Linear actuator and exoskeleton

Abstract

The present disclosure provides a linear actuator and an exoskeleton. The linear actuator comprises a cylinder body, a medium cavity filled with a magneto-rheological medium in the cylinder body, a piston having a locking state of being limited in the middle of the medium cavity and a moving state of moving relative to the cylinder body, a gas filling part in communication with the medium cavity and configured to fill a gas medium into the medium cavity in response to the locking state of the piston to increase the pressure applied to the piston, and a magnetic part in the medium cavity and having a power-on state and a power-off state. When the magnetic part is in the power-on state, a magnetic field is formed to make the magneto-rheological medium form a Bingham fluid to keep the piston in the locking state. When the magnetic part is in the power-off state, the piston is moved to a side away from the cylinder body under the pressure applied by the magneto-rheological medium and / or the gas medium. The exoskeleton comprises a first part, a second part and the linear actuator.

Description

Technical Field

[0001] At least one embodiment of this disclosure relates to a wearable device, and more specifically, to a linear actuator and an exoskeleton. Background Technology

[0002] Exoskeletons are worn on the human body to provide additional force to the user, thereby supporting, protecting, or increasing the user's load-bearing capacity. Based on the different wearing positions, exoskeletons can be divided into upper limb exoskeletons, lumbar exoskeletons, and lower limb exoskeletons.

[0003] Since exoskeletons need to be worn on the human body, a coupling relationship with the body must be established. Taking a lower limb exoskeleton as an example, the first part needs to fit the thigh (including the hip joint), the second part needs to fit the lower leg, and the knee joint needs to fit the knee. When worn, the knee joint needs to accommodate the flexion and extension movements of the thigh and lower leg. Currently, the knee joint of lower limb exoskeletons is mostly composed of a motor and a reducer with a high reduction ratio. Its working principle is that the motor provides power, which is reduced by the reducer to increase the torque, and then the high torque is applied to the exoskeleton (such as the first and second parts).

[0004] The aforementioned lower limb exoskeletons are typically equipped with a reducer with a large reduction ratio to respond to the user's flexion and extension movements. However, this structure results in poor reverse drive performance at the knee joint. Furthermore, since the knee joint mainly relies on motor drive, it requires a large-capacity battery or cable power supply, which limits the exoskeleton's operating time or range of use. Moreover, when the user's knee joint is subjected to a large load (such as when the user jumps from a height), the exoskeleton's knee joint does not have impact resistance, which leads to instability of the exoskeleton. Summary of the Invention

[0005] To address at least one of the above-mentioned and other technical problems in the prior art, this disclosure provides a linear actuator and an exoskeleton. The magnetic part keeps the piston in a locked state relative to the cylinder when energized. The gas filling part is adapted to inject gas medium into the medium cavity in the locked state so as to provide greater pressure to the piston when the piston changes from the locked state to the moving state, thereby forming damping in the opposite direction to the external pressure applied to the piston.

[0006] Embodiments of this disclosure provide a linear actuator, comprising: a cylinder having a medium cavity filled with a magnetorheological medium; a piston having a locked state confined to the middle of the medium cavity and a movable state movable relative to the cylinder; an inflation section communicating with the medium cavity and configured to inject a gaseous medium into the medium cavity in response to the locked state of the piston, thereby increasing the pressure applied to the piston; and a magnetic section disposed within the medium cavity, having an energized state and an de-energized state; wherein, in the energized state, the magnetic section forms a magnetic field to cause the magnetorheological medium to form a Bingham fluid, thereby holding the piston in the locked state; in the de-energized state, the magnetic section is subjected to pressure from the magnetorheological medium and / or the gaseous medium, causing the piston to move toward a side away from the cylinder.

[0007] According to an embodiment of the present disclosure, the piston includes: a piston body movably disposed within the medium cavity and dividing the medium cavity on both axial sides of the piston body into two interconnected sub-cavities; and a piston rod mounted on the piston body and configured to move with the piston body between an extended position away from the cylinder and a retracted position close to the piston body.

