Hydraulic drive system

Abstract

The utility model relates to the technical field of hydraulic driving, and provides a hydraulic driving system. The hydraulic driving system comprises a hydraulic cylinder, a driving oil way and an electric driving structure. The hydraulic cylinder comprises a cylinder body with a cavity, a piston arranged in the cavity in a sliding mode and a piston rod connected to the piston. The piston and the piston rod jointly divide the cavity into a rodless cavity and a rod cavity. The driving oil path is communicated with the rodless cavity and the rod cavity; the electric driving structure is arranged in the rod cavity and comprises a permanent magnet and a winding, the permanent magnet and the winding are sleeved, one is arranged on the cylinder body, and the other is arranged on the piston rod or the piston. According to the hydraulic driving system provided by the invention, the response speed and the response range are improved and expanded through combination of two modes of hydraulic driving and electric driving, and the hydraulic driving system has higher safety redundancy.

Description

Technical Field

[0001] The present application relates to the field of hydraulic drive technology, and in particular to a hydraulic drive system. Background Art

[0002] Hydraulic actuation systems are widely used in the fields of active damping adjustment and active height control of automobile shock absorbers, robotic arm drive of engineering machinery, retraction and extension control of aircraft landing gear, motion control of robot motion mechanisms, and active control of displacement or force of motion testing equipment to provide controllable generalized displacement, driving force, driving torque or damping characteristics.

[0003] In the related art, when a hydraulic pump is used for driving, there is still a problem of insufficient response rate, and the impact vibration generated during the damping adjustment process is large, which weakens the reliability. Utility Model Content

[0004] Based on this, it is necessary to provide a hydraulic drive system that improves the response speed and response range by combining hydraulic drive and electric drive, and has higher safety redundancy.

[0005] A hydraulic drive system includes a hydraulic cylinder, a drive oil circuit and an electric drive structure; the hydraulic cylinder includes a cylinder body with a cavity, a piston slidably arranged in the cavity and a piston rod connected to the piston, the piston and the piston rod together divide the cavity into a rodless cavity and a rod cavity; the drive oil circuit is connected to the rodless cavity and the rod cavity; the electric drive structure is arranged in the rod cavity and includes a permanent magnet and a winding, the two are arranged in a sleeve and one of them is arranged on the cylinder body, and the other is arranged on the piston rod or the piston.

[0006] As can be understood, the integration of permanent magnets and windings within the hydraulic cylinder allows currents in different directions to interact with the magnetic field of the permanent magnets, increasing or decreasing the piston's resistance to movement, thereby enabling adaptive adjustment of the piston's speed. This not only improves the piston's response speed but also meets its capacity to withstand significant shock and vibration, thereby enhancing the reliability and impact resistance of the entire system. Furthermore, the combination of hydraulic and electric drive improves both response speed and range, providing a higher level of safety redundancy.

[0007] In some embodiments, the winding is provided on the piston rod, and the piston rod is provided with an assembly cavity, and the assembly cavity is used to install a connecting wire connected to the winding.

[0008] In some embodiments, the piston is provided with a first one-way valve and a second one-way valve connected between the rodless chamber and the rod chamber, and the two are arranged in parallel; the first one-way valve is used to guide the oil to flow from the rod chamber to the rodless chamber, and the second one-way valve is used to guide the oil to flow from the rodless chamber to the rod chamber; the first one-way valve and the second one-way valve are both configured to open and close in response to the working pressure of the hydraulic cylinder.

[0009] In some embodiments, the hydraulic drive system further includes a first buffer structure, and the first buffer structure is provided in the rodless cavity and / or the rod cavity for limiting the movement of the piston and the piston rod.

[0010] In some embodiments, the lower buffer structure is provided in the rodless cavity, and the upper buffer structure is provided in the rod cavity; the lower buffer structure and the upper buffer structure are arranged opposite to and spaced apart along the axial direction of the piston rod, the lower buffer structure cooperates with the piston to limit the position, and the upper buffer structure cooperates with the permanent magnet or the winding provided on the piston rod to limit the position.

[0011] In some embodiments, the first buffer structure is made of an elastic material; or the upper buffer structure is made of a magnetic body, and the magnetic body is magnetically repelled from the permanent magnet or the winding provided on the piston rod; or the cylinder body has a second interface connected to the rodless cavity, and the lower buffer structure is provided with an oil storage cavity, the oil storage cavity is open on the side facing the piston, and the opening is located on the side of the second interface away from the rod cavity.

[0012] In some embodiments, the piston rod is passed through the piston, and the piston rod has a load end and a buffer end that are opposite to and spaced apart along its own axial direction, and the load end and the buffer end are arranged on opposite sides of the piston; the lower buffer structure is arranged in the rodless cavity, and the lower buffer structure includes a first buffer block and a second buffer block, the first buffer block is arranged at the buffer end, and the second buffer block is arranged at the cavity wall of the rodless cavity, and the first buffer block and the second buffer block are arranged relative to each other and cooperate to limit.

[0013] In some embodiments, the end of the piston rod located outside the cylinder body is the load end, and the hydraulic drive system also includes a second buffer structure, which is arranged outside the cylinder body and located on the side of the cylinder body facing the load end, for supporting the load mechanism.

