Hydraulic system and working machine

Abstract

The invention belongs to the field of engineering machinery, and discloses a hydraulic system and an operation machine.The hydraulic system comprises a motor assembly, a hydraulic control system and a hydraulic control system, the multi-way valve at least comprises a first rotary valve group unit and a second rotary valve group unit which are used for controlling the motor assembly, and other valve group units used for controlling other actuating mechanisms; the hydraulic pump set at least comprises a first main pump and a second main pump which are both open pumps, a hydraulic oil of the first main pump is pumped to the motor assembly, and an oil outlet of the second main pump is provided with a rotary pumping oil way and a bypass pumping oil way connected in parallel. And hydraulic oil pumped by the second main pump can be supplied to the motor assembly through the second rotary valve group and / or supplied to other actuating mechanisms through other valve groups. When the rotary motor rotates independently, oil can be supplied by the multiple rotary pumps together to increase the rotary speed, and when the rotary motor performs composite action, the second main pump can supply oil to other executing mechanisms, so that the rotary speed is controllable and is not influenced by other executing mechanisms.

Description

Technical Field

[0001] The present application belongs to the field of engineering machinery, and specifically, relates to a hydraulic system and an operating machine. Background Art

[0002] Large-tonnage excavators have high requirements for the coordination between various actions during excavation and loading operations. In order to solve the balance between the excavator's rotation action and the action of the working device actuator, most of the existing technologies use a closed system to set a dedicated main pump for the rotation motor for independent control. However, the setting of such a dedicated main pump inevitably has the problem of performance waste. In addition, there is also a method of adding a converging valve, that is, a converging valve is set in front of the main valve, and the pumping hydraulic oil of multiple main pumps is merged to the main valve through the converging valve, and then the main valve core opening is controlled by the program to achieve mutual priority during the rotation action, thereby realizing flow distribution. In this case, although the priority function can be realized, the flow distribution is easily changed due to changes in load, which makes the priority effect change dynamically, resulting in unstable operation coordination. Summary of the invention

[0003] The purpose of this application is to provide a hydraulic system and a working machine to improve the control performance of the rotary action, improve efficiency and save energy.

[0004] To achieve the above objectives, the present application provides a hydraulic system, which is applied to a working machine, and the hydraulic system comprises:

[0005] A motor assembly, comprising a plurality of rotary motors connected in parallel;

[0006] The multi-way valve comprises at least a first rotary valve group and a second rotary valve group for controlling the motor assembly and other valve groups for controlling other actuators;

[0007] The hydraulic pump group at least includes a first main pump and a second main pump, both of which are open pumps. The pumping hydraulic oil of the first main pump is pumped to the motor assembly through the first rotary valve group. The oil outlet of the second main pump is provided with a rotary pumping oil circuit connected to the second rotary valve group and a bypass pumping oil circuit connected in parallel with the rotary pumping oil circuit and connected to the other valve groups. The pumping hydraulic oil of the second main pump can be supplied to the motor assembly through the second rotary valve group and / or supplied to the other actuators through the other valve groups.

[0008] In some embodiments, the hydraulic system comprises:

[0009] a first logic priority valve, disposed in the rotary pumping oil circuit and used to control the flow rate of the rotary pumping oil circuit;

[0010] The second logic priority valve is arranged in the bypass pumping oil passage and is used to control the flow rate of the bypass pumping oil passage.

[0011] In some embodiments, the first logic priority valve and the second logic priority valve have the same structure and both include a cartridge valve and a hydraulic cylinder for driving the cartridge valve core to move. And / or, the first main pump and the second main pump are both variable pumps; and / or, there are multiple second main pumps, and the hydraulic pump group also includes other main pumps that supply oil to the other actuators.

