Non-similar dual-redundant electro-mechanical actuator

Abstract

A non-similar dual-redundancy electro-mechanical actuator proposed by the present invention is safe and reliable, and has a relatively high transmission efficiency. The present invention is realized through the following technical solutions: A redundancy unlocking bushing with a third-order inner convex ring in the middle of the cylinder wall constrains the locking block in the locking block chute of the ring sleeve and the necking ring groove of the lead screw nut through the inner wall convex ring. The left and right return springs at both ends of the third-order inner convex ring are axially constrained by the flanging step ring of the ring sleeve to form a coupled redundancy unlocking bushing. The left upper locking bushing is embedded in the inner ring groove of the piston head, and the dual-redundancy locking spring rings constrained by the inner cavity ring grooves of the left and right upper locking bushings facing each other symmetrically are sealed on the outer circle of the redundancy unlocking bushing. At the same time, the upper steel balls constrained in the upper steel ball locking groove of the actuator cylinder barrel are coupled to the outer circle of the left upper locking bushing through the upper steel ball guiding hole designed at the tail of the piston head, and the lower steel balls passing through the lower steel ball guiding hole are constrained on the concave arc ring of the sleeve shoulder of the right upper locking bushing, thereby constituting a non-similar dual-redundancy electro-mechanical actuator.

Description

Technical Field

[0001] The present invention relates to the field of drive control. It is about a dual-redundancy working structure applied to an electro-mechanical actuator. More specifically, the present invention is about an innovative structure that can improve the mission reliability of the electro-mechanical actuator and realize multi-medium unlocking, locking, extending, and retracting the piston cylinder under the conditions of power failure of the actuator or jamming of the transmission components. Background Art

[0002] At present, the difference between the power-by-wire actuation system and the traditional flight control actuation system, including the current fly-by-wire flight control actuation system, is that it does not need to rely on the complex hydraulic pipelines of the fuselage to send high-pressure hydraulic oil to the aircraft hydraulic system of the actuator systems of each aircraft rudder surface; instead, it directly transmits electrical energy to the rudder surface actuation system to control the deflection of the rudder surface. The purpose of the power-by-wire actuator is to obtain an airborne fly-by-wire actuation system solution with engineering practical value, and the airborne fly-by-wire actuation system has very high requirements for the reliability of the actuator. Due to the slow dynamic response speed, low load stiffness, and difficult-to-solve static error of the electro-mechanical actuator, in addition, the large-power mechanical transmission mechanism is large in volume and heavy in weight, resulting in too large a moment of inertia of the entire fly-by-wire system, making it difficult to implement the electro-mechanical actuator in a high-power airborne transmission system. Moreover, its hydraulic servo system accounts for a relatively large proportion of the system weight, which is not conducive to system integration and reduces the reliability. The electro-mechanical actuator, as a linear motion execution element, is an energy conversion device used to realize the linear reciprocating motion or less than 360° dynamic motion of the working mechanism, and is also a motion control device for the transmission mechanism of maneuvering actions. The basic composition of the currently common electro-mechanical actuator is as follows: a reduction gearbox, transmission components, a ball screw pair, a cylinder block assembly, a piston cylinder assembly, a self-locking assembly, etc. The electro-mechanical actuator with a self-locking device can prevent crosstalk caused by external forces when it stops moving at a limited position, and is usually locked by a mechanical lock inside the actuator cylinder. The common form of the mechanical lock is a steel ball lock, which consists of a steel ball, a lock groove, a conical piston, and a spring, etc. When the actuator does not move, the motor drives a unidirectional fixed-displacement pump, and the overflow valve makes the system in a constant pressure state. The excess flow is discharged through the overflow valve and all is converted into heat. If the heat dissipation condition is not good, the temperature of the actuator rises quickly. Therefore, the electro-hydrostatic actuator of this scheme cannot work for a long time (generally a few minutes to dozens of minutes) and cannot meet the needs of the aircraft for long-term work. How to improve the reliability of the system; how to increase the power density of the system. In terms of improving reliability, the main technology applied is redundancy technology, that is, realizing it through redundant design of the system. The main method to increase the power density of the system is to apply a high-power density motor for transmission. According to reliability analysis, it can be known that the failure rate of a single-redundancy power-by-wire actuator is 10 -4The magnitude is such that if only a single set of systems is adopted, it cannot meet the reliability requirements of the airborne fly-by-wire actuation system. In the single-channel fail-operational mode, the faulty channel must be effectively isolated. Since the ball screw pair cannot self-lock in the reverse direction, the motor of the faulty channel must be braked to prevent the reverse movement of the screw of the faulty channel under the action of the load force, which may affect the operation of the normal channel and thus the effective output of the entire actuator. The safety and force conflict problems of the direct gear meshing redundancy method seriously affect the reliability of the system operation. The differential gear train method has obvious advantages over the gear meshing method. However, in terms of the requirements for machining accuracy and transmission characteristics, it is difficult to meet the requirements in engineering and the feasibility is not high.

