KR102666858B1 - Power transfer device, transmission and fixed structure of axle case - Google Patents

Abstract

A power transmission device that can simplify the structure is provided. Additionally, a power transmission device that can simplify the configuration including a parking brake and a sub-transmission mechanism is provided. Additionally, a transmission device is provided that can switch gear engagement and disengagement in the left and right power transmission mechanisms to a mechanism common to the left and right, and can achieve satisfactory gear engagement. Additionally, a fixing structure for the axle case is provided that can suppress damage to the main body case, etc. even when a large lateral pulling load is applied to the sprocket.
In a state in which hydraulic oil does not flow through the flow paths 38 and 62, the pressing member 41 is pressed against the parking brake 28 side by the elastic force of the spring 43, and the action portion 42 of the pressing member 41 is pressing the clutch plate (27). As a result, the clutch disk 25 and the clutch plate 27 are pressed into contact, the parking brake 28 is engaged, and the first shaft 11 is braked. In addition, the pressing force is transmitted to the two-shaft coupling clutch 33 through the common member 21, and the clutch plate 31 and the clutch disk 32 are pressed into contact. As a result, the two-axis coupling clutch 33 is engaged, and the first shaft 11 and the second shaft 12 are coupled. In addition, normally, the pressing member 1021 is pressed against the parking brake 1018 side by the elastic force of the spring 1023, and the action portion 1022 of the pressing member 1021 presses the clutch plate 1017. there is. As a result, the clutch disk 1015 and the clutch plate 1017 are pressed into contact, the parking brake 1018 is engaged, and the first gear 1011 is braked. From this state, when the movable member 1031 moves to the side away from the parking brake 1018, the movable member 1031 presses the pressing member 1021, and the pressing member 1021 moves away from the parking brake 1018. moves in the direction in which the parking brake 1018 is released, and the braking of the first gear 1011 is released. Additionally, in conjunction with the movement of the moving member 1031, the shift fork 1055 moves and the shifter 1054 moves from the drive position to the neutral position. Additionally, the engagement of the intermediate gears 2112L and 2112R and the shifter gears 2115L and 2115R forms a power transmission path that transmits power to the left and right traveling devices. From that state, when the shifter gears 2115L and 2115R move to the right, the respective engagements between the intermediate gears 2112L and 2112R and the shifter gears 2115L and 2115R are released, resulting in a neutral state in which power is not transmitted to the left and right traveling devices. It becomes a state. Shift forks 2123L and 2123R are coupled to the shifter gears 2115L and 2115R, respectively. The shift fork shaft 2121 supporting the shift forks 2123L and 2123R is provided to be movable in the direction of the rotation axis, and is urged in the left direction by a spring 2129. Additionally, the axle case 3021 integrally includes a cylindrical portion 3022 and a plurality of fixing portions 3023 protruding from the cylindrical portion 3022 to the periphery. Bearings 3025 and 3026 are fitted into both ends of the cylindrical portion 3022 in the axial direction, respectively. The axle 3006 is inserted into the cylindrical portion 3022 and is held by bearings 3025 and 3026 so as to be rotatable relative to the cylindrical portion 3022. The axle case 3021 is fixed to the frame 3031 by screwing bolts 3028 inserted into each fixing portion 3023 into the frame 3031 of the combine 3001.

Description

Fixed structure of power transmission device, transmission device and axle case {POWER TRANSFER DEVICE, TRANSMISSION AND FIXED STRUCTURE OF AXLE CASE}

The present invention relates to a power transmission device that transmits power. Additionally, the present invention relates to a transmission device for work vehicles such as combines. Additionally, the present invention relates to a fixing structure for an axle case that accommodates an axle of a work vehicle.

For example, some work vehicles such as combines employ crawlers as a pair of left and right traveling devices. In a work vehicle employing this crawler, in order to turn the aircraft left and right, it is necessary to shift the power transmitted to the left and right crawlers. For example, when power at a lower speed than the power transmitted to one crawler is transmitted to the other crawler, the aircraft makes a full turn toward the other crawler. Additionally, power in the opposite direction to the power transmitted to one crawler is transmitted to the other crawler, causing the aircraft to spin toward the other crawler.

The power transmission device that transmits power to the left and right crawlers for shifting power or switching transmission paths is provided with a plurality of clutches. In a configuration in which a plurality of clutches are provided, it is common to provide a structure for operating the clutch by hydraulic pressure for each clutch. However, in order to operate the parking brake to maintain the stationary state of the aircraft, the clutch must be operated by a mechanical method rather than hydraulically, so, for example, the parking brake is applied by combining the first and second axes to brake the first axis. When operating, a structure for mechanically operating the clutches is required for each clutch (brake) that brakes the first shaft and the clutch that couples the first shaft and the second shaft. Therefore, the structure of the power transmission device becomes complex and large.

Additionally, for example, in a combine, the power of the drive source is transmitted to a pair of left and right traveling devices through a power transmission device.

The power transmission device is equipped with a parking brake to keep the aircraft stationary. By operating the parking brake, for example, an axle or gear included in the power transmission device is braked. Then, the braking force is applied to the left and right traveling devices, and the stationary state of the aircraft is maintained.

Additionally, among combines, there are those equipped with a mechanical sub-transmission mechanism in the power transmission device. In the sub-transmission mechanism, the shifter is splined with the two gears at a position spanning the two gears, and is in a driving state in which power is transmitted between the gears. When the spline connection between the shifter and one gear is released, power is not transmitted between the two gears, which results in a neutral state in which power is not transmitted to the driving device.

Additionally, for example, in a combine equipped with HST (Hydro Static Transmission), the hydraulic pump of the HST is driven by the power of the engine, and the hydraulic motor is driven by the oil discharged by the hydraulic pump. The power of the hydraulic motor is transmitted to the left and right crawlers through a power transmission mechanism including gears. When the left and right crawlers are driven at the same speed, the aircraft moves straight forward and backward, and when the left and right crawlers are driven with a speed difference, the aircraft turns left and right.

In addition, for example, in a combine, a crawler is adopted as a pair of left and right traveling devices because an irregular ground running ability is required. The axle is connected to the sprocket that serves as the drive wheel of the crawler so that relative rotation is not possible. Then, the power from the drive source is transmitted to the left and right axles through a power transmission mechanism, and the drive wheels of the left and right crawlers are rotated integrally with the axles, respectively.

Fig. 8 is a cross-sectional view showing the structure near the axle of a conventional combine.

The end portion inside the vehicle width direction of the axle 3051 is inserted into the main body case 3052 that accommodates the power transmission mechanism, and is coupled to the gear 3053 in the main body case 3052 so that it cannot rotate relative to it. The outer end of the axle 3051 in the vehicle width direction is coupled to the sprocket 3054 in a non-relatively rotatable manner.

The axle 3051 is between the main body case 3052 and the sprocket 3054 and is covered with the axle case 3055. The axle case 3055 includes a cylindrical case body portion 3056 and a flange portion 3057 that protrudes outward in the rotational radial direction of the axle 3051 from the end of the case body portion 3056 on the side of the main body case 3052. It is available. The case body portion 3056 and the flange portion 3057 are fixed to each other by welding. Then, the flange portion 3057 comes into contact with the outer surface of the main body case 3052, and the tip portion of the bolt 3058 that penetrates the flange portion 3057 is screwed into the main body case 3052, thereby forming the axle case 3055. is fixed to the main body case 3052.

Japanese Patent Publication No. 2018-3916 Japanese Patent Publication No. 2012-62973 Japanese Patent Publication No. 2009-78699

An object of the present invention is to provide a power transmission device that can simplify the structure.

Additionally, conventionally, the parking brake and the sub-transmission mechanism are each provided with an operation mechanism for operation. Therefore, the power transmission device including the parking brake and the sub-transmission mechanism has a complicated structure, and there is a lot of waste in the construction when the sub-transmission mechanism is rarely used in the neutral state.

Another object of the present invention is to provide a power transmission device that can simplify the configuration including a parking brake and a sub-transmission mechanism.

Additionally, in a combine, for purposes such as adjustment or emergency traction, it is necessary to shift gears to a neutral state in which power is not transmitted between the hydraulic motor of the HST and the left and right crawlers. The neutral state can be created, for example, by disengaging the two gears included in the power transmission mechanism between the hydraulic motor and the left crawler and the power transmission mechanism between the hydraulic motor and the right crawler, respectively.

However, in a configuration in which the gears are disengaged independently by each power transmission mechanism on the left and right, mechanisms for engaging and disengaging the gears are required independently on the left and right, and the size of the transmission device including the power transmission mechanism is increased. Additionally, when two gears are meshed from the neutral state, because each gear is in a position where it does not mesh, that is, the teeth of one gear and the tooth grooves of the other gear do not face each other in the direction of the rotation axis, the gears do not mesh properly. There are cases.

Another object of the present invention is to provide a transmission device that can switch gear engagement and disengagement in the left and right power transmission mechanisms to a single mechanism common to the left and right, and can achieve good gear engagement. will be.

In addition, in this configuration, when a large load (lateral pulling load) is applied to the sprocket 3054 in its radial direction, the flange portion 3057 of the axle case 3055 and the main body case 3052 are separated by the bolt 3058. A load in the direction in which the bolt 3058 is removed is applied to the fastening portion. As a result, there is a risk that oil leakage may occur due to damage to the gasket 3059 that seals between the main body case 3052 and the axle case 3055, or the main body case 3052 may be damaged.

