JP6561758B2 - Automatic transmission - Google Patents

Description

  The present invention relates to an automatic transmission including a stepped transmission and a hydraulic continuously variable transmission.

  2. Description of the Related Art Conventionally, in automatic transmissions mounted on vehicles such as automobiles, a parallel shaft gear type stepped transmission that is generally employed as a manual transmission is provided with an actuator for switching clutches and switching gears. There is an added AMT (Automated Manual Transmission). The AMT electrically controls the actuator in accordance with the driver's intention, and performs an automatic shift by executing a series of shift operations including engagement / disengagement of the clutch and switching of the gear position.

  On the other hand, as an automatic transmission mounted on a vehicle, HST (Hydro Static Transmission) which is a hydraulic continuously variable transmission is known (see Patent Document 1). This HST is equipped with a variable displacement pump and a fixed displacement motor. The variable displacement pump is driven by the engine to generate hydraulic pressure, and this hydraulic pressure is converted into rotational force by the fixed displacement motor to perform continuously variable transmission. ing.

Japanese Patent No. 4222583

  However, in the conventional automatic transmission, when a hydraulic continuously variable transmission is added to the stepped transmission, the size of the apparatus may be increased depending on the mounting position of the variable displacement pump in the stepped transmission. there were.

  The present invention has been made paying attention to the above-described problems, and an object thereof is to provide an automatic transmission that includes a stepped transmission and a hydraulic continuously variable transmission and can be downsized. It is.

In the present invention, an input shaft to which power is input from a drive source of a vehicle via a main clutch, a counter shaft for transmitting power to a drive wheel via a final gear, and the input shaft are disposed adjacent to each other. A stepped transmission comprising: a plurality of drive gears; and a plurality of driven gears that mesh with the drive gear to form a plurality of gear pairs and are arranged adjacent to each other on the counter shaft; A hydraulic pump that continuously changes the discharge amount of hydraulic oil by power input from the shaft; and a hydraulic motor that is driven by the hydraulic oil discharged from the hydraulic pump and transmits power to the counter shaft. In the automatic transmission including the continuously variable transmission, a hydraulic pump drive gear for driving the hydraulic pump is disposed on the input shaft at a position closest to the drive source in the axial direction of the input shaft. The hydraulic motor driven gear driven by the output of the hydraulic motor is disposed on the counter shaft at a position closer to the drive source than the driven gear forming the gear pair, and a plurality of levels of the driven gear and the hydraulic pressure A switching clutch for selectively connecting one of the plurality of driven gears and one of the hydraulic motor driven gears to the counter shaft is disposed between the motor driven gear and the hydraulic pump below the input shaft. The hydraulic motor is disposed below the counter shaft, the hydraulic motor driven gear is disposed on the drive source side of the switching clutch in the axial direction of the counter shaft, and the hydraulic pump and the hydraulic pressure this motor, in the axial direction of the counter shaft, the switching clutch side with respect to the hydraulic motor driven gear, and which is disposed on the outer peripheral side of the switching clutch The features.

  As described above, according to the present invention, the hydraulic pump can be disposed close to the drive source side, and the total axial length of the automatic transmission can be shortened. Further, the hydraulic motor can be disposed close to the drive source side, and the overall length in the axial direction of the automatic transmission can be shortened.

  Further, since the vehicle can be moved backward by driving the hydraulic continuously variable transmission, the reverse speed of the stepped transmission can be eliminated, and the total length of the input shaft and the counter shaft can be shortened.

  Further, since the hydraulic pump and the hydraulic motor are arranged on the outer peripheral side of the switching clutch, the axial dimension of the automatic transmission can be shortened. As a result, the stepped transmission and the hydraulic continuously variable transmission are provided, and the size can be reduced.

FIG. 1 is a diagram showing a first embodiment of an automatic transmission according to the present invention, and is a plan view of the automatic transmission. FIG. 2 is a view showing a first embodiment of the automatic transmission of the present invention, and is a side view of the automatic transmission. FIG. 3 is a diagram showing a first embodiment of the automatic transmission according to the present invention, and is a plan view of a hydraulic continuously variable transmission of the automatic transmission. FIG. 4 is a diagram showing a first embodiment of the automatic transmission of the present invention, and is a skeleton diagram of the automatic transmission. FIG. 5 is a diagram showing a second embodiment of the automatic transmission according to the present invention, and is a skeleton diagram of the automatic transmission.

