JP2925472B2 - Automatic transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an automatic transmission, and more particularly, to an automatic transmission having a planetary gear train as a transmission.

[0002]

2. Description of the Related Art As conventional automatic transmissions, three or four forward speeds are used for passenger cars, and three to six forward speeds are used for trucks and buses. Among them, the fifth speed or the sixth speed, which is a multi-speed type, is particularly preferred.
In a high-speed automatic transmission, three or more planetary gear trains and five or more brake and clutch devices for controlling the rotation of the planetary gear train are required. Control becomes very complicated.

[0003] In an automatic transmission for large vehicles such as trucks and buses, a third speed or a fourth speed is sufficient for a route bus or a dust collector which is used only at a low speed. In this case, the speed is changed to the fifth speed or the sixth speed, and two types of transmissions for low speed and high speed are required.

[0004]

As a conventional automatic transmission, there is one disclosed in Japanese Patent Publication No. Hei 6-97065. This automatic transmission has a torque converter and a transmission to which an output from the torque converter is input. The torque converter is a four-element two-stage type having an impeller, a turbine, a first stator, a second stator, and the like. A lock-up clutch is provided between the turbine and a flywheel that is a member on the engine side. I have. The transmission has three forward speeds and one reverse speed, and has two sets of planetary gear trains that share a carrier and have planetary gears meshing with each other on the carrier, and a brake and a clutch for controlling the two planetary gear trains. doing.

In this automatic transmission, the turbine and the first
The output of the stator is input to the transmission, and a larger starting force is obtained as compared with a conventional ordinary torque converter that inputs only the output of the turbine to the transmission.
Further, simplification of the power transmission path is realized. Therefore, it is considered that the use of such an automatic transmission makes it possible to realize a small-sized automatic transmission capable of performing multi-speed shifting.

SUMMARY OF THE INVENTION An object of the present invention is to enable a multi-speed transmission with a small and simple structure. Another object of the present invention is to
It is an object of the present invention to make it possible to perform a small-sized multi-speed transmission for a high-speed vehicle without changing the transmission portion of the automatic transmission disclosed in the above publication.

[0007]

An automatic transmission according to a first aspect of the present invention includes a fluid coupling portion and a transmission portion. The fluid coupling portion has a fluid coupling body to which power is input from a vehicle engine, a first planetary gear train, a lock-up clutch device, and a one-way clutch. A first planetary gear train, a first ring gear connected to an output portion of the fluid coupling body, a plurality of first planetary gears meshing with the first ring gear, a carrier supporting the first planetary gear, A first sun gear that meshes with the planetary gears, and outputs the output rotation of the fluid coupling body from the carrier and the first sun gear. The lock-up clutch device directly transmits or cuts off the power from the engine to the carrier of the first planetary gear train. A one-way clutch is connected to the first sun gear;
Only the rotation in the direction opposite to the output rotation direction of the fluid coupling is transmitted to the output side.

The transmission has a second planetary gear train, a third planetary gear train, a clutch device, and first to third brake devices. A second planetary gear train, a second sun gear connected to the first sun gear via the one-way clutch, a plurality of second planetary gears meshing with the second sun gear, a carrier supporting the second planetary gear, A second ring gear that meshes with the second planetary gear. The third planetary gear train includes a third sun gear connectable to the carrier of the first planetary gear train, and a plurality of third sun gears meshing with the third sun gear and meshing with the second planetary gear and supported by the carrier of the second planetary gear train. It has a third planetary gear and a third ring gear that meshes with the third planetary gear. The clutch device is a device for fastening or releasing the second sun gear and the third sun gear. The first brake device is a device for braking the rotation of the second sun gear. The second brake device is a device for braking the rotation of the second ring gear. The third brake device is a device for braking the rotation of the third ring gear.

Here, the reduction ratio and the direction of rotation are changed by controlling the operation of the clutch device and each brake device. When the lock-up clutch device is in the connected state, the power from the engine is directly input to the transmission unit, and the transmission is shifted and output. On the other hand, in the disengaged state of the lock-up clutch device, the power from the engine is input to the first planetary gear train provided in the fluid coupling portion via the fluid coupling main body, where it is distributed to the carrier and the first sun gear and shifted. It is transmitted to the equipment. Therefore, the gear position can be increased by the amount of connection and release of the lock-up clutch device. Since the first planetary gear train is arranged in the fluid coupling portion, it is possible to avoid an increase in the size of the entire device. Further, as the transmission section, the same transmission section as that of the conventional structure can be used to increase the overall speed.

