Anti-sticking emergency unlocking electromechanical actuator

Abstract

The application discloses a kind of anti-jam emergency unlocking electromechanical actuators, realize the excess of different working medium emergency anti-jam emergency unlocking.The application is realized by the following technical solutions: the piston head tail part is designed with the steel ball guide hole of assembly rigid lock ball, in emergency unlocking, high-pressure emergency medium enters electromechanical actuator outer cylinder cavity from the emergency energy inlet on the tail part of outer cylinder, emergency sliding sleeve is pushed by high-pressure medium of emergency release circuit, compresses the upper locking force spring, the upper locking sliding sleeve of ladder cylinder is pushed from the inner ring of rigid lock ball by high-pressure medium and is separated, rigid lock ball rolls along steel ball guide hole, the upper locking sliding sleeve of ladder cylinder reaches limit position, is separated from lock groove, realizes the mechanical lock unlocking of rigid lock ball, after unlocking, high-pressure medium pushes piston cylinder to extend, and simultaneously, sliding block is radially slid along ring cloth lock groove and is separated from neck lock groove, separates from the inner surface of emergency sliding sleeve, in emergency sliding sleeve reaches limit position, realizes the anti-jam mechanism emergency unlocking in the hollow cavity of piston head.

Description

Technical Field

[0001] This invention relates to the field of electromechanical engineering, specifically to an emergency unlocking and extension structure applied to electromechanical actuators (EMA). More specifically, this invention relates to a servo actuator self-locking structure that improves the safety of electromechanical actuators and enables multi-media emergency unlocking and extension of the piston cylinder in the event of actuator power failure or transmission component jamming. Background Technology

[0002] Electromechanical actuators, as linear motion execution elements, are energy conversion devices used to achieve linear reciprocating motion or less than 360° motion of working mechanisms. Their main function is to receive control commands, convert electrical energy into mechanical energy, overcome external load torque, and achieve predetermined speeds and positions. Common core components of electromechanical actuators typically include: a motor, gearbox, transmission components, ball screw pairs, outer cylinder assembly, piston cylinder assembly, and self-locking components. Although electromechanical actuators are widely used in servo technology, their core transmission components are susceptible to single-point risks of jamming, sticking, and malfunction, making it difficult to achieve higher reliability requirements. This significantly limits their application in high-reliability and high-safety applications. To ensure high reliability, a self-locking function at a specified position is usually added to servo actuators. When receiving control commands from the engine electronic controller, the control switches on and off to lock the actuator at a specific position within its stroke. Considering the impact of the self-locking function on the system, an overload unlocking function is also designed. In the event of hydraulic oil unlocking failure, the actuator itself can automatically unlock. Electromechanical actuators with self-locking devices prevent erratic movement caused by external forces when stopped at a defined position. This is typically achieved by a mechanical lock within the actuator cylinder to address single-point failures in the actuator's transmission components. A common type of mechanical lock is a ball lock, consisting of a ball, locking groove, conical piston, and spring. Currently, as a transmission mechanism, the electromechanical actuator's function is to drive rotation according to commands after being energized. The process from the actuator's motor to the aircraft's control shaft involves deceleration and torque increase. Therefore, when the actuator is not energized, a corresponding locking device needs to be installed on its motor shaft to provide the required locking torque after deceleration and torque increase. Since modern aircraft landing gear is typically retractable, usually using hydraulics for normal retraction and extension, a self-locking mechanism is necessary when a malfunction in the hydraulic servo actuator, electrical system, or other systems prevents the landing gear from being lowered properly. In such cases, the aircraft must have a manual emergency landing gear lowering mechanism, the performance of which directly affects aircraft safety. However, there have been numerous past incidents of aircraft landing gear emergency deployment failures leading to forced landings, highlighting the crucial importance of landing gear emergency deployment systems for ensuring flight safety. In applications with high safety requirements, such as electromechanical actuators used in aircraft landing gear retraction and extension, a certain safety margin is essential. Conventional redundancy solutions employ a primary / backup drive configuration using electric motors or pneumatic motors, representing a dissimilar redundancy design to improve system reliability. Built-in locking solutions utilize ball-bearing locks, enabling actuator positioning, unlocking during retraction and extension, and reliable locking. Actuators with built-in mechanical locks, when the piston or piston cylinder reaches its limit position, are securely fixed by the internal mechanical lock, preventing further movement. Single-point failures due to transmission component jamming are common.To address the single-point failure problem in the transmission mechanism of electromechanical actuators, a common redundancy design for electromechanical actuators is to use a backup motor. When the main motor fails, the backup motor operates to achieve emergency lowering or retraction of the piston cylinder. However, it still relies on electricity for emergency lowering and retraction. Similar to the main-backup drive system of motors and pneumatic motors, this design cannot solve the single-point failure problem of the lead screw pair jamming, resulting in low reliability and limited practicality. Summary of the Invention

