friction and wear reduction in heavy-duty diesel powertrains project wonaco2 - tribodays,...
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Friction and wear reduction inheavy-duty diesel powertrains
Project Wonaco2 - Tribodays, Örnsköldsvik - 2012-11-07
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Project Wonaco2Engine tribology 101ANS TriboconditioningProject focus and resultsSummary
Agenda
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Research project involving ANS, LTU, UU, HH, Volvo Powertrain and ScaniaFunding from ProViking (SSF)Objective was to assess if Triboconditioning could be used to reduce friction in diesel enginesStarted in mid 2010 and soon to be concluded
Project Wonaco2
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Project Wonaco2Engine tribology 101ANS TriboconditioningProject focus and resultsSummary
Agenda
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Emission legislation
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Friction losses in an engine
Friction losses15%
Heat losses (exhaust,
cooling, etc.)60%
Useful kinetic energy
25%
Friction losses
20%
5%
15%60%
Pistonassembly
Crank train
Valve train
Other*
* Auxiliary systems, injection pump, etc.
15% of all energy supplied to an engine is lost due to friction
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Project Wonaco2Engine tribology 101ANS TriboconditioningProject focus and resultsSummary
Agenda
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Steel surface
ProcessFluid
Triboconditioning
TEM-image of the coating
Tool
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CORE METHOD
Turning
USAGE
Application areas and usage
Steel surface
Tool
F
v
Honing
Hydraulic rods
Cylinders
Camshafts
Turbine shafts
Crankshafts Rockdrills
Bearings
Piston pins
APPLICATIONS
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Effect from Triboconditioning
Controlled Running-inPeaks removed (Rpk reduced)Nano-composite TRIBO-layer to reduce friction and wear
Original surface
Triboconditionedsurface
Triboconditioning improves surface finish and deposits a low-friction tribolayer in one
process step
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Tribofilm up close (FIB/TEM)
20-100 nm
Steel substrate
Protective layer from sample preparation
Amorphous deposited film
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Stribeck effect
Lowered boundary frictiondue to easily shearednano-composite coating
Surface layer prevents asperity-asperity contactsand the coating improves oil affinity,hence the shift to the left of the curve
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Project Wonaco2Engine tribology 101ANS TriboconditioningProject focus and resultsSummary
Agenda
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Research focus Wonaco2
How is the topography changed? Before and after?How fine surfaces can be manufactured?Can manufacturing steps be replaced?
How do the process parameters effect the surface (chemistry and topography)?
How can the chemistry in the tribolayer be controlled?What does the film look like? Contents? Hardness? Morphology?
How good are the surfaces in different tribo systems?
Triboconditioning
• Pressure• Time• Chemistry fluid• Chemistry tool• Temperature
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Triboconditioning in Action
Triboconditioning of cylinder liners Triboconditioning of shafts
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Scania roller tappet shaft
Roller tapper shaft, Triboconditioned bearing positions
Schematic picture of Scania valve system
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Scania roller tapper shafts
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0,05
0,1
0,15
0
400
800
1200
1600
2000
2400
Fricti
on ko
ef.
Time [s]
Rocker Arm Shaft "ANS3"
ANS3 Ref1
ANS3 Ref2
ANS3 Coating
Friction reading; ANS triboconditioning vs Reference
Wear marks on counter surface after friction test aboveFrom left to right: ANS triboconditioning, Reference 1, Reference 2
Results – Friction & Wear
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Volvo rocker arm shafts
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Volvo Rocker Arm ShaftResults – Friction & Wear
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0,02
0,04
0,06
0,08
0,1
0,12
0,14
0,16
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
1500
1600
1700
1800
1900
2000
2100
2200
2300
Fric
tion
koe
f.
Time [s]
Volvo Rocker Arm Shaft "1"ANS Classic vs Reference
A4_Ref
A4_Ref
A2_Coating
A2_Coating
A3_Coating
A3_Coating
Wear marks on counter surface after friction test From right to left: Reference, ANS coating A2, ANS coating A3
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Cylinder liners
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Effect from Triboconditioning
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Smoother plateaus
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Reduced RPK
Coated cylinder liner
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Friction reduction - liners
0 50 100 150 200 250 300 3500
0.02
0.04
0.06
0.08
0.1
0.12
ANSStandard
Speed (RPM)
COF
(ave
rage
)Load: 100 NRing: CrN PVD ringOil: SAE 30Oil temperature: 20°C
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Half treated segment (HH)
COATEDStroke: 24mmLoad: 8NVelocities: 1HzTime: 10minNominal contact pressure: 1.42 MPa•10mm wide liner samples•Liner samples half-coated,half-uncoated•New twin land oil control ring
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Project Wonaco2Engine tribology 101ANS TriboconditioningProject focus and resultsSummary
Agenda
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Triboconditioning can be used to reduce frictional losses in heavy duty diesel enginesGood results in 10+ projects so far (Volvo, Scania, Mahle, Federal Mogul, Gnutti, Ford, Atlas Copco Secoroc, Tetra Pak, Hägglunds Drives, Bosch, BodyCote, ...)Wonaco2-projektet gave us a great opportunity to do advanced research in the area of Triboconditioning
We will now continue our work to get the triboconditioning method in production!
Summary
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Published papers
TAE - 2012 STLE - 2012TLT - 2011EcoTrib - 2011
Mattias Karls, +46 70 348 35 [email protected]