JP2007057064A - Automatic transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To intend the downsizing of a transmission by reducing a torque load of a clutch etc. to be fixed with a first-speed forward which the large torque is given from a torque converter when starting a vehicle in an automatic transmission to achieve a sixth-speed forward by 3 clutches and 2 brakes, which shorten the overall length or the external diameter of the clutch etc. by just that much. <P>SOLUTION: The automatic transmission has the first clutch C1 to disconnect and connect an input shaft (Input) with the first carrier PC1, the first brake B1 to disconnect and connect the first carrier PC1 with a case, the second brake B2 to disconnect and connect the first sun gear S1a with the case, the second clutch C2 to disconnect and connect the first sun gear S1b with the second sun gear S2, the third clutch C3 to disconnect and connect the first sun gear S1b with the third carrier PC3, and the first-speed forward is obtained by conclusion of the second clutch C2 with the first brake B1. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an automatic transmission that includes at least three planetary gear sets and that obtains six forward speeds by three clutches and two brakes.

  Conventionally, as this type of automatic transmission, an input shaft, a set of single pinion type planetary gear sets, a planetary gear train combining two sets of single pinion type planetary gear sets, three clutches, two brakes, In addition, there is known an apparatus having an output shaft, in which three clutches and two brakes as friction elements are appropriately engaged and released (see, for example, FIG. 5 of Patent Document 1). .)

  In the automatic transmission of Patent Document 1, it is necessary to input the carrier and the ring gear of the planetary gear train in order to obtain an overdrive gear stage. However, if the input shaft and the output shaft are provided coaxially, the rotation element In a single pinion type planetary gear set in which there are only three, the input paths to both the carrier and the ring gear are not established. For this reason, the input shaft and the output shaft must be arranged in parallel on different axes, which leads to an increase in the size of the transmission.

On the other hand, in Patent Documents 2 and 3, one of the two sets of single pinion type planetary gear sets constituting the planetary gear train is set as a so-called double ring gear type or double sun gear type, and the rotation to the carrier is performed. It has been proposed to perform input and output in the radial direction by a center member.
JP-A-4-219553 International Publication No. 2002/099316 Pamphlet JP 2004-069050 A

  By the way, in the automatic transmission of the proposed examples (Patent Documents 2 and 3), as shown in FIG. 4 of Patent Document 3, for example, the first clutch C1 and the first brake B1 are engaged to move forward 1 At this time, the input rotation is always decelerated in the first planetary gear set G1 and transmitted to the third planetary gear set G3 via the first clutch.

  This means that the maximum torque (stall torque) input from the torque converter at the start of the vehicle or the like is further increased in the first planetary gear set G1 and directly input to the first clutch. It is necessary to increase the capacity of the first clutch in response to a large torque, and it is normally avoided that the first clutch constituted by a wet multi-plate clutch is lengthened or its diameter is increased. Therefore, it is disadvantageous for making the automatic transmission compact.

  The present invention has been made in view of such a point, and the object of the invention is to reduce the load of the clutch due to the stall torque in the six-speed automatic transmission as in the above-mentioned proposed example, and accordingly, the total length of the clutch. Or the outer diameter is shortened to make the transmission compact.

  The invention according to claim 1 of the present application includes an output portion coaxially with the input shaft, and includes first to third planetary gear sets each including a sun gear, a carrier, and a ring gear. By selectively operating the three clutches and the first and second two brakes and switching the driving force transmission path from the input shaft to the output unit, at least the sixth forward speed is obtained. Assumed automatic transmission.

  The output unit, the first ring gear and the second carrier are always connected, the second ring gear and the third carrier are always connected, the input shaft and the third ring gear are always connected, and the third sun gear is used as a case. A first clutch that is always fixed and that connects and disconnects the input shaft and the first carrier; a first brake that connects and disconnects the first carrier and the case; and a second brake that connects and disconnects the first sun gear and the case A second clutch for connecting / disconnecting the first sun gear and the second sun gear, and a third clutch for connecting / disconnecting the first sun gear and the third carrier, and by engaging the second clutch and the first brake. The first speed is the second speed by engaging the second clutch and the second brake, the third speed by engaging the second clutch and the third clutch, and the first clutch. The fourth speed is obtained by engaging the second clutch, the fifth speed is obtained by engaging the first clutch and the third clutch, and the sixth speed is obtained by engaging the first clutch and the second brake. It is composed.

