JPH02146347A - Arranging structure for friction engaging element of automatic transmission - Google Patents

Abstract

PURPOSE:To reduce size in the axial direction by forming a pressure oil chamber by a side wall undercut part in an inner race of a one-way clutch and a pressure receiving part of a piston inserted between an internal peripheral part of the side wall undercut part and an inner cylinder peripheral part. CONSTITUTION:A sun gear 131 of planetary gears connects one end of an inner cylinder 800 forming in its another end part an inner race 820 of a one-way clutch 33 in a stepped cylindrical shape through a contour spread wall part 806. An outer race 840, stopped to an internal wall part of an automatic transmission case 300, is provided to be arranged being opposed to the inner race. While a clutch drum 830 is mounted through a contour spread wall part 832, internally providing a clutch 14 and its operating piston 880. While an undercut part 822, formed in a side wall part of the inner race 820, and a pressure receiving part of the piston 880, inserted between the undercut part and an inner cylinder peripheral part 802, form a pressure oil chamber 890. Thus, size in the axial direction can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an automatic transmission equipped with a starting device and a planetary gear device.

[Prior Art] In an automatic transmission equipped with a starting device and a planetary gear device, a power transmission path that selectively provides input to the components of the planetary gear device and a power transmission path that selectively grips the components of the planetary gear device are used. Shifting is achieved by a path that supports the reaction force by the planetary gear system, and a power transmission path that takes output from other components of the planetary gear system. Frictional engagement elements such as clutches, brakes, one-way clutches, etc. are disposed in each of these paths as necessary, but as the number of gears increases, the number of frictional engagement elements required also increases. This causes an increase in the axial dimension of the transmission.

[Problems to be Solved by the Invention] Of the frictional engagement elements, the elements disposed in the path that receives particularly the reaction force must receive a large reaction force at low speed stages, and the required torque capacity is also large. becomes.

The path that receives the reaction force must ultimately be locked to a fixed member such as a transmission case, and a brake or one-way clutch is provided at this locking portion.

Since the one-way clutch mechanically locks itself in response to a reaction force, it does not require any control means and locks reliably, making it particularly suitable for elements that are subject to large reaction forces.

In the present invention, a one-way clutch with a large torque capacity is disposed at the end of the path that receives this reaction force, and a clutch with a small torque capacity is disposed adjacent to this one-way clutch. This provides an arrangement structure that reduces the axial dimension by using a part of the inner race as the hydraulic chamber of the piston that operates the clutch.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides an inner cylinder (800) whose one end is connected to a sun gear (131) of a planetary gear, and an inner cylinder (800) whose other end is connected to a sun gear (131) of a planetary gear. An inner race (820) of a one-way clutch (33) formed into a stepped cylindrical shape via a wall (806) that expands radially outward.
, an outer race (840) of a one-way clutch that is disposed opposite to the inner race (820) and whose outer peripheral portion is engaged with the inner peripheral wall of the automatic transmission case (300), and a one-way clutch (33). A clutch drum (830) is mounted facing the inner cylinder (800) via a wall (832) extending radially outward from the end of the inner race (820), and a clutch drum (830) is arranged inside the clutch drum (830). an undercut portion (822) formed on the side wall portion of the inner race (820); and an inner peripheral portion (824) of the undercut portion (822). Inner cylinder (8
00) and the outer circumference (802) of the piston (
A hydraulic chamber (890) is formed by the pressure receiving section (880).

[Function] With the above configuration, while the hydraulic pressure is not supplied to the hydraulic chamber (890), the pressure receiving part of the piston (880) is connected to the undercut part (822) formed in the side wall part of the inner race (820).
). Therefore, the clutch (14) and the one-way clutch (33) can be arranged with short axial dimensions.

Note that the above-mentioned symbols in parentheses are in contrast to the drawings, but do not limit the configuration in any way.

[Example] The present invention will be described in detail below based on one drawing.

FIG. 2 shows a skeleton of an automatic transmission embodying the present invention, and the automatic transmission, designated as a whole by reference numeral 1, includes a starting device 2 and a transmission 3. As shown in FIG.

