JP6064850B2 - Automatic transmission - Google Patents

Description

  The present invention relates to an automatic transmission mounted on a vehicle, and belongs to the technical field of a vehicle transmission.

  An automatic transmission mounted on a vehicle generally includes a plurality of planetary gear sets (planetary gear mechanisms) and a plurality of hydraulic friction engagement elements such as clutches and brakes, and these friction engagement elements are selectively controlled by hydraulic control. By being fastened, the power transmission path through each planetary gear set is switched so that a plurality of forward shift speeds and typically one reverse speed speed can be realized.

  For example, Patent Document 1 includes three single-pinion type planetary gear sets and five frictional engagement elements, and by fastening any two of these frictional engagement elements, six forward stages An automatic transmission that realizes one reverse speed is disclosed.

  On the other hand, in recent years, in order to improve the fuel efficiency performance and the speed change performance of the engine, it is required to further increase the number of forward shift speeds, for example, including three planetary gear sets and six friction engagement elements, An automatic transmission that realizes eight forward speeds by combining two frictional engagement elements among the frictional engagement elements is considered.

  However, in this configuration, there are four non-engaged frictional engagement elements at each gear position. Therefore, the sliding resistance between the friction plates in these frictional engagement elements or the viscosity of the lubricating oil between the friction plates. Due to the resistance or the like, the driving loss of the entire transmission increases, and there is a possibility that the effect of improving the fuel consumption performance due to the multi-stage is impaired.

  On the other hand, Patent Document 2 includes two single pinion type planetary gear sets and two double pinion type planetary gear sets, and five friction engagement elements, and selectively selects three of these friction engagement elements. An automatic transmission that achieves eight forward speeds by engaging is disclosed.

  According to this, since the number of friction engagement elements in the non-engaged state at each shift stage is two, the drive loss as described above is suppressed.

JP 2008-298126 A JP 2009-174626 A

  However, in the configuration of the automatic transmission disclosed in Patent Document 2, the direct connection stage with a reduction ratio of 1 is 5 speeds, the reduction stage is 4 stages, and the speed increasing stage is 3 stages, and the reduction ratio is overall. Therefore, there is a concern that the driving force is insufficient when an engine having a small displacement relative to the vehicle weight is mounted. In particular, since the start acceleration performance may be insufficient, the automatic transmission has a large reduction gear ratio for the first gear. For this reason, the gear step between the first and second gears (lower gear ratio / upper gear ratio) The reduction ratio) is larger than the gear steps between the other gears, and appropriate gear step distribution is sacrificed (see the comparative example in FIG. 14).

  To solve this problem, it is conceivable to secure a required driving force and start acceleration while realizing an appropriate gear step distribution by increasing the final reduction ratio. However, in this case, the input gear of the differential mechanism that constitutes the final reduction gear is enlarged, and in particular, the front engine / front drive vehicle in which the transmission is set horizontally and the drive unit is integrated with the differential mechanism. In such a case, the drive unit becomes large and mountability in the engine room becomes a problem.

  Further, in the automatic transmission disclosed in Patent Document 2, it may be considered that the direct coupling stage is set to a high gear stage of 6 speeds or more, but three of the five frictional engagement elements are fastened. Of the 10 combinations, the remaining one combination that is not used at the 1st to 8th speeds and the reverse speed, specifically, the clutches C1 and the brakes B1 and B2, the clutches Ca and Cb are released. Therefore, the carrier Cr in the planetary gear set 8 becomes free, so that no rotational force can be output to the ring gear Rr of the planetary gear set 8 to which the output gear 3 is connected, resulting in a neutral state.

  In other words, in the automatic transmission disclosed in Patent Document 2, it is impossible to provide a new shift stage on the lower speed side than the fifth speed and to make the direct connection stage higher than the sixth speed.

  Also, in this automatic transmission, it is intended to change the connection relationship between the rotating elements of each planetary gear set and the relationship between these rotating elements and the frictional engagement elements in an attempt to set the direct gear to 6th speed or more. However, in general, in the configuration of an automatic transmission, when some changes are made to other parts, and it is possible to realize an appropriate reduction ratio of each shift stage and an appropriate gear step between the shift stages, with a realizable gear size. Eventually, a new configuration of automatic transmission must be created from the beginning.

  At this time, for this type of automatic transmission, in order to ensure mountability in a limited in-vehicle space, the increase in the number of planetary gear sets accompanying the increase in the number of stages prevents the axial dimension from becoming longer. It is required to be compact in the axial direction.