(First embodiment)
Hereinafter, a first embodiment of an automatic transmission according to the present invention will be described with reference to the drawings. 1 to 4 are diagrams showing an automatic transmission according to a first embodiment of the present invention.

  First, the configuration will be described. 1 and 2, a vehicle 100 such as an automobile is equipped with an engine 2 as a drive source and an automatic transmission 1. The automatic transmission 1 includes a stepped transmission 20, a differential 9, and a hydraulic continuously variable transmission 50. The stepped transmission 20 includes an input shaft 21 and a counter shaft 30 installed in parallel with the input shaft 21.

  In FIG. 4, the automatic transmission 1 includes a dry single-plate main clutch 8 and an actuator 14. Power is input to the input shaft 21 of the stepped transmission 20 from the engine 2 (see FIG. 1) via the main clutch 8.

  1, 2, and 4, the input shaft 21 of the stepped transmission 20 has a hydraulic pump drive gear 22, a third speed drive gear 23, and a fourth speed drive gear 24 in order from the engine 2 side. A fifth-speed drive gear 25 is provided. The third speed drive gear 23, the fourth speed drive gear 24, and the fifth speed drive gear 25 are disposed adjacent to each other on the input shaft 21. The hydraulic pump drive gear 22 is disposed on the input shaft 21 at a position closest to the engine 2 in the axial direction of the input shaft 21. The hydraulic pump drive gear 22 drives a later-described hydraulic pump 52 of the hydraulic continuously variable transmission 50.

  The hydraulic pump drive gear 22 and the third speed drive gear 23 are fixed to the input shaft 21. The 4-speed drive gear 24 and the 5-speed drive gear 25 are rotatably installed on the input shaft 21.

  A synchronous meshing device 47 is provided between the fourth-speed drive gear 24 and the fifth-speed drive gear 25. The synchronous meshing device 47 has a shift sleeve 27 and meshing clutches 28 and 29. The shift sleeve 27 is attached to the input shaft 21 so as to be movable in the axial direction of the input shaft 21 and to rotate integrally with the rotation direction of the input shaft 21.

  When the shift sleeve 27 is in the right position in FIG. 4, the fourth speed drive gear 24 is connected to the input shaft 21 by the meshing clutch 28. When the shift sleeve 27 is in the left position in FIG. 4, the fifth speed drive gear 25 is connected to the input shaft 21 by the meshing clutch 29. Thus, the synchronous meshing device 47 selectively connects one of the fourth speed drive gear 24 and the fifth speed drive gear 25 to the input shaft 21.

  The counter shaft 30 of the stepped transmission 20 has a final drive gear 43, a hydraulic motor driven gear 32, a third speed driven gear 33, a fourth speed driven gear 34, and a fifth speed gear sequentially from the engine 2 side. A driven gear 35 and a parking gear 36 are provided. The third speed driven gear 33, the fourth speed driven gear 34, and the fifth speed driven gear 35 are arranged adjacent to the counter shaft 30. The hydraulic motor driven gear 32 is disposed on the counter shaft 30 at a position closer to the engine 2 than the third speed driven gear 33, the fourth speed driven gear 34, and the fifth speed driven gear 35 in the axial direction of the counter shaft 30. Yes. The hydraulic motor driven gear 32 is driven by the output of the hydraulic motor 53.

  The final drive gear 43 is fixed to the counter shaft 30 and meshes with the final driven gear 10 of the differential device 9.

  The counter shaft 30 transmits power to the drive wheels 13 via the final drive gear 43 and the final driven gear 10. More specifically, power is transmitted from the counter shaft 30 to the differential device 9 via the final drive gear 43 and the final driven gear 10, and power is transmitted from the differential device 9 to the drive wheel 13 via the drive shaft 12 extending left and right. The final drive gear 43 and the final driven gear 10 constitute a final gear in the present invention.

  The hydraulic motor driven gear 32 and the third speed driven gear 33 are rotatably installed on the counter shaft 30. The fourth speed driven gear 34, the fifth speed driven gear 35 and the parking gear 36 are fixed to the counter shaft 30.

