WO2007058032A1

WO2007058032A1 - Automatic transmission

Info

Publication number: WO2007058032A1
Application number: PCT/JP2006/320268
Authority: WO
Inventors: Katsuhisa Ishii; Takuya Nakajima; Minoru Todo; Mikio Iwase; Hirofumi Ota; Kazutoshi Nozaki; Atsushi Honda; Masafumi Kinoshita
Original assignee: Aisin Aw Co., Ltd.; Toyota Jidosha Kabushiki Kaisha
Priority date: 2005-11-17
Filing date: 2006-10-11
Publication date: 2007-05-24
Also published as: JP4906046B2; DE112006002160B4; CN101248294A; DE112006002160T5; JP2007139066A; CN101248294B

Abstract

An automatic transmission in which an auxiliary bearing has a minimum axial length to make the transmission lightweight and compact. The automatic transmission has a main bearing (36) and the auxiliary bearing (37). The main bearing (36) is provided between the inner circumference of a boss (31a) of a first drum (31) and the outer circumference of a circular tube support section (27a) and rotatably supports the first drum. The auxiliary bearing (37) is fitted in an end of the inner circumference of the boss of the first drum with a clearance from the circular tube support section, comes into contact with the circular tube support section only when the first drum is tilted in the direction of advance of a vehicle, and has a shorter axial length than the main bearing.

Description

Specification

Automatic transmission

Technical field

TECHNICAL FIELD [0001] The present invention relates to an automatic transmission, and more particularly to an automatic transmission in which a drum is normally supported by only one bearing and the other bearing functions only when an external force is applied. It is.

Background art

[0002] In an automatic transmission having a speed change mechanism that shifts gears in multiple stages by engaging and disengaging a clutch and a brake, the clutch includes a drum, a piston, a canceller, and the like. An automatic transmission generally has two or more clutches.

Disclosure of the invention

Problems to be solved by the invention

[0003] In this type of automatic transmission, the rotation of the drum of the clutch is rotatably supported at one point or two points at both ends using a bearing. If it is supported at one point, the axial length of the bearing needs to be large enough so that the first drum does not tilt more than necessary due to external force. On the other hand, when supporting at two points, each of the two bearings needs durability as a bearing, so it is necessary to secure an axial length sufficient to ensure the durability.

[0004] For this reason, in the conventional automatic transmission, regardless of the one-point support and the two-point support, a bearing having a large axial dimension is arranged at the end of the passage for supplying the hydraulic oil, thereby As a result, the axial length of the drum increases, which is a factor that hinders the light weight and compactness of drums and, consequently, automatic transmissions.

[0005] The present invention has been made in view of the above-described conventional problems, and an automatic transmission capable of being light and compact by making the auxiliary bearing the minimum axial length. It is intended to be provided.

Means for solving the problem

[0006] In order to solve the above problems, the invention according to claim 1 is directed to the traveling direction of the vehicle. An automatic transmission disposed behind an engine, the automatic transmission including a transmission mechanism that disengages and disengages a plurality of clutches and brakes and shifts to a plurality of speeds. And a first hydraulic servo that is operable to operate one of the plurality of clutches, the first drum, and a first piston that forms a first cylinder chamber together with the first drum. A main bearing that is disposed on the inner periphery of the boss portion of the drum and on the outer periphery of the cylindrical support portion and is rotatably fitted to one end of the inner periphery of the boss portion of the first drum and the main bearing that rotatably supports the first drum In addition, the auxiliary support is loosely fitted to the cylindrical support portion, and comes into contact with the cylindrical support portion only when the first drum is inclined in the traveling direction of the vehicle, and has an axial length shorter than that of the main bearing. With bearings It is an.

[0007] In the invention of claim 2, in claim 1, the cylindrical support portion is a boss portion extending from the transmission case, and the speed change mechanism is formed on the boss portion of the transmission case. The first hydraulic oil supply oil passage and the first hydraulic oil supply hole formed in the boss portion of the first drum, and the hydraulic oil supplied to the first cylinder chamber is supplied by the first hydraulic oil supply. The oil passage and the first hydraulic oil supply hole are performed via a pair of seal rings disposed on a boss portion of the transmission case.

