JP2012211672A - Speed change transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To drive a traveling device rearward in a wide speed change range while easily performing the operation of the stop of the traveling device and advance/reverse switching, and to perform the reverse drive by a simple structure.SOLUTION: This speed change transmission device comprises an advance/reverse switching mechanism 50 which can freely change a state to an advance transmission state that a drive force of an input shaft 22 is converted to an advance drive force and transmitted to a plane transmission part 40, and a reverse transmission state that the drive force of the input shaft 22 is converted to a reverse drive force and transmitted to the planetary transmission part 40. The advance/reverser switching mechanism 50 is constituted so as to be switchable to a neutral state that transmission between the input shaft 22 and the planetary transmission part 40 is blocked. There is arranged a clutch mechanism 60 which can switch linkage between a motor shaft 33a of a hydraulic continuous variable transmission 30 and an output rotating body 24 to an on-state and an off-state.

Description

  The present invention combines an input shaft for inputting engine driving force, a hydraulic continuously variable transmission driven by the input shaft, a driving force of the input shaft and an output of the hydraulic continuously variable transmission. The present invention relates to a speed change transmission device provided with a planetary transmission unit that outputs a composite driving force and an output rotating body that outputs a combined driving force.

Conventionally, for example, there has been a transmission gear described in Patent Documents 1 and 2.
In the one described in Patent Document 1, a hydraulic continuously variable transmission (hydraulic continuously variable transmission), a planetary gear mechanism (planetary transmission unit), and two hydraulic pressures are used as a transmission system that transmits engine output to the front and rear wheels. A clutch is provided, and one of the two hydraulic clutches is connected to form an HST mode drive system (HST mode transmission). After the engine output is shifted by the hydraulic continuously variable transmission, the front and rear wheels When the other of the two hydraulic clutches is connected, an HMT mode drive system (HMT mode transmission) is configured, and the output of the hydraulic continuously variable transmission is input to the planetary gear device, The engine output and the output of the hydraulic continuously variable transmission are combined to output a combined driving force, which is transmitted to the front and rear wheels.

  In Patent Document 2, a transmission system that transmits engine output to a front wheel differential mechanism and a rear wheel differential mechanism includes a continuously variable transmission (hydraulic continuously variable transmission), a planetary transmission, A switching device is provided, and the engine output is input to the continuously variable transmission unit and the planetary transmission unit, the planetary gear unit combines the output of the engine and the output of the hydraulic continuously variable transmission, and the planetary gear unit outputs the combined drive The force is input to the forward / reverse switching device and converted into forward drive force and reverse drive force, and then transmitted to the front wheel differential mechanism and the rear wheel differential mechanism.

JP 2001-108061 A JP 2008-195334 A

  An input shaft for inputting engine driving force, a hydraulic continuously variable transmission driven by the input shaft, and a planetary that outputs a combined driving force by combining the driving force of the input shaft and the output of the hydraulic continuously variable transmission In a speed change transmission device provided with a transmission unit and an output rotator that outputs to the traveling device, the engine driving force is not subjected to synthesis by the planetary transmission unit but is subjected to a shift by a hydraulic continuously variable transmission and transmitted to the output rotator. If the HST mode transmission and the HMT mode transmission in which the engine driving force is combined by the planetary transmission unit and transmitted to the output rotating body can be produced, the output performance as shown in FIG. 10 is provided. be able to.

  FIG. 10 is an explanatory diagram showing the relationship between the shift state of the hydraulic continuously variable transmission and the output speed of the output rotor. The horizontal axis of FIG. 10 shows the shift state of the hydraulic continuously variable transmission, and the vertical axis shows the rotation direction and output speed of the output rotating body. “N” on the horizontal axis indicates the neutral position of the hydraulic continuously variable transmission, “−max” on the horizontal axis indicates the highest speed position in the reverse transmission state of the hydraulic continuously variable transmission, “+ Max” indicates the highest speed position in the forward transmission state of the hydraulic continuously variable transmission. The solid line RL shown in FIG. 10 indicates the output of the reverse drive force in a state where the HST mode transmission is exhibited, and the solid line FL indicates the output of the forward drive force in a state where the HST mode transmission is manifested, A solid line FH indicates the output of the forward drive force in a state where the HMT mode transmission is made to appear.

  As indicated by the solid line RL, when the hydraulic continuously variable transmission is operated to the highest speed position “−max” in the reverse transmission state in the state where the HST mode transmission is made to appear, the output speed becomes the maximum reverse speed “ RV ", while maintaining the HST mode transmission, as the hydraulic continuously variable transmission is shifted from the highest speed position" -max "in the reverse transmission state to the neutral position" n ", the reverse output When the speed is reduced and the hydraulic continuously variable transmission reaches the neutral position “n”, the output speed becomes “0”. As indicated by the solid line FL, when the hydraulic continuously variable transmission is shifted from the neutral position “n” to the forward transmission state while maintaining the HST mode transmission, the output is switched from the reverse output to the forward output. As the hydraulic continuously variable transmission is shifted from the neutral position “n” toward the highest speed position “+ max” in the forward transmission state, the forward output speed increases, and the hydraulic continuously variable transmission When the maximum speed position “+ max” in the forward transmission state is reached, the forward output speed becomes “FV1”. As shown by the solid line FH, when the hydraulic continuously variable transmission reaches the maximum speed position “+ max” in the forward transmission state, the HMT mode transmission is displayed instead of the HST mode transmission, and the HMT mode transmission is maintained. As the hydraulic continuously variable transmission is shifted from the highest speed position “+ max” in the forward transmission state to the highest speed position “−max” in the reverse transmission state, the forward output speed increases, and the hydraulic type When the continuously variable transmission reaches the maximum speed position “−max” in the reverse transmission state, the forward output becomes the maximum speed “FV2”.

  In other words, when the HST mode transmission and the HMT mode transmission can be realized, the output is set to zero “0” so that the traveling device can be stopped simply by shifting the hydraulic continuously variable transmission. In addition, the output can be switched between the forward output and the reverse output so that the traveling device can be driven by switching between the forward side and the reverse side. However, the HMT mode transmission can be transmitted with better transmission efficiency than the HST mode transmission, and the forward driving force is transmitted to the output rotating body by the HMT mode transmission, so that the shift range of the reverse output is the forward output speed range. It becomes narrower than the speed change range.

  Applying the conventional technology in which a forward / reverse switching device is provided on the lower side of the transmission direction from the planetary transmission unit, the output of the hydraulic continuously variable transmission and the planetary transmission unit is input to the forward / reverse switching mechanism to move forward drive force and reverse If the driving force is converted to the output rotator after being converted, the reverse output speed change range becomes the same as the forward output speed change range.

  FIG. 11 shows a hydraulic continuously variable transmission and a planetary transmission unit configured to convert the output to a forward drive force and a reverse drive force by a forward / reverse switching mechanism and to transmit the output to an output rotating body. It is explanatory drawing which shows the relationship between the speed change state of a transmission, and the output speed of an output rotary body. The solid lines FL and FH shown in FIG. 11 indicate the output of the forward drive force, and the solid lines RL and RH indicate the output of the reverse drive force.

