Electric excavator

Abstract

The invention discloses an electric excavator, relates to the field of excavators, and aims to improve the performance of an existing electric excavator. The electric excavator comprises a frame, a cab and a hydraulic system. The cab is arranged at one end of the frame in the width direction; the hydraulic system comprises a pump assembly. The pump assembly comprises a first pump, a second pump and a third pump. The first pump is mounted in a middle area in the width direction of the frame; the second pump and the third pump are arranged side by side at the other end of the frame in the width direction. According to the electric excavator provided by the technical scheme, the plurality of independent pumps are adopted in the hydraulic system, and each pump is used for driving the electric excavator to perform different actions, so that a multi-way valve does not need to be arranged, and the problems of low operation efficiency, complicated structure, large size, high manufacturing cost and the like caused by the arrangement of the multi-way valve can be avoided; the operation efficiency of the electric excavator is improved, and the manufacturing cost of equipment is reduced.

Description

Technical Field

[0001] The present invention relates to the field of excavators, and in particular to an electric excavator. Background Art

[0002] Electric excavators are devices that use electricity as a driving energy source. The current electric excavators are obtained by "converting oil to electricity", that is, the traditional diesel excavators are transformed into electric-driven devices. The hydraulic part of the electric excavator still uses a variable hydraulic pump and a multi-way valve structure.

[0003] The inventors have found that there are at least the following problems in the prior art: the variable hydraulic pump has low energy efficiency, and the variable hydraulic pump drives a large throttling loss of the multi-way valve, resulting in low operating efficiency of the hydraulic system; the multi-way valve has a complex structure, a large size, and a high manufacturing cost. Summary of the invention

[0004] The present invention provides an electric excavator to improve the performance of the existing electric excavator.

[0005] An embodiment of the present invention provides an electric excavator, comprising:

[0006] Frame;

[0007] A cab is arranged at one end of the frame in the width direction; and

[0008] Hydraulic system;

[0009] Wherein, the hydraulic system comprises:

[0010] The pump assembly includes a first pump, a second pump and a third pump; the first pump is installed in the middle area of ​​the frame in the width direction; the second pump and the third pump are arranged side by side at the other end of the frame in the width direction.

[0011] In some embodiments, the electric excavator further comprises:

[0012] The rotary drive assembly includes a rotary motor and a rotary actuator; the rotary motor is installed in the middle area of ​​the frame, and the rotary motor is arranged adjacent to the first pump; the rotary actuator is drivingly connected to the rotary motor to rotate under the drive of the rotary motor.

[0013] In some embodiments, the hydraulic system further comprises:

[0014] A hydraulic oil tank is installed in the middle area of ​​the frame, and the hydraulic oil tank is located between the first pump and the rotary motor.

[0015] In some embodiments, the hydraulic system further comprises:

[0016] A first valve is located on one side of the first pump along the width direction of the frame; the first valve is mounted on the frame; and

[0017] The second valve is arranged side by side with the first valve along the length direction of the frame; the second valve is installed on the frame.

[0018] In some embodiments, the second pump is located on a side of the first valve away from the cab; the third pump is located on a side of the second valve away from the first valve; and the second pump and the third pump are both mounted on the vehicle frame.

[0019] In some embodiments, the hydraulic system further comprises:

[0020] The third valve is located at a side of the third pump away from the rotary motor; the third valve is installed on the vehicle frame.

[0021] In some embodiments, the electric excavator further comprises:

[0022] The electrical system includes a battery-changing box, a battery pack, a storage battery and a controller; the battery-changing box is installed at the rear of the vehicle frame; the battery pack is installed inside the battery-changing box; the storage battery is installed on the vehicle frame, and the storage battery is located between the battery-changing box and the cab;

[0023] The controller is installed on a side of the third valve away from the second valve; and the controller is installed on the vehicle frame.

[0024] In some embodiments, the electrical system also includes a pilot motor; the controller is located on the top of the pilot motor, and the controller and the pilot motor are arranged in layers; the hydraulic system also includes a pilot pump, which is connected to the pilot motor drive so as to operate under the drive of the pilot motor.

[0025] In some embodiments, the electric excavator further comprises:

[0026] A thermal management system, including a battery cooling system and a motor cooling system; the battery cooling system is installed inside the battery swap box, and the battery cooling system is constructed to cool the battery pack; the motor cooling system is arranged adjacent to the rotary motor, and the motor cooling system is supported by the frame, and the motor cooling system is constructed to cool the rotary motor.

