WO2011003492A1

WO2011003492A1 - Double-clutch gearbox

Info

Publication number: WO2011003492A1
Application number: PCT/EP2010/003354
Authority: WO
Inventors: Sascha NEUDÖRFER; Andreas Ortmann; Edgar Bothe
Original assignee: Volkswagen Aktiengesellschaft
Priority date: 2009-07-06
Filing date: 2010-06-02
Publication date: 2011-01-13
Also published as: DE102009031786A1

Abstract

The invention relates to a double-clutch gearbox (1) for a motor vehicle, having a first and a second gearbox input shaft (EW1, EW2) and having at least one driveshaft, in particular having a first and a second driveshaft (TW1, TW2), wherein the first gearbox input shaft (EW1) is assigned a first friction clutch (K1) and certain gear stages, preferably a first, a third, a fifth and/or a seventh gear stage, and the second gearbox input shaft (EW2) is assigned a second friction clutch (K2) and certain other gear stages, preferably a second, a fourth and/or a sixth gear stage, wherein the gear stages are formed by a plurality of gearwheel pairs which in each case connect the gearbox input shaft (EW1, EW2) and the at least one driveshaft (TW1, TW2), wherein the gearwheel pairs are formed by in each case one fixed gear (3 to 8) and one loose gear (9 to 16), wherein at least one central synchronization device (23, 24) is provided for the functionally active braking of the gearbox input shafts (EW1, EW2). Braking of the gearbox input shafts (EW1, EW2) in order to reach the synchronous rotational speed can be achieved in an inexpensive manner and with a small installation space requirement in that two central synchronization devices (23, 24) are provided, wherein the two central synchronization devices (23, 24) are designed as loose gear braking devices (25, 26) and in each case one loose gear braking device (25, 26) is operatively assigned to one gearbox input shaft (EW1, EW2), and wherein each loose gear braking device (25, 26) can brake one of the loose gears (9, 11) of the respective gearwheel pair.

Description

description

Double clutch

The invention relates to a dual-clutch transmission for a motor vehicle having a first and a second transmission input shaft and at least one drive shaft, in particular with a first and a second drive shaft, wherein the first transmission input shaft, a first friction clutch and certain gear ratios, vzw. a first, a third, a fifth and / or a seventh gear, are assigned and the second transmission input shaft, a second friction clutch and certain other gear ratios, vzw. a second, a fourth and / or a sixth gear, are assigned, wherein the gear ratios are formed by a plurality of each of the transmission input shaft and the at least one drive shaft connecting gear pairs, wherein the gear pairs are each formed by a fixed gear and a loose wheel, wherein at least one Zentralsynchronisationsvorrichtung is provided for functionally effective deceleration of the transmission input shafts.

Dual clutch transmissions are known and are preferably used in motor vehicles. The dual-clutch transmission has vzw. two concentric with each other

Transmission input shafts, wherein the transmission input shafts each have a separate

Friction clutch is assigned. The two friction clutches form a double clutch. The input waves are also vzw. each assigned a group of gears. The one group of gears includes vzw. the gear steps with odd ordinal number

including the reverse gear and the other group includes vzw. the gear steps with even ordinal number. The gears are in particular unsynchronized. There are vzw. no synchronizers with sliding sleeves, friction rings and the like assigned to the individual idler gears of the gears. Instead, the synchronization of the

Transmission input shafts with at least one Zentralsynchronisationsvorrichtung

performed.

From DE 199 50 679 A1 is an automated dual-clutch transmission for a

Motor vehicle known. The dual-clutch transmission has two transmission input shafts, a drive shaft and unsynchronized gear shift clutches, each of which

Transmission input shafts are assigned a separate friction clutch and a group of gear stages. As a central synchronization device is an auxiliary drive for Synchronization provided. The auxiliary drive is associated with a switch, by means of which the auxiliary drive with each of the transmission input shafts is individually coupled. The auxiliary drive can be designed and arranged such that it can also be used as a braking aid. The auxiliary drive is designed in particular as an electric motor.