  As indicated by the solid line FL, when the hydraulic continuously variable transmission is operated to the neutral position “n” in a state where the HST mode transmission is made to appear, the output becomes zero “0”. While maintaining the HST mode transmission and switching the forward / reverse switching mechanism to the forward transmission state and maintaining the forward transmission state, the hydraulic continuously variable transmission is moved from the neutral position “n” to the maximum speed position “ As the speed change operation is performed toward “+ max”, the forward output speed increases, and when the hydraulic continuously variable transmission reaches the maximum speed position “+ max” in the forward transmission state, the forward output speed becomes “FV1”. become. As indicated by the solid line FH, when the hydraulic continuously variable transmission reaches the maximum speed position “+ max” in the forward transmission state, the HMT mode transmission is displayed instead of the HST mode transmission, and the HMT mode transmission is maintained. And, while maintaining the forward / reverse switching mechanism in the forward transmission state, the hydraulic continuously variable transmission performs a shift operation from the highest speed position “+ max” in the forward transmission state to the highest speed position “−max” in the reverse transmission state. As a result, the forward output speed increases, and when the hydraulic continuously variable transmission reaches the maximum speed position “−max” in the reverse transmission state, the forward output reaches the maximum speed “FV2”. As indicated by the solid line RL, when the hydraulic continuously variable transmission is operated to the neutral position “n”, the forward / reverse switching mechanism is switched to the reverse transmission state, while maintaining the HST mode transmission, the forward / reverse switching mechanism As the hydraulic continuously variable transmission is shifted from the neutral position “n” toward the maximum speed position “+ max” in the forward transmission state, the reverse output speed increases. When the hydraulic continuously variable transmission reaches the maximum speed position “+ max” in the forward transmission state, the reverse output speed becomes “RV1”. As shown by the solid line RH, when the hydraulic continuously variable transmission reaches the maximum speed position “+ max” in the forward transmission state, the HMT mode transmission is displayed by switching to the HST mode transmission, and the HMT mode transmission is maintained. And, while maintaining the forward / reverse switching mechanism in the reverse transmission state, the hydraulic continuously variable transmission performs a shift operation from the highest speed position “+ max” in the forward transmission state to the highest speed position “−max” in the reverse transmission state. As a result, the reverse output speed increases, and when the hydraulic continuously variable transmission reaches the maximum speed position “−max” in the reverse transmission state, the reverse output reaches the maximum speed “RV2.”

  In other words, when the output of the hydraulic continuously variable transmission and the planetary transmission unit is input to the forward / reverse switching mechanism and converted to the forward drive force and the reverse drive force and then transmitted to the output rotating body, the forward drive is performed. When switching to the reverse drive after stopping the traveling device, and when switching to the forward drive after stopping the travel device that was driving backward, the forward / reverse switching mechanism is changed from one of the forward transmission state and the reverse transmission state to the other. It is necessary to switch to.

  An object of the present invention is to provide a speed change transmission apparatus that can easily stop and change the forward / reverse switching of the traveling apparatus, can drive the traveling apparatus backward in a wide speed range, and can have a simple structure. It is in.

The first invention combines an input shaft for inputting engine driving force, a hydraulic continuously variable transmission driven by the input shaft, a driving force of the input shaft and an output of the hydraulic continuously variable transmission. In the transmission transmission device provided with a planetary transmission unit that outputs a combined driving force and an output rotating body that outputs to the traveling device,
A forward transmission state in which the driving force of the input shaft is converted into a forward driving force and transmitted to the planetary transmission portion, and a reverse transmission state in which the driving force of the input shaft is converted into a backward driving force and transmitted to the planetary transmission portion A forward / reverse switching mechanism that can be switched freely is provided.
The forward / backward switching mechanism is configured to be freely switchable to a neutral state in which transmission between the input shaft and the planetary transmission unit is cut off,
A clutch mechanism is provided that can switch the interlocking between the motor shaft of the hydraulic continuously variable transmission and the output rotating body between the on state and the off state.

According to the configuration of the first aspect of the invention, when the forward / reverse switching mechanism is switched to the neutral state, and the clutch mechanism is switched to bring the motor shaft of the hydraulic continuously variable transmission and the output rotor into the interlocked state, The hydraulic continuously variable transmission is driven by the engine driving force input by the input shaft, the engine driving force input by the input shaft is not transmitted to the planetary transmission unit, and the engine driving force is shifted by the hydraulic continuously variable transmission. Then, the HST mode transmission can be made to appear so as to be transmitted to the output rotating body.
When the forward / reverse switching mechanism is switched to the forward transmission state, and the clutch mechanism is switched so that the motor shaft of the hydraulic continuously variable transmission and the output rotating body are switched to the interlocked state, the engine drive input by the input shaft The hydraulic continuously variable transmission is driven by the force, the engine driving force input by the input shaft is converted into the forward driving force by the forward / reverse switching mechanism and transmitted to the planetary transmission unit, and the output of the hydraulic continuously variable transmission is The forward drive force from the forward / reverse switching mechanism is combined by the planetary transmission unit so that the planetary transmission unit outputs the forward combined drive force, and the forward drive combined force is transmitted to the output rotor. HMT mode transmission can be revealed.
When the forward / reverse switching mechanism is switched to the reverse transmission state, and the clutch mechanism is switched so that the motor shaft of the hydraulic continuously variable transmission and the output rotating body are switched to the interlocked state, the engine drive input by the input shaft The hydraulic continuously variable transmission is driven by the force, and the engine driving force input by the input shaft is converted into the backward driving force by the forward / reverse switching mechanism and transmitted to the planetary transmission unit, and the output of the hydraulic continuously variable transmission is The reverse drive force from the forward / reverse switching mechanism is combined with the planetary transmission unit so that the planetary transmission unit outputs the reverse drive force and the reverse drive force is transmitted to the output rotor. HMT mode transmission can be revealed.

  In other words, when the forward / reverse switching mechanism and the clutch mechanism are appropriately operated along with the shifting operation of the hydraulic continuously variable transmission mechanism, the relationship between the shift state of the hydraulic continuously variable transmission and the output speed by the output rotating body is illustrated. As shown in FIG. That is, as shown by the solid line FL in FIG. 7, when the hydraulic continuously variable transmission is operated to the neutral position “n” in the state where the HST mode transmission has appeared, the output becomes zero “0”. While the HST mode transmission is maintained, the forward output speed increases as the hydraulic continuously variable transmission is shifted from the neutral position “n” toward the highest speed position “+ max” in the forward transmission state. When the hydraulic continuously variable transmission reaches the maximum speed position “+ max” in the forward transmission state, the forward output speed becomes “FV1”. As indicated by solid lines FM and FH, when the hydraulic continuously variable transmission reaches the maximum speed position “+ max” in the forward transmission state, the forward HMT mode transmission appears in place of the HST mode transmission, As the hydraulic continuously variable transmission is shifted from the highest speed position “+ max” in the forward transmission state to the highest speed position “−max” in the reverse transmission state while the HMT mode transmission is maintained, the forward output is output. When the speed increases steplessly and the hydraulic continuously variable transmission reaches the maximum speed position “−max” in the reverse transmission state, the forward output becomes the maximum speed “FV2”.

