Electric construction machine

Abstract

An electric shovel (1) is provided with: a hydraulic pump (65) that discharges hydraulic oil; an electric motor (64) for driving the hydraulic pump (65); a hydraulic oil tank (66) for supplying hydraulic oil to the hydraulic pump (65); and an oil suction pipe (70) connected to the hydraulic pump (65) and the working oil tank (66) and extending along an output shaft (64a) of the electric motor (64). In a plan view, the oil suction pipe (70) overlaps the motor (64).

Description

Technical Field

[0001] This disclosure relates to electric construction machinery. Background Technology

[0002] Patent Document 1 discloses an electric excavator as an example of electric construction machinery. The electric excavator includes an electric motor driven by electricity stored in a battery. The electric motor drives a hydraulic pump that supplies pressurized oil to the hydraulic cylinders of the working device.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2020-045630 Summary of the Invention

[0006] The technical problem that the invention aims to solve

[0007] In electric construction machinery, it is necessary to place a large battery in the center of the vehicle body. Therefore, it is preferable to appropriately configure hydraulic related equipment such as hydraulic pumps and electric motors in limited spaces.

[0008] The purpose of this disclosure is to provide an electric engineering machine that can appropriately configure a hydraulic pump and an electric motor in a limited space.

[0009] Technical solutions for solving technical problems

[0010] The electric engineering machinery disclosed herein comprises: a hydraulic pump that discharges working oil; an electric motor that drives the hydraulic pump; a working oil tank that supplies working oil to the hydraulic pump; and an oil suction pipe that is connected to the hydraulic pump and the working oil tank, extends along the output shaft of the electric motor, and overlaps with the electric motor when viewed from above.

[0011] Invention Effects

[0012] According to this disclosure, it is possible to provide an electric construction machine that can appropriately configure a hydraulic pump and an electric motor in a limited space. Attached Figure Description

[0013] Figure 1 This is a perspective view of the electric excavator used in the implementation method.

[0014] Figure 2 This is a perspective view showing the internal structure of the vehicle body cover according to the embodiment.

[0015] Figure 3 This is a side view showing the internal structure of the vehicle body cover according to the embodiment.

[0016] Figure 4This is a top view showing the internal structure of the vehicle body cover according to the embodiment. Detailed Implementation

[0017] (Electric excavator 1)

[0018] The structure of the electric excavator 1 (an example of "electric construction machinery") of this embodiment will be described with reference to the accompanying drawings.

[0019] Figure 1 This is a 3D view of the electric excavator 1 viewed from the right rear.

[0020] In this manual, "up" and "down" refer to above and below with the vertical direction as the reference, "front" and "rear" refer to in front and behind with the direction of travel of the electric excavator 1 as the reference, and "left" and "right" refer to the left and right when facing the front of the electric excavator 1.

[0021] like Figure 1 As shown, the electric excavator 1 has a lower traveling body 2, an upper slewing body 3, a working device unit 4, and a cab 5.

[0022] The lower traveling body 2 has a track frame 20, drive wheels 21, driven wheels 22, and tracks 23. The track frame 20 extends in the front-rear direction. The drive wheels 21 are supported at the rear end of the track frame 20. The driven wheels 22 are supported at the front end of the track frame 20. The tracks 23 are mounted on the drive wheels 21 and the driven wheels 22.

[0023] The upper slewing body 3 is positioned above the lower traveling body 2. The upper slewing body 3 is capable of rotating relative to the lower traveling body 2. The upper slewing body 3 has a slewing frame 31 and a body cover 32.

[0024] The slewing frame 31 is formed as a plate extending in the horizontal direction. The slewing frame 31 is supported on the lower traveling body 2. The slewing frame 31 is capable of rotating relative to the lower traveling body 2.

[0025] The body cover 32 covers the space on the rotating frame 31. The body cover 32 is composed of plate-shaped components. Inside the body cover 32 are housed the battery unit 61, BTMS (Battery Thermal Management System) 62, inverter 63, electric motor 64, hydraulic pump 65, working oil tank 66, and hydraulic valve 67, etc.

[0026] like Figure 1 As shown, the hydraulic pump 65, electric motor 64, and working oil tank 66 are arranged on the side opposite to the cab 5 in the vehicle width direction. The hydraulic pump 65, electric motor 64, and working oil tank 66 are arranged sequentially from the rear. The internal structure of the body cover 32 will be described later.

