JP6149702B2 - Automatic transmission - Google Patents

Description

  The present invention belongs to a technical field related to an automatic transmission that constitutes a multi-stage planetary gear set in which at least two planetary gear sets of a plurality of planetary gear sets are radially overlapped with each other.

  In recent years, in the field of automatic transmissions, efforts have been made to increase the number of shift stages for the purpose of improving fuel efficiency. As one of the multi-stage methods, there is a method of increasing the number of planetary gear sets. In this method, since many planetary gear sets are arranged in the input shaft direction, the size of the automatic transmission in the input shaft direction increases. There is a problem of doing.

  Therefore, Patent Document 1 proposes that a plurality of planetary gear sets are overlapped in the radial direction to form a multi-stage planetary gear set, and power is output from the outermost planetary gear set in the multi-stage planetary gear set. According to this technique, even if the number of planetary gear sets is increased for multistage operation, an increase in the dimension of the automatic transmission in the input shaft direction can be prevented.

US Patent Application Publication No. 2012/0295754

  However, since the outer diameter of the multi-stage planetary gear set is increased in the above-mentioned Patent Document 1, when the counter mechanism is provided, the multi-stage planetary gear set is connected to the counter input unit (usually the counter input gear) or the counter mechanism. There is a possibility of interference with the counter output unit (usually the counter output gear). If the distance between the input shaft and the counter shaft of the counter mechanism is increased in order to eliminate this interference, the automatic transmission becomes larger on the side where the counter mechanism is provided (for example, the rear side of the vehicle).

  Therefore, it is conceivable to arrange the multi-stage planetary gear set at a position shifted in the counter axis direction with respect to the counter input section and the counter output section. In this way, the multi-stage planetary gear set is connected to the counter input of the counter mechanism. The distance between the input shaft and the counter shaft can be reduced without causing interference with the counter and the counter output unit. Then, as in Patent Document 1, it is conceivable to output power from the outermost planetary gear set to the counter shaft.

  However, as in Patent Document 1, power is output from the outermost planetary gear set to the counter shaft, that is, the output portion to the counter mechanism (usually the output gear meshing with the counter input gear) is used as the outermost planetary gear set. The output portion is normally located in the vicinity of the outermost planetary gear set and has substantially the same outer diameter as that of the outermost planetary gear set. For this reason, for example, when the output gear and the counter input gear are meshed, the radius of the counter input gear is substantially the same between the outer peripheral surface of the multi-stage planetary gear set (the outer peripheral surface of the outermost planetary gear set) and the counter shaft. It is difficult to make the distance between the counter shaft and the outer peripheral surface of the outermost planetary gear set smaller than the radius of the counter input gear, resulting in a distance between the input shaft and the counter shaft. Is difficult to reduce.

  The present invention has been made in view of such a point, and an object of the present invention is to provide an output configuration from a multi-stage planetary gear set to a counter mechanism in an automatic transmission including the multi-stage planetary gear set as described above. By devising this, there is an attempt to make the distance between the input shaft and the counter shaft as small as possible.

In order to achieve the above object, in the present invention, an input shaft connected to a power source, a plurality of planetary gear sets arranged coaxially with the input shaft, and any one of the plurality of planetary gear sets It is connected to one planetary gear set, and is disposed so as to extend in parallel with the input shaft, and an output portion for transmitting power from the power source via a power transmission path formed by the plurality of planetary gear sets. A counter shaft disposed on the counter shaft and driven by the output unit; and disposed on the counter shaft at a position away from the counter input unit in the counter shaft direction; A counter output unit for driving a differential input unit of a differential mechanism, and at least two planetary gear sets of the plurality of planetary gear sets For an automatic transmission that constitutes a multi-stage planetary gear set in which gear sets are stacked in the radial direction, the multi-stage planetary gear set is positioned between the counter input section and the counter output section in the input shaft direction. The output section is connected to a planetary gear set other than the outermost planetary gear set in the multi-stage planetary gear set, and further includes a frictional engagement element including a brake, and the brake includes the plurality of planetary gears. Among the sets, it is connected to a planetary gear set other than that constituting the multi-stage planetary gear set, and is arranged on the opposite side of the counter output portion with respect to the counter input portion in the input shaft direction. The configuration is as follows.

  With the above configuration, since the planetary gear set to which the output unit is connected is a planetary gear set other than the outermost planetary gear set, the outer diameter of the output unit is reduced (the outer diameter of the planetary gear set other than the outermost planetary gear set and As a result, the counter shaft can be brought close to the outer peripheral surface of the outermost planetary gear set. Therefore, the distance between the input shaft and the counter shaft can be reduced.

The brake is preferably disposed at a position between the transmission case and the planetary gear set to which the brake is connected, that is, at a radially outer position of the planetary gear set, except for constituting a multistage planetary gear set. Since the outer diameter of the planetary gear set is smaller than the outer diameter of the multi-stage planetary gear set, the brake can be easily disposed at the preferred position. Further, even if the brake is disposed at such a position, the distance between the input shaft and the counter shaft is not affected.

  In the automatic transmission, it is preferable that the outermost planetary gear set in the multi-stage planetary gear set overlaps at least one of the counter input unit and the counter output unit when viewed from the input shaft direction.