[0008] According to an embodiment of this disclosure, the magnetic part is mounted on the piston body and configured to move with the piston body.

[0009] According to an embodiment of the present disclosure, the magnetic part is disposed on the circumferential outer side of the piston body and is configured to form a magnetic field at both ends of the axial direction of the medium cavity in the energized state.

[0010] According to an embodiment of this disclosure, the piston body is provided with a medium flow channel for accommodating the magnetorheological medium and / or the gas medium; the piston further includes a flow-limiting plate pivotally mounted in the medium flow channel, the flow-limiting plate having a flow-limiting hole with a diameter smaller than the inner diameter of the medium flow channel; wherein, in response to the state of the magnetic part, the flow-limiting plate is configured to swing between a blocking position where it is attracted by the magnetic part and covers the medium flow channel, and an open position where it is at least partially misaligned with the medium flow channel, so as to adjust the flow rate allowing the magnetorheological medium to pass through.

[0011] According to an embodiment of this disclosure, the piston rod is provided with an injection channel inside which the gas medium passes through and is filled into the medium cavity.

[0012] According to an embodiment of the present disclosure, the inflation part includes a one-way valve disposed between the inflation channel and the medium cavity, configured to allow the gas medium to enter the medium cavity from the inflation channel and restrict the gas medium from overflowing from the medium cavity.

[0013] According to an embodiment of the present disclosure, the gas injection channel is arranged along the axial direction of the piston rod, and the end located in the medium cavity is configured to communicate with the medium cavity; the inflation part further includes a pressure rod telescopically installed in the gas injection channel, so that the position of the pressure rod is pressed into the gas injection channel.

[0014] According to embodiments of this disclosure, the linear actuator further includes a pressure relief valve disposed on the cylinder body, which is adapted to discharge at least a portion of the gaseous medium in the medium chamber.

[0015] Embodiments of this disclosure also provide an exoskeleton, comprising: a skeletal mechanism including: a first part adapted to be worn on the thigh of a human body; a second part adapted to be worn on the lower leg of a human body and pivotally connected to the first part, wherein the first part and the connection position of the first part are coupled to the lateral side of the knee joint between the thigh and the lower leg; and a linear actuator pivotally mounted between the first part and the second part; wherein, when the piston of the linear actuator changes from a locked state to a moving state, it is adapted to apply a pressure that moves away from the first part and / or the second part to dampen the approaching action of the distant ends of the first part and the second part.

[0016] According to the linear actuator and exoskeleton provided in this disclosure, the magnetorheological medium and magnetic part in the medium cavity cooperate to allow the piston to have a locked state and a moving state in response to the state of the magnetic part. When the magnetic part is de-energized, the piston can move relative to the cylinder body, so that the piston's outward and return movements are unrestricted. When the magnetic part is energized, the piston is confined to the middle of the medium cavity. The gas filling part is suitable for injecting gas medium into the medium cavity in the locked state, so as to provide greater pressure to the piston when the piston changes from the locked state to the moving state, thereby forming damping in the opposite direction to the external pressure applied to the piston, so as to achieve buffering of the external pressure. Furthermore, since the linear actuator only needs power supply when the magnetic part is energized, the linear actuator requires a smaller load, and a smaller capacity battery can be configured to meet the usage requirements, which is beneficial to expanding the application scenarios of the linear actuator. Attached Figure Description

[0017] Figure 1 This is a cross-sectional view of a linear actuator according to an illustrative embodiment of the present disclosure;

[0018] Figure 2 yes Figure 1 A perspective view of the piston valve core portion of the schematic embodiment shown; and

[0019] Figure 3 yes Figure 1The diagram shows a partial enlarged view of the compressor rod portion of an illustrative embodiment. The reference numerals in the diagram have the following specific meanings:

[0020] 1. Cylinder block;

[0021] 11. Pressure relief valve;

[0022] 12. Base plate;

[0023] 13. Cylinder block outer sleeve;

