JP3080057B2 - Automatic transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic transmission for a vehicle, and more particularly, to an automatic transmission mounted on a vehicle having a horizontal engine.

[0002]

2. Description of the Related Art As is well known, an automatic transmission inputs a driving force from a torque converter to a gear transmission mechanism mainly including a planetary gear mechanism, and transmits a transmission path of the driving force in the gear transmission mechanism by a clutch or a brake. By changing the gear ratio, a plurality of shift speeds are set. This type of automatic transmission has an advantage that the components can be arranged side by side on the same axis. However, in general, the output portion is located on the torque converter side, that is, on the side opposite to the input portion side. Therefore, in an automatic transmission mounted on a vehicle of a horizontally mounted engine type, the output portion is centered in the vehicle width direction. In order to set the position closer to the part, a countershaft is arranged in parallel with the gear transmission mechanism, and a final gear provided at one end of the countershaft is configured to output to a front differential or the like.

[0003] On the other hand, gear shifting operations in an automatic transmission are performed by hydraulic pressure.
It is well known that the timing of the pressure reduction greatly affects the durability of the engagement means such as the shift shock and the clutch, and in particular, in the case of an automatic transmission mounted on a vehicle with a horizontal engine, the vehicle width is limited. For this reason, it is strongly demanded that the overall length be as short as possible. For this reason, conventionally, automatic transmissions in which the arrangement of components such as a planetary gear mechanism and a clutch is variously changed have been proposed.

For example, Japanese Patent Application Laid-Open No. 58-163849 discloses that an input shaft is provided on the same axis as a torque converter, an output shaft is arranged in parallel with the input shaft, a clutch and a gear are mounted on each shaft, and A C1 clutch for setting the first forward speed is provided at the shaft end of the input shaft, that is, at the end opposite to the torque converter, independently of the other clutches, and the speed is shifted by a planetary gear mechanism provided on the input shaft. There is described an automatic transmission configured to output a driving force or a driving force shifted between an input shaft and an output shaft from a gear at an end on a torque converter side of an output shaft in a front differential manner. With such a configuration,
Since the C1 clutch is separated from the other clutches, there is no possibility that the hydraulic pressure applied to the other clutches will affect the C1 clutch, so that the seal structure can be made relatively simple.

Japanese Patent Application Laid-Open No. 57-87716 discloses that a first clutch engaged at a first forward speed, a second speed, and a third speed is connected to a gear transmission mechanism mainly composed of a planetary gear mechanism. Are also disposed on the torque converter side, and a second clutch engaged at the third forward speed and the reverse speed is provided on the opposite side of the first clutch with respect to the gear transmission mechanism. An automatic transmission is described in which a driving force is transmitted by a chain from a sprocket provided between the clutch and a planetary gear mechanism coaxial with a front differential. Even with such a configuration, similar to the automatic transmission described above, there is no possibility that the hydraulic pressure of another clutch will affect the clutch engaged in the first to third speeds, so the seal structure thereof Can be relatively simple.

Further, Japanese Patent Application Laid-Open No. 55-33948 discloses an automatic transmission in which one set of a planetary gear mechanism, a clutch, and a brake is provided to perform two forward and two reverse shifts. A configuration in which the clutch is disposed on the torque converter side with respect to the planetary gear mechanism and the clutch is disposed on the opposite side of the planetary gear mechanism with respect to the torque converter is described. Since it is located near the center of the width, the countershaft can be shortened.

[0007]

However, in the structure described in Japanese Patent Application Laid-Open No. 58-163849, the output shaft is also provided with gears and clutches for speed change. Although it may be possible to shorten the overall length, there is a problem that the dimension in the radial direction becomes large, and even if the C1 clutch is independent of the other clutches, the clutch is connected to the shaft of the input shaft. The length of the output shaft is increased by the end-mounted structure, and the length of the output shaft is increased by supporting the shaft end of the output shaft with the casing accommodating the C1 clutch. And other problems.

In general, in an automatic transmission, the hydraulic pump is disposed immediately after the torque converter because the hydraulic pump is directly connected to the pump impeller of the torque converter. If it is located at the farthest position, the hydraulic pressure must be supplied to the C1 clutch via the inside of the input shaft, and therefore the hydraulic pressure for the C1 clutch is affected by the centrifugal force accompanying the rotation of the input shaft. As a result, the shift shock may have worsened.

In the conventional automatic transmission described in Japanese Patent Application Laid-Open No. 57-87716, as described above,
Since the hydraulic pressure of the other clutch does not affect the so-called forward clutch for setting the speed or the third speed, the seal structure in the oil passage for the forward clutch may be simplified. However, since the sprocket is arranged between the forward clutch and the torque converter, the forward clutch must be arranged separately from the hydraulic pump.

