Electric pump device for construction machine, and hydraulic drive system including same

Abstract

This electric pump device for a construction machine is mounted on the construction machine, the electric pump device comprising: a hydraulic pump which includes a drive shaft and discharges hydraulic fluid when the drive shaft rotates; an electric motor which is connected to the drive shaft and rotationally drives the drive shaft; and a support member which supports the hydraulic pump and the electric motor. The support member is provided upright in a first direction orthogonal to a surface on which the construction machine is installed, and supports the hydraulic pump and the electric motor such that the drive shaft extends in the first direction.

Description

Electric pump device for construction machinery and hydraulic drive system equipped with the same

[0001] The present disclosure relates to an electric pump device for a construction machine that is mounted on the construction machine, and a hydraulic drive system for the construction machine.

[0002] BACKGROUND ART Construction machines such as excavators are increasingly being electrified, and the drive source of hydraulic pumps is being replaced from an internal combustion engine with an electric motor. One example of such construction machines is an electric excavator disclosed in Patent Document 1.

[0003] Japanese Patent Application Laid-Open No. 2022-163964

[0004] It is desirable for electric shovels to be manufactured with an external shape similar to that of conventional shovels that use an internal combustion engine as a drive source. On the other hand, it is desirable for electric shovels to be equipped with a larger battery to extend their drive time. Therefore, if the various components of an electric shovel are arranged in the same manner as in a conventional shovel, it is difficult to secure the space required to accommodate a larger battery. Therefore, in order to secure the space, it is desirable for an electric pump device for construction machinery, which is composed of a hydraulic pump and an electric motor, to be configured so that it can be arranged compactly.

[0005] Therefore, an object of the present disclosure is to provide an electric pump device for a construction machine that can be arranged more compactly, and a hydraulic drive system including the same.

[0006] The electric pump device for construction machinery disclosed herein is mounted on a construction machinery and comprises a hydraulic pump including a drive shaft that discharges hydraulic fluid when the drive shaft rotates, an electric motor connected to the drive shaft and driving the drive shaft to rotate, and a support member that supports the hydraulic pump and the electric motor, the support member being erected in a first direction perpendicular to the installation surface of the construction machinery and supporting the hydraulic pump and the electric motor so that the drive shaft extends in the first direction.

[0007] According to the present disclosure, the support member is erected in the first direction and supports the hydraulic pump and the electric motor so that the drive shaft extends in the first direction. This reduces the installation area of ​​the electric pump device as viewed in the first direction, allowing the electric pump device for construction machinery to be arranged more compactly.

[0008] The hydraulic drive system of the present disclosure drives a hydraulic actuator equipped on a construction machine by supplying hydraulic fluid thereto, and comprises the electric pump device for construction machinery described above, and a tank for storing hydraulic fluid and connected to the suction port of the hydraulic pump of the electric pump device for construction machinery via an suction pipe, wherein the tank is positioned adjacent to the electric pump device for construction machinery in a second direction perpendicular to the first direction, and the suction port is formed on the side of the hydraulic pump.

[0009] According to the present disclosure, the tank is disposed adjacent to the electric pump device for construction machinery in the second direction. The suction port connected to the tank via the suction pipe is formed on the side surface of the hydraulic pump. This reduces the length of the suction pipe.

[0010] According to the present disclosure, an electric pump device for a construction machine can be arranged more compactly.

[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. 1 is a perspective view showing a shovel on which a hydraulic drive system of an embodiment according to the present disclosure is mounted. Fig. 2 is a schematic plan view showing the hydraulic drive system mounted on the shovel of Fig. 1. Fig. 3 is an enlarged perspective view showing an electric pump device provided in the hydraulic drive system of Fig. 2. Fig. 4 is an enlarged front view showing the electric pump device of Fig. 3. Fig. 5 is an enlarged cross-sectional view showing a part of the electric pump device of Fig. 3. Fig. 6 is a schematic side view showing the hydraulic drive system of Fig. 2. Fig. 7 is an enlarged perspective view showing an electric pump device of another embodiment.

