Folding propeller mechanism of aircraft and aircraft

Abstract

The invention discloses an aircraft folding type propeller mechanism and an aircraft, the aircraft folding type propeller mechanism comprises a rotating shaft, a driving part, a first propeller and a second propeller; the driving piece is connected with one end of the rotating shaft; the first propeller comprises a first propeller hub and a first propeller blade which are connected with each other, the first propeller hub is fixedly connected to the rotating shaft, a thrust groove is formed in the side, away from the driving part, of the first propeller hub, and a first thrust surface which is obliquely arranged is arranged at the bottom of the thrust groove; the second propeller comprises a second propeller hub and a second propeller blade which are connected, the second propeller hub is movably arranged on the rotating shaft in a sleeving mode and located on the side, away from the driving piece, of the first propeller hub, and a thrust block extending into the thrust groove is arranged on the side, facing the first propeller hub, of the second propeller hub in a protruding mode; and the thrust blocks are matched with the thrust grooves, so that the second paddles are in a folded state or an unfolded state relative to the first paddles. According to the folding propeller mechanism of the aircraft, the resistance of the aircraft in the flight process is reduced, and the flight performance of the aircraft is improved.

Description

Technical Field

[0001] The present application relates to the technical field of aircraft propulsion devices, and in particular to an aircraft foldable propeller mechanism and an aircraft. Background Art

[0002] Urban air mobility aircraft divides its power system configuration into full-tilt, semi-tilt and combined configurations according to whether the power system is reused during vertical take-off and landing and fixed-wing flight.

[0003] Among them, the semi-tilt configuration refers to the reuse of part of the power system through tilting during the vertical take-off and landing process and the fixed-wing flight process, that is, part of the power system (hovering power system) always remains fixed and only provides upward lift, while the remaining power system can tilt around the axis to change the direction of the propeller shaft, provide upward lift during the vertical take-off phase, and provide forward thrust / pull during flight. The composite configuration means that the power systems of the vertical take-off and landing process and the flight process are completely independent and are composed of separate hardware.

[0004] However, whether it is a semi-tilt configuration or a compound configuration, the hovering power system not only does not provide lift during the fixed-wing flight phase, but also generates a certain amount of resistance, increasing the power required for level flight, thereby generating huge flight resistance during the flight of the aircraft, which is not conducive to the flight performance of the aircraft. Summary of the invention

[0005] In view of the above, it is necessary to propose a foldable propeller mechanism for an aircraft and an aircraft to reduce the resistance of the aircraft during flight and improve the flight performance of the aircraft.

[0006] The embodiment of the present application provides a foldable propeller mechanism for an aircraft, comprising a rotating shaft, a driving member, a first propeller and a second propeller; the driving member is connected to one end of the rotating shaft for driving the rotating shaft to rotate; the first propeller comprises a first hub and a first blade connected to each other, the first hub is fixedly connected to the rotating shaft, an arc-shaped thrust groove is provided on a side of the first hub away from the driving member, and the bottom of the thrust groove has a first thrust surface arranged obliquely; the second propeller comprises a second hub and a second blade connected to each other, the second hub is movably sleeved on the rotating shaft and is located at the back of the first hub A thrust block extending into the thrust groove is protruded from the second hub on a side away from the driving member and facing the first hub. The thrust block and the thrust groove cooperate to make the second blade present a folded state or an unfolded state relative to the first blade. In the folded state, the circumferential phase difference between the second blade and the first blade is zero. In the unfolded state, the circumferential phase difference between the second blade and the first blade is a preset value. The first thrust surface is used to abut against the thrust block when the second blade switches between the folded state and the unfolded state.

[0007] In some embodiments, the aircraft foldable propeller mechanism also includes a thrust elastic member, which is sleeved on the rotating shaft and located on the side of the second hub away from the first hub, one end of the thrust elastic member is connected to the rotating shaft, and the other end of the thrust elastic member is transmission-connected to the second hub, and the thrust elastic member is used to apply pressure to the second hub.

[0008] In some embodiments, the aircraft foldable propeller mechanism further includes a sliding bearing, which is sleeved on the rotating shaft and inserted into the second hub, and one end of the thrust elastic member close to the second hub abuts against the sliding bearing.

[0009] In some embodiments, a stop ridge is provided at one end of the rotating shaft away from the driving member along the circumference of the rotating shaft, and one end of the thrust elastic member away from the second hub abuts against the stop ridge.

[0010] In some embodiments, the aircraft foldable propeller mechanism also includes a limit assembly, the limit assembly includes a limit base, the limit base is arranged on the rotating shaft and is located on the side of the second hub away from the first hub, the limit base is used to limit the distance of the second hub away from the first hub, and is used to transfer the lift generated by the second blade to the rotating shaft.

[0011] In some embodiments, an arc-shaped guide groove is provided on the side of the second hub facing away from the first hub, the guide groove is concentric with the rotating shaft, the bottom of the guide groove has an abutment slope, and a limiting hole is provided at the end of the abutment slope away from the first hub; the limiting assembly also includes a limiting elastic part and a limiting part, the limiting part is slidably inserted in the limiting base and arranged opposite to the guide groove, the limiting elastic part is arranged in the limiting base, and the two ends of the limiting elastic part are respectively connected to the limiting base and the limiting part, and the limiting elastic part is used to drive the limiting part to be inserted into the limiting hole when the second blade is in the expanded state.

