JP5796092B2 - Vehicle transmission - Google Patents

Description

    The present invention relates to a vehicle transmission that changes a gear ratio between a power source and drive wheels.

  As a vehicle transmission, a technique described in Patent Document 1 is disclosed. This publication includes a differential mechanism composed of a planetary gear and three frictional engagement elements, and a constantly meshing main transmission mechanism, and the engagement state of the frictional engagement elements of the differential mechanism and the achievement of the main transmission mechanism. A vehicle transmission that achieves a plurality of shift speeds based on the relationship with the shift speeds is disclosed.

JP 2004-1000094 A

However, when further increasing the number of stages without increasing the number of frictional engagement elements, for example, to achieve the eighth speed or higher, it is necessary to add one more gear train to the configuration disclosed in Patent Document 1, and the shaft There is a problem of increasing the size because it becomes longer in the direction.
The present invention has been made paying attention to the above-described problems, and an object of the present invention is to provide a vehicle transmission that can achieve multi-stages of eight speeds or more without causing an increase in size.

In order to achieve the above object, a vehicle transmission according to the present invention includes:
A main transmission mechanism and a differential mechanism;
The main transmission mechanism is
A first shaft, a second shaft, and a third shaft, each having a different axial position;
A cylindrical rotating member arranged coaxially on the outer periphery of the second shaft,
The first shaft is
A high-side reduction gear fixed on the first shaft and constantly meshing with the final reduction gear;
A sixth gear that can be selectively locked to the first shaft by a third sync;
An eighth gear that can be selectively locked to the first shaft by a fourth sync;
The second shaft is
A first input gear that always meshes with the eighth gear;
A second input gear that always meshes with a reverse idler gear that is rotatably supported on the first shaft;
The cylindrical rotating member is
A third input gear fixed on the cylindrical rotating member and constantly meshing with the sixth gear;
The third shaft is
A low-side reduction gear fixed on the third shaft and constantly meshing with the final reduction gear;
A fourth gear that can be selectively locked to the third shaft by the first sync and always meshes with the first input gear;
A first gear that can be selectively locked to the third shaft by the first sync and always meshes with the second input gear;
A reverse gear that can be selectively locked to the third shaft by a second sync and always meshes with the reverse idler gear;
A third gear that can be selectively locked to the third shaft by the second sync and always meshes with the third input gear;
The main transmission mechanism switches the power transmission path by operating the plurality of synchros on the gears on the shafts.
The differential mechanism is
A planetary gear having a first rotating member, a second rotating member and a third rotating member connected to a power source;
A first clutch for selectively connecting two of the first, second and third rotating members of the planetary gear;
A second clutch that selectively connects the second shaft and the second rotating member;
A third clutch for selectively connecting the cylindrical rotating member and the third rotating member;
At least the eighth forward speed is achieved by a combination of locking of the synchros and engagement of the clutches.

  In other words, a vehicular transmission that can achieve eight or more speeds without increasing the axial direction by providing the main transmission mechanism with a three-shaft configuration and disposing the gears and the synchro on each shaft as described above. can do.

1 is a skeleton diagram illustrating a configuration of a vehicle transmission according to a first embodiment. 4 is a table showing characteristics of gear positions of the vehicle transmission according to the first embodiment. FIG. 5 is a characteristic diagram in which a step ratio in the vehicle transmission of the first embodiment is plotted. It is a table | surface showing the characteristic of the gear stage of the vehicle transmission of a comparative example. It is the characteristic view which plotted the interstage ratio in the transmission for vehicles of a comparative example.

  FIG. 1 is a skeleton diagram showing the configuration of the vehicle transmission according to the first embodiment. This vehicle transmission includes a differential mechanism A1 including a planetary gear and a plurality of clutches, and a main transmission mechanism A2 including a plurality of constantly meshing gears for shifting power transmission from the differential mechanism A1.

