engine_and_powertrain conceopt panel operations

hi

1. Engine and powertrain

2. •gearinglosses:
frictionlosses, load-dependent,
churning and squeezing losses attributable to splash lubrication, loadindependent,
•bearinglosses:
frictionlosses, load-dependent,
lubricationlosses, load-independent,
•sealinglosses:
friction losses caused by rotary shaft seals at shaft exits,
friction losses caused by piston rings used to keep oil under pressure at theshiftelements,
•synchronizinglosses:
fluid friction between synchronizer ring and friction cone,
•clutchlosses:
fluid friction with wet running, multi-plate clutches and brakes in automaticgearboxes and
automated manual gearboxes,
•torqueconverterlosses:
losses in the hydrodynamic torque converter,
•auxiliaryunits:
power to drive auxiliary unit
Power to overcome by the engine

3. Powertrain
1)Engine,
2)Clutch,
3)Gear box,
4)Cardan joint,
5)Differential,
6)Drive axle.

4. Powertrain
CROLLA, D. 2009. Automotive Engineering e-Mega Reference, Elsevier Science.

5. KUCHLE, A., NAUNHEIMER, H., BERTSCHE, B., RYBORZ, J., NOVAK, W. & FIETKAU, P. 2010. Automotive
Transmissions: Fundamentals, Selection, Design and Application, Springer Berlin Heidelberg.
The actual torque delivered to the
drivetrain is reduced by the amount
required to accelerate the inertia of
the rotating components.
The total ratio of thepowertrain
Theratioofoutputspeedn2toinput
speedn1ofapowertraincomponentis
definedasspeedconversion
The torque conversion μ

6. Transmision
Gear box
KUCHLE, A., NAUNHEIMER, H., BERTSCHE, B., RYBORZ, J., NOVAK, W. & FIETKAU, P. 2010. Automotive Transmissions: Fundamentals, Selection, Design and Application, Springer Berlin Heidelberg.

7. Gear ratios
KUCHLE, A., NAUNHEIMER, H., BERTSCHE, B., RYBORZ, J., NOVAK, W. & FIETKAU, P. 2010. Automotive Transmissions: Fundamentals, Selection, Design and Application, Springer Berlin Heidelberg.
• move-off underdifficultconditions, iA,max
• reach the required maximum speed iA(vmax,th).
• operate in the fuel-efficient ranges of the engine performance mapiA,min.

8. OverallGear Ratio
•Vehicles with a low specific power output, such as commercial vehicles, need alarger overall gear ratio.
•The same applies for vehicles with diesel engines, whichhave a small engine speed spread.
The overall gear ratio depends on:
•the specific power output of the vehicle
•the engine speed spread
•the intendeduse.

9. The Largest Powertrain Ratio iA,max
•Thegreatesttractionrequirementmustbeknowntodeterminetheratioofthegearwiththe
largesttorquemultiplication.
•Thefrictionlimit−i.e.themaximumforcethatcanbetransmittedbetweenthetyresandthe
road−isaphysicallimitandmustbetakenintoaccountwhenestablishingthetractionFZ,Aat
theroadwheels
•At thedrive wheels a balance must be struck between the maximum requirements of
acceleration,gradient, road surface, payload and trailer load:
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10. Climbingperformance
•The maximum gradient
that can be climbed at an
acceleration of a = 0 m/ss
•This ensures that a trailer can be
towed and steeprampsovercome
with ease.
Acceleration performance
•Themaximumaccelerationon
thelevel.
•Accelerationperformancedependsnot
onlyonthestalltorqueratio,butalsoto
asignificantdegreeonhowcloselythe
gearsapproximatetothetraction
hyperbola.
The Largest Powertrain Ratio iA,max

11. Commercial vehicles
(buildingsitevehicles)
•The largest ratio in commercial vehicles is often dictated by the
vehicle’s intended use.
•building site vehicles and road sweepers have gears for extremely
slow movement
Theseveryhigh-ratio gearsare known as crawler gears.

