
• The thickener is responsible for the
characteristics of the grease
Lubricating Greases
Complex greases generally have a higher drop point.
More resistant to oxidation.
Synthetic thickeners are most resistant to temperature.
Extensive testing is done to verify properties.
The advantage of a lubricating grease over an oil is that it
Remains at the friction point for a longer time.
less effort is required in terms of design.
Its disadvantage is that grease neither dissipates heat nor
removes wear particles from the friction point.

% Weight Loss of Grease Measured
• Typical Grease (Lithium) - 5%
• Water Resistant Grease <2%
• Exceptional < 0.5%
Water, 80o
C (175o
F)
Grease Packed Bearings
ASTM D1264 (DIN 51807)
WATER WASHOUT RESISTANCE
Lubricating Greases

(1) Machinery that runs intermittently or is in storage for an
extended period of time.
(2) Machinery that is not easily accessible for frequent
lubrication.
(3) Machinery operating under extreme conditions such as high
temperatures and pressures, shock loads, or slow speed under
heavy load.
(4) Worn components. Grease maintains thicker films in
clearances enlarged by wear and can extend the life of worn
parts that were previously oil lubricated.
Lubricating Greases - Uses

Grease Characteristics
viscosity
Bleeding, migrationis
penetration
Contaminants.
Corrosion- and rust-resistance
Dropping point
Evaporation
Oxidation stability.
Pump ability.
High & Low temperature effects.

This is another area in which
different manufacturers
give differing
recommendations.
However, to provide
guidance on the amount of
grease to be added for
different size motors, a
grease weight versus shaft
diameter curve was
determined to provide the
most useful information.
Lubricating Greases - Added
How Much Grease Should be Added?

Grease Lubrication Method
Refilling Lubri-
Cup® with 615

Proper lubrication of bearings is a difficult problem to
tackle. Unless the lubrication technician is able to hear
the sound of the bearing during actual lubrication, it's
a guessing game. Now the guesswork is over.
The Ultra-Lube allows you to hear the voice of the bearing
as it is being lubricated. It easily attaches to a grease
gun, turning it into a sensitive listening device.
The Ultra-Lube provides the user with feedback about the
current lubrication status of components about to be
lubricated.
The Ultra-Lube is attached to and becomes an integral part
of the grease-gun.
Upon connecting the gun to the grease nipple the operator
is able to listen to the electronically amplified noise
through the headset and is able to discern problems
associated with lack of lubricant or too much
lubricant.
No additional procedure is necessary other than to
continue to grease components in the normal manner.
Ultra-Lube

Brass Grease Nipples
Straight
90 Deg
45 Deg

Lubricant storage and handling study

All lubricants are the end product of
much careful research, refining, and
testing.
During storage after delivery, however,
several things can happen to impair
quality.
-Careless handling.
-Contamination.
-Exposure to abnormal temperatures.
-Confusion of stocks.
all these factors can result in wastage,
damage to machinery, deterioration of
lubricants, higher maintenance costs,
and loss of production.
Lubricant Handling/Storage

Outdoor Storage
Outdoor storage should be avoided if possible
Keep bungs tight
Lay drums on their sides
Use drum covers
Before removing the
bungs, dry the
drum heads and
wipe them clean of
any contaminant

Indoor Storage
-Storage temperatures should remain moderate at all times.
-Oil house should be located away from industrial contamination.
-Should be kept clean at all times.
-Regular cleaning schedules being maintained.

-Avoid all unnecessary contacts, use protective equipment to prevent contact.
-Remove promptly any petroleum product that gets on the skin.
-Do not use gasoline, naphtha, turpentine, or similar solvents to remove oil
and grease from the skin.
-Use waterless hand cleaner or mild soap with warm water and a soft brush.
-Use only clean towels, not dirty rags.
-Remove all contaminated clothing immediately.
-Launder or dry-clean it thoroughly before reuse.
-Use protective hand cream, and reapply it each time hands are washed.
-After work hours, use simple cream to replace fats and oils removed from the
skin by washing.
-Wash hands and arms at the end of the work day and before eating.
-Get first aid for every cut and scratch.
-Avoid breathing oil mist or solvent vapors.
-Keep work area clean.
-Clean up spilled petroleum products immediately. Keep them out of sewers,
streams, and waterways.
-Contact the medical staff on all potential health-hazard problems.
Oil & Grease Handling
preventive measures for personnel who regularly handle petroleum products

