JP6429684B2 - Harvester power transmission device and harvester - Google Patents

Description

  The present invention relates to a power transmission device for a harvester and a harvester that transmit a driving force of a drive source to a pair of left and right traveling devices.

  A conventional harvester such as a combiner has a drive source such as an engine, a power transmission device composed of a non-transmission device such as an HST and a mechanical speed reducer, and a pair of infinite provided on the left and right of the body of the harvester. A track-type traveling device is provided. The drive source and the power transmission device are disposed at the center of the body frame, and the pair of traveling devices are disposed on the left and right of the body frame, respectively. The driving force output from the driving source is distributed by the power transmission device and transmitted to each of the pair of left and right traveling devices.

JP 2012-211672 A

As the size of the combine increases and the output increases, loads such as traction force and torque applied to the power transmission device also increase. In order to withstand this increased load, it is necessary to structurally strengthen the portion connecting the power transmission device and the traveling device and the bearing of the traveling device.
However, structural reinforcement tends to lead to an increase in the size of parts, and the above left-right distribution type power transmission mechanism has room for improvement in that the minimum ground clearance of the fuselage is lowered. Further, in the left-right distribution type power transmission mechanism as described above, the transmission loss of the driving force during turning is large, and there is room for improvement in terms of smooth turning.

In order to ensure smoothness during turning, it is conceivable to provide two power transmission devices and drive the pair of left and right traveling devices independently.
However, such a left and right independent power transmission mechanism is a hydraulic oil caused by a difference in transmission efficiency between two continuously variable transmissions constituting each of the two power transmission devices and a load applied to the pair of left and right traveling devices. There is a room for improvement in that it is difficult to ensure straight travel performance because a difference occurs in the rotational speed of the pair of left and right traveling devices due to the leakage of oil (oil leak) or the like.

  In particular, it is difficult to adopt a left-right independent power transmission mechanism because the straight-moving combine is important for straightening the self-removing combine.

  The present invention has been made in view of the above circumstances, and provides a power transmission device and a harvesting machine for a harvesting machine that can increase the minimum ground clearance of the airframe and ensure straightness while ensuring smoothness during turning. The purpose is to do.

In order to achieve the above object, a power transmission device for a harvester according to the present invention is characterized in that the power transmission device for a harvester transmits a driving force of a driving source to a pair of left and right traveling devices, the driving source A first hydraulic pump to which a driving force is input, and a first hydraulic pump connected to the first hydraulic pump by a first hydraulic circuit and outputting the input driving force to one of the pair of left and right traveling devices. A hydrostatic first continuously variable transmission including a first hydraulic motor having one output shaft, a second hydraulic pump to which a driving force of the driving source is input, the second hydraulic pump, and a second hydraulic pressure A hydrostatic second continuously variable transmission that is connected by a circuit and includes a second hydraulic motor having a second output shaft that outputs the input driving force to the other traveling device of the pair of left and right traveling devices. a device, the driving force from the first output shaft is input, the first A driving force from the first input shaft provided at a position higher than the first output shaft in a state parallel to the force shaft and the second output shaft, and a state parallel to the second output shaft; A second input shaft provided at a position higher than the second output shaft in a state of being coaxial with the first input shaft, and rotation of the first output shaft and rotation of the second output shaft; , A state switching mechanism that can be switched to a synchronized drive state that matches or a non-tuned drive state that does not match , a first coupling mechanism that transmits drive force from the first output shaft to the first input shaft, An intermediate transmission shaft that is orthogonal to the first output shaft and the first input shaft, and a second coupling mechanism that transmits driving force from the two output shafts to the second input shaft. The second coupling mechanism is orthogonal to the second output shaft and the second input shaft. In that it includes a transmission shaft.

  According to the present invention, since the first continuously variable transmission and the second continuously variable transmission are independent, the first continuously variable transmission and the second continuously variable transmission are connected to a pair of left and right travelings in the body frame. It can be placed in a position close to each of the devices. Since the state switching mechanism can be freely laid out to some extent in the fuselage frame, if it is arranged at a position higher than the position where the first continuously variable transmission and the second continuously variable transmission are arranged, the conventional left-right distribution type Compared to the power transmission mechanism, the minimum ground clearance of the fuselage can be increased.

If the state switching mechanism makes the rotation of the first output shaft and the rotation of the second output shaft non-synchronized, the pair of left and right traveling devices can be driven independently, ensuring smoothness during turning. it can. When the state switching mechanism is set to a synchronous drive state in which the rotation of the first output shaft and the rotation of the second output shaft are made coincident with each other, the independent driving of the pair of left and right traveling devices is impossible, so that straightness can be ensured.
In the present invention, the intermediate transmission shaft in the first connection mechanism and the intermediate transmission shaft in the second connection mechanism are divided in the axial direction between the divided shaft bodies divided in the axial direction and the divided shaft bodies in the axial direction. It is preferable to include a second connecting portion that is connected so as to be relatively movable and not rotatable relative to the circumferential direction.

