CN107917167A - Eight fast double-clutch automatic gearboxes - Google Patents

Abstract

The invention discloses an eight-speed dual-clutch automatic transmission, which includes a double clutch, first and second input shafts, first and second output shafts and a differential, and the first and second input shafts are arranged coaxially; One input shaft is fixed with a reverse gear, fifth gear and third gear driving gear; the second input shaft is fixed with sixth gear, fourth gear and second gear driving gear; the first output shaft is fitted with first gear, fifth gear and sixth gear 1. Second gear driven gear, the second output shaft is equipped with reverse gear, seventh gear, third gear and fourth gear driven gear; the first output shaft is equipped with first gear, fifth gear, second gear and sixth gear synchronizer, the The second output shaft is equipped with synchronizers for reverse gear, seventh gear, third gear and fourth gear, and the eighth gear synchronizer is fixed on the fifth gear driven gear; the first and second output shafts are driven by the first and second main reduction gears. The gears and the final reduction gear are connected to the differential. The invention effectively shortens the axial length and radial length of the transmission, and simplifies the structure.

Description

Eight-speed dual-clutch automatic transmission

technical field

The invention relates to the field of vehicle transmission systems, in particular to an eight-speed dual-clutch automatic transmission applied to vehicles powered by internal combustion engines.

Background technique

In the process of development, automobiles powered by internal combustion engines are faced with the challenge of continuously improving efficiency while ensuring power and comfort. Compared with traditional hydraulic torque converter and planetary gear automatic transmission, dual clutch automatic transmission has higher efficiency and shorter shift time, which has obvious advantages. Generally speaking, a dual-clutch automatic transmission with more gears can increase the transmission ratio range, which is beneficial to increase the wheel torque at start and reduce the engine operating speed, thereby improving the system efficiency and power performance of the powertrain. However, as the number of gears increases, the size of the transmission inevitably increases. Especially for front-wheel-drive models, the increase in the size of the transmission will bring difficulties to the layout of the vehicle.

Therefore, reducing the size of the dual-clutch automatic transmission as far as possible becomes the main goal of many existing inventions or utility models. Take "A Dual Clutch Automatic Transmission for Vehicles" (CN201310442936) disclosed in the Chinese patent literature as an example, there are only 4 gears on the input axis, which makes the axial length short. However, since there are too many driving gears in common, and the driving gears are the weaker gears in the gear pair, the difficulty of gear design is increased and the reliability of the transmission is reduced.

Contents of the invention

In order to solve the above-mentioned defects in the existing dual-clutch transmission technology, the present invention proposes an eight-speed dual-clutch automatic transmission with short axial dimension, small radial dimension and simple and compact structure.

Technical scheme of the present invention is realized like this:

An eight-speed dual clutch automatic transmission comprising a dual clutch, a first input shaft, a second input shaft, a first output shaft, a second output shaft and a differential,

The dual clutch includes a first automatic clutch and a second automatic clutch, two input shafts and two output shafts are arranged parallel to each other, the first input shaft is connected to the first automatic clutch, and the second The two input shafts are connected with the second automatic clutch, the first input shaft and the second input shaft are coaxially arranged, the first input shaft is inside, the second input shaft is outside, and the The first input shaft protrudes from the second input shaft at an end away from the dual clutch;

The first input shaft is fixed with a driving gear for reverse gear, driving gear for fifth and seventh gears, and driving gear for third gear. The sixth-speed driving gear, the fourth-speed driving gear, and the second-speed driving gear are fixed on the second input shaft; Any two of gears, second gear driven gears, and fourth gear driven gears, the second output shaft is fitted with reverse gear driven gears, seventh gear driven gears, third gear driven gears and sixth gear driven gears. gear, second gear driven gear, and fourth gear driven gear that are not set on the first output shaft; the first output shaft is provided with a first gear synchronizer, a fifth gear synchronizer, a sixth gear synchronizer, a second gear Any two of the synchronizer and the fourth gear synchronizer, the second output shaft is provided with a reverse gear synchronizer, a seventh gear synchronizer, a third gear synchronizer, a sixth gear synchronizer, a second gear synchronizer and a fourth gear synchronizer One of the gears that is not installed on the first output shaft, and an eighth-speed synchronizer is provided on the fifth-speed driven gear, and the eighth-speed synchronizer is connected with the sixth-speed driven gear on the first output shaft Or the fourth-speed driven gear or the second-speed driven gear is engaged and disengaged; the end of the first output shaft close to the dual clutch is fixed with the first main deceleration driving gear, and the end of the second output shaft close to the double clutch is fixed with the second Two main reduction driving gears, the first main reduction driving gear and the second main reduction driving gear mesh with a main reduction gear at the same time, and the main reduction gear is fixed on the differential.

