Heavy load take-up and pay-off electro-actuator with non-similar energy emergency extension function

Abstract

The heavy load retractable electromechanical actuator with the non-similar energy emergency extension function can improve the safety of the heavy load retractable electromechanical actuator and realize the redundancy emergency lowering of the piston cylinder of different working media. The piston cylinder inner wall is provided with a boss locking ring, the finger-shaped locking jaw neck groove is embedded in the boss locking ring, the end flange locking jaw inner ring is tightly attached to the outer ring surface of the upper locking bush constrained in the piston cylinder ring cavity by the spring, the flange locking jaw on the end is kept in the locking groove of the boss locking ring, the emergency unlocking mechanism and the emergency forced unlocking function locking mechanism can be unlocked by the emergency medium, when the screw pair is stuck and needs to be extended, the high-pressure medium pushes the upper locking bush to overcome the spring force and is separated from the flange locking jaw inner ring of the finger-shaped locking jaw locking cylinder, is slid off and is moved to the lock release position, the finger-shaped locking jaw locking cylinder is separated from the piston cylinder, the high-pressure medium pushes the piston cylinder to extend, and the emergency extension of the electromechanical actuator is realized.

Description

Technical Field

[0001] This invention relates to actuators widely used in various power devices, especially emergency release structures for electromechanical actuators. More specifically, this invention relates to an innovative structure that improves the safety of heavy-duty retraction and deployment electromechanical actuators by utilizing dissimilar energy sources, such as high-pressure media, to achieve emergency unlocking and lowering of the piston cylinder. Background Technology

[0002] Typically, aircraft landing gear retraction and extension mechanisms primarily utilize hydraulic actuators. In the event of power source failure, the hydraulic actuators release pressure via bypass valves or exhaust valves, allowing the landing gear to lower and lock freely under its own weight and auxiliary aerodynamic force. Traditional hydraulic landing gear retraction and extension systems suffer from drawbacks such as heavy weight, high failure rate, and low efficiency, severely impacting aircraft performance. With technological advancements, electric actuators have been applied to landing gear retraction and extension. Electric retraction and extension systems represent a special application of electromechanical actuation systems in aircraft landing gear. Besides linear drive functionality, they must also lock at designated positions and withstand significant loads. The electric retraction and extension actuator is the main functional component responsible for landing gear retraction and extension. As a linear motion actuator, the electric actuator is an energy conversion device used to achieve linear reciprocating motion or less than 360° oscillating motion of the working mechanism. The basic components of a common electric actuator include: a motor, gearbox, transmission components, ball screw pair, outer cylinder assembly, piston cylinder assembly, and self-locking assembly. An electrically operated actuator with a self-locking device prevents lateral movement caused by external forces when it stops at a designated position. This is typically secured by a mechanical lock within the actuator. The most common type of mechanical lock is a ball lock, which consists of a ball, a locking groove, a conical piston, and a spring. The landing gear electric retraction actuator operates frequently and retracts and extends many times. When the landing gear retraction system malfunctions, the landing gear must be able to extend in an emergency; therefore, the electric retraction actuator must have an emergency extension function. When the landing gear retraction system is stationary, the piston rod of the landing gear retraction actuator may spontaneously extend. The piston rod extends approximately...

[0003] The piston rod end of the retraction / extension actuator did not experience relative displacement (3mm). Traditional electric actuators primarily rely on a motor-driven brake; when the actuator is at its end position, the motor and brake mechanism are de-energized, and the brake, under spring pressure, holds the motor in place. A drawback of this locking device is its inability to withstand the massive impact loads of aircraft landing. In applications with high safety requirements, such as electromechanical actuators used for aircraft landing gear retraction / extension, external mechanical locks are often used instead of internal mechanical locks to bear heavy loads. This locking device is a strut lock; the strut folds when the landing gear retracts and unfolds when it extends, locking the landing gear and bearing the landing load. Therefore, the actuator must have a certain safety margin to ensure the landing gear can still be deployed smoothly in emergency situations. Commonly used electromechanical actuators with redundancy design have a backup motor. When the main motor fails, the backup motor works to achieve emergency lowering or retraction of the piston cylinder. Conventional heavy-duty retraction electromechanical actuators with single redundancy design are not safe enough. This structure cannot solve the problem of emergency lowering or retraction when the lead screw, gear, reducer, etc. are jammed. Summary of the Invention