[0012] In some embodiments, a side of the second hub facing the limit base and a side of the limit base facing the second hub respectively have a matching first friction surface and a second friction surface; or, a side of the second hub facing the limit base and a side of the limit base facing the second hub are respectively provided with matching mortise and tenon structures. In some embodiments, the thrust block has a second thrust surface on a side facing the first thrust surface that is in surface contact with the first thrust surface.

[0013] In some embodiments, the aircraft folding propeller mechanism also includes a first fairing and a second fairing, the first fairing is arranged on the circumferential side of the first hub, the first blade is inserted into the first fairing, the second fairing is arranged on the circumferential side of the second hub and the end of the rotating shaft away from the driving member, the end of the second fairing close to the first fairing is slidably mounted on the end of the first fairing close to the second fairing and is located on the side of the first hub away from the driving member, or the end of the second fairing close to the first fairing is slidably inserted into the end of the first fairing close to the second fairing and is located on the side of the first hub away from the driving member, and the second blade is inserted into the second fairing.

[0014] The aircraft folding propeller mechanism of the embodiment of the present application is provided with an arc-shaped thrust groove on the side of the first hub away from the driving member, a first thrust surface is provided at the bottom of the thrust groove, and a thrust block is provided on the side of the second hub facing the first hub and extends into the thrust groove. When the driving member is not working, the second hub can approach the first hub under the action of its own gravity and inertia or under the action of external force, and the thrust block and the thrust groove cooperate to make the second hub drive the second blade to rotate, so that the second blade and the first blade are in a folded state. When the aircraft folding propeller mechanism is installed on the aircraft, the aircraft does not need the driving member to work during the flight stage, and the second blade and the first blade are automatically in a folded state, thereby reducing the flight resistance generated by the aircraft during the flight, and thus helping to improve the flight performance of the aircraft. In addition, when the driving member is working, the lift generated by the rotation of the second blade makes the second blade in an unfolded state relative to the first blade, thereby facilitating the lifting and hovering of the aircraft.

[0015] An embodiment of the present application also provides an aircraft, including a fuselage and the aircraft folding propeller mechanism as described above, wherein the aircraft folding propeller mechanism is installed on the fuselage, and the aircraft folding propeller mechanism is used to provide lift when the aircraft takes off and lands vertically. When the second blade is in the folded state, the extension direction of the second blade and the extension direction of the first blade are the same as the flight direction of the aircraft.

[0016] The aircraft of the embodiment of the present application provides lift during vertical takeoff and landing by providing an aircraft folding propeller mechanism. The aircraft folding propeller mechanism has a simple structure and is folded and unfolded in a purely mechanical manner, which enables the first blade and the second blade to be automatically folded during the fixed-wing flight of the aircraft, thereby reducing the flight resistance of the aircraft, and thus facilitating the improvement of the flight performance of the aircraft. In addition, by providing that when the second blade is in a folded state, the extension direction of the second blade and the extension direction of the first blade are the same as the flight direction of the aircraft, the flight resistance generated by the aircraft during fixed-wing flight can be further reduced, thereby further improving the flight performance of the aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a three-dimensional structural schematic diagram of the aircraft foldable propeller mechanism provided in an embodiment of the present application.

[0018] Figure 2 yes Figure 1 The three-dimensional structural schematic diagram of the aircraft foldable propeller mechanism without the first fairing and the second fairing is shown.

[0019] Figure 3 yes Figure 1 A schematic diagram of the exploded structure of the aircraft's foldable propeller mechanism is shown.

[0020] Figure 4 yes Figure 3 The three-dimensional structural schematic diagram of the first hub in the aircraft foldable propeller mechanism is shown.

[0021] Figure 5 yes Figure 3 The three-dimensional structural schematic diagram of the second hub in the aircraft foldable propeller mechanism is shown.

[0022] Figure 6 yes Figure 3 A schematic diagram of the three-dimensional structure of the second hub in the aircraft foldable propeller mechanism shown in another angle.

[0023] Figure 7 yes Figure 3 The schematic diagram of the exploded structure of the limiting component in the foldable propeller mechanism of the aircraft is shown.

[0024] Figure 8 yes Figure 3 The diagram shown is a schematic diagram of the force analysis between the thrust slot and the thrust block during the deployment of the second blade.

[0025] Fig. 9 yes Figure 3 The diagram shown is a highly schematic diagram of the movement of the second hub during the deployment of the second blades.

[0026] Fig.10 yes Figure 3 The diagram shown is a schematic diagram of the force analysis of the second hub during the folding process of the second blade.

[0027] Fig.11 It is a schematic diagram of the three-dimensional structure of the aircraft provided in an embodiment of the present application.

[0028] Main component symbols Aircraft 1000, aircraft foldable propeller mechanism 100, rotating shaft 10, stop flange 11, driving member 20, first propeller 30, first hub 31, thrust groove 311, first thrust surface 3111, first limiting surface 3112, second limiting surface 3113, first blade 32, second propeller 40, second hub 41, thrust block 411, second thrust surface 4111, guide groove 412, abutting inclined surface 4121, limiting hole 413, second blade 42, thrust elastic member 50, sliding bearing 60, limiting assembly 70, limiting base 71, sliding hole 711, limiting member 72, limiting elastic member 73, first fairing 80, second fairing 90, fuselage 200, fixed propeller mechanism 300. DETAILED DESCRIPTION

[0029] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0030] In the description of the present application, it should be understood that the terms indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present application, it should be noted that the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0031] In the description of the present application, it should be noted that, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication, it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances. Some embodiments of the present application will be described in detail below in conjunction with the accompanying drawings.

[0032] See also Figure 1 , Figure 2 , Figure 3 and Figure 4 An embodiment of the present application provides a foldable propeller mechanism 100 for an aircraft, including a rotating shaft 10, a driving member 20, a first propeller 30 and a second propeller 40.

