JPH0262466A - Oil passage construction in automatic transmission - Google Patents

Abstract

PURPOSE:To shorten the slidable contact portion of a hub and reduce axial length by providing an aslant oil passage for communication between an annular recess groove bottom formed on the internal surface of the hub matching the supply oil passage of a boss part and the oil chamber of a hydraulic actuator. CONSTITUTION:Hydraulic pressure from a valve body is supplied from a supply oil passage 1 formed in a boss part 2a to the annular recess groove 6 of a hub 3 in slidable contact with the boss part 2a, and further to the oil chamber 5a of a hydraulic actuator 5 via an aslant oil passage 7. Also, the oil passage construction is such that the annular recess groove 6 is formed on the internal surface of the hub 3 and the aslant oil passage 7 from the oil chamber 5 is punched in such a way that the forward end thereof will reach the bottom part 6a of the groove 6. According to the aforesaid construction, it is unnecessary to lead the aslant oil passage 7 up to the internal surface of the hub 3 and can be curtailed accordingly.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Industrial Application Field The present invention relates to an oil passage structure for a hydraulic actuator in an automatic transmission. The present invention relates to an oil passage structure for supplying oil to a hydraulic actuator via an oblique oil passage.

(b) Prior art-m, for example, as shown in FIG. 5, a hub 103 is rotatably supported on a boss portion 102 extending from a case, and a one-way clutch F is mounted on the hub;
In an automatic transmission in which a clutch drum 110 is fixed and a hydraulic actuator 105 for operating a clutch C consisting of a piston 111 is configured, a radial supply oil passage 101a is formed in the boss portion 102, and a boss at the tip of the oil passage is formed. An annular groove 101b is formed on the outer peripheral surface of the hub 103, and an oil passage 107 that communicates the annular groove 101b with the oil chamber 105a of the hydraulic actuator 105 is diagonally arranged.

Recently, as shown in Japanese Unexamined Patent Application Publication No. 62-93546, a first automatic transmission mechanism section having a gear unit that combines a single planetary gear and a dual planetary gear is disposed on the input shaft. We also proposed an automatic transmission in which a second automatic transmission mechanism (additional transmission) consisting of an underdrive and a direct connection is disposed on the countershaft.

In this automatic transmission as well, the second automatic transmission mechanism employs an oil passage structure in which an annular groove is formed in the boss portion and an oblique oil passage is formed in the hub.

(C) Problems to be Solved by the Invention However, in the above-mentioned oil passage structure, it is necessary to form an oil passage diagonally through the hub, and the annular grooves on the left and right sides of the boss portion corresponding to the passages Coupled with the need to form a seal groove in the hub, the hub must be made longer, which is one of the causes of an increase in axial dimension.

In particular, in the above-mentioned automatic transmission for F-F, if a 3-speed automatic transmission mechanism is adopted as the first automatic transmission mechanism part, the relative axial dimension of the counter shaft becomes a problem. There is a demand for a reduction in the axial dimension of the counter shaft, which is located in the upper part and has many restrictions on installation space due to the presence of side frames.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an oil passage structure in an automatic transmission in which an annular groove is formed on the hub side, thereby reducing the axial dimension.

(d) Means for Solving the Problems The present invention has been made in view of the above-mentioned circumstances. For example, referring to FIG. 1, the fixing member boss portion (2a ) on which the hub (
3) and a hydraulic actuator (5) disposed in the hub, the boss portion (2a)
An annular groove (6) is formed on the inner circumferential surface of the hub on a plane aligned with the supply oil passage (1), and the oil of the hydraulic actuator (5) is connected to the bottom (6a) of the groove. Room (5a
) is characterized in that the oil passage (7) is formed diagonally so as to communicate with the oil passage (7).

As an example, as shown in FIG. 2, the automatic transmission may include a first automatic transmission 8! having three forward speeds on an input shaft (9). a second automatic transmission a structure (12) for switching between underdrive and direct connection on a counter shaft (11) parallel to the input shaft (9); a direct clutch (c3) in which an actuator directly connects the second automatic transmission mechanism section (12);
This is an operating hydraulic actuator (5).

(E) Function Based on the above configuration, hydraulic pressure from the valve body is transmitted from the supply oil passage (1) formed in the boss part (2a) to the annular groove (3) in the hub (3) that is in sliding contact with the boss part (2a). 6), and further supplied to the oil chamber (5a) of the hydraulic actuator (5) via the diagonal oil passage (7).

