CN201448405U - A dual-clutch automatic transmission - Google Patents

Abstract

The utility model relates to a dual-clutch automatic transmission, which comprises an input shaft, a reverse gear reversing shaft and a power output device. Two main shafts arranged in line with the input shaft are respectively set on both sides of the input shaft. The input shaft between the two main shafts is Support bearings are installed on the upper shaft; clutches, main shaft angle sensors, reverse drive gears, and forward odd-numbered drive gears are arranged on the two main shafts in sequence, and the reverse gear reversing gear is connected to the reverse gear reversing shaft, and the reverse reversing gear is connected with the The reverse drive gear on the main shaft is meshed; the power take-off device includes a main power take-off shaft and an output shaft, one end of the main power take-off shaft is connected with a main power take-off shaft angle sensor, and a differential is connected between the main power take-off shaft and the output shaft ; There is a reverse gear driven gear on the main power output shaft, and a forward gear driven gear meshed with the forward gear driving gears provided on the two main shafts respectively. It has small volume, few gears, compact structure, light weight and wide transmission power range, and is suitable for use in automobiles.

Description

A dual-clutch automatic transmission

technical field

The utility model relates to a vehicle speed changer, in particular to a double-clutch automatic speed changer without a mechanical synchronizer.

Background technique

The existing dual-clutch automatic transmission includes two clutches, a mechanical shift synchronizer, a shift control system, an electronic control system TCU, and a six-speed transmission. Usually, two wet clutches are combined into an integrated dual clutch, which are respectively fixed on On the two main shafts, the driving gears of the odd and even gears of the transmission are respectively driven and connected with two wet clutches. The two clutches alternately transmit working power to realize switching between gears. This speed change mechanism has the following disadvantages: Since the two wet-type off-stage devices are combined and fixed on the input shaft, although the axial dimension is shortened to a certain extent, due to the use of a mechanical shift synchronizer, the axial length is shortened while the axial length is shortened. A three-axis transmission system has been formed, and the radial dimension increases greatly. This structure makes the structure of the transmission more complicated. At the same time, the combined dual clutch has a complex structure and a larger volume, which increases the difficulty of maintenance. This makes the transmission of this transmission more complicated. The volume and weight are still large, the structure tends to be complicated, and the price tends to be expensive, so it is not suitable for installation on small cars and economical cars.

Contents of the invention

The purpose of the utility model is to provide a dual-clutch automatic transmission without a mechanical shift synchronizer, which has a simple structure, low cost, a small number of gears, and a wide output power range.

The technical idea of this utility model is to set two main shafts, which are respectively fixed on both ends of the input shaft by support bearings, and are set together with the input shaft, and the odd gears are located on the first main shaft, and the even gears are located on the second main shaft. Regardless of upshift speed regulation or downshift speed regulation, it can ensure that the power transmission can be carried out continuously. There is no mechanical synchronizer in the shifting of automatic transmission, and the shifting of all gears is realized by separately controlling the meshing of each driven gear with the matched braking gear, which shortens the displacement distance of the driven gear and reduces the size of the transmission , to expand the speed range, the transmission output power output through the differential.

In order to achieve the above tasks, the utility model takes the following technical solutions:

A dual-clutch automatic transmission, comprising an input shaft, a reverse gear reversing shaft and a power output device, is characterized in that one end of the input shaft is connected to the power output end of the engine, and the other end is connected to the power input end of the oil pump; The first main shaft and the second main shaft arranged in line with the input shaft are respectively sleeved on the side, and a supporting bearing is installed on the input shaft between the first main shaft and the second main shaft;

The first main shaft is sequentially provided with a first clutch, a first main shaft angle sensor, a reverse drive gear and at least one odd-numbered forward drive drive gear, wherein the first clutch is located in the stator coil of the first reversing synchronous motor;

The second main shaft is sequentially provided with a second clutch, a second main shaft angle sensor and at least one even-numbered forward drive gear, wherein the second clutch is located in the stator coil of the second reversing synchronous motor;

The reverse gear reversing shaft is connected with a reverse gear reversing gear, and the reverse gear reversing gear meshes with the reverse gear driving gear on the first main shaft;

The power output device includes a main power output shaft and an output shaft, one end of the main power output shaft is connected with a main power output shaft angle sensor, and a differential is connected between the main power output shaft and the output shaft; The reverse gear driven gear, and the forward gear driven gear respectively meshed with the forward gear driven gears provided on the first main shaft and the second main shaft.