The starting device 2 is a fluid transmission device, and includes a rear cover 204. A turbine runner 208 , which has a pump impeller 206 formed on the inner circumferential wall surface of the rear cover 204 and is disposed opposite to the pump impeller 206 , is held by a turbine shell 210 , and is held by a turbine shell 210 .
0 is connected at its inner peripheral portion to an input shaft 240 which is an output member of the starting device 2 and an input member of the transmission 3.

A stator 214 is disposed between the pump impeller 206 and the turbine runner 208, and the inner peripheral portion of the stator 214 is connected to the outer race of the one-way clutch 216, and the inner race of the one-way clutch 216 is a fixed member. It is attached to the outer periphery of the support shaft 230. A lock-up clutch 220 that directly connects the front cover 202 and the turbine shell 210 is disposed between the front cover 202 and the turbine shell 210.

The input shaft 240 of the transmission 3 is connected to a clutch drum, which is generally designated by the reference numeral 400, and three clutches are disposed inside the clutch drum.In this embodiment, the three clutches are connected to the transmission. From the front side (hereinafter, the engine side will be referred to as the front and the side far from the engine will be referred to as the rear): a fifth clutch 15, which is a coast clutch; The first clutch 11 is a forward clutch. The second clutch 12, which is a direct clutch, is arranged at Jllllt. Another drum 470 is disposed at the rear of the clutch drum 400, and a third clutch 13, which is a reverse clutch, is disposed between the hub 445 that connects the clutch drum 470 and the drum 400. A band-type second brake 22 for controlling the forward gear is provided on the outer periphery of the drum 470.

The hub of the fifth clutch 15 is connected to the front end of a first intermediate shaft 500 disposed at the axial center of the transmission 3, and the hub of the first clutch 11 is connected via the first one-way clutch 31. It is connected to the first intermediate shaft 500 . The front end of the first intermediate shaft 500 is supported by the rear end of the input shaft 240, and the rear end of the first intermediate shaft 500 is supported by the front end of an output shaft 700, which will be described later. The outer periphery of the first intermediate shaft 500 supports the inner periphery of a coaxially arranged second intermediate shaft 550 at two supporting points, and the outer periphery of the second intermediate shaft 550 is coaxially arranged. The inner peripheral portion of the third intermediate shaft 600 is supported by two supporting points. Therefore, the intermediate shaft has a triple shaft structure.

The hub of the second clutch 12 is connected to the front end of the second intermediate shaft 550, and the hub of the second clutch 12 is connected to the front end of the second intermediate shaft 550.
The second drum 470 is connected to the third drum through an inner cylinder 480.
is connected to the front end of the intermediate shaft 600 of.

A planetary gear device is disposed on the outer periphery of the connecting portion between the intermediate shaft and the output shaft. The planetary gear device has a simple planetary gear set with three rows, and from the front side of the transmission 3, the first row, second row,
They are arranged in the order of the third column.

The sun gear 111 of the first row of simple planetary gear sets 110 is connected to the third intermediate shaft 600 and meshes with the pinion 112, and one end of the carrier shaft 113 that supports the pinion 112 is connected to the carrier shaft 113 via the carrier connecting member 114. It is connected to the rear end of the second intermediate shaft 550. The other end of the carrier shaft 113 is connected to the ring gear 125 of the second row simple planetary gear set 120 via a first connection member 150, and further connected to the second one-way clutch 32 via a second connection member 160. outer lace and fourth
The clutch 14 is connected to the hub of the clutch 14. A multi-plate third brake 23 is disposed on the outer periphery of the connecting member 150.

The rear end of the first intermediate shaft 500 is connected to the sun gear 121 of the second row of simple planetary gear sets, and the second row sun gear 121 has a larger outer diameter than the first row sun gear 111. The front end of the shaft 123 of the carrier that supports the pinion 122 that meshes with the sun gear 121 and ring gear 125 of the second row is connected to the ring gear 115 of the first row via the carrier connecting member 116, and the rear end of the shaft 123 is connected to the ring gear 115 of the first row. It is connected to a third row ring gear 135 via a connecting member 126 of another carrier.