[0014] In some embodiments, the driving oil circuit includes a bidirectional hydraulic pump, a restoring valve system and a compression valve system, which are connected in series. The bidirectional hydraulic pump is arranged between the restoring valve system and the compression valve system. The restoring valve system is connected to the rod chamber, and the compression valve system is connected to the rodless chamber.

[0015] In some embodiments, the restoring valve system and the compression valve system both include a damping valve, a bypass valve and a control valve arranged in parallel, the flow directions of the damping valve and the bypass valve are opposite, and the control valve is used to adjust the flow area corresponding to the restoring valve system or the compression valve system.

[0016] In some embodiments, the driving oil circuit further includes a restoring accumulator, which is arranged between the restoring valve system and the bidirectional hydraulic pump; and / or, the driving oil circuit further includes a compression accumulator, which is arranged between the compression valve system and the bidirectional hydraulic pump.

[0017] In some embodiments, the driving oil circuit includes a reversing valve, a pressure supply oil circuit, a return oil circuit and a hydraulic pump, and the hydraulic pump is connected between the pressure supply oil circuit and the return oil circuit; the reversing valve has a first port connected to the rod chamber, a second port connected to the rodless chamber, a third port connected to the pressure supply oil circuit and a fourth port connected to the return oil circuit; the pressure supply oil circuit and the return oil circuit can, under the action of the reversing valve, one of them connects to the rodless chamber and the other connects to the rod chamber.

[0018] In some embodiments, the driving oil circuit also includes a pressure relief oil circuit, which is connected between the pressure supply oil circuit and the return oil circuit and is arranged in parallel with the hydraulic pump, and the pressure relief oil circuit is provided with a pressure relief valve; the pressure supply oil circuit is provided with a third one-way valve in the part between the pressure relief oil circuit and the hydraulic pump, and the third one-way valve is used to guide the oil to flow from the hydraulic pump toward the third port.

[0019] In some embodiments, the pressure supply oil circuit is provided with a high-pressure accumulator, and the oil return oil circuit is provided with an oil tank or a low-pressure accumulator; and / or, the oil return oil circuit is provided with a filter. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the conventional technology, the following briefly introduces the drawings required for use in the embodiments or the conventional technology descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 A partial schematic diagram of a hydraulic drive system provided in one embodiment of the present application;

[0022] Figure 2 A partial schematic diagram of a hydraulic drive system provided in another embodiment of the present application;

[0023] Figure 3A partial schematic diagram of a hydraulic drive system provided in yet another embodiment of the present application;

[0024] Figure 4 A schematic diagram of a drive oil circuit in a hydraulic drive system provided in one embodiment of the present application;

[0025] Figure 5 A schematic diagram of a drive oil circuit in a hydraulic drive system provided in another embodiment of the present application;

[0026] Figure 6 A schematic diagram of a drive oil circuit in a hydraulic drive system provided in yet another embodiment of the present application;

[0027] Figure 7 A schematic diagram of a hydraulic drive system provided in one embodiment of the present application.

[0028] Figure numerals: 10, hydraulic cylinder; 11, cylinder body; 12, piston; 13, piston rod; 20, driving oil circuit; 21, bidirectional hydraulic pump; 22, recovery valve system; 23, compression valve system; 24, accumulator; 25, reversing valve; 26, pressure supply oil circuit; 27, oil return oil circuit; 28, hydraulic pump; 29, pressure relief oil circuit; 30, electric drive structure; 31, permanent magnet; 32, winding; 33, connecting wire; 41, first buffer structure; 41a, upper buffer structure; 41b, lower buffer structure; 401, oil storage chamber; 411, first buffer block; 412, second buffer block; 42, second buffer structure; 121, first one-way valve; 122, second one-way valve; 201, first hydraulic interface; 202, second hydraulic interface ;211, first drive motor;221, restoring damping valve;222, restoring bypass valve;223, restoring control valve;231, compression damping valve;232, compression bypass valve;233, compression control valve;241, restoring accumulator;242, compression accumulator;243, high-pressure accumulator;244, low-pressure accumulator;245, oil tank;251, first port;252, second port;253, third port;254, fourth port;261, third one-way valve;271, filter;281, second drive motor;291, pressure relief valve;292, first access point;1101, rod chamber;1102, rodless chamber;1103, first interface;1104, second interface;1301, assembly chamber. DETAILED DESCRIPTION

[0029] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0030] It should be noted that when a component is referred to as being "fixed to" or "provided on" another component, it may be directly on the other component or there may be a central component. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may be a central component at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in the specification of this application are for illustrative purposes only and do not represent the only implementation method.

[0031] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. Throughout the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0032] In this application, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it can mean that the first feature is directly in contact with the second feature, or the first feature and the second feature are indirectly in contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it can mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is higher in level than the second feature. When a first feature is "below," "below," or "below" a second feature, it can mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is lower in level than the second feature.

[0033] Unless otherwise defined, all technical and scientific terms used in the specification of this application have the same meaning as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used in the specification of this application includes any and all combinations of one or more of the relevant listed items.

