JP2012092941A - Automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a friction loss of an automatic transmission that changes the speed of rotation of an input shaft in a plurality of stages through a plurality of planetary gear mechanisms arranged in a transmission case to output the changed speed of rotation from an output member.SOLUTION: The automatic transmission includes four planetary gear mechanisms PGS1-PGS4, three clutches C1-C3, and three brakes B1-B3. The respective elements of the first and second planetary gear mechanisms PGS1, 2 compose four rotating elements Y1-Y4. The first rotating element Y1 is connected to the input shaft 2, a fourth element Rd is connected to the output member 3, the fourth rotating element Y4 is connected to a second element Cc, and a first element Rc is connected to a sixth element Sd. The first clutch C1 is configured to freely connect the first rotating element Y1 to a fifth element Cd, the second clutch C2 is configured to freely connect the second rotating element Y2 to a second connecting body Rc-Sd, and the third clutch C3 is configured to freely connect the third rotating element Y3 to the fifth element Cd. The first brake B1, the second brake B2 and the third brake B3 are configured to freely fix a first connecting body Y4-Cc, a third element Sc and the fifth element Cd respectively to the transmission case 1.

Description

  The present invention relates to an automatic transmission in which rotation of an input shaft is shifted to a plurality of stages via a plurality of planetary gear mechanisms arranged in a transmission case and output from an output member.

  Conventionally, an automatic operation capable of performing eight forward gears using the first planetary gear mechanism for input, the second and third planetary gear mechanisms for shifting, and the six engaging mechanisms. A transmission is known (see, for example, Patent Document 1).

  In Patent Document 1, the first planetary gear mechanism for input includes a first sun gear and a first ring gear that mesh with each other, one meshing with the first sun gear and the other meshing with the first ring gear. A so-called double pinion type planetary gear mechanism comprising a first carrier that rotatably supports and revolves one pinion (when the carrier is fixed, the sun gear and the ring gear rotate in the same direction. Incidentally, when the ring gear is fixed, the sun gear and the carrier rotate in different directions.

  The first planetary gear mechanism decelerates the rotational speed of a fixed element in which a first sun gear is fixed to a transmission case, an input element in which a first carrier is connected to an input shaft, and a first carrier in which a first ring gear is an input element. Output element.

  In addition, the two planetary gear mechanisms for shifting are engaged with the second sun gear, the third sun gear, and the second ring gear integrated with the third ring gear, and one of them meshes with the second sun gear and the second ring gear. The other is a Ravigneaux type planetary gear mechanism comprising a second carrier that pivotally supports and revolves a pair of second pinions meshing with the third sun gear.

  This Ravigneaux type planetary gear mechanism includes a first rotation element, a second rotation element, and a second rotation element in order with an interval corresponding to the gear ratio in a collinear diagram (a figure in which the ratio of relative speeds of the rotation elements can be represented by a straight line). When the rotating element, the third rotating element, and the fourth rotating element are used, the first rotating element is the second sun gear, the second rotating element is the second carrier integrated with the third carrier, and the third rotating element is the third ring gear. The integrated second ring gear and fourth rotation element become the third sun gear.

  In addition, as an engagement mechanism, a first wet multi-plate clutch that releasably connects a first ring gear that is an output element of the first planetary gear mechanism and a fourth rotation element that is a third sun gear, an input shaft, and a second carrier And a second wet multi-plate clutch for releasably connecting a first rotary element comprising a first ring gear and a second sun gear as output elements. A fourth wet multi-plate clutch for releasably connecting the first carrier as the input element and the first rotating element comprising the second sun gear, and the first rotating element comprising the second sun gear to be disengageable to the transmission case. A first brake for fixing, and a second brake for releasably fixing the second rotating element including the second carrier to the transmission case.

  According to the above configuration, the first speed is established by engaging the first wet multi-plate clutch and the second brake, and the second speed is established by engaging the first wet multi-plate clutch and the first brake. A stage is established, and a third speed stage is established by engaging the first wet multi-plate clutch and the third wet multi-plate clutch, and the first wet multi-plate clutch and the fourth wet multi-plate clutch are engaged. This establishes the fourth gear.

  Further, the fifth speed stage is established by engaging the first wet multi-plate clutch and the second wet multi-plate clutch, and 6 by engaging the second wet multi-plate clutch and the fourth wet multi-plate clutch. By establishing the first gear, engaging the second wet multi-plate clutch and the third wet multi-plate clutch, the seventh gear is established, and by engaging the second wet multi-plate clutch and the first brake. The eighth gear is established.

  In addition, the conventional automatic transmission forms eight rows on the axis of the input shaft. Specifically, in order from the torque converter side, the first row is the fourth clutch and the first brake, the second row is the first planetary gear mechanism, the third row is the first clutch, and the fourth row is the third clutch (the second clutch). The three clutches appear to be in the same row as the first planetary gear mechanism on the skeleton diagram, but in reality, the third clutch piston and the oil passage are formed between the first clutch and the output gear. ), The fifth row is the output gear, the sixth row is the second planetary gear mechanism, the seventh row is the third planetary gear mechanism, and the eighth row is the second clutch and second brake.

JP 2005-273768 A

  In the above-described conventional example, the number of engagement mechanisms engaged at each shift stage is two. Therefore, the friction loss due to dragging of the remaining four engagement mechanisms that are open increases, resulting in a problem that the efficiency of the automatic transmission deteriorates.

  An object of the present invention is to provide an automatic transmission which can reduce friction loss in view of the above points.

  [1] In order to achieve the above object, the present invention includes an input shaft that is rotatably supported in a transmission case and rotated by power from a drive source, and the rotation of the input shaft is performed in a plurality of stages. An automatic transmission that shifts and outputs from an output member is provided with first to fourth planetary gear mechanisms each including three elements including a sun gear, a carrier, and a ring gear, and the first and second planetary gear mechanisms are provided. Each element of the two planetary gear mechanisms constitutes four rotational elements, and the four rotational elements are arranged from one side in the order of arrangement in the collinear chart in which the relative rotational speed ratio of the four rotational elements can be represented by a straight line. Gears in a collinear diagram in which the first rotation element, the second rotation element, the third rotation element, and the fourth rotation element are used, and the three elements of the third planetary gear mechanism can represent the relative rotation speed ratio as a straight line. Order by interval corresponding to the ratio The first element, the second element, and the third element, respectively, and the three elements of the fourth planetary gear mechanism are arranged in the order of arrangement at intervals corresponding to the gear ratio in the nomograph, respectively. As the six elements, the first rotating element is connected to the input shaft, the fourth element is connected to the output member, and the fourth rotating element and the second element are connected to form a first connecting body. A first clutch that connects the first element and the sixth element to form a second connecting body, the first clutch capable of connecting the first rotating element and the fifth element, and the second rotating element; A second clutch that can be connected to the second connecting body, a third clutch that can connect the third rotating element and the fifth element, and a first clutch that can be fixed to the transmission case. One brake, and a second brake that can fix the third element to the transmission case; Six engagement mechanisms including a third brake that can fix the fifth element to the transmission case are provided, and at least three of the six engagement mechanisms are in a connected state or a fixed state. Thus, each shift stage is established.