[0013] A hydraulic drive system 1 and an electric pump device 2 provided therein 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 hydraulic drive system 1 and the electric pump device 2 described below are 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] [Construction Machine] The construction machine 3 shown in FIGS. 1 and 2 performs various tasks by moving a bucket 15 and an attachment such as a crane (not shown). In this embodiment, the construction machine 3 is an electric shovel (hereinafter simply referred to as "shovel") 3. However, the construction machine 3 is not limited to the shovel 3 and may be a crane, a wheel loader, an industrial vehicle such as a forklift, or the like. In other words, the construction machine 3 may be any machine that moves an attachment to perform various tasks. The shovel 3 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 mounted on the traveling device 11 so as to be rotatable about a rotation axis L1 extending in the vertical direction. The boom 13 is mounted 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-to-rear direction. Furthermore, the bucket 15 is provided at the tip of the arm 14 so as to be swingable in the front-to-rear direction or the up-to-down direction. The front-to-rear direction is, for example, 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, such as a hydraulic motor and a cylinder. That is, each of the crawlers 11L, 11R of the traveling unit 11 is provided with a traveling hydraulic motor (not shown). The traveling motor drives the crawlers 11L, 11R by supplying hydraulic fluid. 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 provided with a swing hydraulic motor (not shown). The swing hydraulic motor swings the revolving unit 12 by supplying hydraulic fluid. The boom 13 is provided with a boom cylinder 13a. The arm 14 and the bucket 15 are each provided with an arm cylinder and a bucket cylinder (not shown). The boom cylinder 13a, the arm cylinder, and the bucket cylinder are supplied with hydraulic fluid, which causes the boom 13, the arm 14, and the bucket 15 to swing, respectively.

[0016] [Hydraulic Drive System] The excavator 3 is also equipped with a hydraulic drive system 1 as shown in FIG. 2. More specifically, the hydraulic drive system 1 is disposed within the revolving body 12. The hydraulic drive system 1 supplies hydraulic fluid to each of the hydraulic actuators described above. Furthermore, the hydraulic drive system 1 controls the flow (flow rate and flow direction) of the hydraulic fluid supplied to each hydraulic actuator. The hydraulic drive system 1 configured in this manner includes a tank 4 and an electric pump device 2 as shown in FIG. 2. More specifically, the hydraulic drive system 1 further includes a multi-control valve 5 and a battery 6.

[0017] [Tank] Hydraulic fluid is stored in the tank 4. The hydraulic fluid in the tank 4 is supplied to each of the hydraulic actuators from the electric pump device 2, which will be described in detail later, via the multi-control valve 5. The hydraulic fluid is also returned from each of the hydraulic actuators to the tank 4 via the multi-control valve 5. The tank 4 is arranged, for example, as follows within the revolving structure 12. That is, the revolving structure 12 has a cabin 12b in which a driver (or operator) can ride. A boom 13 is provided on the front side of the revolving structure 12 in a central portion in the left-right direction, and the cabin 12b is arranged on one side in the left-right direction (e.g., the left side) of the revolving structure 12 adjacent to the boom 13. The tank 4 is arranged within the revolving structure 12 on the opposite side of the cabin 12b across the boom 13. That is, the tank 4 is arranged on the front side of the revolving structure 12 adjacent to the boom 13, on the opposite side in the left-right direction from the cabin 12b (the right side in this embodiment).

[0018] [Electric Pump Device] The electric pump device 2, which is an example of an electric pump device for a construction machine, is an electric hydraulic pump device mounted on a shovel 3. The electric pump device 2 includes a hydraulic pump 21 and an electric motor 22. In the electric pump device 2, the hydraulic pump 21 and the electric motor 22 are arranged side by side (i.e., vertically) in a first direction (in the present embodiment, the up-down direction). The electric pump device 2 configured in this manner is disposed on an installation surface 12a within a revolving body 12 of the shovel 3. In the present embodiment, the installation surface 12a is as follows. That is, the installation surface 12a is located on the opposite side of the cabin 12b within the revolving body 12, with the boom 13 in between. More specifically, the installation surface 12a is located behind the tank 4 in a plan view. The electric pump device 2 is installed upright on the installation surface 12a in a first direction (in the present embodiment, the up-down direction) perpendicular to the installation surface 12a. Therefore, the electric pump device 2 is disposed adjacent to the tank 4 while being installed on the installation surface 12a. The electric pump device 2 is also electrically connected to the battery 6. The electric pump device 2 is further connected to the tank 4 via a suction pipe 7a and to the multi-control valve 5 via a discharge pipe 7b.

[0019] The electric pump device 2 configured as described above is driven by current supplied from a battery 6, which will be described later. When driven, the electric pump device 2 draws in hydraulic fluid from the tank 4 via the suction pipe 7a. When driven, the electric pump device 2 discharges hydraulic fluid to the multi-control valve 5 via the discharge pipe 7b. As shown in Figures 3 and 4, the electric pump device 2 includes a support frame 23 in addition to the hydraulic pump 21 and electric motor 22 described above. To explain in more detail, the electric pump device 2 further includes an inverter 24 and a connecting member 25.

