Electromechanical actuator with dissimilar energy emergency

Abstract

The emergency unlocking device comprises a driving mechanism, an outer cylinder, a lead screw, a piston rod, a lead screw nut, an emergency unlocking mechanism and a driving sleeve. A piston rod is arranged in the outer cylinder, a lead screw is arranged in an inner cavity of the piston rod, and the lead screw is connected with the piston rod through a lead screw nut; the driving end of the driving mechanism is connected with the lead screw through a driving sleeve, the other end of the driving sleeve is connected with the lead screw through an emergency unlocking mechanism, and an emergency energy inlet is formed in one side of the outer barrel and used for guiding high-pressure media of non-similar energy into a cavity of the outer barrel during emergency work and driving the emergency unlocking mechanism to unlock the lead screw. The lead screw and the driving sleeve are unlocked, so that the high-pressure medium pushes the piston rod to drive the lead screw nut and the lead screw to overcome the load to extend out, and the piston rod extending task is completed. The device has the advantages of being simple in structure, simple, compact, reliable in performance, small in occupied space, capable of guaranteeing flight safety of the airplane and independent of electric power.

Description

Technical Field

[0001] This invention belongs to the technical field of electromechanical actuators, specifically relating to an electromechanical actuator capable of providing emergency response to dissimilar energy sources. Background Technology

[0002] With the development of modern technology, the mission functions of small or unmanned aerial vehicles (UAVs) have undergone significant development and changes. In emergency situations, aircraft must be able to land safely to protect advanced and expensive onboard equipment and mission-specific equipment. The landing gear of small or unmanned aerial vehicles should have emergency unlocking, safe and rapid deployment, and automatic locking functions. Specifically, the electric retraction actuator is controlled by the aircraft's electrical control system. In the event of an emergency such as a malfunction of the electrical control system or damage to the control system equipment, the upper mechanical lock inside the electric retraction actuator will not be able to open, the electric retraction actuator will not be able to deploy, the aircraft landing gear will not be able to deploy and lock normally, and the aircraft will be unable to land safely, potentially leading to a serious catastrophic accident.

[0003] An actuator, as a linear motion execution element of aircraft landing gear, is an energy conversion device used to achieve linear reciprocating motion or less than 360° motion of the working mechanism. The basic components of a common electromechanical actuator are as follows: motor, gearbox, transmission components, ball screw pair, outer cylinder assembly, piston rod assembly, self-locking assembly, etc. Electromechanical actuators with a self-locking device prevent lateral movement caused by external forces when stopped at a defined position; this is usually achieved by a mechanical lock within the actuator cylinder. The most common type of mechanical lock is a ball lock, which consists of a ball lock, lock groove, conical piston, and spring. In the event of a power failure in the system or a failure of closed-loop position control, the rigid collision and compression between the inner end faces of the ball screw pair at the extreme positions of the electromechanical actuator can cause deformation of the ball screw pair's helical raceway, increasing the clearance, reducing the accuracy of the helical transmission, and even causing the ball screw pair to jam, resulting in the loss of electromechanical actuator function. Generally, actuators with emergency functions are used, but the installation space for these actuators is very limited. Commonly used actuators are electromechanical actuators and hydraulic actuators. Electromechanical actuators have complex emergency response mechanisms. Existing hydraulic actuators have a long axial length, which is not conducive to installation. In addition, their emergency response mechanisms mostly use pneumatic methods and require a dedicated air source.

[0004] Currently, electromechanical actuators, as transmission mechanisms, function 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 amplification. 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 amplification. Since modern aircraft landing gear is typically retractable, usually using hydraulics for normal retraction and extension, if a malfunction occurs in the aircraft's hydraulic or electrical systems, preventing the landing gear from being lowered normally, the aircraft must have measures for manual emergency landing gear deployment. The performance of these measures directly affects the aircraft's safety.

[0005] 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 for aircraft landing gear retraction and extension, a certain safety margin is essential. Commonly used electromechanical actuators with redundancy design employ a backup motor; when the main motor fails, the backup motor activates to achieve emergency deployment or retraction of the piston rod. Conventional dual-redundant electromechanical actuators still rely on electricity for emergency deployment and retraction, posing certain safety hazards, resulting in low safety, low reliability, and limited practicality. Summary of the Invention

[0006] The purpose of this invention is to provide an electromechanical actuator capable of providing emergency response to dissimilar energy sources, thereby addressing the aforementioned problems.