  According to the present invention, as will be apparent from the description of the embodiments described later, among the total of six engagement mechanisms of three clutches and three brakes, three engagement mechanisms are engaged and connected at each shift stage. State or fixed state. Therefore, the number of engagement mechanisms that are not connected and fixed in each gear stage is released is three, and the number of engagement mechanisms that are released in each gear stage is less than that in the conventional case where four engagement mechanisms are opened. The friction loss due to the engaging mechanism can be reduced, and the transmission efficiency of the automatic transmission can be improved.

  [2] In the present invention, the first element is the ring gear of the third planetary gear mechanism, the sixth element is the sun gear of the fourth planetary gear mechanism, and the fourth planetary gear mechanism is the radial direction of the third planetary gear mechanism. It is preferable to arrange the sun gear of the fourth planetary gear mechanism integrally with the ring gear of the third planetary gear mechanism.

  According to this configuration, since the fourth planetary gear mechanism is disposed radially outward of the third planetary gear mechanism, the axial length of the automatic transmission can be shortened.

  [3] In the present invention, any one of the first to fourth rotating elements is constituted by connecting the ring gear of the first planetary gear mechanism and the sun gear of the second planetary gear mechanism. Preferably, the second planetary gear mechanism is disposed radially outward of the first planetary gear mechanism, and the sun gear of the second planetary gear mechanism is configured integrally with the ring gear of the first planetary gear mechanism.

  According to such a configuration, since the second planetary gear mechanism is disposed radially outward of the first planetary gear mechanism, the axial length of the automatic transmission can be shortened.

  [4] In the present invention, the two-way can be switched between a reverse rotation preventing state in which the third element is allowed to rotate forward and preventing reverse rotation, and a forward rotation blocking state in which the third element is prevented from rotating forward and allowed to reverse. It is preferable to provide a clutch. According to this, it is possible to perform the shift at the eighth forward speed, to further reduce the friction loss, and to improve the shift controllability between the shift speeds.

  [5] In the present invention, it is preferable that the third brake is constituted by a meshing mechanism that suppresses friction loss as compared with a wet multi-plate clutch.

  [6] The third brake is configured by a two-way clutch that can be switched between a fixed state in which the fifth element is fixed to the transmission case and a reverse rotation preventing state in which the fifth element is allowed to rotate forward and prevent reverse rotation. You can also. This also makes it possible to suppress the friction loss as compared with the case where the third brake is constituted by a wet multi-plate clutch.

  [7] In the present invention, it is preferable that the third clutch is constituted by a meshing mechanism that suppresses friction loss as compared with a wet multi-plate clutch.

  [8] In the present invention, the first to fourth planetary gear mechanisms include a so-called single pinion comprising a sun gear, a ring gear, and a carrier that rotatably and revolves a pinion that meshes with the sun gear and the ring gear. Type planetary gear mechanism (when the carrier is fixed, the sun gear and the ring gear rotate in different directions, so it is also called a minus planetary gear mechanism or a negative planetary gear mechanism. Incidentally, when the ring gear is fixed, the sun gear and the carrier And rotate in the same direction.).

  According to this, the planetary gear mechanism is a so-called double gear comprising a sun gear, a ring gear, and a carrier that rotatably supports and rotates a pair of pinions that mesh with each other and one meshes with the sun gear and the other meshes with the ring gear. Pinion type planetary gear mechanism (Since the sun gear and the ring gear rotate in the same direction when the carrier is fixed, it is also called the plus planetary gear mechanism or the positive planetary gear mechanism. Incidentally, when the ring gear is fixed, the sun gear and the carrier are different from each other. Compared with the case where the power is transmitted from the input shaft to the output member, the number of places where the gear meshes can be reduced and the transmission efficiency can be further improved. it can.

  [9] In the present invention, a start clutch that can transmit the power of the drive source to the input shaft may be provided.

  [10] In the present invention, the power of the drive source can be transmitted to the input shaft via the torque converter.

The skeleton figure which shows the upper half of the automatic transmission of 1st Embodiment of this invention. The alignment chart which shows ratio of the relative speed of each element of the 1st-4th planetary gear mechanism of the automatic transmission of 1st Embodiment. (A) is explanatory drawing which shows the state of each engagement mechanism in every gear stage of the automatic transmission of 1st Embodiment. (B) is explanatory drawing which shows an example of the gear ratio of each gear stage of 1st Embodiment. (C) is explanatory drawing which shows an example of the common ratio between each gear stage of 1st Embodiment. (D) is explanatory drawing which shows an example of the gear ratio of each planetary gear mechanism of 1st Embodiment, and the reciprocal orange of an automatic transmission. The skeleton figure which shows the upper half of the automatic transmission of 2nd Embodiment of this invention. Sectional drawing which shows an example of the 2 way clutch as a 3rd brake.

[First Embodiment]
FIG. 1 shows a first embodiment of an automatic transmission according to the present invention. In the automatic transmission according to the first embodiment, the driving force output by a driving source ENG such as an internal combustion engine (engine) (not shown) that is rotatably supported in the transmission case 1 is generated by the lockup clutch LC and the damper DA. The input shaft 2 is transmitted via a torque converter TC having an output shaft 2 and the output member 3 is an output gear 3 arranged concentrically with the input shaft 2. The rotation of the output member 3 is transmitted to the left and right drive wheels of the vehicle via a differential gear and a propeller shaft (not shown). Instead of the torque converter TC, a single-plate or multi-plate start clutch configured to be frictionally engageable may be provided.

  In the transmission case 1, first to fourth planetary gear mechanisms PGS 1 to 4 are arranged concentrically with the input shaft 2.

