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Copyright of SOPUS Products
SHELL OPEN GEAR LUBRICANTS WEBINAR SERIES: PART 1 OF 3
Greg Paluska Greg Morris Technical Advisor – Mining Product Application Specialist - Greases
Copyright of SOPUS Products
BEFORE WE GET STARTED…
We respect your time – we will not run more than 55 minutes.
Questions are encouraged during this webinar. Use the “Question” link in the bottom of your screen. We’ll answer all your questions! If we can’t answer them all live, we will have a direct follow-up with you.
An interactive webinar – you’ll be able to participate in several live polling questions. Click your answers onscreen.
A recorded version of this presentation will be sent to all webinar registrants within the next few days.
Copyright of SOPUS Products
SPEAKERS
Greg Paluska
Technical Lead – Fleets & Mining
Leads a team of Lube Service Experts – onboard lubrication and lubrication system support for key mining machinery – Shovels, draglines, mills and kilns
Shell Technical Advisor since 2011
Avid cyclist, enjoys “golfing” and is a sports car enthusiast
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SPEAKERS
Greg Morris
Product Application Specialist – Greases
Part of Global team with the task of integrating field level support and feedback to RD projects
Validation of product performance
Working with OEMs and end users on product performance inquiries
24 years of industry experience -17 years with Shell
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AGENDA
Basics of Gearing and Open Gearing
Types of Open Gear Lubricants
Shell Gadus Open Gear Portfolio
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BASICS OF OPEN GEARING 1.0
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GEAR MANUFACTURING
Pre-forming
Gear turning
Cutting
Gear hobbing
Gear shaping
Quenching/ Hardening
Finishing
Gear shaving
Gear grinding
Gear Honing/ grinding
Final operations
Broaching
Gearbox machining
Gear Quenching Nitriding
Induction or Flame
hardening
Gear milling
Forming
Gear forging
Gear sintering
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Outside diameter
Pitch diameter
Whole depth
Root diameter
Root diameter
Base diameter
Pitch diameter
Line of centers
Driven Pitch Point
Pressure Angle
Driver Dedendum
Addendum
Clearance
GEAR GEOMETRY
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REVIEW – FILM THICKNESS AND COEFFICIENT OF FRICTION
Separating surfaces is critical!
Film thickness is dependent on:
Lubricant Viscosity
Temperature
Load
Size and Speed of Gears
Coe
f of F
rictio
n
ZN/P
Boundary Lubrication
Hydrodynamic Lubrication
Mixed Film Lubrication
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GEAR LUBRICATION REGIMES
Very lightly loaded gears, operating at high speed, are effectively lubricated under the conditions of hydrodynamic or thick-film lubrication
Elasto-hydrodynamic lubrication is the lubrication condition which exist in most gears, but usually NOT open gears.
Heavily loaded gears, especially those operating at low speed, are lubricated under the conditions of mixed film & boundary lubrication. The lubricant film is very thin and there is significant metal-to-metal contact between gear teeth.
Boundary Lubrication
Hydrodynamic Lubrication
Mixed Film Lubrication
Wear Scuffing
Type of Gear failure
Lubrication Condition
Pitting, Micro-pitting
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Mixed Lubrication
High Circumferential Velocity
Low Circumferential Velocity
Courtesy of STLE Lubrication Engineering, May 1990, Page 322 (with permission)
Open Gearing operates under mixed lubrication conditions where linear speeds are low
Pitch line…
LUBRICATION AT GEAR FACE
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GEAR FINISH MAY BE ROUGHER THAN BEFORE
Tooth of a new girth gear Tooth of a new pinion
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LAMBDA RATIO
Mean Oil Film
Thickness (h)
RMS Surface
Roughness
s1
s2
Combined Surface Roughness s = (s12 + s2
2)0.5 { ≈ Ra1 + Ra2 }
l ratio = h s
1, for the case shown
above
RMS (root mean square) – a measure of surface roughness of a surface relating to the centreline average between peaks and valleys of asperities
The l Ratio can provide clues to the prevailing
Lubrication Regime and hence the likelihood of Wear.
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The specific film thickness of the chosen lubricant
should be above the 5% line on the graph to insure maximum performance and gear protection
REDUCE THE PROBABILITY OF SCUFFING AND GEAR DAMAGE
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OPEN GEAR LUBRICATION – SOLID LUBRICANTS
When the oil film is of a comparable thickness to the surface roughness, the condition of boundary lubrication exists.
Under these conditions and also during sliding motion, the addition of solid lubricants in the lubricant can provide additional protection against gear wear.
Friday,
Metal to metal contact due to insufficient lube film thickness
Solid additives act as barrier to the gear surfaces
Covalent
Van
der
Waa
l
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OPEN GEAR LUBRICANT REQUIREMENTS
New gear manufacturing technologies have added increased load and stress on to gears utilized today.