[0012] In some embodiments, the hydraulic system includes a main pilot oil circuit, the first logic priority valve and the second logic priority valve are both hydraulically controlled valves, the hydraulically controlled end of the first logic priority valve is selectively connected to the main pilot oil circuit or hydraulic return oil through a first logic solenoid valve, and the hydraulically controlled end of the second logic priority valve is selectively connected to the main pilot oil circuit or hydraulic return oil through a second logic solenoid valve; wherein, the first rotary valve group and the second rotary valve group are both hydraulically controlled reversing valves, the hydraulically controlled end of the first rotary valve group is selectively connected to the main pilot oil circuit or hydraulic return oil through a first pilot solenoid valve, and the hydraulically controlled end of the second rotary valve group is selectively connected to the main pilot oil circuit or hydraulic return oil through a second pilot solenoid valve.

[0013] In some embodiments, the first logic solenoid valve, the second logic solenoid valve, the first pilot solenoid valve, and the second pilot solenoid valve are all proportional solenoid valves controlled by an operating handle.

[0014] In some embodiments, the hydraulic system comprises:

[0015] a first switch solenoid valve, through which the pilot hydraulic oil of the main pilot oil circuit flows to the first pilot solenoid valve and the second pilot solenoid valve;

[0016] A second switch solenoid valve, the pilot hydraulic oil of the main pilot oil circuit flows to the motor brake oil circuit of the motor assembly through the second switch solenoid valve.

[0017] In some embodiments, the hydraulic pump assembly further comprises:

[0018] A pilot pump, used for supplying oil to the main pilot oil circuit;

[0019] A pilot accumulator is hydraulically connected to the main pilot oil circuit.

[0020] In some embodiments, a first check valve serving as a back pressure valve is provided in the first oil return port oil circuit of the first rotary valve group, a second check valve serving as a back pressure valve and a radiator relatively close to the hydraulic oil tank are provided in series in the second oil return port oil circuit of the second rotary valve group, and a valve port end of the first check valve and a valve port end of the second check valve are hydraulically connected via a connecting pipeline; wherein the back pressure of the first check valve is greater than the back pressure of the second check valve.

[0021] In addition, the present application also provides an operating machine, which includes the above-mentioned hydraulic system.

[0022] In some embodiments, the working machine is an ultra-large excavator with a deadweight of not less than 100 tons.

[0023] In the hydraulic system and working machinery of the present application, the rotary motors are connected in parallel with each other and driven by an open pump. The pumped hydraulic oil of the second main pump can be supplied to the motor assembly through the second rotary valve group and / or supplied to other actuators through other valve groups. In actual work, when performing a single rotary action, it can be supplied by a single main pump or by multiple rotary pumps together, which can increase the rotary speed; when performing a compound action, the first main pump can supply oil to the rotary motor alone, and the second main pump and the remaining main pumps can supply oil to other actuators together, so that the rotary speed can be controlled and not affected by other actuators, thereby improving the control performance of the rotary action and saving energy and reducing consumption.

[0024] Other advantages of the present invention and the technical effects of the preferred embodiments will be further described in the following specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings are used to provide an understanding of the present application and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present application but do not constitute a limitation to the present application. In the accompanying drawings:

[0026] Figure 1 It is a schematic diagram of the composition of a hydraulic system according to a specific embodiment of the present application;

[0027] Figure 2 A hydraulic principle diagram of a hydraulic system according to a specific embodiment of the present application;

[0028] Figure 3 Zoomed in to show Figure 2 The multi-way valve part; and

[0029] Figure 4 Zoomed in to show Figure 2 The motor assembly part.

