A bidirectional electro-hydraulic actuator

Abstract

This invention relates to the field of actuator technology, specifically a bidirectional electro-hydraulic actuator, comprising a reciprocating motion mechanism including a piston, a piston sleeve, and a sealing ring. The piston, piston sleeve, and sealing ring cooperate to form left and right sealing cavities. The piston can cause periodic pressure changes within the sealing cavities during rotation, thereby driving the piston rod to achieve reciprocating linear motion. A rotary control mechanism includes a rotary drive component, a transmission assembly, and a rotary support. The rotary drive component is connected to the piston via the transmission assembly to drive the piston to rotate. This invention achieves strictly alternating bidirectional linear motion output by installing the left and right rotary supports at an angle, so that during the rotation of the rotary drive component, the piston rods on both sides sequentially extend and retract once.

Description

Technical Field

[0001] This invention relates to the field of actuator technology, and in particular to a bidirectional electro-hydraulic actuator. Background Technology

[0002] An electro-hydraulic actuator is an integrated electromechanical device that combines electric drive and hydraulic transmission technologies. It directly drives a hydraulic pump via a servo motor, performing a secondary energy conversion from electrical energy to hydraulic energy to mechanical energy, enabling precise control of position, speed, and torque in linear or rotary motion. Electro-hydraulic actuators offer significant advantages such as high power density, large output force (torque), and fast response speed, and have found wide application in aerospace, industrial automation, valve control, and engineering machinery.

[0003] The fork drive technology in the actuator field has been extensively studied. For example, Chinese patent CN117803624A discloses an actuator driven by a lever and fork. This scheme achieves the flow switching between the oil chamber and the oil hole through the rotation of the piston rod, thereby driving the piston rod to extend or retract. This scheme realizes the reciprocating motion of a single-sided actuator through rotational flow distribution.

[0004] However, in practical industrial applications, when bidirectional linear motion with alternating sides is required, existing electro-hydraulic actuator technology still has the following prominent problems:

[0005] First, traditional electro-hydraulic actuators typically separate the control mechanism (such as an electromagnetic directional valve assembly) from the actuator (such as a hydraulic cylinder), resulting in complex system piping. This not only increases the overall size and installation space but also causes significant response lag due to the long control link, making it difficult to meet the requirements of high-frequency and precise directional switching.

[0006] Secondly, to achieve symmetrical bidirectional reciprocating motion, existing solutions often require two independent drive sources or complex directional valve assemblies. This not only results in a large system size and high energy consumption, but more seriously, the motion phase on the left and right sides is difficult to control precisely, easily leading to asynchronous left and right movements, uneven output due to asymmetrical reciprocating motion, and large motion impacts, which reduces the stability and service life of the equipment. Summary of the Invention

[0007] The purpose of this invention is to provide a bidirectional electro-hydraulic actuator to solve the problems mentioned in the background art.

[0008] The technical solution of the present invention is: a bidirectional electro-hydraulic actuator, comprising...

[0009] A reciprocating motion mechanism, comprising a piston, a piston sleeve, and a sealing ring, wherein the piston, piston sleeve, and sealing ring cooperate to form left and right sealing cavities, and the piston can cause the internal pressure of the sealing cavity to change periodically during rotation, thereby driving the piston rod to achieve reciprocating linear motion;

[0010] A rotation control mechanism, comprising a rotation drive, a transmission assembly, and a rotation bracket, wherein the rotation drive is connected to the piston via the transmission assembly to drive the piston to rotate;

[0011] The rotating bracket includes a left rotating bracket and a right rotating bracket. The left rotating bracket is connected to the piston drive of the reciprocating motion mechanism on the left side, and the right rotating bracket is connected to the piston drive of the reciprocating motion mechanism on the right side. The left rotating bracket and the right rotating bracket are installed at an angle, so that the high and low pressure chambers of the reciprocating motion mechanisms on the left and right sides switch back and forth, thereby driving the piston rods on the left and right sides to achieve a bidirectional action of alternating extension and retraction.