12. The Smallest Powertrain Ratio iA,min
Assuming there is no slip in the power transmission from
wheel to road and thatthe (desired) maximum speed is
reached at maximum engine speed,
Thelimitingfactorsoflegalspeed
restrictionsanddieselenginecut-off
speedmeanthatthemaximumspeed
willoftenbeadesignparameterwhen
developingcommercial vehicle
powertrains.
KUCHLE, A., NAUNHEIMER, H., BERTSCHE, B., RYBORZ, J., NOVAK, W. & FIETKAU, P. 2010. Automotive Transmissions: Fundamentals, Selection, Design and Application, Springer Berlin Heidelberg.

13. Passengercars
The Smallest Powertrain Ratio iA,min
KUCHLE, A., NAUNHEIMER, H., BERTSCHE, B., RYBORZ, J., NOVAK, W. & FIETKAU, P. 2010. Automotive Transmissions: Fundamentals, Selection, Design and Application, Springer Berlin Heidelberg.
OverrevvingDesign
The high level of excesspower PZ,Ex2 makes this
arrangement preferable for sports designs
1/ vmax–Optimum Design
TheexcesspoweravailablePZ,Exisa
measureofaccelerationreserve,andthe
enginespeednMservesasameasureforfuel
consumption
UnderrevvingDesign
The reductionin enginespeed is the important
feature of this design. The operating point moves
intoan area of improved fuel consumption.

14. underrevvingpowertrain ratios to improve fuel economy
a powertrain optimisedforvmax,th
KUCHLE, A., NAUNHEIMER, H., BERTSCHE, B., RYBORZ, J., NOVAK, W. & FIETKAU, P. 2010. Automotive Transmissions: Fundamentals, Selection, Design and Application, Springer Berlin Heidelberg.

15. increase the overall
gear ratio with the
same number of
speeds
Theeffectofincreasingtheoverall
gearratiowiththesamenumber
ofgearsistocreaterelativelylarge
gapsinthepoweroutput,thus
reducingthevehicle’sacceleration
performance.
KUCHLE, A., NAUNHEIMER, H., BERTSCHE, B., RYBORZ, J., NOVAK, W. & FIETKAU, P. 2010. Automotive Transmissions: Fundamentals, Selection, Design and Application, Springer Berlin Heidelberg.

16. reduce the final ratio
(“long axle design”)
Increasingthefinalratio(“long
axledesign”)withthesameoverall
gearratioleadstoasmallerstall
torqueratio,andthustoreduced
climbingperformanceand
increasedclutchstresswhen
moving-off.
KUCHLE, A., NAUNHEIMER, H., BERTSCHE, B., RYBORZ, J., NOVAK, W. & FIETKAU, P. 2010. Automotive Transmissions: Fundamentals, Selection, Design and Application, Springer Berlin Heidelberg.

17. increase the overall gear ratio by
increasing the number of gears –
overdrive –
Thefifthandsixthspeedonmanual
passengercargearboxescanbe
designedasoverdrivestoreduce
enginespeed
KUCHLE, A., NAUNHEIMER, H., BERTSCHE, B., RYBORZ, J., NOVAK, W. & FIETKAU, P. 2010. Automotive Transmissions: Fundamentals, Selection, Design and Application, Springer Berlin Heidelberg.

18. Selectingthe IntermediateGears
The relationship between the ratios of two neighbouringgears, the gear step φ, isgivenby
•Thegreaterthenumberofgears,thebettertheengineexploitsitsefficiencybyadheringto
thetractionhyperbola.Butasthenumberofgearsincreases,sodoesthefrequencyofgearshiftingandthe
weightandsizeofthegearbox.
•Theproportionofdistancetravelledinthelowergearsislow,especiallyinthecaseof
passengercars.
•Theproportionofdistancetravelledineachgeardependsonthespecificpoweroutput
(kW/t),thetrafficconditionsanddriverbehavior
•Thesmallerthegearstepφ,theeasierandmorepleasantthegearshiftaction
•The thermal load on the synchronizer rings is proportional to the square of thegearstep.