[0008] The invention according to claim 3 is the invention according to claim 2, wherein the speed change mechanism is slidably disposed on a second drum and a boss portion of the second drum, and the second drum And a second hydraulic servo having a second piston forming a second cylinder chamber, a second hydraulic oil supply oil passage formed in the boss portion of the transmission case, and a boss portion of the first drum. In addition to having a second hydraulic oil supply hole and a third hydraulic oil supply hole formed in a boss portion of the second drum, the first drum is opened rearward in the traveling direction of the vehicle, The first drum and the second drum are the first spline teeth formed on the outer peripheral surface of the rear end of the boss portion of the first drum in the vehicle traveling direction and the inner periphery of the boss portion of the second drum. Integral rotation by spline engaging part with second spline teeth formed on the surface The main bearing is disposed on the inner peripheral side of the rear end portion in the vehicle traveling direction of the boss portion of the first drum, and the supply of hydraulic oil to the second cylinder chamber is performed as described above. The second hydraulic oil supply oil passage and the second hydraulic oil supply hole are passed through a pair of seal rings disposed on the boss portion of the transmission case, and the second hydraulic oil supply hole and the second hydraulic oil supply hole are provided. 3 The hydraulic oil supply hole and the boss of the first drum And a pair of seal rings disposed between the boss portion of the second drum and the boss portion of the second drum.

[0009] The invention according to claim 4 is the one according to any one of claims 1 to 3, wherein the main bearing is constituted by a metal bush.

The invention's effect

[0010] According to the invention of claim 1, the main bearing is disposed on the inner periphery of the boss portion of the first drum and on the outer periphery of the cylindrical support portion, and rotatably supports the first drum. While being press-fitted into the inner peripheral end of the boss portion of the drum, it is loosely fitted to the cylindrical support portion and comes into contact with the cylindrical support portion only when the first drum is tilted in the traveling direction of the vehicle. The auxiliary bearing has a reduced length, so the auxiliary bearing supports the first drum only when necessary, such as when the first drum is tilted with respect to the traveling direction of the vehicle. The axial length of the first drum can be limited, and the large size of the first drum in the axial direction can be suppressed.

[0011] According to the invention of claim 2, the speed change mechanism includes a first hydraulic oil supply oil passage formed in the boss portion of the transmission case and a first hydraulic oil supply formed in the boss portion of the first drum. The hydraulic oil is supplied to the first cylinder chamber through a first hydraulic oil supply oil passage and a first hydraulic oil supply hole.

In a configuration in which the first drum is supported via a pair of seal rings disposed on the boss portion of the transmission case, the first drum receives the tilt in the vehicle traveling direction by the auxiliary bearing. Further, it is possible to prevent the seal ring that forms the hydraulic oil supply oil passage to the first cylinder chamber from being twisted due to the inclination of the first drum. Therefore, it is possible to prevent leakage of pressure oil even if the seal ring is twisted, and to prevent a decrease in controllability of the first hydraulic servo.

[0012] According to the invention of claim 3, the first drum is opened rearward in the vehicle traveling direction, and the first drum and the second drum are traveling of the vehicle at the boss portion of the first drum. The first spline teeth formed on the outer peripheral surface of the rear end portion in the direction and the second spline teeth formed on the inner peripheral surface of the boss portion of the second drum are engaged with each other so as to be integrally rotatable. The hydraulic oil is supplied to the second cylinder chamber by passing the second hydraulic oil supply passage and the second hydraulic oil supply hole through a pair of seal rings disposed on the boss portion of the mission case. The second hydraulic oil supply hole and the third hydraulic oil supply hole are disposed between the boss portion of the first drum and the boss portion of the second drum. In the case of forming a structure via a pair of seal rings, it is necessary to supply hydraulic oil to the second cylinder chamber via the first drum, so that the first drum tends to be enlarged. Therefore, when the size of the first drum is increased in this way, the first drum is supported by the main bearing while the first drum is supported by the auxiliary bearing when the first drum is tilted in the traveling direction of the vehicle. A compactness can be achieved more suitably by adopting a configuration in which they are performed simultaneously.

[0013] According to the invention of claim 4, since the main bearing is constituted by the metal bush, it is possible to easily realize an axial length sufficient to rotationally support the drum.

Brief Description of Drawings

FIG. 1 is a skeleton diagram showing an automatic transmission according to the present invention.

FIG. 2 is a diagram showing engagement states of brakes and clutches at each gear stage of the automatic transmission in FIG.

FIG. 3 is a cross-sectional view showing an automatic transmission according to an embodiment of the present invention.

FIG. 4 is an enlarged view of a part of FIG.