[0033] The driving member 20 may be a motor. The driving member 20 is connected to one end of the rotating shaft 10 . The driving member 20 is used to drive the rotating shaft 10 to rotate.

[0034] The first propeller 30 includes a first hub 31 and a first blade 32 connected to each other. The first hub 31 is fixedly connected to the rotating shaft 10. An arc-shaped thrust groove 311 is provided on the side of the first hub 31 away from the driving member 20. The thrust groove 311 is concentric with the rotating shaft 10. The bottom of the thrust groove 311 has an inclined first thrust surface 3111. The first thrust surface 3111 extends from one end of the bottom of the thrust groove 311 to the other end.

[0035] The second propeller 40 includes a second hub 41 and a second blade 42 connected to each other. The second hub 41 is movably sleeved on the rotating shaft 10 and is located on the side of the first hub 31 away from the driving member 20. The second hub 41 is provided with a thrust block 411 extending into the thrust groove 311 on the side facing the first hub 31. The second blade 42 can drive the second hub 41 to rotate and move away from the first hub 31 under the action of its own lift. The thrust block 411 and the thrust groove 311 cooperate to make the second blade 42 present a folded state or an unfolded state relative to the first blade 32. In the folded state, the circumferential phase difference between the second blade 42 and the first blade 32 is zero, and in the unfolded state, the circumferential phase difference between the second blade 42 and the first blade 32 is a preset value. The first thrust surface 3111 is used to abut against the thrust block 411 when the second blade 42 switches between the folded state and the unfolded state.

[0036] Specifically, when the driving member 20 is not working, the second hub 41 can be close to the first hub 31 under the action of its own gravity and inertia or under the action of external force, and the thrust block 411 and the thrust groove 311 cooperate to enable the second hub 41 to drive the second blade 42 to rotate. Since the first thrust surface 3111 is inclined, the thrust block 411 eventually moves to the end of the first thrust surface 3111 close to the driving member 20, that is, the lowest position of the first thrust surface 3111. At this time, the phase difference between the angle of the second blade 42 around the rotating shaft 10 and the angle of the first blade 32 around the rotating shaft 10 is zero, and the second blade 42 and the first blade 32 are in a folded state. When the driving member 20 drives the rotating shaft 10 to rotate, the rotating shaft 10 drives the first hub 31 to rotate, and the first hub 31 pushes the thrust block 411 through the first thrust surface 3111 to rotate the second hub 41. The second blade 42 generates lift when rotating and drives the thrust block 411 to separate from the first thrust surface 3111 briefly. Then, the first hub 31 drives the first thrust surface 3111 to push the thrust block 411 again, and this process is repeated. The thrust block 411 is finally located at the end of the first thrust surface 3111 away from the driving member 20, that is, the highest position of the first thrust surface 3111. At this time, the phase difference between the angle of the second blade 42 around the rotating shaft 10 and the angle of the first blade 32 around the rotating shaft 10 is a preset value. In this way, the first blade 32 and the second blade 42 can be automatically folded when the driving member 20 is not working, and automatically unfolded when the driving member 20 is working. When the aircraft folding propeller mechanism 100 is installed to the aircraft 1000 (such as Fig.11 As shown in the figure, the aircraft 1000 does not need the driving member 20 to work during the flight phase. At this time, the first blade 32 and the second blade 42 are automatically folded, thereby reducing the flight resistance generated by the aircraft 1000 during the fixed-wing flight, which is beneficial to improving the flight performance of the aircraft 1000.

[0037] In this embodiment, the aircraft foldable propeller mechanism 100 also includes a limit assembly 70, which is arranged on the rotating shaft 10 and is located on the side of the second hub 41 away from the first hub 31. The limit base 71 limits the second hub 41 from being separated from the rotating shaft 10 when the second blade 42 and the first blade 32 are in the unfolded state.

[0038] In some other embodiments, the shape of the thrust block 411 can also be set to be L-shaped or T-shaped, and correspondingly, the shape of the thrust groove 311 can also be set to be L-shaped or T-shaped. Then, the thrust block 411 and the thrust groove 311 cooperate with each other to limit the second hub 41 from being separated from the rotating shaft 10 when the second blade 42 and the first blade 32 are in the deployed state. The embodiments of the present application do not make specific limitations on this.

[0039] In this embodiment, the number of the first blade 32 and the second blade 42 can be multiple and correspond to each other one by one. The multiple first blades 32 are evenly arranged around the first hub 31, and the multiple second blades 42 are evenly arranged around the second hub 41. In the folded state, the circumferential phase difference between each second blade 42 and the corresponding first blade 32 is zero, and in the unfolded state, the circumferential phase difference between each second blade 42 and the corresponding first blade 32 is a preset value. For ease of understanding and explanation, in this embodiment, the number of the first blade 32 and the second blade 42 is two, and in the unfolded state, the preset value of the circumferential phase difference between each second blade 42 and the corresponding first blade 32 is close to 90 degrees. Obviously, this is not a limitation of the embodiment of the present application.

[0040] In this embodiment, the number of thrust blocks 411 and thrust slots 311 can be multiple and correspond one to one, which is beneficial to improving the stability and accuracy of the thrust blocks 411 and thrust slots 311 cooperating to present the second blade 42 in a folded state or an unfolded state relative to the first blade 32.