Further, in this oil passage structure, an annular groove (6) is formed on the inner peripheral surface of the hub (3), and a bottom (6a) of the groove (6) is formed.
) A diagonal oil passage (7) is bored from the oil chamber (5a) so that the tip reaches the oil chamber (5a). Therefore, the diagonal oil passage (A) does not need to penetrate all the way to the inner circumferential surface of the hub, and can be shortened accordingly.

Note that the symbols in parentheses are used for reference to contrast with each component in the drawings, and do not limit the structure in any way.

(F) Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First, an outline of the automatic transmission A to which the present invention is applied will be explained with reference to FIG.
and front axle shafts 23a and 23b, and on the input shaft 9 there is a torque converter 26 having a lock-up clutch 25 and a first automatic transmission mechanism section 1o.
A second automatic transmission mechanism section 12 is supported on the counter shaft 11, and a front axle shaft 23a is supported on the counter shaft 11.
, 23b, a front differential device 29 is supported.

The first automatic transmission mechanism section 10 is a single planetary gear 3
0 and a dual planetary gear 31, the planetary gear unit 22 has a sun gear S1 of the two planetary gears.
The carriers CR1 and the carriers CR1 are integrally connected to each other, and the pinion that meshes with the sun gear S1 is a long pinion P1. Then, the input shaft 9 and the ring gear R1 of the single planetary gear 30 are connected to the first (
They are connected via a forward) clutch C1, and are also connected to the input shaft 9 via a sun gear S1 and a second (reverse direct) clutch C2. Also,
The sun gear S1 is directly locked by the first brake B1, and its one-way rotation is locked by the second brake B2 via the first one-way clutch F1. Further, the ring gear R2 of the dual planetary gear 31 is directly locked by the third brake B3, and one-way rotation is locked by the second one-way clutch F2. The carrier CRI is connected to a counter drive gear 27 supported by the case partition wall, and the gear 27 serves as an output member of the first automatic transmission mechanism section 10.

Further, the second automatic transmission mechanism section 12 has one single planetary gear 13, and a carrier CR3 of the planetary gear and a sun gear S3 are connected via a third (direct) clutch C3. Also, Sun Gear S
3 is directly locked by a fourth (underdrive) brake B4, and one-way rotation is locked by a third one-way clutch F3. A ring gear R3 is connected to a counter driven gear 33 that meshes with the counter drive gear 27 and becomes an input member of the automatic transmission mechanism section 12, and a carrier CR3 is connected to the counter shaft 11.

Further, a reduction gear 35 serving as an output member of the automatic transmission mechanism section 12 is fixed to the counter shaft 11.

Further, the front differential device 29 includes a differential carrier 36 and left and right side gears 37a, 37b, and a ring gear 39 is fixed to the differential carrier 36, which serves as a gear mount case. The ring gear 39 meshes with the reduction gear 35 to constitute a final reduction mechanism, and left and right side gears 37a and 37b are connected to left and right front axle shafts 23a and 23b, respectively.

Next, the operation of the automatic transmission A will be explained with reference to FIG.

The rotation of the engine crankshaft 21 is controlled by the torque converter 26.
or via the lock-up clutch 25 to the input shaft 9. In the first speed state in the D range, the first clutch C1 is in a connected state, and the fourth brake B4 is also in a locked state. In this state, in the first automatic transmission mechanism section 10, the rotation of the input shaft 9 is transmitted to the sinkle planetary gear 3 via the first clutch C1.
In this state, the link gear R2 of the dual planetary gear 31 is prevented from rotating by the second one-way clutch F2. The rotation is greatly reduced in the direction, and the rotation is taken out from the counter drive gear 27. In the second automatic transmission mechanism section 12, the sun gear S3 is locked by the fourth brake B4 and the third one-way clutch F3, and the rotation from the counter driven gear 33 is transferred from the link gear R3 to the carrier CR3 at a reduced speed. is extracted as

Therefore, the first speed rotation of the first automatic transmission mechanism section 10 and the deceleration rotation of the second automatic transmission mechanism section 12 are combined, and the rotation is transmitted to the front differential device 29 via the reduction gear 35 and the ring gear 39. , which is further transmitted to the left and right front axle shafts 23a and 23b.