Explanation of symbols

[0015] 10 ··· Automatic transmission, 11 · · · Transmission case, 13 · · · Transmission mechanism, 15 · · · Input shaft, 16 · · Output shaft, 20 · 'Planetary gear for reduction, 21 · · · Planetary gear set, 27 · 'Oil pump body, 27a ... Cylindrical support (boss), 31 "' 1st drum, 32 ··· 2nd drum, 33 ·· 'Sleeve member, 35 ··· Fixed sleeve, 36 ··· Main bearing, 37 ··· Auxiliary bearing, 43, 53, 73 • 'Cylinder chamber, 44, 54, 74 ·' Piston, 65, 66 · 'Hydraulic oil supply hole, 95' Spline engagement part, 99, 100 ... 'Seal ring, Sl, S2, S3 ...' Sun gear, Cl, C2, C3-- 'Carrier, R1, R2'. 'Ring gear, C-1 ... 1 clutch, C— 2 ... second clutch, C— 3 • · 'third clutch, C—4' · 'fourth clutch, Β—1 ··' first brake, Β- 2 ·· 'Second brake.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows an automatic transmission 10 suitable for use in, for example, a front engine rear drive type vehicle. The automatic speed changer 10 includes a torque converter 12 and a speed change mechanism 13 in a transmission case 11 attached to a vehicle body. The output from the engine is And input to the input shaft 15 of the automatic transmission 10 via the turbine runner and the turbine runner. The transmission mechanism 13 shifts the rotation input from the input shaft 15 and outputs it to the output shaft 16 connected to the drive wheels. The torque converter 12 is provided with a lockup clutch 17. Further, the input shaft 15 and the output shaft 16 of the automatic transmission 10 are coaxial with respect to the traveling direction of the vehicle. The torque converter 12 is disposed on the front side with respect to the traveling direction of the vehicle, and the output shaft 16 is disposed on the rear side with respect to the traveling direction of the vehicle. In the present embodiment, the torque converter 12 side in the axial direction of the automatic transmission 10 (the vehicle traveling direction front side) is “front”, and the output shaft 16 side (the vehicle traveling direction rear side) is “rear”. It is called.

[0017] The transmission mechanism 13 includes an input shaft 15 that is sequentially supported coaxially within the transmission case 11, a planetary gear 20 for reduction, a planetary gear set 21 that also includes a plurality of planetary gear forces, an output shaft 16, first to fourth Clutches C-1 to C-4 and first and second brakes B1 and B-2.

[0018] A reduction planetary gear 20 that reduces the rotation of the input shaft 15 and transmits it to the reduction rotation member is a sun gear S1 that is always fixed to the transmission case 11 and restricted in rotation, and a carrier C1 that is directly connected to the input shaft 15 The first gear 23A, which is supported by the carrier C1 and meshes with the sun gear S1, the second gear 23B which is supported by the carrier C1 and meshes with the first gear 23A, and the ring gear which meshes with the second gear 23B. Consists of R1.

As an example, planetary gear set 21 is composed of a rabbi type gear set in which a single-pione planetary gear and a double-pione planetary gear are combined.

[0020] The small-diameter first sun gear S2 of the planetary gear set 21 is detachably connected to the ring gear R1 of the deceleration planetary gear 20 by the first clutch C-1, and the large-diameter second sun gear S3 is The clutch C-3 is detachably connected to the ring gear R1 of the speed reduction planetary gear 20, and the fourth clutch C-4 is detachably connected to the input shaft 15 via the carrier C1 of the speed reduction planetary gear 20. The Short pion 25 is engaged with first sun gear S2. The long pinion 26 is mated with the second sun gear S3 and the short pinion 25. These short pion 25 and long pion 26 are rotatably supported by carriers C2 and C3 having a direct connection structure. Ring gear R2 It is connected to the output shaft 16 as an output element.

[0021] The second sun gear S3 is detachably connected to the transmission case 11 by the first brake B-1. The carrier C2 (C3) is detachably connected to the input shaft 15 by the second clutch C-2. The carrier C2 (C3) is detachably coupled to the transmission case 11 by the second brake B-2 and can be locked by the one-way clutch F-1.

[0022] The automatic transmission 10 configured as described above selectively engages the first to fourth clutches C-1 to C-4 and the first and second brakes B-1 and B-2. By disconnecting and selectively connecting or fixing the elements of the input shaft 15, output shaft 16, speed reduction planetary gear 20 and planetary gear set 21, a gear ratio of 8 forward speeds and 2 reverse speeds can be established. it can. In Fig. 2, when the circles for the clutches and brakes corresponding to each gear stage are marked with ◯, the clutch and brake are engaged, and when there is no mark, the clutch is released.

Hereinafter, the operation of each gear stage will be described. When the shift range is P (parking) range and N (neutral) range, all clutches C-1 to C-4 and brakes B1, B-2 are in the disengaged state, so input shaft 15 and output shaft Power transmission to 16 is disconnected.

