Hydraulic system with variable flushing flow

Abstract

The utility model relates to the technical field of hydraulic systems, in particular to a hydraulic system with variable flushing flow, which comprises a hydraulic motor, a flushing shuttle valve and a flushing overweight valve, the hydraulic motor is provided with a first working oil way and a second working oil way, the first working oil way is communicated with a first side control cavity of the flushing shuttle valve, and the second working oil way is communicated with a second side control cavity of the flushing shuttle valve; the flushing override valve is installed on the first working oil way and the second working oil way, the flushing override valve is a reversing valve, the first working oil way can be communicated with the second side control cavity of the flushing shuttle valve, and the second working oil way can be communicated with the first side control cavity of the flushing shuttle valve. According to the utility model, through adding the flushing overweight valve, the overweight shielding of the flushing loop is realized, so that the requirements of the hydraulic motor under different working conditions are met, the response speed and rigidity of the system are improved, the temperature of the motor is reduced, the working conditions of the motor are improved, and the service life of the motor is prolonged.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic system technology, and in particular to a hydraulic system with variable flushing flow rate. Background Technology

[0002] In hydraulic systems, especially closed-loop pump-motor hydraulic systems, a flushing shuttle valve is often added to the hydraulic motor to reduce the hydraulic oil temperature and remove impurities from the system.

[0003] like Figure 1 As shown, the flushing shuttle valve 2 has a first control chamber (e.g., the upper side of the flushing shuttle valve) and a second control chamber (e.g., the lower side of the flushing shuttle valve). The two working oils of the hydraulic motor 1 act as control oils on both sides of the flushing shuttle valve. The acting areas at both ends are the same, but due to the different oil pressures on both sides of the hydraulic motor, different working positions of the flushing shuttle valve are achieved. For example, when the upper side of the hydraulic motor is the inlet and the lower side is the outlet, the pressure acting on the first control chamber is greater than the pressure acting on the second control chamber, while the acting areas are the same. At this time, the flushing shuttle valve is in the upper working position, that is, the oil outlet on the lower side of the hydraulic motor is connected to the oil tank, realizing the flushing function.

[0004] Because the flushing circuit operates continuously during the closed-loop system, the existing flushing flow cannot meet the reversing response requirements when the hydraulic motor needs to reverse rapidly. Furthermore, since the flushing flow cannot be adjusted beyond its authority, the inability to redistribute the flushing flow when the motor is running at high speed causes the hydraulic motor temperature to exceed that of the hydraulic pump, resulting in harsh operating conditions for the motor. Utility Model Content

[0005] To address the shortcomings of existing technologies, the purpose of this utility model embodiment is to provide a hydraulic system with variable flushing flow rate. By adding a flushing overriding valve, the overriding of the flushing circuit is shielded, thereby meeting the needs of the hydraulic motor under different operating conditions, improving the system's response speed and rigidity, reducing the motor's temperature, improving the motor's operating conditions, and extending its service life.

[0006] To achieve the above objectives, the present invention provides the following technical solutions:

[0007] A hydraulic system with variable flushing flow rate includes: a hydraulic motor, a flushing shuttle valve, and a flushing overriding valve; the hydraulic motor has a first working oil circuit and a second working oil circuit, the first working oil circuit being connected to a first-side control chamber of the flushing shuttle valve, and the second working oil circuit being connected to a second-side control chamber of the flushing shuttle valve; the flushing overriding valve is installed on the first working oil circuit and the second working oil circuit, and the flushing overriding valve is a directional valve capable of connecting the first working oil circuit to the second-side control chamber of the flushing shuttle valve, and the second working oil circuit to the first-side control chamber of the flushing shuttle valve.

[0008] Optionally, the area of ​​the first working oil circuit acting on the second side control chamber of the flushing shuttle valve via the flushing overreach valve is equal to the area of ​​the second working oil circuit directly acting on the second side control chamber of the flushing shuttle valve; the area of ​​the second working oil circuit acting on the first side control chamber of the flushing shuttle valve via the flushing overreach valve is equal to the area of ​​the first working oil circuit directly acting on the first side control chamber of the flushing shuttle valve.

