GB2476956A

GB2476956A - Dual clutch multi-speed transmission and vehicle having a dual clutch multi-speed transmission

Info

Publication number: GB2476956A
Application number: GB1000608A
Authority: GB
Inventors: Christian Kunze; Craig S Ross; Serdar Celik
Original assignee: GM Global Technology Operations LLC
Current assignee: GM Global Technology Operations LLC
Priority date: 2010-01-14
Filing date: 2010-01-14
Publication date: 2011-07-20
Also published as: GB201000608D0; CN102128237A; RU2011101360A

Abstract

A dual clutch multi-speed transmission 1 comprises a first input shaft 2 engageable by a first drive clutch 4, a second input shaft 3 engageable by a second drive clutch 5. A single output shaft 7, an intermediate shaft 6 and a first torque transmitting path for driveably coupling the intermediate shaft 6 to the output shaft 7 are also provided. The first torque transmitting mechanism comprises a first gear set 11 having a first gear 12 intermeshing with a second gear 13 and with a third gear 14. The first gear 12 is mounted on the first input shaft 2 or the second input shaft 3, the second gear 13 is mounted on the intermediate shaft 6 and the third gear 14 is mounted on the output shaft 7. Preferably the fist gear 12 is rotatable about the first 2 or second 3 input shafts while the second 13 and third 14 gears are fixed for common rotation with the intermediate 6 and output 7 shafts.

Description

Dual clutch multi-speed transmission and vehicle having a dual clutch multi-speed transmission A transmission is used to couple a prime drive, such as an en-gine, to the final drive, such as a differential, over a range of speed ratios. For example, a transmission of an automotive vehicle may provide between five and eight forward speed ra-tics and at least one reverse ratio.

The power transmission from the prime drive to the transmis-sion is typically interrupted before or during each gear ratio change because the torque transmission devices such as syn-chronizers cannot be actuated whilst transmitting power.

Dual clutch transmissions, such as that disclosed in US 7,353,724 B2, may be operated so as to transmit power whilst changing from an odd numbered gear to an even numbered gear.

Dual clutch transmissions can be thought of as having two automated shift manual transmissions whereby one transmission provides odd numbered gears and one provides even numbered a gears. Each transmission is coupled to the engine by a sepa-rate engine clutch so that shifts between odd numbered a gears and even numbered gears can be accommodated without interrupt-ing the power flow.

For example, while operating in an odd gear, a synchronizer can be actuated to configure the transmission for the next even gear. The engine clutch of the even gear may be actuated to couple the engine to the even gear before the engine clutch of the odd gear is actuated so as to decouple the odd gear from the engine. Therefore, a continuous power flow can be provided whilst changing the gear ratio from an odd gear to an even gear and vice versa in a dual clutch transmission.

However, it is also desirable to provide a transmission which is compact and light so as to be able to accommodate the transmission within the vehicle without increasing the weight and, consequently, reducing the fuel efficiency of the vehi-cle. In particular, in so-called micro-, mini-and small cars, the space available for the transmission is particularly lim-ited so that a compact transmission is desirable for these cars.

Therefore, it is desirable to provide a multi-speed transmis-sion which is efficient and also compact.

The application provides a dual clutch multi-speed transmis-sion which comprises a first input shaft engageable by a first drive clutch, a second input shaft engageable by a second drive clutch, a single output shaft, an intermediate shaft and a first torque transmitting path for driveably coupling the intermediate shaft to the output shaft. The first torque transmitting path comprises a first gear set having a first gear intermeshing with a second gear and intermeshing with a third gear. The first gear is mounted on the first input shaft or the second input shaft, the second gear is mounted on the intermediate shaft and the third gear is mounted on the output shaft.

The first gear is positioned between the second gear and the third gear so as to intermesh with both the second gear and the third gear. The first gear set may be coplanar.

The first torque transmitting path provides a path by which torque can be transmitted from the intermediate shaft via the first input shaft to the output shaft so that the intermediate shaft can drive the output shaft. This arrangement enables the transmission to be packaged more compactly for use in micro-, mini and/or small cars. This arrangement also enables the transmission to have a single output shaft since torque is transferred from the intermediate shaft via a gear mounted on the first or second input shaft to this single output shaft. A single output shaft enables the transmission to be provided in a compact package and also simplifies control of the transmis-sion.

A gear which is mounted on a shaft may be connected for rota-tion about this shaft or mounted for common rotation about this shaft.

A gear that is connected for rotation may also be described as a loose gear which can be connected to its respective shaft by means of a torque transmitting mechanism such as a clutch or synchronizer. When the gear is connected to its shaft by se-lectively actuating the clutch, the gear rotates in common with its shaft and can drive the shaft or be driven by the shaft.

A gear that is connected for common rotation with its respec-tive shaft may also be described as a fixed gear.

A gear of a gear set may also be referred to as a gear wheel and includes a plurality of teeth protruding from its circum-ference which intermesh with teeth of a second and, in some embodiments also a third, gear or gear wheel.

The first input shaft and second input shaft may be arranged concentrically. The first input shaft may be provided by an inner rod and the second input shaft may be provided by a hol- low rod which surrounds the first input shaft. The single out- put shaft may be coupled to a final drive unit or a differen-tial.

The output shaft may be radially displaced from the first and second input shafts. The intermediate shaft may be radially displaced from the two input shafts and from the single output shaft.

In an embodiment, the first gear is connected for rotation about the first input shaft or the second input shaft, the second gear is connected for common rotation about the inter- mediate shaft and the third gear is connected for common rota-tion about the output shaft.

In this embodiment, the central gear of the first gear set is loose and the two outer gears of the gear set are fixed.

Therefore, torque can be transmitted from the fixed second gear, via the loose first gear to the fixed third gear to transmit torque from the intermediate shaft to the output shaft and drive the output shaft.

In further embodiment, the dual clutch multi-speed transmis-sion further comprises a second torque transmitting path for driveably connecting the first input shaft or the second input shaft to the intermediate shaft. The second torque transmit-ting path comprises a second gear set axially spaced from the first gear set.

The second gear set comprises a fourth gear connected for corn-mon rotation about the first input shaft or the second input shaft and a fifth gear connected for rotation about the inter-mediate shaft. The fourth gear is fixed on either the first input shaft or the second input shaft and the fifth gear is loose on the intermediate shaft. The second torque transmit- ting path further comprises a first torque transmitting mecha-nism that is selectively engageable to connect the fifth gear to the intermediate shaft for common rotation of the fifth gear with the intermediate shaft.

