Annular propeller of cross-domain aircraft, cross-domain aircraft and use method of cross-domain aircraft

Abstract

The invention provides an annular propeller of a cross-domain aircraft, the cross-domain aircraft and a use method of the cross-domain aircraft, and belongs to the field of cross-domain aircrafts, the connecting part, close to the downstream, of the connecting part of a propeller blade and a propeller hub is a heel part, and the part, from the blade tip to the heel part, of the propeller blade is a rear section; the rear section comprises a spiral section, a straight section and a movable section, one end of the spiral section extends to the blade tip, the other end of the spiral section extends towards the heel part, the straight section is arranged at the heel part and straightly extends by aligning to the free end of the spiral section, one end of the movable section is inserted into the straight section, and the other end of the movable section abuts against the free end of the spiral section; and the movable section moves towards the straight section and is separated from the spiral section. The rear root part of the annular propeller is provided with the movable section, the movable section can move and enter the straight section, the propeller blades are switched between the annular structure and the non-annular structure, the propelling direction of the propeller blades does not need to be changed according to the change of the navigation environment, and the annular propeller can also be applied to a cross-domain navigation unmanned aerial vehicle.

Description

Technical Field

[0001] The present invention relates to the technical field of cross-domain aircraft, and in particular to a ring-shaped propeller of a cross-domain aircraft, a cross-domain aircraft and a method for using the same. Background Art

[0002] Cross-domain aircraft is a new concept aircraft that can navigate across domains in a variety of media environments. For example, Chinese patent CN113928068A discloses an underwater-air cross-domain aircraft that can dive underwater and fly in the air. In particular, at a time when drones are increasingly widely used, cross-domain navigation drones have a broader application prospect in military and civilian applications.

[0003] The drone can fly, and the main propulsion role is played by the propeller; currently, the use of annular propellers for propulsion on drones has gradually become a hot topic. Compared with conventional non-annular propellers, the advantage of annular propellers is that their propulsion efficiency can be doubled with the same number of blades. However, the application of annular propellers on cross-domain navigation drones has encountered some problems:

[0004] First, the physical properties of water and air are quite different, and there will be significant differences in the operating state and propulsion performance of the annular propeller in the two media.

[0005] Secondly, when the drone is sailing underwater, the propeller's rotating surface is vertical and provides horizontal propulsion. When the drone is sailing in the air, the propeller's rotating surface can be horizontal and provide vertical lift; the propeller's rotating surface can also be vertical and provide horizontal jet thrust. However, annular propellers are usually used as propellers to provide lift, and are not suitable for use as propellers to provide jet thrust. Therefore, cross-domain navigation drones are not suitable for using annular propellers as a propulsion power source, which also limits the application scenarios of annular propellers. Summary of the invention

[0006] In view of this, the present invention proposes a ring-shaped propeller of a cross-domain aircraft, a cross-domain aircraft and a method of using the same, which solves the problem that cross-domain navigation UAVs are not suitable for using ring-shaped propellers as a propulsion power source.

[0007] The technical solution of the present invention is achieved as follows: the present invention provides an annular propeller for a cross-domain vehicle, comprising a hub, a central axis of which is the rotation axis of the annular propeller, and a plurality of blades, which are arranged on the outer peripheral wall of the hub around the central axis; wherein, taking the direction of the annular propeller toward downstream as the first direction, there are two parts where the blades are connected to the hub, and the two connecting parts are arranged at intervals along the first direction, the connecting part close to the downstream is the rear root, and the part of the blade from the blade tip to the rear root is the rear section; the rear section includes a spiral section, a straight section and a movable section, one end of the spiral section extends to the blade tip and the other end extends toward the rear root, the straight section is arranged at the rear root and extends straightly toward the free end of the spiral section, the straight section is a hollow cylinder, the movable section is arranged between the spiral section and the straight section, one end of the movable section is inserted in the straight section and the other end is abutted against the free end of the spiral section, the movable section moves relative to the hub along the extension direction of the straight section, so that the movable section moves toward the straight section and breaks contact with the spiral section.

[0008] On the basis of the above technical solution, preferably, it further includes a telescopic mechanism, which is arranged in the straight section; wherein the telescopic mechanism is connected to the end of the movable section inserted in the straight section, and the telescopic mechanism drives the movable section to move relative to the hub.