19. The velocity/engine-speeddiagram
The saw profile diagram shows the
earliest upshiftpossible without
stalling the engine and the earliest
downshift possible without
exceeding the maximum engine
speed

20. Methodsfor calculating gear steps
geometrical gear steps
(commercial vehicle)
•In the geometric design the gear step φ between the
individual gears always has the same theoretical
value
•Thelower specific power output means all the gear
steps are of equal significance
progressive gearsteps
Passenger vehicle
The ratios of the individual gears n = 1 to z is then given by
In the tractiondiagram the gaps between the effective traction
hyperbola and the traction availableare reduced in the top
gears(improvedshiftingcomfort (smaller φ), and in improved acceleration
performance)
Given the overall gear ratio iG,totand the selected progression factor φ 2, the
baseratio change φ 1 can be calculated

21. Gear ratios

22. Gearshifting
Internal shifting elements in automotive transmissions.
aSliding gear; bdogclutch engagement; cpin engagement; dsynchronizer without locking mechanism;esynchronizer with
locking mechanism; fservo lock synchronizer mechanism (Porschesystem); ghydraulically activated multi-plate clutch for
powershifttransmission;h hydraulically activated multi-plate brake for planetary gear

23. Cross section of a front-wheel-drive manual gearbox
CROLLA, D. 2009. Automotive Engineering e-Mega Reference, Elsevier Science.

24. Cross section of a rear-wheel-drive manual gearbox
CROLLA, D. 2009. Automotive Engineering e-Mega Reference, Elsevier Science.

25. Gearchangingand the synchromesh
•Theworkdonebythesynchromeshassemblyisto
changethespeedoftheinertiaonthelayshaftand
inputshaft,whichincludestheclutchdrivenplate.
•Synchromeshiseffectivelyaconebrakedevice,and
theactionofthedriverinapplyingforcetothesleeve
allowsthetwosidesoftheassemblytotendtowards
thesamespeed.
•Inthefirstpartofthesynchronizingprocess,the
sleeveappliesaloadontothebaulkring,whichis
rotatingatadifferentspeedtotheconeontowhichit
ispushed.
•Thefrictionthatiscreatedbythiscausesthespeedof
thetwopartstobecomethesame.Atthispoint,the
sleeveisabletomovepastthebaulkringandengage
withthegear,andthegearshiftiscomplete
CROLLA, D. 2009. Automotive Engineering e-Mega Reference,
Elsevier Science.

26. HEISLER, H. 2002. Advanced VehicleTechnology, Butterworth-Heinemann.

27. FinalDrives
KUCHLE, A., NAUNHEIMER, H., BERTSCHE, B., RYBORZ, J., NOVAK, W. & FIETKAU, P. 2010. Automotive Transmissions: Fundamentals, Selection, Design and Application, Springer Berlin Heidelberg.
The components derived from this
classification whichfall under the
category “final drive”are:
•axle drive,
•differentialgear,
•hub drive (commercial vehicles) and
•transfer gearbox (in case of multiple
driven axles

28. FinalDrives
Axle Drivesfor PassengerCars
KUCHLE, A., NAUNHEIMER, H., BERTSCHE, B., RYBORZ, J., NOVAK, W. & FIETKAU, P. 2010. Automotive Transmissions: Fundamentals, Selection, Design and Application, Springer Berlin Heidelberg.

29. FinalDrives
Spurgear
•Spurgearaxledrivesarenowcommon
becauseofthepopularityofvehicleswith
transversefront-mountedengines.
•Theaxledriveisdriveneitherdirectlyby
theoutputshaftofthetransmission,orby
idlergears
•Itisnormallyfavourableforthedifferential
cagedriveiftheengineandtransmission
aremountedsidebyside,withthe
disadvantageofhavingdriveshaftsof
unequallengthtothewheels.
•Thereasonsfortheirpopularityarethe
compactnessandlowproductioncostof
spurgears,normallyhelicalcut.
KUCHLE, A., NAUNHEIMER, H., BERTSCHE, B., RYBORZ, J., NOVAK, W. & FIETKAU, P. 2010. Automotive Transmissions: Fundamentals, Selection, Design and Application, Springer Berlin Heidelberg.

