JP7005353B2 - Stepped transmission - Google Patents

Description

The present invention relates to a stepped transmission having a planetary gear mechanism connected to an input shaft.

A stepped transmission equipped with a planetary gear mechanism is known as an automatic transmission for automobiles. Such a stepped transmission is equipped with a thrust bearing that rotatably supports the components of the planetary gear mechanism in the axial direction.
For example, in Patent Document 1, a support plate that supports a planetary pinion, a flange that supports a ring gear, and another hollow shaft member are arranged in this order on the outside of one end of the sun gear of the planetary gear mechanism, and the end surface of the sun gear is arranged. Disclosed are structures in which thrust bearings are arranged between the support plate and the support plate, between the support plate and the ring gear, and between the flange and the end face of the hollow shaft member.

Jitsukaisho 62-174149 Gazette

By the way, in the case of a front-wheel drive vehicle, the engine and the transmission are installed horizontally in the limited space in the width direction of the vehicle. In this case, the layout requires that the axial length of the transmission be as short as possible. On the other hand, as the number of stepped transmissions increases, the number of planetary gear mechanisms used in the transmission increases, and when these are arranged in series along the input shaft, the axial length of the transmission increases. It will increase. Therefore, in order to install such a transmission horizontally, it is necessary to devise a method of keeping the axial length of the transmission short.

The present invention has been devised focusing on such a problem, and an object of the present invention is to make it possible to keep the axial length short in a stepped transmission provided with a planetary gear mechanism.

(1) In order to achieve the above object, the stepped transmission of the present invention is a stepped transmission provided with an input shaft and a planetary gear mechanism driven and connected to the input shaft, and is the planet. The carrier of the gear mechanism is provided with an axial center side extension portion on one of the two support plates that pivotally support the planetary pinion, and both sides of the axial center side extension portion are provided with a first thrust bearing in the axial direction. The ring gears of the planetary gear mechanism are arranged between the outer peripheral side extension portions provided on the both support plates, respectively, and each end surface of the ring gear and each outer peripheral side of the both support plates facing the end faces thereof. A support plate body whose outer diameter is smaller than the inner diameter of the ring gear and its support are axially supported by a second thrust bearing interposed between the extension portion and one of the two outer peripheral side extension portions. It is characterized by being composed of two members, an extension member integrally connected to the outer periphery of the plate body .

( 2 ) It is preferable that an output member is connected to the extension member.

( 3 ) It is preferable that the one support plate provided with the axial center side extension portion is composed of one member.

According to the present invention, the ring gear of the planetary gear mechanism is axially supported by a second thrust bearing interposed between the outer peripheral extension portions of the two support plates, so that the shaft of the stepped transmission is supported. The direction length can be shortened.

It is a schematic cross-sectional view which shows the main part of the stepped transmission which concerns on one Embodiment of this invention, (a) shows this embodiment, (b) shows the comparative example. It is a block diagram which shows the power train of the vehicle which concerns on one Embodiment of this invention. It is a schematic sectional drawing which shows the structural example of the whole mechanism of the stepped transmission which concerns on one Embodiment of this invention. It is a fastening operation table of each friction engagement element for each shift stage of the automatic transmission shown in FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted that the embodiments shown below are merely examples, and there is no intention of excluding the application of various modifications and techniques not specified in the following embodiments. Each configuration of the following embodiments can be variously modified and implemented without departing from the purpose thereof, and can be selected as necessary or combined as appropriate.

[1. Powertrain configuration]
As shown in FIG. 2, the power train of the automobile (hereinafter referred to as a vehicle) according to the present embodiment includes an engine 1 as a drive source, a torque converter 2 with a lockup clutch, and a stepped automatic transmission mechanism (hereinafter referred to as a stepped automatic transmission mechanism). It is equipped with an automatic transmission 4 composed of (referred to as a transmission) 3, a reduction mechanism 5 provided between an output unit (output gear) of the automatic transmission 4 and a drive wheel 7, and a power transmission mechanism composed of a differential 6. .. The engine 1 and the automatic transmission 4 are arranged in series along the vehicle width direction (left-right direction in the figure).