[0041] In this embodiment, the groove walls at both ends of the thrust groove 311 are respectively a first limiting surface 3112 and a second limiting surface 3113, the first limiting surface 3112 is close to the highest position of the first thrust surface 3111, the second limiting surface 3113 is close to the lowest position of the first thrust surface 3111, and the first limiting surface 3112 is higher than the second limiting surface 3113. When the thrust block 411 abuts against the first limiting surface 3112, the second blade 42 and the first blade 32 are in an unfolded state, and when the thrust block 411 abuts against the second limiting surface 3113, the second blade 42 and the first blade 32 are in a folded state.

[0042] Please refer to Figure 5In this embodiment, the first limiting surface 3112 and the side of the thrust block 411 close to the first limiting surface 3112 are both planes, thereby ensuring that when the second blade 42 and the first blade 32 are in the deployed state, the first limiting surface 3112 and the thrust block 411 have sufficient contact surface, which on the one hand improves the accuracy of the first limiting surface 3112 limiting the thrust block 411, and on the other hand improves the service life of the first limiting surface 3112 and the thrust block 411.

[0043] In this embodiment, the thrust block 411 has a second thrust surface 4111 on one side facing the first thrust surface 3111, which is in surface contact with the first thrust surface 3111, and the inclination angle of the second thrust surface 4111 is the same as the inclination angle of the first thrust surface 3111. When the second blade 42 and the first blade 32 are in a folded state or an unfolded state, and the second blade 42 is in the process of folding or unfolding, the second thrust surface 4111 abuts against the first thrust surface 3111, thereby increasing the contact area between the thrust block 411 and the first thrust surface 3111, thereby increasing the stability of the thrust block 411 sliding in the thrust groove 311, and increasing the stability of the first hub 31 rotating the second hub 41 by pushing the thrust block 411 against the first thrust surface 3111.

[0044] In this embodiment, a lubricating liquid (not shown) may be provided between the first thrust surface 3111 and the second thrust surface 4111 , so as to help improve the smoothness of the thrust block 411 sliding in the thrust groove 311 .

[0045] See also Figure 2 and Figure 3 In this embodiment, the aircraft foldable propeller mechanism 100 further includes a thrust elastic member 50, which may be a spring. The thrust elastic member 50 is sleeved on the rotating shaft 10 and is located on the side of the second propeller hub 41 away from the first propeller hub 31. One end of the thrust elastic member 50 is connected to the rotating shaft 10, and the other end of the thrust elastic member 50 is transmission-connected to the second propeller hub 41. The thrust elastic member 50 is used to apply pressure to the second propeller hub 41. In this way, the thrust elastic member 50 always provides thrust to the second propeller hub 41 toward the first propeller hub 31, and when the driving member 20 stops working, it is convenient to quickly adjust the second blade 42 and the first blade 32 to the folded state. In addition, when the second blade 42 and the first blade 32 are in a folded state, the pressure applied by the thrust elastic member 50 limits the thrust block 411 to the lowest position of the first thrust surface 3111. The thrust elastic member 50 also cooperates with the first thrust surface 3111 and the second limiting surface 3113 to form a self-locking effect, ensuring that the second blade 42 and the first blade 32 are always in a stable folded state, preventing the second blade 42 from being unfolded due to wind force and the like.

[0046] In this embodiment, the design of the thrust elastic member 50 needs to meet the following conditions: During the deployment of the second blade 42, when the second blade 42 just begins to deploy (at this time, the second thrust surface 4111 is out of contact with the first thrust surface 3111): Fp1>=K×dh+F 12 , that is, Fp1- F 12 >=K×dh; When the expansion is about to end: Fp2>=K×(h+dh) + F 12 , that is, Fp2- F 12 >=K×(h+dh); During the folding process of the second blade 42, when the second blade 42 just begins to be folded (at this time, the second thrust surface 4111 is out of contact with the first thrust surface 3111): K×(h+dh)>Fp3+ F 22 ; When the second paddle 42 is about to be folded: K× dh>F 22 ; Wherein, K is the stiffness of the thrust elastic member 50, dh is the deformation of the thrust elastic member 50 when the second blade 42 and the first blade 32 are in the folded state, h is the lifting height of the thrust block 411 in the thrust groove 311, h+dh is the deformation of the thrust elastic member 50 when the second blade 42 and the first blade 32 are in the unfolded state, Fp1 is the lift of the second blade 42 corresponding to the second blade 42 driving the second hub 41 to start moving at a rotation speed of RPM1, Fp2 is the lift of the second blade 42 corresponding to the second blade 42 being fully unfolded at a rotation speed of RPM2, Fp3 is the lift of the second blade 42 corresponding to the second blade 42 starting to move downward at a rotation speed of RPM3, RPM3 is not equal to RPM2, F 12 is the friction force between the thrust block 411 and the wall of the thrust groove 311 when the second hub 41 moves upward around the rotation axis 10, F 22 It is the friction force between the thrust block 411 and the groove wall of the thrust groove 311 when the second hub 41 moves downward around the rotation shaft 10 .

[0047] See also Figure 2 and Figure 3 In this embodiment, a stop flange 11 is provided at one end of the rotating shaft 10 away from the driving member 20 along the circumferential direction of the rotating shaft 10, and an end of the thrust elastic member 50 away from the second hub 41 abuts against the stop flange 11. In this way, the thrust elastic member 50 is conveniently connected to the rotating shaft 10.

[0048] In some other embodiments, the end of the thrust elastic member 50 away from the second hub 41 may also be connected to the rotating shaft 10 by welding, bolting, etc., which is not specifically limited in the embodiments of the present application.