[0003] Currently, the two methods for forming the redundancy of the electromechanical actuation system are: using high-reliability fault-tolerant motors to form redundancy and using multiple motors through a mechanical motion synthesis device to form redundancy. High-reliability fault-tolerant motors achieve high reliability through various forms of winding backups. However, all high-reliability motors with non-similar redundancy have a drawback: in the event of a single fault, if similar fault conditions reappear, the remaining windings will also fail. The so-called non-similar redundancy power fly-by-wire actuation system refers to a redundancy actuation system composed of two actuators that use different working principles and different structural components to complete the same task. The most important problem of the primary-backup redundant actuator is that after a fault occurs, it can quickly detect the fault and timely connect the backup actuator. Since the fault detection time and threshold are directly related to the fault transient, too long a fault detection time or too large a threshold will result in too large a fault transient, which may pose a hazard to the aircraft; if the fault detection time is too short or the threshold is too small, it will cause the actuator to be mis-disconnected.

[0004] At present, as an electromechanical actuator for a transmission mechanism, its function is to drive rotation according to instructions after being powered on. The process from the motor of the electromechanical actuator to the rudder shaft of the aircraft is a process of reducing speed and increasing torque. Therefore, when the electromechanical actuator is not powered on, a corresponding locking device needs to be installed on its motor shaft to provide the required locking torque after reducing speed and increasing torque. Since the landing gear of modern aircraft is usually retractable, hydraulic pressure is generally used for the normal retraction and extension of the landing gear. When faults occur in the hydraulic, electrical and other systems of the aircraft, resulting in the inability to lower the landing gear normally, the aircraft must have measures to manually and emergently lower the landing gear, and its working performance directly affects the safety of the aircraft. However, in the past, there have been many cases where the emergency lowering of the landing gear of aircraft was not in place, resulting in the forced landing of the aircraft. It can be seen that the emergency landing gear release system is extremely important for ensuring flight safety. In some application scenarios with high safety requirements, such as electromechanical actuators used for the retraction and extension of aircraft landing gears, they are required to have a certain safety margin. The conventional redundancy scheme adopts the main and standby drive forms of motors and pneumatic motors, which belongs to non-similar redundancy design. In its non-similar redundancy configuration method, the force conflict phenomenon between channels is more serious and cannot be eliminated theoretically, and only effective methods can be taken to limit it. Due to the existence of the force conflict problem, when a motor channel fails, it must be isolated, otherwise the strong coupling effect of the faulty channel will still affect the safety of the servo system itself. These methods have poor safety and are only applicable to redundant actuator systems with the same technology. The common redundant design of electromechanical actuators is to back up one motor. When the main motor fails, the standby motor works to achieve the emergency lowering or retraction of the piston cylinder. It still relies on electricity to achieve emergency retraction and extension. However, like the main and standby drive forms of motors and pneumatic motors, it cannot solve the single-point failure of the screw pair jamming, and the mission reliability is low, so its practicability is limited. Summary of the Invention

[0005] The present invention provides a solution with a simple structure, safety and reliability, high transmission efficiency, and capable of realizing unlocking, locking, extending, and retracting the piston cylinder without relying on electricity. In order to effectively solve the problem that the conventional dual-redundancy electromechanical actuator still needs to rely on electricity to achieve emergency retraction and extension but cannot solve the single-point failure of the screw pair jamming, and realize the redundant operation of different working media to meet the requirements of the full-stroke reciprocating motion of the actuator.