[0030] Description of Reference Numerals

[0031] 1 Engine 2 First main pump

[0032] 3 Second main pump 4 Pilot pump

[0033] 5 First main relief valve 6 Pilot relief valve

[0034] 7 Second main relief valve 8 First rotary valve assembly

[0035] 9 Second rotary valve assembly 10 Motor assembly

[0036] 11 First pilot solenoid valve 12 Second pilot solenoid valve

[0037] 13 Solenoid valve group 14 Pilot accumulator

[0038] 16 First check valve 17 Second check valve

[0039] 18 Radiator 19 Filter

[0040] 20 Hydraulic oil tank 21 Connecting pipes

[0041] 22 Other valve groups

[0042] 101 first rotary motor 102 second rotary motor

[0043] 131 first switch solenoid valve 132 second switch solenoid valve

[0044] 133 Second logic solenoid valve 134 First logic solenoid valve

[0045] 151 First logic priority valve 152 Second logic priority valve

[0046] L1 Rotary pump oil circuit L2 Bypass pump oil circuit

[0047] T1 first oil return port oil circuit T2 second oil return port oil circuit DETAILED DESCRIPTION

[0048] The specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention and are not intended to limit the present invention. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0049] The working machine and the hydraulic system thereof of the present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0050] This application discloses a new hydraulic system, which is applied to working machinery. Figures 2 to 4In a specific embodiment, the novel hydraulic system comprises:

[0051] The motor assembly 10 includes a plurality of rotary motors connected in parallel;

[0052] The multi-way valve comprises at least a first rotary valve group 8 and a second rotary valve group 9 for controlling the motor assembly 10 and other valve groups 22 for controlling other actuators;

[0053] The hydraulic pump group at least includes a first main pump 2 and a second main pump 3, both of which are open pumps. The pumping hydraulic oil of the first main pump 2 is pumped to the motor assembly 10 through the first rotary valve group 8. The oil outlet of the second main pump 3 is provided with a rotary pumping oil circuit L1 connected to the second rotary valve group 9 and a bypass pumping oil circuit L2 connected in parallel with the rotary pumping oil circuit L1 and connected to other valve groups 22. The pumping hydraulic oil of the second main pump 3 can be supplied to the motor assembly 10 through the second rotary valve group 9 and / or supplied to other actuators through other valve groups 22.

[0054] In the present application, the motor assembly 10 includes a plurality of rotary motors connected in parallel. Figure 4 For example, it includes a first rotary motor 101 and a second rotary motor 102, which are connected in parallel, that is, the pumped hydraulic oil of the oil outlet of a single rotary valve group can flow to the two motors at the same time to drive the two motors to rotate. Of course, the motor assembly 10 is not limited to the two motors shown in the figure, and can include more motors connected in parallel. Similarly, the multi-way valve can also include more rotary valve groups, and the other valve groups 22 can be one or more.

[0055] The following description of the working machinery is based on an excavator as an example. Figure 1 Taking a super-large excavator as an example, it may be equipped with multiple main pumps to drive actuators such as travel motors, slewing motors, boom cylinders, dipper arm cylinders, bucket cylinders, etc. Since the actuators are numerous and dispersed, the required hydraulic flow is large, so the number of main pumps is large, and the multi-way valve may also include a main valve coupler and a secondary valve coupler, etc., to respectively control each main pump and the corresponding actuator. It should be noted that the motor assembly 10 in the present application includes a plurality of slewing motors connected in parallel to each other. This slewing motor is relative to a linear motor, etc., and refers to a motor used to drive the actuator to perform a slewing motion, so Figure 1 The travel motor in should belong to the category of the rotary motor in the motor assembly 10.

[0056] exist Figure 2In the embodiment shown, on the basis of two parallel rotary motors, the multi-way valve is correspondingly provided with two rotary valve groups, and the hydraulic pump group includes two main pumps, both of which are open pumps. The pumping hydraulic oil of the first main pump 2 can drive the two rotary motors through the first rotary valve group 8, and at least part of the pumping hydraulic oil of the second main pump 3 can also drive the two rotary motors along the rotary pumping oil path L1 through the second rotary valve group 9. The two can be driven independently or in combination. At least part of the pumping hydraulic oil of the second main pump 3 can also drive other actuators (not shown in the figure) through the bypass pumping oil path L2.