  The differential mechanism A1 includes a sun gear S, a pinion carrier PC connected to an input shaft Input connected to a power source (not shown) and rotatably supporting a pinion meshing with the sun gear S, and a ring gear R meshing with the pinion. An input shaft Input, a cylindrical rotating member M1, and a second shaft x2 are connected to the differential mechanism A1. A first clutch C1 is provided between the sun gear S and the ring gear R. A second clutch C2 is provided between the sun gear S and the second shaft x2. A third clutch C3 is provided between the ring gear R and the cylindrical rotating member M1.

  The main transmission mechanism A2 is connected by a differential mechanism A1, a cylindrical rotary member M1, and a second shaft x2. The main transmission mechanism A2 is composed of three shafts arranged in parallel with the first shaft x1, the second shaft x2, and the third shaft x3, and the gears provided on each shaft are the other gears. Always meshes with the gear on the shaft.

  The first shaft x1 includes a high-side reduction gear GRHi that is fixed to the first shaft x1 and meshes with a differential gear DEF (final reduction gear), a sixth gear G6 that is supported so as to be rotatable relative to the first shaft x1, and a first gear x6. A reverse idler gear GRI supported to be rotatable relative to one shaft x1, a third sync S3 that selectively fixes the sixth gear G6 to the first shaft x1, and a rotatable relative to the first shaft x1. And an eighth gear G8 and a fourth sync S4 that selectively fixes the eighth gear G8 to the first shaft x1. The synchro mechanism may have any known configuration, and may have a configuration such as a synchronous type or a dog clutch, and is not particularly limited.

The second shaft x2 includes a first input gear GIN1 fixed to the second shaft x2 and constantly meshed with an eighth gear G8 and a fourth gear G4 described later, a reverse idler gear GRI fixed to the second shaft x2 and a first gear described later. There is a second input gear GIN2 that always meshes with one gear G1. The second input gear GIN2 has a smaller diameter than the first input gear GIN1.
The cylindrical rotary member M1 is coaxial with the second shaft x2 and is disposed on the outer periphery of the second shaft x2. A third input gear GIN3 having a smaller diameter than the first input gear GIN1 and a larger diameter than the second input gear GIN2 is fixed to the cylindrical rotating member M1 so as to rotate integrally.

  The third shaft x3 includes a low-side reduction gear GRLow that is fixed to the third shaft x3 and meshes with the differential gear DEF, a third gear G3 that is rotatably supported relative to the third shaft x3, and a third shaft x3. A reverse gear GR that is rotatably supported, a second synchro S2 that selectively fixes the third sun gear G3 and the reverse gear GR to the third shaft x3, and a third shaft x3 that is rotatably supported. A first gear G1 that always meshes with the second input gear GIN2, a fourth gear G4 that is supported rotatably relative to the third shaft x3, and always meshes with the first input gear GIN1, and a first gear G1 and a fourth gear G4. A first sync S1 that is selectively fixed to the third shaft x3.

FIG. 2 is a table showing the characteristics of the shift stage of the vehicle transmission according to the first embodiment.
The first speed (1st) is achieved by moving the first sync S1 to the right in FIG. 1 to fix the first gear G1 to the third shaft x3 and engaging the first clutch C1 and the second clutch C2. The That is, the differential mechanism A1 is integrally rotated because the sun gear S and the ring gear R are connected by the engagement of the first clutch C1, and the rotation of the input shaft Input is directly transmitted to the second shaft x2 by the engagement of the second clutch C2. The Then, the driving force is transmitted from the second input gear GIN2 to the first gear G1, and the driving force is transmitted from the low side reduction gear GRLow to the differential gear DEF. At this time, since the high-side reduction gear GRHi is engaged with the differential gear DEF, the first shaft x1 also rotates. However, since both the third sync S3 and the fourth sync S4 are in the neutral state, they are simply brought along. It does not contribute to power transmission.
Therefore, the transmission gear that contributes to power transmission at the first gear is the first gear of the transmission gear group (first gear G1, third gear G3, fourth gear G4, sixth gear G6, and eighth gear G8). Only G1, with a speed ratio of 0.077 and a gear ratio of 13.072.