[0024] 2. Magnetic part;

[0025] 21. Metal ring;

[0026] 22. Coil;

[0027] 23. External wiring;

[0028] 3. Guiding section;

[0029] 31. Limit block;

[0030] 32. Upper cover of the guide;

[0031] 33. Guide;

[0032] 34. Lower end cover of the guide;

[0033] 4. Inflatable section;

[0034] 41. Air compressor rod;

[0035] 411. Air intake slot;

[0036] 412. Limiting groove;

[0037] 413. Sealing ring;

[0038] 42. Air pump outer sleeve;

[0039] 5. Piston;

[0040] 51. Piston rod;

[0041] 52. Lower end cap of the piston;

[0042] 53. Piston valve core;

[0043] 54. Pin;

[0044] 55. Piston upper end cap;

[0045] 56. Piston outer cylinder;

[0046] 57. Medium flow channel;

[0047] 58. Current limiting plate; and

[0048] 59. Pivot component. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0050] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0051] All terms used herein, including technical and scientific terms, have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0052] When using expressions such as "at least one of A, B, and C," the meaning should generally be interpreted according to the understanding of someone skilled in the art. For example, "a system having at least one of A, B, and C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C. Similarly, when using expressions such as "at least one of A, B, or C," the meaning should generally be interpreted according to the understanding of someone skilled in the art. For example, "a system having at least one of A, B, or C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C.

[0053] Figure 1 This is a cross-sectional view of a linear actuator according to an illustrative embodiment of the present disclosure.

[0054] According to the linear actuators provided in this disclosure, such as Figure 1As shown, the device includes a cylinder 1, a piston 5, a gas filling section 4, and a magnetic section 2. The cylinder 1 contains a medium cavity filled with a magnetorheological medium. The piston 5 has a locked state, confined to the center of the medium cavity, and a movable state, moving relative to the cylinder 1. The gas filling section 4 communicates with the medium cavity and is configured to fill the medium cavity with a gaseous medium in response to the locked state of the piston 5, thereby increasing the pressure applied to the piston 5. The magnetic section 2 is disposed within the medium cavity and has an energized state and an de-energized state. When the magnetic section 2 is energized, it forms a magnetic field, causing the magnetorheological medium to form a Bingham fluid, thus holding the piston 5 in the locked state. When the magnetic section 2 is de-energized, the piston 5 is subjected to pressure from the magnetorheological medium and / or the gaseous medium, causing the piston 5 to move towards the side furthest from the cylinder 1.

[0055] In one illustrative embodiment, such as Figure 1 As shown, the cylinder block 1 includes a cylinder block outer sleeve 13 and a base plate 12. Specifically, the cylinder block outer sleeve 13 is constructed as a hollow cylindrical structure, with one end of the cylinder block outer sleeve 13 (as shown in the image)... Figure 1 The upper part (as shown) is equipped with a base plate 12.

[0056] In one illustrative embodiment, such as Figure 1 As shown, the linear actuator also includes a guide section 3. Specifically, the guide section 3 includes a guide 33, which is mounted on the other end of the cylinder outer sleeve 13 (e.g., Figure 1 The piston rod 51, which accommodates the piston 5, extends from the cylinder body 1, and the extension direction of the piston 5's axis coincides with the extension direction of the cylinder body 1's axis. The inner cavity of the cylinder body outer sleeve 13 between the guide 33 and the base plate 12 defines a medium chamber.

[0057] In one illustrative embodiment, such as Figure 1 The guide portion 3 shown also includes an upper guide cap 32 and a lower guide cap 34. Specifically, the upper guide cap 32 and the lower guide cap 34 are respectively disposed on both sides of the guide 33 along its axial direction. Furthermore, the upper guide cap 32 and the lower guide cap 34 are respectively fixed to the cylinder outer sleeve 13 by at least one limiting block 31 to restrict the position of the guide 33 relative to the cylinder outer sleeve 13, thereby sealing the medium cavity.

