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01. Applications for Greases - Copy.pptx
- 1. Copyright of ShellLubricants APPLICATIONS FOR GREASES: SHELL GADUS 2010 1
- 2. Copyright of ShellLubricants WHAT ARE GREASES? 2 A solid or semi-fluid lubricant consisting of a thickening agent in a liquid lubricant Greases are used as a lubricant which stays in position They are used for the lubrication of a wide variety of equipment such as: – Bearings – Couplings – Open gears – Wire ropes / cables
- 3. Copyright of ShellLubricants Oils are the lubricants of 1st choice, but greases are used when: The parts to be lubricated are difficult to reach or require infrequent lubrication An effective seal against contaminant ingress is crucial The system is unable to retain oil Most common applications are in bearings, gears and joints 3 WHEN ARE GREASES USED?
- 4. Copyright of ShellLubricants OIL OR GREASE ? 4 Factors Grease Lubrication Oil Lubrication Temperature Up to 120°C With special grease up to 220°C Up to 200°C Up to high temps with special oils Speed Factors Up to moderate speeds Up to high speeds Load Up to high loads Up to high loads Bearing Design Relatively simple May need to be more complex with arrangements for oil feed Stop-start operation Yes Risk of damage to bearing surfaces Runs for long periods without attention Yes No Central lubricant supply for other machine elements No Grease cannot transfer heat efficiently or operate hydraulic systems Yes Dirty Conditions Yes Good sealing properties prevent entry of contaminates Circulating system with oil filters required
- 5. Copyright of ShellLubricants WHAT İS THE GREASE FOR? 5 The primary function of grease is to lubricate equipment A secondary function such as noise reduction may also be important To protect the application the grease must: Function as a lubricant During shock loading (stop/start) In the presence of water and/or other contaminants During temperature variations Over time Stay in place Adhere to the surfaces Maintain its consistency or mechanical stability during changes to temperature and/or wear and vibration Resist the effect of water wash out
- 6. Copyright of ShellLubricants ADVANTAGES & DİSADVANTAGES OF GREASES 6
- 7. Copyright of ShellLubricants WHAT DOES A CUSTOMER WANT FROM GREASES? The grease must perform its primary protection function This will ensure that the equipment operates correctly It will maintain the equipment’s life Value-oriented customers want to lower their ‘Total cost of ownership’ The costs of equipment failure (either expressed as cost of equipment repair or failure as well as production down time) The cost of maintenance Operational efficiencies The actual cost of the grease (minimal compared to the other two) By choosing the correct lubricant (or grease) the customer can get the most value for the lowest possible cost 7
- 8. Copyright of ShellLubricants WHAT TYPES OF COMPONENTS NEED GREASE? 8 Industrial Bearings Electric motors Couplings Gears Slides Linkages Chains Automotive Bearings Universal and CV Joints Other driveline components Linkages Hinges Brake and seat adjusters Steering gears On-highway Bearings Chassis Wheel hubs Fifth wheel Off-highway Bearings Gears Slides Linkages Chains Pins Buckets Wheel hubs Think about… General purpose greases High temperature greases Greases for specific applications The most important application of greases is for the lubrication of rolling bearings and about 80% of all rolling bearings are lubricated with grease.
- 9. Copyright of ShellLubricants Hot Running Noisy Running Short Life – Frequent Replacement Excessive Vibration Difficult to Turn / Friction 9 Other than Improper design, causes are Lubrication, Installation, Contamination, and or Improper uses Likely that it is a combination SYMPTOMS OF PROBLEMATIC BEARINGS
- 10. Copyright of ShellLubricants Fatigue Failure – 34% End of bearing useful life due to fatigue failure Including improper selection / uses Overloading / Preloaded Improper Handling & Installation – 16% Premature bearing damage Misalignment / Unbalancing Clearance Contamination during operation – 14% Dust, water, steam, chemical, etc Improper seal & seal position Seal damage Improper Lubrication – 36% Wrong Grease Under / Over Grease Compatibility Contaminated Grease 10 CAUSES OF BEARING FAILURES
- 11. Copyright of ShellLubricants 11 IMPROPER LUBRICATION Wrong or low quality grease Under protection, wear / corrosion Leaking / Fling off Not suitable for specified service interval Dirty Grease Abrasive wear Under grease Could be too long service interval Over packed Too much feed / initial fill No drain, wrong seal Causes high internal friction and high temperatures CAUSES OF BEARING FAILURES
- 12. Copyright of ShellLubricants Keep the new grease clean, uncontaminated Use the right grease Set and follow appropriate service volume / interval Regreasing See a good grease past the seal Install a drain for critical & problematic units Open drain when applying grease and leave open for 15 min Monitor temperature if necessary 12 KEYS TO THE PREVENTION OF BEARING FAILURES