Another object of the present invention is to provide a fixing structure for an axle case that can suppress damage to the main body case, etc. even when a large lateral pulling load is applied to the sprocket.

In order to achieve the above object, the power transmission device according to the present invention is a power transmission device that transmits power to a traveling device, and includes a first clutch engaged/disengaged to brake/release the first axis, and a first axis. and a second clutch that is engaged/disengaged in order to engage/disengage the second shaft, and a pressing member that presses one side of the first clutch and the second clutch to engage them, and the first clutch and the second clutch are the same. It is arranged on the axis line so that when one of the first clutch and the second clutch is pressed by the pressing member, the pressing force is transmitted to the other side of the first clutch and the second clutch.

According to this configuration, when one side of the first clutch and the second clutch is pressed and engaged by the pressing member, the pressing force is transmitted to the other side of the first clutch and the second clutch. Thereby, both the first clutch and the second clutch are engaged. Accordingly, it is possible to eliminate the need to provide a structure for operating each first and second clutch, thereby achieving simplification of the structure.

The power transmission device may further include an elastic member, and the pressing member may press the first clutch by the elastic force of the elastic member.

The power transmission device further includes a moving member provided to be movable in a first direction in which the pressing member approaches the first clutch and in a second direction in which the pressing member is spaced apart, and the first clutch is engaged. The first clutch may be released by moving the moving member in the second direction, the moving member pressing the pressing member, and the pressing member moving against the elastic force of the elastic member.

The power transmission device further includes a case, and the moving member has a cylindrical portion inserted into an insertion hole formed in the case, a screw is formed on the cylindrical portion in a portion protruding outside of the case, and the movable member has a cylindrical portion inserted into an insertion hole formed in the case. A configuration in which the moving member moves in the second direction may be adopted by tightening a bolt screwed to the screw of the cylindrical portion. With this configuration, the position of the moving member is determined by the tightening amount of the nut, so the position of the moving member can be adjusted with high precision.

In addition, in order to achieve the above object, the power transmission device according to the present invention is a power transmission device that transmits power to the traveling device, and is used to brake/release the brakes on the first rotor through which the traveling device and the power transmission path are connected. A parking brake that is engaged/released, an elastic member, a pressing member that presses and engages the parking brake by the elastic force of the elastic member, a first direction in which the pressing member approaches the parking brake, and a second direction in which the pressing member is spaced apart from the parking brake. A shifter that moves to a driving position that connects the second rotating body and the third rotating body so that the second rotating body and the third rotating body can be rotated integrally, and a neutral position that releases the connection, in conjunction with the movement of the moving member and the moving member that is provided to be able to move in two directions. Including, the moving member moves in the second direction from the state in which the parking brake is engaged, the moving member presses the pressing member, and the pressing member moves against the elastic force of the elastic member, thereby releasing the parking brake. , the shifter moves from the drive position to the neutral position.

According to this configuration, in normal times, the pressing member is pressed toward the parking brake by the elastic force of the elastic member, the parking brake is engaged by the pressing member, and the first rotating body is braked. When the moving member moves in the second direction from this state, the moving member presses the pressing member, and the pressing member resists the elastic force of the elastic member and moves in the second direction, so that the parking brake is released, and the first rotating body The brake is released. Accordingly, since there is no need for an operation lever to operate (engage) the parking brake, and there is no need to mechanically connect the parking brake and the operation lever, etc., the degree of freedom in the layout of each member constituting the power transmission device is improved.

Additionally, when the parking brake is released, the shifter moves from the drive position to the neutral position in conjunction with the movement of the moving member, and the connection between the second rotary body and the third rotary body is released. Therefore, since the sub-transmission mechanism including the shifter does not require an operating mechanism including an operating lever or the like, the configuration of the power transmission device can be simplified.

An oil chamber is formed between the pressing member and the moving member, and hydraulic pressure is supplied to the oil chamber from a state in which the parking brake is engaged, and the pressing member moves against the elastic force of the elastic member, thereby releasing the parking brake.

The power transmission device further includes a case, and the moving member has a cylindrical portion inserted into an insertion hole formed in the case, a screw is formed on the cylindrical portion in a portion protruding outside of the case, and the movable member has a cylindrical portion inserted into an insertion hole formed in the case. A configuration in which the moving member moves in the second direction may be adopted by tightening the nut screwed to the screw of the cylindrical portion. With this configuration, the position of the moving member is determined by the tightening amount of the nut, so the position of the moving member can be adjusted with high precision.

The third rotating body may be the first rotating body.

In addition, in order to achieve the above object, the transmission device according to the present invention is a transmission device that changes the power of the drive source and transmits it to the left and right traveling devices, and is provided corresponding to each of the left and right traveling devices, and transmits the power from the drive source. It is provided with a transmission gear and a shifter gear movable in the direction of the rotation axis of the transmission gear, a power transmission path is formed by meshing of the transmission gear and the shifter gear, and the shifter gear moves in one direction in the direction of the rotation axis to form the transmission gear. and a left and right power transmission mechanism in which the power transmission path is cut when the engagement of the shifter gear is released, a shift member provided to be movable in the direction of the rotation axis and having a shift fork respectively coupled to the left and right shifter gears, and a shift member. It includes a pressing member that presses in one direction opposite to the direction of the rotation axis.

According to this configuration, a power transmission mechanism is provided corresponding to each of the left and right traveling devices. Each power transmission mechanism is provided with a transmission gear through which power is transmitted from a drive source and a shifter gear movable in the direction of the rotation axis of the transmission gear. In each power transmission mechanism, a power transmission path that transmits power to the traveling device is formed by engagement of the transmission gear and the shifter gear. From the state in which the transmission gear and the shifter gear are engaged, the shifter gear moves in one direction of the rotation axis, thereby disengaging the transmission gear and the shifter gear, thereby cutting the power transmission path. As a result, the transmission device enters a neutral state in which power is not transmitted to the left and right traveling devices.

The shift fork of the shift member is coupled to the left and right shifter gears. The shift member is provided to be movable in the direction of the rotation axis, and is pressed by a pressing member in one direction opposite to the direction of the rotation axis. When the shift member resists the pressing force and moves in one direction of the rotation axis, both left and right shifter gears move in one direction, and the engagement between the left and right transmission gears and the shifter gear is released. When the force that moves the shift member in one direction is released, the shift member moves in the other direction of the rotation axis due to the pressing force of the pressing member. When the teeth of the shifter gear face the tooth grooves of the transmission gear in the direction of the rotation axis, the movement of the shift member causes the teeth of the shifter gear to enter the tooth grooves of the transmission gear, and meshing of the transmission gear and the shifter gear is achieved. On the other hand, when the teeth of the shifter gear do not oppose the tooth grooves of the transmission gear in the direction of the rotation axis, the movement of the shift member causes the teeth of the shifter gear to come into contact with the teeth of the transmission gear, and the shifter gear and the transmission gear do not mesh. Since the shift member is pressed in the other direction of the rotation axis, even if the teeth of the shifter gear come into contact with the teeth of the transmission gear, when the tooth grooves of the transmission gear oppose the teeth of the shifter gear in the direction of the rotation axis due to the rotation of the transmission gear, The teeth of the shifter gear enter the tooth grooves of the transmission gear, and meshing of the transmission gear and the shifter gear is achieved.

Therefore, gear engagement (engagement of the transmission gear and shifter gear) and disengagement in the left and right power transmission mechanisms can be switched to a single mechanism common to the left and right, and the gear engagement can be achieved satisfactorily.

The transmission further includes a unit case that accommodates the power transmission mechanism, and the shift member extends in the direction of the rotation axis, is movably held by the unit case in the direction of the rotation axis, and supports a shift fork on the left and right. A fork shaft may be provided.

In that case, one end of the shift fork shaft extends and protrudes outward through the unit case, is connected to one end of the shift fork shaft, and is rotated using the support shaft extending in a direction perpendicular to the rotation axis direction as a support point. It is desirable to further include an operating member that moves the shift fork shaft in the direction of the rotation axis. Gear engagement and disengagement can be achieved by rotating the operating member.

The operating member may be provided with a shift operation piece supported on the support shaft and connected to the shift fork shaft, and an operation arm supported on the support shaft and rotating integrally with the shift operation piece. In this case, the operation member may be operated from the support shaft. It is preferable that the length from the tip of the arm is greater than the length from the support shaft to the connection portion of the shift operation piece with the shift fork shaft. Thereby, the principle of the lever operates, and even if the force applied to the operating arm is small, the shift fork shaft can be moved satisfactorily by resisting the pressing force of the pressing member.

It is preferable that the unit case be provided with a locking support portion that locks the operating arm in a state in which the transmission gear and the shifter gear are disengaged. After the transmission gear and the shifter gear are disengaged, the disengaged state can be maintained by locking the operating arm to the locking support.

The pressing member is preferably interposed between the unit case and one of the left and right shift forks. As a result, there is no need to separately provide a portion for connecting the pressing member to the shift member, and the configuration of the shift member can be simplified.

On the side of the transmission gear, an annular groove is formed centering on the rotation axis of the transmission gear, and on the circumferential surface of the outer circumference of the groove, a plurality of internal teeth protruding toward the rotation axis are arranged in a circumferential direction of the groove. In addition, the shifter gear may be provided with a plurality of external teeth protruding outward in the rotational radial direction, and the external teeth may be engaged with the transmission gear by fitting into the tooth grooves between adjacent internal teeth of the transmission gear.

