Patent Publication Number: US-2022234434-A1

Title: Electric work vehicle

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an electric work vehicle including a battery, a motor drivable on electric power supplied by the battery, and a travel device drivable by the motor. 
     2. Description of the Related Art 
     JP2018-69926A discloses a work vehicle (“tractor” in JP2018-69926A) including an engine and a travel device drivable by the engine (“front wheels” and “rear wheels” in JP2018-69926A). 
     SUMMARY OF THE INVENTION 
     The work vehicle disclosed in JP2018-69926A may be modified by replacing the engine with a battery and a motor. This will allow the work vehicle to travel without discharging exhaust gas. 
     Batteries, however, tend to generate a relatively large amount of heat. Hot air remaining around a battery can cause the battery to be degraded greatly due to the heat. 
     Preferred embodiments of the present invention provide electric work vehicles each including a battery that can be cooled effectively. 
     A preferred embodiment of the present invention includes a body frame, a battery above the body frame, a motor drivable on electric power supplied by the battery, a travel device drivable by the motor, and a cooling fan positioned forward of the battery to send cooling air to the battery, wherein the body frame and the battery define a ventilation space therebetween, and the cooling fan extends in an up-down direction of a machine body to face both the battery and the ventilation space. 
     A preferred embodiment of the present invention allows cooling air from the cooling fan to flow from an area that extends over the battery and the ventilation space in the up-down direction of the machine body. As a result, a portion of the cooling air from the cooling fan flows toward the battery, whereas another portion thereof flows toward the ventilation space. 
     The cooling air flowing toward the battery cools the battery. The cooling air flowing toward the ventilation space flows under the battery, preventing hot air from remaining between the body frame and the battery. 
     A preferred embodiment of the present invention thereby provides an electric work vehicle including a battery that can be cooled effectively. 
     A preferred embodiment of the present invention may preferably further include a battery support positioned above the body frame and supporting the battery, a first support frame, and a second support frame, wherein the battery support is supported by the first support frame and the second support frame both standing on the body frame, the body frame, the battery support, the first support frame, and the second support frame define a ventilation opening, and the ventilation space communicates with the ventilation opening. 
     With the above configuration, the battery support is spaced apart from and above the body frame, meaning that the battery is also spaced apart from and above the body frame. This reliably allows the body frame and the battery to define a ventilation space therebetween. 
     The above configuration, in addition, allows cooling air flowing through the ventilation space to be let out thereof through the ventilation opening. This allows production of an electric work vehicle including a ventilation space through which cooling air flows suitably. 
     A preferred embodiment of the present invention may preferably further include a cover to accommodate the cooling fan and the battery and including an outlet positioned lateral to the battery and capable of letting air out of the cover, and a plate positioned below the ventilation space, oriented horizontally, and supported by the body frame. 
     With the above configuration, at least a portion of cooling air that the cooling fan supplies toward a front portion of the battery flows to spaces lateral to the battery to be let out through the outlet. This cools the front portion and lateral side portions of the battery effectively. 
     The above configuration, in addition, includes a plate below the ventilation space, preventing cooling air from easily flowing downward from the ventilation space. This prevents cooling air through the ventilation space from failing to reach a back portion of the ventilation space and flowing downward instead. 
     The above configuration allows cooling air to easily reach a back portion of the ventilation space, so as to cool a lower portion of the battery effectively. 
     A preferred embodiment of the present invention may preferably further include an inverter positioned under the battery to convert direct-current electric power from the battery into alternating-current electric power and supply the alternating-current electric power to the motor, wherein the inverter and the battery define a first space therebetween, and the first space is part of the ventilation space. 
     The above configuration allows cooling air supplied by the cooling fan into the ventilation space to cool the inverter. 
     If the inverter and the battery had no space therebetween, cooling air supplied by the cooling fan into the ventilation space would not flow between the inverter and the battery, making it difficult to cool a lower portion of the battery. 
     With the above configuration, in contrast, the inverter and the battery define a first space therebetween as part of the ventilation space. This allows cooling air to pass through a space between the inverter and the battery, thus preventing a situation in which a lower portion of the battery cannot be cooled easily. 
     A preferred embodiment of the present invention may preferably be further structured such that the motor is under the battery, the motor and the battery define a second space therebetween, and the second space is part of the ventilation space. 
     The above configuration allows cooling air supplied by the cooling fan into the ventilation space to cool the motor. 
     If the motor and the battery had no space therebetween, cooling air supplied by the cooling fan into the ventilation space would not flow between the motor and the battery, making it difficult to cool a lower portion of the battery. 
     With the above configuration, in contrast, the motor and the battery define a second space therebetween as part of the ventilation space. This allows cooling air to pass through a space between the motor and the battery, likely preventing a situation in which a lower portion of the battery cannot be cooled easily. 
     A preferred embodiment of the present invention may preferably be further structured such that the motor is in contact with the ventilation space, the electric work vehicle further includes a wind guide plate positioned under the battery and forward of the second space and facing toward the cooling fan. 
     With the above configuration, that portion of the cooling air through the ventilation space which flows toward the second space is, after reaching the wind guide plate, guided downward by the wind guide plate. This allows more cooling air to flow toward the motor, thus cooling the motor suitably. 
     The above and other elements, features, steps, characteristics and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments with reference to the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a right side view of a tractor. 
         FIG. 2  is a right side view of a travel battery and elements therearound. 
         FIG. 3  is a cross-sectional view of the tractor taken along line III-III in  FIG. 2 . 
         FIG. 4  is a cross-sectional view of the tractor taken along line IV-IV in  FIG. 2 . 
         FIG. 5  is a perspective view of a radiator and elements therearound. 
         FIG. 6  is a plan view of a motor and other elements. 
         FIG. 7  provides views of a coupling section and other elements. 