[0012] Furthermore, the rotary drive component is a rotary electromagnet.

[0013] Furthermore, the transmission assembly includes an upper shift fork, a lower shift fork, a bidirectional connecting shaft, a sliding bearing, and a sliding bearing mounting bracket for mounting the sliding bearing; the output end of the rotary drive is connected to the upper shift fork, the upper shift fork and the lower shift fork are engaged in a shifting action, the lower shift fork is fixed to the bidirectional connecting shaft, the bidirectional connecting shaft is rotatably mounted on the rotary bracket, the sliding bearing mounting bracket is mounted on the rotary bracket, and the sliding bearing mounting bracket is connected to the piston through a piston connecting rod.

[0014] Furthermore, the upper shift fork includes an upper shift fork, and the lower shift fork includes a lower shift fork. The lower shift fork is provided with a U-shaped groove, and the upper shift fork is accommodated in the U-shaped groove and can rotate the lower shift fork.

[0015] Furthermore, the left rotating bracket and the right rotating bracket are installed at a 90° stagger.

[0016] Furthermore, the reciprocating motion mechanism also includes an end cap and a fixing head. The end cap is sealed to the outer shell, and the fixing head is used to limit the piston rod.

[0017] Furthermore, the rotation control mechanism is positioned between the reciprocating motion parts on the left and right sides, forming an integrated structure.

[0018] Furthermore, the left and right rotating brackets respectively drive the left and right pistons. During the rotation of the rotating drive component, the piston rods on the left and right sides extend and retract in sequence, realizing bidirectional alternating motion.

[0019] A control method for a bidirectional electro-hydraulic actuator includes the following steps:

[0020] First, start the rotary drive component, which drives the piston to rotate through the transmission assembly;

[0021] Second, when the piston rotates, the pressure inside the left and right sealing cavities formed by the piston, piston sleeve and sealing ring changes periodically, thereby driving the piston rod to achieve reciprocating linear motion.

[0022] Third, by using the left and right rotating brackets installed at an angle, the high and low pressure chambers of the reciprocating parts on the left and right sides can be switched back and forth, driving the piston rods on the left and right sides to achieve a bidirectional action of alternating extension and retraction.

[0023] The beneficial effects of this invention are:

[0024] Compared with existing technologies, this invention uses a rotary drive to drive the piston to rotate. During the rotation, the pressure inside the sealed cavity changes periodically, thereby driving the piston rod to reciprocate linearly, realizing a self-reversing function. The response is more direct and the control is simpler. At the same time, by installing the left and right rotary brackets at an angle, the high and low pressure chambers of the reciprocating parts on the left and right sides can switch back and forth. During the rotation of the rotary drive, the piston rods on the left and right sides complete one extension and one retraction in sequence, realizing strictly alternating bidirectional linear motion output. This ensures precise synchronization of the phase of the left and right movements, eliminating the motion phase error, uneven output, and motion impact problems caused by dual drive sources or complex valve groups in traditional solutions. This improves the stability, reliability, and service life of the equipment. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of the present invention;

[0026] Figure 2 This is a cross-sectional view of the present invention;

[0027] Figure 3 This is a schematic diagram of the rotation control mechanism of the present invention. Detailed Implementation

[0028] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0029] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

[0030] Examples, such as Figures 1-3As shown, a bidirectional electro-hydraulic actuator includes...