[0007] This invention is mainly achieved through the following technical solutions: An electromechanical actuator with an alternative energy source for emergency response includes a drive mechanism, an outer cylinder, a lead screw, a piston rod, a lead screw nut, an emergency unlocking mechanism, and a drive sleeve. The piston rod is housed inside the outer cylinder, and a lead screw is housed within the inner cavity of the piston rod. The lead screw is connected to the piston rod via a lead screw nut. The drive end of the drive mechanism is connected to the lead screw via the drive sleeve, and the other end of the drive sleeve is connected to the lead screw via the emergency unlocking mechanism. An emergency energy inlet is located on one side of the outer cylinder. During emergency operation, a high-pressure medium of an alternative energy source is introduced into the cavity of the outer cylinder to drive the emergency unlocking mechanism, unlocking the lead screw and drive sleeve. This allows the high-pressure medium to push the piston rod, causing the lead screw nut and lead screw to extend over the load, thus extending the piston rod.

[0008] To better realize the present invention, the emergency unlocking mechanism further includes a locking shaft, steel balls, and a spring. The screw and the drive sleeve are respectively provided with an installation cavity and an unlocking cavity on opposite sides. One end of the locking shaft is slidably connected to the installation cavity, and the other end is connected to the unlocking cavity through the spring. Several steel balls are limited and abutted against the outer circumferential side of the locking shaft. One side of the steel balls passes through the screw and is locked with the drive sleeve. The emergency energy inlet is used to introduce a high-pressure medium of dissimilar energy into the cavity of the outer cylinder during emergency operation, pushing the locking shaft to overcome the spring force and disengage it from the inner ring of the circumferentially distributed steel balls, thereby unlocking the screw and the drive sleeve.

[0009] To better realize the present invention, one end of the lead screw is slidably connected to the end of the unlocking cavity of the drive sleeve, and a limiting step is correspondingly provided inside the unlocking cavity; a steel ball hole is provided circumferentially in the mounting cavity, and an annular locking groove is correspondingly provided on the circumferential sidewall of the unlocking cavity; the steel balls are evenly distributed in the steel ball hole, the outer ring of the steel ball is fitted in the corresponding annular locking groove of the gear sleeve, and the inner ring of the steel ball abuts against the locking shaft, so that the steel ball is radially limited by the locking shaft.

[0010] To better realize the present invention, the driving mechanism further includes a servo motor and a motor shaft connecting disc gear transmission mechanism, and a gear is correspondingly provided at one end of the driving sleeve; the servo motor meshes with the gear of the driving sleeve through the motor shaft connecting disc gear transmission mechanism, and is used to drive the lead screw to rotate, and drive the lead screw nut to drive the fitted piston rod to perform telescopic movement.

[0011] To better realize the present invention, a servo motor is further provided below the outer cylinder.

[0012] To better realize the present invention, the circumference of the driving outer cylinder is further rotatably connected to the outer cylinder via a bearing.

[0013] The beneficial effects of this invention are as follows: (1) This invention, when applied as an emergency extension structure on an electromechanical actuator, can improve the safety and reliability of the actuator and realize a multi-medium extension piston rod structure. This invention has the advantages of simple and compact structure, reliable performance, small footprint, ensuring aircraft flight safety, and independence from electricity. This invention effectively solves the problem that conventional dual-redundant electromechanical actuators still rely on electricity for emergency deployment and retraction, and cannot isolate lead screw jamming faults. It realizes multi-redundant emergency operation with different working media and also has an emergency extension function.

[0014] (2) The present invention uses high pressure medium to push the locking shaft to retract, so that the steel ball connecting the drive sleeve and the lead screw is unlocked, the drive sleeve is disengaged from the lead screw, and at the same time the high pressure medium pushes the piston rod to extend. In the case of the actuator losing power or the lead screw pair being stuck, it effectively solves the problem that conventional dual-redundant electromechanical actuators still need to rely on electricity to achieve emergency release and the single-point fault problem of lead screw pair being stuck, and has good practicality. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the electromechanical actuator of the present invention, which provides emergency response to dissimilar energy sources.