[0009] On the basis of the above technical scheme, preferably, the connecting part between the blade and the hub close to the upstream is the front root, the part of the blade from the blade tip to the front root is the front section, the rotation direction of the annular propeller is the second direction, the side edge of the front section along the second direction is the leading edge, and the side edge of the rear section facing away from the second direction is the trailing edge; in the radial section of the annular propeller, a circle is drawn with the central axis as the center and the circle intersects the leading edge and the trailing edge at two points, the maximum distance between the two points is the width L of the blade, the distance from the blade tip to the central axis is the radius R of the blade, and the ratio of R:L is 0.8~1.

[0010] More preferably, in a radial section of the annular propeller, a distance between a free end of the spiral segment and an outer peripheral wall of the hub is no greater than 1 / 3R.

[0011] On the basis of the above technical solution, preferably, a tip portion is provided on the free end of the spiral segment, and the outer contour of the tip portion is a sheet-like streamlined shape; a matching groove is provided on the free end of the movable segment, and the inner contour of the matching groove matches the outer contour of the tip portion, so that when the movable segment abuts against the spiral segment, the tip portion is inserted and wrapped in the matching groove.

[0012] On the basis of the above technical solution, preferably, a groove is provided on the outer peripheral wall of the hub; and the straight section is arranged in the groove.

[0013] More preferably, after the movable section moves and enters the straight section, the outer end surface of the straight section and the outer end surface of the free end of the movable section are flush with the outer peripheral wall of the hub.

[0014] Based on the above technical solution, preferably, the number of blades is a prime number.

[0015] In a second aspect, the present invention further provides a cross-domain vehicle that sails on the water surface or underwater and uses the above-mentioned annular propeller of the cross-domain vehicle, and the number of the annular propeller used in the cross-domain vehicle is at least one.

[0016] In the third aspect, the present invention also provides a method for using a cross-domain vehicle, which adopts the above-mentioned cross-domain vehicle; when the cross-domain vehicle is sailing underwater, the movable section is in contact with the spiral section; when the cross-domain vehicle is sailing on the water surface and a part of any blade is located above the water surface, the movable section moves into the straight section and breaks contact with the spiral section.

[0017] The annular propeller of the cross-domain vehicle, the cross-domain vehicle and the use method thereof of the present invention have the following beneficial effects compared with the prior art:

[0018] (1) The annular propeller of the present invention has a movable section at the rear root, which can move and enter the straight section. When the aircraft is sailing underwater, the movable section and the spiral section maintain contact so that the blades have an annular structure to improve the propulsion efficiency. When the aircraft is sailing in the air, the movable section and the spiral section are out of contact and the blades are switched from the annular structure to the non-annular structure. The blades provide jet propulsion power for the UAV instead of lift, so that the blades do not need to change the propulsion direction according to changes in the navigation environment. By switching the blades between the annular structure and the non-annular structure, the annular propeller can also be applied to cross-domain navigation UAVs, thereby improving the versatility of the annular propeller.

[0019] (2) The rotation radius and maximum width of the annular blade of the present invention have a certain ratio. On the basis of ensuring that the blade has sufficient length to provide propulsion, the maximum width of the blade should not be too small, which will cause the blade to have a slender shape. This will cause the movable section to retreat into the straight section so that the blade switches to a non-annular structure. The overall structural strength of the slender blade will be greatly reduced. Therefore, the above-mentioned risk is avoided by designing the ratio of the rotation radius and the maximum width of the blade.

[0020] (3) The free end of the spiral segment of the present invention is provided with a sheet-like streamlined tip portion, and the movable segment cooperates with the tip portion through a matching groove. On the one hand, when the movable segment abuts against the spiral segment, the tip portion is wrapped in the matching groove to form a wedge-type connection structure, which helps to enhance the connection strength between the movable segment and the spiral segment. On the other hand, when the blade is switched to a non-annular structure, the tip portion helps to reduce the resistance encountered by the blade when it rotates, and improves the airflow environment when the blade rotates, which helps to improve the propulsion efficiency of the propeller. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 is a perspective view of an annular propeller of the present invention;

[0023] Figure 2 A three-dimensional diagram of the annular propeller of the present invention from another perspective;

[0024] Figure 3 A three-dimensional diagram of the annular propeller of the present invention from another perspective;

[0025] Figure 4 A front view comparison diagram of the state change of the annular propeller of the present invention;

[0026] Figure 5 A cross-sectional comparison diagram of the state change of the latter stage of the present invention;

[0027] Figure 6 It is a cross-sectional view of another embodiment of the latter stage of the present invention.