         FIG. 8  is a view of an opening and elements therearound. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The description below describes preferred embodiments of the present invention with reference to drawings. The description below uses terms such as “front” and “forward” to refer to the direction indicated with arrow F in  FIGS. 1 to 3, 6, and 7 , terms such as “back” and “backward” to refer to the direction indicated with arrow B in the same drawings, terms such as “left” and “leftward” to refer to the direction indicated with arrow L in  FIGS. 3, 4, and 6 , terms such as “right” and “rightward” to refer to the direction indicated with arrow R in the same drawings, terms such as “above” and “upward” to refer to the direction indicated with arrow U in  FIGS. 1, 2, and 4 , and terms such as “below” and “downward” to refer to the direction indicated with arrow D in the same drawings. 
       FIG. 1  illustrates a tractor A (as an example of the “electric work vehicle” of the present invention) including left and right front wheels  10  (as an example of the “travel device” for the present invention), left and right rear wheels  11  (as an example of the “travel device” for the present invention), a cover member  12 , and a tiller device  13 . 
     The tractor A further includes a body frame  2  and a driver section  3 . 
     The body frame  2  is supported by the left and right front wheels  10  and the left and right rear wheels  11 . The tiller device  13  is supported by a back portion of the body frame  2 . 
     The cover member  12  is at a front portion of the machine body. The driver section  3  is behind the cover member  12 . 
     The driver section  3  includes a protection frame  30 , a driver&#39;s seat  31 , a steering wheel  32 , and a floor  33 . An operator can sit on the driver&#39;s seat  31  and perform various drive operations in the driver section  3 . 
     Operating the steering wheel  32  changes the direction of the left and right front wheels  10 . The operator can place their feet on the floor  33  when sitting on the driver&#39;s seat  31 . 
     The tractor A, in other words, includes a driver section  3  including a driver&#39;s seat  31  on which an operator is able to sit. 
     The tractor A further includes a travel battery  4  (as an example of the “battery” for the present invention), a motor M, a transmission device T, and a front transmission mechanism FT. 
     The cover member  12  is swingable about an open/close axis Q (see  FIG. 2 ) extending in the left-right direction of the machine body. This allows the cover member  12  to be opened and closed. The cover member  12 , when in the closed state, accommodates the travel battery  4 . The travel battery  4  supplies electric power to the motor M. 
     The motor M is under the travel battery  4 . The motor M is driven on electric power supplied by the travel battery  4 , and transmits its driving force to the transmission device T. 
     The transmission device T is backward of the travel battery  4  and behind the motor M. The front transmission mechanism FT extends forward from the transmission device T. The transmission device T varies the driving force received from the motor M, and transmits the resulting driving force to the left and right rear wheels  11  as well as to the left and right front wheels  10  via the front transmission mechanism FT. This drives the left and right front wheels  10  and the left and right rear wheels  11 . 
     The tractor A, in other words, includes a motor M positioned under the travel battery  4  and drivable on electric power supplied by the travel battery  4 . The tractor A also includes left and right front wheels  10  and left and right rear wheels  11  drivable by the motor M. 
     The transmission device T transmits a portion of the driving force received from the motor M to the tiller device  13 . This drives the tiller device  13 . 
     The above configuration allows the tractor A to travel with use of the left and right front wheels  10  and the left and right rear wheels  11  and simultaneously perform tillage work with use of the tiller device  13 . 
     As illustrated in  FIGS. 2 to 4 , the travel battery  4  is above the body frame  2 . The body frame  2  and the travel battery  4  define a ventilation space S therebetween. 
     The tractor A, in other words, includes a travel battery  4  above the body frame  2 . 
     The ventilation space S is capable of letting air through. 
     The tractor A further includes an inverter  14  under the travel battery  4  and forward of the motor M. 
     The inverter  14  converts direct-current electric power from the travel battery  4  into alternating-current electric power, and supplies the alternating-current electric power to the motor M. 
     The tractor A, in other words, includes an inverter  14  positioned under the travel battery  4  and forward of the motor M and configured to convert direct-current electric power from the travel battery  4  into alternating-current electric power and supply the alternating-current electric power to the motor M. 
     The motor M and the inverter  14  are arranged in the front-back direction of the machine body. 
     The inverter  14  and the travel battery  4  define a first space S 1  therebetween. The first space S 1  is part of the ventilation space S, and is thus capable of letting air through. 
     The motor M and the travel battery  4  define a second space S 2  therebetween. The second space S 2  is part of the ventilation space S, and is thus capable of letting air through. 
     The motor M is positioned in contact with the ventilation space S. 
     The motor M is, in other words, in contact with the ventilation space S. 
     The body frame  2  includes left and right main frames  20  and an inverter support  21 . The left and right main frames  20  extend in the front-back direction of the machine body. 
     The tractor A, in other words, includes a left main frame  20  and a right main frame  20  both extending in the front-back direction of the machine body. 
     The motor M is between the left and right main frames  20 . 
     The inverter support  21  extends over the left and right main frames  20 , and is supported thereby. The inverter support  21  supports the inverter  14 . 
     The inverter  14  is, in other words, supported by the left main frame  20  and the right main frame  20  with the inverter support  21  therebetween. 
       FIG. 3  shows a first left-end position LE 1 , a second left-end position LE 2 , and a third left-end position LE 3 . The first left-end position LE 1  coincides with the left end of the left main frame  20 . The second left-end position LE 2  coincides with the left end of the inverter  14 . The third left-end position LE 3  coincides with the left end of the inverter support  21 . 
     As illustrated in  FIG. 3 , the second left-end position LE 2  is leftward of the first left-end position LE 1 . In other words, the inverter  14  extends farther leftward than the left end of the left main frame  20 . 
     The third left-end position LE 3  is leftward of the first left-end position LE 1  and the second left-end position LE 2 . In other words, the inverter support  21  extends farther leftward than the left end of the left main frame  20 . 
       FIG. 3  also shows a first right-end position RE 1 , a second right-end position RE 2 , and a third right-end position RE 3 . The first right-end position RE 1  coincides with the right end of the right main frame  20 . The second right-end position RE 2  coincides with the right end of the inverter  14 . The third right-end position RE 3  coincides with the right end of the inverter support  21 . 
     As illustrated in  FIG. 3 , the second right-end position RE 2  is rightward of the first right-end position RE 1 . In other words, the inverter  14  extends farther rightward than the right end of the right main frame  20 . 