Inner cylinder 800 integrated with third row sun gear 131
is connected to the inner race of the second one-way clutch 32 and the third one-way clutch 33, and is also connected to the clutch drum 830 of the fourth clutch 14. This clutch drum 830 also serves as a brake drum for the band-type first brake 21.

A carrier shaft 133 supporting the third row of pinions 132
is coupled to the output shaft 700 via the carrier coupling portion 136.

FIG. 1 is a sectional view showing a specific structure of the automatic transmission having the skeleton explained in FIG.

The starting device 2 that constitutes the automatic transmission 1 is a fluid transmission device, and includes a housing 200 that opens on the engine side (front side).
is housed inside. A carrier cover 204 is integrally attached to the rear of the front cover 202, which rotates in response to the rotation of the engine.

The rear force/(-204 has a pump impeller 20 on the inner peripheral wall surface.
A turbine runner 208 formed with a reference number 6 and disposed opposite the pump impeller 206 is held in a turbine shell 210 . The turbine shell 210 is connected at its inner peripheral portion to an input shaft 240 which is an output member of the starting device 2 and an input member of the transmission 3 via a connecting member 211 .

A stator 214 is disposed between the pump impeller 206 and the turbine runner 208, and the inner peripheral portion of the stator 214 is connected to the 7th outer race 215 of the one-way clutch 216, and the inner race 2 of the one-way clutch 216.
17 is attached to the outer periphery of the front end of the support tube 230. A lock-up clutch 220 having a lock-up piston 222 is disposed between the front cover 202 and the turbine shell 210.

A cylindrical case 300 that houses the components of the transmission 3 is connected to the rear of the housing 200, and an oil pump cover 250 and a partition plate 270 are connected to the joint between the housing 200 and the transmission case 300. Attach the oil pump housing 260. An internal gear pump consisting of an external gear 262 and an internal gear 264 is accommodated within the oil pump housing 260, and the inner peripheral portion of the external gear 262 is connected to a shaft 266 that is integral with the carrier cover 204. The center portion of the oil pump cover 250 forms a cylindrical support portion 252 that projects rearward.

The rear outer circumferential portion of the support tube 230 is press-fitted and fixed to the inner circumferential portion of the support portion 252 .

The support tube 230 supports the input shaft at two fulcrums on its inner circumference, and the rear end of the input shaft forms a radially expanding flange. The outer peripheral part of the flange part is the first clutch drum 40
The inner cylinder 410 is connected to the inner periphery of the rear end of the inner cylinder 410, which is integral with the inner cylinder 410. The first clutch 11 and the fifth clutch 15 are housed inside the first clutch drum 400, and a piston 420 for operating the first clutch 11 and a piston 430 for operating the fifth clutch 15 are arranged as a double piston. placed in the structure.

The rear end of the first clutch drum 400 opens rearward, and the second clutch drum 440 is connected via a spline formed on the inner circumference of this opening. Inside the second clutch drum 440, the second clutch 12 and the second clutch 12 are disposed.
A piston 450 for operating the clutch 12 is provided.

The inner circumference of the rear end of the input shaft 240 is connected to the first
supports the outer periphery of the distal end of the intermediate shaft 500.

A radially expanding flange portion 510 is formed at the front portion of the first intermediate shaft 500, and constitutes an inner race of the one-way clutch. This flange portion 510 and the first clutch 11
A first one-way clutch 31 is disposed between the hub 520 and the hub 520. The front end of this flange portion 510 has a fifth
The hub 435 of the clutch 15 is fixed.

A hub 455 of the second clutch 12 housed within the second clutch drum 440 is connected to the front end of the second intermediate shaft 550. The second intermediate shaft 550 has a cylindrical shape, and the outer peripheral portion of the first intermediate shaft 500 supports two fulcrums at the front and rear of its inner peripheral portion. A clutch hub 445 is provided at the rear of the second clutch drum 440, and the third clutch 13 is provided between the third clutch drum 470 and the inner cylinder of the drum 470. A piston 490 is housed between the piston 480 and the piston 480 . The drum 470 also serves as a brake drum for the band-type second brake 22. A front end portion of the inner cylinder 480 is connected to the third intermediate shaft 600 via a connecting member 610.