The second torque transmitting path and the first torque transmitting path, when used together, provide a torque trans-mitting path from either the first input shaft or the second input shaft, via the intermediate shaft, to the output shaft to drive the output shaft.

In order to provide this torque transmitting path, the first torque transmitting mechanism is selectively engageable to connect the fifth gear to the intermediate shaft. Torque from the prime drive is transmitted via either the first input shaft or the second input shaft to the fourth gear, from the fourth gear to the fifth gear of the second gear set, from the fifth gear to the intermediate shaft, from the intermediate shaft to the second gear via the first gear to the third gear of the first gear set and then from the third gear to the out-put shaft and finally, to the final drive or differential.

In further embodiment, the dual clutch multi-speed transmis-sion further comprises a second torque transmitting mechanism that is selectively engageable to connect the first gear to the first input shaft or to the second input shaft for common rotation with the first input shaft or the second input shaft, respectively. When the second torque transmitting mechanism is selectively engaged, torque flows from the first input shaft or the second input shaft via the first gear and the third gear to the output shaft. In this embodiment, the first torque transmitting mechanism is not engaged with the fifth gear on the intermediate shaft so that the first gear and third gear use the second gear and intermediate shaft as an idler whilst the first gear and third gear and the firs gear set drive the output shaft.

Therefore, the first gear set has a double use. In one use, the first gear set is used to provide the first torque trans-mitting path to driveably couple the intermediate shaft to the output shaft. In the second use, the first gear set is used to driveably couple the first or second input shaft to the output shaft by means of the first and third gears of the first gear set. This double use of the first gear set enables a compact package for the transmission to be provided.

In a further embodiment, the fifth gear arranged on the inter-mediate shaft intermeshes with a reverse gear connected for rotation about the output shaft. A third torque transmitting mechanism is provided on the output shaft which is selectively engageable to connect the reverse gear to the output shaft.

When the third torque transmitting mechanism connects the re-verse gear to the output shaft, torque is transmitted from the first input shaft or the second input shaft via the fourth gear that is fixed on the first input shaft or the second in- put shaft, the fifth gear which rotates idly on the intermedi- ate shaft to the reverse gear rotating in common with the out-put shaft.

The second gear set may provide two different torque transmit-ting paths. In one embodiment, the second gear set may be used to transmit torque from the first input shaft or the second input shaft to the intermediate shaft with a forward speed ra-tio and to provide the reverse speed ratio. In one embodiment, the second gear set may be used to transmit torque from the first input shaft or the second input shaft to the intermedi-ate shaft without providing a speed ratio and to provide the reverse speed ratio.

The intermediate shaft may be used to accommodate one speed ratio or more than one speed ratio by mounting one or more than one partial gear set on the intermediate shaft. A partial gear set may be a single gear which intermeshes with a second gear mounted on the first input shaft or second input shaft.

In a further embodiment, the dual clutch multi-speed transmis-sion further comprises a third gear set that is axially spaced from the first gear set and from the second gear set. The third gear set comprises a sixth gear connected for common ro- tation about the first input shaft and a seventh gear con-nected for rotation about the intermediate shaft. The sixth gear is therefore fixed on input shaft and the seventh gear is loose on the intermediate shaft. This embodiment may be used for embodiments in which the fourth gear of the second gear set is also fixed on the first input shaft.

The first torque transmitting mechanism may be a dual torque transmitting mechanism and selectively engageable to connect either the fifth gear of the second gear set to the intermedi- ate shaft or the seventh gear of the third gear set to the in- termediate shaft. In these embodiments, in which the interme-diate shaft is used to provide a two or more speed ratios, the first gear set may be used to transmit torque from the immedi-ate shaft via the first or second input shaft to the output shaft to drive the output shaft as described above.

In this embodiment, the dual clutch multi-speed transmission may comprise three two-way torque transmitting mechanisms. One two-way torque transmitting mechanism is connected to the in-termediate shaft, one two-way torque transmitting mechanism is connected to the second input shaft and one two-way torque transmitting mechanism is connected to the output shaft. This embodiment may be used to provide five forward speed ratios and one reverse speed ratio in which the reverse speed ratio is synchronised. The two-way torque transmitting mechanisms may be provided by dual synchronizers.

In a further embodiment, the first gear of the first gear set is connected for rotation about the first input shaft and the fourth gear of the second gear set is connected for common ro- tation with the second input shaft. The first gear is there-fore loose on the first input shaft and the fourth gear is fixed on the second input shaft. In this embodiment, the first and fourth gears are positioned on a different input shaft in comparison with the embodiment described above.

However, in other embodiments, the first gear of the first gear set and the fourth gear of the second gear set may be ar-ranged on the same input shaft. In an embodiment, the first gear is connected for rotation about the second input shaft and fourth gear is connected for common rotation with the sec-ond input shaft. The first gear is loose on the second input shaft and the fourth gear is fixed on the second input shaft in this embodiment.

In embodiments in which the fourth gear is connected for com-mon rotation with, i.e. is fixed on, the second input shaft, the dual clutch multi-speed transmission may comprise 2 one-way torque transmitting mechanisms and two two-way torque transmitting mechanisms. One one-way torque transmitting mechanism is connected to the intermediate shaft and provides the first torque transmitting mechanism that is selectively engageable to connect the fifth gear to the intermediate shaft. In these embodiments, the second gear set may be used only to transmit torque from the second input shaft to the in-termediate shaft and may not itself provide a forward speed ratio of the transmission.

One of the two-way torque transmitting mechanisms may be con- nected to the input shaft and the other two-way torque trans-mitting mechanism as well as the remaining one-way torque transmitting mechanism may be connected to the output shaft.

Alternatively, both two-way torque transmitting mechanisms may be connected to the output shaft and the remaining one-way torque transmitting mechanism is connected to the first input shaft.

These arrangements of the torque transmitting mechanisms may be used to provide a dual clutch multi-speed transmission with five forward speed ratios and a reverse speed ratio in which not only the forward speed ratios but also the reverse speed ratio are synchronised.

The application also provides a power train including a prime drive, the dual clutch multi-speed transmission according to one of the embodiments described above and a final drive or differential.

The application also provides a vehicle comprising the dual clutch multi-speed transmission according to one of the em-bodiments described above.

Embodiments will now be described with reference to the accom-panying drawings.

