Post on 08-Jan-2017
16 de dezembro de 2016 | 1
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Power Transmission Systems (drivetrain)
Mário Alves (mjf@isep.ipp.pt)
16 de dezembro de 2016 | 2
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Outline
• Drivetrain: definition, main components, configurations
• Clutch assembly
• Transmission
• types and market share
• manual
• automatic
• automatic CVT
• semi-automatic
• Driveshaft
• Differential
• Glossary
• Recommended references
16 de dezembro de 2016 | 3
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Drivetrain: definitions
• Powertrain
• group of components in a vehicle that generate power and deliver it
to the road surface (or water, or air)
• includes engine/motor and drivetrain, i.e. all parts that allow the
power from the engine to get to the wheels
• Drivetrain
• the mechanical parts of the powertrain, the gears and shafts, that
connect the engine to the wheels in a vehicle
• excludes the engine/motor that generates the mechanical power
http://wikidiff.com/powertrain/drivetrain
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Drivetrain: main components
• Drivetrain main blocks
• Clutch
• Transmission (aka Gear Box)
• Drive Shaft (aka Propeller Shaft; front/rear)
• Differential (front/rear)
• Axle Shafts (left/right, front/rear)
http://www.eurotechmotors.com/lit-up-like-a-christmas-tree/
16 de dezembro de 2016 | 5
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Drivetrain configurations – rear/front-wheel drive
http://schoolworkhelper.net/the-drive-train-hydraulic-
brake-system-steering-system/
16 de dezembro de 2016 | 6
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Drivetrain configurations – all combinations
https://mediocremotoring.wordpress.com/2009/09/03/fw
d-awd-rwd-mr-rr-2/
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Drivetrain configurations – pros and cons
• Rear-wheel drive
• under acceleration, the weight balance of a car shifts backward,
pushing down on the rear wheels
• added weight means added traction, under acceleration
• more difficult to control than other drivetrain configurations
http://www.kfz-tech.de/Engl/Biblio/Achsantrieb/Standardantrieb.htm
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Drivetrain configurations – pros and cons
• Front-wheel drive
• under acceleration, the weight balance of a car shifts backward,
pushing down on the rear wheels
• this added weight means reduced traction
• simple construction, less parts
and mechanical losses
• better drivability (easier
steering control)
http://www.kfz-tech.de/Engl/Biblio/Achsantrieb/FrontantriebL.htm
16 de dezembro de 2016 | 9
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Drivetrain configurations – pros and cons
• All-wheel drive
• add weight and mechanical complexity to cars,
• more complex construction, more parts and more weight
• better traction and drivability under harsh conditions
http://www.kfz-tech.de/Engl/Biblio/Allradantrieb/AllradFrLaeP.htm
16 de dezembro de 2016 | 10
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Clutch/transmission – basic operation
http://giphy.com/search/transmission
16 de dezembro de 2016 | 11
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Clutch assembly
• Friction clutch: works through friction/gripping force
http://kids.britannica.com/comptons/article-197024/automobile
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Clutch assembly
• Main components
• flywheel
• friction disc
(aka clutch disk)
• pressure plate
• throw-out bearing
(aka release bearing)
• clutch fork
(aka release fork
or throw-out fork)
http://mechanics.stackexchange.com/questions/18552/ho
w-a-clutch-works
16 de dezembro de 2016 | 13
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Clutch assembly
• Flywheel
• directly driven (1:1 ratio) by crankshaft
• provides a rotating inertial mass for smoother torque delivery
• provides a ring gear for the starter motor to engage on
• provides a driving friction surface for the friction disc
• usually includes reference pin/slots for crankshaft position sensor
http://repairguide.autozone.com/znetrgs/repair_guide_content/en_us/images/0900c152/80/25/18/db/medium/0900c152802518db.gif
http://newautoaa.blogspot.pt/p/distributorless-ignition-system.html
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Clutch assembly