  The third-speed driven gear 33, the fourth-speed driven gear 34, and the fifth-speed driven gear 35 include a third-speed drive gear 23 provided on the input shaft 21, a fourth-speed drive gear 24, and a fifth-speed drive gear 25. The gears are always meshed to form gear pairs for 3rd speed, 4th speed and 5th speed. Thus, the stepped transmission 20 is configured as a parallel shaft gear type transmission mechanism.

  The third speed drive gear 23 and the third speed driven gear 33 form a gear pair corresponding to the third speed. The fourth speed drive gear 24 and the fourth speed driven gear 34 form a gear pair corresponding to the fourth speed. The fifth speed drive gear 25 and the fifth speed driven gear 35 form a gear pair corresponding to the fifth speed. Of these multiple gear pairs, the gear ratio corresponding to the fifth speed is the smallest, and the gear ratio corresponding to the third speed is the largest.

  In the present embodiment, since the gear pair for the third speed having the largest gear ratio among the multiple gear pairs for the third speed, the fourth speed, and the fifth speed is disposed on the engine 2 side, the gear for the third speed The third-speed drive gear 23 and the third-speed driven gear 33 forming a pair are arranged closer to the engine 2 than the other remaining drive gears and driven gears.

  A synchronous meshing device 48 is provided between the hydraulic motor driven gear 32 and the third speed driven gear 33. The synchronous meshing device 48 includes a shift sleeve 37 and meshing clutches 38 and 39.

  The shift sleeve 37 is attached to the counter shaft 30 so as to be movable in the axial direction of the counter shaft 30 and to rotate integrally with the rotation direction of the counter shaft 30. When the shift sleeve 37 is in the right position in FIG. 4, the hydraulic motor driven gear 32 is connected to the counter shaft 30 by the meshing clutch 38. When the shift sleeve 37 is in the left position in FIG. 4, the third speed driven gear 33 is connected to the counter shaft 30 by the meshing clutch 39. Thus, the synchronous meshing device 48 selectively connects one of the third-speed driven gear 33 and the hydraulic motor driven gear 32 to the counter shaft 30. The synchronous meshing device 48 constitutes a switching clutch in the present invention.

  The actuator 14 is electrically controlled by an electronic control unit (not shown), so that the main clutch 8 is engaged and the transmission gear 20 is switched by the stepped transmission 20. The actuator 14 includes a clutch actuator and a shift actuator (not shown). The clutch actuator is used to operate the main clutch 8 and the shift actuator is used to switch the transmission gear in the stepped transmission 20. .

  The shift sleeves 27 and 37 are moved by the actuator 14 to a left position, a right position, or a neutral position in the axial direction (left and right direction in FIG. 1), respectively.

  In the stepped transmission 20, the shift sleeves 27 and 37 are moved in the axial direction, thereby shifting the shift stage to any one of the third speed, the fourth speed, and the fifth speed.

  When the shift sleeve 27 moves to the neutral position in FIG. 4, the input shaft 21 and the fourth speed drive gear 24 are disconnected, and the input shaft 21 and the fifth speed drive gear 25 are disconnected. As a result, the fourth-speed drive gear 24 and the fifth-speed drive gear 25 idle with respect to the input shaft.

  When the shift sleeve 27 moves to the right position in FIG. 4, the input shaft 21 and the fourth speed drive gear 24 are connected, and the input shaft 21 and the fifth speed drive gear 25 are disconnected. As a result, the 4-speed drive gear 24 rotates integrally with the input shaft 21, and power is transmitted between the input shaft 21 and the counter shaft 30 via the 4-speed drive gear 24 and the 4-speed driven gear 34. The

  When the shift sleeve 27 moves to the left position in FIG. 4, the input shaft 21 and the fifth speed drive gear 25 are connected, and the input shaft 21 and the fourth speed drive gear 24 are disconnected. As a result, the 5-speed drive gear 25 rotates integrally with the input shaft 21, and power is transmitted between the input shaft 21 and the counter shaft 30 via the 5-speed drive gear 25 and the 5-speed driven gear 35. The

  When the shift sleeve 37 moves to the neutral position in FIG. 4, the counter shaft 30 and the hydraulic motor driven gear 32 are disconnected, and the counter shaft 30 and the third-speed driven gear 33 are disconnected. As a result, the hydraulic motor driven gear 32 and the third speed driven gear 33 are idled with respect to the counter shaft 30.