[0034] See also Figure 1 、 Figure 2 and Figure 7As shown, the hydraulic drive system provided by one embodiment of the present application includes a hydraulic cylinder 10, a drive oil circuit 20 and an electric drive structure 30. The hydraulic cylinder 10 includes a cylinder body 11, a piston 12 and a piston rod 13. The cylinder body 11 has a cavity. The piston 12 is slidably arranged in the cavity. The piston rod 13 is connected to one side of the piston 12. The piston 12 and the piston rod 13 together divide the cavity into a rodless cavity 1102 and a rod cavity 1101. The drive oil circuit 20 is connected to the rodless cavity 1102 and the rod cavity 1101 to meet the oil circuit circulation and damping adjustment between the rodless cavity 1102 and the rod cavity 1101. The electric drive structure 30 is arranged in the rod cavity 1101 and includes a permanent magnet 31 and a winding 32, both of which are arranged in a sleeve and one of which is arranged on the cylinder body 11 and the other is arranged on the piston rod 13.

[0035] Among them, the end of the piston rod 13 away from the piston 12 is used to connect to the load mechanism, so that the hydraulic drive system can provide stable support for the load mechanism and timely response under different load conditions. In actual use, when the piston 12 moves toward the rodless chamber 1102, the oil in the rodless chamber 1102 is squeezed, causing it to flow out and flow along the drive oil circuit 20 to the rod chamber 1101; when the piston 12 moves toward the rod chamber 1101, the oil in the rod chamber 1101 is squeezed, causing it to flow out and flow along the drive oil circuit 20 to the rodless chamber 1102. In this process, if the piston 12 runs very fast, a current in a specific direction can be connected to the winding 32, causing the winding 32 to generate a magnetic field with a magnetic field opposite to that of the permanent magnet 31, thereby causing the winding 32 to be subjected to the magnetic field resistance of the permanent magnet 31, increasing the running resistance of the piston 12, and thus slowing down the running speed of the piston 12. Conversely, if the piston 12 is moving very slowly, a current can be supplied to the winding 32 in the opposite direction, causing the winding 32 to generate a magnetic field with the same magnetic properties as the permanent magnet 31. This in turn causes the winding 32 to be driven by the magnetic field of the permanent magnet 31, thereby increasing the operating power and speed of the piston 12. Furthermore, if the winding 32 is not energized, the movement of the piston 12 can cause the winding 32 to cut through the permanent magnet 31, generating an induced electromotive force that can be used to recover electrical energy.

[0036] In summary, the hydraulic drive system provided in this embodiment integrates a permanent magnet 31 and a winding 32 within the hydraulic cylinder 10. When currents in different directions flow through the winding 32, they interact with the magnetic field of the permanent magnet 31 to increase or decrease the resistance to the movement of the piston 12, thereby adaptively adjusting the operating speed of the piston 12. This not only improves the response speed of the piston 12 but also satisfies the piston 12's ability to withstand significant shock and vibration, thereby enhancing the reliability and impact resistance of the entire system.

[0037] In some specific embodiments, the permanent magnet 31 is mounted on the wall of the rod cavity 1101 of the cylinder body 11 and is disposed around the outer periphery of the winding 32. The winding 32 is sleeved on the piston rod 13 and includes an iron core and a coil disposed thereon. Alternatively, the permanent magnet 31 may be mounted on the piston rod 13, while the winding 32 is mounted on the wall of the rod cavity 1101 of the cylinder body 11. The interaction between the winding 32 and the permanent magnet 31 is utilized to adjust the operating resistance of the piston 12.

[0038] like Figure 3 As shown, alternatively, the permanent magnet 31 may also be provided on the cylinder 11 , and the winding 32 may be provided on the piston 12 .

[0039] like Figure 1 and Figure 2 As shown, during actual assembly, taking the case of a winding 32 mounted on the piston rod 13 as an example, the piston rod 13 is provided with an assembly cavity 1301 for receiving a connecting wire 33 connected to the winding 32. Assembly cavity 1301 extends from the end of the piston rod 13 facing away from the piston 12, along the axial direction of the piston rod 13, toward the end closer to the piston 12, to a position compatible with the winding 32. Furthermore, at the extended end of assembly cavity 1301, the piston rod 13 is provided with a first wiring hole extending radially through it, connecting to assembly cavity 1301. The connecting wire 33 can be inserted into assembly cavity 1301 and passed through the first wiring hole to connect to the coil within the winding 32, thereby providing current supply.

[0040] Among them, a wiring structure for fixing the connecting wire 33 can also be provided on the cavity wall of the assembly cavity 1301 to avoid the connection wire 33 being messy. Since the end of the piston rod 13 is mostly used to connect the load mechanism, the connecting wire 33 can be directly led out through the end of the assembly cavity 1301 away from the piston 12; or, a second wiring hole is provided at the end of the piston rod 13 away from the piston 12, which runs through the end of the piston rod 13 along its own radial direction, for the wiring setting of the connecting wire 33. In actual use, a sealing structure is provided at least at the first wiring hole to prevent the oil from leaking into the assembly cavity 1301 through the first wiring hole, and then leaking from the assembly cavity 1301 or the second wiring hole. For example, a sealing structure can be provided in both the first wiring hole and the assembly cavity 1301. When there is a second wiring hole, a sealing structure is also provided at the second wiring hole. The sealing structure can be an O-ring.

[0041] Furthermore, the permanent magnet 31 can be bonded to the cavity wall of the rod cavity 1101 using a high-temperature resistant adhesive.

[0042] Furthermore, a buffer can be provided on the side of the piston 12 facing the piston rod 13, which can buffer the collision between the piston 12 and the permanent magnet 31, thereby reducing the collision wear between the two and the abnormal noise generated by the collision during operation.