Figures la to ig illustrate a dual clutch multi-speed trans-mission according to a first embodiment, whereby Figure la illustrates the torque flow through the trans-mission for first forward speed ratio, Figure lb illustrates the torque flow through the trans-mission for second forward speed ratio, Figure lc illustrates the torque flow through the trans-mission for third forward speed ratio, Figure id illustrates the torque flow through the trans-mission for fourth forward speed ratio, Figure le illustrates the torque flow through the trans-mission for fifth forward speed ratio, Figure if illustrates the torque flow through the trans-mission for reverse speed ratio, Figure ig illustrates the gear ratios provided by the transmission of the first embodiment, Figures 2a to 2f illustrate a dual clutch multi-speed trans-mission according to a second embodiment, whereby Figure 2a illustrates the torque flow through the trans-mission for first forward speed ratio, Figure 2b illustrates the torque flow through the trans-mission for second forward speed ratio, Figure 2c illustrates the torque flow through the trans-mission for third forward speed ratio, Figure 2d illustrates the torque flow through the trans-mission for fourth forward speed ratio, Figure 2e illustrates the torque flow through the trans-mission for fifth forward speed ratio, Figure 2f illustrates the torque flow through the trans-mission for reverse speed ratio, Figures 3a to 3f illustrate a dual clutch multi-speed trans-mission according to a third embodiment, whereby Figure 3a illustrates the torque flow through the trans-mission for first forward speed ratio, Figure 3b illustrates the torque flow through the trans-mission for second forward speed ratio, Figure 3c illustrates the torque flow through the trans-mission for third forward speed ratio, Figure 3d illustrates the torque flow through the trans-mission for fourth forward speed ratio, Figure 3e illustrates the torque flow through the trans-mission for fifth forward speed ratio, Figure 3f illustrates the torque flow through the trans-mission for reverse speed ratio, Figures 4a to 4f illustrate a dual clutch multi-speed trans-mission according to a fourth embodiment, whereby Figure 4a illustrates the torque flow through the trans-mission for first forward speed ratio, Figure 4b illustrates the torque flow through the trans-mission for second forward speed ratio, Figure 4c illustrates the torque flow through the trans-mission for third forward speed ratio, Figure 4d illustrates the torque flow through the trans-mission for fourth forward speed ratio, Figure 4e illustrates the torque flow through the trans-mission for fifth forward speed ratio, Figure 4f illustrates the torque flow through the trans-mission for reverse speed ratio, and Figure 5 illustrates the gear ratios provided by the transmissions of embodiments 2 to 4.

Figures la to if illustrate a dual clutch multi-speed trans-mission 1 according to a first embodiment.

The dual clutch multi-speed transmission 1 according to the first embodiment comprises a first input shaft 2 and a second input shaft 3 which is arranged concentrically around the first input shaft 2. The first input shaft 2 is provided by a solid rod and the second input shaft 3 is provided by a hollow rod. The first input shaft 2 is engageable by a first drive clutch 4. The second input shaft 3 engageable by a second drive clutch 5.

The transmission 1 further includes an intermediate shaft 6 that is radially displaced from the first input shaft 2 and second input shaft 3 and a single output shaft 7 that is ra- dially displaced from the intermediate shaft 6, the first in-put shaft 2 and second input shaft 3. The output shaft 7 has a single output pinion 8 which intermeshes with ring gear 9 to transfer torque to the final drive which is illustrated in the embodiments as a differential 10.

The transmission 1 comprises a first gear set 11 comprising a first gear 12 that intermeshes with a second gear 13 and with a third gear 14. The first gear 12 is connected for rotation about the second input shaft 3, the second gear 13 is con-nected for common rotation about the intermediate shaft 6 and the third gear 14 is mounted for common rotation about the output shaft 7. In other words, the first gear 12 is loose on the second input shaft 3, whereas the second gear 13 and the third gear 14 are fixed on the intermediate shaft 6 and output shaft 7, respectively. The first gear set is coplanar and pro-vides a first torque transmitting path for driveably coupling the intermediate shaft 6 to the output shaft 7.

The gears of the various gear sets in the dual clutch trans-mission of all of the embodiments each comprise a toothed gear wheel.

The transmission 1 further comprises a second gear set 15 corn-prising a fourth gear 16 connected for common rotation with the first input shaft 2 and a fifth gear 17 mounted for rota-tion about the intermediate shaft 6, i.e. the fourth gear 16 is fixed to the first input shaft 2 and the fifth gear is loose on the intermediate shaft 6. The fourth gear 16 inter-meshes with the fifth gear 17. In this embodiment, the second gear set is coplanar provides and a first forward speed ratio.

The second gear set 15 provides a second torque transmitting path for transmitting torque from the first input shaft 2 to the intermediate shaft 6 so that the first input shaft 2 can drive the intermediate shaft 6. The intermediate shaft 6 can drive the output shaft 7 by means of the first torque trans-mitting path.

The transmission 1 further includes a third gear set 18 com-prising a sixth gear 19 mounted for rotation about the second input shaft 3 that intermeshes with a seventh gear 20 that is mounted for common rotation with the output shaft 7. The sixth gear 19 is loose on the second input shaft 3 and the seventh gear 20 is fixed on the output shaft 7. The third gear set 18 is coplanar provides the second forward speed ratio in this embodiment.

The transmission 1 also includes a fourth gear set 21 that comprises an eighth gear 22 connected for common rotation about the first input shaft 2 that interrneshes with a ninth gear 23 connected for rotation about the intermediate shaft 6.

The eighth gear 22 is fixed on the first input shaft 2 and the ninth gear 23 is loose on the intermediate shaft 6. In this embodiment, the fourth gear set 21 is coplanar and provides a third forward speed ratio.

The fourth forward speed ratio is provided by the first gear 12 and third gear 14 of the first gear set 11. Therefore, the first gear set 11 has a dual use and provides a fourth forward speed ratio as well as a torque transmitting path from the in-termediate shaft 6 to the output shaft 7.

The transmission 1 further comprises a fifth gear set 24 com-prising a tenth gear 25 connected for common rotation about the first input shaft 2 that intermeshes with an eleventh gear 26 mounted for rotation about the output shaft 7. The tenth gear 25 is fixed on the first input shaft 2 and the eleventh gear 26 is loose on the output shaft 7.

The transmission 1 also includes a reverse gear 27 connected for rotation about the output shaft 7. The reverse gear 27 in-termeshes with the fifth gear 17 of the second gear set 15 which is connected for rotation about the intermediate shaft 6.