• Friction disc (aka clutch disk)
• located between the flywheel and the pressure plate
• friction surfaces make or break contact with the metal flywheel
and pressure plate surfaces, allowing for smooth engagement and
disengagement
http://australianclutch.eu/how-a-clutch-works/
http://www.thecartech.com/subjects/auto_eng/Auto_Clutch.htm
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Clutch assembly
• Pressure plate
• it is fixed to the flywheel with bolts and they rotate together
• applies a clamping force (pressure) which holds the driven
friction disc between it and the flywheel
http://australianclutch.eu/how-a-clutch-works/
http://www.amazon.com/Porsche-Clutch-Pressure-tension-spring/dp/B00ADZFYJO
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Clutch assembly
http://www.thecartech.com/subjects/auto_eng/Auto_Clutch.htm
• Release fork and bearing: hydraulic and mechanical
clutches
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Clutch assembly
http://www.thecartech.com/subjects/auto_eng/Auto_Clutch.htm
• Coil-spring and diaphragm clutches
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Transmission
http://www.nap.edu/read/21744/chapter/7#168
• Objective: to adapt engine to wheels torque & speed
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Transmission – main types
http://www.nap.edu/read/21744/chapter/7#168
• Manual • gears are manually selected through driver-operated clutch engaged and
disengaged by a foot pedal (automobile) or hand lever (motorcycle),
• shift selector types: H-pattern of sequential
• Automatic • no drivers’ action needed; gears are selected via Transmission ECU; main
types:
• based on compound planetary gear trains (gears are automatically selected by the Transmission ECU
• based on CVT (continuous variable transmission – continuous interval or gear ratios)
• Automated manual (aka robotized or semi-automatic) • similar to a manual transmission, but driver changes gears via shifter/paddles
located behind the steering wheel; no need to operate a clutch pedal; main types:
• sequential: gears must be selected in order (selector forks are controlled by ratcheting drum, instead of H lever)
• dual-clutch (DCT): uses two clutches (for even & odd+reverse gears); power flow from the engine is not interrupted
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Transmission – market share, to date
http://www.afr.com/lifestyle/cars-bikes-and-boats/cars/manual-cars-face-extinction-as-congestion-triggers-a-clutch-backlash-20150614-ghni7m
http://energy.gov/eere/vehicles/fact-802-november-4-2013-market-share-transmission-type
Manual
CVT
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Transmission – market share, present/forecast
http://www.infineuminsight.com/insight/dec-2012/gearing-up
https://www3.epa.gov/otaq/fetrends.htm
Automated
manual
Conventional
16 de dezembro de 2016 | 22
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Transmission – manual
http://gustafsonbros.clearmechanic.com/Frames/Part.aspx?id=4025&key=b6e4e887-374d-440b-
ab41-882b1888dccc
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Transmission – manual
http://gustafsonbros.clearmechanic.com/Frames/Part.aspx?id=4025&key=b6e4e887-374d-440b-
ab41-882b1888dccc
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Transmission – manual
http://gustafsonbros.clearmechanic.com/Frames/Part.aspx?id=4025&key=b6e4e887-374d-440b-
ab41-882b1888dccc
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Transmission – manual
http://gustafsonbros.clearmechanic.com/Frames/Part.aspx?id=4025&key=b6e4e887-374d-440b-
ab41-882b1888dccc
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Transmission – manual
http://gustafsonbros.clearmechanic.com/Frames/Part.aspx?id=4025&key=b6e4e887-374d-440b-
ab41-882b1888dccc
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Transmission – manual
• (https://www.youtube.com/watch?v=QPaUJfA1KsY)
https://www.reddit.com/r/educationalgifs/comments/1p245a/ho
w_a_manual_transmission_changes_gears/
Input shaft
(engaged with
clutch disk)
Output shaft
(engaged
driveshaft)
Gear selector
(H-shapped)
Counter shaft
(aka layshaft)
RED means mechanical power
Reverse
idler gear
16 de dezembro de 2016 | 28
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Transmission – automatic
• Main components
• torque converter (fluid coupling clutch)