[0057] In this way, when the excavator performs a single rotation action, it can be driven by a single main pump or by two main pumps, thereby increasing the rotation speed and the flexible control performance of the rotation action. The rotation drive main pump can be controlled to work efficiently and save energy. When the excavator performs a compound action, one main pump can supply oil to the rotation motor alone, and the other main pump and the remaining main pumps can supply oil to other actuators together, so that the rotation speed can be controlled without being affected by other actuators, and the rotation control performance is more outstanding.

[0058] Comparably, in the closed rotary system adopted in the prior art, a dedicated main pump is provided for the rotary motor for use. The disadvantage is that if a high-power main pump is used, the pump cannot exert most of its performance when the rotary speed demand is low, resulting in the phenomenon of a big horse pulling a small cart, resulting in performance waste and pump room space waste, especially for super-large excavators where the main pump position space is particularly tight. If a low-power main pump is used, the rotary speed adjustment range is small, which cannot be met when the rotary speed demand is high. If the confluence technology is adopted, that is, multiple main pumps are merged to the main valve in advance, and then the main valve core opening is controlled by the program to realize the mutual priority during the rotary action, although the priority function can be realized, it is easy to be affected by the change of load to cause the change of flow distribution. According to the energy law of "water flows to low places", the hydraulic oil will flow to the actuator with low pressure, so that the priority effect changes dynamically, resulting in unstable operation coordination.

[0059] Unlike the existing closed rotary hydraulic system, the present application adopts an open hydraulic system. The rotary main pumps are all open pumps. The first and second main pumps can supply oil to the motor assembly individually or together. It is also different from the existing merging method of setting a merging valve in front of the main valve. The present application realizes merging in the motor circuit after the main valve, rather than in front of the main valve.

[0060] It should be noted that in Figure 2In the embodiment shown, the hydraulic oil pumped by the first main pump 2 is all pumped to the motor assembly 10. However, in other embodiments, the first main pump 2 can also be used to divert oil to other actuators, that is, the oil outlet of the first main pump 2 is also provided with a bypass pumping oil path L2 connected to other valve groups 22. Such an embodiment in which the first main pump 2 and the second main pump 3 have the same structure and function is also within the protection scope of the present application.

[0061] from Figure 2 , Figure 3 As can be seen in the figure, the first main pump 2 and the second main pump 3 are both variable pumps, which can adjust the pumping oil port opening of each rotary drive main pump according to the load and speed requirements of the rotary motor 10 to save pumping energy. But obviously, the first main pump 2 and the second main pump 3 can also be gear pumps, etc. Among them, the second main pump 3 is not limited to one as shown in the figure, but can also be multiple, and the same is true for the first main pump 2. Figure 1 The hydraulic pump group may also include one or more other main pumps for supplying oil to other actuators.

[0062] In this embodiment, the hydraulic system further includes a logic priority valve, which is used to control the flow distribution logic and priority of the pumping hydraulic oil between the rotary pumping oil circuit L1 and the bypass pumping oil circuit L2. Figure 2 , Figure 3 In the embodiment, the logic priority valve includes a first logic priority valve 151 disposed in the rotary pumping oil circuit L1 and used to control the flow rate of the rotary pumping oil circuit L1, and a second logic priority valve 152 disposed in the bypass pumping oil circuit L2 and used to control the flow rate of the bypass pumping oil circuit L2. The setting of the logic priority valve can control the priority pumping direction of the hydraulic oil after the pumping hydraulic oil of the second main pump 3 shown in the figure passes through the one-way valve located above the second main relief valve 7 in the figure, that is, preferentially flows to the rotary pumping oil circuit L1, or preferentially flows to the bypass pumping oil circuit L2. This first logic priority valve 151 and the second logic priority valve 152 are used for the flow rate control in the oil circuit, so as to control the priority flow direction of the oil. Of course, the logic priority valve is not limited to the flow control valve shown in this embodiment, but can also be a pressure control valve, etc.