  In the present invention, it is preferable that the state switching mechanism includes a meshing clutch between the first output shaft and the second output shaft that can be switched from either the meshing state or the non-meshing state to the other. It is.

  In the synchronous drive state, the rotation of the first output shaft and the rotation of the second output shaft can be reliably matched by the engagement of the meshing clutch.

  In the present invention, the meshing clutch utilizes the elastic force of an elastic body when switching from the non-meshing state to the meshing state and maintaining the meshing state, and switches from the meshing state to the non-meshing state. It is preferable to use the hydraulic pressure of a hydraulic mechanism that resists the elastic force of the elastic body at the time and when maintaining the non-engaged state.

  In view of general harvesting work, the harvesting machine cuts several rice and wheat while going straight through the field, for example, in the case of reciprocating cutting, it turns at the end of the field and moves to the opposite side of the uncut area, Repeat the following harvesting of rice and wheat. Therefore, the turning time is overwhelmingly shorter than the straight driving time. Since it is only necessary to operate the hydraulic mechanism only at this short timing, it is possible to save energy in that it is not necessary to always operate the hydraulic mechanism.

  In the present invention, the state switching mechanism includes, between the first output shaft and the second output shaft, a multi-plate clutch capable of continuously shifting from either the connected state or the non-connected state to the other. It is preferable that

  By using the slip of the multi-plate clutch, it is possible to gradually shift between the synchronized driving state and the non-synchronized driving state.

  In the present invention, the multi-plate clutch utilizes the elastic force of an elastic body at the time of transition from the connected state to the non-connected state and at the time of maintaining the non-connected state, from the non-connected state to the connected state. It is preferable to use the hydraulic pressure of the hydraulic mechanism that resists the elastic force of the elastic body during the transition and when maintaining the connected state.

  The multi-plate clutch requires a strong pressure contact force in order to prevent the multi-plate clutch from slipping when maintaining the synchronized driving state, that is, when going straight. When this strong pressure contact force is obtained by the elastic force of the elastic body, the strong elastic force of the elastic body is changed during the transition from the tuned drive state to the non-tuned drive state and when the non-tuned drive state is maintained, that is, during turning. In order to overcome this, a hydraulic mechanism capable of generating strong hydraulic pressure is required.

  When the multi-plate clutch is maintained in the synchronized driving state, i.e., when traveling straight, the hydraulic pressure of the hydraulic mechanism is used, and when the transition from the synchronized driving state to the non-synchronized driving state is maintained and when the non-synchronized driving state is maintained, i.e., when turning. By adopting a configuration that uses the elastic force of the elastic body, the elastic body may have a weak elastic force that functions when the oil pressure is lowered, and the hydraulic mechanism also has a weak elastic force. It may be capable of exerting an oil pressure that can be overcome. As compared with an elastic body having a strong elastic force and a hydraulic mechanism capable of generating a strong oil pressure, an elastic body having a weak elastic force and a hydraulic mechanism capable of generating a small oil pressure can be used.

  In the present invention, the state switching mechanism includes a meshing clutch that can be switched from one of the meshing state and the non-meshing state to the other, and a multiple clutch that can be continuously shifted from either the connected state or the non-connected state to the other. It is preferable that a plate clutch is provided in series or in parallel between the first output shaft and the second output shaft.

When the meshing clutch and the multi-plate clutch are provided in parallel between the first output shaft and the second output shaft, the advantages of both the meshing clutch and the multi-plate clutch can be obtained. That is, in the synchronized driving state, the meshing of the meshing clutch enables the rotation of the first output shaft and the rotation of the second output shaft to be surely matched, and by utilizing the slip of the multi-plate clutch, Transition to the non-tuned drive state can be performed gradually.
When a meshing clutch and a multi-plate clutch are provided in series between the first output shaft and the second output shaft, it is possible to select switching by the meshing clutch or switching by the multi-plate clutch.

  In the present invention, the meshing clutch utilizes the elastic force of the first elastic body at the time of switching from the non-meshing state to the meshing state and maintaining the meshing state, and from the meshing state to the non-meshing state. The multi-plate clutch is changed from the connected state to the non-connected state by utilizing the hydraulic pressure of the first hydraulic mechanism that resists the elastic force of the first elastic body at the time of switching and maintaining the non-engaged state. The elastic force of the second elastic body is utilized at the time of transition and at the time of maintaining the disconnected state, and the elastic force of the second elastic body at the time of transition from the disconnected state to the connected state and at the time of maintaining the connected state. It is preferable to use the hydraulic pressure of the second hydraulic mechanism that resists this.