In addition, in the second speed state in the D range, in addition to the engagement of the first clutch C1 and the operation of the fourth brake B4, the second
brake B2 is activated. Then, the first one-way clutch F1 based on the sun gear S1 or the brake B2
The rotation of the ring gear R1 from the input shaft 9 is stopped by the operation of the carrier CRI while causing the ring gear R2 of the dual planetary gear 31 to idle in the forward direction.
is decelerated and rotated in the forward direction, and the rotation is taken out to the counter drive gear 27 as second speed. Further, the second automatic transmission mechanism section 12 remains in the deceleration state, and the front axle is rotated by a combination of the second speed of the first automatic transmission mechanism section 10 and the deceleration rotation of the second automatic transmission mechanism section 12. Shafts 23a, 23
transmitted to b.

At this time, the first brake B1 is also activated, and the large transmission torque reaction force during upshifting is dispersed and carried by both the first brake B1 and the second brake B2, and the engine brake is also activated during coasting. It may be activated.

In the 3rd speed state in the D range, the first automatic transmission Pli mechanism 10 maintains the 2nd speed state, releases the fourth brake B4 in the second automatic transmission mechanism 12, and simultaneously releases the third clutch C3. engage. Then, carrier CR
3 and side gear S3 are integrated, and planetary gear 1
3 rotates integrally and is taken out to the counter shaft 11 through direct rotation. At this time, the fourth brake B4 is switched to the third clutch C.
The third one-way clutch F3 is released early from the engagement of the third one-way clutch F3 to prevent transmission from becoming impossible. Therefore, the second speed rotation of the first automatic transmission mechanism section 10 and the direct rotation of the second automatic transmission mechanism section 12 are combined to obtain the third speed of the automatic transmission A as a whole.

In the fourth speed state in the D range, the second clutch C2 is connected from the third speed state. Then, the power is transmitted from the input shaft 9 to the link gear R1 via the first clutch C1, and is also transmitted to the sun gear S1 via the second clutch C2.
The planetary gear unit 22 rotates integrally, and the direct rotation is transmitted to the counter drive gear 27. The direct rotation of the first automatic transmission mechanism section 10 and the direct rotation of the second automatic transmission mechanism section 12 are combined, and the counter drive gear 27 and the drinking gear 33 are in a predetermined speed increasing relationship, so that the automatic Overdrive rotation is obtained throughout the transmission A. At this time, if the first brake B1 is operating in 2nd and 3rd gears, the first brake B1 is released early when upshifting to 4th gear, and the first one-way clutch Fl is activated. This connects the second clutch C2 while locking the sun gear SL, thereby preventing shift shock from occurring due to changing clutches.

Further, the third range is the same as the state in which the first brake B1 is operated in the second and third speeds in the first, second, and third speeds of the D range.

Further, the 2nd range is the same as the 1st and 2nd speed states of the 3rd range described above.

Further, in the first speed state, the lunge operates the first clutch C.
In addition to the connection of the first brake B4 and the operation of the fourth brake B4, the third
Brake B3 is activated. In this state, in addition to being locked by the second one-way clutch F2, the ring gear R2 is locked by the third brake B3 regardless of the rotational direction, thereby operating the engine brake. Further, the 2nd speed state is the same as 2nd speed in the 2nd range.

In the reverse range, the second clutch C
At the same time, the third brake B3 and the fourth brake B4 are activated. In this state, the input shaft 9
The rotation of is transmitted to the sun gear S1 via the second clutch C2, and in the parenthesized state
Since the link gear R2 of the single planetary gear 30 is fixed by the operation of the third brake B3, the carrier CRI is also reversed while the ring gear R1 of the single planetary gear 30 is being reversed.
The reverse rotation of the carrier is taken out by the counter drive gear 27. Furthermore, the reverse rotation of the counter drive gear 27 is
The speed is decelerated by the second automatic transmission mechanism section 13 and transmitted to the front axle shafts 23a and 23b.

Next, an embodiment embodying the above-mentioned automatic transmission IIA will be described based on FIG. 4.

