Self-driven dual-variable electro-hydrostatic actuator

Abstract

The application relates to the technical field of electro-hydraulic actuators, and discloses a self-driven double-variable electro-hydraulic actuator which comprises a cylinder body, a plurality of plungers, a shell, a power assembly and a variable displacement assembly. The plurality of plungers are arranged on the cylinder body at equal intervals in the circumferential direction. The middle part of the shell is rotationally connected with a main shaft, the cylinder body is sleeved on the main shaft and is fixedly connected with the main shaft. The power assembly comprises a power piece. A gap is arranged between the outer side wall of the cylinder body and the inner side wall of the shell, the power piece is arranged in the gap, the cylinder body is rotated through the power piece, and the power piece is cooled through the movement of the plungers. The variable displacement assembly comprises an adjusting plate and an adjusting piece. The adjusting plate is arranged on the main shaft, the plurality of plungers are arranged in contact with the adjusting plate respectively, the adjusting piece is arranged on the shell, the driving end of the adjusting piece extends into the shell and is connected with the adjusting plate, and the adjusting plate and the power piece are respectively used for adjusting the displacement of the plungers. The application improves the heat dissipation capacity and greatly improves the survivability of the electro-hydraulic actuator through the double-variable mode.

Description

A self-driven dual-variable electro-hydraulic actuator Technical Field

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

[0002] Electro-hydraulic actuators are a type of pump-controlled electro-hydraulic hybrid transmission system. Structurally, they integrate an electric motor, hydraulic pump, hydraulic cylinder, and auxiliary devices into a single unit. This structure simplifies the external oil supply circuit, eliminating the need for complex high-pressure hydraulic pipelines and reducing the risks of hydraulic oil leakage and contamination. This results in greater survivability. The electro-hydraulic coupling retains the excellent control characteristics of electric drives and the high power density of hydraulic drives, giving electro-hydraulic actuators high control precision, a high force-to-weight ratio, and high transmission efficiency. This significantly reduces energy consumption and weight, allowing mobile platforms using electro-hydraulic actuators to have longer operating ranges and lifespans. Due to these advantages, electro-hydraulic actuators are widely used in aerospace, construction machinery, agricultural machinery, robotics, and other fields.

[0003] Electro-hydraulic actuators use an electric motor and a hydraulic pump as power units, converting electrical energy into mechanical energy and then outputting hydraulic energy into the downstream hydraulic circuit. Finally, a hydraulic cylinder outputs linear force, making it the most compact linear actuator currently available. Using an electro-hydraulic actuator as the linear output unit makes the overall structure more compact, the layout simpler, and facilitates system control. Furthermore, the electro-hydraulic actuator itself has high control precision, meeting the needs of applications requiring precise control. In addition, due to the presence of the hydraulic unit, the electro-hydraulic actuator also possesses a certain degree of shock resistance, making it highly suitable for heavy-duty machinery.

[0004] Currently used electro-hydraulic actuators typically link their sub-units via mechanical adapters. In particular, the power unit still relies on the traditional direct connection between the electric motor and the hydraulic pump, limiting the integration of the structure. Furthermore, the limited heat dissipation capacity of the electric motor results in severe overheating, a major factor hindering the development of electro-hydraulic actuators. In addition, most current electro-hydraulic actuators use a single motor control method to achieve pump displacement variation, a simplistic control approach that is increasingly unable to meet the demands of the increasingly complex operating environments of electro-hydraulic actuators.

[0005] Therefore, there is an urgent need for a self-driven dual-variable electro-hydraulic actuator to solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to provide a self-driven dual-variable electro-hydraulic actuator to solve the problems existing in the prior art.

[0007] To achieve the above objectives, the present invention provides the following solution: The present invention provides a self-driven dual-variable electro-hydraulic actuator, comprising a cylinder and a plurality of plungers, wherein the plurality of plungers are equally spaced along the circumference on the cylinder, and further comprising:

[0008] A housing, in which a main shaft is rotatably connected at the center, and a cylinder body is sleeved on the main shaft and fixedly connected to the main shaft;

[0009] A power assembly includes a power component. A gap is provided between the outer wall of the cylinder and the inner wall of the housing. The power component is disposed within the gap. The cylinder rotates through the power component, and the power component dissipates heat through the movement of the plunger.