  With the above configuration, when the second clutch and the first brake are engaged and become the first speed when the vehicle starts, etc., the input rotation is always decelerated in the third planetary gear set, and is applied to the ring gear of the second planetary gear set. Entered. At this time, the engagement of the second clutch connects the sun gear of the second planetary gear set and the sun gear of the first planetary gear set, and the carrier of the first planetary gear set is fixed by the engagement of the first brake. As described above, the input rotation input to the ring gear of the second planetary gear set is decelerated and transmitted from the carrier to the output unit.

  That is, in the above-described configuration, the large torque input from the torque converter at the time of starting or the like as in the conventional example (Patent Documents 2 and 3) is further increased by the constant reduction planetary gear set and directly input to the second clutch. Since the torque load of this clutch is reduced, there is no need to increase the capacity of the clutch, and the total length of the clutch can be shortened or the diameter thereof can be reduced accordingly. It becomes advantageous for the conversion.

  When connecting the rotating elements of the first to third planetary gear sets as described above, if the second planetary gear set is disposed between the first and third planetary gear sets, the connecting member of the rotating elements is It can be simplified as a whole without lengthening, and is preferable (claim 2).

  In addition, in order to obtain the overdrive speed in the above configuration, it is necessary to input the carrier and the ring gear of the first planetary gear set, and considering that the input shaft and the output portion are on the same axis, As in the proposed examples (Patent Documents 2 and 3), the first planetary gear set is preferably a so-called double ring gear type or double sun gear type.

  Specifically, in the invention of claim 3, the first planetary gear set includes two sun gears, one pinion that meshes with each of the sun gears, and a center member that is arranged between the two sun gears and that inputs or outputs rotation. A double sun gear type having a carrier having a ring and one ring gear meshing with the pinion.

  According to a fifth aspect of the present invention, the first planetary gear set includes two ring gears, one pinion that meshes with each of the ring gears, and a center member that is arranged between the two ring gears and that inputs or outputs rotation. A double ring gear type having a carrier and a sun gear meshing with the pinion.

  In these inventions, since rotation input to and output from the carrier can be performed in the radial direction by the center member, even if the input shaft and the output portion are coaxial, both the carrier and the sun gear, or the carrier and the ring gear The input path to both is established.

  Alternatively, as the first planetary gear set, two sets of simple planetary gear sets can be combined and the two carriers and the ring gear can be constantly connected to each other (Claim 4), and two sets of simple planetary gear sets can be used. In combination, both of the carriers and the sun gears can be always connected to each other (claim 6).

  According to the fourth and sixth aspects, as in the third and fifth aspects, even if the input shaft and the output portion are coaxial, both the carrier and the sun gear or the carrier and the ring gear in the first planetary gear set. The input path to both of these is established. However, since two simple planetary gear sets are used in combination as the first planetary gear set, the dimension in the axial direction tends to be large in comparison. On the other hand, in the so-called double ring gear type or double sun gear type, the pinion tends to be long and tilt tends to occur, and the gear noise tends to increase. In this respect, the claims 4 and 6 are more advantageous.

  As described above, according to the automatic transmission according to the present invention, the output unit is disposed coaxially with the input shaft, and the first to third planetary gear sets each including the sun gear, the carrier, and the ring gear are provided. By selectively operating the first to third three clutches and the first and second brakes, and switching the transmission system of the driving force from the input shaft to the output unit, In an automatic transmission configured to obtain six forward speeds, the stall torque input from the torque converter at the time of start of the vehicle or the like is further increased by the constant reduction planetary gear set and is not directly input to the second clutch. The load on the clutch can be reduced, and the size can be reduced accordingly.

  In particular, if the second planetary gear set is disposed between the first and third planetary gear sets, the entire connecting member between the rotating elements can be simplified without lengthening, which is preferable (Claim 2).