  The first planetary gear mechanism PGS1 is a so-called single pinion type planetary gear mechanism (comprising a sun gear Sa, a ring gear Ra, and a carrier Ca that rotatably and revolves a pinion Pa meshing with the sun gear Sa and the ring gear Ra). When the carrier is fixed, the sun gear and the ring gear rotate in different directions, so it is also called a negative planetary gear mechanism or a negative planetary gear mechanism.When the ring gear is fixed, the sun gear and the carrier rotate in the same direction. .).

  The second planetary gear mechanism PGS2 is also a so-called single-pinion type planetary gear mechanism comprising a sun gear Sb, a ring gear Rb, and a carrier Cb that rotatably and revolves the pinion Pb meshing with the sun gear Sb and the ring gear Rb. Consists of.

  The first planetary gear mechanism PGS1 and the second planetary gear mechanism PGS2 are configured so that any two of the three elements including the sun gear, the ring gear, and the carrier of the first planetary gear mechanism PGS1 are replaced with the sun gear of the second planetary gear mechanism PGS2. By connecting to any two of the three elements including the ring gear and the carrier, four rotating elements are configured. Referring to the collinear diagram of the first planetary gear mechanism PGS1 and the second planetary gear mechanism PGS2 shown in the upper part of FIG. 2 (a diagram in which the ratio of the relative rotational speeds of the four rotating elements can be represented by a straight line (speed line)). Then, assuming that each rotation element is, in order from the left, the first rotation element Y1, the second rotation element Y2, the third rotation element Y3, and the fourth rotation element Y4, the first rotation element Y1 is the sun gear of the first planetary gear mechanism PGS1. Sa, the second rotation element Y2 is a ring gear Rb of the second planetary gear mechanism PGS2, and the third rotation element Y3 is a combination of the carrier Ca of the first planetary gear mechanism PGS1 and the carrier Cb of the second planetary gear mechanism PGS2, The four-rotation element Y4 is obtained by connecting the ring gear Ra of the first planetary gear mechanism PGS1 and the sun gear Sb of the second planetary gear mechanism PGS2.

  In the collinear diagram of the first planetary gear mechanism PGS1 and the second planetary gear mechanism PGS2, the lower horizontal line indicates that the rotational speed is “0”, and the upper horizontal line indicates that the rotational speed indicates the rotation of the input shaft. “1” indicates the same “1”.

  When the gear ratio of the first planetary gear mechanism PGS1 (the number of teeth of the ring gear / the number of teeth of the sun gear) is h and the gear ratio of the second planetary gear mechanism PGS2 is i, the distance between the first to fourth rotating elements is , Hi-1: 1: i.

  The third planetary gear mechanism PGS3 is also configured by a so-called single pinion type planetary gear mechanism that includes a sun gear Sc, a ring gear Rc, and a carrier Cc that rotatably and revolves a pinion Pc that meshes with the sun gear Sc and the ring gear Rc. Is done.

  Referring to a collinear diagram of the third planetary gear mechanism PGS3 shown in the middle stage of FIG. 2 (a diagram in which the ratio of the relative rotational speeds of the three elements can be represented by a straight line (speed line)), the third planetary gear mechanism PGS3 If the three elements Sc, Cc, Rc are the first element, the second element, and the third element from the left side in the order of arrangement at intervals corresponding to the gear ratio in the nomograph, respectively, the first element is the ring gear Rc, The second element is the carrier Cc, and the third element is the sun gear Sc. The ratio between the distance between the sun gear Sc and the carrier Cc and the distance between the carrier Cc and the ring gear Rc is set to j: 1, where j is the gear ratio of the third planetary gear mechanism PGS3.

  The fourth planetary gear mechanism PGS4 is also composed of a so-called single pinion type planetary gear mechanism that includes a sun gear Sd, a ring gear Rd, and a carrier Cd that rotatably and revolves a pinion Pd that meshes with the sun gear Sd and the ring gear Rd. Is done.

  Referring to the collinear diagram of the fourth planetary gear mechanism PGS4 shown in the lower part of FIG. 2, the three elements Sd, Cd, Rd of the fourth planetary gear mechanism PGS4 are arranged at intervals corresponding to the gear ratio in the collinear diagram. If the fourth element, the fifth element, and the sixth element are respectively arranged from the left in the order of arrangement, the fourth element is the ring gear Rd, the fifth element is the carrier Cd, and the sixth element is the sun gear Sd. The ratio between the distance between the sun gear Sd and the carrier Cd and the distance between the carrier Cd and the ring gear Rd is set to k: 1, where k is the gear ratio of the fourth planetary gear mechanism PGS4.

  The first rotation element Y <b> 1 is connected to the input shaft 2. The ring gear Rd (fourth element) of the fourth planetary gear mechanism PGS4 is connected to the output member 3 serving as an output gear.

  Further, the fourth rotating element Y4 and the carrier Cc (second element) of the third planetary gear mechanism PGS3 are connected to constitute a first connecting body Y4-Cc. Further, the ring gear Rc (first element) of the third planetary gear mechanism PGS3 and the sun gear Sd (sixth element) of the fourth planetary gear mechanism PGS4 are connected to form a second connected body Ra-Cc.

  The automatic transmission according to the first embodiment includes first to third clutches C1 to C3 and first to third brakes B1 to B3 as engagement mechanisms.

  The first clutch C1 is a wet multi-plate clutch, and is switched between a connected state in which the first rotating element Y1 and the carrier Cd (fifth element) of the fourth planetary gear mechanism PGS4 are connected, and an open state in which this connection is broken. It is configured freely.

  The second clutch C2 is a wet multi-plate clutch, and is configured to be switchable between a connected state in which the second rotating element Y2 and the second connector Rc-Sd are connected and an open state in which this connection is broken.

  The third clutch C3 is a meshing mechanism including a dog clutch or a synchromesh mechanism having a synchronization function, and a coupling state coupling the third rotating element Y3 and the carrier Cd (fifth element) of the fourth planetary gear mechanism PGS4, It is configured to be switchable to an open state in which this connection is broken. The third clutch C3 may be a wet multi-plate clutch or a two-way clutch.

  The first brake B1 is a wet multi-plate brake, and is configured to be switchable between a fixed state in which the first connecting body Y4-Cc is fixed to the transmission case 1 and an open state in which this fixing is released.

  The second brake B2 is a wet multi-plate brake and can be switched between a fixed state in which the sun gear Sc (third element) of the third planetary gear mechanism PGS3 is fixed to the transmission case 1 and an open state in which this fixing is released. It is configured.

