Excavator hydraulic system and excavator

Abstract

The invention discloses an excavator hydraulic system and an excavator. The excavator hydraulic system comprises an actuator, a hydraulic pump and an integrated valve. The actuator comprises a slewing hydraulic motor, a traveling hydraulic motor, a bucket working oil cylinder, a dipper rod working oil cylinder and a boom working oil cylinder. The hydraulic pump is a quadruple pump, which comprises a first pump body, a second pump body, a third pump body and a fourth pump body which are sequentially connected in series. The oil outlet of the first pump body is connected to the oil inlet of the slewing hydraulic motor, the oil outlet of the second pump body is connected to the oil inlet of the dipper rod working oil cylinder, the oil outlets of the third pump body and the fourth pump body are connected to the oil inlet of the integrated valve respectively, and the working oil circuits of the traveling hydraulic motor, the bucket working oil cylinder and the boom working oil cylinder are connected to the oil outlet of the integrated valve respectively. The excavator hydraulic system enables the movements of slewing and boom, dipper rod and bucket to be completely independent, thereby satisfying the coordination of the excavator's compound operations.

Description

Technical Field

[0001] The invention belongs to the technical field of hydraulic systems for engineering machinery, and in particular relates to an excavator hydraulic system and an excavator. Background Art

[0002] An excavator, also known as a backhoe, is an earth-moving machine that uses a bucket to dig materials above or below the bearing surface and load them into a transport vehicle or unload them to a stockpile. An excavator includes several actuators, which mainly include a bucket cylinder, a dipper arm cylinder, a boom cylinder, a slewing motor, and a travel motor. Existing excavator hydraulic systems generally use dual pumps and dual circuits, in which the dual pumps and dual circuits form two independent main oil circuits, one of which is used to realize slewing, left travel, dipper arm movement, and boom movement, and the other is used to realize right travel, bucket movement, boom movement, and standby cylinder movement.

[0003] Although the compound operability of the excavator's dual-pump hydraulic system has been greatly improved, there are still some incoordination in compound operability. For example, when the excavator is moving in a straight line, if the rotation and various devices are operated at the same time, the oil supply of the left travel motor will change, resulting in a zigzag movement when walking; during transportation operations, if the up and down movement of the working device is operated simultaneously during rotation, there will be a problem of a rapid drop in rotation speed. Summary of the invention

[0004] The main object of the present invention is to provide an excavator hydraulic system which can meet the coordination of the excavator's compound operations.

[0005] Another object of the present invention is to provide an excavator whose hydraulic system can meet the coordination of complex operations of the excavator.

[0006] The present invention is achieved through the following technical solutions:

[0007] A first aspect of the present invention provides an excavator hydraulic system, comprising an actuator, a hydraulic pump and an integrated valve, wherein the actuator comprises a rotary hydraulic motor, a travel hydraulic motor, a bucket working cylinder, a dipper arm working cylinder and a boom working cylinder;

[0008] The hydraulic pump is a quadruple pump, which comprises a first pump body, a second pump body, a third pump body and a fourth pump body connected in series in sequence;

[0009] The oil outlet of the first pump body is connected to the oil inlet of the rotary hydraulic motor, the oil outlet of the second pump body is connected to the oil inlet of the boom working cylinder, the oil outlets of the third pump body and the fourth pump body are respectively connected to the oil inlet on the integrated valve, and the working oil circuits of the travel hydraulic motor, the bucket working cylinder and the boom working cylinder are respectively connected to the oil outlet on the integrated valve.

[0010] The hydraulic system for the excavator as described above further comprises a first control valve, a second control valve, a first hydraulic oil tank and a second hydraulic oil tank;

[0011] The oil outlet of the first pump body is connected to the oil inlet of the swing hydraulic motor, the oil outlet of the swing hydraulic motor is connected to the first hydraulic oil tank, the oil inlet of the first pump body is connected to the first hydraulic oil tank, and the first control valve is arranged on the oil circuit between the first pump body and the swing hydraulic motor; the oil outlet of the second pump body is connected to the oil inlet of the boom working cylinder, the oil return port of the boom working cylinder is connected to the second hydraulic oil tank, the oil inlet of the second pump body is connected to the second hydraulic oil tank, and the second control valve is arranged on the oil circuit between the second pump body and the boom working cylinder.

