Aircraft nose cone bend deformation actuation device based on shape memory alloy springs

Abstract

This invention discloses a nose cone bending deformation driving device for an aircraft based on shape memory alloy springs. The device includes a main drive section comprising a base I, three SMA springs, and a lead screw and nut transmission assembly. A compact rotary drive mechanism composed of the three SMA springs is connected to the base I. This compact rotary drive mechanism is connected to the lead screw and nut transmission assembly and outputs rotational motion when the three SMA springs are heated and contracted sequentially. The lead screw and nut transmission mechanism is connected to the nose cone frame of the aircraft and amplifies the rotational motion, outputting it as a linear displacement to drive the nose cone frame to bend and deform. The power source of this invention is a compact rotary drive mechanism driven by three SMA springs. By cleverly combining an SMA spring actuator and a helical drive, the force amplification effect and self-locking action of the helical drive are utilized to meet the bending deformation requirements of the nose cone under actual working conditions.

Description

Technical Field

[0001] This invention belongs to the field of aerospace technology, specifically relating to a flight nose cone bending deformation drive device based on shape memory alloy springs. Background Technology

[0002] Aerospace variability vehicles are reusable space-to-ground transport vehicles capable of entering space and remaining within the atmosphere for extended periods. They possess characteristics such as high speed, strong penetration capabilities, and the ability to rapidly strike predetermined targets, making them crucial future air-based combat weapons. Traditional fixed-configuration nose cone structures are limited by aerodynamic forces, aerothermal properties, time windows, and control feedback, and can no longer meet the performance requirements of aerospace vehicles under multi-mission profiles and complex, variable flight conditions. Variational nose cone mechanisms can adjust the nose cone shape in real time according to flight conditions to achieve optimal aerodynamic and thermal characteristics, enabling optimized flight control and significantly improving maneuverability and combat effectiveness. This is an inevitable choice for aerospace vehicles to cope with complex and variable external environments and has attracted considerable attention from scholars and research institutions both domestically and internationally.

[0003] Shape memory alloy (SMA) is a novel functional material exhibiting shape memory, superelasticity, and sensed elasticity effects. After residual deformation under external force, when its temperature reaches the phase transformation temperature, the SMA filament undergoes a phase transformation, changing from martensite at room temperature to austenite at high temperature. This phase transformation results in a change in the crystal structure, which macroscopically represents the inverse deformation of the SMA filament. Compared to complex mechanisms that utilize displacement or torsion to perform work, SMA filaments utilize their internal phase transformation to perform work, significantly simplifying mechanisms and reducing mass and space requirements.

[0004] Meanwhile, existing SMA actuators mainly utilize SMA element wire or helical springs as driving elements. Wire wire offers high output force and efficiency but a small output stroke; helical springs offer a large stroke but low efficiency and low output force. Therefore, designing a high-efficiency SMA actuator with both large output force and large stroke has always been a hot topic and a challenge in the field of SMA application research. Summary of the Invention

[0005] The purpose of this invention is to provide a bending deformation drive device for an aircraft nose cone based on shape memory alloy springs. Its power source is a compact rotary drive mechanism driven by three SMA springs. During operation, the compact rotary drive mechanism drives a lead screw and nut transmission assembly to output linear motion, and a motion limiting mechanism is designed on the other side of the nose cone bending section. By cleverly combining the SMA spring actuator and the helical drive, the force amplification effect and self-locking action of the helical drive are utilized to meet the bending deformation requirements of the nose cone under actual working conditions.

[0006] This invention provides a nose cone bending deformation driving device for an aircraft based on shape memory alloy springs, comprising a main driving part, which includes a base I, three SMA springs, and a lead screw and nut transmission assembly. A compact rotary driving mechanism composed of the three SMA springs is connected to the base I. The compact rotary driving mechanism is connected to the lead screw and nut transmission assembly and is used to output rotational motion when the three SMA springs are heated and contracted sequentially. The lead screw and nut transmission mechanism is connected to the nose cone frame of the aircraft and is used to amplify the rotational motion and output it in the form of linear displacement, thereby driving the nose cone frame to bend and deform.

