APU air door electric actuating mechanism

Abstract

The APU air door electric actuating mechanism comprises a first shell, a transmission assembly and a second shell which is of an L-shaped structure, a manual friction clutch is installed on the top face of the large end of the second shell, a motor is installed at the small end of the second shell, and the output end of the motor is connected with the input end of a multi-stage differential planet gear speed reducer through an electromagnetic braking clutch. The output end of the multi-stage differential planet gear speed reducer is connected with a first straight gear through a rotating shaft; a second bevel gear is mounted on a movable disc of the manual friction clutch in the vertical direction through a rotating shaft; a first bevel gear is mounted on a multi-stage planet gear of the multi-stage differential planet gear speed reducer in a differential manner, the first bevel gear is meshed with a second bevel gear, and a rotating shaft of a first straight gear penetrates through the first bevel gear; the first bevel gear is rotationally connected with the transmission assembly, the transmission assembly drives the air door to be opened or closed in a small transmission ratio mode, and the control efficiency of the air door is improved.

Description

Technical Field

[0001] This invention belongs to the technical field of aircraft APU damper control structure, and particularly relates to an APU damper electric actuation mechanism. Background Technology

[0002] The APU (Auxiliary Power Unit) of an aircraft requires precise control of its air intake and exhaust via dampers. Currently, linear actuators are commonly used in the aerospace field to drive the opening and closing of these dampers. However, existing actuators suffer from drawbacks such as insufficient control precision, poor real-time position feedback, long hand-cranking time for manual mechanisms, and poor fire resistance, making them unsuitable for engineering requirements.

[0003] In summary, the efficiency and performance of existing linear actuators for driving dampers are relatively low. Summary of the Invention

[0004] The APU damper electric actuator provided by this invention solves the technical problem of low efficiency and performance of existing linear actuators for driving dampers. The technical solution of this invention has many beneficial effects, as described below: An APU damper electric actuation mechanism is disclosed, suitable for driving aircraft dampers. The aircraft is equipped with a motor and a damper. The mechanism comprises a first housing, a transmission assembly, and a second housing arranged in an L-shape. The first housing covers the second housing at its larger end along its length. A manual friction clutch is mounted on the top surface of the larger end of the second housing, and a motor is mounted at its smaller end. The motor is equipped with an electromagnetic brake clutch and is connected to the input end of a multi-stage differential planetary gear reducer. The output end of the multi-stage differential planetary gear reducer is connected to the first spur gear through a rotating shaft. The moving disc of the manual friction clutch is equipped with a second bevel gear in the vertical direction through a rotating shaft. The multi-stage differential planetary gear reducer has a first bevel gear mounted differentially on its multi-stage planetary gears. The first bevel gear meshes with the second bevel gear, and the shaft of the first spur gear passes through the first bevel gear. The first bevel gear is rotatably connected to the transmission assembly, which drives the damper to open or close with a small transmission ratio; When the motor is used as the drive output, the moving and stationary discs of the manual friction clutch engage, and the rotation of the first bevel gear is restricted by the second bevel gear. Based on the multi-stage planetary gear differential principle, the motor transmits power to the transmission assembly through the first spur gear to open or close the damper. When the motor fails, an external manual tool is used to drive the moving and stationary discs of the manual friction clutch to separate. The second bevel gear drives the rotation of the first bevel gear. Based on the multi-stage planetary gear differential principle, the first bevel gear drives the multi-stage differential planetary gear reducer and transmits the power to the first straight gear. The first straight gear then transmits the power to the transmission assembly, and the transmission assembly drives the damper to open or close in a small transmission ratio.