The automatic transmission A has an integrated case consisting of a transaxle case 2, a transaxle housing 41, and a rear cover 42, and the case includes an input shaft 9, a counter shaft 11, and a ring gear mount that serves as a differential carrier for the front differential device 29. A case 36 is rotatably supported. A torque converter 26 having a lock-up clutch 25 and a first automatic transmission mechanism section 10 are disposed on the input shaft 9, and a second automatic transmission mechanism section 12 is disposed on the counter shaft 11. It is set up. Further, a valve body 44 is disposed in the transaxle case 2.

The first automatic transmission mechanism section 10 includes an engine crankshaft 21
The brake section 43 and the output section 4 move toward the rear in the axial direction.
5. Planetary gear unit 22 and clutch section 47
are arranged in this order, and an oil pump 49 is disposed between the brake section 43 and the torque converter 26, and an oil pump 49 is fitted onto the input shaft 9 to freely rotate the hollow shaft 5.
0 is supported.

The planetary gear unit 22 includes a single planetary gear 30 and a dual planetary gear 31 (see FIG. 2), and the single planetary gear 30 supports a sun gear S1, a ring gear R1, and a pinion P1 that mesh with these gears, which are formed on a hollow shaft 50. The dual planetary gear 31 includes a sun gear S1, a ring gear R2, and a ring gear R2 formed on the hollow shaft 50.
It also includes a carrier CR1 that supports a first binion P1 that meshes with the sun gear S1 and a second binion P2 that meshes with the ring gear R2 so that they do not mesh with each other. In both of these planetary gears 30 and 31, the sun gear S1 is composed of a single gear having the same number of teeth formed on the hollow shaft 50, the carrier CR1 is integrally constructed, and the pinion P1 is an integral ring pinion. It is composed of

Further, in the brake section 43, a one-way clutch F1 of the box 1, a first brake B1 consisting of a multi-disc brake, and a second brake B2 consisting of a multi-disc brake are arranged in order from the inner diameter side toward the outer diameter direction. Furthermore, a hydraulic actuator 51 is located adjacent to the first brake B1, and a hydraulic actuator 52 is located adjacent to the second brake B2, which are fixed to the cover of the oil pump 49 and arranged in parallel in the radial direction. There is. Furthermore, the first brake B
1 is connected to the hollow shaft 50, and the inner race of the first one-way clutch F1 is connected to the intermediate shaft 50.
and its outer race is connected to the second brake B
It is connected to 2.

On the other hand, the output section 45 has a counter drive gear 27 located approximately in the center of the first automatic transmission mechanism section 10, and the counter drive gear 27 is connected to the partition wall 2b formed in the axle case 2. It is rotatably supported via a double Chibird bearing, and its boss portion is connected to the carrier CR1 of the planetary gear unit 22. Further, the outer race of the bearing is splined and fitted to the inner peripheral surface of the case partition wall 2b, and a second one-way clutch F2 is attached to the outer peripheral surface of the race extension.

The clutch section 47 includes a first (offward) clutch C1 and a second (direct) clutch C2, and is located at the rear end of the first automatic transmission mechanism section 10 and is located at a portion of the transaxle cover 42. It is stored in. Further, the rear end portion of the input shaft 9 is formed into a sleeve portion 9a so as to fit over the boss portion 42a of the cover 42, and a clutch drum 67 is integrally connected to the sleeve portion 9a. Further, a movable member 69 is fitted to the clutch drum 67 via a spline so as to be slidable only in the axial direction, and a piston member 70 is fitted to the movable member 69. Further, the movable member 69 forms an oil chamber with a cylinder formed from the inner circumferential surface of the clutch drum 67, and the movable member 69 forms an oil chamber with the cylinder formed from the inner circumferential surface of the clutch drum 67.
This constitutes a hydraulic actuator 71 for 1. on the other hand,
The piston member 70 forms an oil chamber between the piston member 70 and a cylinder formed from the inner peripheral surface of the movable member 69, thereby forming a hydraulic actuator 72 for the second clutch C2. Further, a spring 73 is compressed between the piston member 70 and a ring fixed to the sleeve portion 9a.
3 is the piston member 6 of both hydraulic actuators 71 and 72.
It constitutes a return spring common to 9.70. The first clutch C1 is interposed between a spline formed on the inner peripheral surface of the outer diameter part of the clutch drum 67 and a spline formed on the outer peripheral surface of the ring gear R1, and the second clutch C2 is movable. It is interposed between a spline formed on the inner circumferential surface of the outer diameter portion of the member 69 and a spring formed on the outer circumferential surface of the hub portion 50a fixed to the hollow shaft 50.