Further, the first reverse driving gear is arranged on the first input shaft farthest from the dual clutch, and the first output shaft is correspondingly fitted with the first reverse driving gear. driven gear, and a corresponding first-speed synchronizer is arranged, and a reverse-speed driven gear meshed with the first-speed driven gear is correspondingly sleeved on the second output shaft, and a corresponding reverse-speed synchronizer is arranged.

Further, the driving gear of fifth and seventh gears is arranged between a driving gear of reverse gear and driving gear of sixth gear or driven gear of fourth gear or driven gear of second gear. The fifth-speed driven gear meshed with the seventh-speed driving gear is arranged with a corresponding fifth-speed synchronizer, and the seventh-speed driven gear meshed with the fifth- and seventh-speed driving gear is set on the second output shaft and arranged The corresponding seven-speed synchronizer; the eight-speed synchronizer is fixed on the fifth-speed driven gear and engages and disengages with the sixth-speed driven gear or the fourth-speed driven gear or the second-speed driven gear.

Further, the first automatic clutch includes a first driving disc and a first driven disc, the first driving disc and the housing of the double clutch are connected by a spline sliding connection and transmit torque, and the first driven disc The torque is transmitted by a spline connection between the disc and the first input shaft; the second automatic clutch includes a second driving disc and a second driven disc, and a spline is used between the second driving disc and the double clutch housing. The key is slidingly connected and transmits torque, and the second driven plate and the second input shaft are connected by a spline to transmit torque.

Further, it also includes a parking ratchet, and the parking ratchet is arranged on the first output shaft or the second output shaft or on the differential.

The beneficial effects of the present invention are: the present invention provides an eight-speed dual-clutch automatic transmission, which does not adopt the eight-speed driving gear and eight-speed driven gear structure widely used in eight-speed dual-clutch automatic transmissions, but uses the six-speed dual-clutch automatic transmission. , 5th, 7th and 7th gears and synchronizers to realize 8th gear, which effectively shortens the axial length of the transmission and simplifies the structure. And the present invention does not adopt the reverse gear shaft that is widely used in the eight-speed double-clutch automatic transmission usually, but utilizes a reverse gear driving gear, a gear driven gear, reverse gear driven gear and reverse gear synchronizer to realize the reverse gear , In this way, the radial length of the transmission is effectively shortened, further simplifying the structure. It has the following technical effects:

First, 8 forward gears and 1 reverse gear can be realized. Among them, the transmission ratio of the first gear is the ratio of the number of teeth of the driven gear of the first gear to the number of teeth of the driving gear of the first reverse gear; the transmission ratio of the second gear is the ratio of the number of teeth of the driven gear of the second gear to the number of teeth of the driving gear of the second gear; The ratio of the number of teeth of the driven gear to the number of teeth of the driving gear of the third gear, the transmission ratio of the fourth gear is the ratio of the number of teeth of the driven gear of the fourth gear to the number of teeth of the driving gear of the fourth gear, and the transmission ratio of the fifth gear is the number of teeth of the driven gear of the fifth gear and the driving gear of the fifth and seventh gears The ratio of the number of teeth, the transmission ratio of the sixth gear is the ratio of the number of teeth of the driven gear of the sixth gear to the number of teeth of the driving gear of the sixth gear, the transmission ratio of the seventh gear is the ratio of the number of teeth of the driven gear of the seventh gear to the number of teeth of the driving gear of the fifth and seventh gears, and the transmission ratio of the eighth gear is The transmission ratio of the sixth gear or the transmission ratio of the fourth gear or the transmission ratio of the second gear is divided by the transmission ratio of the fifth gear and then multiplied by the transmission ratio of the seventh gear. gear) tooth ratio;

Second, the axial dimension is short. Only 7 gear pairs and 3 synchronizers are arranged in the axial direction;

Third, the radial size is small. The reverse gear shaft is canceled, and there are only 4 axes, which minimizes the radial dimension;