[0009] Optionally, a flow control element, which is a proportional throttle valve, is provided on the oil line connecting the flushing shuttle valve and the oil tank.

[0010] Optionally, a flow control element, which is a proportional relief valve, is provided on the oil line connecting the flushing shuttle valve and the oil tank.

[0011] Another embodiment describes a hydraulic system with variable flushing flow rate, comprising: a hydraulic motor, a flushing shuttle valve, and a flushing overriding valve; the hydraulic motor has a first working oil circuit and a second working oil circuit, the first working oil circuit being connected to a first-side control chamber of the flushing shuttle valve, and the second working oil circuit being connected to a second-side control chamber of the flushing shuttle valve; the flushing overriding valve is installed on the first working oil circuit and the second working oil circuit, and the flushing overriding valve is a directional valve capable of cutting off the connection between the first working oil circuit, the second working oil circuit, and the flushing shuttle valve.

[0012] Another embodiment describes a hydraulic system with variable flushing flow rate, comprising: a hydraulic motor, a flushing shuttle valve, and a flushing overriding valve; the hydraulic motor has a first working oil circuit and a second working oil circuit, the first working oil circuit being connected to a first-side control chamber of the flushing shuttle valve, and the second working oil circuit being connected to a second-side control chamber of the flushing shuttle valve; the flushing overriding valve is installed on the oil circuit connecting the flushing shuttle valve and the oil tank, and the flushing overriding valve is a directional valve capable of cutting off the connection of the oil circuit between the flushing shuttle valve and the oil tank.

[0013] Optionally, the flushing overreach valve, proportional throttle valve, or proportional relief valve is an electrically controlled valve, a hydraulically controlled valve, or a pneumatically controlled valve.

[0014] Optionally, the flushing overreach valve, proportional throttle valve, or proportional relief valve is built into the hydraulic motor or connected to the hydraulic motor via a pipeline.

[0015] One or more technical solutions provided in the embodiments of this utility model have at least the following technical effects or advantages:

[0016] 1. In the variable flushing flow hydraulic system of the present invention, the flushing overriding valve is installed on the first and second working oil circuits and is a directional valve. By changing the oil circuit path, the first working oil circuit is connected to the second control chamber of the flushing shuttle valve, and the second working oil circuit is connected to the first control chamber of the flushing shuttle valve. Under normal working conditions, the flushing circuit can be connected in the traditional way to achieve the flushing function of the hydraulic motor, removing impurities and heat. When the hydraulic motor needs to perform high-frequency directional switching, and the flushing flow may adversely affect its directional switching response, the flushing overriding valve is controlled to switch, increasing the control oil circuits on both sides of the flushing shuttle valve, thereby affecting the oil pressure balance on both sides of the flushing shuttle valve, keeping the flushing shuttle valve in the neutral position, thus shielding the flushing circuit, avoiding interference of the flushing flow with the directional switching operation, and improving the system's response speed and rigidity.

[0017] 2. By adding control oil circuits on both sides of the flushing shuttle valve, the flushing shuttle valve is placed in the neutral position. This control method allows for flexible bypassing of the flushing oil circuit without cutting off the control oil supply. Compared to directly cutting off the control oil supply on both sides of the flushing shuttle valve, there is no need to re-establish the control oil circuit when flushing is required. This makes switching more flexible and allows for a faster response to different system needs in scenarios requiring frequent switching of flushing oil circuit conditions, achieving more precise oil circuit control. This is especially important at low temperatures and when the hydraulic oil is more viscous.

[0018] 3. By adding control oil circuits on both sides of the flushing shuttle valve, since the control oil pressure on both sides of the flushing shuttle valve still exists, the seals and other components of the flushing shuttle valve are still under slight pressure, which can maintain a certain degree of mobility and lubrication. This avoids problems such as dryness and aging of the seals and other components caused by directly cutting off the control oil, thereby extending the service life of the flushing shuttle valve.

[0019] 4. Flushing circuit shielding and flow regulation: Based on the shielding function, the flushing flow can be distributed between the hydraulic pump and the hydraulic motor. When the hydraulic motor generates more heat, the flushing flow can be increased, reducing the severity of the motor's operating conditions and improving the motor's lifespan.