An automatic transmission according to a second aspect of the invention is the automatic transmission according to the first aspect, further comprising an output shaft connected to a carrier supporting the second planetary gear and the third planetary gear.
An automatic transmission according to a third aspect of the present invention is the automatic transmission according to the first or second aspect, wherein the fluid coupling main body is connected to an impeller connected to an engine-side member, and the first ring gear is connected to the impeller via a fluid. Turbine.

An automatic transmission according to a fourth aspect of the present invention is the automatic transmission according to the third aspect, wherein the fluid coupling main body is disposed between the impeller and the turbine, and rotates the second sun gear only in a direction opposite to a rotation direction of the turbine. And a first stator for transmitting the first stator. An automatic transmission according to a fifth aspect of the present invention is the automatic transmission according to the fourth aspect, wherein the fluid coupling body further includes a second stator provided so as to be rotatable only in the same direction as the turbine.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The automatic transmission shown in FIG. 1 has a torque converter 2 as a fluid coupling part to which power is input from an engine 1 and a transmission 3 provided on the output side of the torque converter 2. doing. The torque converter 2 and the transmission 3 are housed in a housing 4.

The torque converter 2 includes a torque converter body 10 and a first torque converter 2 disposed inside the torque converter 2.
It has a planetary gear train 11 and a lock-up clutch device 12 for transmitting power from the engine directly to the output side. As shown in an enlarged manner in FIG. 2, the torque converter main body 10 includes an impeller 15 connected to a crankshaft of an engine, a turbine 16 disposed opposite to the impeller 15 and connected via hydraulic oil, and an impeller 15. 1
And a stator 17 arranged between the turbine 5 and the turbine 16. The impeller 15 is rotatably supported by the housing 4. The impeller 15, the turbine 16 and the stator 17 each have a shell and a blade.

The first planetary gear train 11 is arranged on the turbine inner peripheral side of the torque converter main body 10. The first planetary gear train 11 includes a ring gear R connected to a turbine 16.
1 and a plurality of planetary gears P1 meshing with the ring gear R1
And a cylindrical sun gear S1 arranged at the center and meshing with the planetary gear P1. The plurality of planet gears P1 are held by the carrier 18. The carrier 18 has a connecting portion that holds each planetary gear P1 and a shaft portion that extends rearward from the center of the connecting portion through the center of the sun gear S1. Here, in the first planetary gear train 11, the number of teeth of the ring gear R1 is Zr1, and the number of teeth of the sun gear S1 is Zs1.
It has become.

As shown in FIGS. 1 and 3, the transmission 3
It has a second planetary gear train 20, a third planetary gear train 21, and a rotation control device including a clutch device 22 and a brake device 23 for controlling the rotation of each of the planetary gear trains 20, 21. The second planetary gear train 20 includes a sun gear S2, a planet gear P
2 and a ring gear R2. Note that the second planetary gear train 20 also includes a planetary gear P3 of the third planetary gear train. The planetary gear P2 meshes with the sun gear S2 and the ring gear S2, and also meshes with the planetary gear P3. This meshing state is schematically shown in FIGS. The sun gear S2 is a first one-way clutch 25
And connected to the sun gear S1 of the first planetary gear train 11 via a second one-way clutch 26 and to the stator 17 of the torque converter main body 10. Here, the first one-way clutch 25 is connected to the first planetary gear train 11.
The clutch transmits the output rotation of the sun gear S1 only in a direction opposite to the output rotation (turbine rotation) direction of the torque converter 2. The second one-way clutch 26 is a clutch that transmits the rotation of the stator 17 only in the direction opposite to the rotation direction of the turbine 16. The second planetary gear train 20
The number of teeth of the sun gear S2 is Zs2, and the ring gear R2
Is Zr2.

The third planetary gear train 21 includes a sun gear S
3. It has a planetary gear P3 and a ring gear R3. The sun gear S3 is connected to the carrier 18 of the first planetary gear train 11. Further, the planetary gear P3 extends to the second planetary gear train 20 in the axial direction, and the sun gear S3
And the ring gear R3 and the planetary gears P2 of the second planetary gear train 20. And the second
And the planetary gears P2, P3 of the third planetary gear trains 20, 21
Share a carrier 24, which is connected to an output shaft 30. The third planetary gear train 21
The number of teeth of the sun gear S3 is Zs3, and the ring gear R3
Is Zr3.