[0043] Please continue reading Figure 1 、 Figure 2 and Figure 7 In some embodiments, the piston 12 is provided with a first one-way valve 121 and a second one-way valve 122 that are connected between the rodless chamber 1102 and the rod chamber 1101, and the two are arranged in parallel. The arrangement of the first one-way valve 121 and the second one-way valve 122 can satisfy the oil circulation between the rodless chamber 1102 and the rod chamber 1101, thereby realizing the movement of the piston 12 under the action of hydraulic damping. Among them, the first one-way valve 121 is used to guide the oil to flow from the rod chamber 1101 to the rodless chamber 1102, and the second one-way valve 122 is used to guide the oil to flow from the rodless chamber 1102 to the rod chamber 1101. In other words, the oil can only flow along the rod chamber 1101 toward the rodless chamber 1102 through the first one-way valve 121 and cannot flow in the opposite direction; and the oil can only flow along the rodless chamber 1102 toward the rod chamber 1101 through the second one-way valve 122 and cannot flow in the opposite direction. Such an arrangement can provide relatively stable damping to keep the piston 12 moving smoothly.

[0044] Furthermore, both the first and second one-way valves 121, 122 are configured to open and close in response to the operating pressure of the hydraulic cylinder 10. The operating pressure of the hydraulic cylinder 10 is the load borne by the piston 12. When the load fluctuates, the opening pressure of the first and second one-way valves 121, 122 can be overcome to ensure oil circulation, achieve faster response, and absorb displacement fluctuations of the piston 12. Specifically, the first and second one-way valves 121, 122 are one-way valves with elastic elements, such as spring-loaded one-way valves. Specifically, a spring is installed on the valve disc, and when the spring overcomes the spring's action, the valve disc is pushed open. If the spring fails to overcome the spring's action, the spring presses the valve disc against the valve port, sealing it and ensuring unidirectional flow. Therefore, once the load fluctuation overcomes the elastic action of the spring, the first and second one-way valves 121, 122 can be opened.

[0045] In some specific embodiments, a flow hole connecting the rodless chamber 1102 and the rod chamber 1101 may be opened in the piston 12, and a spring and a valve plate are arranged in the flow hole to form the aforementioned first one-way valve 121 or second one-way valve 122.

[0046] like Figure 1 and Figure 2As shown, in actual use, the cylinder body 11 of the hydraulic cylinder 10 is provided with interfaces for communicating with the drive oil circuit 20 at both the rod chamber 1101 and the rodless chamber 1102, namely a first interface 1103 and a second interface 1104. The first interface 1103 is provided at one end of the rod chamber 1101 axially away from the rodless chamber 1102 along the piston rod 13, and the second interface 1104 is provided at one end of the rodless chamber 1102 axially away from the rod chamber 1101 along the piston rod 13. The first interface 1103 and the second interface 1104 can be provided on the sidewalls or two opposing end surfaces of the cylinder body 11.

[0047] Please combine Figure 1 、 Figure 4 and Figure 7 In some embodiments, the drive circuit 20 includes a bidirectional hydraulic pump 21, a restoring valve system 22, and a compression valve system 23. The three are connected in series, with the bidirectional hydraulic pump 21 positioned between the restoring valve system 22 and the compression valve system 23. The restoring valve system 22 is connected to the rod chamber 1101, while the compression valve system 23 is connected to the rodless chamber 1102. The drive circuit 20 has a first hydraulic port 201 and a second hydraulic port 202. The first hydraulic port 201 can be connected to the first port 1103, and the second hydraulic port 202 can be connected to the second port 1104. The restoring valve system 22 is positioned between the first hydraulic port 201 and the bidirectional hydraulic pump 21, while the compression valve system 23 is positioned between the second hydraulic port 202 and the bidirectional hydraulic pump 21. In actual use, when the bidirectional hydraulic pump 21 is used for driving, if the piston 12 is running at a low speed, the restoring valve system 22 and the compression valve system 23 cooperate to provide damping for changes in piston 12 speed. At the same time, as the damping of the piston 12 is adjusted, the flow rates of the restoring valve system 22 and the compression valve system 23 can also be adjusted to adapt to the corresponding damping adjustment.

[0048] Specifically, both the restoring valve system 22 and the compression valve system 23 include a damping valve and a bypass valve connected in parallel, with the flow directions of the two valves being opposite. Both the damping valve and the bypass valve can be spring-loaded check valves. Therefore, when the operating pressure of the hydraulic cylinder 10 exceeds the opening pressure of the damping valve and the bypass valve, both valves open to adjust the corresponding damping.

[0049] The restoring valve system 22 corresponds to the restoring damping valve 221 and the restoring bypass valve 222, and the compression valve system 23 corresponds to the compression damping valve 231 and the compression bypass valve 232. The restoring damping valve 221 is used to direct oil flow from the rod chamber 1101 to the rodless chamber 1102, and the restoring bypass valve 222 is used to direct oil flow from the rodless chamber 1102 to the rod chamber 1101. The compression damping valve 231 is used to direct oil flow from the rodless chamber 1102 to the rod chamber 1101, and the compression bypass valve 232 is used to direct oil flow from the rod chamber 1101 to the rodless chamber 1102. Therefore, the restoring damping valve 221 and the compression bypass valve 232 cooperate to realize the flow of oil from the rod chamber 1101 to the rodless chamber 1102 , and the compression damping valve 231 and the restoring bypass valve 222 cooperate to realize the flow of oil from the rodless chamber 1102 to the rod chamber 1101 .