  Further, if the first planetary gear set is of a so-called double ring gear type or double sun gear type, the rotation input to the carrier can be performed in the radial direction by the center member, so that the input shaft and the output portion are coaxial. Even in this case, an input path to both the carrier and the sun gear, or both the carrier and the ring gear is established, and a high shift stage including overdrive can be achieved (claims 3 and 5).

Alternatively, if a combination of two simple planetary gear sets is used as the first planetary gear set (Claims 4 and 6), the same effects as those of Claims 3 and 5 can be obtained, and gear noise can be reduced. It becomes advantageous in suppressing.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that the following description of the preferred embodiment is merely illustrative in nature, and is not intended to limit the present invention, its application, or its use.

(Embodiment 1)
FIG. 1 is a skeleton diagram showing a configuration of a transmission gear mechanism when an automatic transmission AT according to Embodiment 1 of the present invention is applied to a power train for an FF vehicle mounted horizontally on a vehicle as an example. (Skeleton diagram). In the figure, Input is an input shaft through which a rotational driving force from a non-illustrated engine as a driving source is input via a torque converter (not shown), and Output is a rotational driving force via a final gear or the like. The output gear (output unit) that outputs to the drive wheel side. The input shaft Input and the output gear Output are arranged on the same axis.

  In the figure, reference numerals GS1 to GS3 denote first to third planetary gear sets having a sun gear, a carrier, and a ring gear as rotational elements, respectively. The first planetary gear set GS1 is a first sun gear divided into two gears. S1a, S1b, the first ring gear R1, the pinion P1 meshing with these gears S1a, S1b, R1, and the pinion P1 are supported and arranged between the divided gears S1a, S1b of the first sun gear. A planetary gear set of a double sun gear type including a first carrier PC1 having a center member CM.

  As shown in FIG. 3, the first carrier PC1 has three (or four) pinion gears P1 to P1 (may be four) arranged at substantially equal intervals in the circumferential direction (although not shown, As shown in FIG. 5B, a disc-like shape having a center hole h at a substantially central position in the direction of the rotation axis X, as can be seen from FIG. A wall (center member CM) is provided.

  Further, although not shown in the drawing, the split gears S1a and S1b of the first sun gear are arranged so that the outer peripheral teeth mesh with the pinion gears P1 to P1, respectively, on both sides in the rotation axis X direction with the center member CM interposed therebetween. Thus, input / output of rotation is performed in the direction of the rotation axis X. Further, rotation input / output to / from the first carrier PC1 can be performed radially inward by the center member CM. Although not shown in the figure, the ring gear R1 is arranged on the outer peripheral side so that the inner peripheral teeth mesh with the pinion gears P1 to P1.

  In other words, even if the input shaft Input is arranged coaxially with the output gear Output, the first sun gear is divided into two gears S1a and S1b, so that the rotation element is practically limited to three. In the planetary gear set GS1, an input path to both the first carrier PC1 and the first sun gears S1a and S1b is established.

  The divided gears S1a and S1b of the first sun gear divided as described above are in mesh with the first pinion gears P1 to P1, so that they are in substantially the same rotational state. Therefore, in the description of the following specification, both are not particularly distinguished, and both are referred to as the first sun gear.

  The second planetary gear set GS2 is a single pinion type planetary gear set having a second sun gear S2, a second ring gear R2, and a second carrier PC2 supporting the second pinion P2 meshing with both the gears S2 and R2. . The third planetary gear set GS3 is a single pinion type planetary gear set having a third sun gear S3, a third ring gear R3, and a third carrier PC3 that supports a third pinion P3 that meshes with both the gears S3 and R3. .

  The first ring gear R1 and the second carrier PC2 are connected (always connected) by a first connecting member M1 so as to rotate integrally with each other, and an output gear Output is attached to the connecting member M1. The second ring gear R2 and the third carrier PC3 are connected by a second connecting member M2 so as to rotate integrally with each other. The input shaft Input and the third ring gear R3 are connected by a third connecting member M3 so as to rotate integrally with each other. Further, the third sun gear R3 is fixed (always fixed) to the case by the fourth connecting member M4.