  Further, in the automatic transmission according to the first embodiment, the reverse rotation preventing state R that is arranged side by side with the second brake B2 and that allows normal rotation of the sun gear Sc (third element) of the third planetary gear mechanism PGS3 and prevents reverse rotation. And a two-way clutch T1 that can be switched between a forward rotation prevention state F that prevents forward rotation and allows reverse rotation of the sun gear Sc (third element) of the third planetary gear mechanism PGS3.

  The third brake B3 is a meshing mechanism including a dog clutch or a synchromesh mechanism having a synchronization function, and a fixed state in which the carrier Cd (fifth element) of the fourth planetary gear mechanism PGS4 is fixed to the transmission case 1, and this fixing. It is configured to be switchable to an open state in which is released.

  The states of the clutches C1 to C3, the brakes B1 to B3, and the 2-way clutch T1 are switched by a transmission control unit (TCU) (not shown) based on vehicle information such as the vehicle traveling speed.

  The fourth planetary gear mechanism PGS4 is disposed radially outward of the third planetary gear mechanism PGS3. The ring gear Rc of the third planetary gear mechanism PGS3 and the sun gear Sd of the fourth planetary gear mechanism PGS4 are integrally configured. As described above, the fourth planetary gear mechanism PGS4 is arranged radially outward of the third planetary gear mechanism PGS3, and the third planetary gear mechanism PGS3 and the fourth planetary gear mechanism PGS4 overlap in the radial direction. The shaft length of the transmission can be shortened.

  The third planetary gear mechanism PGS3 and the fourth planetary gear mechanism PGS4 only have to overlap at least partially in the radial direction, which can reduce the axial length. If they overlap in the direction, the axial length can be shortened the most.

  The output member 3 composed of the output gear is disposed between the second clutch C2 and the third planetary gear mechanism PGS3. The transmission case 1 is provided with a side wall 1a that is positioned between the output member 3 and the second clutch C2 and extends radially inward. The side wall 1 a is provided with a cylindrical portion 1 b that extends inward in the radial direction of the output member 3. The output member 3 is pivotally supported by the cylindrical portion 1b via a bearing. By configuring in this way, the output member 3 can be firmly supported by the cylindrical portion 1b having high mechanical strength connected to the transmission case 1.

  Note that when the output member 3 is pivotally supported by the cylindrical portion 1b as described above, the second clutch C2 may be disposed radially inward of the cylindrical portion 1b. According to this, compared with the case where the output member 3 and the second clutch C2 are arranged side by side in the axial direction as shown in FIG. The shaft length of the transmission can be shortened.

  Next, with reference to FIG. 2 and FIG. 3, the case where each gear stage of the automatic transmission of 1st Embodiment is established is demonstrated.

  When establishing the first gear, the third clutch C3 is in the connected state, the third brake B3 is in the fixed state, and the two-way clutch T1 is in the reverse rotation prevention state R. By setting the third brake B3 to the fixed state, the rotation speed of the carrier Cd (fifth element) of the fourth planetary gear mechanism PGS4 becomes “0”. Further, by bringing the third clutch C3 into the connected state, the third rotating element Y3 and the carrier Cd (fifth element) of the fourth planetary gear mechanism PGS4 are connected, and the rotational speed of the third rotating element Y3 is also “0”. "become. Further, the rotation speed of the sun gear Sc (third element) of the third planetary gear mechanism PGS3 becomes “0” by the action of the two-way clutch T1 in the reverse rotation prevention state R. Then, the rotational speed of the ring gear Rd (fourth element) of the fourth planetary gear mechanism PGS4 to which the output member 3 is connected becomes “1st” shown in FIG. 2, and the first gear is established.

  At the first speed, since the second brake B2 is in the released state, the number of engagement mechanisms released is “4”, but the sun gear Sc (first gear) of the third planetary gear mechanism PGS3 is operated by the action of the two-way clutch T1. Since the rotation speed of (three elements) is “0”, no friction loss occurs in the second brake B2. Therefore, the substantial number of releases in the first gear is “3”.

  If the second brake B2 is also fixed at the first speed, the engine brake can be applied.

  When establishing the second speed, the third clutch C3 is set in the connected state, the first brake B1 is set in the fixed state, and the two-way clutch T1 is set in the reverse rotation prevention state R. By bringing the third clutch C3 into the connected state, the third rotating element Y3 and the carrier Cd (fifth element) of the fourth planetary gear mechanism PGS4 rotate at the same speed. Further, by setting the first brake B1 in a fixed state, the rotational speed of the first coupling body Y4-Cc becomes “0”. Further, the rotation speed of the sun gear Sc (third element) of the third planetary gear mechanism PGS3 becomes “0” by the action of the two-way clutch T1 in the reverse rotation prevention state R.

  Therefore, among the three elements Sc, Cc, Rc of the third planetary gear mechanism PGS3, the rotational speeds of the two elements of the sun gear Sc (third element) and the carrier Cc (second element) are the same speed “0”. Therefore, each element Sc, Cc, Rc of the third planetary gear mechanism PGS3 is in a locked state where relative rotation is impossible, and the rotation speed of the second coupled body Rc-Sd is also “0”. Then, the rotational speed of the ring gear Rd (fourth element) of the fourth planetary gear mechanism PGS4 to which the output member 3 is connected becomes “2nd” shown in FIG. 2, and the second gear is established.

  At the second speed, since the second brake B2 is in the released state, the number of released engagement mechanisms is “4”, but the sun gear Sc (second gear) of the third planetary gear mechanism PGS3 is operated by the two-way clutch T1. Since the rotation speed of (three elements) is “0”, no friction loss occurs in the second brake B2. Further, since the third brake B3 is constituted by the meshing mechanism, the friction loss is suppressed even in the open state as compared with the case where the third brake B3 is constituted by the wet multi-plate brake. Accordingly, the substantial number of releases at the second gear is “2”.

  Further, if the second brake B2 is also fixed at the second speed, the engine brake can be applied.