• gear train – usually a compound planetary (or epicyclical) gear train (or set)
• hydraulically operated brake-bands, multi-plate clutches and multi-plate brakes – to couple or lock the appropriate elements of the planetary gear sets, to obtain different gear ratios
• hydraulic (oil) pump, circuit and solenoid valves
• transmission ECU
http://www.aa1car.com/library/what_goes_wrong_with_cars.htm
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Transmission – automatic
http://dasauto.ae/rwdat.php
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Transmission – automatic
http://dasauto.ae/fwdat.php
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Transmission – automatic
• Torque converter: works through fluid coupling/dragging
force (https://www.youtube.com/watch?v=z5G2zQ_3xTc)
http://kids.britannica.com/comptons/article-197025/automobile
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Transmission – automatic
• Planetary (or epicyclical) gear set (or train)
• it is the center piece of an automatic transmission
• all other elements of the transmission help planetary gear sets to do their RPM/torque conversion task
• Three main components:
• sun gear
• planet gears + planet gears' carrier
• ring gear (or annulus)
• Automatic transmissions use several planetary gear trains
• with 2 planetary gear trains in a row, we can get 4 forward gears and 1 reverse gear
https://wikis.engrade.com/planetarygearsetsoperati
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Transmission – automatic
• Planetary gear set – locking each of the 3 elements
http://bestanimations.com/Science/Gears/planetary-gear-set-animation-9.gif
Carrier locked Ring gear locked Sun gear locked
https://www.psmotion.com/sites/default/files/Planetary%20Gears%202.gif
Carrier and Ring turn same way;
Ring faster than Carrier Sun and Ring turn opposite ways;
Sun faster than Ring
Sun and Carrier turn same way;
Sun faster than Carrier
https://media.giphy.com/media/ABkjT6gSzkwrC/giphy.gif
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Transmission – automatic
• Planetary gear set • one gear set is capable of providing 8 gear modes/ratios
• 2 forward reduction
• 2 forward overdrive
• 2 reverse (reduction + overdrive)
• 1 idle (neutral)
• 1 forward direct (1:1)
• torque/speed/direction is varied by changing the role of each element
• driving (providing power; input), driven (receiving power; output), or locked (stationary)
• these different modes are achieved by driving/holding Sun, Carrier and Ring with bands and clutches
• a clutch drives an input element while a band or one-way clutch holds another element
• this causes the third element to output the desired gear mode/ratio
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Transmission – automatic
• Planetary gear set – calculation of the gear ratio • the gear ratio is defined as the driver/input (angular) speed divided by
the driven/output (angular) speed. Considering Gear 2 as input and Gear 1 as output
• For a gear pair
• Linear speed v at the contact point is equal for the two gears:
• Therefore:
• Considering that the number of gear teeth is proportional to the gear radius:
• Then:
• Finally, considering Gear 2 as input and Gear 1 as output:
http://www.sdcpublications.com/multimedia/978-1-58503-767-4/files/krb/krb_pr_page3.htm
v = 1*r1 = 2*r2
1/2 = r2/r1
N1/N2 = r1/r2
1/2 = N2/N1
R g = in/out
R g = 2/1 = N1/N2
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Transmission – automatic
• Planetary gear set – calculation of the gear ratio
• Terminology
• Number of teeth N
• Angular velocity
• Sun index S
• S and NS
• Ring index R
• R and NR
• Carrier index C
• C and NC
https://wikis.engrade.com/planetarygearsetsoperati
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Transmission – automatic
• Planetary gear set – calculation of the gear ratio
• Important consideration for the computation of the gear ratio
• NS = effective number of teeth of the Sun gear
• NR = effective number of teeth of the Ring gear
• NR > NS (typically 3-4 times greater)
• NC = NS + NR (this is an abstraction; the number of teeth of
the Planet gears does not influence the gear ratio)
• NC > NS and NC > NR
• Example
• NS = 30 (real)
• NR = 90 (real)
• NC = 30 + 90 = 120
https://wikis.engrade.com/planetarygearsetsoperati
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Transmission – automatic