[0031] The reciprocating motion mechanism 1 includes a piston 101, a piston sleeve 102, a housing 103, a sealing ring 104, and a sealing ring 105. The piston 101, piston sleeve 102, and sealing ring 104 cooperate to form left and right sealing cavities. The piston 101 can cause the internal pressure of the sealing cavity to change periodically during rotation, thereby driving the piston rod 1011 to achieve reciprocating linear motion. The specific structure of the reciprocating motion mechanism 1 has been described in the invention patent of a lever-driven actuator with patent number CN117803624A. Specifically, in this invention, in order to achieve the periodic change of the sealing cavity pressure when the piston 101 rotates, the flow distribution structure of the reciprocating motion mechanism 1 is as follows: the outer circumferential surface of the piston 101 is provided with multiple axially extending flow distribution grooves spaced apart in the circumferential direction, and the side wall of the piston sleeve 102 is provided with an oil inlet hole and an oil outlet hole spaced apart in the circumferential direction for connecting a hydraulic source. The distribution channels include a left distribution channel, which is closed at one end and extends through the piston end face to connect to the left sealing cavity, and a right distribution channel, which connects to the right sealing cavity. When the rotation control mechanism 2 drives the piston 101 to rotate to a position where the oil inlet is connected to either right distribution channel, the oil outlet is connected to either left distribution channel. At this time, the right sealing cavity is pressurized by oil inlet, and the left sealing cavity is depressurized by oil outlet, causing the piston rod to extend. Conversely, when the oil inlet is connected to the left distribution channel, the oil outlet is connected to the right distribution channel, the left sealing cavity is pressurized by oil inlet, and the right sealing cavity is depressurized by oil outlet, causing the piston rod to retract. This specific structure ensures the efficient conversion of rotary motion to linear reciprocating motion.

[0032] The biggest improvement in this application is the rotation control mechanism 2, which includes a rotation drive 201, a transmission assembly 202, and a rotation bracket 203. The rotation drive 201 is connected to the piston 101 through the transmission assembly 202 and the rotation bracket 203 to drive the piston 101 to rotate. The piston connecting rod 204 rotates under the drive of the rotation drive 201. Since the piston 101, piston sleeve 102, and sealing ring 104 cooperate to form left and right sealing cavities, the pressure in the sealing cavities rises and falls periodically during rotation, thereby pushing the piston 101 to perform reciprocating linear motion.

[0033] The rotating bracket 203 includes a left rotating bracket 2031 and a right rotating bracket 2032. The left rotating bracket 2031 is connected to the piston 101 of the reciprocating motion mechanism 1 on the left side, and the right rotating bracket 2032 is connected to the piston 101 of the reciprocating motion mechanism 1 on the right side. The left rotating bracket 2031 and the right rotating bracket 2032 are installed at an angle, so that the high and low pressure chambers of the reciprocating motion mechanism 1 on the left and right sides can switch back and forth, thereby driving the piston rods on the left and right sides to achieve a bidirectional action of alternating extension and retraction.

[0034] In an optional embodiment of the present invention, the rotary drive 201 is a rotary electromagnet; by using the rotary electromagnet as a rotary drive, a precise rotation angle and rotation speed can be directly output, driving the transmission assembly 202 to rotate the piston 101.

[0035] In an optional embodiment of the present invention, the transmission assembly 202 includes an upper shift fork 2021, a lower shift fork 2022, a bidirectional connecting shaft 2023, a sliding bearing 2024, and a sliding bearing mounting bracket 2025 for mounting the sliding bearing 2024; the output end of the rotary drive member 201 is connected to the upper shift fork 2021, the upper shift fork 2021 and the lower shift fork 2022 are in a shifting engagement, the lower shift fork 2022 is fixed to the bidirectional connecting shaft 2023, the two ends of the bidirectional connecting shaft 2023 are respectively mounted on the left rotating bracket 2031 and the right rotating bracket 2032, and the sliding bearing mounting bracket 2025 is mounted on the rotating bracket 203. Specifically, the left rotating bracket 2021... Two sets of support rods 2033 are respectively installed on the right rotating bracket 2032 and the support rod 2033. The support rod 2033 and the sliding bearing 2024 on the sliding bearing mounting bracket 2025 are slidably connected. The sliding bearing mounting bracket 2025 is connected to the piston through the piston connecting rod 204. The rotating drive component 201 drives the upper shift fork component 2021 to swing. The upper shift fork component 2021 drives the lower shift fork component 2022 to rotate through the shifting action. The lower shift fork component 2022 drives the bidirectional connecting shaft 2023 to rotate. The bidirectional connecting shaft 2023 transmits the rotational motion to the piston 101 through the sliding bearing mounting bracket 2025 and the piston connecting rod 204, thereby converting the small-angle swing into the reciprocating movement of the piston 101.