[0050] When the piston 12 needs to move toward the rodless chamber 1102, it squeezes the oil in the rodless chamber 1102, forcing it to overcome the opening pressure of the compression damping valve 231 and the return bypass valve 222, causing the oil in the rodless chamber 1102 to flow into the rod chamber 1101; this is compression. Conversely, when the piston 12 needs to move toward the rod chamber 1101, it squeezes the oil in the rod chamber 1101, forcing it to overcome the opening pressure of the return damping valve 221 and the compression bypass valve 232, causing the oil in the rod chamber 1101 to flow into the rodless chamber 1102; this is return.

[0051] like Figure 4 and Figure 7 As shown, both the restoring valve system 22 and the compression valve system 23 further include control valves, which are arranged in parallel with their corresponding damping valves and bypass valves. The restoring valve system 22 corresponds to the restoring control valve 223, while the compression valve system 23 corresponds to the compression control valve 233. The restoring control valve 223 is used to adjust the flow area of ​​the restoring valve system 22, while the compression control valve 233 is used to adjust the flow area of ​​the compression valve system 23, for example, to a larger flow area under high load and a smaller flow area under low load. Both the restoring control valve 223 and the compression control valve 233 utilize variable throttle valves.

[0052] In actual use, the piston 12, permanent magnet 31, winding 32, etc. are disposed in the rod chamber 1101, which occupies a portion of the space within the rod chamber 1101. This results in the actual amount of oil that can be stored in the rod chamber 1101 being less than the amount of oil in the rodless chamber 1102. Therefore, the drive oil circuit 20 further includes an accumulator 24 for compensating the oil in the rodless chamber 1102 and for recovering excess oil that has flowed out of the rodless chamber 1102.

[0053] like Figure 4 and Figure 7As shown, the accumulator 24 optionally includes a restoring accumulator 241 and a compression accumulator 242. The restoring accumulator 241 is disposed between the restoring valve system 22 and the bidirectional hydraulic pump 21, while the compression accumulator 242 is disposed between the compression valve system 23 and the bidirectional hydraulic pump 21. In this manner, the restoring accumulator 241 can be used to compensate for and recover oil in the rod chamber 1101, while the compression accumulator 242 can be used to compensate for and recover oil in the rodless chamber 1102. Furthermore, the accumulator 24 generates its own pressure, which can apply high pressure to both the rodless chamber 1102 and the rod chamber 1101.

[0054] Due to the bidirectional hydraulic pump 21, the entire hydraulic drive system can be arranged symmetrically relative to the bidirectional hydraulic pump 21, allowing for bidirectional adjustment of system flow and achieving efficient, high-speed active damping adjustment. The bidirectional hydraulic pump 21 is connected to a first drive motor 211 to drive the bidirectional hydraulic pump 21 and achieve flow adjustment in a specified direction. When flow adjustment by the bidirectional hydraulic pump 21 is not required, the pressure difference between the two flow ports of the bidirectional hydraulic pump 21 can be used to drive the pump blades within the bidirectional hydraulic pump 21, thereby driving the first drive motor 211 to achieve power generation and energy storage. Therefore, in terms of active bidirectional drive, the forward and reverse rotation control of the bidirectional hydraulic pump 21 and the opening control of the return control valve 223 and the compression control valve 233 can be used to continuously adjust the hydraulic pressure within the rodless chamber 1102 and the rod chamber 1101, thereby generating different hydraulic pressures on both sides of the piston 12 and providing actuation force for the piston 12 in a specified direction. Simultaneously, the operating speed of the piston 12 can be adjusted by combining the aforementioned permanent magnet 31 and winding 32.

[0055] See also Figure 5 and Figure 6 As another example, the drive oil circuit 20 includes a reversing valve 25, a pressure supply oil circuit 26, a return oil circuit 27, and a hydraulic pump 28. The hydraulic pump 28 is connected between the pressure supply oil circuit 26 and the return oil circuit 27. The reversing valve 25 has a first port 251, a second port 252, a third port 253, and a fourth port 254. The first port 251 is connected to the rod chamber 1101, the second port 252 is connected to the rodless chamber 1102, the third port 253 is connected to the pressure supply oil circuit 26, and the fourth port 254 is connected to the return oil circuit 27. Under the action of the reversing valve 25, one of the pressure supply oil circuit 26 and the return oil circuit 27 can be connected to the rodless chamber 1102 or the other to the rod chamber 1101. In other words, by adjusting the valve core position of the reversing valve 25, the high-pressure oil circuit can be adjusted to flow to the rod chamber 1101 or the rodless chamber 1102, meeting the maximum load support requirements of the piston 12.

[0056] The pressure supply oil circuit 26 is provided with a high-pressure accumulator 243, and the oil return oil circuit 27 is provided with an oil tank 245 or a low-pressure accumulator 244. The pressure of the high-pressure accumulator 243 can be maintained at the MPa level, which allows for faster response.