  As described above, the harvesting machine is overwhelmingly shorter when turning than when traveling straight. Since it is only necessary to operate the hydraulic mechanism only at this short timing, it is possible to save energy in that it is not necessary to always operate the hydraulic mechanism. When switching between the synchronized driving state and the non-synchronized driving state, the switching can be performed gradually by utilizing the slip of the multi-plate clutch.

  The harvesting machine according to the present invention is characterized in that it includes a power transmission device for a harvesting machine having any of the characteristics described above.

  It is possible to realize a harvesting machine that can increase the minimum ground clearance of the aircraft and ensure straightness while ensuring smoothness during turning.

Whole view of harvester Explanatory drawing of the power transmission device concerning this invention Explanatory drawing of state switching mechanism Explanatory drawing of state switching mechanism Explanatory drawing of state switching mechanism

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 1, a power transmission device for a harvester according to an embodiment of the present invention is a so-called self-decomposing combine 1 that harvests and thresh rice and wheat while self-propelled in a field as an example of a harvester. Is provided. In the following description, the words with relative directions such as “front”, “back”, “right”, “left”, “up”, “down” are basically based on the traveling direction of the combine 1.

  The combine 1 includes a driving unit 3 in the front right region of the body frame 9, a cutting unit 4 in the front left region, a threshing device 5 in the rear left region, and a grain tank 6 in the rear right region. In the lower part, an endless track type traveling device 2 as an example of a pair of left and right traveling devices is provided. In the present embodiment, the cutting unit 4 is configured to perform six-row cutting. Therefore, the combine 1 cuts the six-row rice and wheat while going straight on the field. For example, in the case of reciprocating cutting, the combine 1 turns at the end of the field and moves to the opposite side of the uncut area, and the next six-row rice and wheat Repeat the mowing.

  As shown in FIG. 2, the engine 7, which is the power source of the combine 1, is supported by an engine support frame 9 a below the support frame of the driver's seat of the driving unit 3 (not shown) in the body frame 9. Yes. That is, the engine 7 is disposed at a position higher than the axle of the pair of left and right traveling devices 2 in the body frame 9.

  The driving force of the output shaft 7a of the engine 7 is transmitted to the mowing unit 4, the threshing device 5 and the like through transmission means such as a transmission belt provided in the work transmission means. Further, the driving force of the output shaft 7a of the engine 7 is also transmitted to the power transmission device 10 directly connected to the output shaft 7a.

  The power transmission device 10 constitutes a main transmission that shifts the driving force of the engine 7, and the driving force shifted here is output to the auxiliary transmissions 8a and 8b, and a pair of left and right travelings from the auxiliary transmissions 8a and 8b. It is transmitted to the starting wheels 2a and 2b of the device 2.

  As shown in FIG. 2, the power transmission device 10 includes a pair of left and right hydrostatic first continuously variable transmission 20 and a second continuously variable transmission 30.

  The first continuously variable transmission 20 includes a first hydraulic circuit having a first hydraulic pump 21, a first hydraulic motor 22, and hydraulic hoses 23 and 24 that connect the first hydraulic pump 21 and the first hydraulic motor 22. Yes.

  The first hydraulic pump 21 is a variable displacement pump that is driven by the driving force of the engine 7, and the angle of the swash plate is steplessly set to the neutral stop position, the forward drive side, and the reverse drive side based on the operation in the operation unit 3. The volume (discharge amount) is changed by changing to. The first hydraulic pump 21 increases the discharge amount of hydraulic oil as the angle of the swash plate increases, and decreases as the angle of the swash plate decreases.

  The first hydraulic motor 22 is composed of a constant capacity type motor with a fixed swash plate, and the first output shaft 25 rotates at a rotational speed corresponding to the amount of hydraulic oil discharged from the first hydraulic pump 21. The driving wheel 2a of the traveling device 2 is driven. That is, the first continuously variable transmission 20 changes the driving force input from the engine 7 steplessly by the first hydraulic pump 21 and outputs it from the first output shaft 25 of the first hydraulic motor 22.

  The second continuously variable transmission 30 includes a second hydraulic circuit having a second hydraulic pump 31, a second hydraulic motor 32, and hydraulic hoses 33 and 34 that connect the second hydraulic pump 31 and the second hydraulic motor 32. Yes.

  The second hydraulic pump 31 is a variable displacement pump that is driven by the driving force of the engine 7, and the angle of the swash plate is steplessly set to the neutral stop position, the forward drive side, and the reverse drive side based on the operation in the operation unit 3. The volume (discharge amount) is changed by changing to. The second hydraulic pump 31 increases the discharge amount of hydraulic oil as the angle of the swash plate increases, and decreases the discharge amount of hydraulic oil as the angle of the swash plate decreases.