In the case of forward first speed, as shown in FIG. 2, the first clutch C-1 is engaged and the one-way clutch F-1 is engaged. As a result, the reduction rotational force of the ring gear R1 of the speed reduction planetary gear 20 is input to the first sun gear S2 of the planetary gear set 21 via the first clutch C-1. Then, the reduced rotational force of the first sun gear S2 is further decelerated via the carrier C2 (C3), whose rotation in one direction is restricted by the one-way clutch F-1, and input to the ring gear R2, and the output shaft 16 is in the first speed. It is decelerated at a gear ratio of During engine braking, the second brake B-2 is engaged in place of the one-way clutch F-1, and the rotation of the carrier C2 (C3) is fixed.

[0025] In the case of the second forward speed, the first clutch C1 is engaged and the first brake B-1 is engaged. As a result, the reduction rotational force of the ring gear R1 of the speed reduction planetary gear 20 is input to the first sun gear S2 via the first clutch C-1, and the second sun gear S3 is fixed by the first brake B1. , Ring gear R2 and output shaft 16 is reduced by the gear ratio of 2nd gear It is rotated forward at high speed.

[0026] In the case of the third forward speed, the first and third clutches C-1 and C-3 are engaged. As a result, the reduction rotational force of the ring gear R1 of the speed reduction planetary gear 20 is input to the first sun gear S2 via the first clutch C-1, and the second sun gear S3 via the third clutch C-3. Therefore, the planetary gear set 21 is rotated, and the ring gear R2 or the output shaft 16 is decelerated at a gear ratio of 3rd speed where the rotation of the input shaft 15 is decelerated by the speed reduction planetary gear 20. It is rotated.

[0027] In the case of forward fourth speed, the first and fourth clutches C-1, C-4 are engaged. As a result, the reduction rotational force of the ring gear R1 of the speed reduction planetary gear 20 is input to the first sun gear S2 via the first clutch C—1, and the rotation of the carrier C1 of the speed reduction planetary gear 20 is the fourth clutch C. — Input to 2nd sun gear S3 via 4, ring gear R2 and then output shaft 16 are rotated forward at a gear ratio of 4th gear.

[0028] In the case of the fifth forward speed, the first and second clutches C-1, C-2 are engaged. As a result, the reduction rotational force of the ring gear R1 of the speed reduction planetary gear 20 is input to the first sun gear S2 via the first clutch C-1, and the rotation of the input shaft 15 is also transmitted via the second clutch C-2. Therefore, the ring gear R2 and the output shaft 16 are decelerated at a gear ratio of 5th speed and rotated forward.

[0029] In the case of forward sixth speed, the second and fourth clutches C-2 and C-4 are engaged. As a result, the input rotational force of the input shaft 15 is input to the second sun gear S3 via the fourth clutch C-4 through the carrier C1 of the speed reduction planetary gear 20, and the rotation of the input shaft 15 is the second rotation. Since it is input to the first and second carriers C2 and C3 that are directly connected via the clutch C2, the planetary gear set 21 is rotated integrally with the input shaft 15, and the ring gear R2 and the output shaft 16 are 6th speed. It is rotated forward with the gear ratio.

[0030] In forward seventh speed, the second and third clutches C-2 and C-3 are engaged. As a result, the rotation of the input shaft 15 is input to the first and second carriers C2 and C3 that are directly connected via the second clutch C-2, and the speed reduction rotation of the ring gear R1 of the speed reduction planetary gear 20 is achieved. Is input to the second sun gear S3 via the third clutch C-3, so that the ring gear R2 and the output shaft 16 are increased in speed by a gear ratio of 7th speed and rotated forward. [0031] In forward 8th speed, the second clutch C2 is engaged, and the first brake B-1 is engaged. As a result, the rotation of the input shaft 15 is input to the first and second carriers C2 and C3 directly connected via the second clutch C-2, and the second sun gear S3 is input by the first brake B-1. Is fixed, so that the ring gear R2 and the output shaft 16 are increased in speed by a gear ratio of 8th gear and rotated forward.

[0032] In the case of the first reverse speed, the third clutch C-3 and the second brake B-2 are engaged. As a result, the rotation of the input shaft 15 is input to the second sun gear S3 via the third clutch C-3, and the directly connected first and second carriers C2 and C3 are fixed by the second brake B2. Therefore, the ring gear R2 and the output shaft 16 are decelerated at the gear ratio of reverse 1st speed and rotated in reverse.