[0063] exist Figure 2 , Figure 3 In the implementation mode, as an example, the first logic priority valve 151 and the second logic priority valve 152 have the same structure and both include a cartridge valve and a hydraulic cylinder for driving the cartridge valve core to move. The cartridge valve has a large flow rate and can meet the maximum flow demand of the oil circuit. The cartridge valve core is driven to move by the hydraulic cylinder, thereby controlling the valve opening of the cartridge valve, and then controlling the flow rate of the oil circuit. It is known to those skilled in the art that the driving mechanism of the cartridge valve core can also be an electric push rod, etc., and is not limited to a hydraulic cylinder.

[0064] The hydraulic system of the present application may include a main pilot oil circuit, Figure 2 , Figure 3 The pilot pump 4 is used to supply oil to the main pilot oil circuit. The pilot pump 4 that can be independently set up for large-tonnage excavators has a large and stable oil supply, making the flow and pressure of the pilot oil more stable and controllable. Of course, the hydraulic oil of the main pilot oil circuit can also be drawn from other main pumps.

[0065] In this embodiment, a separate pilot pump 4 is provided to provide pilot control oil for the hydraulic system, the pilot pressure is determined by the pilot overflow valve 6, and the specific logical function is realized by the solenoid valve group 13 and the pilot solenoid valve; the working pressure of the rotary motor is determined by the overflow valve of the rotary motor itself, and the working pressure of other actuators can be determined by the first main overflow valve 5 and the second main overflow valve 7.

[0066] After having an independent pilot oil source, the first logic priority valve 151 and the second logic priority valve 152 are both hydraulically controlled valves. The hydraulically controlled end of the first logic priority valve 151 is selectively connected to the main pilot oil circuit or hydraulic return oil through the first logic solenoid valve 134, and the hydraulically controlled end of the second logic priority valve 152 is selectively connected to the main pilot oil circuit or hydraulic return oil through the second logic solenoid valve 133. Figure 3 , the pilot oil pumped by the pilot pump 4 flows through the first logic solenoid valve 134 and then flows to the first logic priority valve 151, driving the hydraulic cylinder in the first logic priority valve 151, thereby pushing the valve core of the cartridge valve to move, and adjusting the flow rate and flow distribution priority of the hydraulic oil pumped by the second main pump 3 to the rotary pumping oil circuit L1. It can be seen that through the hydraulic pilot mode independent of the hydraulic circuits of other actuators, during the composite action of rotary action and other actions, the valve core opening control of the rotary valve group is not affected by other valve groups 22, that is, it is not affected by the load of other actuators, so that the rotary speed can be controlled.

[0067] Similarly, the first rotary valve group 8 and the second rotary valve group 9 shown in the figure both use hydraulically controlled reversing valves, and the hydraulically controlled end of the first rotary valve group 8 is selectively connected to the main pilot oil circuit or hydraulic return oil through the first pilot solenoid valve 11, and the hydraulically controlled end of the second rotary valve group 9 is selectively connected to the main pilot oil circuit or hydraulic return oil through the second pilot solenoid valve 12. The pilot solenoid valve can be set at one end or both ends of the rotary valve group. In this embodiment, as an example, the first pilot solenoid valve 11 is respectively set at both ends of the first rotary valve group 8, and the second pilot solenoid valve 12 is respectively set at both ends of the second rotary valve group 9, so that the movement of the valve core of the valve group can be controlled more conveniently, quickly and accurately through the pilot solenoid valves at both ends, without being affected by the load of other actuators.

[0068] In particular, the first logic solenoid valve 134, the second logic solenoid valve 133, the first pilot solenoid valve 11 and the second pilot solenoid valve 12 in this embodiment are all proportional solenoid valves controlled by an operating handle. Through the angle control of the operating handle of the excavator, different currents are given to the pilot solenoid valves, and the pilot solenoid valves output pressures of different sizes, thereby enabling the valve cores of the first rotary valve group 8 and the second rotary valve group 9 to output different flow rates and obtain different rotation speeds. Similarly, through the angle control of the operating handle, different currents are given to the first logic solenoid valve 134 and the second logic solenoid valve 133, and the logic solenoid valves output corresponding pressures of different sizes, thereby enabling the valve cores of the first logic priority valve 151 and the second logic priority valve 152 to output different flow rates through the hydraulic cylinder, thereby achieving the flow distribution of the pumping hydraulic oil of the second main pump 3 to the rotary pumping oil circuit L1 and the bypass pumping oil circuit L2.