[0057] In actual use, the piston 12 of the reversing valve 25 can be actively controlled to be in the middle position. At this time, the first port 251, the second port 252, the third port 253 and the fourth port 254 of the reversing valve 25 are not connected. At this time, it is precisely because of the setting of the first one-way valve 121 and the second one-way valve 122 on the piston 12 that the damping adjustment between the rodless chamber 1102 and the rod chamber 1101 can be met. When the piston 12 needs to move toward the rodless chamber 1102, the valve core can be switched to the left position, causing the third port 253 to be connected with the first port 251 and the fourth port 254 to be connected with the second port 252, that is, the supply pressure oil circuit 26 is connected with the rod chamber 1101, and the return oil circuit 27 is connected with the rodless chamber 1102. The high-pressure accumulator 243 provides high-pressure oil to the rod chamber 1101, and part of the oil in the rodless chamber 1102 flows to the rod chamber 1101, and part flows to the low-pressure accumulator 244 or the oil tank 245. When the piston 12 needs to move toward the rod chamber 1101, the valve core can be switched to the right position, causing the third port 253 to be connected with the second port 252 and the fourth port 254 to be connected with the first port 251, that is, the supply pressure oil circuit 26 is connected with the rodless chamber 1102, and the return oil circuit 27 is connected with the rod chamber 1101. The high-pressure accumulator 243 provides high-pressure oil pressure to the rodless chamber 1102, and part of the oil in the rod chamber 1101 flows to the rodless chamber 1102, and part flows to the low-pressure accumulator 244 or the oil tank 245.

[0058] Please continue reading Figure 5 and Figure 6 Optionally, the hydraulic pump 28 is a one-way hydraulic pump connected to a second drive motor 281 to achieve power drive. The drive oil circuit 20 also includes a pressure relief oil circuit 29, which is connected between the pressure supply oil circuit 26 and the return oil circuit 27 and is arranged in parallel with the hydraulic pump 28. The pressure relief oil circuit 29 is provided with a pressure relief valve 291. The provision of the pressure relief oil circuit 29 allows some oil to flow back to the oil tank 245 on the return oil circuit 27 through the pressure relief oil circuit 29 after the high-pressure accumulator 243 is pressed. In actual use, the connection point between the pressure relief oil circuit 29 and the pressure supply oil circuit 26 is the first connection point 292. The pressure supply oil circuit 26 is also provided with a third one-way valve 261, located between the first connection point 292 and the hydraulic pump 28. The third one-way valve 261 is used to guide the oil flow from the hydraulic pump 28 toward the high-pressure accumulator 243, alleviating the problem of reverse oil flow. In particular, when the high-pressure accumulator 243 is being stamped, part of the oil will flow back after the high-pressure accumulator 243 is stamped. At this time, due to the setting of the third one-way valve 261, the problem of impact caused by the high-pressure oil flowing directly from the high-pressure accumulator 243 to the hydraulic pump 28 can be improved, so the remaining oil can flow to the oil tank 245 along the pressure relief oil circuit 29.

[0059] In actual use, the drive oil circuit 20 also includes a filter 271, which is arranged in the return oil circuit 27. The filter 271 is used to filter the oil to reduce impurities in the oil. Among them, in addition to filtering structures such as filter screens, the filter 271 can also be provided with a magnetic structure to filter iron filings and the like in the oil. Since the hydraulic pump 28, the piston 12 and each valve structure are mostly made of metal materials, such as iron, it is inevitable that very small amounts of iron filings will be generated during the operation of the system. If these iron filings are not handled in time, they may obstruct or scratch the high-precision matching valve cores, pumps and other structures in the system, aggravate system leakage and reduce damping performance. Therefore, the setting of the filter 271 can be used to adsorb iron filings without affecting the flow of hydraulic oil, thereby achieving a filtering effect and improving the reliability of the system.

[0060] Please combine Figure 1 、 Figure 4 、 Figure 5 、 Figure 6 and Figure 7 In summary, in the hydraulic drive system provided by the present application, the first one-way valve 121 and the second one-way valve 122 cooperate with each other to meet the small damping working pressure adjustment between the rodless chamber 1102 and the rod chamber 1101; and the setting of the drive oil circuit 20 can be used to meet the adaptive adjustment of a larger damping range. On this basis, the setting of the electric drive structure 30 is combined to further increase the adjustable damping range of the entire system. In other words, the combination of hydraulic drive and electric drive is used to improve the response speed and response range, and has a higher safety redundancy. Among them, since the electric drive structure 30 is integrated in the rod chamber 1101 of the hydraulic cylinder 10, it is equivalent to immersing it in hydraulic oil, which can also enhance heat dissipation and reduce vibration impact.

[0061] See also Figure 2 and Figure 3 As another example, the hydraulic drive system also includes a first buffer structure 41. The first buffer structure 41 is provided in both the rodless cavity 1102 and the rod cavity 1101. Specifically, the rod cavity 1101 is provided with a first cavity wall, and the rodless cavity 1102 is provided with a second cavity wall, and the first cavity wall and the second cavity wall are arranged opposite to and spaced apart along the axial direction of the piston rod 13. A first buffer structure 41 can be protruded from the first cavity wall, and is referred to as an upper buffer structure 41a; and a first buffer structure 41 can be protruded from the second cavity wall, and is referred to as a lower buffer structure 41b. The upper buffer structure 41a and the lower buffer structure 41b are arranged opposite to and spaced apart along the axial direction of the piston rod 13. The upper buffer structure 41a cooperates with the winding 32 provided on the piston rod 13 to limit the position, and the lower buffer structure 41b cooperates with the piston 12 to limit the position, thereby improving the problem that the piston 12, the winding and the cylinder body 11 are easily damaged due to direct collision.