• Planetary gear set – calculation of the gear ratio
• In the following slides, we are going to address the following
combinations:
• Planet Carrier locked
• Sun as input and Ring as output
• Ring as input and Sun as output
• Ring gear locked
• Sun as input and Carrier as output
• Carrier as input and Sun as output
• Sun gear locked
• Planet as input and Ring as output
• Ring as input and Planet as output
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Transmission – automatic
• Planetary gear set – calculation of the gear ratio
• Planet carrier locked C = 0
• Sun drives (input) and Ring is driven (output)
• R g = in/out = S/R = -NR/NS
• note that
• Sun and Ring turn in opposite ways, so one of the
angular speeds must be negative
• so the gear ratio is negative = reverse
• since NR > NS, results in speed reduction
• For our example
• R g = -NR/NS = -90/30 = -3
• 1 Sun turn = -1/3 Ring turn
http://bestanimations.com/Science/Gears/planetary-gear-set-animation-9.gif
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Transmission – automatic
• Planetary gear set – calculation of the gear ratio
• Planet carrier locked C = 0
• Ring drives (input) and Sun is driven (output)
• R g = in/out = R/S = -NS/NR
• note that
• Sun and Ring turn in opposite ways, so one of the
angular speeds must be negative
• so the gear ratio is negative = reverse
• since NR > NS, results in speed increase
• For our example
• R g = -NS/NR = -30/90 = -1/3
• 1 Ring turn = - 3 Sun turns
http://bestanimations.com/Science/Gears/planetary-gear-set-animation-9.gif
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Transmission – automatic
• Planetary gear set – calculation of the gear ratio
• Ring gear locked R = 0
• Sun drives (input) and Carrier is driven (output)
• R g = in/out = S/C = NC/NS
• note that
• Sun and Ring turn in the same way
• so the gear ratio is positive = forward
• since NC > NS, results in speed reduction
• For our example
• R g = NC/NS = 120/30 = 4
• 1 Sun turn = 1/4 Carrier turn
https://media.giphy.com/media/ABkjT6gSzkwrC/giphy.gif
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Transmission – automatic
• Planetary gear set – calculation of the gear ratio
• Ring gear locked R = 0
• Carrier drives (input) and Sun is driven (output)
• R g = in/out = C/S = NS/NC
• note that
• Sun and Ring turn in the same way
• so the gear ratio is positive = forward
• since NC > NS, results in speed increase
• For our example
• R g = NS/NC = 30/120 = 1/4
• 1 Carrier turn = 4 Sun turns
https://media.giphy.com/media/ABkjT6gSzkwrC/giphy.gif
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Transmission – automatic
https://www.psmotion.com/sites/default/files/Planetary%20Gears%202.gif
• Planetary gear set – calculation of the gear ratio
• Sun gear locked S = 0
• Carrier drives (input) and Ring is driven (output)
• R g = in/out = C/R = NR/NC
• note that
• Carrier and Ring turn in the same way
• so the gear ratio is positive = forward
• since NC > NR, results in speed increase
• For our example
• R g = NR/NC = 90/120 = 3/4
• 3 Carrier turns = 4 Ring turns
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Transmission – automatic
• Planetary gear set – calculation of the gear ratio
• Sun gear locked S = 0
• Ring drives (input) and Carrier is driven (output)
• R g = in/out = R/C = NC/NR
• note that
• Carrier and Ring turn in the same way
• so the gear ratio is positive = forward
• since NC > NR, results in speed decrease
• For our example
• R g = NC/NR = 120/90 = 4/3
• 4 Ring turns = 3 Carrier turns
https://www.psmotion.com/sites/default/files/Planetary%20Gears%202.gif
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Transmission – automatic
• Planetary gear set – calculation of the gear ratio
• In summary, we can get the following gear modes/ratios
(values between parenthesis are computed from the example)
https://wikis.engrade.com/planetarygearsetsoperati
Sun Carrier Ring Gear ratio Speed Direction
output locked input -NR/NS (-1/3) Increases (3x) Reverse
input locked output -NS/NR (-3) Decreases (3x) Reverse
input output locked +NC/NS (4) Decreases (4x) Forward
locked output input +NC/NR (4/3) Decreases (1,33x) Forward
locked input output +NR/NC (3/4) Increases (1.33x) Forward
output input locked +NS/NC (1/4) Increases (4x) Forward
Any two elements locked +1 = input Forward
