Haldex 4'th generation

[Quino]

din cate inteleg din filmuletul

cuplajul haldex contoleaza rotile individual, in caz de necesitate? sau ma insel ?

Daca mai aveti detalii si date tehnice postati-le aici.

[Swat Cat]

nu e individual.... e la fel... doar ca aparent cuplu spatele poate sa ajung la 60% (cred ca printr-un grup mai lung decat fata) si comanda nu cred ca mai e hidraulica

[anorganix]

Comanda e electrica (presiunea hidraulica este creata de o pompa de ulei electrica) si pe spate poate ajunge mai mult de 60%.

[ANdi B.]

NO IT CAN'T! Nu va mai luati dupa ce se scrie pe tot felul de siteuri dubioase sau dupa ce spun cei de la HPA Haldex Gen 4 poate sa transmita maxim 50/50.

"The XWD system can transmit 100 percent of available torque to either the front or rear wheels. However, for those conditions to occur one end of the vehicle would have to lose all traction, like driving on ice for instance. "

[Dr.G.Silviu]

http://www.haldex-xwd.com/

[anorganix]

@Andi: Deci cu postul tau de fapt ce ai vrut sa scoti in evidenta?

Ca poate da mai mult de 50% pe o punte s-a spus deja.

[asap03]

NO IT CAN'T! Nu va mai luati dupa ce se scrie pe tot felul de siteuri dubioase sau dupa ce spun cei de la HPA Haldex Gen 4 poate sa transmita maxim 50/50.

"The XWD system can transmit 100 percent of available torque to either the front or rear wheels. However, for those conditions to occur one end of the vehicle would have to lose all traction, like driving on ice for instance. "

Tu spui ca wikipedia este o sursa tehnica mai buna decat site-ul Haldex pe subiectul asta? In caz ca nu ai observat, uita-te jos la References si vei vedea ca primul link duce chiar spre site-ul Haldex.

Iar citatul tau este incomplet. Doua fraze mai incolo gasesti:

Also up to 85 percent of torque can be transferred by the eLSD between to any single rear wheel if necessary. Adica daca rotile din fata si una din spate sunt pe gheata, poate.

[ANdi B.]

Mai oameni textul e clar voi intelegeti ce doriti :D Haldex 4th gen nu transport mai mult de 50 pe puntea spate atunci cand tractiune exista pentru toate cele doua punti. Adica: daca avem aderenta 100% pe puntea fata si aderenta 100% pe puntea spate haldex nu are cum sa transporte mai mult de 50% din cuplu motor pe puntea spate dar daca puntea fata are aderenta numai 50% si putea spate 100% apunci haldex transporta maxim 75% pe spate ;)

[anorganix]

Cred ca tu intelegi ce vrei...

Ceea ce conteaza e ca poate! Ca asta se intampla doar in anumite conditii e alta treaba si e irelevant in discutia asta.

[Quino]

din cate scrie pe situl lor la haldex, cica in conditii normale ramane 10% din putere pe spate si 90% fata, iar in caz de necesitate poate distribui pana la 90% pe puntea spate. asta am dedus din explicatiie lor.

[ANdi B.]

@anorganix: imi pare rau, nu ai inteles absolut nimic! Intelege fiecare ce doreste dar adevarul este simplu pe curbe cand masina subvireaza haldex niciodata nu va trimite mai mult de 50% pe puntea spate si gata. Fiecare poate intelege ce doreste dar realitatea e una - haldex e 50/50!

[anorganix]

In primul rand ai grija la exprimare, suntem colegi de forum... dar atat; in al doilea rand continui sa te contrazici fara rost.

Atat documentatia Haldex cat si Wikipedia spun un lucru pe care tu il contrazici. Sincer, prefer sa-i cred pe ei. ;)

[xht20]

din cate scrie pe situl lor la haldex, cica in conditii normale ramane 10% din putere pe spate si 90% fata, iar in caz de necesitate poate distribui pana la 90% pe puntea spate. asta am dedus din explicatiie lor.