[0007] Furthermore, the main drive section also includes: a fixing component, a bearing housing, a support component, a deep groove ball bearing I, a deep groove ball bearing II, a bearing end cap, a connecting component I, a connecting component II, and an output component I;

[0008] The lead screw and nut transmission assembly includes a transmission nut, a lead screw, a spring connector, and an end cap; the head cone frame includes head cone frame I, head cone frame II, and head cone frame III;

[0009] The base I is provided with spring connection point I, spring connection point II, and spring connection point III; the three SMA springs are respectively connected to spring connection point I, spring connection point II, and spring connection point III, and are also connected to the three connection holes on the spring connector.

[0010] One end of the lead screw is provided with an eccentric shaft; one end of the eccentric shaft is provided with a shoulder for axial positioning of the spring connector; the shoulder and the spring connector are connected by a clearance fit; the other end of the lead screw is engaged with the transmission nut, and when the lead screw is driven to rotate, the transmission nut outputs axial linear motion; the end cap is fixed to the eccentric shaft of the lead screw by screws for axial positioning and fixing of the spring connector.

[0011] The base I is fixed to the head cone frame I by screws and fastened by the fastener; the lead screw and deep groove ball bearing I are installed in the bearing housing and axially positioned and fixed by the bearing end cap; the bearing housing is fixed to the base I by screws; one end of the support is fixed to the bearing end cap by screws, and the other end is connected to one end of the lead screw through the deep groove ball bearing II, so that it can rotate relative to the lead screw;

[0012] The output component I is fixedly connected to the head cone frame III by screws; both the connecting component I and the connecting component II are provided with two pin holes, which are respectively connected to the transmission nut and the output component I through pin shafts to form a hinge connection, which is used to output the axial linear motion output by the lead screw nut transmission assembly, so that the head cone bends and deforms, and adapts to the radial motion that occurs during its bending deformation.

[0013] Furthermore, the base I has a circular overall outline and is provided with three SMA spring connection points spaced 120° apart and threaded holes required for connection.

[0014] Furthermore, the device also includes an auxiliary limiting mechanism, which includes: a base II, an output component II, a retaining ring, a connecting component III, a connecting component IV, an output component III, a linear bearing, and a shaft end retaining ring;

[0015] The base II is fixed to the head cone frame I by screws, and a fixed shaft integrally connected to the base II is provided on it. The fixed shaft consists of three sections with different shaft diameters and has two shoulders. The output component II is connected to the fixed shaft on the base II by the linear bearing, and the two ends of the linear bearing are axially positioned by the retaining ring. The output component II and the output component III are hinged together by the connecting component III and the connecting component IV. The two shoulders on the fixed shaft integrally connected to the base II are used to limit the axial movement of the linear bearing and the shaft end retaining ring, respectively. The shaft end retaining ring is used to limit the movement of the linear bearing.

[0016] Compared with the prior art, the beneficial effects of the present invention are:

[0017] 1) The bending deformation drive device proposed in this invention is driven by three SMA springs. It cleverly applies the emerging intelligent material actuator and, together with the feedback sensing control module, can realize the integrated design of drive, sensing and control, which greatly reduces the size and weight of the drive device and is of great significance for realizing the lightweight design of aircraft.

[0018] 2) When the main drive part of the bending deformation drive device proposed in this invention is working, it heats the three SMA springs connected to the base and the eccentric screw by energizing them one after another, causing them to contract and rotate, thereby driving the transmission nut to output linear motion and driving the head cone to bend and deform.

[0019] 3) In the bending deformation driving device proposed in this invention, the transmission nut and the head cone shell are connected by two hinges, so that the transmission part can adapt to the radial displacement of the head cone shell while driving the bending deformation.

[0020] 4) The present invention designs an auxiliary limiting mechanism on the other side of the head cone bending deformation part, which can prevent the head cone bending deformation angle from being too large and resulting in a strange configuration; at the same time, the auxiliary limiting mechanism can be used to install sensing and control elements, thereby realizing intelligent driving of head cone bending deformation. Attached Figure Description

[0021] Figure 1 This is an overall assembly diagram of the head cone bending deformation driving device proposed in this invention on the head cone.

[0022] Figure 2 This is a cross-sectional view of the main drive section in the head cone bending deformation drive device proposed in this invention.