  Then, the first to third clutches C1 to C3 and the first and second brakes B1 and B2 are selectively operated to generate a driving force from the input shaft Input to the output gear Output. By switching the transmission path, 6 forward speeds and reverse speeds are obtained. Specifically, first, the first clutch C1 selectively connects and disconnects the input shaft Input and the first carrier PC1 via the center member CM of the first carrier PC1, and the engagement operation table of FIG. Since it is fastened at the 4th to 6th speed on the high speed side, it is also called a high clutch (High / C).

  The second clutch C2 is a clutch that selectively connects / disconnects the first sun gear S1b and the second sun gear S2, and is fastened at the first to fourth speeds on the low speed side, so that the low clutch (Low / C ). The third clutch C3 is a clutch that selectively connects / disconnects the first sun gear S1b and the third carrier PC3. Since the third clutch C3 is engaged at the third speed, the fifth speed, and the reverse speed, the 3/5 / R clutch (3 / 5 / RC).

  Further, the first brake B1 is a brake that selectively connects and disconnects the first carrier PC1 to the case via the center member CM, and is engaged at the first speed and the reverse speed. For this reason, it is also called low-reverse brake (L / R Br.). The second brake B2 is a brake that selectively connects and disconnects the first sun gear S1a to the case, and selectively stops the second sun gear S1a. Since the second brake B2 is engaged at the second speed and the sixth speed, the 2/6 brake (2 / 6 Br.). In addition, as shown by a dotted line in the figure, the one-way clutch OWC may be arranged in parallel with the first brake B1.

  The relationship between the operating states of the clutches C1 to C3 and the brakes B1 and B2 and the shift speeds is summarized as shown in the engagement operation table of FIG. In the figure, (● mark) shows a case where the clutch is engaged, but when the one-way clutch OWC is arranged in parallel with the first brake B1, it is not necessary to engage the first brake B1 at the first forward speed. For example, it may be fastened only when engine braking is necessary, such as manual mode or hold mode.

  Although not shown, a shift hydraulic pressure control device is connected to the first to third clutches C1 to C3 and the first and second brakes B1 and B2, and this shift hydraulic pressure control device is connected to the engagement operation shown in FIG. As shown in the table, a fastening pressure (● mark) and a release pressure (no mark) are created at each shift stage. As such a shift hydraulic pressure control device, a hydraulic control type, an electronic control type, a hydraulic pressure + electronic control type, and the like are conceivable.

(Automatic transmission operation)
Next, the operation at each shift stage of the automatic transmission AT of the present embodiment will be described.

-First forward speed-
As shown in FIG. 2, the first forward speed is obtained by engaging the second clutch C2 and the first brake B1. At this time, first, in the first planetary gear set GS1, the first carrier PC1 is stopped by the engagement of the first brake B1. Further, the first sun gear S1b is connected to the second sun gear S2 of the second planetary gear set GS2 by the engagement of the second clutch C2, and rotates integrally.

  Further, in the third planetary gear set GS3, the forward rotation is input from the input shaft Input to the third ring gear R3. However, since the third sun gear S3 is fixed, the decelerated forward rotation is the third carrier. It is transmitted from the PC 3 to the second ring gear R2 of the second planetary gear set GS2 via the second connecting member M2.

  In this way, in the second planetary gear set GS2 in which the forward rotation is input to the second ring gear R2, the second carrier PC2 rotates at a reduced speed in the same direction. Then, the first ring gear R1 of the first planetary gear set GS1 integrally rotates with the second carrier PC2, but since the first carrier PC1 is fixed in the first planetary gear set GS1, the first carrier PC1 is fixed. The sun gears S1a and S1b rotate in the reverse direction, that is, in the negative direction, and the second sun gear S2 of the second planetary gear set GS2 rotates negatively integrally with the first sun gear S1b. The speed is decelerated from the input rotation (rotation of the second ring gear R2) in which the PC 2 rotates.

  That is, at the first forward speed, the input rotation that is always decelerated in the third planetary gear set GS3 is decelerated according to the gear ratio between the second ring gear R2 and the second pinion P2 of the second planetary gear set GS2, and further the first The gear is decelerated according to the gear ratio between the first ring gear R1 and the first sun gear S1 of the planetary gear set GS1, and is output to the output gear Output.