[0003] To address the problems of jamming, sticking, and clogging in the transmission components of electromechanical actuators, the present invention aims to provide a simple, safe, and reliable solution that enables emergency unlocking and piston cylinder extension without relying on electricity. This effectively solves the single-point fault of conventional dual-redundant electromechanical actuators, which still require electricity for emergency retraction and cannot resolve the issue of lead screw malfunction. The invention provides a multi-redundant emergency unlocking electromechanical actuator for different working media, preventing jamming.

[0004] The technical solution adopted by this invention to solve its technical problem is: an anti-jamming emergency unlocking electromechanical actuator, comprising: an electromechanical actuator outer cylinder 1 connected to a servo motor shaft connecting gear via a gear transmission mechanism; a lead screw transmission pair 8 assembled in the transmission cavity of the outer cylinder 1 and meshing with the gear transmission mechanism; a piston cylinder 6 that performs telescopic movement in the cavity of the outer cylinder 1; and an anti-jamming mechanism. The piston head is hollow and faces the bottom of the cavity of the outer cylinder 1; the outer ring surface of the lead screw nut 7 is fitted onto the inner ring surface of the unlocking sleeve 9; and the bottom of the unlocking sleeve 9 is connected to the lead screw nut... The tail of the mother sleeve 7 has a radially constricted locking groove 15 with a corresponding annular cloth locking groove 16. The unlocking sleeve 9 is provided with a sliding locking block 14 constrained by the annular cloth locking groove 16 and the constricted locking groove 15, and an emergency sliding sleeve 13 coupled to the outer annular surface of the sliding locking block 14. The emergency sliding sleeve 13 is axially constrained to the flanged end face of the unlocking sleeve 9 by the upper locking force spring 12. At the same time, the outer annular surface of the tail is provided with a stepped cylinder upper locking sleeve 11 that constrains the return spring 10 to the stop surface of the stepped hole of the piston head, and is constrained to the end of the stepped cylinder upper locking sleeve 11 by the return spring 10 that maintains the upper locking force. The outer ring surface of the coupling locking spring 12 is stopped by the end face of the stepped hole of the piston head between it and the inner wall of the stepped hole. The above components are designed with a steel ball guide hole 5 for mounting the rigid locking ball 4 at the tail of the piston head, thus forming an anti-jamming mechanism for the outer cylinder 1 to enter the high-pressure emergency medium through the radially connected emergency energy inlet 2 for emergency unlocking. During emergency unlocking, the high-pressure emergency medium, which is different from electrical energy, enters the outer cylinder 1 cavity of the electromechanical actuator from the emergency energy inlet 2 on the tail of the outer cylinder 1. The emergency sliding sleeve 13 is pushed by the high-pressure medium of the emergency release circuit, compressing the locking force. Spring 12 and stepped cylinder locking sleeve 11 are pushed by high pressure medium to disengage from the inner ring of rigid locking ball 4. Rigid locking ball 4 rolls along steel ball guide hole 5. When stepped cylinder locking sleeve 11 reaches the movement limit position, it disengages from locking groove 3, realizing the mechanical lock unlocking of rigid locking ball 4. After unlocking, high pressure medium pushes piston cylinder to extend. At the same time, sliding lock block 14 slides radially along annular cloth locking groove 16, disengages from necked locking groove 15, and disengages from inner ring surface of emergency sleeve 13. When emergency sleeve 13 reaches the movement limit position, the anti-jamming mechanism in the hollow cavity of piston head is unlocked in an emergency.