  The second hydraulic motor 32 is composed of a constant capacity motor with a fixed swash plate, and the second output shaft 35 rotates at a rotational speed corresponding to the discharge amount of hydraulic oil discharged from the second hydraulic pump 31. The driving wheel 2b of the traveling device 2 is driven. That is, the second continuously variable transmission 30 changes the driving force input from the engine 7 steplessly by the second hydraulic pump 31 and outputs it from the second output shaft 35 of the second hydraulic motor 32.

As shown in FIG. 2, the first hydraulic motor 22 and the second hydraulic motor 32 are independently supported at positions close to the traveling device 2 in the body frame 9.
On the other hand, the first hydraulic pump 21 and the second hydraulic pump 31 are independently supported at positions close to the engine 7 in the body frame 9.

By configuring the first hydraulic circuit constituting the first continuously variable transmission 20 with the hydraulic hoses 23 and 24, the first hydraulic pump 21 is disposed at a position close to the engine 7 in the body frame 9, and the first hydraulic motor 22 can be arranged at a position close to the traveling device 2 in the body frame 9.
By configuring the second hydraulic circuit constituting the second continuously variable transmission 30 with the hydraulic hoses 33 and 34, the second hydraulic pump 31 is disposed at a position close to the engine 7 in the body frame 9, and the second hydraulic motor 32 can be arranged at a position close to the traveling device 2 in the body frame 9.
Since each element constituting the power transmission device 10 is distributed and arranged in each frame constituting the body frame 9, each frame only needs to have independent strength.

Between the first hydraulic motor 22 and the second hydraulic motor 32, the rotation of the first output shaft 25 and the rotation of the second output shaft 35 can be switched to a synchronized drive state in which they match or a non-synchronized drive state in which they do not match. A state switching mechanism 50 is provided.
That is, the state switching mechanism 50 is supported by the body frame 9 at a position higher than the position where the first hydraulic motor 22 and the second hydraulic motor 32 are supported. Therefore, the minimum ground clearance of the airframe can be increased as compared with the conventional left-right distribution type power transmission mechanism.
Note that a portion of the body frame 9 where the state switching mechanism 50 is supported and a portion of the body frame 9 where the first hydraulic motor 22 and the second hydraulic motor 32 are supported are not rigidly connected.

The state switching mechanism 50 includes a first input shaft 51 to which the driving force output from the first output shaft 25 is input, and a second input shaft 52 to which the driving force output from the second output shaft 35 is input. I have.
A driving force is transmitted from the first output shaft 25 to the first input shaft 51 via the first coupling mechanism 40, and a driving force is transmitted from the second output shaft 35 to the second input shaft 52 via the second coupling mechanism 41. Is transmitted.

As shown in FIG. 3, the first connecting mechanism 40 connects the first output shaft 25 and the first transmission shaft 43 a so as to be relatively movable in the axial direction and not relatively rotatable in the circumferential direction. The connecting portion 42 and the first transmission shaft 43a are provided with a first bevel gear 43b that rotates together with the first transmission shaft 43a, and a first bevel gear 43b that meshes with the first transmission shaft 43a and transmits the driving force to the second transmission shaft 44a. A second bevel gear 44b, a second connection shaft 45a for connecting the second transmission shaft 44a and the third transmission shaft 46a so as to be relatively movable in the axial direction and not to be relatively rotatable in the circumferential direction; A third bevel gear 46b that is provided on the shaft 46a and rotates together with the third transmission shaft 46a; a fourth bevel gear 47b that meshes with the third bevel gear 46b and transmits a driving force to the fourth transmission shaft 47a; The transmission shaft 47a and the first input shaft 51 can be relatively moved in the axial direction. And, and a third connecting portion 48 for connecting to the circumferential direction relative rotation impossible.
An intermediate transmission shaft orthogonal to the first output shaft 25 and the first input shaft 51, and the second output shaft 35 and the second input shaft 52 by the second transmission shaft 44a, the second connecting portion 45, and the third transmission shaft 46a. An intermediate transmission shaft that is orthogonal to is constructed. The second transmission shaft 44a and the third transmission shaft 46a are divided shaft bodies that are divided at the intermediate transmission shaft.

Relative movement between the first hydraulic motor 22 and the state switching mechanism 50 is allowed by the first connecting portion 42, the second connecting portion 45, and the third connecting portion 48 included in the first connecting mechanism 40.
The second coupling mechanism 41 is also configured in the same manner as the first coupling mechanism 40, and relative movement between the second hydraulic motor 32 and the state switching mechanism 50 is allowed. In addition, about each part which comprises the 2nd connection mechanism 41, the same code | symbol is attached | subjected to the structure corresponding to the 1st connection mechanism 40, and description is abbreviate | omitted.