[0049] See also Figure 2 and Figure 3 In this embodiment, the aircraft foldable propeller mechanism 100 further includes a sliding bearing 60, which is sleeved on the rotating shaft 10 and inserted into the second propeller hub 41. The rotating shaft 10, the second propeller hub 41 and the sliding bearing 60 are coaxial, and one end of the thrust elastic member 50 close to the second propeller hub 41 abuts against the sliding bearing 60. By providing the sliding bearing 60, it is convenient for the thrust elastic member 50 to be transmission-connected with the second propeller hub 41 through the sliding bearing 60, and the provision of the sliding bearing 60 also improves the accuracy and smoothness of the second propeller hub 41 to freely rotate around the rotating shaft 10 and slide up and down.

[0050] See also Figure 2 , Figure 3 and Figure 7 In this embodiment, the limiting assembly 70 includes a limiting base 71, which is arranged on the rotating shaft 10 and located on the side of the second hub 41 away from the first hub 31. The limiting base 71 is used to limit the distance between the second hub 41 and the first hub 31, and is used to transfer the lift generated by the second blade 42 to the rotating shaft 10. Specifically, the limiting base 71 is arranged on the stop convex edge 11. When the second blade 42 and the first blade 32 are in the unfolded state, the limiting base 71 is abutted on the side of the second hub 41 close to the limiting base 71, thereby limiting the second hub 41 from continuing to move upward along the rotating shaft 10, thereby improving the accuracy of the second blade 42 being unfolded under the action of its own lift. In addition, the lift generated by the second blade 42 can also be transmitted to the rotating shaft 10 through the limiting base 71, so that the lift is transmitted to the aircraft 1000 through the driving member 20, so that the aircraft 1000 can hover and rise and fall.

[0051] Please refer to Figure 6 In this embodiment, an arc-shaped guide groove 412 is provided on the side of the second hub 41 away from the first hub 31. The guide groove 412 is concentric with the rotating shaft 10. The bottom of the guide groove 412 has an inclined abutting slope 4121. The abutting slope 4121 extends from one end of the bottom of the guide groove 412 to the other end. The abutting slope 4121 has a limiting hole 413 at the end away from the first hub 31. The limiting assembly 70 also includes a limiting elastic member 73 and a limiting member 72. The limiting member 72 is slidably inserted in the limiting base 71 and arranged opposite to the guide groove 412. The limiting elastic member 73 is arranged in the limiting base 71, and the two ends of the limiting elastic member 73 are respectively connected to the limiting base 71 and the limiting member 72. The limiting elastic member 73 is used to drive the limiting member 72 to insert into the limiting hole 413 when the second blade 42 is in the unfolded state.

[0052] Specifically, the limiting base 71 is provided with a sliding hole 711 on the side facing the second hub 41, the sliding hole 711 is a blind hole, the limiting member 72 can be a pin, the limiting member 72 is slidably arranged in the sliding hole 711, the limiting elastic member 73 can be a spring, the limiting elastic member 73 is arranged in the sliding hole 711, and the two ends of the limiting elastic member 73 are respectively abutted against the bottom of the sliding hole 711 and the limiting member 72.

[0053] When the second blade 42 is in the unfolded state and rotates at high speed, if it is necessary to reduce the lift of the first blade 32 and the second blade 42, it is necessary to reduce the rotation speed of the shaft 10. If there is no rotation restriction between the first hub 31 and the second hub 41, the second hub 41 will rotate around the shaft 10 with the second blade 42 due to the influence of the inertial force, which seriously affects the stability of the lift output of the first blade 32 and the second blade 42, thereby affecting the flight control quality and flight safety. By setting the limiting elastic member 73 to drive the limiting member 72 to insert into the limiting hole 413 when the second blade 42 is in the unfolded state, it can effectively avoid the relative rotation between the first hub 31 and the second hub 41 due to inertia when the first blade 32 and the second blade 42 are in normal working state, which is beneficial to improve the flight control quality and flight safety of the aircraft 1000. In addition, by providing a limiting elastic member 73 and providing an abutment slope 4121 at the bottom of the guide groove 412, when the second blade 42 changes from the unfolded state to the folded state, the limiting elastic member 73 can also drive the limiting member 72 to squeeze the abutment slope 4121, thereby providing a thrust to the second hub 41 toward the first hub 31, thereby improving the efficiency of adjusting the second blade 42 and the first blade 32 to the folded state.

[0054] In this embodiment, when the second blade 42 and the first blade 32 are in a folded state, the axis of the limiting hole 413 intersects perpendicularly with the mounting axis (not shown) of the first blade 32; when the second blade 42 and the first blade 32 are in an unfolded state, the axis of the limiting hole 413 is perpendicular to the mounting axis of the first blade 32 and differs from the rotation axis 10 by a preset value of the phase difference.

[0055] In some other embodiments, the limiting member 72 and the limiting elastic member 73 can be eliminated, and a first friction surface (not shown) and a second friction surface (not shown) that match are respectively provided on the side of the second hub 41 facing the limiting base 71 and the side of the limiting base 71 facing the second hub 41, so that the first hub 31 and the second hub 41 can be limited to rotate relative to each other during deceleration by increasing the friction between the second hub 41 and the limiting base 71. Alternatively, a matching mortise and tenon structure (not shown) or a tenon-mouth structure (not shown) is respectively provided on the side of the second hub 41 facing the limiting base 71 and the side of the limiting base 71 facing the second hub 41, so that the first hub 31 and the second hub 41 can be limited to rotate relative to each other during deceleration by the mortise and tenon structure or the tenon-mouth structure. The embodiments of the present application do not specifically limit this.

