automotive systems course (module 06) - power transmission systems in road vehicles

16 de dezembro de 2016 | 1

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Power Transmission Systems (drivetrain)

Mário Alves ([email protected])

mailto:[email protected]


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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


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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/














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Drivetrain configurations – rear/front-wheel drive

http://schoolworkhelper.net/the-drive-train-hydraulic-

brake-system-steering-system/

http://schoolworkhelper.net/the-drive-train-hydraulic-brake-system-steering-system/

















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Drivetrain configurations – all combinations

https://mediocremotoring.wordpress.com/2009/09/03/fw

d-awd-rwd-mr-rr-2/

https://mediocremotoring.wordpress.com/2009/09/03/fwd-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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• 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






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• 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






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Clutch/transmission – basic operation

http://giphy.com/search/transmission




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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

http://mechanics.stackexchange.com/questions/18552/how-a-clutch-works










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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://www.amazon.com/Porsche-Clutch-Pressure-tension-spring/dp/B00ADZFYJO




















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Clutch assembly


• Release fork and bearing: hydraulic and mechanical

clutches




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Clutch assembly


• 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


• 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










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Transmission – manual

http://gustafsonbros.clearmechanic.com/Frames/Part.aspx?id=4025&key=b6e4e887-374d-440b-

ab41-882b1888dccc

http://gustafsonbros.clearmechanic.com/Frames/Part.aspx?id=4025&key=b6e4e887-374d-440b-ab41-882b1888dccc











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ab41-882b1888dccc












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• (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

https://www.youtube.com/watch?v=QPaUJfA1KsY



https://www.reddit.com/r/educationalgifs/comments/1p245a/how_a_manual_transmission_changes_gears/




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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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http://dasauto.ae/rwdat.php




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http://dasauto.ae/fwdat.php




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• Torque converter: works through fluid coupling/dragging

force (https://www.youtube.com/watch?v=z5G2zQ_3xTc)


https://www.youtube.com/watch?v=z5G2zQ_3xTc








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• 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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• 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










https://www.psmotion.com/sites/default/files/Planetary Gears 2.gif





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• 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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• 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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• 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





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• 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





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• 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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• 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













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• 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













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• 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





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• 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


• since NC > NS, results in speed increase

• For our example

• R g = NS/NC = 30/120 = 1/4

• 1 Carrier turn = 4 Sun turns





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• 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


• 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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• 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


• since NC > NR, results in speed decrease

• For our example

• R g = NC/NR = 120/90 = 4/3

• 4 Ring turns = 3 Carrier turns




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• In summary, we can get the following gear modes/ratios

(values between parenthesis are computed from the example)


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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• 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)





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• Simpson planetary gear set

• see https://www.youtube.com/watch?v=r1BYOOJKyaQ

http://leakylugnut.com/driveline/automatic-transmissions/

https://www.youtube.com/watch?v=r1BYOOJKyaQ

https://www.youtube.com/watch?v=r1BYOOJKyaQ






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• 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








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• 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









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• 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









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• 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









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• Ravigneaux planetary gear set

• see https://www.youtube.com/watch?v=Nbnyo9uUVKg

• https://www.youtube.com/watch?v=Y1zbE21Pzl0


https://www.youtube.com/watch?v=Nbnyo9uUVKg

https://www.youtube.com/watch?v=Nbnyo9uUVKg

https://www.youtube.com/watch?v=Y1zbE21Pzl0

https://www.youtube.com/watch?v=Y1zbE21Pzl0






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• 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)









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• Ravigneaux planetary gear set – 2nd 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









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• 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)









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• 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)









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• Ravigneaux planetary gear set – reverse 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)









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• Control system (generic diagram)

http://www.cvel.clemson.edu/auto/systems/images/sara_ali_transmission.png




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• Control system (ZF OEM)

http://www.aa1car.com/library/2002/us90224.htm




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• Control system (Renesas OEM)

https://www.renesas.com/en-eu/solutions/automotive/powertrain/transmission-control.html








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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

https://www.youtube.com/watch?v=PEq5_b4LWNY

https://www.youtube.com/watch?v=PEq5_b4LWNY

https://www.youtube.com/watch?v=c47caRqbbnE








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• 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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• 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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http://classicmgaccessories.com/articles/f-steptronic-and-tf-stepspeed-cvt-gear-box-mystery-revealed/

• Steptronic






















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http://www.nisentra.com/wiring_diagram-707.html






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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









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Transmission – semi-automatic (single clutch)

• Renault Quickshift 5

http://automotive.roger.free.fr/contenu_auto/transmission.htm




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• Renault Quickshift 5

http://whattruck.ro/renault-master-o-noua-transmisie-semiautomata-zf-quickshift-2014/




















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• ZF 7-speed

http://www.zf.com/corporate/en_de/products/product_range/cars/cars_automated_manual_transmission.shtml




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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

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































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• 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

http://www.team-bhp.com/forum/technical-stuff/168683-ford-powershift-dual-clutch-transmission-dct-technical-overview.html






















https://www.youtube.com/watch?v=6iCRnAUftvI





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• 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


























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• 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)


























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• 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


























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• 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


























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• 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.



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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• 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.



Note that that the second gear is coupled

to the reverse gear on the same shaft
























Sistemas A

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• Ford PowerShift – power delivery 3rd – 6th gears + reverse


























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• 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


























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• Ford PowerShift – TCM clutch actuator

• as the shift actuator, a DC motor moves an actuator level, via worm gear


























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• Honda VFR1200F (1st motorcycle’s DCT)

http://blog.motorcycle.com/2013/04/15/manufacturers/honda/more-european-consumers-

choosing-hondas-dual-clutch-transmission/

http://blog.motorcycle.com/2013/04/15/manufacturers/honda/more-european-consumers-choosing-hondas-dual-clutch-transmission/

















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• Honda VFR1200F (see https://youtu.be/s9PzGhAfgIw)

http://world.honda.com/motorcycle-picturebook/DCT/

https://youtu.be/s9PzGhAfgIw








Sistemas A

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• Honda VFR1200F







Sistemas A

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http://www.autoevolution.com/news/honda-motorcycle-dual-clutch-transmission-explained-22774.html#


Honda VFR1200F

http://www.autoevolution.com/news/honda-motorcycle-dual-clutch-transmission-explained-22774.html















Sistemas A

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• DSG/S-Tronic (longitudinal mounted engines)

http://www.my-gti.com/887/volkswagen-dsg-7-speed-dual-clutch-gearbox-high-output






















Sistemas A

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• DSG/S-Tronic (longitudinal mounted engines)























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• DSG/S-Tronic

• transversal

http://www.myturbodiesel.com/wiki/vw-dsg-direct-shift-gear-

transmission-and-audi-stronic-faq-2/

http://www.myturbodiesel.com/wiki/vw-dsg-direct-shift-gear-transmission-and-audi-stronic-faq-2/























Sistemas A

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• 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


































Sistemas A

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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


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)







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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







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Differential

• Refer also to: https://youtu.be/K4JhruinbWc

http://i.makeagif.com/media/6-18-2015/zRT5hD.gif

https://youtu.be/K4JhruinbWc









Sistemas A

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Glossary (English/Portuguese)

• …


Sistemas A

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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

http://auto.howstuffworks.com/clutch1.htm

http://auto.howstuffworks.com/clutch1.htm

http://www.theautopartsshop.com/carsystem/transmission-system.html
















http://www.thecatalystis.com/gears/



http://benchtophybrid.com/PG_Intro.html



automotive systems course (module 06) - power transmission systems in road vehicles

Engineering