Perfecta dreptate. Asa si este

@anorganix: imi pare rau, nu ai inteles absolut nimic! Intelege fiecare ce doreste dar adevarul este simplu pe curbe cand masina subvireaza haldex niciodata nu va trimite mai mult de 50% pe puntea spate si gata. Fiecare poate intelege ce doreste dar realitatea e una - haldex e 50/50!

Gresesti. Haldex Gen4 poate transmite pana la 90% din putere pe puntea spate in cazuri extreme. Eu zic ca nu are rost sa te facu cu gura mare ca nu suntem la un concurs de care e mai destept, suntem pe un forum unde unii nu stiu si doresc sa invete, sa afle lucruri noi. Daca tu te apuci pe aici si zici ca tu ai dreptate si ceilalti gresesc, nu procedezi corect.

Pana una alta, prefer sa-i cred pe cei care au creat Haldex-ul

deci same s####t... diferent generation....

Almost same shit. Gen2 avea in componenta sa 2 pompe, una hidraulica si una electrica. Gen4 are in componenta o singura pompa electrica. Nu o zic eu ca l-am desfacut, ci oamenii care l-au creat, oamenii care fac upgrade-uri pt el, oamenii care l-au desfacut. Tu Andi mai mult ca sigur nu ai vazut in viata ta un Haldex desfacut (nici eu nu am vazut, dar nu ma apuc acum sa tin morala ca eu sunt smecher)

citez de pe site-ul Haldex.

What is the difference between Generation II (III) and

IV?

In Haldex-coupling Generation II, the hydraulic pressure

used to compress the clutch package, is generated by a hydraulic pump driven by

the differential speed between the in- and outgoing shafts. The small electric

pump in the coupling is used only to create a base pressure, necessary to

activate the system.

In Generation IV, hydraulic pressure is solely created

by a larger electric oilpump. The pump fills an accumulator from which oil is

taken to compress the clutch.

[Dr.G.Silviu]

@Andi Eu zic sa faci un ban cinstit. Ii santajezi pe cei de la Haldex ca tu stii adevarul despre inventia lor, si daca nu-ti vireaza o suma cu 7 cifre in cont, tu le spui tuturor cum stau lucrurile. ;)

[dbk]

Eu cred ca haldex va transfera tot 90% din forta pe puntea fata in situatia data de tine, intrucat nu exista nici o posibilitate de pierdere a tractiunii (ma rog excludem variantele cele mai dramatice: cauciucri extrem de tocite pe puntea fata, demaraj puternic astfel incat puntea fata sa piarda aderenta etc). Ideea e ca acest sistem intervine doar in momentul in care o pierdere a tractiunii pe una din punti este iminenta sau deja s-a produs. Tot ca parere personala, cred ca un sistem torsen ar da o dinamica mai buna masinii in situatia descrisa de tine, pentru ca torsen e setat by default sa faca split intre puntile fata/spate: 50/50 la sistemele mai vechi si 40/60 incepand cu sistemele produse dupa anul 2007. La acestea din urma distributia fortei pe puntea spate poate ajunge pana la 85% (mai putin cred decat la haldex, insa split-ul permanent de forte intarzie momentul de pierdere a aderentei).

Modificat 10 Ianuarie, 2011 de dbk

[Makron]

Ei, uite așa un haldex mi-ar placea mie. Sa fie asistat de senzori care să monitorizeze permanent transferul sarcinii masinii de pe o punte pe altă si să directioneze puterea pe puntea care are o apăsare mai bună.