[0058] In one illustrative embodiment, the gaseous medium includes, but is not limited to, air or compressed air. Under the action of the inflation section, the air injected into the medium cavity can pass through a magnetorheological medium to increase the pressure within the medium cavity. The magnetorheological medium includes, but is not limited to, magnetorheological fluid (MRF). Thus, in the magnetic field formed by the magnetic section, the magnetorheological medium can transform into a high-viscosity, low-flow Bingham fluid, thereby restricting the position of the piston 5 relative to the cylinder 1, allowing the medium cavity to be inflated. Once the magnetic field formed by the magnetic section disappears (i.e., the magnetic section is de-energized), the magnetorheological medium can return to its fluid state, outputting greater pressure under the pressure provided by the gaseous medium, causing the piston to move more rapidly. Furthermore, the magnetorheological fluid (MRF) depends on the applied magnetic field strength, forming a Bingham fluid adapted to the magnetic field strength (for example, when the voltage applied to the magnetic section is low, and the resulting magnetic field strength is low, the magnetorheological fluid can form a fluid state with high viscosity but still flowable). Thus, in the fluid state where the magnetorheological fluid is in a magnetic field but still flowable, it can provide damping for the movement of the piston.

[0059] In this implementation, the magnetorheological medium and magnetic component within the medium cavity cooperate to allow the piston to have both a locked and a moving state in response to the state of the magnetic component. When the magnetic component is de-energized, the piston can move relative to the cylinder, allowing unrestricted outward and return strokes. When the magnetic component is energized, the piston is confined to the center of the medium cavity. The gas filling section is used to inject gas into the medium cavity in the locked state, providing greater pressure to the piston when it changes from the locked to the moving state. This creates damping in the opposite direction to the external pressure applied to the piston, thus buffering the external pressure. Furthermore, since the linear actuator only requires power when the magnetic component is energized, the load required is smaller, allowing for the use of smaller capacity batteries, which expands the application scenarios of the linear actuator.

[0060] According to embodiments of this disclosure, such as Figure 1 As shown, the linear actuator also includes a pressure relief valve 11 disposed on the cylinder 1, which is suitable for discharging at least a portion of the gas medium in the medium chamber.

[0061] In one illustrative embodiment, such as Figure 1 As shown, the pressure relief valve 11 is located in the middle of the base plate 12. Furthermore, the linear actuator is configured to position the piston 5 downwards. Thus, when a gaseous medium is injected into the medium chamber, the gas bubbles formed by the gaseous medium can be suspended in the upper part of the medium chamber, facilitating the discharge of the gaseous medium through the pressure relief valve.

[0062] According to embodiments of this disclosure, such as Figure 1As shown, piston 5 includes piston body and piston rod 51. Piston body is movably disposed within medium cavity and divides the medium cavity on both axial sides of piston body into two interconnected sub-cavities. Piston rod 51 is mounted on piston body and configured to move with piston body between an extended position away from cylinder 1 and a retracted position close to piston body.

[0063] In one illustrative embodiment, such as Figure 1 As shown, the piston body includes a piston outer cylinder 56 with an opening. Specifically, the opening of the piston outer cylinder 56 faces the bottom plate 12 of the cylinder body 1 (e.g., ...). Figure 1 (As shown, the upward setting).

[0064] In one illustrative embodiment, such as Figure 1 As shown, the piston body also includes a lower piston cap 52, an upper piston cap 55, and a piston valve core 53 disposed within the opening of the piston outer cylinder 56. Specifically, the lower piston cap 52 is disposed at the lower part of the opening of the piston outer cylinder 56, the upper piston cap 55 is disposed at the upper part of the opening of the piston outer cylinder 56, and the piston valve core 53 is fixed between the lower piston cap 52 and the upper piston cap 55 by a pin 54, thus confining it within the piston outer cylinder 56.