  As a result, the counter shaft comes close to the outermost planetary gear set in the multi-stage planetary gear set, and thus the distance between the input shaft and the counter shaft is reduced.

In another aspect of the present invention, an input shaft connected to a power source, a plurality of planetary gear sets arranged coaxially with the input shaft, and any one of the plurality of planetary gear sets An output unit that is coupled to transmit power from the power source through a power transmission path formed by the plurality of planetary gear sets, and a counter shaft disposed to extend in parallel with the input shaft; A counter input unit disposed on the counter shaft and driven by the output unit; and a differential input of a differential mechanism disposed on the counter shaft at a position away from the counter input unit in the counter axis direction. And at least two planetary gear sets out of the plurality of planetary gear sets. Constituting a plurality of stages planetary gear set superimposed radially targeting an automatic transmission, the plurality of planetary gear sets, the first sun gear, a first carrier and a first ring gear, the first planetary gear set of single-pinion type A single pinion type second planetary gear set having a second sun gear, a second carrier and a second ring gear, a third pinion type third planetary gear set having a third sun gear, a third carrier and a third ring gear, and A double pinion type fourth planetary gear set having four sun gears, a fourth carrier, and a fourth ring gear, wherein the first carrier and the second ring gear are always connected to the input shaft, and the first ring gear and the third ring gear are The carrier is always connected to the second sun gear. The third sun gear is always connected, the third carrier and the fourth sun gear are always connected, the second carrier and the fourth carrier are always connected, and the third ring gear and the fourth carrier Between the second sun gear and the second ring gear, between the second carrier and the second ring gear, and with the second sun gear. Any one of the second carriers is connected and disconnected by the second clutch, and the first ring gear, the third carrier, and the transmission case are the first. It is configured to be connected / disconnected by a brake, and is configured to be connected / disconnected by a second brake between the third ring gear and the transmission case, and between the first sun gear and the transmission case The multi-stage planetary gear set is composed of the second planetary gear set positioned on the radially outer side and the fourth planetary gear set positioned on the radially inner side. The output unit is coupled to the fourth ring gear of the fourth planetary gear set.

This makes it possible to achieve eight forward speeds and one reverse speed using four planetary gear sets and five frictional engagement elements. Even when four planetary gear sets are used in this way, the multi-stage planetary gear set can prevent an increase in the dimension of the automatic transmission in the input shaft direction, and the output portion is a fourth planetary gear on the radially inner side. Since it is connected to the fourth ring gear of the set, the counter shaft can be brought close to the outer peripheral surface of the second planetary gear set. As a result, the distance between the input shaft and the counter shaft can be reduced. it can.

As described above, according to the automatic transmission of the present invention, it is possible to reduce the distance between the input shaft and the counter shaft, thus, the automatic transmission is, the side of the counter mechanism is provided (for example, after the vehicle Side) can be suppressed.

It is a skeleton figure which shows the automatic transmission which concerns on embodiment of this invention. The engagement state of the first clutch, the second clutch, the first brake, the second brake and the third brake, the gear ratio at each shift stage, and the gear step between the shift stages at each shift stage of the automatic transmission. It is a chart which shows. FIG. 2 is a view corresponding to FIG. 1 illustrating an automatic transmission of a comparative example. FIG. 3 is a view corresponding to FIG. 1 showing a modification of the embodiment. FIG. 9 is a view corresponding to FIG. 1 and showing another modification of the embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a skeleton of an automatic transmission 1 according to an embodiment of the present invention. The automatic transmission 1 is mounted on a vehicle and achieves eight forward speeds and one reverse speed.

  The automatic transmission 1 includes a transmission case 2, an input shaft 3 connected to a power source 4 (specifically, an output shaft of the power source 4), and a plurality of planetary gear sets (in this embodiment, a first planetary gear). Set PL1, second planetary gear set PL2, third planetary gear set PL3 and fourth planetary gear set PL4), five frictional engagement elements CL1, CL2, B1, B2, B3, and four planetary gear sets PL1, PL2, It is connected to any one of the planetary gear sets PL3 and PL4 (in this embodiment, the fourth planetary gear set PL4), and the power from the power source 4 is transmitted by the four planetary gear sets PL1, PL2, PL3, PL4. An output gear 7 serving as an output portion that is transmitted through a formed power transmission path, and a count It includes a mechanism 11.

  In the present embodiment, the input shaft 3 extends from the one side (the right side in FIG. 1) to the other side (the left side in FIG. 1) of the automatic transmission 1. Then, one axial end of the input shaft 3 is connected to the power source 4. Alternatively, the other axial end of the input shaft 3 may be connected to the power source 4, and two power sources 4 are provided, and both ends of the input shaft 3 are connected to the power source 4. Each may be connected.

  The power source 4 may be an internal combustion engine or an electric motor. Further, the input shaft 3 may be directly connected to the power source 4 and may be indirectly connected through, for example, a torque converter or a connection / disconnection clutch. When both ends of the input shaft 3 are connected to the power source 4, respectively, for example, the power source 4 to which one end of the input shaft 3 is connected is an internal combustion engine, and the power to which the other end is connected. The source 4 may be an electric motor.

  In the present embodiment, the vehicle is an FF vehicle, and the power source 4 and the automatic transmission 1 are mounted at the front of the vehicle, and the output shaft and the automatic transmission of the power source 4 in the mounted state. One input shaft 3 extends horizontally in the vehicle width direction of the vehicle.

