Excavator

Abstract

This excavator is provided with a revolving body that is rotatably provided on a traveling device, and comprises: a hydrogen tank that stores hydrogen; a fuel cell that generates power by consuming the hydrogen in the hydrogen tank; and an electric pump device that is driven by electric power generated by the fuel cell and discharges hydraulic fluid. The hydrogen tank and the electric pump device are housed in a housing space inside the revolving body, and the fuel cell is provided in the revolving body and is separated from the housing space.

Description

Excavator

[0001] The present disclosure relates to a shovel equipped with a fuel cell.

[0002] Equipping construction machinery with fuel cells is being considered to achieve carbon neutrality. A known example of an excavator equipped with a fuel cell is the hydraulic excavator described in Patent Document 1. In the hydraulic excavator described in Patent Document 1, the fuel cell generates electricity using hydrogen supplied from a tank and oxygen from the atmosphere. The generated electricity is supplied to an electric pump device. This causes hydraulic oil to be discharged from the electric pump device, and the hydraulic oil is supplied to hydraulic actuators such as a boom cylinder, thereby operating the hydraulic excavator.

[0003] Patent No. 7149447 specification

[0004] In the hydraulic excavator of Patent Document 1, the fuel cell generates a large amount of heat when generating electricity, and therefore, the heat generated by the fuel cell may affect the tank and the electric pump device.

[0005] Therefore, an object of the present disclosure is to provide a shovel that can suppress the influence of heat generated by a fuel cell on the tank and the electric pump device.

[0006] The shovel disclosed herein is an shovel having a rotating body that is rotatably mounted on a traveling device, and is equipped with a hydrogen tank that stores hydrogen, a fuel cell that consumes hydrogen from the hydrogen tank to generate electricity, and an electric pump device that is driven by the electricity generated by the fuel cell and discharges working fluid, wherein the hydrogen tank and the electric pump device are housed in a storage space within the rotating body, and the fuel cell is mounted on the rotating body away from the storage space.

[0007] According to the present disclosure, the fuel cell is mounted on the rotating body away from the storage space, which prevents the temperature in the storage space from rising due to heat generated by the fuel cell. This reduces the thermal impact of the heat generated by the fuel cell on the hydrogen tank and the electric pump device.

[0008] The shovel disclosed herein is an shovel having a rotating body that is rotatably mounted on a traveling device, and is equipped with a hydrogen tank that stores hydrogen, a fuel cell that consumes hydrogen in the hydrogen tank to generate electricity, an electric pump device that is driven by the electricity generated by the fuel cell to discharge working fluid, and a radiator that cools the fuel cell, wherein the hydrogen tank and the electric pump device are housed in an accommodation space within the rotating body, the rotating body includes a ventilation port on one side in a second direction, the radiator is arranged within the rotating body so as to face the ventilation port, and the radiator is arranged so as to overlap the hydrogen tank and the electric pump device when viewed in the second direction.

[0009] According to the present disclosure, the radiator is positioned so as to overlap the hydrogen tank and the electric pump device when viewed in the second direction etc. Therefore, outside air taken in through the ventilation opening can be sent to both the hydrogen tank and the electric pump device, allowing both the hydrogen tank and the electric pump device to be cooled by the outside air.

[0010] According to the present disclosure, it is possible to suppress the influence of heat generated by the fuel cell on the tank and the electric pump device.

[0011] The above and other objects, features, and advantages of the present disclosure will become apparent from the following detailed description of preferred embodiments, which proceeds with reference to the accompanying drawings.

[0012] Fig. 2 is a perspective view showing a shovel according to an embodiment of the present disclosure; Fig. 3 is a plan view showing the shovel of Fig. 1; Fig. 4 is a right side view showing the shovel of Fig. 1; Fig. 5 is a left side view showing the shovel of Fig. 1; Fig. 6 is an enlarged right side view showing the inside of a first cover body of the shovel of Fig. 2 from the right side; Fig. 7 is an enlarged left side view showing the inside of the first cover body of the shovel of Fig. 2 from the left side; Fig. 8 is an enlarged right side view showing the inside of a second cover body of the shovel of Fig. 2 from the right side.

[0013] A shovel 1 according to an embodiment of the present disclosure will be described below with reference to the drawings. Note that the concepts of directions used in the following description are used for convenience of explanation and do not limit the orientation of the configuration of the present disclosure to those directions. Furthermore, the shovel 1 described below is merely one embodiment of the present disclosure. Therefore, the present disclosure is not limited to the embodiment, and additions, deletions, and modifications are possible within the scope of the spirit of the present disclosure.

[0014] [Shovel] The shovel 1 shown in FIG. 1 is an electric shovel that operates using hydrogen as fuel. The shovel 1 includes a traveling device 11, a revolving body 12, a boom 13, an arm 14, and a bucket 15. The traveling device 11 includes, for example, a pair of crawlers 11L, 11R. Each of the crawlers 11L, 11R can be driven to move in various directions. The revolving body 12 is provided on the traveling device 11 so as to be rotatable about a rotation axis L1 extending in the vertical direction. A boom 13, which is an example of a work machine, is provided on the revolving body 12 so as to be swingable in the vertical direction. The arm 14 is provided at the tip of the boom 13 so as to be swingable in the front-rear direction, which is an example of a first direction. Furthermore, the bucket 15 is provided at the tip of the arm 14 so as to be swingable in the front-rear direction or the up-down direction. The front-rear direction is the direction in which the boom 13 extends.

[0015] The traveling unit 11, the revolving unit 12, the boom 13, the arm 14, and the bucket 15 are each provided with a hydraulic actuator (not shown). More specifically, each of the crawlers 11L, 11R of the traveling unit 11 is provided with a travel motor. The travel motors are supplied with hydraulic fluid to drive the crawlers 11L, 11R. This allows the traveling unit 11 to move in various directions. The hydraulic fluid is, for example, a liquid such as oil. The revolving unit 12 is also provided with a swing motor (not shown). The swing motor swings the revolving unit 12 when hydraulic fluid is supplied to it. The boom 13, the arm 14, and the bucket 15 are each provided with a cylinder (not shown). When hydraulic fluid is supplied to each cylinder, the boom 13, the arm 14, and the bucket 15 swing, respectively.