[0006] The technical solution adopted by the present invention to solve its technical problems is as follows: A non-similar dual-redundancy electro-mechanical actuator, comprising: a servo motor 25 whose output gear extends into a transmission cavity from one axial side of an actuator cylinder 1 to engage with a transmission gear 26, a lead screw 16 whose end gear is engaged with the transmission gear 26, a hollow piston cylinder 13 that moves telescopically in the actuator cylinder 1 and a hollow piston head facing the bottom end of the cylinder, and a lead screw 16 sleeved with a lead screw nut 19. It is characterized in that: the actuator cylinder 1 is provided with a non-similar energy inlet 2 that radially communicates with the bottom cavity and a non-similar redundancy inlet 15 that radially communicates with the front movement cavity. An upper ball lock groove 3 for locking the upper ball 4 is formed on the inner wall of the adjacent non-similar energy inlet 2. When the piston cylinder 13 retracts the piston head, the upper ball 4 is locked in the upper ball guide hole 5, and at the same time, the lower ball 12 is locked in the lower ball guide hole 11. A non-similar dual-redundancy automatic lock assembly for controlling the rolling locking and unlocking of the upper ball 4 and the lower ball 12 is provided in the stepped hole on the inner wall of the piston head. High-pressure medium enters the piston head from the non-similar energy inlet 2 at the rear of the actuator cylinder 1 to push out and form a high-pressure cavity at the bottom cavity of the actuator cylinder 1, pushing the automatic lock assembly to move to the right, driving the upper ball 4 and the lower ball 12 to roll, realizing the unlocking of the mechanical lock of the piston cylinder 13. The lower ball 12 follows the piston head and rolls to the lower ball lock groove 14 on the inner wall limit position of the actuator cylinder 1, and the automatic lock assembly pushes the lower ball 12 into the lower ball lock groove 14 to realize the locking of the piston cylinder 13 when it extends. The retraction process is similar. High-pressure medium enters the front cavity of the actuator cylinder 1 from the non-similar redundancy inlet 15 at the end of the actuator cylinder 1, pushing the piston head to retract. The lower ball 12 disengages from the lower ball lock groove 14, driving the automatic lock assembly to move to the left, and locking the upper ball 4 in the upper ball lock groove 3 to realize the locking of the piston cylinder 13 when it retracts.

[0007] The present invention has the following beneficial effects compared with the prior art:

[0008] Based on a non-similar dual-redundancy control strategy, the ball screw and nut are driven by a servo motor, and the displacement is directly transmitted through the ball screw. A locking block chute 9 is arranged at a relative position between the middle part of the ring sleeve 17 and the necking ring groove in the middle of the lead screw nut 19 by sleeving the outer ring surface of the lead screw nut 19 on the inner ring surface of the ring sleeve 17. A locking block 7 restricted by the necking ring groove and the locking block chute 9 and a redundancy unlocking bushing 22 coupled to the locking block 7 are arranged in the middle of the ring sleeve 17. The redundancy unlocking bushing 22 is axially restricted in the middle of the stepped groove of the ring sleeve 17 by a left return spring 24 and a right return spring 18, so that the lead screw nut 19 and the ring sleeve 17 are locked together to form a redundancy switching locking mechanism. Ignoring the influence of the commutation process on the servo motor control, each channel of the non-similar dual-redundancy actuation system performs active position control, with a simple structure and high transmission efficiency.

[0009] Based on the principles of simple reliability, high transmission accuracy, and feasibility in mechanical design, when switching to non-similar energy for operation, the redundancy switching and locking mechanism between the lead screw nut 19 and the collar 17 can be unlocked not only by the high-pressure medium that drives the piston cylinder to extend but also by the high-pressure medium that drives the piston cylinder to retract. This can not only effectively isolate the faults caused by the jamming of the lead screw pair but also, after the occurrence of the jamming fault, complete the normal full-stroke retraction and extension, as well as locking and unlocking operations. Thus, it solves the problem that conventional electro-mechanical actuators cannot solve the single-point fault of the lead screw pair jamming, and can avoid serious catastrophic accidents of equipment caused by the inability to open the mechanical lock inside the actuator or the inability of the piston cylinder to extend or retract, improving the safety of the retraction / extension or opening / closing mechanism. The built-in lock solution adopts the form of a steel ball lock, which can achieve the functions of locking in place of the actuator cylinder, unlocking during retraction / extension, and reliable locking. Other mechanical locks can also be used to improve the system reliability. The results show that the dynamic performance of the non-similar dual-redundancy actuation system is improved compared with that in single-channel operation, and it can still operate normally when a fault occurs in one channel. This enables the electro-mechanical actuator to have the ability of dual-redundancy operation, effectively solving the problem that the actuator cannot complete the full-stroke reciprocating operation of extending and retracting the piston cylinder under the conditions of power failure or jamming of transmission components.

