Friction and Lubrication - jmcastellanosjmcastellanos.docentes.upbbga.edu.co/pdf/Lubrication.pdf ·...
Transcript of Friction and Lubrication - jmcastellanosjmcastellanos.docentes.upbbga.edu.co/pdf/Lubrication.pdf ·...
![Page 1: Friction and Lubrication - jmcastellanosjmcastellanos.docentes.upbbga.edu.co/pdf/Lubrication.pdf · Considering engine speed! (empirical correlation ) Engine speed Empirical Constans](https://reader035.fdocuments.in/reader035/viewer/2022081400/5f25bbe16c52c54dc827a537/html5/thumbnails/1.jpg)
Friction and Lubrication
Presented by J.M. Castellanos
![Page 2: Friction and Lubrication - jmcastellanosjmcastellanos.docentes.upbbga.edu.co/pdf/Lubrication.pdf · Considering engine speed! (empirical correlation ) Engine speed Empirical Constans](https://reader035.fdocuments.in/reader035/viewer/2022081400/5f25bbe16c52c54dc827a537/html5/thumbnails/2.jpg)
Friction: “ Forces actingbetween mechanicalcomponents due to theirrelative motion and forces on and by fluidswhen they move”
![Page 3: Friction and Lubrication - jmcastellanosjmcastellanos.docentes.upbbga.edu.co/pdf/Lubrication.pdf · Considering engine speed! (empirical correlation ) Engine speed Empirical Constans](https://reader035.fdocuments.in/reader035/viewer/2022081400/5f25bbe16c52c54dc827a537/html5/thumbnails/3.jpg)
Lubrication: “ Reduce resistance to Surface-to-Surface motion”
Lubricating fluid
1.Adherence2.Resistance to be squeezed.3.Low force to shear liquid
layers…(viscosity)Adapted from: Royal society of chemistry. Polymer-brush lubrication: a review of recent theoretical advances.http://pubs.rsc.org/en/content/articlelanding/2016/sm/c5sm02919h#!divAbstract
![Page 4: Friction and Lubrication - jmcastellanosjmcastellanos.docentes.upbbga.edu.co/pdf/Lubrication.pdf · Considering engine speed! (empirical correlation ) Engine speed Empirical Constans](https://reader035.fdocuments.in/reader035/viewer/2022081400/5f25bbe16c52c54dc827a537/html5/thumbnails/4.jpg)
What about engine bearings?
Adapted from: Operational Information Hydrodynamic Lubrication.http://www.marinediesels.info/2_stroke_engine_parts/Other_info/hydrodynamic_lubrication.htm Position and thickness of the
mínimum oil film Will dependon tolerances, load, speed and oil viscostiy… mainly 2µm for main
bearings in an engine
![Page 5: Friction and Lubrication - jmcastellanosjmcastellanos.docentes.upbbga.edu.co/pdf/Lubrication.pdf · Considering engine speed! (empirical correlation ) Engine speed Empirical Constans](https://reader035.fdocuments.in/reader035/viewer/2022081400/5f25bbe16c52c54dc827a537/html5/thumbnails/5.jpg)
How friction is accounted for in an Engine?
In power terms!!! Including mechanical efficiency…
…but the most meaninfulg method!(engines of different size working at different speeds)
![Page 6: Friction and Lubrication - jmcastellanosjmcastellanos.docentes.upbbga.edu.co/pdf/Lubrication.pdf · Considering engine speed! (empirical correlation ) Engine speed Empirical Constans](https://reader035.fdocuments.in/reader035/viewer/2022081400/5f25bbe16c52c54dc827a537/html5/thumbnails/6.jpg)
Considering engine speed!(empirical correlation )
Engine speed
Empirical Constans(depend on engine characteristics)
Boundary friction: There is notEnough lubrication to separateSurfaces… TDC, BDC, crankshaft
Hydraulic shear:
Dynamic viscosity of oil
Turbulent dissipation: Intake andexhaust flows (this disipation equatesthe of mass velocity)
![Page 7: Friction and Lubrication - jmcastellanosjmcastellanos.docentes.upbbga.edu.co/pdf/Lubrication.pdf · Considering engine speed! (empirical correlation ) Engine speed Empirical Constans](https://reader035.fdocuments.in/reader035/viewer/2022081400/5f25bbe16c52c54dc827a537/html5/thumbnails/7.jpg)
Likewise!(in terms of the piston average speed)
¡Important!(on magnitude of fmep) At WOT
condition
At idle!!!
fmep ≈ 0.1•imep
fmep ≈ imep
![Page 8: Friction and Lubrication - jmcastellanosjmcastellanos.docentes.upbbga.edu.co/pdf/Lubrication.pdf · Considering engine speed! (empirical correlation ) Engine speed Empirical Constans](https://reader035.fdocuments.in/reader035/viewer/2022081400/5f25bbe16c52c54dc827a537/html5/thumbnails/8.jpg)
Real friction determination(Motor the engine!)