[0020] As shown in FIG. 5 , the hydraulic pump 21 has a drive shaft 21a. The hydraulic pump 21 discharges hydraulic fluid when the drive shaft 21a is driven to rotate. The hydraulic pump 21 is, for example, a tandem pump having two variable displacement pump sections (variable displacement swash plate pumps in this embodiment) 21c, 21d (see also FIG. 4 ). The variable displacement pump sections (hereinafter simply referred to as "pump sections") 21c, 21d share the drive shaft 21a. The pump sections 21c, 21d are arranged side by side in the vertical direction, which is the first direction in which the drive shaft 21a extends. A housing 21e is interposed between the pump sections 21c, 21d. Therefore, in this embodiment, the hydraulic pump 21 is formed to be elongated in the first direction.

[0021] Additionally, a suction port 21f and discharge ports 21g, 21h are formed on a side surface of the hydraulic pump 21. More specifically, one suction port 21f and two discharge ports 21g, 21h are formed on a side surface of the housing 21e. The suction port 21f and the discharge ports 21g, 21h each open in a direction perpendicular to the first direction (e.g., a second direction and a third direction, which will be described in detail later) on the side surface of the housing 21e. In this embodiment, the discharge ports 21g, 21h open in the same direction. Furthermore, the discharge ports 21g, 21h and the suction port 21f open in directions perpendicular to each other. The pump sections 21c, 21d share the single suction port 21f and each have their own discharge ports 21g, 21h. Therefore, the hydraulic pump 21 draws hydraulic fluid through the suction port 21f and discharges hydraulic fluid from the two ports 21g, 21h. The pump sections 21c and 21d are provided with regulators 21i and 21j, respectively, which change the discharge capacity of the pump sections 21c and 21d.

[0022] The electric motor 22 is coupled to the drive shaft 21a. The electric motor 22 rotates and drives the drive shaft 21a. More specifically, the electric motor 22 drives the drive shaft 21a when current is applied. This causes the electric motor 22 to discharge hydraulic fluid from the hydraulic pump 21. The electric motor 22 is, for example, a three-phase AC motor. More specifically, the electric motor 22 is formed in a cylindrical shape and is arranged coaxially with the drive shaft 21a. That is, the electric motor 22 is aligned coaxially with the hydraulic pump 21. That is, the electric motor 22 is aligned in a straight line with the hydraulic pump 21 in the first direction. However, the electric motor 22 does not necessarily have to be aligned in a straight line with the hydraulic pump 21. The electric motor 22 and the hydraulic pump 21 may be arranged parallel to each other but with their axes offset, or the axis of the electric motor 22 may be arranged so as to intersect the drive shaft 21a diagonally or at a right angle.

[0023] The inverter 24 converts DC current into AC current. The inverter 24 is electrically connected to the electric motor 22 and the battery 6, which will be described later. The inverter 24 converts DC current supplied from the battery 6 into AC current and supplies the AC current to the electric motor 22. This causes the electric motor 22 to rotate the drive shaft 21a. The inverter 24 is provided, for example, in the electric motor 22. In this embodiment, the inverter 24 is configured integrally with the electric motor 22 so as to be located on the opposite side of the hydraulic pump 21 in the first direction.

[0024] The connecting member 25 connects the hydraulic pump 21 and the electric motor 22. The connecting member 25 is, for example, a bell housing. The connecting member 25 has a tubular portion 25a and a flange 25b. The tubular portion 25a connects the hydraulic pump 21 and the electric motor 22. More specifically, the tubular portion 25a is formed, for example, in a cylindrical shape. In the present embodiment, the axial line of the tubular portion 25a extends in a first direction and is formed in a tapered shape so that the diameter increases from one side in the first direction (the lower side in this embodiment) to the other side (the upper side in this embodiment) in the first direction. The hydraulic pump 21 is attached to one end of the tubular portion 25a, which is an end on one side in the first direction, and the electric motor 22 is attached to the other end, which is also an end on the one side in the first direction. In this way, the hydraulic pump 21 and the electric motor 22 are connected by the connecting member 25. Inside the cylindrical portion 25a, the drive shaft 21a extends along the axis of the cylindrical portion 25a (i.e., toward the other side of the first direction) and is connected to the electric motor 22. The flange 25b is formed around the entire circumferential direction at the other end of the cylindrical portion 25a. The flange 25b protrudes radially outward from the other end of the cylindrical portion 25a.

