JP2004332803A - Automatic transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automatic transmission in which the torque transmission efficiency with respect to an output shaft and the space efficiency around the output shaft are improved in the automatic transmission arranging a friction engagement device for hydraulically engaging behind a planetary gear unit in a transmission mechanism. <P>SOLUTION: In a transmission case 13, the rear end of an intermediate shaft 19 is interposed in a recess 31 formed in a front end of an output shaft 20, and the planetary gear unit G is arranged at the periphery of the intermediate shaft 19. A clutch C2 for hydraulically engaging is arranged at the position behind the planetary gear unit G and in front of the front end of the output shaft 20. Operating fluid is discharged from an apply oil passage 40 bored in the intermediate shaft 19 into a hydraulic chamber 27 of the clutch C2. Thereby the front end of the output shaft 20 can be reduced in diameter, and the clutch C2 can be arranged inside in the radial direction. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an automatic transmission, and more particularly, to an automatic transmission provided with a frictional engagement device that is hydraulically engaged behind a planetary gear unit in a transmission mechanism.
[0002]
[Prior art]
Generally, in an automatic transmission, rotation torque from an engine is transmitted to an input shaft via a torque converter, and rotation of the input shaft is rotatably coaxially arranged with the input shaft via a transmission mechanism including a planetary gear unit and the like. The power is transmitted to the supported output shaft. Further, the automatic transmission includes a plurality of friction engagement devices including a multi-plate driven plate, a drive plate, and a piston or the like that is hydraulically operated in a direction in which the two plates are engaged in order to selectively operate each shift speed. (Such as a multi-plate clutch) are provided around a rotation axis such as the input shaft. Then, an ATF (Automatic Transmission Fluid) functioning as hydraulic oil and lubricating oil is supplied from an oil pump provided between the torque converter and the speed change mechanism via an oil passage or the like penetrating the shaft. The lubrication is supplied to the engagement device and each lubrication required portion.
[0003]
As an example of such an automatic transmission, in an automatic transmission described in Non-Patent Document 1, as shown in FIG. 5, a convex portion 101a protruding from a rear end of an input shaft 101 is formed at a front end of an output shaft 102. The input shaft 101 and the output shaft 102 are inserted into the recess 102a and supported coaxially so as to be rotatable relative to each other and immovable in the axial direction. A planetary gear unit 103 is disposed on the outer peripheral side near the rear end of the input shaft 101, and an end clutch (multi-plate clutch) 104 is provided on the rear side of the gear unit 103 with a rear end of the input shaft 101 and an output. The shaft 102 is disposed so as to overlap the front end of the shaft 102 in the axial direction. ATF (lubricating oil) is supplied to a sliding portion between the convex portion 101a of the input shaft 101 and the concave portion 102a of the output shaft 102 through a lubricating oil passage 105 formed through the output shaft 102, while the output shaft 102 The ATF (hydraulic oil) is supplied to the end clutch 104 through an apply oil passage 106 formed through the end clutch 104.
[0004]
[Non-patent document 1]
"MITSUBISHI Maintenance Manual R4A1, V4A1 AUTOMATIC TRANSMISSION", edited by Mitsubishi Motors Corporation, October 1998, page 7
[0005]
[Problems to be solved by the invention]
However, the automatic transmission disclosed in Non-Patent Document 1 has the following problem.
That is, the end clutch 104 is disposed at a position that overlaps not only the rear end of the input shaft 101 but also the front end of the output shaft 102 in the axial direction, and the apply oil passage 106 that supplies ATF to the end clutch 104 is formed as described above. It was formed at the front end of the output shaft 102 together with the lubricating oil passage 105 for supplying ATF to the recess 102a. At the front end of the output shaft 102, the oblique hole 106 a is formed from the apply oil passage 106 toward the hydraulic chamber 109 of the cylinder 108 in which the piston 107 of the end clutch 104 is accommodated. For this reason, the front end of the output shaft 102 inevitably becomes large in diameter, and the mass of the output shaft 102 increases, causing not only torque loss, but also impairing space efficiency.