[0020] Additional advantages of this invention will be set forth in the description which follows, and in part will be obvious from the description or may be learned by practice of the invention. Attached Figure Description

[0021] The accompanying drawings, which form part of this specification, are used to provide a further understanding of this utility model. The illustrative embodiments and descriptions of this utility model are used to explain this utility model and do not constitute an undue limitation thereof. Furthermore, the spacing or dimensions between components are exaggerated to show their positions; the schematic diagrams are for illustrative purposes only.

[0022] Figure 1This is a schematic diagram of a hydraulic system provided by existing technology;

[0023] Figure 2 This is a schematic diagram of the hydraulic system provided in Embodiment 1 of this utility model;

[0024] Figure 3 This is a schematic diagram of a proportional throttle valve as a flow control element provided in embodiments 1-3 of this utility model;

[0025] Figure 4 This is a schematic diagram of the proportional relief valve provided in embodiments 1-3 of this utility model as a flow control element;

[0026] Figure 5 This is a schematic diagram of the hydraulic system provided in Embodiment 2 of this utility model;

[0027] Figure 6 This is a schematic diagram of the hydraulic system provided in Embodiment 3 of this utility model;

[0028] In the diagram: 1. Hydraulic motor; 2. Flushing shuttle valve; 3. Flow control element; 4. Flushing overreach valve; Detailed Implementation

[0029] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0030] Terminology Explanation

[0031] Hydraulic motor: A hydraulic actuator that uses hydraulic oil to rotate the motor clockwise or counterclockwise. A hydraulic motor consists of a housing, rotating components, a distribution assembly, a shaft, and other main body parts.

[0032] Solenoid valve: A hydraulic valve whose valve core state is controlled by an electromagnet. The electromagnetic force of the electromagnet can be changed to switch the oil passage or the size of the oil passage or to change the set pressure.

[0033] Example 1

[0034] like Figure 2As shown, this embodiment proposes a hydraulic system with variable flushing flow rate, including: a hydraulic motor 1, a flushing shuttle valve 2, and a flushing overriding valve 4; the hydraulic motor 1 has a first working oil circuit and a second working oil circuit, the first working oil circuit is connected to the first side control chamber of the flushing shuttle valve 2, and the second working oil circuit is connected to the second side control chamber of the flushing shuttle valve 2; the flushing overriding valve 4 is installed on the first working oil circuit and the second working oil circuit, and the flushing overriding valve 4 is a directional valve that can connect the first working oil circuit to the second side control chamber of the flushing shuttle valve 2, and the second working oil circuit to the first side control chamber of the flushing shuttle valve 2.

[0035] Cross-control of the working oil circuit is achieved through the flushing overriding valve 4. When the flushing overriding valve 4 is not activated, the first working oil circuit acts on the first control chamber of the flushing shuttle valve 2, and the second working oil circuit acts on the second control chamber, creating a pressure difference that drives the flushing shuttle valve 2 to switch. When flushing needs to be shielded, the flushing overriding valve 4 ensures that both control chambers of the flushing shuttle valve 2 simultaneously bear equal oil pressure, eliminating the pressure difference and keeping the valve core in the neutral position. This design enables the flushing circuit to achieve dynamic balance while maintaining the connection of the control oil circuit, avoiding the problems of vacuum or sudden pressure changes in the control oil chamber compared to the solution of directly cutting off the oil circuit.

[0036] This flushing circuit shielding method can achieve shielding during the high-frequency commutation process of hydraulic motor 1, avoiding poor motor system stiffness caused by the delayed commutation of flushing shuttle valve 2, slow speed increase after commutation, and improving system response.

[0037] Furthermore, the area of ​​the first working oil circuit acting on the second-side control chamber of the flushing shuttle valve 2 via the flushing overriding valve 4 is equal to the area of ​​the second working oil circuit directly acting on the second-side control chamber of the flushing shuttle valve 2; similarly, the area of ​​the second working oil circuit acting on the first-side control chamber of the flushing shuttle valve 2 via the flushing overriding valve 4 is equal to the area of ​​the first working oil circuit directly acting on the first-side control chamber of the flushing shuttle valve 2. This equality of area causes the control forces on both sides to cancel each other out, thereby ensuring that the flushing shuttle valve 2 remains stably in the neutral position, reliably shielding the flushing circuit and guaranteeing the accuracy and stability of the system control.

