37
1 HOME END Fuchs Indonesia Fuchs Indonesia

Grease basic knowledge_nk0906

Embed Size (px)

Citation preview

Page 1: Grease basic knowledge_nk0906

1

HOME END Fuchs Indonesia

Fuchs Indonesia

Page 2: Grease basic knowledge_nk0906

2

HOME END Fuchs Indonesia

Grease

A solid to semi-fluid product of a thickening agent in a liquid lubricant. Other ingredients imparting general

properties may be included

Page 3: Grease basic knowledge_nk0906

3

HOME END Fuchs Indonesia

• Advantages • Disadvantages

Convenience

Resistance

Protection

Cleanliness

Low Cooling Rate

Contamination

Performance

Limitations

Grease

Page 4: Grease basic knowledge_nk0906

4

HOME END Fuchs Indonesia

Grease Composition

Base Oil70 - 95%

Thickener10 - 20%

Additives5 - 10%

Grease

Page 5: Grease basic knowledge_nk0906

5

HOME END Fuchs Indonesia

Lubricating Greases - Basics and Applications

Page 6: Grease basic knowledge_nk0906

6

HOME END Fuchs Indonesia

Components Used in Grease FormulationBase oils Thickeners Additives

Mineral oils

Synthetic mineral oils

Di-esters

Silicones

Phospate esters

Fluorocarbon

Fluorinated silicone

Chlorinated silicone

Sodium soap

Calcium soap

Lithium soap

Aluminium soap

Barium soap

Aluminium complex

Lithium complex

Bentonite clay

Silica

Carbon/graphite

Polyurea

PTFE

Polyethylene

Indanthrene dye

Phthalocyanine dye

Anti-oxidants

Anti-wear additives

EP additives

Corrosion inhibitors

Friction modifiers

Metal deactivators

VI improvers

Pour-point depressants

Tackiness additives

Water repellants

Dyes

Structure modifiers

Page 7: Grease basic knowledge_nk0906

7

HOME END Fuchs Indonesia

Typical Oils Used in Lubricating Greases• Petroleum

Paraffinic – good VI and thermal stability to 350oF max. temp.

Naphthenic – good low temperature performance to –65oF min

• Synthetic

Nominal Serviceable Temp. Range. oF

Diester - 100 to 400

Fluorosilicone - 50 to 450

Hydrocarbon - 80 to 350

Polyalkylene glycol - 40 to 350

Polyol ester - 50 to 400

Silicone - 100 to 450

Page 8: Grease basic knowledge_nk0906

8

HOME END Fuchs Indonesia

Base Oil For Grease

• Depends on required characteristics of grease.

Flow, viscosity, temp. range and speed.

• Paraffinic and napthenic mineral oils

• Synthetics used for special applications – very

low/very high temp.

• Base oil function is to lubricate

Page 9: Grease basic knowledge_nk0906

9

HOME END Fuchs Indonesia

Thickener Types

•Metal soaps

Lithium, calcium, sodium, barium, aluminium, etc

Complex (I.e. Lithium complex, alumunium complex, Calcium complex)

• Inorganics/non soap

Clays, megalite, montmorilonite, hectorites, bentonites

• Organics

Polyurea

• Fluoro Organic

PTFE

Page 10: Grease basic knowledge_nk0906

10

HOME END Fuchs Indonesia

• Act as a carrierTo release fluid

• Water Resistance

1. Washout Resistance - the ability of the lubricant to stay in the bearing while operating partially or fully submerged (ASTM D1264).

2. Water Absorption - the ability of the grease to deal with the presence of water by either absorbing or resisting the washing and diluting action of the water.

3. Spray Resistance - the ability of the grease to resist displacement from a direct impingement of the water on the greased surface (ASTM D4049).

• Heat Resistance

Thickener Influences

Page 11: Grease basic knowledge_nk0906

11

HOME END Fuchs Indonesia

Grease Additives

Zinc dialkyIdithiophosphates

Dithiocarbamates (Zn, Sb, Pb)

Phosphate esters

Sulfurized fatty acids

Sulfurized hydrocarbons

Chlorinated hydrocarbons

• Anti-Wear/Extreme Pressure Agents

Page 12: Grease basic knowledge_nk0906

12

HOME END Fuchs Indonesia

Aryl amines

Zinc dialkyldithiophosphates

Hinderes phenols

Zinc and amine dithiocarbamates

• Anti-oxidants

Grease Additives

Page 13: Grease basic knowledge_nk0906

13

HOME END Fuchs Indonesia

Sulfonates (Ca, Ba, Li, Mg, Na, Pb, amine salts)

Napthenates (Zn, Ba, Pb)

Carboxylic acid derivatives

Triazoles

Sodium Nitrite

• Rust and Corrosion Inhibitors

Grease Additives

Page 14: Grease basic knowledge_nk0906

14

HOME END Fuchs Indonesia

Molybdenum disulfide

Graphite

PTFE

Powdered fluorocarbons

• Friction Modifiers

Grease Additives

Page 15: Grease basic knowledge_nk0906

15

HOME END Fuchs Indonesia

Polyolefins and olefin copolymers

• Adhesion Promoters

Grease Additives

Page 16: Grease basic knowledge_nk0906

16

HOME END Fuchs Indonesia

Penetration

NLGI Number ASTM Worked Penetration

000 445-475

00 400-430

0 355-385

1 310-340

2 265-295

3 220-250

4 175-205

5 130-160

6 85-115

The depth, in tenths of a millimeter, that a standard cone sinks into a material under prescribed conditions of weight, time and temperature. This depth is described as NLGI numbers.