[0027] In some embodiments, the electrical system further comprises:

[0028] An EVCU mounted on a rear side panel of the cab; and

[0029] The VCU is also installed on the rear side panel of the cab, and the VCU is located on the top of the EVCU.

[0030] In some embodiments, the electric excavator further comprises:

[0031] A counterweight is installed at the rear of the frame.

[0032] The electric excavator provided by the above technical solution has a hydraulic system that uses multiple independent pumps, each pump is used to drive the electric excavator to perform different actions, so there is no need to set up a multi-way valve. This can avoid the problems of low operating efficiency, complex structure, large size, high manufacturing cost, etc. caused by the setting of a multi-way valve, thereby improving the operating efficiency of the electric excavator and reducing the manufacturing cost of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0034] Figure 1 A schematic top view of an electric excavator provided in an embodiment of the present invention.

[0035] Figure 2 A three-dimensional schematic diagram of an electric excavator provided in an embodiment of the present invention.

[0036] Reference numerals:

[0037] 1. Frame; 2. Cab; 3. Hydraulic system; 4. Slewing drive assembly; 5. Electrical system; 6. Counterweight; 7. Turntable;

[0038] 31. Pump assembly; 32. Hydraulic oil tank; 33. First valve; 34. Second valve; 35. Third valve;

[0039] 311, first pump; 312, second pump; 313, third pump;

[0040] 41. Rotary motor;

[0041] 51. Battery replacement box; 52. Battery pack; 53. Battery; 54. Controller; 55. EVCU; 56. VCU; 57. Radiator. DETAILED DESCRIPTION

[0042] Combine the following Figure 1-2The technical solution provided by the present invention is described in more detail. The description of the exemplary embodiments is merely illustrative and is by no means intended to limit the present disclosure and its application or use. The present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to make the present disclosure thorough and complete and to fully express the scope of the present disclosure to those skilled in the art. It should be noted that unless otherwise specifically stated, the relative arrangement of the components and steps, the composition of the materials, the numerical expressions and the numerical values ​​described in these embodiments should be interpreted as being merely exemplary and not limiting.

[0043] The words "first", "second" and similar words used in this disclosure do not indicate any order, quantity or importance, but are only used to distinguish different parts. The words "include" or "comprise" and similar words mean that the elements before the word include the elements listed after the word, and do not exclude the possibility of also including other elements.

[0044] In the present disclosure, when a specific device is described as being located between a first device and a second device, there may or may not be an intermediate device between the specific device and the first device or the second device. When a specific device is described as being connected to other devices, the specific device may be directly connected to the other devices without an intermediate device, or may not be directly connected to the other devices but have an intermediate device.

[0045] All terms used in the present disclosure, including technical terms or scientific terms, have the same meanings as those understood by ordinary technicians in the field to which the present disclosure belongs, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries, such as general dictionaries, should be interpreted as having meanings consistent with their meanings in the context of the relevant technology, and should not be interpreted in an idealized or extremely formal sense, unless explicitly defined herein.

[0046] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment are considered part of the specification.

[0047] The dimensions of the various parts shown in the drawings are not drawn according to the actual proportional relationship. In the drawings, the same reference numerals are attached to common structural elements or structural elements of the same type, and their repeated descriptions are appropriately omitted.

[0048] In the description of the specific embodiments below, for the convenience of explanation, Figure 1 In the figure, an XY coordinate system is established, wherein the X-axis direction corresponds to the left-right direction (the length direction of the electric excavator, which is also the length direction of the frame 1), and the Y-axis direction corresponds to the up-down direction (the width direction of the electric excavator, which is also the width direction of the frame 1).

[0049] See also Figure 1 and Figure 2 , an embodiment of the present invention provides an electric excavator, which can be specifically a 21-ton pure electric excavator. The electric excavator includes a frame 1, a cab 2 and a hydraulic system 3. The cab 2 is arranged at one end of the frame 1 in the width direction. Among them, the hydraulic system 3 includes a pump assembly 31, and the pump assembly 31 includes a first pump 311, a second pump 312 and a third pump 313; the first pump 311 is installed in the middle area of ​​the frame 1 in the width direction; the second pump 312 and the third pump 313 are arranged side by side at the other end of the frame 1 in the width direction.

[0050] The technical solution of the embodiment of the present invention is that the hydraulic system 3 is not provided with a multi-way valve, nor is it provided with a large-capacity pump, but rather adopts a plurality of pumps to be driven in a distributed manner to realize different actions of the electric excavator.