     The third right-end position RE 3  is rightward of the first right-end position RE 1  and the second right-end position RE 2 . In other words, the inverter support  21  extends farther rightward than the right end of the right main frame  20 . 
     The inverter  14 , in other words, extends farther leftward than the left end of the left main frame  20  and farther rightward than the right end of the right main frame  20 . 
     The inverter support  21  also extends farther leftward than the left end of the left main frame  20  and farther rightward than the right end of the right main frame  20 . 
     As illustrated in  FIGS. 2 to 4 , the tractor A includes left and right first support frames  51 , left and right second support frames  52 , and a battery support  53 . 
     The left and right first support frames  51  are forward of the left and right second support frames  52 . The left and right first support frames  51  and the left and right second support frames  52  all stand on the inverter support  21 . 
     The left and right first support frames  51  and the left and right second support frames  52 , in other words, all stand on the body frame  2 . 
     The tractor A further includes a plate-shaped support  38  and a plate-shaped partition member  56  (described later) between the motor M and the travel battery  4 . The plate-shaped support  38  and the plate-shaped partition member  56  are each oriented horizontally. The plate-shaped partition member  56  extends over the plate-shaped support  38 . 
     The tractor A further includes a back portion support frame  59  supported by the body frame  2 . The back portion support frame  59  supports a back end portion of the battery support  53  with the plate-shaped support  38  and the plate-shaped partition member  56  therebetween. 
     The battery support  53  is above the body frame  2 , and is supported by the left and right first support frames  51 , the left and right second support frames  52 , and the back portion support frame  59 . The battery support  53  supports the travel battery  4 . 
     The tractor A, in other words, includes a battery support  53  positioned above the body frame  2  and supporting the travel battery  4 . 
     With the above configuration, the travel battery  4  is supported by the inverter support  21  with the battery support  53 , the left and right first support frames  51 , and the left and right second support frames  52  therebetween. 
     The travel battery  4  is, in other words, supported by the inverter support  21  with the left and right first support frames  51  therebetween, which stand on the inverter support  21 . In addition, the travel battery  4  is supported by the inverter support  21  with the left and right second support frames  52  therebetween, which stand on the inverter support  21 . 
     The tractor A has a left ventilation opening K defined by the body frame  2 , the battery support  53 , the left first support frame  51 , and the left second support frame  52 . 
     The tractor A also has a right ventilation opening K defined by the body frame  2 , the battery support  53 , the right first support frame  51 , and the right second support frame  52 . 
     The left and right ventilation openings K each communicate with the ventilation space S. 
     In other words, the ventilation space S communicates with the left and right ventilation openings K. 
     As illustrated in  FIG. 2 , the battery support  53  includes a bottom plate  53   a . The bottom plate  53   a  is oriented horizontally, and defines and functions as a partition between the travel battery  4  and the inverter  14 . 
     The tractor A, in other words, includes a bottom plate  53   a  as a partition between the travel battery  4  and the inverter  14 . 
     As illustrated in  FIGS. 2 and 4 , the tractor A includes a first plate-shaped member  54  (as an example of the “plate”) and a second plate-shaped member  55  (as an example of the “plate”). 
     The first plate-shaped member  54  and the second plate-shaped member  55  each extend from one of the left and right main frames  20  to the other. The first plate-shaped member  54  is forward of the second plate-shaped member  55 . The first plate-shaped member  54  and the second plate-shaped member  55  are each held in position by the left and right main frames  20 . 
     In other words, the body frame  2  holds the first plate-shaped member  54  and the second plate-shaped member  55  in position. 
     The first plate-shaped member  54  and the second plate-shaped member  55  are below the ventilation space S, and are oriented horizontally. 
     As illustrated in  FIGS. 1 and 3 , the cover member  12  includes an inlet section  12   a . The inlet section  12   a  is capable of letting outside air into the cover member  12 . The inlet section  12   a  is at a front end portion of the cover member  12 . 
     The inlet section  12   a  for the present preferred embodiment is in the form of a plurality of small holes. The present invention is, however, not limited to such an arrangement. The inlet section  12   a  may alternatively be in any other form. The inlet section  12   a  may, for instance, be in the form of a single hole, or include a blower to let outside air in. 
     The cover member  12  includes left and right outlet sections  12   b . The left and right outlet sections  12   b  are each capable of letting air out of the cover member  12 . 
     The cover member  12 , in other words, includes left and right outlet sections  12   b  each capable of letting air out of the cover member  12 . 
     The left outlet section  12   b  is at a left side portion of the cover member  12 , whereas the right outlet section  12   b  is at a right side portion of the cover member  12 . 
     The left outlet section  12   b  is leftward of the travel battery  4 . The right outlet section  12   b  is rightward of the travel battery  4 . The left and right outlet sections  12   b  are, in other words, each lateral to the travel battery  4 . 
     The left and right outlet sections  12   b  for the present preferred embodiment are each in the form of a plurality of small holes. The present invention is, however, not limited to such an arrangement. The left and right outlet sections  12   b  may each alternatively be in any other form. The left and right outlet sections  12   b  may each, for instance, be in the form of a single hole, or include a blower to let air out. 
     As illustrated in  FIGS. 2 to 4 , the tractor A includes a radiator  15  and a water pump  16 . The radiator  15  is forward of the travel battery  4 . 
     The tractor A, in other words, includes a radiator  15  forward of the travel battery  4 . 
     The radiator  15  and the water pump  16  are included in a cooling water path of the tractor A. The water pump  16  forces cooling water to circulate through the cooling water path. The cooling water is cooled by the radiator  15  as it passes therethrough. 
     The tractor A, in other words, includes a water pump  16  to force cooling water to pass through a radiator  15 . 
     The water pump  16  is forward of the motor M and below the inverter  14 . The water pump  16  is supported by the first plate-shaped member  54 . 
     The tractor A further includes a cooling fan  17 . The cooling fan  17  is in front of the travel battery  4 . The cooling fan  17  is, in other words, forward of the travel battery  4 . 