[0012] In the hydraulic system for the excavator as described above, the first pump body and the second pump body are double pumps, and the third pump body and the fourth pump body are double pumps.

[0013] In the hydraulic system for the excavator as described above, the first pump body, the second pump body, the third pump body and the fourth pump body are all variable displacement pumps.

[0014] In the hydraulic system for the excavator as described above, the first pump body, the second pump body, the third pump body and the fourth pump body are all swash plate piston pumps.

[0015] As described above, the hydraulic system of the excavator, the swash plate plunger pump comprises a housing, a transmission shaft, a cylinder body provided with a plunger hole, a plunger adapted to the plunger hole, a ball head is provided at the bottom end of the plunger, the transmission shaft passes through the center of the cylinder body and is connected to the driving shaft of the excavator engine, a distribution plate is provided on the cylinder body, a swash plate is provided at the bottom end of the cylinder body, a sliding shoe is provided on the swash plate, and a ball accommodating cavity adapted to the ball head of the plunger is provided on the sliding shoe.

[0016] In the hydraulic system for the excavator as described above, an adjusting screw is provided on the housing, and the adjusting screw is used to adjust the inclination angle of the swash plate.

[0017] In the hydraulic system for the excavator as described above, the first pump body, the second pump body, the third pump body and the fourth pump body are all gear pumps.

[0018] As described above, the excavator hydraulic system also includes control buttons, which include a left swing control button, a right swing control button, a dipper arm control button, a bucket control button, an arm control button, a left travel control button and a right travel control button. The left swing control button and the right swing control button are both electrically connected to the first control valve, the dipper arm control button is electrically connected to the second control valve, and the bucket control button, the arm control button, the left travel control button and the right travel control button are all electrically connected to the integrated valve.

[0019] A second aspect of the present invention provides an excavator, the excavator comprising the excavator hydraulic system as described above.

[0020] The hydraulic system of the excavator of the present invention comprises an actuator and a hydraulic pump, wherein the actuator comprises a rotary hydraulic motor, a travel hydraulic motor, a bucket working oil cylinder, a dipper rod working oil cylinder and a boom working oil cylinder, and the hydraulic pump is a quadruple pump comprising a first pump body, a second pump body, a third pump body and a fourth pump body, wherein the oil outlet of the first pump body is connected to the oil inlet of the rotary hydraulic motor, the oil outlet of the second pump body is connected to the oil inlet of the dipper rod oil cylinder, and the third pump body and the fourth pump body control the driving of the travel hydraulic motor, the bucket working oil cylinder and the boom working oil cylinder through an integrated valve, because During the operation of the excavator, the swing hydraulic motor and the boom, the dipper arm and the bucket perform many compound actions. The swing hydraulic motor and the boom working cylinder, the dipper arm working cylinder and the bucket working cylinder are set in different hydraulic circuits, and the dipper arm working cylinder and the swing hydraulic motor are driven by separate hydraulic pumps respectively. The dipper arm working cylinder and the swing hydraulic motor are equipped with separate hydraulic circuits. The actions of the swing hydraulic motor and the boom working cylinder, the dipper arm working cylinder and the bucket working cylinder can be completely independent, which meets the coordination of the excavator's compound operations.

[0021] The excavator of the present invention includes the above-mentioned excavator hydraulic system, which arranges the swing hydraulic motor and the boom working cylinder, the dipper arm working cylinder and the bucket working cylinder in different hydraulic circuits, and drives the dipper arm working cylinder and the swing hydraulic motor with separate hydraulic pumps respectively. The dipper arm working cylinder and the swing hydraulic motor are equipped with separate hydraulic circuits, and the movements of the swing and boom, and the dipper arm and bucket can be completely independent, thereby meeting the coordination of the excavator's complex operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1It is a structural diagram of the existing excavator hydraulic system;

[0024] Figure 2 A schematic diagram of the structure of an excavator provided by an embodiment of the present invention;

[0025] Figure 3 A schematic diagram of the structure of an excavator hydraulic system provided by an embodiment of the present invention;

[0026] Figure 4 A schematic structural diagram of a quadruple pump of an excavator hydraulic system provided in an embodiment of the present invention.