As indicated by the solid line RL, when the hydraulic continuously variable transmission is shifted from the neutral position “n” to the highest speed position “−max” in the reverse transmission state while the HST mode transmission is maintained, As the output becomes reverse output and the hydraulic continuously variable transmission is shifted from the neutral position “n” to the maximum speed position “−max” in the reverse transmission state, the reverse output speed increases steplessly. When the hydraulic continuously variable transmission reaches the maximum speed position “−max” in the reverse transmission state, the reverse output speed becomes “RV1”. As indicated by solid lines RM and RH, when the hydraulic continuously variable transmission reaches the maximum speed position “−max” in the reverse transmission state, the reverse HMT mode transmission appears in place of the HST mode transmission, and the reverse side As the hydraulic continuously variable transmission is shifted from the maximum speed position “−max” in the reverse transmission state to the maximum speed position “+ max” in the forward transmission state, the reverse movement of the hydraulic continuously variable transmission is maintained. When the output speed increases steplessly and the hydraulic continuously variable transmission reaches the maximum speed position “+ max” in the forward transmission state, the reverse output speed becomes the maximum speed “RV2”. The maximum reverse output speed “RV2” is higher than the reverse output speed “RV1” when the hydraulic continuously variable transmission is operated to the maximum speed position “−max” in the reverse transmission state.
In the shift range of the forward output speed “FV1” and the reverse output speed “RV1”, it is possible to perform gear shifting and forward / reverse switching without switching the forward / reverse switching mechanism by simply shifting the hydraulic continuously variable transmission. The

Therefore, the travel device can be stopped simply by shifting the hydraulic continuously variable transmission to the neutral position, and the operation can be easily performed simply by shifting the hydraulic continuously variable transmission from the neutral position to the forward or reverse side. The traveling device can be driven by switching between the forward side and the backward side. Further, when the traveling device is driven backward, the HMT mode transmission on the reverse side can be driven over a wide speed range, for example, in a combine or dozer work vehicle Repeating with good operability and moving backwards at a relatively high speed makes it easy and quick to perform alignment and position change, etc.
Furthermore, in order to make the HST mode transmission appear, the forward / reverse switching mechanism can be used as the clutch means to cut off the transmission to the planetary transmission section, and the structure can be simplified.

  According to the second aspect of the present invention, in the engaged state of the clutch mechanism, the sun gear, the planetary gear, and the ring gear that constitute the planetary transmission unit are interlocked so as to be integrally rotatable with respect to the motor shaft of the hydraulic continuously variable transmission. It is configured.

  According to the configuration of the second aspect of the invention, when the HST mode transmission appears, the sun gear, planetary gear and ring gear of the planetary transmission portion rotate integrally with the motor shaft, and the sun gear and planetary gear rotate relative to each other or the planetary gear and ring gear relative to each other. There is no rotation.

  Therefore, transmission in HST mode transmission can be performed while avoiding generation of power loss due to relative rotation of the sun gear, planetary gear, and ring gear.

The third aspect of the present invention is a forward transmission gear supported in a relatively rotatable manner on the input shaft in a state interlocked with the planetary transmission unit;
A forward clutch that is supported on the input shaft so as to be integrally rotatable and slidable so that the forward transmission gear and the input shaft are switched between an interlocked state and an interlocked off state by being engaged and disengaged with respect to the forward gear. Body,
A reverse transmission shaft that supports one of the input gear interlocked with the input shaft and the reverse transmission gear interlocked with the planetary transmission unit so as to be relatively rotatable, and the other is rotatably supported integrally;
Of the input gear and the reverse transmission gear, the clutch gear that is rotatably supported by the reverse transmission shaft is engaged and disengaged, and the clutch gear and the reverse transmission shaft are interlocked. The forward / reverse switching mechanism is configured to include a reverse clutch body that is supported on the reverse transmission shaft so as to be integrally rotatable and slidable so as to be switched between the on state and the interlocking cut state.

  According to the configuration of the third aspect of the invention, the forward clutch body can be supported using the input shaft as a support shaft, and as a result, only the reverse transmission shaft can be used as the transmission shaft to be added. A simple changeover mechanism can be constructed.

  Therefore, the forward / reverse switching mechanism can be constructed simply and inexpensively.

According to the fourth aspect of the present invention, the forward transmission gear and the reverse transmission gear are connected to the planetary transmission portion with the input gear and a transmission gear that is rotatably supported by the input shaft in a state of meshing with the input gear. Placed on the side opposite the side where
The forward transmission gear and the reverse transmission gear are meshed with an input gear provided at a position opposite to the side where the input gear and the transmission gear are located with respect to the sun gear of the planetary transmission unit.

  According to the configuration of the fourth aspect of the invention, the forward / reverse switching mechanism and the planetary transmission unit are compactly assembled so that the outer peripheral portion of the planetary transmission unit enters between the input gear and the reverse transmission gear or between the transmission gear and the forward transmission gear. Can be equipped.

  Therefore, it is possible to obtain the speed change transmission device in a compact state in which the forward / reverse switching mechanism and the planetary transmission unit are compactly combined.

It is a side view which shows the whole combine. It is a schematic front view which shows a transmission structure. It is a vertical front view which shows the speed change transmission apparatus in HST mode transmission. It is a vertical front view which shows the speed change transmission apparatus in the HMT mode transmission of the advance side. It is a vertical front view which shows the speed change transmission apparatus in the reverse side HMT mode transmission. It is explanatory drawing which shows the relationship between the operation state of a hydraulic continuously variable transmission, a forward clutch, a reverse clutch, and an output side clutch mechanism, and the transmission form of a transmission gearbox. It is explanatory drawing which shows the relationship between the speed change state of a hydraulic continuously variable transmission, and the output speed of a speed change transmission apparatus. It is a block diagram which shows a speed change operation apparatus. It is a vertical front view which shows the speed change transmission apparatus provided with another implementation structure. It is explanatory drawing which shows the output performance in the speed change transmission apparatus provided with the comparison structure. It is explanatory drawing which shows the output performance in the speed change transmission apparatus provided with the comparison structure.

Hereinafter, based on the drawings, a description will be given of a case in which a transmission according to the present invention is installed in a combine.
As shown in FIG. 1, a combine is configured to be self-propelled by a pair of left and right crawler type traveling devices 1, 1, and is equipped with a riding type driving unit 2, and a body frame of the traveling body 3, a cutting part 4 connected to the front part of the machine frame 3, a threshing device 5 provided behind the cutting part 4 on the rear side of the machine body frame 3, And a grain tank 6 arranged and provided on the side, and harvesting rice, wheat and the like.