[0004] The purpose of this invention is to address the problem of existing technologies failing to solve the issue of emergency lowering or retraction when lead screws, gears, reducers, etc., are jammed. This invention provides a solution with a simple structure that improves the safety of heavy-duty retraction electromechanical actuators, enables the use of redundant emergency lowering piston cylinders for different working media, and allows for emergency lowering of the piston cylinder without relying on electricity. This effectively solves the problem that conventional dual-redundant electromechanical actuators still require electricity for emergency lowering, and that they cannot function when lead screws, gears, reducers, and other transmission components are jammed.

[0005] The technical solution adopted by this invention to solve its technical problem is: a heavy-duty retractable electromechanical actuator with an emergency extension function of dissimilar energy, comprising: a gear reduction transmission mechanism with a gearbox on one side of the outer cylinder 2 connected radially to the gears via a servo motor spindle; a piston cylinder 3 assembled in the outer cylinder 2 with an emergency air inlet 1; a piston cylinder 3 forming a locking groove 5 with the inner wall of the outer cylinder 2; and a lead screw 8 extending into the piston cylinder 3 via ball bearings and a lead screw nut 7. The characteristic feature is that: a finger-shaped locking pawl locking cylinder 4 connected in the form of a stepped cylinder at the end of the lead screw nut 7 is screwed onto the outer circumference of the end of the lead screw nut 7; a locking ring with a boss on the inner wall of the piston cylinder 3 is radially embedded in the necking groove of the finger-shaped locking pawl locking cylinder 4; a locking bushing 6 providing locking force is radially coupled to the inner annular surface of the finger-shaped locking pawl locking cylinder 4; and a locking ring with a boss on the inner wall of the piston cylinder 3. The stepped protruding ring at the end of the locking bushing 6, which is sealed by a stepped hole ring, constrains the spring 9, which is fitted on the small end of the locking bushing 6, to the end face of the stepped ring cavity of the piston cylinder, forming an emergency unlocking mechanism that can be unlocked by emergency medium and a locking mechanism with emergency forced unlocking function. When the lead screw is stuck and the piston cylinder 3 needs to be extended in an emergency, a non-similar energy source, such as an emergency high-pressure medium, enters the actuator cavity from the air inlet 1 of the outer cylinder 2. The high-pressure medium pushes the locking bushing 6 to overcome the elastic force of the spring 9 and disengage from the inner ring of the flange lock claw of the finger-shaped lock claw cylinder 4. The flange lock claw slides out from the inner ring arc surface of the lock groove 5 and moves to the unlocked position. The finger-shaped lock claw cylinder 4 disengages from the piston cylinder 3, and the high-pressure medium pushes the piston cylinder 3 to extend, realizing the emergency extension of the piston cylinder 3 of the electromechanical actuator.

[0006] The gear transmission mechanism drives the lead screw 8 to rotate, which in turn drives the screw nut 7 to drive the threaded finger-shaped locking cylinder 4 to move linearly and synchronously. This drives the locking surface of the boss locking ring to move the piston cylinder 3, thus realizing the normal retraction and extension of the piston cylinder 3 of the electromechanical actuator.

[0007] Compared with the prior art, the present invention has the following advantages:

[0008] This invention employs a piston cylinder 3 with a locking groove 5, assembled within an outer cylinder 2 containing an emergency air inlet 1. A gear reduction transmission mechanism is radially connected to the main shaft of a servo motor. A lead screw 8, extending into the hollow cavity of the piston cylinder 3 via ball bearings and a lead screw nut 7, is screwed onto the outer circumference of the end of the lead screw nut 7. A finger-shaped locking pawl 4 with a necking groove is screwed onto the end of the lead screw nut 7. A locking bushing 6, coupled to the finger-shaped locking pawl 4 and providing locking force, completes the heavy-duty retraction and deployment electromechanical actuator. This actuator boasts a simple structure, reliable performance, and high mechanical strength. Because the step-driven piston cylinder 3 of the finger-shaped locking pawl 4 makes surface contact with the piston cylinder 3, and the flange-driven locking pawl of the finger-shaped locking pawl 4 pulls the piston cylinder 3 in surface contact, the electromechanical actuator can withstand heavy-duty retraction and deployment. Therefore, it can withstand large stable and dynamic loads, improving the safety of the heavy-duty retraction and deployment electromechanical actuator.