The third intermediate shaft 600 has a cylindrical shape, and two supporting points at the front and rear of its inner circumference are supported by the outer circumference of the second intermediate shaft 550.

A central support member 3 is installed in the center of the transmission case 300.
Get 10. The central support member 310 has an outer circumferential portion joined to an inner circumferential portion of the transmission case, and a central portion formed into a cylindrical portion that protrudes forward. The ring member 310 is press-fitted into the outer peripheral part of the cylindrical part that protrudes forward, and the ring member 31
The inner circumferential portion of the inner cylinder 480 of the third clutch drum 470 is rotatably supported by the outer circumferential portion of the third clutch drum 470 .

The intermediate shaft having a triple structure extends rearward through the inner circumference of the central support member 310, and the outer circumference of the rear end of the first intermediate shaft 500 is supported by the inner circumference of the tip of the output shaft 700. A rear wall 330 is formed at the rear of the transmission case 300, and a rear support member 350 is fixed to the inner circumference of the rear wall 330.

The rear support member 350 includes a cylindrical portion that protrudes toward the front inside the transmission case 300, and the outer diameter of the cylindrical portion is formed into a plurality of stepped portions whose outer diameters gradually become smaller toward the front. . The inner peripheral portion of the front end of the cylindrical portion of the support member 350 is connected to the output shaft 7.
Supports the front outer circumference of 00.

A spigot engagement portion 360 is provided at the rear end of the transmission case 300.
The inner periphery of the rear end of the rear case 370, which is concentrically fitted through the rear case 370, supports the rear outer periphery of the output shaft 700 via a bearing. therefore.

The output shaft 700 is reliably supported by two supporting points, and the first intermediate shaft 500 has its front and rear ends connected to the input shaft 240 and the output shaft 7.
00 is definitely supported.

As explained in the skeleton of FIG. 2, three rows of simple planetary gear sets are arranged on the outer periphery of the connecting portion between the triple-structured intermediate shafts 500, 550, and 600 and the output shaft 700. A first row of sun gear 111 is formed at the rear end of the third intermediate shaft 600 supported on the outermost side, and a pinion 112
The shaft 11 of the carrier supporting the pinion 112 meshing with the
The inner circumferential portion of the carrier connecting member 114 supporting one end of the second intermediate shaft 550 is attached to the outer circumferential portion of the rear end of the second intermediate shaft 550 via a spline. The carrier connecting member 117 that supports the other end of the carrier shaft 113 is a first connecting member 150.
It is connected to the second row ring gear 125 via. Second
The row ring gear 125 is further coupled to the outer race 810 of the second one-way clutch 32 via a second coupling member 160. A multi-plate third brake 23 is disposed on the outer periphery of the first connecting member 150, and a piston 650 for operating the brake 23 is disposed on the rear wall of the central support member 310.

A second row of sun gears 121 is connected to the rear outer peripheral portion of the first intermediate shaft 500 . This second row of sun gear 121 is
It has a larger outer diameter than the sun gear 111 in the row. The front end of the shaft 123 of the carrier that supports the pinion 122 that meshes with the sun gear 121 and ring gear 125 of the second row is connected to the ring gear 115 of the first row through a connecting member 116 of the carrier.
The rear end of the shaft 123 is connected to a third row ring gear 135 via a connecting member 126 of another carrier.

The third row sun gear 131 has its rear end connected to the inner race 870 of the second one-way clutch and also connected to the inner race 820 of the third one-way clutch 33 via the inner cylinder 800 .