  The first planetary gear set PL1 is disposed coaxially with the input shaft 3 and includes a first sun gear S1, a first carrier C1, and a first ring gear R1. The first carrier C1 is provided with a single pinion P1. That is, the first planetary gear set PL1 is a single pinion type planetary gear set.

  The second planetary gear set PL2 is disposed coaxially with the input shaft 3 and includes a second sun gear S2, a second carrier C2, and a second ring gear R2. The second carrier C2 is provided with a single pinion P2. That is, the second planetary gear set PL2 is also a single pinion type planetary gear set.

  The third planetary gear set PL3 is disposed coaxially with the input shaft 3 and includes a third sun gear S3, a third carrier C3, and a third ring gear R3. The third carrier C3 is provided with a single pinion P3. That is, the third planetary gear set PL3 is also a single pinion type planetary gear set.

  The fourth planetary gear set PL4 is disposed coaxially with the input shaft 3 and includes a fourth sun gear S4, a fourth carrier C4, and a fourth ring gear R4. The fourth carrier C4 is provided with a double pinion P4. That is, the fourth planetary gear set PL4 is a double pinion type planetary gear set.

  The second planetary gear set PL2 and the fourth planetary gear set PL4 constitute a multi-stage planetary gear set PL (in this embodiment, a two-stage planetary gear set) that is overlapped in the radial direction, and the second planetary gear set PL2 is in the radial direction. Located on the outer side, the fourth planetary gear set PL4 is positioned on the inner side in the radial direction.

  In the input shaft direction, a multi-stage planetary gear set PL, a third planetary gear set PL3, and a first planetary gear set PL1 are arranged in order from the one side (power source 4 side) of the input shaft 3. The counter mechanism 11 is disposed so as to oppose the multi-stage planetary gear set PL in the radial direction of the input shaft 3. That is, the multistage planetary gear set PL is disposed at a position overlapping the counter mechanism 11 in the input shaft direction, and the first planetary gear set PL1 and the third planetary gear set PL3 do not overlap the counter mechanism 11 in the input shaft direction. It is disposed at a position (a position shifted in the input axis direction with respect to the counter mechanism 11). Specifically, the first planetary gear set PL1 and the third planetary gear set PL3 are disposed on the other side (opposite to the power source 4) with respect to the counter mechanism 11 in the input shaft direction.

  The first carrier C1 and the second ring gear R2 are always connected to the input shaft 3. Further, the first ring gear R1 and the third carrier C3 are always connected, the second sun gear S2 and the third sun gear S3 are always connected, and the third carrier C3 and the fourth sun gear S4 are always connected. The second carrier C2 and the fourth carrier C4 are always connected.

  The five frictional engagement elements are the first clutch CL1, the second clutch CL2, the first brake B1, the second brake B2, and the third brake B3, and are arranged coaxially with the input shaft 3. The first clutch CL1 and the second clutch CL2 are configured by a multi-plate clutch, and the first brake B1, the second brake B2, and the third brake B3 are configured by a multi-plate clutch type in the present embodiment. You may comprise by a formula.

  The first clutch CL1 connects and disconnects the third ring gear R3 and the fourth carrier C4, and the second clutch CL2 connects between the second sun gear S2 and the second ring gear R2. Connect and disconnect.

  The first clutch CL1 is disposed at a position between the multi-stage planetary gear set PL and the third planetary gear set PL3 in the input shaft direction, and the second clutch CL2 is a power of the multi-stage planetary gear set PL in the input shaft direction. It is arranged on the source 4 side.

  The first brake B1 connects / disconnects between the first ring gear R1 and the third carrier C3 and the transmission case 2, and the second brake B2 includes the third ring gear R3 and the transmission. The third brake B3 connects / disconnects between the first sun gear S1 and the transmission case 2.

  Of the four planetary gear sets PL1, PL2, PL3, and PL4, the first brake B1, the second brake B2, and the third brake B3 are planetary gear sets (the first planetary gear set PL1 and It is connected to the third planetary gear set PL3).

  The first brake B1, the second brake B2, and the third brake B3 are a planetary gear set (first planetary gear set PL1, third planetary gear set PL3) to which the transmission case 2 and the brakes B1, B2, B3 are connected. Between the planetary gear sets PL1 and PL2, respectively. As a result, the first brake B1, the second brake B2, and the third brake B3 are opposite to the counter output gear 14 (described later) with respect to the counter input gear 13 (described later) in the counter shaft 11 in the input shaft direction. It is disposed on the opposite side of the source 4.

  The output gear 7 is disposed coaxially with the input shaft 3, is always connected to the fourth ring gear R4, and is configured to be driven by the fourth ring gear R4. The output gear 7 is disposed at a position between the multi-stage planetary gear set PL and the first clutch CL1 in the input shaft direction. The outer diameter of the output gear 7 is smaller than the outer diameter of the multi-stage planetary gear set PL (the outer diameter of the second planetary gear set PL2) and is substantially the same as the outer diameter of the fourth planetary gear set PL4. In FIG. 1, the outer diameter of the output gear 7 is described as being slightly larger than the outer diameter of the fourth planetary gear set PL4, but may be slightly smaller.