  The present invention has been made in view of the above-described actual situation regarding the multi-stage automatic transmission, and can be set to 8 speeds in the direct connection stage, and further, the automatic transmission of 8 forward stages capable of appropriately distributing the gear steps between the respective shift stages. As a result of diligent studies, this was achieved. In particular, this automatic transmission is realized while achieving axial compactness.

  In order to solve the above-described problems, an automatic transmission according to the present invention is configured as follows.

First, the invention according to claim 1 of the present application is
In the transmission case,
An input shaft coupled to the drive source;
An output member disposed coaxially with the input shaft and coupled to a differential mechanism;
A double pinion type first planetary gear set having a first sun gear, a first ring gear and a first carrier;
A double pinion type second planetary gear set having a second sun gear, a second ring gear and a second carrier;
A single pinion type third planetary gear set having a third sun gear, a third ring gear and a third carrier;
A single pinion type fourth planetary gear set having a fourth sun gear, a fourth ring gear, and a fourth carrier;
First, second and third clutches;
First and second brakes;
An automatic transmission with
The input shaft and the second sun gear are always connected,
The output member and the third carrier are always connected,
The first sun gear and the second carrier are always connected,
The first ring gear and the fourth ring gear are always connected,
The second ring gear and the third ring gear are always connected,
The third sun gear and the fourth carrier are always connected,
The first clutch connects and disconnects the first carrier and the third sun gear and the fourth carrier;
The second clutch connects and disconnects the first carrier and the second ring gear and the third ring gear;
The third clutch connects and disconnects the second carrier, the third carrier and the output member;
The first brake connects / disconnects between the first ring gear and the fourth ring gear and the transmission case,
The second brake connects and disconnects the fourth sun gear and the transmission case,
When the first, second, and third clutches are engaged and the first and second brakes are released, an 8th speed with a reduction ratio of 1 is formed, and
The first, second, third and fourth planetary gear sets are arranged in the order of the first, second, third and fourth planetary gear sets from one axial end side.
It is characterized by that.

The invention according to claim 2 is the invention according to claim 1,
Of the first, second and third clutches and the first and second brakes,
First speed is formed when the second clutch, the first brake and the second brake are engaged,
When the first clutch, the second clutch and the first brake are engaged, the second speed is formed,
Third speed is formed when the first clutch, the first brake and the second brake are engaged,
When the first clutch, the third clutch and the first brake are engaged, the fourth speed is formed,
When the third clutch, the first brake and the second brake are engaged, the fifth speed is formed,
Sixth speed is formed when the first clutch, the third clutch and the second brake are engaged,
Seventh speed is formed when the second clutch, the third clutch and the second brake are engaged,
A reverse speed is formed when the second clutch, the third clutch, and the first brake are engaged.
It is characterized by that.

Further, the invention according to claim 3 is the invention according to claim 1 or 2,
The first clutch and the second clutch are disposed between the first planetary gear set and the second planetary gear set in the order of the first clutch and the second clutch from one axial end side,
The third clutch is disposed between the second planetary gear set and the third planetary gear set.
It is characterized by that.

  With the above configuration, according to the first aspect of the present invention, the forward eight-stage automatic transmission including two double pinion type planetary gear sets, two single pinion type planetary gear sets, and five frictional engagement elements. , The direct connection stage can be set to 8 speeds, and the number of deceleration stages is increased as compared with the automatic transmission in which the direct connection stage is 5 speeds.

  Therefore, the overall reduction ratio can be increased, and when applied to a small displacement engine, the final reduction ratio increases, the drive unit increases in size, and the mountability in the engine room deteriorates. The required driving force and start acceleration can be realized while avoiding the above and making it possible to set an appropriate gear step between the respective gears.

  Further, the first, second, third and fourth planetary gear sets are arranged in this order from one end in the axial direction, so that the power transmission member and the second and third ring gears for connecting the first and fourth ring gears. The first, fourth ring gear and second, third ring gear can be connected to each other without the power transmission member for connecting the first and fourth ring gears extending between the planetary gear sets in the radial direction orthogonal to the axial direction. The number of power transmission members extending in the radial direction orthogonal to the axial direction can be reduced as compared with the case where the planetary gear sets are arranged in the other order.

  Specifically, the second and second gears are always connected radially inward of the power transmission member for connecting the first and fourth ring gears that are connected to and disconnected from the transmission case by the first brake. A power transmission member for connecting the three ring gears can be arranged to connect the first, fourth ring gear, and the second and third ring gears without the power transmission member extending in the radial direction between the planetary gear sets, The number of power transmission members extending in the radial direction orthogonal to the axial direction can be reduced.