Therefore, the above-mentioned Japanese Patent Application Laid-Open No. 58-163 is disclosed.
Similarly to the automatic transmission disclosed in Japanese Patent No. 849, hydraulic pressure is supplied to the forward clutch via the input shaft, so that the centrifugal force may affect the hydraulic pressure and the shift shock may be deteriorated. Furthermore, the automatic transmission described in Japanese Patent Application Laid-Open No. 57-87716 is provided with a chain transmission mechanism and a planetary gear mechanism arranged coaxially with a front differential, instead of a countershaft. It may be possible to reduce the shaft length to some extent by being arranged on the front side, that is, closer to the torque converter.

However, if the sprocket is replaced with a counter drive gear and a well-known counter shaft is used, the final gear on the counter shaft is provided on the front side of the counter driven gear meshing with the counter drive gear. As a result, in order to secure a space for the final gear, it is necessary to shift the above-described clutch and gear transmission mechanism further rearward (opposite to the torque converter). That is,
If the configuration described in Japanese Patent Application Laid-Open No. 7-87716 is applied to an automatic transmission having a counter shaft, there is a problem that the shaft length becomes long.

Further, in the automatic transmission described in Japanese Patent Application Laid-Open No. 55-33948, the counter shaft can be shortened, but this is achieved by a two-speed automatic transmission provided with a planetary gear mechanism, a clutch and a brake. Transmission. Therefore, the technique described in Japanese Patent Application Laid-Open No. 55-33948 cannot be immediately applied to an automatic transmission that is provided with a plurality of sets of planetary gear mechanisms, clutches, etc., and that performs a third or higher speed shift. Also in this automatic transmission, since the clutch is disposed on the opposite side of the planetary gear mechanism from the torque converter, the hydraulic pressure for the clutch has to be supplied through the input shaft.
There is a possibility that the shift shock may be deteriorated due to the centrifugal force affecting the hydraulic pressure for the clutch.

An automatic transmission capable of setting three or more forward speeds, wherein a clutch, a counter drive gear, and a gear transmission mechanism are arranged on the same axis in order from the torque converter side. But, Japanese Patent Application No. 61-
293663 (Japanese Patent Application Laid-Open No. 63-145846) (unknown at the time of filing the present application).

However, in this automatic transmission, the clutch disposed between the torque converter and the counter drive gear is a so-called reverse clutch which is engaged to set the reverse speed, and is used for setting the forward speed. The clutch is disposed at a shaft end opposite to the torque converter with the gear transmission mechanism interposed therebetween. For this reason, similarly to the above-described conventional automatic transmission, there is a possibility that the hydraulic pressure supplied to the clutch for setting the forward gear is likely to be affected by the centrifugal force. There was room to be.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to reduce the shaft length and weight of an automatic transmission having a counter shaft, and to further reduce shift shock. It is.

[0016]

In order to achieve the above-mentioned object, a first aspect of the present invention is to attach a gear transmission mechanism comprising a plurality of sets of planetary gear mechanisms arranged on the same axis to a torque converter. And a transmission path of a driving force in the gear transmission mechanism is set to at least four forward gears and one reverse gear by changing engagement and disengagement of a plurality of clutches and brakes. In an automatic transmission that transmits a driving force transmitted from a transmission mechanism to a counter shaft arranged in parallel with a gear transmission mechanism via a counter drive gear, and outputs a driving force from a final gear provided on the counter shaft. A first clutch of the friction engagement device, the first clutch being engaged in the first to third speeds of the forward gear and being released in the fourth speed; A counter drive gear is disposed between the first clutch and the gear transmission mechanism, the counter drive gear being disposed between the first clutch and the gear transmission mechanism with respect to the vehicle transmission mechanism, and the gear transmission mechanism is connected to the first clutch. The first sun gear, the first ring gear disposed concentrically with the first sun gear, the first sun gear and the first pinion meshed with the first ring gear are rotatably held, and the counter drive gear A first planetary gear mechanism having a first carrier connected thereto; a second ring gear connected to the first carrier; a second sun gear disposed concentrically with the second ring gear; and a second ring gear and a second sun gear. A second pinion rotatably holding the second pinion meshed with the second sun gear and having a second carrier connected to the first ring gear; And a gear mechanism, wherein the plurality of clutches and brakes, and a second clutch for transmitting the selectively driving force from the torque converter to the second carrier, the second from the torque converter
A third clutch for selectively transmitting a driving force to the sun gear, a first brake mechanism for selectively stopping rotation of the second sun gear, and a second brake mechanism for selectively stopping rotation of the first ring gear and the second carrier. And a brake mechanism.

[0017] The invention according to claim 2, configured <br/> example pressurized according to claim 1, comprising a case housing at least said counter drive gear and the gear shift mechanism and the clutch and brake, the counter drive gear Are rotatably supported by a supporting portion provided in the case, and the supporting portion is disposed between the counter drive gear and the gear transmission mechanism.