In the case of the second reverse speed, the fourth clutch C-4 and the second brake B-2 are engaged. As a result, the rotation of the input shaft is input to the second sun gear S3 via the fourth clutch C-4 through the carrier C1 of the speed reduction planetary gear 20, and the first and second carriers C2, C2, which are directly connected, are also input. Since C3 is fixed by the second brake B-2, the ring gear R2 and the output shaft 16 are decelerated at the reverse 2nd gear ratio and rotated in reverse.

FIG. 3 and FIG. 4 are mechanism diagrams showing specific configurations of the speed reduction planetary gear 20, the third and fourth clutches C-3, C-4, and the first brake B-1. In the figure, an input shaft 15 is rotatably supported by a transmission case 11, an oil pump body 27 fixed to the transmission case 11, and a stator shaft 30. The stator shaft 30 is press-fitted and fixed to the inner periphery of the boss portion 27a of the oil pump body 27. Further, a speed reduction planetary gear 20 is disposed on the outer peripheral side of the rear end portion of the stator shaft 30, and the sun gear S1 of the speed reduction planetary gear 20 is made non-rotatable by spline engagement.

[0035] In the transmission case 11, a third clutch C-3 having a bottomed cylindrical first drum 31 and a fourth clutch C-4 having a bottomed cylindrical second drum 32 are accommodated. Has been. The fourth clutch C-4 is accommodated on the inner peripheral side of the first drum 31. The first drum 31 is rotatably supported on the outer periphery of the sleeve member 33 press-fitted on the outer periphery of the boss portion 27a of the oil pump body 27. Further, the second drum 32 is supported by a box portion 3 la extending on the inner peripheral side of the first drum 31 and is integrally rotated by a spline engaging portion 95 described later. Engaged as possible.

A plurality of seal members are interposed between the inner periphery of the boss portion 31 a of the first drum 31 and the outer periphery of the sleeve member 33. The rear end of the boss portion 31a of the first drum 31 has a metal bush-like main body disposed on a fixed sleeve 35 fitted to the outer periphery of the rear end portion of the boss portion 27a of the oil pump body 27. The bearing 36 is rotatably supported. The main bearing 36 alone has a sufficient axial length to rotatably support the first drum 31.

[0037] In addition, a metal bush-shaped auxiliary bearing 37 having a shorter axial length than the main bearing 36 is press-fitted into the inner periphery of the other end of the boss 3la (the front end in the vehicle traveling direction). ing. The auxiliary bearing 37 is loosely fitted on the outer periphery of the sleeve member 33 with a gap, and normally does not function as a bearing. The auxiliary bearing 37 abuts on the outer periphery of the sleeve member 33 only when a force against the inclination such as a gyro moment is applied to the first drum 31 and the first drum 31 is inclined more than a predetermined amount in the traveling direction of the vehicle. It functions as a bearing. Accordingly, the capacity of the auxiliary bearing 37 can be reduced as compared with the case where the drum is always supported at two points, so that the minimum axial length can be achieved. Therefore, the press-fitting surface of the first drum 31 for press-fitting the auxiliary bearing 37 can be shortened, and the first drum 31 is prevented from becoming large in the axial direction.

[0038] One end on the opening side of the outer peripheral portion 31b of the first drum 31 is detachably connected to the ring gear R1 of the speed reduction planetary gear 20 via the third clutch C-3! / The The third clutch C-3 is composed of a friction engagement element consisting of a separate plate 41 splined to the outer periphery 31b and a friction plate 42 splined to the ring gear R1, and a first hydraulic servo. Has been. The first hydraulic servo is a canceller disposed in a first piston 44 slidably housed in a first cylinder chamber 43 formed at the bottom of the first drum 31 and a boss 31a of the first drum 31. The plate 91 and a return spring 45 that urges the first piston 44 are configured.

[0039] The inner peripheral portion of the canceller plate 91 is locked to the outer periphery of the boss portion 31a of the first drum 31 by a snap ring 90 so as to be restricted from moving in one axial direction. The outer peripheral portion is liquid-tightly fitted to the inner peripheral surface of the first piston 44, and a first cancel chamber 92 is formed between the canceller plate 91 and the first piston 44. Between the canceller plate 91 and the first piston 44, the first piston 44 is axially released and the third clutch C-3 is released. A return spring 45 is arranged to bias the

[0040] The first cancel chamber 92 receives cancel oil (lubricating oil) from the boss portion 27a of the oil pump body 27, the sleeve member 33 and the cancel oil supply hole 93 formed in the radial direction in the first drum 31. It comes to be supplied. The cancel oil supplied to the first cancel chamber 92 is discharged to the outside through a cancel oil discharge groove 91a formed in the inner peripheral portion of the canceller plate 91. The first cancel chamber 92 has a function of canceling the centrifugal hydraulic pressure generated by the oil in the first cylinder chamber 43.

