JPH0125802Y2 - - Google Patents

Description

[Detailed explanation of the idea]

(Field of Industrial Application) The present invention relates to a power transmission device for an automatic transmission for an automobile. (Prior Art) When the automobile is of a front engine/front drive type, for example, it is advantageous to arrange an automatic transmission for an automobile so that its central axis extends in the width direction of the vehicle. However, since there is a limit to the width of a vehicle, it is desirable that the axial length of an automatic transmission be as short as possible, and for this reason, various proposals have been made to shorten the axial length. For example, Japanese Utility Model Publication No. 55-48836 proposes a clutch device for an automatic transmission in which the outer race of a one-way clutch is stepped and this portion constitutes a stopper for the one-way clutch. (Purpose of the invention) This invention has a more compact structure than the conventional device.
Another object of the present invention is to provide a power transmission device for an automatic transmission for an automobile, which can shorten the shaft length. (Structure of the invention) The power transmission device for an automatic transmission for an automobile of the invention is such that power transmission between a first member and a second member of the automatic transmission is performed between friction plates that are spline-fitted to a clutch drum. An automatic transmission for an automobile, comprising a one-way clutch disposed between one of the first member or the second member and a friction plate, the friction fastening device being intermittent by fastening or releasing the clutch. In the power transmission device, one of the outer race and the inner race of the one-way clutch, which is connected to the friction plate, is extended to a side of the one-way clutch to form an extension part, and an inner race of the one-way clutch is provided with an extension part. The lever constitutes a stopper for the one-way clutch, and a needle bearing is disposed between the extension and a power transmission component adjacent to the extension, and the outer surface of the extension is used as one contact surface of the needle bearing. It is characterized by the following structure. (Effect of the invention) In the power transmission device for an automatic transmission for automobiles having the above structure, the edge of the outer or inner race of the one-way clutch is extended to the side of the one-way clutch to form an extension part, and this extension The inner surface of the part acts as a stopper for the one-way clutch, and the outer surface acts as a contact surface for the needle bearing, so the number of parts is reduced, resulting in a compact structure and reduced assembly man-hours. is reduced, and the axial length can be shortened, which in turn allows the axial length of the automatic transmission to be shortened. (Embodiment) Hereinafter, a power transmission device for an automatic transmission for an automobile according to a preferred embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a schematic diagram showing an automatic transmission for an automobile incorporating a power transmission device according to an embodiment of the present invention. In FIG. 1, reference numeral 1 indicates a crankshaft of an engine (not shown) which is an input shaft, and a torque converter 2 and a multi-speed gearing device 10 are arranged coaxially with this crankshaft 1 in order from the engine side. . The torque converter 2 includes a pump 3, a turbine 4, and a stator 5,
The pump 3 is fixed to the crankshaft 1. The stator 5 is connected to a fixed shaft 7 integrally connected to the case 11 of the multi-speed gearing device 10 via a one-way clutch 6.
rotate on top. The one-way clutch 6 allows the stator 5 to rotate in the same direction as the pump 3, but does not allow it to rotate in the opposite direction. The multi-speed gear device 10 has a base end fixed to the crankshaft 1 and a distal end extending through the center of the multi-speed gear device to drive an oil pump P disposed on the side wall of the device. It has a central shaft 12 connected to the pump. On the outside of this central shaft 12, a hollow turbine whose base end is connected to the turbine 4 of the torque converter 2, whose distal end extends to the side wall of the multi-speed gear unit 10, and is rotatably supported by the side wall. A shaft 13 is provided. A Ravigneau type planetary gear unit 14 is provided on the turbine shaft 13, and this planetary gear unit 14 is connected to a small diameter sun gear 15, and a large diameter sun gear 1 disposed on the side of the small diameter sun gear 15 far from the engine.
6, a long pinion gear 17, a short pinion gear 18, and a ring gear 19.