Fourth, the deformation of the shaft system is small, and the noise and vibration are small. The first gear, second gear and reverse gear are all arranged at the two ends of the shafting close to the bearings, and the force is the best;

Fifth, the possibility of interference between the differential and the first gear driven gear is small. The differential and the first-gear driven gear are respectively arranged at both ends of the shaft system, which avoids the interference between the first-gear driven gear and the differential caused by the excessive speed ratio of the first gear or the excessive differential;

Sixth, the speed ratio distribution and gear design are convenient. Only the 5th/7th gear is a common driving gear, and it is a high gear, which is beneficial to the speed ratio distribution and gear design;

Seventh, good scalability. Through the optimization of the coordination between the synchronizers and the analysis of the number of gear teeth, it is possible to increase the gear under the existing structure.

Description of drawings

Fig. 1 is the schematic diagram of embodiment 1 of eight-speed dual-clutch automatic transmission of the present invention;

Fig. 2 is the schematic diagram of Embodiment 2 of the eight-speed dual-clutch automatic transmission of the present invention;

In conjunction with the accompanying drawings, the following descriptions are made:

1-First input shaft, 2-Second input shaft, 3-First output shaft, 4-Second output shaft, 11-Reverse gear driving gear, 31-First gear driven gear, 22-Second gear driving gear , 32- second gear driven gear, 13- third gear driving gear, 43- third gear driven gear, 24- fourth gear driving gear, 44- fourth gear driven gear, 15- fifth and seventh gear driving gear, 35- five Gear driven gear, 26-sixth gear driving gear, 36-sixth gear driven gear, 47-seventh gear driven gear, 49-reverse gear driven gear, S1-first gear synchronizer, S2-second gear synchronizer, S3-third gear synchronizer, S4-fourth gear synchronizer, S5-fifth gear synchronizer, S6-sixth gear synchronizer, S7-seventh gear synchronizer, S8-eighth gear synchronizer, SR-reverse gear synchronizer, 30 -the first main reduction driving gear, 40-the second main reduction driving gear, 50-the main reduction gear, 100-double clutch, C1-the first automatic clutch, C2-the second automatic clutch, 600-the parking ratchet.

Detailed ways

In order to understand the technical content of the present invention more clearly, the following examples are given in detail, the purpose of which is only to better understand the content of the present invention but not to limit the protection scope of the present invention.

Example 1

As shown in Figure 1, the eight-speed dual-clutch automatic transmission applied to automobiles includes two first automatic clutch C1 and second automatic clutch C2 on the same axis, the first input shaft 1, the second input shaft 2, the first Output shaft 3 , second output shaft 4 , first final reduction drive gear 30 , second final reduction drive gear 40 , final reduction gear 50 , differential 5 . The crankshaft of the engine is connected to the housing of the dual clutch via a flexible disc. The two input shafts 1, 2 and the two output shafts 3, 4 are arranged parallel to each other. The dual clutch 100 includes a first automatic clutch C1 and a second automatic clutch C2. The first automatic clutch C1 includes a first driving disc and a first driven disc. And transmit torque, between the first driven disc and the first input shaft 1, the torque is transmitted by spline connection, the second automatic clutch C2 includes the second driving disc and the second driven disc, the second driving disc and the housing of the double clutch There is a splined sliding connection between them to transmit torque, and a splined connection is used between the second driven plate and the second input shaft 2 to transmit torque. The first input shaft 1 and the second input shaft 2 are arranged coaxially, the first input shaft 1 is inside, the second input shaft 2 is outside, and the first input shaft 1 protrudes from the end away from the double clutch (C1, C2) Second input shaft 2. On the first input shaft 1, a reverse gear driving gear 11, fifth and seventh gear driving gears 15, and third gear driving gear 13 are fixed successively from an end far away from the double clutch, wherein one gear and reverse gear share a reverse gear driving gear 11, five gears Block and seven gears share five or seven gears driving gear 15. On the second input shaft 2, a sixth-speed driving gear 26, a fourth-speed driving gear 24, and a second-speed driving gear 22 are successively fixed from an end away from the dual clutch. Correspondingly, on the first output shaft 3 from one end far away from the dual clutch, the first gear driven gear 31, the fifth gear driven gear 35, the sixth gear driven gear 36, and the second gear driven gear 32 are sequentially set. On the output shaft 4, reverse gear driven gear 49, seventh gear driven gear 47, third gear driven gear 43, and fourth gear driven gear 44 are sequentially sleeved from an end away from the dual clutch. On the first output shaft 3, there are also a first gear synchronizer S1, a fifth gear synchronizer S5, a sixth gear synchronizer S6, a second gear synchronizer S2, and an eighth gear synchronizer S8 is fixed on the fifth gear driven gear 35 and can be connected with the sixth gear. The driven gear 36 is engaged and disengaged, and the second output shaft 4 also has a reverse gear synchronizer SR, a seventh gear synchronizer S7, a third gear synchronizer S3, and a fourth gear synchronizer S4. The end of the first output shaft 3 close to the double clutch is fixed with the first main reduction driving gear 30, and the end of the second output shaft 4 close to the double clutch is also fixed with a parking ratchet 600 and the second main reduction driving gear 40. The driving gear 30 and the second main reduction driving gear 40 mesh with the main reduction gear 50 at the same time, and the main reduction gear 50 is fixedly connected with the shell of the differential 5, and finally the power is transmitted to both sides through the axle shafts 9 on both sides of the differential 5 on the wheel. The effect of this arrangement is that only 7 gear pairs and 3 synchronizers are arranged in the axial direction, the axial size is compact, it is convenient to distribute the speed ratio of each gear, and the gear life is long.