[0010] A variable displacement assembly includes an adjusting plate and an adjusting member. The adjusting plate is disposed on the main shaft, and a plurality of plungers are respectively disposed in contact with the adjusting plate. The adjusting member is disposed on the housing, and the driving end of the adjusting member extends into the housing and is connected to the adjusting plate. The adjusting plate and the power member are respectively used to adjust the displacement of the plungers.

[0011] Preferably, the power component includes a rotor winding and a stator winding. The rotor winding is fixedly connected to the outer wall of the cylinder body, and the stator winding is fixedly connected to the inner wall of the housing. A gap is provided between the rotor winding and the stator winding, and a rotational torque is generated between the rotor winding and the stator winding to drive the cylinder body to rotate.

[0012] Preferably, the adjusting plate is a swashplate, a ball plug is fixedly connected to the main shaft, the swashplate is sleeved on the main shaft and rotatably connected to the ball plug, one end of the plunger is in contact with the swashplate, and the swashplate is connected to the power component.

[0013] Preferably, the adjusting component includes a rotating shaft rotatably connected to the housing, one end of the rotating shaft extending into the housing and fixedly connected to the side wall of the swashplate, and the other end of the rotating shaft extending out of the housing and coaxially fixedly connected to a worm gear, and a worm rotatably connected to the housing, the worm gear meshing with the worm gear.

[0014] Preferably, the rotor winding is a permanent magnet ring, and the stator winding is electrically connected to an external power source.

[0015] Preferably, both ends of the housing are provided with end caps, and a sealing ring is provided between the end caps and the housing, and the sealing ring is fixedly connected to the end caps.

[0016] Compared with the prior art, the present invention has the following advantages and technical effects:

[0017] This invention provides a self-driven dual-variable electro-hydraulic actuator. A separate motor structure is formed by a power component. This motor structure, along with the cylinder and several plungers, enables self-drive and adjustment capabilities. Simultaneously, the internal hydraulic flow during plunger operation mitigates the impact of motor structure temperature variations on output performance. Furthermore, a variable displacement component further regulates the hydraulic pump's displacement. The power component and the variable displacement component together form a dual-variable mode, significantly improving the survivability of the electro-hydraulic actuator. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 is a schematic diagram of the overall structure of the present invention;

[0020] Figure 2 is a schematic diagram of the variable displacement component structure of the present invention;

[0021] Figure 3 is a schematic diagram of the internal structure of the housing of the present invention;

[0022] Figure 4 is a schematic diagram illustrating the working principle of this invention;

[0023] Figure 5 is a schematic diagram of the oil flow in the electro-hydraulic drive mode of the present invention;

[0024] Figure 6 is a schematic diagram of the oil flow in the energy recovery mode of the present invention;

[0025] The components are: 1. Housing; 2. Main shaft; 3. Cylinder block; 4. Piston; 5. Rotor winding; 6. Stator winding; 7. Adjusting plate; 8. Ball plug; 9. Shaft; 10. Worm gear; 11. Worm; 12. End cover. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] Referring to Figures 1-4, the present invention provides a self-driven dual-variable electro-hydraulic actuator, including a cylinder body 3 and a plurality of plungers 4, wherein the plurality of plungers 4 are equally spaced along the circumference on the cylinder body 3, and further comprising:

[0029] The housing 1 has a main shaft 2 rotatably connected to the middle of the housing 1, and the cylinder 3 is sleeved on the main shaft 2 and fixedly connected to the main shaft 2.

[0030] The power assembly includes a power component. A gap is provided between the outer wall of the cylinder 3 and the inner wall of the housing 1. The power component is located in the gap. The cylinder 3 rotates through the power component. The power component dissipates heat through the movement of the plunger 4.

