Transmission

Abstract

To downsize a transmission.SOLUTION: A transmission comprises an input shaft, an output shaft, a first intermediate shaft, a second intermediate shaft, an input clutch, a first clutch, and a second clutch. The first intermediate shaft is arranged between the input shaft and the output shaft in a power transmission path. The second intermediate shaft is arranged between the first intermediate shaft and the output shaft in the power transmission path. The input clutch transmits rotation of the input shaft to the first intermediate shaft in an engagement state. The first clutch transmits rotation of the first intermediate shaft to the second intermediate shaft in an engagement state. The second clutch transmits rotation of the second intermediate shaft to the output shaft in an engagement state. The input clutch is arranged on the input shaft. The first clutch is arranged on the first intermediate shaft. The second clutch is arranged on the second intermediate shaft.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to transmissions. [Background technology]

[0002] Some transmissions include an input shaft, an output shaft, and an intermediate shaft arranged between the input shaft and the output shaft in a power transmission path. For example, the transmission of Patent Document 1 includes an input shaft, a first intermediate shaft, a second intermediate shaft, an output shaft, and a plurality of gears and a plurality of clutches connecting these shafts. In this transmission, the rotation of the input shaft is transmitted to the first intermediate shaft by engaging any one of the clutches (16, 18) arranged on the input shaft. The rotation of the first intermediate shaft is transmitted to the second intermediate shaft by engaging any one of the clutches (24, 28) arranged on the first intermediate shaft. Then, the rotation of the second intermediate shaft is transmitted to the output shaft by engaging any one of the clutches (41, 43) provided on the output shaft. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] U.S. Patent No. 4,589,295 Summary of the Invention [Problem to be solved by the invention]

[0004] As described above, when the number of transmission shafts, gears, and clutches increases due to the increase in the number of stages in a transmission, the transmission becomes larger. An object of the present disclosure is to reduce the size of the transmission. [Means for solving the problem]

[0005] A transmission according to a first aspect of the present disclosure includes an input shaft, an output shaft, a first intermediate shaft, a second intermediate shaft, an input clutch, a first clutch, and a second clutch. The first intermediate shaft is disposed between the input shaft and the output shaft in a power transmission path. The second intermediate shaft is disposed between the first intermediate shaft and the output shaft in a power transmission path. The input clutch transmits rotation of the input shaft to the first intermediate shaft in an engaged state. The first clutch transmits rotation of the first intermediate shaft to the second intermediate shaft in an engaged state. The second clutch transmits rotation of the second intermediate shaft to the output shaft in an engaged state. The input clutch is disposed on the input shaft. The first clutch is disposed on the first intermediate shaft. The second clutch is disposed on the second intermediate shaft.

[0006] A transmission according to a second aspect of the present disclosure includes an input shaft, an output shaft, a first intermediate shaft, a second intermediate shaft, an input low idler gear, an input high idler gear, a first low fixed gear, a first high fixed gear, an input low clutch, an input high clutch, a first low idler gear, a first high idler gear, a second low fixed gear, a second high fixed gear, a first low clutch, a first high clutch, a second low idler gear, a second high idler gear, an output low fixed gear, an output high fixed gear, a second low clutch, and a second high clutch. The first intermediate shaft is disposed between the input shaft and the output shaft in a power transmission path. The second intermediate shaft is disposed between the first intermediate shaft and the output shaft in a power transmission path. The input low idler gear is disposed on the input shaft and can rotate idly relative to the input shaft. The input high idler gear is disposed on the input shaft and can rotate idly relative to the input shaft. The first low fixed gear is disposed on the first intermediate shaft and meshes with the input low idler gear. The first high fixed gear is disposed on the first intermediate shaft and meshes with the input high idler gear. The input low clutch, in an engaged state, engages the input low idler gear with the input shaft and transmits the rotation of the input shaft to the first intermediate shaft. The input high clutch, in an engaged state, engages the input high idler gear with the input shaft and transmits the rotation of the input shaft to the first intermediate shaft. The first low idler gear is disposed on the first intermediate shaft and can rotate idly relative to the first intermediate shaft. The first high idler gear is disposed on the first intermediate shaft and can rotate idly relative to the first intermediate shaft. The second low fixed gear is disposed on the second intermediate shaft and meshes with the first low idler gear. The second high fixed gear is disposed on the second intermediate shaft and meshes with the first high idler gear. The first low clutch, in an engaged state, engages the first low idler gear with the first intermediate shaft and transmits the rotation of the first intermediate shaft to the second intermediate shaft. The first high clutch, in an engaged state, engages the first high idler gear with the first intermediate shaft and transmits rotation of the first intermediate shaft to the second intermediate shaft. The second low idler gear is disposed on the second intermediate shaft and is capable of idling relative to the second intermediate shaft. The second high idler gear is disposed on the second intermediate shaft and is capable of idling relative to the second intermediate shaft. The output low fixed gear is disposed on the output shaft and meshes with the second low idler gear. The output high fixed gear is disposed on the output shaft and meshes with the second high idler gear.The second low clutch, in an engaged state, engages the second low idler gear with the output shaft and transmits the rotation of the second intermediate shaft to the output shaft. The second high clutch, in an engaged state, engages the second high idler gear with the output shaft and transmits the rotation of the second intermediate shaft to the output shaft. The input low clutch and the input high clutch are disposed on the input shaft. The first low clutch and the first high clutch are disposed on the first intermediate shaft. The second low clutch and the second high clutch are disposed on the second intermediate shaft.