On the first input shaft 1, a reverse gear driving gear 11 shared by the first gear and the reverse gear is fixed at the farthest end of the double clutch, and the first gear driven gear 11 meshed with the reverse gear driving gear 11 is set on the first output shaft 3. The gear 31 is also provided with a corresponding first-speed synchronizer S1, and the second output shaft 4 is fitted with a reverse-speed driven gear 49 meshing with the first-speed driven gear 31 and is provided with a corresponding reverse-speed synchronizer SR. The advantage of this arrangement is that the reverse gear and the 1st gear are arranged at the same end of the transmission, next to the bearing, and the force is the best, and it avoids the differential gear 5 located at the other end of the transmission from being connected with the 1st gear driven gear 31 or the reverse gear driven gear. The possibility of gear 49 interfering. In addition, this arrangement avoids the use of the reverse gear shaft, and only has 4 axes, making the radial dimension the smallest.

On the first input shaft 1, the five-seventh gear driving gear 15 shared by the fifth gear and the seventh gear is fixed, and the fifth gear meshed with the five-seventh gear driving gear 15 shared by the fifth gear and the seventh gear is set on the first output shaft 3 The driven gear 35 is also arranged with a corresponding fifth-speed synchronizer S5, and the second output shaft 4 is set with a seventh-speed driven gear 47 that is meshed with the fifth- and seventh-speed driving gear 15 shared by the fifth and seventh gears and is arranged with corresponding gears. The seven-speed synchronizer S7. The advantage of this arrangement is that the fifth gear and the seventh gear are high gears, and they share the fifth and seventh gears driving gear 15, which is beneficial to the speed ratio distribution and gear design, and because the speed ratio is small, the fifth and seventh gears driving gear 15 are larger, It is beneficial to ensure the strength and life of the driving gear 15 .

In other embodiments, the parking ratchet can also be arranged on the first output shaft or on the differential.

The specific power transmission route is described as follows:

When the vehicle starts, the gear of the transmission is the first gear, which is realized by the gear shift actuator engaging the first gear synchronizer S1 with the first gear driven gear 31, and then engaging the first automatic clutch C1, while the second automatic clutch C2 is disengaged (The state changes from engaged to disengaged for a normally closed clutch and remains disengaged for a normally open clutch). At this time, the torque of the engine is transmitted to the first input shaft 1 through the first automatic clutch C1, then to the first gear driven gear 31 through a reverse gear driving gear 11, and then to the first output shaft through the first gear synchronizer S1 3. It is transmitted to the main reduction gear 50 through the first main reduction driving gear 30, and finally to the axle shafts and wheels on both sides through the differential 5.