[0027] Description of reference numerals:

[0028] 1-actuator;

[0029] 2-Hydraulic pump;

[0030] 3-Integrated valve;

[0031] 4- first control valve;

[0032] 5- Second control valve;

[0033] 11- Rotary hydraulic motor;

[0034] 12-travel hydraulic motor;

[0035] 13-Bucket working cylinder;

[0036] 14-arm working cylinder;

[0037] 15- Boom working cylinder;

[0038] 21-first pump body;

[0039] 22- second pump body;

[0040] 23- third pump body;

[0041] 24- fourth pump body;

[0042] 211-housing;

[0043] 212-transmission shaft;

[0044] 213-cylinder body;

[0045] 214- plunger;

[0046] 215-distributor plate;

[0047] 216-swash plate;

[0048] 217-slip boots;

[0049] 218-Adjusting screw. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] In the description of the present invention, it should be understood that the terms "including" and "having" and any variations thereof used herein are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products or apparatuses.

[0052] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be internal communication between two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated.

[0053] The existing excavator hydraulic system adopts dual pumps and dual circuits. Figure 1 This is a schematic diagram of the hydraulic system of an existing excavator. Figure 1 As shown, the double pump is composed of a first hydraulic pump 1' and a second hydraulic pump 2'. The first hydraulic pump 1' and the second hydraulic pump 2' are used to pressurize the hydraulic oil of the hydraulic system of the excavator. One of the main oil circuits is used to realize rotation, left travel, dipper rod movement, and boom movement, and the other main oil circuit is used to realize right travel, bucket movement, boom movement, and standby cylinder movement. When the existing double pump is used in the hydraulic system of the excavator, there is an incoordination of compound operation. For example, when traveling in a straight line, if the rotation and various actuators are operated at the same time, the oil supply of the left travel motor will change, resulting in a zigzag phenomenon when traveling; during the handling operation, if the up and down movement of the working device is operated at the same time during the rotation, there will be a problem of a rapid decrease in the rotation speed.

[0054] Based on the above problems, the present invention proposes an excavator hydraulic system and an excavator.

[0055] The excavator hydraulic system and the excavator provided by the present invention are described in detail below in conjunction with specific embodiments.

[0056] Embodiment 1:

[0057] Figure 2 A schematic diagram of the structure of an excavator provided by an embodiment of the present invention, Figure 3 For a structural diagram of the hydraulic system of an excavator provided by an embodiment of the present invention, please refer to Figure 2 and Figure 3 As shown, this embodiment provides an excavator hydraulic system, including an actuator 1, a hydraulic pump 2 and an integrated valve 3, wherein the actuator includes a rotary hydraulic motor 11, a travel hydraulic motor 12, a bucket working cylinder 13, a dipper arm working cylinder 14 and a boom working cylinder 15;

[0058] The hydraulic pump 2 includes a first pump body 21, a second pump body 22, a third pump body 23 and a fourth pump body 24. The first pump body 21, the second pump body 22, the third pump body 23 and the fourth pump body 24 are connected in series to form a quadruple pump; the oil outlet of the first pump body 21 is connected to the oil inlet of the rotary hydraulic motor 11, the oil outlet of the second pump body 22 is connected to the oil inlet of the boom working cylinder 14, the oil outlets of the third pump body 23 and the fourth pump body 24 are respectively connected to the oil inlet on the integrated valve 3, the working oil circuits of the travel hydraulic motor 12, the bucket working cylinder 13 and the boom working cylinder 15 are respectively connected to the oil outlet of the integrated valve 3, and the third pump body 23 and the fourth pump body 24 are used to drive the travel hydraulic motor 12, the bucket working cylinder 13 and the boom working cylinder 15.

[0059] The rotary hydraulic motor 11 of this embodiment is used to drive the rotation of the upper rotary body of the excavator, the travel hydraulic motor 12 is used to drive the forward and backward movement of the lower travel body of the excavator, the bucket working cylinder 13 is used to drive the bucket movement, the arm working cylinder 14 is used to drive the arm movement, and the boom working cylinder 15 is used to drive the boom movement.

