A propeller

Abstract

The present application provides a propeller, belonging to the propeller field, comprising a hub shaft; a first blade is arranged around the hub shaft; a second blade is arranged between two adjacent first blades; the second blade moves synchronously relative to the hub, so that the second blade has a first position and a second position; when the second blades are all in the first position, the first blades and the second blades are all located in the same rotation plane; when the second blades are all in the second position, the first blades and the second blades are located in front and back rotation planes respectively. The present application separates all the blades in the same rotation plane into front and back rotation planes by moving the second blades, avoids the coupling effect of water and air on the single-layer blades during the cross-domain process, ensures the power continuity and stability of the cross-domain switching process, and integrates two sets of blades on the same hub, which can dynamically adjust the relative position of the two sets of blades according to the working condition.

Description

Technical Field

[0001] This invention relates to the field of propeller technology, and more particularly to a propeller. Background Technology

[0002] Cross-domain unmanned vehicles (UAVs) are a new type of unmanned aerial vehicle capable of repeatedly crossing the water-air interface and continuously navigating in both media. They possess both aerial flight and underwater navigation capabilities, and have broad application prospects in fields such as ocean observation, communication relay, reconnaissance and surveillance, emergency search and rescue, and time-sensitive strikes. Because water's density is approximately 800 times that of air, and its physical properties such as viscosity differ significantly, motor-propeller systems suitable for air media generate high torque at low speeds when operating underwater. The motor's output torque limits its speed, preventing it from reaching its efficient output range, and easily leading to motor stalling or even overload damage during operation.

[0003] Currently, propeller design faces two main technical challenges: First, single-layer fixed propellers, under the same configuration, cannot simultaneously achieve efficient propulsion performance for both water and air media. Second, during the transition of a trans-domain vehicle from underwater to aerial flight, there is a transitional phase where part of the propeller blades remains submerged while the other part is above the water surface. At this point, the blades are simultaneously subjected to the coupling effects of both water and air. Due to the significant density difference between water and air, the forces on the blades are extremely unbalanced, causing a sharp drop or even loss of propeller thrust. This results in a severe power shortage during this critical phase, making it difficult for the vehicle to complete a stable trans-domain transition. This power gap during the transition phase is a key technical challenge that urgently needs to be addressed in the field of trans-domain vehicles.

[0004] To address the aforementioned issues, existing technologies have proposed several improvement solutions. For example, CN115649423B discloses a coaxial dual-propeller structure for a cross-medium aircraft, which achieves power switching by placing the water propeller and the air propeller on the same shaft, allowing the air propeller to move axially along the spline shaft. However, this essentially uses two independent propeller components, resulting in a complex structure and increased system mass. CN121106654A discloses a cross-medium variable-body propeller whose blades can switch between folded and unfolded states around a hinge axis to adapt to different media. However, this solution relies on a complex folding mechanism, and the structural reliability under high-speed rotation needs to be verified. Therefore, there is an urgent need to design a novel propeller configuration that addresses the limitations of existing propeller configurations in handling different water and air conditions and the difficulty in eliminating power loss during cross-medium aircraft operations. Summary of the Invention

[0005] In view of this, the present invention proposes a propeller to solve the problem that the configuration of existing propellers cannot take into account different working conditions in water and air, and it is also difficult to eliminate the loss of power during the water-air cross-domain process of the vehicle.

[0006] The technical solution of the present invention is implemented as follows: The present invention provides a propeller, including a hub that rotates along its own axial direction; a plurality of first blades arranged axially around the hub; and a plurality of second blades arranged axially around the hub and respectively disposed between two adjacent first blades; wherein the plurality of second blades move synchronously relative to the hub, so that the second blades have a first position and a second position; when the plurality of second blades are all in the first position, the plurality of first blades and the plurality of second blades are all located on the same rotation plane relative to the radial surface of the hub; when the plurality of second blades are all in the second position, the plurality of first blades and the plurality of second blades are located on two front and rear rotation planes relative to the radial surface of the hub, respectively.