The second gear (2nd) moves the first sync G1 and the third gear G3 by moving the first sync S1 to the right in FIG. 1 and moving the second sync S2 to the right in FIG. This is achieved by fixing to the 3 shaft x3 and engaging the second clutch C2 and the third clutch C3. That is, in the differential mechanism A1, the rotation of the input shaft Input is input to the pinion carrier PC, the rotation of the sun gear S is transmitted to the second shaft x2 via the second clutch C2, and the rotation of the ring gear R is the first. It is transmitted to the cylindrical rotating member M1 via the three clutch C3. The rotation of the second shaft x2 is transmitted to the first gear G1 via the second input gear GIN2, and the rotation of the cylindrical rotating member M1 is transmitted to the third gear G3. At this time, the differential mechanism A1 absorbs the rotational speed difference between the rotation of the second shaft x2 and the rotation of the cylindrical rotating member M1, and an intermediate gear position between the first gear and the third gear can be achieved.
Therefore, the transmission gear that contributes to power transmission in the second gear is the first gear of the transmission gear group (first gear G1, third gear G3, fourth gear G4, sixth gear G6, and eighth gear G8). G1 and the third gear G3 have a speed ratio of 0.123 and a gear ratio of 8.161. Further, the gear ratio between the first gear and the second gear (the gear ratio of the first gear / the gear ratio of the second gear) is 1.602.

The third speed (3rd) is achieved by moving the second synchro S2 to the right in FIG. 1 to fix the third gear G3 to the third shaft x3 and engaging the first clutch C1 and the third clutch C3. Is done. That is, the differential mechanism A1 is rotated integrally because the sun gear S and the ring gear R are connected when the first clutch C1 is engaged, and the rotation of the input shaft Input is directly transmitted to the cylindrical rotating member M1 when the third clutch C3 is engaged. Is done. The rotation transmitted to the cylindrical rotation member M1 is transmitted from the third input gear GIN3 to the third gear G3, and the driving force is transmitted from the low side reduction gear GRLow to the differential gear DEF. At this time, since the high-side reduction gear GRHi is engaged with the differential gear DEF, the first shaft x1 also rotates. However, since both the third sync S3 and the fourth sync S4 are in the neutral state, they are simply brought along. It does not contribute to power transmission.
Therefore, the transmission gear that contributes to power transmission at the third speed is the third gear of the transmission gear group (first gear G1, third gear G3, fourth gear G4, sixth gear G6, and eighth gear G8). G3, the speed ratio is 0.182, and the gear ratio is 5.481. Further, the gear ratio between the second gear and the third gear (the gear ratio of the second gear / the gear ratio of the third gear) is 1.489.

The fourth speed (4th) is achieved by moving the first sync S1 to the left in FIG. 1 to fix the fourth gear G4 to the third shaft x3 and engaging the first clutch C1 and the second clutch C2. Is done. That is, the differential mechanism A1 is integrally rotated because the sun gear S and the ring gear R are connected by the engagement of the first clutch C1, and the rotation of the input shaft Input is directly transmitted to the second shaft x2 by the engagement of the second clutch C2. The The rotation transmitted to the second shaft x2 is transmitted from the first input gear GIN1 to the fourth gear G4 on the first shaft x1, and the driving force is transmitted from the low side reduction gear GRLow to the differential gear DEF. At this time, since the high-side reduction gear GRHi is engaged with the differential gear DEF, the first shaft x1 also rotates. However, since both the third sync S3 and the fourth sync S4 are in the neutral state, they are simply brought along. It does not contribute to power transmission.
Therefore, the transmission gear that contributes to power transmission at the fourth speed is the fourth gear of the transmission gear group (first gear G1, third gear G3, fourth gear G4, sixth gear G6, and eighth gear G8). G4, with a speed ratio of 0.246 and a gear ratio of 4.063. The inter-step ratio between the third speed stage and the fourth speed stage (gear ratio of the third speed stage / gear ratio of the fourth speed stage) is 1.602.