[0005] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects: By arranging planetary gear reducers, multi-stage spur gear drives, and worm gear drives within a limited space, the APU damper electro-actuator mechanism achieves a compact structure and smooth transmission, while simultaneously fulfilling electric, manual, position feedback, and overtravel protection functions. The output shaft position is controlled by the voltage ratio feedback from the RVDT angular displacement sensor, improving the output shaft motion control accuracy. The small transmission ratio characteristic of the internal gear ring input and two- or multi-stage planetary gear reducer motion coupling output reduces hand-cranking time, facilitating high-temperature coating and the use of aerospace-grade carbon-graphite sealing materials. This meets the fire resistance requirements of the APU damper electro-actuator mechanism, which withstands temperatures of 1100℃±80℃ for 5 minutes. Furthermore, the position feedback from the RVDT angular displacement sensor and microswitch signal feedback improves the electric reliability of the APU damper electro-actuator mechanism. Attached Figure Description

[0006] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0007] Figure 1 This is a front view and sectional view of the overall structure of the present invention; Figure 2 This is a schematic diagram of the structure of two shells; Figure 3 This is an exploded diagram of a gear transmission. Figure 4 This is the left view of the second shell; Figure 5 This is the front sectional view of the shaft assembly; Figure 6 A schematic diagram of a sensor mounting bracket; Figure 7 Schematic diagram of the second shell; Figure 8 A schematic diagram showing the internal gear ring for the first bevel gear; Figure 9This is a schematic diagram of the assembly of the second bevel gear and the first spur gear; Figure 10 A schematic diagram showing the moving and stationary plates of a manual friction clutch, wherein... 1. Brushless DC motor; 2. Motor housing; 3. Two-stage differential planetary gear reducer; 4. First bevel gear; 5. Manual friction clutch; 5a. Second bevel gear; 6. First spur gear; 7. Second spur gear; 8. Third spur gear; 9. Mounting bracket; 10. First housing; 11. Ball screw; 12. Second housing; 13. First micro switch; 14. First cover plate; 15. Second micro switch; 16. Output shaft; 17. Shaft assembly; 17b. Sealing ring; 17c. Sealing ring cover plate; 18. Double spur gear; 19. Fifth spur gear; 20. Sixth spur gear; 21. Worm gear; 22. Worm wheel; 23. Sensor input shaft; 24. Sensor mounting bracket; 25. RVDT angular displacement sensor; 26. Guide plate; 27. First small shaft; 28. Nut; 29. ​​Second small shaft; 30. Precision screw; 31. Electromagnetic filter assembly. Detailed Implementation

[0008] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of the present invention.

[0009] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this invention, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0010] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. The drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0011] Furthermore, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that aspects can be practiced without these specific details. To enable those skilled in the art to better understand the invention, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined as "first" and "second" may explicitly or implicitly include one or more of that feature. In the description of the invention, unless otherwise stated, "a plurality of" means two or more.