[0006]
Further, an end clutch 104 is arranged on the outer peripheral side of the front end of the output shaft 102 having such a large diameter, and the piston 107 slides in the cylinder 108 in the axial direction. Therefore, since the piston 107 having a ring shape in a plan view has an inner diameter larger than the outer diameter of the front end portion of the output shaft 102, the outer diameter of the piston 107 is further increased due to space limitations, and the operating oil is increased. However, it was difficult to increase the pressure receiving area. Therefore, a large number of friction plates (driven plates, etc.) in the end clutch 104 is required due to the relationship with the pressing force proportional to the size of the pressure receiving area. As a result, the rotational resistance of the end clutch 104 during idling causing torque loss is increased. Also, there is a problem that the axial dimension related to space efficiency cannot be reduced.
[0007]
The present invention has been made in view of such circumstances, and an object of the present invention is to provide an automatic transmission that can improve torque transmission efficiency related to an output shaft and space efficiency around the output shaft. is there.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 is characterized in that the rear end of the first shaft on the front side in the axial direction is inserted into a recess formed at the front end of the second shaft on the rear side in the axial direction. A first shaft and a second shaft are coaxially arranged so as to be rotatable relative to each other and immovable in the axial direction. A planetary gear unit is provided on the outer peripheral side of the first shaft, and the first shaft and the second shaft are arranged rearward of the planetary gear unit. A multi-plate frictional engagement device that is engaged by hydraulic pressure is disposed at a position on the front side of the front end of the two shafts, and an apply oil passage formed through the first shaft with respect to the frictional engagement device. The hydraulic oil is discharged and supplied.
[0009]
According to a second aspect of the present invention, in the first aspect, lubricating oil is applied to a sliding portion between the rear end of the first shaft and the concave portion of the second shaft. The lubricating oil passage for supplying is further formed so as to penetrate.
[0010]
According to a third aspect of the present invention, in the first or second aspect, an oil hole communicating with the inside of the recess from the outer peripheral surface side is formed at a front end of the second shaft. A front end side opening of an apply oil passage is formed on the outer peripheral surface of the first shaft at a position corresponding to the friction engagement device, and the apply oil passage is located at a position in the recess where oil can be guided from the oil hole. It is characterized in that a rear end side opening is formed.
[0011]
According to a fourth aspect of the present invention, in the third aspect of the invention, an outer layer-side oil seal is provided at both axial positions of the outer peripheral surface of the second shaft with the oil hole interposed therebetween, while the inside of the recess is formed. Wherein an inner layer side oil seal is provided at least at an axially front position on both axial sides of the oil hole.
[0012]
According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, the friction engagement device discharges hydraulic oil from an apply oil passage of the first shaft. It is provided with a piston in a ring shape in plan view that slides in the axial direction upon receiving the supply, and the inner peripheral edge of the piston slides along the outer peripheral surface of the first shaft via an oil seal. It was characterized by.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment in which the present invention is embodied in an automatic transmission mounted on a vehicle will be described below with reference to FIGS.
[0014]
As shown in FIG. 1, the automatic transmission 11 of the present embodiment includes a main body case 14 including a converter housing 12 and a transmission case 13, and a torque converter 15 and a speed change mechanism 16 are housed in the main body case 14. I have. An input shaft of a transmission mechanism 16 into which a rotational torque from an engine output shaft (not shown) is input into the main body case 14 through an oil flow in the torque converter 15 or through a mechanical connection by a lock-up clutch 17. 18 is rotatably supported. On the rear end side (the right end side in FIG. 1) of the input shaft 18, the intermediate shaft 19 and the output shaft 20 of the transmission mechanism 16 are coaxially arranged with the input shaft 18 so as to be rotatable relative to each other and in the axial direction. Supported by immovable to.