From DE 102 43 278 A1 discloses a device for synchronizing a

Double clutch transmission known. As the central synchronization device is a braking device for synchronizing the rotational speed of the switching gear parts in a gear change from a lower gear to a higher target gear used. The

Brake device has for each partial transmission of the dual clutch transmission at least one of a transmission input shaft of the respective sub-transmission associated

Transmission input shaft brake on. The transmission input shaft brakes can be controlled via a control device such that the braking of the respective

Transmission input shaft required Bremsleistuπg on one of a respective target gear stage associated synchronous speed via the respective transmission input shaft brake can be generated. The transmission input shaft brakes act directly on the transmission input shaft. The transmission input shaft brakes thereby supportive for further the synchronizer associated with the idler gears. The gear stages are assigned gearshift clutches which are made when inserting the gears via axial displacement of shift rods with attached to these shift sleeves each have a connection between a loose wheel and the loose wheel supporting drive shaft. The synchronizers are designed as friction rings, which come in contact with the axial displacement of the shift sleeve with this. As a result, the faster rotating transmission input shaft is braked with respect to the drive shaft in a switching operation. The transmission input shaft brakes support the Synchronisiereinrichtüngen the dual clutch transmission.

From DE 102 14 478 B4 a dual-clutch transmission for a motor vehicle is known. The dual-clutch transmission has a first transmission input shaft, which is associated with at least one first gear stage and a second transmission input shaft, which is associated with at least one second gear stage. Further, a central synchronization device

intended. The central synchronization device has two planetary gear sets, which are assigned to the transmission input shafts such that both during upshifting and downshifting from a first to a second gear and both upshifting and downshifting from a second to a first gear, a synchronization in the sense of braking or an acceleration of the transmission input shafts is possible. The planetary gear sets are coupled to the transmission input shafts. From DE 34 17 504 A1 a multi-step transmission for a motor vehicle is known. The multi-step transmission has a main shaft equipped with sliding sleeves and two auxiliary shafts. One or both auxiliary shafts are equipped in one embodiment with a brake as Zentralsynchronisationsvorrichtung. The auxiliary shafts also have a planetary gear for synchronization.

The dual-clutch transmissions known in the prior art are not yet optimally configured. The known Zentralsynchronisationsvorrichtungen require axial space. In particular, the Planetenradsätze / -getriebe need as a central synchronization large axial space. The known Zentralsynchronisationsvorrichtuπgen are also complex and require a plurality of components, whereby the maintenance and the associated costs is increased.

The invention is therefore the object of a dual-clutch transmission of the type mentioned in such a way and further, that a costly and space-consuming braking the transmission input shafts to achieve the

Synchronous speed is avoided.

The aforementioned object is now achieved for the dual-clutch transmission in that two Zentralsyπchronisationsvorrichtungen are provided, the two

Centric synchronization devices are designed as Losradbremsvorrichtungen and each one Losradbremsvorrichtung a transmission input shaft is operatively associated, and wherein with each Losradbremsvorrichtung one of the idler gears of the respective gear pair is braked. The Losradbremsvorrichtungen are arranged in particular radially to the braked loose wheels. This allows a cost-effective and compact design

To provide dual clutch transmission. The vzw. "Indirect" deceleration of

Transmission input shafts are made by braking the idler gears. One of the braked idler gears is vzw. a gear stage of the first transmission input shaft and the other of the braked idler gears is vzw. assigned to another gear stage of the other transmission input shaft. The one braked idler gear is vzw. a gear with a straight