[0065] In one illustrative embodiment, such as Figure 1 As shown, the piston body divides the medium chambers located on both sides of the piston valve core 53 axially into a first sub-chamber (e.g., Figure 1 The cylindrical portion of the medium chamber located above the piston valve core 53 (as shown) and the second sub-chamber (such as...) Figure 1 The annular portion of the medium chamber shown is located between the piston outer cylinder 56 and the piston lower end cap 52, below the piston valve core 53.

[0066] In one illustrative embodiment, such as Figure 1 As shown, the piston lower end cover 52, piston valve core 53, and piston upper end cover 55 together form a through medium flow channel. In detail, the piston valve core 53 serves as the main body of the medium flow channel, and the piston lower end cover 52 and piston upper end cover 55 are respectively provided with openings at positions facing the main body of the medium flow channel. These two openings serve as the input and output ports for the piston's outgoing and return strokes, respectively.

[0067] In one illustrative embodiment, such as Figure 1 As shown, the opening provided inside the piston upper end cap 55 is configured to extend along the axial direction of the piston (e.g., Figure 1 (As shown in the vertical direction), the opening inside the piston lower end cover 52 is constructed in an L-shape, and the part facing the piston valve core 53 (as shown in the vertical direction) Figure 1 The upper part (as shown) is configured to extend along the axial direction of the piston (e.g.) Figure 1The portion that is far from the piston valve core 53 (as shown in the up-down direction) Figure 1 The lower part (as shown) is configured to extend in the radial direction of the piston (e.g.) Figure 1 (as shown in the left and right directions) to connect the first sub-cavity and the second sub-cavity.

[0068] According to embodiments of this disclosure, such as Figure 1 As shown, the magnetic part 2 is mounted on the piston body and is configured to move with the piston body.

[0069] According to embodiments of this disclosure, such as Figure 1 As shown, the magnetic part 2 is disposed on the circumferential outer side of the piston body and is configured to form a magnetic field at both ends along the axial direction of the medium cavity when energized.

[0070] In one illustrative embodiment, such as Figure 1 As shown, the magnetic part 2 includes a metal ring 21 (such as a copper alloy ring or an aluminum alloy ring), a coil 22, and an external wire 23. Specifically, the metal ring 21 is disposed between the upper piston cap 55 and the lower piston cap 52, and covers the outside of the piston valve core 53. The coil 22 is disposed outside the metal ring 21 to form a coil along the axial direction of the piston (e.g., ...) when energized. Figure 1 The magnetic poles (including the N pole and the S pole) extend in the vertical direction as shown. Furthermore, one end of the external wire 23 is connected to the coil, and the other end is configured to be led out from the cylinder 1 to be connected to an external circuit to control the coil's conduction or deactivation.

[0071] In this embodiment, the magnetic part is configured to form magnetic poles along the extension direction of the piston, and in the energized state, it is located on both sides of the piston (e.g., Figure 1 The media cavities (i.e., the first sub-cavity and the second sub-cavity) shown on the upper and lower sides are both within the magnetic field of the magnetic part, so as to form Bingham fluid under the action of the magnetic field, thereby clamping the piston and restricting the position of the piston relative to the cylinder.

[0072] Figure 2 yes Figure 1 A perspective view of the piston valve core portion of the schematic embodiment shown.

[0073] According to embodiments of this disclosure, such as Figure 1 and Figure 2 As shown, the piston body is provided with a medium flow channel 57 for accommodating magnetorheological media and / or gaseous media. The piston 5 also includes a flow restrictor 58 pivotally mounted within the medium flow channel 57. The flow restrictor 58 is configured to swing between a blocking position where it is attracted by the magnetic part 2 and covers the medium flow channel 57, and an open position where it is at least partially misaligned with the medium flow channel 57, in response to the state of the magnetic part 2, so as to regulate the flow rate allowing the magnetorheological media to pass through.

[0074] In one illustrative embodiment, such as Figure 2 As shown, the piston upper end cap 55 and / or piston lower end cap 52 are configured to extend along the axial direction of the piston valve core 53 (e.g., ...). Figure 1 A gap is formed in the vertical direction shown. Furthermore, the axial end of the piston valve core 53 near the lower piston cap 52 (as shown) Figure 1 The lower end shown is configured to pivotally mount the flow limiter 58 via the pivot 59.