[0023] Figure 3 This is an overall structural diagram of the main drive section in the head cone bending deformation drive device proposed in this invention.

[0024] Figure 4 This is a detailed internal view of the main drive section in the head cone bending deformation drive device proposed in this invention.

[0025] Figure 5 This is a part drawing of the lead screw in the head cone bending deformation drive device proposed in this invention.

[0026] Figure 6 This is a part drawing of the transmission nut in the head cone bending deformation drive device proposed in this invention.

[0027] Figure 7 This is a structural diagram of the lead screw and nut transmission assembly in the head cone bending deformation drive device proposed in this invention.

[0028] Figure 8 This is a cross-sectional view of the auxiliary limiting mechanism in the head cone bending deformation driving device proposed in this invention.

[0029] Figure 9 This is a structural diagram of the auxiliary limiting mechanism in the head cone bending deformation driving device proposed in this invention.

[0030] Numbering on the map:

[0031] 1-Main drive section, 2-Auxiliary limiting mechanism, 3-Head cone frame I, 4-Head cone frame II, 5-Head cone frame III, 11-Fixing component, 12-Base I, 13-Bearing seat, 14-Support component, 151-Deep groove ball bearing I, 152-Deep groove ball bearing II, 16-Bearing end cover, 17-Screw and nut transmission assembly, 181-Connector I, 182-Connector II, 19-Output component I, 121-Spring connection point I, 122-Spring connection point II, 123-Spring connection point III, 171-Transmission nut, 172-Screw, 173-Spring connector, 174-End cover, 21-Base II, 22-Output component II, 23-Snap ring, 241-Connector III, 242-Connector IV, 25-Output component III, 26-Linear bearing, 27-Shaft end retaining ring, 31-Frame base I, 32-Frame base II. Detailed Implementation

[0032] The present invention will now be described in detail with reference to the embodiments shown in the accompanying drawings. However, it should be noted that these embodiments are not intended to limit the present invention. All equivalent changes or substitutions in function, method, or structure made by those skilled in the art based on these embodiments are within the scope of protection of the present invention.

[0033] This embodiment provides a bending deformation drive device for an aircraft nose cone based on shape memory alloy springs. Its power source is a compact rotary drive mechanism driven by three SMA springs. During operation, the compact rotary drive mechanism drives the lead screw and nut transmission assembly to output linear motion, and an auxiliary limiting mechanism is designed on the other side of the nose cone bending section. By cleverly combining the SMA spring driver and the helical transmission, the force amplification effect and self-locking effect of the helical transmission are used to meet the bending deformation needs of the nose cone under actual working conditions.

[0034] like Figure 1 , Figure 4 and Figure 9 As shown, the bending deformation driving device includes: a main driving part 1 and an auxiliary limiting part 2. In the main driving part 1, three shape memory alloy springs connected to the base I 12 form a compact rotary driving mechanism, serving as the power source for the device. The rotary motion output by this compact rotary driving mechanism is amplified by the lead screw and nut transmission assembly 17 and output as a linear displacement, thereby driving the head cone frame III 5 to undergo bending deformation. The output part is designed with hinge connector I 181 and connector II 182 to accommodate the radial movement during the bending deformation process of the head cone. The auxiliary limiting part 2 on the other side of the frame adopts the same motion transmission form as the main driving part; the difference is that a linear bearing 26 is added between the output component II 22 and the base II 21 to reduce frictional resistance.

[0035] like Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, the main drive section includes: a fixing component 11, a base I 12, three SMA springs, a bearing housing 13, a support component 14, a deep groove ball bearing I 151 and a deep groove ball bearing II 152, a bearing end cover 16, a lead screw and nut transmission assembly 17, a connecting component I 181 and a connecting component II 182, and an output component I 19.

[0036] Three SMA springs are connected to spring connection points I121, II122, and III123 on the base I12, respectively, and then simultaneously connected to three connection holes on the spring connector 173. During operation, the three SMA springs are heated sequentially, causing them to contract in a certain order, and the rotary drive mechanism can output rotational motion (by changing the heating order of the three SMA springs, the rotation direction of the rotary drive mechanism can be changed). The base I12 has a circular overall outline. Due to space constraints and to avoid interference, two corners are cut off at the bottom. It has three SMA spring connection points spaced 120° apart and threaded holes for connecting with other components. The spring connector 173 is clearance-fitted with the connection structure on the lead screw 172 and can rotate around the axis.