Machinery Storage Protection
Storage Protection
Equipment amount of time required to store.
-corrosion inhibiting of inactive process.
-type of equipment.
-expected length of inactivity.
-Service time.
Petrochemical
companies will
usually develop
their standards
to take these
criteria.
must ensure that all its products in their
prescribed use and subsequent disposal
shall not create a significant hazard to the
public health or environment.
Company policy

9,5% by oils 0,5% by solid lubricants only
90% by greases
selecting the suitable Lubricant

revolution or DN - factor
D = external bearing diameter [mm]
d = internal bearing diameter [mm]
n = revolution per minute [rpm]
dm= medium bearing diameter [mm] = ———
D + d
2
DN = ——— • nD + d
2

Dependance of Relubrication Intervals on Tempearture
100
85
70
55
40
Lubrication interval°C
Temperature at the outer ring
l above 70°C the factor 0,5 applies
for each temperature rise of 15°C
i.e. with a temperature rise from e.g.
70°C up to 85°C the service life of
the grease is cut by half.
l below 70°C the factor 2 applies
for each temperature drop of 15°C
i.e. with a temperature drop from
e.g.
70°C down to 55 °C the service life
of the grease is doubled.

Lubrication with Solid Lubricants
Deep groove ball bearings with increased clearance
required at:
l high temperatures > + 200 °C
l high temperature variations
l low speed

Desiccant Breather Function
Keeps head space clean & dry
Design varies by manufacturer.
In/out air vents.
Air diffuser/oil mist
foam filter.
Press-in mounting, varying
adapter options.
Particulate filter element.
Hydrophilic agent
adsorbs water,
indicates condition by
color change.
Second particulate filter
element protects
against migration of
desiccant.
Second foam filter stops
oil mist during
exhalation, evenly
distributes air.
Durable, shock
absorbing housing.

Contamination
• It’s the most frequent problem that affects sample integrity.
– Wear metals
– Water
– Unusual color
– Particular matter

The primary objective of Contamination Management is
optimal system cleanliness.
1. Increased fluid usage life
2. Reduced component wear
3. Less machine down-time
4. Optimal machine performance
Optimal system cleanliness will give you:
All this will result in significant
cost savings for your plant.
objective of Contamination Management

Purpose
• To give an understanding of the oil analysis program and
what is required to ensure that oil sampling from applicable
equipment is successfully accomplished.
Oil Analysis
Objectives
-Condition Monitoring Program
-Improve equipment
reliability/readiness
-Lower maintenance costs
-Reduce resource usage
-Maintenance diagnostic tool-
predictive maintenance

Methods of Analysis
• Spectrometric
• Viscomentry
• Crackle Test
• Ferrography
• Infrared
Spectrosopy

Elements Tested For
• Aluminum
• Antimony
• Barium
• Boron
• Calcium
• Chromium
• Copper
• Iron
• Lead
• Magnesium
• Molybdenum
• Nickel
• Phosphorus
• Potassium
• Silicon
• Silver
• Sodium
• Tin
• Titanium
• Zinc
Methods of Analysis
Contamination
Wear metals Water color Particular matter

90
80
70
60
50
40
30
20
10
0.002 3.0 6.0
% WATER IN OIL
%REDUCTIONINFATIGUELIFE
48
78
83
• Mobil Oil evaluation on bearing fatigue life
– 0.002% water reduces fatigue life 48%
– 6.0% water reduces fatigue life 83%
– 0.002% water is 1 drop of water in a quart of oil
Water Contamination Problem