  Thus, at the first forward speed, the maximum torque (stall torque) input from the torque converter when the vehicle starts, etc. is shared by all the rotating elements of the first to third planetary gear sets G1 to GS3, and the first to fourth It is transmitted through all the connecting members M1 to M4, and the second clutch C2 is not always immediately downstream of the speed reduction planetary gear set, and an excessive load is not applied, which is advantageous in terms of strength.

-2nd forward-
At the second forward speed, as shown in FIG. 2, the first brake B1 at the first forward speed is released and the second brake B2 is engaged. That is, the second forward speed is obtained by engaging the second clutch C2 and the second brake B2. At this time, in the first planetary gear set GS1, the divided gear S1a of the first sun gear is stopped by the engagement of the second brake B2, and thus the divided gear S1b is also stopped. Similarly to the first forward speed, the second sun gear S2 is also stopped because the first sun gear S1b is connected to the second sun gear S2 by engaging the second clutch C2.

  In this state, when the forward rotation is input to the third ring gear R3 and the decelerated forward rotation is transmitted to the second ring gear R2 as in the first forward speed, the second sun gear S2 is moved as described above. Since the second carrier PC2 is stopped, the second carrier PC2 outputs to the output gear Output the rotation in the positive direction that is decelerated according to the gear ratio between the second pinion P2 and the second ring gear R2. That is, at the second forward speed, the decelerated rotation input from the input shaft Input is output to the output gear Output as a decelerated rotation that is faster than the first forward speed.

-3rd forward speed-
At the third forward speed, as shown in FIG. 2, the second brake B2 at the second forward speed is released and the second clutch C3 is engaged. That is, the third forward speed is obtained by engaging the second clutch C2 and the third clutch C3. At this time, the second sun gear S2 and the second ring gear R2 rotate together in the second planetary gear set GS2 by engaging both the second and third clutches C2 and C3. Similarly, when the input rotation constantly decelerated by the third planetary gear set GS3 is transmitted to the second ring gear R2, this is output as it is from the second carrier PC2 to the output gear Output.

-Forward 4th-
At the fourth forward speed, as shown in FIG. 2, the third clutch C3 at the third forward speed is released and the first clutch C1 is engaged. That is, the fourth forward speed is obtained by engaging the first clutch C1 and the second clutch C2. At this time, similarly to the first to third forward speeds, the input rotation that is always decelerated by the third planetary gear set GS3 is input to the second ring gear R2 of the second planetary gear set GS2, and the output gear is output from the second carrier PC2. Output to Output. On the other hand, the rotation input from the input shaft Input to the first carrier PC1 of the first planetary gear set GS1 via the first clutch C1 is output from the first ring gear R1 to the output gear Output.

  At that time, the first sun gear S1b and the second sun gear S2 that are connected to each other by the engagement of the second clutch C2 rotate integrally, and the rotation of the sun gears S1b and S2 decelerates the rotation in the first planetary gear set GS1. On the other hand, the second planetary gear set GS2 functions to increase the rotation speed and match the output rotations of the two. Thus, at the fourth forward speed, the input rotation from the input shaft Input is slightly decelerated in the two paths and output to the output gear Output.

-5th forward-
At the fifth forward speed, as shown in FIG. 2, the second clutch C2 at the fourth forward speed is released and the third clutch C3 is engaged. That is, the fifth forward speed is obtained by engaging the first clutch C1 and the third clutch C3. At this time, as in the first to third forward speeds, the input rotation always decelerated by the third planetary gear set GS3 is input to the second ring gear R2 of the second planetary gear set GS2, but the second sun gear S2 is free. No power is transmitted through the second planetary gear set GS2.

  On the other hand, the input rotation always decelerated by the third planetary gear set GS3 as described above is also transmitted to the first sun gear S1b of the first planetary gear set GS1 via the third clutch C3. At the same time, rotation is input to the first carrier PC1 of the first planetary gear set GS1 from the input shaft Input via the first clutch C1, and the rotations of these two paths are combined in the first planetary gear set GS1. The first ring gear R1 is output to the output gear Output. This output rotation is slightly faster than the input rotation.