[0069] In this embodiment, if Figure 3 As shown, the solenoid valve group 13 also includes:

[0070] A first switch solenoid valve 131 , through which the pilot hydraulic oil of the main pilot oil circuit flows to the first pilot solenoid valve 11 and the second pilot solenoid valve 12 ;

[0071] The second switch solenoid valve 132 , the pilot hydraulic oil of the main pilot oil circuit flows to the motor brake oil circuit of the motor assembly 10 through the second switch solenoid valve 132 .

[0072] The first switch solenoid valve 131 is integrated in the solenoid valve group 13 and used as a safety valve. Only when the switch solenoid valve is turned on, the first pilot solenoid valve 11 and the second pilot solenoid valve 12 can control the valve core of the rotary valve group. Similarly, the second switch solenoid valve 132 is also used as a safety valve, which can guide the hydraulic oil of the pilot pump 4 to the motor brake oil circuit, thereby releasing the brake of the rotary motor.

[0073] In this embodiment, the hydraulic pump group also includes a pilot accumulator 14, which is hydraulically connected to the main pilot oil circuit, that is, an accumulator is arranged next to the first switch solenoid valve 131, which can realize the oil replenishment and pressure stabilization effect on the main pilot oil circuit when the reversing valve core is actuated.

[0074] In terms of the oil return of the motor assembly 10, a first check valve 16 serving as a back pressure valve is provided in the first oil return port oil circuit T1 of the first rotary valve group 8, and a second check valve 17 serving as a back pressure valve and a radiator 18 relatively close to the hydraulic oil tank 20 are provided in series in the second oil return port oil circuit T2 of the second rotary valve group 9; the valve port end of the first check valve 16 and the valve port end of the second check valve 17 are hydraulically connected via a connecting pipe 21; wherein the back pressure of the first check valve 16 is greater than the back pressure of the second check valve 17.

[0075] The control oil output by the pilot pump 4 acts on the first rotary valve group 8 and the second rotary valve group 9 through the solenoid valve group 13, the first pilot solenoid valve 11 and the second pilot solenoid valve 12, so as to distribute different amounts of hydraulic oil to the rotary motor under different working conditions. The low-pressure hydraulic oil after passing through the rotary motor first passes through the return oil ports of the first rotary valve group 8 and the second rotary valve group 9, flows to the first return oil port oil circuit T1 and the second return oil port oil circuit T2, the hydraulic oil passing through the first check valve 16 directly passes through the filter 19 and returns to the hydraulic oil tank 20, and the hydraulic oil passing through the second check valve 17 first passes through the radiator 18, and then passes through the filter 19 and returns to the hydraulic oil tank 20.

[0076] It can be seen that the high-pressure oil output by the main pump is distributed through the main valve, and becomes low-pressure oil after the rotary motor does work, including the low-pressure oil returned from other actuators, which can pass through the main valve to the first check valve 16 and the second check valve 17, and then pass through the radiator 18 and the filter 19 and then return to the hydraulic oil tank 20. Among them, the back pressure of the first check valve 16 is greater than the back pressure of the second check valve 17, ensuring that the hydraulic oil heated up after work passes through the radiator 18 first to cool the hydraulic system. And when the oil volume reaches a certain amount, due to the increase in pipeline pressure, the two check valves will pass oil at the same time, improving the oil return efficiency and not forming pressure.