Bine, totul

[Swat Cat]

deci cuplajul haldex este pus ca diferential central.... deci el blocheaza puntiile fata cu spate ( adica sa aiba aceasi turatie)

cand haldexul este cuplat maxim fata si spate au distributia 50% ca mai mult nu exista (adica se imparte cuplu egal)

discutia cu 90% din cuplu pe spate apare atunci cand puntea fata este "in aer" si masina are tractiune doar pe puntea din spate.....

mergand normal cu tactiune buna si ct... fata are 95% adica masinile cu haldex au un coportament de tractiune fata

[andrei122]

Buna seara tuturor

Ma bag si eu in seama

Ati inteles cu totii gresit functionarea cuplajului Haldex.Acest cuplaj nu poate sa dea mai mult de 50% din cuplu din totalul disponibil deoarece acest cuplaj este conectat prin intermediul cardanului de cutia de viteze si mai exact de catre arborele ce antreneaza rotile pe fata.Rotile din fata pot transmite cuplul motorului pana la 100%(asta in cazul in care haldexul are o problema si nu functioneaza )si de minim 50% in cazul in care cuplejul este functional.Haldexul generatia a 2 si a 3-a transmite cuplul unui diferential normal pe cand generatia 4 cuplajul transmite cuplul unui diferential de tip Torsten (LSD) dar mult mai avansat(controlat de calculatorul Haldex+ABS/ESP).Cuplul poate fi transferta mai mult de 50% catre spate doar daca pe masina exista cutie de transfer/diferential central dar la VAG nu exista nici un model care sa aiba asa ceva(poate AMAROK).

Haldexul mi-a mancat o gramada de timp la un Volvo XC90(generatia a 3-a) si il cunosc aproape la perfectie.

Daca supar pe cineva sau doriti detali..............

[Quino]

Nu superi pe nimeni doar discutam. Parerea mea si nu numai este ca te inseli atunci afirmi ca :" Acest cuplaj nu poate sa dea mai mult de 50% din cumplul total disponibil .... "

Din toate discutiile pe care le-am prins pana acum de haldex un lucru este clar: haldex poate sa dea 90% din cuplu pe orice punte asta inseamna ca in conditiile de panta, spatele poate sa 'traga' in anumnite conditii (derapaj, etc) cu 90% din putere, paft confirmat si de un dealer skoda si nu era in interes de vanzare.

Inca o chestiune; la plecarea de pa loc rapoartele intre punti sunt 50%-50% .

Intrebarea care ma macina pe mine este: ce se intampla cand 3 roti pierd aderenta ?! este haldex-ul in stare sa dea 90% din putere pe o singura roata !?

p.s.: era un filmulet pe youtube postat pe la inceputul thread-ului cu o animatie despre distributia puterii la haldex...

[dbk]

Haldexul mi-a mancat o gramada de timp la un Volvo XC90(generatia a 3-a) si il cunosc aproape la perfectie.

E de fapt generatia a 2-a de Haldex pe XC90, si in conditii normale de drum, transmite 95% din forta catre puntea fata.

@Quino: nu cred ca poate Haldex-ul sa transfere forta pe o singura roata. Uite aici un test edificator, unde participa si Passat 3C si reuseste sa se descurce onorabil insa nu poate transmite forta la o singura roata:

Modificat 26 Ianuarie, 2011 de dbk

[anorganix]

1. Catre toti expertii in Haldex: mai cititi odata informatiile postate pe haldex.com.

2. Hadex gen. 3 de pe Volvo cred ca e cam offtopic aici din moment ce titlul topicului este Haldex 4th Generation.

[ANdi B.]

bine a zis anorganix NUMAI CA trebuie sa intelegem ce zic ei despre haldex 4th gen. Uitati un post foarte interesant despre haldex:

mra ozAudi Regular User

Join DateMay 2007Posts278Thanks0Thanked 0 Times in 0 Posts

This is a bit long but repost of an audi owner's email sent to Haldex asking some questions around how the haldex works:

1) haldex claim 100% torque transfer to the rear is possible. Is it? Some

people dispute this, but I believe it requires 100% slip of the front wheels

for this to be the case. i.e. In real conditions it would never happen, the

more realistic split is 50-70% under full load and some slip. I came to this

conclusion because the front wheels are always driven.

2) There is much dispute over whether the haldex LSC delivers torque to the rear if and only if the front wheels slip. It's my belief that the torque

transfer can and does occur in response to wide throttle openings, even

before any slippage occurs. Can you confirm?