Page 17: Grease basic knowledge_nk0906

17

HOME END Fuchs Indonesia

Factors In Deciding NLGI Grades• Speed

The higher the speed the harder the grease, so for high

speeds use no. 3. The maximum outer race speed for grease-

lubricated rolling bearings is about 15 m/s (3000 ft/min)

• Bearing size

Use a harder grease in a large bearing, No.3 or even no.4

• Sealing

If there is a particular need for effective sealing, use a harder

grease, No.3 or No.4

Page 18: Grease basic knowledge_nk0906

18

HOME END Fuchs Indonesia

Factors In Deciding NLGI Grades

• Shock loads or vibration

Shock load or vibration tends to cause grease to slump into

the moving components causing churning. A harder grease

minimizes the problem, so use No.3 or No.4. (Note that normal

steady loading does not strongly influence the grade)

• Temperature

Page 19: Grease basic knowledge_nk0906

19

HOME END Fuchs Indonesia

Some basic rules:

Low speeds Greases with high base oil viscosity and high loads and EP and / or solid lubricants

like Graphite or MoS2

High speeds Greases with low base oil viscosity

Oscill. movement Greases with white solid lubricants

High or low Greases with synthetic base oilstemperatures

Grease SelectionGrease Selection

Page 20: Grease basic knowledge_nk0906

20

HOME END Fuchs Indonesia

Important factors on Grease selection

1. Bearing design

2. Bearing speed

3. Load

4. Temperature

5. Environmental conditions

Page 21: Grease basic knowledge_nk0906

21

HOME END Fuchs Indonesia

Grease Incompatibility

Page 22: Grease basic knowledge_nk0906

22

HOME END Fuchs Indonesia

Base fluid compatibility

Öl-Typ

Mineralöl Polyalfa-olefin

Poly-glykol

Ester,synth.

Natives Öl Alkoxy-fluoröl

Silikonöl

Mineralöl + + - + + - -

Polyalfa-olefin + + - + + - -Polyglykol - - + - - - -Ester,synth. + + - + + - -Natives Öl + + - + + - -Alkoxy-fluoröl - - - - - + -Silikonöl - - - - - - +

Page 23: Grease basic knowledge_nk0906

23

HOME END Fuchs Indonesia

Calculation of lubricant consumptionCalculation of lubricant consumption

Effective lubrication is the combination of a suitable lubricant, right re-lubrication intervals and the optimum re-lubrication quantity.

„The more, the better“ is (nearly) always wrong. Over-lubrication leads to preliminary bearing failure and causes additional costs.

Frequent re-lubrication with small quantities is better than seldom re-lubrication in huge quantities. Optimization is necessary, because frequent re-lubrication needs more time.

Page 24: Grease basic knowledge_nk0906

24

HOME END Fuchs Indonesia

When calculating the optimum grease quantity, the free volume in the bearing as well as free space in the housing has to be considered.

First fill of bearing:

Fill the bearing completely, fill free space in the housing only with a quantity which allows, that grease coming out of the bearing during operation can remain in the housing to avoid undesired heating of the grease and the bearing. Sometimes sealing discs can be helpful.

Calculation of lubricant consumption:Calculation of lubricant consumption:

Page 25: Grease basic knowledge_nk0906

25

HOME END Fuchs Indonesia

Exceptions:

very high speeds:fill bearing and housing only to one third to avoid

ineffective working of the grease

very low speeds:fill bearing and housing completely to ensure

lubrication of all parts. In this case inner friction of the grease can be neglected.

Calculation of lubricant consumptionCalculation of lubricant consumption

Page 26: Grease basic knowledge_nk0906

26

HOME END Fuchs Indonesia

Calculation of the free bearing volume:Calculation can be done with the dimensions and weights given by the suppliers of the bearings with the following formula:

V ≈ π/4 . B . (D² - d²) . 10-3 - G . 1000 / 7,8 [cm³]

V - free bearing volume in cm³ d - Inner diameter in mmB - Bearing width in mm G - Weight in kgD - Outer diameter in mm

Calculation of lubricant consumptionCalculation of lubricant consumption

Page 27: Grease basic knowledge_nk0906

27

HOME END Fuchs Indonesia

Basic quantities when using grease guns:

One stroke with a conventional (DIN) or withSYSTEM REINER-Grease Gun gives ca. 1,5 - 2 ccm of grease.