[0007] A transmission according to a third aspect of the present disclosure includes a plurality of transmission shafts and a plurality of clutches. The plurality of transmission shafts include an input shaft, an output shaft, and an intermediate shaft. The intermediate shaft is disposed between the input shaft and the output shaft in a power transmission path. The plurality of clutches respectively connect the plurality of transmission shafts in an engaged state, and transmit rotation of the upstream transmission shaft to the downstream transmission shaft. All of the plurality of clutches are disposed on the upstream transmission shaft. Effect of the Invention

[0008] In the transmission according to the present disclosure, the multiple clutches are all disposed on the upstream transmission shaft in the path of transmission of driving force. The torque of the upstream transmission shaft is smaller than the torque of the downstream transmission shaft. Therefore, the multiple clutches can be made smaller than when all or part of the multiple clutches are provided on the downstream transmission shaft. This allows the transmission to be made smaller. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a side view of a work machine according to an embodiment. [Diagram 2] FIG. 2 is a skeleton diagram showing a configuration of a transmission. [Diagram 3] FIG. 2 is a diagram showing the arrangement of transmission shafts and gears as viewed from the axial direction of each transmission shaft of the transmission. [Figure 4] 2 is a schematic diagram showing the configuration of a control system for a transmission mounted on a work machine. FIG. [Diagram 5]4 is a table showing the engaged and disengaged states of a number of clutches at each speed stage. [Figure 6] FIG. 4 is a diagram showing a driving force transmission path in a first forward speed in the transmission. [Figure 7] FIG. 4 is a diagram showing a driving force transmission path in a second forward speed in the transmission. [Figure 8] FIG. 4 is a diagram showing a driving force transmission path in a third forward speed in the transmission. [Figure 9] FIG. 4 is a diagram showing a driving force transmission path in a fourth forward speed in the transmission. [Figure 10] FIG. 4 is a diagram showing a driving force transmission path in a fifth forward speed in the transmission. [Figure 11] FIG. 4 is a diagram showing a driving force transmission path in a sixth forward speed in the transmission. [Figure 12] FIG. 4 is a diagram showing a driving force transmission path in a seventh forward speed in the transmission. [Figure 13] FIG. 4 is a diagram showing the path of driving force transmission in the eighth forward speed in the transmission. [Figure 14] FIG. 4 is a diagram showing a driving force transmission path in a first reverse gear in the transmission. [Figure 15] FIG. 4 is a diagram showing a driving force transmission path in second reverse gear in the transmission. [Figure 16] FIG. 4 is a diagram showing a driving force transmission path in third reverse gear in the transmission. [Figure 17] FIG. 4 is a diagram showing a driving force transmission path in the fourth reverse gear in the transmission. [Figure 18] FIG. 4 is a diagram showing a driving force transmission path in the fifth reverse gear in the transmission. [Figure 19] FIG. 4 is a diagram showing a driving force transmission path in the sixth reverse gear in the transmission. [Figure 20] FIG. 4 is a diagram showing a driving force transmission path in the seventh reverse gear in the transmission. [Figure 21]FIG. 4 is a diagram showing the path of driving force transmission in the eighth reverse gear in the transmission. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a side view of a work machine 1 according to the embodiment. The work machine 1 according to the embodiment is a motor grader. As shown in FIG. 1, the work machine 1 includes a vehicle body 2, running wheels 3A, 4A, 4B, and a working implement 9. The vehicle body 2 includes a front frame 11, a rear frame 12, a cab 13, and a power room 14. The running wheels 3A, 4A, 4B include a front wheel 3A and rear wheels 4A, 4B. The running wheels 3A, 4A, 4B are provided on the left and right, respectively, but only the left front wheel 3A and rear wheels 4A, 4B are shown in FIG. 1.

