Field work machine

Abstract

To provide a field working machine hardly causing winding of seedlings, straws, etc.SOLUTION: The working vehicle includes a prime mover for generating power, a hydrostatic continuously variable transmission 45 having a hydraulic pressure pump to which the power from the prime mover is transmitted and a hydraulic motor for outputting the power, and a fan 46 connected to a shaft 45a part of either the hydraulic pressure pump or the hydraulic motor to generate cool air. The fan 46 includes a connecting portion side 45a connected to the shaft side 46A, a plurality of blade portion side 46A extending from the connecting portion side 45a outward in the radial direction around the shaft side 46B, and a frame portion side 46B connected to an outer peripheral portion of the plurality of blade portion side 46B and surrounding the plurality of blade portion side 46C from the outer peripheral side.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a field work machine. [Background technology]

[0002] In conventional farm work machines, as described in Patent Document 1, for example, a fan is connected to the input shaft of a hydraulic continuously variable transmission. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-090681 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, Patent Document 1 discloses a rice transplanter, but in some cases, a furrow cutter, a weeder, etc. are attached to the rear of the rice transplanter, and the rice transplanter is used as a multipurpose machine. In such cases, long seedlings or straw may get caught in the blades of the fan, and there is a risk that the seedlings or straw may get wrapped around the rotating shaft of the fan.

[0005] An object of the present invention is to provide a farm work machine that is less likely to become entangled with seedlings, straw, etc. [Means for solving the problem]

[0006] The field work machine of the present invention is equipped with a prime mover that generates power, a hydrostatic continuously variable transmission having a hydraulic pump to which the power from the prime mover is transmitted and a hydraulic motor that outputs the power, and a fan that is connected to the shaft of either the hydraulic pump or the hydraulic motor and generates cooling air, the fan having a connecting portion connected to the shaft, a plurality of blade portions extending radially outward from the connecting portion with the shaft as the center, and a frame portion connected to the outer periphery of the plurality of blade portions and surrounding the plurality of blade portions from the outer periphery.

[0007] According to the present invention, the outer periphery of the fan blade is covered by a frame, which reduces the risk of long seedlings, straw, etc., becoming entangled in the fan blade and also reduces the risk of seedlings, straw, etc., becoming entangled around the fan's rotating shaft, resulting in a field work machine that is less likely to become entangled with seedlings, straw, etc.

[0008] In the present invention, it is preferable that the width of the frame portion in the axial direction of the shaft is wider than the width of each of the plurality of blade portions in the axial direction.

[0009] With this configuration, the outer periphery of the blade is covered over the entire width by the frame, which reduces the risk of long seedlings, straw, etc., getting caught in the blade of the fan.

[0010] In the present invention, it is preferable that the continuously variable transmission is arranged in a state where it is biased to one side of the center point of the left and right of the aircraft body, and that the fan is arranged laterally outside the aircraft body with respect to the continuously variable transmission.

[0011] With this configuration, even in an environment where the fan is likely to come close to seedlings, straw, etc. due to the configuration in which the continuously variable transmission is biased outward from the side of the machine body, the outer periphery of the fan blades is covered by the frame, reducing the risk of long seedlings, straw, etc. getting caught in the fan blades. Furthermore, with this configuration, even in locations where there is tight clearance with surrounding parts and it is difficult to attach a cover, etc., measures can be taken with the fan alone, so there are fewer restrictions on installation.

[0012] In the present invention, left and right running devices are provided that are capable of running on the ground based on the power from the prime mover, and it is preferable that the fan is located between the running device on one of the left and right sides and the continuously variable transmission when viewed in a plane.

[0013] With this configuration, even in an environment where the fan is close to the running gear due to the continuously variable transmission being biased outward to the side of the machine and seedlings, straw, etc. are likely to come into contact with the fan, the outer periphery of the fan blade is covered by the frame, reducing the risk of long seedlings, straw, etc. getting caught in the fan blade.

[0014] In the present invention, a transmission shaft is provided that is positioned between the left and right running devices in a plan view, rotates based on the power of the prime mover, and transmits the power to the left and right running devices, and a transmission case that is also positioned sideways to the body and accommodates the transmission shaft, and it is preferable that the fan overlaps with the transmission case in a plan view and is positioned above the transmission case.