[0015]
In the transmission case 13, a planetary gear unit G serving as a main body of the transmission mechanism 16 and a plurality of frictional engagement devices (selective clutches C1 to C3 and multiple The brakes B1 to B3) having a plate structure are disposed at positions on the outer peripheral side of the rotation shaft such as the intermediate shaft 19 or the like. A valve body 21 containing various valves (not shown) is attached to a lower portion of the transmission case 13, and the output shaft 20 passes through the rear end wall 13 a of the transmission case 13 from the valve body 21. A plurality of oil passages (not shown) are formed, such as an oil passage 22 extending in the radial direction. An adapter 23 is joined and fixed to the rear end face of the transmission case 13, and the rear end of the output shaft 20 projects rearward from a bearing hole 23 a formed at the center of the adapter 23.
[0016]
As shown in FIGS. 2 and 3, the speed change mechanism 16 is configured as a speed change mechanism having four forward speeds and one reverse speed. The planetary gear unit G includes two sun gears S1 and S2 having different diameters, a single ring gear R, and a long pinion gear P1 externally meshed with the large diameter sun gear S1 and internally meshed with the ring gear R. I have. Further, the planetary gear unit G is also provided with a short pinion gear P2 externally meshed with the small-diameter sun gear S2 and also externally meshed with the long pinion gear P1, and a carrier CR for supporting both the pinion gears P1 and P2. It constitutes a Ravigneaux type gear unit.
[0017]
The large-diameter sun gear S1 is connected to the input shaft 18 via a reverse clutch C3 which is engaged during reverse travel, and can be locked to the transmission case 13 via a one-way clutch F1 and a brake B2. Further, it can be locked to the transmission case 13 via the brake B1. The small-diameter sun gear S2 is connected to the input shaft 18 via a forward low-speed clutch C1 that is engaged in first to third speeds.
[0018]
The carrier CR is connected to the input shaft 18 via a forward high speed clutch C2 engaged at the third speed and the fourth speed, and can be locked to the transmission case 13 via a brake B3. Further, the one-way clutch F2 can be rotatably locked in one direction to the transmission case 13. The ring gear R is connected to the output shaft 20 so as to be integrally rotatable. The brakes B1 and B2 are forward brakes that are engaged during forward travel, and the brake B3 is a reverse brake that is engaged during reverse travel (but is also engaged during first-speed engine braking).
[0019]
Next, a configuration related to a hydraulic circuit provided on the intermediate shaft 19 and the output shaft 20, which are main components of the automatic transmission 11 according to the present invention, and an ATF (Automatic Transmission Fluid) is formed via the hydraulic circuit. The specific structure of the supplied clutch C2 for the high speed forward stage will be described in detail.
[0020]
First, the clutch C2 will be described. As shown in FIG. 4, the clutch C2 is located axially rearward of the planetary gear unit G and forward of the front end of the output shaft 20 with the opening side of the clutch drum 24 in the axial direction. It is arranged so as to face the front side. The clutch drum 24 includes a cylindrical drum portion 24a and a half-substantially donut-shaped (ring shape in plan view) cylinder portion 24b that is continuous to the axial rear side of the drum portion 24a. Is connected by welding or the like to a flange 19 a protruding from the outer peripheral surface of the intermediate shaft 19.
[0021]
A piston 25 having an outer surface shape similar to the inner surface shape of the cylinder portion 24b and having a ring shape in a plan view when viewed from the axial direction is provided on the inner surface side of the cylinder portion 24b. An oil seal 26 is provided on the outer peripheral surface of the intermediate shaft 19 corresponding to the inner peripheral edge of the piston 25. The inner peripheral edge of the piston 25 extends along the outer peripheral surface of the intermediate shaft 19. And slides in the axial direction. That is, the hydraulic chamber 27 is formed between the piston 25 and an axially opposed surface portion including not only the inner surface of the cylinder portion 24b but also the opposed surface (left surface in FIG. 4) of the flange portion 19a on the piston side. Thus, a large area of the pressure receiving portion 25a that receives the hydraulic pressure from the hydraulic chamber 27 is secured.