[0011] The rear frame 12 is connected to the front frame 11. The front frame 11 can be articulated left and right relative to the rear frame 12. A cab 13 and a power room 14 are disposed on the rear frame 12. A driver's seat is disposed in the cab 13. The power room 14 is disposed rearward of the cab 13. The front frame 11 extends forward from the rear frame 12. A front wheel 3A is attached to the front frame 11. Rear wheels 4A, 4B are attached to the rear frame 12.

[0012] The work implement 9 is movably connected to the vehicle body 2. The work implement 9 includes a support member 15 and a blade 16. The blade 16 is disposed between the front wheels 3A and the rear wheels 4A. The blade is disposed below the front frame 11. The support member 15 is movably connected to the vehicle body 2. The support member 15 supports the blade 16.

[0013] The work machine 1 is equipped with an engine 5, a torque converter 6, a transmission 7, and a drive shaft 8. The torque converter 6 is connected to the engine 5. The transmission 7 is connected to the engine 5 via the torque converter 6. The drive shaft 8 is connected to the transmission 7. The transmission 7 changes the speed of the driving force from the engine 5 and transmits it to the rear wheels 4A, 4B. The transmission 7 transmits the driving force from the engine 5 to the rear wheels 4A, 4B via the drive shaft 8 and an axle (not shown).

[0014] Fig. 2 is a skeleton diagram showing the configuration of the transmission 7. Fig. 3 is a diagram showing the arrangement of the transmission shafts and gears as viewed from the axial direction of each transmission shaft of the transmission 7. The transmission 7 according to this embodiment has eight forward speeds and eight reverse speeds. As shown in Figs. 2 and 3, the transmission 7 includes an input shaft 20, a reversing shaft 30, a first intermediate shaft 40, a second intermediate shaft 50, and an output shaft 60.

[0015] The input shaft 20 is connected to the engine 5 via a torque converter 6. The reversing shaft 30, the first intermediate shaft 40, and the second intermediate shaft 50 are arranged between the input shaft 20 and the output shaft 60 in a driving force transmission path. The reversing shaft 30 is arranged downstream of the input shaft 20 in the transmission path. The first intermediate shaft 40 is arranged downstream of the input shaft 20 in the transmission path. The second intermediate shaft 50 is arranged downstream of the first intermediate shaft 40 in the transmission path. The output shaft 60 is arranged downstream of the second intermediate shaft 50 in the transmission path. The output shaft 60 is connected to the drive shaft 8.

[0016] The input shaft 20, the reversing shaft 30, the first intermediate shaft 40, the second intermediate shaft 50, and the output shaft 60 are arranged parallel to one another. As shown in Fig. 3, the reversing shaft 30 is arranged below the input shaft 20. The reversing shaft 30 is arranged shifted in the left-right direction from the input shaft 20. The left-right direction refers to the axial direction of each of the transmission shafts 20, 30, 40, 50, 60 and the direction perpendicular to the up-down direction.

[0017] The first intermediate shaft 40 is disposed below the input shaft 20. The first intermediate shaft 40 is disposed below the reversing shaft 30. The first intermediate shaft 40 is disposed offset in the left-right direction from the input shaft 20 and the reversing shaft 30. The second intermediate shaft 50 is disposed below the first intermediate shaft 40. The second intermediate shaft 50 is disposed offset in the left-right direction from the first intermediate shaft 40. The second intermediate shaft 50 is disposed offset in the left-right direction from the reversing shaft 30. The output shaft 60 is disposed below the second intermediate shaft 50. The output shaft 60 is disposed directly below the input shaft 20. The output shaft 60 is disposed offset in the left-right direction from the second intermediate shaft 50.

[0018] The transmission 7 includes an input gear 21, an input low idler gear 22, an input high idler gear 23, an input low clutch 24, and an input high clutch 25. The input gear 21, the input low idler gear 22, the input high idler gear 23, the input low clutch 24, and the input high clutch 25 are disposed on an input shaft 20. The input gear 21 is fixed to the input shaft 20. The input low idler gear 22 and the input high idler gear 23 are capable of idling with respect to the input shaft 20. The input low clutch 24, in an engaged state, engages the input low idler gear 22 with the input shaft 20. The input high clutch 25, in an engaged state, engages the input high idler gear 23 with the input shaft 20.