[0036] In an optional embodiment of the present invention, the upper shift fork 2021 includes an upper shift fork, and the lower shift fork 2022 includes a lower shift fork 2022a. The lower shift fork 2022a is provided with a U-shaped groove 2022b. The upper shift fork is accommodated in the U-shaped groove 2022b and can rotate the lower shift fork 2022a. The upper shift fork extends into the U-shaped groove 2022b of the lower shift fork. When the upper shift fork swings with the rotation drive member 201, its sidewall contacts the sidewall of the U-shaped groove 2022b and applies a tangential force, pushing the lower shift fork 2022a to rotate around the axis. The U-shaped groove structure allows the upper shift fork to have a certain axial and radial movement margin in the groove, avoiding rigid jamming.

[0037] In an optional embodiment of the present invention, the left rotating bracket 2031 and the right rotating bracket 2032 are installed at 90° staggered. The left rotating bracket 2031 and the right rotating bracket 2032 respectively control the rotation phase of the left and right pistons 101. When the two are staggered at 90°, when the left piston 101 moves to the maximum extension position (corresponding to the pressure peak value), the right piston is exactly in the retracted position (corresponding to the pressure valley value), and vice versa. In this way, under the rotation of the rotating drive 201, the left and right piston rods complete one extension and one retraction in sequence, forming a strictly alternating bidirectional motion.

[0038] In an optional embodiment of the present invention, the reciprocating motion mechanism 1 further includes an end cap 106 and a fixing head 107. The end cap 106 is sealed to the outer shell 103, and the fixing head 107 is used to limit the piston rod 1011. The end cap 106 and the outer shell 103 form a closed hydraulic cavity through the sealed connection to prevent oil leakage and maintain internal pressure. The fixing head 107 is installed at the extended end of the piston rod 1011. When the piston rod 1011 extends to the limit position, the fixing head 107 contacts the limiting surface of the outer shell 103 to prevent the piston rod 1011 from extending further, ensuring the integrity of the sealed cavity and preventing oil leakage.

[0039] In an optional embodiment of the present invention, the rotary control mechanism 2 is disposed between the reciprocating motion parts on the left and right sides to form an integrated structure; the rotary drive component 201, the transmission component 202 and the rotary support 203 are arranged in the middle position of the two sets of reciprocating motion mechanisms on the left and right sides, and the three share a common mounting base to improve integration and reliability.

[0040] In an optional embodiment of the present invention, the left rotating bracket 2031 and the right rotating bracket 2032 respectively drive the left piston and the right piston. During the rotation of the rotating drive member 201, the piston rods on the left and right sides sequentially complete one extension and one retraction, realizing bidirectional alternating motion. When the rotating drive member 201 rotates, the left rotating bracket 2031 drives the left piston 101 to complete one cycle of pressure change, that is, from high pressure to low pressure, corresponding to the piston rod from the extended to the retracted state. Since the angles of the left and right rotating brackets are staggered, the pressure change of the right piston is 90° ahead or behind. Therefore, the right piston rod extends at the same time as the left piston rod retracts, alternating sequentially, thereby outputting alternating bidirectional linear motion. The motion is continuous and without interruption, improving work efficiency.

[0041] A control method for a bidirectional electro-hydraulic actuator includes the following steps:

[0042] First, start the rotary drive component, which drives the piston 101 to rotate through the transmission assembly 202;

[0043] Second, when the piston 101 rotates, the pressure inside the left and right sealing cavities formed by the piston 101, piston sleeve 102, and sealing ring 103 changes periodically, thereby driving the piston rod to achieve reciprocating linear motion.