[0027] The working device unit 4 includes a working device 40 and a working device drive unit 41. The working device 40 includes a boom 42, a boom 43, and a bucket 44. The working device drive unit 41 includes a boom cylinder 45, a boom cylinder 46, and a bucket cylinder 47. The boom cylinder 45, boom cylinder 46, and bucket cylinder 47 are operated by working oil supplied from a hydraulic valve 67.

[0028] The cab 5 is located on the left front end of the slewing frame 31. Various operating components are installed inside the cab 5.

[0029] (Internal structure of vehicle body cover 32)

[0030] Figure 2 This is a three-dimensional view of the internal structure of the vehicle body cover 32 as seen from the right front. Figure 3 This is a side view of the internal structure of the vehicle body cover 32 from the right side. Figure 4 This is a top view of the internal structure of the vehicle body cover 32.

[0031] The vehicle body cover 32 houses a battery pack 61, a BTMS 62, an inverter 63, an electric motor 64, a hydraulic pump 65, a working oil tank 66, and a hydraulic valve 67.

[0032] The battery unit 61 is located on the rear end of the rotary frame 31. Figure 4 As shown, the battery unit 61 is positioned approximately at the center of the rotating frame 31 in the vehicle width direction. The vehicle width direction is synonymous with the left-right direction. The battery unit 61 supplies DC power to the inverter 63.

[0033] The battery unit 61 includes multiple battery packs stacked vertically and a water jacket for circulating a heating medium. Multiple batteries are arranged inside each battery pack. Through the circulation of the heating medium within the water jacket, each battery is maintained within a suitable temperature range (e.g., 20°C to 35°C). The battery unit 61 also functions as a counterweight, as is common in conventional hydraulic excavators.

[0034] The BTMS62 is positioned above the battery unit 61. The BTMS62 manages the temperature of the battery unit 61. The BTMS62 supplies a heat transfer fluid, used for cooling or heating the battery unit 61, to the water jacket of the battery unit 61.

[0035] Inverter 63 is positioned in front of battery unit 61. Inverter 63 converts the direct current supplied from battery unit 61 into alternating current of the desired frequency. Inverter 63 is electrically connected to motor 64 via high-voltage cable 68. Inverter 63 supplies alternating current to motor 64 via high-voltage cable 68. In this embodiment, two high-voltage cables 68 are used, but the number of high-voltage cables 68 can be appropriately varied.

[0036] The electric motor 64 is located on the side end of the rotary frame 31 (right end in this embodiment) in front of the hydraulic pump 65 and behind the working oil tank 66.

[0037] like Figure 3 and Figure 4 As shown, the front end of the motor 64 is located further back than the rotation center Ax of the upper rotating body 3. The line La, representing the position of the front end of the motor 64 in the forward-backward direction, extends backward from the rotation center Ax of the upper rotating body 3 by a distance Da. The distance Da is not particularly limited and can be appropriately set to a value greater than 0.

[0038] The electric motor 64 is electrically connected to the inverter 63 via a high-voltage cable 68. The electric motor 64 is driven by AC power supplied from the inverter 63 via the high-voltage cable 68. Specifically, the electric motor 64 rotates a drive shaft 64a arranged in the front-to-back direction. Figure 3 and Figure 4 As shown, the drive shaft 64a is connected to the rotating shaft 65a of the hydraulic pump 65, which will be described later. The electric motor 64 drives the hydraulic pump 65 by rotating the drive shaft 64a.

[0039] The electric motor 64 is fixed to the hydraulic pump 65 via a coupling 69. The coupling 69 is formed in annular shape. The coupling 69 is splinedly engaged with both the electric motor 64 and the hydraulic pump 65.

[0040] The hydraulic pump 65 is located on the side end (right end in this embodiment) of the rotary frame 31, behind the motor 64.

[0041] The hydraulic pump 65 has a rotating shaft 65a arranged in the front-to-back direction. The axis of the rotating shaft 65a of the hydraulic pump 65 is substantially aligned with the axis of the drive shaft 64a of the electric motor 64. The rotating shaft 65a of the hydraulic pump 65 is connected to the drive shaft 64a of the electric motor 64 inside the coupling 69. Alternatively, the rotating shaft 65a of the hydraulic pump 65 can also be connected to the drive shaft 64a of the electric motor 64 via an intermediate component.