[0016] The revolving unit 12 is configured as follows. That is, as shown in FIG. 2 , the revolving unit 12 includes, for example, a cabin 12a, a first cover body 12b, a second cover body 12c, and a passage 12d. The cabin 12a is configured to allow a driver or operator to ride in. The cabin 12a is located, for example, on the front side of the revolving unit 12, which is an example of one side in the first direction. More specifically, the cabin 12a is located forward of the hydrogen tank 21 and the electric pump device 23, which will be described in detail later. A boom 13 is provided on the front side of the revolving unit 12 in a central portion in the left-right direction, which is an example of a second direction. The cabin 12a is located on the left side of the boom 13, which is one side in the left-right direction. The positions of the boom 13 and the cabin 12a on the revolving unit 12 will be described based on a state in which the boom 13 extends in the fore-and-aft direction.

[0017] The first cover body 12b is disposed on the rear side, which is an example of the other side in the first direction, of the revolving unit 12. In this embodiment, the first cover body 12b constitutes substantially the entire part of the revolving unit 12 rearward of the revolving axis L1. The first cover body 12b is disposed rearward of the cabin 12a of the revolving unit 12. A first storage space 12e is formed within the first cover body 12b, and the revolving unit 12 includes the first storage space 12e covered by the first cover body 12b. In this embodiment, the first storage space 12e is formed rearward of the revolving axis L1.

[0018] The second cover body 12c is disposed on the front side of the revolving unit 12. In this embodiment, the second cover body 12c is disposed on the revolving unit 12 forward of the revolving axis L1. More specifically, the second cover body 12c is disposed on the opposite side of the boom 13 from the cabin 12a. A second storage space 12f is formed within the second cover body 12c, and the revolving unit 12 includes the second storage space 12f covered by the second cover body 12c. In this embodiment, the second storage space 12f is formed in front of the revolving axis L1.

[0019] The passage 12d is disposed in the middle of the revolving body 12 in the fore-and-aft direction. More specifically, the passage 12d is disposed between the first cover body 12b and the second cover body 12c in the fore-and-aft direction, which is an example of a first direction. The passage 12d is provided to extend from the right side surface, which is the other side in the left-right direction, of the revolving body 12. The passage 12d is a passage through which workers move to perform maintenance on various components disposed within the revolving body 12 (the first storage space 12e and the second storage space 12f in this embodiment), for example. The first cover body 12b and the second cover body 12c are separated from each other in the fore-and-aft direction by the passage 12d.

[0020] A frame 16 is also provided within the rotating body 12. More specifically, the frame 16 is provided in the first storage space 12e. As will be described in detail later, a hydrogen tank 21 and an electric pump device 23 are attached to the frame 16. More specifically, the frame 16 is a rectangular parallelepiped frame extending in the left-right direction. The frame 16 is formed, for example, in a U-shape when viewed from the side in the left-right direction. That is, the frame 16 is disposed in the first storage space 12e with its opening facing upward. In this embodiment, the frame 16 is disposed in the middle of the first storage space 12e in the front-rear direction. The hydrogen tank 21 and the electric pump device 23, which will be described in detail later, are housed within the frame 16.

[0021] As shown in FIG. 3 , a ventilation opening 12g is formed on one side surface (the right side surface in this embodiment) of the rotating body 12 in the left-right direction. More specifically, the ventilation opening 12g is formed on the right side surface of the first cover body 12b. The ventilation opening 12g is connected to the inside of the rotating body 12 (more specifically, the first storage space 12e). Therefore, air can be taken in through the ventilation opening 12g into the first storage space 12e. As shown in FIG. 4 , an inspection hatch 12h is formed on the other side surface (the left side surface in this embodiment) of the rotating body 12 in the left-right direction. More specifically, the inspection hatch 12h is formed on the left side surface of the first cover body 12b. The inspection hatch 12h allows for inspection of various components housed in the first storage space 12e. In addition, an openable / closable door 12i is provided at the inspection hatch 12h, and by opening the openable / closable door 12i, the first storage space 12e can be seen through the inspection hatch 12h.

[0022] As shown in FIG. 2 , the excavator 1 also includes a hydraulic drive system 2, a cooling device 3, and a duct 4. The hydraulic drive system 2 supplies hydraulic fluid to each of the hydraulic actuators described above to drive the hydraulic actuators. The hydraulic drive system 2 is disposed within the revolving bed 12. The hydraulic drive system 2 includes multiple hydrogen tanks 21, a fuel cell 22, and an electric pump device 23. In this embodiment, the hydraulic drive system 2 includes two hydrogen tanks 21. However, the number of hydrogen tanks 21 included in the hydraulic drive system 2 is not limited to two, and may be three or more, or may be one. The hydraulic drive system 2 also includes a supply system unit 24 and a multi-control valve (not shown).

[0023] [Hydrogen Tank] The two hydrogen tanks 21 shown in FIG. 5 store hydrogen to be supplied to the fuel cell 22 (see FIG. 2). The two hydrogen tanks 21 are connected to the fuel cell 22 via a supply system unit 24, which will be described in detail later. The two hydrogen tanks 21 are also connected to the fuel cell 22 via the supply system unit 24 (not shown) and supply hydrogen to the fuel cell 22. In this embodiment, the hydrogen tank 21 includes a tank body 21a and a tank valve 21b, as shown in FIG. 6. The tank body 21a is, for example, cylindrical and elongated in the axial direction, and stores hydrogen therein. Here, the axial direction is the direction in which the axis of the tank body 21a (i.e., the hydrogen tank 21) extends. The tank valve 21b is provided at the mouth of the tank body 21a and seals the tank body 21a. The tank valve 21b also controls the flow of hydrogen filled into and discharged from the tank body 21a.