[0022]
A spring retainer 28 is disposed on the inner surface of the transmission case 13 so as to be axially immovable at a position axially forward of the piston 25 and opposite to a plane portion of the piston 25. A return spring 29 is interposed between the spring retainer 28 and the piston 25 so as to expand and contract as the piston 25 moves in the axial direction. That is, when ATF (hydraulic oil) is supplied into the hydraulic chamber 27, the hydraulic pressure presses and compresses the piston 25 that moves to the front side in the axial direction, and the ATF is drained from within the hydraulic chamber 27. In this case, the piston 25 is extended in the axial direction based on the urging force to return the piston 25 to the position shown in FIG.
[0023]
As shown in FIG. 4, a plurality of friction plates 30 are disposed at positions corresponding to the outer peripheral edge of the piston 25 on the inner surface side of the drum portion 24 a of the clutch drum 24. Each of the friction plates 30 includes a plurality of (four in FIG. 4) driven plates 30a that are spline-engaged with the inner surface of the drum portion 24a to prevent the slippage toward the front in the axial direction, and a hub 32 that is connected to the carrier CR. And a plurality of (three in FIG. 4) drive plates 30b that are spline-engaged with each other are arranged alternately in the axial direction. When the piston 25 moves forward in the axial direction against the urging force of the return spring 29 due to the hydraulic pressure in the hydraulic chamber 27, the piston 25 is pressed by the outer peripheral edge thereof and the driven plate 30a and the drive plate 30b are pressed. The clutch engagement state can be obtained by the frictional engagement of.
[0024]
On the other hand, as shown in FIG. 4, the output shaft 20 has an axial rear end portion inserted and supported in a bearing hole 23a of the adapter 23, and an axial front end portion has a transmission case 13 rear end. It is inserted and supported in a bearing hole 13b formed through the wall 13a. A recess 31 is formed at the front end of the output shaft 20 from the front to the rear in the axial direction and passes through the center of the shaft. The recess 31 has a rear end of the intermediate shaft 19 (specifically, the flange). The portion on the rear end side with respect to the portion 19a) is inserted and supported in a fitting mode in which the intermediate shaft 19 and the output shaft 20 can be relatively rotated.
[0025]
A base end of a hub 32 having a front end connected to a ring gear R of the planetary gear unit G through the outside of the clutch C2 is connected to an outer peripheral surface of a front end of the output shaft 20 by welding or the like. The shaft 20 is configured to rotate integrally with the ring gear R via a hub 32. As can be understood from FIG. 4, the space outside the hub 32 (the space between the rear end wall 13a of the transmission case 13 and the hub 32) is formed by the piston 33 of the brake B3, the return spring 34, This is a space for disposing the spring retainer 35 and the like.
[0026]
On the outer peripheral surface of the front end of the output shaft 20 inserted and supported in the bearing hole 13b of the transmission case 13, a position corresponding to the oil passage 22 from the valve body 21 is provided at an outer layer side oil extending annularly in the circumferential direction. A groove 36 is formed, and a radial oil hole 37 communicating with the inside of the concave portion 31 is formed from the bottom surface of the outer layer oil groove 36. A pair of front and rear outer layer oil seals 38 are provided on both axial sides (front and rear sides) of the oil hole 37 between the outer peripheral surface of the output shaft 20 and the inner peripheral surface of the bearing hole 13b. The ATF supplied from the oil passage 22 to the oil hole 37 is prevented from leaking out of the transmission case 13.