  As a result, the number of thrust bearings disposed between the power transmission members of this type can be reduced, so that the entire automatic transmission can be made compact in the axial direction. Thereby, the mounting property to the limited vehicle-mounted space can be improved.

  Further, according to the invention described in claim 2, by appropriately setting the number of teeth of the sun gear and the ring gear of each planetary gear set, an appropriate reduction ratio can be realized for the first to seventh speeds and the reverse speed. .

  Furthermore, according to the invention described in claim 3, the first and second clutches are disposed between the first planetary gear set and the second planetary gear set in the order of the first and second clutches from one end in the axial direction. The third clutch is disposed between the second planetary gear set and the third planetary gear set, so that the adjacent first and second clutches are arranged so as to overlap each other in the radial direction, thereby further reducing the axial compactness. Can be achieved.

1 is a skeleton diagram of an automatic transmission according to an embodiment of the present invention. 3 is a fastening table of frictional engagement elements of the automatic transmission. FIG. 4 is a skeleton diagram and a reduction ratio diagram illustrating a fastening state of a frictional engagement element at the first speed. FIG. 4 is a skeleton diagram and a reduction ratio diagram illustrating a fastening state of a frictional engagement element at the second speed. FIG. 4 is a skeleton diagram and a reduction ratio diagram showing a fastening state of a frictional engagement element at the third speed. FIG. 4 is a skeleton diagram and a reduction ratio diagram illustrating a fastening state of a frictional engagement element at the fourth speed. FIG. 6 is a skeleton diagram and a reduction ratio diagram illustrating a fastening state of a frictional engagement element at the fifth speed. FIG. 6 is a skeleton diagram and a reduction ratio diagram illustrating a fastening state of a frictional engagement element at the sixth speed. FIG. 6 is a skeleton diagram and a reduction ratio diagram illustrating a fastening state of a frictional engagement element at the seventh speed. FIG. 7 is a skeleton diagram and a reduction ratio diagram illustrating a fastening state of a frictional engagement element at the eighth speed. FIG. 4 is a skeleton diagram and a reduction ratio diagram illustrating a fastening state of a frictional engagement element at a reverse speed. It is a table | surface of the example of the number of teeth of the gear which comprises a planetary gear set. It is a table | surface which shows the reduction ratio and gear step in the case of the number of teeth example of FIG. It is the graph which illustrated the gear step of FIG. 13 with the comparative example. 1 is a skeleton diagram of an automatic transmission in which the automatic transmission according to the present embodiment is different in arrangement of gear sets and frictional engagement elements. It is a skeleton figure of an automatic transmission concerning a modification of this embodiment.

  Embodiments of the present invention will be described below.

  FIG. 1 is a skeleton diagram showing a configuration of an automatic transmission 10 according to an embodiment of the present invention. The automatic transmission 10 is arranged in a transmission case 11 on the same axis line. And an output shaft 13 as an output member. From the input side (drive source side) on the left side of the figure, a double pinion type first and second planetary gear set (hereinafter simply referred to as “first” PG1, PG2) (single and second gear sets) and single and pinion type third and fourth planetary gear sets (hereinafter simply referred to as "third and fourth gear sets") PG3 and PG4.

  In addition, between the first gear set PG1 and the second gear set PG2, the first clutch CL1 and the second clutch CL2 are connected to the other end side from one axial side which is the input side of the first clutch CL1 and the second clutch CL2. A third clutch CL3 is disposed between the second gear set PG2 and the third gear set PG3. In the vicinity of the fourth gear set PG4, first and second brakes BR1 and BR2 are arranged from the input side.

  Each of the first to fourth gear sets PG1 to PG4 has three rotating elements. As these rotating elements, the first gear set PG1 has a first sun gear S1, a first ring gear R1, and a first carrier C1. The second gear set PG2 has a second sun gear S2, a second ring gear R2, and a second carrier C2, and the third gear set PG3 has a third sun gear S3, a third ring gear R3, and a third carrier C3, The four gear set PG4 includes a fourth sun gear S4, a fourth ring gear R4, and a fourth carrier C4.