The second gear set 15 also has a dual use as it provides the first forward speed ratio and the reverse gear ratio.

When viewed along the axes of the input shafts 2, 3, interme-diate shaft 6 and output shaft 7, the shafts have a generally triangular arrangement in which the intermediate shaft 6 is positioned at the apex above the first and second input shafts 2, 3 and the output shaft 7. The output shaft 7 is positioned laterally adjacent the two concentric input shafts 2, 3.

The transmission 1 further comprises three dual torque trans- mission mechanisms 28, 29, 30 in the form of dual synchroniz- ers. A first dual synchronizer 28 is connected to the interme-diate shaft 6 and is positioned between the fifth gear 17 of the second gear set 15 and the ninth gear 23 of the fourth gear set 21 so as to be able to connect either the fifth gear 17 or the ninth gear 23 for common rotation about the interme-diate shaft 6 and drive the intermediate shaft 6.

A second dual synchronizer 29 is connected to the second input shaft 3 between the first gear 12 of the first gear set 11 and the sixth gear 19 of the third gear set 18 so as to be able to connect either the first gear 12 or the sixth gear 19 to the second input shaft 3 for common rotation with the second input shaft 3. When the first gear 12 is connected for common rota-tion with the second input shaft 3, the first gear set 11 and, in particular, the first gear 12 and third gear 14 of the first gear set 11, can drive the output shaft 7. When the sixth gear 19 is connected for common rotation with the second input shaft 3, the third gear set 18 can drive the output shaft 7.

A third dual synchronizer 30 is connected to the output shaft 7 and is positioned between the reverse gear 27 and the elev-enth gear 26 of the fifth gear set 24 so as to connect either the reverse gear 27 or the eleventh gear 26 for common rota-tion with the output shaft 7 so that the reverse gear or the fifth gear set can drive the output shaft 7.

The diameters of the respective gears and displacement of the intermediate shaft 6 and upper shaft 7 from a common axis of the first input shaft 2 and second input shaft 3 are also il-lustrated in the figures.

The output pinion 8 is positioned at the same end of the transmission 1 as the first drive clutch 4 and second drive clutch 5. The order of the position of the gear sets on the second input shaft 3 and first input shaft 2 starting from the first drive clutch 4 and second drive clutch 5 (from right to left in the drawings) is third gear set 18, first gear set 11, fifth gear set 24, fourth gear set 21 and second gear set 15.

The reverse gear 27 is coplanar with the second gear set 15.

The odd forward speed ratios, i.e. the first, third and fifth forward gears are provided by the second gear set 15, the fourth gear set 21 and the fifth gear set 24, respectively.

These gear sets are also denoted in the figures by the numbers 1, 3 and 5. The gear sets 15, 21 and 24 providing the odd for-ward speed ratios are coupled to the first input shaft 2. The even forward speed ratios, i.e. the second and fourth forward gears, are provided by the first gear set 11 and the third gear set 18 and are coupled to the second output shaft 3.

These gear sets are denoted in the figures by the numbers 2 and 4. The reverse speed gear 27 is denoted in the figures by R. The first input shaft 2 is longer than the second input shaft 3 and protrudes beyond the second input shaft 3 so that the gear sets 15, 21 and 24 providing the odd gears are positioned adjacent the gear sets 11, 18 providing the even gears.

Figure la illustrates the torque flow through the transmission 1 for the first forward speed ratio. The first drive clutch 4 is actuated to engage and drive the first input shaft 2 and the first synchronizer 28 is selectively actuated to engage the fifth gear 17 of the second gear set and connect it for common rotation with the intermediate shaft 6.

Torque is transmitted from the prime drive by the first input shaft 2 and by means of the fourth gear 16 and fifth gear 17 of the second gear set 15 to the intermediate shaft 6. The torque is then transmitted by means of the first gear set 11 from the intermediate shaft 6 via the fixed second gear 13 on the intermediate shaft 6, the loose first gear 12 on the sec-ond input shaft 3 to the third gear 14 which is fixed on the output shaft 7 in order to drive the output shaft 7. The torque is then transmitted from the output shaft 7 to drive the differential 10 by means of the output pinion 8 and ring gear 9. The torque path has a winding path with a clockwise, circular looped portion.

To shift from the first forward speed ratio to a second for-ward speed ratio, the second synchronizer 29 is selectively engaged with the sixth gear 19 of the third gear set 18 to connect the sixth gear 19 to the second input shaft 3 for com-mon rotation with the second input shaft 3. The first drive clutch 4 is disengaged from the first input shaft 2 so as to decouple the first input clutch 4 from the prime drive and the second drive clutch 5 is engaged with a second input shaft 3 approximately simultaneously. The second input shaft 3 is now coupled to the prime drive. Thus the torque flow as illus-trated in Figure la for the first gear is interrupted between the prime drive and the first input shaft 2.

The torque flow through transmission 1 for the second forward speed ratio is illustrated in Figure lb. The torque flows from the prime drive and is transmitted via the second input shaft 3 by means of the sixth gear 19 and seventh gear 20 of the third gear set 18 directly to the output shaft 7 to drive the output shaft and the differential 10 by means of the output pinion 8 and ring gear 9.

To shift from the second forward speed ratio into the third forward speed ratio, the first synchronizer 28 is connected to the ninth gear 23 of the fourth gear set 21, the second engine clutch 5 is decoupled from the second input shaft 3 and the first engine clutch 4 is engaged with the first input shaft 2.

The first input shaft 2 is now driven by the prime drive.

Figure lc illustrates the torque flow through the transmission 1 when the third forward speed ratio is selected. Torque from the prime drive is transmitted into the transmission 1 via the first input shaft 2 and then via the eighth gear 22 and ninth gear 23 of the fourth gear set 21 to the intermediate shaft 6.

The torque is transmitted by means of the first torque trans- mitting mechanism of the first gear set 11 from the intermedi-ate shaft 6 to the output shaft 7.

In particular, torque is transmitted by the second gear 13 connected for common rotation with the intermediate shaft 6 to the first gear 12, which idles on the second input shaft 2, and then to the fourth gear 14 which is connected for common rotation with the output shaft 7 to drive the output shaft 7.

The torque is then transmitted from the output shaft 7 to the differential 10 by means of the output pinion 8 and ring gear 9.

