Work vehicles

Abstract

The objective is to provide a work vehicle that can secure space beneath it to step over crops. [Solution] The work vehicle includes a motor and a gear case connected to the motor, wherein the motor and the gear case are located on the upper part of the vehicle body.

Description

Technical Field

[0007] ,

[0001] The present disclosure relates to a work vehicle.

Background Art

[0002] Patent Document 1 describes an electric work vehicle including a left motor, a right motor, a coolant circulation flow path, and a pump, and provided with a coolant distribution mechanism that adjusts the flow rate ratio of the coolant flowing from the pump according to the traveling state to improve the cooling efficiency of the motor.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the electric work vehicle described in Patent Document 1, since the motor is provided at a low position of the vehicle body, the space under the vehicle body is narrow. As a result, it was difficult to straddle tall crops.

[0005] In view of the above problems, an object of the present disclosure is to provide a work vehicle capable of securing a space for straddling crops under the vehicle body.

Means for Solving the Problems

[0006] A work vehicle according to an aspect of the present disclosure is a work vehicle including a motor and a gear case connected to the motor, wherein the motor and the gear case are located above the vehicle body.

Effects of the Invention

[0007] According to the present disclosure, the work vehicle can secure a space for straddling crops under the vehicle body.

Brief Description of the Drawings

[0008] [Figure 1] Figure 1 is a perspective view showing one form of implementation using a work vehicle. [Figure 2] Figure 2 is a perspective view of the work vehicle. [Figure 3] Figure 3 is a plan view of the work vehicle shown in Figure 2. [Figure 4] Figure 4 is a left side view of the work vehicle shown in Figure 2. [Figure 5] Figure 5 is a right side view of the work vehicle shown in Figure 2. [Figure 6] Figure 6 is a diagram showing the configuration of the work vehicle. [Figure 7] Figure 7 is a schematic diagram showing a deformed work vehicle. [Figure 8] Figure 8 is a schematic diagram showing a deformed work vehicle. [Figure 9] Figure 9 is a schematic diagram showing a deformed work vehicle. [Figure 10] Figure 10 is a schematic diagram showing a deformed work vehicle. [Figure 11] Figure 11 is a magnified perspective view of the motor and its surroundings. [Figure 12] Figure 12 is a side view of the connection box with the lid removed. [Modes for carrying out the invention]

[0009] <Summary of the embodiments of this disclosure> The embodiments of this disclosure are outlined below.

[0010] (1) A work vehicle according to one aspect of the present disclosure is a work vehicle including a motor and a gear case connected to the motor, wherein the motor and the gear case are located on the upper part of the vehicle body.

[0011] This simplifies the configuration of the lower part of the work vehicle, as the motor and gear case are located on top of the vehicle. As a result, the work vehicle has enough space underneath to step over crops.

[0012] (2) In the work vehicle according to (1) above, the vehicle body includes traveling units that are respectively positioned on both sides in the width direction and support the front wheels and the rear wheels, and the motor and the gear case may be positioned above each of the traveling units.

[0013] As a result, since the motor and the gear case are positioned above both sides in the width direction of the vehicle body, the work vehicle can secure a space for straddling crops under the work vehicle.

[0014] (3) In the work vehicle according to (2) above, the traveling unit includes a radiator that cools the cooling water of the motor, and a pipe that connects between the motor and the radiator and guides the cooling water, and the height from the ground contact surfaces of the front wheels and the rear wheels to the upper end of the motor may be higher than the height from the ground contact surface to the lower end of the radiator, and the height from the ground contact surface to the lower end of the motor may be lower than the height to the upper end of the radiator.

[0015] As a result, the height from the ground surface to the motor is substantially the same as the height from the ground surface to the radiator, so the pipe can be linearly connected between the motor and the radiator.

[0016] (4) In the work vehicle according to any one of (1) to (3) above, the gear case includes a first gear case that is positioned closer to the center side of the vehicle body than the motor, and a second gear case that is positioned closer to the outer side of the vehicle body than the first gear case, and the upper end of the second gear case contacts the upper end of the motor, and a plane that is horizontal in the width direction of the vehicle body may be orthogonal to a vector indicating the vertical direction of the vehicle body.

[0017] As a result, the upper end of the motor 26 coincides with the upper end of the second reduction gear without deviation within the allowable range, so a configuration for exerting the functions of the work vehicle, such as a battery cooling duct, can linearly pass above the motor and the second gear case.

[0018] (5) In the work vehicle described in (2) or (3) above, the travel unit includes a first frame and a second frame extending in the longitudinal direction of the vehicle body, wherein the second frame is located below the first frame, and the vertical center position of the motor and the radiator may be located between the upper end of the first frame and the lower end of the second frame.

[0019] Because the motor and radiator are positioned between the first and second frames, they are aligned horizontally. This allows the piping to connect the motor and radiator in a straight line.