30. FinalDrives
Bevelgear
•Inpowertrainswheretheengineislongitudinally
mounted,andinall-wheeldrives,thepowerflowto
thewheelshastobeturnedthrough90°.
•Theaxledrivecanbeintegratedinthetransmission
housing(transaxledesign),ordesignedasan
independentassembly,asinvehicleswithstandard
drive
•Inpassengercars,hypoiddrivesareusuallyused,in
whichthebeveldrivepinionengagesbelowtheaxial
centreofthecrowngear.
•Thisoffsetmakesthediameterofthebeveldrive
pinionlarger,andthecrowngearcanbesmallerfor
thesameloadthaninhelicalbeveldrivesinwhichthe
axesintersect.
•Theoffsetalsoenablesthepropellershafttobe
mountedlower,reducingthesizeofthetransmission
tunnel
KUCHLE, A., NAUNHEIMER, H., BERTSCHE, B., RYBORZ, J., NOVAK, W. & FIETKAU, P. 2010. Automotive Transmissions: Fundamentals, Selection, Design and Application, Springer Berlin Heidelberg.

31. FinalDrives
WormGear Axle Drive
There are now no more axle drives with worm gear axle drive in
production. Thistype of drive was used in some Peugeot models in the
1970s.
•The worm gear axle drive does have significant advantages.
•It offers large multiplications in a compact space
•The worm can be locatedbelow or above the worm gearwheel
•Mounting the worm above the gearwheel gives the vehicle good ground
clearance,a particular advantage for off-road vehicles.
KUCHLE, A., NAUNHEIMER, H., BERTSCHE, B., RYBORZ, J., NOVAK, W. & FIETKAU, P. 2010. Automotive Transmissions: Fundamentals, Selection, Design and Application, Springer Berlin Heidelberg.

32. Differential
•Workingprincipal:
•Ifbothcrownwheels,connectedbyhalfaxlewithwheels,arerotatingwith
thissamespeedtheplantdoesnotrotateandthusthedifferentialdoesnot
operate.
•Thepowerdriveisprovidedtothewheelsastheirwouldbeconnectedwith
eachotherbyrigidaxle.Thiswouldonlyhappenedwhenthecardrives
straightandthedynamicradiusindexofbothwheelsisthesame.
•Inrealitythisispracticallyimpossible.

33. Moment transferred by half axis
•Consideringfrictionalmomentofthe
differentialmechanismMT,thenthemoments
ofbothhalfaxisM1andM2canbedescribed
as:
•SubtractingM1–M2:
•Oranotherway:




t
t
MMM
MMM
02
01
5,0
5,0 T
MMM 2
21
 575,055,0
5,0
0
0
0
max2,1
0max2,1




M
MM
M
M
MM
T

 021
5,0MMM 

34. The clutch system
1) flywheel, 2) central disc, 3) pressure plate, 4) clutch pedal

35. 1/ Clutch plate:
a driving plate;
b friction lining;
c cushion spring;
d torsion spring(driving operation);
e torsion spring (idle operation);
f friction device;
g hub;
2/ pressure plate assembly:
h return flat spring;
i pressure plate;
j pressure plate housing;
k diaphragmspring;
3/ clutch actuation:
l release bearing;
m sliding sleeve;
n release lever;
4/ flywheel

36. Diaphragmclutch engaged and disengaged

37. a)Clutchplatewithtorsiondamper(passenger
car);
b)flexibleclutchplate(passengercar);
c)rigidclutchplate(passengercar);
d)clutchplatewithtorsiondampers
(commercialvehicle);
e)clutchplatewithcerametallicliningpads
(commercialvehicle)

38. Literature
CROLLA, D. 2009. Automotive Engineering e-Mega Reference, ElsevierScience.
GARRETT, T. K., NEWTON, K. & STEEDS, W. 2000. Motor Vehicle, ElsevierScience.
HEISLER, H. 2002. Advanced VehicleTechnology, Butterworth-Heinemann.
NUNNEY, M. 2015. Light and Heavy Vehicle Technology, Routledge.
WONG, J. Y. 2001. Theoryof GroundVehicles, Wiley.