In addition, in order to achieve the above object, the fixing structure of the axle case according to the present invention is a structure for fixing the axle case that accommodates the axle of the work vehicle, and the axle case includes a cylindrical portion into which the axle is inserted, and a cylindrical portion from the cylindrical portion. It has a fixed part integrally protruding outward in the radial direction of the axle, and the fixed part is fixed to the frame of the work vehicle.

According to this configuration, the axle case is fixed to the frame of the work vehicle, so even when a large lateral pulling load is applied to the drive wheel to which the axle is coupled, damage to the main body case, etc., which houses the power transmission mechanism that transmits power to the axle, is suppressed. can do.

The work vehicle is provided with a power transmission mechanism that transmits power to the axle, and a main body case that accommodates the power transmission mechanism. The main body case is provided with a cylindrical insertion portion that extends in the axial direction of the axle and into which the axle is inserted, The cylindrical portion of the axle case may not be fixed to the insertion portion but may be inserted into the insertion portion.

According to the present invention, simplification of the structure can be achieved.

Additionally, according to the present invention, it is possible to simplify the configuration including the parking brake and the auxiliary transmission mechanism.

Furthermore, according to the present invention, gear engagement and disengagement in the left and right power transmission mechanisms can be switched to a single mechanism common to the left and right, and the gear engagement can be achieved satisfactorily.

Furthermore, according to the present invention, even when a large lateral pulling load is applied to the sprocket, damage to the main body case, etc. can be suppressed.

Figure 1A is a cross-sectional view showing the configuration of a main part of a power transmission device according to an embodiment of the present invention, and shows a parking brake and a two-axis coupling clutch in an engaged state.
FIG. 1B is a cross-sectional view showing the configuration of a main part of a power transmission device according to an embodiment of the present invention, and shows a state in which the parking brake and the two-axis engagement clutch are released by hydraulic pressure.
FIG. 1C is a cross-sectional view showing the configuration of a main part of a power transmission device according to an embodiment of the present invention, and shows a state in which the parking brake is released and the two-axis coupling clutch is engaged.
1D is a cross-sectional view showing the configuration of the main part of the power transmission device according to one embodiment of the present invention, and shows the parking brake and the two-axis engagement clutch in a released state.
FIG. 2A is a cross-sectional view showing the configuration of a main part of a power transmission device according to another embodiment of the present invention, and shows a state in which the parking brake is engaged.
FIG. 2B is a cross-sectional view showing the configuration of a main part of a power transmission device according to another embodiment of the present invention, and shows a state in which hydraulic oil is supplied to the oil chamber to release the parking brake.
FIG. 2C is a cross-sectional view showing the configuration of main parts of a power transmission device according to another embodiment of the present invention, and shows a state in which the parking brake is released and the shifter is positioned in the neutral position.
Figure 3 is a right side view showing the front part of the combine on which the transmission device according to another embodiment of the present invention is mounted.
Fig. 4 is a diagram showing a partial configuration of the transmission device.
Fig. 5 is a cross-sectional view showing a part of the transmission device and shows the configuration from the hydraulic motors of the left HST and right HST all the way to the traveling device.
Fig. 6A is a cross-sectional view showing the configuration of the neutral transmission mechanism, and shows a state in which the second left intermediate gear and the left shifter gear are engaged, and the second right intermediate gear and the right shifter gear are engaged.
FIG. 6B is a cross-sectional view showing the configuration of the neutral transmission mechanism, and shows a state in which the second left intermediate gear and the left shifter gear are disengaged, and the second right intermediate gear and the right shifter gear are disengaged.
Fig. 6C is a cross-sectional view showing the configuration of the neutral shifting mechanism, and shows a state in which the second left intermediate gear and the left shifter gear are disengaged and the second right intermediate gear is in contact with the right shifter gear.
FIG. 6D is a cross-sectional view showing the configuration of the neutral transmission mechanism, and shows a state in which the second left intermediate gear and the left shifter gear are engaged, and the second right intermediate gear and the right shifter gear are engaged.
Fig. 7 is a cross-sectional view showing the structure near the axle of the combine according to one embodiment of the present invention.
Fig. 8 is a cross-sectional view showing the structure near the axle of a conventional combine.

Below, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<Power transmission device>

1A, 1B, 1C, and 1D are cross-sectional views showing the configuration of main parts of the power transmission device 1 according to one embodiment of the present invention.

The power transmission device 1 is mounted on a combine, for example, and transmits power to the left and right traveling devices. The combine may be a two-pump, two-motor configuration equipped with HST (Hydro Static Transmission) for each of the left and right traveling devices, or may be configured with an HST in common for the left and right traveling devices. do.

The power transmission device 1 includes a first shaft 11 and a second shaft 12. The first shaft 11 is formed in a cylindrical shape. The second shaft 12 is formed in a cylindrical shape. And, the first axis 11 is inserted into the second axis 12 along the center line of the second axis 12, so that the center line of the first axis 11 and the center line of the second axis 12 coincide, The first axis 11 and the second axis 12 form a dual axis structure. A needle bearing 13 is interposed between the first shaft 11 and the second shaft 12. As a result, the first shaft 11 is rotatably supported on the second shaft 12 via a needle bearing 13. In addition, the second shaft 12 is rotatably held in the case 15 forming the outer shell of the power transmission device 1 via a bearing 14.

The first shaft 11 is formed with a portion having a certain length in the direction of the rotation axis from one end surface having a smaller diameter than the portion exceeding the certain length. And, splines 16 are formed in the small diameter portion. The common member 21 is splined to the spline 16. The common member 21 includes an annular portion 22 extending from the first axis 11 in the direction of its rotation diameter, and an annular portion extending from the tip of the annular portion 22 to one side in the direction of the rotation axis of the first shaft 11. 1 It has a cylindrical portion 23 and a second cylindrical portion 24 extending from the distal end of the annular portion 22 to the other side in the direction of the rotation axis of the first shaft 11.

On the outer peripheral surface of the first cylindrical portion 23, a plurality of annular plate-shaped clutch disks 25 are held at intervals in the direction of the rotation axis of the first cylindrical portion 23. The case 15 has a third cylindrical portion 26 formed in a cylindrical shape that surrounds the outside of the first cylindrical portion 23 in parallel with the first cylindrical portion 23 . On the inner peripheral surface of the third cylindrical portion 26, a plurality of annular plate-shaped clutch plates 27 are held at intervals in the direction of the center line of the third cylindrical portion 26. The clutch disks 25 and clutch plates 27 are arranged alternately in the center line direction. When the clutch disk 25 and the clutch plate 27 are pressed into contact, rotation of the clutch disk 25 is prevented, and when their pressure contact is released, rotation of the clutch disk 25 is allowed. That is, the clutch disk 25 and the clutch plate 27 constitute the parking brake 28 that is engaged/released to brake/release the first shaft 11.

On the inner peripheral surface of the second cylindrical portion 24, a plurality of annular clutch plates 31 are held at intervals in the direction of the rotation axis of the second cylindrical portion 24. The second cylindrical portion 24 faces the second axis 12 from the radially outer side of the second axis 12 . On the outer peripheral surface of the second shaft 12, at a portion opposite to the second cylindrical portion 24, a plurality of annular clutch disks 32 are held at intervals in the direction of the rotation axis of the second shaft 12. there is. The clutch plates 31 and clutch disks 32 are arranged alternately in the direction of the rotation axis. When the clutch plate 31 and the clutch disk 32 are press-contacted, the first shaft 11 and the second shaft 12 are coupled to rotate as one body, and when their press-contact is released, the first shaft 11 and The second axis 12 is separated so that relative rotation is possible. That is, the clutch plate 31 and the clutch disk 32 constitute a two-axis coupling clutch 33 that is engaged/released to engage/disengage the first shaft 11 and the second shaft 12. there is.

Additionally, a spring 34 is interposed in a compressed state between the annular portion 22 of the common member 21 and the surface formed by the difference in diameter on the outer peripheral surface of the first shaft 11.

A piston 35 is provided on the side opposite to the spring 34 with respect to the annular portion 22 of the common member 21. The piston 35 is externally fitted to the first shaft 11 and is provided to be movable in the direction of the rotation axis of the first shaft 11. A cylinder 36 is provided on the side opposite to the annular portion 22 with respect to the piston 35. The cylinder 36 is externally fitted to the first axis 11 and is fixedly provided with respect to the first axis 11 . And, an oil chamber 37 is formed between the piston 35 and the cylinder 36. Inside the first shaft 11, a flow path 38 is formed. The flow path 38 is connected to the oil chamber 37 through the connection flow path 39.

A pressing member 41 is provided on the side opposite to the two-axis engagement clutch 33 with respect to the parking brake 28. The pressing member 41 has an annular action portion 42 that presses the portion where the clutch disk 25 and the clutch plate 27 overlap. A plurality of springs 43 are interposed between the pressing member 41 and the case 15, and the pressing member 41 rides on the clutch plate 27 side by the elastic force of the springs 43. I am being sexually pressured.

A through hole 44 is formed in the pressing member 41. The through hole 44 has cylindrical surfaces 45 and 46 centered around the rotation axis of the first axis 11 in this order from the first axis 11 side. The cylindrical surface 46 has a smaller diameter than the cylindrical surface 45, and has an annular step surface 47 between the cylindrical surfaces 45 and 46.