[0009] This invention uses a finger-shaped locking claw to hold the flange locking claw at the end of the locking cylinder 4 within the locking groove 5 of the aforementioned boss locking ring. The resulting emergency unlocking mechanism, which can be unlocked by an emergency medium, and the locking mechanism with an emergency forced unlocking function, effectively prevent jamming. It avoids serious equipment accidents caused by jammed transmission components such as the lead screw in the actuator cylinder, which prevent the cylinder from opening. This effectively solves the problem that conventional dual-redundant electromechanical actuators still rely on electricity for emergency release, and that they cannot operate when transmission components such as the lead screw, gears, and reducers are jammed. When the electromechanical actuator cylinder is functioning normally, the locking mechanism is in a locked state. The lead screw nut 7 drives the threadedly connected finger-shaped locking claw cylinder 4 to move linearly and synchronously, thereby driving the piston cylinder 3 to overcome heavy loads through the flange locking claw of the finger-shaped locking claw cylinder 4. In case of emergency operation, the emergency medium entering the actuator can push the locking bushing 6 out of the inner ring of the flange locking claw of the finger-shaped locking claw cylinder 4, causing the flange locking claw of the finger-shaped locking claw cylinder 4 to disengage from the locking groove 5, thereby unlocking the piston cylinder 3 and the finger-shaped locking claw cylinder 4, and pushing the piston cylinder 3 out. Because the step of the finger-shaped locking claw cylinder 4 pushes the piston cylinder 3 into surface contact, and the flange locking claw of the finger-shaped locking claw cylinder 4 pulls the piston cylinder 3 into surface contact, the electromechanical actuator can withstand heavy loads for retraction and extension. When the transmission component is jammed or loses power and an emergency extension of the piston cylinder 3 is required, emergency high-pressure gas or other high-pressure medium enters the actuator from the air inlet 1 of the outer cylinder 2. The high-pressure gas pushes the locking bushing 6 to overcome the elastic force of the spring 9 and disengage from the inner ring of the flange locking claw of the finger-shaped locking claw cylinder 4, allowing the flange locking claw of the finger-shaped locking claw cylinder 4 to disengage from the locking groove 5 of the piston cylinder 3 to unlock. The high-pressure medium pushes the piston cylinder 3 out, realizing the emergency extension. It effectively solves the problem of insufficient safety due to the single-redundancy design of conventional heavy-duty take-up and take-down electromechanical actuators.

[0010] This invention utilizes a dissimilar energy source, such as an emergency high-pressure medium, which enters the actuator cavity through the air inlet 1 of the outer cylinder 2. The high-pressure medium pushes the locking bushing 6 to overcome the spring force of the spring 9 and disengage from the inner ring of the flange locking claw of the finger-shaped locking claw cylinder 4. The flange locking claw then slides out of the inner ring arc surface of the locking groove 5 and moves to the unlocked position, disengaging the finger-shaped locking claw cylinder 4 from the piston cylinder 3. The high-pressure medium then pushes the piston cylinder 3 to extend. This rapid and thorough separation, along with quick and smooth unlocking and accurate operation, allows for emergency deployment or retraction without the need for electricity. This invention is applicable to emergency actuation schemes using dissimilar energy sources for heavy-duty deployment and retraction electromechanical actuators.

[0011] This invention utilizes a dissimilar energy source, different from electrical energy, to isolate faults such as jamming of moving parts like the lead screw assembly and to provide an emergency extension of the piston cylinder 3. By constructing an emergency unlocking mechanism that can be unlocked by an emergency medium and a locking mechanism with an emergency forced unlocking function between the piston cylinder 3 and the lead screw nut 7, the locking mechanism can be unlocked by the emergency medium in emergency situations such as lead screw assembly jamming, thus disengaging the piston rod 3 from the lead screw nut 7. This improves the safety of heavy-duty retractor-deployment electromechanical actuators and enables emergency unlocking and piston cylinder deployment using a dissimilar energy source, such as a high-pressure medium. Attached Figure Description

[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.