[0051] Specifically, the pump assembly 31 includes three pumps: a first pump 311, a second pump 312 and a third pump 313. The three pumps are dispersedly arranged at different positions of the frame 1. From the width direction of the frame 1, the first pump 311 is located in the middle position of the width direction of the frame 1, and the second pump 312 and the third pump 313 are arranged at or near the lower side of the width direction of the frame 1. Specifically, the second pump 312 is arranged and installed along the lower side of the frame 1, and the third pump 313 is close to the lower side of the frame 1, but compared with the second pump 312, the position of the third pump 313 is closer to the center line L of the width direction of the frame 1. The cab 2 is arranged on the upper side of the width direction of the frame 1. The second pump 312 and the third pump 313 are roughly balanced with the weight of the cab 2, so that the load on both sides of the frame 1 in its own width direction is basically balanced. On the other hand, the first pump 311, the second pump 312, and the third pump 313 are respectively used to drive the electric excavator to perform different actions. Distributing the three pumps also facilitates connecting each pump to the driven component.

[0052] Continue to see Figure 1 In some embodiments, the second pump 312 is located on a side of the first valve 33 away from the cab 2 ; the second pump 312 is mounted on the vehicle frame 1 . The third pump 313 is located on a side of the second valve 34 away from the first valve 33 ; the third pump 313 is also mounted on the vehicle frame 1 .

[0053] Specifically, the first pump 311 is drivingly connected to the first valve 33 to drive the electric excavator to move left and extend and retract the boom cylinder.

[0054] The second pump 312 is drivingly connected to the second valve 34 to drive the electric excavator to move right, lift the boom, and merge.

[0055] The third pump 313 is drivingly connected to the third valve 35, and is used to drive the boom to be raised and lowered, the arm cylinder to be extended and retracted, and the bucket cylinder to be extended and retracted.

[0056] The first pump 311 and the third pump 313 merge to jointly drive the extension and retraction action of the boom cylinder, which can increase the hydraulic oil supply of the boom cylinder and make the action of the boom more stable and reliable.

[0057] The second pump 312 and the third pump 313 merge to jointly drive the lifting and lowering action of the boom, making the lifting action of the boom more stable and reliable.

[0058] The electric excavator provided by the above technical solution has various components of the hydraulic system 3 arranged in a decentralized manner. The entire hydraulic system 3 no longer needs to be provided with a multi-way valve. For each action, the first pump 311, the second pump 312, and the third pump 313 only need to be connected to the associated actuators, and the connection of the hydraulic pipeline is simpler and more efficient. When a pump fails or needs to be repaired, it will not affect the normal operation of other pumps. The fault tolerance efficiency of the entire electric excavator is higher and the reliability is more guaranteed.

[0059] Continue to see Figure 1 In some embodiments, the electric excavator further includes a slewing drive assembly 4, which includes a slewing motor 41 and a slewing actuator (not shown in the figure). The slewing motor 41 drives the slewing actuator to move so as to realize the slewing action of the electric excavator. The slewing motor 41 is installed in the middle area of ​​the frame 1, and the slewing motor 41 is arranged adjacent to the first pump 311. The slewing actuator is connected to the slewing motor 41 to rotate under the drive of the slewing motor 41. The slewing center of the entire electric excavator is relatively close to the center of the frame 1. The slewing motor 41 is arranged in the middle area of ​​the frame 1. When driving the electric excavator to rotate, the number of components required for the entire slewing transmission mechanism is small, the slewing drive efficiency is high, and the energy consumption is low. In addition, the weight of the slewing motor 41 is large. Arranging the slewing motor 41 in the middle area of ​​the frame 1 also makes the load of the frame 1 more reasonable.

[0060] Continue to see Figure 1 In some embodiments, the hydraulic system 3 further includes a hydraulic oil tank 32, which is installed in the middle area of ​​the frame 1 and is located between the first pump 311 and the slewing motor 41. The hydraulic oil tank 32 can provide hydraulic oil for each pump. The hydraulic oil tank 32 is arranged in the middle area of ​​the frame 1. On the one hand, the length of each hydraulic pipeline connected from the hydraulic oil tank 32 is relatively short. On the other hand, the position of the hydraulic oil tank 32 can avoid the larger components such as the cab 2, the second pump 312, and the third pump 313, so that the arrangement position of each component of the electric excavator is more reasonable.

[0061] Continue to see Figure 1 In some embodiments, the hydraulic system 3 further includes a first valve 33 and a second valve 34. The first valve 33 is located on one side of the first pump 311 along the width direction of the frame 1; the first valve 33 is installed on the frame 1. The second valve 34 is arranged side by side with the first valve 33 along the length direction of the frame 1; the second valve 34 is installed on the frame 1.