[0025] As shown in FIG. 6 , a support frame 23, which is an example of a support member, is erected in a first direction (in the present embodiment, the vertical direction) on the installation surface 12a of the shovel 3. The support frame 23 supports the hydraulic pump 21 and the electric motor 22 so that the drive shaft 21a extends in the vertical direction when erected. That is, the support frame 23 supports the hydraulic pump 21 and the electric motor 22 so that they are vertically oriented (i.e., aligned vertically). In the present embodiment, the support frame 23 is a substantially rectangular parallelepiped frame as shown in FIGS. 3 to 5 . The support frame 23 supports the hydraulic pump 21 and the electric motor 22 so that the hydraulic pump 21 is positioned below the electric motor 22. More specifically, the support frame 23 includes a support portion 31, an attachment portion 32, and a vibration-isolating member 33. The support frame 23 also includes a hoisting device 34.

[0026] The support part 31 is a member extending in the vertical direction. The support part 31 has an installation part 31a on its lower side, and is erected on the installation surface 12a so that the installation part 31a is placed on the installation surface 12a. The support part 31 is formed, for example, in the shape of a roughly rectangular parallelepiped frame. More specifically, the support part 31 has the installation part 31a, four leg parts 31b, and a top surface part 31c.

[0027] The installation portion 31a is a portion that is installed on the installation surface 12a. In this embodiment, the installation portion 31a is a rectangular plate in a plan view. Note that the installation portion 31a may be the lower end portion 31f of the leg portion 31b, as described in detail later (see FIG. 7 , which will be described in detail later). The leg portion 31b is a rod-shaped member extending in the vertical direction. The leg portion 31b is, for example, a hollow rectangular column. However, the leg portion 31b may also be a hollow cylindrical column, a solid rectangular column or column, a channel steel, an L-shaped steel, or the like. The leg portions 31b are provided at the four corners of the installation portion 31a and extend upward from the installation portion 31a. The top surface portion 31c is placed on and fixed to the four leg portions 31b. In this embodiment, the top surface portion 31c is, for example, a rectangular plate, and the leg portions 31b are fixed to the four corners. Furthermore, a communication hole 31d is formed in the top surface portion 31c as shown in Fig. 5. A connecting member 25 is inserted into the communication hole 31d of the top surface portion 31c.

[0028] The mounting portion 32 is provided with the hydraulic pump 21 and the electric motor 22. More specifically, the mounting portion 32 has a mounting surface 32a. The hydraulic pump 21 and the electric motor 22 are mounted to the mounting surface 32a via the connecting member 25. The mounting portion 32 is placed on and fixed to the support portion 31 (more specifically, the top surface portion 31c) via a vibration-isolating member 33, which will be described in detail later. More specifically, the mounting portion 32 is formed in a generally rectangular plate shape. The mounting portion 32 has a through-hole 32b. The through-hole 32b passes through the mounting portion 32 in the vertical direction. The drive shaft 21a is inserted through the through-hole 32b. In this embodiment, the cylindrical portion 25a of the connecting member 25 is also inserted through the through-hole 32b. Meanwhile, the through-hole 32b has a smaller diameter than the flange 25b. Therefore, the flange 25b is placed on the periphery of the through-hole 32b in the mounting portion 32. That is, the flange 25b is placed on a mounting surface 32a, which is the upper surface of the mounting portion 32. Then, while the flange 25b is placed on the mounting surface 32a, it is fixed by a plurality of fastening members 32c, such as bolts. In this way, the hydraulic pump 21 and the electric motor 22 are attached to the mounting portion 32 via the connecting member 25.

[0029] The mounting portion 32 is attached to the support portion 31 as follows. That is, the mounting portion 32 is attached to the support portion 31 via the vibration-isolating member 33 as described above. At this time, the mounting portion 32 is attached to the support portion 31 with the mounting surface 32a facing upward, which is the other side of the first direction. In other words, the mounting portion 32 is attached to the support portion 31 so that the flange 25b is positioned above the mounting portion 32. As a result, the hydraulic pump 21 is positioned below the electric motor 22, which is the other side of the first direction. The mounting portion 32 is attached to the support portion 31 so that the hydraulic pump 21 attached to the mounting surface 32a is positioned above the installation portion 31a. As a result, the hydraulic pump 21 can be raised above the installation portion 31a.