[0012] like Figures 1 to 10 The APU damper electro-actuator shown is suitable for driving aircraft dampers, enabling precise control of opening and closing. Aircraft are equipped with motors and dampers. Its core purpose is to provide an APU damper electro-actuator with manual operation and short hand-cranking time. This mechanism can execute commands from the aircraft's ECU (Electronic Control Unit), driving the damper to a precise position and providing real-time position feedback. Simultaneously, in a fault mode where the electric function fails, and to support ground personnel maintaining or testing on the ground, it allows for quick manual operation to drive the damper. It includes a first housing 10, a transmission assembly, and a second housing 12 with an L-shaped structure (the smaller end of the second housing 12 is mounted on the aircraft's structural frame, such as the aircraft skin). The first housing 10 covers the larger end of the second housing 12 along its length. A prior art manual friction clutch 5 is mounted on the top surface of the larger end of the second housing 12, and a motor 1 is mounted on the smaller end. An installation area is provided between the first housing 10 and the second housing 12. An L-shaped mounting bracket 9 is provided inside the second housing 12. (See [reference]). Figure 7 As shown, the mounting bracket 9 is provided with multiple movable slots or holes for mounting parts or electronic components, wherein, The electromagnetic brake clutch of motor 1 (ensuring that motor 1 can only output and is not driven to rotate during the time of use) is connected to the input end of multi-stage differential planetary gear reducer 3. The output end of multi-stage differential planetary gear reducer 3 is connected to the first straight gear 6 through a rotating shaft. The moving plate of manual friction clutch 5 is equipped with a second bevel gear 5a in the vertical direction through a rotating shaft. The multi-stage differential planetary gear reducer 3 has a first bevel gear 4 installed in a differential manner on the multi-stage planetary gears. The first bevel gear 4 meshes with the second bevel gear 5a, and the shaft of the first straight gear 6 passes through the first bevel gear 4. The first bevel gear 4 is rotatably connected to the transmission assembly. When the ground crew manually drives the manual friction clutch 5, the transmission assembly can drive the damper to open or close in a small transmission ratio. When the motor 1 is used as the drive output, the moving plate and stationary plate of the manual friction clutch 5 are engaged, and the rotation of the first bevel gear 4 is restricted by the second bevel gear 5a. Based on the multi-stage planetary gear differential principle, the motor 1 transmits power to the transmission assembly through the first spur gear 6 to open or close the damper. When motor 1 fails, the moving and stationary discs of the manual friction clutch 5 are separated by an external manual tool. The second bevel gear 5a drives the rotation of the first bevel gear 4. Based on the multi-stage planetary gear differential principle, the first bevel gear 4 drives the multi-stage differential planetary gear reducer 3 and transmits the power to the first straight gear 6. The first straight gear 6 then transmits the power to the transmission assembly. The transmission assembly drives the damper to open or close in a small transmission ratio, reducing the time ground staff spend manually cranking the manual friction clutch 5 to open or close.

[0013] Furthermore, the first bevel gear 4 includes a mounting part and a bevel gear part. The bevel gear part meshes with the second bevel gear 5a. An internal gear ring is provided on the inner ring surface of the mounting part. The internal gear ring is differentially connected to the multi-stage planetary gears of the differential planetary gear reducer 3. The differential connection means that when the motor 1 is delivering power, the bevel gear part is restricted by the second bevel gear 5a. At this time, the moving plate and stationary plate of the manual friction clutch 5 are engaged, restricting the rotation of the first bevel gear 4. When the motor 1 fails, the operator drives the moving plate and stationary plate of the manual friction clutch 5 to separate using a tool. At this time, the moving plate drives the second bevel gear 5a to rotate, and the second bevel gear 5a drives the bevel gear part of the first bevel gear 4 to rotate, which drives the rotation of the multi-stage differential planetary gear reducer 3. The rotation of the multi-stage differential planetary gear reducer 3, based on the multi-stage planetary gear differential principle, can drive the first spur gear 6 to rotate.

[0014] In one embodiment, the transmission assembly includes a second spur gear 7, a double-linked third spur gear 8, a ball screw 11, and an output shaft 16. A rectangular guide block is provided on the end face of the output shaft 16 facing the side of the third spur gear 8, and the other end is connected to the drive end of the damper. The top of the first spur gear 6 meshes with the top of the second spur gear 7, and the bottom of the second spur gear 7 meshes with the large gear of the double-linked third spur gear 8. The mounting end of the ball screw 11 is keyed to the third spur gear 8, and the screw end of the ball screw 11 is threaded to the output shaft 16. The mounting bracket of the second housing 12 is connected to the shaft assembly 17 at one end. The mounting bracket can nest the output shaft 16. The mounting bracket is provided with a first limiting groove, which converts the rotation of the output shaft 16 into linear movement to open or close the damper.