[0020] (6) In the work vehicle described in (2) or (3) above, the travel unit includes a first frame and a second frame extending in the longitudinal direction of the vehicle body, wherein the second frame is located below the first frame, and the gear case includes a first gear case located in a direction toward the center of the vehicle body than the motor, and a second gear case located outward from the vehicle body than the first gear case, wherein the height from the ground contact surfaces of the front and rear wheels to the upper end of the second gear case and the height from the ground contact surfaces to the upper end of the motor may be lower than the height from the ground contact surfaces to the upper end of the first frame.

[0021] As a result, the upper end of the motor and the upper end of the second gear case do not protrude above the upper end of the first frame, so that components necessary for the operation of the work vehicle, such as the battery cooling duct, can pass in a straight line over the motor and the second gear case.

[0022] <Details of the Embodiment of the Invention> The embodiments of the invention will be described in detail below with reference to the drawings. At least some of the embodiments described below may be combined in any way.

[0023] [1-1. Overall configuration of work vehicles] Figures 1 and 2 are perspective views showing one embodiment of a work vehicle. This work vehicle 10 has an exterior member 9, and Figure 2 shows the exterior member 9 removed. The exterior member 9 is attached to the frames 20 and 21 of the work vehicle 10. The exterior member 9 protects the various components of the work vehicle 10 and enhances its aesthetic appearance. Figures 3, 4, and 5 are a top view, left side view, and right side view of the work vehicle 10 shown in Figure 2. Figure 6 is a diagram showing the configuration of the work vehicle 10.

[0024] The work vehicle 10 has a running gear 12 and travels on fields and roads. In the case of the work vehicle 10 of this embodiment, the direction pointed to by arrow X1 in each figure is the basic direction of travel and is defined as "forward". In each figure, the direction pointed to by arrow X2 is the opposite direction of the basic direction of travel and is defined as "rear". In each figure, the direction pointed to by arrow Y1 is defined as "left", the direction pointed to by arrow Y2 is defined as "right", the direction pointed to by arrow Z1 is defined as "up", and the direction pointed to by arrow Z2 is defined as "down".

[0025] The work vehicle 10 is capable of moving straight in both forward and backward directions, as well as turning left (left turn) and turning right (right turn), thanks to its running gear 12. The running gear 12 is located at four locations on the front, rear, left, and right sides of the vehicle body 11, and each running gear 12 has wheels 25. The work vehicle 10 has a hydraulic motor, which allows the direction of the wheels 25 (the direction in which the wheels 25 roll) to be changed within a 360-degree range. Therefore, the work vehicle 10, which can move forward and backward, can move in a straight line in all 360 degrees. Note that an electric motor may be used instead of the hydraulic motor. Alternatively, the work vehicle 10 may be able to change the direction of the wheels 25 from the basic direction of travel within a range of 0 to 90 degrees, for example, by a hydraulic cylinder. When the direction of the wheels 25 changes by 90 degrees from the basic direction of travel, its rolling direction becomes either left or right. The work vehicle 10 can also move straight in either the left or right direction. Furthermore, the work vehicle 10 may be able to change the direction of its wheels 25 within a range of 0 to -90 degrees using the hydraulic cylinder, from its initial state in the basic direction of travel. Since the direction of the wheels 25 can be changed within a range of 0 to 90 degrees and within a range of 0 to -90 degrees from its initial state in the basic direction of travel, and since it is possible to move forward and backward, the work vehicle 10 can move in a straight line in all 360 degrees.

[0026] The work vehicle 10 connects to the work machine 19 via a coupling device 15. Figures 1, 2, 4, and 5 show the work machine 19 as a dashed line. The work machine 19 has a configuration and functions for performing various tasks. The tasks performed by the work machine 19 include, but are not limited to, agricultural work, industrial work (civil engineering, construction, etc.), and transportation work. The work vehicle 10 travels together with the work machine 19, while the work machine 19 performs its tasks.

[0027] In this embodiment, the work performed by the implement 19 is agricultural work. The implement 19 is, for example, a spraying device for applying fertilizer or chemicals to a field, a seeding device for sowing seeds, a tilling device for cultivating the soil, a tilling device for tilling the soil, a weeding device for weeding, a soil mounding device for mounding soil, etc. The implement 19 is replaced according to the required work.

[0028] The components of the work vehicle 10 will now be described. The work vehicle 10 has one vehicle body 11 and four running gears 12 for moving the vehicle body 11. The work vehicle 10 in this embodiment has a coupling device 15 attached to the vehicle body 11. The coupling device 15 is a device for connecting a work machine 19 to the vehicle body 11. The coupling device 15 has a lifting mechanism 70 for raising and lowering the work machine 19. The specific configuration of the coupling device 15 will be described later.

[0029] The coupling device 15 allows the work equipment 19 to be detached. The work vehicle 10 allows the coupling device 15 to be detached. If the work equipment 19 is not needed for the work vehicle 10, the work equipment 19 is detached from the coupling device 15. Furthermore, the coupling device 15 may be detached from the vehicle body 11. The work vehicle 10 can run with the coupling device 15 attached, even if the work equipment 19 has been detached, and the work vehicle 10 can also run with both the coupling device 15 and the work equipment 19 detached from the vehicle body 11.