No element locked neutral neutral
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Transmission – automatic
• Compound planetary gear trains
• planetary gear sets are combined to get more gear ratios:
• Simpson planetary gear set
• shared sun gear, 2 carriers and 2 ring gears
• provides 3 forward gears (actually 4, but two of them are equal), neutral and reverse: 3rd is always direct 1:1 drive
• Ravigneaux planetary gear set
• shared ring gear, 2 carriers and 2 sun gears
• Provides 4 forward gears, neutral and reverse
• Multistage systems
• association of several planetary gear sets
• e.g. Lepelletier gear train = planetary gear set + Ravigneaux planetary gear set (provides 6 forward gears, neutral and reverse)
https://wikis.engrade.com/planetarygearsetsoperati
16 de dezembro de 2016 | 47
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Transmission – automatic
• Simpson planetary gear set
• see https://www.youtube.com/watch?v=r1BYOOJKyaQ
http://leakylugnut.com/driveline/automatic-transmissions/
16 de dezembro de 2016 | 48
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Transmission – automatic
• Simpson planetary gear set – 1st gear
• input (engine) torque is locked to the front ring gear
• front ring gear drives the front carrier gears
• front carrier gears drive the sun
• rear carrier is held
• sun gear drives the rear planet gears
• rear planet gears drive the rear ring gear
that is locked to the output shaft
http://pt.slideshare.net/shahroulnizam/planetary-gear-set
16 de dezembro de 2016 | 49
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Transmission – automatic
• Simpson planetary gear set – 2nd gear
• input (engine) torque is locked to the front ring gear
• front ring gear drives the front carrier gears
• sun gear is held
• Front planet gears rotate around the sun gear
• Front planet carrier is forced to turn
• This turns the output shaft since the planet carrier is
locked to the output shaft
http://pt.slideshare.net/shahroulnizam/planetary-gear-set
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Transmission – automatic
• Simpson planetary gear set – 3rd gear (direct drive)
• input (engine) torque is locked to the front ring & sun gears
• Since sun and ring gear are rotating at the same speed, the front
planet carrier is forced to rotate with them, at the same speed
• Since front carrier is locked to the output shaft, direct drive (1:1)
occurs
http://pt.slideshare.net/shahroulnizam/planetary-gear-set
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Transmission – automatic
• Simpson planetary gear set – reverse
• input (engine) torque is received by the sun gear (as in 3rd gear)
• Sun gear drives the rear planet gears counterclockwise
• rear planet carrier is held; the rear planet gears drive the rear ring
gear counterclockwise
• rear ring gear is locked to the output shaft that turns at the same
speed and direction as the rear ring gear
http://pt.slideshare.net/shahroulnizam/planetary-gear-set
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Transmission – automatic
• Ravigneaux planetary gear set
• see https://www.youtube.com/watch?v=Nbnyo9uUVKg
• https://www.youtube.com/watch?v=Y1zbE21Pzl0
http://leakylugnut.com/driveline/automatic-transmissions/
16 de dezembro de 2016 | 53
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Transmission – automatic
• Ravigneaux planetary gear set – 1st gear
• Input (engine) torque is locked to the small sun gear
• planet carrier is held
• Sun gear drives short planet gears
• Short planet gears drive the long planet gears
• Long planet gears drive ring gear that is locked to the output shaft
(with a speed reduction)
http://pt.slideshare.net/shahroulnizam/planetary-gear-set
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Transmission – automatic
• Ravigneaux planetary gear set – 2nd gear
• Input (engine) torque is locked to the small sun gear
• Small sun gear drives the short planet gears
• short planet gears drive the long planet gears that rotate around
the large sun gear
• Large sun gear is held
• This rotation drives the ring gear that is locked to the output shaft
http://pt.slideshare.net/shahroulnizam/planetary-gear-set
16 de dezembro de 2016 | 55
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Transmission – automatic
• Ravigneaux planetary gear set – 3rd gear (direct drive)