A moving member 51 is provided between the first shaft 11 and the pressing member 41. The moving member 51 includes a flat cylindrical first cylindrical portion 52 having an outer diameter corresponding to the cylindrical surface 45 of the pressing member 41, and a first axis 11 with respect to the first cylindrical portion 52. ) side and the second cylindrical portion 53 having an outer diameter corresponding to the cylindrical surface 46 of the pressing member 41, and a first axis 11 side with respect to the second cylindrical portion 53. It is formed on the opposite side and has a third cylindrical part 54 that has a smaller diameter and extends longer than the second cylindrical part 53.

And, the first cylindrical portion 52 is sandwiched in a portion surrounded by the cylindrical surface 45 of the pressing member 41. The second cylindrical portion 53 is inserted into a portion surrounded by the cylindrical surface 46 of the pressing member 41. The third cylindrical portion 54 passes through the through hole 44 of the pressing member 41 and is inserted into the insertion hole 55 formed through the case 15. In the third cylindrical portion 54, a screw 57 is formed in a portion that protrudes outward of the case 15, and a nut 58 is screwed to the portion where the screw 57 is formed.

Between the pressing member 41 and the moving member 51, an oil chamber 61 is formed. Additionally, a flow path 62 is formed in the moving member 51 along its center line. The flow path 62 is open at the front end surface of the third cylindrical portion 54. Additionally, the flow path 62 is connected to the oil chamber 61 through the connection flow path 63.

<Action>

In a state in which hydraulic oil does not flow through the passages 38 and 62, as shown in FIG. 1A, the pressing member 41 is pressed against the parking brake 28 side by the elastic force of the spring 43, and the pressing member 41 The action portion 42 of ) is pressing the clutch plate 27. As a result, the clutch disk 25 and the clutch plate 27 are pressed into contact, the parking brake 28 is engaged, and the first shaft 11 is braked. In addition, the pressing force is transmitted to the two-shaft coupling clutch 33 through the common member 21, and the clutch plate 31 and the clutch disk 32 are pressed into contact. As a result, the two-axis coupling clutch 33 is engaged, and the first axis 11 and the second axis 12 are coupled.

From this state, as shown in FIG. 1B, when hydraulic oil (pressure oil) is supplied to the flow path 62 and the hydraulic oil is supplied from the flow path 62 to the oil chamber 61 through the connection flow path 63, the oil chamber 61 ), the pressing member 41 resists the elastic force of the spring 43 and moves in a direction away from the parking brake 28. As a result, the parking brake 28 is released, and the braking of the first axis 11 is released. In addition, since the transmission of the pressing force to the two-axis coupling clutch 33 is eliminated, the two-axis coupling clutch 33 is also released, and the coupling of the first shaft 11 and the second shaft 12 is released. As a result, the first axis 11 and the second axis 12 can rotate independently.

Afterwards, as shown in FIG. 1C, hydraulic oil is also supplied to the oil passage 38, and when the hydraulic oil is supplied from the oil passage 38 to the oil chamber 37 through the connection oil passage 39, the hydraulic oil in the oil chamber 37 As a result, the piston 35 presses the common member 21. Due to this pressing force, the clutch plate 31 and clutch disk 32 of the two-axis engagement clutch 33 are pressed into contact. As a result, the two-axis coupling clutch 33 is engaged, and the first shaft 11 and the second shaft 12 are coupled.

When towing or adjusting the combine, the nut 58 is tightened. When the nut 58 is tightened, the moving member 51 moves to a side away from the parking brake 28. During movement of the movable member 51, as shown in FIG. 1D, the peripheral portion of the movable member 51 comes into contact with the pressing member 41, and the moving member 51 presses the pressing member 41. As a result, the pressing member 41 moves in a direction away from the parking brake 28, the parking brake 28 is released, and the braking of the first axis 11 is released. In addition, since the transmission of the pressing force to the two-axis coupling clutch 33 is eliminated, the two-axis coupling clutch 33 is also released, and the coupling of the first shaft 11 and the second shaft 12 is released. As a result, the first axis 11 and the second axis 12 can rotate independently.

<Action effect>

As described above, the parking brake 28 and the two-axis engagement clutch 33 can be released by supplying the hydraulic oil to the passage 62, and by stopping the supply of the hydraulic oil, the parking brake 28 and the two-axle engagement clutch 33 can be released. The coupling clutch 33 can be engaged. The parking brake 28 and the two-axis engagement clutch 33 can be operated by a single hydraulic operation structure. Additionally, an operating lever is not required to operate the parking brake 28. Therefore, the structure of the power transmission device 1 can be simplified.

In addition, below, other embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<Power transmission device>

2A, 2B, and 2C are cross-sectional views showing the configuration of main parts of a power transmission device 1001 according to another embodiment of the present invention.

The power transmission device 1001 is mounted on a combine, for example, and transmits power to the left and right traveling devices. The combine may have a two-pump, two-motor configuration equipped with an HST (Hydro Static Transmission) corresponding to each of the left and right traveling devices, or may be configured with an HST in common for the left and right traveling devices. It's okay.

The power transmission device 1001 includes a first gear 1011. The first gear 1011 is always connected to the driving device and the power transmission path. A shaft portion 1012 is formed integrally with the first gear 1011. The shaft portion 1012 has a substantially cylindrical shape that protrudes to one side from an end surface on one side of the first gear 1011, and has an axis common to the first gear 1011. The inner ring of the bearing 1013 is externally fitted and fixed to the shaft portion 1012. The outer ring of the bearing 1013 is held non-rotatably in the case 1014 forming the outer shell of the power transmission device 1001. As a result, the first gear 1011 and the shaft portion 1012 are rotatably held in the case 1014 via the bearing 1013. In the shaft portion 1012, a plurality of annular plate-shaped clutch disks 1015 are held at intervals in the direction of the rotation axis of the shaft portion 1012.

The case 1014 has a cylindrical portion 1016 formed in a cylindrical shape concentric with the axial portion 1012. The cylindrical portion 1016 surrounds the outer periphery of the shaft portion 1012 and faces the shaft portion 1012 in the rotational radial direction. On the inner peripheral surface of the cylindrical portion 1016, a plurality of annular plate-shaped clutch plates 1017 are held at intervals in the direction of the center line of the cylindrical portion 1016. The clutch disks 1015 and clutch plates 1017 are arranged alternately in the direction of the center line of the cylindrical portion 1016. When the clutch disk 1015 and the clutch plate 1017 are pressed into contact, rotation of the clutch disk 1015 is prevented, and when their pressure contact is released, rotation of the clutch disk 1015 is allowed. That is, the clutch disk 1015 and the clutch plate 1017 constitute the parking brake 1018 that is engaged/disengaged to brake/release the first gear 1011 and the shaft portion 1012.

A pressing member 1021 is provided on one side of the clutch plate 1017 and on the side opposite to the bearing 1013. The pressing member 1021 has an annular action portion 1022 that presses the portion where the clutch disk 1015 and the clutch plate 1017 overlap. A plurality of springs 1023 are interposed between the pressing member 1021 and the case 1014, and the pressing member 1021 rides on the clutch plate 1017 side by the elastic force of the springs 1023. I am being sexually pressured.

A through hole 1024 is formed in the pressing member 1021. The through hole 1024 has cylindrical surfaces 1025, 1026, and 1027 centered on the rotation axis of the first gear 1011 in this order from the first gear 1011 side. The cylindrical surface 1026 has a smaller diameter than the cylindrical surface 1025, and the cylindrical surface 1027 has a smaller diameter than the cylindrical surface 1026. Accordingly, the through hole 1024 has an annular step surface 1028 between the cylindrical surfaces 1025 and 1026.

A moving member 1031 is provided between the first gear 1011 and the pressing member 1021. The moving member 1031 includes a flat cylindrical first cylindrical portion 1032 having an outer diameter corresponding to the cylindrical surface 1025 of the pressing member 1021, and a first gear 1011 relative to the first cylindrical portion 1032. ) side and the second cylindrical portion 1033 having an outer diameter corresponding to the cylindrical surface 1027 of the pressing member 1021, and the first gear 1011 side with respect to the second cylindrical portion 1033. It is formed on the opposite side and has a third cylindrical part 1034 that has a smaller diameter and extends longer than the second cylindrical part 1033.

And, the first cylindrical portion 1032 is fitted in a portion surrounded by the cylindrical surface 1025 of the pressing member 1021. The second cylindrical portion 1033 is inserted into a portion surrounded by the cylindrical surface 1027 of the pressing member 1021. The third cylindrical portion 1034 passes through the through hole 1024 of the pressing member 1021 and is inserted into the insertion hole 1035 formed through the case 1014. In the third cylindrical portion 1034, a screw 1036 is formed on a portion that protrudes out of the case 1014, and a nut 1037 is screwed onto the portion where the screw 1036 is formed.

The space between the first cylindrical portion 1032 and the cylindrical surface 1025 is sealed with a seal ring 1041. Additionally, the space between the second cylindrical portion 1033 and the cylindrical surface 1027 is sealed with a seal ring 1042. As a result, an oil chamber 1043 is formed between the pressing member 1021 and the moving member 1031. Additionally, a flow path 1044 is formed in the moving member 1031 along its center line. The flow path 1044 is open at the front end surface of the third cylindrical portion 1034. Additionally, the flow path 1044 is connected to the oil chamber 1043 through the connection flow path 1045.