[0010] The present invention uses two actuation configurations with different working principles and different structural elements to complete the same task to form a dual-redundancy actuation system. This dual-redundancy actuation system adopts the main-backup working mode. Its main channel uses an electro-actuation configuration with a relatively high dynamic response speed, and the backup channel uses a high-pressure actuation configuration with a relatively simple structure and high reliability. When a common-mode fault occurs in the actuation system, the product can still continue to operate, improving the system reliability. The technical structure of this solution is simple, and it can also be seen from the reliability analysis that the redundant actuator can meet the reliability requirements of the fly-by-wire control system. Therefore, this solution can basically meet the requirements of the airborne fly-by-wire actuation system.

[0011] The present invention can be applied to the field of drive control with very high requirements for reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a longitudinal sectional schematic view of the structure of the non-similar dual-redundancy electro-mechanical actuator piston cylinder in the retracted state of the present invention.

[0013] In the figure: 1 actuator cylinder, 2 non-similar energy inlet, 3 upper steel ball lock groove, 4 upper steel ball, 5 upper steel ball guide hole, 6 left lock groove, 7 lock block, 8 inner wall convex ring, 9 lock block sliding groove, 10 lower ring groove, 11 lower steel ball guide hole, 12 lower steel ball, 13 piston cylinder, 14 lower steel ball lock groove, 15 non-similar redundancy inlet, 16 lead screw, 17 collar, 18 right return spring, 19 lead screw nut, 20 upper locking bushing on the right, 21 dual-redundancy locking spring, 22 redundancy unlocking bushing, 23 upper locking bushing on the left, 24 left return spring, 25 servo motor, 26 transmission gear.

[0014] The present invention will be further described below in conjunction with the accompanying drawings and embodiments, but the present invention is not limited to the scope of the described embodiments. All these concepts should be regarded as the disclosed content of the present technology and the protection scope of the present invention. Specific embodiments

[0015] Refer to Figure 1 . In the preferred embodiment described below, a non-similar dual-redundancy electro-mechanical actuator includes: a servo motor 25 whose output gear extends axially from one side of the actuator cylinder 1 into the transmission cavity and meshes with the transmission gear 26, a lead screw 16 whose end gear is meshed with the transmission gear 26, a hollow piston cylinder 13 that moves telescopically in the actuator cylinder 1 and a hollow piston head facing the bottom end of the cylinder, and a lead screw 16 sleeved with a lead screw nut 19, wherein: the actuator cylinder 1 is provided with a non-similar energy inlet 2 that radially communicates with the bottom cavity and a non-similar redundancy inlet 15 that radially communicates with the front movement cavity. An upper ball lock groove 3 for locking the upper ball 4 is formed on the inner wall of the adjacent non-similar energy inlet 2. When the piston cylinder 13 retracts, the piston head locks the upper ball 4 in the upper ball guide hole 5, and at the same time locks the lower ball 12 in the lower ball guide hole 11. A non-similar dual-redundancy automatic lock assembly for controlling the rolling locking and unlocking of the upper ball 4 and the lower ball 12 is provided in the stepped hole on the inner wall of the piston head. High-pressure medium enters the piston head from the non-similar energy inlet 2 at the rear of the actuator cylinder 1, pushing out the bottom cavity of the actuator cylinder 1 to form a high-pressure cavity, and driving the automatic lock assembly to move to the right, driving the upper ball 4 and the lower ball 12 to roll, realizing the unlocking of the mechanical lock of the piston cylinder 13. The lower ball 12 follows the piston head and rolls to the lower ball lock groove 14 on the extreme position of the inner wall of the actuator cylinder 1. The automatic lock assembly pushes the lower ball 12 into the lower ball lock groove 14, realizing the locking of the piston cylinder 13 when it extends. The retraction process is similar. High-pressure medium enters the front cavity of the actuator cylinder 1 from the non-similar redundancy inlet 15 at the end of the actuator cylinder 1, pushing the piston head to retract. The lower ball 12 disengages from the lower ball lock groove 14, driving the automatic lock assembly to move to the left, and locking the upper ball 4 in the upper ball lock groove 3, realizing the locking of the piston cylinder 13 when it retracts.