[0041] The first piston 44 extends along the inner periphery of the outer peripheral portion 31b of the first drum 31, and the tip portion thereof is arranged corresponding to the side of the friction engagement element of the third clutch C3. ing. The first cylinder chamber 43 of the hydraulic servo is formed in the boss portion 27a of the oil pump body 27 through the supply passage 47 that also has oil holes formed in the sleeve member 33 and the boss portion 31a of the first drum 31. It is communicated with the oil passage that is formed. The oil passage formed in the boss part 27a is connected to a hydraulic control device (not shown), and the first piston 44 is slid by the spring force of the return spring 45 by the pressure oil supplied from the hydraulic control device. The friction engagement element of the third clutch C 3 is frictionally engaged. Further, when the supply of pressure oil is stopped, the frictional engagement of the frictional engagement element is released by the spring force of the return spring 45.

[0042] The second drum 32 is disposed inside the first piston 44 of the third clutch C-3. A boss portion 32a disposed on the boss portion 31a of the first drum 31 is provided on the inner peripheral side of the second drum 32, and an outer peripheral portion 32b is provided on the outer peripheral side. As shown in FIG. 4, an inner spline 32c is formed on the inner periphery of the rear end of the boss portion 32a of the second drum 32. The inner spline 32c is formed in front of the boss portion 31a of the first drum 31. It is spline-engaged with an outer spline 31c formed on the outer periphery of the side end. A spline engaging portion 95 is constituted by the first spline teeth composed of the outer splines 31c and the second spline teeth composed of the inner splines 32c.

[0043] The opening side (rear side) end of the outer peripheral portion 32b of the second drum 32 is detachably connected to the carrier C1 of the speed reduction planetary gear 20 via the fourth clutch C-4. It has become. The fourth clutch C-4 includes a separate plate 51 splined to the inner periphery of the outer peripheral portion 32b and a flexion plate 52 splined to the outer periphery of the clutch hub 56 coupled to the carrier C1. And a second hydraulic servo. ing. The second hydraulic servo is a canceller disposed in a second piston 54 slidably housed in a second cylinder chamber 53 formed at the bottom of the second drum 32 and a boss 31a of the first drum 31. The plate 97 and the return spring 55 that urges the second piston 54 are configured. One end of the second piston 54 is spline-engaged with the inner periphery of the outer peripheral portion 32b of the second drum 32, and is disposed behind the friction engagement element of the fourth clutch C-4. The second piston 54 is disposed on the outer peripheral side of the boss portion 32a of the second drum 32 in which the spline engaging portion 95 is formed.

A canceller plate 97 is disposed on the outer periphery of the rear end portion of the boss portion 31 a of the first drum 31 so as to be restricted from moving in one axial direction by a snap ring 96. The outer diameter side of the second piston 54 is fitted into the inner peripheral surface of the second piston 54, and a second cancel chamber 98 is formed between the canceller plate 97 and the second piston 54. Between the canceller plate 97 and the second piston 54, there is disposed a return spring 55 that urges the second piston 54 to open the fourth clutch C-4 in the axial direction.

[0045] The first drum 31, the friction engagement element including the separation plate 41 and the friction plate 42, the first cylinder chamber 43, the first piston 44, the return spring 45, and the first drum 31 and the first piston 44 are used to A third clutch C-3 is constituted by a densely formed hydraulic servo, and a friction engagement element, a first piston 44, and a return spring 45 are accommodated in the first drum 31.

Similarly, the second drum 32, the friction engagement element including the separation plate 51 and the friction plate 52, the second piston 54, the return spring 55, and the second drum 32 and the second piston 54 are formed in a liquid-tight manner. The fourth clutch C-4 is configured by the hydraulic servo, and the friction engagement element, the second piston 54, and the return spring 55 are accommodated in the second drum 32.

[0047] The pressure oil supply passage 60 includes a plurality of second hydraulic oil supply holes 65 formed in the boss portion 31a of the first drum 31 in the radial direction at equal circumferential positions, and a boss portion 32a of the second drum 32. And a plurality of third hydraulic oil supply holes 66 formed radially at equiangular positions on the circumference and an annular oil passage 67 formed between the boss portions 31a and 32a. The hydraulic oil supply holes 65 and 66 communicate with each other through an annular oil passage 67. On the sleeve member 33, a pair of seal rings 99 are disposed on both axial sides of the second hydraulic oil supply hole 65. On the boss portion 31a of the first drum 31, seal rings (O-rings) 100 are disposed on both axial sides of the second and third hydraulic oil supply holes 65 and 66, respectively. Is formed.