[0062] Among them, the upper buffer structure 41a and the lower buffer structure 41b can both be made of elastic materials. For example, they can be made of rubber material or silicone material, and attached to the cavity wall of the cylinder body 11. The upper buffer structure 41a is provided with a through hole for the piston rod 13 to pass through. For example, the upper buffer structure 41a adopts an annular rubber pad. Alternatively, the upper buffer structure 41a and the lower buffer structure 41b can also directly adopt springs, and the upper buffer structure 41a is sleeved on the outside of the piston rod 13. Another alternative is that the upper buffer structure 41a and the lower buffer structure 41b can also be a combination of springs and rubber pads.

[0063] In other embodiments, the upper buffer structure 41a is made of a magnetic body, and the magnetic body is magnetically repelled from the permanent magnet 31 or the winding 32 provided on the piston rod 13. Taking the winding 32 provided on the piston rod 13 as an example, the magnetic field generated by the winding 32 being energized and the magnetic field of the magnetic body repel each other, and then when the piston 12 moves, a force opposite to the direction of movement can be applied, thereby reducing the risk of direct collision between the piston rod 13 and the cylinder body 11. If the permanent magnet 31 is provided on the piston rod 13, the magnetic field of the magnetic body and the magnetic field of the permanent magnet 31 repel each other. Among them, the magnetic body can also be set as an electromagnet, which can be magnetically attracted when powered on. When an electromagnet is used, a sensor can also be installed to detect whether the electromagnet generates a magnetic field.

[0064] like Figure 2 As shown, in yet another embodiment, the lower buffer structure 41b is provided with an oil storage chamber 401, the side of the oil storage chamber 401 facing the piston 12 is open, and the opening is located on the side of the second interface 1104 away from the rod chamber 1101. The lower buffer structure 41b is protruding from the second cavity wall of the rodless cavity 1102, and the side wall of the lower buffer structure 41b facing the piston 12 is recessed with the oil storage chamber 401 along the axial direction of the piston rod 13 away from the piston 12. The opening of the oil storage chamber 401 is located on the side of the second interface 1104 away from the first interface 1103, ensuring that the oil can circulate normally through the drive oil circuit 20. When the piston 12 moves toward the rodless cavity 1102, the oil in the oil storage chamber 401 will be squeezed to generate an interaction force to act on the piston 12, thereby generating a certain buffering force on the piston 12, reducing the risk of the piston 12 directly contacting the cylinder body 11.

[0065] Among them, the oil storage chamber 401 is gradually expanded along the direction from the rod chamber 1101 to the rodless chamber 1102, and a spiral drainage groove is provided on the cavity wall of the oil storage chamber 401, which has a certain flow guiding effect on the oil, so that the oil forms a spiral flow in the oil storage chamber 401 in the opposite direction of the movement direction of the piston 12, further increasing the buffering force acting on the piston 12.

[0066] Alternatively, the first buffer structure 41 may be provided only in the rod cavity 1101 , or only in the rodless cavity 1102 .

[0067] like Figure 3 As shown, as another example, the piston rod 13 has a load end and a buffer end that are arranged opposite and spaced apart along its own axial direction. The load end extends out of the cylinder body 11 for connection to the load mechanism, and the piston rod 13 is inserted into the piston 12 so that the buffer end is located within the rodless cavity 1102, which is equivalent to the load end and the buffer end being arranged on opposite sides of the piston 12. The lower buffer structure 41b includes a first buffer block 411 and a second buffer block 412. The first buffer block 411 is provided at the buffer end of the piston rod 13, and the second buffer block 412 is protruding from the second side wall. The first buffer block 411 moves with the piston 12 and piston rod 13 to cooperate with the second buffer block 412 for limiting position.

[0068] Among them, the first buffer block 411 and the second buffer block 412 can both be rubber pads, or both be springs, or a combination of rubber pads and springs, or one of them can be a rubber pad and the other can be a spring, etc. As long as the first buffer block 411 and the second buffer block 412 can abut against the limit position and play a mobile buffering effect, it will be fine.

[0069] Alternatively, the first buffer block 411 and the second buffer block 412 can both be made of magnetic materials, and the magnetic forces of the two magnetic materials repel each other, thus playing a buffering role. Of course, electromagnets can also be used.

[0070] Alternatively, the first buffer block 411 may have an oil reservoir 401 recessed on a side facing away from the buffer end, and the second buffer block 412 may extend into the oil reservoir 401 to squeeze the oil within the reservoir 401, thereby utilizing the flow resistance of the oil to provide a buffering effect. The second buffer block 412 may also be arranged to gradually expand along the axial direction of the piston rod 13 from the load end toward the buffer end.

[0071] See also Figure 2 and Figure 3 As another example, the hydraulic actuation system further includes a second buffer structure 42, disposed outside the cylinder body 11. The second buffer structure 42 is used to support the load mechanism. Specifically, by disposing the second buffer structure 42 outside the cylinder body 11, and located on the side of the cylinder body 11 facing the load end of the piston rod 13, the second buffer structure 42 provides support and cushioning for the load mechanism, thereby reducing the risk of the load mechanism directly colliding with the cylinder body 11 and causing damage to the cylinder body 11. The second buffer structure 42 may be a rubber pad, a rubber block, a spring, or a combination thereof.

[0072] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0073] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of patent protection for the present application shall be determined by the appended claims.