To shift from the third forward speed ratio to the fourth for-ward speed ratio, the second synchronizer 29 connected to the first gear 12 for common rotation with the second input shaft 3. The second prime clutch 5 is engaged with the second input shaft 3 and the first prime clutch 4 is disengaged from the first input shaft 2. The torque flow to the first input shaft 2 is interrupted and the second input shaft 3 is now driven by the prime drive.

As is illustrated in Figure id, torque flows from the prime drive to the second input shaft 3 and via the first gear 12 and third gear 14 of the first gear set 11 to drive the output shaft 7. The torque flows from the output shaft 7 to the dif-ferential 10 by means of the output pinion 8 and ring gear 9.

The first gear set 11, therefore, provides a first torque path for transmitting torque from the intermediate shaft 6 to the output shaft 7 so that the second and fourth gear sets 15, 21 arranged on the intermediate shaft 6 are able to drive the output shaft 7 and the fourth forward speed ratio by transmit-ting torque from the second input shaft 3 to the output shaft 7 and drive the output shaft when the first gear 12 is con-nected for common rotation with the second input shaft 3. The first synchronizer 28 is not connected to either the fifth gear 17 or the ninth gear 23 connected for rotation about the intermediate shaft 6. When the fourth forward speed ratio is selected, the third gear 13 of the first gear set 11 which is fixed on the intermediate shaft 6 and the intermediate shaft 6 idle.

To shift from the fourth forward speed to the fifth forward speed, the third synchronizer 30 is selectively engaged with the eleventh gear 26 of the fifth gear set 24, the first drive clutch 4 is engaged to the first input shaft 2 and the second drive clutch 5 is disengaged from the second input shaft 3 so that torque is transmitted from the prime drive to the first input shaft 2.

Figure le illustrates the torque flow when the fifth forward speed ratio is selected. When the fifth forward speed ratio is selected, torque is transmitted from the first input shaft 2, directly to the output shaft 7 via the tenth gear 25 and elev-enth gear 26 of the fifth gear set 24 to drive the output shaft 7.

The torque flow put for providing a reverse gear ratio is ii-lustrated in figure if. For a reverse speed ratio, the first engine clutch 4 is engaged with the first input shaft 2 and the second drive clutch 5 is disengaged from the second input shaft 3. The third synchronizer 30 is engaged with the reverse gear 27 so as to connect the reverse gear 27 for common rota-tion with the output shaft 7. The reverse gear 27 intermeshes with the fifth gear 17 of the second gear set 15 which is con-nected for rotation on the intermediate shaft 6. To provide a reverse speed ratio, the first synchronizer 28 is not coupled to fifth gear 17 so that the fifth gear idles. The torque is transmitted from the prime drive by the first input shaft 2, and to the fourth gear 16 and fifth gear 17 of the second gear set 15 and from the fifth gear 17, which idles on the interme-diate shaft 6, to the reverse gear 27 which is connected to the output shaft 7 to drive the output shaft 7.

The second gear set 15 has a dual use as it provides the re-verse speed ratio and the first forward speed ratio.

The gear ratio which may be achieved for each of the forward speed ratios and reverse speed ratio of the transmission 1 are illustrated in Figure 1g. The target ratio is arbitrary and represents a pre-determined desired ratio.

Figures 2a to 2f illustrate a transmission 1' according to a second embodiment. The transmission 1' of the second embodi-ment comprises a first input shaft 2 and second input shaft 3 arranged concentrically, an intermediate shaft 6 and a single output shaft 7 as in the first embodiment.

Also as in the first embodiment, the gear sets providing the odd forward speed ratios are driven by the first input shaft 2 and the gear sets providing the even forward speed ratios are driven by the second input shaft 3. However, in contrast to the first embodiment, the reverse speed ratio is driven by the second input shaft 3 rather than the first input shaft 2.

The transmission 1' of the second embodiment also differs from the transmission 1 of the first embodiment in the axial posi-tion of the gear sets and in the number and position of the torque transmitting mechanisms provided.

The gear sets of the transmission 1' of the second embodiment are arranged axially spaced from one another in the following order starting from the input to the first and second input shafts 2,3: second gear set 15, third gear set 18, first gear set 11, fourth gear set 21 and fifth gear set 24. The reverse gear 27 is coplanar with the second gear set 15 and is posi-tioned at the opposing end of the output shaft 7 compared to its position in the first embodiment illustrated in figures la to lf.

The first gear set 11 comprises a first gear 12 which is con-nected for rotation about the first input shaft 2. The first gear 12 intermeshes with a second gear 13 fixed for common ro-tation about the intermediate shaft 6 and also intermeshes with a third gear 14 fixed for common rotation about the out-put shaft 7. The first gear 12 is mounted loose on the first input shaft 2, whereas the second gear 13 and third gear 14 are fixed on the intermediate shaft 6 and output shaft 7, re-spectively. The first gear set 11 provides a first torque transmitting path from the intermediate shaft 6 to the output shaft 7, as in the first embodiment.

The second gear set 15 comprises a fourth gear 16 which is fixed for common rotation about the second input shaft 3. The fourth gear 16 intermeshes with the fifth gear 17 connected for rotation about be intermediate shaft 6. The second gear set 15 provides a second torque transmitting path from the second input shaft 3 to the intermediate shaft 6. This second torque transmitting path may be used in combination with the first torque transmitting path from the intermediate shaft 6 to the output shaft 7 provided by the first gear set 11.

In the transmission 1' of the second embodiment, the torque is transmitted in the opposing direction, that is from right to left in the drawings, by the intermediate shaft 6 compared to the transmission 1 of the first embodiment, whereby the torque is transmitted from left to right in the drawings by the in-termediate shaft 6.

The transmission 1' further includes a third gear set 18 which comprises a sixth gear 19 mounted for common rotation about the second input shaft 3 which intermeshes with a seventh gear connected for rotation about the output shaft 7.

The transmission 1' comprises a fourth gear set 21 which com-prises an eighth gear 22 that intermeshes with a ninth gear 23. The eighth gear 22 is connected for rotation about the first input shaft 2. In contrast to the first embodiment, the ninth gear is connected for common rotation about the output shaft 7 rather than for rotation about the intermediate shaft 6.

A fifth gear set 24 comprises a tenth gear 25 intermeshing with an eleventh gear 26. As in the first embodiment, the tenth gear 25 is mounted for common rotation about the first input shaft 2 and the eleventh gear 26 is mounted for rotation about the output shaft 7.

The transmission 1' according to the second embodiment com-prises four synchronizers. Two of the four synchronises are one-way synchronizers and two of the four synchronizers are dual or two-way synchronizers. A first one-way synchronizer 31 is connected to the intermediate shaft 7 so as to be selec-tively engageable with the fifth gear 17 of the second gear set 15.