  The state switching mechanism 50 is provided in order to synchronize the rotation of the first output shaft 25 and the rotation of the second output shaft 35. In the present embodiment, the state switching mechanism 50 is constituted by a meshing clutch as shown in FIG. .

  The meshing clutch includes a first meshing portion 53 provided inside the casing at the end of the first input shaft 51 so as to be relatively movable in the axial direction and not relatively rotatable in the circumferential direction, and a second input. The first meshing portion 53 is provided at the end of the shaft 52 and the first meshing portion 53 is configured so that the second meshing portion 55 meshable with the first meshing portion 53 and the first meshing portion 53 and the second meshing portion 55 mesh with each other. The first meshing portion 53 is arranged so that the compression coil spring 54 as an elastic body that generates an elastic force that biases in the direction of the second meshing portion 55 does not mesh with the first meshing portion 53 and the second meshing portion 55. And an operating rod 57 for moving in the direction away from the second meshing portion 55. The operating rod 57 is operated by the hydraulic pressure of a hydraulic mechanism (not shown). Although not particularly illustrated, the hydraulic mechanism is configured by a hydraulic pump or the like that is driven by the driving force of the engine 7.

  The state switching mechanism 50 includes the rotation of the first output shaft 25 and the rotation of the second output shaft 35 that are relatively high and low torque in the transmission system of the driving force from the engine 7 to the traveling device 2. In this configuration, the first meshing portion 53 and the second meshing portion 55 are engaged with each other. Therefore, the rotation of the first output shaft 25 and the rotation of the second output shaft 35 are synchronized in a place where the rotational force of the driving force from the engine 7 to the traveling device 2 is low and high. Compared with the case where it does, the 1st meshing part 53 and the 2nd meshing part 55 can be created with an inexpensive material.

  By the way, the difference between the rotation speed of the first output shaft 25 and the rotation speed of the second output shaft 35 to be matched by the state switching mechanism 50 is the transmission efficiency of the first continuously variable transmission 20 and the second continuously variable transmission 30. This is due to a difference or leakage of hydraulic oil (oil leak) according to the load applied to the left and right traveling devices 2. By making the first continuously variable transmission 20 and the second continuously variable transmission 30 and the left and right traveling apparatuses 2 have the same configuration, the rotational speed of the first output shaft 25 to be matched by the state switching mechanism 50 and the second The difference in the rotational speed of the output shaft 35 can be reduced.

  The driving unit 3 is provided with a steering operation tool (lever or handle) for determining the traveling direction of the combine 1, a shift operation tool (lever) for determining the travel direction and speed of the combine 1 in a stepless manner, and the like. The steering operation tool and the shift operation tool are linked to a steering device that independently changes the angle of the swash plate of the first hydraulic pump 21 and the second hydraulic pump 31. As a result, the combine 1 is configured to freely move straight, reverse, turn right, turn left, and stop.

  When the steering operation tool is operated in a straight line, the steering device operates the swash plates of the first hydraulic pump 21 and the second hydraulic pump 31 at the same angle so that the hydraulic oil having the same discharge amount is supplied to the first hydraulic motor 22. The driving wheels 2a and 2b, that is, a pair of left and right traveling devices, are supplied to the second hydraulic motor 32 and driven by the first output shaft 25 and the second output shaft 35 through the auxiliary transmission devices 8a and 8b. 2 is driven at the same speed, and the combine 1 goes straight.

  In this state, when the transmission operating tool is operated forward or backward, the first hydraulic pump 21 and the second hydraulic pump 31 are operated forward or backward while maintaining the swash plate at the same angle. The traveling speed of the combine 1 can be changed, forward / reverse switching or stopping can be performed.

  When the steering operation tool is operated in a straight line, the first continuously variable transmission 20 and the second continuously variable transmission 30 change the same amount of driving force input from the same engine 7 in the same manner. However, the difference between the transmission efficiency of the first continuously variable transmission 20 and the second continuously variable transmission 30 and the two travels should be the same. When a difference occurs in the output rotational speed due to leakage of hydraulic oil (oil leak) or the like according to the load applied to the apparatus, that is, when a difference occurs in the driving force output to the pair of left and right traveling apparatuses 2, the combine 1 Does not travel straight, but turns in the direction of smaller driving force.

  In order to avoid such unintended turning, when the steering operation tool is operated in a straight line, the engagement clutch that is the state switching mechanism 50 is engaged with the first engagement portion 53 and the second engagement portion 55 so that the first engagement portion 53 is engaged. A synchronized drive state is achieved in which the rotation of the one input shaft 51 and the rotation of the second input shaft 52, that is, the rotation of the first output shaft 25 and the rotation of the second output shaft 35 coincide with each other.

