combine

Abstract

Traditionally, there was a problem with the pressure sensing port of the continuously variable transmission being contaminated by dust and mud splashes from the harvesting equipment while the vehicle was in motion. [Solution] In a combine harvester in which the output rotation of a continuously variable transmission 20 is transmitted to a running gear 2 and a harvesting gear 4 via a transmission 23, the output rotation of the engine 22 is transmitted to the first shaft 29 and second shaft 32 of the transmission 23 via an input shaft 25 from the continuously variable transmission 20, the first shaft 29 is provided with a harvesting output pulley 31 that outputs to the harvesting gear 4 and a second gear 43 that rotates to the running gear 2, a clutch 48 is provided between the first gear 30 that is always meshed with the gear 27 of the input shaft 25 of the transmission and the second gear 43, and a notch 70 is provided on either the left or right upper side of the transmission case 21, with at least the lower side closed in a front view, and the mounting metal part 71 of the continuously variable transmission 20 is arranged within the notch 70.

Description

Technical Field

[0004]

[0001] The present invention relates to a combine harvester.

Background Art

[0002] Conventionally, the rotation of an engine is input from the upper part of a transmission case, transmitted and output to a traveling device from a lower idler gear for driving, and a cutting device is driven in synchronization with this traveling speed. A configuration in which the rotation of the engine is shifted by a continuously variable transmission attached to the side surface of the transmission case is known (Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above-known example, since the continuously variable transmission is simply attached to the side surface of the transmission case, there is a problem that the pressure inspection port of the continuously variable transmission is contaminated by dust and mud splashed from the cutting device during traveling. That is, similar to the regular inspection of ordinary automobiles, a combine harvester also performs regular inspections. As part of the inspection of the traveling system, it may be necessary to check whether oil is being supplied to the continuously variable transmission 20 at a specified pressure. This hydraulic pressure inspection is performed by attaching a pressure gauge to the pressure inspection port of the continuously variable transmission. The pressure inspection port is usually protected by a screw cap. During pressure inspection, the screw cap of the pressure inspection port is removed and the pressure gauge is attached there. However, if the periphery of the pressure inspection port is contaminated with mud or the like, there is a risk that mud will enter the oil passage in the continuously variable transmission during pressure inspection and contaminate even the oil passage, which may cause a serious failure. Therefore, the present application devises the configuration of the transmission, makes the shape of the transmission case suitable for the arrangement of the continuously variable transmission, and aims to facilitate maintenance work. [Means for solving the problem]

[0005] The invention of claim 1 is a combine harvester in which a continuously variable transmission 20 for increasing / decelerating the output rotation of the engine 22 and switching the direction of rotation is provided downstream of the transmission path of the engine 22, and the output rotation of the continuously variable transmission 20 is transmitted to the running gear 2 and the harvesting gear 4 via a transmission 23, wherein the output rotation of the engine 22 is transmitted to the first shaft 29 and the second shaft 32 of the transmission 23 via an input shaft 25 from the continuously variable transmission 20, and the first shaft 29 is, The combine harvester is characterized by having a harvesting output pulley 31 that outputs to the harvesting device 4, a second gear 43 that rotates to the traveling device 2, a clutch 48 between the first gear 30 which is always meshed with the gear 27 of the input shaft 25 of the transmission and the second gear 43, and a notch 70 which is closed at least on the lower side when viewed from the front on either the left or right side of the upper part of the transmission case 21, with the mounting metal part 71 of the continuously variable transmission 20 arranged within the notch 70. The invention of claim 2 is a combine harvester characterized in that the notch 70 is formed above a shaft housing 73 in which a shaft adjacent to the shaft that outputs rotation from the output shaft of the HST is housed. The invention of claim 3 is a combine in which the mounting metal portion 71 of the continuously variable transmission 20 overlaps with the transmission case 21 when viewed in a direction perpendicular to the input shaft 25 of the continuously variable transmission 20. The invention of claim 4 is a combine harvester in which the continuously variable transmission 20 has oil passages (not shown) arranged vertically in the left-right direction with respect to the direction of machine travel, and vertical pressure detection ports 74 for mounting a pressure gauge 75 for pressure detection are connected to each of the upper and lower oil passages, and the pressure detection ports 74 are closed by screw caps 76 when not measuring pressure, and a space S for attaching and detaching the screw cap 76 is provided between the lower screw cap 76 and the upper surface of the shaft housing 73. [Effects of the Invention]