[0030] The vibration-isolating members 33 are disposed between the mounting portion 32 and the support portion 31. The vibration-isolating members 33 suppress the transmission of vibrations from the mounting portion 32 to the support portion 31. That is, the vibration-isolating members 33 suppress the transmission of vibrations from the hydraulic pump 21 and the electric motor 22 to the support portion 31. The vibration-isolating members 33 are, for example, vibration-isolating rubber. However, the vibration-isolating members 33 are not limited to vibration-isolating rubber and may be vibration-isolating mechanisms such as dampers and hydraulic mounts. In this embodiment, the vibration-isolating members 33 are formed, for example, in a disk shape. Note that the vibration-isolating members 33 do not necessarily have to be disk-shaped and may be polygonal, etc. The vibration-isolating members 33 are provided at the four corners of the top surface portion 31c. The mounting portion 32 is placed on the four vibration-isolating members 33. The mounting portion 32 and the top surface portion 31c are fastened together by fastening members such as bolts inserted into each of the four vibration-isolating members 33, with the four vibration-isolating members 33 interposed between the mounting portion 32 and the top surface portion 31c. The vibration-isolating members 33 arranged in this manner are positioned between the mounting portion 32 and the top surface portion 31c, and therefore are positioned closer to the center of gravity of the pump unit 8 consisting of the hydraulic pump 21 and the electric motor 22 than if they were positioned between the installation portion 31a and the installation surface 12a.

[0031] The hoisting fixture 34 is used to hoist the support frame 23. More specifically, the hoisting fixture 34 is used to hoist the electric pump device 2 itself. The hoisting fixture 34 can be attached to a hoisting device (not shown), such as a crane. More specifically, a hoisting fixture, such as a hook of the hoisting device, can be attached to the hoisting fixture 34. The electric pump device 2 is then hoisted by pulling up the hoisting fixture. In this embodiment, four hoisting fixtures 34 are provided on the mounting portion 32, and each of the hoisting fixtures 34 is provided at one of the four corners of the mounting portion 32. The hoisting fixtures 34 may be arranged so that the drive shaft 21a extends substantially vertically when the electric pump device 2 is hoisted by the hoisting fixture, i.e., so that the center of gravity of the multiple hoisting fixtures 34 is located on the drive shaft 21a in a plan view.

[0032] [Multi-Control Valve] The multi-control valve 5 supplies the hydraulic fluid discharged from the electric pump device 2 to each of the hydraulic actuators and controls the flow of the supplied hydraulic fluid. Explaining in more detail, as described above, the multi-control valve 5 is connected to the hydraulic pump 21 (more specifically, the discharge ports 21g and 21h) of the electric pump device 2 via the discharge pipe 7b. The multi-control valve 5 configured in this manner is located behind the boom 13 within the revolving unit 12. In this embodiment, the multi-control valve 5 is located adjacent to the electric pump device 2 within the revolving unit 12.

[0033] [Battery] The battery 6 is electrically connected to the electric pump device 2 (more specifically, the inverter 24). The battery 6 supplies direct current to the inverter 24. The battery 6 is disposed inside the revolving structure 12. More specifically, the battery 6 is disposed rearward of the electric pump device 2 inside the revolving structure 12. In this embodiment, a counterweight 16 is disposed at the rearmost position inside the revolving structure 12. The battery 6 is disposed between the counterweight 16 and the electric pump device 2.

[0034] [Arrangement of the Electric Pump Device] As shown in FIG. 6 , the electric pump device 2 is installed upright on the installation surface 12a within the revolving structure 12. The tank 4 is located on one side of the second direction of the electric pump device 2. The second direction is a direction perpendicular to the first direction, which corresponds to the front-to-rear direction in this embodiment. The one side of the second direction corresponds to the forward direction in this embodiment. The electric pump device 2 is also arranged so that the suction port 21f of the hydraulic pump 21 faces one side of a third direction. Here, the third direction is a direction perpendicular to the first and second directions, which corresponds to the left-to-right direction in this embodiment. The one side of the third direction corresponds to the opposite direction to the direction in which the multi-control valve 5 is located relative to the electric pump device 2, which corresponds to the rightward direction in this embodiment. As shown in FIG. 2 , the revolving structure 12 has an opening / closing door 12c formed on the right side of the electric pump device 2, and the suction port 21f faces the opening / closing door 12c. As described above, the suction port 21f is connected to the suction pipe 7a. Therefore, the intake pipe 7a can be exposed to the outside by opening the door 12c, which makes it easier to perform maintenance on the intake pipe 7a.