[0056] See also Figure 1 and Figure 3 In this embodiment, the aircraft foldable propeller mechanism 100 also includes a first fairing 80 and a second fairing 90. The first fairing 80 is arranged on the peripheral side of the first hub 31, and the first blade 32 is inserted into the first fairing 80. The second fairing 90 is arranged on the peripheral side of the second hub 41 and the end of the rotating shaft 10 away from the driving member 20. The end of the second fairing 90 close to the first fairing 80 is slidably sleeved on the end of the first fairing 80 close to the second fairing 90 and is located on the side of the first hub 31 away from the driving member 20, or the end of the second fairing 90 close to the first fairing 80 is slidably inserted into the end of the first fairing 80 close to the second fairing 90 and is located on the side of the first hub 31 away from the driving member 20, and the second blade 42 is inserted into the second fairing 90.

[0057] By providing the first fairing 80 and the second fairing 90, the resistance of the aircraft 1000 during flight can be effectively reduced, thereby facilitating the improvement of the flight performance of the aircraft 1000. In addition, by providing an end of the second fairing 90 close to the first fairing 80 to be slidably sleeved on an end of the first fairing 80 close to the second fairing 90, or an end of the second fairing 90 close to the first fairing 80 to be slidably inserted on an end of the first fairing 80 close to the second fairing 90, when the second blade 42 and the first blade 32 are in the deployed state, the second fairing 90 and the first fairing 80 are not separated in the axial direction, thereby effectively preventing the airflow from entering between the second fairing 90 and the first fairing 80 and improving the resistance of the aircraft 1000 during flight, thereby further facilitating the improvement of the flight performance of the aircraft 1000.

[0058] The process of unfolding the second blade 42 of the aircraft foldable propeller mechanism 100 of the embodiment of the present application is roughly as follows: Step 1: After receiving the control system signal of the aircraft 1000 , the driving member 20 drives the rotating shaft 10 to rotate from a stationary state and gradually increases the speed to a desired range, thereby driving the first propeller hub 31 to rotate.

[0059] Step 2: Since the second thrust surface 4111 of the thrust block 411 on the second hub 41 is pressed against the first thrust surface 3111 , when the first hub 31 starts to rotate, the first thrust surface 3111 and the second thrust surface 4111 simultaneously push the second hub 41 to rotate.

[0060] Step 3: As the rotation speed increases, the second blade 42 will generate an upward lift until the lift exceeds the thrust generated by the compression of the thrust elastic member 50 , and the second hub 41 will move above the rotating shaft 10 under the lift of the second blade 42 .

[0061] Step 4: When the second hub 41 moves upward, the first thrust surface 3111 and the second thrust surface 4111 will separate, and the second hub 41 will instantly lose the power of rotation. Theoretically, the rotation speed will not increase or even decrease at the moment of separation.

[0062] Step 5: After the first thrust surface 3111 and the second thrust surface 4111 separate, the first hub 31 continues to accelerate, so the first thrust surface 3111 will quickly catch up with the second thrust surface 4111 and keep in contact. At this point, the angles of the first blade 32 and the second blade 42 around the rotation axis 10 will have a certain phase difference.

[0063] Step six: Repeat steps two to five, the limiting member 72 gradually abuts against the abutting inclined surface 4121 and the limiting elastic member 73 is compressed until the phase difference between the angles of the first blade 32 and the second blade 42 around the rotating shaft 10 is close to 90 degrees. Since the first limiting surface 3112 and the thrust block 411 cooperate to limit, and the limiting elastic member 73 drives the limiting member 72 to insert into the limiting hole 413 for limiting, the phase difference between the angles of the first blade 32 and the second blade 42 around the rotating shaft 10 will be maintained at about 90 degrees. At this time, the first blade 32 and the second blade 42 are in the expanded state.

[0064] See also Figure 8 and Fig. 9 During the unfolding of the second blade 42, the height h of the thrust block 411 of the second hub 41 in the thrust groove 311 and the distance h1 between the side of the second hub 41 facing the limiting base 71 and the side of the limiting base 71 facing the second hub 41 when the second blade 42 is in the folded state satisfy the following relationship: h1>=h, preferably, h1=h.

[0065] In addition, after the second thrust surface 4111 contacts the first thrust surface 3111, the interaction force F1 between the thrust block 411 and the first thrust surface 3111 perpendicular to the first thrust surface 3111 is: , wherein Fx1 is the interaction force between the thrust block 411 and the first thrust surface 3111 in the horizontal direction when the second hub 41 rotates around the rotating shaft 10, the component Fx1 symmetrically distributed around the axis of the rotating shaft 10 provides the torque for the second hub 41 to rotate around the rotating shaft 10, and Fz1 is the thrust for the second hub 41 to move upward along the rotating shaft 10.

[0066] The folding process of the second blade 42 of the aircraft foldable propeller mechanism 100 of the embodiment of the present application is roughly as follows: Step 1: After receiving the control system signal of the aircraft 1000 , the driving member 20 gradually stops working, and drives the first propeller hub 31 and the rotating shaft 10 to gradually stop rotating.

[0067] Step 2: When the second blade 42 gradually decreases its rotation speed following the second hub 41, the lift generated by the second blade 42 will gradually decrease. Therefore, under the thrust of the thrust elastic member 50 and the gradually decreasing lift of the second blade 42, the second hub 41 will gradually move toward the first hub 31 until the limiting member 72 disengages from the limiting hole 413.