  The output gear 7 meshes with a counter input gear 13 as a counter input portion of the counter mechanism 11 and drives the counter input gear 13. The counter mechanism 11 includes a counter shaft 12 disposed so as to extend in parallel with the input shaft 3, the counter input gear 13 disposed on the counter shaft 12 and driven by the output gear 7, and the counter A counter output gear 14 is provided on the shaft 12 as a counter output unit. The counter shaft 12, the counter input gear 13, and the counter output gear 14 are configured to rotate integrally. The counter output gear 14 meshes with a diff ring gear 22 as a diff input portion of the differential mechanism 21 to drive the diff ring gear 22. The counter shaft 12 is located on the vehicle rear side and the upper side with respect to the input shaft 3. Further, the counter shaft 12 is rotatably supported by counter bearings 15 (in the present embodiment, tapered roller bearings) respectively disposed at both ends of the counter shaft 12.

  The counter input gear 13 and the counter output gear 14 are arranged away from each other in the counter axis direction (also the input axis direction). That is, the counter input gear 13 is positioned near the end of the counter shaft 12 on the side far from the power source 4, and the counter output gear 14 is positioned near the end of the counter shaft 12 near the power source 4. Yes.

  The differential mechanism 21 has a differential case 23 fixed to the differential ring gear 22. The differential ring gear 22 and the differential case 23 are supported by a differential bearing 28 (in this embodiment, a tapered roller bearing) so as to be rotatable around the central axis of the differential ring gear 22.

  In the differential case 23, two differential pinion gears 24 and two differential side gears 25 arranged concentrically with the differential ring gear 22 are disposed. Each differential pinion gear 24 is fixed to the differential case 23 and meshes with the two differential side gears 25. Each differential pinion gear 24 is configured to rotate around the central axis of the differential ring gear 22 together with the differential case 23 and to rotate about the central axis of each differential pinion gear 24. Each differential pinion gear 24 transmits the rotation to the two differential side gears 25 when the differential case 23 rotates about the central axis of the differential ring gear 22. At this time, if the loads applied to the two differential side gears 25 are the same, the differential pinion gear 24 does not rotate, and the rotation of the differential case 23 is transmitted to the two differential side gears 25 at the same rotational speed. As the differential pinion gear 24 rotates, the differential rotation is transmitted to the two differential side gears 25.

  The two differential side gears 25 are respectively connected to left and right drive shafts 26 arranged concentrically with the differential side gear 25, and the left and right drive shafts 26 are arranged in the vehicle width direction (the input shaft 3 and the counter). It extends in a direction parallel to the shaft 12 and is connected to left and right front wheels (not shown). Thus, the power generated in the output gear 7 is transmitted to the front wheels of the vehicle via the counter mechanism 11 and the differential mechanism 21. The left and right drive shafts 26 are located on the vehicle rear side and the lower side with respect to the counter shaft 12.

  Next, the speed change method of the automatic transmission 1 will be described.

  FIG. 2 shows the engaged state of the first clutch CL1, the second clutch CL2, the first brake B1, the second brake B2, and the third brake B3 at each shift stage. A circle indicates that it has been fastened, and a blank indicates that it has been fastened.

  Further, FIG. 2 shows the gears at the respective speeds when the constituent gears of the first planetary gear set PL1, the second planetary gear set PL2, the third planetary gear set PL3, and the fourth planetary gear set PL4 are set as follows. Ratio (reduction ratio) and gear steps between gears (first gear ratio / second gear ratio, second gear ratio / third gear ratio, third gear ratio / third gear ratio) Fourth gear ratio, Fourth gear ratio / Fifth gear ratio, Fifth gear ratio / Sixth gear ratio, Sixth gear ratio / Seventh gear ratio, Seventh gear ratio Speed gear ratio / Eighth speed gear ratio) are also shown. In the gear ratio of FIG. 2, the ratio orange (first gear ratio / eighth gear ratio) is 7.533.

The number of teeth of each component gear is
1st sun gear S1: 54, 1st ring gear R1: 86, single pinion gear P1: 16
Second sun gear S2: 54, second ring gear R2: 108, single pinion gear P2: 27
Third sun gear S3: 54, third ring gear R3: 86, single pinion gear P3: 16
4th sun gear S4: 46, 4th ring gear R4: 108, double pinion gear P4: 31
It has become. In addition, the said number of teeth is an illustration, Comprising: It does not restrict to this.

  The reverse speed is formed by engaging the first clutch CL1 and the second brake B2. At this time, the first carrier C1 and the second ring gear R2 connected to the input shaft 3 rotate in the same direction as the input shaft 3 at the rotational speed N0, where the rotational speed of the input shaft 3 is N0. Hereinafter, unless otherwise noted, the direction of rotation is the same as that of the input shaft 3, and when rotating in the direction opposite to the rotation of the input shaft 3, this is described.

  Due to the engagement of the second brake B2, the third ring gear R3 is fixed and does not rotate. Further, the fourth carrier C4 and the second carrier C2 connected to the third ring gear R3 are not rotated by the engagement of the first clutch CL1.

  The first ring gear R1, the third carrier C3, and the fourth sun gear S4 rotate at the same rotational speed and at the rotational speed N10 in the direction opposite to the rotation of the input shaft 3, and the second sun gear S2 and the third sun gear S3 The rotation speed is the same as that of the input shaft 3 and is higher than that of N10.