- 13. Copyright of ShellLubricants APPLİCATİON METHOD FOR GREASES 13 Manual Method Grease gun (risk of over greasing and/ or mixing the greases) Spatula (high risk of contamination) Brush (for open gears, high risk of contamination) Automatic Method Single point lubricator (Shell Tactic EM device that can be filled with required grease) Centralized lubricating systems Single line (single point injectors or progressive) Multiple lines with single point injectors Two line systems with progressive distributors
- 14. Copyright of ShellLubricants TECHNOLOGY OF GREASES Greases consist of three important components: The lubricating fluid The additives The thickener (soap or non-soap) The thickener is the critical component in ensuring that the grease stays in place and selection of thickener depends on the specific operating requirements Operating temperature Shear stability Water resistance Pumpability There are a variety of thickeners on the market Lithium Lithium complex Calcium Aluminium complex Calcium Sulphonate Polyurea Clay Others 14
- 15. Copyright of ShellLubricants COMPOSİTİON DİFFERENCE OF GREASES AND OİLS 15 Base oil (65 - 98%) Additives (0-15%) Thickener (2-20%) Base oil (85 - 95%) Additives (5 - 15%) Oil Grease Formulation Oil Formulation Grease
- 16. Copyright of ShellLubricants GREASE MINERAL SYNTHETIC BASE OIL Antiwear / EP Anticorrosion Antioxidant Increasing adhesive ability Metal deactivation ADDITIVES THICKENER Non soap Non organic Clay Silica Gel organic Polyurea Soap simple Li Ca Ba Al Na mixed Li/Ca complex Li Ca Al Na COMPONENTS OF A GREASE 16
- 17. Copyright of ShellLubricants BASE OIL AFFECT ON GREASE 17 Types Naphthenic Synthetic Ester Paraffinic Group I Group II Synthetic (PAO) Smoother Appearance Higher Yields Coarser Appearance Lower Yields
- 18. Copyright of ShellLubricants SELECTİON OF GREASES – THİCKENER/SOAP TYPES 18 Selection of thickener is determined primarily by temperature and mechanical stability (i.e. load and bearing speed) Lithium soap = Shell ALVANIA Lithium soap based greases have been the industry standard products for more than 50 years. They are suitable for many industrial applications Shell invented Lithium based multipurpose grease technology Lithium complex = Shell ALBIDA Lithium complex based greases have a more complex chemical structure. This makes them more resilient to the effects of temperature and mechanical stress Lithium complex greases typically last longer than Lithium greases Other thickeners Shell offers many other thichener types for different specialist or niche applications
- 19. Copyright of ShellLubricants The thickener functions in a similar manner to a washing sponge: under light pressure on the sponge, only a little water is forced out of it ... … but under heavy pressure, a lot of water is ejected. FUNCTİON OF A THİCKENER 19
- 20. Copyright of ShellLubricants OPERATION TEMPERATURES 20 Normal Range Extended Range Depending on Base Fluid and Additives
- 21. Copyright of ShellLubricants Al Al Cx Ca Ca Cx Clay Li Li/Ca Li Cx Polyurea Al Al Cx Calcium Ca Cx Clay Lithium Li/Ca Li Cx Polyurea incompatible, cleaning of the bearing or gear box is recommended grease are compatible, no special measures to be taken borderline compatibility, more frequent regreasing is recommended at the beginning to eliminate quickly the old grease COMPATİBİLİTY OF GREASES 21
- 22. Copyright of ShellLubricants KEY GREASE PROPERTIES Dropping Point High Temperature Capability Consistency Flow properties Varies with temperature Depends on the amount and type of thickener used 22
- 23. Copyright of ShellLubricants DROPPING POINT 23 Temperature where grease is fluid and drops from test orifice Like a Melting Point - - A temperature range Usable Temperature is less than the Dropping Point
- 24. Copyright of ShellLubricants DROPPING POINT RANGE FOR GREASES 24 °F °C Calcium 265-285 129-140 Lithium 380-400 193-204 Li Complex 450+ 232+ Other Complexes Polyurea Microgel® (clay) >500 >260
- 25. Copyright of ShellLubricants UNDISTURBED, UNWORKED, AND WORKED PENETRATION 25 Grease Working Apparatus Undisturbed – in the container Unworked – minimum of handling Worked – after 60 double strokes of working on a grease working apparatus The penetrometer measures the penetration of a cone into the surface of the grease. This penetration value relates to the NLGI grade
- 26. Copyright of ShellLubricants NLGI Grade Worked Penetration Description 0.1 mm, 25°C 000 445 - 475 Fluid 00 400 - 430 Semi-fluid 0 355 - 385 Very soft 1 310 - 340 Soft 2 265 - 295 Med soft 3 220 - 250 Medium 4 175 - 205 Stiff 5 130 - 160 Very stiff 6 85 - 115 Block NLGI CONSISTENCY GRADES 26
- 27. Copyright of ShellLubricants SELECTİON OF GREASES – CONSİSTENCY Grease consistency is classified according to the NLGI grading system developed by the National Lubricating Grease Institute and this system specifies nine grades ranging from: 000 (softest or most “fluid”) to 6 (stiffest) NLGI Grade 2 is the most common Grade 000 to 1 can be used in centralized lube systems (for automated re-greasing i.e. they are “pumpable”) 27