  When the shift sleeve 37 moves to the right position in FIG. 4, the counter shaft 30 and the hydraulic motor driven gear 32 are connected, and the counter shaft 30 and the third speed driven gear 33 are disconnected.

  As a result, the hydraulic motor driven gear 32 rotates integrally with the counter shaft 30, and power is transmitted from the hydraulic motor 53 to the counter shaft 30 via the hydraulic motor drive gear 57 and the hydraulic motor driven gear 32.

  When the shift sleeve 37 moves to the left position in FIG. 4, the counter shaft 30 and the third-speed driven gear 33 are connected, and the counter shaft 30 and the hydraulic motor driven gear 32 are not connected.

  As a result, the 3-speed driven gear 33 rotates integrally with the counter shaft 30, and power is transmitted between the input shaft 21 and the counter shaft 30 via the 3-speed drive gear 23 and the 3-speed driven gear 33. The

  As described above, the automatic transmission 1 is configured as an AMT (Automated Manual Transmission), and an actuator 14 is added to the parallel shaft gear type stepped transmission 20, and the main clutch 8 is engaged and shifted by the actuator 14. The stage is switched.

  A parking pole (not shown) is provided in the vicinity of the parking gear 36. When the pawl portion of the parking pole meshes with the parking gear 36, the rotation of the counter shaft 30 is restricted, and the movement of the vehicle 100 is restricted.

  The stepped transmission 20 is provided with a speed reduction unit 3, and the speed reduction unit 3 includes an intermediate gear shaft 4, a speed reduction driven gear 5, and a speed reduction drive gear 6. The reduction driven gear 5 and the reduction drive gear 6 are fixed to the intermediate gear shaft 4 so as to be integrally rotatable.

  The reduction driven gear 5 meshes with the hydraulic pump drive gear 22. The rotation of the hydraulic pump drive gear 22 is decelerated when it is transmitted to the reduction driven gear 5. The reduction drive gear 6 meshes with an input gear 65 (to be described later) of the hydraulic continuously variable transmission 50.

  The rotation of the reduction drive gear 6 is decelerated when it is transmitted to the input gear 65. Thus, the deceleration unit 3 decelerates the rotation transmitted from the input shaft 21 and transmits the decelerated rotation to the hydraulic continuously variable transmission 50. This prevents rotation exceeding the allowable rotational speed from being input to the hydraulic continuously variable transmission 50.

  The hydraulic continuously variable transmission 50 is configured as an HST (Hydro Static Transmission) that performs a stepless change by hydraulic pressure, and includes an HST input shaft 51 and a variable displacement hydraulic pump coupled to the HST input shaft 51. 52, a fixed displacement hydraulic motor 53, and an oil passage 54 through which hydraulic oil flows from the hydraulic pump 52 to the hydraulic motor 53.

  The hydraulic pump 52 is disposed below the input shaft 21 and the intermediate gear shaft 4. The hydraulic motor 53 is disposed below the counter shaft 30.

  In the present embodiment, the hydraulic pump 52 and the hydraulic motor 53 are disposed on the outer peripheral side of the synchronous meshing device 48. Further, the hydraulic pump 52 and the hydraulic motor 53 are arranged adjacent to each other in the circumferential direction of the automatic transmission 1. Note that the hydraulic pump 52 and the hydraulic motor 53 may be disposed adjacent to each other in the radial direction of the automatic transmission 1.

  That is, in the present embodiment, the hydraulic pump 52 and the hydraulic motor 53 are arranged adjacent to each other in the radial direction or the circumferential direction of the automatic transmission 1, so that the hydraulic pump 52 and the hydraulic motor 53 are axially connected to the automatic transmission 1. The axial length of the automatic transmission 1 is shortened compared to the case where the automatic transmission 1 is disposed adjacent to the automatic transmission device 1.

  An input gear 65 is fixed to the HST input shaft 51 so as to be integrally rotatable, and the input gear 65 meshes with the reduction drive gear 6 of the reduction unit 3. The rotation of the input shaft 21 is transmitted to the HST input shaft 51 after being decelerated through the deceleration unit 3.