The technical effect brought by the dual-clutch automatic transmission of the present utility model is:

(1) Due to the dual-clutch structure, the odd-numbered gears are located on the first main shaft, and the even-numbered gears are located on the second main shaft. No matter whether the speed is upshifted or downshifted, the power transmission can be guaranteed continuously. Greatly improved operating comfort and economical use;

(2) The structure of the double-clutch separation arrangement can well bring out the advantages of the traditional clutch, and it is also easy to use and maintain;

(3) The first main shaft and the second main shaft are arranged at intervals, and are fitted together with the input shaft, so that the structure of the transmission is simple, reasonable and compact, and the radial size of the transmission is reduced. Compared with the traditional manual transmission, the weight is basically the same;

(4) The dual-clutch automatic transmission uses an angle sensor to measure the gear position, eliminating the need for a mechanical synchronizer in an ordinary gear transmission. The gear shift is carried out in an electric drive mode, and the gear shift is rapid and accurate without shifting impact, which improves the operating comfort performance and transmission life.

(5) The dual-clutch automatic transmission adopts traditional clutches and gears to transmit power to ensure that the transmission can be used for power transmission in a wide range from small power to high power, and is suitable for different types of vehicles from small cars to heavy vehicles.

(6) Since the mechanical shift synchronizer is omitted and the electric drive is used for synchronous shifting, the number and weight of the mechanical parts of the transmission are reduced, and the reliability of the transmission is greatly improved.

(7) The first gear and the reverse gear of the utility model share a driven gear, which makes the structure of the transmission more compact, the number of gears is less, and the weight of the transmission is effectively reduced.

In a word, the structure of the automatic transmission of the present invention has fewer transmission gears and a small size of the whole machine, which not only greatly improves the working comfort of the transmission, but also improves the transmission performance of the transmission and simplifies the structure. Suitable for use on cars.

Description of drawings

Fig. 1 is the structural representation of an embodiment of the utility model, and this embodiment is a six forward gears, a reverse gear speed changer;

FIG. 2 is a schematic side view of FIG. 1 .

The marks in the figure respectively indicate: 1. Input shaft; 2. Angle sensor of the first main shaft; 3. First clutch; 4. Stator coil of the first reversing synchronous motor; 5. Support bearing of the first main shaft; 6. Active reverse gear Gear; 7. Drive gear for first gear forward; 8. Drive gear for third gear forward; 9. Drive gear for fifth gear forward; 10. First main shaft; 11. Input shaft support bearing: 12. Second main shaft; 13. Second gear forward Driving gear; 14. Forward fourth-speed driving gear; 15. Forward sixth-speed driving gear; 16. Second gear shift synchronous motor stator coil; 17. Second clutch; 18. Second main shaft angle sensor; 19. Oil pump; 20. Power take-off shaft; 21, differential; 22, forward sixth gear driven gear; 23, forward fourth gear driven gear; 24, forward second gear driven gear; 25, forward fifth gear driven gear; 26, forward third gear Gear driven gear; 27, forward first gear, reverse gear driven gear; 28, main PTO angle sensor; 29, main PTO shaft; 30, reverse reversing gear; 31, support of main PTO shaft 29 bearings.

Below in conjunction with accompanying drawing, the utility model is described in further detail.

Detailed ways

Referring to Fig. 1, Fig. 1 is a structural schematic diagram of an embodiment of the present invention, including a dual-clutch automatic transmission with six forward gears and one reverse gear. It includes an input shaft 1, a reverse gear reversing shaft and a power output device. One end of the input shaft 1 is connected to the power output end of the engine, and the other end is connected to the power input end of the oil pump 19; The first main shaft 10 and the second main shaft 12 arranged coaxially, the first main shaft 10 and the second main shaft 12 are hollow shafts, and a supporting bearing 11 is installed on the input shaft 1 between the first main shaft 10 and the second main shaft 12; Both ends of a main shaft 10 and a second main shaft 12 are fixed by support bearings 5 respectively; the input shaft 1 is a solid straight shaft passing through the first clutch 3 and the second clutch 17 .