• Input (engine) torque is locked to the small sun gear and planetary
gear carrier (they rotate together as a single unit)
• long planet gears drive the ring gear that is locked to the output
shaft (with a direct drive – 1:1 gear ratio)
http://pt.slideshare.net/shahroulnizam/planetary-gear-set
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Transmission – automatic
• Ravigneaux planetary gear set – 4rd gear (overdrive)
• Input (engine) torque is locked to the planetary gears carrier
• the long planet gears “walk” around the big sun gear
• the big sun gear is held
• this “walk” drives the ring gear that is locked to the output shaft
(with a speed increase – overdrive)
http://pt.slideshare.net/shahroulnizam/planetary-gear-set
16 de dezembro de 2016 | 57
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Transmission – automatic
• Ravigneaux planetary gear set – reverse gear
• Input (engine) torque is locked to the small sun gear
• the planetary gear carrier is held
• The clockwise rotation of the reverse sun gear drives the long
planet gears counterclockwise
• The long planet gears then drive the ring gear that is locked to the
output shaft (with a speed reduction)
http://pt.slideshare.net/shahroulnizam/planetary-gear-set
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Transmission – automatic
• Control system (generic diagram)
http://www.cvel.clemson.edu/auto/systems/images/sara_ali_transmission.png
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Transmission – automatic
• Control system (ZF OEM)
http://www.aa1car.com/library/2002/us90224.htm
16 de dezembro de 2016 | 60
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Transmission – automatic
• Control system (Renesas OEM)
https://www.renesas.com/en-eu/solutions/automotive/powertrain/transmission-control.html
16 de dezembro de 2016 | 61
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Transmission – automatic CVT
• Continuous Variable Transmission (CVT)
• https://www.youtube.com/watch?v=PEq5_b4LWNY
• https://www.youtube.com/watch?v=c47caRqbbnE
http://auto.howstuffworks.com/cvt3.htm
http://www.autoslexikon.hu/c.htm
Toroidal CVT Pulley-based CVT
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Transmission – automatic CVT
• Pros
• continuous range of effective gear ratios
• engine can operate at optimal torque/power or fuel economy
• fewer parts compared to conventional transmissions, thus cheaper
• smooth “stepless” driver experience
• Cons
• lower mechanical efficiency than manual transmission
• steady acceleration+ lack of gear changes may be “boring”
• driving belts deterioration
• Manufacturers
• Audi, Honda, Hyundai, Subaru, Toyota, GM (own CVTs)
• JATCO (Nissan’s subsidiary and world-leading manufacturer), Team Industries, Bosch, NSK
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Transmission – automatic CVT
• Nissan XTRONIC CVT
• 7.3:1 gear ratio with “sub-planetary” gear set for reverse gear
http://www.nissan-global.com/EN/TECHNOLOGY/OVERVIEW/next_cvt.html
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Transmission – automatic CVT
http://classicmgaccessories.com/articles/f-steptronic-and-tf-stepspeed-cvt-gear-box-mystery-revealed/
• Steptronic
16 de dezembro de 2016 | 65
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Transmission – automatic CVT
http://www.nisentra.com/wiring_diagram-707.html
16 de dezembro de 2016 | 66
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Transmission – semi-automatic
• Semi-automatic transmission
• aka clutch-less manual transmission, automated manual
transmission, robotized manual transmission, flappy-paddle gear
shift or paddle-shift gearbox
• does not change gears automatically, but rather facilitates manual
gear changes by avoiding the need to press a clutch pedal while
changing gears
• uses electronic sensors, pneumatics, processors and actuators to
execute gear shifts on input from the driver (or by a computer, in
fully automatic mode)
• can use one (single) or two (dual) clutches
• dual-clutch transmissions (DCT) are more common
nowadays
https://www.renesas.com/en-eu/solutions/automotive/powertrain/transmission-control.html
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Transmission – semi-automatic (single clutch)
• Renault Quickshift 5
http://automotive.roger.free.fr/contenu_auto/transmission.htm