  That is, the cutting unit 4 includes a cutting unit frame 4a that extends from the front portion of the body frame 3 so as to be able to swing up and down in the forward direction. The weeding tool 4b provided at the front end of the mowing unit 4 moves up and down to a lowering work position where the weeding tool 4b is lowered near the ground, and a rising non-working position where the weeding tool 4b is raised from the ground. When the mowing unit 4 is lowered to the lowering work position and the traveling machine body is run, the mowing unit 4 causes the planted culm to be harvested by the weeding tool 4b to be introduced into the path, and the planting that has been induced and introduced into the path. While raising the standing cereal and raising it by the device 4c, it is cut by the clipper type reaping device 4d, and the chopped cereal is supplied to the threshing device 5 by the supply device 4e. The threshing device 5 sandwiches the stock side of the harvested cereal meal from the supply device 4e by the threshing feed chain 5a and conveys it toward the rear of the machine body, and supplies the tip side of the harvested cereal meal to the handling room (not shown). The threshing process is performed, and the threshing grain is fed into the grain tank 6.

  The engine 8 is provided below the driver seat 2 a provided in the driving unit 2, and the driving force output from the engine 8 is driven by a pair of left and right traveling by the transmission structure 10 including the transmission case 11 provided at the front end of the body frame 3. It is configured to transmit to the devices 1 and 1.

  FIG. 2 is a front view showing a schematic structure of the transmission structure 10. As shown in this figure, the transmission structure 10 is provided with the engine driving force from the output shaft 8a of the engine 8 on the lateral side of the upper end portion of the transmission case 11 via the transmission mechanism 12 provided with the transmission belt 12a. Input to the transmission transmission device 20 and the output of the transmission transmission device 20 is input to the traveling mission 13 housed in the mission case 11 to the left of the pair of left and right steering clutch mechanisms 14, 14 provided in the traveling mission 13. The power is transmitted from the steering clutch mechanism 14 to the drive shaft 1a of the left traveling device 1, and is transmitted from the right steering clutch mechanism 14 to the drive shaft 1a of the right traveling device 1.

  The transmission structure 10 includes a cutting mission 15 incorporated in the mission case 11, and the output of the transmission 20 is input to the cutting mission 15 and transmitted from the cutting output shaft 16 to the drive shaft 4 f of the cutting unit 4.

The transmission 20 will be described.
As shown in FIG. 3, the transmission 20 includes a planetary transmission unit 20 </ b> A having a transmission case 21 having a lateral side connected to the upper end side of the transmission case 11, and a side connected to the transmission case 11 of the transmission case 21. And a hydraulic continuously variable transmission 30 having a casing 31 connected to the lateral side opposite to the above.

  The transmission case 21 houses a main case portion 21 a that houses the planetary transmission unit 40 and the forward / reverse switching mechanism 50, a coupling portion between the input shaft 22, the transmission shaft 23, and the hydraulic continuously variable transmission 30, and the transmission case 21. And a connection case portion 21 b for connecting the port block 34 of the casing 31. The transmission case 21 is connected to the transmission case 11 at a bulging portion 21c that is bulged outwardly on the lateral side of the lower side surface where the output rotating body 24 of the main case portion 21a is located. The size of the connecting case portion 21b in the vertical direction of the traveling machine body is smaller than the size of the main case portion 21a in the vertical direction of the traveling machine body. The main case portion 21a is formed so that the longitudinal cross-sectional shape when viewed in the longitudinal direction of the fuselage is a longitudinally long shape, and the casing 31 is formed such that the longitudinal sectional shape when viewed in the longitudinal direction of the aircraft is longitudinally elongated. While the portion 20A and the hydraulic continuously variable transmission 30 are arranged in the lateral direction of the vehicle body, the lateral width of the vehicle body as the entire transmission gear transmission 20 becomes small, and the transmission gear transmission device 20 does not protrude laterally in the lateral direction of the traveling vehicle body. Then, it is connected to the lateral side of the mission case 11 in a compact state. An oil filter 20F is disposed upward on the upper surface of the casing 31, and further downsizing is achieved by preventing the oil filter 20F from protruding outward.

  The planetary transmission unit 20A includes a laterally-facing input shaft 22 that is rotatably supported on the upper end side of the transmission case 21, and a transmission that is rotatably supported in parallel or substantially parallel to the input shaft 22 on the lower end side of the transmission case 21. A shaft 23 and a rotary shaft type output rotor 24, a planetary transmission unit 40 supported by the transmission shaft 23, and a forward / reverse switching mechanism 50 provided across the input shaft 22 and the carrier 41 of the planetary transmission unit 40. I have.

  The input shaft 22 is arranged so as to be aligned coaxially with the pump shaft 32 a of the hydraulic continuously variable transmission 30. The input shaft 22 is configured to be coupled to the output shaft 8a of the engine 8 via the transmission mechanism 12 on the side projecting laterally outward from the transmission case 21, and the joint on the opposite side to the side coupled to the engine 8 The hydraulic continuously variable transmission 30a is connected to the pump shaft 32a of the hydraulic continuously variable transmission 30 so as to be freely rotatable. The engine driving force is input via the transmission mechanism 12, and the hydraulic continuously variable transmission is driven by the engine driving force. The hydraulic pump 32 of the machine 30 is driven.

  The output rotating body 24 is arranged on the same side as the side where the engine connection side of the input shaft 22 is located with respect to the hydraulic continuously variable transmission 30 so as to be aligned coaxially with the motor shaft 33a of the hydraulic continuously variable transmission 30. Has been. The output rotator 24 is configured to be interlocked with the input portion of the traveling mission 11 on the side projecting laterally outward from the speed change case 21, and receives the driving force from the planetary transmission portion 40 and the hydraulic continuously variable transmission 30. Output to the pair of left and right traveling devices 1, 1 via the traveling mission 13.

  The hydraulic continuously variable transmission 30 includes a hydraulic pump 32 in which a pump shaft 32a is rotatably supported on an upper end side of a casing 31, and a hydraulic motor in which a motor shaft 33a is rotatably supported on a lower end side of the casing 31. 33. The hydraulic pump 32 is a variable displacement axial plunger pump, and the hydraulic motor 33 is a variable displacement axial plunger motor. The hydraulic motor 33 is driven by pressure oil that is discharged by the hydraulic pump 32 and supplied through an oil passage formed inside the port block 34. The hydraulic continuously variable transmission 30 is supplied with supplementary hydraulic fluid by a charge pump 90 provided on the engine coupling side of the input shaft 22. The charge pump 90 includes a rotor 90 a that is connected to the input shaft 22 so as to be integrally rotatable, and a pump casing 90 b that is detachably connected to the transmission case 21.

  Therefore, the hydraulic continuously variable transmission 30 is switched to the forward transmission state, the reverse transmission state, and the neutral state by performing an angle changing operation of the swash plate 32b included in the hydraulic pump 32. When the hydraulic continuously variable transmission 30 is operated to switch to the forward transmission state, the engine driving force transmitted from the input shaft 22 to the pump shaft 32a is converted into the forward driving force and output from the motor shaft 33a for reverse transmission. When the operation is switched to the state, the engine driving force transmitted from the input shaft 22 to the pump shaft 32a is converted into the reverse driving force and output from the motor shaft 33a, and the engine is driven in both the forward transmission state and the reverse transmission state. The driving force is steplessly shifted and output. When the hydraulic continuously variable transmission 30 is switched to the neutral state, the output from the motor shaft 33a is stopped.