On the side opposite to the bearing 1013 with respect to the first gear 1011, a second gear 1051 is provided having a rotation axis common to the first gear 1011. A first spline portion 1052 and a second spline portion 1053 are provided between the first gear 1011 and the second gear 1051. The first spline portion 1052 forms an annular shape centered on the rotation axis of the first gear 1011 and has splines on its outer peripheral surface. The second spline portion 1053 forms an annular shape centered on the rotation axis of the second gear 1051 and has splines on its outer peripheral surface. The outer peripheral surface of the first spline portion 1052 and the outer peripheral surface of the second spline portion 1053 are formed to have the same diameter.

A shifter 1054 is externally fitted into the first spline portion 1052 and the second spline portion 1053. Splines are formed on the inner peripheral surface of the shifter 1054, and the shifter 1054 has a drive position that spans the first spline portion 1052 and the second spline portion 1053 and is spline-engaged with them, and a second spline portion. 1 It is movable to a neutral position where the spline is engaged only with the spline portion 1052.

A shift fork 1055 is connected to the shifter 1054. The shift fork 1055 is supported on a shaft 1056 extending parallel to the rotation axis of the first gear 1011. The shaft 1056 is connected to a connecting portion 1057 extending in the radial direction from the first cylindrical portion 1032 of the moving member 1031, and is provided to be movable integrally with the moving member 1031.

<Action effect>

Normally, as shown in FIG. 2A, the pressing member 1021 is pressed against the parking brake 1018 side by the elastic force of the spring 1023, and the action portion 1022 of the pressing member 1021 is pressed to the clutch plate ( 1017) is being put under pressure. As a result, the clutch disk 1015 and the clutch plate 1017 are pressed into contact, the parking brake 1018 is engaged, and the first gear 1011 is braked.

From this state, as shown by hatching in FIG. 2B, hydraulic oil (pressure oil) is supplied to the flow path 1044, and when the hydraulic oil passes through the connection flow path 1045 and is supplied to the oil chamber 1043, the oil chamber 1043 ), the pressing member 1021 resists the elastic force of the spring 1023 and moves in a direction away from the parking brake 1018. As a result, the parking brake 1018 is released, and the braking of the first gear 1011 is released.

Therefore, there is no need for an operating lever, etc. to operate (engage) the parking brake 1018, and there is no need to mechanically connect the parking brake 1018 and the operating lever, etc., so each of the power transmission devices 1001 The degree of freedom in layout of members is improved.

When towing or adjusting the combine, the nut 1037 is tightened from the state shown in FIG. 2A. When the nut 1037 is tightened, the moving member 1031 moves to the side away from the parking brake 1018. During the movement of the movable member 1031, as shown in FIG. 2C, the first cylindrical portion 1032 of the movable member 1031 comes into contact with the step surface 1028 of the pressing member 1021, and the movable member 1031 Presses the pressing member 1021. As a result, the pressing member 1021 moves in a direction away from the parking brake 1018, the parking brake 1018 is released, and the braking of the first gear 1011 is released.

Also, at that time, in conjunction with the movement of the moving member 1031, the shift fork 1055 moves, the shifter 1054 moves from the drive position to the neutral position, and the first gear 1011 and the second gear 1051 ) is disconnected. Therefore, since the sub-transmission mechanism including the shifter 1054 does not require an operating mechanism including an operating lever or the like, the configuration of the power transmission device 1001 can be simplified. Additionally, since the position of the shift fork 1055 is determined by the tightening amount of the nut 1037, separation from the shifter 1054 can be prevented.

In addition, below, other embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<Combine>

FIG. 3 is a right side view showing the front part of the combine 2001 on which the transmission device 2032 according to another embodiment of the present invention is mounted.

Combine (2001) is a work vehicle that harvests grain stems and threshes grain from grain stems while traveling on a field. The body 2011 of the combine 2001 is supported by a pair of left and right traveling devices 2012. In the traveling device 2012, a crawler having a non-ground running ability is adopted to enable the combine 2001 to run on the pavement.

The body 2011 is provided with a steering wheel 2013, a reaping device 2014, a threshing device 2015, and a grain tank 2016.

The steering wheel 2013 is disposed above the front end of the traveling device 2012. The steering wheel 2013 is provided with a driver's seat 2017 on which the operator sits, and an operation panel 2018 that is operated by the operator is provided, for example, from the front to the left of the driver's seat 2017. The operation panel 2018 is provided with a main shift lever 2021 and a steering lever 2022.

The main shift lever 2021 is provided so that it can be displaced from the neutral position to the forward position on the front side and the reverse position on the rear side. When the main shift lever 2021 is operated from the neutral position to the forward position, power in the forward direction is transmitted to the left and right traveling devices 2012, and the body 2011 moves forward. On the other hand, when the main shift lever 2021 is operated from the neutral position to the reverse position, power in the reverse direction is transmitted to the left and right traveling devices 2012, and the aircraft 2011 moves backward. When the main shift lever 2021 returns to the neutral position from the forward or reverse position, the aircraft 2011 stops. Additionally, the forward or reverse speed can be changed depending on the amount of operation of the main shift lever 2021.

The steering lever 2022 is provided to be tiltable left and right and forward and backward. By tilting the steering lever 2022 to the left or right, the aircraft 2011 can be switched between going straight, turning left, and turning right. Furthermore, the harvesting device 2014 can be raised and lowered by tilting the steering lever 2022 forward and backward.

The harvesting device 2014 is arranged in front of the traveling device 2012. The harvesting device 2014 is equipped with a cutting hole 2023 at its front end, and is equipped with a harvesting blade 2024 behind the cutting hole 2023. The cutting tool 2023 and the harvesting blade 2024 are supported on the harvesting device frame 2025. At the rear end of the harvesting device frame 2025, a horizontal harvesting frame 2026 extending in the left and right directions is provided. One end of the main harvesting frame 2027 is connected to the horizontal harvesting frame 2026. The main harvesting frame 2027 extends rearward from the horizontal harvesting frame 2026, and its other end (provided at the front lower end, its rear end) is rotatably connected to the frame of the body 2011. By tilting the steering lever 2022 in the front-back direction, a cylinder (not shown) can be operated to swing the main harvesting frame 2027, and by the swing, the splitter 2023 and the harvesting blade 2024 ) is raised high from the ground, and the splitter 2023 and the cutting blade 2024 are raised to a lowered position close to the ground. When the aircraft (2011) moves forward with the splitter (2023) and the cutting blade (2024) positioned in the lowered position, the base of the grain stem installed in the field is divided by the splitter (2023), and the grain stem is cut into the cutting blade (2024). is harvested by

The threshing device 2015 and the grain tank 2016 are arranged left and right above the traveling device 2012 and at the rear position of the reaping device 2014. The harvested grain stem is conveyed to the threshing device 2015 by the harvesting device 2014. The threshing device 2015 conveys the bottom side of the grain stem to the rear side with a threshing feed chain, supplies the top side of the grain stem to the processing chamber, and threshes it. And grains are conveyed from the threshing apparatus 2015 to the grain tank 2016, and grains are stored in the grain tank 2016. The grain discharge auger 2028 is continuously installed in the grain tank 2016, and the grain stored in the grain tank 2016 can be discharged to the outside of the device by the grain discharge auger 2028.

<Transmission device>

FIG. 4 is a diagram showing a partial configuration of the transmission device 2032 of the combine 2001. In FIG. 4, the configuration from the engine 2031 to the left HST (2033) and right HST (2034) is shown as a skeleton diagram, and the configuration regarding the left HST (2033) and right HST (2034) is shown as a hydraulic circuit diagram.

The combine 2001 is equipped with an engine 2031 and a transmission device 2032 that changes the power of the engine 2031 and transmits it to the traveling device 2012.

The transmission device 2032 includes a left HST (Hydro Static Transmission) 2033 and a right HST 2034.

The left HST 2033 connects the hydraulic pump 2041 and the hydraulic motor 2042 to the first flow path 2043 and the second flow path 2044 so that the hydraulic oil circulates between the hydraulic pump 2041 and the hydraulic motor 2042. ) has a closed-circuit configuration. The first flow path 2043 is connected to the first port 2045 of the hydraulic pump 2041 and the first port 2046 of the hydraulic motor 2042. The second flow path 2044 is connected to the second port 2047 of the hydraulic pump 2041 and the second port 2048 of the hydraulic motor 2042.

Additionally, the left HST 2033 is additionally provided with a charge pump 2051. The charge pump 2051 is a fixed displacement hydraulic pump, and discharges hydraulic oil into the charge passage 2053 by rotating the pump rotation shaft 2052. The charge passage 2053 is connected to the first passage 2043 through the first check valve 2054 and to the second passage 2044 through the second check valve 2055. Additionally, the charge passage 2053 is connected to the oil tank 2057 through a charge relief valve 2056.

By the function of the charge relief valve 2056, the hydraulic pressure in the charge passage 2053 is maintained at a predetermined charge pressure. When the hydraulic pressure of the first flow path 2043 is lower than the hydraulic pressure of the charge flow path 2053, that is, the charge pressure, the first check valve 2054 is opened, and the flow from the charge flow path 2053 through the first check valve 2054 is opened. Hydraulic oil is supplied to the first flow path 2043. In addition, when the hydraulic pressure in the second flow path 2044 becomes lower than the charge pressure, the second check valve 2055 opens, and the second flow path 2044 flows from the charge flow path 2053 through the second check valve 2055. Hydraulic oil is supplied. As a result, the hydraulic pressure in the first flow path 2043 and the second flow path 2044 is maintained above the charge pressure.