[0042] Hydraulic pump 65 is connected to working oil tank 66 via suction pipe 70. Suction pipe 70 is a pipe that guides working oil from working oil tank 66 to hydraulic pump 65. Hydraulic pump 65 is connected to hydraulic valve 67 via supply pipe 71. Supply pipe 71 is a pipe that guides working oil from hydraulic pump 65 to hydraulic valve 67. In this embodiment, two supply pipes 71 are used, but the number of supply pipes 71 can be appropriately changed.

[0043] When the rotating shaft 65a of the hydraulic pump 65 rotates along with the drive shaft 64a of the motor 64, the hydraulic pump 65 draws in working oil from the suction pipe 70 and discharges working oil to the supply pipe 71. Thus, working oil is supplied from the working oil tank 66 to the hydraulic valve 67.

[0044] The working oil tank 66 is disposed on the side end (right end in this embodiment) of the rotary frame 31 in front of the motor 64. The working oil tank 66 is a box-shaped container. The working oil tank 66 stores working oil inside.

[0045] The working oil tank 66 supplies working oil to the hydraulic pump 65 via the suction pipe 70. The front end of the suction pipe 70 is connected to the lower end of the working oil tank 66. The working oil stored in the working oil tank 66 is drawn into the hydraulic pump 65 through the suction pipe 70.

[0046] Hydraulic valve 67 is disposed on the side end (right end in this embodiment) of the rotary frame 31 in front of the working oil tank 66. Working oil discharged from hydraulic pump 65 is supplied to hydraulic valve 67 via supply pipe 71. Hydraulic valve 67 supplies working oil to the working device drive unit 41 of working device unit 4. Thus, the working device 40 of working device unit 4 is driven.

[0047] High-voltage cable 68 is connected to inverter 63 and motor 64. High-voltage cable 68 supplies power from battery unit 61 via inverter 63 to motor 64.

[0048] like Figure 4 As shown, the high-voltage cable 68 extends from the motor 64 toward the center in the vehicle width direction. In this embodiment, the motor 64 is located on the right end of the rotary frame 31, therefore the high-voltage cable 68 extends to the left from the motor 64 toward the inverter 63. Figure 4 In the middle, the center of the vehicle width direction is represented by the line Lb passing through the center of the vehicle width direction of the rotating frame 31.

[0049] like Figure 4 As shown, the high-voltage cable 68 is positioned, when viewed from above, closer to the center of the vehicle width direction than the outer edge of the motor 64 in the vehicle width direction. In this embodiment, the motor 64 is located on the right end of the rotary frame 31, therefore the high-voltage cable 68 is positioned closer to the center of the vehicle width direction than the right outer edge of the motor 64. The outer edge of the motor 64 in the vehicle width direction is, when viewed from above, adjacent to the vehicle body cover 32 within the motor 64 (in... Figure 4 Not shown in the image, please refer to the diagram. Figure 1 The relative area. Figure 4 In the diagram, the right outer edge of the motor 64 is represented by line Lc.

[0050] The oil suction pipe 70 is connected to the hydraulic pump 65 and the working oil tank 66. For example... Figure 4 As shown, the oil suction pipe 70 extends along the drive shaft 64a of the motor 64. In this embodiment, the drive shaft 64a of the motor 64 extends in the front-rear direction, therefore the oil suction pipe 70 also extends in the front-rear direction.

[0051] Here, as Figure 4As shown, in a top view, the oil suction pipe 70 overlaps with the motor 64. In a top view, the oil suction pipe 70 passes inside the motor 64. The oil suction pipe 70 does not extend to the left or right of the motor 64. In this embodiment, the oil suction pipe 70 is positioned below the motor 64. Therefore, the oil suction pipe 70 extends in the front-to-back direction between the motor 64 and the rotating frame 31.

[0052] like Figure 4 As shown, the oil suction pipe 70 consists of a horizontal pipe 70a and a vertical pipe 70b. The horizontal pipe 70a extends horizontally (in this embodiment, front-to-back) below the electric motor 64 and the hydraulic pump 65. The vertical pipe 70b extends vertically below the hydraulic pump 65. The front end of the horizontal pipe 70a is connected to the lower end of the working oil tank 66. The rear end of the horizontal pipe 70a is connected to the lower end of the vertical pipe 70b. The upper end of the vertical pipe 70b is connected to the lower surface of the hydraulic pump 65.