[0024] The two hydrogen tanks 21 are arranged within the rotating structure 12, for example, as follows. That is, each of the hydrogen tanks 21 is accommodated in the first storage space 12e, as shown in FIG. 2 . More specifically, each of the hydrogen tanks 21 is accommodated within the frame 16 in the first storage space 12e. The two hydrogen tanks 21 are arranged vertically side by side at the rear of the frame 16. Furthermore, the hydrogen tanks 21 are arranged so that their axes (i.e., the axes of the tank bodies 21a) are parallel to each other and extend in the left-right direction. Furthermore, for each hydrogen tank 21, the tank valve 21b is located on the left side, as shown in FIG. 6 . The two hydrogen tanks 21 are attached to the frame 16 via mounting members 25 and fixed to the rotating structure 12.

[0025] 2, the two hydrogen tanks 21 are arranged so that the tank valves 21b are on the inspection hatch 12h side. That is, the tank valves 21b are arranged so that they face the inspection hatch 12h. On the other hand, the right-hand portions of the two hydrogen tanks 21 are arranged so that they face the ventilation opening 12g.

[0026] [Supply System Unit] The supply system unit 24 shown in Figure 6 controls the flow of hydrogen supplied from the hydrogen tank 21 to the fuel cell 22. The supply system unit 24 is disposed on the inspection hatch 12h side of the hydrogen tank 21 within the revolving structure 12. More specifically, the supply system unit 24 is disposed adjacent to the tank valve 21b. As a result, the supply system unit 24 is disposed on the inspection hatch 12h side of the hydrogen tank 21 within the revolving structure 12. The supply system unit 24 is also connected to the fuel cell 22 via piping (not shown), and hydrogen from the hydrogen tank 21 is supplied to the fuel cell 22 via the supply system unit 24 and piping (not shown). The configuration of the supply system unit 24 will be described in more detail below.

[0027] The supply system unit 24 includes a piping member 24a. The piping member 24a is connected to each of the two hydrogen tanks 21. Hydrogen discharged from each hydrogen tank 21 flows through the piping member 24a. The supply system unit 24 also includes at least one valve. In this embodiment, the supply system unit 24 has multiple valves, which constitute a valve group 24b. Each valve in the valve group 24b adjusts the supply of hydrogen from the hydrogen tank 21 to the fuel cell 22. Each of the multiple valves is, for example, a high-pressure pressure-reducing valve, a shut-off valve, a low-pressure pressure-reducing valve, a manual valve, or the like. Each valve in the valve group 24b reduces the high-pressure hydrogen stored in the hydrogen tank 21 to a low pressure (e.g., 100 kPa) and supplies it to the fuel cell 22. The piping member 24a and each valve in the valve group 24b are attached to, for example, a mounting plate 24c to form a unit, which is then attached to the frame 16 via the mounting plate 24c.

[0028] [Fuel Cell] The fuel cell 22 shown in FIG. 2 generates electricity by consuming hydrogen from the hydrogen tank 21. More specifically, the fuel cell 22 generates electricity using hydrogen supplied from the hydrogen tank 21 and oxygen taken in from the outside air. In this embodiment, compressed air is supplied to the fuel cell 22 by a compression machine (not shown), such as a compressor. The fuel cell 22 then generates electricity using the oxygen and hydrogen contained in the compressed air. The fuel cell 22 is also electrically connected to an electric pump device 23 and supplies the generated electricity to the electric pump device 23. This drives the electric pump device 23. The fuel cell 22 may be a single cell, or may have a stack structure in which cells are stacked.

[0029] The fuel cell 22 is disposed within the rotating body 12 at a distance from the first accommodation space 12e. More specifically, the first accommodation space 12e accommodates not only the hydrogen tank 21 but also the electric pump device 23, as will be described in detail later. Therefore, the fuel cell 22 is disposed at a distance from the hydrogen tank 21 and the electric pump device 23. In this embodiment, the fuel cell 22 is disposed in the second accommodation space 12f, as also shown in FIG. 7 . That is, the fuel cell 22 is provided forward of the rotation axis L1. In this embodiment, the fuel cell 22 is disposed forward of the first cover body 12b. The fuel cell 22 is also disposed at a position overlapping the cabin 12a in the second direction. By being accommodated in the second accommodation space 12f, the fuel cell 22 is disposed at a distance from the hydrogen tank 21 and the electric pump device 23, with the two cover bodies 12b, 12c and the passage 12d sandwiched between them.

[0030] [Electric Pump Device] The electric pump device 23 shown in FIG. 2 is an electrically driven hydraulic pump device. The electric pump device 23 is driven by electric power supplied from the fuel cell 22 and discharges hydraulic fluid. More specifically, the electric pump device 23 includes a hydraulic pump 31 and an electric motor 32. The hydraulic pump 31 discharges hydraulic fluid when driven to rotate. The hydraulic pump 31 is, for example, a tandem swash plate piston pump. Note that the hydraulic pump 31 may be a single swash plate piston pump or another type of hydraulic pump, such as a bent axis pump or a gear pump. The electric motor 32 is connected to the hydraulic pump 31. The electric motor 32 receives electric power to rotate and drive the hydraulic pump 31, thereby discharging hydraulic fluid from the hydraulic pump 31. In this embodiment, the hydraulic pump 31 and the electric motor 32 share a drive shaft (not shown), and the hydraulic pump 31 and the electric motor 32 are arranged in a straight line.

[0031] The electric pump device 23 configured as described above is disposed within the revolving structure 12, for example, as follows. That is, the electric pump device 23 is accommodated in the first accommodation space 12e. More specifically, the electric pump device 23 is accommodated within the frame 16 in the first accommodation space 12e. The electric pump device 23 is disposed in front of the hydrogen tank 21 within the frame 16. Note that the electric pump device 23 and the hydrogen tank 21 may be disposed in reverse front-to-back within the frame 16. The electric pump device 23 is disposed spaced apart from the two hydrogen tanks 21 in the front-to-back direction. Furthermore, the electric pump device 23 is accommodated within the frame 16 so as to be parallel to the hydrogen tanks 21. That is, the electric pump device 23 is disposed so that the hydraulic pump 31 and the electric motor 32 are aligned in the left-to-right direction. Furthermore, in this embodiment, the electric pump device 23 is disposed within the revolving structure 12 so that the electric motor 32 is located to the right of the hydraulic pump 31. That is, the electric pump device 23 is disposed with the electric motor 32 close to the fuel cell 22 .