[0062] The first valve 33 and the second valve 34 are arranged in parallel, and the first valve 33 and the second valve 34 are located on the side of the second pump 312 close to the center line L in the width direction of the frame 1. The first valve 33 cooperates with the first pump 311 to realize the electric excavator to walk on one side, such as walking on the left; in addition, the first pump 311 is also used to realize the telescopic action of the boom cylinder. The second valve 34 cooperates with the second pump 312 described later to realize the electric excavator to walk on the other side, such as walking on the right; in addition, the second pump 312 is also used to drive the boom lifting and merging actions.

[0063] Continue to see Figure 1 In some embodiments, the hydraulic system 3 further includes a third valve 35, which is located on a side of the third pump 313 away from the rotary motor 41; the third valve 35 is installed on the vehicle frame 1. The third valve 35 is relatively close to the third pump 313, and the third valve 35 is hydraulically connected to the third pump 313. Driven by the third pump 313, the third pump 313 is used to drive the lifting and lowering of the boom, the extension and retraction of the arm cylinder, and the extension and retraction of the bucket cylinder.

[0064] See also Figure 2 In some embodiments, the electric excavator further includes an electrical system 5, which includes a battery-swap box 51, a battery pack 52, a storage battery 53, and a controller 54. The battery pack 52 is installed inside the battery-swap box 51; the storage battery 53 is installed on the frame 1, and the storage battery 53 is located between the battery-swap box 51 and the cab 2. The controller 54 is installed on the side of the third valve 35 away from the second valve 34; the controller 54 is installed on the frame 1. The battery pack 52 is used to provide 618V DC high voltage electricity. The storage battery 53 is used to provide 24V low voltage electricity.

[0065] The battery-changing box 51 is installed at the rear of the vehicle frame 1. The size of the battery-changing box 51 is relatively large. The battery-changing box 51 is located at the rear of the vehicle frame 1 and is balanced with the cab 2 located on the vehicle body, so that the weight distribution of the head and tail of the electric excavator is balanced.

[0066] The battery pack 52 is used to provide power to the main components, such as the first pump 311, the second pump 312 and the third pump 313. The three pumps are all driven by working motors. One or more working motors can be provided to drive each pump.

[0067] The electrical system 5 further includes a radiator 57, which can cool various components arranged near it. The radiator 57 is arranged adjacent to the battery-changing box 51, and the radiator 57 is located on the side of the battery-changing box 51 facing the cab 2.

[0068] In some embodiments, the electrical system 5 further includes a pilot motor (not shown); the controller 54 is located on top of the pilot motor, and the controller 54 and the pilot motor are arranged in layers. The hydraulic system 3 further includes a pilot pump, which is connected to the pilot motor driving to operate under the drive of the pilot motor. The controller 54 is located on top of the turntable 7.

[0069] The pilot motor is fixedly connected to the pilot pump by bolts. The pilot motor drives the pilot pump to rotate, and the pilot pump transmits the hydraulic oil to the oil-consuming components.

[0070] For an electrically driven excavator, in some embodiments, the electric excavator further includes a thermal management system, which includes a battery cooling system and a motor cooling system; the battery cooling system is installed inside the battery exchange box 51, and the battery cooling system is configured to cool the battery pack 52; the motor cooling system is arranged adjacent to the rotary motor 41, and the motor cooling system is supported by the frame 1, and the motor cooling system is configured to cool the rotary motor 41. The thermal management system is used to control the temperature of the battery pack 52 so that the temperature of the battery pack 52 will not be too high during charging and operation, effectively ensuring the safety of the use of the battery pack 52. When the temperature of the battery pack 52 exceeds the set safety temperature range, the battery cooling system will start to cool the battery pack 52 or increase the supply of coolant and reduce the temperature of the coolant to achieve a better cooling effect on the battery pack 52.

[0071] In some embodiments, the electrical system 5 further includes an EVCU 55 and a VCU 56 . The EVCU 55 is installed on the rear side panel of the cab 2 ; the VCU 56 is also installed on the rear side panel of the cab 2 , and the VCU 56 is located on the top of the EVCU 55 .

[0072] EVCU55 is the abbreviation of electric vehicle control unit, which means electric vehicle complete control unit in Chinese. VCU56 is the abbreviation of vehicle control unit, which means vehicle control unit in Chinese.