[0016] The automatic lock assembly includes: a left upper lock bushing 23 and a right upper lock bushing 20 that are closely attached to the inner wall of the stepped hole of the piston head and control the rolling locking and unlocking of the upper ball 4 and the lower ball 12, a redundancy unlocking bushing 22 that is symmetrically sleeved with the left upper lock bushing 23 and the right upper lock bushing 20 in opposite directions, a dual-redundancy locking spring 21 that is constrained in the outer ring surface of the redundancy unlocking bushing 22 and the mating annular cavity of the above-mentioned left and right upper lock bushings, a left return spring 24 and a right return spring 18 that are constrained by the three-step inner convex symmetric stepped holes on both sides of the redundancy unlocking bushing 22, and a lock block chute 9 in which the circumferentially distributed lock blocks 7 are constrained on the ring sleeves 17 and the lead screw nut 19 ring surface by the three-step inner convex ring 8 of the redundancy unlocking bushing 22.

[0017] After the upper steel ball 4 is unlocked, the end face of the ring sleeve 17 contacts the bottom end of the piston head hole, pushing the piston tube 13 to extend out of the tube mouth of the actuator cylinder 1. When it extends to the limit position, the lower steel ball 12 follows the piston head and rolls to the lower steel ball lock groove 14 on the inner wall of the actuator cylinder 1. The outer ring surface of the right upper locking bushing 20 is inserted into the lower end of the lower steel ball 12, realizing the mechanical lock of the lower steel ball 12.

[0018] The retraction process is similar. When the piston barrel 13 retracts, the high-pressure medium enters the front cavity of the actuator cylinder barrel 1 and the hollow piston head from the non-similar margin inlet 15 on the end of the actuator cylinder barrel 1. The margin unlocking sleeve 22 is pushed to the left by the high-pressure medium entering through the annular gap, compressing the left return spring 24, and pushing the margin unlocking sleeve 22 to the left until the margin unlocking sleeve 22 is compressed to the inner end face of the left flange step ring of the annular sleeve 17, and the locking block 7 of the inner wall convex ring 8 will be squeezed into the lower annular groove 10 and disengaged from the margin unlocking sleeve 22. At the same time, the high-pressure medium pushes the right locking sleeve 20, and the lower steel ball 12 follows the piston head to roll into the lower steel ball guide hole 11, and the upper steel ball 4 follows the piston head to roll to the upper steel ball lock groove 3 on the inner wall limit position of the actuator cylinder barrel 1, and the upper steel ball 4 is pushed into the upper steel ball lock groove 3 to achieve the retraction and locking of the piston barrel 13.

[0019] When the electric actuator is driven by electric energy, the output end gear of the servo motor 25 drives the end of the lead screw 16 to rotate through the transmission gear 26. The lead screw nut 19 mounted on the spiral raceway of the lead screw 16 drives the left flange step ring of the ring sleeve 17 to push the left locking bushing 23 to overcome the elastic force of the double redundant locking spring 21, and the upper steel ball 4 rolls out along the upper steel ball guide hole 5, realizing the mechanical lock unlocking of the upper steel ball 4.

[0020] The non-similar dual-redundancy electromechanical actuator is driven by a non-similar energy source different from electrical energy: hydraulic or pneumatic pressure. The high-pressure medium enters the piston head from the non-similar energy inlet 2 at the rear of the actuator cylinder 1 to push the piston head out of the bottom high-pressure chamber of the actuator cylinder 1. The redundancy unlocking bushing 22 is pushed by the high-pressure medium, compressing the right return spring 18, pushing the redundancy unlocking bushing 22 inner wall convex ring 8 to move to the right until the redundancy unlocking bushing 22 is compressed to the inner end face of the right flange step ring of the ring sleeve 17, and the locking block 7 radially disengages from the locking block slide groove 8 to the outside, disengages from the annular surface of the inner wall convex ring 8, and slides into the left lock groove 6 of the redundancy unlocking bushing 22, and the ring sleeve 17 disengages from the screw nut 19. At the same time, the high-pressure medium pushes the left upper locking bushing 23, and the upper steel ball 4 rolls out of the upper steel ball lock groove 3 and disengages from the inner ring of the upper steel ball 4, realizing the mechanical lock unlocking of the upper steel ball 4.

[0021] Without paying any creative work, the present invention can also obtain other technical solutions based on the above embodiments, and equivalent changes made within the scope of protection of the present invention should fall within the scope of protection of the present invention and belong to the scope of protection of the present invention.