[0006] In the invention of claim 1, the first shaft 29, which rotates at a variable speed by the continuously variable transmission 20, is equipped with a first gear 30, a second gear 43, a harvesting output pulley 31, and a clutch 48 for switching between the first gear 30 and the second gear 43. As a result, the upper structure of the transmission case 21 can be made compact, and a notch 70 can be formed on the upper part of the continuously variable transmission 20. Therefore, the continuously variable transmission 20 is protected by the shaft housing 73 for forming the notch 70, preventing contamination by dust from the harvesting device 4 and mud splashes from the running device 2 while it is in motion. In the invention of claim 2, the notch 70 is formed above the shaft housing 73 in which the shaft 32 adjacent to the shaft 29 that outputs rotation from the output shaft 24 of the continuously variable transmission 20 is housed. Therefore, the notch 70 can be constructed using the components of the transmission case 21, resulting in a rational configuration. In the invention of claim 3, the mounting metal portion 71 of the continuously variable transmission 20 is configured to overlap with the transmission case 21 when viewed perpendicular to the input shaft (output shaft 24) 25 of the continuously variable transmission 20. Therefore, the mounting metal portion 71 of the continuously variable transmission 20 is protected by the shaft housing portion 73, preventing contamination by dust from the harvesting device 4 and mud splashes from the running device 2 during operation. In the invention of claim 4, the continuously variable transmission 20 has oil passages arranged vertically in the left-right direction with respect to the direction of machine travel, and each of the upper and lower oil passages is provided with a vertical pressure detection port 74 for mounting a pressure gauge 75 for pressure detection. The pressure detection port 74 is closed by a screw cap 76 when not measuring pressure, and a space S for attaching and detaching the screw cap 76 is provided between the lower screw cap 76 and the shaft housing 73. As a result, the mounting metal part 71 of the continuously variable transmission 20 can be provided with a pressure detection port 74 that communicates with the oil passages inside the continuously variable transmission 20, and the lower screw cap 76 that closes the pressure detection port 74 is protected by the shaft housing 73, which suppresses the adhesion of mud and straw debris. As a result, pressure detection maintenance can be performed simply by removing the screw cap 76 and attaching the pressure gauge 75 to the pressure detection port 74, making maintenance work easy. [Brief explanation of the drawing]

[0007] [Figure 1]Side view of a combine harvester. [Figure 2] Perspective view of the transmission. [Figure 3] A schematic front view of the same. [Figure 4] A schematic front view of the same. [Figure 5] A schematic diagram of the belt mechanism that outputs power from the transmission to the harvesting device. [Figure 6] Side view and front view of the same. [Figure 7] Diagram of another embodiment. [Figure 8] A longitudinal front view of the transmission case before the installation of the continuously variable transmission (CVT). [Figure 9] A longitudinal front view of a transmission case equipped with a continuously variable transmission. [Figure 10] Enlarged cross-sectional view of the clutch section of the transmission case. [Figure 11] Front view of a continuously variable transmission. [Figure 12] Right side view of a continuously variable transmission. [Figure 13] Plan view of a continuously variable transmission. [Figure 14] Bottom view of a continuously variable transmission. [Best Mode for Carrying Out the Invention]

[0008] One embodiment of the present invention will be described with reference to the drawings, where 1 is the machine frame, 2 is a traveling device located below the machine frame 1, 3 is a threshing device located above the machine frame 1, 4 is a harvesting device located in front of the machine frame 1, 5 is a grain tank located on the side of the threshing device 3 for temporarily storing the grain removed from the threshing device 3, and 6 is a control unit. The mowing device 4 has a grass divider 8 at the front and a grass lifter 9 positioned behind the grass divider 8. 12 is a feeder chain. The travel device 2 is configured to allow changes in travel speed using a hydraulic continuously variable transmission (HST) 20, and the rotation transmitted to the harvesting device 4 is also configured to change in sync with the travel speed of the travel device 2. That is, the rotation from the engine 22 is input to the hydraulic continuously variable transmission 20, and the rotation continuously variable by the hydraulic continuously variable transmission 20 is output to the traveling device 2 and the mowing device 4 via the transmission 23, and the mowing device 4 is driven at a working speed synchronized with the traveling speed. The transmission 23 is housed in the transmission case 21.

[0009] The hydraulic continuously variable transmission 20 is provided on the upper part of either the left or right side of the transmission case 21, and the output shaft 24 of the hydraulic continuously variable transmission 20 is connected to the input shaft 25 of the transmission 23. An output gear 27 is provided on the input shaft 25. In the vicinity of the input shaft 25, a first shaft (mowing output shaft) 29 for outputting to the mowing device 4 is provided, and a first gear (driven gear) 30 rotatably provided on the first shaft 29 is constantly meshed with the output gear 27. The end of the first shaft 29 protrudes outside the transmission case 21, and a mowing output pulley 31 is attached. A second gear 43 is separately provided on the first shaft 29. In the vicinity of the first shaft 29, a second shaft (countershaft) 32 is provided, a third gear (counter gear) 46 is fixed to the second shaft 32, and the third gear 46 is constantly meshed with the driven gear 30. A fourth gear 45 is separately provided on the second shaft 32, and the fourth gear 45 is constantly meshed with the second gear 43. A fifth gear 47 is provided at an intermediate position of the second shaft 32, and the rotation is output to the third shaft via the fifth gear 47, and finally transmitted to a side clutch (not shown) to drive-rotate the wheel shaft 40, drive the traveling device 2, and make the machine body travel. When one of the left and right side clutches is disengaged, a slow turn can be made, and when the brake is further applied, a sharp turn is possible.