     When the cover member  12  is in the closed state, the radiator  15  and the cooling fan  17  are accommodated in the cover member  12 . 
     The tractor A, in other words, includes a cover member  12  capable of accommodating the cooling fan  17  and the travel battery  4 . 
     The cooling fan  17  extends in the up-down direction of the machine body to face both the travel battery  4  and the ventilation space S. The cooling fan  17  also extends in the up-down direction of the machine body to face both the travel battery  4  and the inverter  14 . 
     The cooling fan  17  blows cooling air backward. This causes outside air to enter the cover member  12  through the inlet section  12   a  and pass through the radiator  15 , thus cooling the radiator  15 . 
     The cooling fan  17  is, in other words, forward of the travel battery  4 , and cools the radiator  15 . 
     The cooling fan  17  sends cooling air to a front portion of the travel battery  4  and to the ventilation space S. 
     The tractor A, in other words, includes a cooling fan  17  positioned forward of the travel battery  4  and configured to send cooling air to the travel battery  4 . 
     The cooling fan  17  sends cooling air to a front portion of the travel battery  4 , at least a portion of which cooling air flows to a space leftward of the travel battery  4  and to a space rightward of the travel battery  4  to be let out through the left and right outlet sections  12   b . This cools the front portion and lateral side portions of the travel battery  4 . 
     The cooling fan  17  sends cooling air to the ventilation space S, a portion of which cooling air reaches the first space S 1  and then passes through the left and right ventilation openings K and the left and right outlet sections  12   b  to be let out of the cover member  12 . 
     This cools a lower portion of the travel battery  4  and the inverter  14 . 
     Another portion of the cooling air, which the cooling fan  17  sends to the ventilation space S, reaches the first space S 1  and then continues to flow through the ventilation space S to pass through the second space S 2 . 
     This cools a lower portion of the travel battery  4 , the inverter  14 , and the motor M. 
     As illustrated in  FIG. 2 , the tractor A includes a horizontally oriented plate-shaped partition member  56  between the battery support  53  and the motor M. 
     The plate-shaped partition member  56  includes a wind guide plate  56   a . The wind guide plate  56   a  is a front end portion of the plate-shaped partition member  56  which is bent downward. The wind guide plate  56   a  is thus oriented vertically, and faces toward the cooling fan  17 . 
     The tractor A, in other words, includes a wind guide plate  56   a  facing toward the cooling fan  17 . 
     The wind guide plate  56   a  is under the travel battery  4  and forward of the second space S 2 . 
     This allows that portion of the cooling air through the ventilation space S which flows toward the second space S 2  to be guided by the wind guide plate  56   a  to downward thereof. This in turn allows more cooling air to flow toward the motor M, thus cooling the motor M with cooling air suitably. 
     As illustrated in  FIGS. 3 to 5 , the tractor A includes a reserve tank  5  for the radiator  15 . The reserve tank  5  stores cooling water. The reserve tank  5  is forward of the travel battery  4  and rightward of the radiator  15 . 
     As illustrated in  FIGS. 2 to 5 , the tractor A includes an auxiliary battery  18  and a voltage converter  19 . The auxiliary battery  18  supplies electric power to various auxiliaries such as the cooling fan  17 . 
     The travel battery  4  transmits electric power to the voltage converter  19 , which then steps down the voltage of the electric power and supplies the resulting electric power to the auxiliary battery  18 . 
     The tractor A, in other words, includes a voltage converter  19  positioned forward of the travel battery  4  and configured to step down the voltage of electric power from the travel battery  4  and supply the resulting electric power to the auxiliary battery  18 . 
     The auxiliary battery  18  and the voltage converter  19  are forward of the travel battery  4  and rightward of the radiator  15 . The voltage converter  19  is oriented to have a longitudinal direction extending in the up-down direction of the machine body. 
     As illustrated in  FIG. 3 , the voltage converter  19  and the radiator  15  are laterally next to each other in a plan view. The radiator  15 , the voltage converter  19 , and the auxiliary battery  18  are laterally next to one another in a plan view. 
     The voltage converter  19  is between the radiator  15  and the auxiliary battery  18  in a plan view. 
     The radiator  15 , the voltage converter  19 , and the reserve tank  5  are laterally next to one another in a plan view. 
     The voltage converter  19  is between the radiator  15  and the reserve tank  5  in a plan view. 
     As illustrated in  FIGS. 3 and 4 , the reserve tank  5  is over the auxiliary battery  18 . The reserve tank  5  and the auxiliary battery  18  are arranged in the up-down direction of the machine body. 
     As illustrated in  FIGS. 2 and 3 , the tractor A includes an cooler CL. The cooler CL cools an operating fluid of the tractor A as it passes through the cooler CL. 
     As illustrated in  FIGS. 2, 3, and 5 , the radiator  15  is held in place by a radiator frame  57  in the shape of an angular arch. The radiator frame  57  surrounds the radiator  15 . 
     The tractor A, in other words, includes a radiator frame  57  having a shape of an angular arch surrounding the radiator  15  and holding the radiator  15  in place. 
     The radiator frame  57  includes a left side plate  57   a , a top plate  57   b , a right side plate  57   c , a first top plate support  57   d , and a second top plate support  57   e.    
     The left side plate  57   a  is a left portion of the radiator frame  57 . The top plate  57   b  is a top portion of the radiator frame  57 . The right side plate  57   c  is a right portion of the radiator frame  57 . 
     The left side plate  57   a  and the right side plate  57   c  are each oriented vertically, and are arranged in the left-right direction. The left side plate  57   a  and the right side plate  57   c  face each other. 
     The first top plate support  57   d  extends leftward from an upper end portion of the left side plate  57   a . The second top plate support  57   e  extends rightward from an upper end portion of the right side plate  57   c . The top plate  57   b  is placed on and supported by the upper surface of the first top plate support  57   d  and the upper surface of the second top plate support  57   e.    
     The voltage converter  19  is attached to the radiator frame  57 . Specifically, the voltage converter  19  is attached to the right surface of the right side plate  57   c.    