Ordnungszahl assigned. The other braked idler gear is vzw. a gear with an odd ordinal assigned. For example. can be assigned to the braked idler gears of the first and fourth gear. Since the idler gears can have different diameters, the actuation pressure is adapted to the required friction torque as a function of the diameter. The two Losradbremsvorrichtungen are vzw. independently controllable. The Losradbremsvorrichtungen can be constructed similar to a disc brake. The respective idler brake device may, for example, have a friction lining, wherein the friction lining can be pressed by a hydraulic cylinder against the braked idler gear. The friction lining may in particular be displaceable axially towards the idler gear. The Losradbremsvorrichtung has vzw. a caliper which at least partially surrounds the corresponding idler gear on its outer circumference. As a result, the braked idler gear between the friction lining and the caliper is braked. By rules of the

Actuating pressure is braked the associated input shaft via the gear pair with the braked idler gear. The disadvantages mentioned above are therefore avoided and achieved corresponding advantages.

There are now a variety of ways to design the dual-clutch transmission according to the invention in an advantageous manner and further. For this purpose, reference may first be made to the claims subordinate to claim 1. In the following, a preferred embodiment of the invention will now be explained in more detail with reference to the drawing and the associated description. In the drawing shows:

Fig. 1 in a schematic representation of the essential components of a

Dual clutch transmission.

In Fig. 1, at least partially, a dual-clutch transmission 1 is shown for a motor vehicle not shown in detail.

The dual-clutch transmission 1 has a first transmission input shaft EW1 and a second transmission input shaft EW2. The dual-clutch transmission 1 also has a first drive shaft TW1 and a second drive shaft TW2. The first transmission input shaft EW1 is associated with a first friction clutch K1. The second transmission input shaft EW2 is associated with a second friction clutch K2. The two friction clutches KLund K2 form a double clutch 2. The first transmission input shaft EW1 is operatively connected or connectable to the first friction clutch K1 and the second transmission input shaft EW2 is operatively connected or connected to the second friction clutch K2.

The first friction clutch K1, the first transmission input shaft EW1 and the first drive shaft TW1 form vzw. a unspecified here, first transmission branch. The second

Friction clutch K2, the second transmission input shaft EW2 and the second drive shaft TW2 form vzw. another unspecified here, second transmission branch.

The first transmission input shaft EW1 are certain gear ratios, vzw. a first, a third, a fifth and / or a seventh gear, associated. The second transmission input shaft EW2 are certain other gear stages, vzw vzw. assigned a second, a fourth and / or a sixth gear. The second transmission input shaft EW2 is vzw. as a hollow shaft educated. The second transmission input shaft EW2 surrounds the first transmission input shaft EW1. The first transmission input shaft EW1 is arranged coaxially with the second transmission input shaft EW2. The first transmission input shaft EW1 are the gear stages with odd ordinal number, namely the gear stages one, three, five and seven assigned. The second transmission input shaft EW2 are the gear stages with even atomic number and vzw.

additionally assigned a reverse gear R. The term gear ratio refers in the context of the application on gears for the forward drive. The gear for the

Reverse gear is referred to as reverse gear R throughout.

The gear stages are formed by a plurality of respective gear pairs input to the transmission input shaft EW1 and EW2 and the respective associated drive shaft TW1, TW2. These

Gear pairs are arranged correspondingly effective between the respective transmission input shafts EW1 and EW2 and a drive shaft TW1 and TW2. The two

Transmission input shafts EW1 and EW2 are therefore also associated with corresponding gears. These gear wheels associated with the transmission input shafts EW1 and EW2 are vzw. formed as fixed wheels 3 to 8. Ie. these fixed gears 3 to 8 are non-rotatably arranged on the respective transmission input shaft EW1 and EW2. The fixed wheels 3 to 6 are assigned to the first transmission input shaft EW1 and the fixed wheels 7 and 8 are the second

Gear input shaft assigned EW2.

The first drive shaft TW1 are gears, vzw vzw. the idler gears 9, 10, 11 and 12 assigned. The second drive shaft TW2 are gears, vzw vzw. the loose wheels 13, 14, 15 and 16 assigned.