Claims

1. A hydraulic drive system, characterized in that: include: A hydraulic cylinder (10) comprises a cylinder body (11) having a cavity, a piston (12) slidably disposed in the cavity, and a piston rod (13) connected to the piston (12), wherein the piston (12) and the piston rod (13) together divide the cavity into a rodless cavity (1102) and a rod cavity (1101); A driving oil circuit (20) communicating with the rodless chamber (1102) and the rod chamber (1101); An electric drive structure (30) is provided in the rod cavity (1101) and comprises a permanent magnet (31) and a winding (32), both of which are sleeved and one of which is provided on the cylinder body (11) and the other is provided on the piston rod (13) or the piston (12).

2. The hydraulic drive system according to claim 1, characterized in that: The piston (12) is provided with a first one-way valve (121) and a second one-way valve (122) communicating between the rodless chamber (1102) and the rod chamber (1101), and the two are arranged in parallel; The first one-way valve (121) is used to guide oil to flow from the rod chamber (1101) to the rodless chamber (1102), and the second one-way valve (122) is used to guide oil to flow from the rodless chamber (1102) to the rod chamber (1101); The first one-way valve (121) and the second one-way valve (122) are both configured to open and close in response to the working pressure of the hydraulic cylinder (10).

3. The hydraulic drive system according to claim 1, characterized in that: The hydraulic drive system further includes a first buffer structure (41), and the first buffer structure (41) is provided in the rodless chamber (1102) and / or the rod chamber (1101), for limiting the movement of the piston (12) and the piston rod (13).

4. The hydraulic drive system according to claim 3, characterized in that: The portion provided in the rodless cavity (1102) is a lower buffer structure (41b), and the portion provided in the rod-equipped cavity (1101) is an upper buffer structure (41a); The lower buffer structure (41b) and the upper buffer structure (41a) are arranged opposite to each other and spaced apart along the axial direction of the piston rod (13); the lower buffer structure (41b) cooperates with the piston (12) to limit the position, and the upper buffer structure (41a) cooperates with the permanent magnet (31) or the winding (32) provided on the piston rod (13) to limit the position.

5. The hydraulic drive system according to claim 4, characterized in that: The first buffer structure (41) is made of elastic material; or, The upper buffer structure (41a) is made of a magnetic body, and the magnetic body and the permanent magnet (31) or the winding (32) provided on the piston rod (13) are magnetically repelled; or, The cylinder body (11) has a second interface (1104) provided on the rodless chamber (1102), and the lower buffer structure (41b) is provided with an oil storage chamber (401), the oil storage chamber (401) is open on the side facing the piston (12), and the opening is located on the side of the second interface (1104) away from the rod chamber (1101).

6. The hydraulic drive system according to claim 3, characterized in that: The piston rod (13) is provided through the piston (12), and the piston rod (13) has a load end and a buffer end which are arranged opposite to each other and spaced apart along its own axial direction, and the load end and the buffer end are arranged on opposite sides relative to the piston (12); The lower buffer structure (41b) is arranged in the rodless cavity (1102), and the lower buffer structure (41b) includes a first buffer block (411) and a second buffer block (412). The first buffer block (411) is arranged at the buffer end, and the second buffer block (412) is arranged at the cavity wall of the rodless cavity (1102). The first buffer block (411) and the second buffer block (412) are arranged relative to each other and cooperate to limit.

7. The hydraulic drive system according to claim 3, characterized in that: The end of the piston rod (13) located outside the cylinder body (11) is a load end. The hydraulic drive system further comprises a second buffer structure (42). The second buffer structure (42) is arranged outside the cylinder body (11) and is located on the side of the cylinder body (11) facing the load end, and is used to support the load mechanism.

8. The hydraulic drive system according to any one of claims 1 to 7, characterized in that: The driving oil circuit (20) includes a bidirectional hydraulic pump (21), a restoring valve system (22) and a compression valve system (23), which are connected in series. The bidirectional hydraulic pump (21) is arranged between the restoring valve system (22) and the compression valve system (23). The restoring valve system (22) is connected to the rod chamber (1101), and the compression valve system (23) is connected to the rodless chamber (1102).

9. The hydraulic drive system according to any one of claims 1 to 7, characterized in that: The driving oil circuit (20) includes a reversing valve (25), a pressure supply oil circuit (26), an oil return oil circuit (27), and a hydraulic pump (28), wherein the hydraulic pump (28) is connected between the pressure supply oil circuit (26) and the oil return oil circuit (27); The reversing valve (25) has a first port (251) connected to the rod chamber (1101), a second port (252) connected to the rodless chamber (1102), a third port (253) connected to the pressure supply oil circuit (26), and a fourth port (254) connected to the oil return circuit (27); Under the action of the reversing valve (25), one of the pressure supply oil circuit (26) and the oil return oil circuit (27) can be connected to the rodless chamber (1102) and the other to the rod chamber (1101).

10. The hydraulic drive system according to claim 9, characterized in that: The driving oil circuit (20) further includes a pressure relief oil circuit (29) connected between the pressure supply oil circuit (26) and the oil return oil circuit (27) and arranged in parallel with the hydraulic pump (28); the pressure relief oil circuit (29) is provided with a pressure relief valve (291); The pressure supply oil circuit (26) is provided with a third one-way valve (261) at a portion between the pressure relief oil circuit (29) and the hydraulic pump (28). The third one-way valve (261) is used to guide oil from the hydraulic pump (28) to flow toward the third port (253).

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