[0015] With this configuration, the seedlings, straw, etc. located below the transmission case and the fan are located on opposite sides of the transmission case, so that long seedlings, straw, etc. come into contact with the transmission case before getting caught on the fan, further reducing the risk of the seedlings, straw, etc. getting caught on the fan.

[0016] In the present invention, the running device is a wheel, which extends vertically and is arranged laterally outward of the vehicle body relative to the horizontal transmission shaft, and which receives power from the horizontal transmission shaft and transmits it to the wheel; and a vertical transmission case which is connected to the laterally outward end of the horizontal transmission case, which houses the vertical transmission shaft, and which rotates around the rotation axis of the vertical transmission shaft to steer the wheel, and it is preferable that the upper part of the vertical transmission case is located above the upper end of the wheel and overlaps with the fan in a side view.

[0017] With this configuration, even if debris is kicked up by the wheels, the debris is received by the vertical transmission case, reducing the risk of the debris becoming entangled in the fan.

[0018] In the present invention, it is preferable that the traveling device is a wheel, and the lower end of the fan is located above the upper end of the wheel.

[0019] With this configuration, even if impurities are kicked up by the wheels, the risk of the impurities becoming entangled in the fan is reduced.

[0020] In the present invention, it is preferable that the fan be disposed closer to the side where the continuously variable transmission is located than the midpoint between the travel device and the continuously variable transmission on the left or right side.

[0021] With this configuration, the fan is positioned closer to the continuously variable transmission than the wheels, allowing the fan to be as far away from the wheels as possible, which reduces the risk of debris getting tangled in the fan even if it is kicked up by the wheels.

[0022] In the present invention, a seedling planting device is provided for planting seedlings on the surface of a rice paddy, and it is preferable that the continuously variable transmission device is a row-to-row continuously variable transmission device that changes the speed of power from the prime mover and transmits it to the seedling planting device.

[0023] This configuration reduces the risk of long seedlings, straw, etc. getting caught in the fan while cooling the inter-plant continuously variable transmission. [Brief explanation of the drawings]

[0024] [Figure 1] FIG. 1 is an overall side view of a riding rice transplanter. [Figure 2] FIG. 1 is an overall plan view of a riding rice transplanter. [Figure 3] FIG. [Figure 4] FIG. [Figure 5] FIG. 2 is a diagram illustrating a configuration of a pressure reducing unit. [Figure 6] FIG. 2 is a diagram showing a hydraulic circuit of an inter-section transmission and a pressure reducing section. [Figure 7] FIG. 2 is a side view showing the configuration of an inter-row transmission and a fan. DETAILED DESCRIPTION OF THE INVENTION

[0025] An embodiment of the present invention will be described with reference to the drawings. In the following description, unless otherwise specified, the direction of arrow F in the drawings will be referred to as "front," the direction of arrow B as "rear," the direction of arrow L as "left," and the direction of arrow R as "right." Furthermore, the direction of arrow U in the drawings will be referred to as "up," and the direction of arrow D as "down."

[0026] [Overall configuration of the rice transplanter] The riding rice transplanter (an example of a "rice transplanter") of this embodiment will be described below. As shown in Fig. 1, the riding rice transplanter is provided with a link mechanism 3 and a hydraulic cylinder 4 for driving the link mechanism 3 up and down at the rear of a machine body 11 having right and left front wheels 1 and right and left rear wheels 2, and a seedling planting device 5 is supported at the rear of the link mechanism 3.

[0027] The seedling planting device 5 comprises a planting transmission case 6 arranged at a predetermined interval in the left-right direction, a rotating case 7 rotatably supported on the right and left rear sides of the planting transmission case 6, a pair of planting arms 8 provided at both ends of the rotating case 7, a float 9, and a seedling tray 10.

[0028] [Configuration around the driving section] As shown in FIGS. 1 and 2, a body 11 is provided with a driver's seat 13 and a steering handle 14 for steering the front wheels 1.

[0029] Right and left support frames 16 are provided on the right and left front portions of the machine body 11, and spare seedling trays 15 are supported on the support frames 16. A support frame 17 is connected across the upper portions of the right and left support frames 16.