The fifth gear stage (5th) moves the first synchro S1 to the left in FIG. 1 to fix the fourth gear G4 to the third shaft x3, and moves the third synchro S3 to the right in FIG. This is achieved by fixing the sixth gear G6 to the first shaft x1 and engaging the second clutch C2 and the third clutch C3. That is, in the differential mechanism A1, the rotation of the input shaft Input is input to the pinion carrier PC, the rotation of the sun gear S is transmitted to the second shaft x2 via the second clutch C2, and the rotation of the ring gear R is the first. It is transmitted to the cylindrical rotating member M1 via the three clutch C3. The rotation of the second shaft x2 is transmitted to the fourth gear G4 via the first input gear GIN1, and the rotation of the cylindrical rotation member M1 is transmitted to the sixth gear G6 via the third input gear GIN3. At this time, since the first clutch C1 is released, the difference in rotational speed between the rotation of the second shaft x2 and the rotation of the cylindrical rotary member M1 is absorbed by the differential mechanism A1, and the fourth speed and the sixth speed. Intermediate speed is achieved. At this time, since the driving force is input to the differential gear DEF from both the high side reduction gear GRHi side fixed to the first shaft x1 and the low side reduction gear GRLow side fixed to the third shaft x3, Two power transmission paths to the differential gear DEF can be secured, and the load acting on the tooth surface can be reduced. Thereby, the durability of the transmission can be improved.
That is, the transmission gear that contributes to power transmission at the fifth speed is the fourth gear of the transmission gear group (first gear G1, third gear G3, fourth gear G4, sixth gear G6, and eighth gear G8). G4 and sixth gear G6 have a speed ratio of 0.320 and a gear ratio of 3.127. The inter-step ratio between the 4th speed stage and the 5th speed stage (gear ratio of 4th speed stage / gear ratio of 5th speed stage) is 1.300.

The sixth speed (6th) is achieved by moving the third synchro S3 to the right in FIG. 1 to fix the sixth gear G6 to the first shaft x1 and engaging the first clutch C1 and the third clutch C3. The That is, in the differential mechanism A1, since the sun gear S and the ring gear R are connected by the engagement of the first clutch C1, the rotation is integrated, and the rotation of the input shaft Input is directly rotated by the engagement of the third clutch C3. It is transmitted to member M1. The driving force is transmitted from the third input gear GIN3 fixed to the cylindrical rotating member M1 to the sixth gear G6, and the high-side reduction gear GRHi fixed to the first shaft x1 that rotates integrally with the sixth gear G6. Transmits the driving force to the differential gear DEF. At this time, since the differential gear DEF is engaged with the low-side reduction gear GRLow, the third shaft x3 also rotates. However, since both the first sync S1 and the fourth sync S4 are in the neutral state, they are simply brought along. It does not contribute to power transmission.
Therefore, the transmission gear that contributes to power transmission at the sixth speed is the sixth gear of the transmission gear group (first gear G1, third gear G3, fourth gear G4, sixth gear G6, and eighth gear G8). G6, speed ratio is 0.375, gear ratio is 2.667. The inter-step ratio between the fifth gear and the sixth gear (gear ratio of fifth gear / gear ratio of sixth gear) is 1.172.