[0019] The transmission 7 includes a reverse gear 31, a reverse low idler gear 32, a reverse high idler gear 33, a reverse low clutch 34, and a reverse high clutch 35. The reverse gear 31, the reverse low idler gear 32, the reverse high idler gear 33, the reverse low clutch 34, and the reverse high clutch 35 are disposed on a reversing shaft 30. The reverse gear 31 is fixed to the reversing shaft 30. The reverse gear 31 meshes with the input gear 21. As a result, the reversing shaft 30 is constantly rotating in the opposite direction to the input shaft 20 in response to the rotation of the input shaft 20. The reverse low idler gear 32 and the reverse high idler gear 33 are capable of idling with respect to the reversing shaft 30. The reverse low idler gear 32 meshes with a first low fixed gear 41. The reverse high idler gear 33 meshes with a first high fixed gear 42. The reverse low clutch 34 engages the reverse low idler gear 32 with the reversing shaft 30 in an engaged state. The reverse high clutch 35, when engaged, causes the reverse high idler gear 33 to engage with the reverse shaft 30.

[0020] The transmission 7 includes a first low fixed gear 41, a first high fixed gear 42, a first low idler gear 43, a first high idler gear 44, a first low clutch 45, and a first high clutch 46. The first low fixed gear 41, the first high fixed gear 42, the first low idler gear 43, the first high idler gear 44, the first low clutch 45, and the first high clutch 46 are disposed on a first intermediate shaft 40. The first low fixed gear 41 and the first high fixed gear 42 are fixed to the first intermediate shaft 40. The first low fixed gear 41 meshes with the input low idler gear 22 and the reverse low idler gear 32. The first high fixed gear 42 meshes with the input high idler gear 23 and the reverse high idler gear 33. The first low idler gear 43 and the first high idler gear 44 are capable of idling with respect to the first intermediate shaft 40. In an engaged state, the first low clutch 45 engages the first low idler gear 43 with the first intermediate shaft 40. In an engaged state, the first high clutch 46 engages the first high idler gear 44 with the first intermediate shaft 40.

[0021] The transmission 7 includes a second low fixed gear 51, a second high fixed gear 52, a second low idler gear 53, a second high idler gear 54, a second low clutch 55, and a second high clutch 56. The second low fixed gear 51, the second high fixed gear 52, the second low idler gear 53, the second high idler gear 54, the second low clutch 55, and the second high clutch 56 are disposed on a second intermediate shaft 50. The second low fixed gear 51 and the second high fixed gear 52 are fixed to the second intermediate shaft 50. The second low fixed gear 51 meshes with the first low idler gear 43. The second high fixed gear 52 meshes with the first high idler gear 44. The second low idler gear 53 and the second high idler gear 54 are capable of idling with respect to the second intermediate shaft 50. In an engaged state, the second low clutch 55 engages the second low idler gear 53 with the second intermediate shaft 50. In an engaged state, the second high clutch 56 engages the second high idler gear 54 with the second intermediate shaft 50.

[0022] The transmission 7 includes an output low fixed gear 61 and an output high fixed gear 62. The output low fixed gear 61 and the output high fixed gear 62 are arranged on an output shaft 60. The output low fixed gear 61 and the output high fixed gear 62 are fixed to the output shaft 60. The output low fixed gear 61 meshes with the second low idler gear 53. The output high fixed gear 62 meshes with the second high idler gear 54. No clutch is arranged on the output shaft 60.

[0023] Fig. 4 is a schematic diagram showing the configuration of a control system for the transmission 7 mounted on the work machine 1. As shown in Fig. 4, the work machine 1 is equipped with a shift operation device 71, a control valve 72, and a controller 73. The shift operation device 71 can be operated by an operator to change the speed stage of the transmission 7. The shift operation device 71 includes, for example, a shift lever.

[0024] The control valve 72 includes a plurality of valves corresponding to the plurality of clutches 24, 25, 34, 35, 45, 46, 55, and 56. The control valve 72 controls the flow rate of hydraulic oil supplied to the plurality of clutches 24, 25, 34, 35, 45, 46, 55, and 56 of the transmission 7 in response to a command signal from the controller 73. The plurality of clutches 24, 25, 34, 35, 45, 46, 55, and 56 are hydraulic clutches, and are switched between a disengaged state and an engaged state in response to the hydraulic pressure of the supplied hydraulic oil.

[0025] The controller 73 controls the control valve 72 to control the hydraulic pressure of each of the clutches 24, 25, 34, 35, 45, 46, 55, and 56. In this way, the controller 73 switches the speed stage of the transmission 7 in response to the operation of the shift operation device 71 by switching between an engaged state and a disengaged state of each of the multiple clutches 24, 25, 34, 35, 45, 46, 55, and 56. Alternatively, the controller 73 may automatically switch the speed stage of the transmission 7 based on the vehicle speed or the engine rotation speed, without depending on the operation of the shift operation device 71.