The first main shaft 10 is provided with the first clutch 3, the first main shaft angle sensor 2, the reverse gear driving gear 6, the forward first gear driving gear 7, the forward third gear driving gear 8, and the forward fifth gear driving gear 9 from left to right. And the reverse reversing gear 30, wherein the first clutch 3 is located in the stator coil 4 of the first reversing synchronous motor;

The second main shaft 12 is provided with a second clutch 17, a second main shaft angle sensor 18, a forward six-speed driving gear 15, a forward fourth-speed driving gear 14, and a forward second-speed driving gear 13 from right to left, wherein the second clutch 17 is located in the stator coil 16 of the second commutation synchronous motor;

The reverse gear reversing shaft is connected with a reverse gear reversing gear 30, and the reverse gear reversing gear 30 meshes with the reverse gear driving gear 6 on the first main shaft 10;

The power take-off device comprises a main power output shaft 29 and an output shaft 20, and one end of the main power output shaft 29 is connected with a main power output shaft angle sensor 28, and a differential 21 is connected between the main power output shaft 29 and the output shaft 20; The output shaft 29 has the reverse drive gear 6, the drive gear 7 for the first gear, the drive gear 8 for the third gear, the drive gear 9 for the fifth gear, and the drive gear for the sixth gear that are respectively arranged on the first main shaft 10 and the second main shaft 12. 15. Forward fourth gear driving gear 14, forward second gear driving gear 13 meshing forward first gear, reverse driven gear 27, forward third gear driven gear 26, forward fifth gear driven gear 25, forward second gear Driven gear 24, forward fourth gear driven gear 23, forward sixth gear driven gear 22.

The reverse reversing gear 30 transmits power to the reverse driven gear 27 on the main power output shaft 29 , and transmits power to the output shaft 20 through the differential 21 .

The driving gear 7 of forward first gear and the driving gear 6 of reverse gear share a driven gear 27 .

The first main shaft 10 and the first clutch 3 constitute a first shifting synchronous motor integrated rotor; the second main shaft 12 and the second clutch 17 constitute a second shifting synchronous motor integrated rotor.

The first main shaft angle sensor 2 and the main power output shaft angle sensor 28 are jointly used to measure the meshing position of the odd gear and the reverse gear, so as to ensure correct gear shifting; the second main shaft angle sensor 18 and the main power output shaft angle The sensors 28 are commonly used to measure the meshing position of the driving and driven gears of the even gears to ensure correct gear shifting.

The forward sixth gear driven gear 22 installed on the active power output shaft 29, the forward fourth gear driven gear 23, the forward second gear driven gear 24, the forward five gear driven gear 25, the forward third gear driven gear 26, the forward first gear. Gear, reverse gear driven gear 27 are connected by spline, and slide left and right along output shaft 29.

The forward sixth gear driven gear 22 installed on the active power output shaft 29, the forward fourth gear driven gear 23, the forward second gear driven gear 24, the forward five gear driven gear 25, the forward third gear driven gear 26, the forward first gear. Gear and reverse gear driven gear 27 are also provided with respective shifting and position locking control mechanisms (not shown in the figure), which are connected to the first main shaft angle sensor 2, the second main shaft angle sensor 18 and the main power output shaft angle. The sensors 28 cooperate to adjust the rotational speeds of the corresponding driving gears respectively at the stator coil 4 of the first commutation synchronous motor and the stator coil 16 of the second commutation synchronous motor.

Both sides of the main power output shaft 29 are supported by support bearings 31 .

The first clutch 3 and the second clutch 17 are wet or dry clutches.

In order to save the space of the transmission and reduce the volume of the transmission, the first main shaft 10 and the second main shaft 12 are arranged at intervals and fitted on the input shaft 1. The radial dimension is greatly reduced without increasing the axial dimension. , Changing the general dual-clutch three-shaft transmission into a two-shaft dual-clutch transmission, the overall volume and weight of the transmission are basically the same as the traditional manual transmission.

The working principle of the six-speed automatic dual-clutch automatic transmission of this embodiment is: when the vehicle is at rest, because the first clutch 3 and the second clutch 17 are in a disengaged state, no power is transmitted.