[0027]
On the other hand, on the outer peripheral surface of the rear end of the intermediate shaft 19, an inner-layer-side oil groove 39 extending annularly in the circumferential direction is formed at a position corresponding to the oil hole 37 of the output shaft 20. An apply oil passage 40 for supplying ATF as hydraulic oil to the hydraulic chamber 27 of the clutch C2 is formed in the inside thereof in an axial direction. The apply oil passage 40 has a rear end side opening 40a formed at one position at the bottom of the inner layer oil groove 39 and a position on the outer peripheral surface of the intermediate shaft 19 corresponding to the hydraulic chamber 27 of the clutch C2. , A front end side opening 40b is formed. A pair of front and rear inner layer oil seals 41 are provided at both axial positions sandwiching the oil hole 37 between the outer peripheral surface of the intermediate shaft 19 and the inner peripheral surface of the concave portion 31. The ATF supplied to the rear end side opening 40a is prevented from leaking out of the transmission case 13.
[0028]
In addition, inside the intermediate shaft 19, an oil pump 42 (see FIG. 1) provided between the torque converter 15 and the speed change mechanism 16 is formed to penetrate the input shaft 18 separately from the apply oil passage 40. A lubricating oil passage 44 to which the ATF is supplied from the front side in the axial direction via the oil passage 43 is formed so as to penetrate along the axial direction. A lateral hole 44a is formed in the rear end portion of the intermediate shaft 19 from the lubricating oil passage 44 in a direction orthogonal to the axial direction, and the lateral hole 44a and the outer peripheral surface of the rear end portion of the intermediate shaft 19 are output. The ATF is configured to be supplied as lubricating oil to a sliding portion of the shaft 20 with the inner peripheral surface of the concave portion 31.
[0029]
Therefore, next, the operation of the automatic transmission 11 according to the present embodiment configured as described above will be described focusing on the operation relating to the apply oil passage 40 and the lubricating oil passage 44 formed in the intermediate shaft 19. .
[0030]
When the vehicle shifts to the high-speed running state of the third speed or higher when the vehicle is running forward, ATF of the line pressure (operating pressure) for operating the clutch C2 is discharged and supplied from the valve body 21 to the oil passage 22. You. Then, the ATF is supplied from the oil passage 22 to the outer layer oil groove 36 of the output shaft 20 located in the bearing hole 13b, and further the ATF is recessed from the outer layer oil groove 36 through the radial oil hole 37. The oil is supplied to the inner-layer oil groove 39 of the intermediate shaft 19 located inside. In this case, the ATF of the line pressure (operating pressure) can be unnecessarily leaked from the oil passage 22 to the inner layer side by the respective sealing functions of the outer layer side oil seal 38 and the inner layer side oil seal 41. The oil is surely guided to the oil groove 39.
[0031]
The ATF guided to the inner oil groove 39 then flows into the apply oil passage 40 from the inner oil groove 39 through the rear end opening 40a of the apply oil passage 40, and further flows into the apply oil passage 40. The oil is supplied to the hydraulic chamber 27 of the clutch C2 from the front end side opening 40b of the apply oil passage 40. Then, the hydraulic pressure in the hydraulic chamber 27 increases, and the piston 25 that has received the hydraulic pressure in the pressure receiving portion 25a moves axially forward (to the left in FIG. 4) against the urging force of the return spring 29, and the driven plate Each friction plate 30 is pressed so that the frictional engagement between the drive plate 30a and the drive plate 30b occurs.
[0032]
Then, the clutch C2 is connected by the frictional engagement of the friction plates 30, and the rotational torque from the planetary gear unit G shifted to the third gear or higher is transmitted to the output shaft 20 via the ring gear R and the hub 32. Then, the output shaft 20 rotates at a predetermined rotation speed based on the transmission torque. When a brake pedal (not shown) is depressed during the high-speed traveling of the third speed or higher, the output shaft 20 is disposed in the space between the hub 32 and the rear end wall 13a on the outer peripheral side of the front end. The piston 33 of the brake B3 moves toward the front side in the axial direction against the urging force of the return spring 34 to perform the brake operation.