[0030] A measuring device 18 is attached to the support frame 17 at a portion located at the lateral center CL of the airframe 11 in a plan view. The measuring device 18 is equipped with a receiving device (not shown) that acquires position information using a satellite positioning system, and an inertial measurement unit (not shown) that detects the inclination (pitch angle, roll angle) of the airframe 11.

[0031] [Configuration around the transmission case] As shown in Figure 1, a transmission case 20 is supported at the front of the vehicle body 11, and right and left front wheels 1 are supported on front axle cases 21 connected to the right and left lateral sides of the transmission case 20. A rear axle case 22 is supported at the rear of the vehicle body 11, and right and left rear wheels 2 are supported on the rear axle case 22.

[0032] 1 and 3, an engine 23 is supported in the front portion of the transmission case 20. A hydrostatic continuously variable transmission 24 is connected to the left lateral side portion of the transmission case 20, and power from the engine 23 is transmitted to an input shaft 24a of the continuously variable transmission 24 via a transmission belt 25.

[0033] The continuously variable transmission 24 is configured to be able to change speeds continuously between a neutral position, forward travel, and reverse travel, and is operated by a speed change lever 30 provided on the left side of the steering handle 14.

[0034] [Configuration of the driving transmission system for the front and rear wheels] 3, a pump 26 is connected to the right lateral side of the transmission case 20, and the pump 26 supplies hydraulic oil to the hydraulic cylinder 4. The input shaft 24a of the continuously variable transmission 24 is inserted into the transmission case 20, and a transmission shaft 27 is connected between the input shaft 26a of the pump 26 and the input shaft 24a of the continuously variable transmission 24.

[0035] Transmission shafts 28, 29 are supported in the left-right direction inside the transmission case 20, and the output shaft 24b of the continuously variable transmission 24 is connected to an end of the transmission shaft 28. A gear-type sub-transmission device 31 is provided inside the transmission case 20 and extends across the transmission shafts 28, 29.

[0036] The auxiliary transmission 31 includes a low-speed gear 32 and a high-speed gear 33 connected to the transmission shaft 28, and a shift gear 34 fitted to the outside of the transmission shaft 29 by a spline structure so as to be rotatable and slidable integrally with the transmission shaft 28. The shift gear 34 can be slid using an auxiliary speed change lever (not shown) provided near the driver's seat 13.

[0037] In the auxiliary transmission 31, when the shift gear 34 is engaged with the low-speed gear 32, the power of the transmission shaft 28 is transmitted to the transmission shaft 29 at a low speed, and when the shift gear 34 is engaged with the high-speed gear 33, the power of the transmission shaft 28 is transmitted to the transmission shaft 29 at a high speed. Here, when planting work is being performed in a paddy field, the auxiliary transmission 31 is operated to the low-speed state, and when traveling at high speed on a road or the like, the auxiliary transmission 31 is operated to the high-speed state.

[0038] Right and left front axles 35 that transmit power to the right and left front wheels 1 are supported across the transmission case 20 and the front axle case 21, and a front wheel differential device 36 is provided between the right and left front axles 35. A transmission gear 37 connected to the transmission shaft 29 is in mesh with a transmission gear 38 connected to a case 36a of the front wheel differential device 36.

[0039] An output shaft 39 is supported in the front-to-rear direction at the rear of the transmission case 20. A bevel gear 40 connected to a case 36a of the front wheel differential device 36 is engaged with a bevel gear 39a formed at the front of the output shaft 39.

[0040] As shown in Figures 1 and 3, a transmission shaft 41 is connected to the rear of the output shaft 39 via a universal joint (not shown), and the rear of the transmission shaft 41 is connected to the input shaft (not shown) of the rear axle case 22 via a universal joint (not shown).

[0041] With the above configuration, the power changed in speed by the continuously variable transmission 24 is transmitted from the output shaft 24b of the continuously variable transmission 24 to the right and left front wheels 1 via the transmission shaft 28, the sub-transmission 31, the transmission shaft 29, the transmission gears 37 and 38, the front wheel differential device 36, and the front axle 35. In addition, the power transmitted to the front wheel differential device 36 is transmitted to the right and left rear wheels 2 via the bevel gear 40, the output shaft 39 (bevel gear 39a), the transmission shaft 41, and a transmission shaft (not shown) inside the rear axle case 22.