  In order to establish the third speed, the second clutch C2 and the third clutch C3 are connected and the two-way clutch T1 is set to the reverse rotation prevention state R. By setting the second clutch C2 in the connected state, the second rotating element Y2 and the second connected body Rc-Sd rotate at the same speed. Further, by bringing the third clutch C3 into the connected state, the third rotating element Y3 and the carrier Cd (fifth element) of the fourth planetary gear mechanism PGS4 rotate at the same speed. Further, the rotation speed of the sun gear Sc (third element) of the third planetary gear mechanism PGS3 becomes “0” by the action of the two-way clutch T1 in the reverse rotation prevention state R. Then, the rotational speed of the ring gear Rd (fourth element) of the fourth planetary gear mechanism PGS4 to which the output member 3 is connected becomes “3rd” shown in FIG. 2, and the third gear is established.

  At the third speed, since the second brake B2 is in the released state, the number of engagement mechanisms released is "4", but the sun gear Sc (first gear) of the third planetary gear mechanism PGS3 is operated by the action of the two-way clutch T1. Since the rotation speed of (three elements) is “0”, no friction loss occurs in the second brake B2. Further, since the third brake B3 is constituted by the meshing mechanism, the friction loss is suppressed even in the open state as compared with the case where the third brake B3 is constituted by the wet multi-plate brake. Accordingly, the substantial number of releases at the third speed is “2”.

  Further, if the second brake B2 is fixed at the third speed, the engine brake can be applied.

  When establishing the fourth speed, the first clutch C1 and the third clutch C3 are in the connected state, and the two-way clutch T1 is in the reverse rotation prevention state R. By setting the first clutch C1 and the third clutch C3 in the connected state, the carrier Cd (fifth element) of the first rotating element Y1, the third rotating element Y3, and the fourth planetary gear mechanism PGS4 is “1” having the same speed. Rotate with.

  In addition, since the first rotation element Y1 and the third rotation element Y3 rotate at the same speed “1”, the first to fourth rotation elements Y1 to Y4 are in a locked state in which the relative rotation is impossible. The rotation speed of the rotation element Y4, that is, the first coupling body Y4-Cc is “1”.

  Further, the rotation speed of the sun gear Sc (third element) of the third planetary gear mechanism PGS3 becomes “0” by the action of the two-way clutch T1 in the reverse rotation prevention state R. Then, the rotational speed of the ring gear Rd (fourth element) of the fourth planetary gear mechanism PGS4 to which the output member 3 is connected becomes “4th” shown in FIG. 2, and the fourth speed stage is established.

  At the fourth speed, since the second brake B2 is in the released state, the number of engagement mechanisms released is “4”, but the sun gear Sc (first gear) of the third planetary gear mechanism PGS3 is operated by the action of the two-way clutch T1. Since the rotation speed of (three elements) is “0”, no friction loss occurs in the second brake B2. Further, since the third brake B3 is constituted by the meshing mechanism, the friction loss is suppressed even in the open state as compared with the case where the third brake B3 is constituted by the wet multi-plate brake. Therefore, the substantial number of releases at the fourth speed is “2”.

  Further, if the second brake B2 is fixed at the fourth speed, the engine brake can be applied.

  When establishing the fifth gear, the first to third clutches C1 to C3 are connected and the two-way clutch T1 is set to the reverse rotation prevention state R. By setting the first clutch C1 and the third clutch C3 in the connected state, the carrier Cd (fifth element) of the first rotating element Y1, the third rotating element Y3, and the fourth planetary gear mechanism PGS4 is “1” having the same speed. Rotate with.

  In addition, since the first rotating element Y1 and the third rotating element Y3 rotate at the same speed “1”, the first to fourth rotating elements Y1 to Y4 enter a locked state in which the relative rotation is impossible. The rotation speed of the rotation element Y2 is “1”.

  Further, by setting the second clutch C2 in the connected state, the second connected body Rc-Sd rotates at “1” at the same speed as the second rotating element Y2. For this reason, the sun gear Sd (sixth element) of the fourth planetary gear mechanism PGS4 and the carrier Cd (fifth element) rotate at “1” at the same speed, and each element Sd, Cd of the fourth planetary gear mechanism PGS4. , Rd are in a locked state where relative rotation is impossible, and the rotational speed of the ring gear Rd (fourth element) of the fourth planetary gear mechanism PGS4 to which the output member 3 is connected is also “1”, and the fifth gear is established. The

  At the fifth speed, since the two-way clutch T1 is in the reverse rotation prevention state R, the forward rotation of the sun gear Sc (third element) of the third planetary gear mechanism PGS3 is allowed.

  When the sixth speed is established, the first clutch C1 and the second clutch C2 are connected and the second brake B2 is fixed. By setting the first clutch C1 in the connected state, the first rotating element Y1 and the carrier Cd (fifth element) of the fourth planetary gear mechanism PGS4 rotate at “1” at the same speed. Moreover, the 2nd rotation element Y2 and 2nd coupling body Rc-Sd rotate at the same speed by making the 2nd clutch C2 into a connection state. Further, by setting the second brake B2 in a fixed state, the rotational speed of the sun gear Sc (third element) of the third planetary gear mechanism PGS3 becomes “0”. Then, the rotational speed of the ring gear Rd (fourth element) of the fourth planetary gear mechanism PGS4 to which the output member 3 is connected becomes “6th” shown in FIG. 2, and the sixth gear is established.

  At the sixth speed, the second brake B2 is in a fixed state, and the two-way clutch T1 may be in either the reverse rotation prevention state R or the forward rotation prevention state F. However, the transmission control unit (not shown) is a two-way clutch when a downshift from the sixth gear to the fifth gear is predicted based on vehicle information such as travel speed so that the gear can be smoothly shifted. When T1 is in the reverse rotation prevention state R and an upshift from the sixth gear to the seventh gear is predicted based on the vehicle information, the two-way clutch T1 is switched to the forward rotation prevention state F.

  When establishing the seventh gear, the first clutch C1 and the second clutch C2 are connected, the first brake B1 is fixed, and the two-way clutch T1 is set to the forward rotation prevention state F. By setting the first clutch C1 in the connected state, the first rotating element Y1 and the carrier Cd (fifth element) of the fourth planetary gear mechanism PGS4 rotate at “1” at the same speed. Moreover, the 2nd rotation element Y2 and 2nd coupling body Rc-Sd rotate at the same speed by making the 2nd clutch C2 into a connection state.

  Further, by setting the first brake B1 in a fixed state, the rotational speed of the first coupling body Y4-Cc becomes “0”. Then, the rotational speed of the ring gear Rd (fourth element) of the fourth planetary gear mechanism PGS4 to which the output member 3 is connected becomes “7th” shown in FIG. 2, and the seventh gear is established.