[0075] In one illustrative embodiment, such as Figure 2 As shown, the current limiting plate 58 is configured as a ring-shaped (or ring-like) sheet structure. In detail, the current limiting plate 58 is made of a material that can be attracted by magnetic materials (such as a metal material or alloy material containing iron, cobalt, or nickel).

[0076] In this embodiment, the flow-limiting plate 58 is configured to be subjected to forces along the axial direction of the piston (e.g., when the magnetic part is energized) Figure 2 The attractive force (extending in the vertical direction as shown) covers the medium flow channel 57. When the magnetic part is de-energized, the magnetorheological medium and the gas medium are configured to enter the second sub-cavity from the first sub-cavity through the medium flow channel. The flow limiting plate 58 is flipped downward by the action of the magnetorheological medium to increase the cross-sectional area defined by the holes provided on the medium flow channel and the flow limiting plate 58, so as to increase the flow rate of the magnetorheological medium and / or the gas medium allowed to pass through, so that the magnetorheological medium can pass through the medium flow channel quickly.

[0077] According to embodiments of this disclosure, such as Figure 1 and Figure 3 As shown, the piston rod 51 has an injection channel inside that allows gas medium to pass through and be filled into the medium cavity.

[0078] According to embodiments of this disclosure, such as Figure 1 As shown, the inflation section 4 includes a one-way valve 43 disposed between the inflation channel and the medium chamber, configured to allow the gas medium to enter the medium chamber from the inflation channel and restrict the gas medium from overflowing from the medium chamber.

[0079] According to embodiments of this disclosure, such as Figure 1 As shown, the gas injection channel is arranged along the axial direction of the piston rod 51, and the end located in the medium cavity is configured to communicate with the medium cavity. The inflation part 4 also includes a retractable air compressor 41 installed in the gas injection channel, so that the position of the gas medium air compressor 41 is pressed into the gas injection channel.

[0080] In one illustrative embodiment, such as Figure 1 As shown, the piston rod 51 is constructed as a hollow structure. Furthermore, an air cylinder outer sleeve 42 is fitted inside the piston 51, and an air injection channel is defined inside the air cylinder outer sleeve.

[0081] In one illustrative embodiment, such as Figure 1 As shown, the air intake side of the air injection channel is located at the end of the piston rod 51 that extends from the cylinder body 1 (e.g., Figure 1 (As shown in the lower end). Furthermore, the outlet side of the air injection channel is located on the radial side of the piston rod 51 within the cylinder body 1 (e.g., Figure 1 (As shown on the left).

[0082] In one illustrative embodiment, such as Figure 1 As shown, a one-way valve 43 is installed between the outlet side of the gas injection channel and the piston rod 51. Specifically, the one-way valve 43 is configured to allow the gas medium to flow from one side of the gas injection channel (e.g., the outlet side of the gas injection channel). Figure 1 (As shown on the right) passes through and enters the medium cavity side (such as the right side). Figure 1 (As shown on the left).

[0083] Figure 3 yes Figure 1 A partial enlarged view of the compressor rod portion of the schematic embodiment shown.

[0084] In one illustrative embodiment, such as Figure 3 As shown, the end of the compressor rod 41 located within the air injection channel (the lower end shown in the figure) has two outwardly protruding flanges spaced apart along the axial direction of the compressor rod 41 (i.e., as shown in the figure). Figure 3 As shown in the first and second flanges, a sealing ring 413 is fitted on the outer side of the air compressor 41 between the two flanges. The sealing ring is confined within a limiting groove 412 provided circumferentially along the air compressor 41 and is configured to be movable along the axial direction of the air compressor 41 (e.g., ...). Figure 3 (As shown in the up-down direction) moves. Specifically, the intake side near the injection channel (e.g.) Figure 3 The outer diameter of the first flange (shown on the upper side) is configured to be approximately the same as the inner diameter of the injection channel, so as to abut against the inner wall of the injection channel, near the outlet side of the injection channel (e.g., Figure 3 The outer diameter of the second flange (shown on the lower side) is configured to be smaller than the inner diameter of the air injection channel. Furthermore, the outer diameter of the compressor rod between the first and second flanges is smaller than the inner diameter of the sealing ring 413.