[0037] The base I12 is fixed to the head cone frame I3 by screws and fastened by fastener 11. The lead screw 172 and deep groove ball bearing I151 in the lead screw nut transmission assembly 17 are installed in the bearing seat 13, and the other side is axially positioned and fixed by the bearing end cover 16. The bearing seat 13 is fixed to the base I12 by four screws. One end of the support member 14 is fixed to the bearing end cover 16 by screws, and the other end is connected to one end of the lead screw 172 by the deep groove ball bearing II152, so that it can rotate relative to the lead screw. Both the connecting member I181 and the connecting member II182 have two pin holes, which are connected to the transmission nut 171 and the output member I19 by pins to form a hinge connection. They are mainly used to output the axial linear movement output by the lead screw nut transmission assembly 17 to cause the head cone to bend and deform, and at the same time, they can adapt to the radial movement that occurs during the bending and deformation process. The output member I19 is fixed to the head cone frame III5 by screws.

[0038] like Figure 3 , Figure 4As shown, the lead screw and nut transmission assembly 17 includes: a transmission nut 171, a lead screw 172, a spring connector 173, and an end cap 174. One end of the lead screw 172 is designed with an eccentric shaft, and the other end of the eccentric shaft has a shoulder for axial positioning of the spring connector 173. It is connected to the spring connector 173 via a clearance fit. Theoretically, when one of the extended SMA springs contracts due to heat, it can drive the entire lead screw to rotate 120°. The other end of the lead screw 172 engages with the transmission nut 171. When the lead screw 172 is driven to rotate, the transmission nut 172 outputs axial linear motion. The end cap 174 is fixed to the eccentric shaft of the lead screw 172 by two small screws, mainly for axial positioning and fixing of the spring connector 173.

[0039] like Figure 1 , Figure 8 and Figure 9 As shown, the auxiliary limiting part 2 mainly includes: base II 21, output part II 22, snap ring 23, connector III 241, connector IV 242, output part III 25, linear bearing 26, and shaft end retaining ring 27. This part does not have a drive source and moves with the main drive part. The base II 21 is fixed to the head cone frame I 3 by screws. It has a fixed shaft that is integrated with the base and consists of three sections with different shaft diameters and two shoulders. The output part II 22 is connected to the fixed shaft on the base II 21 by a linear bearing 26. The two ends of the linear bearing 26 are axially positioned by snap rings 23. The connection between the output part II 22 and the output part III 25 is also hinged by the connector III 241 and the connector IV 242, which is consistent with the main drive part. The two shoulders on the fixed shaft integrated with the base II 21 axially limit the linear bearing 26 and the shaft end retaining ring 27, respectively. The shaft end retaining ring 27 also limits the movement of the linear bearing 26. In this way, the movement limiting part can limit the movement in two bending directions during the bending deformation of the head cone, preventing the bending deformation angle from being too large and causing a strange configuration.

[0040] The process of bending deformation of the aircraft nose cone is as follows: the three SMA springs of the main drive part are heated in a certain order and contracted. This causes the lead screw of the transmission component to rotate through the eccentric shaft, and then drives the transmission nut to output axial linear motion through the helical transmission. In this way, the nose cone frame can be bent and deformed.

[0041] The nose cone bending deformation drive device of this aircraft has the following technical advantages:

[0042] 1) The bending deformation drive device is driven by three SMA springs. It cleverly applies the emerging smart material actuator and, together with the feedback sensing control module, can realize the integrated design of drive, sensing and control, which greatly reduces the size and weight of the drive device and is of great significance for realizing the lightweight design of aircraft.

[0043] 2) When the main drive unit is working, the three SMA springs connected to the base and the eccentric screw are heated by powering on them one after another, causing them to contract in sequence, which drives the screw to rotate, thereby driving the transmission nut to output linear motion, and driving the head cone to bend and deform.

[0044] 3) In the connection structure between the transmission nut and the head cone housing, the transmission nut and the output structure are connected by two hinges, so that the transmission part can adapt to the radial displacement of the head cone housing while driving it to bend and deform.