In the seventh speed (7th), the sixth sync G6 is fixed to the first shaft x1 by moving the third sync S3 to the right in FIG. 1, and the fourth sync S4 is moved to the left in FIG. This is achieved by fixing the eighth gear G8 to the first shaft x1 and engaging the second clutch C2 and the third clutch C3. That is, in the differential mechanism A1, the rotation of the input shaft Input is input to the pinion carrier PC, the rotation of the sun gear S is transmitted to the second shaft x2 via the second clutch C2, and the rotation of the ring gear R is the first. It is transmitted to the cylindrical rotating member M1 via the three clutch C3. The rotation of the second shaft x2 is transmitted to the eighth gear G8 via the first input gear GIN1, and the rotation of the cylindrical rotation member M1 is transmitted to the sixth gear G6 via the third input gear GIN3. At this time, since the first clutch C1 is disengaged, the differential speed difference between the rotation of the second shaft x2 and the rotation of the cylindrical rotary member M1 is absorbed by the differential mechanism A1, and the sixth gear and the eighth gear. Intermediate speed is achieved. At this time, the driving force is input to the differential gear DEF from the high-side reduction gear GRHi side fixed to the first shaft x1. The differential gear DEF is always engaged with the low-side reduction gear GRLow. However, since both the first synchro S1 and the second synchro S2 are in the neutral state, they are merely brought together and do not contribute to power transmission.
Therefore, the transmission gear that contributes to power transmission at the seventh speed is the sixth gear of the transmission gear group (first gear G1, third gear G3, fourth gear G4, sixth gear G6, and eighth gear G8). G6 and eighth gear G8, with a speed ratio of 0.430 and a gear ratio of 2.326. The inter-step ratio between the sixth speed and the seventh speed (gear ratio of sixth speed / gear ratio of seventh speed) is 1.147.

The eighth gear (8th) is achieved by moving the fourth synchro S4 to the left in FIG. 1 to fix the eighth gear G8 to the first shaft x1 and engaging the first clutch C1 and the second clutch C2. The That is, in the differential mechanism A1, since the sun gear S and the ring gear R are connected by the engagement of the first clutch C1, the rotation is integrated and the rotation of the input shaft Input is directly performed by the engagement of the second clutch C2. transmitted to x2. Then, the driving force is transmitted from the first input gear GIN1 fixed to the second shaft x2 to the eighth gear G8, and from the high side reduction gear GRHi fixed to the first shaft x1 rotating integrally with the eighth gear G8. The driving force is transmitted to the differential gear DEF. At this time, since the differential gear DEF meshes with the low-side reduction gear GRLow, the third shaft x3 also rotates. However, since both the first synchro S1 and the second synchro S2 are in the neutral state, they are simply brought along. It does not contribute to power transmission.
Therefore, the transmission gear that contributes to power transmission at the eighth speed is the eighth gear of the transmission gear group (first gear G1, third gear G3, fourth gear G4, sixth gear G6, and eighth gear G8). G8 with a speed ratio of 0.542 and a gear ratio of 1.846. Further, the inter-step ratio between the seventh gear and the eighth gear (the gear ratio of the seventh gear / the gear ratio of the eighth gear) is 1.260.

The reverse gear (Rev) is achieved by moving the second synchro S2 to the left side in FIG. 1 to fix the reverse gear GR to the third shaft x3 and engaging the first clutch C1 and the second clutch C2. That is, in the differential mechanism A1, since the sun gear S and the ring gear R are connected by the engagement of the first clutch C1, the rotation is integrated and the rotation of the input shaft Input is directly performed by the engagement of the second clutch C2. transmitted to x2. Then, the driving force is transmitted from the second input gear GIN2 to the reverse idler gear GRI, and transmitted to the reverse gear GR that is always meshed with the reverse idler gear GRI in a state where the rotation direction is reversed. As a result, the reverse rotation is transmitted from the low-side reduction gear GRLow to the differential gear DEF via the third shaft x3, thereby achieving the reverse gear. The differential gear DEF is always meshed with the high-side reduction gear GRHi, but the reverse idler gear GRI is simply supported so as to be rotatable relative to the first shaft x1, and there is no problem.
Therefore, the transmission gear that contributes to power transmission in the reverse gear is the reverse gear GR, and the speed ratio is -0.091 and the gear ratio is -10.980. Further, the gear ratio between the reverse gear and the first gear (the gear ratio of the reverse gear / the gear ratio of the first gear) is -0.840.