  At the seventh speed, since the 2-way clutch T1 is in the forward rotation prevention state F, the reverse rotation of the sun gear Sc (third element) of the third planetary gear mechanism PGS3 is allowed.

  When establishing the eighth gear, the first clutch C1 is set to the connected state, the first brake B1 and the second brake B2 are set to the fixed state, and the two-way clutch T1 is set to the forward rotation prevention state F. By setting the first clutch C1 in the connected state, the first rotating element Y1 and the carrier Cd (fifth element) of the fourth planetary gear mechanism PGS4 rotate at “1” at the same speed. Further, by setting the first brake B1 in a fixed state, the rotational speed of the first coupling body Y4-Cc becomes “0”.

  Further, by setting the second brake B2 in a fixed state, the rotational speed of the sun gear Sc (third element) of the third planetary gear mechanism PGS3 becomes “0”. Then, the rotational speed of the ring gear Rd (fourth element) of the fourth planetary gear mechanism PGS4 to which the output member 3 is connected becomes “8th” shown in FIG. 2, and the eighth gear is established.

  Since the second brake B2 is fixed at the eighth speed, the eighth speed can be established even when the two-way clutch T1 is in the reverse rotation prevention state R. However, in this embodiment, the two-way clutch T1 is in the forward rotation prevention state F at the eighth speed so that the downshift to the seventh speed can be performed smoothly.

  In order to establish the reverse gear, the second clutch C2 is engaged, the third brake B3 is fixed, and the 2-way clutch T1 is set to the forward rotation prevention state F. By setting the second clutch C2 in the connected state, the second rotating element Y2 and the second connected body Rc-Sd rotate at the same speed. Further, by setting the third brake B3 in a fixed state, the rotational speed of the carrier Cd (fifth element) of the fourth planetary gear mechanism PGS4 becomes “0”. Further, the rotation speed of the sun gear Sc (third element) of the third planetary gear mechanism PGS3 becomes “0” by the action of the two-way clutch T1 in the forward rotation prevention state F. Then, the rotational speed of the ring gear Rd (fourth element) of the fourth planetary gear mechanism PGS4 to which the output member 3 is connected becomes “Rvs” in the reverse direction (rotation in the direction in which the vehicle moves backward) shown in FIG. Established. If the second brake B2 is also fixed in the reverse gear, the engine brake can be applied.

  A speed line indicated by a dotted line in FIG. 2 represents that each element of the other planetary gear mechanisms rotates (idle) following the planetary gear mechanism that transmits power among the four planetary gear mechanisms PGS1 to PGS4. ing.

  FIG. 3A is a diagram summarizing and displaying the states of the clutches C1 to C3, the brakes B1 to B3, and the two-way clutch T1 at each of the above-described shift speeds. The rows of the clutches C1 to C3 and the brakes B1 to B3 “◯” indicates a connected state or a fixed state, and a blank indicates an open state. “R” in the row of the two-way clutch T1 indicates a reverse rotation prevention state, “F” indicates a forward rotation prevention state, and an underlined portion indicates the third planetary gear mechanism by the action of the two-way clutch T1. A state in which the rotational speed of the sun gear Sc (third element) of the PGS3 is “0” is shown.

  3B, the gear ratio h of the first planetary gear mechanism PGS1 is 3.771, and the gear ratio i of the second planetary gear mechanism PGS2 is 3.800, as shown in FIG. The gear ratio (the rotational speed of the input shaft 2 / the speed of the output member 3) when the gear ratio j of the third planetary gear mechanism PGS3 is 2.376 and the gear ratio k of the fourth planetary gear mechanism PGS4 is 1.826. Rotation speed). According to this, as shown in FIG. 3 (c), the common ratio (ratio of gear ratios between the respective gears) becomes appropriate, and the ratio orange (gear ratio / first gear) shown in FIG. The gear ratio of the 8th gear is also appropriate.

  According to the automatic transmission of the first embodiment, eight forward speeds can be changed. Further, at each shift stage, the number of wet multi-plate clutches and wet multi-plate brakes to be released is three or less, so that friction loss can be suppressed and driving force transmission efficiency can be improved.

  In addition, the 5th speed is a predetermined medium speed, the 1st speed to the 5th speed, which is a predetermined medium speed, and the 6th speed to the 8th speed exceeding the 5th speed, which is a predetermined medium speed. Is defined as the high speed range, and in the high speed range from the 6th speed to the 8th speed exceeding the predetermined 5th speed, which is the middle speed, the meshing mechanism has less friction loss than the wet multi-plate clutch. The configured third clutch C3 is in the released state.

  Further, the third brake B3 that is opened at all the gear speeds except the first gear and the reverse gear is also constituted by a meshing mechanism. Therefore, in the high speed range, the number of wet multi-plate clutches and wet multi-plate brakes to be released is 1, and the friction loss when the vehicle is traveling at high speed can be reduced to improve the fuel efficiency.

  Further, the third clutch C3 formed of the meshing mechanism is only switched between a connected state and an opened state between the fifth and sixth speeds, which are predetermined medium speed stages. Since the transmission torque (transmission driving force) in the third clutch C3 at the fifth speed (predetermined medium speed) is relatively small, even if the third clutch C3 is constituted by a dog clutch as a meshing mechanism, the fifth speed is It is possible to smoothly switch between the connected state and the released state at the time of shifting between the sixth speed.

  Further, since all the planetary gear mechanisms PGS1 to PGS4 are constituted by so-called single pinion type planetary gear mechanisms, a pair of sun gear and ring gear mesh with each other, one meshes with the sun gear and the other meshes with the ring gear. A so-called double pinion type planetary gear mechanism comprising a carrier that rotatably and revolves the pinion (when the carrier is fixed, the sun gear and the ring gear rotate in the same direction, so the plus planetary gear mechanism or the positive planetary gear mechanism Incidentally, when the ring gear is fixed, the number of meshing of the gear on the transmission path of the driving force can be reduced as compared with a configuration in which the sun gear and the carrier rotate in different directions. Efficiency can be improved.

  In addition, since the 2-way clutch T1 is provided together with the second brake B2, there is no need to switch the state of the second brake B2 when shifting between the 4th speed stage and the 5th speed stage, and the shift controllability is improved. The

  In the first embodiment, the third clutch C3 and the third brake B3 are configured by the meshing mechanism. However, even if both are configured by the wet multi-plate clutch and the wet multi-plate brake, The effect of the present invention can be obtained in that the number of opened wet multi-plate clutches and wet multi-plate brakes can be suppressed to 3 or less, and friction loss can be suppressed.