  The hydraulic continuously variable transmission 50 includes a charge pump 56, and an HST input shaft 51 is connected to the charge pump 56. The charge pump 56 pumps hydraulic oil from an oil tank (not shown) and supplies it to the hydraulic pump 52 by the driving force transmitted to the HST input shaft 51.

  In FIG. 3, the hydraulic pump 52 includes a movable swash plate 58, and the angle of the movable swash plate 58 is continuously changed between a forward position indicated by a solid line and a reverse position indicated by a broken line. Further, a neutral position indicated by a broken line is set between the forward position and the backward position of the movable swash plate 58. When the movable swash plate 58 is in the forward movement position, suction and discharge corresponding to the movable swash plate 58 are performed in the hydraulic pump 52, hydraulic oil is discharged in one direction of the oil passage 54, and the hydraulic motor 53 is moved in the forward direction. Rotate accordingly. When the movable swash plate 58 is in the retracted position, suction and discharge are reversed in the hydraulic pump 52 and when the movable swash plate 58 is in the advanced position, and hydraulic oil is discharged in the other direction of the oil passage 54. The hydraulic motor 53 rotates corresponding to the backward direction. When the movable swash plate 58 is in the neutral position, hydraulic oil is not discharged from the hydraulic pump 52. The hydraulic pump 52 changes the angle of the movable swash plate 58 steplessly in a forward tilting area between the neutral position and the forward position and in a backward tilting area between the neutral position and the backward position. Change the discharge direction and discharge amount of hydraulic oil to An HST output shaft 55 is connected to the hydraulic motor 53, and the rotation of the hydraulic motor 53 is output from the HST output shaft 55.

  In this way, the hydraulic continuously variable transmission 50 changes the angle of the movable swash plate 58 of the hydraulic pump 52 to perform a stepless shift in the forward direction and the reverse direction, and to use the power at the shifted rotational speed. The power is output from the hydraulic motor 53. The hydraulic continuously variable transmission 50 has a speed range corresponding to the first forward speed, the second forward speed, and the reverse speed. In other words, the hydraulic continuously variable transmission 50 is responsible for shifting in the low speed range.

  1 to 4, the differential device 9 includes a final driven gear 10 and a differential mechanism 11. A final drive gear 43 of the stepped transmission 20 and a final drive gear 72 of the hydraulic continuously variable transmission 50 are engaged with the final driven gear 10.

  The differential device 9 shifts the driving force transmitted to the final driven gear 10 by the stepped transmission 20 or the hydraulic continuously variable transmission 50 from the left and right drive shafts 12 via the differential mechanism 11 to the drive wheels 13. Output to.

  The automatic transmission 1 configured as described above transmits the driving force transmitted from the engine 2 to the intermediate gear shaft 4 according to the driver's operation and the traveling speed of the vehicle 100, or the stepped transmission 20 or the hydraulic non-transmission device. The gear is shifted by one of the step transmission 50 and transmitted to the differential device 9.

  Further, in the automatic transmission 1, as described below, the hydraulic continuously variable transmission 50 is responsible for shifting in the low speed range, and the stepped transmission 20 is responsible for shifting in the medium speed range and the high speed range.

  The operation of the automatic transmission 1 when the vehicle 100 is stopped, when moving forward, and when moving backward will be described.

(When the vehicle is stopped)
When the vehicle is stopped, the main clutch 8 is connected, and the power of the engine 2 is input to the input shaft 21. The power input to the input shaft 21 is transmitted to the hydraulic pump 52 via the speed reduction unit 3 and the HST input shaft 51, and drives the hydraulic pump 52.

  In addition, when the vehicle is stopped, the shift sleeve 27 is moved to the neutral position in FIG. 4 by the actuator 14 and the shift sleeve 37 is moved to the right position in FIG. The power transmission from 21 to the countershaft 30 is cut off.

  When the vehicle is stopped, the movable swash plate 58 of the hydraulic pump 52 is set to the neutral position. When the movable swash plate 58 is in the neutral position, the hydraulic pump 52 does not generate hydraulic pressure, so hydraulic fluid is not discharged from the hydraulic pump 52 to the hydraulic motor 53, and the hydraulic motor 53 does not generate driving force. For this reason, the vehicle 100 stops with the main clutch 8 connected.