[0016] Among them: 1-outer cylinder, 2-emergency energy inlet, 3-lead screw nut, 4-lead screw, 5-piston rod, 6-motor, 7-steel ball, 8-locking shaft, 9-drive sleeve, 10-spring. Detailed Implementation

[0017] Example 1: An electromechanical actuator with an emergency dissimilar energy source includes: a drive mechanism, an outer cylinder 1, a lead screw 4, a piston rod 5, a lead screw nut 3, an emergency unlocking mechanism, and a drive sleeve 9. The piston rod 5 is housed inside the outer cylinder 1, and the lead screw 4 is housed within the inner cavity of the piston rod 5. The lead screw 4 is connected to the piston rod 5 via the lead screw nut 3. The drive end of the drive mechanism is connected to the lead screw 4 via the drive sleeve 9, and the other end of the drive sleeve 9 is connected to the lead screw 4 via the emergency unlocking mechanism. An emergency energy inlet 2 is provided on one side of the outer cylinder 1, used to introduce a high-pressure medium of a dissimilar energy source into the cavity of the outer cylinder 1 during emergency operation. This drives the emergency unlocking mechanism, unlocking the lead screw 4 and the drive sleeve 9, so that the high-pressure medium pushes the piston rod 5, causing the lead screw nut 3 and the lead screw 4 to extend over the load, completing the task of extending the piston rod 5.

[0018] Preferably, such as Figure 1 As shown, the emergency unlocking mechanism includes a locking shaft 8, steel balls 7, and a spring 10. The screw 4 and the drive sleeve 9 are respectively provided with an installation cavity and an unlocking cavity on opposite sides. One end of the locking shaft 8 is slidably connected to the installation cavity, and the other end is connected to the unlocking cavity through the spring 10. Several steel balls 7 are limited and abutted against the outer circumferential side of the locking shaft 8. One side of the steel balls 7 passes through the screw 4 and is locked in place with the drive sleeve 9. The emergency energy inlet 2 is used to introduce a high-pressure medium of dissimilar energy into the cavity of the outer cylinder 1 during emergency operation, pushing the locking shaft 8 to overcome the elastic force of the spring 10, causing it to disengage from the inner ring of the circumferentially distributed steel balls 7, thus unlocking the screw 4 and the drive sleeve 9.

[0019] One end of the lead screw 4 is slidably connected to the end of the unlocking cavity of the drive sleeve 9, and a limiting step is correspondingly provided inside the unlocking cavity; the mounting cavity is provided with a steel ball 7 hole in the circumferential direction, and the circumferential sidewall of the unlocking cavity is correspondingly provided with an annular locking groove; the steel balls 7 are evenly distributed in the steel ball 7 hole, the outer ring of the steel ball 7 is fitted in the corresponding annular locking groove of the gear sleeve, and the inner ring of the steel ball 7 abuts against the locking shaft 8, so that the steel ball 7 is radially limited by the locking shaft 8.

[0020] In use, the servo motor 6 is connected to the gear on the outside of the drive sleeve 9 in the sealed cavity of the outer cylinder 1 via a gear transmission mechanism connected to the motor shaft 6. The drive sleeve 9 is assembled in the sealed cavity of the outer cylinder 1 and meshes with the gear transmission mechanism connected to the motor shaft 6. The piston rod 5 extends and retracts in the sealed cavity of the outer cylinder 1. The lead screw nut 3 is nested in the piston head. The steel balls 7 are evenly distributed in the steel ball holes of the lead screw 4. The outer ring of the steel balls 7 fits in the corresponding annular locking groove of the drive sleeve 9. The steel balls 7 are radially limited by the locking shaft 8, which is held in the locked position by the elastic force of the spring 10.

[0021] The servo motor 6 drives the sleeve 9 to rotate through the gear transmission mechanism of the motor 6 shaft connection disc, which in turn drives the lead screw 4 to rotate, driving the lead screw nut 3 to drive the fitted piston rod 5 to perform telescopic movement. In emergency operation, a high-pressure medium, which is different from electrical energy, enters the cavity of the outer cylinder 1 through the emergency energy inlet 2 on the outer ring surface of the outer cylinder 1, pushing the locking shaft 8 to overcome the elastic force of the spring 10 and disengage from the inner ring of the circumferentially distributed steel balls 7. The steel balls 7 roll radially inward along the holes of the steel balls 7 evenly distributed in the lead screw 4, disengaging from the annular locking groove of the drive sleeve 9. The steel ball 7 lock is unlocked in an emergency, and the high-pressure medium pushes the piston rod 5 to drive the lead screw nut 3 and the lead screw 4 to extend over the load. In the case of actuator power failure or lead screw 4 jamming, the task of extending the piston rod 5 is completed.