On the other hand, the second automatic transmission mechanism section 12 has one single planetary gear 13, and a counter driven gear 33 is rotatably supported on the counter shaft 11 via a bearing 75. Further, a reduction gear 35 is fixed on the counter shaft 11, and the counter shaft 11 is rotatably supported at both ends by bearings 88 and 89 and installed in the transaxle case 2.

Next, the second automatic transmission mechanism section 12 will be explained in detail based on FIG.

The planetary gear 13oy ring gear R3 is connected to the counter driven gear 33, and the planetary gear 13oy ring gear R3 is connected to the counter driven gear 33.
The carrier CR3 supporting the counter shaft 11 is integrally formed with the counter shaft 11 bulging in the outer diameter direction. Furthermore, sun gear S3
There are bushings 90.91. on the shaft 11. The drum 77 is fixed to the outer diameter of the hub 3 and has a fourth (underdrive) brake consisting of a band rake on its outer circumferential surface. B4 is engaged. Further, the hub 7 fixed to the inner peripheral surface of the drum 77 and the carrier CR3
A third (direct) clutch consisting of multiple plates is interposed between the clutch C3 and the tram 77, and a piston member 15 is fitted in an oil-tight manner between the hub 3 and the tram 77 adjacent to the clutch C3. Together, they constitute a hydraulic actuator 5 for operating the clutch C3. An oil chamber 5a of the hydraulic actuator 5 is formed in a space formed by the piston member 15, the drum 77, and the hub 3. Furthermore, a check valve 86 is disposed on the piston member 15 to eliminate centrifugal oil pressure during rotation.

A spring 73 is compressed between the piston member 15 and a ring 82 fixed to the hub 3, and serves as a return spring for the piston member 15. Further, a boss portion 2a is formed at the end of the transaxle case 2, and the counter shaft 11 is rotatably supported by the boss portion 2a via the aforementioned bearing 83. Furthermore,
A lubricating oil hole 11a is formed in the center of the counter shaft 11, and horizontal holes 11b are formed in the radial direction of the shaft 11, and a plug 92 is formed at the tip of the lubricating oil hole 11a.
is installed and is configured to lubricate various parts as appropriate. Note that the lubricating oil hole 11a is connected to the carrier C described above.
It is directly connected to a lubricating oil hole 16 formed in the pinion Ra, and the oil hole 16 is connected to a lubricating oil hole 17 formed in the pinion P3. It is connected to an oil hole 18 formed in. Further, an extension part of the hub 3 is fitted onto the outer peripheral surface of the boss part 2a, and the extension part constitutes an inner race of the third one-way clutch F3. And the third
A one-way clutch F3 is arranged between the inner race and the transaxle case 2. Furthermore, the one-way clutch F3 has an oil passage 3 formed in the hub 3.
A is connected to the oil hole 11b, and is appropriately lubricated with lubricating oil supplied from the oil hole 11b.

Furthermore, a carrier cover is attached to the side of the transaxle case 2.
42 is fixed with bolts, and the rear cover 42
A pipe 1a for supplying hydraulic pressure from a part body 44 (see FIG. 4) is arranged inside. Further, an oil hole 1b is formed in the axial direction in the host portion 2a of the axle case 2, and a fan-shaped or arc-shaped groove is connected to the tip of the oil hole and opens on the outer peripheral surface of the boss portion 2a. 1c is formed, and the pipe 1a is connected to the oil hole 1b in an oil-tight manner to constitute the supply oil path 1. On the other hand, the fan-shaped (arc-shaped) groove 1 is formed on the inner circumferential surface of the hub 3 that comes into sliding contact with the boss portion 2a
An annular groove 6 is formed on the same plane as c, and an oil passage 7 is formed obliquely from the oil chamber 5a of the hydraulic actuator 5 toward the bottom 6a of the annular groove 6. In addition, seal grooves 2c and 2d are formed near both sides of the annular groove 6 on the outer peripheral surface of the boss portion 2a.
A seal ring is inserted into the groove to prevent oil leakage when hydraulic pressure is supplied.