The dual clutch transmission 1 has vzw. seven gears for forward driving on. In another embodiment, the dual clutch transmission 1 vzw. have six (or less) or even more than seven gears for forward driving. In addition, this indicates

Doppelkupplungsgetriebe 1 a reverse gear R for reversing on.

The gear stages are formed by the respective transmission input shaft EW1 and EW2 and the associated drive shaft TW1 and TW2 connecting gear pairs with one of the fixed gears 3 to 8 and one of the meshing engaging idler gears 9 to 16.

The first gear and the fifth gear are each by the first

Gear input shaft EW1 and the first drive shaft TW1 connecting gear pairs formed, the gear pairs are each formed by the fixed wheels 4 and 6 and the idler gears 9 and 10. The fixed wheels 4 and 6 are rotatably associated with the first transmission input shaft EW1. Here, the first gear is formed by the gears "4 and 9" and the fifth

Gear ratio formed by gears "6 and 10".

The fourth gear is through a second transmission input shaft EW2 and the first

The reverse gear R is formed by a fixed gear 8 and the idler gear 12, wherein the fixed gear 8 and the idler gear 12 via an intermediate shaft 17 associated with one of these intermediate shaft 17 Intermediate 18 communicate with each other.

The seventh and third gear stages are formed by the first transmission input shaft EW1 and the second drive shaft TW2 connecting gear pairs, the gear pairs are each formed by one of the fixed gears 3 and 5 and one of the idler gears 13 and 14 respectively. The fixed gear 3 forms with the idler gear 13, the gear pair for the seventh gear. The fixed gear 5 forms with the idler gear 14, the gear pair for the third gear.

The sixth gear stage and the second gear stage are formed by the second transmission input shaft EW2 and the second drive shaft TW2 connecting gear pairs, wherein the

Gear pairs are each formed by one of the fixed wheels 7, 8 and one of the idler gears 15 and 17 respectively.

The dual-clutch transmission 1 further has a Achsabtriebsrad 19, wherein the

Achsabtriebsrad 19 rotatably connected to an axle 20 is connected. The axle 20 is connected to a differential gear 21. The Achsabtriebsrad 19 is of the two

Drive shafts TW1 and TW2 driven via unspecified fixed wheels. The

Differential gear 21 transmits the applied torque to the drive wheels 22, as indicated schematically by unspecified arrows.

The gears one to seven are vzw. unsynchronized. The omission of

Synchronizers allow for faster shifting, lower drag torque and lower total cost of ownership. Alternatively, at least one of the gear stages can also be provided with a synchronizing device.

Vzw. At least one central synchronization device 23, 24 is provided for functionally effective deceleration of the transmission input shafts EW1, EW2.

The disadvantages mentioned above are now avoided by having two

Central synchronization devices 23, 24 are provided, the two

Central synchronization devices 23 and 24 as Losradbremsvorrichtungen 25, 26th are formed and each a Losradbremsvorrichtung 25 and 26 a

Transmission input shaft EW1 or EW2 is associated with effective, and with each

Losradbremsvorrichtung one of the idler gears 9, 11 of the respective gear pair is braked. The Losradbremsvorrichtungen 25 and 26 have the advantage that the axial space of the dual clutch transmission 1 does not need to be extended. The two braked idler gears 9, 11 are in the preferred embodiment shown here Ausführungsuπgsbeispiel the same drive shaft, here vzw. associated with the first drive shaft TW1. In particular, the two brakesbare Losräder 9, 11 associated with different gear ratios / gear pairs. The one braked idler gear 9 is an odd gear, vzw. assigned to the first gear. The other braked idler gear 11 is a straight gear, vzw. assigned to the fourth gear. It is conceivable that the two braked idler gears of the two

Losradbremsvorrichtungen are also assigned to each different drive shafts. This depends on the particular application. Vzw. is important that each of the

Transmission input shafts EW1 or EW2 via a correspondingly provided

Losradbremsvorrichtung can be slowed down or synchronized accordingly.