[0042] A multi-plate brake 42 is fitted to the output shaft 39, and the brake 42 can be put into a braking state by stepping on a brake pedal 43 shown in Figure 2. By applying the brake to the output shaft 39 with the brake 42, the front wheels 1 and rear wheels 2 can be braked.

[0043] [Configuration of the work transmission system for the seedling planting device] As shown in Figure 4, a hydrostatic planting inter-row transmission 45 is connected to the right lateral side of the transmission case 20, and an input shaft 45a of the inter-row transmission 45 is connected to the transmission shaft 28. The input shaft 45a of the inter-row transmission 45 protrudes from the opposite side of the transmission case 20, and a fan 46 that sends cooling air to the inter-row transmission 45 is connected to the protruding portion of the input shaft 45a of the inter-row transmission 45.

[0044] Transmission shafts 47 and 48 are supported in the left-right direction inside the transmission case 20, and an output shaft 45b of the inter-section transmission device 45 is connected to an end of the transmission shaft 47.

[0045] The control device (not shown) and the actuator (not shown) rotate the speed change operating shaft 45c so that the distance between the stocks is based on the settings set by the operator, and the stock change transmission 45 is operated to the forward side, reverse side, and neutral position.

[0046] A cylindrical transmission shaft 49 is rotatably fitted onto the outside of the transmission shaft 47 via a needle bearing, and a transmission gear 50 having two sets of gears is rotatably fitted onto the outside of the transmission shaft 48 via a bearing. A transmission gear 47a formed on the transmission shaft 47 meshes with a large diameter gear portion of the transmission gear 50, and a transmission gear 51 connected to the transmission shaft 49 meshes with a small diameter gear portion of the transmission gear 50.

[0047] A gear-type variable speed transmission 52 is provided inside the transmission case 20 across the transmission shafts 48, 49, and a bevel gear 53 is connected to the transmission shaft 48. An output shaft 54 ​​is supported in the front-to-rear direction at the rear of the transmission case 20, and a bevel gear 55 is fitted onto the front of the output shaft 54 ​​via a drive clutch 56, with the bevel gears 53, 55 meshing with each other.

[0048] As shown in FIG. 4, the variable speed transmission device 52 includes a constant speed gear 58 and a variable speed gear 59 connected to the transmission shaft 49, and a constant speed gear 60 and a variable speed gear 61 fitted onto the transmission shaft 48 so as to be rotatable relative to each other, with the constant speed gears 58 and 60 meshing with each other and the variable speed gears 59 and 61 meshing with each other.

[0049] A key-shaped speed-changing member 62 is slidably supported inside the transmission shaft 48, and by sliding the speed-changing member 62 to engage with one of the constant velocity gear 60 and the variable velocity gear 61, the constant velocity gear 60 and the variable velocity gear 61 to which the speed-changing member 62 is engaged can be connected to the transmission shaft 48.

[0050] The constant velocity gears 58, 60 are circular gears with the same diameter. As a result, when the speed-changing member 62 is engaged with the constant velocity gear 60, the power of one rotation of the transmission shaft 49 is transmitted to the transmission shaft 48 as power of one rotation at a constant angular velocity.

[0051] The variable speed gears 59, 61 are elliptical gears, eccentric gears, or non-circular gears. When the speed-changing member 62 is engaged with one of the variable speed gears 61, the power of one rotation of the transmission shaft 49 is transmitted to the transmission shaft 48 as power of one rotation, but the angular velocity within one rotation changes between high and low.

[0052] As shown in Figures 1 and 4, a transmission shaft 57 is connected to the rear of the output shaft 54 ​​via a universal joint (not shown), and the rear of the transmission shaft 57 is connected to the input shaft (not shown) of the seedling planting device 5 via a universal joint (not shown).

[0053] With the above configuration, the power changed in speed by the continuously variable transmission 24 is transmitted from the output shaft 24b of the continuously variable transmission 24 to the inter-station transmission 45 via the transmission shaft 28 and the input shaft 45a of the inter-station transmission 45.