First and second clutch devices 20 and 21 are arranged in parallel on the side of the planetary gear unit 14 that is far from the engine. The first clutch device 20 connects and disconnects power transmission between the small diameter sun gear 15 and the turbine shaft 13 via the first one-way clutch 22. On the other hand, the second clutch device 21 is connected in parallel with the first clutch device 20 to connect and disconnect power transmission between the small diameter sun gear 15 and the turbine shaft 13. A first brake device 2 is disposed radially outwardly of the second clutch device 21.
3 is placed. This first brake device 2
3 is a band brake, which includes a brake drum 23a connected to the large-diameter sun gear 16 and a brake band 23b hung on the brake drum.
has. radially outward of the first clutch device 20 and the first brake device 2
A third clutch device 24 is disposed on the side of the first brake device 23, and this third clutch device 24 is connected to the brake drum 23a of the first brake device 23.
The power transmission between the large-diameter sun gear 16 and the turbine shaft 13 is switched on and off through the . A carrier 14a of the planetary gear unit 14 and a case 10a of the multi-speed gear device 10 are arranged radially outwardly of the planetary gear unit 14.
A second brake device 25 is arranged to engage and disengage the. The first and second brake devices 23
and 25, a second one-way clutch device 26 is disposed in parallel with the second brake device 25 for engaging and disengaging the carrier 14a and the case 10a. On the side of the planetary gear unit 14 on the engine side, a carrier 14a of the planetary gear unit and the turbine shaft 13 are arranged.
a fourth clutch device 2 for intermittent power transmission between
7 is placed. This fourth clutch device 2
An output gear 28 connected to a ring gear 19 is arranged on the side of the engine 7 on the engine side. In addition, the reference numeral 29 in the figure indicates the turbine shaft 1.
3 shows a lock-up clutch for directly connecting the crankshaft 1 to the crankshaft 1 without going through the torque converter 2. Next, with reference to FIG. 2, the structure of each of the above-mentioned devices constituting the automatic transmission will be explained. Second Clutch Device 21 This second clutch device 21 is spline-coupled to the turbine shaft 13 and includes a clutch drum 21b that is integrally supported by a support portion 21a having a substantially U-shaped cross section. . A clutch hub 21 is located inside the clutch drum 21b.
c is arranged, and this clutch hub 21c is
It is integrally supported by a support portion 21d spline-coupled to the small diameter sun gear 15. The clutch drum 21b and the clutch hub 21c each support alternately arranged clutch disks 21e. A piston 21f, which has a shape corresponding to the contour of the inner wall of the support part 21 and has a substantially U-shaped cross section, is fitted inside the support part 21a.
A hydraulic oil chamber 21g is formed between the piston 21f and the support body 21a.
By controlling the supply of hydraulic oil to 1g,
The second clutch device 21 is engaged or disengaged by pushing or releasing the clutch disk 21e. As is clear from the figure, the base of the support portion 21d of the clutch hub 21c constitutes the inner race of the first one-way clutch 22. First clutch device 20 Piston 21f of the second clutch device 21
serves also as the clutch drum 20a of the first clutch device 20 and a support portion 20b that integrally supports the clutch drum 20a. A clutch hub 20c is disposed inside the clutch drum 20a, and the base of the clutch hub 20c is integrally supported by a support portion 20d that constitutes the outer race of the one-way clutch 22. The clutch drum 20a and the clutch hub 20c each support alternately arranged clutch disks 20e. A piston 20f is fitted inside the support portion 20b, and a hydraulic oil chamber 20g is formed between the piston 20f and the support portion 20b. By controlling the supply of hydraulic oil to the hydraulic oil chamber 20g, the clutch disk 20e is pushed or released, and the first clutch device 20 is engaged or disengaged. In the figure, 20h indicates a return spring for the pistons 20f, 21f of the first and second clutch devices 20, 21. Third clutch device 24 This third clutch device 24 is connected to the support portion 2.
