JP2019124251A - Stepped transmission - Google Patents

Abstract

To reduce an axial length in a stepped transmission including a planetary gear mechanism.SOLUTION: A stepped transmission includes an input shaft 30A, and planetary gear mechanisms 33, 34 connected to the input shaft 30A. A carrier 33C of the planetary gear mechanism 33 is provided with a shaft center-side extention portion 33E3 on one supporting plate 33C2 of both supporting plates 33C1, 33C2 journaling a planetary pinion 33P, both surfaces of the shaft center-side extension portion 33E3 are axially supported by first thrust bearings 41, 42, and a ring gear 33R of the planetary gear mechanism 33 is disposed between outer periphery-side extension portions 33E1, 33E2 respectively disposed on both supporting plates 33C1, 33C2, and axially supported by second thrust bearings 43, 44 respectively disposed between each end face of the ring gear 33R and each of the outer periphery-side extension portions 33E1, 33E2 opposed thereto.SELECTED DRAWING: Figure 1

Description

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

A stepped transmission provided 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 for supporting a planetary pinion on the outside of one end of a sun gear of a planetary gear mechanism, a flange for supporting a ring gear, and another hollow shaft member are arranged in this order to There is disclosed a structure in which thrust bearings are disposed 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.

Japanese Utility Model Publication No. 62-174149

  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 vehicle width direction of the vehicle. In this case, in terms of layout, it is required to shorten the axial length of the transmission as much as possible. On the other hand, the number of planetary gear mechanisms used for the transmission increases with the progress of multistage geared transmission, and when these are arranged in series along the input shaft, the axial length of the transmission becomes It will increase. For this reason, in order to horizontally install such a transmission, it is necessary to devise a method for reducing the axial length of the transmission.

  The present invention has been made in view of such problems, and it is an object of the present invention to make it possible to shorten the axial length in a stepped transmission provided with a planetary gear mechanism.

  (1) In order to achieve the above object, a stepped transmission according to the present invention is a stepped transmission including an input shaft and a planetary gear mechanism drivingly connected to the input shaft, the planetary The carrier of the gear mechanism is provided with an axial extension on one of the two support plates for supporting the planetary pinion, and the axial extension of each of the axial extensions is made by the first thrust bearing. And the ring gear of the planetary gear mechanism is disposed between the outer peripheral extensions respectively provided on the two support plates, and the respective end faces of the ring gear and the respective outer peripheral sides of the two support plates opposed thereto. It is characterized in that it is axially supported by a second thrust bearing interposed between the extension and the extension.

  (2) One of the two outer peripheral extensions has two members, a support plate main body whose outer diameter is smaller than the inner diameter of the ring gear, and an extension member integrally connected to the outer peripheral side of the support plate main body It is preferable to be composed of

  (3) Preferably, an output member is connected to the extension member.

  (4) It is preferable that the one support plate provided with the axial center side extension part is configured by one member.

  According to the present invention, since the ring gear of the planetary gear mechanism is axially supported by the second thrust bearing interposed between the outer peripheral extensions of the two support plates, the shaft of the geared transmission is obtained. The direction length can be shortened.

It is a typical sectional view showing an important section of a stepped transmission concerning one embodiment of the present invention, (a) shows this embodiment, (b) shows the comparative example. It is a block diagram showing the powertrain of the vehicle concerning one embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic cross section which shows the structural example of the whole mechanism of the stepped transmission concerning one Embodiment of this invention. It is a fastening operation table | surface of each friction engagement element for every gear stage of the automatic transmission shown in FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the embodiments described below are merely illustrative, and there is no intention to exclude the application of various modifications and techniques that are not specified in the following embodiments. The configurations of the following embodiments can be variously modified and implemented without departing from the scope of the invention, and can be selected or combined as appropriate.

[1. Power Train Configuration]
As shown in FIG. 2, the powertrain of a car (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 stepped It has an automatic transmission 4 consisting of a transmission 3, a power transmission mechanism consisting of a reduction mechanism 5 provided between an output (output gear) of the automatic transmission 4 and the drive wheels 7 and a differential 6. . The engine 1 and the automatic transmission 4 are arranged in series along the vehicle width direction (left and right direction in the figure).

  The stepped transmission 3 is coupled to the engine 1 via a torque converter 2 having a lockup clutch, and includes various frictional engagement elements (clutch or brake), and engages or releases these frictional engagement elements. Thus, each gear is achieved. The engagement or disengagement of various frictional engagement elements and the engagement state of the lockup clutch of the torque converter 2 are controlled by switching the oil supply state by controlling a required solenoid valve or the like provided in the hydraulic circuit unit (not shown). Do. 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 a planetary gear mechanism (planet gear mechanism) 33,. The planetary gear mechanism 33 is configured to include rotating elements such as a sun gear 33S, a carrier 33C, and a ring gear 33R. The planetary gear mechanism 34 is also configured to include rotating elements such as a sun gear 34S, a carrier 34C, and a ring gear (not shown).