[0030] The vehicle body 11 has a central frame 20 and a pair of side frames 21, 21 located on the left and right sides of the central frame 20. The left side frame 21 may be described as having the designation "21L", and the right side frame 21 may be described as having the designation "21R". The running gear 12, including the wheels 25, is mounted on the side frames 21. Each of the pair of side frames 21, 21 is displaceable relative to the central frame 20, and the work vehicle 10 can be deformed according to the work content or usage conditions such as the shape of the road surface.

[0031] Figures 7, 8, 9, and 10 are schematic diagrams showing a deformed work vehicle 10. As shown in Figures 7 and 8, the central frame 20 and the left side frame 21L and the right side frame 21R are relatively displaceable in the left-right and up-down directions. The left side frame 21L and the right side frame 21R are independently displaceable. The work vehicle 10 has displacement actuators 13 that allow the central frame 20 and the side frames 21L and 21R to be displaced relatively in the left-right and up-down directions.

[0032] The work vehicle 10 has left and right actuators 131 and up and down actuators 132 as displacement actuators 13. The left and right actuators 131 (see Figure 7) extend and retract, displacing the side frames 21L and 21R, respectively, in the left and right directions relative to the central frame 20. As a result, the work vehicle 10 changes the distance between the left and right wheels 25 according to the width of the furrows in the field, for example, and travels accordingly.

[0033] The vertical actuator 132 (see Figure 8) extends and retracts, displacing the central frame 20 vertically relative to the side frames 21L and 21R. The central frame 20 becomes higher than the side frames 21L and 21R. As a result, the work vehicle 10 changes the position of the central frame 20 vertically according to the height of the furrows in the field, for example, and travels while straddling the furrows.

[0034] The central frame 20 and the side frames 21L and 21R each only need to be displaceable in at least one of the left-right and up-down directions relative to each other. To this end, the work vehicle 10 only needs to have displacement actuators 13 in the direction that allows the side frames 21L and 21R to be displaced.

[0035] The longitudinal deformation of the vehicle body 11 occurs within the central frame 20. That is, as shown in Figure 10, the central frame 20 mounts the battery 16 (first battery 16A) and the case 205 that houses the battery 16. The case 205 can be displaced in the longitudinal direction by the longitudinal actuators 133. The battery 16 (first battery 16A) is heavy. As the battery 16 (first battery 16A) is displaced in the longitudinal direction within the central frame 20, the vehicle body 11 deforms, and its center of gravity can be changed. For example, when the work vehicle 10 travels on an inclined surface, it changes its center of gravity depending on its posture or depending on the work machine 19 it is connected to.

[0036] As another example of the deformation of the work vehicle 10 in the longitudinal direction (see Figure 9), the work vehicle 10 may have a longitudinal actuator 133 as a displacement actuator 13, and the longitudinal actuator 133 may extend and retract to relatively displace the central frame 20 and the side frames 21L and 21R, respectively, in the longitudinal direction. By displacing the central frame 20 in the longitudinal direction, the center of gravity of the vehicle body 11 can be changed.

[0037] Thus, in the configurations shown in Figures 7 and 8, the central frame 20 and the side frames 21L and 21R are each displaceable relative to each other in at least one of the left-right and up-down directions. The displacement actuator 13 displaces the central frame 20 and the side frames 21L and 21R relative to each other in at least one of the left-right and up-down directions. As shown in Figure 10, the central frame 20 has a case 205 that houses the battery 16 (first battery 16A). The case 205 is housed in the central frame 20 and is displaceable in the front-rear direction. The displacement actuator 13 displaces the case 205 in the front-rear direction within the central frame 20.

[0038] Each of the above-described forms of work vehicle 10 deforms its vehicle body 11 according to, for example, the shape of the road surface it is traveling on. The work vehicle 10 can operate with the work machine 19 while traveling with the vehicle body 11 deformed.

[0039] The work vehicle 10 (see Figures 2 to 5) has four running gears 12 located on the front, rear, left, and right sides of the vehicle body 11. The running gears 12 are attached to each of the left and right side frames 21. The left front running gear 12 may be described as "12LF", the right front running gear 12 as "12RF", the left rear running gear 12 as "12LR", and the right rear running gear 12 as "12RR".

[0040] Each running gear 12 has wheels 25, a motor 26 for driving, a reduction gear 27, and a power transmission unit 28 including gears and shafts. The rotational force of the motor 26 is reduced by the reduction gear 27, and the reduced power is transmitted to the wheels 25 through the power transmission unit 28, causing the wheels 25 to rotate. This allows the work vehicle 10 to move. The reduction gear corresponds to a "gear case".