Each of the Losradbremsvorrichtungen 25, 26 has vzw. an unspecified

Friction lining and an unspecified hydraulic cylinder, wherein the friction lining with the hydraulic cylinder against the respective idler gear 9 and 11 can be pressed. Vzw. Each of the Losradbremsvorrichtungen 25, 26 is formed similar to a disc brake. The

Losradbremsvorrichtungen 25 and 26 may each have a brake caliper 27, 28, wherein the brake caliper 27, 28, the braked idler gear 9 and 11 vzw. at least partially encompasses. The friction lining is vzw. arranged relative to the idler gear 9 and 11 axially displaceable. The friction lining may in particular be arranged axially displaceable relative to the brake caliper 27, 28. The Losradbremsvorrichtungen 25, 26, in particular the unspecified hydraulic cylinders are vzw. independently controllable. Of the

Operating pressure in the hydraulic cylinder is vzw. adapted to the diameter of the idler gears 9, 11.

In an upshift, the corresponding transmission input shaft EW1 or EW2 by means of the idler brake device 25, 26 indirectly, vzw. namely "indirectly" braked

Losradbremsvorrichtung 25 acts on the non-rotatable gear 4 to the first

Transmission input shaft EW1. The Losradbremsvorrichtung 26 acts on the non-rotatable gear 7 to the second - here outer - transmission input shaft EW2.

When downshifts an acceleration of the respective transmission input shaft EW1, EW2 is required. One possibility, the respective transmission input shaft EW1, EW2

accelerate, is to close the associated friction clutch K1, K2 and the Transmission input shaft EW1, EW2 by means of the motor shaft 29 to accelerate. In synchronism of the rotational speeds of the idler gear 9 to 16 and the associated drive shaft TW1 and TW2 could be the respective idler gear 9 to 16 with not shown here form-fitting

Clutches are connected to the respective drive shaft TW1 or TW2.

Vzw. Furthermore, a lock system is provided, wherein when a gear is engaged, the other gear ratios are locked. For example, if the first gear is engaged, the other six gears and the reverse gear R are locked.

With the dual-clutch transmission designed in this way according to the invention, the disadvantages mentioned above are therefore avoided and corresponding advantages are achieved.

Reference number list

1 dual-clutch transmission

2 double clutch

3 fixed wheel

4 fixed wheel

5 fixed wheel

6 fixed wheel

7 fixed wheel

8 fixed wheel

9 idler gear

10 idler gear

11 idler gear

12 idler gear

13 idler gear

14 idler gear

15 idler gear

16 idler gear

17 intermediate shaft

18 intermediate wheel

19 axle driven wheel

20 axle output

21 differential gear

22 drive wheels

23 Central Synchronization Device

24 central synchronization device

25 Losradbremsvorrichtung

26 Losradbremsvorrichtung

27 caliper

28 caliper

29 motor shaft

K1 friction clutch

K2 friction clutch EW1 first transmission input shaft

EW2 second transmission input shaft

TW1 first shoot

TW2 second drive shaft

R reverse gear

Claims

claims

1. Double clutch transmission (1) for a motor vehicle, with a first and a second transmission input shaft (EW1, EW2) and at least one drive shaft, in particular with a first and with a second drive shaft (TW1, TW2), wherein the first

Transmission input shaft (EW1) a first friction clutch (K1) and certain gear ratios, vzw. a first, a third, a fifth and / or a seventh gear, are assigned, and the second transmission input shaft (EW2), a second friction clutch (K2) and certain other gear ratios, vzw. a second, a fourth and / or a sixth gear, are assigned, wherein the gear stages by a plurality of each of the

Gear input shaft (EW1, EW2) and the at least one drive shaft (TW1, TW2) connecting gear pairs are formed, wherein the gear pairs by a fixed gear (3 to 8) and a loose wheel (9 to 16) are formed, wherein at least one

Central synchronization device (23, 24) is provided for functionally effective deceleration of the transmission input shafts (EW1, EW2), characterized in that two central synchronization devices (23, 24) are provided, the two

Central synchronization devices (23, 24) as Losradbremsvorrichtungen (25, 26) are formed and in each case a Losradbremsvorrichtung (25, 26) of a

Transmission input shaft (EW1, EW2) is associated with effective, and with each

Losradbremsvorrichtung (25, 26) of the loose wheels (9, 11) of the respective gear pair is braked.