[0026] FIG. 5 is a table showing the engaged and disengaged states of the multiple clutches 24, 25, 34, 35, 45, 46, 55, 56 at each speed stage. In FIG. 5, F1 to F8 indicate forward speed stages from 1st to 8th speed stages. R1 to R8 indicate reverse speed stages from 1st to 8th speed stages. FL indicates the input low clutch 24. FH indicates the input high clutch 25. RL indicates the reversing low clutch 34. RH indicates the reversing high clutch 35. 1L indicates the first low clutch 45. 1H indicates the first high clutch 46. 2L indicates the second low clutch 55. 2H indicates the second high clutch 56. The circles in each column of FIG. 5 indicate the engaged state. The blank columns indicate the disengaged state.

[0027] As shown in Fig. 5, when the speed stage of the transmission 7 is the first forward speed, the controller 73 engages the input low clutch 24, the first low clutch 45, and the second low clutch 55, and disengages the other clutches. As a result, the driving force from the engine 5 is transmitted from the input shaft 20 to the output shaft 60 via the input low clutch 24, the input low idler gear 22, the first low fixed gear 41, the first intermediate shaft 40, the first low clutch 45, the first low idler gear 43, the second low fixed gear 51, the second intermediate shaft 50, the second low clutch 55, the second low idler gear 53, and the output low fixed gear 61, as shown in Fig. 6.

[0028] When the speed stage of the transmission 7 is the second forward speed, the controller 73 engages the input high clutch 25, the first low clutch 45, and the second low clutch 55, and disengages the other clutches. As a result, the driving force from the engine 5 is transmitted from the input shaft 20 to the output shaft 60 via the input high clutch 25, the input high idler gear 23, the first high fixed gear 42, the first intermediate shaft 40, the first low clutch 45, the first low idler gear 43, the second low fixed gear 51, the second intermediate shaft 50, the second low clutch 55, the second low idler gear 53, and the output low fixed gear 61, as shown in FIG.

[0029] When the speed stage of the transmission 7 is the third forward speed, the controller 73 engages the input low clutch 24, the first high clutch 46, and the second low clutch 55, and disengages the other clutches. As a result, the driving force from the engine 5 is transmitted from the input shaft 20 to the output shaft 60 via the input low clutch 24, the input low idler gear 22, the first low fixed gear 41, the first intermediate shaft 40, the first high clutch 46, the first high idler gear 44, the second high fixed gear 52, the second intermediate shaft 50, the second low clutch 55, the second low idler gear 53, and the output low fixed gear 61, as shown in FIG.

[0030] When the speed stage of the transmission 7 is the fourth forward speed, the controller 73 engages the input high clutch 25, the first high clutch 46, and the second low clutch 55, and disengages the other clutches. As a result, the driving force from the engine 5 is transmitted from the input shaft 20 to the output shaft 60 via the input high clutch 25, the input high idler gear 23, the first high fixed gear 42, the first intermediate shaft 40, the first high clutch 46, the first high idler gear 44, the second high fixed gear 52, the second intermediate shaft 50, the second low clutch 55, the second low idler gear 53, and the output low fixed gear 61, as shown in FIG.

[0031] When the speed stage of the transmission 7 is the fifth forward speed, the controller 73 engages the input low clutch 24, the first low clutch 45, and the second high clutch 56, and disengages the other clutches. As a result, the driving force from the engine 5 is transmitted from the input shaft 20 to the output shaft 60 via the input low clutch 24, the input low idler gear 22, the first low fixed gear 41, the first intermediate shaft 40, the first low clutch 45, the first low idler gear 43, the second low fixed gear 51, the second intermediate shaft 50, the second high clutch 56, the second high idler gear 54, and the output high fixed gear 62, as shown in FIG.

[0032] When the speed stage of the transmission 7 is the sixth forward speed, the controller 73 engages the input high clutch 25, the first low clutch 45, and the second high clutch 56, and disengages the other clutches. As a result, the driving force from the engine 5 is transmitted from the input shaft 20 to the output shaft 60 via the input high clutch 25, the input high idler gear 23, the first high fixed gear 42, the first intermediate shaft 40, the first low clutch 45, the first low idler gear 43, the second low fixed gear 51, the second intermediate shaft 50, the second high clutch 56, the second high idler gear 54, and the output high fixed gear 62, as shown in FIG.