  The planetary transmission unit 40 is disposed on the same side as the side where the engine connection side of the input shaft 22 is positioned with respect to the hydraulic continuously variable transmission 30 and is positioned between the motor shaft 33 a and the output rotating body 24. . The planetary transmission unit 40 is configured to freely rotate a sun gear 42 supported by the transmission shaft 23, a plurality of planetary gears 43 that mesh with the sun gear 42, a ring gear 44 that meshes with each planetary gear 43, and a plurality of planetary gears 43. And a carrier 41 to be supported. The carrier 41 includes an arm portion 41a that rotatably supports the planetary gear 43 at the extended end portion, and a cylindrical shaft portion 41b to which the base end sides of the plurality of arm portions 41a are connected. The transmission shaft 23 is rotatably supported via a bearing.

  The transmission shaft 23 and the motor shaft 33a are connected so as to be integrally rotatable via a joint 23a, and the transmission shaft 23 and the sun gear 42 are connected so as to be integrally rotatable via a spline structure. The shaft 33a is interlocked with the shaft 33a so as to be integrally rotatable.

  The ring gear 44 and the output rotating body 24 are integrally rotatable by an annular planetary interlocking body 26 and an annular output side interlocking body 27 that are externally fitted to the transmission shaft 23 so as to be relatively rotatable side by side in the axial direction. It is linked to. That is, the planetary interlocking body 26 includes a plurality of engagement arm portions 26 a that extend radially and integrally from the outer peripheral portion of the planetary interlocking body 26. The plurality of engagement arm portions 26 a are engaged with a plurality of locations of the ring gear 44, and the planetary interlocking body 26 is interlocked with the ring gear 44 so as to be integrally rotatable. The output-side interlocking body 27 is engaged with the planetary-side interlocking body 26 so as to be integrally rotatable with an engaging claw 27a, and is integrally engaged with the output rotating body 24 with a spline structure. The interlocking body 26 and the output rotating body 24 are connected so as to be rotatable together. The planetary interlocking body 26 is supported on the transmission shaft 23 through a bearing so as to be relatively rotatable. The output side interlocking body 27 is rotatably supported by the transmission case 21 via a bearing.

  The forward / reverse switching mechanism 50 includes a forward transmission gear 51 rotatably supported on the input shaft 22 via a needle bearing, a forward clutch 52 provided across the forward transmission gear 51 and the input shaft 22, and the input shaft 22. Relative rotation to the reverse transmission shaft 53 in mesh with a reverse transmission shaft 53 rotatably supported by the transmission case 21 in a parallel or substantially parallel arrangement and a transmission gear 54 rotatably supported by the input shaft 22. A reverse rotation input gear 55 supported, a reverse clutch 56 provided across the input gear 55 and the reverse transmission shaft 53, and a reverse transmission gear 57 provided on the reverse transmission shaft 53 so as to be integrally rotatable are configured. It is.

  The forward transmission gear 51 and the reverse transmission gear 57 are meshed with an input gear 41 c of the carrier 41 that is rotatably provided integrally with the cylindrical shaft portion 41 b of the carrier 41. The input gear 55 and the transmission gear 54 are located on the opposite side of the planetary transmission unit 40 from the side where the forward transmission gear 51 and the reverse transmission gear 57 are located. The forward transmission gear 51 and the reverse transmission gear 57 mesh with the input gear 41 c of the planetary transmission unit 40 located on the opposite side of the sun gear 42 from the side where the input gear 55 and the transmission gear 54 are located.

  The forward clutch 52 is a clutch mechanism provided across the forward clutch body 52a supported by the input shaft 22 so as to be integrally rotatable and slidable, and one end side of the forward clutch body 52a and the lateral side portion of the forward transmission gear 51. And a main body 52b. The forward clutch body 52a is slidably operated by a hydraulic piston 58 fitted in the end of the forward clutch body 52a. The clutch mechanism main body 52b is configured as a mesh clutch so that the engagement claw provided on the forward clutch body 52a and the mesh claw provided on the forward transmission gear 51 are engaged and disengaged to switch between the on state and the off state. It is.

  The reverse clutch 56 includes a reverse clutch body 56 a that is supported on the reverse transmission shaft 53 so as to be integrally rotatable and slidable, and a clutch mechanism that is provided across one end side of the reverse clutch body 56 a and the lateral side portion of the input gear 55. And a main body 56b. The reverse clutch body 56a is slidably operated by a hydraulic piston 59 fitted in the end portion of the reverse clutch body 56a. The clutch mechanism main body 56b is configured as a meshing clutch so that the engagement claw provided on the reverse clutch body 56a and the engagement claw provided on the input gear 55 are engaged and disengaged to switch between the on state and the off state. is there.

  The forward / reverse switching mechanism 50 is in a forward transmission state when the forward clutch 52 is switched to the engaged state and the reverse clutch 56 is switched to the disengaged state, and is connected to the engine coupling side of the input shaft 22 and the hydraulic continuously variable transmission. The driving force of the input shaft 22 is input from the forward clutch body 52a located between the machine connecting sides, the driving force of the input shaft 22 is converted into the forward driving force, and the forward transmission gear 51 is transferred to the carrier 41 of the planetary transmission unit 40. introduce.

  The forward / reverse switching mechanism 50 is switched to the disengaged state of the forward clutch 52 and is switched to the engaged state of the reverse clutch 56 to enter the reverse transmission state. The driving force of the input shaft 22 is input from the transmission gear 54 located between the machine connection sides, the driving force of the input shaft 22 is converted into the reverse driving force, and transmitted from the reverse transmission gear 57 to the carrier 41 of the planetary transmission unit 40. To do.

  The forward / reverse switching mechanism 50 is neutralized when the forward clutch 52 and the reverse clutch 56 are switched to the disengaged state, and the input shaft 22 and the carrier 41 of the planetary transmission unit 40 are disconnected from each other.

  An output-side clutch mechanism 60 including a clutch body 61 externally fitted to the transmission shaft 23 is provided across the sun gear 42 and the planetary-side interlocking body 26 of the planetary transmission unit 40.

  The clutch body 61 is slidably operated toward the sun gear 42 against the energizing spring 62 when pressure oil is supplied to an oil chamber formed on the inner peripheral side of the clutch body 61, so that the clutch body 61 is in the cut position. When the pressure oil is discharged from the oil chamber, the urging spring 62 is slid toward the planetary interlocking body 26 to switch to the entry position. When the clutch body 61 is switched to the entering position, the clutch pawl 61 a provided on the clutch body 61 and the clutch pawl provided on the planetary interlocking body 26 are engaged with each other, so that the clutch body 61 is integrated with the planetary interlocking body 26. Connect freely. The clutch body 61 is slid while maintaining a state in which the clutch body 61 is engaged with the sun gear 42 by the engaging claws 61b so as to be integrally rotatable. When the clutch body 61 is switched to the disengagement position, the clutch pawl 61a is disengaged from the planetary interlocking body 26.