[0028] In the figure: 1. hub; 2. blade; 21. rear section; 22. front section; 211. spiral section; 212. straight section; 213. movable section; 214. tip; 201. rear root; 202. front root; 203. matching groove; 204. groove; 3. telescopic mechanism. DETAILED DESCRIPTION

[0029] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] like Figure 1 As shown, combined Figure 2 and Figure 4 The annular propeller of a cross-domain vehicle of the present invention comprises:

[0031] The central axis of the hub 1 is the rotation axis of the annular propeller.

[0032] A plurality of blades 2 are arranged on the outer peripheral wall of the hub 1 around the central axis. With the direction of the annular propeller toward the downstream as the first direction, there are two parts where the blade 2 is connected to the hub 1, and the two connection parts are arranged at intervals along the first direction. The connection part close to the downstream is the rear root 201, and the part of the blade 2 from the blade tip to the rear root 201 is the rear section 21. The purpose of this scheme is to design a propeller that can switch between an annular structure and a non-annular structure. One feasible implementation scheme is based on the principle of designing a movable part at the rear root 201 of the annular blade 2. Through the displacement of the movable part, the blade 2 is switched between a completed annular structure and a broken ring structure with a gap.

[0033] Specifically, the rear section 21 includes a spiral section 211 , a straight section 212 and a movable section 213 .

[0034] Among them, one end of the spiral segment 211 extends to the blade tip and the other end extends toward the rear root 201. The spiral segment 211 extends along the spiral generatrix during the extension process. Therefore, if the movable part is a part of the spiral segment 211, the structure of the movable part is difficult to design and its movable range is also difficult to control.

[0035] Therefore, the inventors thought whether it is possible to add a section of the blade 2 at the rear root 201, which extends straight. On the one hand, it will not affect the extension state of the spiral section 211 along the spiral generatrix. On the other hand, the straight extension section can be split into a fixed part and a movable part, so that the blade 2 can be switched between a complete ring and a broken ring. Specifically, the straight section 212 is arranged at the rear root 201 and extends straightly to the free end of the spiral section 211. The straight section 212 is a hollow cylinder; and the movable section 213 is arranged between the spiral section 211 and the straight section 212; when the blade 2 is a ring structure, one end of the movable section 213 is inserted into the straight section 212 and the other end is in contact with the free end of the spiral section 211; and when the blade 2 is a broken ring structure, the movable section 213 moves relative to the hub 1 along the extension direction of the straight section 212, so that the movable section 213 moves toward the straight section 212 and breaks contact with the spiral section 211. By adopting the above design, the blade 2 can realize the function of switching between the annular structure and the non-annular structure, so that the annular propeller can also be applied to cross-domain navigation drones, thereby improving the versatility of the annular propeller.

[0036] exist Figure 5 In a preferred embodiment shown, in order to drive the movable section 213 to move, a telescopic mechanism 3 is also included.

[0037] The telescopic mechanism 3 is arranged in the straight section 212; the telescopic mechanism 3 can be a hydraulic telescopic rod, a telescopic gas rod, or a telescopic electric rod. The telescopic mechanism 3 is connected to the end of the movable section 213 inserted in the straight section 212, and the telescopic mechanism 3 drives the movable section 213 to move relative to the hub 1. In addition, a locking mechanism is also required to be arranged in the straight section 212 to lock the position of the movable section 213, so as to avoid the need to use the telescopic mechanism 3 to maintain the position of the movable section 213.

[0038] exist Figure 4 In a preferred embodiment shown, combined with Figure 3 , this solution is not applicable to all types of annular propellers, especially annular blades 2 in a slender shape. The reason is that although the annular blades 2 in a slender shape can also use this solution to achieve the switching of the blades 2 between the annular structure and the non-annular structure, when they are deformed into a non-annular structure, the rear section 21 is longer and is only connected to the front section 22 through the blade tip. At this time, the structural strength of the slender blade 2 is very poor. Once it starts to rotate, the rear section 22 of the blade 2 will break due to factors such as centrifugal force and wind resistance. It can be seen that the ratio of the diameter length to the width of the annular blade 2 applicable to this case should not be too large. Specifically, the connection part between the blade 2 and the hub 1 close to the upstream is the front root 202, and the part of the blade 2 from the blade tip to the front root 202 is the front section 22. The rotation direction of the annular propeller is the second direction, and the side edge of the front section 22 along the second direction is the leading edge, and the side edge of the rear section 21 facing away from the second direction is the following edge.