FIG. 5 shows an example of the number of teeth of each planetary gear train.
The rotation control device includes a clutch device 22 for engaging and disengaging the sun gear S2 of the second planetary gear train 20 and the sun gear S3 of the third planetary gear train 21, and a rotation of the sun gear S2 of the second planetary gear train 20. First brake device B1 for braking
And a second brake device B2 that brakes the rotation of the ring gear R2 of the second planetary gear train 20 and a third brake device B3 that brakes the rotation of the ring gear R3 of the third planetary gear train 21. .

Next, the operation will be described with reference to FIG. In the embodiment having the above configuration, the shift speed is set to the forward 5
Speed and reverse 2nd speed. [First forward speed] In this case, only the third brake device B3 is turned on (operated: braked), whereby the third planetary gear train 2
The rotation of the first ring gear R3 is braked. The other brake devices B1 and B2 are turned off (non-operating: released), and the lock-up clutch device 12 and the clutch device 22 are each turned off (disconnected).

Here, the power from the engine is supplied to the first planetary gear train 1 through the turbine 16 of the torque converter 2.
1 and distributed to the carrier 18 and the sun gear S1. The power distributed to the sun gear S1 is input to the sun gear S2 via the first one-way clutch 25 and the second planetary gear train 20, and the power distributed to the carrier 18 is input to the sun gear S3 of the third gear train. You. Here, since the sun gear S3 rotates forward and the sun gear S2 rotates reversely,
The power via the turbine 16 is reduced by the first planetary gear train 11 and input to the second and third planetary gear trains 20 and 21. Then, the speed is further reduced by the second and third planetary gear trains 20 and 21 and output from the output shaft 30. Further, part of the power input to the torque converter 2 is also output from the stator 17 to the third planetary gear train 21 via the second one-way clutch 26 and the second planetary gear train 20, and the output is They are combined and output from the output shaft 30. As shown in FIG. 6, the reduction ratio in this case is (Zs3 + Zr3) /Zs3+Zs1.Zr3. (Zs2 + Zs3) / (Zs2.Zs3.
Zr1). FIG. 6 also shows a fastening element, and “OW
"C" indicates the first one-way clutch 25, "L / U" indicates the lock-up clutch device 12, "B1 to B3" indicates the first to third brake devices B1 to B3, and "C1" indicates the clutch device 22. Each is shown. FIG. 7 is a speed diagram showing the relationship between the input and output rotational speeds. At this first speed, the ring gear R1 of the first planetary gear train 11 is input,
Since the planetary gear P3 of the planetary gear train 21 outputs, its reduction ratio is shown by (H0 / H1) in FIG.

As described above, at the first speed, the power from the turbine 16 and the stator 17 of the torque converter 2 is combined and output. Therefore, as shown in the traction characteristics of FIG. 8, a large starting force can be obtained. [Second forward speed] In this case, the third brake device B3 is turned on, and the lock-up clutch device 12 is turned on (coupled). Further, the other brake devices B1, B2 and the clutch device 22 are turned off.

Here, the power from the engine is directly transmitted to the sun gear S3 of the third planetary gear train 21 via the lock-up clutch device 12, and the third planetary gear train 21
And is output from the output shaft 30. The reduction ratio in this case is (Zs3 + Zr3) / Zs3, as shown in FIG. In the velocity diagram of FIG. 7, it is indicated by (H0 / H2).

[ Third Forward Speed] In this case, only the first brake device B1 is turned on, and the rotation of the sun gear S2 of the second planetary gear train 20 is braked. Second and third brake devices B
2, B3, the lock-up clutch device 12 and the clutch device 22 are turned off. Here, the power from the engine is transmitted to the first planetary gear train 11 via the turbine 16 of the torque converter 2. Here, since the sun gear S1 is fixed to the housing 4 by the first brake device B1 via the first one-way clutch 25, the power is reduced by the first planetary gear train 11 and is transmitted from the carrier 18 to the third planetary gear train. 21 sun gears S3 are input. The power input to the sun gear S3 is reduced by the third planetary gear train 21 and output from the output shaft 30. The stator 17 of the torque converter 2 is fixed to the housing 4 by the first brake device B1 via the second one-way clutch 26. As shown in FIG. 6, the reduction ratio in this case is (Zs2 + Zr3) / Zs3 + Zs1 · Zr3 · (Zs2 + Zs3) / (Zs3 · Zr1 ·
Zr3). In the velocity diagram of FIG. 7, it is indicated by (H0 / H3).