Upshifting process:

When the first gear needs to be obtained, the shift mechanism (not shown in the figure) (under the driving cooperation of the gearshift synchronous motor stator coil 4) pre-flicks the first gear driven gear 27 and hangs up the first gear driving gear 7, and the first gear hangs up. After that, the first clutch 3 is closed, the engine power is transmitted to the first main shaft 10 through the first clutch 3, the driving gear 7 of the first gear on the first main shaft 10 is meshed and transmitted to the driven gear 27 of the first gear, and the input power is driven by the first gear through the first gear. The moving gear 27 is transmitted to the main power output shaft 29 through variable speed, and then the output shaft 20 is driven by the differential 21 to output first gear power. At this time, the forward second speed driven gear 24 coaxial with the forward first speed driven gear 27 rotates synchronously. Next, the customized coil 16 of the second reversing synchronous motor drives the second main shaft 12 to rotate. Toggle the forward second gear driven gear 24 in advance, hang up the forward second gear driving gear 13, after hanging the second gear, the second reversing synchronous motor stator coil 16 stops working, and the second main shaft 12 advances the second gear driven gear 24 Drive forward second gear driving gear 13 to rotate, and then drive the second main shaft to rotate. First gear power transmission.

When the second gear needs to be obtained, the shifting mechanism (not shown in the figure) has engaged the second gear in advance as mentioned above, and first disengages the first clutch 3. After the first clutch 3 is disengaged, the first gear meshing gear exits the power transmission, and at the same time When the second clutch 17 is closed, the first clutch 3 is completely disengaged before the second clutch 17 is closed, which does not affect the closing of the second clutch. After the second clutch is closed, the input power is transmitted to the second-speed driving gear 13 through the second clutch 17 , and mesh with the second gear driven gear 24 to drive the main power output shaft 29 to rotate, and then drive the output shaft 20 through the differential 21 to output the second gear power. After the second clutch 17 is closed, the stator coil 4 of the first reversing synchronous motor drives its rotor (that is, the first clutch 3), so that the forward third gear driven gear 8 and the main power output shaft 29 rotate synchronously. The gears 26 are in the same phase, and the shift mechanism (not shown in the figure) drives the forward third gear driven gear 26 to mesh with the forward third gear driving gear 8, and the third gear is engaged in advance. After the third gear is engaged, the first reversing synchronous motor The stator coil 4 stops working. At this moment, the third gear is pre-engaged, and the third gear driving gear 8 and the first main shaft 10 are driven by the second gear driven gear 24 to rotate freely without affecting the second gear power transmission.

When the third gear needs to be obtained, the shift mechanism (not shown in the figure) has engaged the third gear in advance as previously mentioned, and first disengages the second clutch 17. After the second clutch 17 is disengaged, the second gear meshing gear exits the power transmission, and at the same time When the first clutch 3 is closed, the second clutch 17 is completely separated before the first clutch 3 is closed, which does not affect the closing of the first clutch. After the first clutch 3 is closed, the input power is transmitted to the third-speed driving gear 8 through the first clutch 3 , and mesh with the forward driven gear 26 to drive the main power output shaft 29 to rotate, and then drive the output shaft 20 through the differential 21 to output third gear power. After the first clutch 3 is closed, the second reversing synchronous motor stator coil 16 drives its rotor (that is, the second clutch 17), so that the forward fourth gear driven gear 14 and the forward fourth gear driven gear 29 rotate synchronously with the main power output shaft 29. 23 are in the same phase, the shift mechanism (not shown in the figure) drives the forward fourth gear driven gear 23 to mesh with the forward fourth gear driving gear 14, and the fourth gear is engaged in advance. After the fourth gear is engaged, the second reversing synchronous motor stator Coil 16 stops working, and at this moment, completes the pre-engagement gear of 4th gear, advances 4th gear driving gear 14 and second main shaft 12 freely rotates under the drive of 3rd gear driven gear 26, does not affect 3rd gear power transmission.