[0054] The power changed in speed by the inter-plant transmission device 45 is transmitted from the output shaft 45b of the inter-plant transmission device 45 to the seedling planting device 5 via the transmission shaft 47 (transmission gear 47a), transmission gears 50, 51, transmission shaft 49, variable speed transmission device 52, transmission shaft 48, bevel gears 53, 55, planting clutch 56, output shaft 54, and transmission shaft 57.

[0055] When the planting clutch 56 is operated to the transmission state, power is transmitted to the seedling planting device 5, and the seedling planting device 5 operates.

[0056] When the seedling planting device 5 is activated, as shown in Fig. 2, the seedling tray 10 is driven to reciprocate sideways, while the rotating case 7 is driven to rotate counterclockwise in Fig. 5, and the two sets of planting arms 8 alternately pick up seedlings from the bottom of the seedling tray 10 and plant them on the rice field surface. As a result, as shown in Fig. 5, seedlings are planted intermittently in the rice field surface at preset intervals along the traveling direction of the machine body 11.

[0057] When the planting clutch 56 is operated to the disconnected state, power to the seedling planting device 5 is cut off, the seedling planting device 5 stops, and the seedling tray 10 and the rotating case 7 stop.

[0058] [Configuration of the inter-row transmission] As shown in Figures 5 and 6, the inter-row transmission 45 includes an axial plunger type variable displacement hydraulic pump 71, an axial plunger type hydraulic motor 72, and a closed circuit 73 connecting the hydraulic pump 71 and the hydraulic motor 72.

[0059] The closed circuit 73 connecting the hydraulic pump 71 and the hydraulic motor 72 includes a high-pressure oil passage 73H that supplies pressurized oil from the hydraulic pump 71 to the hydraulic motor 72, and a low-pressure oil passage 73L that returns pressurized oil from the hydraulic motor 72 to the hydraulic pump 71. A charge circuit 74 for replenishing the closed circuit 73 with pressurized oil is connected across the high-pressure oil passage 73H and the low-pressure oil passage 73L.

[0060] The hydraulic pump 71 is driven by power transmitted from the engine 23 via the input shaft 45a. The hydraulic pump 71 discharges pressure oil in an amount corresponding to the swash plate angle and supplies it to the hydraulic motor 72. The hydraulic motor 72 outputs power corresponding to the discharge amount of the hydraulic pump 71.

[0061] The inter-section transmission 45 includes a pressure reducing section 75 that reduces the pressure of the pressure oil supplied to the hydraulic motor 72 .

[0062] The pressure reducing section 75 includes a relief valve 76, an orifice 77, a first oil passage 78 connecting the relief valve 76 and the orifice 77 to the high pressure side oil passage 73H, and a second oil passage 79 connecting the relief valve 76 to the low pressure side oil passage 73L.

[0063] When the workload of the seedling planting device 5 increases and the pressure of the hydraulic oil in the high-pressure oil passage 73H exceeds the set value set by the relief valve 76, part of the hydraulic oil in the high-pressure oil passage 73H flows to the low-pressure oil passage 73L via the relief valve 76. This adjusts the pressure of the hydraulic oil in the high-pressure oil passage 73H.

[0064] Orifice 77 is provided at the end of first oil passage 78, i.e., between first oil passage 78 and relief valve 76. The inner diameter of orifice 77 is smaller than the inner diameter of first oil passage 78. With this configuration, even if the pressure of the hydraulic oil in high-pressure side oil passage 73H increases and causes relief valve 76 to open, it is possible to prevent a sudden drop in the pressure of the hydraulic oil in high-pressure side oil passage 73H.