[0033]
On the other hand, when the brake operation state of the brake B3 is continued and the vehicle shifts from the high-speed traveling state of the third speed or higher to the low-speed traveling state of the second speed or lower, the ATF is drained from the hydraulic chamber 27. Then, in the clutch C2, the piston 25 moves axially rearward (to the right in FIG. 4) by the urging force of the return spring 29, and the frictional engagement state of the friction plates 30 including the driven plate 30a and the drive plate 30b is established. It is released. Then, the connection state of the clutch C2 is released, and then the output shaft 20 rotates according to the rotation torque transmitted from the planetary gear unit G based on the connection of the clutch C1 for the forward low speed.
[0034]
Further, as described above, between the inner peripheral surface of the concave portion 31 of the output shaft 20 that rotates based on the transmission torque from the planetary gear unit G and the outer peripheral surface of the rear end of the intermediate shaft 19 inserted into the concave portion 31. ATF is supplied from the lubricating oil passage 44 as lubricating oil. Therefore, when the output shaft 20 and the intermediate shaft 19 rotate relatively, the inner peripheral surface of the concave portion 31 of the output shaft 20 and the outer peripheral surface of the rear end of the intermediate shaft 19 come into sliding contact with each other. Unnecessary seizure due to the supply of ATF (lubricating oil) from the lubricating oil passage 44 is also prevented.
[0035]
Therefore, according to the above embodiment, the following effects can be obtained.
(1) In the above-described embodiment, the apply oil passage 40 that supplies ATF (hydraulic oil) to the forward high speed clutch (friction engagement device) C2 is not the front end of the output shaft 20 but the front end of the output shaft 20. The rear end portion is inserted into and supported by the intermediate shaft (first shaft) 19 in the concave portion 31 formed in the portion. For this reason, the output shaft 20 can be reduced in diameter by reducing its front end portion and suppressing an increase in mass as much as there is no need to form an apply oil passage unlike the related art, and based on the rotational torque from the planetary gear unit G side. The torque transmission efficiency during rotation can be improved.
[0036]
(2) In the above embodiment, the front end of the output shaft 20 can be made small in diameter at the rear part in the transmission case 13, so that an extra space can be secured on the outer peripheral side of the front end of the output shaft 20 unlike the conventional case. Therefore, it is possible to arrange the piston 33 of the brake B3, for example, by utilizing the surplus space, so that the space efficiency of the automatic transmission 11 can be improved. Further, the clutch C2 can also be disposed radially inward as compared with the related art when viewed from the intermediate shaft 19 and the output shaft 20, so that the space efficiency can be further improved.
[0037]
(3) In the above embodiment, not only the apply oil passage 40 but also the sliding portion between the outer peripheral surface of the rear end portion of the intermediate shaft 19 and the inner peripheral surface of the concave portion 31 of the output shaft 20 inside the intermediate shaft 19. A lubricating oil passage 44 for supplying the lubricating oil to is formed. Therefore, since the lubricating oil passage 44 conventionally formed in the output shaft 20 is formed through the intermediate shaft 19, the diameter of the front end of the output shaft 20 can be further reduced, and the torque transmission efficiency and the space efficiency can be further improved. Can be improved.
[0038]
(4) In the above embodiment, the recess 31 in which the rear end of the intermediate shaft 19 is inserted and supported into the apply oil passage 40 formed through the intermediate shaft 19 to discharge and supply the ATF to the hydraulic chamber 27 of the clutch C2. Hydraulic oil can be introduced through the oil hole 37 communicating from the outer peripheral surface side of the output shaft 20 inside. For this reason, the ATF is supplied from the valve body 21 to the outer peripheral surface of the front end of the output shaft 20 via the oil passage 22 in substantially the same configuration as in the related art. Even when the rear end portion is formed so as to penetrate the intermediate shaft 19 inserted and supported therein, the design of the hydraulic circuit for supplying the ATF can be facilitated.