[0033] When the speed stage of the transmission 7 is the seventh forward speed, the controller 73 engages the input low clutch 24, the first high clutch 46, and the second high clutch 56, and disengages the other clutches. As a result, the driving force from the engine 5 is transmitted from the input shaft 20 to the output shaft 60 via the input low clutch 24, the input low idler gear 22, the first low fixed gear 41, the first intermediate shaft 40, the first high clutch 46, the first high idler gear 44, the second high fixed gear 52, the second intermediate shaft 50, the second high clutch 56, the second high idler gear 54, and the output high fixed gear 62, as shown in FIG.

[0034] When the speed stage of the transmission 7 is the eighth forward speed, the controller 73 engages the input high clutch 25, the first high clutch 46, and the second high clutch 56, and disengages the other clutches. As a result, the driving force from the engine 5 is transmitted from the input shaft 20 to the output shaft 60 via the input high clutch 25, the input high idler gear 23, the first high fixed gear 42, the first intermediate shaft 40, the first high clutch 46, the first high idler gear 44, the second high fixed gear 52, the second intermediate shaft 50, the second high clutch 56, the second high idler gear 54, and the output high fixed gear 62, as shown in FIG.

[0035] When the speed stage of the transmission 7 is the first reverse speed, the controller 73 engages the reverse low clutch 34, the first low clutch 45, and the second low clutch 55, and disengages the other clutches. As a result, the driving force from the engine 5 is transmitted from the input shaft 20 to the output shaft 60 via the input gear 21, the reverse gear 31, the reverse shaft 30, the reverse low clutch 34, the reverse low idler gear 32, the first low fixed gear 41, the first intermediate shaft 40, the first low clutch 45, the first low idler gear 43, the second low fixed gear 51, the second intermediate shaft 50, the second low clutch 55, the second low idler gear 53, and the output low fixed gear 61, as shown in FIG.

[0036] When the speed stage of the transmission 7 is the second reverse speed, the controller 73 engages the reverse high clutch 35, the first low clutch 45, and the second low clutch 55, and disengages the other clutches. As a result, the driving force from the engine 5 is transmitted from the input shaft 20 to the output shaft 60 via the input gear 21, the reverse gear 31, the reverse shaft 30, the reverse high clutch 35, the reverse high idler gear 33, the first high fixed gear 42, the first intermediate shaft 40, the first low clutch 45, the first low idler gear 43, the second low fixed gear 51, the second intermediate shaft 50, the second low clutch 55, the second low idler gear 53, and the output low fixed gear 61, as shown in FIG.

[0037] When the speed stage of the transmission 7 is the third reverse speed, the controller 73 engages the reverse low clutch 34, the first high clutch 46, and the second low clutch 55, and disengages the other clutches. As a result, the driving force from the engine 5 is transmitted from the input shaft 20 to the output shaft 60 via the input gear 21, the reverse gear 31, the reverse shaft 30, the reverse low clutch 34, the reverse low idler gear 32, the first low fixed gear 41, the first intermediate shaft 40, the first high clutch 46, the first high idler gear 44, the second high fixed gear 52, the second intermediate shaft 50, the second low clutch 55, the second low idler gear 53, and the output low fixed gear 61, as shown in FIG.

[0038] When the speed stage of the transmission 7 is the fourth reverse speed, the controller 73 engages the reverse high clutch 35, the first high clutch 46, and the second low clutch 55, and disengages the other clutches. As a result, the driving force from the engine 5 is transmitted from the input shaft 20 to the output shaft 60 via the input gear 21, the reverse gear 31, the reverse shaft 30, the reverse high clutch 35, the reverse high idler gear 33, the first high fixed gear 42, the first intermediate shaft 40, the first high clutch 46, the first high idler gear 44, the second high fixed gear 52, the second intermediate shaft 50, the second low clutch 55, the second low idler gear 53, and the output low fixed gear 61, as shown in FIG.

[0039] When the speed stage of the transmission 7 is the fifth reverse speed, the controller 73 engages the reverse low clutch 34, the first low clutch 45, and the second high clutch 56, and disengages the other clutches. As a result, the driving force from the engine 5 is transmitted from the input shaft 20 to the output shaft 60 via the input gear 21, the reverse gear 31, the reverse shaft 30, the reverse low clutch 34, the reverse low idler gear 32, the first low fixed gear 41, the first intermediate shaft 40, the first low clutch 45, the first low idler gear 43, the second low fixed gear 51, the second intermediate shaft 50, the second high clutch 56, the second high idler gear 54, and the output high fixed gear 62, as shown in FIG.