[0041] The left front running gear 12LF and the left rear running gear 12LR are mounted on the left side frame 21L, and together they constitute the left running unit UL. Therefore, the left running unit UL corresponds to the "running unit that supports the front and rear wheels." The left running unit UL (hereinafter referred to as the left running unit UL) includes the left second battery 16L mounted on the side frame 21L, the subjunction box 24L, and inverters 31 connected to the two running motors 26, one at the front and one at the rear. The right front running gear 12RF and the right rear running gear 12RR are mounted on the right side frame 21R, and together they constitute the right running unit UR. Therefore, the right running unit UR corresponds to the "running unit that supports the front and rear wheels." The right running unit UR (hereinafter referred to as the right running unit UR) includes the right second battery 16R mounted on the side frame 21R, the sub-junction box 24R, and inverters 31 connected to the two running motors 26, one at the front and one at the rear. The central frame 20 houses the first battery 16A, the hydraulic unit 17, and the main junction box 24A, and together these constitute the central unit UC. The entire system, including the left drive unit UL, the right drive unit UR, and the central unit UC, is referred to as the vehicle body BC. In this embodiment, as described above (see Figure 9), the case 205 housing the first battery 16A is displaced in the front-rear direction within the central frame 20. In contrast, the hydraulic unit 17 and other equipment, including the main junction box 24A, are not displaced in the front-rear direction.

[0042] The work vehicle 10 has steering actuators 29 that change the rolling direction of each of the four wheels 25 of the running gear 12 (see Figure 3). In this embodiment, the running gear 12 is supported by the side frame 21 and is capable of swinging around its vertical axis. The steering actuator 29 is mounted between the side frame 21 and the running gear 12. The steering actuator 29 changes the orientation of the running gear 12 by extending and retracting. This changes the rolling direction of the wheels 25, and thus changes the direction of travel of the work vehicle 10.

[0043] The work vehicle 10 includes a control device 14, a battery 16, a hydraulic unit 17, and a cooling unit 23. The control device 14 controls the operation of each piece of equipment in the work vehicle 10, including the travel device 12 (motor 26), displacement actuator 13, steering actuator 29, hydraulic unit 17, and cooling unit 23.

[0044] Battery 16 is a rechargeable battery that can be discharged and recharged. Battery 16 supplies power to each piece of equipment in the work vehicle 10. In this embodiment (see Figure 6), the work vehicle 10 has one first battery 16A and two second batteries 16L and 16R. The first battery 16A is mounted on the central frame 20. One second battery 16L is mounted on the left side frame 21L, and the other second battery 16R is mounted on the right side frame 21R.

[0045] In this embodiment, the displacement actuator 13 and the steering actuator 29 are composed of hydraulic cylinders. The hydraulic unit 17 generates hydraulic pressure to extend and retract the hydraulic cylinders. The hydraulic unit 17 includes a tank for storing hydraulic fluid, a hydraulic pump, a motor 171 for driving the hydraulic pump, various valves, and hydraulic piping. The hydraulic unit 17 is mounted at the rear of the central frame 20.

[0046] The coupling device 15 (see Figure 4) has a hydraulic cylinder 73 as an actuator for raising and lowering the work equipment 19. The hydraulic unit 17 of the vehicle body 11 has hydraulic piping for supplying hydraulic pressure to the coupling device 15 (hydraulic cylinder 73). Furthermore, when the work equipment 19 is operated hydraulically, the hydraulic unit 17 has hydraulic piping for supplying hydraulic pressure to the work equipment 19. These hydraulic pipes are connected to a vehicle-side coupling of the vehicle body 11. The vehicle-side coupling is provided at the rear of the vehicle body 11 (central frame 20) and at the lower fixing portion 41.

[0047] When the coupling device 15 is attached to the fixing part 41 of the vehicle body 11, the coupling 88 (see Figure 13) of the coupling device 15 is connected to the vehicle-side coupling 44. The hydraulic piping (pipe 89) of the coupling device 15 is connected to the coupling 88, and hydraulic fluid from the hydraulic unit 17 is supplied to the hydraulic cylinder 73 of the coupling device 15 and the hydraulic equipment of the work machine 19 through the hydraulic piping (liquid piping 36, pipe 89).

[0048] The cooling unit 23 (see Figure 3) includes a first cooling unit 231 for cooling the battery 16 (16A, 16L, 16R), a second cooling unit 232 for cooling the motor 171 that drives the hydraulic pump of the hydraulic unit 17, and a third cooling unit 233 for cooling the motor 26 of the traction device 12. Each cooling unit has a heat exchanger or the like for cooling the cooling medium. The third cooling unit 233 corresponds to a "radiator" that cools the cooling water of the motor 26.

[0049] The first cooling unit 231 and the second cooling unit 232 are mounted on the central frame 20 and are located in front of the first battery 16A. The third cooling unit 233 is mounted on the front of each of the side frames 21L and 21R. In this embodiment, the first cooling unit 231 is air-cooled, while the second cooling unit 232 and the third cooling unit 233 are water-cooled.

[0050] The work vehicle 10 (see Figure 6) has a junction box 24 and inverters 31 connected to each motor. In this embodiment, the junction box 24 has a main junction box 24A and sub-junction boxes 24L and 24R. The main junction box 24A is mounted on the central frame 20. The sub-junction boxes 24L and 24R are mounted on the side frames 21L and 21R. Each inverter 31 receives power from the main junction box 24A or the sub-junction boxes 24L and 24R and outputs a predetermined amount of power to each motor.