[0015] Working principle: When motor 1 is working, the moving friction disc and the stationary friction disc of the manual friction clutch 5 are engaged. The moving friction disc is connected to the second bevel gear 5a via an involute spline, and is also floatingly connected to the manual input shaft of the manual friction clutch 5. When inputting in the forward direction, the general-purpose hand tool rotates the manual input shaft, causing the moving friction disc and the stationary friction disc to separate, and the moving friction disc drives the second bevel gear 5a to rotate. When inputting in the reverse direction, the moving friction disc and the stationary friction disc are in contact, and the moving friction disc is subjected to the static friction braking torque of the stationary friction disc, preventing the moving friction disc from rotating. When the torque on the first bevel gear 4 is input through the second bevel gear 5a, it cannot drive the manual input shaft of the manual friction clutch 5 to rotate, and the manual friction clutch 5 cannot transmit power in the reverse direction. When 1 fails, the moving and stationary discs are engaged. At the manual input end, in the forward input direction, the universal manual tool rotates the manual friction clutch 5's manual input shaft, separating the moving and stationary friction discs. The moving friction disc drives the second bevel gear 5a to rotate, which in turn drives the first bevel gear 4. After the first bevel gear 4 rotates, it drives the reducer 3 to rotate, which in turn drives the first spur gear 6. The first spur gear 6 then sequentially drives the second spur gear 7 and the third spur gear 8. The third spur gear 8 drives the ball screw 11, which, through the output shaft 16 mounted on the ball screw 11, opens or closes the aircraft's vents. When the first bevel gear 4 rotates (input) and the second-stage planetary carrier of the two-stage differential planetary gear reducer 3 rotates (output), the input-output transmission ratio is approximately 1. This small transmission ratio results in a short hand-cranking time. Simultaneously, the transmission from the second bevel gear 5a to the first spur gear 6 reduces the installation space of the two-stage planetary gear reducer 3.

[0016] Preferably, generally, the length of the shaft assembly 17 is less than the length of the output shaft 16. The shaft assembly includes a support shaft 17a, a sealing ring 17b, and a sealing ring cover plate 17c. The support shaft 17a has a hole in its central region for linear movement of the output shaft 16, and a second limiting groove with a shape adapted to a rectangular guide block is formed at the bottom of the hole. One end of the support shaft 17a is installed on the outer side of the smaller end of the second housing 12 in the length direction, and the other end is a free end. A mounting hole is opened along the length direction. A first limiting groove is provided on the bottom surface of the mounting hole, and a second limiting groove can be connected to the first limiting groove. The second limiting groove is used to convert the rotation of the output shaft 16 into linear motion. The sealing ring 17b is installed on the end of the support shaft 17a away from the first spur gear 6 and is axially limited by the sealing ring cover plate 17c. The width and height of the second limiting groove are the same as those of the first limiting groove. Both the support shaft 17a and the sealing ring cover plate 17c are ellipses with streamlined features, which allows air to flow smoothly and reduces wind resistance.

[0017] In one embodiment, a first microswitch 13 and a second microswitch 15 are installed inside the second housing 12. The first microswitch 13 and the second microswitch 15 are respectively communicatively connected to an external controller. A safety transmission component for protecting the transmission assembly is rotatably connected to the pinion side of the third spur gear 8. When the safety transmission component is driven to rotate in the forward or reverse direction, it can respectively touch the first micro switch 13 and the second micro switch 15 and feed back information to the controller, so as to facilitate the control of the motor output or to stop the rotation of external manual tools by external personnel.

[0018] In one embodiment, the safety transmission assembly includes a sixth spur gear 20, a nut 28, a precision screw 30 threadedly connected to the nut 28, a first small shaft 27, and a second small shaft 29. Two guide plates 26 are provided at the bottom of the mounting bracket 9 and on the inner bottom surface of the second housing 10, or the bottom of the mounting bracket 9 has a groove for assembling the guide plates 26. A third limiting groove is formed between the two guide plates 26, and a first micro switch 13 and a second micro switch 15 are installed at intervals. The third limiting groove is located below the first limiting groove. The sixth spur gear 20 meshes with the pinion of the third spur gear 8 on one side; The mounting end of the precision screw 30 is keyed to the sixth spur gear 20, and the top of the nut 28 is integrally provided with a protrusion, which can slide in the third limiting groove; One end of the first small shaft 27 is mounted on the bottom surface of the nut 28, and the other end is set with a tapered structure, which can touch the second micro switch 15 to make the controller receive a feedback signal to stop the extension of the output shaft 16. One end of the second small shaft 29 is mounted on the bottom surface of the nut 28 and is spaced apart from the first small shaft 27. The other end is set with a tapered structure, which can touch the first micro switch 13 to make the controller receive a feedback signal to stop the retraction of the output shaft 16. During the extension or retraction of the output shaft 16, the gears and their RVDT angular displacement sensors are protected to prevent continued power output after the damper is opened or closed, which could damage the parts and electronic components.