As described above, at the third speed, the power from the torque converter 2 is output only from the turbine 16, is reduced by the first planetary gear train 11, and is further reduced by the second and third planetary gear trains 20, 21. Is decelerated and output. [Fourth forward speed] In this case, the first brake device B1 and the lock-up clutch device 12 are turned on, and the other brake devices B2 and B3 and the clutch device 22 are turned off.

Here, as in the case of the second speed, the power from the engine is directly transmitted to the sun gear S3 of the third planetary gear train 21 via the lock-up clutch device 12, and
And the output shaft 30 which is reduced by the third planetary gear trains 20 and 21.
Output from Since the sun gear S2 of the second planetary gear train 20 is fixed in this case, the reduction ratio is (Zs2 + Zs3) / Zs3, as shown in FIG. In the velocity diagram of FIG. 7, it is indicated by (H0 / H4).

[ Fifth forward speed] In this case, the clutch device 2
2 is turned on, and the other brake devices B2 and B3 are turned off. In this case, when the lockup clutch device 12 is on, power is directly output, but when it is off, power is output via the turbine 16 of the torque converter 2.

Here, the motive power from the engine is selectively transmitted to the sun gears S2 and S3 of the second and third planetary gear trains 20 and 21 via the lock-up clutch device 12 or the turbine 16; Since 22 is on, the speed reduction ratio is “1”. [First reverse speed] In this case, only the second brake device B2 is turned on, and the other brake devices B1, B3, the lock-up clutch device 12, and the clutch device 22 are turned off.

Here, the power transmission path from the engine is the same as in the first forward speed, but since the ring gear R2 of the second planetary gear train 20 is fixed, the power transmission path from the carrier 18 of the first planetary gear train 11 is set. Forward rotation force is converted to reverse rotation force. Also,
The reverse rotation force from the sun gear S1 is applied to the second and third planetary gear trains 2
The output is decelerated at 0 and 21. Here, output shaft 3
0 rotates in the reverse direction, and the reduction ratio in this case is-(Zr2-Zs3) /Zs3-Zs1.Zr2. (Zs2 + Zs3) / (Zs2.Zs3
・ Zr1) In the velocity diagram of FIG. 7, (H0 / Hr1)
Indicated by

[ Second reverse speed] In this case, the second brake device B2 and the lock-up clutch device 12 are turned on. The power transmission path here is the same as in the case of the second forward speed, but the output rotation is in the opposite direction as in the case of the first reverse speed, and the reduction ratio is-(Zr2-Zs3) / Zs3. Also, in the velocity diagram of FIG. 7, it is indicated by (H0 / Hr2).

In such an embodiment, an automatic transmission having five forward speeds and two reverse speeds can be realized without changing the structure of the transmission having three forward speeds and one reverse speed. Further, since the first planetary gear device 11 for multi-stage is provided in the torque converter, it is possible to prevent the entire device from becoming large. [Other Embodiments] (a) FIG. 9 shows a fluid coupling portion according to another embodiment. The configuration on the transmission side is the same as that of the above-described embodiment. FIG. 10 shows the traction characteristics of the embodiment shown in FIG.

The fluid coupling portion of this embodiment is different in the configuration of the torque converter main body 40. That is, the torque converter main body 40 includes an impeller 41 connected to an engine-side member, a turbine 42 disposed opposite to the impeller 41, and a first stator 43 and a second stator 44 disposed therebetween. have. And
The ring gear R <b> 1 of the first planetary gear train 11 is connected to the turbine 42. The first stator 43 is connected to the second planetary gear train 20 on the transmission side via a one-way clutch 45, and power is transmitted only when the turbine 42 is rotating in the reverse direction. The second stator 44 is fixed to the housing 4 via a one-way clutch 46. The second stator 44 is fixed only at the time of reverse rotation with respect to the turbine 42, and idles at the time of normal rotation.