[0060] In this embodiment, the first pump body 21, the second pump body 22, the third pump body 23 and the fourth pump body 24 are a quadruple pump. The first pump body 21, the second pump body 22, the third pump body 23 and the fourth pump body 24 are connected in series to form a quadruple pump, which is reliable in operation and low in cost.

[0061] The hydraulic system of the excavator of this embodiment does not change the working principle of the hydraulic system of the excavator. The oil outlet of the first pump body 21 is connected to the oil inlet of the rotary hydraulic motor 11, the oil outlet of the second pump body 22 is connected to the oil inlet of the bucket working cylinder 14, the hydraulic oil circuit driving the rotary hydraulic motor 11 and the hydraulic oil circuit driving the bucket working cylinder 14 are independently arranged, the oil outlets of the third pump body 23 and the fourth pump body 24 are respectively connected to the oil inlet on the integrated valve 3, and the working oil circuits of the travel hydraulic motor 12, the bucket working cylinder 13 and the boom working cylinder 15 are separately connected. It is separately connected with the oil outlet on the integrated valve 3, so as to realize complete independence of the boom movement and the rotation movement, the bucket arm movement and the bucket movement. A separate hydraulic pump is used to drive the bucket arm working cylinder 14 and the rotation hydraulic motor 11. When the excavator is moving in a straight line, the rotation is operated at the same time, or the boom or the bucket arm is operated simultaneously during the up and down movement of the excavator. The coordination of the excavator's compound operability is ensured, the stability of the excavator's hydraulic system is improved, and the independent first closed loop and the second closed loop reduce throttling measures in the hydraulic system, thereby improving the engine power to a certain extent.

[0062] The hydraulic system of the excavator of the present invention comprises an actuator and a hydraulic pump, wherein the actuator comprises a rotary hydraulic motor, a travel hydraulic motor, a bucket working oil cylinder, a dipper rod working oil cylinder and a boom working oil cylinder, and the hydraulic pump comprises a first pump body, a second pump body, a third pump body and a fourth pump body, wherein the first pump body is connected to the rotary hydraulic motor and forms a first closed loop between the first pump body and the rotary hydraulic motor, the second pump body is connected to the dipper rod oil cylinder to form a closed loop, and forms a second closed loop between the second pump body and the dipper rod oil cylinder, and the third pump body and the fourth pump body drive the travel hydraulic motor, the bucket working oil cylinder and the dipper rod working oil cylinder through an integrated valve Working cylinder and boom working cylinder, because the excavator has a lot of complex movements of rotation and boom, arm and bucket during work, the swing hydraulic motor and boom working cylinder, arm working cylinder and bucket working cylinder are arranged in different closed circuits, and the arm working cylinder and swing hydraulic motor are driven by separate hydraulic pumps respectively. The arm working cylinder and swing hydraulic motor are equipped with separate hydraulic circuits, and the movements of the swing hydraulic motor and boom working cylinder, arm working cylinder and bucket working cylinder can be completely independent, which meets the coordination of the excavator's complex operations.

[0063] The hydraulic system of the excavator of this embodiment further includes a first control valve 4, a second control valve 5, a first hydraulic oil tank and a second hydraulic oil tank;

[0064] The oil outlet of the first pump body 21 is connected to the oil inlet of the swing hydraulic motor 11, the oil outlet of the swing hydraulic motor 11 is connected to the first hydraulic oil tank, the oil inlet of the first pump body 21 is connected to the first hydraulic oil tank, and the first control valve 4 is arranged on the oil circuit between the first pump body 21 and the swing hydraulic motor 11; the oil outlet of the second pump body 22 is connected to the oil inlet of the boom working cylinder, the oil return port of the boom working cylinder 14 is connected to the second hydraulic oil tank, the oil inlet of the second pump body 22 is connected to the second hydraulic oil tank, and the second control valve 5 is arranged on the oil circuit between the second pump body 22 and the boom working cylinder 14. The first pump body 21 controls the working oil circuit of the rotary hydraulic motor 11 through the first control valve 4, the second pump body 22 controls the working oil circuit of the boom working cylinder 14 through the second control valve 5, and the third pump body 23 and the fourth pump body 24 control the working oil circuit of the travel hydraulic motor 12, the working oil circuit of the bucket working cylinder 13 and the working oil circuit of the boom working cylinder 15 through the integrated valve 3.