  Here, the first and second gear sets PG1 and PG2 of the double pinion type include a first pinion meshed with the first and second sun gears S1 and S2, respectively, the first pinion and the first and second ring gears R1, The second pinions meshed with R2 are supported by the first and second carriers C1 and C2, respectively. The single pinion type third and fourth gear sets PG3 and PG4 have pinions meshed with the third and fourth sun gears S3 and S4 and the third and fourth ring gears R3 and R4, respectively. Are supported by the third and fourth carriers C3 and C4, respectively.

  In the automatic transmission 10, the first sun gear S1 and the second carrier C2, the first ring gear R1 and the fourth ring gear R4, the second ring gear R2 and the third ring gear R3, and the third sun gear S3. And the fourth carrier C4 are always connected. The input shaft 12 is always connected to the second sun gear S2, and the output shaft 13 is always connected to the third carrier C3.

  The first clutch CL1 is disposed between the first carrier C1, the third sun gear S3, and the fourth carrier C4 so as to connect and disconnect them. The second clutch CL2 The first carrier C1 is disposed between the second ring gear R2 and the third ring gear R3 so as to connect and disconnect them, and the third clutch CL3 is connected to the second carrier C2 and the third ring gear R3. It is disposed between the carrier C3 and the output shaft 13 so as to connect and disconnect them.

  Further, the first brake BR1 is disposed between the transmission case 11 and the first ring gear R1 and the fourth ring gear R4 so as to connect and disconnect them, and the second brake BR2 includes: It is arranged between the transmission case 11 and the fourth sun gear S4 so as to connect and disconnect them.

  According to this automatic transmission 10, with the above configuration, as shown in the fastening table of FIG. 2, the first to eighth forward speeds can be achieved by selectively fastening three friction fastening elements from five friction fastening elements. A reverse speed is formed.

  Next, the mechanism by which the reduction ratio is determined for each gear according to the combination of fastening of the frictional engagement elements shown in FIG. 2 will be described with reference to FIGS.

  FIGS. 3 to 11 (a) show the frictional engagement elements that are fastened at the gears by shading, and FIG. 3 (b) shows the reduction ratios of the gears. As shown in the figure, in this reduction ratio diagram, the lateral spacing between the rotating elements in each gear set PG1 to PG4 is determined by the respective gear ratio, and in the double pinion type gear sets PG1 and PG2, the carrier, ring gear, sun gear In the single pinion type gear sets PG3 and PG4, the ring gear, the carrier, and the sun gear are arranged in this order.

  The vertical axis represents the rotational speed, the input rotational speed, that is, the rotational speed of the input shaft 12 and the second sun gear S2 always connected to the input shaft 12 is "1", and the rotational speed of the rotating element fixed by the brake is "1". 0 ”. Further, the rotational speeds of the rotational elements that are always connected and the rotational elements that are connected by the clutch are equal. N1 to N8 and Nr indicate the rotational speeds at the respective speeds of the rotation output from the second carrier C2 or the third carrier C3 to the output shaft 13, and the reciprocal of the output speed is the deceleration at the corresponding speed stage. It becomes a ratio.

  First, at the first speed, as shown in FIG. 3, since the second clutch CL2 and the first and second brakes BR1 and BR2 are engaged, first, the first carrier C1 and the second, which are always connected, The third ring gears R2 and R3 are connected to rotate the same, and the rotation speeds of the first and fourth ring gears R1 and R4 and the fourth sun gear S4 become “0”. Further, in the fourth gear set PG4, when the rotational speeds of the fourth sun gear S4 and the fourth ring gear R4 become “0”, the entire fourth gear set PG4 is fixed and always connected to the fourth carrier C4. The rotation speed of the third sun gear S3 is also “0”.

  Since these conditions and the first sun gear S1 and the second carrier C2 are always connected, the rotation speed of the third carrier C3 with respect to the rotation speed “1” of the second sun gear S2 is determined, and this rotation The speed becomes the output rotation speed N1.

  Next, in the second speed, as shown in FIG. 4, since the first and second clutches CL1 and CL2 and the first brake BR1 are engaged, first, the first carrier C1 and the fourth carrier C4 are connected. Then, these and the third sun gear S3 always connected to the fourth carrier C4 rotate in the same direction, and the first carrier C1 and the second and third ring gears R2 and R3 always connected are connected, As a result, the third sun gear S3 and the third ring gear R3 rotate together with the first carrier C1, the third gear set PG3 is integrated, and the third carrier C3 is also the same. Rotate.

  The rotational speeds of the first and fourth ring gears R1 and R4 are set to “0”, and the first sun gear S1 and the second carrier C2 are always connected. 1 ", the rotational speed of each of the rotating elements rotating the same is determined, and this rotational speed is output from the third carrier C3 as the output rotational speed N2.