[0018] The invention according to claim 3, configured <br/> example pressurized according to claim 1, wherein with Cow tongue drive gear to mesh with the counter driven gear is provided on said counter shaft, said final gear is the counter driven gear It is characterized in that it is arranged on the torque converter side in the axial direction.

According to a fourth aspect of the present invention, in addition to the configuration of the first aspect, a hydraulic pump is disposed between the torque converter and the first clutch on the same axis as the torque converter and the first clutch. It is characterized by having.

According to a fifth aspect of the present invention, in addition to the configuration of the fourth aspect, the first clutch includes a drum containing a piston for engaging the clutch, and the hydraulic pump includes a first clutch. A boss having a boss protruding toward the side along the axial direction is provided at the center, and the drum is rotatably fitted to and supported by the boss.

According to a sixth aspect of the present invention, in addition to the configuration of the fifth aspect, an oil passage for supplying and discharging hydraulic pressure for moving the piston is formed in the boss portion.

According to a seventh aspect of the present invention, in addition to any one of the first to sixth aspects, a differential mechanism integrally provided with a driven gear meshed with the final gear is provided, and the differential mechanism comprises:
It is characterized in that a bulging portion protruding toward the torque converter in the axial direction of the driven gear is provided.

The invention according to claim 8 is characterized in that a gear transmission mechanism comprising a plurality of sets of planetary gear mechanisms arranged on the same axis is connected to a torque converter, and a transmission path of a driving force in the gear transmission mechanism is By changing a plurality of clutches and brakes by engaging / disengaging them, at least three forward speeds and one reverse speed are set, and the driving force from the gear transmission mechanism is shifted through a counter drive gear. In an automatic transmission that transmits to a counter shaft arranged in parallel with the mechanism and outputs driving force from a final gear provided on the counter shaft, the gear transmission mechanism selectively drives the driving force from the torque converter. The first sun gear to be transmitted, the first ring gear disposed concentrically with the first sun gear, and the first sun gear and the first sun gear. A first planetary gear mechanism rotatably holding a first pinion meshed with the ring gear and having a first carrier connected to the counter drive gear; and a second ring gear connected to the first carrier. A second sun gear arranged concentrically with the second ring gear and a second pinion meshed with the second ring gear and the second sun gear are rotatably held, and a second carrier connected to the first ring gear is provided. And a second planetary gear mechanism having: a first clutch that selectively transmits driving force from the torque converter to the first sun gear; A second clutch for selectively transmitting a driving force to the second carrier; and selectively driving the second sun gear from the torque converter. Third transmitting a
, A first brake mechanism for selectively stopping rotation of the second sun gear, and a second brake mechanism for selectively stopping rotation of the first ring gear and the second carrier. The first clutch is disposed closer to the torque converter than the gear transmission mechanism, and the counter drive gear is disposed between the first clutch and the gear transmission mechanism. And

According to the first to eighth aspects of the present invention,
By controlling the engagement and disengagement of the plurality of clutches and brakes, the automatic transmission is set to an appropriate gear position, the driving force output from the gear transmission mechanism is transmitted from the counter drive gear to the counter shaft, and Output from the final gear. Since the first clutch is disposed closer to the torque converter than the counter drive gear, the configuration of the oil passage for supplying and discharging the hydraulic pressure to and from the first clutch is simplified, and the first clutch is engaged. When the predetermined gear is set in combination, the hydraulic pressure of the first clutch is not affected by the centrifugal force, so that the hydraulic pressure is stabilized, and as a result, the deterioration of the shift shock is prevented.

In particular, when the first clutch is engaged in the first to third speeds of the forward gear and disengaged in the fourth speed as in the first aspect of the present invention, the accelerator is operated while the vehicle is running. Even in the case where the shift between the third speed and the fourth speed is frequently performed due to a change in the opening degree or the vehicle speed, deterioration of the shift shock is prevented beforehand, and the riding comfort is improved.

According to the first to eighth aspects of the present invention, since the counter drive gear is disposed closer to the torque converter than the gear transmission mechanism, the counter driven gear meshing with the counter drive gear can also be disposed closer to the torque converter. As a result, the counter shaft is shortened, so that the whole can be made compact and lightweight.

Further, according to the first to eighth aspects of the present invention, the final gear usually has a smaller diameter than the counter driven gear, and a space is generated on the outer peripheral side of the final gear. Since the clutch is disposed closer to the torque converter than the counter drive gear, that is, disposed on the front side, the first clutch can be disposed closer to the outer peripheral side of the final gear to effectively use the space. The outer diameter can be reduced while shortening the length.