[0065] [Fan Composition] As shown in FIG. 4, the fan 46, which sends cooling air to the inter-row transmission 45, is connected to a protruding portion of the input shaft 45a of the inter-row transmission 45. The fan 46 rotates as the input shaft 45a rotates, generating cooling air. The fan 46 is located between the right front wheel 1 and the inter-row transmission 45 in a plan view. The inter-row transmission 45 is positioned so as to be biased to the right of the center of the vehicle body 11. The fan 46 is also located laterally outboard of the vehicle body relative to the inter-row transmission 45. The lower end of the fan 46 is located above the upper end of the right front wheel 1 (FIG. 7). The fan 46 is positioned so as to be biased toward the inter-row transmission 45 rather than midway between the right front wheel 1 and the inter-row transmission 45 (FIG. 4). The front wheel 1 corresponds to the "travel device" and the "wheel." The inter-row transmission 45 corresponds to the "continuously variable transmission" and the "inter-row transmission."

[0066] The right front axle case 21 is disposed below the fan 46. The front axle case 21 has a horizontal axle case 21A oriented laterally along the left-right direction of the aircraft body and a vertical axle case 21B oriented vertically. The horizontal axle case 21A accommodates the front axle 35. That is, the right front axle case 21 accommodates the right front axle 35. The right front axle 35 and the right horizontal axle case 21A extend laterally along the aircraft body. The vertical axle case 21B is a kingpin case extending downward from the outer end of the horizontal axle case 21A laterally of the aircraft body. A vertical transmission shaft (not shown) is accommodated inside the vertical axle case 21B. The vertical transmission shaft inside the vertical axle case 21B is well known and is not shown in the figure, but the vertical transmission shaft extends vertically and is interlocked with an axle (not shown) inside a flange-type axle case 21C via a bevel gear. The vertical transmission shaft (not shown) is disposed laterally outward of the vehicle body relative to the front axle 35. That is, the vertical transmission shaft (not shown) extends vertically laterally outward of the vehicle body relative to the front axle 35.

[0067] The lateral axle case 21A is connected to the upper part of the vertical axle case 21B. At this connection, the front axle 35 and a vertical transmission shaft housed inside the vertical axle case 21B are interlocked via a bevel gear (not shown). Therefore, the vertical transmission shaft (not shown) receives power from the front axle 35 and transmits it to the wheels. The lower part of the vertical axle case 21B and the front wheel 1 are connected via a flange-type axle case 21C. The vertical axle case 21B is configured to be able to steer the front wheel 1 by rotating about the rotation axis of the vertical transmission shaft inside. In other words, the vertical axle case 21B is connected to the outer end of the vehicle body of the lateral axle case 21A, houses the vertical transmission shaft, and is configured to be able to steer the front wheel 1 by rotating about the rotation axis of the vertical transmission shaft.

[0068] The left and right front axles 35 are located between the left and right front wheels 1 in a plan view. The right front axle 35 is driven to rotate based on the power of the engine 23 and transmits the power to the right front wheel 1. As shown in FIG. 4, the fan 46 overlaps with the right front axle case 21 in a plan view and is located above the right front axle case 21. The lateral axle case 21A corresponds to the "lateral transmission case." The front axle 35 corresponds to the "lateral transmission shaft." The longitudinal axle case 21B corresponds to the "longitudinal transmission case."

[0069] On the right side of the machine body 11 (on the outer side of the machine body 11) relative to the inter-row transmission 45, there are provided a link mechanism (brake system link mechanism) spanning the brake 42 and brake pedal 43, and a link mechanism (each-row clutch system link mechanism) spanning an operating lever (not shown) for each-row clutch provided near the control handle 14 and an each-row clutch (not shown) provided on the seedling planting device 5. The brake system link mechanism is adjacent to the right side of the machine body 11 relative to the fan 46. In addition, the each-row clutch system link mechanism is adjacent to and directly above the fan 46. In a plan view of the machine body 11, the each-row clutch system link mechanism and the fan 46 partially overlap.

[0070] 4 and 7, the fan 46 has a connecting portion 46A connected to the input shaft 45a, a plurality of blade portions 46B, and a frame portion 46C. Each of the plurality of blade portions 46B extends radially outward from the connecting portion 46A, centered on the input shaft 45a. The frame portion 46C is connected to the outer peripheries of the plurality of blade portions 46B and surrounds the plurality of blade portions 46B from the outer periphery.

[0071] In the rice transplanter of this embodiment, a seedling planting device 5 is supported at the rear of the link mechanism 3. Instead of the seedling planting device 5, a furrow cutter, weeder, etc. can be attached to the rear of the link mechanism 3. Therefore, the rice transplanter of this embodiment can also be used as a furrow cutter or weeder.