[0005] Compared with the prior art, the present invention has the following advantages:

[0006] This invention employs a lead screw transmission pair 8, which meshes with the gear transmission mechanism within the transmission cavity of the outer cylinder 1, a piston cylinder 6 that performs telescopic movements of the outer cylinder 1, and an anti-jamming mechanism. The structure is simple, with high mechanical strength, and can withstand large stable and dynamic loads. It reduces mechanical vibration, lowers noise, and improves the working environment. The anti-jamming mechanism is achieved by fitting the outer ring surface of the lead screw nut 7 onto the inner ring surface of the unlocking sleeve 9. A ring-shaped locking groove 16 is positioned opposite the radially constricted locking groove 15 at the tail of the lead screw nut 7 at the bottom of the unlocking sleeve 9. The unlocking sleeve 9 is also equipped with a sliding locking block 14 constrained by the ring-shaped locking groove 16 and the constricted locking groove 15, and an emergency sliding sleeve 13 coupled to the sliding locking block 14. The emergency sliding sleeve 13 is axially constrained by an upper locking spring 12 to the flanged end face of the unlocking sleeve 9, thus locking the lead screw nut 7 and the unlocking sleeve 9 together. This design features a well-designed and compact installation structure that occupies little space. It allows the lead screw nut 7 to be locked together with the unlocking sleeve 9, while also being able to be unlocked by high-pressure media, effectively isolating the lead screw pair from jamming.

[0007] This invention designs a sealing structure on the inner and outer circles of the emergency sliding sleeve 13, allowing it to be driven by an emergency medium to open the mechanical lock of the anti-jamming mechanism. Similarly, it designs a corresponding sealing structure on the inner and outer circles of the locking sleeve 11 of the stepped cylinder, allowing it to be driven by an emergency medium to open the mechanical lock of the rigid locking ball 4 of the electromechanical actuator. This ensures that in the event of an emergency operation, the emergency medium entering the actuator can drive the mechanical lock to unlock, causing the lead screw nut 7 to disengage from the unlocking sleeve 9 and extending the piston cylinder 6. This solves the problem of single-point failure of lead screw pair jamming that conventional electromechanical actuators cannot address, and avoids serious catastrophic accidents caused by the inability to open the mechanical lock inside the actuator or the inability of the piston cylinder 6 to extend, thus improving the safety of the retraction or opening / closing mechanism.

[0008] This invention employs a high-pressure emergency medium that enters the outer cylinder 1 cavity of the electromechanical actuator through the emergency energy inlet 2 at the tail of the outer cylinder 1. The emergency sliding sleeve 13 is pushed by the high-pressure medium to disengage from the outer ring surface of the sliding lock block 14. The sliding lock block 14 slides radially along the ring lock groove 16 and disengages from the necked lock groove 15, thereby unlocking the mechanical lock of the anti-jamming mechanism in the hollow cavity of the piston head. The locking sliding sleeve 11 on the stepped cylinder is pushed by the high-pressure medium to disengage from the inner ring of the rigid lock ball 4. The rigid lock ball 4 rolls along the steel ball guide hole 5 and disengages from the lock groove 3, thereby unlocking the mechanical lock of the rigid lock ball 4. After unlocking, the high-pressure medium pushes the piston cylinder to extend. In the case of actuator power failure or transmission component jamming, this invention effectively solves the problem that conventional dual-redundant electromechanical actuators still rely on electricity for emergency retraction and extension but cannot solve the single-point failure of screw pair jamming. Attached Figure Description

[0009] Embodiments of this application will now be described in detail with reference to the accompanying drawings, enabling those skilled in the art to readily implement this application. However, it should be noted that this application is not limited to the embodiments but can be implemented in many other ways. In the drawings, irrelevant parts of the description have been omitted for brevity, and the same reference numerals denote the same parts throughout.

[0010] Figure 1 This is a schematic diagram of the locked state structure of the anti-jamming emergency unlocking electromechanical actuator of the present invention.

[0011] In the diagram: 1 Outer cylinder, 2 Emergency energy inlet, 3 Locking groove, 4 Rigid locking ball, 5 Steel ball guide hole, 6 Piston cylinder, 7 Lead screw nut, 8 Lead screw transmission pair, 9 Unlocking sleeve, 10 Return spring, 11 Stepped cylinder locking sleeve, 12 Locking force spring, 13 Emergency sleeve, 14 Sliding block, 15 Necked locking groove, 16 Ring cloth locking groove.