3) With particular regard to the Audi S3 (or TT). Do you know if the

steering angle is taken into account when deciding whether to increase or

decrease the torque transfer? i.e. is it purely throttle/slip related or is

actually much more complex? If possible, some explanation would be useful. For example, if there is 10% to the rear and I turn a corner, would it increase to 30 or 40% to provide increased stability. If so, would be that

due to a natural left/right speed difference or a result of steering angle

change (ESP sensor)?

4) There is much debate on the "constant speed" torque transfer to the rear.

i.e. travelling on a road at 30 or 70MPH, how much torque is transferred to

the rear? Is it speed dependant?

5) Does the torque transfer under acceleration depend on the current vehicle

speed? If so, can you provide characteristic details?

Any further information you can provide would be appreciated, in particular how the haldex LSC operates in conjunction with the ESP and whether the ESP can affect the transfer of torque.

The folk on the forums are an enthusiastic bunch who appreciate technical

explanations to technical problems. If there's anything else you can provide beyond the questions I've asked, that would be very welcome. Once again, I thank you again for taking the time to read my questions.

Cheers.

Mark.

Reply from Haldex -----------

Dear Mark,

I am pleased to see that you like your Audi S3 with the haldex AWD system and that you disagree with your Torsen friends when it comes to the excellent abilities of the haldex AWD System. It is a fact that the

electronically controlled haldex AWD system provides a much wider range of possibilities over a purely mechanical system. We are also convinced, after having delivered 500.000 haldex AWD systems to the market since our start in 1998, that we also have the best electronically controlled AWD system on the market.

We have put together some answers on your questions that I hope will be

helpful in your discussions in the Audi forum.

1. There are situations where near 100% torque transfer to the rear axle

occur. An example is if the front wheels are on ice and the rear wheels are

on tarmac. In that case the front wheels have (almost) no grip. In that

case, the haldex coupling will transfer all torque to the rear axle and

prevent front wheel spin. On uniform surfaces however, the coupling can not transfer all torque to the rear axle. See below.

2. We need slip over the coupling in order to be able to transfer torque.

That slip (rotational speed difference between the front and rear axle) is

created by different tyre rolling radius (front to rear) and drive slip

between the tyre and road. The rolling raduis difference can be created by

differently worn tyres (or different dimensions, something that should be

avoided) and different load. In most cars, the front axle has a greater load

than the rear axle, which causes the roll radius of the front tire to be

smaller than the one for the rear tyres (given the same nominal size). This

gives us the possibility to transfer torque to the rear axle also when no

slip occurrs on the front tyres.

If you have differently worn tyres on the front and rear axles, the new

tyres should always be on the rear axle. This is true no matter if the car

is FWD, RWD or AWD, since you otherwise risk heavy and uncontrollable

oversteer in situations such as aqua planing. In this case, putting the worn

tyres at the front also helps not to reduce the maximum transferable torque (maximum rear axle torque).

During cruising which a constant velocity, we have the possibility to

transfer up to 40-45% of the torque to the rear axle, given nominal tyres.

During acceleration, the weight transfer increase the front tyre slip and

decreases the rear axle slip, giving us the possibility to achieve more or

less the same torque distribution as the dynamic weight distribution.

Generally speaking, depending on the vehicle somewhere around 60-70% is possible to achieve during a full acceleration. Note that we are still

talking about a uniform surface, with no spin on the front wheels.

When cornering , there is in most cars a tendency for the inner front wheel

to lift and spin. In that situation, we can increase the torque transfer

even further.

So far I have only spoken about what possibilities there is to transfer

torque. How much is actually transferred depends also on how the haldex

coupling is controlled. The engine torque and gas pedal position are

together with the wheel speeds and the engine speed the most important

signals that are used in the control. Brake, ABS and ESP signals are also

very important for enabling co-existance between the AWD system and the ABS/ESP system. We control the coupling in order to prevent wheel spin as well as removing it quicky if it should occur.