One of the dual synchronizers 33 is mounted on the second in-put shaft 2 so as to be selectively engageable with either the first gear 12 of the first gear set 11 or with the eighth gear 22 of the fourth gear set 21. Two synchronizers are connected to the output shaft 7. A one-way synchronizer 32 is connected to the output shaft 7 so as to be selectively engageable with the eleventh gear 26 of the fifth gear set 24. A dual synchro- nise at 34 is connected to the output shaft 7 so as to be se-lectively engageable with either the sixth gear 19 of the third gear set 18 or with the reverse gear 27.

The reverse gear 27 intermeshes with the fifth gear 17 of the second gear set 15 and is coplanar with the second gear set 15. The reverse gear 27 is spaced apart from the fourth gear 16 of the second gear set 15.

In the transmission 1' of the second embodiment, the first forward speed ratio is provided by the fifth gear set 24, the second speed ratio and the fifth forward speed ratio are pro-vided by the first gear set 11, the third forward speed ratio is provided by the fourth gear set 21, the fourth forward speed ratio is provided by the third gear set 18 and the sec-ond gear set 15 is used to provide the reverse speed ratio.

Figures 2a to 2f illustrate the torque flow for the five for-ward speed ratios and one reverse speed ratio provided by the transmission 1' which transmit torque from the non-illustrated prime drive, such as an internal combustion engine, to the fi-nal drive illustrated in the figures as a differential 10.

To shift the transmission 1' into the first forward speed ra-tio, the first drive clutch 4 is engaged with the first input shaft 2 and the second drive clutch 5 is disengaged from the second input shaft 3. The first input shaft 2 is driven by the prime drive and torque flow from the prime drive to the second input shaft 3 is interrupted. The third synchronizer 32 is en-gaged with the eleventh gear 26 of the fifth gear set 24.

Torque is transmitted by the first input shaft 2 via the tenth gear 25, the eleventh gear 26 to the output shaft 7 to drive the output shaft, the single output pinion 8, the ring gear 9 and the differential 10.

To shift from the first forward speed to the second forward speed, the first synchronizer 31 is selectively engaged with the fifth gear 17 so as to connect the fifth gear 17 for corn-mon rotation with the intermediate shaft 6. The first drive clutch 4 is disengaged from the first input shaft 2 and the second drive clutch 5 is engaged with the second input shaft 3.

Figure 2b illustrates the torque flow when the second forward speed ratio is selected. Torque is transferred from the prime drive by the second input shaft 3 via the fourth gear 16 and fifth gear 17 of the second gear set 15 to drive the interrne-diate shaft 6 and the first gear set 11 comprising the second gear 13 fixed on the intermediate shaft 6, the first gear 12 which idles about the first input shaft 2, and the third gear 14 fixed on the output shaft 7 so as to drive the output shaft 7, the output pinion 8, ring gear 9 and differential 10. The second gear set 15 is used to transmit the torque from the second input shaft 3 to the intermediate shaft 6 and the first gear set is used to transmit the torque from the intermediate shaft 6 to the output shaft 7 via the first gear 11 idling on the first input shaft 2.

To shift from the second forward speed to the third forward speed, the second synchronizer 33 is selectively engaged with the eighth gear 22 of the fourth gear set 21, the second drive clutch 5 is disengaged from the second input shaft 3 and the first drive clutch 4 is engaged with the first input shaft 2.

Once the third forward speed is selected, as illustrated in Figure 2c, torque is transferred from the prime drive via the first input shaft 2, the eighth gear 22, the ninth gear 23 of the fourth gear set 21 to the output shaft 7 and from the out- put shaft 7 to the differential 10 by means of the output pin-ion S and ring gear 9.

To shift from the third forward speed ratio to the fourth for-ward speed ratio, the fourth synchronizer 34 is selectively engaged with the seventh gear 24 to connect the seventh gear 24 for common rotation with the output shaft 7. The first drive clutch 4 is disengaged from the first input shaft 2 and the second drive clutch 5 is engaged with the second input shaft 3.

The torque flow through the transmission 1' when the fourth forward speed ratio is selected is illustrated in Figure 2d.

Torque from the prime drive is transmitted by the second input shaft 3 to the sixth gear 19 and seventh gear 20 of the third gear set 18 to drive the output shaft 7 and the differential 10 via the output pinion 8 and ring gear 9.

To shift from the fourth forward speed ratio to the fifth for-ward speed ratio, the second synchronizer 33 is selectively engaged with the first gear 12 of the first gear set 11, the second drive clutch 5 is disengaged from the second input shaft 3 and the first drive clutch 4 is engaged with the first input shaft 2.

When the fifth forward speed is selected, torque is transmit-ted, as illustrated in Figure 2e, from the prime drive by the input shaft 2 to the first gear 12 and third gear 14 of the first gear set 11 to drive the output shaft 7, output pinion 8, ring gear 9 and differential 10. Since the first gear 12 also intermeshes with the second gear 13 connected for common rotation about the intermediate shaft 6, the second gear 13 and the intermediate shaft 6 idle when the fifth forward speed is selected.

The reverse speed ratio is provided by selectively engaging the dual synchronizer 34 with the reverse gear 27 so that the reverse gear 27 rotates in common with the output shaft 7. The second drive clutch 5 is engaged with the second input shaft 3 and the first drive clutch 4 is disengaged from the first in-put shaft 2. Torque is transmitted from the prime drive by the second input shaft 3 via the fixed fourth gear 16 and the loose fifth gear 17 of the second gear set 15 to the reverse gear 27 arranged on the output shaft 7 in order that the re-verse gear 27 drives the output shaft 7 since the reverse gear 27 intermeshes with the fifth gear 17.

The torque flow for the reverse speed ratio is illustrated in Figure 2f. Once the reverse speed ratio is selected, the fourth gear 16 mounted for common rotation about the second input shaft 3 drives the reverse gear 27, which is selectively connected to the output shaft 7 for common rotation with the output shaft 7, via the fifth gear 17 which idles about the intermediate shaft 6.

Figures 3a to 3f illustrate a transmission 1'' according to a third embodiment. In the third embodiment, the order of the gear sets of the transmission 1'' and the arrangement of the gears about the intermediate shaft 2, second input shaft 3 and output shaft 7 is the same as in the second embodiment. The third embodiment differs from the second embodiment in the ar-rangement of two of the synchronizers.