[0007] Based on the above technical solutions, preferably, a plurality of second blades move synchronously back and forth relative to the hub along the axial direction of the hub, or a plurality of second blades move synchronously back and forth relative to the hub along the axial direction of the hub and simultaneously move synchronously circumferentially around the hub.

[0008] More preferably, the number of first blades and second blades are equal, and the first blades and second blades are alternately arranged around the axial direction of the hub; when the second blades move synchronously to the second position relative to the hub along the axial direction of the hub, the first blades and second blades are alternately staggered; when the second blades move synchronously relative to the hub along the axial direction of the hub and simultaneously move circumferentially around the hub to the second position, the first blades and second blades are respectively arranged in pairs along the axial direction of the hub.

[0009] More preferably, it also includes several movable seats, each on which several second blades are respectively provided; wherein, a groove is provided on the outer circumference of the blade hub, with the two ends of the groove extending toward the first position and the second position respectively, and the movable seats are disposed in the groove and move back and forth along the groove.

[0010] More preferably, the rotor hub includes a shell with a groove on its outer peripheral wall; a sliding sleeve fitted inside the shell and having several movable seats on its outer peripheral wall; wherein, when several second blades move synchronously to a second position relative to the rotor hub along the rotor hub axially, the sliding sleeve moves relative to the shell along the rotor hub axially; when several second blades move synchronously to the rotor hub along the rotor hub axially and simultaneously move synchronously circumferentially around the rotor hub axially to the second position, the sliding sleeve moves relative to the shell along the rotor hub axially and simultaneously rotates relative to the shell axis.

[0011] In a further preferred embodiment, the sliding sleeve moves close to the inner circumferential wall of the shell, and the axial length of the sliding sleeve is greater than the axial length of the sliding groove along the hub, so that the sliding sleeve always separates the sliding groove from the interior of the shell during the movement.

[0012] More preferably, the propeller hub also includes a shaft, which is disposed inside the shell and rotates axially relative to the shell; and a bushing, which is disposed inside the shell and sleeved on the shaft; wherein the bushing is connected to the inner circumferential wall of the sliding sleeve, and the bushing is threadedly connected to the shaft, and when the shaft rotates, the bushing drives the sliding sleeve to move synchronously along the shaft.

[0013] More preferably, the propeller hub also includes two positioning sleeves, which are disposed inside the shell and respectively disposed at both ends of the shaft; wherein, both positioning sleeves are connected to the inner wall of the shell, and the two positioning sleeves are respectively sleeved on both ends of the shaft, and the shaft rotates relative to the two positioning sleeves.

[0014] More preferably, the propeller hub also includes a gear ring, which is fitted onto one end of the shaft and rotates synchronously with the shaft; a gear, which cooperates with the gear ring and drives the gear ring to rotate; and a drive mechanism, which is disposed inside the housing and connected to the gear to drive the gear to rotate.

[0015] More preferably, it also includes a main shaft for driving the propeller hub to rotate axially; wherein the shaft is a hollow rod tube with both ends through it, the main shaft is inserted inside the shaft along the axial center of the shell tube, and the two ends of the main shaft are respectively connected to the two ends of the shell tube and drive the shell tube to rotate synchronously.

[0016] The propeller of the present invention has the following advantages over the prior art: (1) By enabling the second blade to move, the present invention divides all blades that were originally located on the same plane of rotation into two independent planes of rotation. During the water-air transition, when the vehicle is partially submerged in water, the blades that originally crossed the water-air interface can be placed on two different planes, avoiding the coupling effect of water and air on a single blade, eliminating the phenomenon of sudden drop in thrust or even loss of force due to force imbalance, and ensuring the power continuity and stability of the transition process. At the same time, the present invention integrates two sets of blades on the same hub and can dynamically adjust the relative position of the two sets of blades according to the working conditions. When the vehicle is in the air, all blades are on the same plane of rotation to obtain the best air propulsion efficiency. When the vehicle is underwater, the blades are arranged in layers to optimize underwater propulsion performance and realize the efficient compatibility of a single propeller with two media, avoiding the redundant weight problem caused by carrying two independent power propulsion systems.