3. Steering angle is not a signal used in the control of the coupling in VW

group cars. The reason for this is that the steering angle is not available

in most cars as it is only present when an ESP system is mounted. We do

however calculate the curve radius from the wheel speeds. We have software ready using more signals as the steering angle that we offer to the vehicle manufacturers. This enables further optimisation of handling performance.

4. It may vary a bit with speed (and road surface), but without going into

details a figure of around 10-15% would be typical. It is enough to help

stabilising the car while at the same time saving fuel and reducing the

temperature of certain driveline components. As soon as the driver starts to accelerate or decelerate, more torque is transferred.

5. Yes it does. In general, a higher percentage of the torque is transferred

to the rear axle in low velicities than in high ones. This is partly due to

the fact that the total available driveline torque is larger at lower speeds

(and lower gears), thus causing more weight transfer to the rear axle. In

order to achieve consequent handling characteristics (as well as optimised

traction), more torque must then be transferred to the rear axle.

6. The haldex coupling is completely compatible with ABS and ESP systems. In order to optimise the performance of the ABS/ESP system, it is possible to open the haldex couplng during ABS braking or a stability control brake intervension. The ABS/ESP antispinn and stability control also depend very much on being able to calculate the vehicle velocity. That is very easy with 2WD, but as soon as you have the possibility of four wheels spinning it gets very complicated. The haldex coupling and ABS/ESP system interface make it easier to obtain a good reference velocity.

In the cars where the haldex coupling is available today, additional signals

available with ESP are not used. We do however have software using these

signals. This enables further optimisation of handling performance and life

span of driveline components.

During calibration of the haldex coupling , we try to optimise the traction

and handling performance of the car. These are however not the only aspects that are important. The final calibration is alway a compromise between traction, handling, the life span of driveline components, temperatures in driveline components, fuel consumption and more. If the car manufacturer wants the same calibration to be used in several different cars, a new compromise has to be made. Different manufacturers do have different strategies about this. Some tend to let many cars share the same calibration while others want to optimise each car individually.

I hope that this answers your questions.

Best Regards

Ulf Herlin

Vice President, Marketing

Sper ca asa s-a lamurit problema distribuirii cuplului. cand ai tractiune 100% pe fata haldex nu o sa fie niciodata capabil sa transfere pe puntea spate mai mult de 50% - asta e fizica mecanica, imi pare rau dar asta e adevarul!

[monaco]

Buna ziua!

Am si eu o Skoda Octavia 4x4 din 2005. Am schimbat ieri la service "pompa pt. tractiunea integrala" (asa este trecuta pe factura) asta deoarece se aprindea pe bord martorul ESP. Cand mi-am luat masina, i-am vazut pe cei de la service ca se cam scarpina in cap si i-am intrebat ce este. Mi-au zis ca uleiul scurs din diferentialul Haldex avea culoarea neagra, ceea ce nu este normal si ei nu stiu sa-mi spuna de la ce este chestia asta si ce ar trebui sa fac.

Daca aveti vreo idee, va rog luminati-ma si pe mine ca sa-i pot lumina si eu mai departe pe cei de la service.

Ma bucur totusi ca nu se mai aprinde pe bord martorul de ESP.

Multumesc,

[Quino]

@Quino: nu cred ca poate Haldex-ul sa transfere forta pe o singura roata. Uite aici un test edificator, unde participa si Passat 3C si reuseste sa se descurce onorabil insa nu poate transmite forta la o singura roata

am sapat si am gasit .. offf greu mai era ... : http://www.haldex-xwd.com/ la sectiunea technical este descris modul de functionare si transmisie a tractiunii ... in concluzie se poate duce 85% pe o singura roata .

[TheBoogieMan]

Poate duce 85% pe o roata, insa in scenariul prezentat in filmuletul respectiv nu poate sa urce avand aderenta pe o singura roata.

Mai era un test din ala (pe care nu reusesc sa-l gasesc) in care aparea un subaru legacy care reusea sa urce avand aderenta doar pe o roata.