     The tractor A includes a first hose  6   a , a second hose  6   b , a water supply section  6   c , and a third hose  6   d , which are included in the cooling water path of the tractor A. 
     The first hose  6   a  includes a first end connected to the radiator  15  and a second end connected to the water supply section  6   c.    
     The tractor A, in other words, includes a first hose  6   a  connected to the radiator  15 . 
     The second hose  6   b  includes a first end connected to the water supply section  6   c  and a second end connected to the voltage converter  19 . 
     The third hose  6   d  is connected to the voltage converter  19 . 
     An operator can supply cooling water into the water supply section  6   c . The cooling water flows sequentially through the third hose  6   d , the voltage converter  19 , the second hose  6   b , the water supply section  6   c , the first hose  6   a , and the radiator  15 . 
     As illustrated in  FIGS. 2, 3, and 5 , the tractor A includes a support  7  and a cover support  58 . The support  7  is supported by the radiator frame  57 , and extends upward from an upper portion of the radiator frame  57 . 
     The tractor A, in other words, includes a support  7  extending upward from an upper portion of the radiator frame  57 . 
     The cover support  58  is in the shape of a bar. The cover support  58  includes a first end portion coupled to an upper end portion of the support  7  in such a manner as to be swingable in the up-down direction about a swing axis P extending in the front-back direction of the machine body. 
     When the cover member  12  is in the open state, swinging the cover support  58  upward to a standing position allows its second end portion to come into contact with an inner wall surface of the cover member  12 . With the second end portion of the cover support  58  in contact with the inner wall surface of the cover member  12 , the cover member  12  is supported by the cover support  58 . 
     The above configuration allows the cover support  58  to support the cover member  12  in the open state. 
     The tractor A, in other words, includes a cover support  58  coupled to an upper end portion of the support  7  and capable of supporting the cover member  12  in the open state. 
     The cover member  12 , in the closed state, accommodates the voltage converter  19 , the first hose  6   a , the radiator frame  57 , the reserve tank  5 , and the auxiliary battery  18 . 
     The tractor A, in other words, includes a cover member  12  capable of being opened and closed and of accommodating the voltage converter  19 , the radiator  15 , the first hose  6   a , and the radiator frame  57 . 
     The support  7  includes a first portion  71 , a second portion  72 , and a third portion  73 . 
     The first portion  71  extends upward from an upper portion of the radiator frame  57 . The first portion  71  includes a lower end portion connected to the upper portion of the radiator frame  57 . 
     The second portion  72  extends forward from a middle portion of the first portion  71  in the up-down direction of the machine body. The second portion  72  is oriented horizontally. 
     The third portion  73  extends substantially downward from a front end portion of the second portion  72 , and is connected to an upper portion of the radiator frame  57 . The third portion  73  is oriented obliquely in a lower front direction. The third portion  73  includes a back end portion connected to the front end portion of the second portion  72 , and includes a front end portion connected to the upper portion of the radiator frame  57 . 
     The support  7 , in other words, includes (i) a first portion  71  extending upward from an upper portion of the radiator frame  57 , (ii) a second portion  72  extending forward from a middle portion of the first portion  71  in the up-down direction of the machine body, and (iii) a third portion  73  extending substantially downward from a front end portion of the second portion  72  and connected to an upper portion of the radiator frame  57 . 
     The first hose  6   a  extends through an area AR defined by the first portion  71 , the second portion  72 , and the third portion  73 . 
     The description below describes the first portion  71  in detail. The first portion  71  includes a support stay  71   a  and a vertical fixed portion  71   b . The support stay  71   a  is in the shape of a long plate, and extends in the up-down direction of the machine body along the left side plate  57   a . The support stay  71   a  has a lower end portion bolted to a back end portion of an upper end portion of the left side plate  57   a.    
     The vertical fixed portion  71   b  is in the shape of a long plate, and extends in the up-down direction of the machine body. The vertical fixed portion  71   b  has a dimension smaller than the support stay  71   a  in the up-down direction of the machine body. 
     The vertical fixed portion  71   b  is perpendicular to the support stay  71   a , and is fixed to its left surface. The vertical fixed portion  71   b , the second portion  72 , and the third portion  73  are integral with one another. 
     The above-mentioned area AR is defined by the support stay  71   a , the second portion  72 , and the third portion  73 . 
     As illustrated in  FIGS. 2 to 5 , the tractor A includes a horizontally oriented support plate SP at a front portion thereof. The support plate SP supports the radiator  15 , the cooling fan  17 , the auxiliary battery  18 , the voltage converter  19 , the radiator frame  57 , and the cooler CL. 
     As illustrated in  FIGS. 1 and 2 , the tractor A includes a hydraulic pump  60 . The hydraulic pump  60  supplies operating fluid to an operating mechanism to operate the tiller device  13 . The hydraulic pump  60  controls the supply of operating fluid to operate the tiller device  13 . 
     Specifically, the tractor A includes a lifting/lowering mechanism  36  as an operating mechanism for a work device. The hydraulic pump  60  supplies operating fluid to the lifting/lowering mechanism  36  to operate the lifting/lowering mechanism  36 , which then lifts and lowers the tiller device  13 . The tiller device  13  includes a tiller section  13   a  with a drive section connected to a PTO shaft  37  of the tractor A. The tiller device  13  performs tillage work with use of power from the PTO shaft  37 . 
     As illustrated in  FIGS. 2, 4, and 6 , the hydraulic pump  60  is next to the motor M. 
     As illustrated in  FIG. 2 , the motor M is held in place by a front portion support frame  50  and a back portion support frame  59 . 
     The front portion support frame  50  extends from one of the left and right main frames  20  to the other, and is fixed to respective lower portions of the left and right main frames  20 . The front portion support frame  50  is under a front portion of the motor M and supports it. 
     The back portion support frame  59  extends beyond the left and right main frames  20 . The back portion support frame  59  is in contact with a back end portion of the motor M and holds a back portion of the motor M in place. 
     As illustrated in  FIGS. 2 and 6 , the hydraulic pump  60  is in front of and attached to the back portion support frame  59 . The hydraulic pump  60  is held in place by the back portion support frame  59 . 