  Therefore, the clutch mechanism 60 on the output side is operated to switch the clutch body 61 to the disengaged position, thereby disengaging the sun gear 42 and the planetary-side interlocking body 26, thereby interlocking the motor shaft 33a with the output rotating body 24. In this state, the first transmission state in which the ring gear 44 of the planetary transmission unit 40 and the output rotator 24 are interlocked so as to be integrally rotatable appears, and the combined driving force of the planetary transmission unit 40 can be output from the output rotator 24. To.

  The clutch mechanism 60 on the output side integrates the motor shaft 33a with the output rotating body 24 by interlocking the sun gear 42 and the planetary side interlocking body 26 so that the clutch body 61 is switched to the entering position. The second transmission state to be interlocked in a rotatable manner appears, the output of the output by the hydraulic continuously variable transmission 30 can be output from the output rotating body 24, and the sun gear 42 and the transmission shaft 23 are interlocked so as to be integrally rotatable, so that the ring gear 44 and the planetary-side interlocking body 26 are interlocked so as to be integrally rotatable, so that the sun gear 42, the planetary gear 43, and the ring gear 44 can rotate integrally with the motor shaft 33a so that the planetary gear 43 does not rotate. To.

  Accordingly, the planetary transmission unit 40 is operated from the input shaft 22 via the forward / reverse switching mechanism 50 by switching the forward / reverse switching mechanism 50 to the forward transmission state and switching the output-side clutch mechanism 60 to the disconnected state. The forward drive force is input to the carrier 41, the output from the motor shaft 33a of the hydraulic continuously variable transmission 30 is input to the sun gear 42 via the transmission shaft 23, and the forward drive force and the hydraulic continuously variable transmission from the input shaft 22 are input. The output of the machine 30 is combined to generate the forward combined drive force, and the generated forward combined drive force is output from the ring gear 44 via the planetary interlocking body 26 and the output interlocking body 27 to the output rotating body 24. Output to.

  The planetary transmission unit 40 is moved backward from the input shaft 22 via the forward / reverse switching mechanism 50 when the forward / reverse switching mechanism 50 is switched to the reverse transmission state and the output-side clutch mechanism 60 is switched to the disconnected state. The driving force is input to the carrier 41, the output from the motor shaft 33a of the hydraulic continuously variable transmission 30 is input to the sun gear 42 via the transmission shaft 23, the forward driving force from the input shaft 22 and the hydraulic continuously variable transmission 30 are input. Are combined with each other to generate a reverse-side combined driving force, and the generated reverse-side combined driving force is output from the ring gear 44 to the output rotating body 24 via the planetary-side interlocking body 26 and the output-side interlocking body 27. To do.

  The planetary transmission unit 40 is disconnected from the input shaft 22 when the forward / reverse switching mechanism 50 is operated to the neutral state.

  FIG. 6 is an explanatory diagram showing the relationship between the operation state of the hydraulic continuously variable transmission 30, the forward clutch 52, the reverse clutch 56, and the output-side clutch mechanism 60 and the transmission mode of the transmission 20. “Forward” shown in FIG. 6 indicates the forward transmission state of the hydraulic continuously variable transmission 30, and “reverse” indicates the reverse transmission state of the hydraulic continuously variable transmission 30. “OFF” shown in FIG. 6 indicates the disengagement state of the forward clutch 52, the reverse clutch 56 and the output-side clutch mechanism 60, and “ON” indicates the engagement of the forward clutch 52, the reverse clutch 56 and the output-side clutch mechanism 60. Indicates the state. FIG. 3 is a longitudinal front view showing the transmission 20 in a state where the HST mode transmission appears.

  FIG. 3 is a longitudinal front view showing the transmission 20 in the HST mode transmission. As shown in FIGS. 3 and 6, when the forward clutch 52 and the reverse clutch 56 are controlled to be switched off, and the output side clutch mechanism 60 is switched to the engaged state, the transmission device 20 performs HST mode transmission. It becomes a state to appear. When the transmission 20 is in the HST mode transmission state, the engine drive force input to the input shaft 22 is not transmitted to the planetary transmission unit 40, and the engine drive force input to the input shaft 22 is hydraulically stepped. The speed is changed by the machine 30, and the driving force after the speed change is transmitted from the motor shaft 33a to the output rotating body 24 through the transmission shaft 23, the sun gear 42, the clutch body 61, the planetary side interlocking body 26 and the output side interlocking body 27 for output. This is transmitted from the rotating body 24 to the pair of left and right traveling devices 1, 1.

  FIG. 4 is a longitudinal front view showing the speed change transmission device 20 in forward HMT mode transmission. 4 and 6, when the forward clutch 52 is controlled to be switched on and the reverse clutch 56 and the output-side clutch mechanism 60 are switched to the switched state, the shift transmission device 20 is controlled to be switched to the forward HMT. The mode transmission will appear. When the forward transmission side HMT mode transmission is established, the transmission 20 is converted to forward drive force by the forward / reverse switching mechanism 50 and transmitted to the planetary transmission unit 40 by the forward / reverse switching mechanism 50, and the planetary transmission unit. 40, the forward drive force from the forward / reverse switching mechanism 50 and the output from the motor shaft 33a of the hydraulic continuously variable transmission 30 are combined to generate the forward drive force, and the forward drive force generated is generated. Is transmitted from the ring gear 44 to the output rotating body 24 via the planetary-side interlocking body 26 and the output-side interlocking body 27 and from the output rotating body 24 to the pair of left and right traveling devices 1, 1.

  FIG. 5 is a longitudinal front view showing the speed change transmission device 20 in the reverse-side HMT mode transmission. 5 and 6, when the reverse clutch 56 is controlled to be switched on and the forward clutch 52 and the output side clutch mechanism 60 are controlled to be switched off, the reverse transmission HMT is controlled. The mode transmission will appear. When the reverse transmission side HMT mode transmission is established, the transmission 20 is converted to a reverse drive force by the forward / reverse switching mechanism 50 and transmitted to the planetary transmission unit 40 by the forward / reverse switching mechanism 50, thereby transmitting the planetary transmission unit. 40, the reverse drive force from the forward / reverse switching mechanism 50 and the output from the motor shaft 33a of the hydraulic continuously variable transmission 30 are combined to generate the reverse drive force, and the generated reverse drive force is generated. Is transmitted from the ring gear 44 to the output rotating body 24 via the planetary-side interlocking body 26 and the output-side interlocking body 27 and from the output rotating body 24 to the pair of left and right traveling devices 1, 1.