[0017] (2) Through the design of the sliding sleeve and the shell, the present invention realizes two motion modes: axial movement of the second blade relative to the hub and axial movement superimposed with circumferential movement. This provides multiple options for dynamic adjustment of the propeller configuration and enhances the adaptability and flexibility of the system. Furthermore, it provides two arrangement modes after the blades are layered, namely the alternating staggered mode and the front and rear paired mode. Users can flexibly choose according to the different working conditions of the navigation mission, further improving the environmental adaptability and mission diversity of the propeller.

[0018] (3) The present invention integrates the threaded drive, the sliding groove guide and other kinematic pairs into the inside of the propeller hub. During the operation of the sliding sleeve, the sliding groove is always separated from the inside of the shell, which effectively prevents the external medium from entering the inside of the shell and corroding the transmission components. The structure has excellent sealing performance and high reliability in long-term use. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a perspective view of the propeller of the present invention when the second blade is in the first position; Figure 2 This is a perspective view of the propeller of the present invention when the second blade is in the second position; Figure 3 This is a perspective view of the propeller of another embodiment of the present invention when the second blade is in the first position; Figure 4 This is a perspective view of the propeller of another embodiment of the present invention when the second blade is in the second position; Figure 5 This is an axial cross-sectional view of the second blade of the propeller hub of the present invention when it is in the first position; Figure 6 This is an axial cross-sectional view of the second blade of the rotor hub of the present invention when it is in the second position; Figure 7 For the present invention Figure 5 Enlarged view of point A in the middle.

[0021] In the diagram: 1. Hub; 11. Shell; 12. Sliding sleeve; 13. Shaft; 14. Bushing; 15. Positioning sleeve; 16. Gear ring; 17. Gear; 18. Drive mechanism; 101. Slide groove; 2. First blade; 3. Second blade; 4. Movable seat; 5. Main shaft. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0023] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention based on the specific circumstances.

[0024] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention.

[0025] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0026] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0027] The following disclosure provides numerous different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. Additionally, examples of various specific processes and materials are provided in this invention; however, those skilled in the art will recognize the applicability of other processes and / or the use of other materials.

[0028] like Figure 1 As shown, combined with Figures 2 to 4 The present invention provides a propeller comprising a hub 1, a first blade 2, and a second blade 3.

[0029] The hub 1 rotates along its own axis. As the rotating main body of the entire propeller, the hub 1 rotates along its own axis under the drive of its own drive device, such as an electric motor, thereby driving the blades to rotate and generate thrust.

[0030] A plurality of first blades 2 and a plurality of second blades 3 are arranged axially around the hub 1; the plurality of second blades 3 are respectively arranged between two adjacent first blades 2; theoretically, the number of first blades 2 and second blades 3 can also be different, in which case one, two, or three second blades 3 can be arranged between two adjacent first blades 2, or one, two, or three first blades 2 can be arranged between two adjacent second blades 3. However, considering factors such as propeller stability in actual operation, in this embodiment, the number of first blades 2 and second blades 3 is the same, so they are arranged alternately and evenly. The plurality of second blades 3 move synchronously relative to the hub 1, so that the second blades 3 have a first position and a second position; each second blade 3 maintains the same displacement, the same speed, and the same time phase during the movement, to ensure the balance and stability of the overall structure of the group of second blades 3 during the movement, and to avoid unbalanced torque caused by asynchronous movement of the blades.