When the fourth gear needs to be obtained, the gearshift mechanism (not shown) has engaged the fourth gear in advance as previously mentioned, and first disengages the first clutch 3, and the first clutch 3 is completely disengaged before the second clutch 17 is closed. Affects the closing of the second clutch. After the first clutch 3 is separated, the meshing gear 8 of the forward third gear exits the power transmission, and at the same time closes the second clutch 17. After the second clutch 17 is closed, the input power is transmitted to the forward fourth gear through the second clutch 17 Driving gear 14, and meshes with forward fourth gear driven gear 23, drives main power output shaft 29 to rotate, drives output shaft 20 to output fourth gear power through differential gear 21 again. After the second clutch 17 is closed, the stator coil 4 of the first reversing synchronous motor drives its rotor (that is, the first clutch 3), so that the forward five-speed driven gear 9 and the main power output shaft 29 rotate synchronously. 25 are in the same phase, and the shift mechanism (not shown in the figure) drives the driven gear 25 of the fifth forward gear to mesh with the driving gear 9 of the fifth forward gear. Coil 4 stops work, and at this moment, finish five gears pre-engaged gear, advance five gears driving gear 9 and first main shaft 10 freely rotate under the drive of forward four gears driven gear 23, do not affect forward four gears power transmission.

When the fifth gear needs to be obtained, the shifting mechanism (not shown) has engaged the fifth gear in advance as previously mentioned, and first disengages the second clutch 17, and the second clutch 17 disengages the forward fourth gear driving gear 14 and the forward fourth gear that are engaged. The gear driven gear 23 exits the power transmission and closes the first clutch 3 at the same time. After the first clutch 3 is closed, the input power is transmitted to the forward five-speed forward driving gear 9 through the first clutch 3, and meshes with the forward driven gear 25. Drive the main power output shaft 29 to rotate, then drive the output shaft 20 through the differential 21 to output fifth gear power. After the first clutch 3 is closed, the second reversing synchronous motor stator coil 16 drives its rotor (that is, the second clutch 17), so that the forward six-speed driven gear 15 and the main power output shaft 29 rotate synchronously. 22 are in the same phase, the shift mechanism (not shown in the figure) drives the forward sixth gear driven gear 22 to mesh with the forward sixth gear driving gear 15, and the sixth gear is engaged in advance. After the sixth gear is engaged, the second reversing synchronous motor stator Coil 16 stops working, and at this moment, finish six gears pre-engagement gear, forward six gears driving gear 15 and second main shaft 12 freely rotate under the drive of forward five gears driven gear 25, do not affect forward five gears power transmission.

When the sixth gear needs to be obtained, the shift mechanism (not shown in the figure) has engaged the sixth gear in advance as previously mentioned, and first disengages the first clutch 3, and the first clutch 3 is completely disengaged before the second clutch 17 is closed. Affects the closing of the second clutch. After the first clutch 3 is separated, the forward fifth-speed meshing gear exits power transmission, and at the same time closes the second clutch 17. After the second clutch 17 is closed, the input power is transmitted to the sixth-speed driving gear through the second clutch 17 15, and meshes with the driven gear 22 to drive the main power output shaft 29 to rotate, and then drive the output shaft 20 through the differential 21 to output sixth gear power. After the second clutch 17 was closed, because it had reached the highest gear position, it kept the first main shaft 10 hanging up the fifth gear, and got ready for downshifting operation. Now, five gears are pre-engaged, and the driving gear 9 of the fifth gear and the first main shaft 10 rotate freely under the drive of the driven gear 22 of the sixth gear forward, without affecting the power transmission of the sixth gear forward.

The reverse gear operation is similar to the first gear operation. When the reverse gear is needed, the shift mechanism (not shown) is pre-engaged with the reverse gear driving gear 6, the reverse gear driven gear 27 is engaged with the reversing wheel 30, and the first clutch 3 is closed, the second clutch 17 is disengaged, the power is transmitted to the first main shaft 10, the reverse drive gear 6 meshes with the reverse shifting wheel 30 and rotates, and the reverse shifting wheel 30 meshes with the reverse driven gear 27 to rotate, thereby driving the driving force The output shaft 29 rotates, and then the output shaft 20 is driven by the differential 21 to output reverse gear power.

Downshifting process: The downshifting process is similar to the above-mentioned upshifting process, except that the operation steps of the clutch and gear selection are opposite to the above process. When shifting gears, first disengage the gear that is being engaged, and then close the pre-engaged gear. After the pre-engaged gear is closed, pre-engage the lower gear until the lowest gear is reached.

Skip gear operation: Skip gear shift operation can be divided into upshift operation and downshift operation, which is a combined operation of the above-mentioned up-down gear operation. The process and steps are similar to the above-mentioned up-speed shift or down-speed shift operation. Here No longer.