Adapted from: Motored engine. PULKRABEK, W.W. Engineering Fundamentals of the Internal Combustion Engine: PEARSON PRENTICE HALL, 2003
At WOT and withoutFiring!!!
0
![Page 9: Friction and Lubrication - jmcastellanosjmcastellanos.docentes.upbbga.edu.co/pdf/Lubrication.pdf · Considering engine speed! (empirical correlation ) Engine speed Empirical Constans](https://reader035.fdocuments.in/reader035/viewer/2022081400/5f25bbe16c52c54dc827a537/html5/thumbnails/9.jpg)
Like this!!(Motor the engine!)
![Page 10: Friction and Lubrication - jmcastellanosjmcastellanos.docentes.upbbga.edu.co/pdf/Lubrication.pdf · Considering engine speed! (empirical correlation ) Engine speed Empirical Constans](https://reader035.fdocuments.in/reader035/viewer/2022081400/5f25bbe16c52c54dc827a537/html5/thumbnails/10.jpg)
Adapted from: Friction Losses for varius engine componentes. PULKRABEK, W.W. Engineering Fundamentals of the Internal Combustion Engine: PEARSON PRENTICE HALL, 2003
In terms of TF!(Total Friction)
About 75%TF at high loads!
50%TF
20% TF!(That´s why compression ringsbecome thiner and thiner… up to1 mm!!!!!Every additional compression ring adds +- 10 kPa to fmep!!!!)
25% TF!
10% TF!
15% TF!
![Page 11: Friction and Lubrication - jmcastellanosjmcastellanos.docentes.upbbga.edu.co/pdf/Lubrication.pdf · Considering engine speed! (empirical correlation ) Engine speed Empirical Constans](https://reader035.fdocuments.in/reader035/viewer/2022081400/5f25bbe16c52c54dc827a537/html5/thumbnails/11.jpg)
Adapted from: Friction Losses on pistons and piston rings. PULKRABEK, W.W. Engineering Fundamentals of the Internal Combustion Engine: PEARSON PRENTICE HALL, 2003
…and more!Piston momentarly stops!
There is small friction at U=0!!(Piston stretching or compressing &Deflections connecting rod)
![Page 12: Friction and Lubrication - jmcastellanosjmcastellanos.docentes.upbbga.edu.co/pdf/Lubrication.pdf · Considering engine speed! (empirical correlation ) Engine speed Empirical Constans](https://reader035.fdocuments.in/reader035/viewer/2022081400/5f25bbe16c52c54dc827a537/html5/thumbnails/12.jpg)
Adapted from: fmep vs piston average speed. PULKRABEK, W.W. Engineering Fundamentals of the Internal Combustion Engine: PEARSON PRENTICE HALL, 2003
…finally!
![Page 13: Friction and Lubrication - jmcastellanosjmcastellanos.docentes.upbbga.edu.co/pdf/Lubrication.pdf · Considering engine speed! (empirical correlation ) Engine speed Empirical Constans](https://reader035.fdocuments.in/reader035/viewer/2022081400/5f25bbe16c52c54dc827a537/html5/thumbnails/13.jpg)
![Page 14: Friction and Lubrication - jmcastellanosjmcastellanos.docentes.upbbga.edu.co/pdf/Lubrication.pdf · Considering engine speed! (empirical correlation ) Engine speed Empirical Constans](https://reader035.fdocuments.in/reader035/viewer/2022081400/5f25bbe16c52c54dc827a537/html5/thumbnails/14.jpg)
𝜑
𝜃
Side thrustForce Ft
Crank angle ϴ
Gas pressure P
Frictionforce Ff
Adapted from: Piston and rod forces in a crankshaft mechanism fully assembled by contacts. EnginSoftSpa. https://www.youtube.com/watch?v=TvpIxgDMp4M
What about forces on the Piston orthe cylinder?