[0031] When several second blades 3 are in the first position, several first blades 2 and several second blades 3 are located on the same rotation plane relative to the radial surface of the hub 1. At this time, the first blades 2 and the second blades 3 together form a single-layer propeller structure, and each blade rotates in coordination at the same height, which is suitable for use scenarios when the vehicle is sailing in water or flying in the air. When several second blades 3 are all in the second position, several first blades 2 and several second blades 3 are located on two front and rear rotation planes relative to the radial surface of the hub 1, respectively. Specifically, the first blades 2 remain in their original radial plane position, while the second blades 3 move axially to another radial plane relative to the hub 1, so that the first blades 2 and the second blades 3 form a coaxial double propeller structure with front and rear layers. In this state, since the two sets of blades are distributed on two different rotation planes, when the vehicle transitions from water to air, even if the blade group as a whole crosses the water surface, because the different blades are distributed at different heights, each blade will not be at the water surface boundary between air and water at the same time, thus avoiding the phenomenon of a single blade crossing two phases of medium and eliminating the thrust loss problem in the transition stage.

[0032] Meanwhile, the configuration where the first blade 2 and the second blade 3 are distributed across two rotating planes, compared to a configuration with a single rotating plane but more blades, shows, experimentally, that for a coaxial double-layer propeller rotating in the same direction, under the condition that the rotational speed of the hub 1 remains constant and the spacing between the double-layer blades is reasonable, the total thrust can reach 1.9 to 2.1 times that of a single-layer blade propeller, almost doubling the thrust, if the interference between the two layers of blades is not considered. This is because the flow environment of the two layers of blades is nearly independent, and the mutual interference is much less than that of a densely arranged blade in the same plane. Therefore, the configuration where the first blade 2 and the second blade 3 are distributed across two rotating planes can provide greater propulsion when navigating in water. Thus, this design can flexibly switch configurations according to the needs of the navigation mission, taking into account the propulsion efficiency under various operating conditions such as underwater navigation, aerial flight, and cross-domain transitions, with a compact structure, without the need for two independent propulsion systems.

[0033] exist Figure 1 and Figure 2 In one embodiment shown, several second blades 3 move synchronously back and forth relative to the hub 1 along the axial direction of the hub 1, that is, the second blades 3 only reciprocate linearly along the axial direction of the hub 1. This causes several first blades 2 and several second blades 3 to be alternately staggered. However, in this configuration, the two layers of blades that are staggered back and forth can reduce mutual interference and turbulence when they rotate coaxially. Figure 3 and Figure 4In one embodiment shown, several second blades 3 move synchronously back and forth relative to the hub 1 along the axial direction of the hub 1 and simultaneously move synchronously circumferentially around the hub 1. That is, the movement trajectory of the second blades 3 is a spiral line along the outer peripheral wall of the hub 1, which causes several first blades 2 and several second blades 3 to be arranged in pairs back and forth along the axial direction of the hub 1. In this configuration, the first blades 2 and second blades 3 are aligned front and back, which can significantly improve propulsion efficiency and obtain better hydrodynamic performance.

[0034] exist Figures 1 to 4 In one embodiment shown, the number of first blades 2 and second blades 3 are equal, and the first blades 2 and second blades 3 are arranged alternately around the axial direction of the hub 1; Figure 1 and Figure 2 In one embodiment shown, when several second blades 3 move synchronously to a second position relative to the hub 1 along the axial direction of the hub 1, that is, the second blades 3 only perform linear reciprocating motion along the axial direction of the hub 1, several first blades 2 and several second blades 3 are alternately staggered. However, in this configuration, the alternating staggered arrangement makes the front and rear blades staggered during rotation, avoiding airflow or water flow interference between the front and rear blades, which is beneficial to reducing fluid resistance and improving propulsion efficiency, and is suitable for most conventional working conditions. Figure 3 and Figure 4 In one embodiment shown, when several second blades 3 move synchronously relative to the hub 1 along the axial direction of the hub 1 and simultaneously move synchronously circumferentially around the hub 1 to a second position, that is, when the movement trajectory of the second blades 3 is a spiral line along the outer peripheral wall of the hub 1, several first blades 2 and several second blades 3 are respectively arranged in pairs along the axial direction of the hub 1. In this configuration, the first blades 2 and the second blades 3 are aligned front and back, so that the two layers of blades form a series propulsion structure, which theoretically can obtain a higher thrust density and is suitable for application scenarios that require high thrust output, such as underwater high-speed navigation or climb phase.