[0085] In one illustrative embodiment, such as Figure 3 As shown, at least one axially extending air inlet groove 411 is provided on the outer edge of the first flange. Furthermore, the axial position of the sealing ring 413 is relative to the air inlet groove 411 along the axial direction of the compressor rod 41 (e.g., ...). Figure 3 The orthographic projections of the seal ring 413 (shown in the up and down direction) coincide to seal the air inlet groove 411 when the seal ring 413 abuts against the first flange, so that a sealed air injection chamber is formed between the seal 411 and the air outlet side of the air injection channel.

[0086] In this implementation, the compressor rod reciprocates along the injection channel (e.g. Figure 3 During the process (as shown in the up-down direction), the seal moves with the compressor cylinder to force the gas medium into the injection channel and finally into the medium cavity (e.g., when the compressor rod moves upward, the seal ring is located as shown in the up-down direction). Figure 3 The lower part, as shown, accommodates gas entering below the second flange through the air inlet groove. Furthermore, when the compressor rod descends, the sealing ring is positioned as follows: Figure 3 The upper part shown is used to seal the air inlet groove 411, so that the gas medium in the sealed air injection chamber is forced into the medium chamber.

[0087] The exoskeleton provided in this disclosure (not shown in the figures) includes a skeletal mechanism and a linear actuator. The skeletal mechanism includes a first part and a second part. The first part is adapted to be worn on the thigh of a human body. The second part is adapted to be worn on the lower leg of a human body and is pivotally connected to the first part. The connection point of the first part and the second part is coupled to the lateral side of the knee joint between the thigh and the lower leg. The linear actuator is pivotally mounted between the first and second parts. When the piston 5 of the linear actuator changes from a locked state to a movable state, it is adapted to apply a distancing pressure to the first and / or second parts to dampen the approaching motion of the distancing ends of the first and second parts.

[0088] In one illustrative embodiment, the first and second parts are, but are not limited to, configured as fully covered or partially covered. Furthermore, a linear actuator is disposed on one side of the first and second parts (e.g., on the lateral side of the lower limb) to avoid obstructing the approach and deployment of the first and second parts, thus allowing the exoskeleton to adapt to the flexion and extension movements of the lower limb.

[0089] In this implementation, the exoskeleton is worn on the user's lower limbs. Depending on the usage scenario (e.g., jumping from a height), if the user determines that their lower limbs will bear significant force, they can first select a suitable flexion range, positioning the piston in the center of the cylinder. Then, the magnetic part is energized to maintain the aforementioned flexion range, and the exoskeleton is inflated. After inflation, the magnetic field strength of the magnetic part can be reduced (e.g., by lowering the voltage) or the magnetic part can be de-energized, causing the piston to extend its stroke to overcome external pressure on the user's lower limbs, providing cushioning. Once the action is complete, the user can open the pressure relief valve to release the gas from the medium chamber for the next use.

[0090] In this implementation, the user's flexion and extension movements are unimpeded when the magnetic part of the linear actuator is de-energized. Furthermore, since the linear actuator only requires a brief power supply when generating an electromagnetic field, its power requirements are significantly reduced compared to existing motor-driven exoskeletons, eliminating the need for large-capacity batteries or power cords, thus expanding the exoskeleton's application scenarios. Moreover, when the magnetic part is energized, the linear actuator applies greater pressure to the piston, providing damping in the opposite direction to the externally applied pressure when releasing the piston, thereby protecting the user and improving the stability of the exoskeleton.