[0031] The variable displacement assembly includes an adjusting plate 7 and an adjusting component. The adjusting plate 7 is mounted on the main shaft 2, and several plungers 4 are respectively in contact with the adjusting plate 7. The adjusting component is mounted on the housing 1, and the driving end of the adjusting component extends into the housing 1 and connects to the adjusting plate 7. The adjusting plate 7 and the power component are respectively used to adjust the displacement of the plungers 4.

[0032] The scheme is further optimized. The power components include a rotor winding 5 and a stator winding 6. The rotor winding 5 is fixedly connected to the outer wall of the cylinder body 3, and the stator winding 6 is fixedly connected to the inner wall of the housing 1. A gap is provided between the rotor winding 5 and the stator winding 6. The rotational torque generated between the rotor winding 5 and the stator winding 6 drives the cylinder body 3 to rotate.

[0033] Referring to Figure 3, the cylinder 3 of the hydraulic pump acts as a rotating component to perform oil suction and discharge. The rotational torque generated by the motor structure formed between the rotor winding 5 and the stator winding 6 drives the cylinder 3 to rotate, realizing the self-driving function of the power component, while reducing mechanical losses and further improving transmission efficiency.

[0034] Referring to Figure 3, in one embodiment of the present invention, the coupling structure of the motor structure and the hydraulic pump in the power assembly allows the motor structure to be immersed in internal oil. During the operation of the electro-hydraulic actuator, the exchange of oil will carry away some of the heat of the motor structure, achieving an oil cooling effect and reducing the impact of temperature changes on the output characteristics of the electric structure.

[0035] The scheme is further optimized. The adjusting plate 7 is a swashplate. A ball plug 8 is fixedly connected to the main shaft 2. The swashplate is sleeved on the main shaft 2 and rotatably connected to the ball plug 8. One end of the plunger 4 is in contact with the swashplate. The swashplate is connected to the power component.

[0036] Referring to Figures 2 and 3, the swashplate can be adjusted around the main shaft 2. One end of the plunger 4 is in contact with the swashplate. By adjusting the tilt angle of the swashplate, the movement distance of the plunger 4 can be adjusted when the cylinder block 3 rotates, thereby adjusting the overall displacement.

[0037] The scheme is further optimized. The adjusting component includes a rotating shaft 9 rotatably connected to the housing 1. One end of the rotating shaft 9 extends into the housing 1 and is fixedly connected to the side wall of the swashplate. The other end of the rotating shaft 9 extends out of the housing 1 and is coaxially fixedly connected to a worm gear 10. A worm 11 is rotatably connected to the housing 1 and meshes with the worm gear 10.

[0038] Referring to Figures 1 and 2, the worm gear 11 is controlled by a separate servo motor (not shown in the figures). When the hydraulic pump needs to change its displacement, the worm gear 11 is rotated to drive the worm wheel 10 to rotate. When the worm wheel 10 rotates, it drives the connected swashplate to rotate, thereby changing the swashplate tilt angle. The rotation angle is controlled by the servo motor, which has high control precision. Furthermore, the self-locking function of the worm wheel 10 and the worm gear 11 ensures the stability of the pump's output displacement.

[0039] The scheme was further optimized so that rotor winding 5 is a permanent magnet ring and stator winding 6 is electrically connected to an external power source.

[0040] The stator winding 6 is connected to an external power source via wires. By supplying alternating current to the stator winding 6, the rotational torque generated by the stator winding 6 and the permanent magnet ring will drive the hydraulic cylinder (i.e., the rotor winding 5) to rotate, thus realizing the self-driving function of the power component, while reducing mechanical losses and further improving transmission efficiency.

[0041] In a further optimized design, end caps 12 are provided at both ends of the housing 1, and a sealing ring is provided between the end cap 12 and the housing 1, with the sealing ring fixedly connected to the end cap 12.

[0042] Referring to Figure 3, the spindle 2 and the end cover 12 are rotatably connected by bearings to ensure the stable rotation of the spindle 2.

[0043] In one embodiment of this application, the self-driven dual-variable electro-hydraulic actuator of the present invention is driven by a power component. Electrical energy is input to the power component to achieve a dual-variable mode, that is, controlling the motor structure speed (controlling the current magnitude) and the swashplate tilt angle to change the output flow of the hydraulic pump. Furthermore, the coupling structure between the motor structure and the hydraulic pump enables the electro-hydraulic actuator to have a self-driving function. In addition to the power component, the electro-hydraulic actuator also includes a solenoid valve for controlling the on / off state of the hydraulic circuit, an accumulator and a check valve forming a hydraulic compensation structure for receiving leakage flow and compensating for circuit hydraulic fluid, a relief valve for limiting the maximum pressure of the hydraulic circuit, and an axial force output by the hydraulic cylinder.

[0044] The application process:

[0045] Electro-hydraulic drive mode: Referring to Figure 4, in drive mode, electrical energy is input to the actuator, the power component in Figure 3 starts and runs automatically, outputs flow, and the oil flows into the hydraulic cylinder in Figure 4 through the hydraulic route, driving the hydraulic cylinder to actively extend and retract the external load. The extension and retraction state is controlled by the power component in Figure 3; the oil flow direction is shown in Figure 5.

[0046] Energy recovery mode: Referring to Figure 4, in the recovery mode, power is input from the hydraulic cylinder in Figure 4 to the hydraulic circuit. The external load drives the hydraulic cylinder to move linearly, and the output flow drives the power component in Figure 3 to rotate. At this time, the power component in Figure 3 is in the working mode of hydraulic motor and generator, outputting electrical energy to the outside; the oil flow direction is shown in Figure 6.

[0047] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to 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 of this invention.

[0048] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A self-driven dual-variable electro-hydraulic actuator, comprising a cylinder (3) and a plurality of plungers (4), wherein the plurality of plungers (4) are equally spaced along the circumference on the cylinder (3), characterized in that, Also includes: A housing (1) has a main shaft (2) rotatably connected to its center. A cylinder (3) is fitted onto the main shaft (2) and fixedly connected to it. A power assembly includes a power component. A gap is provided between the outer wall of the cylinder (3) and the inner wall of the housing (1). The power component is located within the gap. The cylinder (3) rotates through the power component, and the power component dissipates heat through the movement of the plunger (4). A variable displacement assembly includes an adjusting plate (7) and an adjusting component. The adjusting plate (7) is located on the main shaft (2). Several plungers (4) are respectively in contact with the adjusting plate (7). The adjusting component is located on the housing (1). The driving end of the adjusting component extends into the housing (1) and connects to the adjusting plate (7). The adjusting plate (7) and the power component are respectively used to adjust the displacement of the plunger (4). The power component includes a rotor winding (5) and a stator winding (6). The rotor winding (5) is fixedly connected to the outer wall of the cylinder body (3), and the stator winding (6) is fixedly connected to the inner wall of the housing (1). The adjusting plate (7) is a swashplate. A ball plug (8) is fixedly connected to the main shaft (2). The swashplate is sleeved on the main shaft (2) and rotatably connected to the ball plug (8). One end of the plunger (4) is in contact with the swashplate. The swashplate is connected to the power component. The adjusting component includes a rotating shaft (9) rotatably connected to the housing (1). One end of the rotating shaft (9) extends into the housing (1) and is fixedly connected to the side wall of the swashplate. The other end of the rotating shaft (9) extends out of the housing (1) and is coaxially fixedly connected to a worm gear (10). A worm (11) is rotatably connected to the housing (1). The worm (11) meshes with the worm gear (10).

2. The self-driven dual-variable electro-hydraulic actuator according to claim 1, characterized in that: A gap is provided between the rotor winding (5) and the stator winding (6), and a rotational torque is generated between the rotor winding (5) and the stator winding (6) to drive the cylinder (3) to rotate.

3. The self-driven dual-variable electro-hydraulic actuator according to claim 2, characterized in that: The rotor winding (5) is a permanent magnet ring, and the stator winding (6) is electrically connected to an external power source.

4. The self-driven dual-variable electro-hydraulic actuator according to claim 1, characterized in that: Both ends of the housing (1) are provided with end caps (12), and a sealing ring is provided between the end caps (12) and the housing (1), and the sealing ring is fixedly connected to the end caps (12).

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