![Page 15: Friction and Lubrication - jmcastellanosjmcastellanos.docentes.upbbga.edu.co/pdf/Lubrication.pdf · Considering engine speed! (empirical correlation ) Engine speed Empirical Constans](https://reader035.fdocuments.in/reader035/viewer/2022081400/5f25bbe16c52c54dc827a537/html5/thumbnails/15.jpg)
Adapted from: . http://www.car-engineer.com/the-honda-exlink-engine/
Ft
Ff Fr
Fp
FBD of the piston…
𝜃
±Adapted from. http://www.car-engineer.com/Renault 2013 innovations for improved engine fuel efficiency/
Major sidethrust
https://global.honda/innovation/technology/power/Exlink-picturebook.html
![Page 16: Friction and Lubrication - jmcastellanosjmcastellanos.docentes.upbbga.edu.co/pdf/Lubrication.pdf · Considering engine speed! (empirical correlation ) Engine speed Empirical Constans](https://reader035.fdocuments.in/reader035/viewer/2022081400/5f25bbe16c52c54dc827a537/html5/thumbnails/16.jpg)
How friction forces are reduced?
Less piston mass!…
Shorter skirts!…closer tolerances
Smaller piston rings!…
Offset piston pin!To reduce side thrust force…
Adapted from. http://www.car-engineer.com/Renault 2013 innovations forimproved engine fuel efficiency/
Adapted from: He, Z., Xie, W., Zhang, G., Hong, Z., & Zhang, J. (2014). Piston dynamic characteristics analyses based on FEM method Part I: Effected by piston skirt parameters. Advances in Engineering Software, 75, 68-85.
![Page 17: Friction and Lubrication - jmcastellanosjmcastellanos.docentes.upbbga.edu.co/pdf/Lubrication.pdf · Considering engine speed! (empirical correlation ) Engine speed Empirical Constans](https://reader035.fdocuments.in/reader035/viewer/2022081400/5f25bbe16c52c54dc827a537/html5/thumbnails/17.jpg)
How friction forces are reduced?
Oversquare engines!…stroke is smaller than bore (higherHeat transfer losses)
Using crossheads!…
Adapted from: http://www.marinediesels.info/2_stroke_crosshead_engine_access.htm
![Page 18: Friction and Lubrication - jmcastellanosjmcastellanos.docentes.upbbga.edu.co/pdf/Lubrication.pdf · Considering engine speed! (empirical correlation ) Engine speed Empirical Constans](https://reader035.fdocuments.in/reader035/viewer/2022081400/5f25bbe16c52c54dc827a537/html5/thumbnails/18.jpg)
![Page 19: Friction and Lubrication - jmcastellanosjmcastellanos.docentes.upbbga.edu.co/pdf/Lubrication.pdf · Considering engine speed! (empirical correlation ) Engine speed Empirical Constans](https://reader035.fdocuments.in/reader035/viewer/2022081400/5f25bbe16c52c54dc827a537/html5/thumbnails/19.jpg)
Engine Lubrication system
Adapted from: http://gkforeverybody.blogspot.com.co/p/motor-mechanic.html
https://youtu.be/guoxmqCnPbk
![Page 20: Friction and Lubrication - jmcastellanosjmcastellanos.docentes.upbbga.edu.co/pdf/Lubrication.pdf · Considering engine speed! (empirical correlation ) Engine speed Empirical Constans](https://reader035.fdocuments.in/reader035/viewer/2022081400/5f25bbe16c52c54dc827a537/html5/thumbnails/20.jpg)
1.Full flow filtration.2.Bypass oil filtration.3.Combination.
4.Shunt filtration.
Filtration strategies
https://youtu.be/SBYEviKFlXA
![Page 21: Friction and Lubrication - jmcastellanosjmcastellanos.docentes.upbbga.edu.co/pdf/Lubrication.pdf · Considering engine speed! (empirical correlation ) Engine speed Empirical Constans](https://reader035.fdocuments.in/reader035/viewer/2022081400/5f25bbe16c52c54dc827a537/html5/thumbnails/21.jpg)
Lubricating Oil
1.Reduce Friction and wear.2.Coolant.3.Remove contaminants.4.Enhance ring seal5.Slow corrossion6.Stability at high T range.7.Long life span.8.Low cost.
Antifoam agents
Oxidation inhibitor
Pour point depressant
Antirust agents
Detergents
Antiwear agents
Friction reducers
Viscosity index improvers
![Page 22: Friction and Lubrication - jmcastellanosjmcastellanos.docentes.upbbga.edu.co/pdf/Lubrication.pdf · Considering engine speed! (empirical correlation ) Engine speed Empirical Constans](https://reader035.fdocuments.in/reader035/viewer/2022081400/5f25bbe16c52c54dc827a537/html5/thumbnails/22.jpg)
Adapted from: Dynamic viscosity vs Temperature. PULKRABEK, W.W. Engineering Fundamentals of the Internal Combustion Engine: PEARSON PRENTICE HALL, 2003