[0065] Optionally, in this embodiment, the first pump body 21 and the second pump body 22 can be configured as a double pump, and the third pump body 23 and the fourth pump body 24 can be configured as a double pump, and the actuator of the excavator can be driven by using two double pumps.

[0066] Preferably, the first pump body 21, the second pump body 22, the third pump body 23 and the fourth pump body 24 are all inclined plate piston pumps. Figure 4 For a schematic diagram of the structure of the quadruple pump of the hydraulic system of the excavator provided by the embodiment of the present invention, please refer to Figure 4 As shown, the swash plate plunger pump includes a housing 211, a transmission shaft 212, a cylinder body 213 provided with a plunger hole, a plunger 214 adapted to the plunger hole, a ball head provided at the bottom end of the plunger 214, the transmission shaft 212 passes through the center of the cylinder body 213 and is connected to the drive shaft of the excavator engine, a valve plate 215 is provided on the cylinder body 213, a swash plate 216 is provided at the bottom end of the cylinder body, a sliding shoe 217 is provided on the swash plate 216, and a ball accommodating cavity adapted to the ball head of the plunger is provided on the sliding shoe. The first pump body 21, the second pump body 22, the third pump body 23 and the fourth pump body 24 of this embodiment all adopt a swash plate plunger pump, which has a compact structure, low cost and convenient maintenance.

[0067] Furthermore, the housing 211 is provided with an adjusting screw 218, which is used to adjust the inclination angle of the swash plate. In this embodiment, the inclination angle of the swash plate 216 is adjusted by providing the adjusting screw 218, thereby changing the maximum displacement and the minimum displacement of the swash plate piston pump.

[0068] Optionally, the first pump body 21, the second pump body 22, the third pump body 23 and the fourth pump body 24 of this embodiment may also be gear pumps.

[0069] In this embodiment, a control handle is also included, and control buttons are arranged on the control handle. The control buttons include a left turn button, a right turn button, a stick button, a bucket button, a boom button, a left walk button and a right walk button. The left turn button and the right turn button are both electrically connected to the first solenoid valve, the stick button is electrically connected to the second solenoid valve, and the bucket button, the boom button, the left walk button and the right walk button are all electrically connected to the integrated valve electromagnetic.

[0070] In this embodiment, because the excavator performs many complex actions of rotation and boom, and arm and bucket during operation, the rotation hydraulic motor 11 and the boom working cylinder 15, the arm working cylinder 14 and the bucket working cylinder 13 are arranged in different oil return circuits, and the arm working cylinder 14 and the rotation hydraulic motor 11 are driven by a separate hydraulic pump, and the arm working cylinder 14 and the rotation hydraulic motor 11 are equipped with separate hydraulic circuits. The movements of rotation and boom, and arm and bucket can be completely independent. This design can greatly reduce throttling measures and reduce unnecessary throttling power.

[0071] Embodiment 2:

[0072] This embodiment provides an excavator, and the excavator includes the excavator hydraulic system described in the first embodiment.

[0073] The hydraulic system of the excavator includes an actuator, a hydraulic pump and an integrated valve, wherein the actuator includes a rotary hydraulic motor, a travel hydraulic motor, a bucket working cylinder, a dipper rod working cylinder and a boom working cylinder;

[0074] The hydraulic pump is a quadruple pump, which comprises a first pump body, a second pump body, a third pump body and a fourth pump body connected in series in sequence;

[0075] The oil outlet of the first pump body is connected to the oil inlet of the rotary hydraulic motor, the oil outlet of the second pump body is connected to the oil inlet of the boom working cylinder, the oil outlets of the third pump body and the fourth pump body are respectively connected to the oil inlet on the integrated valve, and the working oil circuits of the travel hydraulic motor, the bucket working cylinder and the boom working cylinder are respectively connected to the oil outlet on the integrated valve.