[0035] The electric pump device 2 is also arranged so that the discharge ports 21g, 21h of the hydraulic pump 21 face rearward. As described above, the discharge pipe 7b is connected to the discharge ports 21g, 21h. Therefore, the discharge pipe 7b is arranged between the electric pump device 2 and the battery 6. This facilitates maintenance of the discharge pipe 7b.

[0036] [Installation of Electric Pump Device] The electric pump device 2 is installed inside the revolving body 12 of the excavator 3 as follows. That is, a suspending fixture of a suspending device (not shown) is attached to the suspending fixture 34 of the electric pump device 2. After attachment, the electric pump device 2 is lifted by the suspending device and transported onto the installation surface 12a. Thereafter, the installation portion 31a of the electric pump device 2 is lowered onto the installation surface 12a. As a result, the electric pump device 2 is erected on the installation surface 12a. Therefore, the electric pump device 2 can be easily installed on the installation surface 12a inside the revolving body 12.

[0037] [Operation of Hydraulic Drive System] When DC current flows from the battery 6 to the electric pump device 2, the electric pump device 2 operates as follows. Specifically, the inverter 24 converts the DC current to AC current and passes it to the electric motor 22. The electric motor 22 then drives the drive shaft 21a to rotate. As a result, the hydraulic pump 21 draws hydraulic fluid from the tank 4 through the suction port 21f via the suction pipe 7a and discharges it from the discharge ports 21g and 21h. The hydraulic fluid is guided from the discharge ports 21g and 21h through the discharge pipe 7b to the multi-control valve 5, and is further supplied to each of the hydraulic actuators via the multi-control valve 5. This allows each of the hydraulic actuators to be operated.

[0038] In the electric pump device 2 of this embodiment, the support frame 23 is erected upward and supports the hydraulic pump 21 and the electric motor 22 so that the drive shaft 21a extends upward. This reduces the installation area of ​​the electric pump device 2 when viewed from above, allowing the electric pump device 2 to be arranged more compactly.

[0039] In the electric pump device 2 of this embodiment, the hydraulic pump 21 is supported by the support frame 23 so as to be located below the electric motor 22. This prevents hydraulic fluid leaking from the hydraulic pump 21 from splashing onto the electric motor 22.

[0040] Furthermore, in the electric pump device 2 of this embodiment, the support frame 23 supports the hydraulic pump 21 so that the hydraulic pump 21 is disposed above the installation portion 31a. Therefore, when the electric pump device 2 is installed, the hydraulic pump 21 is disposed above and spaced apart from the installation surface 12a. This prevents the hydraulic pump 21 from being damaged by rubbing against the installation surface 12a due to vibration of the hydraulic pump 21.

[0041] Furthermore, in the electric pump device 2 of this embodiment, the connecting member 25 has a flange 25b, and the flange 25b is placed and fixed on the mounting surface 32a of the support frame 23. Therefore, the load of the hydraulic pump 21 is received by the connecting member 25, so that the load on the electric motor 22 can be suppressed.

[0042] Furthermore, in the electric pump device 2 of this embodiment, the vibration-isolating member 33 is disposed between the mounting portion 32 and the support portion 31. Therefore, the vibration-isolating member 33 can be disposed in a vertical position close to the center of gravity of the pump unit 8, which is made up of the hydraulic pump 21 and the electric motor 22. This makes it possible to suppress vibrations transmitted to the vibration-isolating member 33, thereby further improving the vibration-isolating performance.

[0043] Furthermore, in the electric pump device 2 of this embodiment, the four hoisting fixtures 34 are attached to the attachment surface 32a of the attachment portion 32. This makes it easier to hoist the electric pump device 2.

[0044] In the hydraulic drive system 1 of this embodiment, the tank 4 is disposed adjacent to the electric pump device 2 in the front-rear direction. The suction port 21f, which is connected to the tank 4 via the suction pipe 7a, is formed on the side surface of the hydraulic pump 21. This allows the length of the suction pipe 7a to be reduced.

[0045] <Other Embodiments> In the electric pump device 2 of this embodiment, the hydraulic pump 21 and the electric motor 22 are aligned coaxially. However, the axis of the electric motor 22 may be arranged so as to intersect (e.g., perpendicular to) the axis of the hydraulic pump 21. That is, in the electric pump device 2, the drive shaft 21a of the hydraulic pump 21 may be arranged vertically so as to extend in the first direction. Furthermore, the hydraulic pump 21 is not limited to a tandem pump and may be a single pump. Furthermore, the hydraulic pump 21 is not limited to a swash plate pump and may be a bent-axis pump or a gear pump. Furthermore, the hydraulic pump 21 may be arranged on the other side (i.e., above) of the electric motor 22 in the first direction. Furthermore, the hydraulic pump 21 may be located at the same position as the installation portion 31a or lower than the installation portion 31a. Furthermore, the electric motor 22 is not limited to a three-phase AC motor and may be another motor, such as a servo motor.