[0072] When a furrow cutter or weeder is attached to the rear of the link mechanism 3 and the rice transplanter is used as a furrow cutter or weeder, it is conceivable that long seedlings or straw may get caught in the fan 46 and become entangled in the input shaft 45a. If this occurs, it may become difficult for the input shaft 45a to rotate, and the operating efficiency of the inter-row transmission 45 may decrease.

[0073] As shown in FIGS. 4 and 7 , in this embodiment, a frame 46C surrounds the multiple blade portions 46B from the outer periphery. The width of the frame 46C in the left-right direction of the machine body is wider than the width of the blade portions 46B in the left-right direction of the machine body. In other words, the width of the frame 46C in the axial direction of the input shaft 45a is wider than the width of each of the multiple blade portions 46B in the axial direction of the input shaft 45a. Therefore, the entire width of the blade portions 46B in the direction of the rotational axis of the fan 46 is covered by the frame 46C. With this configuration, compared to a configuration without the frame 46C, seedlings or straw that come into contact with the frame 46C are not entangled in the blade portions 46B and are less likely to become entangled around the input shaft 45a.

[0074] Furthermore, since the fan 46 has a frame portion 46C, even if the components around the fan 46 (for example, the above-mentioned brake system link mechanism and each row clutch system link mechanism) compete for space and make it difficult to install a cover, the fan 46 alone can be configured to make it difficult for seedlings or straw to become entangled.

[0075] 7, the upper part of the vertical axle case 21B is located above the upper end of the front wheel 1 and overlaps with the fan 46 in a side view. As a result, even if debris is kicked up by the front wheel 1, the debris is received by the vertical axle case 21B, reducing the risk of the debris becoming entangled in the fan 46.

[0076] [Another embodiment] Hereinafter, another embodiment in which the above embodiment is modified will be exemplified.

[0077] (1) In the above embodiment, the fan 46 is coupled to the protruding portion of the input shaft 45a of the inter-row transmission 45. However, this is not limiting, and the fan 46 may be coupled to the output shaft 45b of the inter-row transmission 45. That is, the fan 46 may be coupled to the shaft of either the hydraulic pump 71 or the hydraulic motor 72. In addition, the fan 46 may be configured to be coupled to the input shaft 24a or the output shaft 24b of the continuously variable transmission 24.

[0078] (2) In the above embodiment, the width of the frame portion 46C in the axial direction of the input shaft 45a is wider than the width of each of the blade portions 46B in the axial direction. This embodiment is not limited thereto, and the width of the frame portion 46C in the axial direction of the input shaft 45a may be equal to or smaller than the width of each of the blade portions 46B in the axial direction. Additionally, the fan 46 may be provided with a protective portion extending from one of the left and right edges or both left and right sides of the frame portion 46C in the width direction around the entire periphery toward the side where the connecting portion 46A is located (the radially inner side of the fan 46). The protective portion extends radially inward from the frame portion 46C around the entire periphery. The protective portion covers the outer periphery of the blade portions 46B from the outside. This configuration further reduces the risk of foreign matter entering from the left and right directions.

[0079] (3) In the above embodiment, the inter-row transmission 45 is disposed so as to be biased to the right with respect to the lateral center CL of the machine body 11. The fan 46 is disposed on the right side of the machine body relative to the inter-row transmission 45. This embodiment is not limiting, and the inter-row transmission 45 may be disposed so as to be biased to the left with respect to the lateral center CL of the machine body 11. The fan 46 may be disposed on the left side of the machine body relative to the inter-row transmission 45. That is, the fan 46 may be configured to be located between the front wheel 1 (traveling device) on one of the left and right sides and the inter-row transmission 45 in a plan view. Alternatively, the fan 46 may be configured to be located between the rear wheel 2 (traveling device) on one of the left and right sides and the inter-row transmission 45 in a plan view.

[0080] (4) In the above embodiment, the fan 46 overlaps with the front axle case 21 in a plan view. However, the fan 46 may not overlap with the front axle case 21 in a plan view.