[0051] The work vehicle 10 has a charging port 32, a DC-DC converter 33, and an OBC / DC-DC converter 34. The DC-DC converter 33 transforms (steps down or steps up) the power supplied from the battery 16A to supply to other electrical equipment such as the control device 14. The OBC / DC-DC converter 34 includes an onboard charger and a DC-DC converter. The OBC / DC-DC converter 34 is connected to the charging port 32. The charging port 32 is mounted on the vehicle body 11 and is connected to an external power source located at a charging station or the like. The OBC / DC-DC converter 34 converts the power supplied from the charging port 32 into power to charge the battery 16A.

[0052] [1-2. Motor Placement] <Positional relationship between the vehicle and the motor> As shown in Figures 2 to 5, the work vehicle 10 includes a motor 26 and a reduction gear 27 connected to the motor 26. The motor 26 and reduction gear 27 are located on the upper part of the vehicle body BC. Specifically, the running gear 12 has, in the Z1 direction from the ground surface on which the wheels 25 make contact, a power transmission unit 28 including wheels 25, gears and shafts, a reduction gear 27, and a motor 26 for driving. The running gear 12 is connected to the frame 21 at the lower end of the motor 26 and reduction gear 27. Since the frame 21 is located on the upper part of the vehicle body BC, the motor 26 and reduction gear 27 are located on the upper part of the vehicle body BC.

[0053] Since the motor 26 and reduction gear 27 are located on the upper part of the vehicle body BC, the work vehicle 10 includes the wheels 25 and power transmission unit 28 on its lower part, but does not include the reduction gear 27 and motor 26. As a result, the lower structure of the work vehicle 10 is simplified compared to when the wheels 25, power transmission unit 28, reduction gear 27, and motor 26 are included on the lower part, and the work vehicle 10 can have space in the central part of the work vehicle 10 when viewed from the front or rear direction for stepping over crops.

[0054] The vehicle body BC includes the running units UL and UR. The running units UL and UR are located on opposite sides of the vehicle body in the width direction, respectively. That is, running unit UL is on the left side and running unit UR is on the right side. As shown in Figures 3 to 5, the motor 26 and the reduction gear 27 are located on top of running units UL and UR, respectively. Since running unit UL is located on the left side of the vehicle body BC and running unit UR is located on the right side of the vehicle body BC, the running gear 12 is located at both the left and right ends of the vehicle body BC.

[0055] As a result, the work vehicle 10 can secure space below its central portion when viewed from the front or rear to straddle crops. Not limited to crops, if the agricultural work involves creating furrows, the work vehicle 10 can secure space below it to straddle the furrows. Furthermore, since the travel units UL and UR are displaceable in the left-right direction relative to the central unit UC, the space to straddle crops can be secured according to the width of the crops. Not limited to the width of the crops, if the agricultural work involves creating furrows, the work vehicle 10 can secure space to straddle according to the width of the furrows.

[0056] <Positional relationship between the motor and the gearbox> Figure 11 is an enlarged perspective view of area A in Figure 3, which includes the motor 26 and the area around the motor 26. The first reduction gear 27a is connected to the motor 26, reduces the rotational force output by the motor 26, and transmits the rotational force to the second reduction gear 27b. The second reduction gear 27b is connected to the first reduction gear 27a, further reduces the rotational force reduced by the first reduction gear 27a, and transmits the rotational force to the power transmission unit 28.

[0057] Based on Figure 11, the positional relationship between the motor 26 and the reduction gear 27 will be explained. The reduction gear 27 includes a first reduction gear 27a and a second reduction gear 27b. The first reduction gear 27a corresponds to the "first gear case," and the second reduction gear 27b corresponds to the "second gear case." The first reduction gear 27a is located on the Y2 side of the motor 26. The second reduction gear 27b is located on the Y1 side of the first reduction gear 27a. The motor 26 is located in the X2 direction of the second reduction gear 27b. Therefore, when viewing the reduction gear 27 and motor 26 from the side, i.e., from the Y2 direction, the first reduction gear 27a overlaps with the second reduction gear 27b and motor 26. However, a part of the first reduction gear 27a is not hidden by the second reduction gear 27b and motor 26 and is directly visible. That is, the upper end of the first reduction gear 27a protrudes more than the upper end of the second reduction gear 27b and motor 26.

[0058] Furthermore, the plane that contacts the upper end of the second reduction gear 27b and the upper end of the motor 26, and is horizontal in the width direction, i.e., left-right direction, of the vehicle body BC, is perpendicular to the vector indicating the vertical direction of the vehicle body BC. In other words, the upper end of the motor 26 coincides with the upper end of the second reduction gear 27b without any deviation within the allowable range. To put it another way, the height from the ground surface to the upper end of the motor 26 and the height from the ground surface to the upper end of the second reduction gear 27b are substantially the same height.

[0059] As a result, space is secured above the motor 26 and the second reduction gear 27b, allowing the configuration necessary for the operation of the work vehicle, such as the battery cooling duct 113, to pass in a straight line over the motor 26 and the second reduction gear 27b. The battery cooling duct 113 connects the second battery 16L and the first cooling unit 231, and is a duct that guides the refrigerant that cools the second battery 16L to the first cooling unit 231.