  FIG. 3 is a characteristic diagram in which the interstage ratio in the vehicle transmission of the first embodiment is plotted. As shown in FIG. 3, it can be seen that the inter-step ratio at each shift stage gradually decreases as the shift to the high shift stage is performed. In general, it is known that the gear ratio of the transmission is abruptly changed at an intermediate gear speed, resulting in deterioration of gear shift characteristics (shift shock or acceleration characteristics). In the vehicle transmission according to the first embodiment, an appropriate interstage ratio characteristic can be obtained, and the gear can be rhythmically changed.

  In order to achieve the respective gear positions, the first clutch C1, the second clutch C2, and the third clutch C3 are each engaged, and at the time of shifting, the shifting can be achieved by changing only one clutch. Thus, a stable speed change can be achieved without causing complication of control such as double switching.

  Similarly, even in the first sync S1, the second sync S2, the third sync S3, and the fourth sync S4, one sync is generated at the second speed, the fifth speed and the seventh speed where a plurality of syncs operate. A state in which two synchros are engaged with each other can be achieved only by operating, and a stable speed change can be achieved without causing complication of control such as double operation.

  Further, even in the gear ratio, the range of 13.072 to 1.846 is covered, so that a sufficiently wide ratio coverage (gear ratio range) can be obtained, and drivability and fuel consumption can be improved. .

  Here, a comparative example in which the same mechanical configuration as that of the first embodiment and achieving nine forward speeds is compared with the first embodiment that achieves eight forward speeds will be described. FIG. 4 is a table showing the characteristics of the shift stage of the vehicle transmission of the comparative example, and FIG. 5 is a characteristic diagram in which the inter-stage ratio in the vehicle transmission of the comparative example is plotted. In the comparative example, the fourth speed stage of the comparative example is added as a new shift stage between the third speed stage and the fourth speed stage of the first embodiment, and the fourth speed stage to the eighth speed stage of the embodiment are changed to the fifth speed stage of the comparative example. It is moved as 9th gear.

  With the same configuration as the vehicle transmission of the first embodiment, it is theoretically possible to achieve the ninth forward speed. However, as shown in the characteristic diagram of FIG. 5, the fourth gear added in the comparative example has a remarkably low value between the third gear and the third gear, which is not preferable as a shift characteristic. Thus, in the first embodiment, the fourth shift speed of the comparative example in which the characteristics are remarkably deteriorated as described above is eliminated, and the transmission is configured as the eighth forward speed, thereby obtaining good shift characteristics.

As described above, the effects listed below can be obtained in the first embodiment.
(1) having a first shaft x1, a second shaft x2 and a third shaft x3, each having a different axial position, and a cylindrical rotating member M1 arranged coaxially on the outer periphery of the second shaft x2,
The first shaft x1 is selectively engaged with the first shaft x1 by the high-side reduction gear GRHi fixed on the first shaft x1 and constantly meshing with the differential gear DEF (final reduction gear) and the third synchro S3. A sixth gear G6 that can be stopped, and an eighth gear G8 that can be selectively locked to the first shaft x1 by the fourth synchro S4;
The second shaft x2 has a first input gear GIN1 that always meshes with the eighth gear G8, and a second input gear GIN2 that always meshes with the reverse idler gear GRI.
The cylindrical rotating member M1 has a third input gear GIN3 that is fixed on the cylindrical rotating member M1 and that meshes with the sixth gear G6 at all times.
The third shaft x3 can be selectively locked to the third shaft x3 by the low-side reduction gear GRLow fixed on the third shaft x3 and constantly meshing with the differential gear DEF, and the first sync S1. A fourth gear G4 that is always meshed with the first input gear GIN1, and a first gear G1 that can be selectively locked to the third shaft x3 by the first synchro S1 and always meshed with the second input gear GIN2. The reverse gear GR that can be selectively locked to the third shaft x3 by the second synchro S2 and always meshed with the reverse idler gear GRI, and the third shaft x3 selectively by the second synchro S2 A third gear G3 that can be locked and always meshes with the third input gear GIN3;
The main transmission mechanism A2 that switches the power transmission path by operating a plurality of synchros on the gears on each of these shafts,
Select a pinion carrier PC (first rotating member) connected to the power source, a planetary gear having a sun gear S and a ring gear R (second and third rotating members), and two of the rotating members of the planetary gear First clutch C1 that is connected in an engaged manner, second clutch C2 that selectively connects second shaft x2 and sun gear S (second rotating member), cylindrical rotating member M1, and ring gear R (third rotating member) A differential mechanism A1 having a third clutch C3 that selectively couples
And at least the eighth forward speed is achieved by a combination of locking of each synchro and fastening of each clutch.