  Next, at the third speed, as shown in FIG. 5, since the first clutch CL1 and the first and second brakes BR1 and BR2 are engaged, first, the first, fourth ring gears R1, R4 and fourth The rotational speed of the sun gear S4 is “0”, the entire fourth gear set PG4 is fixed, and the rotational speed of the fourth carrier C4 and the rotational speed of the first carrier C1 connected thereto are also “0”. Accordingly, the entire first gear set PG1 is also fixed, and the rotational speed of the first sun gear S1 is also “0”.

  Further, the first and fourth gear sets PG1 and PG4 are fixed as a whole, so that the second carrier C2 always connected to the first sun gear S1 and the third sun gear S3 always connected to the fourth carrier C4. The rotation speed is also “0”.

  And by these conditions and the fact that the second ring gear R2 and the third ring gear R3 are always connected, the rotational speed of the third carrier C3 with respect to the input rotational speed “1” of the second sun gear S2 is determined, This rotational speed becomes the output rotational speed N3.

  Next, in the fourth speed, as shown in FIG. 6, since the first and third clutches CL1 and CL3 and the first brake BR1 are engaged, the first carrier C1 and the fourth carrier C4 are connected, These and the third sun gear S3 always connected to the fourth carrier C4 rotate in the same direction, the second carrier C2 and the third carrier C3 are connected, and the first and second carriers C2 are always connected to the first carrier C2. The sun gear S1 rotates in the same direction. Then, the rotation speeds of the first ring gear R1 and the fourth ring gear R4 are “0”.

  Since these conditions and the second ring gear R2 and the third ring gear R3 are always connected, the rotational speed of the third carrier C3 with respect to the input rotational speed “1” to the second sun gear S2 is determined, and this rotation The speed becomes the output rotation speed N4.

  Next, at the fifth speed, as shown in FIG. 7, since the third clutch CL3 and the first and second brakes BR1 and BR2 are engaged, first, the first, fourth ring gears R1, R4 and fourth The rotational speed of the sun gear S4 becomes “0”, the entire fourth gear set PG4 is fixed, and the rotational speed of the fourth carrier C4 and the third sun gear S3 always connected thereto is also “0”. Further, the second carrier C2 and the third carrier C3 are connected and rotate in the same direction.

  Since these conditions and the second ring gear R2 and the third ring gear R3 are always connected and rotate the same, the rotational speed of the third carrier C3 with respect to the input rotational speed “1” to the second sun gear S2 is This rotational speed is determined as the output rotational speed N5.

  Next, at the sixth speed, as shown in FIG. 8, since the first and third clutches CL1 and CL3 and the second brake BR2 are engaged, the first carrier C1 and the fourth carrier C4 are first connected. And the third sun gear S3 always connected to the fourth carrier C4 rotate in the same direction, and the second carrier C2 and the third carrier C3 are connected and always connected to the second carrier C2. The first sun gear S1 rotates in the same direction. Then, the rotation speed of the fourth sun gear S4 becomes “0”.

  Since these conditions, the second and third ring gears R2 and R3 are always connected, and the first and fourth ring gears R1 and R4 are always connected, the input rotation to the second sun gear S2 The rotation speed of the third carrier C3 with respect to the speed “1” is determined, and this rotation speed becomes the output rotation speed N6.

  Next, at the seventh speed, as shown in FIG. 9, since the second and third clutches CL2 and CL3 and the second brake BR2 are engaged, first, the second carrier that is always connected to the first carrier C1. The ring gear R2 and the third ring gear R3 are connected to rotate the same, and the second carrier C2 and the third carrier C3 are connected to each other, and the first sun gear S1 is always connected to the second carrier C2. And rotate the same. Then, the rotation speed of the fourth sun gear S4 becomes “0”.

  From these conditions, the first and fourth ring gears R1 and R4 are always connected, and the third sun gear S3 and the fourth carrier C4 are always connected. The rotational speed of the third carrier C3 with respect to the input rotational speed “1” is determined, and this rotational speed becomes the output rotational speed N7.

  Next, at the eighth speed, as shown in FIG. 10, the first, second, and third clutches CL1, CL2, and CL3 are engaged, so that the first carrier C1 and the fourth carrier C4 are connected to each other. The third sun gear S3 always connected to the fourth carrier C4 rotates in the same direction, and the first carrier C1, the second ring gear R2 and the third ring gear R3 always connected, and these rotate in the same direction. To do. Further, the second carrier C2 and the third carrier C3 are connected, and these and the first sun gear S1 always connected to the second carrier C2 rotate in the same direction.