(When the vehicle moves forward)
When the driver selects forward and the vehicle 100 travels in a low speed range, the automatic transmission 1 moves the shift sleeve 37 to the right position in FIG. 4 by the actuator 14, thereby counting the hydraulic motor driven gear 32. Fastened to the shaft 30. Here, the low speed range is a speed range corresponding to the first speed and the second speed of the shift stage.

  Further, the automatic transmission 1 sets the movable swash plate 58 of the hydraulic pump 52 to the forward position. When the movable swash plate 58 is set at the forward movement position, the hydraulic pump 52 discharges hydraulic oil in a direction corresponding to the forward movement direction, and the hydraulic motor 53 rotates in a direction corresponding to the forward movement direction.

  As a result, the rotation in the forward direction changed by the hydraulic continuously variable transmission 50 is transmitted to the drive wheels 13 via the final drive gear 43, the final driven gear 10, and the drive shaft 12, and the vehicle 100 moves forward.

  In the low speed range corresponding to the first and second gears, the automatic transmission 1 changes the movable swash plate 58 of the hydraulic continuously variable transmission 50 to adjust the amount of hydraulic oil discharged from the hydraulic motor 53. As a result, the speed is changed steplessly.

  On the other hand, when the vehicle 100 travels in the middle speed range and the high speed range, the automatic transmission 1 moves the shift sleeve 37 to the neutral position in FIG. 4 while the main clutch 8 is once disconnected (released) by the actuator 14. As a result, the hydraulic motor driven gear 32 is released from the counter shaft 30. Here, the medium speed range and the high speed range are speed ranges corresponding to the third speed, the fourth speed, and the fifth speed of the shift stage.

  Thereafter, the automatic transmission device 1 fastens the third speed driven gear 33 to the counter shaft 30 by moving the shift sleeve 37 to the left position in FIG. As a result, the vehicle 100 travels with the power shifted by the meshing of the third-speed drive gear 23 and the third-speed driven gear 33.

  Thereafter, the automatic transmission 1 drives the actuator 14 based on an acceleration request from the driver, etc., and performs a shift to the fourth and fifth gears.

(When the vehicle moves backward)
When the driver selects reverse, the automatic transmission 1 uses the actuator 14 to move the shift sleeves 27 and 37 to the neutral position in FIG. 4, so that the counter shaft 30 is changed from the input shaft 21 in the stepped transmission 20. The power transmission to is cut off.

  And the automatic transmission 1 fastens the hydraulic motor driven gear 32 to the counter shaft 30 by moving the shift sleeve 37 to the right position in FIG.

  Further, the automatic transmission 1 sets the movable swash plate 58 of the hydraulic pump 52 to the retracted position. Thereby, since the position of the movable swash plate 58 is opposite to that at the time of forward movement, the hydraulic motor 53 rotates in the direction opposite to that at the time of forward movement. For this reason, the final driven gear 10 rotates in the direction opposite to that at the time of forward movement, and the vehicle 100 moves backward.

  As described above, in the automatic transmission 1, the hydraulic continuously variable transmission 50 is responsible for shifting in the low speed range corresponding to the forward first speed, the second speed, and the reverse speed, and the forward third speed, the fourth speed, The stepped transmission 20 is responsible for shifting in the middle speed range and the high speed range corresponding to the fifth speed.

  Therefore, in the low speed range, the hydraulic continuously variable transmission 50 can perform a stepless and smooth speed change without interrupting power transmission. Further, in the medium speed range and the high speed range, which are the speed ranges during steady running, the stepped transmission 20 is used for shifting, so there is no loss of power transmission due to hydraulic oil, and power transmission efficiency during steady running. Can improve fuel efficiency.

  As described above, according to the automatic transmission 1 of the present embodiment, the hydraulic pump drive gear 22 that drives the hydraulic pump 52 is disposed on the input shaft 21 at a position closest to the engine 2 in the axial direction of the input shaft 21. Yes.

  As a result, the hydraulic pump 52 can be disposed close to the engine 2 side, and the overall axial length of the automatic transmission 1 can be shortened.