[0053] (feature)

[0054] (1) In the electric excavator 1, when viewed from above, the suction pipe 70 overlaps with the motor 64. Therefore, compared to the case where the suction pipe 70 does not overlap with the motor 64, the area required in the vehicle width direction to accommodate the motor 64 and the suction pipe 70 together can be reduced. Therefore, the hydraulic pump 65 and the motor 64 can be appropriately arranged in a limited space.

[0055] (2) In the electric excavator 1, the suction pipe 70 is positioned below the motor 64. This makes it easy to connect the front end of the suction pipe 70 to the lower end of the working oil tank 66. Therefore, working oil free of air bubbles can be drawn from the working oil tank 66 into the suction pipe 70.

[0056] (Modifications of the implementation method)

[0057] The embodiments of the present invention have been described above, but the present invention is not limited thereto and can be appropriately modified without departing from the technical concept of the invention.

[0058] (Variation Example 1)

[0059] In the above embodiment, the hydraulic pump 65, the electric motor 64, and the working oil tank 66 are disposed on the right end of the slewing frame 31, but they can also be disposed on the left end of the slewing frame 31. In this case, the operator's cab 5 is disposed on the right end of the slewing frame 31.

[0060] (Variation Example 2)

[0061] In the above embodiment, the front end of the motor 64 is located behind the rotation center Ax of the upper rotating body 3, but it can also overlap with the rotation center Ax, or it can be located in front of the rotation center Ax.

[0062] (Variation Example 3)

[0063] In the above embodiment, the hydraulic valve 67 is positioned in front of the working oil tank 66, but is not limited thereto. The position of the hydraulic valve 67 can be changed as appropriate.

[0064] (Variation Example 4)

[0065] In the above embodiment, the high-voltage cable 68 extends from the motor 64 toward the center in the vehicle width direction, but is not limited thereto. For example, the high-voltage cable 68 may also extend from the motor 64 toward the front or rear.

[0066] (Variation Example 5)

[0067] In the above embodiment, the high-voltage cable 68 is positioned, when viewed from above, closer to the center of the vehicle width direction than the outer edge of the motor 64 in the vehicle width direction, but it is not limited to this. For example, if it is only a part of the high-voltage cable 68, it may also be positioned, closer to the outer edge of the vehicle width direction than the outer edge of the motor 64 in the vehicle width direction.

[0068] (Variation Example 6)

[0069] In the above embodiment, the hydraulic pump 65, the electric motor 64, and the working oil tank 66 are arranged sequentially from the rear, but they can also be arranged sequentially from the front.

[0070] (Variation Example 7)

[0071] In the above embodiment, the oil suction pipe 70 is disposed below the motor 64, but it can also be disposed above the motor 64.

[0072] (Variation Example 8)

[0073] In the above embodiments, an electric excavator was described as an example of electric construction machinery, but electric construction machinery is not limited to this. Electric construction machinery can operate simply by using the power of a battery device; examples of such electric construction machinery include electric wheel loaders and motorized graders.

[0074] Explanation of reference numerals in the attached figures

[0075] 1: Electric excavator

[0076] 2: Lower driving body

[0077] 3: Upper Rotating Body

[0078] 31: Rotary frame

[0079] 32: Vehicle body cover

[0080] 4: Working device unit

[0081] 5: Driver's cab

[0082] 61: Battery device

[0083] 62: BTMS

[0084] 63: Inverter

[0085] 64: Electric motor

[0086] 65: Hydraulic pump

[0087] 66: Working oil tank

[0088] 67: Hydraulic valve

[0089] 68: High-voltage cable

[0090] 69: Coupling

[0091] 70: Oil suction pipe

[0092] 80: Distribution panel

Claims

1. An electric engineering machine, characterized in that, have: A hydraulic pump discharges working oil; An electric motor drives the hydraulic pump; A working oil tank that supplies working oil to the hydraulic pump; An oil suction pipe, which connects to the hydraulic pump and the working oil tank, extends along the output shaft of the electric motor. When viewed from above, the oil suction pipe overlaps with the electric motor.

2. The electric engineering machinery according to claim 1, characterized in that, The oil suction pipe is located below the electric motor.

3. The electric engineering machinery according to claim 1 or 2, characterized in that, The working oil tank is located in front of the electric motor.

Images