As the vehicle continues to accelerate and reaches the point where the first gear is up to the second gear, the shift actuator will engage the second gear synchronizer S2 with the second gear driven gear 32, and then engage the second automatic clutch C2, while the first automatic The clutch C1 is disengaged, and after the first automatic clutch C1 is completely disengaged, the shift actuator disengages the first gear synchronizer S1 from the first gear driven gear 31 . At this time, the torque of the engine is transmitted to the second input shaft 2 through the second automatic clutch C2, then to the second gear driven gear 32 through the second gear driving gear 22, and then to the first output shaft 3 through the second gear synchronizer S2 , is transmitted to the final reduction gear 50 through the first main reduction driving gear 30 , and finally transmitted to the axle shafts and wheels on both sides through the differential 5 .

As the vehicle continues to accelerate and reaches the shift point from second gear to third gear, the shift actuator will engage the third gear synchronizer S3 with the third gear driven gear 43, and then engage the first automatic clutch C1, while the second automatic clutch C1 will be engaged. The clutch C2 is disengaged, and after the second automatic clutch C2 is completely disengaged, the shift actuator disengages the second gear synchronizer S2 from the second gear driven gear 32 . At this time, the torque of the engine is transmitted to the first input shaft 1 through the first automatic clutch C1, then to the third gear driven gear 43 through the third gear driving gear 13, and then to the second output shaft 4 through the third gear synchronizer S3 , is transmitted to the final reduction gear 50 through the second main reduction driving gear 40 , and finally transmitted to the axle shafts and wheels on both sides through the differential 5 .

As the vehicle continues to accelerate and reaches the shift point from third gear to fourth gear, the shift actuator will engage the fourth gear synchronizer S4 with the fourth gear driven gear 44, and then engage the second automatic clutch C2, while the first automatic The clutch C1 is disengaged, and after the first automatic clutch C1 is completely disengaged, the shift actuator disengages the third gear synchronizer S3 from the third gear driven gear 43 . At this time, the torque of the engine is transmitted to the second input shaft 2 through the second automatic clutch C2, then to the fourth-speed driven gear 44 through the fourth-speed driving gear 24, and then to the second output shaft 4 through the fourth-speed synchronizer S4 , is transmitted to the final reduction gear 50 through the second main reduction driving gear 40 , and finally transmitted to the axle shafts and wheels on both sides through the differential 5 .

As the vehicle continues to accelerate and reaches the shift point from fourth gear to fifth gear, the shift actuator engages the fifth gear synchronizer S5 with the fifth gear driven gear 35, and then engages the first automatic clutch C1, while the second automatic clutch C1 is engaged. The clutch C2 is disengaged, and after the second automatic clutch C2 is completely disengaged, the shift actuator disengages the fourth gear synchronizer S4 from the fourth gear driven gear 44 . At this time, the torque of the engine is transmitted to the first input shaft 1 through the first automatic clutch C1, then to the fifth gear driven gear 35 through the fifth and seventh gear driving gear 15, and then to the first output shaft through the fifth gear synchronizer S5 3. It is transmitted to the main reduction gear 50 through the first main reduction driving gear 30, and finally to the axle shafts and wheels on both sides through the differential 5.

As the vehicle continues to accelerate and reaches the shift point from fifth to sixth gear, the shift actuator will engage the sixth-speed synchronizer S6 with the sixth-speed driven gear 36, and then engage the second automatic clutch C2, while the first automatic The clutch C1 is disengaged. After the first automatic clutch C1 is completely disengaged, the gear shift actuator disengages the fifth gear synchronizer S5 from the fifth gear driven gear 35 . At this time, the torque of the engine is transmitted to the second input shaft 2 through the second automatic clutch C2, then to the sixth-speed driven gear 36 through the sixth-speed driving gear 26, and then to the first output shaft 3 through the sixth-speed synchronizer S6 , is transmitted to the final reduction gear 50 through the first main reduction driving gear 30 , and finally transmitted to the axle shafts and wheels on both sides through the differential 5 .

As the vehicle continues to accelerate and reaches the shift point from sixth to seventh gear, the shift actuator will engage the seventh gear synchronizer S7 with the seventh gear driven gear 47, and then engage the first automatic clutch C1, while the second automatic The clutch C2 is disengaged, and after the second automatic clutch C2 is completely disengaged, the shift actuator disengages the sixth-speed synchronizer S6 from the sixth-speed driven gear 36 . At this time, the torque of the engine is transmitted to the first input shaft 1 through the first automatic clutch C1, then to the seventh-speed driven gear 47 through the seventh-speed driving gear 15, and then to the second output shaft 4 through the seventh-speed synchronizer S7 , is transmitted to the final reduction gear 50 through the second main reduction driving gear 40 , and finally transmitted to the axle shafts and wheels on both sides through the differential 5 .