The utility model is not limited to the above embodiments, as long as the power output device of the automatic transmission with dual off-stage devices includes a gear shift mechanism without a mechanical synchronizer, the double clutch adopts a separate arrangement, and also serves as a gear shift synchronous motor rotor, and the angle sensor synchronizes each Gear gear meshing should be regarded as the protection scope of the present utility model.

Claims (10)

1. a dual-clutch automatic transmission, comprising an input shaft (1), a reverse gear reversing shaft and a power take-off, is characterized in that one end of the input shaft (1) is connected to the power output end of the engine, and the other end is connected to the oil pump ( 19) at the power input end; the first main shaft (10) and the second main shaft (12) arranged in line with the input shaft (1) are respectively set on both sides of the input shaft (1), and the first main shaft (10) A supporting bearing (11) is installed on the input shaft (1) between the second main shaft (12); The first main shaft (10) is sequentially provided with a first clutch (3), a first main shaft angle sensor (2), a reverse drive gear (6) and at least one forward odd-numbered drive gear, wherein the first clutch (3) located in the stator coil (4) of the first reversing synchronous motor; The second main shaft (12) is sequentially provided with a second clutch (17), a second main shaft angle sensor (18) and at least one forward even-numbered driving gear, wherein the second clutch (17) is located in the second commutation In the synchronous motor stator coil (16); The reverse gear reversing shaft is connected with a reverse gear reversing gear (30), and the reverse gear reversing gear (30) is meshed with the reverse gear driving gear (6) on the first main shaft (10); Described power output device comprises main power output shaft (29) and output shaft (20), main power output shaft (29) one end is connected with main power output shaft angle sensor (28), main power output shaft (29) and output A differential (21) is connected between the shafts (20); a reverse gear driven gear (27) is arranged on the main power output shaft (29), and is set on the first main shaft (10) and the second main shaft (12) The forward gear driven gear of the forward gear is meshed with the forward gear driven gear respectively. 2. The dual-clutch automatic transmission according to claim 1, characterized in that the reverse gear (30) transmits power to the reverse driven gear (27) on the main power output shaft (29) , and transmit power to the output shaft (20) through the differential (21). 3. The dual-clutch automatic transmission as claimed in claim 1, characterized in that, said odd-numbered and even-numbered forward driving gears include a forward first gear driving gear (7), a forward second gear driving gear (13), and a forward third gear driving gear. Gear (8), forward four gears driving gear (14), forward five gears driving gear (9), forward six gears driving gear (15). 4. The dual-clutch automatic transmission according to claim 3, characterized in that, the first forward gear (7) and the reverse gear (6) share a driven gear (27). 5. The dual-clutch automatic transmission according to claim 1, characterized in that, the first main shaft (10) and the second main shaft (12) are hollow shafts, and the input shaft (1) runs through the first Solid straight shaft for clutch (3) and second clutch (17). 6. The double-clutch automatic transmission according to claim 1, characterized in that, the first main shaft (10) and the first clutch (3) constitute a first shift synchronous motor integrated rotor; the second main shaft (12) and the second clutch (17) constitute the second shift synchronous motor integrated rotor. 7. The dual-clutch automatic transmission according to claim 1, characterized in that, the first main shaft angle sensor (2) and the main power output shaft angle sensor (28) are jointly used to measure odd gears and reverse gears The meshing position of the main and driven gears to ensure correct shifting; the second main shaft angle sensor (18) and the main PTO shaft angle sensor (28) are used together to measure the meshing position of the driving and driven gears in even gears to ensure correct gear shifting. shift gears. 8. The dual-clutch automatic transmission according to claim 1, characterized in that, the forward driven gear and the reverse driven gear installed on the main power output shaft (29) are connected by splines, and along the Output shaft (29) slides left and right. 9. The dual-clutch automatic transmission according to claim 1, characterized in that: the forward driven gear and the reverse driven gear installed on the main power output shaft (29) are also provided with their own shifting and position Locking control mechanisms, they cooperate with the first main shaft angle sensor (2), the second main shaft angle sensor (18) and the main power output shaft angle sensor (28), respectively in the first reversing synchronous motor stator coil (4) and the second The stator coil (16) of the two-way commutation synchronous motor adjusts the speed of the corresponding driving gear. 10. The dual-clutch automatic transmission according to claim 1, characterized in that, the first clutch (3) and the second clutch (17) are wet or dry clutches.

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