[0012] The present invention will be further described below with reference to the accompanying drawings and embodiments, but this does not limit the invention to the scope of the described embodiments. All these concepts should be considered as the content disclosed in this technology and the scope of protection of this invention. Detailed Implementation

[0013] Reference Figure 1In the preferred embodiment described below, an anti-jamming emergency unlocking electromechanical actuator includes: an electromechanical actuator outer cylinder 1 connected to a servo motor shaft connecting gear via a gear transmission mechanism; a lead screw transmission pair 8 assembled in the transmission cavity of the outer cylinder 1 and meshing with the gear transmission mechanism; a piston cylinder 6 that performs telescopic movement in the cavity of the outer cylinder 1; and an anti-jamming mechanism. The piston head is hollow and faces the bottom end of the cavity of the outer cylinder 1; the outer ring surface of the lead screw nut 7 is fitted onto the inner ring surface of the unlocking sleeve 9; and the bottom of the unlocking sleeve 9 is aligned with the tail diameter of the lead screw nut 7. A ring-shaped locking groove 16 is provided at a position opposite to the necking locking groove 15. The unlocking sleeve 9 is provided with a sliding locking block 14 constrained by the ring-shaped locking groove 16 and the necking locking groove 15, and an emergency sliding sleeve 13 coupled to the outer ring surface of the sliding locking block 14. The emergency sliding sleeve 13 is axially constrained to the flanged ring end face of the unlocking sleeve 9 by the locking force spring 12. At the same time, the outer ring surface of the tail is provided with a stepped cylinder locking sliding sleeve 11 that constrains the return spring 10 to the stop surface of the stepped hole of the piston head, and is constrained to the stepped cylinder locking sliding sleeve 11 by the return spring 10 that maintains the locking force and is coupled and locked at the end of the stepped cylinder locking sliding sleeve 11. The outer ring surface of the force spring 12 is stopped by the end face of the stepped hole of the piston head between it and the inner wall of the stepped hole. The above components are designed with a steel ball guide hole 5 for mounting the rigid locking ball 4 at the tail of the piston head, thus forming an anti-jamming mechanism for the outer cylinder 1 to enter the high-pressure emergency medium through the radially connected emergency energy inlet 2 for emergency unlocking. During emergency unlocking, the high-pressure emergency medium, which is different from electrical energy, enters the outer cylinder 1 cavity of the electromechanical actuator from the emergency energy inlet 2 on the tail of the outer cylinder 1. The emergency sliding sleeve 13 is pushed by the high-pressure medium of the emergency release circuit, compressing the locking spring. 12. The stepped cylinder locking sleeve 11 is pushed by the high-pressure medium to disengage from the inner ring of the rigid locking ball 4. The rigid locking ball 4 rolls along the steel ball guide hole 5. When the stepped cylinder locking sleeve 11 reaches the limit position of movement, it disengages from the locking groove 3, realizing the mechanical unlocking of the rigid locking ball 4. After unlocking, the high-pressure medium pushes the piston cylinder to extend. At the same time, the sliding locking block 14 slides radially along the annular locking groove 16, disengages from the necked locking groove 15, and disengages from the inner ring surface of the emergency sleeve 13. When the emergency sleeve 13 reaches the limit position of movement, the anti-jamming mechanism in the hollow cavity of the piston head is unlocked in an emergency.

[0014] During normal operation, the servo motor drives the lead screw transmission pair 8 to rotate through the gear transmission mechanism, which in turn drives the lead screw nut 7 to push the step of the unlocking sleeve 9 of the set to push the locking sleeve 11 and the emergency sleeve 13 of the stepped cylinder. Together, they overcome the elastic movement of the locking force spring 12 and the return spring 10. The rigid locking ball 4 rolls along the steel ball guide hole 5, disengaging the rigid locking ball 4 from the lock groove 3, thus realizing the mechanical unlocking of the rigid locking ball 4. After unlocking, the end face of the unlocking sleeve 9 pushes the piston cylinder to extend.

[0015] The anti-jamming mechanism includes: an unlocking sleeve 9 that locks the lead screw nut 7 together; an annular cloth locking groove 16 that radially corresponds to the necking locking groove 15 at the tail of the lead screw nut 7; a sliding locking block 14 constrained by the annular cloth locking groove 16 and the necking locking groove 15; and an emergency sliding sleeve 13 coupled to the sliding locking block 14. The emergency sliding sleeve 13 is axially constrained by the upper locking spring 12 on the flanged end face of the unlocking sleeve 9. The space between the unlocking sleeve 9, which is fitted on the outer annular surface of the lead screw nut 7, and the inner annular end face space that is interconnected with the small end step of the piston head passing through the lead screw transmission pair 8 forms the lock bottom movement limit position.