Claims

1. A non-similar dual-redundancy electro-mechanical actuator, comprising: A servo motor (25) whose output end gear extends into the transmission cavity from one axial side of the actuator cylinder (1) and meshes with the transmission gear (26). The transmission gear (26) meshes with the end gear of the lead screw (16). There is a hollow piston cylinder (13) that performs telescopic movement in the actuator cylinder (1) and a hollow piston head facing the bottom end of the cylinder, as well as a lead screw (16) sleeved with a lead screw nut (19). It is characterized in that: on the actuator cylinder (1), there are non-similar energy inlets (2) radially communicating with the bottom cavity and non-similar redundancy inlets (15) radially communicating with the front movement cavity. On the inner wall of the adjacent non-similar energy inlet (2), there is an upper ball lock groove (3) for locking the upper ball (4). When the piston cylinder (13) retracts the piston head, the upper ball (4) is locked in the upper ball guiding hole (5), and at the same time, the lower ball (12) is locked in the lower ball guiding hole (11). On the stepped hole of the inner wall of the piston head, there is a non-similar dual-redundancy automatic lock assembly for controlling the rolling locking and unlocking of the upper ball (4) and the lower ball (12). High-pressure medium enters the piston head from the non-similar energy inlet (2) at the rear of the actuator cylinder (1), pushing out the bottom cavity of the actuator cylinder (1) to form a high-pressure chamber, driving the automatic lock assembly to move to the right, driving the upper ball (4) and the lower ball (12) to roll, realizing the unlocking of the mechanical lock of the piston cylinder (13). The lower ball (12) follows the piston head and rolls to the lower ball lock groove (14) at the extreme position of the inner wall of the actuator cylinder (1). The automatic lock assembly pushes the lower ball (12) into the lower ball lock groove (14), realizing the locking of the extension of the piston cylinder (13). The retraction process is similar. High-pressure medium enters the front cavity of the actuator cylinder (1) from the non-similar redundancy inlet (15) at the end of the actuator cylinder (1), pushing the piston head to retract. The lower ball (12) disengages from the lower ball lock groove (14), driving the automatic lock assembly to move to the left, locking the upper ball (4) in the upper ball lock groove (3), and realizing the locking of the retraction of the piston cylinder (13); The automatic lock assembly includes: a left upper lock bushing (23) and a right upper lock bushing (20) that are closely attached to the inner wall of the stepped hole of the piston head and control the rolling locking and unlocking of the upper ball (4) and the lower ball (12). A redundancy unlocking bushing (22) in which the left upper lock bushing (23) and the right upper lock bushing (20) are symmetrically sleeved with each other. A dual-redundancy locking spring (21) constrained in the outer ring surface of the redundancy unlocking bushing (22) and the mating ring cavity of the above left and right upper lock bushings. A left return spring (24) and a right return spring (18) constrained by the three-step inner convex symmetric stepped holes on both sides of the redundancy unlocking bushing (22), and the redundancy unlocking bushing (22) through its three-step inner wall convex ring (8) constrains the circumferentially distributed lock blocks (7) in the lock block chute (9) of the ring sleeve (17) and the necking groove on the ring surface of the lead screw nut (19).

2. The non-similar dual-redundancy electro-mechanical actuator according to claim 1, characterized in that: When the piston barrel (13) retracts, the high-pressure medium enters the front cavity of the actuator cylinder (1) and the hollow piston head from the dissimilar redundancy inlet (15) at the end of the actuator cylinder (1). The redundancy unlocking bushing (22) is pushed to move left by the high-pressure medium entering through the annular gap, compressing the left return spring (24), and pushing the redundancy unlocking bushing (22) to move left until the redundancy unlocking bushing (22) is compressed to the inner end face of the left flanging step ring of the collar (17). The inner wall convex ring (8) squeezes the locking block (7) into the lower annular groove (10), disengaging from the redundancy unlocking bushing (22). At the same time, the high-pressure medium pushes the upper right locking bushing (20), and the lower steel ball (12) rolls with the piston head into the lower steel ball guiding hole (11). The upper steel ball (4) rolls with the piston head to the upper steel ball locking groove (3) at the limit position of the inner wall of the actuator cylinder (1), and the upper steel ball (4) is pushed into the upper steel ball locking groove (3) to achieve the retraction locking of the piston barrel (13).