Further, according to the second aspect of the present invention, since the support portion of the counter drive gear is disposed between the counter drive gear and the gear transmission, a portion accommodating the gear transmission is provided; Since the portion accommodating the first clutch can be separated by the support portion, oil acting on another clutch or brake disposed on the gear transmission mechanism side flows into the first clutch side. Can be prevented. That is, since the supporting portion also has a function of separating the first clutch from the other clutch and the brake, a special seal for preventing the influence of the hydraulic pressure on the other clutch on the first clutch is provided. This is unnecessary, so that the sealing structure can be simplified.

Further, according to the third aspect of the present invention, since the final gear is disposed closer to the torque converter in the axial direction than the counter driven gear, the first clutch can be used by utilizing the space on the outer peripheral side of the final gear. Because it can be arranged and the shaft length of the counter shaft can be shortened,
The overall configuration can be reduced in size.

[0030]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a skeleton diagram showing an embodiment of the present invention in principle. The automatic transmission shown here is mounted on a vehicle of an engine horizontal type, and overdrive is performed by two sets of planetary gear mechanisms. At least four forward speeds and one reverse speed are set.

That is, the engine 1 is arranged in the width direction of the vehicle, and a pump impeller 3 constituting a torque converter 2 is provided on its crankshaft with a drive plate and a front cover (each not shown). Are connected through means of (1). The torque converter 2 includes a pump impeller 3 and a turbine runner 4,
The turbine runner 4 has a well-known configuration in which a stator 5 is disposed so as to be opposed to the stator 5 or a direct coupling clutch (not shown) is additionally provided. 6), and the stator 5 is mounted on a fixed shaft 8 via a one-way clutch 7.

A hydraulic pump 9 is provided adjacent to the torque converter 2 on the same axis. This hydraulic pump 9
Is fixed to a transmission case 10, and its rotor is connected to a hollow shaft (not shown) integral with the outer shell of the pump impeller 3, so that the hydraulic pump 9 is substantially directly driven by the engine 1. It is configured to be.

Following the hydraulic pump 9, a first clutch (hereinafter referred to as a forward clutch) C1 and a counter drive gear 11 are sequentially arranged on the same axis. The forward clutch C1 is engaged by hydraulic pressure in the same manner as a general clutch, and is configured such that a clutch drum is connected to the input shaft 6 and its driving force is transmitted to a gear transmission mechanism 12 described below. ing. The counter drive gear 11 is for transmitting the driving force from the gear transmission mechanism 12 to a counter shaft 13 described later, and is rotatably attached to the transmission case 10 via a bearing 14.

The bearing 14 and a part of the transmission case 10 allow the interior of the transmission case 10 to have an area where the gear transmission mechanism 12 and the clutch brake are arranged, and an area where the forward clutch C1 and the counter drive gear 11 are arranged. It is partitioned.
That is, the bearing 14 and the transmission case 10
Corresponds to the supporting portion of claim 2.

The gear transmission mechanism 12 is mainly composed of first and second planetary gear mechanisms (front and rear planetary gears) 15 and 16 arranged on the same axis. A first sun gear 17 is connected to the forward clutch C1, and
A first carrier 18 holding a plurality of first pinions 18 </ b> A meshed with the sun gear 17 is connected to the counter drive gear 11. The first ring gear 19 of the first planetary gear mechanism 15 and the second sun gear 2 of the second planetary gear mechanism 16
2 that holds a plurality of second pinions 20A that mesh with
The carrier 20 is connected so as to be integrated, and the second ring gear 21 of the second planetary gear mechanism 16 and the first carrier 18 of the first planetary gear mechanism 15 are connected so as to be integrated.

The second clutch C2 for transmitting the driving force from the input shaft 6 to the gear transmission mechanism 12 is
, The input shaft 6 and the second carrier 20 of the second planetary gear mechanism 16 are connected to and disconnected from each other. Input shaft 6
A third clutch C3 for connecting and disconnecting the second sun gear 22 of the second planetary gear mechanism 16 and the second clutch C2
Therefore, the third clutch C3 is also disposed on the opposite side of the forward clutch C1 with respect to the gear transmission mechanism 12.

Further, the second planetary gear mechanism 16
A fourth clutch C4 is provided between the carrier 20 and the second ring gear 22 for connecting and disconnecting them, and a first brake B1, which is a band brake, is disposed on the outer peripheral side of the clutch drum. Therefore, the clutch drum doubles as the brake drum. The second carrier 20 engages between the clutch drum and the second carrier 20 when the second carrier 20 attempts to rotate in the reverse direction relative to the clutch drum (rotation in the direction opposite to the rotation direction of the engine 1). A first one-way clutch F1 is provided.

A second one-way clutch F2 is provided between the clutch drum and the transmission case 10 to be engaged when the clutch drum tries to rotate in the reverse direction. Further, the first ring gear 19 of the first planetary gear mechanism 15 and the second carrier 2 of the second planetary gear mechanism 16
A second brake B2 for selectively fixing 0 is provided between the transmission case 10 and the second brake B2.