[0010] A continuously variable transmission 20 for increasing or decreasing the output rotation speed of the engine 22 and switching the rotation direction (forward and reverse rotation) is provided on the downstream side of the transmission path of the engine 22. The continuously variable transmission 20 outputs the rotation to the traveling device 2 and the mowing device 4 via the transmission 23, and the combine is configured such that the output rotation of the engine 22 is transmitted from the output shaft 24 of the continuously variable transmission 20 to the first shaft 29, the second shaft 32, and the third shaft 26 of the transmission 23 via the input shaft 25 of the transmission 23. The first shaft 29 is provided with a first gear 30 that always meshes with the gear 27 of the input shaft 25 of the transmission, a second gear 43, and a clutch (clutch sleeve) 48 that rotates integrally with the first shaft 29 between the first gear 30 and the second gear 43. The second shaft 32 is provided with a third gear 46 that always meshes with the first gear 30, a fourth gear 45 that always meshes with the second gear 43, and a fifth gear 47 that transmits rotation to the third shaft 26. The first gear 30 is provided with an engaging portion 50 that engages with the engaging portion 48A of the clutch 48, and the second gear 43 is provided with an engaging portion 51 that engages with the engaging portion 48B of the clutch 48.

[0011] In this case, the clutch 48 may have any configuration as long as it can switch the transmission of the rotation of the first gear 30 or the second gear 43 to the first shaft 29. For example, in the present embodiment, the clutch 48 is a clutch sleeve (clutch release bearing) provided with a sleeve and is configured to be axially slidable on the first shaft 29. Therefore, while having a transmission mechanism for shifting to the mowing device 4, the transmission loss of the output is small, and it is possible to reduce the weight, size, and increase the number of mowing speed changes by adopting a two-stage pulley for the mowing output. In the present embodiment, the first gear 30 is rotatably attached to the first shaft 29, and when it is joined to the clutch 48, the rotation of the first gear 30 is transmitted to the first shaft 29. Similarly, the second gear 43 is rotatably attached to the first shaft 29, and when it is joined to the clutch 48, the rotation of the second gear 43 is transmitted to the first shaft 29.

[0012] The variable speed rotation of the continuously variable transmission 20 is provided by two transmission paths: a direct transmission path from the output shaft of the continuously variable transmission 20 to the harvesting device 4 via gears transmitted to the first shaft 29, and a bypass transmission path from the first shaft 29 via a separately provided second shaft 32, which returns the drive rotation to the first shaft 29 and outputs it to the harvesting device 4 (Figure 4). Therefore, the variable speed rotation from the continuously variable transmission 20 can be transmitted directly to the first shaft 29 via a transmission path and output to the harvesting device 4, reducing the number of meshing gears and rotating shafts and minimizing power transmission loss. Additionally, by transmitting the variable speed rotation of the continuously variable transmission 20 to the first shaft 29 via a second shaft 32, which is provided separately from the first shaft 29, and then via a second gear 43, the rotation of the continuously variable transmission 20 can be transmitted to the harvesting device 4 via two transmission paths within the transmission case 21.

[0013] A gear 27 on the output shaft 24 of the continuously variable transmission 20 is constantly engaged with the first gear 30 on the first shaft 29 located near the output shaft 24. The rotation of the first gear 30 is transmitted to the harvesting output pulley 31 located on the first shaft 29 protruding from the transmission case 21, and output to the harvesting device 4, thus forming a direct transmission path. A second gear 43, which is rotatably mounted separately on the first shaft 29, is provided with a second gear 43 that rotates by transmission from the second shaft 32 located near the first shaft 29, forming a bypass transmission path. A clutch 48 is provided between the first gear 30 and the second gear 43 to selectively switch and transmit the rotation of either the first gear 30 or the second gear 43 to the first shaft 29, thereby switching between the direct transmission path and the bypass transmission path. Therefore, the variable speed rotation from the continuously variable transmission 20 can be directly transmitted to the first shaft 29 via a transmission path and output to the harvesting device 4, reducing the number of meshing gears and rotating shafts and minimizing power transmission loss. Additionally, rotation can be transmitted to the first shaft 29 via a bypass transmission path that transmits rotation from a second shaft 32 (which is provided separately from the first shaft 29) to a harvesting output pulley 31 and a second gear 43 (which is also provided separately), thereby outputting to the harvesting device 4. Thus, the rotation of the continuously variable transmission 20 can be varied and transmitted to the harvesting device 4 via two separate transmission paths.