3. The dissimilar dual-redundancy electro-mechanical actuator according to claim 1, characterized in that: When the electro-mechanical actuator is driven by electric energy, the output end gear of the servo motor (25) drives the end gear of the lead screw (16) to rotate through the transmission gear (26). The lead screw nut (19) sleeved on the spiral raceway of the lead screw (16) drives the left flanging step ring of the collar (17) to push the upper left locking bushing (23) to move together against the elastic force of the dual-redundancy locking spring (21). The upper steel ball (4) rolls out along the upper steel ball guiding hole (5) to achieve the unlocking of the mechanical lock of the upper steel ball (4).

4. The dissimilar dual-redundancy electro-mechanical actuator according to claim 1, characterized in that: After the upper steel ball (4) is unlocked, the end face of the collar (17) abuts against the bottom end of the end hole of the piston head, pushing the piston barrel (13) to extend out of the barrel mouth of the actuator cylinder (1). When it extends to the limit position, the lower steel ball (12) rolls with the piston head to the lower steel ball locking groove (14) on the inner wall of the actuator cylinder (1), and the outer ring surface of the upper right locking bushing (20) is clamped into the lower end of the lower steel ball (12) to achieve the locking of the mechanical lock of the lower steel ball (12).

5. The dissimilar dual-redundancy electro-mechanical actuator according to claim 1, characterized in that: When the piston barrel (13) retracts, the high-pressure medium enters the front cavity of the actuator cylinder (1) and the hollow piston head from the dissimilar redundancy inlet (15) at the end of the actuator cylinder (1). The redundancy unlocking bushing (22) is pushed to move left by the high-pressure medium, compressing the left return spring (24), and pushing the inner wall convex ring (8) of the redundancy unlocking bushing (22) to move left until the redundancy unlocking bushing (22) is compressed to the inner end face of the left flanging step ring of the collar (17). The locking block (7) disengages from the inner wall convex ring (8) of the redundancy unlocking bushing (22) and is squeezed into the lower annular groove (10). At the same time, the high-pressure medium pushes the upper right locking bushing (20) to disengage from the inner ring of the lower steel ball (12), and the lower steel ball (12) rolls with the piston head into the lower steel ball guiding hole (11), and the lower steel ball (12) disengages from the lower steel ball locking groove (14) to achieve the unlocking of the mechanical lock of the lower steel ball (12).

6. The dissimilar dual-redundancy electro-mechanical actuator according to claim 3, It is characterized in that: When the dissimilar dual-redundancy electro-mechanical actuator is driven by a dissimilar energy source different from electrical energy, i.e., hydraulic or pneumatic pressure, the high-pressure medium enters from the dissimilar energy source inlet (2) at the rear of the actuator cylinder (1), pushes the piston head to move forward and vacate the high-pressure chamber at the bottom of the actuator cylinder (1). The redundancy unlocking bushing (22) is pushed by the high-pressure medium, compresses the right return spring (18), and pushes the inner wall convex ring (8) of the redundancy unlocking bushing (22) to move to the right until the redundancy unlocking bushing (22) is compressed to the inner end face of the right flanging step ring of the collar (17). The lock block 7 radially disengages outward from the lock block chute (9), disengages from the ring surface of the inner wall convex ring (8), and slides into the left lock groove (6) of the redundancy unlocking bushing (22). The collar (17) disengages from the lead screw nut (19). At the same time, the high-pressure medium pushes the upper-position locking bushing (23) to disengage from the inner ring of the upper-position steel ball (4), and the upper-position steel ball (4) rolls and disengages from the upper-position steel ball lock groove (3), realizing the unlocking of the mechanical lock of the upper-position steel ball (4).

7. The dissimilar dual-redundancy electro-mechanical actuator according to claim 5, It is characterized in that: After unlocking, the high-pressure medium pushes the piston cylinder (13) to retract. The lock block (7) slides along the inner wall convex ring (8) of the redundancy unlocking bushing (22). When retracted to the limit position, it slides into the lower ring groove (10). The collar (17) disengages from the lead screw nut (19). The elastic force of the dual-redundancy locking spring (21) pushes the upper-position locking bushing (23), and the upper-position steel ball (4) rolls along the upper-position steel ball guide hole (5) to lock the upper-position steel ball (4) into the upper-position steel ball lock groove (3), realizing the locking of the mechanical lock of the upper-position steel ball (4).

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