In the transmission 1'' of the third embodiment, a one-way synchronizer 32 is arranged on the first input shaft 2 between the eighth gear 22 of the fourth gear set 21 and the first gear 12 of the first gear set 11 on the first input shaft 2 so that the synchronizer 32 is selectively engageable with the first gear 12. A dual synchronizer 33 is mounted on the output shaft 7 so as to be selectively engageable with either the eleventh gear 26 of the fifth gear set 24 or the ninth gear 23 of the fourth gear set 24.

In contrast to the transmission 1' of the second embodiment, in the transmission 1'' of the third embodiment, the eighth gear 22 of the fourth gear set 21 is connected for common ro-tation with the first input shaft 2 and the ninth gear 23 is mounted for rotation with the output shaft 7.

As in the first and second embodiments, the odd forward speed ratios are driven by the first input shaft 2 and the even for-ward speed ratios are driven by the second input shaft 3. The reverse gear 27 is driven by the second input shaft 3 as in the second embodiment.

To shift the transmission 1'' into the first forward speed ra-tio, the first drive clutch 4 is engaged with the first input shaft 2 and the second drive clutch 5 is disengaged from the second input shaft 3. The dual synchronizer 33 is engaged with the eleventh gear 26 of the fifth gear set 24. As illustrated in Figure 3a, torque is transmitted by the first input shaft 2 via the tenth gear 25, the eleventh gear 26 to the output shaft 7 to drive the output shaft, the single output pinion 8, the ring gear 9 and the differential 10.

To shift from the first forward speed to the second forward speed, the first synchronizer 31 is selectively engaged with the fifth gear 17 so as to connect the fifth gear 17 for com-mon rotation with the intermediate shaft 6. The first drive clutch 4 is disengaged from the first input shaft 2 and the second drive clutch 5 is engaged with the second input shaft 3. Torque flow from the prime drive to the first input shaft 2 is interrupted.

When the second forward speed ratio is selected, the torque flow from the prime drive to the final drive is as illustrated in Figure 3b. Torque is transferred from the prime drive by the second input shaft 3 via the fourth gear 16 and fifth gear 17 of the second gear set 15 to drive the intermediate shaft 6 and the first gear set 11 comprising the second gear 13 fixed on the intermediate shaft 6, the first gear 12 which idles about the first input shaft 2, and the third gear 14 fixed on the output shaft 7 to drive the output shaft 7, the output pinion 8, ring gear 9 and differential 10. The second gear set is used to transmit the torque from the second input shaft 3 to the intermediate shaft 6 and the first gear set is used to transmit the torque from the intermediate shaft 6 to the output shaft 7 via the first gear 11 idling on the first input shaft 2.

To shift from the second forward speed to the third forward speed, the second synchronizer 33 is selectively engaged with the ninth gear 23 of the fourth gear set 21 to connect the ninth gear 23 for common rotation with the output shaft 7. The second drive clutch 5 is disengaged from the second input shaft 3 to interrupt the torque flow to the second input shaft 3 and the first drive clutch 4 is engaged with the first input shaft 2.

Once the third forward speed is selected, torque is trans-ferred from the prime drive via the first input shaft 2, the eighth gear 22 and the ninth gear 23 of the fourth gear set 21 to the output shaft 7 and from the output shaft 7 to the dif-ferential 10 by means of the output pinion 8 and ring gear 9, as illustrated in Figure 3c.

To shift from the third forward speed ratio to the fourth for-ward speed ratio, the fourth synchronizer 34 is selectively engaged with the seventh gear 24 to connect the seventh gear 24 for common rotation with the output shaft 7. The first drive clutch 4 is disengaged from the first input shaft 2 thus interrupting the torque flow from the prime drive to the first input shaft 2 and the second drive clutch 5 is engaged with the second input shaft 3.

Figure 3d illustrates the torque flow for the fourth forward speed ratio. Torque from the prime drive is transmitted by the second input shaft 3 to the sixth gear 19 and seventh gear 20 of the third gear set 18 to drive the output shaft 7 and the differential 10 via the output pinion 8 and ring gear 9.

To shift from the fourth forward speed ratio to the fifth for-ward speed ratio, the one-way synchronizer 32 mounted on the first input shaft 2 is selectively engaged with the first gear 12 of the first gear set 11. The second drive clutch 5 is dis-engaged from the second input shaft 3 to interrupt the torque flow from the prime drive to the second input shaft 3 and the first drive clutch 4 is engaged with the first input shaft 2 so that the prime drive now drives the first input shaft 2.

When the fifth forward speed is selected, as illustrated in Figure 3e, torque is transmitted from the prime drive by the input shaft 2 to the first gear 12 and third gear 14 of the first gear set 11 to drive the output shaft 7, output pinion 8, ring gear 9 and differential 10. Since the first gear 12 also intermeshes with the second gear 13 connected for common rotation about the intermediate shaft 6, the second gear 13 and the intermediate shaft 6 idle when the fifth forward speed is selected.

The reverse speed ratio is provided by selectively engaging the dual synchronizer 34 with the reverse gear 27 so that the reverse gear 27 rotates in common with the output shaft 7. The second drive clutch 5 is engaged with the second input shaft 3 and the first drive clutch 4 is disengaged from the first in-put shaft 2.

As illustrated in Figure 3f, torque is transmitted from the prime drive by the second input shaft 3 via the fourth gear 16 and fifth gear 17 of the second gear set 15 to the reverse gear 27 arranged on the output shaft 7 since the reverse gear 27 intermeshes with the fifth gear 17. Once the reverse speed ratio is selected, the fourth gear 16 mounted for common rota-tion about the second input shaft 3 drives the reverse gear 27 that is selectively connected to the output shaft 7 for common rotation with the output shaft 7 via the fifth gear 17 which idles about the intermediate shaft 6.

Figures 4a to 4f illustrate a transmission 1''' according to a fourth embodiment. The arrangement of the gear sets and syn-chronizers is the same as in the third embodiment. The fourth embodiment differs from the third embodiment in that the even gears are coupled to the first input shaft 2 and the odd gears are coupled to the second input shaft 3. This is the opposite arrangement as in the third embodiment. The reverse speed ra- tio is driven by the second input shaft 3 as in the transmis-sions 1', 1'' of the second and third embodiments.