16 de dezembro de 2016 | 68
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Transmission – semi-automatic (single clutch)
• Renault Quickshift 5
http://whattruck.ro/renault-master-o-noua-transmisie-semiautomata-zf-quickshift-2014/
16 de dezembro de 2016 | 69
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Transmission – semi-automatic (single clutch)
• ZF 7-speed
http://www.zf.com/corporate/en_de/products/product_range/cars/cars_automated_manual_transmission.shtml
16 de dezembro de 2016 | 70
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Transmission – semi-automatic (dual clutch)
• Dual-clutch transmissions (DCT)
• combines the convenience of an automatic transmission with the
fuel efficiency of a manual transmission
• two separate clutches: one for odd and one for even gear sets
• no need for a torque converter
• ECU preselects next gear and engages the appropriate clutch
precisely when required (smooth shifting and optimal efficiency)
• fuel efficiency:
• 3–5% better than MT
• 5–10% better than AT
http://www.mathworks.com/company/newsletters/articles/optimizing-performance-and-fuel-economy-of-a-dual-
clutch-transmission-powertrain-with-model-based-design.html?requestedDomain=www.mathworks.com
16 de dezembro de 2016 | 71
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Transmission – semi-automatic (dual clutch)
• Ford PowerShift
http://www.team-bhp.com/forum/technical-stuff/168683-ford-powershift-dual-clutch-
transmission-dct-technical-overview.html
Detailed operation video:
https://www.youtube.com/
watch?v=6iCRnAUftvI
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Transmission – semi-automatic (dual clutch)
• Ford PowerShift – dual clutches/input shafts
• unlike in manual transmissions, clutches are held open by springs
(do not transmit torque); need to be electrically actuated to close
• Input shafts have fixed gears
• Clutch #1 is connected to inner shaft
• Clutch #2 is connected to outer shaft
http://www.team-bhp.com/forum/technical-stuff/168683-ford-powershift-dual-clutch-
transmission-dct-technical-overview.html
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Transmission – semi-automatic (dual clutch)
• Ford PowerShift – output shafts
• output shafts with free wheeling gears
• 2nd gear is coupled to the reverse gear on the same shaft (both
free-wheel when not engaged, but they do so together)
http://www.team-bhp.com/forum/technical-stuff/168683-ford-powershift-dual-clutch-
transmission-dct-technical-overview.html
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Transmission – semi-automatic (dual clutch)
• Ford PowerShift – differential
• both output shafts transfer torque via the output pinion to a
common differential shaft
• differential shaft is not in the same plane as the output shafts
http://www.team-bhp.com/forum/technical-stuff/168683-ford-powershift-dual-clutch-
transmission-dct-technical-overview.html
16 de dezembro de 2016 | 75
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Transmission – semi-automatic (dual clutch)
• Ford PowerShift – Synchronizer Sleeves & Selector Forks
• synchronizer sleeves/forks allow free-wheeling gears to match
the speed of the output shaft and to lock the gears
http://www.team-bhp.com/forum/technical-stuff/168683-ford-powershift-dual-clutch-
transmission-dct-technical-overview.html
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Transmission – semi-automatic (dual clutch)
• Ford PowerShift – power delivery 1st gear
• torque delivery from the input clutches to the differential is
indicated with a broken red line (- - - -)
• Clutch 1 is actuated, so engine torque comes in through the inner
(yellow) input shaft (Clutch 2 is not actuated)
• sleeve/fork for gears 1/5 is actuated to lock gear 1.
http://www.team-bhp.com/forum/technical-stuff/168683-ford-powershift-dual-clutch-
transmission-dct-technical-overview.html
Note that both output shafts rotate
although only the lower output shaft is
driven directly by the input - the top shaft
rotates as it is driven indirectly by the
differential and the pinion
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Transmission – semi-automatic (dual clutch)
• Ford PowerShift – power delivery 2nd gear
• Clutch 2 is actuated, so engine torque comes in through the outer
(blue) input shaft
• sleeve/fork for gears 2/6 is actuated to lock gear 2.