[0014] In other words, in conventional configurations, all rotation of the continuously variable transmission 20 is transmitted from the first shaft 29 through the second shaft 32 back to the first shaft 29 and then to the harvesting device 4. This increases the number of meshing gears and rotating shafts, resulting in transmission losses. However, the present invention solves this problem and suppresses transmission losses. A clutch 48 is provided on a first shaft 29 between a first gear 30 and a second gear 43 so as to be able to slide freely. An engaging portion 50 is provided on the clutch 48 side of the first gear 30 to engage with and disengage from the engaging portion 48A of the clutch 48, and an engaging portion 51 is provided on the clutch 48 side of the second gear 43 to engage with and disengage from the engaging portion 48B of the clutch 48. Therefore, when the engagement portion 48A of the clutch 48 is connected to the first gear 30, rotation is transmitted from the output shaft 24 of the continuously variable transmission 20 → input shaft 25 of the transmission case 21 → gear 27 → first gear 30 → clutch 48 → first shaft 29 and output to the harvesting device 4. Also, when the clutch 48 is switched and connected to the second gear 43, the rotation transmitted from the output shaft 24 of the continuously variable transmission 20 → input shaft 25 of the transmission case 21 → gear 27 → first gear 30 → third gear 46 → second shaft 32 → fourth gear 45 → second gear 43 → clutch 48 → first shaft 29 is output to the harvesting device 4.

[0015] In other words, the first gear 30 provided on the first shaft 29 is configured to serve both as a transmission gear for transmitting the variable speed rotation of the continuously variable transmission 20 to other rotating shafts and as an input gear for transmitting rotation to the first shaft 29, thereby creating a direct transmission path, simplifying the transmission path, and suppressing transmission losses. The first gear 30 and the second gear 43 are configured such that the rotation transmitted by the first gear 30 to the first shaft 29 is the standard speed, and the rotation transmitted by the second gear 43 to the first shaft 29 is the high-speed rotation (rotation for tilting). Therefore, while being able to handle the harvesting of lodged grain stalks, the configuration of the transmission path for the commonly used standard speed harvesting operation is simplified, thereby suppressing transmission loss and improving the durability of the transmission path. A continuously variable transmission (CVT) 20, which increases or decreases the output rotation speed of the engine 22 and switches the direction of rotation (forward or reverse rotation), is provided on either the left or right side of the transmission case 21 downstream of the transmission path of the engine 22. The CVT 20 has two transmission paths: a direct transmission path in which the rotation is transmitted from the output shaft of the CVT 20 via gears to the first shaft 29 and output to the harvesting device 4; and a detour transmission path in which the drive rotation transmitted indirectly to the first shaft 29 via a separately provided second shaft 32 is returned to the first shaft 29 and output to the harvesting device 4.

[0016] Therefore, the variable speed rotation from the continuously variable transmission 20 can be transmitted directly to the first shaft 29 via a transmission path and output to the harvesting device 4, reducing the number of meshing gears and rotating shafts and minimizing power transmission loss. Additionally, by transmitting the variable speed rotation of the continuously variable transmission 20 to the first shaft 29 via a second shaft 32, which is provided separately from the first shaft 29, and then via a second gear 43, the rotation of the continuously variable transmission 20 can be transmitted to the harvesting device 4 via two transmission paths within the transmission case 21. A gear 27 on the output shaft 24 of the continuously variable transmission 20 is constantly engaged with the first gear 30 on the first shaft 29 located near the output shaft 24. The rotation of the first gear 30 is transmitted to the harvesting output pulley 31 located on the first shaft 29 protruding from the transmission case 21, and output to the harvesting device 4, thus forming a direct transmission path. A second gear 43, which is rotatably mounted separately on the first shaft 29, is provided with a second gear 43 that rotates by transmission from the second shaft 32 located near the first shaft 29, forming a bypass transmission path. A clutch 48 is provided between the first gear 30 and the second gear 43 to selectively switch and transmit the rotation of either the first gear 30 or the second gear 43 to the first shaft 29, thereby switching between the direct transmission path and the bypass transmission path.

[0017] Therefore, the variable speed rotation from the continuously variable transmission 20 can be directly transmitted to the first shaft 29 via a transmission path and output to the harvesting device 4, reducing the number of meshing gears and rotating shafts and minimizing transmission loss of output. In addition, rotation can be transmitted to the first shaft 29 via a bypass transmission path from the second shaft 32, which is provided separately from the first shaft 29, through a second gear 43, and output to the harvesting device 4. Thus, the rotation of the continuously variable transmission 20 can be varied and transmitted to the harvesting device 4 via two transmission paths. In other words, in conventional configurations, all rotation of the continuously variable transmission 20 is transmitted from the first shaft 29 through the second shaft 32 back to the first shaft 29 and then to the harvesting device 4. This increases the number of meshing gears and rotating shafts, resulting in transmission losses. However, the present invention solves this problem and suppresses transmission losses. A clutch 48 is provided on the first shaft 29 between the first gear 30 and the second gear 43. An engaging portion 50 is provided on the clutch 48 side of the first gear 30 to engage with and disengage from the engaging portion 48A of the clutch 48, and an engaging portion 51 is provided on the clutch 48 side of the second gear 43 to engage with and disengage from the engaging portion 48B of the clutch 48.