[0060] <Positional relationship between the motor and the frame> Next, the positional relationship between the frame 21, which is included in the running units UL and UR, and the motor 26 will be explained. The frame 21 includes a first frame 21a and a second frame 21b. The first frame 21a and the second frame 21b are frames that extend in the longitudinal direction of the vehicle body BC parallel to the ground surface. The second frame 21b is located below the first frame 21a. Furthermore, the height from the ground surface to the upper end of the second reduction gear 27b and the height from the ground surface to the upper end of the motor 26 are lower than the height from the ground surface to the upper end of the first frame 21a.

[0061] As a result, the upper end of the motor 26 and the upper end of the second reduction gear 27b do not protrude beyond the upper end of the first frame 21a. This ensures that space is secured above the motor 26 and the second reduction gear 27b, allowing components necessary for the operation of the work vehicle, such as the battery cooling duct 113, to pass in a straight line above the motor 26 and the second reduction gear 27b.

[0062] [1-3. Arrangement of motor and cooling unit] Based on Figure 11, the relationship between the arrangement of the motor 26 and the third cooling unit 233 will be explained. Hereinafter, the third cooling unit 233 will be referred to as the cooling unit 233.

[0063] <motor> Motor 26 is a motor for operating the work vehicle 10. The work vehicle 10 is an electric vehicle for performing agricultural work. Therefore, it is desirable that the motor used in motor 26 meets the following requirements. (1) The motor output must be sufficient for agricultural work. (2) Agricultural work includes tasks whose timing cannot be changed, such as those where harvesting cannot be done at the optimal time, resulting in reduced yield and quality. For this reason, the reliability of the motor must be high. One type of motor that meets these requirements is a water-cooled motor. Hereafter, motor 26 will be assumed to be a water-cooled motor.

[0064] Water-cooled motors have the following characteristics: (1) By using a water cooling system, the cooling efficiency is higher compared to air cooling. Therefore, the size and weight of the motor can be reduced. (2) Water-cooled motors are suitable for applications requiring high output because they are less likely to generate heat during operation under high load. (3) Because the water cooling system cools the motor and prevents heat buildup, water-cooled motors have higher reliability than air-cooled motors.

[0065] A water-cooled motor, in its basic configuration, includes a stator, rotor, shaft, and bearings, similar to a conventional motor. The water-cooled motor further includes a configuration for cooling the motor. This configuration includes cooling pipes that guide the cooling water that cools the water-cooled motor. The cooling pipes are arranged to be wound around the stator or to circulate within the stator. The cooling pipes can be made of any material that conducts heat well and is not corroded by the cooling water, such as copper, aluminum, or their alloys. The cooling water is, for example, water, but may contain various additives such as antifreeze to prevent freezing. The cooling water circulating around the stator removes heat from the stator. The cooling water is cooled by heat exchange with the outside air by a heat dissipation unit provided separately from the water-cooled motor.

[0066] If the motor 26 is a water-cooled motor, the travel units UL and UR further include a cooling unit 233 and cooling water piping 111. The cooling unit 233 is a heat exchanger (radiator) that cools the cooling water of the motor 26. The cooling water piping 111 corresponds to "piping" that connects the motor 26 and the radiator (cooling unit 233) and guides the cooling water.

[0067] <Connection Box> The motor 26 is further provided with a connection box 30 at its Y1 end. The connection box 30 is a connection box for connecting the motor 26 to the motor 26, compactly housing the electrical wiring 122 and the cooling water piping 111 at the Y1 end of the motor 26. The electrical wiring 122 is the wiring that supplies power to the motor 26.

[0068] Figure 12 is a side view of the connection box 30 with the lid 30b that closes the connection box removed. The connection box 30 houses electrical wiring 122 that supplies power to the power connection terminal 121 of the motor 26, and cooling water piping 111 that guides cooling water to the cooling water inlet / outlet 123 of the motor 26. Specifically, the connection box 30 includes a connection box body 30a and a lid 30b, and has a D-shape in side view, for example. The connection box body 30a has a mounting plate 125 and a side wall 126. The mounting plate 125 is a plate that is attached to the motor 26. The side wall 126 intersects with the mounting plate 125, for example, at a right angle. The side wall 126 includes a first side wall 126a and a second side wall 126b which is different from the first side wall 126a. The first side wall 126a and the second side wall 126b include flat portions. For example, the first side wall 126a is perpendicular to the X1 and X2 directions (vertical plane). The second side wall 126b, unlike the first side wall 126b, is perpendicular to the Z1 and Z2 directions (horizontal plane). As a result, the first side wall 126a and the second side wall 126b are perpendicular to each other and are different planes. Although this example was explained using the case where the first side wall 126a and the second side wall 126b are perpendicular, the first side wall 126a and the second side wall 126b may intersect at any angle, except that they are on the same plane.