  The carrier 34C of the planetary gear mechanism 34 is coupled to the input shaft 30A so as to rotate integrally. An output gear (output unit) 30B is coupled to a carrier 33C of the planetary gear mechanism 33 via a coupling 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 to rotate integrally with each other via a connecting shaft 30C. The ring gear 33R of the planetary gear mechanism 33 is connected to a friction engagement element such as a brake or a clutch (not shown) via a connection shaft 30F, and rotation of the ring gear 33R is appropriately restricted by these friction engagement elements.

  Each rotating element of the planetary gear mechanism 33, 34 is directly or indirectly supported by the radial bearing and the thrust bearing on the transmission case etc., and each rotates concentrically with the input shaft 30A at a predetermined axial position. It is supposed to A connecting shaft 30C in which a sun gear 33S of the planetary gear mechanism 33 and a 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.

  The thrust bearing of the planetary gear mechanism 33 will be described. The carrier 33C of the planetary gear mechanism 33 is provided with support plates 33C1 and 33C2 for pivotally supporting the planetary pinion 33P. Among them, one support plate (base plate) 33C2 is provided with an axial extension 33E3 extended to the axial side, and both surfaces of the axial extension 33E3 are respectively provided by the first thrust bearings 41 and 42. It is axially supported between the sun gears 33S and 34S (other members may be interposed).

  Further, on the one support plate 33C2 and the other support plate (carrier plate) 33C1, outer peripheral side extending portions 33E2 and 33E1 extended to the outer peripheral side are provided, and between the outer peripheral side extending portions 33E2 and 33E1 Ring gear 33R is arranged. Second thrust bearings 43 and 44 are interposed between the respective end faces of the ring gear 33R and the respective outer peripheral side extensions 33E2 and 33E1, and the ring gear 33R is axially moved by the second thrust bearings 43 and 44. It is supported.

  Further, since the support plate 33C2 is configured by 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 extension 33E1 is formed separately from the main body 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 of a connecting shaft (extension member) 30H integrally coupled with the support plate main body It consists 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 disposed between the outer peripheral side extension portions 33E2 and 33E1 of the support plates 33C2 and 33C1, and the second thrust bearing 43, Since the shaft 44 is supported in the axial direction, the axial length of the stepped transmission 3 can be shortened.

  FIG. 1 (b) shows a stepped transmission 3 'according to a comparative example, and in the comparative example of FIG. 1 (b), corresponding members corresponding to the present embodiment shown in FIG. 1 (a) Although the reference numerals are given, the corresponding members having the same structure as that of 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 a dash (') .

  As shown in FIG. 1B, in the comparative example, an axial center side extension portion extended to the axial center side is provided on one support plate 33C2 'of the planetary gear mechanism 33'. Further, substantially in the same manner as in Patent Document 1, a flange portion extending to the inner peripheral side is formed on a connecting shaft 33F 'to which the ring gear 33R of the planetary gear mechanism 33 is integrally connected. The axial center extension and the flange are axially supported between the sun gears 33S and 34S by thrust bearings 45-47. Therefore, in order to support each gear in the thrust direction, an axial space in which the plate thickness of the two plates of the axial center side extension 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 plate 33C2 is supported by the first thrust bearings 41 and 42. Only the axial space obtained by adding the plate thickness of one plate of the side extension 33E3 and the two axial lengths of the first thrust bearings 41 and 42 may be sufficient. The axial length can be shortened by the reduction in the number of bearings (length L).

  As shown in FIG. 2, in a front wheel drive vehicle, when the engine 1 and the stepped transmission 3 are disposed transverse to the vehicle, the main part of the power train in the limited space between the left and right front wheels However, if the axial length is large, as in the case of the stepped transmission 3 'of the comparative example, the placement becomes difficult, but in the main stepped transmission 3, the axial length is shortened. Therefore, the arrangement of the main part of the power train becomes easy.

  The outer peripheral extension 33E1 of the support plate 33C1 on one side (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 comprised from two members with the connecting shaft (extension member) 30H integrally connected with these, the assemblability of a transmission improves.

  That is, when assembling the transmission, for example, as shown by a white arrow in FIG. 1A, each member is moved from one end to the other end (from the left to the right in the example of FIG. 1A). If the assembly is done while assembling, the assembly can be carried out smoothly. However, the support plates 33C2 and 33C1 and the planetary pinions 33P are preferably assembled in advance as a carrier assembly from the viewpoint of quality assurance.

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

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 the ring gear 33R can be assembled without interference without interference with the main body portion of the support plate 33C1. .
Thereafter, the connection shaft (extension member) 30F is moved as shown by the white arrow, assembled, and connected to the main body portion of the support plate 33C1, whereby 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 main stepped transmission 3 will be described.
As shown in FIG. 3, in the geared 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 coaxially arranged in series. It has nine forward first and ninth forward gears and a reverse gear. Each of the planetary gear mechanisms 31 to 34 includes sun gears 31S to 34S, carriers 31C to 34C, and ring gears 31R to 34R.