  That is, a vehicle transmission capable of achieving the eighth speed or more without increasing the axial direction by arranging the gears and the synchro on each shaft as described above, with the main transmission mechanism A2 having a three-shaft configuration. Can be provided.

  Further, according to this configuration, when the fifth speed is achieved in the case of Example 1 and the sixth speed is achieved in the case of the comparative example, the differential gear DEF has a high gear fixed to the first shaft x1. Since driving force is input from both the side reduction gear GRHi side and the low side reduction gear GRLow side fixed to the third shaft x3, it is possible to secure two power transmission paths to the differential gear DEF, The load acting on the tooth surface can be reduced. Thereby, the durability of the transmission can be improved.

  (2) The planetary gear is a simple planetary gear having a sun gear S, a pinion carrier PC that supports the pinion, and a ring gear R. Therefore, the configuration is not complicated as in the double pinion mechanism, and the cost can be reduced while ensuring the quietness.

(3) The first rotating member is a pinion carrier PC, the second rotating member is a sun gear S, the third rotating member is a ring gear R,
The first gear G1 is locked by the first synchro S1, and the first gear is achieved by engaging the first clutch C1 and the second clutch C2,
The first gear G1 is locked by the first synchro S1, the third gear G3 is locked by the second synchro S2, and the second gear C2 and the third clutch C3 are engaged to achieve the second gear.
The third gear G3 is locked by the second synchro S2, and the third gear is achieved by engaging the first clutch C1 and the third clutch C3.
The fourth gear G4 is locked by the first synchro S1, and the fourth speed is achieved by engaging the first clutch C1 and the second clutch C2.
The fourth gear G4 is locked by the first sync S1 and the sixth gear G6 is locked by the third sync S3, and the fifth gear is achieved by engaging the second clutch C2 and the third clutch C3.
The sixth gear G6 is locked by the third synchro S3, and the sixth gear is achieved by engaging the first clutch C1 and the third clutch C3.
The sixth gear G6 is locked by the third synchro S3 and the eighth gear G8 is locked by the fourth synchro S4, and the seventh gear is achieved by engaging the second clutch C2 and the third clutch C3.
The eighth gear G8 is locked by the fourth synchro S4, and the eighth gear is achieved by engaging the first clutch C1 and the second clutch C2.

Therefore, as described based on the relationship with the comparative example, it is possible to configure the gear stage after eliminating the gear stage in which the gear ratio is deteriorated, and to provide a vehicle transmission having a good gear ratio. be able to.
In order to achieve the respective gear positions, the first clutch C1, the second clutch C2, and the third clutch C3 are each engaged, and at the time of shifting, the shifting can be achieved by changing only one clutch. Thus, a stable speed change can be achieved without causing complication of control such as double switching.
Similarly, even in the first sync S1, the second sync S2, the third sync S3, and the fourth sync S4, one sync is generated at the second speed, the fifth speed and the seventh speed where a plurality of syncs operate. A state in which two synchros are engaged with each other can be achieved only by operating, and a stable speed change can be achieved without causing complication of control such as double operation.
Further, even in the gear ratio, the range of 13.072 to 1.846 is covered, so that a sufficiently wide ratio coverage (gear ratio range) can be obtained, and drivability and fuel consumption can be improved. .