[0068] Step 3: After the stopper 72 is released from the stopper hole 413, the first hub 31 is subjected to the resistance of the driving member 20, and the rotation speed is reduced faster. Since the second blade 42 and the second hub 41 can rotate around the rotating shaft 10, the second hub 41 rotates in the folding direction around the rotating shaft 10 under the thrust of the thrust elastic member 50 and its own inertia force, until the thrust block 411 contacts the second stopper surface 3113, and the second blade 42 is folded. In this step, since the first hub 31 decelerates faster, the first thrust surface 3111 and the second thrust surface 4111 are always in a separated or weakly contacted state.

[0069] Step 4: After the second blade 42 is folded, even when the aircraft 1000 is flying at high speed, the second blade 42 cannot generate a large lift, and the first thrust surface 3111 and the second thrust surface 4111 always keep in contact. Since the first thrust surface 3111 and the second thrust surface 4111 are inclined surfaces, the thrust block 411 forms a self-locking effect with the first thrust surface 3111 and the second limit surface 3113 under the thrust of the thrust elastic member 50, so the second blade 42 and the first blade 32 will form a stable folded state.

[0070] See also Fig.10 During the folding process of the second blade 42, when the speed of the driving member 20 decreases and the second blade 42 needs to be folded, the force analysis of the second hub 41 is as follows: Fz 21 >Fz22 +Fz 23 , where Fz 21 is the thrust applied to the second hub 41 by the thrust elastic member 50 after being compressed, Fz 22 is the friction force generated between the thrust block 411 and the wall of the thrust groove 311 when the second hub 41 moves downward along the rotating shaft 10, Fz 23 is the lift generated when the second blade 42 rotates. When the above relationship is satisfied, the second hub 41 will move downward along the rotating shaft 10.

[0071] In addition, when the driving member 20 reduces its rotational speed, the rotational speed of the first hub 31 will be reduced synchronously because it is directly connected to the driving member 20 through the rotating shaft 10, while the rotational speed of the second hub 41 will be lower than that of the first hub 31 due to the inertia force. Therefore, during the folding process of the second blade 42, a gap ds can always be maintained between the second thrust surface 4111 and the first thrust surface 3111, which provides space for the second hub 41 to move downward along the rotating shaft 10.

[0072] To summarize, the aircraft foldable propeller mechanism 100 of the embodiment of the present application is provided with an arc-shaped thrust groove 311 on the side of the first hub 31 away from the driving member 20, a first thrust surface 3111 is provided at the bottom of the thrust groove 311, and a thrust block 411 is protruded from the side of the second hub 41 facing the first hub 31 and extends into the thrust groove 311. When the driving member 20 is not working, the second hub 41 can approach the first hub 31 under the action of its own gravity and inertia or under the action of external force, and the thrust block 411 and the thrust groove 311 cooperate to enable the second hub 41 to drive the second blade 42 to rotate, thereby putting the second blade 42 and the first blade 32 in a folded state. When the aircraft foldable propeller mechanism 100 is installed on the aircraft 1000, the aircraft 1000 does not need the driving member 20 to work during the flight stage, and the second blade 42 and the first blade 32 are automatically in a folded state, thereby reducing the flight resistance generated by the aircraft 1000 during the flight, thereby facilitating the improvement of the flight performance of the aircraft 1000. In addition, when the driving member 20 is working, the lift generated by the rotation of the second blade 42 causes the second blade 42 to be in an unfolded state relative to the first blade 32, thereby facilitating the lifting and hovering of the aircraft 1000.

[0073] In addition, the aircraft folding propeller mechanism 100 of the embodiment of the present application can automatically follow the working state of the driving member 20 to realize the active deployment and folding of the first blade 32 and the second blade 42. It adopts a pure mechanical structure, has a simple structure, reliable functions, small space occupation, and low weight cost, and does not require electric drive equipment such as a servo (not shown) to assist the first blade 32 and the second blade 42 in deployment and folding, thereby reducing the complexity of the system, verification costs, and material costs. During the flight of the aircraft 1000, the pilot or the flight control system does not need to actively control the deployment and folding process, which simplifies the difficulty of the control system design and reduces the pilot's operating burden. Furthermore, since the first blade 32 and the second blade 42 can be actively deployed and folded according to the working state of the driving member 20, it is ensured that the aircraft folding propeller mechanism 100 can be used for stall protection when the aircraft 1000 is fixed in flight, thereby helping to improve the safety performance of the aircraft 1000.

[0074] Please refer to Fig.11 The embodiment of the present application also provides an aircraft 1000, including a body 200 and the above-mentioned aircraft foldable propeller mechanism 100, the aircraft foldable propeller mechanism 100 is installed on the body 200, and the aircraft foldable propeller mechanism 100 is used to provide lift when the aircraft 1000 takes off and lands vertically. When the second blade 42 is in a folded state, the extension direction of the second blade 42 and the extension direction of the first blade 32 are the same as the flight direction of the aircraft 1000. Specifically, the driving member 20 of the aircraft foldable propeller mechanism 100 is connected to the body 200.

[0075] The aircraft 1000 of the embodiment of the present application provides lift when the aircraft 1000 takes off and lands vertically by providing the aircraft folding propeller mechanism 100. The aircraft folding propeller mechanism 100 has a simple structure and is folded and unfolded in a purely mechanical manner, which enables the first blade 32 and the second blade 42 to be automatically folded during the fixed-wing flight of the aircraft 1000, thereby reducing the flight resistance of the aircraft 1000, and further facilitating the improvement of the flight performance of the aircraft 1000. In addition, by setting the second blade 42 in the folded state so that the extension direction of the second blade 42 and the extension direction of the first blade 32 are the same as the flight direction of the aircraft 1000, the flight resistance generated by the aircraft 1000 during the fixed-wing flight can be further reduced, thereby further improving the flight performance of the aircraft 1000.