[0040] When the speed stage of the transmission 7 is the sixth reverse speed, the controller 73 engages the reverse high clutch 35, the first low clutch 45, and the second high clutch 56, and disengages the other clutches. As a result, the driving force from the engine 5 is transmitted from the input shaft 20 to the output shaft 60 via the input gear 21, the reverse gear 31, the reverse shaft 30, the reverse high clutch 35, the reverse high idler gear 33, the first high fixed gear 42, the first intermediate shaft 40, the first low clutch 45, the first low idler gear 43, the second low fixed gear 51, the second intermediate shaft 50, the second high clutch 56, the second high idler gear 54, and the output high fixed gear 62, as shown in FIG.

[0041] When the speed stage of the transmission 7 is the seventh reverse speed, the controller 73 engages the reverse low clutch 34, the first high clutch 46, and the second high clutch 56, and disengages the other clutches. As a result, the driving force from the engine 5 is transmitted from the input shaft 20 to the output shaft 60 via the input gear 21, the reverse gear 31, the reverse shaft 30, the reverse low clutch 34, the reverse low idler gear 32, the first low fixed gear 41, the first intermediate shaft 40, the first high clutch 46, the first high idler gear 44, the second high fixed gear 52, the second intermediate shaft 50, the second high clutch 56, the second high idler gear 54, and the output high fixed gear 62, as shown in FIG.

[0042] When the speed stage of the transmission 7 is the eighth reverse speed, the controller 73 engages the reverse high clutch 35, the first high clutch 46, and the second high clutch 56, and disengages the other clutches. As a result, the driving force from the engine 5 is transmitted from the input shaft 20 to the output shaft 60 via the input gear 21, the reverse gear 31, the reverse shaft 30, the reverse high clutch 35, the reverse high idler gear 33, the first high fixed gear 42, the first intermediate shaft 40, the first high clutch 46, the first high idler gear 44, the second high fixed gear 52, the second intermediate shaft 50, the second high clutch 56, the second high idler gear 54, and the output high fixed gear 62, as shown in FIG.

[0043] In the transmission 7 according to the present embodiment described above, the multiple clutches 24, 25, 34, 35, 45, 46, 55, 56 are all disposed on the upstream transmission shaft in the path of transmission of driving force. The torque of the upstream transmission shaft is smaller than the torque of the downstream transmission shaft. Therefore, the multiple clutches 24, 25, 34, 35, 45, 46, 55, 56 can be made smaller than when all or some of the multiple clutches 24, 25, 34, 35, 45, 46, 55, 56 are provided on the downstream transmission shaft. This allows the transmission 7 to be made smaller.

[0044] In detail, the input low clutch 24 and the input high clutch 25 for transmitting driving force from the input shaft 20 to the first intermediate shaft 40 are disposed on the input shaft 20 which is the upstream side of the input shaft 20 and the first intermediate shaft 40. The first low clutch 45 and the first high clutch 46 for transmitting driving force from the first intermediate shaft 40 to the second intermediate shaft 50 are disposed on the first intermediate shaft 40 which is the upstream side of the first intermediate shaft 40 and the second intermediate shaft 50. The second low clutch 55 and the second high clutch 56 for transmitting driving force from the second intermediate shaft 50 to the output shaft 60 are disposed on the second intermediate shaft 50 which is the upstream side of the second intermediate shaft 50 and the output shaft 60.

[0045] The torque of the input shaft 20 is smaller than the torque of the first intermediate shaft 40. The torque of the first intermediate shaft 40 is smaller than the torque of the second intermediate shaft 50. The torque of the second intermediate shaft 50 is smaller than the torque of the second intermediate shaft 50. Therefore, the multiple clutches 24, 25, 34, 35, 45, 46, 55, and 56 can each be made smaller. In this way, all of the multiple clutches 24, 25, 34, 35, 45, 46, 55, and 56 are disposed on the upstream transmission shaft, thereby making the transmission 7 smaller in size.

[0046] Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible without departing from the gist of the invention.