The stepped transmission 3 is coupled to the engine 1 via a torque converter 2 with a lockup clutch, includes various friction engagement elements (clutch or brake), and engages or disengages these friction engagement elements. Thereby, each shift stage is achieved. The engagement or disengagement of various friction engagement elements and the engagement state of the lockup clutch of the torque converter 2 are controlled by controlling the required solenoid valve or the like provided in the hydraulic circuit unit (not shown) to switch the oil supply state. Do it. Further, the hydraulic circuit unit is controlled by an automatic transmission controller (not shown) according to the traveling state of the vehicle.

[2. Configuration of automatic transmission]
As shown in FIG. 1A, the stepped transmission 3 has planetary gear mechanisms (planetary gear mechanisms) 33 and 34. The planetary gear mechanism 33 includes each rotating element of the sun gear 33S, the carrier 33C, and the ring gear 33R. The planetary gear mechanism 34 is also configured to include each rotating element of the sun gear 34S, the carrier 34C, and the ring gear (not shown).

The carrier 34C of the planetary gear mechanism 34 is connected to the input shaft 30A so as to rotate integrally. The output gear (output unit) 30B is connected to the carrier 33C of the planetary gear mechanism 33 via the connecting shaft 30H so as to rotate integrally. Further, the sun gear 33S of the planetary gear mechanism 33 and the sun gear 34S of the planetary gear mechanism 34 are connected so as to rotate integrally via the connecting shaft 30C. The ring gear 33R of the planetary gear mechanism 33 is connected to a friction engaging element such as a brake or a clutch (not shown) via a connecting shaft 30F, and rotation is appropriately regulated by these friction engaging elements.

Each of the rotating elements of the planetary gear mechanisms 33 and 34 is directly or indirectly supported by the transmission case or the like by the radial bearing and the thrust bearing, and each of them rotates concentrically with the input shaft 30A and at a predetermined axial position. It is designed to do. The connecting shaft 30C in which the sun gear 33S of the planetary gear mechanism 33 and the sun gear 34S of the planetary gear mechanism 34 are integrally connected is supported by the input shaft 30A or the transmission case by radial bearings and thrust bearings (not shown).

Explaining the thrust bearing of the planetary gear mechanism 33, the carrier 33C of the planetary gear mechanism 33 is provided with support plates 33C1 and 33C2 for pivotally supporting the planetary pinion 33P. Of these, one support plate (base plate) 33C2 is provided with an axial center side extension portion 33E3 extended to the axial center side, and both sides of the axial center side extension portion 33E3 are provided with first thrust bearings 41 and 42, respectively. It is supported in the axial direction between the sun gears 33S and 34S (other members may intervene).

Further, one support plate 33C2 and the other support plate (carrier plate) 33C1 are provided with outer peripheral side extension portions 33E2, 33E1 extended to the outer peripheral side, and between these outer peripheral side extension portions 33E2, 33E1. The ring gear 33R is arranged. Second thrust bearings 43, 44 are interposed between each end surface of the ring gear 33R and the outer peripheral side extension portions 33E2, 33E1 facing the end surface, and the ring gear 33R is axially connected by the second thrust bearings 43, 44. It is supported.

Further, since the support plate 33C2 is composed of one member, the outer peripheral side extension portion 33E2 of the support plate 33C2 is integrally formed with the main body portion (support plate main body) of the support plate 33C2, but the support plate 33C1 The outer peripheral side extension portion 33E1 is formed separately from the main body portion of the support plate 33C1. That is, the support plate 33C1 has a main body portion (support plate main body) whose outer diameter R2 is smaller than the inner diameter R1 of the ring gear 33R, and a radial extension portion of the connecting shaft (extension member) 30H integrally connected to the support plate main body. It is composed of two members.

[3. Action and effect]
The stepped transmission 3 according to the present embodiment is configured as described above, and the ring gear 33R is arranged between the outer peripheral side extension portions 33E2, 33E1 of the support plates 33C2, 33C1, and the second thrust bearing 43, Since it is supported in the axial direction by 44, the axial length of the stepped transmission 3 can be shortened.

FIG. 1B shows a stepped transmission 3'according to a comparative example, and in the comparative example of FIG. 1B, the member corresponding to the present embodiment shown in FIG. 1A corresponds to the member. Although the reference numerals are given, the corresponding members having the same structure as the present embodiment are given the same reference numerals, and the corresponding members having a structure different from that of the present embodiment are given the same reference numerals with dashes ('). ..