[0077] Among them, see Figure 3 , the oil outlet of the first main pump 2 can be connected to the first oil return port oil circuit T1 through the middle position of the first rotary valve group 8 and the middle position of the corresponding other valve group 22 in turn; similarly, the oil outlet of the second main pump 3 can be connected to the second oil return port oil circuit T2 through the middle position of the second rotary valve group 9 and the middle position of the corresponding other valve group 22 in turn. It can be seen that when the rotary valve group and other valve groups are not working and are in the middle position, the pumping hydraulic oil of the main pump can be returned through the middle positions of the two valve groups in turn and through the corresponding first oil return port oil circuit T1 and second oil return port oil circuit T2. When any one of the rotary valve group and other valve groups is working, the pumping oil of the main pump can only be pumped to the actuator in the working state.

[0078] In addition, the first oil return port oil circuit T1 and the second oil return port oil circuit T2 are also connected to an oil replenishment circuit, which is connected to the working oil circuit of the rotary motor. Figure 3 As shown in the figure, one end of the oil replenishment circuit is connected to the first oil return port oil circuit T1 or the second oil return port oil circuit T2, and the other end is connected to the oil circuits at both ends of the motor through a one-way valve. Once the low-pressure side oil circuit lacks oil, vacuum suction will be formed to replenish the oil from the oil return port oil circuit, the oil replenishment circuit, and the one-way valve to the low-pressure oil side of the motor.

[0079] The present application also discloses a working machine, which includes the above-mentioned hydraulic system. The working machine is not limited to the above-mentioned excavator, but can also be any large machine with a rotary motor, such as a large crawler crane. In this embodiment, the working machine is an ultra-large excavator with a deadweight of not less than 100 tons. In such an ultra-large excavator, the hydraulic system is provided. Figure 1 The multiple motors, cylinders, etc. shown also need to be equipped with multiple main pumps, which leads to problems of oil supply distribution and action coordination. However, this application redesigns the rotary pipeline and control logic of the hydraulic system, so that when the excavator performs a single rotary action, two main pumps can jointly supply oil, which can increase the rotation speed; when the excavator performs a compound action, one main pump can supply oil to the rotary motor alone, and the other main pump and the remaining main pumps can jointly supply oil to other actuators, so that the rotation speed can be controlled and not affected by other actuators; this hydraulic system is also provided with a logic priority valve, which can assist in realizing the priority between the actuators during compound actions, and the priority level can be adjusted; the coordination of the excavator operation is improved, so that the driver can perform high-value work more efficiently.

[0080] By setting a logic priority valve in the main valve, in combination with the solenoid valve group 13, mutual priority of certain effects between the actuators can be achieved. When the first logic priority valve 151 located in front of the rotary joint is controlled by the first logic solenoid valve 134, the priority of other actuators to the rotary function can be achieved. When the second logic priority valve 152 located after the rotary joint is controlled by the second logic solenoid valve 133, the priority of the rotary function to other actuators can be achieved, and the actuator in front of which the logic priority valve is located is non-prioritized, and the proportional solenoid valves receive different currents and different priority levels (that is, different priority levels of flow distribution).

[0081] It should be noted that the present implementation mode combined with the accompanying drawings is only an example and does not impose any number restrictions on the main pumps, rotary valve groups, and rotary motors involved in the rotary control; any form of allocating the hydraulic oil of other actuators to the rotary motor in a certain period of time by setting a flow distribution valve, as well as adding or reducing the number of logic priority valves at any position, the form of logic priority valves, are all alternative solutions and fall within the scope of protection of this application.

[0082] In the description of the present application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present application, "plurality" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0083] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0084] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0085] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A hydraulic system, applied to an operating machine, characterized in that: The hydraulic system comprises: A motor assembly (10) includes a plurality of rotary motors connected in parallel; A multi-way valve, comprising at least a first rotary valve assembly (8) and a second rotary valve assembly (9) for controlling the motor assembly (10), and other valve assemblies (22) for controlling other actuators; A hydraulic pump assembly comprises at least a first main pump (2) and a second main pump (3), both of which are open pumps; the pumping hydraulic oil of the first main pump (2) is pumped to the motor assembly (10) through the first rotary valve assembly (8); the oil outlet of the second main pump (3) is provided with a rotary pumping oil circuit (L1) connected to the second rotary valve assembly (9) and a bypass pumping oil circuit (L2) connected in parallel with the rotary pumping oil circuit (L1) and connected to the other valve assembly (22); the pumping hydraulic oil of the second main pump (3) can be supplied to the motor assembly (10) through the second rotary valve assembly (9) and / or supplied to the other actuators through the other valve assembly (22).