[0081] (5) In the above embodiment, the fan 46 is connected to the input shaft 45a of the inter-plant transmission 45. However, the present invention is not limited to this embodiment, and the fan 46 may be connected to, for example, the input shaft 24a or the output shaft 24b of the continuously variable transmission 24 that changes the speed of the power from the engine 23 and transmits it to the right and left front wheels 1 and rear wheels 2.

[0082] (6) The prime mover that generates the power is not limited to the engine 23, but may be, for example, an electric motor.

[0083] The configurations disclosed in the above embodiments (including other embodiments, the same applies hereinafter) can be applied in combination with configurations disclosed in other embodiments, unless a contradiction arises. Furthermore, the embodiments disclosed in this specification are merely examples, and the present invention is not limited to these, and can be modified as appropriate within the scope of the purpose of the present invention. [Industrial Applicability]

[0084] The present invention is applicable to field work machines. [Explanation of symbols]

[0085] 1: Front wheels (running gear, wheels) 5: Seedling planting device 11: Aircraft 21A: Horizontal axle case (horizontal transmission case) 21B: Vertical axle case (vertical transmission case) 23: Engine (prime mover) 35: Front axle (transmission axle) 45: Inter-row variable speed device (continuously variable speed device, inter-row variable speed device) 45a: Input shaft (shaft) 46: Fan 46A: Connection part 46B: Blade section 46C: Frame 71: Hydraulic pump 72: Hydraulic motor

Claims

1. A prime mover that generates power, a hydrostatic continuously variable transmission having a hydraulic pump to which the power from the prime mover is transmitted and a hydraulic motor to which the power is output; a fan connected to a shaft of either the hydraulic pump or the hydraulic motor and generating cooling air; The fan has a connecting portion connected to the shaft, a plurality of blade portions extending radially outward from the connecting portion around the shaft, and a frame portion connected to the outer periphery of the plurality of blade portions and surrounding the plurality of blade portions from the outer periphery.

2. The field work machine according to claim 1 , wherein the width of the frame in the axial direction of the shaft is wider than the width of each of the plurality of blade portions in the axial direction.

3. The continuously variable transmission is disposed in a state where it is biased to one side of the left or right with respect to a center portion of the left and right of the aircraft body, The field work machine according to claim 1 , wherein the fan is disposed laterally outward of the machine body relative to the continuously variable transmission.

4. The vehicle is provided with left and right traveling devices capable of traveling on the ground based on the power from the prime mover, The field work machine according to claim 3 , wherein the fan is located between the traveling device on one of the left and right sides and the continuously variable transmission in a plan view.

5. a lateral transmission shaft that is located between the left and right traveling devices in a plan view, and that is rotationally driven based on the power of the prime mover to transmit the power to the left and right traveling devices, and that is oriented laterally to the machine body; a lateral transmission case facing the side of the aircraft and accommodating the lateral transmission shaft; The field work machine according to claim 4, wherein the fan overlaps with the lateral transmission case in a plan view and is positioned above the lateral transmission case.

6. The running device is a wheel, a vertical transmission shaft that extends vertically and is disposed laterally outward of the fuselage with respect to the lateral transmission shaft, the vertical transmission shaft receiving power from the lateral transmission shaft and transmitting it to the wheels; a longitudinal transmission case connected to the outer end of the lateral transmission case laterally of the aircraft, accommodating the longitudinal transmission shaft, and rotatable about the rotation axis of the longitudinal transmission shaft to steer the wheels; The field work machine according to claim 5, wherein an upper portion of the vertical transmission case is located above upper ends of the wheels and overlaps with the fan in a side view.

7. The running device is a wheel, The field work machine according to claim 4, wherein a lower end of the fan is positioned above an upper end of the wheel.

8. 5. The field work machine according to claim 4, wherein the fan is positioned closer to the side where the continuously variable transmission is located than a position midway between the traveling device and the continuously variable transmission on the left or right side.

9. A seedling planting device is provided to plant seedlings on the rice paddy surface.

9. The field work machine according to claim 1, wherein the continuously variable transmission is an inter-row continuously variable transmission that changes the speed of power from the prime mover and transmits it to the seedling planting device.

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