As shown in FIG. 1 (b), in the comparative example, one support plate 33C2'of the planetary gear mechanism 33'is provided with an axial center side extension portion extended to the axial center side. Further, substantially similar to that of Patent Document 1, a flange portion extending to the inner peripheral side is formed on the connecting shaft 33F'in which the ring gear 33R of the planetary gear mechanism 33 is integrally connected. The extension portion on the axial center side and the flange portion are supported in the axial direction between the sun gears 33S and 34S by thrust bearings 45 to 47. Therefore, in order to support each gear in the thrust direction, the axial space in which the plate thicknesses of the two plates of the axial center side extension portion and the flange portion and the three axial lengths of the thrust bearings 45 to 47 are added. Is required.

On the other hand, in the stepped transmission 3 according to the present embodiment, the ring gear 33R is supported via the support plates 33C2 and 33C1, and the support plates 33C2 are only supported by the first thrust bearings 41 and 42. Only the axial space in which the plate thickness of one plate of the side extension 33E3 and the two axial lengths of the first thrust bearings 41 and 42 are added is sufficient, and the number of plates and the thrust are different from those of the comparative example. The axial length can be shortened by the amount that the number of bearings is reduced (length L).

As shown in FIG. 2, in a front-wheel drive vehicle, when the engine 1 and the stepped transmission 3 are arranged horizontally with respect to the vehicle, the main part of the power train is in the limited space between the left and right front wheels. If the axial length is large as in the stepped transmission 3'in the comparative example, the arrangement becomes difficult, but in this stepped transmission 3, the axial length is shortened. Therefore, the arrangement of the main part of the power train becomes easy.

On the other hand, the outer peripheral side extension portion 33E1 of the support plate 33C1 [on the left side in FIG. 1A] has a main body portion (support plate main body) whose outer diameter R2 is smaller than the inner diameter R1 of the ring gear 33R and the support plate main body. Since it is composed of two members, that is, a connecting shaft (extension member) 30H that is integrally connected to the transmission, the assembling property of the transmission is improved.

That is, when assembling the transmission, for example, as shown by the white arrow in FIG. 1 (a), each member is moved from one end side to the other end side (in the example of FIG. 1 (a), from the left side to the right side). If you assemble while letting it assemble, you can assemble smoothly. However, it is preferable to assemble the support plates 33C2 and 33C1 and the planetary pinion 33P in advance as carrier assemblies in order to ensure quality.

In this transmission, the planetary pinion 33P is preliminarily assembled to the main body of the support plate 33C2 and the support plate 33C1 to form a carrier assembly, and this carrier assembly is moved as shown by the white arrow to the axial center side of the support plate 33C2. Assemble the extension 33E3 so that both sides are supported in the axial direction by the first thrust bearings 41 and 42, respectively. After that, the ring gear 33R is moved and assembled as shown by the white arrow.

In the state where the carrier assembly is assembled, the outer diameter R2 of the main body portion of the support plate 33C1 is smaller than the inner diameter R1 of the ring gear 33R, so that the ring gear 33R can be assembled without interference with the main body portion of the support plate 33C1. ..
After that, if the connecting shaft (extension member) 30F is moved and assembled as shown by the white arrow and connected to the main body portion of the support plate 33C1, the assembly of the planetary gear mechanism 33 can be completed.

[4. Example of overall configuration of transmission mechanism]
Here, a specific overall configuration example of the stepped transmission 3 will be described.
As shown in FIG. 3, in the stepped transmission 3, four planetary gear mechanisms of a first planetary gear mechanism 31, a second planetary gear mechanism 32, a third planetary gear mechanism 33, and a fourth planetary gear mechanism 34 are arranged coaxially in series. It has 9 forward speeds and 9 reverse speeds of the 1st to 9th speeds. Each planetary gear mechanism 31 to 34 includes sun gears 31S to 34S, carriers 31C to 34C, and ring gears 31R to 34R.