2. The hydraulic system according to claim 1, characterized in that: The hydraulic system comprises: a first logic priority valve (151), arranged in the rotary pumping oil circuit (L1) and used to control the flow rate of the rotary pumping oil circuit (L1); A second logic priority valve (152) is provided in the bypass pumping oil passage (L2) and is used to control the flow rate of the bypass pumping oil passage (L2).

3. The hydraulic system according to claim 2, characterized in that: The first logic priority valve (151) and the second logic priority valve (152) have the same structure and both comprise a cartridge valve and a hydraulic cylinder for driving a valve core of the cartridge valve to move; And / or, the first main pump (2) and the second main pump (3) are both variable displacement pumps; And / or, there are multiple second main pumps (3), and the hydraulic pump group also includes other main pumps that supply oil to the other actuators.

4. The hydraulic system according to claim 2, characterized in that: The hydraulic system comprises a main pilot oil circuit, the first logic priority valve (151) and the second logic priority valve (152) are both hydraulically controlled valves, the hydraulically controlled end of the first logic priority valve (151) is selectively connected to the main pilot oil circuit or hydraulic return oil through a first logic solenoid valve (134), and the hydraulically controlled end of the second logic priority valve (152) is selectively connected to the main pilot oil circuit or hydraulic return oil through a second logic solenoid valve (133); Wherein, the first rotary valve assembly (8) and the second rotary valve assembly (9) are both hydraulically controlled reversing valves, the hydraulically controlled end of the first rotary valve assembly (8) is selectively connected to the main pilot oil circuit or hydraulic return oil through a first pilot solenoid valve (11), and the hydraulically controlled end of the second rotary valve assembly (9) is selectively connected to the main pilot oil circuit or hydraulic return oil through a second pilot solenoid valve (12).

5. The hydraulic system according to claim 4, characterized in that: The first logic solenoid valve (134), the second logic solenoid valve (133), the first pilot solenoid valve (11) and the second pilot solenoid valve (12) are all proportional solenoid valves controlled by an operating handle.

6. The hydraulic system according to claim 4, characterized in that: The hydraulic system comprises: a first switch solenoid valve (131), through which the pilot hydraulic oil of the main pilot oil circuit flows to the first pilot solenoid valve (11) and the second pilot solenoid valve (12); A second switch solenoid valve (132), the pilot hydraulic oil of the main pilot oil circuit flows to the motor brake oil circuit of the motor assembly (10) through the second switch solenoid valve (132).

7. The hydraulic system according to claim 4, characterized in that: The hydraulic pump unit also includes: A pilot pump (4), used for supplying oil to the main pilot oil circuit; A pilot accumulator (14) is hydraulically connected to the main pilot oil circuit.

8. The hydraulic system according to any one of claims 1 to 7, characterized in that: A first check valve (16) serving as a back pressure valve is provided in the first oil return port oil circuit (T1) of the first rotary valve assembly (8); a second check valve (17) serving as a back pressure valve and a radiator (18) relatively close to a hydraulic oil tank (20) are provided in series in the second oil return port oil circuit (T2) of the second rotary valve assembly (9); a valve port end of the first check valve (16) and a valve port end of the second check valve (17) are hydraulically connected via a connecting pipeline (21); wherein the back pressure of the first check valve (16) is greater than the back pressure of the second check valve (17).

9. A working machine, characterized in that: The working machine includes the hydraulic system according to any one of claims 1 to 8.

10. The working machine according to claim 9, characterized in that: The operating machinery is an extra-large excavator with a deadweight of not less than 100 tons.

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