[0039]
(5) In the above embodiment, the outer layer oil seal 38 is provided at both axial positions sandwiching the oil hole 37 between the outer peripheral surface of the output shaft 20 and the inner peripheral surface of the bearing hole 13b. An inner layer oil seal 41 is provided at both axial positions sandwiching the oil hole 37 between the outer peripheral surface of the shaft 19 and the inner peripheral surface of the concave portion 31. Therefore, from the oil passage 22 on the valve body 21 side to the apply oil passage 40 via the oil hole 37 whose opening faces the inside of the bearing hole 13a through which the output shaft 20 is inserted and supported and the inside of the recess 31 into which the intermediate shaft 19 is inserted and supported. Even when the ATF is supplied, it is possible to reliably prevent the ATF from leaking out of the transmission case 13.
[0040]
(6) In the above embodiment, the piston 25 of the clutch C2 is configured to slide in the axial direction along the outer peripheral surface of the intermediate shaft 19 with the oil seal 26 interposed therebetween. Therefore, the piston 25 has a large pressure receiving area of the pressure receiving portion 25a that receives the oil pressure when the ATF is supplied to the hydraulic chamber 27, and therefore the pressing force when the friction plates 30 of the clutch C2 are engaged is increased. That is, the number of friction plates 30 required for coupling (friction engagement) of the clutch C2 can be reduced accordingly. Therefore, the device cost can be reduced by reducing the number of parts, and the rotational resistance generated due to the sliding contact between the driven plate 30a and the drive plate 30b during idling can be reduced, which also contributes to the improvement of the torque transmission efficiency. it can.
[0041]
The above embodiment may be changed to another embodiment (another example) as described below.
In the above embodiment, the oil seal 26 is provided on the outer peripheral surface of the intermediate shaft 19 corresponding to the inner peripheral edge of the piston 25 in the clutch C2, but the oil seal 26 is provided on the inner peripheral side of the piston 25. Is also good.
[0042]
In the above-described embodiment, the inner layer oil seal 41 is provided at both axial positions sandwiching the oil hole 37 between the outer peripheral surface of the intermediate shaft 19 and the inner peripheral surface of the recess 31. Unlike the seal 38, the inner layer oil seal 41 may be provided only at the axial front position sandwiching the oil hole 37.
[0043]
In the above embodiment, the rear end opening 40 a of the apply oil passage 40 formed in the intermediate shaft 19 is formed at the bottom of the inner oil groove 39 formed at a position corresponding to the oil hole 37 of the output shaft 20. The rear end side opening 40a and the oil hole 37 are configured to correspond to each other in the axial direction. However, if the ATF oil can be introduced from the oil hole 37, the rear end side opening 40a of the apply oil passage 40 formed on the outer peripheral surface side of the intermediate shaft 19 is not necessarily located in the axial direction with the oil hole 37. It is not necessary to correspond.
[0044]
In the above embodiment, both the apply oil passage 40 and the lubricating oil passage 44 are formed to penetrate inside the intermediate shaft 19, but only the apply oil passage 40 is formed to penetrate inside the intermediate shaft 19, and the lubricating oil passage 44 is formed. May be formed at the front end of the output shaft 20 as before. In this case, if the lubricating oil passage is formed in the front end of the output shaft 20 in the radial direction, it is possible to prevent the front end of the output shaft 20 from increasing in diameter.
[0045]
In the above embodiment, the ATF is supplied from the oil passage 22 on the valve body 21 side through the oil hole 37 formed in the output shaft 20 into the apply oil passage 40 of the intermediate shaft 19; The supply may not be performed through the oil hole 37 formed in the above. For example, the ATF may be configured to be supplied to the apply oil passage 40 of the intermediate shaft 19 from the front side in the axial direction via an oil passage 43 formed through the input shaft 18.
[0046]
In the above-described embodiment, the ATF is disposed at a position axially rearward of the planetary gear unit G and forward of the front end of the output shaft 20, and ATF is supplied from the apply oil passage 40 of the intermediate shaft 19 to perform the engagement operation. Although the clutch C2 has been described as an example of the friction engagement device to be described, the clutch C2 need not always be embodied. For example, any one of the other clutches C1, C3 and the brakes B1 to B3 may be embodied by replacing the arrangement position of the clutch C2 in the above embodiment.