  Since the first ring gear R1 rotates at the rotation speed N10 in the direction opposite to the rotation of the input shaft 3, and the first carrier C1 rotates at N0, the first sun gear S1 rotates at a rotation speed higher than N0.

  Since the fourth sun gear S4 rotates at N10 in the opposite direction to the rotation of the input shaft 3 and the fourth carrier C4 does not rotate, the fourth ring gear R4 (that is, the output gear 7) is opposite to the rotation of the input shaft 3. In this direction, the rotation speed is lower than N10.

  The first speed is formed by engaging the first clutch CL1 and the first brake B1. At this time, the first carrier C1 and the second ring gear R2 rotate at the rotation speed N0.

  By engaging the first brake B1, the first ring gear R1, the third carrier C3, and the fourth sun gear S4 are fixed and do not rotate.

  Since the first carrier C1 rotates at N0 and the first ring gear R1 does not rotate, the first sun gear S1 rotates at a higher rotational speed than N0.

  By engaging the first clutch CL1, the second carrier C2, the third ring gear R3, and the fourth carrier C4 rotate at the same rotational speed N11 that is lower than N0. The second sun gear S2 and the third sun gear S3 rotate at the same rotational speed and in the opposite direction to the rotation of the input shaft 3.

  Since the fourth sun gear S4 does not rotate and the fourth carrier C4 rotates at N11, the fourth ring gear R4 (that is, the output gear 7) rotates at a rotation speed N1 lower than N11.

  The second speed is formed by engaging the first brake B1 and the second brake B2. At this time, the first carrier C1 and the second ring gear R2 rotate at the rotation speed N0.

  By engaging the first brake B1, the first ring gear R1, the third carrier C3, and the fourth sun gear S4 are fixed and do not rotate. Further, the third ring gear R3 is also fixed and does not rotate by the engagement of the second brake B2. Since the third carrier C3 and the third ring gear R3 do not rotate, the third sun gear S3 does not rotate, and the second sun gear S4 coupled to the third sun gear S3 does not rotate.

  Since the first carrier C1 rotates at N0 and the first ring gear R1 does not rotate, the first sun gear S1 rotates at a higher rotational speed than N0.

  Since the second sun gear S2 does not rotate and the second ring gear R2 rotates at N0, the second carrier C2 rotates at a rotation speed N12 (> N11) lower than N0 and is connected to the second carrier C2. The 4-carrier C4 also rotates at N12.

  Since the fourth sun gear S4 does not rotate and the fourth carrier C4 rotates at N12, the fourth ring gear R4 (that is, the output gear 7) rotates at a rotation speed N2 (> N1) lower than N12.

  The third speed is formed by engaging the second clutch CL2 and the first brake B1. At this time, the first carrier C1 and the second ring gear R2 rotate at the rotation speed N0.

  By engaging the second clutch CL2, the second sun gear S2, the second ring gear R2, and the second carrier C2 rotate integrally, that is, rotate at the same rotational speed N0. The third sun gear S3 connected to the second sun gear S2 also rotates at N0, and the fourth carrier C4 connected to the second carrier C2 also rotates at N0.

  By engaging the first brake B1, the first ring gear R1, the third carrier C3, and the fourth sun gear S4 are fixed and do not rotate.

  Since the first carrier C1 rotates at N0 and the first ring gear R1 does not rotate, the first sun gear S1 rotates at a higher rotational speed than N0. Further, since the third sun gear S3 rotates at N0 and the third carrier C3 does not rotate, the third ring gear R3 rotates in the direction opposite to the rotation of the input shaft 3.

  Since the fourth sun gear S4 does not rotate and the fourth carrier C4 rotates at N0, the fourth ring gear R4 (that is, the output gear 7) rotates at a rotation speed N3 (> N2) lower than N0.

  The fourth speed is formed by engaging the second clutch CL2 and the second brake B2. At this time, the first carrier C1 and the second ring gear R2 rotate at the rotation speed N0.

  By engaging the second clutch CL2, the second sun gear S2, the second ring gear R2, and the second carrier C2 rotate at the same rotational speed N0. The third sun gear S3 connected to the second sun gear S2 also rotates at N0, and the fourth carrier C4 connected to the second carrier C2 also rotates at N0.

  Due to the engagement of the second brake B2, the third ring gear R3 is fixed and does not rotate. Since the third ring gear R3 does not rotate and the third sun gear S3 rotates at N0, the third carrier C3 rotates at a rotation speed N13 lower than N0, and the first ring gear R1 coupled to the third carrier C3 and The fourth sun gear S4 also rotates at N13.

  Since the first carrier C1 rotates at N0 and the first ring gear R1 rotates at N13, the first sun gear S1 rotates at a higher rotational speed than N0.

  Since the fourth sun gear S4 rotates at N13 and the fourth carrier C4 rotates at N0, the fourth ring gear R4 (that is, the output gear 7) has a rotational speed N4 (> N3) higher than N13 and lower than N0. Will rotate.

  The fifth speed is formed by engaging the first clutch CL1 and the second clutch CL2. At this time, the first carrier C1 and the second ring gear R2 rotate at the rotation speed N0.