  FIG. 7 shows the relationship between the speed change state of the hydraulic continuously variable transmission 30 and the output speed of the output rotating body 24 of the speed change transmission 20 in a state where the engine 8 is accelerator-set so as to output a set driving force at a constant speed. It is explanatory drawing which shows a relationship. The horizontal axis in FIG. 7 indicates the shift state of the hydraulic continuously variable transmission 30, “n” indicates the neutral position of the hydraulic continuously variable transmission 30, and “−max” indicates the hydraulic continuously variable transmission. 30 indicates the highest speed position in the reverse transmission state, and “+ max” indicates the highest speed position in the forward transmission state of the hydraulic continuously variable transmission 30. The vertical axis in FIG. 7 indicates the output speed by the output rotating body 24. The solid line RL and the solid line FL shown in FIG. 7 indicate that the forward clutch 52 and the reverse clutch 56 are controlled to be switched to the disengaged state and the output side clutch mechanism 60 is controlled to be switched to the engaged state, that is, the transmission 20 is set to HST. It shows the change in output speed when operated in the mode transmission mode. Solid lines FM and FH shown in FIG. 7 indicate that the forward clutch 52 is controlled to be switched to the engaged state and the reverse clutch 56 and the output side clutch mechanism 60 are switched to the disconnected state, that is, the transmission 20 is connected to the forward side. The change of the output speed when operated in the state of HMT mode transmission is shown. Solid lines RM and RH shown in FIG. 7 indicate that the reverse clutch 56 is controlled to be switched on and the forward clutch 52 and the output-side clutch mechanism 60 are switched to the switched state, that is, the transmission 20 is connected to the reverse side. The change of the output speed when operated in the state of HMT mode transmission is shown.

  As shown in FIG. 6 and as indicated by the solid line FL in FIG. 7, in the state where the forward clutch 52 and the reverse clutch 56 are controlled to be disengaged and the output side clutch mechanism 60 is controlled to be in the engaged state, When the continuously variable transmission 30 is operated to the neutral position “n”, the output becomes zero “0”.

  While the forward clutch 52 and the reverse clutch 56 are maintained in the disengaged state and the output-side clutch mechanism 60 is maintained in the engaged state, the hydraulic continuously variable transmission 30 moves from the neutral position “n” to the highest speed position “ When a speed change operation is performed toward “+ max”, the forward drive force is output. While the forward clutch 52 and the reverse clutch 56 are maintained in the disengaged state and the output-side clutch mechanism 60 is maintained in the engaged state, the hydraulic continuously variable transmission 30 moves from the neutral position “n” to the highest speed position “ As the speed change operation is performed toward “+ max”, the forward output increases steplessly. When the hydraulic continuously variable transmission 30 reaches the maximum speed position “+ max” in the forward transmission state, the output speed becomes the forward intermediate speed “FV1”.

  As shown in FIG. 6 and as indicated by solid lines FM and FH in FIG. 7, when the hydraulic continuously variable transmission 30 reaches the maximum speed position “+ max” in the forward transmission state, the forward clutch 52 is switched to the engaged state. The output-side clutch mechanism 60 is controlled to be switched off, the forward clutch 52 is maintained in the engaged state, and the reverse clutch 56 and the output-side clutch mechanism 60 are maintained in the disconnected state, while the hydraulic continuously variable transmission is performed. As the machine 30 is shifted from the highest speed position “+ max” in the forward transmission state toward the highest speed position “−max” in the reverse transmission state, the forward output is increased steplessly from the intermediate speed “FV1”. To do. When the hydraulic continuously variable transmission 30 reaches the maximum speed position “−max” in the reverse transmission state, the output becomes the maximum forward speed “FV2”.

  As shown in FIG. 6 and indicated by the solid line RL in FIG. 7, the forward clutch 52 and the reverse clutch 56 are maintained in the disengaged state, and the output-side clutch mechanism 60 is maintained in the engaged state, so that the hydraulic continuously variable When the transmission 30 is shifted from the neutral position “n” toward the highest speed position “−max” in the reverse transmission state, the reverse drive force is output. While the forward clutch 52 and the reverse clutch 56 are maintained in the disengaged state, and the output-side clutch mechanism 60 is maintained in the engaged state, the hydraulic continuously variable transmission 30 is moved from the neutral position “n” to the highest speed position “ As the speed change operation is performed toward “−max”, the reverse output increases steplessly. When the hydraulic continuously variable transmission 30 reaches the maximum speed position “−max” in the reverse transmission state, the output speed becomes the reverse intermediate speed “RV1”.

  As shown in FIG. 6 and as indicated by solid lines RM and RH in FIG. 7, when the hydraulic continuously variable transmission 30 reaches the maximum speed position “−max” in the reverse transmission state, the reverse clutch 56 is engaged. The switching is controlled, the output side clutch mechanism 60 is controlled to be switched off, the reverse clutch 56 is maintained in the engaged state, the forward clutch 52 and the output side clutch mechanism 60 are maintained in the disconnected state, and the hydraulic continuously variable As the transmission 30 is shifted from the highest speed position “−max” in the reverse transmission state to the highest speed position “+ max” in the forward transmission state, the reverse output increases steplessly from the intermediate speed “RV1”. Speed up. When the hydraulic continuously variable transmission 30 reaches the maximum speed position “+ max” in the forward transmission state, the output becomes the maximum reverse speed “RV2”.

  “N” shown in FIG. 7 indicates a horizontal line when the solid lines FH and FM are extended beyond the maximum speed position “+ max” on the forward side of the hydraulic continuously variable transmission 30 to a point where the output rotation becomes zero “0”. Indicates the axis value. When the value of the horizontal axis of the maximum speed position “+ max” on the forward side of the hydraulic continuously variable transmission 30 is 1, N = 1.6 to 2.2. That is, the capacities of the hydraulic pump 32 and the hydraulic motor 33 in the hydraulic continuously variable transmission 30 and the transmission gear ratio of the planetary transmission unit 40 are set so that N = 1.6 to 2.2.

  FIG. 8 is a block diagram showing a speed change operation device 71 that changes the speed of the speed change transmission device 20. As shown in this figure, the shift operation device 71 is connected to the shift operation unit 30a of the hydraulic continuously variable transmission 30, and the operation units 52c, 56c, and 60a of the forward clutch 52, the reverse clutch 56, and the output-side clutch mechanism 60. A linked control device 72, a shift detection sensor 73 linked to the control device 72, an engine speed sensor 74, a transmission output speed sensor 75, and an output speed sensor 76 are provided.

  The shift operation unit 30a is configured by an electric actuator or a hydraulic actuator that performs an angle changing operation of the swash plate 32b of the hydraulic pump 32 in the hydraulic continuously variable transmission 30. The operation portion 52c of the forward clutch 52 is constituted by an operation valve connected to the hydraulic piston 58 via an operation oil passage formed inside the input shaft 22, and the forward clutch body 52a is operated by operating the hydraulic piston 58. The forward clutch 52 is switched by performing a sliding operation. The operation portion 56c of the reverse clutch 56 is constituted by an operation valve connected to the hydraulic piston 59 through an operation oil passage formed inside the reverse transmission shaft 53, and operates the hydraulic piston 59 to operate the reverse clutch body. The reverse clutch 56 is changed over by sliding the operation 56a. The operation portion 60 a of the output-side clutch mechanism 60 is configured by an operation valve connected to the oil chamber of the clutch body 61 via an operation oil passage formed inside the transmission shaft 23. By supplying and discharging the operating oil to and from the chamber, the clutch body 61 is slid and the output side clutch mechanism 60 is switched.