[0069] The lead wires 127, cooling pipe, and signal wires 128 pass through the area where the mounting plate 125 and the motor 26 overlap, and are led into the connection box 30. The lead wire 127 is for supplying power to the motor 26. The lead wire 127 is connected to the power connection terminal 121 provided inside the connection box 30. Then the electrical wire 122 is connected to the power connection terminal 121. The electrical wire 122 is the wiring that carries power and is housed inside the connection box 30. The electrical wire 122 penetrates the first side wall 126a and is connected to the inverter 31. The electrical wire 122 may also penetrate the first side wall 126a via a through terminal.

[0070] The cooling pipe is a pipe that guides the cooling water that cools the stator of the motor 26. The end of the cooling pipe that is drawn into the connection box 30 is an inlet and outlet for the cooling water that cools the motor 26. Hereinafter, this inlet and outlet will be referred to as the cooling water inlet and outlet 123. The cooling water piping 111 is connected to the cooling water inlet and outlet 123. The cooling water piping 111 is housed inside the connection box 30 and guides the cooling water to the cooling water inlet and outlet 123. The cooling water piping 111 penetrates the second side wall 126b and is connected to the cooling unit 233. As a result, the electrical wiring 122 penetrates the first side wall 126a, and the cooling water piping 111 penetrates the second side wall 126b, which is different from the first side wall 126a. As a result, the electrical wiring 122 and the cooling water piping 111 are introduced into the connection box 30 from different side walls, allowing the connection box 30 to be configured more compactly than if they were introduced into the connection box 30 from the same side wall. The cooling water piping 111 may also pass through the second side wall 126b via a through-pipe 129 that penetrates the second side wall 126b.

[0071] Cooling water flows in from one of the cooling water inlets and outlets 123, is guided by the cooling pipe, circulates around the stator, removes heat from the stator, and flows out from the other of the cooling water inlets and outlets 123. The flowing-out cooling water is then guided by the other of the cooling water piping 111 and flows into the cooling unit 233. The cooling unit 233 is a heat exchanger that performs heat exchange between the cooling water and the outside air. The cooling water that flows into the cooling unit 233 is cooled by heat exchange with the outside air and flows out of the cooling unit 233. The cooling water that flows out of the cooling unit 233 is guided by the other of the cooling water piping 111 and flows back into one of the cooling water inlets and outlets 123. A water pump (not shown) installed in the middle of the cooling water piping 111 circulates the cooling water. As a result, the heat generated by the motor 26 is dissipated from the cooling unit 233.

[0072] <Positional relationship between the junction box and the motor> The connection box 30 is located on the opposite side of the motor 26's output. Specifically, since the reduction gear 27 is connected to the output shaft of the motor 26, the opposite side of the motor 26's output is the side opposite the motor 26 to the side where the reduction gear 27 is located. As a result, the electrical wiring and cooling water piping housed in the connection box 30 are introduced to the motor 26 from the opposite side of its output. That is, if the electrical wiring and cooling water piping enter from the left side of the work vehicle 10, the output shaft of the motor 26 will output from the right side, and if the electrical wiring and cooling water piping enter from the right side of the work vehicle 10, the output shaft of the motor 26 will output from the left side. As a result, both the connection box 30 and the motor 26 are located on the same axis passing through the motor 26's output shaft, enabling a compact arrangement. The motor 171, on which the connection box 30 is installed, also exhibits a similar effect.

[0073] <Positional relationship between the connection box, the running unit, and the central unit> The motors 26 provided in the left travel unit UL and the right travel unit UR are located closer to the center of the central unit UC than the connection box 30. As a result, the connection box 30 is located further outward from the central unit UC than the motors 26, making it easier for workers to access the connection box 30 and facilitating assembly and maintenance of wiring, etc. Furthermore, at least a portion of the connection box 30 overlaps with the motors 26 in a side view of the central unit UC. This allows the motor 26's lead wiring 127, cooling pipes, and signal wiring 128 to pass through the overlapping portion of the motors 26 and the connection box 30.

[0074] <Relationship between motor and cooling unit heights> Next, the relationship between the heights of the motor 26 and the cooling unit 233 will be explained. As shown in Figures 4 and 5, the first height from the ground surface of the front wheel 25 and the rear wheel 25 to the vertical center position of the motor 26 and the second height from the ground surface to the vertical center position of the cooling unit 233 are the same. This allows the cooling water piping 111 to connect the motor 26 and the cooling unit 233 in a straight line. The first and second heights are not limited to being the same; the height from the ground surface to the upper end of the motor 26 may be higher than the height from the ground surface to the lower end of the cooling unit 233, and the height from the ground surface to the lower end of the motor 26 may be lower than the height to the upper end of the cooling unit 233. Within this range, the height from the ground surface to the motor will be approximately the same as the height from the ground surface to the radiator, so the cooling water piping 111 can connect the motor 26 and the cooling unit 233 in a straight line. Furthermore, by straightening the cooling water piping 111, the number of components constituting the cooling water piping 111 is reduced compared to when the cooling water piping 111 has a complex configuration. Also, since the flow of the cooling water is straight, the risk of vibration caused by the cooling water is reduced.