The left HST (2033) includes a hydraulic pump (2041), a hydraulic motor (2042), a first flow path (2043), a second flow path (2044), a first check valve (2054), a second check valve (2055), and a charger. It is configured as an integrated HST containing a relief valve (2056) and the like in a single case.

The hydraulic pump 2041 is a variable displacement swash plate piston pump and includes a cylinder block, a plurality of pistons radially arranged within the cylinder block, and a pump swash plate on which the pistons slide. The hydraulic pump 2041 and the charge pump 2051 have a pump rotation shaft 2052 in common, and the cylinder block is provided to rotate integrally with the pump rotation shaft 2052.

In order to change the inclination angle of the pump swash plate of the hydraulic pump 2041, an electronically controlled servo piston 2058 is provided. The servo piston 2058 has a first pressure chamber 2062 to which hydraulic pressure is supplied from the pressure control valve 2061 on the forward side, and a second pressure chamber 2064 to which hydraulic pressure is supplied from the pressure control valve 2063 on the backward side. ) has. In addition, the servo piston 2058 has a rod 2065 that is linearly driven by the differential pressure between the first pressure chamber 2062 and the second pressure chamber 2064, and by the linear drive of this rod 2065, The inclination angle of the pump swash plate changes.

The larger the inclination angle of the pump swash plate with respect to the axis of the pump rotation axis 2052 of the hydraulic pump 2041 (the rotation axis of the cylinder block), the smaller the discharge amount of hydraulic oil from the hydraulic pump 2041, and the inclination angle of the pump swash plate. At 90°, discharge of hydraulic oil from the hydraulic pump 2041 stops. Additionally, when the inclination angle of the pump swash plate exceeds 90° (when the inclination is reversed), the discharge direction of hydraulic oil from the hydraulic pump 2041 is reversed compared to when the inclination angle is less than 90°.

The hydraulic motor 2042 is a variable displacement inclined plate piston motor, and includes a motor rotation shaft 2071, a cylinder block 2072 (see FIG. 5) that rotates integrally with the motor rotation shaft 2071, and a radial structure within the cylinder block 2072. It is equipped with a plurality of pistons 2073 (see FIG. 5) arranged in and a motor swash plate 2074 (see FIG. 5) capable of pressurizing the pistons 2073. When the inclination angle of the motor swash plate 2074 with respect to the axis of the motor rotation axis 2071 of the hydraulic motor 2042 (the rotation axis of the cylinder block 2072) is constant, the amount of hydraulic oil supplied to the hydraulic motor 2042, i.e. As the amount of hydraulic oil discharged from the hydraulic pump 2041 increases, the rotation speed of the motor rotation shaft 2071 increases.

Additionally, when the amount of hydraulic oil supplied to the hydraulic motor 2042 is constant, the larger the inclination angle of the motor swash plate 2074, the lower the rotation speed of the motor rotation shaft 2071. In order to change the inclination angle of the motor swash plate 2074 of the hydraulic motor 2042, a sub-shift piston 2075 is provided. A low-speed switching valve 2076 and a high-speed switching valve 2077 are connected to the sub-speed piston 2075. The low-speed switching valve 2076 is turned on, the high-speed switching valve 2077 is turned off, and hydraulic pressure is supplied from the low-speed switching valve 2076 to the sub-shift piston 2075, so that the rod of the sub-shift piston 2075 ( 2078) is located at a low speed position, and the inclination angle of the motor swash plate 2074 becomes relatively large. On the other hand, the low-speed switching valve 2076 is turned off and the high-speed switching valve 2077 is turned on, and hydraulic pressure is supplied from the high-speed switching valve 2077 to the sub-shift piston 2075. The rod 2078 is located at a high-speed position, and the inclination angle of the motor swash plate 2074 becomes relatively small. Therefore, by switching on/off the low-speed switching valve 2076 and the high-speed switching valve 2077, the high-speed stage at which the rotation speed of the motor rotation shaft 2071 is relatively large and the low-speed stage at which the rotation speed of the motor rotation shaft 2071 is relatively small. It can be switched to 2nd stage.

Since the right HST 2034 has the same configuration as the left HST 2033, the parts corresponding to the parts of the left HST 2033 are given the same reference numerals as those parts. , the explanation is omitted.

The power of the engine 2031 is input to each pump rotation shaft 2052 of the left HST 2033 and the right HST 2034. Specifically, a pulley 2082 is provided on the output shaft 2081 of the engine 2031 so that it cannot rotate relative to it. The transmission device 2032 has an input shaft 2083 extending parallel to the output shaft 2081 of the engine 2031. A pulley 2084 is provided on the input shaft 2083 so that it cannot be relatively rotated. Between the pulleys 2082 and 2084, an endless belt 2085 is wound and hung. Additionally, an input gear 2086 is provided on the input shaft 2083 so that it cannot rotate relative to it. The input gear 2086 is meshed with an intermediate gear 2087, and the intermediate gear 2087 is meshed with a pump gear 2088 that cannot be rotated relative to the pump rotation shaft 2052 of the right HST 2034. The pump gear 2088 is engaged with a pump gear 2089 that is provided so as not to rotate relative to the pump rotation shaft 2052 of the left HST 2033.

As a result, the power of the engine 2031 is transmitted from the output shaft 2081 to the pulley 2084 through the pulley 2082 and the belt 2085, and rotates the input shaft 2083 integrally with the pulley 2084. . Then, the power (rotation) of the input shaft 2083 is transmitted from the input gear 2086 through the intermediate gear 2087 to the pump gear 2088 of the right HST 2034, and is integrated with the pump gear 2088. , the pump rotation shaft 2052 of the right HST 2034 is rotated in a predetermined direction. In addition, the power of the input shaft 2083 is transmitted from the input gear 2086 to the pump gear 2088 of the right HST 2034 through the intermediate gear 2087, and further from the pump gear 2088 to the pump gear 2089. is transmitted to the pump gear 2089 and rotates the pump rotation shaft 2052 of the left HST 2033 in a predetermined direction and the opposite direction. Therefore, when the angle of the pump swash plate inclination of each hydraulic pump 2041 of the left HST 2033 and the right HST 2034 is the same, the motor rotation shaft 2071 of the hydraulic motor 2042 of the left HST 2033 The motor rotation shafts 2071 of the hydraulic motor 2042 of the right HST 2034 rotate in opposite directions.

FIG. 5 is a cross-sectional view showing a part of the transmission device 2032 and shows the configuration from the hydraulic motors 2042 of the left HST 2033 and the right HST 2034 all the way to the traveling device 2012.

Each hydraulic motor 2042 of the left HST 2033 and the right HST 2034 has a motor rotation axis 2071 arranged on the same axis (so that it has a common axis), and the axis is the axis of the left and right axles. They are arranged symmetrically left and right, parallel to each other.

In addition, in the following description, the motor rotation shaft 2071 of the left HST 2033 is referred to as “motor rotation shaft 2071L,” and the motor rotation shaft 2071 of the right HST 2034 is referred to as “motor rotation shaft 2071R.” do.

The outer end portions of the motor rotation shafts 2071L and 2071R in the left and right directions are rotatably supported on the unit case 2101 forming the outer shell of the transmission device 2032 via bearings 2102L and 2102R, respectively. Motor output gears 2103L and 2103R are supported at the left and right inner ends of the motor rotation shafts 2071L and 2071R, respectively, so that they cannot rotate relative to each other.

A first intermediate shaft 2104 and a second intermediate shaft 2105 are provided between the motor rotation shafts 2071L and 2071R and the axles. Each axis of the first intermediate shaft 2104 and the second intermediate shaft 2105 is parallel to the axis of the motor rotation shafts 2071L and 2071R. The first intermediate shaft 2104 is non-rotatably supported by the unit case 2101. The left end of the second intermediate shaft 2105 is rotatably supported on the unit case 2101 via a bearing 2106. A cylindrical sleeve 2107 is externally fitted into the right portion 2105R of the second intermediate shaft 2105. The inner ring of the bearing 2108 is externally fitted into the sleeve 2107 so that relative rotation is not possible. The outer ring of the bearing 2108 is fixed to the unit case 2101. As a result, the second intermediate shaft 2105 is rotatably held by the unit case 2101.

On the first intermediate shaft 2104, a first left intermediate gear 2111L and a first right intermediate gear 2111R are arranged left and right and rotatably held. The motor output gear 2103L on the left is meshed with the first left intermediate gear 2111L, and the motor output gear 2103R on the right is meshed with the first right intermediate gear 2111R. On the left part 2105L and the right part 2105R of the second intermediate shaft 2105, a second left intermediate gear 2112L and a second right intermediate gear 2112R are arranged left and right and fixedly held, respectively. . The first left intermediate gear 2111L is meshed with the second left intermediate gear 2112L, and the first right intermediate gear 2111R is meshed with the second right intermediate gear 2112R.

An annular groove portion 2113L centered on the axis of the second intermediate shaft 2105 is formed on the left side of the second left intermediate gear 2112L. At the left end of the groove portion 2113L, a plurality of internal teeth 2114L protruding toward the rotation center are formed arranged in the circumferential direction. To the left of the second left intermediate gear 2112L, a left shifter gear 2115L is provided. The left shifter gear 2115L is held by the left portion 2105L of the second intermediate shaft 2105 so as to be non-relatively rotatable and movable in the axis direction of the second intermediate shaft 2105. The left shifter gear 2115L has a plurality of external teeth 2116L on its outer peripheral surface. In the outer tooth 2116L, a notch 2117 is formed along the entire circumference near the right side.