[0047]
In the above embodiment, the rear end of the intermediate shaft 19 as the first shaft is inserted into the recess 31 formed at the front end of the output shaft 20 as the second shaft, and the apply shaft is inserted into the intermediate shaft 19. Although the oil passage 40 and the lubricating oil passage 44 are formed, the input shaft 18 may be configured as the first shaft instead of the intermediate shaft 19. That is, the length of the input shaft 18 is formed to be longer toward the rear side in the axial direction, and the rear end thereof is inserted and supported in the concave portion 31 of the output shaft 20. The lubricating oil passage 44 may be formed. In this case, a sleeve or the like connected to the small-diameter sun gear S2 may be rotatably inserted and supported on the outer peripheral side of the input shaft 18 as necessary.
[0048]
【The invention's effect】
According to the present invention, in an automatic transmission in which a friction engagement device that engages hydraulically is operated behind a planetary gear unit in a transmission mechanism, the torque transmission efficiency related to the output shaft and the space efficiency around the output shaft are reduced. Can be good.
[Brief description of the drawings]
FIG. 1 is an overall schematic explanatory diagram of an automatic transmission according to an embodiment.
FIG. 2 is a skeleton diagram of a transmission mechanism.
FIG. 3 is an engagement diagram showing an engagement relationship of each friction engagement device in the transmission mechanism.
FIG. 4 is an enlarged partially broken sectional view around an output shaft which forms a main part in the embodiment.
FIG. 5 is an enlarged partially broken sectional view around an output shaft in a conventional automatic transmission.
[Explanation of symbols]
11 ... automatic transmission, 19 ... intermediate shaft (first shaft), 20 ... output shaft (second shaft), 25 ... piston, 26 ... oil seal, 31 ... recess, 33 ... piston, 37 ... oil hole, 38 ... Outer layer oil seal, 40 ... Apply oil path, 40a ... Rear end opening, 40b ... Front end opening, 41 ... Inner layer oil seal, 44 ... Lubricating oil path, C1-C3 ... Clutch (friction engagement device, B1- B3: brake (friction engagement device); G: planetary gear unit.

Claims (5)

The rear end of the first shaft on the front side in the axial direction is inserted into a recess formed at the front end of the second shaft on the rear side in the axial direction, and the first and second shafts are coaxially arranged so as to be rotatable relative to each other. And a planetary gear unit is disposed on the outer peripheral side of the first shaft, and is engaged by a hydraulic pressure at a position rearward of the planetary gear unit and forward of a front end of the second shaft. An automatic transmission in which a multi-plate friction engagement device is provided, and hydraulic oil is discharged and supplied to the friction engagement device from an apply oil passage formed through the first shaft. 2. The automatic transmission according to claim 1, wherein a lubricating oil passage for supplying lubricating oil to a sliding portion between a rear end portion of the first shaft and a concave portion of the second shaft is further formed in the first shaft. Machine. The front end of the second shaft has an oil hole communicating with the inside of the recess from the outer peripheral surface side, while the outer peripheral surface of the first shaft has a front end of an apply oil passage at a position corresponding to the friction engagement device. The automatic transmission according to claim 1, wherein a side opening is formed, and a rear end side opening of the apply oil passage is formed in the recess at a position where oil can be guided from the oil hole. On the outer peripheral surface of the second shaft, an outer layer side oil seal is provided at both axial positions sandwiching the oil hole, and at least an axial layer is provided at an axial front position among the axial positions sandwiching the oil hole within the concave portion. 4. The automatic transmission according to claim 3, wherein a side oil seal is provided. The friction engagement device includes a ring-shaped piston in a plan view that receives the supply of hydraulic oil from the apply oil passage of the first shaft and slides in the axial direction, and an inner peripheral edge of the piston is the first shaft. The automatic transmission according to any one of claims 1 to 4, wherein the automatic transmission is configured to slide along an outer peripheral surface of the shaft with an oil seal interposed therebetween.

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