[0073] In the embodiment of the present invention, the functions of EVCU55 and VCU56 are different: EVCU55 is the overall controller of the high-voltage part of the electric excavator, responsible for the control and status monitoring of the entire high-voltage system including power-on, charging and other processes, and is also connected to the communication with the main controller of the low-voltage part. VCU56 is used to collect information from hydraulic sensors and relays to control the operation of the hydraulic system of the entire vehicle.

[0074] In some embodiments, the electric excavator further comprises a counterweight 6, which is mounted on the rear of the frame 1. The counterweight 6 is detachably mounted on the rear of the frame 1, and the weight of the counterweight 6 can be flexibly changed according to the model and load capacity of the electric excavator.

[0075] In the description of the present invention, it is necessary to understand that the terms "center", "longitudinal", "lateral", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the protection content of the present invention. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0076] In the description of the present invention, each technical feature may be combined with other technical features where feasible.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein, but these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An electric excavator, characterized in that: include: Frame (1); A cab (2) is arranged at one end of the vehicle frame (1) in the width direction; as well as Hydraulic system (3); Wherein, the hydraulic system (3) comprises: The pump assembly (31) comprises a first pump (311), a second pump (312) and a third pump (313); the first pump (311) is installed in the middle area of ​​the frame (1) in the width direction; the second pump (312) and the third pump (313) are arranged side by side at the other end of the frame (1) in the width direction.

2. The electric excavator according to claim 1, characterized in that: Also includes: A rotary drive assembly (4) comprises a rotary motor (41) and a rotary actuator; the rotary motor (41) is mounted in the middle area of ​​the frame (1), and the rotary motor (41) is arranged adjacent to the first pump (311); the rotary actuator is drivingly connected to the rotary motor (41) so as to rotate under the drive of the rotary motor (41).

3. The electric excavator according to claim 2, characterized in that: The hydraulic system (3) further comprises: A hydraulic oil tank (32) is installed in the middle area of ​​the frame (1), and the hydraulic oil tank (32) is located between the first pump (311) and the rotary motor (41).

4. The electric excavator according to claim 2, characterized in that: The hydraulic system (3) further comprises: a first valve (33) located on one side of the first pump (311) along the width direction of the frame (1); the first valve (33) is mounted on the frame (1); and The second valve (34) is arranged side by side with the first valve (33) along the length direction of the frame (1); the second valve (34) is installed on the frame (1).

5. The electric excavator according to claim 4, characterized in that: The second pump (312) is located on a side of the first valve (33) away from the cab (2); the third pump (313) is located on a side of the second valve (34) away from the first valve (33); the second pump (312) and the third pump (313) are both mounted on the vehicle frame (1).

6. The electric excavator according to claim 5, characterized in that: The hydraulic system (3) further comprises: The third valve (35) is located on a side of the third pump (313) away from the rotary motor (41); the third valve (35) is mounted on the vehicle frame (1).

7. The electric excavator according to claim 6, characterized in that: Also includes: An electrical system (5) comprises a battery-changing box (51), a battery pack (52), a storage battery (53) and a controller (54); the battery-changing box (51) is installed at the rear of the vehicle frame (1); the battery pack (52) is installed inside the battery-changing box (51); the storage battery (53) is installed on the vehicle frame (1), and the storage battery (53) is located between the battery-changing box (51) and the cab (2); The controller (54) is installed on a side of the third valve (35) away from the second valve (34); the controller (54) is installed on the vehicle frame (1).

8. The electric excavator according to claim 7, characterized in that: The electrical system (5) further comprises a pilot motor; the controller (54) is located on top of the pilot motor, and the controller (54) and the pilot motor are arranged in layers; The hydraulic system (3) further comprises a pilot pump, which is drivingly connected to the pilot motor so as to operate under the drive of the pilot motor.

9. The electric excavator according to claim 7, characterized in that: Also includes: A thermal management system, comprising a battery cooling system and a motor cooling system; the battery cooling system is installed inside the battery swap box (51), and the battery cooling system is constructed to cool the battery pack (52); the motor cooling system is arranged adjacent to the rotary motor (41), and the motor cooling system is supported by the vehicle frame (1), and the motor cooling system is constructed to cool the rotary motor (41).

10. The electric excavator according to claim 7, characterized in that: The electrical system (5) further comprises: An EVCU (55) mounted on a rear side panel of the cab (2); and The VCU (56) is also installed on the rear side panel of the cab (2), and the VCU (56) is located on the top of the EVCU (55).

11. The electric excavator according to claim 1, characterized in that: Also includes: A counterweight (6) is installed at the rear of the vehicle frame (1).

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