[0075] <Positional relationship between the frame, motor, and cooling unit> Returning to Figure 11, the positional relationship between the frame 21, which includes the running units UL and UR, and the motor 26 and cooling unit 233 will be explained. As described above, the first frame 21a and the second frame 21b are frames that extend in the longitudinal direction of the vehicle body BC parallel to the ground surface. The second frame 21b is located below the first frame 21a. The vertical center position of the motor 26 and cooling unit 233 is located between the upper end of the first frame 21a and the lower end of the second frame 21b.

[0076] Specifically, the lower end of the motor 26 and the lower end of the reduction gear 27 are connected to the second frame 21b. The upper end of the motor 26 and the upper end of the reduction gear 27 are located near the first frame 21a when viewed from the Y2 direction. As a result, the vertical center of the motor 26 is located between the upper end of the first frame 21a and the lower end of the second frame 21b.

[0077] On the other hand, the upper end of the cooling unit 233 is located near the first frame 21a when viewed from the Y1 direction, and the lower end of the cooling unit 233 is located near the second frame 21b when viewed from the Y1 direction. As a result, the vertical center of the cooling unit 233 is located between the upper end of the first frame 21a and the lower end of the second frame 21b. Consequently, the motor 26 and the cooling unit 233 are positioned parallel to the ground surface.

[0078] One end of the cooling water pipe 111 is connected to the upper end of the motor 26, and the other end is connected to the upper end of the cooling unit 233. This allows the cooling water pipe 111 to connect the motor 26 and the cooling unit 233 in a straight line.

[0079] The embodiments disclosed herein are illustrative in all respects and not restrictive. The scope of the present invention is not limited to the embodiments described above, and includes all modifications within the scope equivalent to the configurations described in the claims. [Explanation of Symbols]

[0080] 9 Exterior components 10 Work vehicles 11. Vehicle body 12, 12LF, 12LR, 12RF, 12RR running gear 13 Displacement actuator 14 Control device 15. Coupling device 16. Battery 16A First Battery, 16L Second Battery 17 Hydraulic unit 19 Work equipment 20. Central frame; 21, 21L, 21R. Side frames. 21a First frame 21b Second frame 23 Cooling unit 24 Junction box 24A Main Junction Box 24L, 24R Subjunction Box 25 wheels, 26 motors, water-cooled motors 27 Reducer 27a First reducer 27b Second reducer 28 Power transmission section 29 Steering actuator 30 Connection box 30a Connection box body 30b Lid 31 Inverter 32 Charging port 33, 34 Converter 41 Fixed part 70 Lifting mechanism 73 Hydraulic cylinder 88 Coupling 111 Cooling water piping 113 Battery cooling duct 121 Power connection terminal 122 Electrical wiring 123 Coolant inlet / outlet 125 Mounting plate 126 Side wall 126a 1st side wall 126b 2nd side wall 127 Wiring pull-out 131 Left and right actuators 132 Up / Down Actuator 133 Front / Rear Actuator 171 Motor 205 Case 231 First cooling unit 232 Second cooling unit 233 Third Cooling Unit BC Body UC Central Unit, UL, UR Running Unit

Claims

1. A work vehicle including a motor and a gear case connected to the motor, The motor and the gear case are located on the upper part of the vehicle body. Work vehicle.

2. The vehicle body includes running units located on each side in the width direction, supporting the front and rear wheels, The motor and the gear case are located on the upper part of each of the travel units. The work vehicle according to claim 1.

3. The aforementioned travel unit is A radiator for cooling the motor's cooling water, Includes a piping that connects the motor and the radiator and guides the cooling water, The height from the ground contact surfaces of the front and rear wheels to the upper end of the motor is greater than the height from the ground contact surface to the lower end of the radiator, and The height from the ground surface to the lower end of the motor is lower than the height to the upper end of the radiator. The work vehicle according to claim 2.

4. The gear case comprises a first gear case located in a direction toward the center of the vehicle body than the motor, It includes a second gear case located further outward from the vehicle body than the first gear case, The plane that is in contact with the upper end of the second gear case and the upper end of the motor, and is horizontal in the width direction of the vehicle body, is perpendicular to the vector indicating the vertical direction of the vehicle body. A work vehicle according to any one of claims 1 to 3.

5. The aforementioned running unit includes a first frame and a second frame extending in the longitudinal direction of the vehicle body. The second frame is located below the first frame, The central position of the motor and the radiator in the vertical direction is located between the upper end of the first frame and the lower end of the second frame. A work vehicle according to claim 2 or claim 3.

6. The aforementioned running unit includes a first frame and a second frame extending in the longitudinal direction of the vehicle body. The second frame is located below the first frame, The gear case comprises a first gear case located in a direction toward the center of the vehicle body than the motor, It includes a second gear case located further outward from the vehicle body than the first gear case, The height from the contact surface of the front wheel and the rear wheel to the upper end of the second gear case, and the height from the contact surface to the upper end of the motor, are lower than the height from the contact surface to the upper end of the first frame. A work vehicle according to claim 2 or claim 3.

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