  By engaging the second clutch CL2, the second sun gear S2, the second ring gear R2, and the second carrier C2 rotate at the same rotational speed N0. The third sun gear S3 connected to the second sun gear S2 also rotates at N0, and the fourth carrier C4 connected to the second carrier C2 also rotates at N0. In addition, when the first clutch CL1 is engaged, the third ring gear R3 coupled to the fourth carrier C4 also rotates at N0.

  Since the third sun gear S3 and the third ring gear R3 rotate at N0, the third carrier C3 also rotates at N0, and the fourth sun gear S4 connected to the third carrier C3 also rotates at N0.

  Since the fourth carrier C4 and the fourth sun gear S4 rotate at N0, the fourth ring gear R4 (that is, the output gear 7) rotates at the same rotation speed N5 (> N4) as N0.

  The sixth speed is formed by engaging the second clutch CL2 and the third brake B3. At this time, the first carrier C1 and the second ring gear R2 rotate at the rotation speed N0.

  By engaging the second clutch CL2, the second sun gear S2, the second ring gear R2, and the second carrier C2 rotate at the same rotational speed N0. The third sun gear S3 connected to the second sun gear S2 also rotates at N0, and the fourth carrier C4 connected to the second carrier C2 also rotates at N0.

  By engaging the third brake B3, the first sun gear S1 is fixed and does not rotate. Since the first carrier C1 rotates at N0 and the first sun gear S1 does not rotate, the first ring gear R1 rotates at a rotation speed N14 higher than N0, and the third carrier C3 connected to the first ring gear R1 and the first carrier The 4 sun gear S4 also rotates at N14.

  Since the third carrier C3 rotates at N14 and the third sun gear S3 rotates at N0, the third ring gear R4 rotates at a higher rotational speed than N14.

  Since the fourth sun gear S4 rotates at N14 and the fourth carrier C4 rotates at N0, the fourth ring gear R4 (that is, the output gear 7) has a rotational speed N6 (> N5) higher than N0 and lower than N14. Will rotate.

  The seventh speed is formed by engaging the first clutch CL1 and the third brake B3. At this time, the first carrier C1 and the second ring gear R2 rotate at the rotation speed N0.

  By engaging the third brake B3, the first sun gear S1 is fixed and does not rotate. Since the first carrier C1 rotates at N0 and the first sun gear S1 does not rotate, the first ring gear R1 rotates at the rotation speed N14 higher than N0, and the third carrier C3 connected to the first ring gear R1 and The fourth sun gear S4 also rotates at N14.

  By engaging the first clutch CL1, the third ring gear R3, the fourth carrier C4, and the second carrier C2 rotate at a rotational speed N15 that is higher than N0 and lower than N14. The second sun gear S2 and the third sun gear S3 rotate at the same rotation speed and higher than N14.

  Since the fourth sun gear S4 rotates at N14 and the fourth carrier C4 rotates at N15, the fourth ring gear R4 (that is, the output gear 7) has a rotational speed N7 (> N6) higher than N15 and lower than N14. Will rotate.

  The eighth speed is formed by engaging the second brake B2 and the third brake B3. At this time, the first carrier C1 and the second ring gear R2 rotate at the rotation speed N0.

  By engaging the third brake B3, the first sun gear S1 is fixed and does not rotate. Since the first carrier C1 rotates at N0 and the first sun gear S1 does not rotate, the first ring gear R1 rotates at the rotation speed N14 higher than N0, and the third carrier C3 connected to the first ring gear R1 and The fourth sun gear S4 also rotates at N14.

  Due to the engagement of the second brake B2, the third ring gear R3 is fixed and does not rotate. Since the third ring gear R3 does not rotate and the third carrier C3 rotates at N14, the third sun gear S3 rotates at a higher rotational speed N16 than N14, and the second sun gear S2 connected to the third sun gear S3 also Rotate at N16.

  Since the second sun gear S2 rotates at N16 and the second ring gear R2 rotates at N0, the second carrier C2 rotates at a rotational speed N17 higher than N0 and lower than N16 and is connected to the second carrier C2. The fourth carrier C4 also rotates at N17.

  Since the fourth sun gear S4 rotates at N14 and the fourth carrier C4 rotates at N17, the fourth ring gear R4 (that is, the output gear 7) has a rotational speed N8 (> N7) higher than N14 and lower than N17. Will rotate.

  In the present embodiment, the multi-stage planetary gear set PL is disposed at a position between the counter input gear 13 and the counter output gear 14 in the input shaft direction (counter shaft direction). Further, the output gear 7 is connected to a planetary gear set (in the present embodiment, a fourth planetary gear set PL4) other than the outermost planetary gear set in the multi-stage planetary gear set PL. Further, the outermost planetary gear set (second planetary gear set PL2 in this embodiment) in the multi-stage planetary gear set PL overlaps the counter input gear 13 and the counter output gear 14 when viewed from the input shaft direction (counter shaft direction). ing. Note that the counter output gear 14 may have a small outer diameter and only the second planetary gear set PL2 and the counter input gear 13 may overlap when viewed from the input shaft direction.

  Here, FIG. 3 shows an automatic transmission of a comparative example in which the radial positional relationship between the second planetary gear set PL2 and the fourth planetary gear set PL4 is opposite to that of the above embodiment (FIG. 3). The same parts as those in FIG.