  Therefore, even if there is a difference in transmission efficiency between the first continuously variable transmission 20 and the second continuously variable transmission 30 or leakage of hydraulic oil (oil leak) according to the load applied to the two traveling devices, Since the driving forces output to the pair of left and right traveling devices 2 coincide with each other, it is possible to ensure straightness.

  When the steering operation tool is turned to the right while the combine 1 is traveling straight ahead, the angle at which the current angle of the swash plate of the first hydraulic pump 21 is determined by the operating position of the transmission operation tool is controlled by the steering device. In this state, the angle of the swash plate of the second hydraulic pump 31 is operated to the side where the discharge amount decreases.

  Thereby, the rotation speed of the second output shaft 35 of the second hydraulic motor 32 driven by the hydraulic oil discharged from the second hydraulic pump 31 is the first hydraulic pressure driven by the hydraulic oil discharged from the first hydraulic pump 21. It becomes less than the rotation speed of the first output shaft 25 of the motor 22, and the combine 1 turns to the right. The more the steering operation tool is operated to the right turning side, the more the swash plate angle of the second hydraulic pump 31 is operated to the side where the discharge amount becomes lower, and the combine 1 turns right with a smaller turning radius. . When the steering operation tool is operated so that the discharge angle of the swash plate of the second hydraulic pump 31 becomes zero, the combine 1 pivots to the right with the traveling device 2 stopped.

  When the steering operation tool is turned to the left while the combine 1 is traveling straight, the angle at which the current angle of the swash plate of the second hydraulic pump 31 is determined by the operating position of the transmission operation tool is controlled by the steering device. In this state, the angle of the swash plate of the first hydraulic pump 21 is operated to the side where the discharge amount becomes lower.

  Thus, the rotation speed of the first output shaft 25 of the first hydraulic motor 22 driven by the hydraulic oil discharged from the first hydraulic pump 21 is the second hydraulic pressure driven by the hydraulic oil discharged from the second hydraulic pump 31. The number of rotations of the second output shaft 35 of the motor 32 becomes less, and the combine 1 turns to the left. The greater the steering operation tool is operated to the left turning side, the more the angle of the swash plate of the first hydraulic pump 21 is operated to the side where the discharge amount becomes lower, and the combine 1 turns left with a smaller turning radius. When the steering operation tool is operated so that the swash plate angle of the first hydraulic pump 21 becomes zero, the combine 1 turns to the left with the traveling device 2 stopped.

  Further, when the first output shaft 25 and the second output shaft 35 are rotated in the opposite directions, the rotation direction of one traveling device 2 driven by the driving force output from the first hydraulic motor 22, Since the rotation direction of the other traveling device 2 driven by the driving force output from the two hydraulic motors 32 is reversed, the combine 1 makes a super turn on the spot.

  As described above, when the steering operation tool is turned, the meshing clutch that is the state switching mechanism 50 prevents the first meshing portion 53 and the second meshing portion 55 from meshing with each other, so that the first input shaft Since the rotation of 51 and the rotation of the second input shaft 52, that is, the rotation of the first output shaft 25 and the rotation of the second output shaft 35 are not matched, the combine 1 can turn smoothly. .

[Another embodiment]
(1) Each of the above-described embodiments is an example of the present invention, and the present invention is not limited by the above description. The specific configuration of each part is appropriately set within the range where the effects of the present invention are exhibited. Change design is possible.

(2) The state switching mechanism 50 may be composed of a multi-plate clutch as shown in FIG.
The multi-plate clutch has an axial center on the inner periphery of a cylindrical portion provided inside the casing so as to be relatively movable in the axial direction at the end of the first input shaft 51 and not relatively rotatable in the circumferential direction. A friction plate 58 slidably disposed in the direction and a friction plate 59 slidably disposed in the axial direction around the second input shaft 52, and the friction plate 58 and the friction plate A hydraulic cylinder 60 that generates an oil pressure in a direction in which the pressure contact with 59 is pressed, and a compression coil spring 56 as an elastic body that generates an elastic force in a direction in which the pressure contact by the hydraulic cylinder 60 is released. The hydraulic cylinder 60 is operated by the hydraulic pressure of a hydraulic mechanism (not shown). Although not particularly illustrated, the hydraulic mechanism is configured by a hydraulic pump or the like that is driven by the driving force of the engine 7.

The connection state and non-connection state of the friction plate 58 and the friction plate 59 are determined by the relationship between the hydraulic pressure generated by the hydraulic cylinder 60 and the elastic force of the compression coil spring 56. If the oil pressure is greater than the elastic force, the friction plate 58 and the friction plate 59 are brought into pressure contact. By gradually weakening the pressing force of the hydraulic cylinder 60, the friction plate 58 and the friction plate 59 gradually begin to slide, eventually becoming larger, and finally the friction plate 58 and the friction plate 59 are changed from the connected state to the disconnected state. And migrate.
When the pressing force of the hydraulic cylinder 60 is gradually increased in the non-connected state, the friction plate 58 and the friction plate 59 shift from the non-connected state to the connected state, the slip gradually decreases, and finally the friction is generated. The plate 58 and the friction plate 59 are pressed against each other so as not to slide.
In this way, by using the slip of the friction plate 58 and the friction plate 59, it is possible to gradually shift between the synchronized drive state and the non-synchronized drive state.