[0019] In one embodiment, an electromagnetic filter assembly 31 is also included. The electromagnetic filter assembly 31 is connected to the brushless DC motor 1, the first micro switch 13, the second micro switch 15 and the RVDT angular displacement sensor 25 respectively through wires. It can withstand surge voltage and peak voltage, meet lightning protection requirements and filter out electromagnetic interference.

[0020] In one embodiment, the motor housing 2, the first housing 10, the second housing 12, and the cover plate 14 at the bottom of the second housing 12 are all coated with a special heat-insulating coating for hypersonic aircraft surfaces and an aliphatic acrylic polyurethane surface paint. The purpose is to not only withstand flame combustion at 1100℃±80℃ for 5 minutes, but also to create a sealed environment resistant to humidity, mold, and salt spray, allowing for normal electric operation after combustion. The sealing ring 17b uses aerospace-grade carbon-graphite sealing material, meeting the requirements for flame combustion at 1100℃±80℃ for 5 minutes.

[0021] In one embodiment, an angular displacement sensor assembly for feedback of the movement distance of the output shaft 16 is also included. The angular displacement sensor assembly includes a double spur gear 18, a sensor mounting bracket 24, a worm gear 22, and an RVDT angular displacement sensor 25. The sensor mounting bracket 24 is mounted on the side of the mounting bracket facing the first housing 10. A sensor input shaft 23 is mounted along the length of the sensor mounting bracket 24. The RVDT angular displacement sensor 25 is mounted at one end of the sensor input shaft 23, and the worm gear 22 is mounted at the other end. The other side of the pinion of the third spur gear 8 meshes with the large gear of the double spur gear 18. The pinion of the double spur gear 18 meshes with the fifth spur gear 19, and the fifth spur gear 19 is connected to the worm 21 by a semi-circular key. The bottom end of the worm gear 22 meshes with the rotating end of the worm 21 (the other end of the worm 21 is rotatably mounted on the first or second housing). The worm gear 22 drives the sensor input shaft 23 to rotate, and the angular displacement of the sensor input shaft 23 is fed back to the controller through the RVDT angular displacement sensor 25. Since both are driven by the first spur gear 6 and the third spur gear 8, the linear movement distance of the output shaft 16 can only be calculated by the controller through intelligent software.

[0022] Furthermore, when the RVDT angular displacement sensor 25 rotates counterclockwise by 37.444°, the output Va-Vb / Va+Vb voltage ratio ranges from 0.4136 to 0.4138, and when it rotates clockwise by 37.444°, the output Va-Vb / Va+Vb voltage ratio ranges from -0.4138 to -0.4136, enabling the aircraft controller to perform high-precision control on the movement of the output shaft 16.