[0076] The excavator of this embodiment includes the above-mentioned excavator hydraulic system, which arranges the swing hydraulic motor and the boom working cylinder, the dipper arm working cylinder and the bucket working cylinder in different hydraulic circuits, and drives the dipper arm working cylinder and the swing hydraulic motor with separate hydraulic pumps respectively. The dipper arm working cylinder and the swing hydraulic motor are equipped with separate hydraulic circuits, and the movements of the swing and boom, and the dipper arm and bucket can be completely independent, thereby meeting the coordination of the excavator's complex operations.

[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 replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An excavator hydraulic system, Features: It includes an actuator, a hydraulic pump, an integrated valve, a first control valve and a second control valve, wherein the actuator includes a rotary hydraulic motor, a travel hydraulic motor, a bucket working cylinder, a dipper rod working cylinder and a boom working cylinder; The hydraulic pump is a quadruple pump, which comprises a first pump body, a second pump body, a third pump body and a fourth pump body connected in series in sequence; The oil outlet of the first pump body is connected with the oil inlet of the swing hydraulic motor, and is only used to supply oil to the swing hydraulic motor; the first control valve is arranged on the oil circuit between the first pump body and the swing hydraulic motor; the oil outlet of the second pump body is connected with the oil inlet of the boom working cylinder, and is only used to supply oil to the boom working cylinder; the second control valve is arranged on the oil circuit between the second pump body and the boom working cylinder; the oil outlets of the third pump body and the fourth pump body are respectively connected with the oil inlet on the integrated valve, and the working oil circuits of the travel hydraulic motor, the bucket working cylinder and the boom working cylinder are respectively connected with the oil outlet on the integrated valve.

2. The excavator hydraulic system according to claim 1, Features: Also includes a first hydraulic oil tank and a second hydraulic oil tank; The oil outlet of the first pump body is connected to the oil inlet of the swing hydraulic motor, the oil outlet of the swing hydraulic motor is connected to the first hydraulic oil tank, and the oil inlet of the first pump body is connected to the first hydraulic oil tank; the oil outlet of the second pump body is connected to the oil inlet of the boom working cylinder, the oil return port of the boom working cylinder is connected to the second hydraulic oil tank, and the oil inlet of the second pump body is connected to the second hydraulic oil tank.

3. The hydraulic system for an excavator according to claim 1, Features: The first pump body and the second pump body are double pumps, the third pump body and the fourth pump body are double pumps, and two double pumps constitute the quadruple pump.

4. The hydraulic system for an excavator according to claim 1, Features: The first pump body, the second pump body, the third pump body and the fourth pump body are all variable displacement pumps.

5. The hydraulic system for an excavator according to any one of claims 1 to 4, Features: The first pump body, the second pump body, the third pump body and the fourth pump body are all swash plate plunger pumps.

6. The hydraulic system for an excavator according to claim 5, Features: The swash plate plunger pump includes a housing, a transmission shaft, a cylinder body provided with a plunger hole, a plunger adapted to the plunger hole, a ball head is provided at the bottom end of the plunger, the transmission shaft passes through the center of the cylinder body and is connected to the drive shaft of the excavator engine, a distribution plate is provided on the cylinder body, a swash plate is provided at the bottom end of the cylinder body, a sliding shoe is provided on the swash plate, and a ball accommodating cavity adapted to the ball head of the plunger is provided on the sliding shoe.

7. The hydraulic system for an excavator according to claim 6, Features: The housing is provided with an adjusting screw, and the adjusting screw is used to adjust the inclination angle of the swash plate.

8. The hydraulic system for an excavator according to claim 1, Features: The first pump body, the second pump body, the third pump body and the fourth pump body are all gear pumps.

9. The hydraulic system for an excavator according to claim 2, Features: It also includes control buttons, which include a left swing control button, a right swing control button, a dipper arm control button, a bucket control button, a boom control button, a left travel control button and a right travel control button. The left swing control button and the right swing control button are both electrically connected to the first control valve, the dipper arm control button is electrically connected to the second control valve, and the bucket control button, the boom control button, the left travel control button and the right travel control button are all electrically connected to the integrated valve.

10. An excavator, It is characterized in that The excavator comprises the excavator hydraulic system according to any one of claims 1-9.

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