-6 forward speed-
At the sixth forward speed, as shown in FIG. 2, the third clutch C3 at the fifth forward speed is released and the second brake B2 is engaged. That is, the sixth forward speed is obtained by engaging the first clutch C1 and the second brake B2. At this time, since the first sun gear S1a is stopped in the first planetary gear set GS1 by engaging the second brake B2, the first carrier is input from the input shaft Input via the first clutch C1 in the same manner as the fourth and fifth forward speeds. When rotation is input to PC1, the rotation is accelerated and output from the first ring gear R1 to the output gear Output. That is, at the sixth forward speed, the input rotation is increased only through the first planetary gear set GS1 and output.

-Reverse speed-
The reverse speed is obtained by engaging the third clutch C3 and the first brake B1, as shown in FIG. At this time, similarly to the fifth forward speed, the input rotation always decelerated by the third planetary gear set GS3 is transmitted to the first sun gear S1b of the first planetary gear set GS1 via the third clutch C3. Since the first carrier PC1 is stopped by engaging the first brake B1 as in the first forward speed, the decelerated rotation transmitted to the first sun gear S1b is reversed as described above, and the first ring gear R1 It is output to the output shaft Output.

(Features of automatic transmission)
As described above, the automatic transmission AT of the present embodiment includes the first to third three single pinion type planetary gear sets GS1 to GS3, the first to third three clutches C1 to C3, and the first The second two brakes B1 and B2 are selectively operated to obtain the sixth forward speed and the reverse speed. In other words, the transmission AT does not include a complex type planetary gear set such as a Ravigneaux type, does not require a double pinion type, and the number of clutches, brakes and the like that connect and disconnect the rotating elements is five or less. It is relatively small, and is advantageous for downsizing, cost and weight reduction, noise reduction, and the like.

  Although not described in detail, the transmission AT has a range in which the planetary gear ratios of the planetary gear sets GS1 to GS2 can be generally applied as in the conventional example (Patent Documents 2 and 3). (For example, the number of sun gear teeth / the number of ring gear teeth = 0.35 to 0.65, preferably 0.38 to 0.60), and the condition that the interstage ratio decreases as the high speed stage is said to be preferable. While achieving this, a sufficiently wide gear ratio (forward 1st speed / 6th speed = 5.5-6.0) can be obtained. Moreover, it is not necessary to increase the diameters of the first to third ring gears R1 to R3 so much that the radial dimension of the transmission case does not increase.

  Further, when the input shaft Input and the output gear Output are arranged coaxially so as not to increase the radial dimension of the transmission case, in order to obtain an overdrive shift stage at the fifth and sixth forward speeds (at least the sixth speed). In either of the first or second planetary gear sets GS1 and GS2 that are not always decelerated, an input / output path to both the carrier and the ring gear or both the carrier and the sun gear is required. In the automatic transmission AT, the first planetary gear set GS1 is a double sun gear type as described above, and is input to the center member CM between the two first sun gears S1a and S1b from the inside in the radial direction. The gear stage is established.

  In addition, at the sixth forward speed at the maximum gear position, as described above, the input rotation is increased only through the first planetary gear set GS1 and output to the output gear Output, and output from the input. Since the number of rotating elements involved in the transmission of rotation up to is minimal, mechanical loss is greatly reduced and efficiency is increased.

  Furthermore, the rotational speed of any of the rotating elements does not become excessively high in all of the first to sixth forward speeds, which is advantageous in terms of durability and reliability. The number of clutches C1 to C3 and brakes B1 and B2 to be engaged and disengaged when switching to adjacent gears, such as the third speed, is always one by one as shown in the engagement operation table (FIG. 2). Because there is, controllability is also high.

  In addition, in the present embodiment, as described above, at the first forward speed in which the stall torque is input from the torque converter when the vehicle is started, the input large torque is applied to the first to third planetary gear sets G1 to GS3. It is shared by all the rotating elements, and is transmitted through all the first to fourth connecting members M1 to M4. As in the conventional example (Patent Documents 2 and 3), the stall torque is generated. It is further increased by the constantly decelerating planetary gear set and is not directly input to the second clutch C2.