[0018] Therefore, when the clutch 48 is connected to the first gear 30, rotation is transmitted from the output shaft 24 of the continuously variable transmission 20 → input shaft 25 of the transmission case 21 → gear 27 → first gear 30 → clutch 48 → first shaft 29 and output to the harvesting device 4. Also, when the clutch 48 is switched and connected to the second gear 43, rotation transmitted from the output shaft 24 of the continuously variable transmission 20 → input shaft 25 of the transmission case 21 → gear 27 → first gear 30 → third gear 46 → second shaft 32 → fourth gear 45 → second gear 43 → clutch 48 → first shaft 29 is output to the harvesting device 4. In other words, by configuring the first gear 30 provided on the first shaft 29 to serve as both a transmission gear that transmits the variable speed rotation of the continuously variable transmission 20 to another rotating shaft (second shaft 32) and an input gear that transmits rotation to the first shaft 29, a direct transmission path can be constructed, simplifying the transmission path and suppressing transmission losses.

[0019] The first gear 30 and the second gear 43 are configured such that the rotation transmitted by the first gear 30 to the first shaft 29 is the standard speed, and the rotation transmitted by the second gear 43 to the first shaft 29 is the high-speed rotation (rotation for tilting). Therefore, while being able to handle the harvesting of lodged grain stalks, the configuration of the transmission path for the commonly used standard speed harvesting operation is simplified, thereby suppressing transmission loss and improving the durability of the transmission path. The harvesting output pulley 31 is composed of a pair of pulley bodies 53, and the pulley bodies 53A and 53B of the pair of harvesting output pulleys 31 have different diameters. As a result of miniaturizing the transmission 23, it became possible to arrange a double pulley, which was not possible with conventional designs, and the number of gear shifting stages was increased to four. In other words, by switching between the first gear 30 and the second gear 43 using the clutch 48, a two-speed transmission is achieved. Furthermore, by using a double pulley to create a two-speed transmission configuration, the transmission output to the harvesting device 4 can be configured into four stages.

[0020] This configuration, with its increased number of speed settings, allows for the selection and setting of a harvesting speed that matches the crop (matching the degree of lodging of the grain stalks). Furthermore, increasing the harvesting speed thins the layer of grain stalks being transported, reducing the threshing load. The transmission path from the harvesting output pulley 31 to the harvesting device 4 is configured to use separate tension pulleys 55 to switch the transmission between each of the pair of belts 54, and the switching of the tension pulleys 55 is performed by a lever 56 or a motor 57 (Figures 5 and 6). An engagement portion 50 is provided on the first gear 30, which is rotationally transmitted from a gear 27 located on the input shaft 25 of the continuously variable transmission 20. Therefore, the variable speed rotation from the continuously variable transmission 20 can be transmitted to the engagement portion 48A of the clutch 48 via the engagement portion 50 of the first gear 30, and the first gear 30 and the clutch 48 can directly form a transmission path, reducing the number of meshing gears and rotating shafts, and thus reducing the output to the harvesting device 4, thereby reducing the transmission loss of the output.

[0021] This reduces the number of parts and assembly time in the transmission mechanism from the continuously variable transmission 20 to the harvesting device 4, makes the transmission 23 lighter, reduces the environmental impact by reducing the number of parts, and improves durability by increasing the thickness of the first gear 30, which is used frequently. Furthermore, the reduction in the number of parts on the upper part of the mission case 21 results in a lighter weight, which lowers the center of gravity of the mission case 21, stabilizing the aircraft's attitude and improving the aircraft's flight stability. Furthermore, the first shaft 29 of the transmission case 21 of the present invention has a structure with fewer gears on the shaft compared to conventional transmission structures, which reduces the load on the shaft and allows for a thinner shaft diameter than conventional transmission structures. Furthermore, the first shaft 29 has a structure with fewer gears on the shaft compared to conventional transmission structures, which allows for a shorter shaft length. This reduces shaft deflection, resulting in less noise and vibration. In addition, the weight of the machine can be reduced, improving fuel efficiency. The harvesting cylinder is positioned in the center of the machine frame 1 in the left-right direction. Therefore, by positioning the support position of the harvesting device 4 at the center of the machine, the stability of the machine is improved.