  The multi-stage planetary gear set PL in the automatic transmission of the comparative example is composed of a fourth planetary gear set PL4 positioned on the radially outer side and a second planetary gear set PL2 positioned on the radially inner side. The arrangement and the engaged state of the first clutch CL1, the second clutch CL2, the first brake B1, the second brake B2, and the third brake B3 at the respective shift speeds are the same as in the above embodiment. The output gear 7 is also connected to the fourth ring gear R4 of the fourth planetary gear set PL4 as in the above embodiment. For this reason, the outer diameter of the output gear 7 is substantially the same as the outer diameter of the multi-stage planetary gear set PL (the outer diameter of the fourth planetary gear set PL4), and is larger than that of the above embodiment.

  In the automatic transmission of the comparative example, the outer diameter of the output gear 7 is substantially the same as the outer diameter of the multi-stage planetary gear set PL, so that the multi-stage planetary gear set PL has the counter input gear 13 and the counter output in the input shaft direction. Even if it is located between the gear 14 and the counter shaft 12 between the outer peripheral surface of the multi-stage planetary gear set PL (the outer peripheral surface of the fourth planetary gear set PL4) and the counter shaft 12, the radius of the counter input gear 13 is substantially the same. The same interval occurs, and it is difficult to make the distance between the counter shaft 12 and the outer peripheral surface of the fourth planetary gear set PL4, which is the outermost planetary gear set, smaller than the radius of the counter input gear 13. In order to reduce the distance between the counter shaft 12 and the outer peripheral surface of the fourth planetary gear set PL4, that is, to move the counter shaft 12 toward the input shaft 3, the outer diameter of the output gear 7 is set to the same level as the above embodiment. Although it is necessary to reduce the size, a member that connects the fourth carrier C4 and the first clutch CL1, a member that connects the third ring gear R3 and the first clutch CL1, and a third carrier C3 are provided inside the output gear 7. And the fourth sun gear S4 are present, it is difficult to reduce the outer diameter of the output gear 7. Therefore, in the automatic transmission of the comparative example, it is difficult to reduce the distance between the input shaft 3 and the counter shaft 12.

  On the other hand, in the above embodiment, the outer diameter of the output gear 7 can be reduced by disposing the fourth planetary gear set PL4 to which the output gear 7 is connected inside the second planetary gear set PL2. As a result, the second planetary gear set PL2 can be overlapped with the counter input gear 13 when viewed from the input shaft direction. That is, the counter shaft 12 can be brought close to the outer peripheral surface of the second planetary gear set PL2. Therefore, the distance between the input shaft 3 and the counter shaft 12 can be reduced. Therefore, the dimension of the automatic transmission 1 including the counter mechanism 11 in the direction in which the input shaft 3 and the counter shaft 12 face each other (particularly, the dimension of the automatic transmission 1 in the vehicle front-rear direction) can be reduced.

  Further, in the above embodiment, as shown in FIG. 2, the gear ratio between the gears can be made appropriate and the gear step between the gears is good (excellent in feeling for the driver of the vehicle). Stuff).

  The present invention is not limited to the embodiment described above, and can be substituted without departing from the spirit of the claims.

  For example, in the above embodiment, the second clutch CL2 is configured to connect and disconnect between the second sun gear S2 and the second ring gear R2, but instead, the second clutch CL2 is configured as shown in FIG. The second carrier C2 and the second ring gear R2 may be connected or disconnected, or as shown in FIG. 5, the second sun gear S2 and the second carrier C2 may be connected or disconnected. That is, the second clutch CL2 is intended to rotate the second sun gear S2, the second carrier C2, and the second ring gear R2 integrally (rotate at the same rotational speed) by the engagement thereof. For the purpose, any two components of the second sun gear S2, the second carrier C2, and the second ring gear R2 in the second planetary gear set PL2 may be connected or disconnected.

  In the above embodiment, power transmission from the fourth planetary gear set PL4 to the counter mechanism 11 is performed by meshing the output gear 7 and the counter input gear 13, but it is performed via a chain or a belt. Also good. In this case, the output unit driven by the fourth ring gear R4 of the fourth planetary gear set PL4 and the counter input unit of the counter mechanism 11 are configured by a chain sprocket around which the chain is wound and a pulley around which the belt is wound. Similarly, power transmission from the counter mechanism 11 to the differential mechanism 21 may be performed via a chain or a belt. Also in this case, the counter output part of the counter mechanism 11 and the differential input part of the differential mechanism 21 are constituted by a chain sprocket around which a chain is wound and a pulley around which a belt is wound.

  When the output unit and the counter input unit of the counter mechanism 11 are configured with gears as in the above embodiment, the second planetary gear set PL2 and the counter input unit (counter input gear 13) are viewed from the input shaft direction. Although overlapped, the second planetary gear set PL2 and the counter input unit may not overlap when the chain sprocket or pulley is used. In short, when viewed from the input shaft direction, the second planetary gear set PL2 may overlap with both the counter input unit and the counter output unit, may overlap with only one of them, or may not overlap with either. Basically, the second planetary gear set PL2 is overlapped with at least one of the counter input unit and the counter output unit when viewed from the input shaft direction, so that the counter shaft 12 has an outer peripheral surface of the second planetary gear set PL2. It is preferable to be close to.

  Furthermore, in the above-described embodiment, the multi-stage planetary gear set PL is a two-stage planetary gear set, but it may be configured with three or more stages. In this case, the output gear 7 (output unit) only needs to be connected to a planetary gear set other than the outermost planetary gear set in the multistage planetary gear set.