In the fourth embodiment, the first gear set 11 is used to provide the first forward speed ratio and the fifth forward speed ratio. The second speed ratio is provided by the fifth gear set 24, the third speed ratio by the third gear set 18, the fourth forward speed ratio by the fourth gear set 21. The reverse speed ratio is provided by the second gear set 15 as in the second and third embodiments.

To shift the transmission 1''' into the first forward speed ratio, the first synchronizer 31 is selectively engaged with the fifth gear 17 so as to connect the fifth gear 17 for com-mon rotation with the intermediate shaft 6. The second drive clutch 5 is engaged with the second input shaft 3 and the first drive clutch 4 is disengaged from the first input shaft 3. Torque to the first input shaft 2 is interrupted and the second input shaft 3 is driven by the prime drive.

When the first forward speed ratio is selected, the torque flow is as illustrated in Figure 4a. Torque is transferred from the prime drive by the second input shaft 3 via the fourth gear 16 and fifth gear 17 of the second gear set 15 to drive the intermediate shaft 6. The intermediate shaft 6 drives the output shaft 7 via the first gear set 11 comprising the second gear 13 fixed on the intermediate shaft 6, the first gear 12 which idles about the first input shaft 2, and the third gear 14 fixed on the output shaft 7. The output shaft 7 drives the output pinion 8, ring gear 9 and differen-tial 10. The second gear set 15 is used to transmit the torque from the second input shaft 3 to the intermediate shaft 6 and the first gear set 11 is used to transmit the torque from the intermediate shaft 6 to the output shaft 7 via the first gear 11 idling on the first input shaft 2.

To shift from the first forward speed ratio to the second for-ward speed ratio, the synchronizer 33 connected to the output shaft 7 is engaged with the eleventh gear 26 of the fifth gear set 24. The second drive clutch 5 is disengaged from the sec-ond input shaft 3 thus interrupting the torque flow from the prime drive to the second input shaft 3 and the first drive clutch 4 is engaged with the first input shaft 3.

When the second forward speed ratio is selected, torque is transmitted by the second input shaft 2 via the tenth gear 25, the eleventh gear 26 to the output shaft 7 to drive the output shaft, the single output pinion 8, the ring gear 9 and the differential 10, as illustrated in Figure 4b.

To shift from the second forward speed to the third forward speed, the fourth synchronizer 34 is selectively engaged with the seventh gear 24 to connect the seventh gear 24 for common rotation with the output shaft 7. The first drive clutch 4 is disengaged from the first input shaft 2 and the second drive clutch 5 is engaged with the second input shaft 3.

The Torque flow for the third forward speed ratio is illus- trated in Figure 4c. Torque from the prime drive is transmit- ted by the second input shaft 3 to the sixth gear 19 and sev-enth gear 20 of the third gear set 18 to drive the output shaft 7 and the differential 10 via the output pinion 8 and ring gear 9.

To shift from the third forward speed ratio to the fourth for-ward speed ratio, the synchronizer 33 is selectively engaged with the ninth gear 22 of the fourth gear set 21, the second drive clutch 5 is disengaged from the second input shaft 3 in-terrupting the torque flow from the prime drive to the second input shaft 3 and the first drive clutch 4 is engaged with the first input shaft 2. The prime drive now drives the first in-put shaft 2.

As illustrated in Figure 4d, once the third forward speed is selected, torque is transferred from the prime drive via the first input shaft 2, the eighth gear 22, the ninth gear 23 of the fourth gear set 21 to drive the output shaft 7 and from the output shaft 7 to the differential 10 by means of the out-put pinion 8 and ring gear 9.

To shift from the fourth forward speed ratio to the fifth for-ward speed ratio, the synchronizer 32 connected to the first input shaft 2 is selectively engaged with the first gear 12 of the first gear set 11. The second drive clutch 5 is disengaged from the second input shaft 3 and the first drive clutch 4 is engaged with the first input shaft 2.

The torque flow for the fifth forward speed is illustrated in Figure 4e. Torque is transmitted from the prime drive by the input shaft 2 to the first gear 12 and third gear 14 of the first gear set 11 to drive the output shaft 7, output pinion 8, ring gear 9 and differential 10. Since the first gear 12 also intermeshes with the second gear 13 connected for common rotation about the intermediate shaft 6, the second gear 13 and the intermediate shaft 6 idle when the fifth forward speed is selected.

The reverse speed ratio is provided by selectively engaging the dual synchronizer 34 with the reverse gear 27 so that the reverse gear 27 rotates in common with the output shaft 7. The synchronizer 31 on the intermediate shaft 6 is disengaged from the fifth gear 17 so that the fifth gear 17 idles. The second drive clutch 5 is engaged with the second input shaft 3 and the first drive clutch 4 is disengaged from the first input shaft 2.

The torque flow for the reverse speed ratio is illustrated in Figure 4f. Torque is transmitted from the prime drive by the second input shaft 3 via the fixed fourth gear 16 and loose fifth gear 17 of the second gear set 15 to the reverse gear 27 arranged on the output shaft 7 since the reverse gear 27 in-termeshes with the fifth gear 17 in order that the reverse gear 27 drives the output shaft 7. Once the reverse speed ra- tio is selected, the fourth gear 16 mounted for common rota-tion about the second input shaft 3 drives the reverse gear 27 that is selectively connected to the output shaft 7 for common rotation with the output shaft 7 via the fifth gear 17 which idles about the intermediate shaft 6.

Figure 5 illustrates the gear ratios provided by the transmis-sions of embodiments 2 to 4 illustrated in Figures 2a to 2f, 3a to 3f and 4a to 4f, respectively.

The provision of an intermediate shaft 6 and the dual purpose of the first gear set 11 and second gear set 15 in all of the embodiments provides a dual clutch transmission which is com-pact and particularly suitable for micro-mini-and small cars in which the space available is particularly restricted.

Reference numbers J; 1'; 1''; 1''' transmission 2 first input shaft 3 second input shaft 4 first drive clutch second drive clutch 6 intermediate shaft 7 output shaft 8 output pinion 9 ring gear differential 11 first gear set 12 first gear 13 second year 14 third gear second gear set 16 fourth gear 17 fifth gear 18 third gear set 19 sixth gear seventh gear 21 fourth gear set 22 eighth gear 23 ninth gear 24 fifth gear set tenth gear 26 eleventh gear 27 reverse gear 28 first two-way synchronizer 29 second two-way synchronizer third to two-way synchronizer 31 first one-way synchronizer 32 second one-way synchronizer 33 first two-way synchronizer 34 second two-way synchronizer