A drum 830 formed opposite to the inner cylinder 800
The fourth clutch 14 and a piston 880 for operating the fourth clutch 14 are housed inside, and the clutch hub 815 is connected to the outer race 810 of the second one-way clutch 32 . A band-type first brake 21 is disposed on the outer periphery of the clutch drum 830, and the clutch drum 830 is connected to the brake 21.
Also serves as the brake drum. Third one-way clutch 33
The outer periphery of the outer race 840 is the transmission case 300.
is fixed to the inner wall of the

A carrier shaft 133 supporting the third row of pinions 132
is supported by a connecting portion 136 formed at the front end of the output shaft 7 (>O).A parking gear 710 and a speedometer drive gear 730 are mounted on the outer periphery of the output shaft 700 inside the rear case 370. A claw 720 that is attached to the parking gear 710 and coupled to the gear 710 is provided on the outside of the parking gear 710. A connecting member 750 is fixed to the rear end of the output shaft with a nut 755.

A rotation sensor 305.3 for detecting the rotation speed of rotating members is installed in the main parts inside the transmission case 300 and rear case 370.
06, 307 to obtain information for controlling the frictional engagement elements.

A hydraulic control device (not shown) is attached to the bottom of the transmission case 300 and covered with a cover 309 that also serves as an oil pan.

As described above, this automatic transmission is equipped with a 3-row simple planetary gear set as a planetary gear device, and uses 5 clutches, 3 brakes, and 3 one-way clutches to achieve 5 forward speeds and 1 reverse speed. The operation of each friction engagement element is shown below.

Note that in the above table, the 0 mark indicates that the frictional engagement element is engaged, and the (0) mark indicates that it is engaged during engine braking.

Next, FIGS. 3 to 6 show power transmission paths from 1st speed to 4th speed.

FIG. 3 shows the power transmission path at the first speed, where the input from the input shaft 240 is transmitted from the clutch drum 400 to the first clutch 11, and from the first one-way clutch 31 to the first intermediate shaft 500. is transmitted to the sun gear 121 of the second row simple planetary gear set. The ring gear 125 in the second row is connected to the second one-way clutch 32 via the connecting member 160, and since the second one-way clutch 32 is engaged, the inner cylinder 800 is connected to the sun gear 131 in the third row. The third
It is fixed by a one-way clutch 33. Therefore, the second
The column carriers 123 are driven at reduced speed. This power is transmitted to the third row ring gear 135 connected to the carrier 123.
transmitted to. As mentioned above, the third row sun gear 13
1 is fixed, the input of the ring gear 135 decelerates and drives the shaft 133 of the third row carrier, and the coupling part 136
is transmitted to the output shaft 700 via. In other words, the second row decelerates, and the third row decelerates, but the input of the first speed, where the transmitted torque is the largest, is transmitted through the second row sun gear, which has a large outer diameter, so the width of the sun gear The third one-way clutch 33 receives the reaction force of the ring gear 125 in the second row and the reaction force of the sun gear 131 in the third row, so it requires a large capacity.

FIG. 4 shows the power transmission path when the vehicle is in second gear, and is different from the first gear in that the sun gear 111 in the first row is fixed. That is, when shifting from the first speed to the second speed, the second brake 22 is engaged to fix the first row sun gear 111 that is integrated with the third intermediate shaft 600. As a result, the second one-way clutch 32 is released, and the first row of carriers 11
3 and the ring gear 125 of the second row are also released. The third row, like the first speed, acts as a speed reducer that fixes the sun gear.

FIG. 5 shows the state of 3rd gear. To shift from 2nd to 3rd gear, release the second brake 22 and press the second clutch 1.
2. Input is transmitted from the first intermediate shaft 500 to the sun gear 121 in the second row, and from the second intermediate shaft 550 to the carrier 113 in the first row. The third row, like the first and second speeds, acts as a speed reducer that fixes the sun gear.

FIG. 6 shows the power transmission path in 4th gear. 4th gear is in a so-called direct connection state, and the planetary gear set does not rotate relative to each other. To shift from 3rd gear to 4th gear, the fourth clutch 14 is engaged. match. As a result, the carrier 113 in the first row, the ring gear 125 in the second row, and the sun gear 131 in the third row
is connected, and the third one-way clutch 33 is released.

The power of the input shaft 240 is transferred to the output shaft 70 without being subjected to speed change.
0.