     In other words, the motor M and the hydraulic pump  60  are both held in place by the same back portion support frame  59 . 
     As illustrated in  FIG. 6 , the motor M includes a motor output shaft  61  as its output shaft. The motor output shaft  61  is provided with a first rotor  64  configured to rotate integrally with the motor output shaft  61 . 
     The tractor A, in other words, includes a first rotor  64  attached to the motor output shaft  61  and configured to rotate integrally with the motor output shaft  61 . 
     The hydraulic pump  60  includes a pump input shaft  62  as its input shaft. The pump input shaft  62  is provided with a second rotor  65  configured to rotate integrally with the pump input shaft  62 . 
     The tractor A, in other words, includes a second rotor  65  attached to the pump input shaft  62  as an input shaft of the hydraulic pump  60  and configured to rotate integrally with the pump input shaft  62 . 
     The tractor A also includes an endless rotary body  66  wound around the first rotor  64  and the second rotor  65 . 
     The tractor A, in other words, includes an endless rotary body  66  windable around the first rotor  64  and the second rotor  65 . 
     The endless rotary body  66  for the present preferred embodiment is a belt. The present invention is, however, not limited to such an arrangement. The endless rotary body  66  is not necessarily a belt, and may be a chain, for example. 
     The above configuration allows the motor M to transmit its driving force to the hydraulic pump  60  via the motor output shaft  61 , the first rotor  64 , the endless rotary body  66 , the second rotor  65 , and the pump input shaft  62 . This drives the hydraulic pump  60 . 
     The tractor A, in other words, includes a hydraulic pump  60  drivable by the motor M to supply operating fluid to the tiller device  13 . 
     The transmission device T includes a transmission input shaft  63  as its input shaft. The transmission input shaft  63  is coupled to the motor output shaft  61  with a coupling section  8 . This allows the transmission input shaft  63  to rotate integrally with the motor output shaft  61 . 
     Specifically, as illustrated in  FIG. 7 , the motor output shaft  61  and the transmission input shaft  63  each have a cylinder shape extending in the front-back direction of the machine body. The coupling section  8  includes a coupling shaft  81  and a pin  82 . 
     The coupling shaft  81  extends in the front-back direction of the machine body. The coupling shaft  81  includes a front end portion inserted in the motor output shaft  61  and in spline engagement therewith. The coupling shaft  81  includes a back end portion inserted in the transmission input shaft  63  and in spline engagement therewith. 
     The transmission input shaft  63  includes a pin hole  63   a , in which the pin  82  is insertable. The pin  82  is, when inserted, behind the coupling shaft  81  to prevent it from sliding backward. 
     In the state illustrated on the left side of  FIG. 7 , the transmission input shaft  63  and the motor output shaft  61  are incapable of rotation relative to each other. 
     The tractor A, in other words, includes a coupling section  8  configured to couple the transmission input shaft  63  and the motor output shaft  61  to each other in such a manner that the transmission input shaft  63  and the motor output shaft  61  are incapable of rotation relative to each other. 
     As illustrated in  FIG. 7 , the coupling section  8  is switchable between a coupling state and a non-coupling state. In the coupling state, the coupling section  8  couples the transmission input shaft  63  and the motor output shaft  61  to each other. In the non-coupling state, the coupling section  8  does not couple the transmission input shaft  63  and the motor output shaft  61  to each other. 
       FIG. 7  illustrates on the left side the coupling section  8  in the coupling state. In this state, the transmission input shaft  63  and the motor output shaft  61  are incapable of rotation relative to each other as described above. The transmission input shaft  63  thus rotates integrally with the motor output shaft  61 . 
     In other words, while the coupling section  8  is in the coupling state, the transmission input shaft  63  rotates integrally with the motor output shaft  61 . 
     With the pin  82  has been pulled out of the pin hole  63   a , and the coupling shaft  81  has been slid backward, the coupling section  8  is in the state illustrated on the right side of  FIG. 7 , that is, in the non-coupling state. 
     In this state, the coupling shaft  81  is spaced apart from the motor output shaft  61 , with a gap G between the front end of the coupling shaft  81  and the back end of the motor output shaft  61 . 
     The gap G is between the front end of the transmission input shaft  63  and the back end of the motor output shaft  61 , and is larger than the width of the endless rotary body  66 . This allows the endless rotary body  66  to pass through the gap G in a case where the endless rotary body  66  has been removed from the first rotor  64  or the second rotor  65 . 
     In other words, while the coupling section  8  is in the non-coupling state, the front end of the transmission input shaft  63  and the back end of the motor output shaft  61  define a gap G that allows the endless rotary body  66  to pass therethrough in a case where the endless rotary body  66  has been removed. 
     As illustrated in  FIG. 7 , the first rotor  64  includes a first segment  67  and a second segment  68 . The first segment  67  is forward of the second segment  68 . As illustrated on the left side of  FIG. 7 , the second segment  68  has a front surface in contact with the back surface of the first segment  67 . 
     The first segment  67  includes a wind-around section  67   a  and a flange section  67   b . The wind-around section  67   a  allows the endless rotary body  66  to be wound therearound. The flange section  67   b  protrudes radially at a front end portion of the first segment  67 . 
     The second segment  68  is in the shape of a disk. The second segment  68  is fixed to the back end of the wind-around section  67   a  with use of a plurality of fixation bolts  69 . The second segment  68  has an outer diameter equal to that of the flange section  67   b.    
     With this configuration, removing the plurality of fixation bolts  69  allows the second segment  68  to be removed as illustrated on the right side of  FIG. 7 . With the second segment  68  removed, moving the endless rotary body  66  backward allows the endless rotary body  66  to be removed from the first rotor  64  easily. 
     With the coupling section  8  in the non-coupling state, an operator can remove the endless rotary body  66  from the first rotor  64  and pass the endless rotary body  66  through the gap G to remove the endless rotary body  66  from the tractor A easily. 
     To attach the endless rotary body  66  to the tractor A, an operator can, for example, pass the endless rotary body  66  through the gap G, and wind the endless rotary body  66  around the wind-around section  67   a  for the state illustrated on the left side of  FIG. 7  to be achieved. The operator can easily attach the endless rotary body  66  to the tractor A as such. 