[0023] When the motor is in electric operation, the manual friction clutch 5 is in a non-operating state and cannot transmit power in the reverse direction. The electrical signal is sent to the brushless DC motor 1 and the RVDT angular displacement sensor 25 through the electrical connector of the electromagnetic filter assembly 31. The second bevel gear 5a of the manual friction clutch 5 fixes the first bevel gear 4. The output shaft of the brushless DC motor 1 rotates, and the spur gear on the output shaft drives the two-stage differential planetary gear reducer 3. Through the transmission of the first spur gear 6, the second spur gear 7, and the third spur gear 8, the ball screw 11 rotates. The rectangular guide block of the output shaft 16 is located in the guide groove of the second housing 12 and cannot rotate. The output shaft 16 moves linearly. The connector installed at the front end of the output shaft 16 is hinged to the aircraft APU damper. When the output shaft 16 moves linearly, the damper can be fully opened / closed. Simultaneously, the input shaft of the RVDT angular displacement sensor 25 is driven by the pinion of the third spur gear 8, the double spur gear 18, the fifth spur gear 19, the worm 21, the worm wheel 22, and the sensor input shaft 23, which drives the input shaft of the RVDT angular displacement sensor 25 to rotate. The RVDT angular displacement sensor 25 outputs a position signal to the aircraft ECU in real time. When the aircraft ECU receives a signal with a voltage ratio of 0.4137 from the RVDT angular displacement sensor 25, the aircraft ECU issues a closed position signal. The APU damper electric actuator controller disconnects the DC 28V power supply of the brushless DC motor 1. The electromagnetic clutch of the brushless DC motor 1 immediately brakes the motor output shaft, so that the output shaft 16 is immediately held in the current position, and the aircraft APU damper is in the fully closed position. When the brushless DC motor 1 rotates in the opposite direction, the output shaft 16 extends in the opposite direction. When the aircraft ECU receives a signal with a voltage ratio of -0.4137 from the RVDT angular displacement sensor 25, the aircraft ECU sends an open position signal. The APU damper electric actuator controller disconnects the DC 28V power supply of the brushless DC motor 1. The electromagnetic clutch of the brushless DC motor 1 immediately brakes the motor output shaft, so that the output shaft 16 is immediately held in the current position, and the aircraft APU damper is in the fully open position.

[0024] When the motor is operating, if the RVDT angular displacement sensor 25 fails and cannot feed back the voltage ratio signal to the aircraft ECU, the output shaft 16 will exceed its predetermined stroke during the closing process. In the fully closed position, if the output shaft 16 continues to retract or the aircraft ECU cannot receive the voltage ratio signal from the RVDT angular displacement sensor 25, the APU damper will fully open / move. When it moves 2mm, the second small shaft 29 presses the first micro switch 13, sending a switch signal to the APU damper electro-actuator controller. The APU damper electro-actuator controller then disconnects the DC 28V power supply to the brushless DC motor 1, and the electromagnetic clutch of the brushless DC motor 1 immediately brakes the motor output shaft, keeping the output shaft 16 in its current position. In the fully open position, if the output shaft 16 continues to extend and moves 2mm, the first small shaft 27 presses the second micro switch 15, sending a switch signal to the APU damper electro-actuator controller. The APU damper electro-actuator controller then disconnects the DC 28V power supply to the brushless DC motor 1, and the electromagnetic clutch of the brushless DC motor 1 immediately brakes the motor output shaft, keeping the output shaft 16 in its current position.

[0025] The second spur gear 7, the third spur gear 8, the double spur gear 18, the sixth spur gear 20, etc. mentioned above are mounted on the side of the mounting bracket 9 facing the first housing 10 by means of a rotating shaft, bearing, or other fixed gears, thereby ensuring the stability of these gears.

[0026] The product provided by this invention has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are merely for the purpose of helping to understand the core ideas of this invention. It should be noted that those skilled in the art can make various improvements and modifications to the invention without departing from the principles of the invention, and these improvements and modifications also fall within the safety scope of the invention claims.