[0016] For reference, in the description of the exemplary embodiment, the rigid locking ball 4 is installed in the steel ball guide hole 5 on the outer ring stepped cylinder of the piston head of the piston cylinder 6, the upper end is installed in the locking groove 3 on the inner ring surface of the outer cylinder 1 with a diameter equivalent to that of the rigid locking ball 4, and the lower end rests on the outer ring surface of the locking sleeve 11 on the stepped cylinder.

[0017] The sliding lock block 14 is installed in the annular cloth lock groove 16 of the unlocking sleeve 9, with one end embedded in the radial necking lock groove 15 of the lead screw nut 7, and the other end resting against the inner annular surface of the emergency sliding sleeve 13.

[0018] According to the exemplary embodiment, when the piston cylinder 6 retracts, the rigid locking ball 4 is located in the locking groove 3 and the steel ball guide hole 5 on the inner surface of the outer cylinder 1, and its lower end rests against the outer ring surface of the stepped cylinder upper locking sleeve 11, thus achieving locking. When emergency unlocking and piston cylinder extension are required, the high-pressure emergency medium enters the inner cavity of the electromechanical actuator outer cylinder 1 from the emergency energy inlet 2, pushing the emergency sleeve 13 to overcome the elastic force of the locking force spring 12 and disengage from the outer end of the sliding lock block 14, and the screw nut 7 disengages from the unlocking sleeve 9, thereby achieving complete disengagement of the screw nut 7 from the piston cylinder 6; at the same time, the high-pressure emergency medium pushes the stepped cylinder upper locking sleeve 11 to overcome the elastic force of the return spring 10 and disengage from the lower end of the rigid locking ball 4 out of the stepped arm movement gap, so that the rigid locking ball 4 is driven by the piston cylinder 6 to disengage from the locking groove 3, and the high-pressure emergency medium pushes the piston cylinder 6 to extend.

[0019] Although embodiments of the present invention have been shown and described above in detail, the description of the embodiments is only for the purpose of helping to understand the present invention; at the same time, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the content of this specification should not be construed as limiting the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An anti-jamming emergency unlocking electromechanical actuator, comprising: An electromechanical actuator outer cylinder (1) connected to a servo motor shaft gear via a gear transmission mechanism, a lead screw transmission pair (8) meshing with the gear transmission mechanism and assembled in the transmission cavity of the outer cylinder (1), a piston cylinder (6) extending and retracting in the cavity of the outer cylinder (1), and an anti-jamming mechanism are characterized in that: the piston head is hollow and faces the bottom of the cavity of the outer cylinder (1), the outer ring surface of the lead screw nut (7) is fitted onto the inner ring surface of the unlocking sleeve (9), and an annular locking groove (16) is provided at the bottom of the unlocking sleeve (9) relative to the radially constricted locking groove (15) at the tail of the lead screw nut (7), and the unlocking sleeve (9) is also provided with an annular locking groove (16). The locking sleeve (9) is provided with a sliding locking block (14) constrained by the annular locking groove (16) and the necking locking groove (15), and an emergency sliding sleeve (13) coupled to the outer annular surface of the sliding locking block (14). The emergency sliding sleeve (13) is axially constrained by the upper locking force spring (12) to the end face of the flange ring of the unlocking sleeve (9). At the same time, the outer annular surface of the tail is provided with a stepped cylinder upper locking sleeve (11) that constrains the return spring (10) to the stop surface of the stepped hole of the piston head, and is constrained by the return spring (10) that maintains the upper locking force to the outer annular surface of the stepped cylinder upper locking sleeve (11) and the platform. Between the inner walls of the stepped hole, the piston head stepped hole end face is stopped. The above components are designed with a steel ball guide hole (5) for mounting a rigid locking ball (4) at the tail of the piston head, thus forming an anti-jamming mechanism for the outer cylinder (1) to radially connect to the emergency energy inlet (2) to enter the high-pressure emergency medium for emergency unlocking. During emergency unlocking, the high-pressure emergency medium, which is different from electrical energy, enters the outer cylinder (1) cavity of the electromechanical actuator from the emergency energy inlet (2) at the tail of the outer cylinder (1). The emergency sliding sleeve (13) is pushed by the high-pressure medium of the emergency release circuit, compressing the locking spring (12), and the stepped cylinder is locked. The sliding sleeve (11) is pushed by the high-pressure medium to disengage from the inner ring of the rigid locking ball (4). The rigid locking ball (4) rolls along the steel ball guide hole (5) and locks the sliding sleeve (11) on the stepped cylinder to reach the limit position of movement. It disengages from the locking groove (3) to realize the mechanical lock unlocking of the rigid locking ball (4). After unlocking, the high-pressure medium pushes the piston cylinder to extend. At the same time, the sliding locking block (14) slides radially along the ring cloth locking groove (16) and disengages from the necked locking groove (15) and disengages from the inner ring surface of the emergency sliding sleeve (13). When the emergency sliding sleeve (13) reaches the limit position of movement, the anti-jamming mechanism in the hollow cavity of the piston head is unlocked in an emergency.