[0076] In this embodiment, the aircraft 1000 also includes a fixed propeller mechanism 300 installed on the body 200. The fixed propeller mechanism 300 is used to provide lift when the aircraft 1000 takes off and lands vertically, and to provide pulling force or thrust when the aircraft 1000 is flying. By setting up the fixed propeller mechanism 300, the flight performance of the aircraft 1000 can be further improved.

[0077] It is obvious to those skilled in the art that the present application is not limited to the details of the exemplary embodiments described above, and that the present application can be implemented in other specific forms without departing from the spirit or essential features of the present application. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present application is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present application.

[0078] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present application and are not intended to limit it. Although the present application has been described in detail with reference to the preferred embodiments, a person of ordinary skill in the art should understand that the technical solution of the present application may be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present application.

Claims

1. A foldable propeller mechanism for an aircraft, characterized in that: include: Rotating shaft; A driving member connected to one end of the rotating shaft and used for driving the rotating shaft to rotate; A first propeller, comprising a first propeller hub and a first propeller blade connected to each other, wherein the first propeller hub is fixedly connected to the rotating shaft, an arc-shaped thrust groove is provided on a side of the first propeller hub away from the driving member, and a groove bottom of the thrust groove has an inclined first thrust surface; The second propeller includes a second hub and a second blade connected to each other. The second hub is movably mounted on the rotating shaft and is located on a side of the first hub away from the driving member. A thrust block extending into the thrust groove is protruded from the second hub toward the first hub. The thrust block and the thrust groove cooperate to make the second blade present a folded state or an unfolded state relative to the first blade. In the folded state, the circumferential phase difference between the second blade and the first blade is zero. In the unfolded state, the circumferential phase difference between the second blade and the first blade is a preset value. The first thrust surface is used to abut against the thrust block when the second blade switches between the folded state and the unfolded state.

2. The aircraft foldable propeller mechanism according to claim 1, characterized in that: The aircraft foldable propeller mechanism also includes a thrust elastic member, which is sleeved on the rotating shaft and located on the side of the second hub away from the first hub, one end of the thrust elastic member is connected to the rotating shaft, and the other end of the thrust elastic member is transmission-connected to the second hub, and the thrust elastic member is used to apply pressure to the second hub.

3. The aircraft foldable propeller mechanism according to claim 2, characterized in that: The aircraft foldable propeller mechanism also includes a sliding bearing, which is sleeved on the rotating shaft and inserted into the second propeller hub, and one end of the thrust elastic member close to the second propeller hub abuts against the sliding bearing.

4. The aircraft foldable propeller mechanism according to claim 2, characterized in that: One end of the rotating shaft away from the driving member is provided with a stop convex edge along the circumference of the rotating shaft, and one end of the thrust elastic member away from the second hub is in contact with the stop convex edge.

5. The aircraft foldable propeller mechanism according to claim 2, characterized in that: The aircraft foldable propeller mechanism also includes a limit assembly, which includes a limit base. The limit base is arranged on the rotating shaft and is located on the side of the second hub away from the first hub. The limit base is used to limit the distance between the second hub and the first hub, and is used to transfer the lift generated by the second blade to the rotating shaft.

6. The aircraft foldable propeller mechanism according to claim 5, characterized in that: An arc-shaped guide groove is provided on the side of the second hub facing away from the first hub, the guide groove is concentric with the rotating shaft, the bottom of the guide groove has an abutment slope, and a limiting hole is provided at the end of the abutment slope away from the first hub; the limiting assembly also includes a limiting elastic part and a limiting part, the limiting part is slidably inserted in the limiting base and arranged opposite to the guide groove, the limiting elastic part is arranged in the limiting base, and the two ends of the limiting elastic part are respectively connected to the limiting base and the limiting part, and the limiting elastic part is used to drive the limiting part to be inserted into the limiting hole when the second blade is in the expanded state.

7. The aircraft foldable propeller mechanism according to claim 5, characterized in that: A side of the second hub facing the limiting base and a side of the limiting base facing the second hub respectively have a first friction surface and a second friction surface that match each other; or, A side of the second hub facing the limiting base and a side of the limiting base facing the second hub are respectively provided with matching mortise and tenon structures.

8. The aircraft foldable propeller mechanism according to claim 1, characterized in that: The thrust block has a second thrust surface on a side facing the first thrust surface that is in surface contact with the first thrust surface.

9. The aircraft foldable propeller mechanism according to claim 1, characterized in that: The aircraft folding propeller mechanism also includes a first fairing and a second fairing, the first fairing is arranged on the circumferential side of the first hub, the first blade is inserted into the first fairing, the second fairing is arranged on the circumferential side of the second hub and the end of the rotating shaft away from the driving member, the end of the second fairing close to the first fairing is slidably mounted on the end of the first fairing close to the second fairing and is located on the side of the first hub away from the driving member, or the end of the second fairing close to the first fairing is slidably inserted into the end of the first fairing close to the second fairing and is located on the side of the first hub away from the driving member, and the second blade is inserted into the second fairing.

10. An aircraft, characterized in that: It comprises a fuselage and a foldable propeller mechanism for an aircraft as described in any one of claims 1 to 9, wherein the foldable propeller mechanism for an aircraft is mounted on the fuselage, and is used to provide lift when the aircraft takes off and lands vertically, and when the second blade is in the folded state, the extension direction of the second blade and the extension direction of the first blade are the same as the flight direction of the aircraft.

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