Claims

1. An APU flap actuation mechanism adapted for driving an aircraft flap, the aircraft being provided with an electric motor and a flap, characterized in that, It comprises a first shell (10), a transmission assembly and a second shell (12) arranged in L-shaped structure, the first shell (10) covers the second shell (12) on the large end side of the second shell length direction, the large end top of the second shell (12) is provided with a manual friction clutch (5), and the small end is provided with a motor (1), wherein, The motor (1) is provided with an electromagnetic brake clutch and is connected with the input end of a multi-stage differential planetary gear reducer (3), the output end of the multi-stage differential planetary gear reducer (3) is connected with a first spur gear (6) through a rotating shaft, and the moving disc of the manual friction clutch (5) is provided with a second bevel gear (5a) in the vertical direction through the rotating shaft; The multi-stage planetary gear of the multi-stage differential planetary gear reducer (3) is provided with a first bevel gear (4) in a differential manner, the first bevel gear (4) is engaged with the second bevel gear (5a), and the rotating shaft of the first spur gear (6) penetrates the first bevel gear (4); The first bevel gear (4) is rotatably connected with the transmission assembly, and the transmission assembly drives the opening or closing of the damper in a small transmission ratio; When the motor (1) is used as a driving output, the moving disc and the static disc of the manual friction clutch (5) are combined, the rotation of the first bevel gear (4) is limited through the second bevel gear (5a), based on the multi-stage planetary differential principle, the motor (1) drives the transmission assembly through the first spur gear (6) to open or close the damper; When the motor (1) fails, the moving disc and the static disc of the manual friction clutch (5) are separated by using an external manual tool, the second bevel gear (5a) drives the rotation of the first bevel gear (4), the multi-stage differential planetary gear reducer (3) is driven by the first bevel gear (4) based on the multi-stage planetary differential principle, and is transmitted to the first spur gear (6), the transmission assembly is driven by the first spur gear (6), and the transmission assembly drives the opening or closing of the damper in a small transmission ratio.

2. The APU damper actuation mechanism of claim 1, wherein, The transmission assembly comprises a second spur gear (7), a double-type third spur gear (8), a ball screw (11) and an output shaft (16), the end face of the output shaft (16) on the side of the third spur gear (8) is provided with a rectangular guide block, and the other end is connected with the driving end of the damper, wherein The first spur gear (6) is engaged with the top of the second spur gear (7), and the bottom of the second spur gear (7) is engaged with the large gear of the double-type third spur gear (8); The mounting end of the ball screw (11) is key-connected with the third spur gear (8), and the screw end of the ball screw (11) is threadedly connected with the output shaft (16); One end of the mounting frame of the second shell (12) is butt-jointed with the shaft assembly (17), the mounting frame can nest the output shaft (16), the mounting frame is provided with a first limiting groove, the rotation of the output shaft (16) is converted into linear movement through the first limiting groove, so as to open or close the damper.

3. The APU damper actuation mechanism of claim 2, wherein, The length of the shaft assembly (17) is less than the length of the output shaft (16).

4. The APU damper actuation mechanism of claim 2, wherein, The shaft assembly comprises a supporting shaft (17a), a sealing ring (17b) and a sealing ring cover plate (17c), the supporting shaft (17a) is provided with a hole in the central region for linear movement of the output shaft (16), and a second limiting groove is formed in the bottom of the hole and is adapted to the shape of the rectangular guide block, One end of the supporting shaft (17a) is mounted on the outer side surface of the small end of the second shell (12) in the length direction, the other end is a free end, and a mounting hole is formed in the length direction, the bottom surface of the mounting hole is provided with the first limiting groove, and the second limiting groove can be connected to the first limiting groove, and the second limiting groove is used for converting the rotation of the output shaft (16) into linear motion; The sealing ring (17b) is mounted on the end of the supporting shaft (17a) away from the first spur gear (6) and is axially limited by the sealing ring cover plate (17c), and the second limiting groove has the same width and height as the first limiting groove; The supporting shaft (17a) and the sealing ring cover plate (17c) are both ellipses with streamline characteristics, so that air flows smoothly and wind resistance is reduced.