  Although the first embodiment has been described above, the present invention is not limited to the configuration of the first embodiment. In the first embodiment, a simple planetary gear is used as the differential mechanism A1, but a double pinion type planetary gear, a Ravigneaux type planetary gear, or a Simpson type planetary gear may be used, and an appropriate number of rotating members can be obtained. There is no particular problem.

  In the first embodiment, the vehicle transmission with eight forward speeds is shown. However, it may be configured as a vehicle transmission with fewer speeds, for example, the seventh forward speed and the sixth speed. In this case, it is possible to select only a gear having better characteristics, so that it is possible to improve drivability and fuel consumption.

Claims (2)

A main transmission mechanism and a differential mechanism;
The main transmission mechanism is
A first shaft, a second shaft, and a third shaft, each having a different axial position;
A cylindrical rotating member arranged coaxially on the outer periphery of the second shaft,
The first shaft is
A high-side reduction gear fixed on the first shaft and constantly meshing with the final reduction gear;
A sixth gear that can be selectively locked to the first shaft by a third sync;
An eighth gear that can be selectively locked to the first shaft by a fourth sync;
The second shaft is
A first input gear that always meshes with the eighth gear;
A second input gear that always meshes with a reverse idler gear that is rotatably supported on the first shaft;
The cylindrical rotating member is
A third input gear fixed on the cylindrical rotating member and constantly meshing with the sixth gear;
The third shaft is
A low-side reduction gear fixed on the third shaft and constantly meshing with the final reduction gear;
A fourth gear that can be selectively locked to the third shaft by the first sync and always meshes with the first input gear;
A first gear that can be selectively locked to the third shaft by the first sync and always meshes with the second input gear;
A reverse gear that can be selectively locked to the third shaft by a second sync and always meshes with the reverse idler gear;
A third gear that can be selectively locked to the third shaft by the second sync and always meshes with the third input gear;
The main transmission mechanism switches the power transmission path by operating the plurality of synchros on the gears on the shafts.
The differential mechanism is
A planetary gear having a first rotating member, a second rotating member and a third rotating member connected to a power source;
A first clutch for selectively connecting two of the first, second and third rotating members of the planetary gear;
A second clutch that selectively connects the second shaft and the second rotating member;
A third clutch for selectively connecting the cylindrical rotating member and the third rotating member;
The first rotating member is the pinion carrier, the second rotating member is the sun gear, and the third rotating member is the ring gear;
The first gear is locked by the first sync, and the first gear is achieved by fastening the first clutch and the second clutch,
The first gear is locked by the first sync, the third gear is locked by the second sync, and the second gear is achieved by engaging the second clutch and the third clutch,
The third gear is locked by the second sync, and the third gear is achieved by engaging the first clutch and the third clutch,
The fourth gear is locked by the first sync, and the first gear and the second clutch are fastened to achieve the fourth speed,
The fourth gear is locked by the first sync and the sixth gear is locked by the third sync, and the fifth gear is achieved by engaging the second clutch and the third clutch.
The sixth gear is locked by the third sync, and the sixth gear is achieved by fastening the first clutch and the third clutch,
The sixth gear is locked by the third sync and the eighth gear is locked by the fourth sync, and the seventh gear is achieved by engaging the second clutch and the third clutch.
A transmission for a vehicle that achieves the eighth speed by engaging the eighth gear with the fourth sync and engaging the first clutch and the second clutch . The vehicle transmission according to claim 1, wherein
The planetary gear is a transmission for a vehicle, which is a simple planetary gear having a sun gear, a pinion carrier that supports the pinion, and a ring gear.

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