As the vehicle continues to accelerate and reaches the shift point from seventh to eighth, the shift actuator will engage the eighth-speed synchronizer S8 with the sixth-speed driven gear 36, and keep the seventh-speed synchronizer S7 and the seventh-speed driven gear 47 remains engaged. Then the second automatic clutch C2 is engaged while the first automatic clutch C1 is disengaged. At this time, the torque of the engine is transmitted to the second input shaft 2 through the second automatic clutch C2, then to the sixth-speed driven gear 36 through the sixth-speed driving gear 26, and then to the fifth-speed driven gear through the eighth-speed synchronizer S8 35. The fifth-speed driven gear 35 is transmitted to the seventh-speed driven gear 47 through the fifth- and seventh-speed driving gear 15, and then passed to the second output shaft 4 through the seventh-speed synchronizer S7, and then passed to the second final reduction drive gear 40. The final reduction gear 50 is finally transmitted to the axle shafts and wheels on both sides via the differential 5 .

When the vehicle is engaged in the reverse gear, the way to realize it is that the shift actuator engages the reverse gear synchronizer SR with the reverse gear driven gear 49, and then engages the first automatic clutch C1, and at the same time disengages the second automatic clutch C2 (for normal The state of the closed clutch changes from engaged to disengaged, and the state of the normally open clutch remains disengaged). At this time, the torque of the engine is transmitted to the first input shaft 1 through the first automatic clutch C1, then through a reverse driving gear 11, through a first gear driven gear 31, to the reverse driven gear 49, and then through the reverse gear. The driven gear 49 is transmitted to the second output shaft 4, passed to the final reduction gear 50 through the second main reduction driving gear 40, and finally transmitted to the axle shafts and wheels on both sides through the differential 5.

As the vehicle decelerates and reaches the shift point for downshifting, the shift actuator first engages the synchronizer of the lower gear with the driven gear of the gear, then engages the corresponding automatic clutch of the lower gear, and then engages the upper gear. The corresponding automatic clutch of the first gear is disengaged, and finally the synchronizer of the higher gear is separated from the driven gear of the gear, except when the eighth gear is lowered to the seventh gear.

For example, when the vehicle decelerates to the shift point of the eighth gear down to the seventh gear, the shift actuator will first engage the first automatic clutch C1, and at the same time separate the second automatic clutch C2, and then connect the eighth gear synchronizer S8 to the sixth gear. The driven gear 36 is disengaged.

When the vehicle continues to decelerate and reaches the shift point of downshifting from the seventh gear to the sixth gear, the shift actuator first engages the sixth gear synchronizer S6 with the sixth gear driven gear 36, then engages the second automatic clutch C2, and then engages the first automatic clutch C2. The automatic clutch C1 is separated, and the seventh-speed synchronizer S7 is separated from the seventh-speed driven gear 47 at last. The following gears are all carried out in a similar manner when they will be blocked.

Even better, the eight-speed dual-clutch automatic transmission can jump gears according to the needs of road conditions, such as directly shifting from first gear to third gear or fourth gear or other gears, and directly from eighth gear to sixth gear or fifth gear or other gears. gear.

At the same time, the present invention has other transmission paths, which are respectively:

Special transmission path 1: the eighth-speed clutch S8 is engaged with the sixth-speed driven gear 36, the third-speed clutch S3 is closed, the first automatic clutch C1 is disengaged, and the second automatic clutch C2 is engaged. At this time, the power of the engine is transmitted through the second automatic clutch C2 On the second input shaft 2, it is transmitted to the sixth-speed driven gear 36 through the sixth-speed driving gear 26, and then transmitted to the fifth-speed driven gear 35 through the eighth-speed synchronizer S8, and the fifth-speed driven gear 35 passes through the fifth-speed driven gear. The seventh-speed driving gear 15 is transmitted to the first input shaft 1, and the first input shaft 1 is transmitted to the third-speed driven gear 43 through the third-speed driving gear 13, and then transmitted to the second output shaft 4 through the third-speed synchronizer S3. The second final reduction drive gear 40 is transmitted to the final reduction gear 50 , and finally transmitted to the axle shafts and wheels on both sides via the differential 5 .