2. dual-clutch transmission according to claim 1, characterized in that the one of the braked idler gears (26) of a gear with a straight ordinal number and that other of the braked idler gears (25) is associated with a gear with an odd ordinal number.

3. dual-clutch transmission according to claim 1 or 2, characterized in that one of the two Losradbremsvorrichtungen (25) is associated with the idler gear (9) of the first gear and the other of the two Losradbremsvorrichtungen (26) is associated with the idler gear (11) of the fourth gear ,

4. dual-clutch transmission according to one of the preceding claims, characterized in that two power welders (TW1, TW2) are provided.

5. dual-clutch transmission according to one of the preceding claims, characterized

characterized in that the loose wheels (9 to 16) arranged on the drive shafts (TW1, TW2) and the non-rotatable gears (3 to 8) rotatably on the

Transmission input shafts (EW1, EW2) are arranged.

6. dual-clutch transmission according to one of the preceding claims, characterized

characterized in that the two braked idler gears (9, 11) are assigned to different gear stages or gear pairs such that each

Transmission input shaft (EW1, EW2) with one of the two loose wheels (9, 11) is operatively connected.

7. dual-clutch transmission according to one of the preceding claims, characterized

characterized in that the different gear ratios or pairs of gears with the respective braked loose wheels (9, 11) are each effectively arranged on the one hand between one of the transmission input shafts (EW1, EW2) and on the other hand between one of the drive shafts (TW1, TW2).

8. dual-clutch transmission according to one of the preceding claims, characterized

characterized in that the different gear ratios or pairs of gears with the respective braked loose wheels (9, 11) between on the one hand in each case the

Transmission input shafts (EW1, EW2) and on the other hand with the same drive shaft (TW1, TW2) are effectively arranged.

9. dual-clutch transmission according to one of the preceding claims, characterized

characterized in that the Losradbremsvorrichtuπg (25, 26) comprises a friction lining and a hydraulic cylinder, wherein the friction lining with the hydraulic cylinder against the idler gear (9, 11) can be pressed.

10. dual-clutch transmission according to one of the preceding claims, characterized

characterized in that the Losradbremsvorrichtungen (25, 26) each have a brake caliper (27, 28), wherein the brake caliper (27, 28) each surrounds the braked idler gear (9, 11).

11. dual-clutch transmission according to one of the preceding claims, characterized

characterized in that the friction lining is disposed axially displaceable relative to the idler gear (9, 11).

12. dual-clutch transmission according to one of the preceding claims, characterized

characterized in that the friction lining in the caliper (27, 28) is arranged axially displaceable.

13. dual-clutch transmission according to one of the preceding claims, characterized

in that the actuating pressure in the hydraulic cylinder is adapted to the diameter of the loose wheels (9, 11).

14. Double clutch transmission according to one of the preceding claims, characterized

characterized in that the Losradbremsvorrichtungen (25, 26) are independently controllable.

15. Double clutch transmission according to one of the preceding claims, characterized

characterized in that seven speed steps are provided for the forward drive.

16. Dual clutch transmission according to one of the preceding claims, characterized

in that additionally a reverse gear (R) is provided.

17. Dual-clutch transmission according to one of the preceding claims, characterized

characterized in that the Losradbremsvorrichtungen (25, 26) are arranged substantially radially to the braked loose wheels (9, 11).