[0038] On the other hand, the existing hydraulic motor 1 uses a mechanically set overflow valve or a fixed-diameter throttling orifice for flushing. Because the flushing flow cannot be adjusted beyond its authority, the flushing flow cannot be redistributed when the motor is running at high speed, causing the temperature of the hydraulic motor 1 to be higher than that of the hydraulic pump, and the motor is in a relatively harsh working condition.

[0039] Based on this, a flow control element 3 is installed on the oil line connecting the flushing shuttle valve 2 and the oil tank. The flow control element 3 is a proportional throttle valve (such as...). Figure 3 As shown in the figure, the flushing overreach valve 4 is not shown.

[0040] The original motor's flushing flow control element 3 was replaced with a proportional throttle valve instead of a fixed-diameter damping orifice. The advantage of a proportional throttle valve is that its opening size can be precisely adjusted via electrical or hydraulic signals, thus achieving stepless adjustment of the flushing flow. In actual operation, when the system needs to reduce the motor's flushing flow, the opening of the proportional throttle valve can be reduced; conversely, increasing the opening increases the flushing flow. This adjustability allows the hydraulic system to flexibly distribute the flushing flow according to different working conditions, different heat dissipation requirements, and motor load, optimizing the overall system performance. Furthermore, when it is necessary to disable the flushing circuit, the opening of the proportional throttle valve can be completely closed, achieving more reliable flushing circuit control.

[0041] In another implementation (such as) Figure 4 As shown in the figure (the flushing overreach valve 4 is not shown), a flow control element 3 is provided on the oil line connecting the flushing shuttle valve 2 and the oil tank. The flow control element 3 is a proportional relief valve.

[0042] The original motor's flushing flow control element 3 was changed from a mechanically set relief valve to a proportional relief valve. The proportional relief valve works by controlling the flow rate through the flushing circuit by setting its relief pressure. When the system needs to reduce the flushing flow rate, the relief setting value of the proportional relief valve can be increased, so that oil only flows back to the oil tank through the relief valve when the oil pressure exceeds the set value, thus reducing the actual flow rate used for flushing. Conversely, decreasing the relief setting value increases the flushing flow rate. Like a proportional throttle valve, the proportional relief valve also has precise adjustment capabilities, allowing for rapid adjustment of the flushing flow rate according to the system's real-time needs, achieving precise flow distribution to meet the heat dissipation and impurity flushing requirements under different operating conditions. Moreover, when it is necessary to shield the flushing circuit, the relief setting value of the proportional relief valve can be adjusted to be much higher than the low-pressure side pressure, preventing oil from flowing back to the oil tank through the relief valve, thereby achieving the shielding function of the flushing circuit and enhancing the system's control flexibility and reliability of the flushing circuit.

[0043] Example 2

[0044] like Figure 5 As shown, the difference between this embodiment and Embodiment 1 lies in the flushing overreach valve 4. Specifically, the hydraulic system with variable flushing flow includes a hydraulic motor 1, a flushing shuttle valve 2, and a flushing overreach valve 4. The hydraulic motor 1 has a first working oil circuit and a second working oil circuit. The first working oil circuit is connected to the first side control chamber of the flushing shuttle valve 2, and the second working oil circuit is connected to the second side control chamber of the flushing shuttle valve 2. The flushing overreach valve 4 is installed on the first working oil circuit and the second working oil circuit. The flushing overreach valve 4 is a directional valve that can cut off the connection between the first working oil circuit, the second working oil circuit, and the flushing shuttle valve 2.

[0045] During normal operation, the flushing circuit is normally open. The flushing shuttle valve 2 reverses under the pressure difference between the motor's inlet and outlet oil, opening the flushing oil circuit and performing flushing operations on the hydraulic motor 1. The flushing overriding valve 4 is located in front of the flushing shuttle valve 2. When it is necessary to shield the flushing circuit, such as during the high-frequency reversing phase of the motor, to avoid the adverse effects of the flushing flow on the reversing response, the flushing overriding valve 4 is controlled to switch to the cut-off position, thereby blocking the oil circuit connection between the working oil circuit and the flushing shuttle valve 2, causing the flushing circuit to stop working. This direct oil circuit cut-off control method is simple and reliable to operate, can quickly shield the flushing circuit, meets the system's needs under special operating conditions, and effectively improves the system's adaptability and responsiveness.