The countershaft 1 extends parallel to the input shaft 6.
The counter shaft 13 is disposed on the outer peripheral side of the forward clutch C1 and the counter drive gear 11, and both ends thereof are supported by the transmission case 10 via bearings 23 and 24. This counter shaft 13 is for setting the output position to the center side in the width direction, similarly to the conventional one.

A counter driven gear 25 that meshes with the counter drive gear 11 and a final gear 26 that is an output gear are mounted on the counter shaft 13. The final gear 26 has a smaller diameter than the counter driven gear 25. The final gear 26 is provided at an extended position in the radial direction of the forward clutch C1 so that the output portion is located closer to the center.

Therefore, the counter shaft 13 is located at the distance between the forward clutch C1 and the counter drive gear 11,
It is formed as a short shaft whose length is approximately the same as the length of the part for the bearings 23 and 24. Also Final Gear 2
6 is smaller in diameter than the counter driven gear 25, the forward clutch C1 extends to near the outer periphery of the final gear 26. That is, the counter shaft 13 is arranged close to the input shaft 6 so that a large space does not occur on the outer periphery of the final gear 26, and as a result,
The overall dimension in the radial direction is reduced, and the dimension in the axial direction is significantly reduced by arranging the forward clutch C1 by effectively utilizing the space on the outer peripheral side of the final gear 26. Have been.

The final gear 26 is meshed with a final driven gear 28 of the front differential 27. As shown in FIG. 1, the front differential 27 has a bulging portion projecting in the axial direction of the final driven gear 28 in the same direction as the torque converter 2. Are accommodated. That is, interference between the front differential 27 and the counter drive gear 11 is avoided.

The above-described automatic transmission can be set to four forward speeds and one reverse speed. The engagement and disengagement of the frictional engagement devices such as the clutches and the brakes when setting each shift speed. The state is shown in the operation chart of FIG. In FIG. 2, a mark “○” indicates an engaged state,
In addition, the mark ◎ indicates that the vehicle is engaged during engine braking, and a blank indicates a released state.

Here, each shift speed set as shown in FIG. 2 will be briefly described. First, when only the forward clutch C1 is engaged, the first planetary gear mechanism 15
The first sun gear 17 rotates forward (rotation in the same direction as the rotation of the engine 1), and the one-way clutches F1, F
2 engages and the first ring gear 19 is fixed, so that the first carrier 18, that is, the counter drive gear 11 is decelerated with respect to the input shaft 6 and rotates forward. That is, the first forward speed is set.

When the fourth clutch C4 is engaged from this state, the second sun gear 22 of the second planetary gear mechanism 16 that has been rotating in the reverse direction until then is rotated by the second one-way clutch F2 via the fourth clutch C4. Fixed, and accordingly the second carrier 20 of the second planetary gear mechanism 16, ie,
Since the first ring gear 19 of the first planetary gear mechanism 15 slowly rotates forward, the counter drive gear 11 integrated with the first carrier 18 rotates forward slightly faster than in the above-described case, and reaches the second forward speed.

When the second clutch C2 is further engaged,
Second planetary gear mechanism 1 connected to second clutch C2
6 and the first carrier of the first planetary gear mechanism 15.
Since the ring gear 19 is integrated, the first planetary gear mechanism 15 receives the input from both the first sun gear 17 and the first ring gear 19. Rotate together,
No acceleration / deceleration action is performed. That is, the counter drive gear 11 integrated with the first carrier 18 rotates in the same direction as the input shaft in the same direction as the input shaft, and the speed ratio becomes the third speed of “1”.

From the third speed state, the forward clutch C
When the first brake B1 is disengaged and the first brake B1 is engaged, the second planetary gear mechanism 16 inputs the second sun gear 22 to the second carrier 20 in a fixed state. Is accelerated with respect to the input shaft 6 and rotates forward. Therefore, the counter drive gear 11 connected to the second ring gear 21 via the first carrier 18 of the first planetary gear mechanism 15 is accelerated with respect to the input shaft 6 and rotates forward. That is, the gear ratio is “1”
The following is the fourth speed (overdrive stage). Therefore, the first brake B1 constitutes a brake mechanism for selectively fixing the second sun gear 22 together with the fourth clutch C4.

On the other hand, when the third clutch C3 and the second brake B2 are engaged, the second planetary gear mechanism 16 receives an input from the second sun gear 22 with the second carrier 20 fixed. Therefore, the second ring gear 21, that is, the counter drive gear 11 integrated therewith is
, The motor rotates in reverse, and reverses.

FIG. 3 shows the arrangement of the forward clutch C1, the counter drive gear 11, and the counter shaft 13 in the above configuration more specifically. That is, a boss 30 is formed on the cover 29 of the casing of the hydraulic pump 9, and the drum 31 of the forward clutch C <b> 1 is fitted around the boss 30 so as to rotate while maintaining a liquid-tight state. Further, a piston 32 that moves in the axial direction is accommodated therein.