A substantially inverted L-shaped support portion 24a that is integral with 1a.
clutch drum 24 integrally supported by
It is equipped with b. A clutch hub 24c is arranged inside and opposite the clutch drum 24b, and the clutch hub 24c is formed by an extension of the brake drum 23a of the first brake device 23. Clutch drum 24b and clutch hub 24c each support alternating brake discs 24d.
A piston 24e is fitted inside the support portion 24a, and the piston 24e and the support portion 24a
A hydraulic oil chamber 24f is formed between them. By controlling the supply of hydraulic oil to the hydraulic oil chamber 24f, the clutch disc 24d is pressed or released, and the third clutch device 20
It is designed to engage and disengage. This third clutch device 24 includes a diaphragm type return spring 24 for the piston 24e.
It is equipped with g. The reason why a diaphragm type return spring is used in this third clutch device 24 is that this diaphragm type is thin and does not require a large space. Fourth clutch device 27 This fourth clutch device 27 is spline-coupled to the turbine shaft 13 and includes a clutch drum 27b that is integrally supported by a support portion 27a having a substantially inverted U-shaped cross section. There is. Inside this clutch drum 27b, a clutch hub 2
7c is arranged, and this clutch hub 27c
is the carrier 14 of the planetary gear unit 14
It is supported by a. The above clutch drum 27b
The clutch hubs 27c and 27c each support alternately arranged brake discs 27d. A piston 27e formed by sheet metal processing is fitted inside the support portion 27a. A hydraulic oil chamber 27 is located between the piston 27e and the support portion 27a.
By controlling the supply of hydraulic oil to the hydraulic oil chamber 27f, the clutch disc 27d is pressed or released.
The fourth clutch device 27 is engaged and disengaged. This fourth clutch is also provided with a diaphragm type return spring 27g, similar to the third clutch device 24 described above. First Brake Device 23 The brake drum 23a of the first brake device 23 is supported by a support portion 23c that is integrally supported by the large diameter sun gear 16. Therefore, when this first brake device 23 is activated,
The large diameter sun gear 16 is fixed. Second brake device 25 This second brake device 25 is a disc type brake, and its brake drum 25a
is the carrier 14a of the planetary gear unit 14.
It is supported by a support portion 25b that is integrally fixed to the support portion 25b. Therefore, this second brake device 2
3 is activated, the carrier 14a is fixed. First one-way clutch 22 This one-way clutch 22 has an outer race 22a as shown in FIGS. 3 and 4.
and an inner lace 22b, and an outer lace 2
One end of 2a is connected to the one-way clutch 22
The stopper 22c extends to the side of the stopper 22c. Further, the outer surface of this stopper 22c is connected to the clutch drum 21b of the second clutch device 21.
This constitutes one abutment surface 22d of the needle bearing NB, which is disposed between the needle bearing NB and the support portion 21a of the needle bearing NB. Functions of the multi-speed gear device 10 The multi-speed gear device 10 having the structure described above has the following features:
It has four forward speeds and one reverse speed.
First, second, third and fourth clutch devices 2
0, 21, 24 and 27, and the first and second brake devices 23 and 25, a desired gear stage can be obtained.
In the above configuration, the operational relationship between each gear stage, clutch, and brake is shown in the table below.

[Table] Hereinafter, the functions of the first and second one-way clutches 22 and 26 will be explained. Second one-way clutch 26 This one-way clutch 26 prevents the carrier 14a from reversing during 1st gear, and when shifting from 1 to 2 and from 2 to 2.