  The geared transmission 3 includes an input shaft 30A to which rotation is input from the engine via a torque converter, an output gear 30B for outputting rotation to the drive wheels 7 via power transmission mechanisms 5 and 6, and planetary gear mechanisms 31 to Intermediate shafts 30C and 30D are provided to connect between the 34 specific elements. By selectively combining the required elements of each of the planetary gear mechanisms 31 to 34, the required power transmission path is configured and the corresponding gear 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 carrier 31C of the first planetary gear mechanism 31 is coupled to rotate the connecting shaft 30J integrally. A second clutch C2 is interposed between the 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 connection shafts 30I and 30J and the second clutch C2.

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

  The ring gear 31R of the first planetary gear mechanism 31 and the carrier 32C of the second planetary gear mechanism 32 are both 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 coupling shaft 30L is coupled 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 coupling shaft 30L and the intermediate shaft 30C. Accordingly, the carrier 31C of the first planetary gear mechanism 31 is coupled to the intermediate shaft 30C via the third clutch C3. Furthermore, a first brake B1 is interposed between the transmission case 3A and a connecting shaft 30J that rotates integrally with the carrier 31C of the first planetary gear mechanism 31.

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

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

  In the geared transmission 3 configured in this manner, the friction engagement elements 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 are provided. The combination of engagement achieves any one of the first to ninth forward nine speeds and any one of the reverse stages.

  FIG. 4 is a fastening operation table showing the fastening state of each friction engagement element for each gear position of the step-variable transmission 3. As shown in FIG. In FIG. 4, ○ indicates that the frictional engagement element is in the engaged state, and the blank indicates that the frictional engagement element is in the released state. Steps 1 to 9 indicate the first to ninth forward speeds, and Rev on the number of steps indicates the reverse.

  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 frictional engagement 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 frictional engagement 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 frictional engagement 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 frictional engagement 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 frictional engagement elements are released. In order to achieve the sixth speed, the first clutch C1, the second clutch C2, and the third clutch C3 are engaged, and the other frictional engagement elements are released.

  Also, to achieve the seventh speed, the third brake B3, the first clutch C1, and the third clutch C3 are engaged, and the other frictional engagement 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 frictional engagement elements are released. In order to achieve the ninth speed, the first brake B1, the third brake B3 and the first clutch C1 are engaged, and the other frictional engagement elements are released. In order to achieve the reverse gear, the first brake B1, the second brake B2 and the third brake B3 are engaged, and the other frictional engagement elements are released.

  The shift control by engagement and release of each friction engagement element of the stepped transmission 3 is performed by an automatic transmission controller. The automatic transmission controller determines the shift (switching of the gear) based on the accelerator opening degree, the sensor, the vehicle information such as the engine speed, etc., and controls the hydraulic circuit unit to set each friction engagement element (C1 to C1). C3, B1 to B3) are engaged or released.

[5. Others] Although the embodiment of the present invention has been described above, the stepped transmission according to the present invention can be implemented by appropriately changing the above-described embodiment without departing from the spirit of the present invention.
For example, the arrangement configuration of the thrust bearing for axially supporting the ring gear of the planetary gear mechanism of the present invention can be widely applied to a stepped transmission that is configured to include the planetary gear mechanism.

  In the above embodiment, the present invention is applied to a stepped transmission including two planetary gear mechanisms 33 and 34. However, the present invention is not limited to this, and three or more planetary gears may be used. It goes without saying that the present invention is also applicable to a geared transmission having a mechanism and achieving more gear stages.

1 Engine (drive source)
2 Torque converter 3 Stepped transmission (Stepped automatic transmission mechanism)
REFERENCE SIGNS LIST 4 automatic transmission 5 speed reduction mechanism 6 differential 7 drive wheel 30A input shaft 30B output gear 30C, 30D intermediate shaft 30E to 30L connecting shaft 31 to 34 first to fourth 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 extension 33E3 Axial extension 41, 42 First thrust bearing 43, 44 Second thrust bearing B1 to B3 Brake (frictional engagement element)
C1 to C3 clutch (friction engagement element)
Inner diameter of R1 ring gear 33R R2 Outer diameter of main part (support plate main body) of support plate 33C1

Claims (4)

A stepped transmission comprising an input shaft and a planetary gear mechanism drivingly connected to the input shaft,
The carrier of the planetary gear mechanism is provided with an axial extension on one of two support plates for supporting the planetary pinion, and both surfaces of the axial extension are respectively provided by the first thrust bearing. Axially supported,
The ring gear of the planetary gear mechanism is disposed between the outer peripheral extensions respectively provided on the two support plates, and each end face of the ring gear and each outer peripheral extension of the both support plates opposed thereto A stepped transmission characterized in that it is axially supported by a second thrust bearing interposed therebetween. One of the two outer peripheral extensions is constituted by two members of a support plate main body whose outer diameter is smaller than the inner diameter of the ring gear, and an extension member integrally connected to the outer periphery of the support plate main body The stepped transmission according to claim 1, characterized in that: The geared transmission according to claim 2, wherein an output member is connected to the extension member. 4. The step-variable transmission according to claim 3, wherein the one support plate provided with the axial center extension portion is constituted by one member.

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