[0045] 4) By setting an auxiliary limiting mechanism on the other side of the head cone bending deformation part, the angle of head cone bending deformation can be prevented from being too large and resulting in a strange configuration; at the same time, the auxiliary limiting mechanism can be used to install sensing and control elements, thereby realizing intelligent driving of head cone bending deformation.

[0046] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. A shape memory alloy spring based aircraft nose cone flexure actuation device, characterized by, The system includes a main drive section (1) and an auxiliary limiting mechanism (2). The main drive section (1) includes a base I (12), three SMA springs, a screw and nut transmission assembly (17), a fixing part (11), a bearing seat (13), a support part (14), a deep groove ball bearing I (151), a deep groove ball bearing II (152), a bearing end cap (16), a connecting part I (181), a connecting part II (182), and an output part I (19). A compact rotary drive mechanism composed of the three SMA springs is connected to the base I (12). The compact rotary drive mechanism is connected to the screw and nut transmission assembly (17) and is used to output rotary motion when the three SMA springs are heated and contracted in sequence. The screw and nut transmission assembly (17) is connected to the nose cone frame of the aircraft and is used to amplify the rotary motion and output it in the form of linear displacement, thereby driving the nose cone frame to bend and deform. The lead screw and nut transmission assembly (17) includes a transmission nut (171), a lead screw (172), a spring connector (173), and an end cap (174); the head cone frame includes head cone frame I (3), head cone frame II (4), and head cone frame III (5); The base I (12) is provided with spring connection point I (121), spring connection point II (122) and spring connection point III (123); the three SMA springs are respectively connected to the spring connection point I (121), spring connection point II (122) and spring connection point III (123), and are also connected to the three connection holes on the spring connector (173); One end of the lead screw (172) is provided with an eccentric shaft; one end of the eccentric shaft is provided with a shoulder for axial positioning of the spring connector (173); the shoulder and the spring connector (173) are connected by a clearance fit; the other end of the lead screw (172) is engaged with the transmission nut (171), and when the lead screw (172) is driven to rotate, the transmission nut (171) outputs axial linear motion; the end cap (174) is fixed to the eccentric shaft of the lead screw (172) by screws for axial positioning and fixing of the spring connector (173); The base I (12) is fixed to the head cone frame I (3) by screws and fastened by the fastener (11); the lead screw (172) and the deep groove ball bearing I (151) are installed in the bearing seat (13) and axially positioned and fixed by the bearing end cap (16); the bearing seat (13) is fixed to the base I (12) by screws; one end of the support (14) is fixed to the bearing end cap (16) by screws, and the other end is connected to one end of the lead screw (172) through the deep groove ball bearing II (152) so that it can rotate relative to the lead screw (172); The output component I (19) is fixedly connected to the head cone skeleton III (5) by screws; the connector I (181) and connector II (182) are each provided with two pin holes, which are respectively connected to the transmission nut (171) and the output component I (19) by pin shafts to form a hinge connection, which is used to output the axial linear motion output by the lead screw nut transmission assembly (17), so that the head cone bends and deforms, and adapts to the radial motion that occurs during its bending deformation. The auxiliary limiting mechanism (2) includes: base II (21), output component II (22), snap ring (23), connector III (241), connector IV (242), output component III (25), linear bearing (26), and shaft end retaining ring (27); The base II (21) is fixed to the head cone frame I (3) by screws. A fixed shaft is provided on it and is integrally connected to the base II (21). The fixed shaft consists of three sections with different shaft diameters and has two shaft shoulders. The output component II (22) is connected to the fixed shaft on the base II (21) by the linear bearing (26). The two ends of the linear bearing (26) are axially positioned by the snap ring (23). The output component II (22) and the output component III (25) are hinged together by the connector III (241) and the connector IV (242). The two shaft shoulders on the fixed shaft integrally connected to the base II (21) are used to limit the axial movement of the linear bearing (26) and the shaft end retaining ring (27). The shaft end retaining ring (27) is used to limit the movement of the linear bearing (26).

2. The shape memory alloy spring based aircraft nose cone bend deformation actuation apparatus of claim 1, wherein, The base I (12) has a circular overall outline and is provided with three SMA spring connection points spaced 120° apart and threaded holes for connection.

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