The stepped transmission 3 includes an input shaft 30A in which rotation is input from the engine via a torque converter, an output gear 30B that outputs rotation to drive wheels 7 via power transmission mechanisms 5 and 6, and a planetary gear mechanism 31 to. It includes intermediate shafts 30C and 30D that connect 34 specific elements. By selectively combining the required elements of the planetary gear mechanisms 31 to 34, the required power transmission path is configured and the corresponding shift stage is achieved.

That is, the sun gear 31S of the first planetary gear mechanism 31 and the carrier 34C of the fourth planetary gear mechanism 34 are directly coupled to the input shaft 30A of the stepped transmission 3. Therefore, the sun gear 31S of the first planetary gear mechanism 31 and the carrier 34C of the fourth planetary gear mechanism 34 always rotate integrally with the input shaft 30A.

Further, the connecting shaft 30I is coupled to the input shaft 30A of the stepped transmission 3 so as to rotate integrally, and the connecting shaft 30J is coupled to the carrier 31C of the first planetary gear mechanism 31 so as to rotate integrally. A second clutch C2 is interposed between these connecting shafts 30I and 30J. Therefore, the input shaft 30A is connected to the carrier 31C of the first planetary gear mechanism 31 via the connecting shafts 30I and 30J and the second clutch C2.

The output gear 30B of the stepped transmission 3 is connected via a connecting shaft 30K so as to rotate integrally with the carrier 33C of the third planetary gear mechanism 33. Therefore, the carrier 33C of the third planetary gear mechanism 33 always rotates integrally with the output gear 30B. Further, the connecting shaft 30H is coupled to the carrier 33C of the third planetary gear mechanism 33 so as to rotate integrally, and the connecting shaft 30G is coupled to the ring gear 34R of the fourth planetary gear mechanism 34 so as to rotate integrally. A first clutch C1 is interposed between these connecting shafts 30H and 30G. Therefore, the output gear 30B is connected to the ring gear 34R of the fourth planetary gear mechanism 34 via the first clutch C1.

The ring gear 32R of the second planetary gear mechanism 32, the sun gear 33S of the third planetary gear mechanism 33, and the sun gear 34S of the fourth planetary gear mechanism 34 are all directly connected to the intermediate shaft 30C. Therefore, the ring gear 32R of the second planetary gear mechanism 32, the sun gear 33S of the third planetary gear mechanism 33, and the sun gear 34S of the fourth planetary gear mechanism 34 always rotate integrally.

Both the ring gear 31R of the first planetary gear mechanism 31 and the carrier 32C of the second planetary gear mechanism 32 are directly connected to the intermediate shaft 30D. Therefore, the ring gear 31R of the first planetary gear mechanism 31 and the carrier 32C of the second planetary gear mechanism 32 always rotate integrally.

A connecting shaft 30L is connected to the carrier 31C of the first planetary gear mechanism 31 so as to rotate integrally, and a third clutch C3 is interposed between the connecting shaft 30L and the intermediate shaft 30C. Therefore, the carrier 31C of the first planetary gear mechanism 31 is connected to the intermediate shaft 30C via the third clutch C3. Further, a first brake B1 is interposed between the connecting shaft 30J that rotates integrally with the carrier 31C of the first planetary gear mechanism 31 and the transmission case 3A.

Further, the connecting shaft 30E is connected to the sun gear 32S of the second planetary gear mechanism 32 so as to rotate integrally, and a third brake B3 is interposed between the connecting shaft 30E and the transmission case 3A.

Further, the connecting shaft 30F is connected to the ring gear 33R of the third planetary gear mechanism 33 so as to rotate integrally, and the second brake B2 is interposed between the connecting shaft 30F and the transmission case 3A.

In the stepped transmission 3 configured in this way, each friction engaging element such as the first clutch C1, the second clutch C2, the third clutch C3, the first brake B1, the second brake B2, and the third brake B3 Depending on the combination of fastenings, any of the 9 forward speeds and the reverse speed of the 1st to 9th speeds is achieved.

FIG. 4 is a fastening operation table showing the fastening state of each friction engaging element for each shift stage of the stepped transmission 3. In FIG. 4, a circle indicates that the friction engaging element is in the fastened state, and a blank indicates that the friction engaging element is in the released state. The number of stages 1 to 9 indicates the first forward speed to the ninth speed, and the Rev of the number of stages indicates the reverse stage.