  Therefore, in the third gear set PG3, the third sun gear S3 and the third ring gear R3 rotate the same as the first carrier C1, the third gear set is integrated, and the third carrier C3 rotates the same as these, The second carrier C2 connected to this also rotates the same.

  Accordingly, in the second gear set PG2, the second carrier C2 and the second ring gear R2 also rotate in the same manner as the respective rotating elements, and the second gear set PG2 is also integrated. As a result, the rotational speed of the second carrier C2 and the third carrier C3 connected thereto is also "1" with respect to the input rotational speed "1" to the second sun gear S2, and this rotational speed is the output rotational speed N8. It becomes. That is, the eighth gear is a direct coupling stage with a reduction ratio of “1”.

  At this time, the first and fourth gear sets PG1 and PG4 also rotate integrally at the same rotational speed as the second and third gear sets PG2 and PG3, and all of the first to fourth gear sets PG1 to PG4 have the input rotational speed “ 1 ”will rotate together.

  Further, at the reverse speed, as shown in FIG. 11, since the second and third clutches CL2 and CL3 and the first brake BR1 are engaged, first, the first carrier C1 and the second ring gear that is always connected are firstly connected. R2 and the third ring gear R3 are connected to rotate the same, and the second carrier C2 and the third carrier C3 are connected to each other, and the first sun gear S1 is always connected to the second carrier C2. Rotate the same.

  Then, in the first and second gear sets PG1, PG2, the first sun gear S1 and the second sun gear S2 that rotate the same from the condition that the rotation speed of the second sun gear S2 is "1" and the rotation speed of the first ring gear R1 is "0" The rotational speed of the carrier C2 is determined, and this rotational speed becomes a negative output rotational speed Nr.

  As described above, the rotational speeds N1 to N8 and Nr are set to N1 <N2 <N3 <N4 <N5 <N6 <N7 <N8 and Nr <0 by combining the five frictional engagement elements shown in FIG. In addition, since N8 = 1 by the above-described configuration, an automatic transmission in which the eighth speed is a direct connection stage with a reduction gear ratio “1” can be obtained with eight forward speeds and one reverse speed.

  Therefore, the number of speed reduction stages is larger than that of, for example, a 5-speed automatic transmission, and the overall reduction ratio can be increased. When applied to a small displacement engine, the final speed reduction is achieved. It is necessary to suppress the increase in the ratio, the accompanying increase in the size of the differential gear or drive unit, the deterioration in the mountability in the engine room, etc., and the setting of appropriate gear steps between the respective gears. It becomes possible to realize the driving force and start acceleration performance.

  Here, if the number of teeth of each gear of the first to fourth gear sets PG1 to PG4 is set as shown in FIG. 12, for example, the reduction ratio of each gear stage and the gear steps between adjacent forward gear stages are shown in FIG. As shown.

  Compared with the automatic transmission in which the direct connection stage described in the above-mentioned Patent Document 2 is a 5-speed automatic transmission according to FIG. As a result, the gear step between the first and second gears is extremely larger than that between the other gears. On the other hand, in the automatic transmission 10 according to the embodiment of the present invention, each gear is The gear steps in between are within a narrow range of 1.1 to 1.4, and a very even distribution of gear steps is realized.

  The automatic transmission 10 described above is also arranged in the order of the first, second, third, and fourth gear sets PG1, PG2, PG3, and PG4 from one end in the axial direction, so that the first, fourth ring gear R1, The power transmission member for connecting R4 and the power transmission member for connecting the second and third ring gears R2, R3 do not extend in the radial direction perpendicular to the axial direction between the gear sets, and the first and fourth ring gears R1, R4 and the second and third ring gears R2 and R3 can be connected to each other, and in the radial direction orthogonal to the axial direction, compared to the case where the first to fourth gear sets PG1 to PG4 are arranged in the other order. The number of extending power transmission members can be reduced.

  FIG. 15 is a skeleton diagram of an automatic transmission in which the arrangement of the gear set and the frictional engagement element is different from that of the automatic transmission according to the present embodiment. Also in the automatic transmission 100 shown in FIG. 15, the double pinion type first and second gear sets and the single pinion type third and fourth gear sets are arranged on the input shaft and the output shaft arranged on the same axis. And first, second, and third clutches, and first and second brakes.