[0032] The electric pump device 23 is also connected to a multi-control valve (not shown). Explaining in more detail, the electric pump device 23 is connected to each hydraulic actuator (not shown) via the multi-control valve. The multi-control valve controls the flow of hydraulic fluid discharged from the electric pump device 23 and supplies it to each hydraulic actuator. This allows the traveling device 11, the revolving unit 12, the boom 13, the arm 14, and the bucket 15 to be operated.

[0033] [Cooling Device] The cooling device 3 cools a heat source provided within the rotating body 12. The heat source is, for example, a fuel cell 22. In this embodiment, the heat source further includes a working fluid and a compressor in addition to the fuel cell 22. The cooling device 3 includes a radiator core 41a and a cooling fan 42a. In this embodiment, the cooling device 3 further includes an oil cooler core 41b and a compressor cooler core 41c. The cooling device 3 also includes cooling fans 42b to 42d. The number of cores 41a to 41c, which are heat exchangers, is not limited to three, as long as it includes at least the radiator core 41a. In addition to the cores 41a to 41c described above, the cooling device 3 may also include a heat exchanger for an air conditioner or a heat exchanger for a converter. The number of cooling fans 42a to 42d is also not limited to four, as long as it includes at least the cooling fan 42a. The cooling device 3 may also include a plurality of cooling fans integrated into one.

[0034] The radiator core 41a cools the fuel cell 22. More specifically, a coolant that cools the fuel cell 22 flows through the radiator core 41a. The radiator core 41a cools the coolant by exchanging heat between the coolant flowing therethrough and a fluid such as outside air or a refrigerant. In this embodiment, the radiator core 41a is an air-cooled heat exchanger that cools the coolant by exchanging heat between the coolant flowing therethrough and outside air. More specifically, the radiator core 41a is connected to the fuel cell 22 by a cooling pipe 3a. The cooling pipe 3a is arranged to circulate the coolant between the radiator core 41a and the fuel cell 22. The cooling pipe 3a is also provided with a circulation pump 3b. The circulation pump 3b circulates the coolant between the radiator core 41a and the fuel cell 22. As a result, the circulating coolant absorbs heat from the fuel cell 22 and releases the absorbed heat from the radiator core 41a. In this way, the radiator core 41a cools the fuel cell 22. The radiator core 41a may be a water-cooled heat exchanger.

[0035] The oil cooler core 41b cools the hydraulic fluid. More specifically, hydraulic fluid discharged from the multi-control valve to a hydraulic fluid tank (both not shown) flows through the oil cooler core 41b. The oil cooler core 41b cools the hydraulic fluid by exchanging heat between the hydraulic fluid flowing therethrough and a fluid such as outside air or a refrigerant. In this embodiment, the oil cooler core 41b is an air-cooled heat exchanger that cools the hydraulic fluid by exchanging heat between the hydraulic fluid flowing therethrough and outside air. As a result, the hydraulic fluid releases heat absorbed by the electric pump device 23 and the multi-control valve through the oil cooler core 41b. Note that the oil cooler core 41b may also be a water-cooled heat exchanger.

[0036] The compressor cooler core 41c cools the compressor (not shown). More specifically, a coolant that cools the compressor flows through the compressor cooler core 41c. The compressor cooler core 41c cools the coolant by exchanging heat between the coolant flowing therethrough and a fluid such as outside air or a refrigerant. In this embodiment, the compressor cooler core 41c is an air-cooled heat exchanger that cools the coolant by exchanging heat between the coolant flowing therethrough and outside air. More specifically, the compressor cooler core 41c is connected to the compressor by a cooling pipe (not shown). The cooling pipe is arranged to circulate the coolant between the compressor cooler core 41c and the compressor. The cooling pipe is also provided with a circulation pump (not shown). The circulation pump circulates the coolant between the compressor cooler core 41c and the compressor. As a result, the circulating coolant absorbs heat in the compressor and releases the absorbed heat through the compressor cooler core 41c, which may be a water-cooled heat exchanger.

[0037] The four cooling fans 42a to 42d take in outside air from the ventilation opening 12g into the revolving unit 12. The four cooling fans 42a to 42d then take in the outside air and blow it against each of the cores 41a to 41c, thereby cooling the coolant and working fluid. In this embodiment, the cooling fans 42a to 42d suck outside air into the revolving unit 12 from the ventilation opening 12g, and blow air against each of the cores 41a to 41c, thereby further cooling the coolant and working fluid.

[0038] The cooling device 3 configured as described above is disposed on the rotating unit 12 as follows. That is, the cooling device 3 is disposed within the rotating unit 12 so as to face the ventilation opening 12g. More specifically, as shown in FIG. 5 , the cooling device 3 is disposed so as to overlap the hydrogen tank 21 and the electric pump device 23 when viewed from the left to right. In this embodiment, the cooling device 3 is disposed between the ventilation opening 12g and the two hydrogen tanks 21. The cooling device 3 is also disposed between the ventilation opening 12g and the electric pump device 23. This allows the cooling device 3 to send air from the cooling fans 42a to 42d to the hydrogen tanks 21 and the electric pump device 23. In this embodiment, the cooling device 3 overlaps the entire hydrogen tank 21 and the electric pump device 23, but it may also overlap partially. Note that the cooling device 3 does not necessarily need to be disposed between the ventilation opening 12g and both the hydrogen tanks 21 and the electric pump device 23, as long as it faces the ventilation opening 12g.