[0046] In the electric pump device 2 of this embodiment, the hydraulic pump 21 and the electric motor 22 are connected by a connecting member 25, but the hydraulic pump 21 and the electric motor 22 may be directly attached to the support frame 23 (more specifically, the mounting portion 32). The suspending fixture 34 does not necessarily have to be provided on the mounting portion 32, but may be provided on the support portion 31. The flange 25b does not necessarily have to be formed around the entire circumferential circumference of the cylindrical portion 25a. The flange may be configured as follows. That is, the flange may be configured by a plurality of protrusions that protrude radially outward from the cylindrical portion 25a and are spaced apart from one another in the circumferential direction, and the shape of the protrusions is not important.

[0047] In the electric pump device 2 of this embodiment, a reinforcing member 31e may be bridged between two adjacent leg portions 31b of the support frame 23 (see FIG. 7). As shown in FIG. 7, the lower end portion 31f of each leg portion 31b may serve as the installation portion, or another member may serve as the installation portion. Although the support frame 23 is formed in a frame shape consisting of multiple leg portions 31b, it may also be formed in a hollow cylindrical shape. Furthermore, in the support frame 23, the vibration-isolating member 33 is provided between the top surface portion 31c and the mounting portion 32. However, it may also be provided between the mounting portion 32 and the flange 25b. In this case, the vibration-isolating member 33 may be formed, for example, in a ring shape so as to be fitted to the cylindrical portion 25a. The vibration-isolating member 33 may also be provided between the installation portion 31a and the installation surface 12a, and between the leg portion 31b and the installation portion 31a. Furthermore, if the hydraulic pump 21 can be positioned away from the installation surface 12a by, for example, cutting out the installation surface 12a, a portion of the hydraulic pump 21 may protrude below the installation surface 12a.

[0048] In the hydraulic drive system 1 of this embodiment, the electric pump device 2 is disposed adjacent to the tank 4, but the electric pump device 2 may also be disposed away from the tank 4. Furthermore, the suction port 21f of the electric pump device 2 does not necessarily have to open in one of the third directions, but may open in one and the other of the second directions, or in the other of the third directions. Similarly, the direction in which the discharge ports 21g, 21h open is not limited to the other of the second directions.

[0049] <Illustrative embodiment> An electric pump device in a first aspect is mounted on a construction machine and comprises a hydraulic pump including a drive shaft that discharges hydraulic fluid when the drive shaft rotates, an electric motor that is connected to the drive shaft and drives the drive shaft to rotate, and a support member that supports the hydraulic pump and the electric motor, the support member being erected in a first direction perpendicular to the installation surface of the construction machine and supporting the hydraulic pump and the electric motor so that the drive shaft extends in the first direction.

[0050] According to the above aspect, the support member is erected in the first direction and supports the hydraulic pump and the electric motor so that the drive shaft extends in the first direction. This reduces the installation area of ​​the electric pump device as viewed in the first direction, thereby enabling the electric pump device for construction machinery to be arranged more compactly.

[0051] In a second aspect, the electric pump device is the electric pump device of the first aspect, wherein the support member has an installation portion that is installed on the installation surface on one side in a first direction, and the hydraulic pump is supported by the support member so as to be positioned on one side in the first direction of the electric motor.

[0052] According to the above aspect, the hydraulic pump is supported by the support member so as to be located on the other side of the electric motor in the first direction. This makes it possible to prevent working fluid leaking from the hydraulic pump from splashing onto the electric motor.

[0053] In a third aspect, in the electric pump device of the second aspect, the support member supports the hydraulic pump so that the hydraulic pump is disposed on the other side in the first direction relative to the installation portion.

[0054] According to the above aspect, the support member supports the hydraulic pump so that the hydraulic pump is disposed on the other side in the first direction from the installation portion. Therefore, when the electric pump device for a construction machine is installed, the hydraulic pump is disposed away from the installation surface on the other side in the first direction. This prevents the hydraulic pump from being damaged by rubbing against the installation surface due to vibration of the hydraulic pump.