[0044] Third, by using the left rotating bracket 2031 and the right rotating bracket 2032, which are installed at an angle, the high and low pressure chambers of the reciprocating motion mechanism 1 on the left and right sides are switched to each other, driving the piston rods on the left and right sides to achieve a bidirectional action of alternating extension and retraction.

[0045] In the description of this specification, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing the technical solution of this patent and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this patent application.

[0046] 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 indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this patent application, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0047] In this specification, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this specification according to the specific circumstances.

[0048] In this specification, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0049] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

Claims

1. A bidirectional electro-hydraulic actuator, characterized in that: include A reciprocating motion mechanism, comprising a piston, a piston sleeve, and a sealing ring, wherein the piston, piston sleeve, and sealing ring cooperate to form left and right sealing cavities, and the piston can cause the internal pressure of the sealing cavity to change periodically during rotation, thereby driving the piston rod to achieve reciprocating linear motion; A rotation control mechanism, comprising a rotation drive, a transmission assembly, and a rotation bracket, wherein the rotation drive is connected to the piston via the transmission assembly to drive the piston to rotate; The rotating bracket includes a left rotating bracket and a right rotating bracket. The left rotating bracket is connected to the piston drive of the reciprocating motion mechanism on the left side, and the right rotating bracket is connected to the piston drive of the reciprocating motion mechanism on the right side. The left rotating bracket and the right rotating bracket are installed at an angle, so that the high and low pressure chambers of the reciprocating motion mechanisms on the left and right sides switch back and forth, thereby driving the piston rods on the left and right sides to achieve a bidirectional action of alternating extension and retraction.

2. The bidirectional electro-hydraulic actuator according to claim 1, characterized in that: The rotary drive component is a rotary electromagnet.

3. The bidirectional electro-hydraulic actuator according to claim 1 or 2, characterized in that: The transmission assembly includes an upper shift fork, a lower shift fork, a bidirectional connecting shaft, a sliding bearing, and a sliding bearing mounting bracket for mounting the sliding bearing. The output end of the rotary drive is connected to the upper shift fork, and the upper shift fork engages with the lower shift fork. The lower shift fork is fixed to the bidirectional connecting shaft, which is rotatably mounted on the rotary support. The sliding bearing mounting bracket is mounted on the rotary support, and the sliding bearing mounting bracket is connected to the piston via a piston connecting rod.

4. The bidirectional electro-hydraulic actuator according to claim 3, characterized in that: The upper shift fork includes an upper shift fork, and the lower shift fork includes a lower shift fork. The lower shift fork is provided with a U-shaped groove, and the upper shift fork is accommodated in the U-shaped groove and can rotate the lower shift fork.

5. The bidirectional electro-hydraulic actuator according to claim 1, characterized in that: The left rotating bracket and the right rotating bracket are installed at a 90° angle to each other.

6. The bidirectional electro-hydraulic actuator according to claim 1, characterized in that: The reciprocating motion mechanism further includes an end cap and a fixing head. The end cap is sealed to the outer shell, and the fixing head is used to limit the piston rod.

7. The bidirectional electro-hydraulic actuator according to claim 1, characterized in that: The rotation control mechanism is located between the reciprocating parts on the left and right sides, forming an integrated structure.

8. The bidirectional electro-hydraulic actuator according to claim 1, characterized in that: The left and right rotating brackets drive the left and right pistons respectively. During the rotation of the rotating drive, the piston rods on the left and right sides extend and retract in sequence, realizing bidirectional alternating motion.

9. A control method for a bidirectional electro-hydraulic actuator, characterized in that: Includes the following steps, First, start the rotary drive component, which drives the piston to rotate through the transmission assembly; Second, when the piston rotates, the pressure inside the left and right sealing cavities formed by the piston, piston sleeve and sealing ring changes periodically, thereby driving the piston rod to achieve reciprocating linear motion. Third, by using the left and right rotating brackets installed at an angle, the high and low pressure chambers of the reciprocating parts on the left and right sides can be switched back and forth, driving the piston rods on the left and right sides to achieve a bidirectional action of alternating extension and retraction.

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