[0039] More specifically, in the cooling device 3, the cores 41a to 41c are arranged so as to face the ventilation opening 12g. In this embodiment, the cores 41a to 41c are arranged so that their main surfaces face the ventilation opening 12g and are aligned vertically and vertically relative to one another. The cooling fans 42a to 42d are arranged behind the cores 41a to 41c, i.e., on the opposite side of the ventilation opening 12g from the cores 41a to 41c. Note that the cooling fans 42a to 42d may also be arranged in front of the cores 41a to 41c, i.e., between the cores 41a to 41c and the ventilation opening 12g. The cooling fans 42a to 42d are arranged vertically and vertically, similar to the cores 41a to 41c. More specifically, the cooling fans 42a to 42d are arranged so as to extend in a direction perpendicular to the direction in which the hydrogen tank 21 and the electric pump device 23 extend. That is, the rotation axis of each of the cooling fans 42a to 42d extends in the same direction as the hydrogen tank 21 and the electric pump device 23, respectively. Note that the extending direction includes those inclined by ±30 degrees relative to the direction in which the rotation axis extends. This allows cooling air to be sent from the cooling fans 42a to 42d to the hydrogen tank 21 and the electric pump device 23 in a direction parallel to the direction in which they each extend. Because the hydrogen tank 21 and the electric pump device 23 are arranged parallel to but spaced apart from each other, air can pass between the hydrogen tank 21 and the electric pump device 23. Note that "parallel" includes those inclined by ±30 degrees relative to one another. Therefore, the hydrogen tank 21 and the electric pump device 23 can be cooled efficiently.

[0040] [Duct] The duct 4 connects the downwind side of the cooling device 3 and the second accommodation space 12f. As a result, the duct 4 guides the outside air sent from the cooling device 3 into the second accommodation space 12f, allowing the outside air to cool the fuel cell 22. More specifically, the duct 4 is provided so as to bridge the two accommodation spaces 12e, 12f. That is, the duct 4 extends from the first accommodation space 12e to the second accommodation space 12f. One end of the duct 4 is disposed within the first cover body 12b (i.e., the first accommodation space 12e), and the other end is disposed within the second cover body 12c (i.e., the second accommodation space 12f).

[0041] Furthermore, the duct 4 is disposed adjacent to the cooling device 3. More specifically, the duct 4 is disposed adjacent to the downwind side of the cooling device 3. The duct 4 is disposed, for example, facing the cooling device 3. In this embodiment, the duct 4 is disposed such that an opening 4a at one end (hereinafter referred to as the "inlet") faces the cooling fan 42a of the cooling device 3. Note that the inlet of the duct 4 does not necessarily have to face the cooling fan 42a, but may face the other cooling fans 42b to 42d. This allows the cooling device 3 to send outside air taken in through the ventilation opening 12g into the duct 4. On the other hand, an opening 4b at the other end (hereinafter referred to as the "exhaust outlet") faces the fuel cell 22. This allows the duct 4 to blow the outside air sent therein toward the fuel cell 22, thereby cooling the fuel cell 22.

[0042] [Operation of the Shovel] In the shovel 1, the hydraulic drive system 2 operates as follows. That is, in the hydraulic drive system 2, hydrogen is supplied from the hydrogen tank 21 to the fuel cell 22 via the supply system unit 24. As a result, the fuel cell 22 generates electricity using hydrogen and oxygen in the atmosphere. The generated electricity is supplied from the fuel cell 22 to the electric pump device 23. To explain in more detail, the generated electricity is supplied from the fuel cell 22 to the electric motor 32. As a result, the electric motor 32 drives the hydraulic pump 31, which discharges hydraulic fluid. The hydraulic fluid is supplied to each of the hydraulic actuators via the multi-control valve, thereby driving each hydraulic actuator. In this way, the shovel 1 operates.

[0043] In the excavator 1 configured as described above, the fuel cell 22 generates a large amount of heat when generating electricity, and the fuel cell 22 is cooled using a cooling device 3 or the like. That is, the circulation pump 3b sends coolant from the cooling device 3 to the fuel cell 22 via the cooling piping 3a. The coolant is sent to the fuel cell 22 and absorbs the heat generated by the fuel cell 22. The coolant is then returned to the radiator core 41a via the cooling piping 3a. In the radiator core 41a, heat exchange occurs between the coolant and outside air taken in through the ventilation opening 12g, thereby cooling the coolant. Furthermore, by driving the cooling fans 42a to 42d, more outside air is taken in through the ventilation opening 12g and directed at the radiator core 41a. This further cools the coolant. The cooled coolant is then sent from the cooling device 3 to the fuel cell 22 by the circulation pump 3b. In this way, in the excavator 1, the fuel cell 22 is cooled by the coolant.

[0044] Furthermore, in the shovel 1, outside air taken in through the ventilation opening 12g is sent to the second accommodation space 12f via the duct 4. The sent outside air is then blown onto the fuel cell 22, thereby cooling the fuel cell 22. Furthermore, in the shovel 1, the fuel cell 22 is disposed away from the hydrogen tank 21 and the electric pump device 23. Therefore, the effect of heat emitted from the fuel cell 22 on the hydrogen tank 21 and the electric pump device 23 is suppressed.

[0045] Furthermore, in the excavator 1, the working fluid and the compressor are cooled using the cooling device 3. That is, in the excavator 1, when the working fluid is guided to the oil cooler core 41b of the cooling device 3, the oil cooler core 41b exchanges heat between the working fluid and the outside air taken in through the ventilation opening 12g. This cools the working fluid. Furthermore, by driving the cooling fans 42a to 42d, more outside air can be taken in through the ventilation opening 12g and applied to the oil cooler core 41b. This further cools the working fluid.

[0046] Furthermore, in the excavator 1, coolant is sent from the compressor cooler core 41c to the compressor. As a result, the coolant absorbs heat generated by the compressor. The coolant is then returned to the compressor cooler core 41c. The compressor cooler core 41c exchanges heat between the coolant and outside air taken in through the ventilation opening 12g. Furthermore, by driving the cooling fans 42a to 42d, more outside air can be taken in through the ventilation opening 12g and blown onto the fans 42a to 42d. This further cools the coolant supplied to the compressor. The cooled coolant is then sent from the compressor cooler core 41c to the compressor. In this way, in the excavator 1, the compressor is cooled by the coolant.