The following are key requirements of open gear lubricants
Adhesiveness to gears
Water wash and spray resistance
Load carrying capability
Protection against wear and corrosion
Health and safety concerns
Resistance to centripetal acceleration – cannot “fling” off the gears
Capability of easy removal – slumpable into drains
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AGMA SPECIFICATIONS FOR OPEN GEARS
Ambient Temperature °C
Intermittent Spray Gravity Feed of Force Dripped Non-residual
lubricant Residual type lubricant
-10 to +5 4140 cSt at 40°C 428.5 cSt at 100°C 4140 cSt at 40°C
+5 to +20 6120 cSt at 40°C 857 cSt at 100°C 6120 cSt at 40°C
+20 to 50 190 cSt at 100°C 857 cSt at 100°C 190 cSt at 100°C
Above is taken from AGMA 9005-E02
Pitchline velocity: V t <7.5 m/s Quantities dictated by gearing size and timing (subject of future webinar)
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OEM SPECIFICATIONS
BE OGL SD 4713 P&H Rev 464 Metso OG
Viscosity -50 to 10 C – min 680 -20 to 40C – min 1860 10 to 50C – min 3600
- 3,300 SSU @100C (Asphaltic) 870 SSU @100C (All others)
Four Ball Wear Scar 0.7 1.0 .75 mm
Four Ball Weld Point Load Wear Index
800 (w/out diluents)
120
400
250
250 kg
45
Lincoln Ventmeter 600 400
Viscosity is key property to consider as it does most of the work Four Ball Weld Point is great indicator of shock loading capability Lincoln ventmeter critical for lubrication systems where venting is necessary
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OPEN GEAR COMPONENTS AND CHOICES
2.0
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KEY COMPONENTS OF OPEN GEAR LUBRICANTS
Base Oils – High base oil viscosity Asphaltic base
Thickeners (same as typical greases)
Additives Extreme pressure, Solids,
Antioxidants, Tackifier
Solvents
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ASPHALTIC OPEN GEAR LUBRICANTS
Also known as “Crater Lube,” residual compounds and black oils
Older technology that has been proven and is widely accepted in the mining industry
Formulated with high viscosity base oil, bitumen or asphaltic base, and low flash point diluent
Use the principle of oil separating mating surfaces – thus no solids required
Typically applied via spray systems
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ADVANTAGES/LIMITATIONS OF ASPHALTIC LUBRICANTS
ADVANTAGES
Asphaltic base provides high viscosity characteristic to provide separation of mating tooth surfaces
DISADVANTAGES
First generation asphaltic lubes typically used chlorine based solvents
Excellent as the flammability was low, and performance was excellent
Chlorine was identified as harmful to the environment, thus was banned
Presence of polycyclic aromatics that are environmentally objectionable
Petroleum based solvents have lower flash points
Poor high and low temp performance
Oxidize and fall off easily at high temps
Tendency to crack and peel off during cold temperatures
Tendency to build up in root of teeth
Tend to attract dust leading to potential for more abrasive wear
Solvent volume is ‘wasted’ as customers pay for mobility component that does not lubricate
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Newer technology of open gear lubricants
Same general application, however is typically applied in shorter time quantities in smaller amounts
Formulated just as any other grease would be (Base oil, thickener, additives)
Solvent used for mobility and spray potential in low ambient temperature applications (Gadus S4 OGT is neat, but has limited temperature due to lack of solvent)
SEMI-FLUID GREASE FORMULATIONS
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ADVANTAGES/LIMITATIONS OF GREASE FORMULATIONS
ADVANTAGES
Forms a dry, tacky protective film and thus does not attract dirt and dust as much
Improved housekeeping due to better tackiness on the gears
Potential for consolidation by using is various other applications (MPG)
Suitable for mobile equipment and stationary/plant based gearing
DISADVANTAGES
Consumption is sometimes higher
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HIGH VISCOSITY SYNTHETIC GEAR OILS
Newest technology of open gear lubricants
Typically formulated with high viscosity synthetic base oils (PAO and POE) along with EP and MoS2
Do not use solvents for mobility – can be developed at lower viscosities
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ADVANTAGES/LIMITATIONS OF HEAVY OIL FORMULATIONS
ADVANTAGES
Lower traction coefficient – lower pinion operating temperatures
High viscosity enhances adhesiveness to gears
Allows for gear to operate close to full-film lubricating regime
DISADVANTAGES
Potentially difficult to pump or move in cold temperatures
May require drum heaters and heat tracing
Much higher up-front cost compared to all other OGLs
Modifications to intermittent spray systems may be required to spray these lubricants
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SHELL PORTFOLIO OF OPEN GEAR LUBRICANTS
3.0
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SHELL OGL PRODUCT DATA POINTS
Several Types (“Families”), Several applications, Many products
Product type Shell Gadus Product Name Solids Base oil type Base oil vis @ 40oC NLGI grade
Bitumastic S1 OG 1600 None Mineral 1,500 000
Bentonite
S2 OG 40
Moly/Graphite
Semi Syn 655 000 S2 OG 50 Semi Syn 870 00 S2 OG 80 Semi Syn 1,625 0 S2 OG 85 Semi Syn 1,625 1
Aluminium complex S4 OGXK
Moly/Graphite Mineral 4,000 00/000
S4 OG MS* Mineral 4,000 0/00 S4 OGT Mineral 5,500 0
Aluminium complex S4 OGH 160 Moly/Graphite Mineral 4,100 00
Aluminium complex S3 Repair Graphite Mineral 550 00
Oil S2 OG Clear Oil 6800
None Semi Syn 6,800 Fluid
S2 OG Clear Oil 20000 Semi Syn 20,000 Fluid
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SHELL OPEN GEAR APPLICATION RANGES
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SHELL GADUS S4 OGT IN HOIST GEAR OF SOUTH AMERICAN ELECTRIC ROPE SHOVEL (BE 495)
Excellent coverage
Good adhesion to gearing
Little to no severe wear patterns
Max temperature 52C
Ambient closer to 22C
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CAT 7495 – USING GADUS S4 OGT
Excellent coverage
Good adhesion to gearing
Swing Rack
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CAT 7495 – USING GADUS S4 OGT (CONT’D)
Hoist Crowd
Both gear sets show excellent coverage after many months of use
Gear lubricant is providing the wear protection it needs to
Next steps in open gear optimization is grease delivery!
Contamination control, grease system design
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Q & A
Submit questions in the lower right corner of your screen.
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CONTACT US
Do you have more questions about how to better your lubrication practices? Greg Paluska [email protected] Greg Morris [email protected]