[0055] In a fourth aspect, the electric pump device is the electric pump device of any one of the first to third aspects, further comprising a connecting member that connects the hydraulic pump and the electric motor, the support member including a mounting surface, the connecting member having a flange, and the flange being placed on and fixed to the mounting surface.

[0056] According to the above aspect, the connecting member has a flange, and the flange is placed on and fixed to the mounting surface of the support member. Therefore, the load of the hydraulic pump is borne by the connecting member, so that the load on the electric motor can be suppressed.

[0057] In a fifth aspect, the electric pump device is the electric pump device of the fourth aspect, wherein the support member includes a support part having an installation portion to be installed on the installation surface on one side in a first direction, a mounting part having the installation surface and placed on the support part, and a vibration-damping member that suppresses the transmission of vibrations from the hydraulic pump and the electric motor to the support part, and the vibration-damping member is arranged between the installation part and the support part or between the installation part and the connecting member.

[0058] According to the above aspect, the vibration-damping member is disposed between the mounting portion and the support portion or between the mounting portion and the connecting member. This allows the vibration-damping member to be disposed in a vertical position close to the center of gravity of the pump unit consisting of the hydraulic pump and the electric motor. This reduces vibrations transmitted to the vibration-damping member, thereby further improving vibration-damping performance.

[0059] In a sixth aspect, the electric pump device is the electric pump device of the fourth aspect, wherein the support member includes a plurality of suspending devices for suspending the support member, and the plurality of suspending devices are attached to the mounting surface.

[0060] According to the above aspect, the plurality of lifting devices are attached to the ceiling surface, which makes it easier to lift the electric pump device for construction machinery.

[0061] A hydraulic drive system in a seventh aspect supplies hydraulic fluid to a hydraulic actuator provided on a construction machine to drive it, and includes an electric pump device of any of the first to sixth aspects, and a tank for storing hydraulic fluid and connected to an intake port of the hydraulic pump of the electric pump device for construction machinery via an intake piping, wherein the tank is positioned adjacent to the electric pump device for construction machinery in a second direction perpendicular to the first direction, and the intake port is formed on a side of the hydraulic pump.

[0062] According to the above aspect, the tank is disposed adjacent to the electric pump device for a construction machine in the second direction. The suction port connected to the tank via the suction pipe is formed on a side surface of the hydraulic pump. This reduces the length of the suction pipe.

[0063] 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 electric pump device for construction machinery that is mounted on construction machinery, comprising: a hydraulic pump that includes a drive shaft and discharges hydraulic fluid when the drive shaft rotates; an electric motor that is connected to the drive shaft and drives the drive shaft to rotate; and a support member that supports the hydraulic pump and the electric motor, wherein the support member is erected in a first direction perpendicular to the installation surface of the construction machine and supports the hydraulic pump and the electric motor so that the drive shaft extends in the first direction.

2. An electric pump device for construction machinery as described in claim 1, wherein the support member has an installation portion that is installed on the installation surface on one side in a first direction, and the hydraulic pump is supported by the support member so as to be located on the one side in the first direction of the electric motor.

3. An electric pump device for construction machinery as set forth in claim 2, wherein the support member supports the hydraulic pump so that the hydraulic pump is positioned on the other side in the first direction from the installation portion.

4. An electric pump device for construction machinery as described in claim 1, further comprising a connecting member that connects the hydraulic pump and the electric motor, the support member including a mounting surface, the connecting member having a flange, and the flange being placed on and fixed to the mounting surface.

5. The electric pump device for construction machinery as described in claim 4, wherein the support member includes a support part having an installation portion on one side in a first direction that is installed on the installation surface, a mounting part having the mounting surface and placed on the support part, and a vibration-damping member that suppresses the transmission of vibrations from the hydraulic pump and the electric motor to the support part, and the vibration-damping member is disposed between the mounting part and the support part or between the mounting part and the connecting member.

6. An electric pump device for construction machinery as described in claim 4, wherein the support member includes a plurality of hoisting devices for hoisting the support member, and the plurality of hoisting devices are attached to the mounting surface.

7. A hydraulic drive system that supplies hydraulic fluid to a hydraulic actuator provided on a construction machine to drive it, comprising: an electric pump device for construction machinery as described in claim 1; and a tank for storing hydraulic fluid and connected to an intake port of the hydraulic pump of the electric pump device for construction machinery via an intake piping, wherein the tank is arranged adjacent to the electric pump device for construction machinery in a second direction perpendicular to the first direction, and the intake port is formed on a side of the hydraulic pump.

Images