  Further, the 2-way clutch T1 may be omitted. In this case, when establishing the first to fourth gears, the second brake B2 may be fixed.

  Similarly to the second embodiment to be described later, the second planetary gear mechanism PGS2 is arranged radially outward of the first planetary gear mechanism PGS1, and the ring gear of the first planetary gear mechanism PGS1 constituting the fourth rotating element Y4. Ra and the sun gear Sb of the second planetary gear mechanism PGS2 may be integrally connected. According to this, the axial length can be further shortened.

  Further, the third brake B3 is in a fixed state in which the carrier Cd (fifth element) of the fourth planetary gear mechanism PGS4 is fixed to the transmission case 1, and the positive state of the carrier Cd (fifth element) of the fourth planetary gear mechanism PGS4. A two-way clutch that is switchable between a reverse rotation prevention state that allows rotation and prevents reverse rotation may be used. An example of the two-way clutch will be specifically described with reference to FIG.

  The two-way clutch TW as the third brake B3 in FIG. 5 is spaced from the inner ring TW1 connected to the carrier Cd (fifth element) of the fourth planetary gear mechanism PGS4 and the radially outward of the inner ring TW1. And an outer ring TW2 coupled to the transmission case 1 and a holding ring TW3 disposed between the inner ring TW1 and the outer ring TW2.

  A plurality of cam surfaces TW1a are formed on the outer peripheral surface of the inner ring TW1. The retaining ring TW3 is provided with a plurality of cutout holes TW3a corresponding to the cam surface TW1a. A roller TW4 is accommodated in the cutout hole TW3a. The two-way clutch TW includes first and second electromagnetic clutches not shown. The first electromagnetic clutch is configured to connect the outer ring TW2 and the holding ring TW3 when energized. When the first electromagnetic clutch is not energized, the holding ring TW3 is configured to be rotatable relative to the inner ring TW1 and the outer ring TW2.

  Further, as shown in FIG. 5A, the diameter of the roller TW4 is such that when the roller TW4 is at the center of the cam surface TW1a, the gap A is opened, and as shown in FIGS. 5B and 5C, When the roller TW4 is at the end of the cam surface TW1a, the roller TW4 is set to contact the inner ring TW1 and the outer ring TW2.

  When the first electromagnetic clutch is not energized, the holding ring TW3 can freely rotate, so that the roller TW4 continues to be positioned at the center of the cam surface TW1a as shown in FIG. Can do. Accordingly, the two-way clutch TW is in a state in which the inner ring TW1 can freely rotate.

  When the first electromagnetic clutch is energized, the holding ring TW3 is fixed to the transmission case 1 via the outer ring TW2. In this case, regardless of whether the inner ring TW1 rotates forward or backward, as shown in FIGS. 5B and 5C, the holding ring TW3 is fixed, so that the roller TW4 moves on the cam surface TW1a. It will be located at the end.

  At this time, the roller TW4 is sandwiched between the cam surface TW1a and the inner peripheral surface of the outer ring TW2, and the rotation of the inner ring TW1 is prevented. That is, the two-way clutch TW is in a fixed state.

  The second electromagnetic clutch has a first state in which the holding ring TW3 is connected to the inner ring TW1 in a state where the notch hole TW3a is located at one end of the cam surface TW1a as shown in FIG. As shown in (c), the second state in which the retaining ring TW3 is coupled to the inner ring TW1 with the notch hole TW3a positioned at the other end of the cam surface TW1a, and the coupling between the retaining ring TW3 and the inner ring TW1 It is configured to be switchable to an open state that cuts off.

  If the clockwise direction in FIG. 5 is the reverse direction, the two-way clutch TW disconnects the outer ring TW2 and the holding ring TW3 from the first electromagnetic clutch in a state where the first electromagnetic clutch is not energized (energization off state). 2 When the electromagnetic clutch is in the first state, the reverse rotation prevention state is established.

  When the third brake B3 is configured by such a 2-way clutch TW, the 2-way clutch TW is set to the reverse rotation prevention state at the forward speed from the first speed to the eighth speed and fixed at the reverse speed. Thus, each gear stage can be established. Similarly to the effect of the two-way clutch T1 when upshifting from the fourth speed to the fifth speed, the state of the two-way clutch TW as the third brake B3 when upshifting from the first speed to the second speed Since there is no need to switch between, the shift controllability of the automatic transmission is improved. When the engine brake is applied at the first speed, the two-way clutch TW as the third brake B3 may be set in a fixed state.

  Further, if the third brake B3 is configured with the above-described two-way clutch, unlike the case where the third brake B3 is configured with a friction engagement type brake, no friction loss occurs in the third brake B3. Accordingly, as in the case where the third brake B3 is configured by the meshing mechanism, the friction loss can be suppressed as the whole automatic transmission.

  According to the two-way clutch TW configured as described above, the carrier Cd (fifth element) of the fourth planetary gear mechanism PGS4 to the transmission case 1 is added to the fixed state and the reverse rotation prevented state described above. It can be configured to be switchable between an open state in which the fixation is released and a forward rotation prevention state in which the forward rotation of the carrier Cd (fifth element) of the fourth planetary gear mechanism PGS4 is prevented and the reverse rotation is allowed.

  Specifically, when the first electromagnetic clutch is turned off and the second electromagnetic clutch is released, the two-way clutch TW has a roller TW4 mounted on the cam surface TW1a as shown in FIG. It will be in the state which continues being located in a center part, and will be in the state which can rotate inner ring TW1 freely with respect to outer ring TW2, ie, an open state.

  Further, the first electromagnetic clutch is turned off, and the second electromagnetic clutch is moved to the inner ring with the retaining ring TW3 in a state where the notch hole TW3a is located at the other end of the cam surface TW1a as shown in FIG. By setting it as the 2nd state connected with TW1, it will be in the state in which normal rotation of inner ring TW1 is blocked | prevented and reverse rotation is permitted, ie, a normal rotation blocking state.

  Accordingly, the above-described second electromagnetic clutch of the two-way clutch TW is omitted, and the two-way clutch TW as the third brake B3 can be switched only between the fixed state and the released state by switching the first electromagnetic clutch. You can also. In this case, each shift stage can be established by switching to the fixed state at the first speed and the reverse speed and switching from the second speed to the eighth speed.