[0047] In the excavator 1 of this embodiment, the fuel cell 22 is provided in the revolving body 12 away from the first accommodation space 12e. This makes it possible to suppress a temperature rise in the first accommodation space 12e caused by heat generated by the fuel cell 22. This makes it possible to suppress the thermal effects of the heat generated by the fuel cell 22 on the hydrogen tank 21 and the electric pump device 23. Furthermore, the fuel cell 22 and the electric pump device 23 can be appropriately cooled.

[0048] Furthermore, in the excavator 1 of this embodiment, the hydrogen tank 21 and the electric pump device 23 are housed in the first housing space 12e covered by the first cover body 12b, and the fuel cell 22 is housed in the second housing space 12f covered by the second cover body 12c. Because the hydrogen tank 21, the electric pump device 23, and the fuel cell 22 are housed in the housing spaces 12e, 12f covered by different cover bodies 12b, 12c, respectively, the thermal effect of the heat generated by the fuel cell 22 on the hydrogen tank 21 and the electric pump device 23 can be further suppressed.

[0049] Furthermore, in the excavator 1 of this embodiment, the passage 12d is disposed between the first cover body 12b and the second cover body 12c. Therefore, the passage 12d is disposed between the two accommodation spaces 12e, 12f, and the fuel cell 22 can be further separated from the hydrogen tank 21 and the electric pump device 23. Therefore, the thermal effects of the heat generated by the fuel cell 22 on the hydrogen tank 21 and the electric pump device 23 can be further suppressed.

[0050] Furthermore, in the excavator 1 of this embodiment, the fuel cell 22 is provided on the front side of the revolving unit 12 on which the boom 13 is provided, and the first accommodation space 12e is formed on the rear side of the revolving unit 12. Therefore, the fuel cell 22 and the first accommodation space 12e can be spaced further apart in the revolving unit 12. This makes it possible to further suppress the thermal effects of heat generated by the fuel cell 22 on the hydrogen tank 21 and the electric pump device 23.

[0051] Furthermore, in the excavator 1 of this embodiment, the fuel cell 22 is provided on the left-right opposite side of the cabin 12a with respect to the boom 13. Therefore, the fuel cell 22 can be disposed away from the first accommodation space 12e while effectively utilizing the space in the revolving unit 12.

[0052] Furthermore, in the excavator 1 of this embodiment, the revolving body 12 includes a duct 4 that connects the downwind side of the cooling device 3 with the second accommodation space 12f. Therefore, the air taken in from the ventilation opening 12g can be sent by the cooling device 3 to the fuel cell 22 via the duct 4. This allows the fuel cell 22 to be cooled.

[0053] Furthermore, in the excavator 1 of this embodiment, the cooling device 3 is arranged so as to overlap the hydrogen tank 21 and the electric pump device 23 when viewed from the left to right. Therefore, the taken-in outside air can be sent to both the hydrogen tank 21 and the electric pump device 23, and the taken-in outside air can cool both the hydrogen tank 21 and the electric pump device 23.

[0054] Furthermore, in the excavator 1 of this embodiment, the hydrogen tank 21 and the electric pump device 23 are disposed at a distance from each other in the front-to-rear direction. This allows outside air taken in to pass between the hydrogen tank 21 and the electric pump device 23. This means that the hydrogen tank 21 and the electric pump device 23 are prevented from interfering with the flow of outside air. This prevents heat from building up in the first housing space 12e. This improves the cooling performance of the hydrogen tank 21 and the electric pump device 23.

[0055] Furthermore, in the excavator 1 of this embodiment, the revolving body 12 includes a ventilation port 12g on the right side surface thereof that is connected to the first storage space 12e. The hydrogen tank 21 and the electric pump device 23 are arranged side by side in the front-to-rear direction in the first storage space 12e. Therefore, outside air taken in through the ventilation port 12g can flow between the hydrogen tank 21 and the electric pump device 23. This allows the electric pump device 23 to be further cooled.

[0056] Furthermore, in the excavator 1 of this embodiment, the revolving body 12 includes an inspection hatch 12h, and the supply system unit 24 is provided on the inspection hatch 12h side relative to the hydrogen tank 21. Therefore, since the supply system unit 24 is disposed on the inspection hatch 12h side, the maintainability of the supply system unit 24 can be improved.

[0057] <Other Embodiments> In the shovel 1 of this embodiment, the two hydrogen tanks 21, the electric pump device 23, and the fuel cell 22 are housed in different cover bodies 12b, 12c. However, they may be housed in a single cover body. In this case, two storage spaces 12e, 12f are formed within the single cover body. The two storage spaces 12e, 12f may be physically separated by a partition or the like within the single cover body, or may be separated by a distance. That is, it is sufficient that the fuel cell 22 is disposed away from the first storage space 12e. In addition, in the shovel 1 of this embodiment, the passage 12d is formed between the two cover bodies 12b, 12c, but the passage 12d does not necessarily have to be formed. For example, the shovel 1 may have only one cover body, and the passage 12d is formed on the front side of the cover body. In this case, within the cover body, the space rearward of the cabin 12a constitutes the first storage space, and the space to the right of the cabin 12a constitutes the second storage space. Furthermore, the position of the fuel cell 22 does not necessarily have to be on the right side of the boom 13 (i.e., on the opposite side of the boom 13 from the cabin 12a), but may be on the left side or rear side of the boom 13.

[0058] In the shovel 1 of this embodiment, the ventilation port 12g is formed on the right side of the shovel 1, but it may also be formed on the left side or both the right and left sides. Furthermore, the cooling device 3 does not necessarily need to overlap both the hydrogen tank 21 and the electric pump device 23 when viewed in the left-right direction, and it may also overlap at least one or neither. Furthermore, although the shovel 1 of this embodiment is provided with the duct 4, it does not have to be provided with the duct 4. For example, a ventilation port connected to the second storage space 12f may be formed on the side or front of the shovel 1, so that outside air can be taken into the second storage space 12f through this ventilation port.