[0039] If in the radial section of the annular propeller, a circle is drawn with the central axis as the center and the circle intersects with the leading edge and the trailing edge at two points, the maximum distance between the two points is the width L of the blade 2, the distance from the tip of the blade 2 to the central axis is the radius R of the blade 2, and the ratio of R:L is 0.8 to 1. At this time, the ratio of the diameter length to the width of the blade 2 is between 1:1 and 5:4, and the blade 2 has a structure similar to a circle or an ellipse. At this time, the blade 2 has good structural strength after forming a broken ring.

[0040] exist Figure 4 In a preferred embodiment shown, in order to further improve the structural strength of the blade 2 after switching to the broken ring structure, in the radial section of the annular propeller, the distance between the free end of the spiral segment 211 and the outer peripheral wall of the hub 1 is no more than 1 / 3R, so the extension length of the spiral segment 211 is not too long, thereby avoiding the probability of its breakage during rotation; in addition, at this time, the hook structure formed by the spiral segment 211 at the rear section 21 is also shorter, making the shape of the blade 2 more similar to a conventional non-annular propeller, which helps to reduce the noise generated by the blade 2 during rotation.

[0041] exist Figure 5In a preferred embodiment shown, in order to reduce the wind resistance that the blade 2 may encounter after switching to the broken ring structure, a tip portion 214 is provided on the free end of the spiral segment 211. The outer contour of the tip portion 214 is a streamlined sheet shape. The tip portion 214 helps to reduce the resistance encountered by the blade 2 when rotating, and improves the airflow environment when the blade 2 rotates, which helps to improve the propulsion efficiency of the propeller. A matching groove 203 is provided on the free end of the movable segment 213. The inner contour of the matching groove 203 matches the outer contour of the tip portion 214, so that when the movable segment 213 abuts against the spiral segment 211, the tip portion 214 is inserted and wrapped in the matching groove 203. The tip portion 214 is wrapped in the matching groove 203 to form a wedge connection structure, which helps to enhance the connection strength between the movable segment 213 and the spiral segment 211.

[0042] exist Figure 6 In a preferred embodiment shown, a groove 204 is provided on the outer wall of the hub 1; the straight section 212 is arranged in the groove 204 to prevent the straight section 212 from protruding from the outer wall of the hub 1 to form a blade 2 similar to a shorter blade, thereby avoiding increasing the blade frequency noise of the propeller.

[0043] exist Figure 6 In a preferred embodiment shown, specifically, after the movable section 213 moves and enters the straight section 212, the outer end surface of the straight section 212 and the outer end surface of the free end of the movable section 213 are flush with the outer peripheral wall of the hub 1. Therefore, assuming that when the blades 2 are in an annular structure, the number of blades 2 is three, then when it is switched to a non-annular structure, the number of blades 2 remains three.

[0044] exist Figure 1 In a preferred embodiment shown, the number of blades 2 is a prime number. Avoiding the number of blades 2 from being an even number can significantly reduce the modes generated by the propeller rotation. The reason is the same as that the blades 2 of a conventional non-annular propeller are usually also a prime number.

[0045] like Figure 1 As shown, a cross-domain vehicle of the present invention sails on the water surface or underwater and adopts the annular propeller of the cross-domain vehicle mentioned above, and the number of the annular propeller adopted by the cross-domain vehicle is at least one.

[0046] like Figure 1 As shown, combined Figure 4A method for using a cross-domain vehicle of the present invention adopts the above-mentioned cross-domain vehicle; when the cross-domain vehicle is sailing underwater, the movable section 213 abuts against the spiral section 211, and the blade 2 is an annular structure at this time, so that the vehicle uses an annular propeller when sailing in an underwater environment. Compared with a non-annular propeller, an annular propeller can provide greater propulsion and reduce blade frequency noise; when the cross-domain vehicle is sailing on the water surface and a part of any blade 2 is located above the water surface, the movable section 213 moves into the straight section 212 and disengages from the spiral section 211, so that the blade 2 switches to a non-annular structure. At this time, the propeller does not need to change the thrust direction to provide horizontal jet thrust for the vehicle to sail in the air.