  That is, since the torque load of the second clutch C2 that is engaged at the first forward speed where the maximum torque is applied is not so large, the overall length of the multi-plate clutch can be shortened or the diameter thereof can be reduced accordingly. This is advantageous for making the AT itself compact.

  In addition, in the present embodiment, the rotation elements of the first to third planetary gear sets GS1 to GS3 arranged in order in the axial direction as shown in FIG. It is always connected or fixed by the connecting members M1 to M4. With this layout, the connecting structure of the rotating elements of the first to third planetary gear sets GS1 to GS3 can be simplified as a whole.

(Modification)
In the automatic transmission AT of the embodiment, as described above, the first planetary gear set GS1 is a double sun gear type, and an input path to both the first carrier PC1 and the first sun gears S1a and S1b is established. However, it is not limited to this.

  That is, as in the modification shown in FIG. 4, the first planetary gear set GS1 is replaced with a double sun gear type, and two sets of simple planetary gear sets are combined, and the ring gears R1a and R1b and the carriers PC1a and PC1b are respectively connected. It can also be always connected. If it carries out like this, similarly to the said embodiment, in the 1st planetary gear set GS1, the input path | route to both 1st carrier PC11a, PC1b and 1st sun gear S1a, S1b will be materialized.

  However, since two sets of simple planetary gear sets are used in combination, there is a tendency that the dimension in the axial direction becomes large in comparison. On the other hand, when the so-called double ring gear type is used as in the above-described embodiment, the pinion gear is generally long and easily tilted, and the gear noise tends to increase. Therefore, in this respect, the modified example is more advantageous. is there.

(Embodiment 2)
FIG. 5 shows a configuration of a transmission gear mechanism of an automatic transmission AT according to Embodiment 2 of the present invention. In Embodiment 2, the first planetary gear set GS1 is not a double sun gear type, but a double ring gear type. The input path to both the first carrier PC1 and the first ring gears R1a and R1b is established. Accordingly, the layout of the first connecting member M1, the first and second brakes B1 and B2, the second clutch C2, and the like has been mainly changed.

  Except for this point, the configuration of the automatic transmission AT of the second embodiment is the same as that of the first embodiment, and the first connecting member M1, the first and second brakes B1, B2, the layout of which is changed, Since the second clutch C2 and the like have the same function, substantially the same members including those are denoted by the same reference numerals, and the description thereof is omitted. Note that the divided gears R1a and R1b of the divided first ring gear are not distinguished from each other except where particularly necessary, and are simply referred to as first ring gears, as in the case of the first sun gears S1a and S1b of the embodiment. And

  In the second embodiment, the first planetary gear set GS1 of the double ring gear type includes the first ring gears R1a and R1b divided into two gears, one pinion gear P1 meshing with each of the first ring gears R1a and R1b, and the first ring gear R1a, The first carrier PC1 is disposed between the two gears R1b and has a center member CM that inputs or outputs rotation, and one first sun gear S1 that meshes with the pinion gear P1.

  The first connecting member M1 always connects one gear R1a of the first ring gear divided as described above so as to rotate integrally with the second carrier PC2, and outputs to the other gear R1b. A gear Output is attached. The first brake B1 and the first clutch C1 are provided so as to connect and disconnect the transmission case or the input shaft Input via the first carrier PC1 and its center member CM, respectively.

  As in the first embodiment, the second brake B2 selectively connects and disconnects the first sun gear S1 to the case. In the second embodiment, the inner peripheral end is coupled to the first sun gear S1, The first and second planetary gear sets GS1, GS2 are arranged between the outer peripheral portion of the rotary connecting member extending toward the outer peripheral side and the transmission case. The second clutch C2 selectively connects / disconnects the first sun gear S1 and the second sun gear S2 as in the first embodiment, but this selectively connects the rotary connecting member and the second sun gear S2. It is provided to connect and disconnect.

  Therefore, in the automatic transmission AT of the second embodiment, the first planetary gear set GS1 is a double ring gear type, and the rotation input to the first carrier PC1 can be performed radially outward by the center member CM. There are the same features as those of the first embodiment described above.