http://www.team-bhp.com/forum/technical-stuff/168683-ford-powershift-dual-clutch-
transmission-dct-technical-overview.html
Note that that the second gear is coupled
to the reverse gear on the same shaft
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Transmission – semi-automatic (dual clutch)
• Ford PowerShift – power delivery 3rd – 6th gears + reverse
http://www.team-bhp.com/forum/technical-stuff/168683-ford-powershift-dual-clutch-
transmission-dct-technical-overview.html
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Transmission – semi-automatic (dual clutch)
• Ford PowerShift – TCM shift actuator
• two electric motors actuate in spur gears, which rotate gear selector
drums through a specific angle
• thus, a rotational motion produced by the electric motors can be
converted into front-to-back movement of the selector forks
http://www.team-bhp.com/forum/technical-stuff/168683-ford-powershift-dual-clutch-
transmission-dct-technical-overview.html
16 de dezembro de 2016 | 80
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Transmission – semi-automatic (dual clutch)
• Ford PowerShift – TCM clutch actuator
• as the shift actuator, a DC motor moves an actuator level, via worm gear
http://www.team-bhp.com/forum/technical-stuff/168683-ford-powershift-dual-clutch-
transmission-dct-technical-overview.html
16 de dezembro de 2016 | 81
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Transmission – semi-automatic (dual clutch)
• Honda VFR1200F (1st motorcycle’s DCT)
http://blog.motorcycle.com/2013/04/15/manufacturers/honda/more-european-consumers-
choosing-hondas-dual-clutch-transmission/
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Transmission – semi-automatic (dual clutch)
• Honda VFR1200F (see https://youtu.be/s9PzGhAfgIw)
http://world.honda.com/motorcycle-picturebook/DCT/
16 de dezembro de 2016 | 83
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Transmission – semi-automatic (dual clutch)
• Honda VFR1200F
http://world.honda.com/motorcycle-picturebook/DCT/
16 de dezembro de 2016 | 84
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Transmission – semi-automatic (dual clutch)
• Honda VFR1200F
http://world.honda.com/motorcycle-picturebook/DCT/
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http://www.autoevolution.com/news/honda-motorcycle-dual-clutch-transmission-explained-22774.html#
Transmission – semi-automatic (dual clutch)
Honda VFR1200F
16 de dezembro de 2016 | 86
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Transmission – semi-automatic (dual clutch)
• DSG/S-Tronic (longitudinal mounted engines)
http://www.my-gti.com/887/volkswagen-dsg-7-speed-dual-clutch-gearbox-high-output
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Transmission – semi-automatic (dual clutch)
• DSG/S-Tronic (longitudinal mounted engines)
http://www.my-gti.com/887/volkswagen-dsg-7-speed-dual-clutch-gearbox-high-output
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Transmission – semi-automatic (dual clutch)
• DSG/S-Tronic
• transversal
http://www.myturbodiesel.com/wiki/vw-dsg-direct-shift-gear-
transmission-and-audi-stronic-faq-2/
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Transmission – semi-automatic (dual clutch)
• PDK (Porche)
• 7-speed
• 100 ms gear change
http://www.total911.com/technology-explained-pdk-gearbox/
http://www.caranddriver.com/features/a-tale-of-two-porsche-seven-speeds-manual-and-pdk-tech-dept
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Driveshaft and Universal Joints
• Aims at transmitting rotational power across a distance, through a
variable angle, at constant speed
• driveshaft or propeller shaft
• Universal joints (U-joints), Constant-Velocity joints (CV-joints)
or cardans
http://kids.britannica.com/comptons/article-197031/automobile
https://commons.wikimedia.org/wiki/File:Cardan-joint_spline-shaft_topview_transparent_animated.gif
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Differential
• Maximizes power delivery to the drive-wheels, allowing
different speeds for each (left/right) axle
• allows outer wheel to rotate faster than inner wheel during a turn
• results in loss of traction if one wheel is slipping (e.g. ice, sand,
oil under that wheel)
http://kids.britannica.com/comptons/article-197032/automobile
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Differential
• Operation
• driveshaft pinion drives differential ring gear & case (in white)
• differential pinions (in white) drive left and right axles
• mean rotational speed of both axles is constant and equal to
rotational speed of ring gear & case
http://kids.britannica.com/comptons/article-197032/automobile
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Differential
• Refer also to: https://youtu.be/K4JhruinbWc
http://i.makeagif.com/media/6-18-2015/zRT5hD.gif
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Glossary (English/Portuguese)
• …
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Recommended references
• http://auto.howstuffworks.com/clutch1.htm
• http://www.theautopartsshop.com/carsystem/transmission-system.html
• http://leakylugnut.com/driveline/automatic-transmissions/
• https://www.youtube.com/watch?v=QPaUJfA1KsY
• https://youtu.be/K4JhruinbWc
• How to calculate gear ratio for planetary gear train:
https://www.youtube.com/watch?v=bWtK5mzuddo
• Planetary gear set simulator: http://www.thecatalystis.com/gears/
• Planetary gear set simulator: http://benchtophybrid.com/PG_Intro.html