5. The APU damper actuation mechanism of claim 2, wherein, The second shell (12) is provided with a first micro switch (13) and a second micro switch (15), the first micro switch (13) and the second micro switch (15) are respectively connected to an external controller in communication, and the small gear of the third spur gear (8) is rotatably connected to a safety transmission assembly for protecting the transmission assembly, wherein When the safety transmission assembly is driven to rotate in the forward or reverse direction, it can respectively touch the first micro switch (13) and the second micro switch (15) and feed back information to the controller, so as to facilitate the control of the output of the motor or the stop of the rotation of the external manual tool by the external personnel.

6. The APU damper actuation mechanism of claim 5, wherein, The safety transmission assembly comprises a sixth spur gear (20), a nut (28), a precision screw rod (30) threadedly connected with the nut (28), a first small shaft (27) and a second small shaft (29), the mounting frame is provided with a third limiting groove, the first micro switch (13) and the second micro switch (15) are spaced apart and mounted on the mounting frame, and the third limiting groove is located below the first limiting groove, wherein The sixth spur gear (20) is engaged with one side of the small gear of the third spur gear (8); The mounting end of the precision screw rod (30) is keyed connected with the sixth spur gear (20), the top end of the nut (28) is integrally provided with a protrusion, and the protrusion can slide in the third limiting groove; One end of the first small shaft (27) is mounted on the bottom surface of the nut (28), and the other end is provided in a tapered structure and can touch the second micro switch (15), so that the controller receives a feedback signal to stop the extension of the output shaft (16); One end of the second small shaft (29) is mounted on the bottom surface of the nut (28) and is spaced apart from the first small shaft (27), and the other end is provided in a tapered structure and can touch the first micro switch (13), so that the controller receives a feedback signal to stop the retraction of the output shaft (16).

7. The APU damper actuation mechanism of claim 6, wherein, Also include electromagnetic filter components (31), the electromagnetic filter components (31) are connected by wire brushless DC motor (1), first micro switch (13), second micro switch (15) and RVDT angular displacement sensor (25) respectively, can withstand surge voltage and peak voltage, meet lightning protection requirements, filter out electromagnetic interference.

8. The APU damper actuation mechanism of claim 7, wherein, The cover (2), the first shell (10), the second shell (12) and the cover plate (14) at the bottom of the second shell (12) of the motor are coated with a special heat-insulating coating for hypersonic aircraft surfaces and an aliphatic acrylic polyurethane surface paint.

9. The APU damper actuation mechanism of claim 6, wherein, Also include angular displacement sensor assembly for feedback output shaft (16) movement distance, the angular displacement sensor assembly includes double straight gear (18), sensor mounting bracket (24), worm gear (22) and RVDT angular displacement sensor (25), the mounting bracket is installed towards the side of the first shell (10) sensor mounting bracket (24), the sensor mounting bracket (24) is installed with sensor input shaft (23) in length direction, one end of sensor input shaft (23) is installed with RVDT angular displacement sensor (25), the other end is installed with worm gear (22), wherein, The other side of the pinion of the third spur gear (8) is engaged with the gear of the double straight gear (18), the pinion of the double straight gear (18) is engaged with the fifth spur gear (19), and the fifth spur gear (19) is connected with the worm (21) through a semicircular key; The bottom end of the worm gear (22) is rotationally engaged with the worm (21), the sensor input shaft (23) is driven to rotate by the worm gear (22), and the angular displacement of the sensor input shaft (23) is fed back to the controller by the RVDT angular displacement sensor (25), the linear movement distance of the output shaft (16) is driven by the first spur gear (6) and the third spur gear (8), and only the controller can calculate the linear movement distance of the output shaft (16) through intelligent software.

10. The APU damper actuation mechanism of claim 9, wherein, When the RVDT angular displacement sensor (25) rotates counterclockwise by 37.444°, the output (Va-Vb) / (Va+Vb) voltage ratio range is 0.4136-0.4138, and when it rotates clockwise by 37.444°, the output (Va-Vb) / (Va+Vb) voltage ratio range is -0.4138--0.4136, so that the aircraft controller can control the movement of the output shaft (16) with high precision.

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