In this case, at the first forward speed, the third speed, and the first reverse speed in which the power is transmitted via the torque converter, the fluid easily enters the impeller 41 by the second stator 44, and the efficiency is improved. . (B) FIG. 11 shows still another embodiment, and FIG. 12 shows its traction characteristics. This embodiment differs only in the configuration of the body 50 of the fluid coupling. That is, in this embodiment, the main body 50 has only the impeller 51 and the turbine 52 and is a fluid coupling. Ring gear R of first planetary gear train 11
1 is connected to the turbine 52.

[0032]

As described above, according to the present invention, it is possible to perform a multi-stage shift with a small and simple configuration. Further, it is possible to achieve a multi-stage transmission without changing the configuration of the transmission portion of the conventional automatic transmission.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an automatic transmission according to an embodiment of the present invention.

FIG. 2 is an enlarged partial view of the torque converter.

FIG. 3 is an enlarged partial view of the transmission portion.

FIG. 4 is a schematic front view of second and third planetary gear trains.

FIG. 5 is a diagram showing the number of gear teeth of each planetary gear train.

FIG. 6 is a diagram showing a fastening element and a reduction ratio at each shift speed of the device.

FIG. 7 is a velocity diagram of the device.

FIG. 8 is a traction characteristic diagram of the device.

FIG. 9 is a schematic configuration diagram of a fluid coupling portion according to another embodiment.

FIG. 10 is a traction characteristic diagram.

FIG. 11 is a schematic configuration diagram of a fluid coupling portion according to still another embodiment.

FIG. 12 is a traction characteristic diagram.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine 2 Torque converter 3 Transmission 4 Housing 10 Torque converter main body 11 First planetary gear train 12 Lock-up clutch device 15 Impeller 16 Turbine 17 Stator 20 Second planetary gear train 21 Third planetary gear train 22 Clutch device B1, B2 B3 brake device 25 one-way clutch 30 output shaft

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F16H 47/06-47/08 F16H 3/44-3/78

Claims (5)

(57) [Claims] 1. An automatic transmission having a fluid coupling portion and a transmission portion, wherein the fluid coupling portion includes a fluid coupling main body to which power is input from a vehicle engine, and an output portion of the fluid coupling main body. A first ring gear connected to the first ring gear; a plurality of first planetary gears meshing with the first ring gear; a carrier supporting the first planetary gear;
A first planetary gear train having a first sun gear meshing with a planetary gear, and outputting the output rotation of the fluid coupling main body from the carrier and the first sun gear; and a carrier of the first planetary gear train for transmitting power from the engine. A lock-up clutch device for directly transmitting or disconnecting the fluid coupling, and a one-way clutch connected to the first sun gear and transmitting only rotation in a direction opposite to an output rotation direction of the fluid coupling to an output side, The transmission includes: a second sun gear connected to the first sun gear via the one-way clutch; a plurality of second planetary gears meshing with the second sun gear; and a carrier supporting the second planetary gears; A second planetary gear train having a second ring gear meshing with the second planetary gear; a third sun gear connectable to a carrier of the first planetary gear train; and a third sun gear. A third planetary gear train having a plurality of third planetary gears that mesh with and mesh with the second planetary gears and are supported by the carrier of the second planetary gear train; and a third ring gear that meshes with the third planetary gears. A clutch device for engaging or disengaging the second sun gear and the third sun gear; a first brake device for braking the rotation of the second sun gear; and a braking device for braking the rotation of the second ring gear. An automatic transmission, comprising: a second brake device; and a third brake device for braking rotation of the third ring gear. 2. An output shaft connected to a carrier that supports the second planetary gear and the third planetary gear.
The automatic transmission according to claim 1. 3. The fluid coupling body includes an impeller connected to a member on the engine side, and a turbine connected to the impeller via a fluid and having the first ring gear attached thereto. 3. The automatic transmission according to 1 or 2. 4. The fluid coupling body further includes a first stator disposed between the impeller and the turbine and transmitting only rotation in a direction opposite to a rotation direction of the turbine to the second sun gear. The automatic transmission according to claim 3. 5. The automatic transmission according to claim 4, wherein the fluid coupling body further includes a second stator provided so as to be rotatable only in the same direction as the turbine.