This serves to determine the shift timing during the first shift. As can be seen from the above table, the reverse rotation of the carrier 14a is prevented in 1st gear, and the carrier 14a is allowed to rotate forward in 2nd gear, and the large diameter sun gear 16
must be fixed. For this reason, 1-2
When changing gears, it is necessary to operate means for freeing the carrier 14 and means for fixing the large diameter sun gear 16, that is, the first brake device 23. If the means for freeing the carrier 14 is a band brake, the large diameter sun gear 16 must be fixed after first freeing the carrier 14a, resulting in a temporary neutral state and a time lag. On the other hand, when a one-way clutch is used as the above-mentioned means, as in this device, the carrier 14a becomes free and rotates forward at the moment the large-diameter sun gear 16 is fixed due to the action of the one-way clutch, so there is no time lag. It is possible to shift gears with good timing. Meanwhile, the carrier 14a rotates forward, and the ring gear 1
If the carrier 14a is fixed when shifting from the 2nd gear state in which gear 9 is rotating at the 2nd gear speed, the rotation of the ring gear 19 will be lower by the rotation amount of the carrier 14a than when the ring gear 19 is in the 2nd gear. try to For this reason, the carrier 14 is
If a is fixed unconditionally and all at once, a shift shock will occur. In order to prevent this shift shock, it is sufficient to wait until the engine speed increases to the first speed speed or until the vehicle speed decreases before shifting. However, timing the fixing of the carrier 14a and the release of the large-diameter sun gear 16 is extremely difficult if a band brake is used. In comparison, when a one-way clutch is used, the carrier 14a can continue to rotate at the second speed even after the large-diameter sun gear 16 is released, and only when it reaches the same speed as the ring gear 19 does the small-diameter sun gear 15 start moving. The driving force is now transmitted, and the 2-
It is possible to take the timing when shifting to 1st gear. First one-way clutch 22 This one-way clutch 22 functions to determine the shift timing when shifting from 3 to 4 and when shifting from 4 to 3. As can be seen from the above table, in the third gear, the clutch devices 21 and 27 are engaged and rotate together, while the clutch devices 21 and 27 are engaged and rotate together.
At high speed, the clutch 21 must be released, the small diameter sun gear 15 must rotate at an increased speed, and the large diameter sun gear 16 must be fixed. Under these conditions 3→4
When changing gears, if only a normal clutch is used, a neutral state is required temporarily, but if a one-way clutch is used, just by fixing the large diameter sun gear 16, the small diameter sun gear 15 will speed up from that moment. Therefore, there is no time lag, and the 3rd to 4th gear shift can be performed with accurate timing. On the other hand, in 4th gear, the small diameter sun gear 15 is rotating at an increased speed, so in order to shift from 4th gear to 3rd gear, the engine rotation speed (input rotation) must increase or
Alternatively, it is necessary to wait until the rotation (output rotation) of the ring gear 19 decreases before fixing the small diameter sun gear 15. It is difficult to obtain this timing with a normal clutch, but by using a one-way clutch, when the input rotation and the rotation of the small diameter sun gear 15 match, the driving force from the input side can be automatically transmitted, resulting in a good timing. You can change gears at the right time.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram illustrating the basic configuration of a power transmission device for an automobile according to an embodiment of the present invention, and FIG. 2 is an axial cross-section showing the structure of the multi-speed gear device shown in FIG. 1 in detail. 3 is an enlarged sectional view of the clutch device shown in FIG. 2, and FIG. 4 is an enlarged sectional view of the clutch device shown in FIG.
FIG. 3 is an enlarged sectional view showing only the main parts of the clutch device shown in the figure. 22...First one-way clutch, 22a...
Outer lace, 22b... Inner lace, 22c
... Stopper, 22d... Contact surface, NB... Needle bearing.

Claims (1)

[Scope of utility model registration request] A friction coupling device is provided in which power transmission between the first member and the second member of the automatic transmission is interrupted by coupling or disengaging friction plates spline-fitted to the clutch drum. In a power transmission device for an automatic transmission for an automobile, comprising a one-way clutch disposed between a member or a second member and a friction plate, the friction plate of an outer race and an inner race of the one-way clutch. one of the sides connected to the one-way clutch extends to the side of the one-way clutch to form an extension;
The inner surface of the extension constitutes a stopper for the one-way clutch, and a needle bearing is disposed between the extension and a power transmission component adjacent to the extension. A power transmission device for an automatic transmission for an automobile, characterized in that it is configured as one contact surface of a bearing.