  The shift detection sensor 73 detects the operation position of the shift lever 77 and outputs the detection result to the control device 72. The engine speed sensor 74 detects the speed of the engine 8 and outputs the detection result to the control device 72. The transmission output rotation speed sensor 75 detects the output rotation speed of the hydraulic continuously variable transmission 30 and outputs the detection result to the control device 72. The output speed sensor 76 detects the output speed of the transmission 20 and outputs the detection result to the controller 72.

  The control device 72 is configured using a microcomputer and includes a shift control means 78. The shift control means 78 is configured so that the shift state of the hydraulic continuously variable transmission 30 corresponds to the operation position of the shift lever 77 based on detection information from the shift detection sensor 73 and the transmission output rotation speed sensor 75. Then, the shift control unit 30a is operated to control the shift of the hydraulic continuously variable transmission 30.

  The shift control means 78 detects the rotational speed of the accelerator-set engine 8 on the basis of information detected by the engine rotational speed sensor 74 in addition to controlling the shift of the hydraulic continuously variable transmission 30, Based on the detection information from the detection sensor 73, the transmission output speed sensor 75, and the output speed sensor 76, the transmission 20 is operated in the HST mode transmission, the forward HMT mode transmission and the reverse side as shown in FIGS. The operation unit 52c, the operation unit 56c, and the operation unit 60a are operated to switch the forward clutch 52, the reverse clutch 56, and the output-side clutch mechanism 60 at a predetermined timing so that the HMT mode transmission appears.

[Another implementation structure]
FIG. 9 is a longitudinal front view showing the transmission device 20 having another embodiment structure. As shown in this figure, in the transmission 20 having a separate implementation structure, a charge pump 90 that supplies hydraulic oil for replenishment to the hydraulic continuously variable transmission 30 is provided at the end of the pump shaft 32a. is there. The charge pump 90 includes a rotor 90a that is connected to the pump shaft 32a so as to be integrally rotatable, and a pump casing 90b that is detachably connected to the casing 31.

[Another Example]
(1) In the embodiment described above, the transmission ratio from the input shaft 22 to the carrier 41 in the forward transmission state and the transmission ratio from the input shaft 22 to the carrier 41 in the reverse transmission state are the same or substantially the same. Although the example in which the switching mechanism 50 is configured is shown, the forward / backward travel is configured such that the transmission ratio from the input shaft 22 to the carrier 41 in the forward transmission state is different from the transmission ratio from the input shaft 22 to the carrier 41 in the reverse transmission state. A switching mechanism may be employed. In this case, the solid lines RM and RH indicating the output speed in the reverse-side HMT mode transmission and the solid lines FM and FH indicating the output speed in the forward-side HMT mode transmission have the same inclination angle with respect to the horizontal axis. Therefore, the maximum speed of the reverse output and the maximum speed of the forward output are the same or different.

(2) In the above-described embodiment, the reverse clutch 56 is provided across the input gear 55 and the reverse transmission shaft 53. However, the input gear 55 is supported by the reverse transmission shaft 53 so as to be integrally rotatable, and the reverse drive is performed. The transmission gear 57 may be supported on the reverse transmission shaft 53 so as to be relatively rotatable, and the reverse clutch 56 may be provided between the reverse transmission gear 57 and the reverse transmission shaft 53.

(3) In the above-described embodiments, the forward clutch 52, the reverse clutch 56, and the output-side clutch mechanism 60 are configured as meshing clutches, but may be configured as frictional clutches. Good.

(4) In the above embodiment, the forward drive force and the reverse drive force from the forward / reverse switching mechanism 50 are input to the carrier 41 of the planetary transmission unit 40, and the drive force of the ring gear 44 of the planetary transmission unit 40 is output to the output rotator 24. However, the forward drive force and the reverse drive force from the forward / reverse switching mechanism 50 are input to the ring gear 44 of the planetary transmission unit 40, and the drive force of the carrier 41 of the planetary transmission unit 40 is output. You may comprise and implement so that it may transmit to the rotary body 24. FIG.

(5) In the above-described embodiment, an example in which the hydraulic motor 33 is configured as a variable displacement type has been described. However, the hydraulic motor 33 may be configured as a fixed displacement type.

  The present invention can be used for various vehicles such as a rice transplanter and a transporter in addition to a combine.

DESCRIPTION OF SYMBOLS 1 Traveling device 22 Input shaft 24 Output rotary body 30 Hydraulic continuously variable transmission 33a Motor shaft 40 Planetary transmission part 41c Input gear 42 Sun gear 43 Planetary gear 44 Ring gear 50 Forward / reverse switching mechanism 51 Forward transmission gear 52a Forward clutch body 53 Reverse transmission Shaft 54 Transmission gear 55 Input gear 56a Reverse clutch body 57 Reverse transmission gear 60 Clutch mechanism

Claims (4)

An input shaft for inputting engine driving force, a hydraulic continuously variable transmission driven by the input shaft, and a combined driving force by combining the driving force of the input shaft and the output of the hydraulic continuously variable transmission. A transmission transmission device provided with an output planetary transmission section and an output rotating body output to the traveling device,
A forward transmission state in which the driving force of the input shaft is converted into a forward driving force and transmitted to the planetary transmission portion, and a reverse transmission state in which the driving force of the input shaft is converted into a backward driving force and transmitted to the planetary transmission portion A forward / reverse switching mechanism that can be switched freely is provided.
The forward / backward switching mechanism is configured to be freely switchable to a neutral state in which transmission between the input shaft and the planetary transmission unit is cut off,
A speed change transmission apparatus provided with a clutch mechanism capable of switching the interlocking between a motor shaft of the hydraulic continuously variable transmission and the output rotating body between an on state and a cut state.   The sun gear, the planetary gear, and the ring gear that constitute the planetary transmission unit are configured to interlock with a motor shaft of the hydraulic continuously variable transmission in the engaged state of the clutch mechanism. Item 1. The transmission according to Item 1. A forward transmission gear supported rotatably on the input shaft in a state interlocked with the planetary transmission unit;
A forward clutch that is supported on the input shaft so as to be integrally rotatable and slidable so that the forward transmission gear and the input shaft are switched between an interlocked state and an interlocked off state by being engaged and disengaged with respect to the forward gear. Body,
A reverse transmission shaft that supports one of the input gear interlocked with the input shaft and the reverse transmission gear interlocked with the planetary transmission unit so as to be relatively rotatable, and the other is rotatably supported integrally;
Of the input gear and the reverse transmission gear, the clutch gear that is rotatably supported by the reverse transmission shaft is engaged and disengaged, and the clutch gear and the reverse transmission shaft are interlocked. The forward / reverse switching mechanism is configured to include a reverse clutch body that is supported by the reverse transmission shaft so as to be integrally rotatable and slidable so as to switch between an on state and an interlocked cut state. The transmission device described. The input gear and a transmission gear that is rotatably supported by the input shaft in a state of meshing with the input gear are defined as a side on which the forward transmission gear and the reverse transmission gear are positioned with respect to the planetary transmission unit. On the other side,
4. The forward transmission gear and the reverse transmission gear are meshed with an input gear provided at a position opposite to the side where the input gear and the transmission gear are located with respect to a sun gear of the planetary transmission unit. The transmission device described.

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