Sampling Methods
• Valve
• Pump
• Drain

Acceptable Contamination Levels
Sensitivity: Main protection
Type of system: Low pressure systems
with large clearances
Typicalcomponents Ram pumps
Particle
sizes
Range of
counts ISO
> 5 µm 1,000,000 21 /17
> 15 µm 64,000
> 5 µm 250,000 19/15
> 15 µm 16,000
> 5 µm 130,000 18/14
> 15 µm 8,000
> 5 µm 16,000 15/11
> 15 µm 1,000
> 5 µm 4,000 13/9
> 15 µm 250
Sensitivity: Average
Type of system: Low pressure heavy industrial
systems
Typicalcomponents Gearpumps, manual and poppet
valves cylinders
Sensitivity: Important
Type of system: Generalmachinery& mobile
systems. Medium pressure,
medium capacity
Typicalcomponents Vanepumps, spool valves
Sensitivity: Critical
Type of system: High performanceand high
pressure long life systems,
i.e., aircraft,machinetool
Typicalcomponents Industrialservo valves
Sensitivity: Super critical
Type of system: Silt sensitive control system
with very high reliability.
Laboratoryor aerospace
Typicalcomponents High perf. servo valves

Air Contaminant
Air can exist in oil in
three different states:
dissolved.
entrained .
foam.
Causes of Excessive Air
Contamination
-When a lubricating oil
becomes contaminated
with water
-loss of antifoam additives
-suction leaks
-poor reservoir design
-using the wrong viscosity

Effects of Air Contamination
Air contamination can have negative effects on the machine and
the lubricant.
Air can damage a lubricating oil by increasing the rate of
oxidation
reducing its heat transfer coefficient and reducing its film strength
Machine wear can be generated by air contamination by several
mechanisms
film thickness become compressible.
In hydraulics, entrained air can create other problems as well,
such as spongy operations, loss of controls and an increased
likelihood of surface deposits in valves.

Contamination Control
C
o
n
t
a
m
i
n
a
t
i
o
n
ISO
22/19
21/17
20/15
19/16
18/15
17/14
16/13
15/12
14/11
13/10
12/09
Component Life
Component Life Over Time
----
------------
-----
Clean New Oil
10,000
2,500
25,000
Keep it Clean-Cool-Dry Desiccant Breathers Oil Safe System Color Coding
Storage solutions Personnel training Monitor/improve
Source– CaterpillarContaminationControlBasic TrainingProgram
157.7 lb/yr
78.9 lb/yr
19.7 lb/yr

Total Impact of Lubrication on Costs

Plain bearings
Plain bearings and bushings come in a
wide variety of shapes, sizes, types
of surface contact modes, material
compositions and operating profiles,
including:
• Single-sided
• Double-sided
• Vertical shaft
• Horizontal shaft
• Solid housing
• Split housing
• Thin wall
• Thick wall ..etc
Plain or journal bearings are used
for high radial loads and low- to
high speeds. Typical applications
include turbines, large milling
systems, engine cranks, compressors,
gearboxes, shaft bearing supports, ...
Task-Lubricant selection for plain bearing

Shaft
Rotation
Fluid dynamic pressure
support shaft floating
Oil flow
Groove
<= 5μm
performs longer life by no metal contact with shaft to bearing

Under normal operating
conditions, the lubrication
regime is a hydrodynamic
full-fluid film. A
hydrodynamic film occurs
when there is sufficient
lubricant between the
lubricated surfaces at the
point of loading to form a
fluid wedge that separates
the sliding surfaces. In this
state, the lubricated
components do not touch
each another, reducing
friction and wear.
Stribeck Curve.
This is represented by Z*N/P
where
Z = viscosity,
N = speed (rpm)
P = load.
Z*N/P

If the load or the speed changes, the lubricant viscosity must be
adjusted to compensate for the change.
the following approximation equation gives an estimate of what
the final outcome should be.
u = ∏* d * n
where
u = surface speed
d = bore diameter, meters
n = shaft speed, revolutions per second
∏ = 3.1415
The first step is to estimate the machine’s surface speed
Second step -estimate the machine’s unit surface pressure.
ρ = w/I*d
Where
ρ = pressure, kN/m2
l = bearing width
d = shaft diameter
w = load, kN
1 2

This is intended only to be a rough
approximation for the sake of
illustrating the principles behind
lubricant selection.
Please consult with a lubrication
engineering professional prior to
attempting to make any change
in the lubricant selection for any
actual operating machines
Note:
Once known these values
can be plotted on a table for
a rough estimate of
minimum allowable viscosity
Other considerations
The final lubricant type decision
should include considerations
for oxidation stability, corrosion
protection, wear protection,
water and air separation
properties, etc.