[0048] The outer periphery of the outer peripheral portion 31b of the first drum 31 is detachably connected to the transmission case 11 via the first brake B-1. The first brake B-1 is a friction consisting of a separate plate 71 splined to the inner periphery of the mission case 11 and a friction plate 72 splined to the outer periphery of the outer periphery 3 lb of the first drum 31. It is composed of an engagement element and a hydraulic servo. The hydraulic servo includes a piston 74 slidably housed in an oil chamber 73 formed in the mission case 11 and a return spring 75 that urges the piston 74.

[0049] The tip of the piston 74 extends to the side of the friction engagement element of the first brake B-1. The oil chamber 73 of the hydraulic servo is connected to the hydraulic control device via an unillustrated oil passage formed in the mission case 11, and the piston 74 is connected to the return spring 75 by the pressure oil supplied from the hydraulic control device. It is slid against the spring force and frictionally engages the friction engagement element of the first brake B-1. Further, when the supply of pressure oil is stopped, the frictional engagement of the frictional engagement element is released by the spring force of the return spring 75! /.

In addition, a lubrication supply passage 81 is formed in the input shaft 15, and lubricating oil discharged from an unillustrated oil pump is supplied to the supply passage 81 via the hydraulic control device and the supply hole 83. It has become so. A plurality of rows of supply holes 84, 85 are communicated with the supply passage 81, and the lubricating oil is supplied to each part in the transmission case 11 through these supply holes 84, 85. Lubricating oil supplied into the mission case 11 is scattered radially outward by centrifugal force action and supplied to various parts such as the planetary gear 20 for reduction, clutches C3 and C4, brake B-1, and bearings.

[0051] The first drum 31 described above is rotated integrally with the ring gear R1 of the speed reduction planetary gear 20 by the engagement of the third clutch C-3. The first drum 31 is rotated together with the second drum 32 that is rotated integrally with the carrier C1 of the speed reduction planetary gear 20 by the engagement of the fourth clutch C-4. In a normal state, the first drum 31 is rotatably supported by the boss portion 27a of the oil pump body 27 through the fixed sleeve 35 only by the main bearing 36. The auxiliary bearing 37 is loosely fitted on the outer periphery of the sleeve member 33 with a gap, and does not function as a bearing.

However, when the vehicle turns left and right while the first drum 31 rotates, a phenomenon occurs in which the first drum tilts in the axial direction (the traveling direction of the vehicle) due to the generation of a gyro moment. As described above, when an axially inclined external force such as a gyro moment acts on the first drum 31 and the first drum 31 is inclined at a predetermined angle, the auxiliary bearing 37 comes into contact with the outer periphery of the sleeve member 33, and the bearing Function as. As described above, since the auxiliary bearing 37 functions as an emergency, it does not require durability and can have a minimum axial length. In addition, since the auxiliary bearing 37 receives the inclination of the first drum in the axial direction, the first drum squeezes the seal ring interposed in the oil passage that supplies hydraulic oil to the first cylinder chamber 43, and enters the first cylinder chamber 43. It can be prevented that the supplied hydraulic oil leaks and the controllability of the first hydraulic servo is lowered.

[0053] According to the above-described embodiment, the inner periphery of one end of the boss portion 31a of the first drum 31 has a metal bush shape on the fixed sleeve 35 fitted to the outer periphery of the tip end portion of the boss portion 27a of the oil pump body 27. The main bearing 36 is rotatably supported via the main bearing 36, and the main bearing 36 alone has a sufficient axial length to rotatably support the first drum 31. Only by this, the first drum 31 can be rotatably supported on the boss portion 27a of the oil pump body 27. Also, a metal bush-shaped auxiliary bearing 37 with a short axial length is attached to the inner periphery of the other end of the boss portion 31a. The auxiliary bearing 37 normally does not function as a bearing so that the sleeve member 33 does not function. The auxiliary bearing 37 does not require durability and can have a minimum axial length because the outer periphery of the auxiliary bearing 37 is loosely fitted. As a result, a plurality of supply passages for supplying pressure oil to the first and second cylinder chambers 43 and 53 of the hydraulic servos of the third and fourth clutches C-3 and C-4 are formed in the boss portion 31a and the sleeve. In spite of being provided on the mating surface with the member 33, the first drum 31 and the supporting device that supports the first drum 31 can be prevented from becoming large in the axial direction. Enables compactness and compactness

[0054] In the embodiment described above, the automatic transmission capable of achieving a gear ratio of 8 forward speeds and 2 reverse speeds has been described, but the present invention is not limited to such an example. Nagu bearing It can be applied to a wide range of automatic transmissions having a drum supported by the motor.