[0022] The harvesting output pulley 31 is constructed using a so-called double pulley system. In this case, the harvesting output pulleys 31 of the double pulley system will have different diameters. As a result of the miniaturization of the transmission 23, it became possible to arrange a double pulley, which was not possible with conventional designs, and the number of gear shifting stages increased to four. In other words, by switching between the first gear 30 and the second gear 43 using the clutch 48, a two-speed transmission is achieved, and by further configuring a two-speed transmission using a double pulley, the transmission can be configured with four gear stages. This configuration, with its increased number of speed settings, allows for the selection and setting of a harvesting speed tailored to the crop. Increasing the harvesting speed thins the layer of grain being transported, thereby reducing the threshing load. The transmission path from the harvesting output pulley 31 to the harvesting device 4 is configured to use separate tension pulleys 55 to switch the transmission on each of the pair of belts 54. Therefore, increasing the harvesting speed thins the straw layer and reduces the threshing load. The tension pulley 55 is switched using lever 56.

[0023] The mounting configuration of the tension pulley 55 is arbitrary, but as an example, a pair of tension pulleys 55 are provided on the left and right sides, each in contact with the belt 54, the tension pulleys 55 are attached to the ends of the arms 58, the base of the arms 58 are rotatably attached to the fixed part, and levers 56 are attached to the base of the arms 58 so that the arms 58 can rotate together (Figure 6). Therefore, when either the left or right lever 56 is operated, it contacts the belt 54, turning on the power transmission and outputting power to the harvesting device 4. The lever 56 may also be extended vertically and configured to be directly operable from the control unit 6. The switching of the tension pulley 55 may also be configured to use a motor 57. In this case, a motor 57 can be installed in place of the lever 56 in Figure 6. The configuration will use a single motor 57 for switching. Therefore, the switching mechanism can be configured simply.

[0024] In this case, the configuration of the tension switching mechanism is arbitrary, but the rotating body 60 is fixed to the output shaft of the motor 57, and the rotating body 60 and a pair of levers 56 are connected via an arm 61 and a rod 62 (Figures 2 and 7). Therefore, when the motor 57 is energized and the rotating body 60 is rotated once, one arm 61 engages the tension pulley 55, and the other arm 61 disengages the tension pulley 55. In addition, the output to the harvesting device 4 can be stopped separately from the tension switching mechanism by stopping the output of the continuously variable transmission 20 or by using the harvesting clutch (not shown), etc. The second gear 43, which is rotationally transmitted from the output gear 27 of the continuously variable transmission 20 via a bypass transmission path, is provided with an engagement portion 51, and the rotation is transmitted to the clutch 48 via the engagement portion 51 to rotate the first shaft 29. Furthermore, by making the number of teeth of the second gear 43 less than the number of teeth of the first gear 30, the first shaft 29 is configured to rotate at high speed.

[0025] In other words, when the engagement portion 48B of the clutch 48 is engaged with the engagement portion 51 of the second gear 43, the rotation of the second gear 43 is transmitted to the first shaft 29 via the clutch 48, and the harvesting device 4 is driven at high speed as the lodging speed via the belt drive from the harvesting output pulley 31. An engagement portion 51 is provided on the second gear 43, which is rotationally transmitted from the gear 27 of the continuously variable transmission 20. The engagement portion 51 is used to transmit rotation to the clutch 48, thereby rotating the first shaft 29. The first shaft 29 rotates at a standard speed, and the rotational transmission to the first shaft 29 is cut off by moving the clutch 48.

[0026] In other words, when the clutch 48 is moved to the left in the diagram, the engagement portion 48B of the clutch 48 that is engaged with the engagement portion 51 of the second gear 43 disengages from the engagement portion 51 of the second gear 43, and the drive rotation transmitted from the gear 27 to the first shaft 29 is interrupted as the clutch 48 moves to a neutral position. The rotation from the gear 27 of the continuously variable transmission 20 is transmitted at high speed through a bypass transmission path: first gear 30 → third gear 46 → second shaft 32 → fourth gear 45 → second gear 43. The engagement portion 48B of the clutch 48 is moved to the right in the diagram and engages with the engagement portion 51 of the second gear 43, causing the first shaft 29 to rotate at high speed (lodging speed) and driving the harvesting device 4 to rotate at high speed. In other words, when the clutch 48 is moved to the right in Figure 3 and the engaging portion 48B of the clutch 48 is engaged with the engaging portion 51 of the second gear 43, the rotation of the second gear 43 is transmitted to the first shaft 29 via the clutch 48, and the harvesting device 4 is driven at high speed via the belt drive from the harvesting output pulley 31.