- 28. Copyright of ShellLubricants 185 Med. Med. Fair - Fair Med. Exc. 1.0 Med. 185 Good Med. Good - Med. Med. - Exc. 1.4 Exc. Good 250 Good - Med. Good Good Good Poor 1.8 Exc. 240 Fair - Good - Med. Med. Med. Poor 1.5 Med. Exc. 250 Good Poor Fair - Med. Med. Poor 1.6 Med. >300 Med. - Poor - Good Med. - Med. Poor 1.5 Good Med. Good >300 Good - Med. Good - Good Good Fair 1.9 Exc. Exc. 270 Exc. Exc. Good - Exc. Exc. Fair 2.5 Exc. Property Thickener Drop Mech. Anti- Water Thermal Grease Grease Rel. Point 0 C Stability Wear Resist. Stability LIfe Noise Cost Lithiu m Li/Ca Mixed Soap Lithium Complex Calcium Complex Aluminum Complex Clay Soap/Clay Mixed Base Polyurea GREASES TYPES & TYPİCAL PROPERTIES 28
- 29. Copyright of ShellLubricants SELECTİON OF GREASES – EQUİPMENT 29 Selection of greases is determined by the equipment that the grease is going to protect and its operating conditions. Terminology relates to the type of shock loading that is most likely to occur. Regular Load = RL Smooth running and high speed bearings which are most commonly found in electric motors ISO 100/150 viscosity base oil Extreme Pressure = EP Medium Duty = MD Bearings and gears subject to some shock motion. (stop/start) Most gears and some larger bearings ISO 150/220/320 viscosity base oil Heavy Duty = HD Severe Duty = SD Equipment subjected to heavy shock loading. Relatively few applications ISO 460/680/1000 viscosity base oil There are also EPX, MDX, HDX, and SDX for very heavy duty applications These greases contain lubricating solids and are mainly used in gears, sliding contacts, and high contact loads
- 30. Copyright of ShellLubricants Consistency (Thickener Content) Operating Temperature (Thickener Type and Oil Type) Lubrication performance (Oil) Operating Parameters Vibrations, Dirt, Dust, Humidity etc. (Thickener Type) Corrosion Protection (Additives and Oil) Bearing Load (Additive and Oil) Bearing Speed (rpm) (Thickener and Oil) QUİCK SUMMARY 30
- 31. Copyright of ShellLubricants SHELL GREASE FAMİLY 31 Shell Gadus S3 V 460 D 2 Shell Gadus is the family name for all Shell greases Relative performance level (from S1 to S5) Thickene r guide Special feature or application Oil viscosit y NLGI grade
- 32. Copyright of ShellLubricants Key SHELL GREASE FAMİLY 32 KEY LETTERS USED A = Wet (aqueous) conditions C = Coloured grease P = Extreme pressue D = Contains solids (MoS2, graphite, etc.) OG = Open gear T = Extreme temperature applications (polyurea) V = Versatile (lithium, lithium-calcium or lithium complex) U = Non-melting (microgel / clay) Q = Noice-dampening (quiet) Shell Gadus S2 V 220 AD 2
Editor's Notes
- #17 The Base Oil used to make a grease is of primary importance since it provides the main lubricating ability of a grease. A base oil is fundamentally described by its viscosity as a grease is fundamentally described by its consistency. By now each of you should have a clear concept of viscosity. Another key property of a base oil is its TYPE. Most mineral oils may be considered either NAPHTHENIC or PARAFFINIC. These hydrocarbons are primarily differentiated by differences in their molecular structures. Naphthenic oils are comprised of mostly cyclic carbon bonds and usually provide the best thickening effect of the two. In other words, the thickener is more “soluble” in these base stocks. The resulting grease made with Naphthenic base stocks usually apprears smooth. Paraffinic oils are comprised of mostly straight chain carbon bonds and similar thickener systems are typically less “soluble” in these base stocks compared to Naphthenic oils. However, the chemical structure of paraffinic oils promotes oxidative stability and better elastomer compatibility. Synthesized hydrocarbons, i.e. SYNTHETIC BASE OILS, are the other class of base oils used to make greases. Synthetic base oils are often manufactured to possess outstanding extreme properties (i.e. very good low temperature characteristics) compared to mineral oils. They are also more expensive. All three types of base oil may be used alone or in combination to make various greases.
- #22 There are 2 basic properties used to fundamentally describe a grease. These properties are the Dropping Point and the Consistency of a grease. The dropping point is the temperature where the thickener melts and becomes fluid in the oil phase. At the DP temperature, the grease has the texture and fluidity of the base oil. A grease will become more fluid and uncharacteristic of its nature as the DP is approached. At temperatures very near the DP, the grease will not perform well for extended periods of time. Therefore, manufacturers commonly quote a Maximum Usable Temperature at which sustained performance of a grease will be allowed. It is lower than the DP. How low depends on the inherent properties of the grease. DPs for grease vary and are usually a function of the type of thickner used. An expression denoting the thickness of a grease is known as its “Consistency”. It is analogous to the VISCOSITY of an oil. Greases are most basically described by their consistency as denoted as being, for example, a Grade 1 or Grade 2, etc. The classification of greases according to various grades of consistency may be described by PENETRATION NUMBERS... (On to next slide)
- #28 A summary of grease characteristics is shown