  Since these components are the same as those of the automatic transmission 10, the same reference numerals as those of the automatic transmission 10 are used for the first to fourth gear sets, the rotation elements thereof, and the respective frictional engagement elements.

  The automatic transmission 100 is different from the automatic transmission 10 in the order of arrangement of the first to fourth gear sets on the axis, and the arrangement of the frictional engagement elements is different accordingly. That is, the rotation elements in each gear set, that is, the connection relationship between the sun gear, the ring gear, and the carrier, and the relationship between the rotation elements that are connected / disconnected to / from the transmission case by the brakes, or are mutually connected by the clutch are all the same. Yes, the three frictional engagement elements are selectively engaged according to the engagement table shown in FIG. 2, so that, similarly to the automatic transmission 10, the eight forward speeds and the reverse speeds are formed, and the eighth speed is the direct connection stage. It becomes.

  In the automatic transmission 100, a second gear set PG2, a first gear set PG1, a fourth gear set PG4, and a third gear set PG3 are arranged on the input shaft 112 and the output shaft 113 from the input side.

  A third clutch CL3 is disposed between the second gear set PG2 and the first gear set PG1, and between the first gear set PG1 and the fourth gear set PG4, the second clutch CL2 and the first clutch CL1 are connected from the input side. The first brake BR1 and the second brake BR2 are arranged from the input side in the vicinity of the fourth gear set PG4.

  In the automatic transmission 100 configured as described above, the transmission case 11 is provided by the first brake BR1 between the second and third gear sets PG2 and PG3 having the second and third ring gears R2 and R3 that are always connected. And first and fourth gear sets PG1 and PG4 having first and fourth ring gears R1 and R4 that are always connected and connected.

  For this reason, the power transmission member for connecting the second and third ring gears R1 and R4 cannot be disposed radially outside the first and fourth ring gears R1 and R4, and the second and third sun gears R2 , R3 are arranged on the inner side in the radial direction, and are provided so as to extend in the radial direction at portions indicated by reference numerals M101 and M102.

  In the automatic transmission 100, a power transmission member for connecting the first sun gear S1 and the second carrier C2 that are always connected is provided so as to extend in the radial direction at a portion indicated by reference numeral M103 and is always connected. A power transmission member for connecting the third sun gear S3 and the fourth carrier C4 is provided to extend in the radial direction at portions indicated by reference numerals M104 and M105.

  In these five portions denoted by reference numerals M101 to M105, it is necessary to secure an axial space only for the power transmission member extending in the radial direction, and thus the axial dimension of the automatic transmission 100 is long.

  On the other hand, as shown in FIG. 1, the automatic transmission 10 according to the present embodiment includes first and fourth ring gears R1 and R4 that are connected to and disconnected from the transmission case 11 by the first brake BR1. Between the first and fourth gear sets PG1 and PG4, second and third gear sets PG2 and PG3 having second and third ring gears R2 and R3 that are always connected are arranged.

  Therefore, a power transmission member for connecting the second and third ring gears R2 and R3 is arranged on the radially inner side of the power transmission member for connecting the first and fourth ring gears R1 and R4, and the power transmission member Can be connected to the first and fourth ring gears R1 and R4 and the second and third ring gears R2 and R3 without extending in the radial direction between the planetary gear sets.

  The power transmission member for connecting the first sun gear S1 and the second carrier C2 that are always connected, and the power transmission member for connecting the third sun gear S3 and the fourth carrier C4 that are always connected are also described. The first sun gear S1, the second carrier C2, the third sun gear S3, and the fourth carrier C4 can be connected without the members extending in the radial direction between the planetary gear sets.

  As described above, in the automatic transmission 10, the first, second, third, and fourth gear sets PG1, PG2, PG3, and PG4 are arranged in this order from one end in the axial direction, whereby the first to fourth gear sets PG1. The number of power transmission members extending in the radial direction perpendicular to the axial direction can be reduced as compared with the case where PG4 is arranged in another order.

  As a result, the number of thrust bearings disposed between the power transmission members of this type can be reduced, so that the entire automatic transmission can be made compact in the axial direction. Thereby, the mounting property to the limited vehicle-mounted space can be improved.

  Further, the first and second clutches CL1 and CL2 are arranged in the order of the first and second clutches CL1 and CL2 from one end in the axial direction between the first gear set PG1 and the second gear set PG2, and the third clutch CL3 is By arranging between the second gear set PG2 and the third gear set PG3, the first and second clutches CL1 and CL2 adjacent to each other are arranged so as to overlap each other in the radial direction, thereby further reducing the axial direction. Can be achieved.