  Further, according to the automatic transmission 1 of the present embodiment, the hydraulic motor driven gear 32 driven by the output of the hydraulic motor 53 forms a gear pair with the counter shaft 30 in the axial direction of the counter shaft 30. The gear 33 is disposed closer to the engine 2 than the fourth speed driven gear 34 and the fifth speed driven gear 35.

  Accordingly, the hydraulic motor 53 can be disposed close to the engine 2 side, and the overall length of the automatic transmission 1 in the axial direction can be shortened.

  Further, according to the automatic transmission 1 of the present embodiment, a plurality of stages of gears between the third-speed driven gear 33, the fourth-speed driven gear 34, and the fifth-speed driven gear 35 and the hydraulic motor driven gear 32 are provided. A synchronous meshing device 48 for selectively connecting one of the driven gear and one of the hydraulic motor driven gear 32 to the counter shaft 30 is disposed.

  Thereby, since the hydraulic continuously variable transmission 50 can be driven and the vehicle 100 can be moved backward, the reverse speed of the stepped transmission 20 can be eliminated, and the total length of the input shaft 21 and the counter shaft 30 can be shortened. it can.

  Further, according to the automatic transmission 1 of the present embodiment, the hydraulic pump 52 and the hydraulic motor 53 are disposed on the outer peripheral side of the synchronous meshing device 48.

  Thereby, the dimension of the axial direction of the automatic transmission 1 can be shortened. As a result, the stepped transmission 20 and the hydraulic continuously variable transmission 50 are provided, and the size can be reduced.

  Further, according to the automatic transmission 1 of the present embodiment, the gear pair having the largest gear ratio among the plurality of gear pairs is arranged on the engine 2 side.

  Accordingly, the third-speed driven gear 33 that forms the gear pair with the largest speed ratio has a relatively large diameter, and the fifth-speed driven gear 35 that forms the gear pair with the smallest speed ratio has a relatively small diameter. Therefore, the outer diameter of the automatic transmission 1 can be reduced by arranging the hydraulic pump 52 and the hydraulic motor 53 close to each other in the vicinity of the 5-speed driven gear 35.

  Further, according to the automatic transmission 1 of the present embodiment, the hydraulic pump 52 and the hydraulic motor 53 are disposed adjacent to each other in the radial direction or the circumferential direction.

  Thereby, since the hydraulic pump 52 and the hydraulic motor 53 are not disposed adjacent to each other in the axial direction, the automatic transmission 1 can be downsized in the axial direction.

  In addition, since the hydraulic pump 52 and the hydraulic motor 53 are disposed adjacent to each other, the oil passage 54 that connects the hydraulic pump 52 and the hydraulic motor 53 can be shortened, so that transmission loss of hydraulic oil in the oil passage 54 can be reduced. The transmission efficiency of the hydraulic continuously variable transmission 50 can be improved.

(Second Embodiment)
The automatic transmission 1 according to the second embodiment differs from the first embodiment in the installation positions of a plurality of gear pairs in the stepped transmission 20. Components similar to those in the first embodiment will be described with the same reference numerals as those in the first embodiment.

  In FIG. 5, the input shaft 21 is provided with a hydraulic pump drive gear 22, a fifth speed drive gear 25, a fourth speed drive gear 24, and a third speed drive gear 23 in order from the engine 2 side. ing.

  The hydraulic pump drive gear 22 and the fifth speed drive gear 25 are fixed to the input shaft 21. The third speed drive gear 23 and the fourth speed drive gear 24 are rotatably installed on the input shaft 21. A synchronous meshing device 47 is provided between the third-speed drive gear 23 and the fourth-speed drive gear 24.

  On the other hand, the counter shaft 30 has a final drive gear 43, a hydraulic motor driven gear 32, a fifth speed driven gear 35, a fourth speed driven gear 34, and a third speed driven gear 33 in order from the engine 2 side. A parking gear 36 is provided.

  The final drive gear 43 is fixed to the counter shaft 30 and meshes with the final driven gear 10 of the differential device 9. Thereby, the countershaft 30 transmits power to the drive wheels 13 via the final drive gear 43 and the final driven gear 10.

  The hydraulic motor driven gear 32 and the fifth speed driven gear 35 are rotatably installed on the counter shaft 30. The third speed driven gear 33, the fourth speed driven gear 34, and the parking gear 36 are fixed to the counter shaft 30.