In the automatic transmission embodying the present invention, as is clear from the engagement state of the frictional engagement elements of each gear stage and the power transmission path explained above, the third gear is shifted from the first gear to the third gear. The directional clutch 33 is engaged to achieve deceleration by receiving the reaction force applied to the sun gear 131 of the third row simple planetary gear set.

Particularly in the first speed, the one-way clutch 33 also receives the reaction force applied to the second row ring gear, so the third one-way clutch 33 needs to have a large capacity and a high rigidity at the mounting part. On the other hand, the fourth clutch 14 is engaged when shifting from third speed to fourth speed, and has a characteristic that the torque capacity is relatively small, but the heat capacity is sufficiently secured.

The present invention provides a structure in which clutches and one-way clutches can be arranged rationally by utilizing the above characteristics.

FIG. 7 is a sectional view showing an embodiment of the present invention.

A rear wall 330 is provided at the rear of the cylindrical case 300 of the transmission.
A spline 302 is provided on the inner wall of the rear end of the case 300. The inner periphery of the rear wall 330 is formed into a round hole, and the rear support member 350 is concentrically attached to this round hole using a spigot engagement part 352. The rear support member 350 projects toward the front of the transmission case,
It is formed into a three-stage cylindrical portion whose outer diameter decreases in order with its outer circumferential portion facing forward. The large diameter cylindrical portion 354 supports the inner circumference of the inner race 820 of the third one-way clutch 33 at its outer circumference via a bearing. inner lace 820
The outer race of the third one-way clutch 33 facing the third one-way clutch 33 has a spline 842 on its outer periphery, and is engaged and connected to a spline 302 provided on one inner wall of the transmission case 300. The inner periphery of the inner race 820 is integrated with the inner cylinder 800 via the wall 806, and the inner periphery of the tip of the inner cylinder 800 is connected to the third spline 804 via the spline 804.
It is connected to a simple planetary sun gear 131 of the column. The inner peripheral part of the inner cylinder 800 is connected to the rear support member 350.
It is supported by the outer periphery of the medium diameter cylindrical portion 356 and the outer periphery of the small diameter cylindrical portion 358 . The inner peripheral portion of the small diameter cylindrical portion 358 of the rear support member 350 supports the output shaft 700.

A clutch drum 830 having an outer diameter larger than the outer diameter of the inner race 820 is connected to the outer circumferential portion of the inner race 820 of the third one-way clutch 33 via a wall portion 832 thereof. Inside the clutch drum 830 there is a fourth
A fourth clutch 14 is arranged, and a hub 8 of the fourth clutch 14 is arranged.
15 is the outer race 810 of the second one-way clutch 32
Connect to. The outer peripheral portion of this clutch drum 830 is
It also serves as the drum for the brake 21.

The outer race 810 is connected to the ring gear of the second row of simple planetary gear sets via the second connecting member 160. Inner race 8 of second one-way clutch 32
The inner circumferential portion of the gear 70 fits into the sun gear 131 of the third row simple planetary gear set via a spline 872.

As explained in FIGS. 1 and 2, since the third one-way clutch 33 is a member that receives a large reaction force, the outer race 840. The outer diameter and width of the inner race 820 are made large to ensure sufficient capacity, and the wall portion of the transmission case that engages the outer race 840 is also selected to have high rigidity.

In the present invention, the piston 8 that operates the fourth clutch 14 utilizes an inner race having a large diameter and width.
80 are arranged rationally. That is, as mentioned above,
Since the fourth clutch 14 only requires a relatively small torque capacity, the piston to be operated may also be small. Therefore, an outer peripheral part 884 and an inner peripheral part 882 forming the pressure receiving part of the piston 880
The outer diameter of the outer circumferential portion 884 is made smaller than the entire outer diameter of the piston 880, so that the outer circumferential portion 884 protrudes toward the inner race 820 of the third one-way clutch 33. Inner race 820 of third one-way clutch 33
has an outer diameter smaller than the outer diameter of the clutch drum 830 of the fourth clutch 14, and the inner cylinder 8
00 through a wall portion 806. Therefore,
An undercut portion 82 is formed on the side wall portion of this inner race 820.
2, and the inner circumferential surface 824 of this undercut portion 822
A hydraulic cylinder is formed between the inner cylinder 800 and the outer peripheral surface 802 of the inner cylinder 800. Then, the outer peripheral portion 8 of the piston 880
84 and the inner peripheral portion 882 are inserted into this hydraulic cylinder to form a hydraulic chamber 890 between it and the side wall portion of the inner race 820. Since the piston 880 is inserted into the hydraulic chamber 890 using the undercut portion 822 formed in the inner race 820, the axial dimension can be shortened.