[0047] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A ring propeller for a cross-domain vehicle, It is characterized in that include: a hub (1), the central axis of which is the rotation axis of the annular propeller, A plurality of blades (2) are arranged around the central axis on the outer peripheral wall of the hub (1); Wherein, with the direction of the annular propeller toward downstream as a first direction, there are two locations where the blade (2) is connected to the hub (1), and the two connection locations are arranged at intervals along the first direction, the connection location close to the downstream is a rear root (201), and the portion of the blade (2) from the blade tip to the rear root (201) is a rear section (21); The rear section (21) comprises a spiral section (211), a straight section (212) and a movable section (213); one end of the spiral section (211) extends to the blade tip and the other end extends toward the rear root (201); the straight section (212) is arranged at the rear root (201) and extends straightly aligned with the free end of the spiral section (211); the straight section (212) is a hollow cylinder; the movable section (213) is arranged between the spiral section (211) and the straight section (212); one end of the movable section (213) is inserted into the straight section (212) and the other end is in contact with the free end of the spiral section (211); the movable section (213) moves relative to the hub (1) along the extension direction of the straight section (212), so that the movable section (213) moves toward the straight section (212) and is out of contact with the spiral section (211).

2. The annular propeller of a cross-domain vehicle according to claim 1, It is characterized in that Also includes: A telescopic mechanism (3) is arranged in the straight section (212); The telescopic mechanism (3) is connected to the movable section (213) inserted at the end of the straight section (212), and the telescopic mechanism (3) drives the movable section (213) to move relative to the propeller hub (1).

3. The annular propeller of a cross-domain vehicle according to claim 1, Features: The connecting portion of the blade (2) and the hub (1) close to the upstream is a front root (202), the portion of the blade (2) from the blade tip to the front root (202) is a front section (22), the rotation direction of the annular propeller is a second direction, the side edge of the front section (22) along the second direction is a leading edge, and the side edge of the rear section (21) facing away from the second direction is a following edge; In the radial section of the annular propeller, a circle is drawn with the central axis as the center and the circle intersects with the leading edge and the trailing edge at two points, the maximum distance between the two points is the width L of the blade (2), the distance from the tip of the blade (2) to the central axis is the radius R of the blade (2), and the ratio of R:L is 0.8 to 1.

4. The annular propeller of a cross-domain vehicle according to claim 3, Features: In the radial section of the annular propeller, the distance between the free end of the spiral segment (211) and the outer peripheral wall of the hub (1) is no greater than 1 / 3R.

5. The annular propeller of a cross-domain vehicle according to claim 1, Features: A tip portion (214) is provided on the free end of the spiral section (211), and the outer contour of the tip portion (214) is a sheet-like streamlined shape; A matching groove (203) is provided on the free end of the movable section (213), and the inner contour of the matching groove (203) matches the outer contour of the tip portion (214), so that when the movable section (213) and the spiral section (211) are in contact, the tip portion (214) is inserted into and wrapped in the matching groove (203).

6. The annular propeller of a cross-domain vehicle according to claim 1, Features: A groove (204) is provided on the outer peripheral wall of the hub (1); and the straight section (212) is arranged in the groove (204).

7. The annular propeller of a cross-domain vehicle according to claim 6, Features: After the movable section (213) moves and enters the straight section (212), the outer end surface of the straight section (212) and the outer end surface of the free end of the movable section (213) are flush with the outer peripheral wall of the hub (1).

8. The annular propeller of a cross-domain vehicle according to claim 1, Features: The number of the blades (2) is a prime number.

9. A cross-domain vehicle, Features: Sailing on the water surface or underwater, and using the annular propeller of the cross-domain vehicle according to any one of claims 1 to 8, the number of the annular propeller of the cross-domain vehicle is at least one.

10. A method for using a cross-domain vehicle, Features: Using a cross-domain navigation vehicle as described in claim 9; When the cross-domain vehicle is sailing underwater, the movable section (213) abuts against the spiral section (211); When the cross-domain vehicle is sailing on the water surface and a portion of any of the blades (2) is located above the water surface, the movable section (213) moves into the straight section (212) and breaks contact with the spiral section (211).

Images