2. The anti-jamming emergency unlocking electromechanical actuator as described in claim 1, characterized in that: During normal operation, the servo motor drives the lead screw transmission pair (8) to rotate through the gear transmission mechanism, which in turn drives the lead screw nut (7) to drive the step of the end face of the unlocking sleeve (9) of the set to push the locking sleeve (11) and the emergency sleeve (13) of the stepped cylinder together to overcome the elastic movement of the locking force spring (12) and the return spring (10). The rigid locking ball (4) rolls along the steel ball guide hole (5) and disengages the rigid locking ball (4) from the lock groove (3), realizing the mechanical lock unlocking of the rigid locking ball (4). After unlocking, the end face of the unlocking sleeve (9) pushes the piston cylinder to extend.

3. The anti-jamming emergency unlocking electromechanical actuator as described in claim 1, characterized in that: The anti-jamming mechanism includes: an unlocking sleeve (9) that locks the lead screw nut (7) together; an annular cloth locking groove (16) that radially corresponds to the necked locking groove (15) at the tail of the lead screw nut (7); a sliding locking block (14) constrained by the annular cloth locking groove (16) and the necked locking groove (15); and an emergency sliding sleeve (13) coupled to the outer annular surface of the sliding locking block (14). The emergency sliding sleeve (13) is axially constrained by the upper locking spring (12) on the flanged end face of the unlocking sleeve (9). The unlocking sleeve (9) fitted on the outer annular surface of the lead screw nut (7) and the inner annular end face space that is cross-linked with the small end step of the piston head passing through the lead screw transmission pair (8) form the lock bottom movement limit position.

4. The anti-jamming emergency unlocking electromechanical actuator as described in claim 1, characterized in that: The rigid locking ball (4) is installed in the steel ball guide hole (5) on the outer ring stepped cylinder of the piston head of the piston cylinder (6). The upper end is installed in the locking groove (3) on the inner ring surface of the outer cylinder (1) and is equivalent to the diameter of the rigid locking ball (4). The lower end rests on the outer ring surface of the locking sleeve (11) on the stepped cylinder.

5. The anti-jamming emergency unlocking electromechanical actuator as described in claim 1, characterized in that: The sliding lock block (14) is installed in the annular cloth lock groove (16) of the unlocking sleeve (9), with one end embedded in the radial necking lock groove (15) of the lead screw nut (7) and the other end resting on the inner annular surface of the emergency sliding sleeve (13).

6. The anti-jamming emergency unlocking electromechanical actuator as described in claim 1, characterized in that: When the piston cylinder (6) retracts, the rigid locking ball (4) is located in the locking groove (3) and the steel ball guide hole (5) on the inner surface of the outer cylinder (1), and the lower end rests against the outer ring surface of the locking sleeve (11) on the stepped cylinder, thus achieving locking.

7. The anti-jamming emergency unlocking electromechanical actuator as described in claim 1, characterized in that: When emergency unlocking and piston cylinder extension are required, high-pressure emergency medium enters the inner cavity of the outer cylinder (1) of the electromechanical actuator from the emergency energy inlet (2), pushing the emergency sliding sleeve (13) to overcome the elastic force of the locking spring (12) and disengage from the outer end of the sliding lock block (14). The screw nut (7) disengages from the unlocking sleeve (9), thereby achieving complete disengagement of the screw nut (7) from the piston cylinder (6). At the same time, the high-pressure emergency medium pushes the stepped cylinder locking sliding sleeve (11) to overcome the elastic force of the return spring (10) and disengage from the lower end of the rigid locking ball (4) from the stepped arm to move out of the gap, so that the rigid locking ball (4) is driven by the piston cylinder (6) to disengage from the lock groove (3), and the high-pressure emergency medium pushes the piston cylinder (6) to extend.

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