One end of a fixed shaft 8 for holding the stator 5 is tightly fitted on the inner peripheral side of the boss portion 30, and an oil passage 33 for supplying a hydraulic pressure for operating the piston 32 is provided. It is formed to penetrate the inside of the cover 29 and the fixed shaft 8. On the other hand, the input shaft 6 has a two-part structure of a first shaft 6a on the torque converter 2 side and a second shaft 6b on the gear transmission mechanism 12 side, and the tip end of the first shaft 6a is a fixed shaft 8
Are rotatably held via an inner peripheral bearing 34 and are connected to be integrated with the drum 31. The second
The shaft 6b is spline-fitted to the tip of the first shaft 6a.

A large number of friction plates 35 are spline-fitted on the inner surface of the outer peripheral wall of the drum 31, and other friction plates 36 alternately arranged therewith are spline-fitted on the outer peripheral surface of the clutch hub 37. Torque is transmitted by pressing these friction plates 35 and 36 by the piston 32. The clutch hub 37 is rotatably fitted to the outer periphery of the second shaft 6b via a bearing 38, and is connected to the first sun gear 17 of the first planetary gear mechanism 15.

The counter drive gear 11 is arranged coaxially close to the forward clutch C 1, and is supported by the transmission case 10 via a bearing 14.

A counter driven gear 25 and a final gear 26 are provided adjacent to the counter shaft 13 arranged in parallel with the input shaft 6, and the final gear 26 is constituted by a small diameter gear so as to reduce the speed. And is located closer to the center in the vehicle width direction, that is, closer to the torque converter 2, and therefore the forward clutch C
1 and the final gear 26 are arranged side by side in the radial direction. That is, the outer diameter of the forward clutch C1 is set to be larger than the outer diameter of the counter drive gear 11 in order to increase the transmission torque capacity as much as possible, but the forward clutch C1 uses the space on the outer peripheral side of the final gear 26. It is arranged.

According to this embodiment, by controlling the engagement and disengagement of a plurality of clutches and brakes, the automatic transmission is set to an appropriate shift speed, and the driving force output from the gear transmission mechanism 12 is reduced. It is transmitted from the counter drive gear 11 to the counter shaft 13 and output from the final gear 26.

Therefore, the automatic transmission basically shown in FIG. 1 can be specifically configured as shown in FIG. And since the forward clutch C1 is independent of the other clutches, the configuration of the oil passage for supplying the hydraulic pressure to the forward clutch C1 is simplified. For this reason, the forward clutch C
The first hydraulic pressure is hardly affected by the centrifugal force, and deterioration of the shift shock is prevented.

By the way, in an automatic transmission having a gear transmission mechanism for performing at least four forward speeds and one reverse speed, a predetermined clutch is engaged at least in first to third forward speeds, and There is a possibility of performing control to release at high speed. Since this type of clutch is engaged at the time of starting, a large torque capacity is required, and at the same time, the clutch is engaged in a state where the variation range of the driving torque is large, so that it is necessary to increase the hydraulic pressure control accuracy. The shift between the third speed and the fourth speed is frequently performed by changing the vehicle speed and the accelerator opening during normal running, and the clutch is rotating. In this case, the shift shock frequently occurs and the riding comfort is greatly impaired.
Therefore, also in this respect, high hydraulic pressure control accuracy is required.

According to this embodiment, the forward clutch C1 is engaged at the first to third forward speeds and released at the fourth speed.
Are disposed closer to the torque converter 2 than the counter drive gear 11 is. For this reason, even when the forward clutch C1 is engaged / disengaged and the shift between the third speed and the fourth speed is frequently performed, the deterioration of the shift shock is prevented beforehand, and the riding comfort is improved.

Further, according to this embodiment, since the counter drive gear 11 is disposed closer to the torque converter 2 than the gear transmission mechanism 12, the counter driven gear 25 meshing with the counter drive gear 11 can also be disposed closer to the torque converter 2.
As a result, the counter shaft 13 is shortened, so that the whole can be made compact and lightweight.

Furthermore, according to this embodiment, the final gear 26 is usually smaller in diameter than the counter driven gear 11, so that a space is created on the outer peripheral side of the final gear 26. Since the clutch 11 is disposed closer to the torque converter 2 than the gear 11, that is, on the front side, the forward clutch C1 can be disposed closer to the outer peripheral side of the final gear 26 to effectively use the space. Can be shortened and the outer diameter can be reduced at the same time.

According to this embodiment, since the bearing 14 supporting the counter drive gear 11 and a part of the transmission case 10 are arranged between the counter drive gear 11 and the gear transmission mechanism 12, Since the portion accommodating the transmission mechanism 12 and the portion accommodating the forward clutch C1 can be separated by the bearing 14 and a part of the transmission case 10, the clutch disposed on the gear transmission mechanism 12 side is provided. In addition, the oil acting on the brake can be prevented from flowing into the forward clutch C1.