  The multi-plate clutch requires a strong pressure contact force in order to prevent the friction plate 58 and the friction plate 59 from slipping when maintaining the synchronized driving state, that is, when going straight. When the strong pressure contact force is obtained by the elastic force of the compression coil spring, the strong elasticity of the compression coil spring is obtained when shifting from the tuned drive state to the non-tuned drive state and when maintaining the non-tuned drive state, that is, during turning. In order to overcome the force, a hydraulic mechanism capable of generating a strong hydraulic pressure is required.

  When maintaining the synchronized drive state, i.e., when traveling straight, the hydraulic pressure of the hydraulic cylinder 60 is used to shift the multi-plate clutch from the synchronized drive state to the unsynchronized drive state, and when maintaining the unsynchronized drive state, i.e., when turning. Since the compression coil spring 56 is configured to use the elastic force, the compression coil spring 56 may be of a weak elastic force that functions when the oil pressure is lowered, and the hydraulic cylinder 60 However, it may be capable of exerting an oil pressure to overcome the weak elastic force.

  (3) The state switching mechanism 50 may have a configuration in which a meshing clutch and a multi-plate clutch are provided in parallel between the first output shaft 25 and the second output shaft 35, as shown in FIG.

  The mesh clutch is basically the same as the mesh clutch shown in FIG. 3, and the multi-plate clutch is basically the same as the multi-plate clutch shown in FIG. Then, the first meshing portion 53 of the meshing clutch and the friction plate 58 of the multi-plate clutch are connected so as to rotate integrally, the second meshing portion 55 of the meshing clutch, and the second input shaft 52 of the multi-plate clutch. And are connected so as to rotate integrally.

  According to such a configuration, the meshing clutch can surely match the rotation of the first output shaft 25 and the rotation of the second output shaft 35, and the multi-plate clutch utilizes the slip of the friction plate 58 and the friction plate 59. By doing so, the transition between the tuned drive state and the non-tuned drive state can be performed gradually.

  (4) The state switching mechanism 50 includes a meshing clutch as shown in FIG. 3 and a multi-plate clutch shown in FIG. 4 between the first output shaft 25 and the second output shaft 35 in series. Also good. As a result, it is possible to select between switching by the meshing clutch and switching by the multi-plate clutch.

  (5) The state switching mechanism 50 may be a known clutch such as a fluid clutch, a centrifugal clutch, or an electromagnetic clutch, or a differential device used in an automobile or the like.

  (6) The transmission of the driving force from the first output shaft 25 to the first input shaft 51 by the first coupling mechanism 40 is not limited to the configuration by meshing of the gears such as the first bevel gear 43b, but for example, the first transmission The driving force is transmitted from the first output shaft 25 to the first input shaft 51 by a power transmission belt or power transmission chain disposed on the sprocket provided on the shaft 43a and the sprocket provided on the fourth transmission shaft 47a. May be. The same applies to the second connecting mechanism 41.

  (7) In the first continuously variable transmission 20, the first hydraulic pump 21 and the first hydraulic motor 22 are integrally provided in the same casing, and an oil passage disposed in the casing as a first hydraulic circuit. Therefore, the first hydraulic pump 21 and the first hydraulic motor 22 may be connected to each other. The same applies to the second continuously variable transmission 30.

  The power transmission device according to the present invention can be used not only for a self-removing combine but also for an ordinary combine. Moreover, it can be used not only for a combine but also for other harvesting machines.

DESCRIPTION OF SYMBOLS 1 Combine 2 Traveling apparatus 2a Starting wheel 2b Starting wheel 3 Driving | running | working part 4 Cutting part 5 Threshing apparatus 6 Grain tank 7 Engine 7a Output shaft 8a Subtransmission 8b Subtransmission 9 Body frame 9a Engine support frame 10 Power transmission apparatus 20 First continuously variable transmission 21 First hydraulic pump 22 First hydraulic motor 23 Hydraulic hose 24 Hydraulic hose 25 First output shaft 30 Second continuously variable transmission 31 Second hydraulic pump 32 Second hydraulic motor 33 Hydraulic hose 34 Hydraulic hose 35 Second output shaft 40 First connection mechanism 41 Second connection mechanism 42 First connection portion 43a First transmission shaft 43b First bevel gear 44a Second transmission shaft (intermediate transmission shaft, split shaft body)
44b Second bevel gear 45 Second connecting portion (intermediate transmission shaft)
46a Third transmission shaft (intermediate transmission shaft, split shaft)
46b 3rd bevel gear 47a 4th transmission shaft 47b 4th bevel gear 48 3rd connection part 50 State switching mechanism 51 1st input shaft 52 2nd input shaft 53 1st meshing part 54 Compression coil spring 55 2nd meshing part 56 Compression Coil spring 57 Operating rod 58 Friction plate 59 Friction plate 60 Hydraulic cylinder