  In the second embodiment, as in the modification of the first embodiment, the first planetary gear set GS1 is replaced with a double ring gear type, and two sets of simple planetary gear sets are combined so that the two sun gears and the carriers are always connected. It can also be made. If this is done, the dimension in the axial direction tends to be large, but it is advantageous for suppressing gear noise.

  In the first and second embodiments, the automatic transmission AT according to the present invention is applied to a lateral power train for an FF vehicle. However, the present invention can also be applied to a lateral power train for an RR vehicle. It is. Furthermore, although the example which installs an engine and a torque converter in the left side of a figure was demonstrated, it is also possible to install in the right side.

  The present invention is an automatic transmission for a vehicle and is particularly lightweight and compact because it achieves six forward speeds with five or fewer friction elements, and is particularly useful for mounting on a passenger car.

1 is a schematic diagram showing a schematic configuration of an automatic transmission according to Embodiment 1 of the present invention. It is a fastening operation table of the automatic transmission. It is a perspective view which shows an example of a carrier of a double sun gear type. FIG. 10 is a view corresponding to FIG. 1 according to a modified example in which two simple planetary gear sets are combined instead of the double ring gear type planetary gear set. FIG. 3 is a view corresponding to FIG. 1 according to Embodiment 2 using a double ring gear type planetary gear set.

Explanation of symbols

AT automatic transmission B1 first brake B2 second brake C1 first clutch,
C2 Second clutch C3 Third clutch CM Center member GS1 First planetary gear set GS2 Second planetary gear set GS3 Third planetary gear set Input Input shaft Output Output gear (output unit)
PC1 1st carrier PC2 2nd carrier PC3 3rd carrier R1, R1a, R1b 1st ring gear R2 2nd ring gear R3 3rd ring gear S1, S1a, S1b 1st sun gear S2 2nd sun gear S3 3rd sun gear

Claims (6)

An output portion is disposed coaxially with the input shaft, and includes first to third planetary gear sets each including a sun gear, a carrier, and a ring gear, and includes the first to third clutches and the first and second clutches. In an automatic transmission that selectively obtains at least six forward speeds by selectively operating the two brakes and switching the transmission system of the driving force from the input shaft to the output unit,
The output unit, the first ring gear and the second carrier are always connected, the second ring gear and the third carrier are always connected, the input shaft and the third ring gear are always connected, and the third sun gear is always fixed to the case. And
A first clutch that connects and disconnects the input shaft and the first carrier;
A first brake for connecting and disconnecting the first carrier and the case;
A second brake for connecting and disconnecting the first sun gear and the case;
A second clutch that connects and disconnects the first sun gear and the second sun gear;
A third clutch for connecting and disconnecting the first sun gear and the third carrier,
The first speed is established by engaging the second clutch and the first brake, the second speed is established by engaging the second clutch and the second brake, and the third speed is established by engaging the second clutch and the third clutch. The fourth speed is obtained by engaging the first clutch and the second clutch, the fifth speed is established by engaging the first clutch and the third clutch, and the sixth speed is established by engaging the first clutch and the second brake. An automatic transmission characterized by being configured to obtain. The automatic transmission according to claim 1, wherein
An automatic transmission, wherein the second planetary gear set is disposed between the first and third planetary gear sets. The automatic transmission according to claim 1 or 2,
The first planetary gear set includes two sun gears, one pinion that meshes with each of the sun gears, a carrier that is disposed between the two sun gears and has a center member that inputs or outputs rotation, and one that meshes with the pinion. An automatic transmission characterized by being a double sun gear type equipped with a ring gear. The automatic transmission according to claim 1 or 2,
The first planetary gear set is an automatic transmission characterized in that two simple planetary gear sets are combined and their carriers and ring gears are always connected to each other. The automatic transmission according to claim 1 or 2,
The first planetary gear set includes two ring gears, one pinion that meshes with each of the ring gears, a carrier that is disposed between the two ring gears and has a center member that inputs or outputs rotation, and one that meshes with the pinion. An automatic transmission which is of a double ring gear type having a sun gear. The automatic transmission according to claim 1 or 2,
The first planetary gear set is an automatic transmission in which two simple planetary gear sets are combined and their carriers and sun gears are always connected to each other.

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