According to this embodiment, the bearing 14 for supporting the counter drive gear 11 and a part of the transmission case 10 are arranged between the counter drive gear 11 and the gear transmission mechanism 12, so that the gear Since the portion accommodating the transmission mechanism 12 and the portion accommodating the forward clutch C1 can be separated by the bearing 14 and a part of the transmission case 10, they are arranged on the gear transmission mechanism 12 side. Oil acting on other clutches and brakes can be prevented from flowing into the forward clutch C1.

That is, since the bearing 14 and a part of the transmission case 10 also have a function of separating the forward clutch C1 from the other clutches and brakes, the influence of the hydraulic pressure on the other clutches on the forward clutch C1. No special seal is required to prevent
Therefore, the seal structure can be simplified.

Further, according to this embodiment, since the final gear 26 is disposed closer to the torque converter 2 in the axial direction than the counter driven gear 25, the forward clutch C1 is utilized by utilizing the space on the outer peripheral side of the final gear 26. Can be arranged, and the axial length of the counter shaft 13 can be shortened, so that the overall configuration can be reduced in size.

The present invention is also applicable to an automatic transmission having a gear transmission mechanism capable of setting at least three forward speeds and one reverse speed.

[0065]

As described above, claims 1 to 8 are as described above.
According to the invention, by controlling the engagement and disengagement of the plurality of clutches and brakes, the automatic transmission is set to an appropriate shift speed, and the driving force output from the gear transmission mechanism is
It is transmitted from the counter drive gear to the counter shaft and output from the final gear. Further, since the first clutch is disposed closer to the torque converter than the counter drive gear, the configuration of the oil path for supplying the hydraulic pressure to the first clutch is simplified, and the first clutch is engaged. When the predetermined gear is set, the first
Since the hydraulic pressure of the clutch is not affected by the centrifugal force, the hydraulic pressure is stabilized, and as a result, deterioration of the shift shock is prevented.

In particular, when the first clutch is engaged in the first to third speeds of the forward gear and disengaged in the fourth speed as in the first aspect of the present invention, the accelerator is operated while the vehicle is running. 9. Even when the shift between the third speed and the fourth speed is frequently performed due to a change in the opening degree or the vehicle speed, deterioration of the shift shock is prevented beforehand, and the riding comfort is improved. According to the invention, since the counter drive gear is disposed closer to the torque converter than the gear transmission mechanism, the counter driven gear meshing with the counter drive gear can also be disposed closer to the torque converter, and as a result,
The counter shaft is shortened, so that the whole can be made compact and lightweight.

Further, according to the invention of claims 1 to 8, the final gear is usually smaller in diameter than the counter driven gear, and a space is created on the outer peripheral side of the final gear. Since the clutch is disposed closer to the torque converter than the counter drive gear, that is, disposed on the front side, the first clutch can be disposed closer to the outer peripheral side of the final gear to effectively use the space. The outer diameter can be reduced while shortening the length.

According to the second aspect of the present invention, since the support portion of the counter drive gear is disposed between the counter drive gear and the gear transmission, a portion accommodating the gear transmission is provided. Since the portion accommodating the first clutch can be separated by the support portion, oil acting on another clutch or brake disposed on the gear transmission mechanism side flows into the first clutch side. Can be prevented. That is, since the supporting portion also has a function of separating the first clutch from the other clutch and the brake, a special seal for preventing the influence of the hydraulic pressure on the other clutch on the first clutch is provided. This is unnecessary, so that the sealing structure can be simplified.

Further, according to the third aspect of the present invention, since the final gear is disposed closer to the torque converter in the axial direction than the counter driven gear, the first clutch can be used by utilizing the space on the outer peripheral side of the final gear. Because it can be arranged and the shaft length of the counter shaft can be shortened,
The overall configuration can be reduced in size.

[Brief description of the drawings]

FIG. 1 is a skeleton diagram showing in principle one embodiment of an automatic transmission according to the present invention.

FIG. 2 is an operation chart showing clutch and brake engagement / disengagement states at each shift speed in the automatic transmission shown in FIG. 1;

FIG. 3 is a sectional view specifically showing an arrangement state of a forward clutch, a counter drive shaft, and a counter shaft shown in FIG. 1;

[Explanation of symbols]

 2 Torque converter 6 Input shaft 9 Hydraulic pump 11 Counter drive gear 12 Gear transmission mechanism 13 Counter shaft 15, 16 Planetary gear mechanism 18A, 20A Pinion 25 Counter driven gear 26 Final gear C1, C2, C3, C4 Clutch B1, B2 Brake F1, F2 one-way clutch

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Ito 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (56) References JP-A-62-210129 (JP, A) JP-A-54-74956 (JP, A) JP 47-42703 (JP, B1) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16H 3/44-3/78