[0047] The work machine 1 is not limited to a motor grader, and may be another machine such as a wheel loader. The configuration of the transmission 7 is not limited to that of the above embodiment, and may be changed. For example, in the above embodiment, when the driving force is transmitted via the reversing shaft 30, the work machine 1 moves backward. However, when the driving force is transmitted via the reversing shaft 30, the work machine 1 may move forward. The control valve 72 may be directly controlled in response to the operation of the shift operation device 71, not by a signal from the controller 73. The multiple clutches 24, 25, 34, 35, 45, 46, 55, 56 are not limited to hydraulic clutches, and may be electromagnetic clutches. [Industrial Applicability]

[0048] According to the present disclosure, the transmission can be made smaller. [Explanation of symbols]

[0049] 7: transmission, 20: input shaft, 22: input low idler gear, 23: input high idler gear, 24: input low clutch, 25: input high clutch, 30: reversing shaft, 34: reversing low clutch, 35: reversing high clutch, 40: first intermediate shaft, 41: first low fixed gear, 42: first high fixed gear, 43: first low idler gear, 44: first high idler gear, 45: first low clutch, 46: first high clutch, 50: second intermediate shaft, 51: second low fixed gear, 52: second high fixed gear, 53: second low idler gear, 54: second high idler gear, 55: second low clutch, 56: second high clutch, 61: output low fixed gear, 62: output high fixed gear, 60: output shaft

Claims

1. An input shaft; An output shaft; a first intermediate shaft disposed between the input shaft and the output shaft in a power transmission path; a second intermediate shaft disposed in the transmission path between the first intermediate shaft and the output shaft; an input clutch that transmits rotation of the input shaft to the first intermediate shaft in an engaged state; a first clutch that transmits rotation of the first intermediate shaft to the second intermediate shaft in an engaged state; a second clutch that transmits rotation of the second intermediate shaft to the output shaft in an engaged state; Equipped with The input clutch is disposed on the input shaft, the first clutch is disposed on the first intermediate shaft, The second clutch is disposed on the second intermediate shaft. transmission.

2. A reversing shaft that rotates in a direction opposite to that of the input shaft due to the rotation of the input shaft; a reversing clutch that, in an engaged state, transmits rotation of the reversing shaft to the first intermediate shaft; Further equipped with The reversing clutch is disposed on the reversing shaft.

2. The transmission of claim 1.

3. An input shaft; An output shaft; a first intermediate shaft disposed between the input shaft and the output shaft in a power transmission path; a second intermediate shaft disposed in the transmission path between the first intermediate shaft and the output shaft; an input low idler gear that is disposed on the input shaft and is capable of idling relative to the input shaft; an input high idler gear that is disposed on the input shaft and is capable of idling relative to the input shaft; a first low fixed gear disposed on the first intermediate shaft and meshing with the input low idler gear; a first high fixed gear disposed on the first intermediate shaft and meshing with the input high idler gear; an input low clutch that, in an engaged state, engages the input low idler gear with the input shaft and transmits rotation of the input shaft to the first intermediate shaft; an input high clutch that, in an engaged state, engages the input high idler gear with the input shaft and transmits rotation of the input shaft to the first intermediate shaft; a first low idler gear that is disposed on the first intermediate shaft and is capable of idling relative to the first intermediate shaft; a first high idler gear disposed on the first intermediate shaft and rotatable idler with respect to the first intermediate shaft; a second low fixed gear disposed on the second intermediate shaft and meshing with the first low idler gear; a second high fixed gear disposed on the second intermediate shaft and meshing with the first high idler gear; a first low clutch that, in an engaged state, engages the first low idler gear with the first intermediate shaft and transmits rotation of the first intermediate shaft to the second intermediate shaft; a first high clutch that, in an engaged state, engages the first high idler gear with the first intermediate shaft and transmits rotation of the first intermediate shaft to the second intermediate shaft; a second low idler gear disposed on the second intermediate shaft and rotatable idler gear relative to the second intermediate shaft; a second high idler gear disposed on the second intermediate shaft and rotatable idler with respect to the second intermediate shaft; an output low fixed gear disposed on the output shaft and meshing with the second low idler gear; an output high fixed gear disposed on the output shaft and meshing with the second high idler gear; a second low clutch that, in an engaged state, engages the second low idler gear with the output shaft and transmits rotation of the second intermediate shaft to the output shaft; a second high clutch that, in an engaged state, engages the second high idler gear with the output shaft and transmits rotation of the second intermediate shaft to the output shaft; Equipped with the input low clutch and the input high clutch are disposed on the input shaft, the first low clutch and the first high clutch are disposed on the first intermediate shaft, the second low clutch and the second high clutch are disposed on the second intermediate shaft. transmission.

4. a plurality of transmission shafts including an input shaft, an output shaft, and an intermediate shaft disposed between the input shaft and the output shaft in a power transmission path; a plurality of clutches that connect the plurality of transmission shafts in an engaged state to transmit rotation of the upstream transmission shaft to the downstream transmission shaft; Equipped with The plurality of clutches are all disposed on the upstream side of the transmission shaft. transmission.

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