Special transmission path 2: the eighth-speed clutch S8 is engaged with the sixth-speed driven gear 36, the first-speed clutch S1 is closed, the first automatic clutch C1 is disengaged, and the second automatic clutch C2 is engaged. At this time, the power of the engine is transmitted through the second automatic clutch C2 On the second input shaft 2, it is transmitted to the sixth-speed driven gear 36 through the sixth-speed driving gear 26, and then transmitted to the fifth-speed driven gear 35 through the eighth-speed synchronizer S8, and the fifth-speed driven gear 35 passes through the fifth-speed driven gear. The seventh gear driving gear 15 is transmitted to the first input shaft 1, the first input shaft 1 is transmitted to the first gear driven gear 31 through a reverse gear driving gear 11, and then transmitted to the first output shaft 3 through the first gear synchronizer S1, It is transmitted to the final reduction gear 50 through the first main reduction driving gear 30 , and finally transmitted to the axle shafts and wheels on both sides through the differential 5 .

Special transmission path 3: the eighth-speed clutch S8 is engaged with the sixth-speed driven gear 36, the fourth-speed clutch S4 is closed, the first automatic clutch C1 is engaged, and the second automatic clutch C2 is separated. At this time, the power of the engine is transmitted through the first automatic clutch C1 On the first input shaft 1, it is transmitted to the fifth-speed driven gear 35 through the fifth-speed and seventh-speed driving gear 15, and then transmitted to the sixth-speed driven gear 36 through the eighth-speed synchronizer S8, and then passed by the sixth-speed driven gear 36 The sixth gear driving gear 26 is transmitted to the second input shaft 2, and the second input shaft 2 is transmitted to the second gear driven gear 32 through the second gear driving gear 13, and then transmitted to the second output shaft 4 through the second gear synchronizer S2. The second final reduction drive gear 40 is transmitted to the final reduction gear 50 , and finally transmitted to the axle shafts and wheels on both sides via the differential 5 .

Special transmission path 4: the eighth-speed clutch S8 is engaged with the sixth-speed driven gear 36, the second-speed clutch S2 is closed, the first automatic clutch C1 is engaged, and the second automatic clutch C2 is separated. At this time, the power of the engine is transmitted through the first automatic clutch C1 On the first input shaft 1, it is transmitted to the fifth-speed driven gear 35 through the fifth-speed and seventh-speed driving gear 15, and then transmitted to the sixth-speed driven gear 36 through the eighth-speed synchronizer S8, and then passed by the sixth-speed driven gear 36 The sixth-speed driving gear 26 is transmitted to the second input shaft 2, and the second input shaft 2 is transmitted to the second-speed driven gear 32 through the second-speed driving gear 22, and then transmitted to the first output shaft 3 through the second-speed synchronizer S2. The first final reduction drive gear 30 is transmitted to the final reduction gear 50 , and finally transmitted to the axle shafts and wheels on both sides via the differential 5 .

The above four special transmission paths are only used in special working conditions because the speed ratio is similar to a certain gear between the first gear and the eighth gear, or the power cannot be interrupted when switching to the special transmission path.

In the present invention, only the fifth gear and the seventh gear share the driving gear, and the design of the speed ratios of gears other than the eighth gear is not affected by the speed ratios of the fifth gear and the seventh gear, which is beneficial to the design of the speed ratio of the transmission.

Example 2

As shown in Figure 2, compared with Embodiment 1, the difference of the eight-speed dual-clutch automatic transmission shown in Embodiment 2 is that: the second input shaft 2 is sequentially fixed with a fourth-speed driving gear 24, The sixth-speed driving gear 26, the second-speed driving gear 22, the fourth-speed driven gear 34 are correspondingly set on the first output shaft 3, and the sixth-speed driven gear 46 is correspondingly set on the second output shaft 4; correspondingly, the fourth-speed synchronous The synchronizer S4 is arranged on the first output shaft 3, the sixth-speed synchronizer S6 is arranged on the second output shaft 4, the eighth-speed synchronizer S8 is fixed on the fifth-speed driven gear 35 and can be engaged with the fourth-speed driven gear 34 and Separation; like this, can guarantee that the speed ratio of the eighth gear is smaller than the speed ratio of the seventh gear, so as to meet the actual requirements.