Further, as shown in FIG. 4, the front differential device 29 has a ring gear mount case 36 that serves as a differential carrier, and the case 36 is rotatably supported by the housing 41 and the case 2 via bearings. . Furthermore, a large-diameter ring gear 39 that meshes with the reduction gear 35 is fixed on the mount case 36, and a pinion gear 81 is rotatably supported inside the mount case 39 by a pinion shaft 80. 8
Left and right side gears 37a and 37b meshing with the gear 1 are rotatably supported. And the side gears 37a, 37
Left and right front axle shafts 23a and 23b are respectively fitted and connected to b.

Since the present embodiment has the above-described configuration, the rotation appropriately changed in speed by the first automatic transmission mechanism section 10 is transmitted from the counter driven gear 33 to the second automatic transmission mechanism section 12. In 1st and 2nd speeds in D range, lunge, 2 range, and 3 range, the fourth (underdrive) brake B4 and the third one-way clutch F
3, the sun gear S3 is stopped, the second automatic transmission mechanism section 12 is in an underdrive (decelerated rotation) state, and the rotation is taken out to the carrier CR3. Further, the decelerated rotation is combined with the rotation appropriately changed in speed by the first automatic transmission mechanism section 10 and transmitted to the front differential device 29.

Further, in the third and fourth speeds, the third (direct) clutch C3 is engaged. That is, the hydraulic pressure of the engaged clutch C3 is supplied from the valve body 44 to the fan-shaped (arc-shaped) concave groove IC through the pipe 1a and the oil hole 1b. Furthermore, the groove 1
0, the oil is supplied to the oil chamber 5a of the hydraulic actuator 5 through an annular groove 6 formed in the hub 2, an oil passage 7, the piston 15 is extended, and the third clutch C3 is engaged.

In this state, the fourth (underdrive) brake B
4 is released, and based on the engagement of the third (direct) clutch C3, carrier CR3 and sun gear S3
The two rotate together, resulting in direct rotation. The direct rotation is then combined with the rotation suitably shifted in the first automatic transmission mechanism section 10 and transmitted to the front differential device 29.

(g) As described in detail, according to the present invention, it is sufficient to drill the diagonal oil passage (7) up to the bottom (6a) of the groove (6), and the hub (
It is shorter than the one that penetrates to the inner circumferential surface of the hub (3), so the sliding contact portion of the hub (3) can be made shorter accordingly, and the axial dimension can be shortened.

In particular, when applied to the supply oil passage structure of the hydraulic actuator (5) for direct clutch (C3) operation in the second automatic transmission mechanism (12) disposed on the countershaft (11), the countershaft (11) has severe restrictions. 11) can be shortened in the axial direction, and the mounting performance of the automatic transmission (A) can be improved.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an oil passage structure according to the present invention, Fig. 2 is a schematic diagram showing an automatic transmission to which the invention is applied, Fig. 3 is a diagram showing its operation, and Fig. 4 is an automatic transmission thereof. It is a sectional view showing the whole machine. FIG. 5 is a diagram showing a conventional example. 1... Supply oil path 1a... Vibrator 1b.
...Oil passage IC...Fan-shaped or circular arc groove 2...
Transaxle case 2a...boss part
3...Hub 5...Hydraulic actuator
5a... Oil chamber 6... Annular groove 6a... Bottom 7... Diagonal oil path 9... Input shaft
DESCRIPTION OF SYMBOLS 10... First automatic transmission mechanism part 11... Counter shaft 12... Second automatic transmission mechanism part C3... Third (direct) clutch

Claims (1)

[Scope of Claims] 1. An automatic transmission comprising a hub that rotatably slides on a fixed member boss portion having a supply oil passage, and a hydraulic actuator disposed on the hub, the boss portion having the following features: An annular groove is formed on the inner circumferential surface of the hub on a plane aligned with a supply oil passage, and an oil passage is formed diagonally so as to communicate the bottom of the groove with the oil chamber of the hydraulic actuator. An oil passage structure in an automatic transmission characterized by the following. 2. The automatic transmission is provided with a first automatic transmission mechanism consisting of three forward speeds on the input shaft, and a second automatic transmission mechanism that switches between underdrive and direct coupling on a counter shaft parallel to the input shaft.
2. The oil passage structure in an automatic transmission according to claim 1, wherein the hydraulic actuator is a direct clutch operation hydraulic actuator directly connected to the second automatic transmission mechanism.