Calculation of lubricant consumptionCalculation of lubricant consumption

Page 28: Grease basic knowledge_nk0906

28

HOME END Fuchs Indonesia

Re-lubrication quantities and -intervals depend very much on the real operating conditions. Therefore, exact calculation is extremely difficult.

In the past data of practical applications were collected which were used as a data base for calculations for specific application fields. These calculations use factors for special operating conditions which were found by studying numerous similar applications.

Difficulties arise from the determination of these correction factors as well as from the use of specialised greases with a performance being much higher than that of conventional Li-soap-mineral-oil greases.

Calculation of lubricant consumptionCalculation of lubricant consumption

Page 29: Grease basic knowledge_nk0906

29

HOME END Fuchs Indonesia

Correction factors for re-lubrication intervals

f1 - Dust and moisture (0.1 ... 0.9)f2 - Shocks, vibrations (0.1 ... 0.9)f3 - Temperature higher than 70°C (0.1 ... 0.9)f4 - High load (0.1 ... 1.0)f5 - Air flow through the bearing (0.1 ... 0.7)

The reduced re-lubrication interval is then calculated by multiplying all these single factors:

tfq = f1. f2

. f3. f4

. f5. tf

Calculation of lubricant consumptionCalculation of lubricant consumption

Page 30: Grease basic knowledge_nk0906

30

HOME END Fuchs Indonesia

ASTM Grease Tests

Page 31: Grease basic knowledge_nk0906

31

HOME END Fuchs Indonesia

Mechanical dynamic testing of lubricating greasesMechanical dynamic testing of lubricating greasesFE 8-bearings

FBT-balls

Emcor-machines

Timken-machine with specimen

Page 32: Grease basic knowledge_nk0906

32

HOME END Fuchs Indonesia

Lubricating GreasesLubricating GreasesProperties:

Consistency (NLGI-grade)

Temperature range

EP-properties

Base oil viscosity and type

Thickener

Solid lubricants

Classification (DIN 51502):

e.g. K P F 2 K -20

Classification

Page 33: Grease basic knowledge_nk0906

33

HOME END Fuchs Indonesia

Grease Troubleshooting Guide

Application Symptom Possible Cause Check For

Noise Condition of bearing Worn or brinelled bearing

Over greasing Too frequent application

Bearing packed too full

Excessive grease charge

Starvation Insufficient application frequency

Incorrect product Wrong base oil viscosity

Seals Mechanical damage

Incorrect installation

Over greasing Too frequent application

Excessive amount applied

Incorrect product Too soft for application or softening in service

Incompatibility of grease Admixture of grease

Excessive leakage

High bearing temp.

Bearings Rolling contact

Page 34: Grease basic knowledge_nk0906

34

HOME END Fuchs Indonesia

Application Symptom Possible Cause Check For

Excessive wear Deficient load carrying (EP)

Starvation

Contamination (dirt,dust)

Bearing life exceeded

Improper installation

Grease too stiff (channeling)

High temperature High operating temperature

Misalignment Correct alignment

Overheating Improper distribution Grease too stiff

Incorrect grooving

Starvation Infrequent application

Defective lubricator

Excessive wear

Bearings Plain

Incorrect grease Mechanical stability

Starvation Infrequent application

Defective lubricator

Incorrect grease Load carrying (EP)

Temperature range

Bearings Rolling contact

Frequent bearing replacement

Grease Troubleshooting Guide

Page 35: Grease basic knowledge_nk0906

35

HOME END Fuchs Indonesia

Application Symptom Possible Cause Check For

Grease too soft Product penetration

Milling down of product

Incompatibility of greases Admixture of greases

Noisy gearbox Lack of lubrication Improper lubricant level

Grease to stiff

Lack of lubrication Improper lubricant level

Grease too stiff

Overheating

Churning High grease level

Grease too stiff

Tooth breakage

Pitting

Wear and scoring Lack of lubrication Improper lubricant level

Grease too stiff

Incorrect product used Consistency, EP, quality and base oil viscosity

Abbrasive wear Lubricant contamination

Not usually lubricant related

Mostly poor design and fatigue related While not generally lubricant related, a heavier grease or base oil may retard progression of pitting

Alignment Not lubricant related

Excessive leakageGears Enclosed

Grease Troubleshooting Guide

Page 36: Grease basic knowledge_nk0906

36

HOME END Fuchs Indonesia

Application Symptom Possible Cause Check For

Gear wear Lack of lubrication Incorrect lubricant

Incorrect application frequency

Build up on gears or in roots Excessive lubricant Application frequency

Lubricant type

Airborne dirt

Sliding Surfaces

Universal Joints

Electric Motors Electric malfunction

High temperature

Couplings

Non-uniform motion Lack of lubrication Application frequency

Proper grease type

Excessive wear Insufficient lubrication Lubricant EP, temperature quality

Application frequency

Grease slumpability

Excessive grease leakage Application frequency and quantity

Dry coupling Excessive grease leakage Damaged seals

Grease consistency

Keyway openings

Initial fill

Gears Open

Grease Troubleshooting Guide

Page 37: Grease basic knowledge_nk0906

37

HOME END Fuchs Indonesia

Thank you