[0027] Furthermore, the tooth width (gear width) of the first gear 30 is set to be greater than or equal to the tooth width of the second gear 43. This improves the durability of the first gear 30, which is used frequently. It is preferable to configure the left wall 69 of the transmission case 21 and the second gear 43 to be relatively close together, and to shorten the first shaft 29 that generates the harvesting output to the vicinity of the second gear 43. This makes it possible to miniaturize the transmission case 21. Therefore, since the length of the first shaft 29 is shortened, the deflection of the first shaft 29 itself can be reduced, resulting in reduced noise and vibration. Figure 8 is a longitudinal front view of another embodiment of the continuously variable transmission 20 before it is mounted on the transmission case 21, and Figure 10 is an enlarged cross-sectional view of the clutch 48 portion of this transmission case 21.

[0028] However, the transmission case 21 is configured to receive the rotation of the engine 22 from above, transmit it to the travel device 2 via the wheel gear 40 on the lower side, and drive the harvesting device 4 in synchronization with the travel speed. Therefore, the configuration in which the continuously variable transmission 20 is mounted on either the left or right side of the transmission case 21 is well known. However, in conventional examples, the continuously variable transmission 20 was simply mounted on the side of the transmission case 21, which presented the problem of the mounting metal part of the continuously variable transmission 20 being contaminated by dust and mud splashes from the harvesting device 4 while it was in motion. Therefore, the present invention is configured by providing a notch 70 on either the left or right side of the upper part of the transmission case 21, with at least the lower side closed when viewed from the front, and arranging the mounting metal part (pressure detection port) 71 of the continuously variable transmission 20 within the notch 70 (Figure 8).

[0029] Therefore, the mounting metal portion 71 of the continuously variable transmission 20 is protected by the shaft housing portion 73 which forms the notch portion 70, preventing contamination by dust from the harvesting device 4 and mud splashes from the running device 2 while the vehicle is in motion. The notch 70 is formed above the shaft housing 73, which houses the shaft 32 adjacent to the shaft 27 that outputs rotation from the output shaft 24 of the continuously variable transmission 20. Therefore, the notch 70 can be constructed using the components of the transmission case 21, resulting in a rational configuration. The mounting metal portion 71 of the continuously variable transmission 20 is configured to overlap with the transmission case 21 when viewed perpendicular to the input shaft (output shaft 24) 25 of the continuously variable transmission 20.

[0030] In other words, in a side view, the vertical imaginary line L passing through the input shaft 25 of the continuously variable transmission 20 is positioned to overlap with the mounting metal portion 71 (Figure 9). Therefore, the mounting metal portion 71 of the continuously variable transmission 20 is protected by the shaft housing portion 73 to prevent contamination by dust from the harvesting device 4 during operation and mud splashes from the running device 2. In this case, when viewed from the side, it is preferable to make the front-to-rear width of the shaft housing 73 greater than the front-to-rear width of the mounting metal portion 71 of the continuously variable transmission 20, as this improves the protective function. The continuously variable transmission 20 has oil passages (not shown) arranged vertically in the left-right direction relative to the direction of machine travel, and each of the upper and lower oil passages is provided with a vertical pressure detection port 74 into which a pressure gauge 75 for pressure detection is mounted. The pressure detection port 74 is closed by a screw cap 76 when not in use for pressure detection, and a space S for attaching and detaching the screw cap 76 is provided between the lower screw cap 76 and the shaft housing 73 (Figure 9).

[0031] Therefore, a pressure sensing port 74 communicating with the oil passage inside the continuously variable transmission 20 can be provided on the mounting metal part 71 of the continuously variable transmission 20, and the lower screw cap 76 that closes the pressure sensing port 74 is protected by the shaft housing part 73, which suppresses the adhesion of mud and straw debris. As a result, pressure sensing maintenance can be performed simply by removing the screw cap 76 and attaching a pressure gauge 75 to the pressure sensing port 74, making maintenance work easy. The configuration of the continuously variable transmission 20 is arbitrary, but at a minimum, oil passages are arranged vertically in the left-right direction relative to the direction of the machine's travel, and vertical pressure detection ports 74, on which pressure gauges 75 for pressure detection are mounted, are provided to connect each of the upper and lower oil passages. Since the continuously variable transmission (CVT) 20 is configured to transmit power from its output shaft 24 to the first shaft 29 of the transmission case 21 via the input shaft 25 of the transmission 23, and then output from the first shaft 29 to the harvesting output pulley 31, the width of the transmission case 21 in the area where the CVT 20 is installed can be reduced, and as a result, a notch 70 can be formed on either the left or right side of the upper part of the transmission case 21, with at least the lower side closed when viewed from the front.