[0091] It should also be noted that the directional terms mentioned in the embodiments, such as "up," "down," "front," "back," "left," and "right," are only for reference to the directions in the accompanying drawings and are not intended to limit the scope of protection of this disclosure. Throughout the drawings, the same elements are represented by the same or similar reference numerals. Conventional structures or constructions will be omitted where they may cause confusion in understanding this disclosure.

[0092] The embodiments of this disclosure have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of this disclosure. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. The scope of this disclosure is defined by the appended claims and their equivalents. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of this disclosure, and all such substitutions and modifications should fall within the scope of this disclosure.

Claims

1. A linear actuator, characterized in that, include: The cylinder body (1) is provided with a medium cavity filled with magnetorheological medium; A piston (5) having a locked state confined to the middle of the medium cavity and a movable state moving relative to the cylinder (1), the piston (5) comprising: A piston body is movably disposed within the medium cavity, dividing the medium cavity on both axial sides of the piston body into two interconnected sub-cavities. The piston body contains a medium flow channel (57) for accommodating the magnetorheological medium and the gas medium. A piston rod (51) is mounted on the piston body and is configured to move with the piston body between an extended position away from the cylinder (1) and a retracted position close to the body. The piston rod (51) has an injection channel inside that accommodates the gas medium to pass through and fill the medium cavity. The injection channel is arranged along the axial direction of the piston rod (51), and the end located in the medium cavity is configured to communicate with the medium cavity. The inflation section (4), communicating with the medium cavity, is configured to inject gas medium into the medium cavity in response to the locking state of the piston (5) to increase the pressure applied to the piston (5). The inflation section (4) also includes a retractable air compressor (41) mounted in the gas injection channel to press the position of the air compressor (41) into the gas injection channel. The inflation section (4) includes a one-way valve (43) disposed between the gas injection channel and the medium cavity, configured to allow the gas medium to enter the medium cavity from the gas injection channel and restrict the gas medium from overflowing from the medium cavity; and The magnetic part (2) is disposed in the dielectric cavity and has an energized state and an de-energized state; In the energized state, the magnetic part (2) forms a magnetic field to make the magnetorheological medium form Bingham fluid to keep the piston (5) in the locked state. In the de-energized state, the magnetic part (2) is subjected to pressure from the magnetorheological medium and the gas medium, causing the piston (5) to move to the side away from the cylinder (1).

2. The actuator according to claim 1, characterized in that, The magnetic part (2) is mounted on the piston body and is configured to move with the piston body.

3. The actuator according to claim 2, characterized in that, The magnetic part (2) is disposed on the circumferential outer side of the piston body and is configured to form a magnetic field at both ends of the medium cavity in the energized state.

4. The actuator according to claim 1, characterized in that, The piston (5) further includes a flow limiting plate (58) pivotally mounted in the medium flow channel (57), and the flow limiting plate (58) is provided with a flow limiting hole with a diameter smaller than the inner diameter of the medium flow channel (57). The flow limiting plate (58) is configured to swing between a blocking position in response to the state of the magnetic part (2) so that the flow limiting plate (58) covers the medium flow channel (57) and an open position that is at least partially misaligned with the medium flow channel (57) in order to adjust the flow rate that allows the magnetorheological medium to pass through.

5. The actuator according to any one of claims 1 to 4, characterized in that, It also includes a pressure relief valve (11) disposed on the cylinder (1), which is adapted to discharge at least a portion of the gas medium in the medium chamber.

6. An exoskeleton, characterized in that, include: Skeletal structure, including: The first part is designed to be worn on the thigh. The second part is suitable for wearing on the lower leg and is pivotally connected to the first part, wherein the first part and the connection point of the first part are coupled to the lateral side of the knee joint between the thigh and the lower leg; and The linear actuator as described in any one of claims 1 to 5 is pivotally mounted between the first part and the second part; When the piston (5) of the linear actuator changes from the locked state to the moving state, it is suitable for applying a pressure that is far apart to the first part and / or the second part, so as to dampen the approaching action of the far apart ends of the first part and the second part.

Images