[0046] In this embodiment, a flow control element 3 is provided on the oil line connecting the flushing shuttle valve 2 and the oil tank. The flow control element 3 is a proportional throttle valve or a proportional relief valve, with the same effect as in embodiment 1.

[0047] Example 3

[0048] like Figure 6 As shown, the difference between this embodiment and Embodiment 1 lies in the flushing overreach valve 4. Specifically, the variable flushing flow hydraulic system includes: a hydraulic motor 1, a flushing shuttle valve 2, and a flushing overreach valve 4; the hydraulic motor 1 has a first working oil circuit and a second working oil circuit, the first working oil circuit is connected to the first side control chamber of the flushing shuttle valve 2, and the second working oil circuit is connected to the second side control chamber of the flushing shuttle valve 2; the flushing overreach valve 4 is installed on the oil circuit connecting the flushing shuttle valve 2 and the oil tank, and the flushing overreach valve 4 is a directional valve that can cut off the connection of the oil circuit between the flushing shuttle valve 2 and the oil tank.

[0049] Under normal operating conditions, the flushing oil circuit is unobstructed. Oil flows from the hydraulic motor 1, passes through the flushing shuttle valve 2, and then flows back to the oil tank via the flushing overriding valve 4, completing the flushing cycle and removing impurities and heat. The flushing overriding valve 4 is located downstream of the flushing shuttle valve 2. When the motor needs to perform high-frequency reversing operations or when the flushing flow needs to be reduced to meet the functional requirements of other systems, the flushing overriding valve 4 is controlled to reverse, closing the oil circuit between the flushing shuttle valve 2 and the oil tank. This prevents the flushing circuit from operating normally, effectively shielding the flushing function. This shielding method acts directly on the downstream oil circuit of the flushing circuit, requiring only low pressure. It can quickly and effectively stop the circulation of flushing oil, is relatively easy to operate, and has minimal impact on other parts of the system, providing strong support for the flexible operation of the system under different working conditions.

[0050] In this embodiment, a flow control element 3 is provided on the oil line connecting the flushing shuttle valve 2 and the oil tank. The flow control element 3 is a proportional throttle valve or a proportional relief valve, with the same effect as in embodiment 1.

[0051] Example 4

[0052] This embodiment describes the newly added valves in embodiments 1-3. The flushing overreach valve 4, proportional throttle valve or proportional relief valve are hydraulic or pneumatic valves.

[0053] Electro-controlled valves receive electrical signals and convert them into mechanical or hydraulic signals to control the oil circuit. They offer rapid response, high control precision, and easy integration with modern electronic control systems. They can achieve complex control logic and precise flow regulation, making them suitable for highly automated hydraulic systems. Hydraulic control valves utilize the hydraulic oil itself as the control medium, controlling valve action through oil pressure changes. They feature strong control force and fast response, making them suitable for high-pressure, high-flow hydraulic systems. They also eliminate the need for an additional electrical control system, reducing system complexity and cost. Pneumatic control valves use compressed air as the control signal, offering advantages such as sensitive action and low environmental pollution. They are particularly suitable for working environments with special fire and explosion protection requirements, such as chemical and coal mining industries. The availability of multiple control methods allows for flexible configuration based on the needs of actual application scenarios, improving system adaptability and reliability. Whether in conventional industrial equipment or special environments, they can effectively achieve precise control of the flushing circuit, meeting the requirements of different working conditions. Alternatively, the opening can be mechanically switched and adjusted directly via a joystick.

[0054] The flushing overreach valve 4, proportional throttle valve, or proportional relief valve is built into the hydraulic motor 1, or connected to the hydraulic motor 1 through a pipeline.