[0032] This allows the mounting metal portion 71 of the continuously variable transmission 20 to be positioned within the notch 70, and the mounting metal portion 71 of the continuously variable transmission 20 is protected by the shaft housing portion 73 that constitutes the notch 70, preventing contamination by dust from the harvesting device 4 and mud splashes from the running device 2 while the vehicle is in motion. Furthermore, because the first shaft 29 has fewer gears on the shaft compared to conventional transmission structures, the shaft length of the first shaft 29 can be shortened. This reduces the amount of shaft deflection, thus reducing noise and vibration. Furthermore, the outer end surface 73A of the shaft housing portion 73 is offset and protrudes to the right of the end surface 70A of the notch portion 70 of the transmission case 21, thereby protecting the lower side of the mounting metal portion 71.

[0033] Furthermore, the shape of the notch 70 in the transmission case 21 can be adjusted so that the continuously variable transmission 20 is positioned closer to the center of the front center line of the transmission case 21. This reduces the amount of protrusion of the continuously variable transmission 20 from the end face 70A of the notch 70 in the transmission case 21, thus increasing the freedom of layout for peripheral devices other than the transmission case 21. For similar reasons, the continuously variable transmission 20 is positioned close to the centerline of the transmission case 21, allowing the input shaft of the continuously variable transmission 20 from the engine 22 to be shortened, reducing the amount of protrusion (offset) of the continuously variable transmission 20 from the transmission case 21, and increasing the freedom of layout. In this embodiment, the left side in the direction of the aircraft's movement is made smaller, and a notch 70 is formed on the left side of the transmission case 21 to provide the continuously variable transmission 20. The continuously variable transmission 20 and the harvesting output pulley 31 are arranged in a straight line, allowing the first shaft 29 to be made shorter and smaller in diameter.

[0034] The continuously variable transmission 20 is located near the transmission case 21. In this transmission case 21, at least the input shaft 22A from the engine 22 is made thinner. As a result, the input shaft 22A has fewer gears on the shaft compared to conventional transmission structures, which allows for a shorter shaft length. Consequently, the amount of shaft deflection is reduced, resulting in less noise and vibration. [Explanation of symbols]

[0035] 1...Machine frame, 2...Running gear, 3...Threshing gear, 4...Harvesting gear, 5...Grain tank, 6...Control unit, 20...Hydraulic continuously variable transmission, 21...Transmission case, 22...Engine, 22A...Input shaft, 23...Transmission, 24...Output shaft, 25...Input shaft, 26...Third shaft, 27...Output gear (output gear) 27, 29...First shaft (harvesting output shaft), 30...First gear (driven gear), 31...Harvesting output pulley, 32...Second shaft (counter shaft), 40...Wheel gear, 41...Wheel shaft, 43... 2nd gear, 45...4th gear, 46...3rd gear (counter gear), 47...5th gear, 48...clutch, 48A...engaging part, 48B...engaging part, 50...engaging part, 51...engaging part, 53...pulley body, 54...belt, 55...tension pulley, 56...lever, 57...motor, 58...arm, 60...rotating body, 61...arm, 62...rod, 70...notch, 70A...end face, 71...mounting metal part, 73...shaft housing part, 73A...outer end face, 74...pressure sensing port, 75...pressure gauge, 76...screw cap.

Claims

1. In a combine harvester, a continuously variable transmission (20) that increases or decreases the output rotation speed of the engine (22) and switches the direction of rotation is provided downstream of the transmission path of the engine (22), and the output rotation speed of the continuously variable transmission (20) is transmitted to the running gear (2) and the harvesting gear (4) via a transmission (23), the output rotation speed of the engine (22) is transmitted to the first shaft (29) and second shaft (32) of the transmission (23) via an input shaft 25 from the continuously variable transmission (20), and the first shaft (29) has, A combine harvester is provided with a harvesting output pulley (31) that outputs to a harvesting device (4), a second gear (43) that rotates to a traveling device (2), a clutch (48) between a first gear (30) that is always meshed with a gear (27) on the input shaft (25) of the transmission and the second gear (43), and a notch (70) is provided on either the left or right side of the upper part of the transmission case (21), with at least the lower side closed when viewed from the front, and the mounting metal part (71) of the continuously variable transmission (20) is arranged within the notch (70).

2. The combine harvester according to claim 1, characterized in that the notch (70) is formed above a shaft housing (73) which houses a shaft adjacent to the shaft that outputs rotation from the output shaft of the HST.

3. A combine harvester according to claim 1 or claim 2, wherein the mounting metal portion (71) of the continuously variable transmission (20) overlaps with the transmission case (21) when viewed in a direction perpendicular to the input shaft (25) of the continuously variable transmission (20).

4. The continuously variable transmission (20) has oil passages (not shown) arranged vertically in the left-right direction relative to the direction of machine travel, and vertical pressure detection ports (74) for mounting pressure gauges (75) for pressure detection are connected to each of the upper and lower oil passages, and the pressure detection ports (74) are closed by screw caps (76) when not measuring pressure, and a space S for attaching and detaching the screw caps (76) is provided between the lower screw cap (76) and the upper surface of the shaft housing (73) of the upper and lower screw caps (76).

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