  Further, in the first embodiment, description has been given of performing the forward eight-speed shift. However, for example, the second speed and the seventh speed may be omitted, and the sixth forward speed may be achieved.

[Second Embodiment]
The automatic transmission according to the second embodiment of the present invention will be described with reference to FIG. In the automatic transmission of the second embodiment, instead of the torque converter, a damper DA and a single-plate or multi-plate start clutch C0 capable of transmitting power by friction engagement are provided, and the fourth planetary gear mechanism PGS4 is provided. The second planetary gear mechanism PGS2 is arranged between the first planetary gear mechanism PGS1 and the third clutch C3 without being arranged radially outward of the third planetary gear mechanism PGS3, and the diameter of the first planetary gear mechanism PGS1. The ring member Ra of the first planetary gear mechanism PGS1 and the sun gear Sb of the second planetary gear mechanism PGS2, which are arranged outward in the direction and constitute the fourth rotating element Y4, are integrally connected, and an output member 3 comprising an output gear is provided. Except for the point arranged between the first planetary gear mechanism PGS1 and the fourth planetary gear mechanism PGS4, it is configured in the same way as in the first embodiment, and the respective shift stages can be established in the same way.

  Also by the automatic transmission of the second embodiment, the same operational effects as those of the first embodiment can be obtained. In the second embodiment, a torque converter may be used instead of the starting clutch C0 as in the first embodiment.

DESCRIPTION OF SYMBOLS 1 ... Transmission case, 2 ... Input shaft, 3 ... Output member, ENG ... Drive source, LC ... Lock-up clutch, DA ... Damper, TC ... Torque converter, PGS1 ... First planetary gear mechanism, Sa ... Sun gear, Ca ... Carrier, Ra ... ring gear, Pa ... pinion, PGS2 ... second planetary gear mechanism, Sb ... sun gear, Cb ... carrier, Rb ... ring gear, Pb ... pinion, PGS3 ... third planetary gear mechanism, Sc ... sun gear (third element) , Cc ... carrier (second element), Rc ... ring gear (first element), Pc ... pinion, PGS4 ... fourth planetary gear mechanism, Sd ... sun gear (sixth element), Cd ... carrier (fifth element), Rd ... Ring gear (fourth element), Pd ... Pinion, C1 to C3 ... First to third clutches, B1 to B3 ... First to third brakes, T1 ... Two-way clutch, Y1 Y4 ... first to fourth rotating element, TW ... 2-way clutch (third brake).

Claims (10)

An automatic transmission that includes an input shaft that is rotatably supported in a transmission case and that is rotated by power from a drive source, and that rotates the input shaft in multiple stages and outputs the output shaft from an output member. ,
There are provided first to fourth planetary gear mechanisms each having three elements including a sun gear, a carrier, and a ring gear,
Each element of the first and second planetary gear mechanisms constitutes four rotating elements, and the relative rotational speed ratios of the four rotating elements can be represented by straight lines in the arrangement order in the collinear chart, The four rotating elements are designated as a first rotating element, a second rotating element, a third rotating element, and a fourth rotating element, respectively, from one side,
The three elements of the third planetary gear mechanism are a first element, a second element, and a third element, respectively, in order of arrangement at intervals corresponding to the gear ratio in the collinear chart in which the relative rotational speed ratio can be represented by a straight line. ,
Three elements of the fourth planetary gear mechanism as a fourth element, a fifth element, and a sixth element, respectively, in order of arrangement at intervals corresponding to the gear ratio in the collinear diagram,
The first rotating element is connected to the input shaft, the fourth element is connected to the output member, the fourth rotating element and the second element are connected to form a first connecting body, A second connected body is configured by connecting one element and the sixth element,
A first clutch capable of connecting the first rotating element and the fifth element;
A second clutch capable of connecting the second rotating element and the second connecting body;
A third clutch capable of connecting the third rotating element and the fifth element;
A first brake capable of fixing the first connector to the transmission case;
A second brake capable of fixing the third element to the transmission case;
Six engagement mechanisms comprising a third brake that can fix the fifth element to the transmission case;
An automatic transmission characterized in that each shift stage is established by bringing at least three of the six engagement mechanisms into a connected state or a fixed state. The automatic transmission according to claim 1, wherein
The first element is a ring gear of the third planetary gear mechanism;
The sixth element is a sun gear of the fourth planetary gear mechanism;
The fourth planetary gear mechanism is disposed radially outward of the third planetary gear mechanism;
The automatic transmission according to claim 4, wherein a sun gear of the fourth planetary gear mechanism is configured integrally with a ring gear of the third planetary gear mechanism. The automatic transmission according to claim 1 or 2,
Any one of the first to fourth rotating elements is configured by connecting a ring gear of the first planetary gear mechanism and a sun gear of the second planetary gear mechanism,
The second planetary gear mechanism is disposed radially outward of the first planetary gear mechanism;
An automatic transmission, wherein a sun gear of the second planetary gear mechanism is integrally formed with a ring gear of the first planetary gear mechanism. The automatic transmission according to any one of claims 1 to 3,
A two-way clutch that is switchable between a reverse rotation preventing state that allows forward rotation of the third element and prevents reverse rotation and a forward rotation blocking state that prevents forward rotation of the third element and allows reverse rotation is provided. Automatic transmission featured. The automatic transmission according to any one of claims 1 to 4,
The automatic transmission is characterized in that the third brake is constituted by a meshing mechanism. The automatic transmission according to any one of claims 1 to 3,
The third brake is configured by a two-way clutch that can be switched between a fixed state in which the fifth element is fixed to the transmission case and a reverse rotation preventive state in which the fifth element is allowed to rotate forward and prevent reverse rotation. An automatic transmission characterized by that. The automatic transmission according to any one of claims 1 to 6,
The automatic transmission is characterized in that the third clutch is constituted by a meshing mechanism. The automatic transmission according to any one of claims 1 to 7,
The first to fourth planetary gear mechanisms are constituted by a single-pinion type planetary gear mechanism that includes a sun gear, a ring gear, and a carrier that rotatably and revolves a pinion that meshes with the sun gear and the ring gear. An automatic transmission characterized by that. The automatic transmission according to any one of claims 1 to 8,
2. An automatic transmission comprising a starting clutch capable of transmitting power of the driving source to the input shaft. The automatic transmission according to any one of claims 1 to 8,
The automatic transmission is characterized in that the power of the drive source is transmitted to the input shaft via a torque converter.

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