Hydraulic pressure is supplied to the hydraulic chamber 890 through an annular oil passage 350a that communicates with an oil passage provided in the rear support member 350, but the outer diameter of the outer peripheral portion 884 of the pressure receiving portion of the piston 880 is small. The centrifugal oil pressure generated by the rotation is also reduced, and the piston 880 can be reliably returned to its original position only by the return spring 886 provided between the inner cylinder 800 and the inner cylinder 800 without the need for a check valve for discharging residual pressure.

In addition, an inner cylinder 800 in which a piston 880 is disposed
The inner cylinder 800 maintains a non-rotating state from 1st to 3rd gear, and when shifting from 3rd to 4th gear, operates the piston and engages the fourth clutch 14, which causes the inner cylinder 800 to start rotating. When the inner cylinder 800 is in a non-rotating state, hydraulic pressure can be supplied from the rear support member 350, which is a fixed member, and reliable hydraulic control can be achieved.

[Effects of the Invention] As described above, the present invention extends the inner cylinder of a clutch connected to the sun gear of a planetary gear set to integrally form an inner race of a one-way clutch, and an undercut portion is formed on the side wall of the inner race. This undercut is used to locate the hydraulic chamber of the piston that operates the clutch, allowing for a rational arrangement of a one-way clutch with a large torque capacity and a clutch with a relatively small torque capacity. I can do it,
The axial dimension can be shortened.

In addition, the inner cylinder of the clutch drum and the inner race of the one-way clutch are manufactured integrally with one member.
It has high machining accuracy and improves concentricity, so smooth gear shifting can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an automatic transmission embodying the present invention. Figure 2 is an explanatory diagram showing the skeleton, Figure 3 is an explanatory diagram showing the power transmission path in 1st gear, Figure 4 is an explanatory diagram showing the power transmission path in 2nd gear, and Figure 5 is an explanatory diagram showing the power transmission path in 3rd gear. FIG. 6 is an explanatory diagram showing the power transmission path when the vehicle is in 4th gear, and FIG. be. 1... Automatic transmission, 2... Starting device, 3... Transmission, 14... Fourth clutch, 33... Third one-way clutch, 131...
... Sun gear of the third row simple planetary gear set, 800 ... Inner cylinder, 820 ... Inner race. 822...Undercut part, 830...Clutch drum, 840...Outer race. 880...Piston, 890...Hydraulic chamber. Patent author Masaaki Suzuki, patent attorney (two others)

Claims (1)

[Claims] (1) In an automatic transmission equipped with a starting device and a planetary gear device, an inner cylinder is connected at one end to the sun gear of the planetary gear, and a wall portion that extends outward in the radial direction is connected to the other end of the inner cylinder. The inner race of the one-way clutch is formed into a stepped cylindrical shape, the outer race of the one-way clutch is disposed opposite to the inner race, and its outer periphery is locked to the inner peripheral wall of the case of the automatic transmission. The directional clutch includes a clutch drum mounted opposite to the inner cylinder via a wall extending radially outward from an end of the inner race of the directional clutch, a clutch disposed inside the clutch drum, and a piston for operating the clutch, An automatic transmission characterized in that a hydraulic chamber is formed by an undercut portion formed in the side wall portion of the inner race and a pressure receiving portion of a piston inserted between the inner periphery of the undercut portion and the outer periphery of the inner cylinder. Arrangement structure of frictional engagement elements of the machine.