Claims (8)

(57) [Claims] 1. A gear transmission mechanism comprising a plurality of sets of planetary gear mechanisms arranged on the same axis is arranged following a torque converter, and a transmission path of a driving force in the gear transmission mechanism includes a plurality of clutches and brakes. Engagement
At least 4 forward steps and 1 reverse step by releasing and changing
The transmission speed is set to the first gear, and the driving force transmitted from the gear transmission mechanism is transmitted to a counter shaft arranged in parallel with the gear transmission mechanism via a counter drive gear, and provided on the counter shaft. An automatic transmission that outputs a driving force from a final gear, wherein the first to third gears of the forward gear are selected from the plurality of clutches.
A first clutch engaged at a high speed and released at a fourth speed is disposed closer to the torque converter than the gear transmission mechanism, and a first clutch is disposed between the first clutch and the gear transmission mechanism. The gear drive mechanism includes a first sun gear connected to the first clutch, a first ring gear disposed concentrically with the first sun gear, and a first sun gear and a first sun gear. A first planetary gear mechanism rotatably holding a first pinion meshed with the one ring gear and having a first carrier connected to the counter drive gear; and a second ring gear connected to the first carrier. A second sun gear disposed concentrically with the second ring gear and a second pinion meshed with the second ring gear and the second sun gear are rotatably held; and , A second ring gear connected to the first ring gear.
A second planetary gear mechanism having a carrier, wherein the plurality of clutches and brakes include a second clutch for selectively transmitting a driving force from the torque converter to the second carrier; A third clutch for selectively transmitting a driving force to the sun gear; a first brake mechanism for selectively stopping rotation of the second sun gear; and a second brake for selectively stopping rotation of the first ring gear and the second carrier. An automatic transmission characterized in that the automatic transmission includes a brake mechanism. And a case accommodating at least the counter drive gear and the gear transmission mechanism, the clutch and the brake, wherein the counter drive gear is rotatably supported by a support portion provided in the case, and the support is provided. The automatic transmission according to claim 1, wherein a portion is disposed between the counter drive gear and a gear transmission mechanism. 3. A counter driven gear meshed with the counter drive gear is provided on the counter shaft, and the final gear is disposed closer to the torque converter in the axial direction than the counter driven gear. The automatic transmission according to claim 1. 4. The automatic pump according to claim 1, wherein a hydraulic pump is arranged between the torque converter and the first clutch on the same axis as the torque converter and the first clutch. transmission. 5. The first clutch includes a drum accommodating a piston for engaging the clutch,
The hydraulic pump includes a casing having a boss portion at a center portion protruding along the axial direction toward the first clutch, and the drum is rotatably fitted to and supported by the boss portion. The automatic transmission according to claim 4, wherein: 6. The automatic transmission according to claim 5, wherein an oil passage for supplying and discharging a hydraulic pressure for moving the piston is formed in the boss portion. 7. A differential mechanism provided integrally with a driven gear meshed with the final gear is provided, and the differential mechanism includes a bulging portion protruding toward the torque converter in the axial direction of the driven gear. The automatic transmission according to any one of claims 1 to 6, wherein: 8. A gear transmission mechanism comprising a plurality of sets of planetary gear mechanisms arranged on the same axis is arranged following a torque converter, and a transmission path of a driving force in the gear transmission mechanism comprises a plurality of clutches and brakes. Engagement
By releasing and changing, at least three forward steps and one reverse step
The transmission gear is set to a first gear, and the driving force from the gear transmission mechanism is transmitted to a counter shaft arranged in parallel with the gear transmission mechanism via a counter drive gear, and a final gear provided on the counter shaft. An automatic transmission that outputs a driving force from a first sun gear to which a driving force from the torque converter is selectively transmitted, and a first ring gear disposed concentrically with the first sun gear. These first
A first planetary gear mechanism, which rotatably holds a first pinion meshed with the sun gear and the first ring gear, and includes a first carrier connected to the counter drive gear; and a first planetary gear mechanism connected to the first carrier. A second ring gear, a second sun gear arranged concentrically with the second ring gear, a second pinion meshed with the second ring gear and the second sun gear are rotatably held, and are connected to the first ring gear. A second planetary gear mechanism having a second carrier, and further comprising: a first clutch for selectively transmitting a driving force from the torque converter to the first sun gear; A second selectively transmitting a driving force from the torque converter to the second carrier;
, A third clutch for selectively transmitting a driving force from the torque converter to the second sun gear, a first brake mechanism for selectively stopping rotation of the second sun gear, and the first ring gear And a second brake mechanism for selectively stopping the rotation of the second carrier, wherein the first clutch is disposed closer to the torque converter than the gear transmission mechanism, and An automatic transmission, wherein the counter drive gear is disposed between a clutch and the gear transmission mechanism.