[0059] In the excavator 1 of this embodiment, the hydrogen tank 21 and the electric pump device 23 are arranged side by side in the first direction, but they may also be arranged side by side in the second direction. Also, in the excavator 1 of this embodiment, the hydrogen tank 21 and the electric pump device 23 are arranged spaced apart from each other in the first direction, but they may also be arranged so as to overlap each other in the first direction. Also, in the excavator 1 of this embodiment, the supply system unit 24 and the tank valve 21b are arranged on the inspection hatch 12h side, but they may also be arranged on the ventilation opening 12g side.

[0060] In the excavator 1 of this embodiment, the multiple actuators that drive the traveling device 11, the revolving body 12, the boom 13, the arm 14, and the bucket 15 do not necessarily all need to be hydraulic actuators. It is sufficient that at least one of the multiple actuators is a hydraulic actuator, and the others may be electric actuators.

[0061] <Illustrative embodiment> In a first aspect, the shovel is an shovel having a rotating body that is rotatably mounted on a traveling device, and is equipped with a hydrogen tank that stores hydrogen, a fuel cell that consumes hydrogen from the hydrogen tank to generate electricity, and an electric pump device that is driven by the electricity generated by the fuel cell and discharges working fluid, wherein the hydrogen tank and the electric pump device are housed in a storage space within the rotating body, and the fuel cell is provided on the rotating body away from the storage space.

[0062] According to the above aspect, the fuel cell is provided on the rotating body away from the storage space. This makes it possible to suppress a temperature rise in the storage space due to heat generated by the fuel cell. This in turn makes it possible to suppress the thermal effects of heat generated by the fuel cell on the hydrogen tank and the electric pump device.

[0063] In a second aspect, the shovel is the shovel of the first aspect, wherein the rotating body includes a first storage space that is the storage space and is covered by a first cover body, and a second storage space that is covered by a second cover body different from the first cover body and is positioned away from the first storage space, and the fuel cell is stored in the second storage space.

[0064] According to the above aspect, the hydrogen tank, the electric pump device, and the fuel cell are housed in respective housing spaces covered by different cover bodies, thereby further suppressing the thermal impact of the heat generated by the fuel cell on the hydrogen tank and the electric pump device.

[0065] In a third aspect, in the shovel of the second aspect, the rotating body has a passageway, and the passageway is disposed between the first cover body and the second cover body.

[0066] According to the above aspect, since the passage is disposed between the two storage spaces, the fuel cell can be further separated from the hydrogen tank and the electric pump device, thereby further suppressing the thermal effects of heat generated by the fuel cell on the hydrogen tank and the electric pump device.

[0067] In a fourth aspect, the shovel is an shovel according to any one of the first to third aspects, wherein the rotating body has a work machine on one side in a first direction, the fuel cell is provided on one side in the first direction relative to the rotation axis of the rotating body, and the storage space is formed on the other side in the first direction relative to the rotation axis of the rotating body.

[0068] According to the above aspect, the fuel cell is provided on one side of the rotating body in the first direction on which the work machine is mounted, and the storage space is formed on the other side of the rotating body in the first direction. This allows the fuel cell to be spaced further apart from the storage space in the rotating body, thereby further reducing the thermal effects of heat generated by the fuel cell on the hydrogen tank and the electric pump device.

[0069] In a fifth aspect, the shovel is the shovel of the fourth aspect, wherein the rotating body includes a cabin, and the fuel cell is provided on the opposite side of the cabin from the work machine in a second direction perpendicular to the first direction.

[0070] According to the above aspect, the fuel cell is provided on the opposite side of the cabin in the second direction with respect to the work machine. Therefore, the fuel cell can be disposed away from the accommodation space while effectively utilizing the space in the rotating body.

[0071] In a sixth aspect, the shovel is the shovel of the second or third aspect, further comprising a cooling device for cooling the fuel cell and a duct, the rotating body including a ventilation port on one side in a second direction perpendicular to the first direction, the cooling device being arranged within the rotating body so as to face the ventilation port, and the duct connecting the downwind side of the cooling device with the second storage space.

[0072] According to the above aspect, the rotating body further includes a duct that connects the leeward side of the cooling device with the second accommodation space. Therefore, the air taken in through the ventilation opening can be sent to the fuel cell through the duct by the cooling fan, thereby cooling the fuel cell.

[0073] In a seventh aspect, the shovel is the shovel of the second or third aspect, wherein the rotating body includes a cooling device for cooling the fuel cell, and a ventilation port on one side in a second direction perpendicular to the first direction, the cooling device being arranged within the rotating body so as to face the ventilation port and overlapping the hydrogen tank and the electric pump device when viewed in the second direction.

[0074] According to the above aspect, the cooling device is disposed so as to overlap the hydrogen tank and the electric pump device when viewed in the second direction, and therefore the taken-in outside air can be sent to both the hydrogen tank and the electric pump device, allowing both the hydrogen tank and the electric pump device to be cooled by the taken-in outside air.

[0075] In an eighth aspect of the present invention, in the excavator of the seventh aspect, the hydrogen tank and the electric pump device are arranged at an interval from each other in the first direction.

[0076] According to the above aspect, the hydrogen tank and the electric pump device are disposed at a distance from each other in the first direction. This allows the taken-in outside air to pass between the hydrogen tank and the electric pump device. This means that the hydrogen tank and the electric pump device are prevented from interfering with the flow of the taken-in outside air. This prevents heat from building up in the storage space. This improves the cooling performance of the hydrogen tank and the electric pump device.

[0077] In a ninth aspect, the shovel is the shovel of any one of the first to eighth aspects, wherein the rotating body includes a ventilation port on one side in a second direction perpendicular to the first direction and connected to the storage space, and the hydrogen tank and the electric pump device are arranged in the storage space side by side in the first direction.

[0078] According to the above aspect, the rotating body includes a ventilation port on one side in a second direction perpendicular to the first direction and connected to the storage space. The hydrogen tank and the electric pump device are arranged in the storage space side by side in the first direction. Therefore, outside air taken in through the ventilation port can flow between the hydrogen tank and the electric pump device, thereby further cooling the electric pump device.