  The above-described embodiments are merely examples, and the scope of the present invention should not be interpreted in a limited manner. The scope of the present invention is defined by the scope of the claims, and all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

  The present invention provides an input shaft connected to a power source, a plurality of planetary gear sets arranged coaxially with the input shaft, and an output connected to any one of the plurality of planetary gear sets. A counter shaft disposed so as to extend in parallel with the input shaft, a counter input portion disposed on the counter shaft and driven by the output portion, and disposed on the counter shaft. And a counter output unit that drives a differential input unit of a differential mechanism, and is useful for an automatic transmission that constitutes a multi-stage planetary gear set in which at least two planetary gear sets of the plurality of planetary gear sets are radially overlapped with each other. It is.

DESCRIPTION OF SYMBOLS 1 Automatic transmission 2 Transmission case 3 Input shaft 4 Power source 7 Output gear (output part)
12 Counter shaft 13 Counter input gear (Counter input section)
14 Counter output gear (Counter output section)
21 differential mechanism 22 differential input section PL multi-stage planetary gear set PL1 first planetary gear set PL2 second planetary gear set PL3 third planetary gear set PL4 fourth planetary gear set S1 first sun gear S2 second sun gear S3 third sun gear S4 fourth sun gear S4 fourth sun gear 1 carrier C2 2nd carrier C3 3rd carrier C4 4th carrier R1 1st ring gear R2 2nd ring gear R3 3rd ring gear R4 4th ring gear CL1 1st clutch (friction engagement element)
CL2 2nd clutch (friction engagement element)
B1 First brake (friction engagement element)
B2 Second brake (friction engagement element)
B3 Third brake (friction engagement element)

Claims (3)

An input shaft coupled to the power source;
A plurality of planetary gear sets arranged coaxially with the input shaft;
An output unit coupled to any one of the plurality of planetary gear sets, wherein power from the power source is transmitted via a power transmission path formed by the plurality of planetary gear sets;
A counter shaft arranged to extend parallel to the input shaft;
A counter input unit disposed on the counter shaft and driven by the output unit;
A counter output unit disposed on the counter shaft at a position away from the counter input unit in the counter axis direction, and driving the differential input unit of the differential mechanism;
An automatic transmission that constitutes a multi-stage planetary gear set in which at least two planetary gear sets of the plurality of planetary gear sets are radially overlapped with each other,
The multi-stage planetary gear set is disposed at a position between the counter input unit and the counter output unit in the input shaft direction,
The output unit is connected to a planetary gear set other than the outermost planetary gear set in the multi-stage planetary gear set ,
A friction engagement element including a brake;
The brake is connected to a planetary gear set other than that of the plurality of planetary gear sets among the plurality of planetary gear sets, and the counter output unit is defined in the input shaft direction with respect to the counter input unit. An automatic transmission which is disposed on the opposite side . The automatic transmission according to claim 1 , wherein
An automatic transmission characterized in that an outermost planetary gear set in the multi-stage planetary gear set overlaps at least one of the counter input unit and the counter output unit when viewed from the input shaft direction. An input shaft coupled to the power source;
A plurality of planetary gear sets arranged coaxially with the input shaft;
An output unit coupled to any one of the plurality of planetary gear sets, wherein power from the power source is transmitted via a power transmission path formed by the plurality of planetary gear sets;
A counter shaft arranged to extend parallel to the input shaft;
A counter input unit disposed on the counter shaft and driven by the output unit;
A counter output unit disposed on the counter shaft at a position away from the counter input unit in the counter axis direction, and driving the differential input unit of the differential mechanism;
An automatic transmission that constitutes a multi-stage planetary gear set in which at least two planetary gear sets of the plurality of planetary gear sets are radially overlapped with each other,
The plurality of planetary gear sets is
A single pinion type first planetary gear set having a first sun gear, a first carrier, and a first ring gear;
A single pinion type second planetary gear set having a second sun gear, a second carrier, and a second ring gear;
A single pinion type third planetary gear set having a third sun gear, a third carrier, and a third ring gear; and
A double pinion type fourth planetary gear set having a fourth sun gear, a fourth carrier, and a fourth ring gear;
The first carrier and the second ring gear are always connected to the input shaft;
The first ring gear and the third carrier are always connected,
The second sun gear and the third sun gear are always connected,
The third carrier and the fourth sun gear are always connected,
The second carrier and the fourth carrier are always connected,
The third ring gear and the fourth carrier are configured to be connected / disconnected by a first clutch,
Between any one of the second sun gear and the second ring gear, between the second carrier and the second ring gear, and between the second sun gear and the second carrier, It is configured to be connected / disconnected by the second clutch,
The first ring gear and the third carrier and the transmission case are configured to be connected / disconnected by a first brake,
The third ring gear and the transmission case are configured to be connected / disconnected by a second brake,
The first sun gear and the transmission case are configured to be connected / disconnected by a third brake,
The multi-stage planetary gear set includes the second planetary gear set positioned on the radially outer side and the fourth planetary gear set positioned on the radially inner side, and in the input shaft direction, the counter input unit and the It is arranged at a position between the counter output part,
The automatic transmission, wherein the output unit is connected to a fourth ring gear of the fourth planetary gear set.

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