In other embodiments, it can also be arranged that: the second input shaft 2 is sequentially fixed with the second-speed driving gear 22 , the fourth-speed driving gear 24 , and the sixth-speed driving gear 26 from the end away from the dual clutch. That is to say, the positions of any two gears between the second gear driving gear, the fourth gear driven gear and the sixth gear driven gear on the second input shaft 2 are exchanged.

The above embodiments are detailed descriptions of preferred embodiments of the present invention with reference to the accompanying drawings. Those skilled in the art can make various modifications or changes to the above embodiments without departing from the essence of the present invention, all of which fall within the protection scope of the present invention.

Claims (5)

1. an eight-speed dual-clutch automatic transmission, characterized in that, comprises dual clutches, a first input shaft, a second input shaft, a first output shaft, a second output shaft and a differential, The dual clutch includes a first automatic clutch and a second automatic clutch, two input shafts and two output shafts are arranged parallel to each other, the first input shaft is connected to the first automatic clutch, and the second The two input shafts are connected with the second automatic clutch, the first input shaft and the second input shaft are coaxially arranged, the first input shaft is inside, the second input shaft is outside, and the The first input shaft protrudes from the second input shaft at an end away from the dual clutch; The first input shaft is fixed with a driving gear for reverse gear, driving gear for fifth and seventh gears, and driving gear for third gear. The sixth-speed driving gear, the fourth-speed driving gear, and the second-speed driving gear are fixed on the second input shaft; Any two of gears, second gear driven gears, and fourth gear driven gears, the second output shaft is fitted with reverse gear driven gears, seventh gear driven gears, third gear driven gears and sixth gear driven gears. gear, second gear driven gear, and fourth gear driven gear that are not set on the first output shaft; the first output shaft is provided with a first gear synchronizer, a fifth gear synchronizer, a sixth gear synchronizer, a second gear Any two of the synchronizer and the fourth gear synchronizer, the second output shaft is provided with a reverse gear synchronizer, a seventh gear synchronizer, a third gear synchronizer, a sixth gear synchronizer, a second gear synchronizer and a fourth gear synchronizer One of the gears that is not installed on the first output shaft, and an eighth-speed synchronizer is provided on the fifth-speed driven gear, and the eighth-speed synchronizer is connected with the sixth-speed driven gear on the first output shaft Or the fourth-speed driven gear or the second-speed driven gear is engaged and disengaged; the end of the first output shaft close to the dual clutch is fixed with the first main deceleration driving gear, and the end of the second output shaft close to the double clutch is fixed with the second Two main reduction driving gears, the first main reduction driving gear and the second main reduction driving gear mesh with a main reduction gear at the same time, and the main reduction gear is fixed on the differential. 2. The eight-speed dual-clutch automatic transmission according to claim 1, characterized in that: the first reverse driving gear is arranged on the first input shaft farthest from the dual clutch, and on the first output shaft Correspondingly set the first gear driven gear meshed with the first reverse gear, and arrange the corresponding first gear synchronizer, the second output shaft is correspondingly fitted with the first gear driven gear meshed with the first gear. The reverse gear driven gear is equipped with a corresponding reverse synchronizer. 3. The eight-speed dual-clutch automatic transmission according to claim 2, characterized in that: the fifth and seventh gears are arranged between a reverse gear and a sixth gear or a fourth driven gear or a second driven gear. Between the gears, the first output shaft is fitted with a fifth-speed driven gear meshing with the fifth- and seventh-speed driving gears, and a corresponding fifth-speed synchronizer is arranged on the first output shaft. The seventh-speed driven gear meshed with the fifth- and seventh-speed driving gears is arranged with a corresponding seventh-speed synchronizer; the eighth-speed synchronizer is fixed on the fifth-speed driven gear and is connected with the sixth-speed driven gear or 4th speed driven gear or 2nd speed driven gear engages and disengages. 4. The eight-speed dual-clutch automatic transmission according to claim 1, characterized in that: the first automatic clutch includes a first driving disc and a first driven disc, and a connection between the first driving disc and the housing of the dual clutch The first driven disc and the first input shaft are connected by a spline to transmit torque; the second automatic clutch includes a second driving disc and a second driven disc. disc, the second driving disc and the housing of the dual clutch are connected by a spline to transmit torque, and the second driven disc and the second input shaft are connected by a spline to transmit torque. 5. The eight-speed dual-clutch automatic transmission according to claim 1, further comprising a parking ratchet arranged on the first output shaft or the second output shaft or on the differential.