[0013] Figure 1 This is a schematic diagram of the normal operating state of a heavy-duty retractable electromechanical actuator with an emergency extension function for non-similar energy sources.

[0014] Figure 2 yes Figure 1 Schematic diagram of a finger-shaped locking claw of an electromechanical actuator.

[0015] In the diagram: 1. Air inlet, 2. Outer cylinder, 3. Piston cylinder, 4. Finger-shaped locking claw, 5. Locking groove, 6. Locking bushing, 7. Lead screw nut, 8. Lead screw, 9. Spring. Detailed Implementation

[0016] See Figure 1 , Figure 2In the preferred embodiment described below, a heavy-duty retractable electromechanical actuator with an emergency extension function for dissimilar energy sources includes: a gear reduction transmission mechanism with a gearbox on one side of the outer cylinder 2 connected radially to the gears via a servo motor spindle; a piston cylinder 3 assembled in the outer cylinder 2 with an emergency air inlet 1; a piston cylinder 3 forming a locking groove 5 with the inner wall of the outer cylinder 2; and a lead screw 8 extending into the piston cylinder 3 via ball bearings and a lead screw nut 7. The characteristic feature is that: a finger-shaped locking pawl lock cylinder 4 connected in the form of a stepped cylinder at the end of the lead screw nut 7 is screwed onto the outer circumference of the end of the lead screw nut 7; a locking ring with a boss on the inner wall of the piston cylinder 3 is radially embedded in the necked groove of the finger-shaped locking pawl lock cylinder 4; a locking bushing 6 providing locking force is radially coupled to the inner annular surface of the finger-shaped locking pawl lock cylinder 4; and the inner wall of the piston cylinder 3 has a boss... The stepped protruding ring at the end of the locking bushing 6, which is sealed by the stepped hole ring of the locking ring, constrains the spring 9, which is fitted on the small end of the locking bushing 6, to the end face of the stepped ring cavity of the piston cylinder, forming an emergency unlocking mechanism that can be unlocked by emergency medium and a locking mechanism with emergency forced unlocking function. When the lead screw is stuck and the piston cylinder 3 needs to be extended in an emergency, the emergency high-pressure medium enters the actuator cavity from the air inlet 1 of the outer cylinder 2. The high-pressure medium pushes the locking bushing 6 to overcome the elastic force of the spring 9 and disengage from the inner ring of the flange lock claw of the finger-shaped lock claw cylinder 4. The flange lock claw slides out from the inner ring arc surface of the lock groove 5 and moves to the unlocked position. The finger-shaped lock claw cylinder 4 disengages from the piston cylinder 3, and the high-pressure medium pushes the piston cylinder 3 to extend, realizing the emergency extension of the piston cylinder 3 of the electromechanical actuator.

[0017] The locking bushing 6 is a stepped cylinder body that is sealed in the hollow step at the large end of the piston cylinder 3 and in the hollow sealing step hole at the front small end. The spring 9 is encapsulated between the end face of the large end step ring and the end face of the hollow step at the large end of the piston cylinder 3 by the sealing ring on the large end step ring and the sealing ring on the lower end head.

[0018] The step of the finger-shaped locking cylinder 4 pushes the protrusion of the piston cylinder 3 to engage with the locking ring. The protruding ring of the finger-shaped locking cylinder 4 pulls the piston cylinder 3 synchronously. When the transmission component is jammed or loses power and the piston cylinder 3 needs to be extended in an emergency, emergency high-pressure gas or other high-pressure medium enters the actuator from the air inlet 1 of the outer cylinder 2. [Z1] pushes the upper locking bushing 6 coupled to the finger-shaped locking cylinder 4, overcomes the elastic force of the spring 9, and disengages from the inner ring of the flange locking claw of the finger-shaped locking cylinder 4. The flange locking claw of the finger-shaped locking cylinder 4 disengages from the locking groove 5 of the piston cylinder 3 to unlock. The high-pressure medium pushes the piston cylinder 3 to extend in an emergency.