An annular groove portion 2113R centered on the axis of the second intermediate shaft 2105 is formed on the right side of the second right intermediate gear 2112R. At the right end of the groove portion 2113R, a plurality of internal teeth 2114R protruding toward the rotation center are formed arranged in the circumferential direction. To the right of the second right intermediate gear 2112R, a right shifter gear 2115R is provided. The right shift gear 2115R is held by the sleeve 2107 so as to be non-relatively rotatable and movable in the axis direction of the second intermediate shaft 2105. The right shifter gear 2115R has a plurality of external teeth 2116R on its outer peripheral surface.

<Neutral shifting mechanism>

FIGS. 6A, 6B, 6C, and 6D are cross-sectional views showing the configuration of the neutral shifting mechanism 2120.

The shifting device 2032 is provided with a neutral shifting mechanism 2120 for generating a neutral state. The neutral shifting mechanism 2120 includes a shift member consisting of a shift fork shaft 2121, a left shift fork 2122L, and a right shift fork 2122R.

The shift fork shaft 2121 is provided at a position spaced apart from the second intermediate shaft 2105 in a direction perpendicular to the axis direction. The shift fork shaft 2121 has a center line extending parallel to the axis of the second intermediate shaft 2105, and is held by the unit case 2101 so as to be movable in the direction of the center line.

The left shift fork 2122L is fixed to the shift fork shaft 2121, and extends and protrudes from the shift fork shaft 2121 toward the left shifter gear 2115L in a direction perpendicular to the center line of the shift fork shaft 2121. there is. On the outer peripheral surface of the left shifter gear 2115L, a concave portion 2123L is formed along the entire circumference. The distal end of the left shift fork 2122L is fitted into the concave portion 2123L of the left shifter gear 2115L with a margin to allow rotation of the left shifter gear 2115L.

The right shift fork 2122R is fixed to the shift fork shaft 2121 and extends and protrudes from the shift fork shaft 2121 toward the right shifter gear 2115R in a direction perpendicular to the center line of the shift fork shaft 2121. there is. On the outer peripheral surface of the right shifter gear 2115R, a concave portion 2123R is formed along the entire circumference. The distal end of the right shift fork 2122R is fitted into the concave portion 2123R of the right shifter gear 2115R with a margin to allow rotation of the right shifter gear 2115R.

At the left end of the shift fork shaft 2121, an operating groove 2124 extending in the circumferential direction is formed. The distal end of a cylindrical operating protrusion 2126 extending from the distal end of the shift operating piece 2125 toward the shift fork shaft 2121 enters the operating groove 2124 from the radial direction of the shift fork shaft 2121. At the base end of the shift operation piece 2125, a support shaft 2127 is fixedly provided orthogonal to both the center line direction of the shift fork shaft 2121 and the direction in which the shift operation piece 2125 extends. The support shaft 2127 is rotatably supported by the unit case 2101. On the support shaft 2127, an operating arm 2128 extending in a direction perpendicular to both the axis of the support shaft 2127 and the direction in which the shift operation piece 2125 extends is supported so as not to rotate relative to it. The length from the center of the support shaft 2127 to the tip of the operating arm 2128 is longer than the length from the center of the support shaft 2127 to the center of the operating projection 2126.

Between the unit case 2101 and the right shift fork 2122R, a coiled spring 2129 externally fitted to the shift fork shaft 2121 is interposed in a compressed state. As a result, the elastic force of the spring 2129 is applied to the right shift fork 2122R, and the shift fork shaft 2121 is urged to the left by the elastic force.

In a state in which the operating arm 2128 is not being operated, as shown in FIG. 6A, the shift fork shaft 2121 is located at the left end of the movable range, and the outer tooth 2116L of the left shifter gear 2115L is positioned at the second It meshes with the inner tooth 2114L of the left middle gear 2112L, and the outer tooth 2116R of the right shifter gear 2115R meshes with the inner tooth 2114R of the second right middle gear 2112R.

Therefore, the power (rotation) transmitted from the motor rotation shaft 2071L to the second left intermediate gear 2112L through the first left intermediate gear 2111L is transmitted from the second left intermediate gear 2112L to the left shifter gear 2115L. ) and is transmitted from the left shifter gear 2115L to the left axle through a gear train (not shown) to drive the left traveling device 2012. The power transmission mechanism on the left side is formed by a gear train that transmits power from the first left intermediate gear 2111L, the second left intermediate gear 2112L, the left shifter gear 2115L, and the left shifter gear 2115L to the axle on the left side. It is composed.

In addition, the power (rotation) transmitted from the motor rotation shaft 2071R to the second right intermediate gear 2112R through the first right intermediate gear 2111R is from the second right intermediate gear 2112R to the right shifter gear 2115R. and is transmitted from the right shift gear 2115R to the right axle through a gear train (not shown), thereby driving the right traveling device 2012. A power transmission mechanism on the right side is provided by a gear train that transmits power from the first right intermediate gear 2111R, the second right intermediate gear 2112R, the right shifter gear 2115R, and the right shifter gear 2115R to the axle on the right side. It is composed.

When the operation arm 2128 is operated to lift the tip, as the operation arm 2128 rotates, the shift operation piece 2125 rotates the support shaft 2127 to the support point, and the shift fork shaft 2121 moves to the right. move in the direction In a state where the shift fork shaft 2121 is located at the right end of the movable range, as shown in FIG. 6B, the outer tooth 2116L of the left shifter gear 2115L and the inner tooth 2114L of the second left intermediate gear 2112L ) is released, and the engagement of the outer tooth 2116R of the right shifter gear 2115R and the inner tooth 2114R of the second right intermediate gear 2112R is released. Therefore, the power (rotation) transmitted from the motor rotation shaft 2071 to the second left intermediate gear 2112L through the first left intermediate gear 2111L is transmitted from the second left intermediate gear 2112L to the left shifter gear 2115L. ) and is not transmitted to the right shifter gear (2115R). That is, the transmission device 2032 is in a neutral state in which power from the engine 2031 (left HST 2033 and right HST 2034) is not transmitted to the left and right axles.

At the distal end of the operating arm 2128, an arc-shaped locking support concave portion 2131 that is concave upward is formed. By locking the locking support concave portion 2131 to the locking support convex portion 2132 fixed to the unit case 2101, the neutral state of the transmission device 2032 can be maintained.

When the locking support concave portion 2131 is separated from the locking support convex portion 2132 and the force for lifting the tip of the operating arm 2128 is released, the shift fork shaft ( 2121) moves to the left. When the outer tooth 2116R of the right shifter gear 2115R opposes the tooth groove between the inner teeth 2114R of the second right intermediate gear 2112R, the right shifter gear is moved by movement of the shift fork shaft 2121. The external tooth 2116R of 2115R enters the tooth groove of the second right intermediate gear 2112R, and the second right intermediate gear 2112R and the right shifter gear 2115R are meshed. On the other hand, when the external tooth 2116R of the right shifter gear 2115R does not oppose the tooth groove of the second right intermediate gear 2112R, the shift fork shaft 2121 moves, as shown in FIG. 6C. Likewise, the outer tooth 2116R of the right shifter gear 2115R abuts the inner tooth 2114R of the second right intermediate gear 2112R, and the right shifter gear 2115R and the second right intermediate gear 2112R are not engaged. No. At this time, the portion to the right of the notch 2117 of the outer tooth 2116L of the left shifter gear 2115L (hereinafter simply referred to as the “outer tooth 2116L”) and the inside of the second left intermediate gear 2112L. A gap occurs between these (2114L).

Since the shift fork shaft 2121 is pressed in the left direction by the spring 2129, the outer tooth 2116R of the right shifter gear 2115R is in contact with the inner tooth 2114R of the second right intermediate gear 2112R. When the second right intermediate gear 2112R rotates and the outer teeth 2116R of the right shifter gear 2115R oppose the tooth grooves of the second right intermediate gear 2112R, as shown in FIG. 6D, the shift fork The shaft 2121 moves further to the left, so that the outer teeth 2116R of the right shifter gear 2115R enter the tooth grooves of the second right intermediate gear 2112R.

After that, the shift fork shaft 2121 moves further to the left, so that the outer teeth 2116L of the left shifter gear 2115L oppose the tooth groove between the inner teeth 2114L of the second left intermediate gear 2112L. When doing so, the external tooth 2116L of the left shifter gear 2115L enters the tooth groove of the second left intermediate gear 2112L, and the second left intermediate gear 2112L and the left shifter gear 2115L are engaged. On the other hand, when the external teeth 2116L of the left shifter gear 2115L do not oppose the tooth grooves of the second left intermediate gear 2112L, the left shifter gear 2115L is moved by the shift fork shaft 2121. )'s external tooth (2116L) is in contact with the internal tooth (2114L) of the second left middle gear (2112L), and the left shifter gear (2115L) and the second left middle gear (2112L) are not engaged.

Since the shift fork shaft 2121 is pressed in the left direction by the spring 2129, the external tooth 2116L of the left shifter gear 2115L is in contact with the internal tooth 2114L of the second left intermediate gear 2112L. When the second left intermediate gear 2112L rotates and the external teeth 2116L of the left shifter gear 2115L oppose the tooth grooves of the second left intermediate gear 2112L, the shift fork shaft 2121 rotates to the left. Moving further, the outer tooth 2116L of the left shifter gear 2115L enters the tooth groove of the second left intermediate gear 2112L.