[0022] This invention uses a high-pressure medium to push the locking shaft 8 back, thereby unlocking the steel ball 7 connecting the drive sleeve 9 and the lead screw 4, disengaging the drive sleeve 9 from the lead screw 4. At the same time, the high-pressure medium pushes the piston rod 5 to extend. In the case of power failure of the actuator or jamming of the lead screw 4, this invention effectively solves the problem of single-point failure of conventional dual-redundant electromechanical actuators that still rely on electricity for emergency release and the problem of jamming of the lead screw 4.

[0023] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. An electromechanical actuator capable of providing emergency response to dissimilar energy sources, characterized in that, The device includes a drive mechanism, an outer cylinder (1), a lead screw (4), a piston rod (5), a lead screw nut (3), an emergency unlocking mechanism, and a drive sleeve (9). The piston rod (5) is installed inside the outer cylinder (1), and the lead screw (4) is installed in the inner cavity of the piston rod (5). The lead screw (4) is connected to the piston rod (5) through the lead screw nut (3). The drive end of the drive mechanism is connected to the lead screw (4) through the drive sleeve (9), and the other end of the drive sleeve (9) is connected to the lead screw (4) through the emergency unlocking mechanism. An emergency energy inlet (2) is provided on one side of the outer cylinder (1) for introducing a high-pressure medium of dissimilar energy into the cavity of the outer cylinder (1) during emergency work, driving the emergency unlocking mechanism to unlock the lead screw (4) and the drive sleeve (9), so that the high-pressure medium pushes the piston rod (5) to drive the lead screw nut (3) and the lead screw (4) to overcome the load and extend, thus completing the task of extending the piston rod (5).

2. The electromechanical actuator with dissimilar energy emergency response capability according to claim 1, characterized in that, The emergency unlocking mechanism includes a locking shaft (8), steel balls (7) and a spring (10). The screw (4) and the drive sleeve (9) are respectively provided with an installation cavity and an unlocking cavity on opposite sides. One end of the locking shaft (8) is slidably connected to the installation cavity, and the other end is connected to the unlocking cavity through the spring (10). Several steel balls (7) are limited and abutted against the outer circumferential side of the locking shaft (8). One side of the steel balls (7) passes through the screw (4) and is locked with the drive sleeve (9). The emergency energy inlet (2) is used to introduce a high-pressure medium of dissimilar energy into the cavity of the outer cylinder (1) during emergency work, push the locking shaft (8) to overcome the elastic force of the spring (10), and make it disengage from the inner ring of the circumferentially distributed steel balls (7), thereby unlocking the screw (4) and the drive sleeve (9).

3. An electromechanical actuator with dissimilar energy emergency response capability according to claim 2, characterized in that, One end of the lead screw (4) is slidably connected to the end of the unlocking cavity of the drive sleeve (9), and a limiting step is correspondingly provided inside the unlocking cavity; a steel ball (7) hole is provided in the circumferential direction of the mounting cavity, and an annular locking groove is correspondingly provided on the circumferential sidewall of the unlocking cavity; the steel balls (7) are evenly distributed in the steel ball (7) hole, the outer ring of the steel ball (7) is fitted in the corresponding annular locking groove of the gear sleeve, and the inner ring of the steel ball (7) abuts against the locking shaft (8) so that the steel ball (7) is radially limited by the locking shaft (8).

4. An electromechanical actuator with dissimilar energy emergency response capability according to claim 1, characterized in that, The drive mechanism includes a servo motor (6) and a gear transmission mechanism for the motor (6) shaft connecting disc. A gear is provided at one end of the drive sleeve (9). The servo motor (6) meshes with the gear of the drive sleeve (9) through the gear transmission mechanism for the motor (6) shaft connecting disc, and is used to drive the lead screw (4) to rotate. The lead screw nut (3) drives the fitted piston rod (5) to perform telescopic movement.

5. An electromechanical actuator with dissimilar energy emergency response capability according to claim 4, characterized in that, A servo motor (6) is provided below the outer cylinder (1).

6. An electromechanical actuator with dissimilar energy emergency response capability according to claim 1, 4, or 5, characterized in that, The circumference of the drive outer cylinder (1) is rotatably connected to the outer cylinder (1) via bearings.

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