[0079] In a tenth aspect, the shovel is the shovel of any one of the first to ninth aspects, further comprising a valve for controlling the flow of hydrogen supplied from the hydrogen tank to the fuel cell, and the rotating body includes a ventilation port on one side in a second direction perpendicular to the first direction, and an inspection hatch on the other side in the second direction, the ventilation port and the inspection hatch being connected to the storage space, and the valve being positioned on the inspection hatch side relative to the hydrogen tank.

[0080] According to the above aspect, the rotating body includes an inspection hatch, and the supply system unit is provided on the inspection hatch side relative to the hydrogen tank. Therefore, since the supply system unit is located on the inspection hatch side, it is possible to improve maintainability of the supply system unit.

[0081] In an eleventh aspect, the shovel is an shovel having a rotating body that is rotatably mounted on a traveling device, and is equipped with a hydrogen tank that stores hydrogen, a fuel cell that consumes hydrogen in the hydrogen tank to generate electricity, an electric pump device that is driven by the electricity generated by the fuel cell and discharges working fluid, and a radiator that cools the fuel cell, wherein the hydrogen tank and the electric pump device are housed in an accommodation space within the rotating body, the rotating body includes a ventilation port on one side in a second direction, the radiator is arranged within the rotating body so as to face the ventilation port, and the radiator is arranged so as to overlap the hydrogen tank and the electric pump device when viewed in the second direction.

[0082] According to the above aspect, the radiator is positioned so as to overlap the hydrogen tank and the electric pump device when viewed in the second direction etc. Therefore, outside air taken in through the ventilation opening can be sent to both the hydrogen tank and the electric pump device, and therefore both the hydrogen tank and the electric pump device can be cooled by the outside air.

[0083] In a twelfth aspect, the shovel is the eleventh aspect, wherein the hydrogen tank and the electric pump device are arranged at an interval from each other in the first direction.

[0084] According to the above aspect, the hydrogen tank and the electric pump device are disposed at a distance from each other when viewed in the first direction. This allows cooling air to pass through the gap between the hydrogen tank and the electric pump device. This means that the hydrogen tank and the electric pump device are prevented from interfering with the flow of cooling air. This prevents heat from building up in the storage space. This reduces the impact of heat generated by the fuel cell on the hydrogen tank and the electric pump device.

[0085] From the above description, many modifications and other embodiments of the present disclosure will be apparent to those skilled in the art. Therefore, the above description should be construed as illustrative only and is provided for the purpose of teaching those skilled in the art the best mode for carrying out the present disclosure. Details of the structure and / or function thereof can be substantially changed without departing from the spirit of the present disclosure.

Claims

1. An excavator having a rotating body that is rotatably mounted on a traveling device, comprising: a hydrogen tank for storing hydrogen; a fuel cell that consumes hydrogen in the hydrogen tank to generate electricity; and an electric pump device that is driven by the electricity generated by the fuel cell and discharges working fluid, wherein the hydrogen tank and the electric pump device are accommodated in an accommodation space within the rotating body, and the fuel cell is mounted on the rotating body away from the accommodation space.

2. The shovel described in claim 1, wherein the rotating body includes a first storage space that is the storage space and is covered by a first cover body, and a second storage space that is covered by a second cover body different from the first cover body and is positioned away from the first storage space, and the fuel cell is accommodated in the second storage space.

3. The shovel according to claim 2, wherein the rotating body has a passageway, and the passageway is disposed between the first cover body and the second cover body.

4. A shovel as described in claim 1, wherein a work machine is provided on one side in a first direction of the rotating body, the fuel cell is provided on one side in the first direction with respect to the rotation axis of the rotating body, and the storage space is formed on the other side in the first direction with respect to the rotation axis of the rotating body.

5. A shovel as described in claim 4, wherein the rotating body includes a cabin, and the fuel cell is provided on the opposite side of the cabin from the working machine in a second direction perpendicular to the first direction.

6. The excavator as described in claim 2, further comprising a cooling device for cooling the fuel cell and a duct, wherein the rotating body includes a ventilation port on one side in a second direction perpendicular to the first direction, the cooling device is arranged within the rotating body so as to face the ventilation port, and the duct connects the leeward side of the cooling device to the second storage space.

7. A shovel as described in claim 2, wherein the rotating body includes a cooling device for cooling the fuel cell, and a ventilation port on one side in a second direction perpendicular to the first direction, the cooling device being positioned within the rotating body so as to face the ventilation port and overlapping the hydrogen tank and the electric pump device when viewed in the second direction.

8. The shovel according to claim 7, wherein the hydrogen tank and the electric pump device are spaced apart from each other in the first direction.

9. The excavator as described in claim 1, wherein the rotating body includes a ventilation port on one side surface in a second direction perpendicular to the first direction and connected to the storage space, and the hydrogen tank and the electric pump device are arranged in the storage space side by side in the first direction.

10. The shovel described in claim 1, further comprising a valve for controlling the flow of hydrogen supplied from the hydrogen tank to the fuel cell, wherein the rotating body includes a vent hole on one side in a second direction perpendicular to the first direction and an inspection hatch on the other side in the second direction, the vent hole and the inspection hatch are connected to the storage space, and the valve is positioned on the inspection hatch side relative to the hydrogen tank.

11. An excavator having a rotating body that is rotatably mounted on a traveling device, comprising: a hydrogen tank for storing hydrogen; a fuel cell that consumes hydrogen in the hydrogen tank to generate electricity; an electric pump device that is driven by the electricity generated by the fuel cell and discharges working fluid; and a radiator that cools the fuel cell, wherein the hydrogen tank and the electric pump device are accommodated in an accommodation space within the rotating body, the rotating body includes a ventilation port on one side in a second direction, the radiator is arranged within the rotating body so as to face the ventilation port, and the radiator is arranged so as to overlap the hydrogen tank and the electric pump device when viewed in the second direction.

12. The shovel according to claim 11, wherein the hydrogen tank and the electric pump device are spaced apart from each other in the first direction.

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