[0055] Integrating the valve into the hydraulic motor 1 effectively reduces the need for external piping connections, shortens the oil transmission path, and lowers pressure loss and leakage risks in the pipelines. It also helps reduce the overall size of the hydraulic system, improving its integration and compactness, which is significant for space-constrained equipment or devices. Conversely, when internal valve integration is not feasible due to factors such as ease of maintenance, cost control, or system layout requirements, external piping connections are a viable solution. With proper piping design and layout, the valve can still control the flushing circuit, ensuring normal system operation. This flexible installation method provides more options for hydraulic system design and application, better meeting the specific needs of different users and application scenarios.

[0056] Although the specific embodiments of the present utility model have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present utility model. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solution of the present utility model are still within the scope of protection of the present utility model.

Claims

1. A hydraulic system with variable flushing flow rate, characterized in that, include: Hydraulic motor, flushing shuttle valve, and flushing overreach valve; The hydraulic motor has a first working oil circuit and a second working oil circuit. The first working oil circuit is connected to the first side control chamber of the flushing shuttle valve, and the second working oil circuit is connected to the second side control chamber of the flushing shuttle valve. The flushing overreach valve is installed on the first working oil circuit and the second working oil circuit. The flushing overreach valve is a reversing valve that can connect the first working oil circuit with the second side control chamber of the flushing shuttle valve, and the second working oil circuit with the first side control chamber of the flushing shuttle valve.

2. The hydraulic system with variable flushing flow rate as described in claim 1, characterized in that, The area of ​​the first working oil circuit acting on the second side control chamber of the flushing shuttle valve via the flushing overriding valve is equal to the area of ​​the second working oil circuit directly acting on the second side control chamber of the flushing shuttle valve; the area of ​​the second working oil circuit acting on the first side control chamber of the flushing shuttle valve via the flushing overriding valve is equal to the area of ​​the first working oil circuit directly acting on the first side control chamber of the flushing shuttle valve.

3. The hydraulic system with variable flushing flow rate as described in claim 1, characterized in that, A flow control element, which is a proportional throttle valve, is installed on the oil line connecting the flushing shuttle valve and the oil tank.

4. The hydraulic system with variable flushing flow rate as described in claim 1, characterized in that, A flow control element, which is a proportional relief valve, is installed on the oil line connecting the flushing shuttle valve and the oil tank.

5. A hydraulic system with variable flushing flow rate, characterized in that, include: Hydraulic motor, flushing shuttle valve, and flushing overreach valve; The hydraulic motor has a first working oil circuit and a second working oil circuit. The first working oil circuit is connected to the first side control chamber of the flushing shuttle valve, and the second working oil circuit is connected to the second side control chamber of the flushing shuttle valve. The flushing overreach valve is installed on the first working oil circuit and the second working oil circuit. The flushing overreach valve is a directional valve that can cut off the connection between the first working oil circuit, the second working oil circuit and the flushing shuttle valve.

6. The hydraulic system with variable flushing flow rate as described in claim 5, characterized in that, A flow control element is provided on the oil line connecting the flushing shuttle valve and the oil tank. The flow control element is a proportional throttle valve or a proportional relief valve.

7. A hydraulic system with variable flushing flow rate, characterized in that, include: Hydraulic motor, flushing shuttle valve, and flushing overreach valve; The hydraulic motor has a first working oil circuit and a second working oil circuit. The first working oil circuit is connected to the first side control chamber of the flushing shuttle valve, and the second working oil circuit is connected to the second side control chamber of the flushing shuttle valve. The flushing overreach valve is installed on the oil line connecting the flushing shuttle valve and the oil tank. The flushing overreach valve is a directional valve that can cut off the connection between the flushing shuttle valve and the oil tank.

8. The hydraulic system with variable flushing flow rate as described in claim 7, characterized in that, A flow control element is provided on the oil line connecting the flushing shuttle valve and the oil tank. The flow control element is a proportional throttle valve or a proportional relief valve.

9. The hydraulic system with variable flushing flow rate as described in any one of claims 1-8, characterized in that, The flushing overreach valve, proportional throttle valve, or proportional relief valve is an electrically controlled valve, a hydraulically controlled valve, or a pneumatically controlled valve.

10. The hydraulic system with variable flushing flow rate as described in any one of claims 1-8, characterized in that, The flushing overreach valve, proportional throttle valve, or proportional relief valve is built into the hydraulic motor or connected to the hydraulic motor via a pipeline.

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