Claims (9)

A power transmission device for a harvester that transmits a driving force of a driving source to a pair of left and right traveling devices,
The first hydraulic pump to which the driving force of the driving source is input, and the first hydraulic pump and the first hydraulic circuit are connected to each other, and the input driving force is transmitted to one of the left and right traveling devices. A hydrostatic first continuously variable transmission including a first hydraulic motor having a first output shaft for outputting;
The second hydraulic pump to which the driving force of the driving source is input, and the second hydraulic pump and the second hydraulic circuit are connected to each other, and the input driving force is transmitted to the other traveling device of the pair of left and right traveling devices. A hydrostatic second continuously variable transmission comprising a second hydraulic motor having a second output shaft for outputting;
The driving force from the first output shaft is input, the first input shaft provided at a position higher than the first output shaft in a state parallel to the first output shaft, and from the second output shaft A driving force is input, and has a second input shaft provided at a position higher than the second output shaft in a state parallel to the second output shaft and in the same axis as the first input shaft; A state switching mechanism capable of switching the rotation of the first output shaft and the rotation of the second output shaft to a synchronized drive state that matches or a non-tuned drive state that does not match;
A first coupling mechanism that transmits driving force from the first output shaft to the first input shaft;
A second coupling mechanism for transmitting a driving force from the second output shaft to the second input shaft,
The first coupling mechanism includes an intermediate transmission shaft orthogonal to the first output shaft and the first input shaft,
The power transmission device for a harvester, wherein the second coupling mechanism includes an intermediate transmission shaft orthogonal to the second output shaft and the second input shaft . The intermediate transmission shaft in the first connection mechanism and the intermediate transmission shaft in the second connection mechanism are capable of relative movement in the axial direction between the divided shaft bodies divided in the axial direction and the divided shaft bodies, and The power transmission device for a harvesting machine according to claim 1 , further comprising a second coupling portion coupled so as not to be relatively rotatable in the circumferential direction . The state switching mechanism is
The power transmission of the harvester according to claim 1 or 2 , wherein a meshing clutch that can be switched from either the meshing state or the non-meshing state to the other is provided between the first output shaft and the second output shaft. apparatus. The meshing clutch is
When switching from the non-engaged state to the meshed state and maintaining the meshed state, the elastic force of the elastic body is used,
4. The power transmission device for a harvester according to claim 3, wherein an oil pressure of a hydraulic mechanism that resists an elastic force of the elastic body is used when switching from the meshing state to the non-meshing state and maintaining the non-meshing state. . The state switching mechanism is
The harvest according to claim 1 or 2 , wherein a multi-plate clutch capable of continuously shifting from either the connected state or the non-connected state to the other is provided between the first output shaft and the second output shaft. Machine power transmission device. The multi-plate clutch is
At the time of transition from the connected state to the disconnected state and maintaining the disconnected state, utilizing the elastic force of the elastic body,
6. The power transmission device for a harvester according to claim 5 , wherein an oil pressure of a hydraulic mechanism that resists an elastic force of the elastic body is used when transitioning from the disconnected state to the connected state and maintaining the connected state. The state switching mechanism is
A meshing clutch capable of switching from one of the meshing state and the non-meshing state to the other; and
A multi-plate clutch capable of continuously shifting from either the connected state or the non-connected state to the other,
The power transmission device for a harvester according to claim 1 or 2 , wherein the power transmission device is provided in series or in parallel between the first output shaft and the second output shaft. The meshing clutch is
When switching from the non-engaged state to the meshed state and maintaining the meshed state, use the elastic force of the first elastic body,
When switching from the meshing state to the non-meshing state and maintaining the non-meshing state, utilizing the hydraulic pressure of the first hydraulic mechanism that resists the elastic force of the first elastic body,
The multi-plate clutch is
When transitioning from the connected state to the disconnected state and maintaining the disconnected state, utilizing the elastic force of the second elastic body,
8. The harvester according to claim 7 , wherein an oil pressure of a second hydraulic mechanism that resists an elastic force of the second elastic body is used when transitioning from the disconnected state to the connected state and maintaining the connected state. Power transmission device.   The harvester provided with the power transmission device of the harvester as described in any one of Claim 1 to 8.

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