     As illustrated in  FIG. 8 , the tractor A includes a tension adjusting mechanism  9 . The tension adjusting mechanism  9  includes a tension ring  91 , a long linkage member  92 , and an adjuster  93 . 
     The tension ring  91  is in contact with the endless rotary body  66 , and applies tension thereto. The tension ring  91  is supported by the body frame  2  with the linkage member  92  therebetween. 
     The adjuster  93  is manually operable. Manually operating the adjuster  93  moves the linkage member  92  in its longitudinal direction. The movement of the linkage member  92  causes the tension ring  91  to also move in the longitudinal direction of the linkage member  92 . This changes the tension of the endless rotary body  66 . 
     With this configuration, the tension adjusting mechanism  9  is manually operable to adjust the tension of the endless rotary body  66 . 
     The tractor A, in other words, includes a tension adjusting mechanism  9  manually operable to adjust the tension of the endless rotary body  66 . 
     As illustrated in  FIGS. 1, 2, and 8 , the driver section  3  includes a wall  34  and an opening cover member  35 . 
     The wall  34  defines and functions as a partition that separates the driver&#39;s seat  31  from the endless rotary body  66  and the tension adjusting mechanism  9 . The wall  34  includes an opening  34   a  in the vicinity of the tension adjusting mechanism  9 . The opening  34   a  is also in the vicinity of the front end of the floor  33 . 
     The opening cover member  35  is detachably attached to the wall  34  to close the opening  34   a . Detaching the opening cover member  35  exposes the opening  34   a . Attaching the opening cover member  35  closes the opening  34   a.    
     Specifically, the opening cover member  35  is attached to the wall  34  with use of a bolt(s) b 1 . Removing the bolt b 1  allows the opening cover member  35  to be detached. While  FIG. 8  shows only one bolt b 1 , the number of bolts b 1  may be any number of one or more. 
     The driver section  3 , in other words, includes a wall  34  defining and functioning as a partition that separates the driver&#39;s seat  31  from the endless rotary body  66  and the tension adjusting mechanism  9 . The driver section  3  also includes an opening cover member  35  capable of exposing and closing the opening  34   a.    
     Preferred embodiments of the present invention are, however, not limited to such an arrangement. The opening cover member  35  may be attachable to the wall  34  without use of a bolt b 1 . For instance, a preferred embodiment of the present invention may be arranged such that the opening cover member  35  has a protrusion, whereas the wall  34  has a depression and that fitting the protrusion into the depression causes the opening cover member  35  to be attached to the wall  34 . 
     An operator can remove the opening cover member  35  to easily reach the adjuster  93  through the opening  34   a.    
     The above configuration allows cooling air from the cooling fan  17  to flow from an area that extends over the travel battery  4  and the ventilation space S in the up-down direction of the machine body. This means that a portion of the cooling air from the cooling fan  17  flows toward the travel battery  4 , whereas another portion thereof flows toward the ventilation space S. 
     The cooling air flowing toward the travel battery  4  cools the travel battery  4 . The cooling air flowing toward the ventilation space S flows under the travel battery  4 . This prevents hot air from remaining between the body frame  2  and the travel battery  4 . 
     The configuration described above therefore allows production of a tractor A including a travel battery  4  that can be cooled effectively. 
     The preferred embodiments described above are mere examples. The present invention is not limited thereto, and may be altered as appropriate. 
     ALTERNATIVE PREFERRED EMBODIMENTS 
     The tractor A may include a single first support frame  51  or three or more first support frames  51 . 
     The tractor A may include a single second support frame  52  or three or more second support frames  52 . 
     The tractor A may have a single ventilation opening K or three or more ventilation openings K. 
     The cover member  12  may include a single outlet section  12   b  or three or more outlet sections  12   b.    
     The cover member  12  may have a single vent hole that doubles as an inlet section  12   a  and an outlet section  12   b.    
     The second portion  72  is not necessarily oriented horizontally. The second portion  72  may be, for instance, oriented obliquely in an upper front direction or a lower front direction. 
     The third portion  73  is not necessarily oriented in a lower front direction. The third portion  73  may, for instance, be oriented vertically or extend from a front end portion of the second portion  72  in a lower back direction. 
     The coupling shaft  81  may be slidable forward. In this case, the back end of the coupling shaft  81  and the front end of the transmission input shaft  63  may define a gap G. 
     The coupling shaft  81  may be slidable backward such that its front end is moved backward of the front end of the transmission input shaft  63 . In this case, the back end of the motor output shaft  61  and the front end of the transmission input shaft  63  may define a gap G. 
     The second segment  68  may be fixed to the back end of the wind-around section  67   a  with use of a single fixation bolt  69 . 
     The second segment  68  may be fixed to the back end of the wind-around section  67   a  without use of fixation bolts  69 . The present invention may be arranged, for instance, such that the first segment  67  has a protrusion, whereas the second segment  68  has a depression and that fitting the protrusion into the depression causes the second segment  68  to be fixed to the back end of the wind-around section  67   a.    
     The second segment  68  may have an outer diameter different from that of the flange section  67   b.    
     The motor M is not necessarily in contact with the ventilation space S. 
     The tractor A may be a hybrid tractor including an engine as well. 
     The wind guide plate  56   a  may be absent. 
     The plate-shaped partition member  56  may be absent. 
     The motor M and the travel battery  4  do not necessarily define a second space S 2  therebetween. 
     The second space S 2  may not be part of the ventilation space S. The second space S 2  may, in other words, be separated from the ventilation space S. 
     The inverter  14  and the travel battery  4  do not necessarily define a first space S 1  therebetween. 
     The first space S 1  may not be part of the ventilation space S. The first space S 1  may, in other words, be separated from the ventilation space S. 
     The cover member  12  may be absent. 
     The cover member  12  may be incapable of accommodating at least one or even all of the travel battery  4 , the reserve tank  5 , the first hose  6   a , the radiator  15 , the cooling fan  17 , the auxiliary battery  18 , the voltage converter  19 , and the radiator frame  57 . 