  The third-speed driven gear 33, the fourth-speed driven gear 34, and the fifth-speed driven gear 35 include a third-speed drive gear 23 provided on the input shaft 21, a fourth-speed drive gear 24, and a fifth-speed drive gear 25. The gears are always meshed to form gear pairs for 3rd speed, 4th speed and 5th speed.

  In the present embodiment, since the gear pair for the fifth speed having the smallest gear ratio among the plurality of gear pairs for the third speed, the fourth speed, and the fifth speed is arranged on the engine 2 side, the gear for the fifth speed is provided. The fifth-speed drive gear 25 and the fifth-speed driven gear 35 that form a pair are arranged closer to the engine 2 than the other remaining drive gears and driven gears. A synchronous meshing device 48 is provided between the hydraulic motor driven gear 32 and the fifth speed driven gear 33.

  As described above, according to the automatic transmission device 1 of the present embodiment, the gear pair having the smallest speed ratio among the plurality of gear pairs is arranged on the engine 2 side.

  As a result, the fifth-speed driven gear 35 that forms the gear pair with the smallest speed ratio has a relatively small diameter, so that the inertia weight of the fifth-speed driven gear 35 is small. For this reason, when the 5-speed driven gear 35 having a small inertia weight is connected to the counter shaft 30 by the synchronous meshing device 48, the switching time required for the connection can be shortened.

  While embodiments of the invention have been disclosed, it will be apparent to those skilled in the art that changes may be made without departing from the scope of the invention. All such modifications and equivalents are intended to be included in the following claims.

  DESCRIPTION OF SYMBOLS 1 ... Automatic transmission, 2 ... Engine (drive source), 8 ... Main clutch, 10 ... Final driven gear (final gear), 20 ... Stepped transmission, 21 ... Input shaft, 22 ... hydraulic pump drive gear, 23 ... 3-speed drive gear (drive gear), 24 ... 4-speed drive gear (drive gear), 25 ... 5-speed drive gear ( Drive gear), 30 ... counter shaft, 32 ... hydraulic motor driven gear, 43 ... final drive gear (final gear), 47 ... synchronous meshing device (switching clutch), 50 ... hydraulic Continuously variable transmission, 52 ... hydraulic pump, 53 ... hydraulic motor, 100 ... vehicle

Claims (4)

An input shaft to which power is input from the drive source of the vehicle via the main clutch;
A countershaft that transmits power to the drive wheels via a final gear;
A plurality of drive gears disposed adjacent to each other on the input shaft;
A stepped transmission having a plurality of driven gears meshed with the drive gear to form a plurality of gear pairs and disposed adjacent to the counter shaft;
A hydraulic pump that changes the discharge amount of hydraulic oil steplessly by the power input from the input shaft;
A hydraulic continuously variable transmission having a hydraulic motor driven by hydraulic oil discharged from the hydraulic pump and transmitting power to the countershaft;
The hydraulic pump drive gear for driving the hydraulic pump is disposed on the input shaft at a position closest to the drive source in the axial direction of the input shaft,
The hydraulic motor driven gear driven by the output of the hydraulic motor is disposed on the counter shaft at a position closer to the drive source than the driven gear forming the gear pair in the axial direction of the counter shaft,
A switching clutch that selectively connects one of the plurality of driven gears and the hydraulic motor driven gear to the counter shaft is disposed between the plurality of driven gears and the hydraulic motor driven gear,
The hydraulic pump is disposed below the input shaft;
The hydraulic motor is disposed below the counter shaft,
The hydraulic motor driven gear is disposed on the drive source side of the switching clutch in the axial direction of the counter shaft,
The automatic transmission, wherein the hydraulic pump and the hydraulic motor are arranged on the switching clutch side and on the outer peripheral side of the switching clutch with respect to the hydraulic motor driven gear in the axial direction of the counter shaft. .   2. The automatic transmission according to claim 1, wherein a gear pair having the largest gear ratio among the plurality of gear pairs is arranged on the drive source side.   2. The automatic transmission according to claim 1, wherein a gear pair having the smallest gear ratio among the plurality of gear pairs is arranged on the drive source side.   The automatic transmission according to any one of claims 1 to 3, wherein the hydraulic pump and the hydraulic motor are disposed adjacent to each other in a radial direction.