Task 2 – Causes of bearing failure
• Improper Lubrication - 43%
– How Much, How Often, What Type, What Thickness,
– What Properties are Important
• Improper Mounting - 27%
– Alignment,Work Area, General Practices, Inventory Control
and Storage of Bearings
• Other Lubrication Causes - 21%
– Separation in Storage
– Temperature Limit Exceeded
– Moisture Contamination
– Other Contamination
• Fatigue - 9% Ultimate L10 Life Expectancy
64% of Bearing Failures are Lubrication Related IS Not The Whole Story
In the Industry We Serve, Most Bearings Fail Due To Some Form of
CORROSION

Task 3 - Gears Lubrication
• Proper Lubrication with timely addition / replacement
plays vital role in maintaining the gear boxes with
efficiency and increasing its working life.
• Oil level should be checked in all the gear boxes oil
indicators / dip sticks.
• Oil level should be in between the minimum and
maximum limits of the dip stick (or indicator).
• Testing of the lubricating oils used to be carried out
periodically. The following tests are to be done…
1. Dirt contamination
2. Moisture
3. Volatile materials (Benzene, kerosene, spirit etc,)
4. Viscosity
5. Acidity
6. Alkalinity due to soda (Na2 Co3) etc.,

• Worm gears are used to transmit power
& motion between shafts at right angles
• Worm gears normally consist of a small
diameter steel gear worm and a larger
diameter bronze wheel
• Because of the high degree of sliding (5-
20%), the efficiency of worm gears is
lower than for spur or helical units – ~
75 - 85%
• To MINIMIZE WEAR & MAXIMIZE
EFFICIENCY, synthetic Poly Alkylene
Glycol (PAG)- based lubricants are used
in these applications
Synthetic Gear Oils for Worm Gear Lubrication
Bronze wheel
Steel worm

Benefits in Using Synthetic Gear Oils
Mineral-based gear oils typically have a finite performance life
determined by temperatures (low and high), loads, ambient
conditions
• Synthetic gear oils typically provide the following benefits
over mineral oils:
– Improved oxidative & thermal stability
– Improved viscosity-temperature behavior
– Extension of oil change intervals
– Reduced energy consumption
– Improved gear efficiency
– Reduced oil temperatures
– Savings on maintenance and waste disposal costs
– Reduced vibration

Troubleshooting
Symptom: Oil pressure decrease, oil temp. steady
Cause: …………………………………………
Symptom: Slight drop in oil pressure, steady or slight rise in oil
temp.
Cause: ……………………………………………………
Faulty air-induction systems
Leaking cooling systems
Loose cross-over fuel lines
Abnormal wear rates of moving metal parts

 Reprocessing is the most common method of recycling used
oil in the U.S. Each year processors treat approximately 750
million gallons of used oil.
 Seventy-five percent of used oil is being reprocessed and
marketed to:
• 43% asphalt plants;
• 14% industrial boilers (factories);
• 12% utility boilers (electric power plants, homes, etc.);
• 12% steel mills;
• 5% cement/lime kilns;
• 5 % marine boilers (tankers or bunker fuel);
• 4% pulp and paper mills;
• 6% other.
Oil Recycling

Saves Money
• Oil/lubricant products (Good One)
• Oil/lubricant filters
• Repairs by early detection
By Using

LUBRICATION
Right lubricant is applied
to the right place,
on the right machine,
in the right amount,
at the right time.

Types of Greases
Calcium grease.
Calcium or lime grease, the first of the modern production greases
can lubricate satisfactorily to temperatures around 93 EC (200 EF).
1
lime grease
does not emulsify in water and is excellent at
resisting “wash out.”
manufacturing cost is
relatively low
maximum temperature of around 110 EC (230
EF).

Types of Greases
Calcium complex grease2
Aluminum gre ase.
Aluminum grease is normally clear and produced from high-viscosity oils.

Principles of lubrication new

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