  Note that the automatic transmission 10 according to the present embodiment is of a vertical type for front engines and rear drive vehicles in which the input and output shafts are arranged on the same axis, but the same regarding the gear set and the frictional engagement element. With this configuration, it is possible to configure a horizontal automatic transmission for a front engine / front drive vehicle or the like.

  As shown in FIG. 16, in the automatic transmission 10 ′ changed to the horizontal type, the input side (drive source side) is the same side as the output side (right side in the figure) with respect to the vertical type automatic transmission 10. Thus, the input shaft 12 'connected to the drive source extends from the right side to the left side in the drawing and is connected to the second sun gear S2.

  Further, instead of the output shaft 13 in the vertical automatic transmission 10, an output gear 13 ′ is arranged on the input side, and is connected to the third carrier C 3 like the output shaft 13. Other configurations are the same as those of the vertical automatic transmission 10.

  The output gear 13 ′ is connected to an input gear of a differential mechanism integrated with the automatic transmission 10 ′ through a gear on a counter shaft (not shown). The final reduction gear is composed of the gear train up to the input gear.

  As described above, according to the present invention, an automatic transmission with eight forward speeds capable of setting the direct connection speed to the eighth speed and appropriately setting the gear step between the respective gear speeds is realized. There is a possibility that the present invention is suitably used in the field of vehicle automatic transmission or vehicle manufacturing technology.

10, 10 ', 100 Automatic transmission 11 Transmission case 12, 12' Input shaft 13 Output shaft 13 'Output gear PG1-PG4 First to fourth planetary gear sets S1-S4 Sun gear R1-R4 Ring gear C1-C4 Carrier CL1- CL3 first to third clutches BR1, BR2 first and second brakes

Claims (3)

In the transmission case,
An input shaft coupled to the drive source;
An output member disposed coaxially with the input shaft and coupled to a differential mechanism;
A double pinion type first planetary gear set having a first sun gear, a first ring gear and a first carrier;
A double pinion type second planetary gear set having a second sun gear, a second ring gear and a second carrier;
A single pinion type third planetary gear set having a third sun gear, a third ring gear and a third carrier;
A single pinion type fourth planetary gear set having a fourth sun gear, a fourth ring gear, and a fourth carrier;
First, second and third clutches;
First and second brakes;
An automatic transmission with
The input shaft and the second sun gear are always connected,
The output member and the third carrier are always connected,
The first sun gear and the second carrier are always connected,
The first ring gear and the fourth ring gear are always connected,
The second ring gear and the third ring gear are always connected,
The third sun gear and the fourth carrier are always connected,
The first clutch connects and disconnects the first carrier and the third sun gear and the fourth carrier;
The second clutch connects and disconnects the first carrier and the second ring gear and the third ring gear;
The third clutch connects and disconnects the second carrier, the third carrier and the output member;
The first brake connects / disconnects between the first ring gear and the fourth ring gear and the transmission case,
The second brake connects and disconnects the fourth sun gear and the transmission case,
When the first, second, and third clutches are engaged and the first and second brakes are released, an 8th speed with a reduction ratio of 1 is formed, and
The first, second, third and fourth planetary gear sets are arranged in the order of the first, second, third and fourth planetary gear sets from one axial end side.
An automatic transmission characterized by that. Of the first, second and third clutches and the first and second brakes,
First speed is formed when the second clutch, the first brake and the second brake are engaged,
When the first clutch, the second clutch and the first brake are engaged, the second speed is formed,
Third speed is formed when the first clutch, the first brake and the second brake are engaged,
When the first clutch, the third clutch and the first brake are engaged, the fourth speed is formed,
When the third clutch, the first brake and the second brake are engaged, the fifth speed is formed,
Sixth speed is formed when the first clutch, the third clutch and the second brake are engaged,
Seventh speed is formed when the second clutch, the third clutch and the second brake are engaged,
A reverse speed is formed when the second clutch, the third clutch, and the first brake are engaged.
The automatic transmission according to claim 1. The first clutch and the second clutch are disposed between the first planetary gear set and the second planetary gear set in the order of the first clutch and the second clutch from one axial end side,
The third clutch is disposed between the second planetary gear set and the third planetary gear set.
The automatic transmission according to claim 1 or 2, wherein the automatic transmission is provided.

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