     The outlet sections  12   b  may be absent. 
     The inlet section  12   a  may be absent. 
     The outlet sections  12   b  are not necessarily lateral to the travel battery  4 . The outlet sections  12   b  may be backward of the travel battery  4 , for instance. 
     The first plate-shaped member  54  may be absent. 
     The second plate-shaped member  55  may be absent. 
     The first plate-shaped member  54  is not necessarily oriented horizontally. The first plate-shaped member  54  may, for instance, be inclined in a lower front direction or a lower back direction. 
     The second plate-shaped member  55  is not necessarily oriented horizontally. The second plate-shaped member  55  may, for instance, be inclined in a lower front direction or a lower back direction. 
     The ventilation space S does not necessarily communicate with the ventilation openings K. 
     The ventilation openings K may be absent. 
     The first support frames  51  do not necessarily stand on the body frame  2 . 
     The second support frames  52  do not necessarily stand on the body frame  2 . 
     The first support frames  51  may be absent. 
     The second support frames  52  may be absent. 
     The first hose  6   a  does not necessarily extend through an area AR defined by the first portion  71 , the second portion  72 , and the third portion  73 . The first hose  6   a  may, for instance, extend through an area forward of the third portion  73 . 
     The support  7  does not necessarily include a second portion  72  or a third portion  73 . 
     The cover support  58  may be absent. 
     The support  7  may be absent. 
     The tractor A may not include at least one or even all of the first hose  6   a , the second hose  6   b , the water supply section  6   c , and the third hose  6   d.    
     The voltage converter  19  may be oriented to have a longitudinal direction extending in the front-back or left-right direction of the machine body. 
     The voltage converter  19  is not necessarily attached to the radiator frame  57 . 
     The radiator frame  57  may be absent. 
     The reserve tank  5  and the auxiliary battery  18  are not necessarily arranged in the up-down direction of the machine body, and may be arranged in, for example, the left-right direction of the machine body. 
     The radiator  15 , the voltage converter  19 , and the reserve tank  5  are not necessarily laterally next to one another in a plan view. For instance, the reserve tank  5  may be over the voltage converter  19 . 
     The radiator  15 , the voltage converter  19 , and the auxiliary battery  18  are not necessarily laterally next to one another in a plan view. For instance, the auxiliary battery  18  may be over the voltage converter  19 . 
     The cooling fan  17  may blow cooling air in a direction other than backward. The cooling fan  17  may blow cooling air forward, for example. 
     The cooling fan  17  may be above or below the inverter  14 . 
     The bottom plate  53   a  may be absent. 
     The inverter support  21  may be rightward of the left end of the left main frame  20 . 
     The inverter support  21  may be leftward of the right end of the right main frame  20 . 
     The inverter support  21  may be absent. In this case, the inverter  14  is supported directly by the left main frame  20  and the right main frame  20 . 
     The inverter  14  may be rightward of the left end of the left main frame  20 . 
     The inverter  14  may be leftward of the right end of the right main frame  20 . 
     The body frame  2  does not necessarily include left and right main frames  20 . The body frame  2  may include, for example, a single frame member. 
     The water pump  16  is not necessarily forward of the motor M, and may be backward of the motor M, for instance. 
     The water pump  16  may be above the inverter  14 . 
     The motor M is not necessarily between the left and right main frames  20 , and may be above the left and right main frames  20 , for instance. 
     The hydraulic pump  60  is not necessarily supported by the back portion support frame  59 . In other words, the motor M and the hydraulic pump  60  are not necessarily both held in place by the same back portion support frame  59 . 
     The opening cover member  35  may be incapable of exposing and closing the opening  34   a . The opening cover member  35  may be unremovable, for instance. 
     The wall  34  does not necessarily have an opening  34   a.    
     The wall  34  may be absent. 
     The opening cover member  35  may be absent. 
     The tension adjusting mechanism  9  may be absent. 
     The endless rotary body  66  may, after being removed, be incapable of passing through the gap G. 
     The coupling section  8  is not necessarily switchable from the coupling state to the non-coupling state. 
     The coupling section  8  may be absent. 
     The first rotor  64  and the second rotor  65  may both be gears that mesh with each other. In this case, the endless rotary body  66  may be absent. 
     The transmission input shaft  63  does not necessarily rotate integrally with the motor output shaft  61 . For instance, the transmission input shaft  63  and the motor output shaft  61  may be interlocked with each other with use of a plurality of gears. 
     The transmission device T is not necessarily backward of the motor M, and may be forward of the motor M, for instance. 
     The tiller device  13  may be replaced with any of (i) various devices such as a fertilizer distributing device, an agent sparging device, a disseminating device, and a harvesting device and (ii) work devices such as a loader and a shovel. 
     The wind guide plate  56   a  is not necessarily oriented vertically, and may be, for instance, inclined in a lower front direction or a lower back direction. 
     The motor M is not necessarily under the travel battery  4 , and may be over the travel battery  4 , for instance. 
     The inverter  14  is not necessarily under the travel battery  4 , and may be over the travel battery  4 , for instance. 
     The voltage converter  19  and the radiator  15  are not necessarily laterally next to each other in a plan view. For instance, the voltage converter  19  may be over the radiator  15 . 
     The radiator  15  may be backward of the travel battery  4 . 
     The voltage converter  19  may be backward of the travel battery  4 . 
     The voltage converter  19  may be absent. 
     The auxiliary battery  18  may be absent. 
     The motor M and the inverter  14  may be next to each other in the left-right direction of the machine body or be arranged in the up-down direction of the machine body. 
     The transmission device T may be forward of the travel battery  4 . 
     The hydraulic pump  60  may be relatively far from the motor M. 
     The hydraulic pump  60  may be drivable by a power source other than the motor M. 
     Preferred embodiments of the present invention are applicable to not only tractors but also various electric work vehicles such as combines, rice transplanters, and construction machines. 
     While preferred embodiments of the present invention have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present invention. The scope of the present invention, therefore, is to be determined solely by the following claims.