By the above, meshing of the second left intermediate gear 2112L and the left shifter gear 2115L and meshing of the second right intermediate gear 2112R and the right shifter gear 2115R are achieved.

<Action effect>

As described above, the neutral shifting mechanism 2120 engages/disengages the second left intermediate gear 2112L and the left shifter gear 2115L, and engages/disengages the second right intermediate gear 2112R and the right shifter gear 2115R. Engagement/disengagement can be switched, and good gear engagement can be achieved.

In order to move the shift fork shaft 2121, the tip of the operation protrusion 2126 extending from the tip of the shift operation piece 2125 enters the operating groove 2124 formed in the shift fork shaft 2121, and the shift operation is performed. An operating arm 2128 that rotates integrally with the shift operation piece 2125 is supported on the support shaft 2127 that supports the piece 2125. And, the length from the center of the support shaft 2127 to the tip of the operating arm 2128 is longer than the length from the center of the support shaft 2127 to the center of the operating projection 2126. Therefore, the principle of leverage operates, and even if the force applied to the operating arm 2128 is small, the shift fork shaft 2121 can be moved satisfactorily by resisting the pressing force of the spring 2129.

Additionally, the spring 2129 is interposed between the unit case 2101 and the right shift fork 2122R. As a result, there is no need to separately provide a portion connecting one end of the spring 2129 to the shift fork shaft 2121, thereby simplifying the configuration of the shift fork shaft 2121.

In addition, below, other embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<Fixing structure of axle case>

FIG. 7 is a cross-sectional view showing the structure near the right axle 3006 of the combine 3001 according to another embodiment of the present invention.

The combine 3001 is equipped with a power transmission mechanism 3003 that transmits the power of an engine (not shown) to the traveling device 3002. The traveling device 3002 is, for example, a crawler with a non-stop running ability and is provided with a sprocket 3004. The power transmission mechanism 3003 includes a Hydro Static Transmission (HST), a transmission 3005, and left and right axles 3006. The power of the engine is shifted by the HST and transmitted from the HST to the left and right axles 3006 through the transmission 3005. The left and right axles 3006 are respectively coupled to the left and right sprockets 3004 so that they cannot rotate relative to each other. Accordingly, when the power of the engine is transmitted to the axle 3006, the sprocket 3004 rotates integrally with the axle 3006.

The transmission 3005 is accommodated in the main body case 3011. In the main body case 3011, a wall portion 3012 extending in a direction perpendicular to the vehicle width direction of the combine 3001 and a cylindrical insertion portion 3013 extending and protruding outward in the vehicle width direction from this wall portion 3012 are formed integrally. It is done. On the inner peripheral surface of the insertion portion 3013, two gasket grooves 3014 and 3015 are formed at intervals in the width direction of the vehicle, each covering the entire circumference in the circumferential direction. Ring-shaped gaskets 3016 and 3017 are fitted into the gasket grooves 3014 and 3015, respectively.

The axle 3006 is inserted into the axle case 3021. The axle case 3021 is a cast metal product and has a cylindrical portion 3022 and a plurality of fixing portions 3023 protruding from the cylindrical portion 3022 to the periphery.

The end of the cylindrical portion 3022 on the main body case 3011 side is inserted into the insertion portion 3013 of the main body case 3011. Within the insertion portion 3013, the gaskets 3016 and 3017 come into contact with the outer peripheral surface of the cylindrical portion 3022, thereby making the space between the inner peripheral surface of the insertion portion 3013 and the outer peripheral surface of the cylindrical portion 3022 liquid-tight. It is sealed. Additionally, at a position outside the gaskets 3016 and 3017 in the vehicle width direction, a bolt 3024 is inserted into the insertion portion 3013 of the main body case 3011, and a groove 3025 formed on the outer peripheral surface of the cylindrical portion 3022 ) contains the tip of the bolt 3024. The bolt 3024 is used to prevent the axle case 3021 from coming off when it is attached to the main body case 3011. Therefore, depending on the bolt 3024, the cylindrical portion 3022 is not fixed to the insertion portion 3013.

Bearings 3026 and 3027 are fitted into both ends of the cylindrical portion 3022 in the axial direction, respectively. The axle 3006 is inserted into the cylindrical portion 3022 and is held by bearings 3026 and 3027 so as to be rotatable relative to the cylindrical portion 3022. Then, the axle 3006 enters the main body case 3011 and is coupled to the gear 3028 included in the power transmission mechanism 3003 within the main body case 3011 in a non-relatively rotatable manner.

For example, four fixing parts 3023 are provided. The two fixing parts 3023 are arranged in the vehicle width direction and are formed in a substantially semicircular plate shape extending upward and protruding from the upper end of the outer peripheral surface of the cylindrical part 3022. The remaining two fixing parts 3023 are arranged in the vehicle width direction and are formed in a substantially semicircular plate shape extending downward from the lower end of the outer peripheral surface of the cylindrical part 3022.

And the axle case 3021 is fixed to the frame 3031 by screwing the bolts 3029 inserted into each fixing part 3023 into the frame 3031 of the combine 3001.

In addition, although the right axle 3006 is shown in FIG. 7, the left axle 3006 is, for example, a configuration in which the right axle 3006 is left and right reversed.

<Action effect>

As described above, since the axle case 3021 is fixed to the frame 3031 of the combine 3001, even when a large horizontal pulling load is applied to the sprocket 3004 to which the axle 3006 is coupled, power is applied to the axle 3006. Damage to the main body case 3011, etc., where the power transmission mechanism 3003 that transmits is accommodated, can be suppressed.

Additionally, in the axle case 3021, the axle case 3055 has the configuration of the conventional axle case 3055 shown in FIG. 8, that is, the case body portion 3056 and the flange portion 3057 are fixed to each other by welding. Compared to , the structure of the axle case 3021 is simple and improvement in strength can be achieved. Additionally, in the configuration of the axle case 3021, welding processing is unnecessary, so processing costs can be reduced.

<Variation example>

Although embodiments of the present invention have been described above, the present invention can also be implemented in other forms.

For example, in the above-described embodiment, a configuration for moving the shift fork shaft 2121 by rotating the operation arm 2128 was dealt with, but the operating member operated to move the shift fork shaft 2121 is: The configuration may be such that the shift fork shaft 2121 is moved by straight-line operation along the center line of the shift fork shaft 2121.

In addition, although the combine (2001, 3001) was discussed as an example of a work vehicle, the present invention is not limited to the combine (2001, 3001), but also includes harvesters for harvesting vegetables such as carrots, radishes, green beans, and cabbage, and other combines. (2001, 3001) and can be applied to other work vehicles.

In addition, various design changes can be made to the above-described configuration within the scope of the matters described in the patent claims.

1: Powertrain
11: 1st axis
12: 2nd axis
28: Parking brake (first clutch)
33: Two-axis coupling clutch (second clutch)
41: Absence of compression
43: Spring (elastic member)
51: no moving member
55: insertion hole
58: nut
1001: Power transmission device
1011: First gear (first rotor, third rotor)
1014: Case
1018: Parking brake
1021: Absence of compression
1023: Spring
1031: No movement
1035: Insertion hole
1036: screw
1037: Nut
1043: Lost
1051: Second gear (second rotor)
1054: shifter
2012: Driving device
2032: Shifter
2112L: 2nd left intermediate gear (transmission gear)
2112R: 2nd right intermediate gear (transmission gear)
2113L, 2113R: Groove
2114L, 2114R: Internal teeth
2115L: Left Shifter Gear
2115R: Right shifter gear
2116L, 2116R: external teeth
2120: Neutral shifting mechanism
2121: Shift fork shaft
2122L: Left shift fork
2122R: Right shift fork
2125: Shift operation
2126: operating protrusion
2127: support shaft
2128: operating arm
2129: Spring (pressure member)
2132: Jamming support convex portion (Hanging support portion)
3001: Combine (work vehicle)
3003: Power transmission mechanism
3004: Sprocket (driving wheel)
3006: Axle
3011: Body case
3013: Insertion part
3021: Axle case
3022: barrel section
3023: Fixing part
3031: frame

Claims (18)

It is a power transmission device that transmits power to the driving device,
a first clutch engaged/disengaged to brake/release the first axis;
A second clutch engaged/disengaged to engage/disengage the first and second shafts,
An elastic member,
It includes a pressing member that presses and engages the first clutch by the elastic force of the elastic member,
a moving member provided to be movable in a first direction in which the pressing member approaches the first clutch and in a second direction in which the pressing member is spaced apart from the first clutch;
Contains a case,
The first clutch and the second clutch are arranged on the same axis so that when the first clutch is pressed by the pressing member, the pressing force is transmitted to the second clutch,
From the state in which the first clutch is engaged, the moving member moves in the second direction, the moving member presses the pressing member, and the pressing member moves against the elastic force of the elastic member, thereby 1 The clutch is released,
The moving member has a cylindrical portion inserted into an insertion hole formed in the case,
In the cylindrical portion, a screw is formed on a portion that protrudes to the outside of the case,
A power transmission device wherein the moving member moves in the second direction by tightening a nut screwed to the screw of the cylindrical portion outside the case. According to paragraph 1,
A power transmission device further comprising an oil chamber supplied with pressure oil for separating the pressing member from the first clutch by resisting the elastic force of the elastic member. delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete