Miniature electro-hydrostatic actuator for driving finger exoskeleton equipment

Abstract

The invention discloses a miniature electro-hydrostatic actuator for driving finger exoskeleton equipment. The miniature electro-hydrostatic actuator is characterized by comprising a motor driving module, a direct-drive two-dimensional plunger pump module, a miniature hydraulic cylinder module and a finger exoskeleton equipment module, a power output shaft of the motor driving module is connected with the power input end of the direct-drive type two-dimensional plunger pump module and used for providing driving force. The direct-drive type two-dimensional plunger pump module comprises a pump cylinder body and a plunger assembly, a plunger cavity is formed in the pump body, and the plunger assembly can be driven by the motor driving module to reciprocate in the plunger cavity; according to the miniature electro-hydrostatic actuator system, a direct-drive pump control hydraulic system structure is adopted in the structural design, the system flow is directly controlled by the direct-current brushless motor, and due to the high-rotating-speed characteristic of the direct-current brushless motor, the response speed of the miniature electro-hydrostatic actuator system is higher.

Description

Technical Field

[0001] This invention belongs to the field of robotics technology, specifically relating to a miniature electro-hydraulic actuator for driving a finger exoskeleton device. Background Technology

[0002] In existing technologies, electro-hydraulic actuators are a new type of high-performance servo hydraulic system that converts electrical energy into hydraulic energy and then into mechanical energy. Originating in the aerospace field, they are characterized by compact structure, high efficiency, small size, and convenient control, making them highly suitable for applications with high power density. Currently, the demands for high speed, high flexibility, and intelligence in automated equipment across various fields such as exoskeletons, medical rehabilitation machinery, marine electromechanical systems, and aerospace are placing higher requirements on the miniaturization and intelligence of hydraulic components and systems.

[0003] Traditional electro-hydraulic actuators consist of components such as servo motors, hydraulic pumps, valve assemblies, accumulators, and hydraulic cylinders. Consequently, the hydraulic valve assembly itself is relatively large, increasing the overall size of the electro-hydraulic actuator. In human bionic exoskeleton technology, the electro-hydraulic actuator serves as the power element. The challenge lies in designing a compact structure that matches the size and weight of the integrated prosthesis design.

[0004] On the other hand, as the core hydraulic component of electro-hydraulic actuators, the size and performance indicators of the hydraulic pump are crucial to the electro-hydraulic actuator. Although traditional piston pumps have advantages such as high efficiency, long service life, and high control precision, these pumps have complex structures, high manufacturing precision requirements, and relatively high usage and maintenance costs. Summary of the Invention

[0005] To overcome the shortcomings of existing technologies, this invention provides a miniature electro-hydraulic actuator for driving finger exoskeleton devices, thereby solving the technical problems of traditional plunger pumps, such as large size, complex structure, and high maintenance costs.

[0006] To achieve the above objectives, the specific technical solution of the present invention is as follows: A miniature electro-hydraulic actuator for driving a finger exoskeleton device includes a motor drive module, a direct-drive two-dimensional plunger pump module, a miniature hydraulic cylinder module, and a finger exoskeleton equipment module.

[0007] The power output shaft of the motor drive module is connected to the power input end of the direct-drive two-dimensional plunger pump module to provide driving force. The direct-drive two-dimensional plunger pump module includes a pump cylinder body and a plunger assembly. A plunger chamber is formed inside the pump body, and the plunger assembly reciprocates within the plunger chamber under the drive of a motor drive module. When the plunger assembly moves away from the pump cylinder body in the discharge direction, it creates a negative pressure within the plunger chamber, drawing in hydraulic oil. When the plunger assembly moves closer to the pump cylinder body in the discharge direction, the hydraulic oil within the plunger chamber is compressed and forced into the micro hydraulic cylinder module.

[0008] The micro hydraulic cylinder module is connected to the direct-drive two-dimensional plunger pump module via hydraulic lines, and the output end of its piston rod is connected to the finger exoskeleton equipment module to drive the finger exoskeleton equipment module to perform bending and stretching movements.

[0009] Furthermore, the direct-drive two-dimensional plunger pump module also includes an oil tank assembly. The oil tank assembly is fixed to the end of the pump cylinder body and has an inlet and outlet oil pipe connected to the plunger chamber in the pump cylinder body. The pump cylinder body has an inlet and an outlet oil port connected to the inlet and outlet oil pipes, respectively. The inlet and outlet oil ports are spaced apart axially along the pump cylinder body, with the outlet oil port located near the end of the oil tank assembly. The inlet and outlet oil ports are staggered circumferentially.

[0010] Furthermore, the plunger assembly includes a two-dimensional piston and a power switching assembly. The plunger chamber is located on the pump cylinder body. The two-dimensional piston is rotatably connected within the plunger chamber and can rotate under the drive of the motor drive module. The power switching assembly is mounted on the outer ring of the two-dimensional piston and is used to push it to move along the axial direction when the two-dimensional piston rotates. An oil reservoir is provided at the end of the two-dimensional piston. The oil reservoir and the inner wall of the pump cylinder body cooperate to form a sealed distribution cavity. The side wall of the distribution cavity has oil suction distribution windows and oil discharge distribution windows arranged axially at intervals.

[0011] Furthermore, the power switching assembly includes an end face cam and two sets of axial drive components. The end face cam is fixed on the two-dimensional piston. Each side of the end face cam has two protrusions; the two protrusions are symmetrically arranged on the circular periphery of the end face cam, and adjacent sides form concave portions with the corresponding circular periphery of the end face cam. The two sides of the end face cam are divided into an oil suction drive surface near the two-dimensional piston push end and an oil discharge drive surface away from the two-dimensional piston push end. The protrusions on the oil suction drive surface and the protrusions on the oil discharge drive surface are staggered.

[0012] Furthermore, the axial drive assembly includes a suspension and two sets of symmetrically arranged roller units. Each set of roller units is symmetrically arranged within the plunger cavity of the pump cylinder body and is rotatably connected to the pump cylinder body. The suspension is fixedly connected to the pump cylinder body and has multiple positioning slots near each set of roller units. Each set of roller units corresponds to one positioning slot.

[0013] Furthermore, the motor drive module includes an adapter plug, an adapter cover, a brushless DC motor, a rotating shaft, and a motor housing. The adapter plug is fixed to the end of the adapter cover. The adapter cover is fixedly connected to one end of the motor housing. The brushless DC motor is installed inside the motor housing, and one end of its power output shaft is connected. The other end of the shaft passes through the motor end cover and is connected to the two-dimensional piston drive in the direct-drive two-dimensional plunger pump module.

[0014] Furthermore, a connecting groove is provided at the end of the rotating shaft near the two-dimensional piston. The end of the two-dimensional piston extends into the connecting groove. A transmission connector is fixed to the outer ring of the two-dimensional piston. A limiting groove is provided on the inner wall of the connecting groove to cooperate with the transmission connector. The transmission connector slides in conjunction with the limiting groove.

[0015] Furthermore, the outer ring of the two-dimensional piston has a mounting hole that mates with the transmission connector. The end of the transmission connector extends into the mounting hole, and an elastic element is provided between it and the bottom of the hole. The end of the limiting groove on the rotating shaft is spaced apart from the end of the rotating shaft.

[0016] Furthermore, the miniature hydraulic cylinder module includes a rear cylinder head, a cylinder body, a front cylinder head, a piston rod, and a Glyd ring. The cylinder body is a hollow cylindrical structure. The rear and front cylinder heads are fixed to both ends of the cylinder body. The piston rod is disposed inside the cylinder body and can slide along the cylinder body's axial direction. An integrally formed partition is provided in the middle of the piston rod. The partition divides the cylinder body's interior into a push chamber and a reset chamber. Push and reset inlets are respectively provided on the side walls of the push and reset chambers. The push and reset inlets are connected to the drain and inlet pipes on the main body of the oil tank via hydraulic lines.

[0017] Furthermore, the finger exoskeleton module includes a hydraulic cylinder base, a linkage mechanism, a transmission mechanism, a bushing, a support base, and multiple finger joints. The miniature hydraulic cylinder module is fixed to the support base via the hydraulic cylinder base. The linkage mechanism includes multiple sets of sequentially connected linkage units, each set of linkage units having a quadrilateral linkage structure. The piston rod in the miniature hydraulic cylinder module is connected to the linkage unit located at the first end via the transmission mechanism. The linkage at the last end of each linkage unit is hinged to each finger joint. The joints of each finger joint are hinged together.

[0018] Compared with the prior art, the present invention has the following advantages: 1. The micro electro-hydraulic actuator system structure design of the present invention adopts a direct-drive pump-controlled hydraulic system structure, which directly controls the system flow rate by a DC brushless motor. Due to the high speed characteristics of the DC brushless motor, the micro electro-hydraulic actuator system has a faster response speed.

[0019] 2. The components of the micro electro-hydraulic actuator system in this invention are miniaturized. The DC brushless motor is model D1806, with an overall size of 26mm × 18mm. The micro motor direct-drive two-dimensional plunger pump, through its unique two-dimensional piston structure and end-face cam, gives the pump both rotational and sliding degrees of freedom. Compared to traditional piston pumps that only perform reciprocating motion for oil suction and discharge, the micro two-dimensional electric pump performs both axial reciprocating motion of the two-dimensional piston for oil suction and discharge and rotational reciprocating motion for flow distribution. This design makes the plunger occupy less space. Thanks to this structure, the micro two-dimensional electric pump has a very small overall size of 37mm × 18mm. The micro hydraulic cylinder has an overall size of 39mm × 10mm, making the structure of the micro electro-hydraulic actuator simpler and the overall size smaller. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the structure of the motor drive module and the direct-drive two-dimensional plunger pump module in this invention; Figure 3 This is a schematic diagram showing the relative positions of the two-dimensional piston and the end face cam in this invention. Figure 2 (Enlarged view of part A in the middle) Figure 4 This is a schematic diagram of the structure of the pump cylinder body and the two-dimensional piston in this invention; Figure 5 This is a schematic diagram of the end face cam in this invention; Figure 6 This is a schematic diagram of the main body of the pump cylinder in this invention; Figure 7 This is a schematic diagram showing the location of the oil drain port of the pump cylinder body in this invention. Figure 6 (Cross-section view in the BB direction) Figure 8 This is a schematic diagram showing the location of the oil suction port of the pump cylinder body in this invention; Figure 9 This is a schematic diagram showing the relative positions of the oil inlet and outlet of the pump cylinder body in this invention. Figure 8 (Central CC direction section view); Figure 10 This is a schematic diagram of the structure of the finger exoskeleton device module in this invention; Figure 11 This is a schematic diagram of the micro hydraulic cylinder module in this invention.

[0021] Reference numerals: 1. Motor drive module; 2. Direct-drive two-dimensional plunger pump module; 3. Miniature hydraulic cylinder module; 4. Finger exoskeleton device module; 101. Aviation connector; 102. Aviation connector cover; 103. DC brushless motor; 104. Shaft; 105. Motor housing; 106. Motor end cover; 201. Washer; 202. Roller body; 203. Two-dimensional piston; 204. Pump plug; 205. Oil tank body; 206. Oil tank plug; 207. Oil tank nut; 208. Spring; 209. Cylinder seal ring; 210. Pump cylinder body; 21 01. Oil intake port; 2102. Oil outlet port; 211. First locating pin; 212. Suspension; 213. Protrusion; 214. Recess; 215. Oil intake distribution window; 216. Oil outlet distribution window; 217. End face cam; 301. Cylinder head; 302. Step seal; 303. Cylinder block; 304. Front cylinder head; 305. Cylinder head seal ring; 306. Piston rod; 307. Glyd ring; 401. Hydraulic cylinder seat; 402. Linkage mechanism; 403. Second locating pin; 404. Finger joint; 405. Bushing; 406. Support base. Detailed Implementation

[0022] In the description of this invention, it should be understood that the terms "one end", "the other end", "outer side", "upper side", "inner side", "horizontal", "coaxial", "center", "end", "length", "outer end", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing this invention and simplifying the description, 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.

[0023] The invention will now be further described with reference to the accompanying drawings.

[0024] like Figure 1 and 2 As shown, a miniature electro-hydraulic actuator for driving a finger exoskeleton device includes a motor drive module 1, a direct-drive two-dimensional plunger pump module 2, a miniature hydraulic cylinder module 3, and a finger exoskeleton device module 4. The power output shaft of the motor drive module 1 is connected to the power input end of the direct-drive two-dimensional plunger pump module 2 to provide driving force. like Figure 2-9As shown, the direct-drive two-dimensional plunger pump module 2 includes a pump cylinder body 210 and a plunger assembly. A plunger cavity is formed inside the pump body, and the plunger assembly can reciprocate within the plunger cavity under the drive of the motor drive module 1. When the plunger assembly moves away from the pump cylinder body 210 in the discharge direction, a negative pressure is formed within the plunger cavity, and external hydraulic oil is drawn into the plunger cavity through the oil inlet channel under atmospheric pressure. When the plunger assembly moves closer to the pump cylinder body 210 in the discharge direction, the hydraulic oil within the plunger cavity is compressed and forced into the micro hydraulic cylinder module 3.

[0025] The miniature hydraulic cylinder module 3 is connected to the direct-drive two-dimensional piston pump module 2 via hydraulic lines. The output end of its piston rod 306 is connected to the finger exoskeleton equipment module 4 to drive the finger exoskeleton equipment module 4 to perform bending and stretching movements.

[0026] Furthermore, the pump cylinder body 210 has an internally hollow cylindrical structure. The inner cavity of the pump cylinder body 210 forms a plunger cavity that mates with the plunger assembly. A pump plug 204 is fixed to the end of the pump cylinder body 210 for sealing.

[0027] like Figure 2 As shown, the direct-drive two-dimensional plunger pump module 2 also includes an oil tank assembly. The oil tank assembly is fixed to the end of the pump cylinder body 210, and has an inlet and outlet oil pipe connected to the plunger cavity in the pump cylinder body 210. The pump cylinder body 210 has an oil suction port 2101 and an oil discharge port 2102, respectively connected to the inlet and outlet oil pipes. The oil suction port 2101 and the oil discharge port 2102 are spaced apart axially in the pump cylinder body 210, with the oil discharge port 2102 located at the end closest to the oil tank assembly. The oil suction port 2101 and the oil discharge port 2102 are distributed at 90° angles in the circumferential direction.

[0028] In this embodiment, the fuel tank assembly includes a fuel tank body 205, a fuel tank plug 206, and a fuel tank nut 207. The fuel tank body 205 is a hollow cylindrical structure, with one end threadedly connected to the pump cylinder body 210, and the other end fixedly sealed by the fuel tank nut 207. The fuel tank plug 206 is slidably connected within the fuel tank body 205, and a spring 208 is provided between it and the fuel tank nut 207. An inlet and outlet oil pipe are located on the side of the fuel tank body 205.

[0029] Furthermore, the outer wall of the pump cylinder body 210 is provided with multiple mounting slots. Each mounting slot is equipped with a cylinder body 303 sealing ring 209. When the pump cylinder body 210 is connected to the oil tank body 205, the cylinder body 303 sealing ring 209 is sleeved on the outer ring of the pump cylinder body 210, thereby sealing the connection between the oil tank body 205 and the pump cylinder body 210.

[0030] like Figure 2 and 3As shown, the plunger assembly includes a two-dimensional piston 203 and a power switching assembly. The plunger chamber is located on the pump cylinder body 210. The two-dimensional piston 203 is rotatably connected within the plunger chamber and can rotate under the drive of the motor drive module 1. The power switching assembly is mounted on the outer ring of the two-dimensional piston 203 and is used to push the two-dimensional piston 203 to move along its axial direction when it rotates.

[0031] An oil reservoir is provided at the end of the two-dimensional piston 203. The oil reservoir and the inner wall of the pump cylinder body 210 cooperate to form a sealed distribution cavity. Oil suction distribution windows 215 and oil discharge distribution windows 216 are provided on the side wall of the distribution cavity at intervals along the axial direction.

[0032] In practical use, the two-dimensional piston 203, driven by the motor drive module 1 and the power switching component, has two working positions: an oil suction position and an oil discharge position. The oil discharge position is located on the pump cylinder body 210 at the end closest to the oil tank assembly, while the oil suction position is located at the end furthest from the oil tank assembly. For example... Figure 3 As shown, in the initial state, the two-dimensional piston 203 is in the oil discharge position. The oil discharge distribution window 216 on the two-dimensional piston 203 is connected to the oil discharge port 2102 on the pump cylinder body 210.

[0033] When the direct-drive two-dimensional plunger pump module 2 needs to draw hydraulic oil, the two-dimensional piston 203, driven by the motor drive module 1 and the power switching component, switches from the discharge position to the suction position. The internal space of the flow distribution cavity formed between the two-dimensional piston 203 and the pump cylinder body 210 gradually increases with the movement of the two-dimensional piston 203, creating a negative pressure state inside. Simultaneously, the discharge flow distribution window 216 on the two-dimensional piston 203 gradually misaligns with the discharge port 2102 on the pump cylinder body 210, gradually reducing the communication area; the communication area between the suction flow distribution window 215 on the two-dimensional piston 203 and the suction port 2101 on the pump cylinder body 210 gradually increases. When the two-dimensional piston 203 has fully moved to the suction position, the suction flow distribution window 215 on the two-dimensional piston 203 and the suction port 2101 on the pump cylinder body 210 are fully connected. The negative pressure in the flow distribution cavity enables the direct-drive two-dimensional plunger pump module 2 to draw oil.

[0034] When the direct-drive two-dimensional plunger pump module 2 needs to discharge oil, the two-dimensional piston 203, driven by the motor drive module 1 and the power switching component, resets from the oil suction position to the oil discharge position. The internal space of the flow distribution cavity formed between the two-dimensional piston 203 and the pump cylinder body 210 gradually decreases with the movement of the two-dimensional piston 203, resulting in a high-pressure state inside. The oil suction distribution window 215 on the two-dimensional piston 203 and the oil suction port 2101 on the pump cylinder body 210 are closed due to misalignment. Simultaneously, the communication area between the oil discharge distribution window 216 on the two-dimensional piston 203 and the oil discharge port 2102 on the pump cylinder body 210 gradually increases. High-pressure hydraulic oil is output from the oil discharge distribution window 216, flows through the oil discharge port 2102 and the oil discharge pipe, and then enters the micro hydraulic cylinder module 3. The micro hydraulic cylinder module 3 then drives the finger exoskeleton device module 4 to execute bending commands.

[0035] like Figure 4 and 5 As shown, the power switching assembly includes an end face cam 217 and two sets of axial drive components. The end face cam 217 is fixed to the center of the two-dimensional piston 203. Each side of the end face cam 217 has two protrusions 213; the two protrusions 213 are symmetrically arranged on the circumferential edge of the end face cam 217, and adjacent sides form concave portions 214 with the corresponding circumferential edge of the end face cam 217.

[0036] The two sides of the end face cam 217 are divided into an oil suction drive surface near the pushing end of the two-dimensional piston 203 and an oil discharge drive surface away from the pushing end of the two-dimensional piston 203. The protrusions 213 on the oil suction drive surface and the protrusions 213 on the oil discharge drive surface are staggered. Two sets of axial drive components are respectively arranged on both sides of the end face cam 217. When the axial drive component on the oil suction drive surface abuts against the protrusion 213 on the oil suction drive surface, the axial drive component on the oil discharge drive surface abuts against the concave portion 214 of the oil discharge drive surface.

[0037] During actual oil suction and discharge operations, the motor drive module 1 drives the two-dimensional piston 203 to rotate, which in turn drives the end face cam 217 to rotate synchronously. When the oil suction drive surface of the end face cam 217 switches from alignment with the concave portion 214 and the corresponding axial drive component to alignment with the protruding portion 213, it will move away from the pushing end under the drive of the axial drive component, thus achieving the purpose of drawing hydraulic oil. Conversely, when the oil discharge drive surface of the end face cam 217 switches from alignment with the concave portion 214 and the corresponding axial drive component to alignment with the protruding portion 213, the oil discharge operation will be performed.

[0038] In this embodiment, the axial drive assembly includes a suspension 212 and two sets of symmetrically arranged roller units. Each set of roller units is symmetrically arranged within the plunger cavity of the pump cylinder body 210 and is rotatably connected to the pump cylinder body 210. The suspension 212 is fixedly connected to the pump cylinder body 210 and has multiple positioning slots near each set of roller units. Each set of roller units corresponds to one positioning slot, providing auxiliary positioning during installation.

[0039] In this embodiment, the roller unit includes a roller body 202 and a first positioning pin 211. The inner wall of the pump cylinder body 210 has a connecting hole that mates with the first positioning pin 211. The first positioning pin 211 is rotatably connected within the connecting hole. The roller body 202 is fixed to the inner end of the positioning pin, and its rotation relative to the end face cam 217 is achieved through the first positioning pin 211.

[0040] like Figure 2 As shown, the motor drive module 1 includes a connector 101, a connector cover 102, a brushless DC motor 103, a shaft 104, a motor housing 105, and a motor end cover 106. The connector 101 is fixed to the end of the connector cover 102, enabling electrical connection between the motor drive module 1 and an external control system. The connector cover 102 is fixedly connected to one end of the motor housing 105, forming the front-end protective structure of the motor drive module 1. The brushless DC motor 103 is installed inside the motor housing 105, with one end of its power output shaft 104 connected. The other end of the shaft 104 passes through the motor end cover 106 and is connected to the two-dimensional piston 203 in the direct-drive two-dimensional plunger pump module 2. The motor end cover 106 is fixed between the motor housing 105 and the brushless DC motor 103, serving as a limiting and supporting element for the installation of the brushless DC motor 103.

[0041] Furthermore, a connecting groove is provided at the end of the rotating shaft near the two-dimensional piston. The end of the two-dimensional piston extends into the connecting groove. A transmission connector is fixed to the outer ring of the two-dimensional piston. A limiting groove is provided on the inner wall of the connecting groove to cooperate with the transmission connector. The transmission connector slides in conjunction with the limiting groove, allowing the two-dimensional piston to have the freedom of axial sliding while rotating.

[0042] In some embodiments, the outer ring of the two-dimensional piston has a mounting hole that mates with a transmission connector. The end of the transmission connector extends into the mounting hole, and an elastic element is provided between it and the bottom of the hole. A limiting groove on the rotating shaft is spaced apart from the end of the rotating shaft. When installing the two-dimensional piston and the rotating shaft, the transmission connector is first pressed into the mounting hole. Then, the two-dimensional piston is inserted into the connecting slot of the rotating shaft. When the mounting hole on the two-dimensional piston rotates to the position of the limiting groove, the transmission connector extends out of the mounting hole under the action of the elastic element, and its end extends into the limiting groove. This allows the two-dimensional piston to slide freely axially while its outward sliding limit is limited by the transmission connector, preventing disengagement.

[0043] In some embodiments, a washer 201 is provided between the suspension 212 and the motor housing 105.

[0044] like Figure 10 and 11 As shown, the miniature hydraulic cylinder module 3 includes a rear cylinder cover 301, a cylinder body 303, a front cylinder cover 304301, a piston rod 306, and a Gladley ring 307. The cylinder body 303 is a hollow cylindrical structure. The rear cylinder cover 301 and the front cylinder cover 304301 are fixed to both ends of the cylinder body 303, forming a closed hydraulic drive chamber inside the cylinder body 303.

[0045] The piston rod 306 is located inside the cylinder body 303 and can slide along the axial direction of the cylinder body 303. Specifically, an integrally formed partition is provided in the middle of the piston rod 306. The partition divides the inner cavity of the cylinder body 303 into a push chamber and a reset chamber. Push inlets and reset inlets are respectively provided on the side walls of the push chamber and the reset chamber. The push inlets and the reset inlets are connected to the oil drain pipe and the oil inlet pipe on the oil tank body 205 through hydraulic lines, respectively.

[0046] When the direct-drive two-dimensional plunger pump module 2 performs suction and discharge operations, the hydraulic oil in the reset chamber of the cylinder 303 enters the distribution chamber through the hydraulic lines and the inlet pipe. Subsequently, the two-dimensional plunger switches from the suction position to the discharge position. High-pressure hydraulic oil enters the push chamber in the cylinder 303 from the direct-drive two-dimensional plunger pump module 2 through the discharge pipe, pushing the piston rod 306 outward along the axis of the cylinder 303, thereby driving the finger exoskeleton device module 4 to achieve finger bending movements.

[0047] In this embodiment, a step seal 302 and a cylinder head 301 sealing ring are respectively provided between the rear cylinder head 301, the front cylinder head 304301 and the cylinder block 303. The step seal 302 and the cylinder head 301 sealing ring achieve a sealing fit between the rear cylinder head 301, the front cylinder head 304301 and the cylinder block 303, ensuring the sealing performance of the end of the cylinder block 303.

[0048] like Figure 10As shown, the finger exoskeleton module 4 includes a hydraulic cylinder base 401, a linkage mechanism 402, a transmission mechanism, a bushing 405, a support base 406, and multiple finger joints 404. The miniature hydraulic cylinder module 3 is fixed to the hydraulic cylinder base 401. The top of the hydraulic cylinder base 401 is rotatably connected to the support base 406, allowing the drive end of the transmission mechanism to perform circular motion around the center when the miniature hydraulic cylinder module 3 extends or retracts. The linkage mechanism 402 includes multiple sets of sequentially connected linkage units, each set of linkage units having a quadrilateral linkage structure. The piston rod 306 in the miniature hydraulic cylinder module 3 is connected to the linkage unit located at the first end via the transmission mechanism. The linkage at the tail end of each linkage unit is hinged to each finger joint 404. The joints of each finger joint 404 are hinged together.

[0049] In practical use, when the piston rod 306 of the micro hydraulic cylinder module 3 extends outward, it drives the first-end connecting rod unit to move and deform through the transmission mechanism. Since each group of connecting rod units adopts a quadrilateral connecting rod structure, the deformation of the first-end connecting rod unit will drive the subsequent connecting rod units to move in sequence. Specifically, the first-end connecting rod unit changes angle under the thrust of the piston rod 306, and transmits the force to the next connecting rod unit through the hinge point. Each connecting rod unit drives the corresponding finger joint 404 to rotate around the hinge axis at the joint in sequence, thereby realizing the transformation of the entire finger exoskeleton equipment module 4 from an extended state to a bent state.

[0050] In this embodiment, the transmission mechanism includes a transmission base, a rotary transmission component, and a transmission connecting rod. The transmission base is fixed to the support base 406. The rotary transmission component is rotatably connected to the transmission base. The piston rod 306 in the micro hydraulic cylinder module 3 is hinged to the rotary transmission component via a bushing 405, so that when the piston rod 306 extends or retracts, it drives the rotary transmission component to rotate circumferentially. The two ends of the transmission connecting rod are respectively connected to the rotary transmission component and the connecting rod unit located at the first end. In this embodiment, the linkage unit includes a vertical linkage, a horizontal linkage, and a drive linkage that are hinged together in sequence. The bottom of the drive linkage is hinged to a corresponding finger joint 404. In some embodiments, in two adjacent linkage units, the drive linkage in the first linkage unit serves as the vertical linkage of the adjacent linkage unit.

[0051] Furthermore, an auxiliary link is provided between the finger joint 404 located in the first segment and the vertical link in the first link unit. One end of the auxiliary link is hinged to the vertical link in the corresponding link unit, and the other end is hinged to the finger joint 404 in the first segment via a second positioning pin 403.

[0052] The working principle of this invention is as follows: Taking the clockwise rotation of the DC brushless motor 103 as an example, the controller sends a control signal to the DC brushless motor 103, and the two-dimensional piston 203 rotates under the drive of the motor. At the same time, the roller body 202 located on the oil suction drive surface side of the end face cam 217 rolls from the concave part 214 to the convex part 213 relative to the end face cam 217, thereby driving the two-dimensional piston 203 to move away from the push end. During this process, the internal space of the flow distribution cavity formed between the two-dimensional piston 203 and the pump cylinder body 210 gradually increases with the movement of the two-dimensional piston 203, and the interior is in a negative pressure state. As the oil suction distribution window 215 on the two-dimensional piston 203 and the oil suction port 2101 on the pump cylinder body 210 gradually increase in connection area, since there is no oil in the distribution cavity, the cylinder body 303 is surrounded by an oil tank and connected to the right chamber of the hydraulic cylinder, the distribution cavity is in a low-pressure state, and the direct-drive two-dimensional piston pump module 2 is in the oil suction working state. Furthermore, as the connection area between the oil suction port 2101 and the oil suction distribution window 215 increases, the amount of oil suction increases.

[0053] After the distribution cavity draws in oil, as the two-dimensional piston 203 continues to rotate to the midpoint of its axial stroke, the communication area between the suction distribution window 215 and the suction port 2101 gradually decreases until it is no longer connected. At this time, the suction distribution window 215 and the discharge distribution window 216 of the two-dimensional piston 203 are in a cut-off state with the suction port 2101 and the discharge port 2102, and the direct-drive two-dimensional plunger pump module 2 is in a non-working state.

[0054] Next, the two-dimensional piston 203 continues to rotate, causing the oil suction drive surface of the end face cam 217 to switch from alignment with the protrusion 213 and the corresponding axial drive component to alignment with the concave portion 214. At the same time, the oil discharge drive surface of the end face cam 217 switches from alignment with the concave portion 214 and the corresponding axial drive component to alignment with the protrusion 213, and drives the two-dimensional piston 203 to move towards the pushing end side.

[0055] During the above process, the communication area between the oil discharge distribution window 216 of the two-dimensional piston 203 and the oil discharge port 2102 gradually increases, and the communication area reaches its maximum when the axial stroke of the two-dimensional piston 203 reaches the oil discharge position. The distribution groove containing high-pressure oil is connected to the push chamber of the hydraulic cylinder through the oil tank body 205. At this time, the pump is in the oil discharge state.

[0056] During the aforementioned process of completing one oil suction and discharge cycle, the DC brushless motor 103 drives the two-dimensional piston 203 to rotate 180° and perform one axial reciprocating motion. During the oil suction and discharge process, when the suction distribution window 215 and the discharge distribution window 216 are closed to the suction port 2101 and the discharge port 2102, the volume of the sealed cavity decreases due to the incompressibility of the fluid, and the pressure inside the cavity increases. However, since this stage is very brief, it will not cause the mechanism to jam or oil leakage leading to a decrease in volumetric efficiency.

[0057] Based on the pump's suction and discharge process described above, it can be concluded that the two-dimensional piston 203 completes two suction and discharge processes with one revolution, and also performs two axial reciprocating movements. Due to the continuous high-speed rotation of the DC brushless motor 103, the pump exhibits very strong suction and discharge performance. Furthermore, thanks to the leak-proof design of the oil tank spring 208 and sealing rings, the pump boasts high volumetric efficiency.

[0058] Furthermore, through the continuous suction and discharge of oil by the pump, the piston rod 306 on the hydraulic cylinder is driven to move continuously to the right axial direction. The piston rod 306 is connected to the connecting rod mechanism 402 through the bushing 405, which drives the connecting rod mechanism 402 and the finger joint 404 to bend downward. Since the exoskeleton equipment is worn on the finger, the above process can realize the auxiliary movement of the finger.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A micro electro-hydraulic actuator for driving a finger exoskeleton device, characterized by: The motor driving module, the direct drive two-dimensional plunger pump module, the micro hydraulic cylinder module and the finger exoskeleton equipment module are connected through the hydraulic pipeline. The power output shaft of the motor driving module is connected with the power input end of the direct drive two-dimensional plunger pump module, and is used for providing driving force. The direct drive two-dimensional plunger pump module comprises a pump cylinder body and a plunger assembly, and a plunger cavity is arranged in the pump body. When the plunger assembly moves in the liquid discharging direction away from the pump cylinder body, negative pressure is formed in the plunger cavity to suck hydraulic oil. The micro hydraulic cylinder module is connected with the direct drive two-dimensional plunger pump module through the hydraulic pipeline, the output end of the piston rod of the micro hydraulic cylinder module is connected with the finger exoskeleton equipment module, and the micro hydraulic cylinder module is used for driving the finger exoskeleton equipment module to bend and stretch.

2. The micro electro-hydrodynamic actuator for driving a finger exoskeleton apparatus according to claim 1, wherein: The direct drive two-dimensional plunger pump module further comprises an oil tank assembly.

3. The micro electro-hydrodynamic actuator for driving a finger exoskeleton apparatus according to claim 2, wherein: The plunger cavity is arranged in the pump cylinder body.

4. The micro electro-hydrodynamic actuator for driving a finger exoskeleton apparatus according to claim 3, wherein: The plunger assembly comprises a two-dimensional piston and a power switching assembly.

5. The micro electro-hydrodynamic actuator for driving a finger exoskeleton apparatus according to claim 4, wherein: The plunger cavity is arranged in the pump cylinder body. The two-dimensional piston is rotatably connected in the plunger cavity and can rotate under the driving of the motor driving module. The power switching assembly is installed on the outer ring of the two-dimensional piston and is used for pushing the two-dimensional piston to move along the axial direction when the two-dimensional piston rotates. The end of the two-dimensional piston is provided with an oil storage groove. The oil storage groove and the inner wall of the pump cylinder body cooperatively form a closed flow distribution cavity. The power switching assembly comprises an end face cam and two groups of axial driving assemblies. The end face cam is fixed on the two-dimensional piston. The two sides of the end face cam are provided with two protrusions. The two protrusions are symmetrically arranged on the circumferential edge of the end face cam, and the adjacent side and the corresponding circumferential edge of the end face cam form a concave part. The two sides of the end face cam are divided into an oil suction driving surface close to the pushing end of the two-dimensional piston and an oil discharge driving surface away from the pushing end of the two-dimensional piston. The protrusions on the oil suction driving surface and the protrusions on the oil discharge driving surface are arranged in a staggered manner. The axial driving assembly comprises a suspension and two groups of symmetrically arranged roller units. Each group of roller units is symmetrically arranged in the plunger cavity of the pump cylinder body and is rotatably connected with the pump cylinder body. The suspension is fixedly connected with the pump cylinder body and is provided with a plurality of positioning grooves close to each group of roller units. Each group of roller units corresponds to one positioning groove.

6. The micro electro-hydrodynamic actuator for driving a finger exoskeleton apparatus according to claim 3, wherein: The motor driving module comprises a navigation plug, a navigation plug cover, a direct current brushless motor, a rotating shaft and a motor cover; the navigation plug is fixed at the end of the navigation plug cover; the navigation plug cover is fixedly connected with one end of the motor cover; the direct current brushless motor is installed inside the motor cover, and the power output shaft of the direct current brushless motor is connected with one end of the rotating shaft; the other end of the rotating shaft is connected with a two-dimensional piston in the direct drive type two-dimensional piston pump module through the motor end cover.

7. The micro electro-hydrodynamic actuator for driving a finger exoskeleton apparatus according to claim 6, wherein: The rotating shaft is provided with a connecting clamping groove near one end of the two-dimensional piston; the end of the two-dimensional piston extends into the connecting clamping groove; the outer ring of the two-dimensional piston is fixed with a transmission connecting piece; a limiting groove matched with the transmission connecting piece is formed in the inner wall of the connecting clamping groove; the transmission connecting piece is in sliding fit with the limiting groove.

8. The micro electro-hydrodynamic actuator for driving a finger exoskeleton apparatus according to claim 7, wherein: The outer ring of the two-dimensional piston is provided with a mounting hole matched with the transmission connecting piece; the end of the transmission connecting piece extends into the mounting hole, and an elastic piece is arranged between the end of the transmission connecting piece and the bottom of the hole; the end of the limiting groove on the rotating shaft is arranged in a spaced manner with the end of the rotating shaft.

9. The micro electro-hydrodynamic actuator for driving a finger exoskeleton apparatus according to claim 1, wherein: The micro hydraulic cylinder module comprises a rear cylinder cover, a cylinder body, a front cylinder cover, a piston rod and a Gley ring; the cylinder body is a hollow columnar structure; the rear cylinder cover and the front cylinder cover are fixed at the two ends of the cylinder body; the piston rod is arranged inside the cylinder body and can slide along the axial direction of the cylinder body; a partition piece is integrally formed in the middle of the piston rod; the partition piece divides the inner cavity of the cylinder body into a pushing chamber and a reset chamber; a pushing liquid inlet and a reset liquid inlet are respectively formed in the side walls of the pushing chamber and the reset chamber; the pushing liquid inlet and the reset liquid inlet are respectively connected with an oil discharge pipeline and an oil inlet pipeline on the oil tank body through a hydraulic pipeline.

10. The micro electro-hydrodynamic actuator for driving a finger exoskeleton apparatus according to claim 1, wherein: The finger exoskeleton equipment module comprises a hydraulic cylinder seat, a connecting rod mechanism, a transmission mechanism, a shaft sleeve, a support base and multiple finger joints; the micro hydraulic cylinder module is fixed on the support base through the hydraulic cylinder seat; the connecting rod mechanism comprises multiple groups of connecting rod units connected in sequence, and each group of connecting rod units is in a quadrilateral connecting rod structure; the piston rod in the micro hydraulic cylinder module is connected with the connecting rod unit at the head end through the transmission mechanism; the connecting rod at the tail end in each group of connecting rod units is hingedly connected with each finger joint; the adjacent finger joints are hingedly connected.

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