[0019] High-pressure gas pushes the locking bushing 6 to overcome the elastic force of the spring 9 and disengage from the inner ring of the flange of the finger-shaped locking cylinder 4, so that the flange of the finger-shaped locking cylinder 4 can disengage from the locking groove 5 of the piston cylinder 3 to unlock. The high-pressure medium pushes the piston cylinder 3 to extend, realizing emergency extension.

[0020] 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. A heavy load retractable electro-mechanical actuator with non-similar energy emergency extension function, comprising: A gear reduction transmission mechanism with a gearbox on one side of the outer cylinder (2) is connected to the gear radially via the main shaft of a servo motor. It is assembled in the outer cylinder (2) with an emergency air inlet (1). A piston cylinder (3) with a locking groove (5) is formed with the inner wall of the outer cylinder (2). A lead screw (8) extends into the piston cylinder (3) via a ball bearing and a lead screw nut (7). The feature is that a finger-shaped locking pawl (4) connected to the outer circle of the end of the lead screw nut (7) is screwed on. The finger-shaped locking pawl (4) is connected in the form of a stepped cylinder at the tail. The locking ring of the inner wall of the piston cylinder (3) is radially embedded in the necking groove of the finger-shaped locking pawl (4). The locking bushing (6) provides locking force by radial coupling of the inner ring surface of the finger-shaped locking pawl (4). The locking ring of the inner wall of the piston cylinder (3) is sealed at the end of the locking bushing (6) by a stepped hole ring in front of the locking ring of the inner wall of the piston cylinder (3). The stepped protruding ring constrains the spring (9) fitted on the small end of the upper locking bushing (6) to the end face of the stepped ring cavity of the piston cylinder, forming an emergency unlocking mechanism that can be unlocked by emergency medium and a locking mechanism with emergency forced unlocking function; when the lead screw pair is stuck and the piston cylinder (3) needs to be extended in an emergency, the emergency high pressure medium enters the actuator cavity from the air inlet (1) of the outer cylinder (2), and the high pressure medium pushes the upper locking bushing (6) to overcome the elastic force of the spring (9) and disengage from the inner ring of the flange lock claw of the finger-shaped lock claw lock cylinder (4). The flange lock claw slides out from the inner ring arc surface of the lock groove (5) and moves to the unlocked position to unlock. The finger-shaped lock claw lock cylinder (4) is separated from the piston cylinder (3), and the high pressure medium pushes the piston cylinder (3) to extend, realizing the emergency extension of the piston cylinder (3) of the electromechanical actuator; The locking bushing (6) is a stepped cylinder that is sealed in the hollow step at the large end of the piston cylinder (3) and in the hollow sealing step hole at the front small end. The spring (9) is encapsulated between the end face of the large end step ring and the end face of the hollow step at the large end of the piston cylinder (3) by the sealing ring on the large end step ring and the sealing ring on the lower end head.

2. The heavy-duty retractable electromechanical actuator with an emergency extension function for dissimilar energy sources as described in claim 1, characterized in that: The gear transmission mechanism drives the lead screw (8) to rotate, and through the lead screw nut (7), it drives the finger-shaped locking pawl (4) connected to it to make linear synchronous motion, which pushes the locking surface of the boss locking ring step to drive the piston cylinder (3) to move, so as to realize the normal retraction and extension of the piston cylinder (3) of the electromechanical actuator.

3. The heavy-duty retractable electromechanical actuator with an emergency extension function for dissimilar energy sources as described in claim 1, characterized in that: The step of the finger-shaped locking cylinder (4) pushes the boss locking ring of the piston cylinder (3) to match the contact surface. The convex ring locking claw of the finger-shaped locking cylinder (4) pulls the piston cylinder (3) synchronously. When the transmission component is jammed or loses power and the piston cylinder (3) needs to be extended in an emergency, emergency high-pressure gas or other high-pressure medium enters the actuator from the air inlet (1) of the outer cylinder (2), pushes the upper locking bushing (6) coupled to the finger-shaped locking cylinder (4), overcomes the elastic force of the spring (9), and disengages from the inner ring of the flange locking claw of the finger-shaped locking cylinder (4). The flange locking claw of the finger-shaped locking cylinder (4) disengages from the locking groove (5) of the piston cylinder (3) to unlock. The high-pressure medium pushes the piston cylinder (3) to extend in an emergency.

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