Further, in the above-described embodiment, the planetary gear set 21 has been described by taking as an example a rabbi type gear set in which the single-pione planetary gear and the double beon planetary gear are combined. Any planetary gear set having a plurality of (two or more) planetary gears is not limited to the rabbi gear set, and any configuration can be adopted.

Furthermore, in the above-described embodiment, the sleeve member 33 and the fixed sleeve 35 are fitted on the outer periphery of the boss portion 27a of the oil pump body 27, and one end of the first drum 31 is fixed to the fixed sleeve 35. An auxiliary bearing 37 that is rotatably supported through the main bearing 36 and is loosely fitted to the sleeve member 33 is provided at the other end of the first drum 31. The sleeve member 33 and the fixed sleeve 35 are one of the cylindrical support portions in the claims. Part. It is possible to eliminate the sleeve member 33 and the fixing sleeve 35 and directly support the first drum 31 on the cylindrical support portion (boss portion 27a).

Thus, the specific configuration described in the above embodiment is merely an example of the present invention, and the present invention is not limited to such a specific configuration. It goes without saying that various aspects can be adopted without departing from the gist.

Industrial applicability

[0058] An automatic transmission according to the present invention is provided at the rear of an engine with respect to the traveling direction of a vehicle, and includes an automatic transmission provided with a transmission mechanism that disengages and disengages a plurality of clutches and brakes into a plurality of stages. Suitable for use in.

Claims

The scope of the claims

[1] An automatic transmission disposed behind the engine with respect to the traveling direction of the vehicle,

The automatic transmission includes a transmission mechanism that disengages and disengages a plurality of clutches and brakes to shift to a plurality of stages.

The speed change mechanism includes a cylindrical support portion;

A first hydraulic servo that has a first drum and a first piston that forms a first cylinder chamber together with the first drum, and that allows one of the plurality of clutches to be operated; and the first drum A main bearing that is disposed on an inner periphery of the boss portion and an outer periphery of the cylindrical support portion, and rotatably supports the first drum;

While being press-fitted into one end of the inner periphery of the boss portion of the first drum and loosely fitting with the cylindrical support portion, the first drum comes into contact with the cylindrical support portion only when tilted in the traveling direction of the vehicle. An automatic transmission comprising: an auxiliary bearing having an axial length shorter than that of the main bearing.

[2] In Claim 1, the cylindrical support portion is a boss portion extending from a transmission case, and the speed change mechanism is a first hydraulic oil supply oil passage formed in a boss portion of the transmission case; A first hydraulic oil supply hole formed in the boss portion of the first drum,

The hydraulic oil is supplied to the first cylinder chamber by a pair of seal rings provided on the boss portion of the transmission case, the first hydraulic oil supply oil passage and the first hydraulic oil supply hole. An automatic transmission characterized by being performed via

[3] In Claim 2, the speed change mechanism is slidably disposed on a second drum and a boss portion of the second drum, and forms a second cylinder chamber together with the second drum. A second hydraulic servo having two pistons;

A second hydraulic oil supply oil passage formed in the boss portion of the transmission case; a second hydraulic oil supply hole formed in the boss portion of the first drum; and a second hydraulic oil supply hole formed in the boss portion of the second drum. 3 With a hydraulic oil supply hole,

The first drum is opened toward the rear in the vehicle traveling direction,

The first drum and the second drum are located after the vehicle traveling direction of the boss portion of the first drum. The first spline teeth formed on the outer peripheral surface of the side end portion and the second spline teeth formed on the inner peripheral surface of the boss portion of the second drum are engaged with each other so as to be integrally rotatable,

The main bearing is disposed on the inner peripheral side of the rear end of the boss portion of the first drum in the vehicle traveling direction,

The hydraulic oil is supplied to the second cylinder chamber by a pair of seal rings arranged on the boss portion of the transmission case, the second hydraulic oil supply oil passage and the second hydraulic oil supply hole. And a pair of seal rings disposed between the boss portion of the first drum and the boss portion of the second drum, with the second hydraulic oil supply hole and the third hydraulic oil supply hole interposed therebetween. An automatic transmission characterized in that it is carried out through

An automatic transmission in which the main bearing is constituted by a metal bush.