As shown in FIG. 4, in order to achieve the first speed, the second brake B2, the third brake B3, and the third clutch C3 are engaged, and the other friction engaging elements are released. To achieve the second speed, the second brake B2, the second clutch C2, and the third clutch C3 are engaged, and the other friction engaging elements are released. To achieve the third speed, the second brake B2, the third brake B3, and the second clutch C2 are engaged, and the other friction engaging elements are released.

To achieve the fourth speed, the second brake B2, the third brake B3, and the first clutch C1 are engaged, and the other friction engaging elements are released. To achieve the fifth speed, the third brake B3, the first clutch C1 and the second clutch C2 are engaged, and the other friction engaging elements are released. To achieve the sixth speed, the first clutch C1, the second clutch C2, and the third clutch C3 are engaged, and the other friction engaging elements are released.

Further, in order to achieve the 7th speed, the 3rd brake B3, the 1st clutch C1 and the 3rd clutch C3 are engaged, and the other friction engaging elements are released. To achieve the eighth speed, the first brake B1, the first clutch C1 and the third clutch C3 are engaged, and the other friction engaging elements are released. To achieve the ninth speed, the first brake B1, the third brake B3, and the first clutch C1 are engaged, and the other friction engaging elements are released. To achieve the reverse stage, the first brake B1, the second brake B2, and the third brake B3 are fastened, and the other friction engaging elements are released.

It should be noted that the automatic transmission controller performs shift control by engaging and disengaging each friction engaging element of the stepped transmission 3. The automatic transmission controller determines the shift (switching of the shift stage) based on the vehicle information such as the accelerator opening, the sensor, and the engine speed, and controls the hydraulic circuit unit to control each friction engagement element (C1 to Engage and disengage C3, B1 to B3).

[5. Others] Although the embodiments of the present invention have been described above, the stepped transmission according to the present invention can be implemented by appropriately modifying the above embodiments without departing from the spirit of the present invention.
For example, the arrangement configuration of the thrust bearing that supports the ring gear of the planetary gear mechanism in the axial direction of the present invention can be widely applied to a stepped transmission configured with the planetary gear mechanism.

Further, in the above embodiment, the case where the present invention is applied to a stepped transmission composed of two planetary gear mechanisms 33 and 34 is shown, but the present invention is not limited to this, and the present invention is not limited to this, and a large number of three or more planetary gears. Needless to say, it can be applied to a stepped transmission having a mechanism and achieving a larger number of gears.

1 Engine (drive source)
2 Torque converter 3 Stepped transmission (stepped automatic transmission mechanism)
4 Automatic transmission 5 Deceleration mechanism 6 Differential 7 Drive wheel 30A Input shaft 30B Output gear 30C, 30D Intermediate shaft 30E to 30L Connecting shaft 31 to 34 1st to 4th Planetary gear mechanism 31C to 34C Carrier 31R to 34R Ring gear 31S to 34S Sun gear 33C1 , 33C2 Support plate 33E1, 33E2 Outer peripheral side extension 33E3 Axial center side extension 41,42 1st thrust bearing 43,44 2nd thrust bearing B1 to B3 Brake (friction engagement element)
C1 to C3 clutch (friction engagement element)
R1 Inner diameter of ring gear 33R R2 Outer diameter of main body of support plate 33C1 (support plate main body)

Claims (3)

A stepped transmission having an input shaft and a planetary gear mechanism driven and connected to the input shaft.
The carrier of the planetary gear mechanism is provided with an axial center side extension portion on one of the two support plates that pivotally support the planetary pinion, and both sides of the axial center side extension portion are each provided with a first thrust bearing. Axialally supported,
The ring gear of the planetary gear mechanism is arranged between the outer peripheral side extension portions provided on the two support plates, respectively, and the end faces of the ring gear and the outer peripheral side extension portions of both support plates facing the end faces thereof. Axialally supported by a second thrust bearing intervened between
One of the extension portions on both outer peripheral sides is composed of two members, a support plate body having an outer diameter smaller than the inner diameter of the ring gear, and an extension member integrally connected to the outer periphery of the support plate body. A stepped transmission characterized by being . The stepped transmission according to claim 1 , wherein an output member is connected to the extension member. The stepped transmission according to claim 2 , wherein the one support plate provided with the axial center side extension portion is composed of one member.

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