[0035] exist Figure 1 In one embodiment shown, a movable seat 4 is also included.

[0036] The hub 1 has grooves 101 on its outer circumferential surface. The number of grooves 101 is equal to the number of movable seats 4, and each groove 101 corresponds to one movable seat 4. The two ends of the grooves 101 extend towards the first position and the second position, respectively. That is, the grooves 101 extend from the circumferential angle of the first position along the outer circumferential wall of the hub 1 to the circumferential angle of the second position. The extension direction of the grooves 101 corresponds to the movement trajectory of the second blade 3 from the first position to the second position. If the second blade 3 only moves axially, the grooves 101 extend axially along the hub 1; if the second blade 3 moves both axially and circumferentially, the grooves 101 extend helically along the outer circumferential wall of the hub 1.

[0037] Several movable seats 4 are respectively equipped with several second blades 3. The movable seats 4 are disposed within the slide groove 101 and reciprocate along the slide groove 101. The movable seats 4 serve as a connecting bridge between the second blades 3 and the hub 1, and are responsible for constraining the movement of the second blades 3 to a predetermined trajectory. The shape of the movable seats 4 is adapted to the cross-section of the slide groove 101, and is usually T-shaped or dovetail-shaped to prevent the movable seats 4 from dislodging from the slide groove 101 during movement.

[0038] exist Figure 5 In one embodiment shown, the propeller hub 1 includes a housing 11 and a sliding sleeve 12.

[0039] The outer peripheral wall of the shell 11 has a sliding groove 101. The shell 11 serves as the outer shell component of the propeller hub 1, and its interior is used to accommodate the transmission structure and drive components.

[0040] The sliding sleeve 12 is fitted inside the shell 11 and has several movable seats 4 on its outer peripheral wall. The sliding sleeve 12 can move relative to the shell 11 inside the shell 11, thereby driving the movable seats 4 to move along the sliding groove 101. The movement mode of the sliding sleeve 12 is also different depending on the movement mode of the second blade 3: when several second blades 3 move synchronously to the second position relative to the hub 1 along the axial direction of the hub 1, the sliding sleeve 12 moves relative to the shell 11 along the axial direction of the hub 1, that is, the sliding sleeve 12 moves linearly; when several second blades 3 move synchronously relative to the hub 1 along the axial direction of the hub 1 and simultaneously move synchronously circumferentially around the hub 1 to the second position, the sliding sleeve 12 moves relative to the shell 11 along the axial direction of the hub 1 and simultaneously rotates relative to the shell 11, that is, the sliding sleeve 12 performs a composite movement of linear sliding and circumferential rotation simultaneously inside the shell 11. By setting the sliding sleeve 12 as an intermediate connecting component, the movement of each second blade 3 can be uniformly driven by a single sliding sleeve 12, thereby ensuring the synchronicity of the movement of each second blade 3. The structure is compact and the transmission is efficient, which greatly simplifies the mechanical design of synchronous driving of multiple blades.

[0041] exist Figure 6In one embodiment shown, considering that the transoceanic vehicle needs to frequently enter and exit the water, if the interior of the propeller hub 1 is directly exposed to the external environment, it is prone to corrosion failure of the transmission components due to water ingress. Therefore, in order to seal the interior of the propeller hub 1, the sliding sleeve 12 moves closely against the inner peripheral wall of the shell 11. The outer peripheral wall of the sliding sleeve 12 and the inner peripheral wall of the shell 11 are precisely fitted together, leaving a small gap between them, but a sealing ring, such as an O-ring or lip seal, is used for dynamic sealing. The axial length of the sliding sleeve 12 is greater than the length of the groove 101 along the axial direction of the propeller hub 1, so that the sliding sleeve 12 always separates the groove 101 from the interior of the shell 11 during its movement. No matter where the sliding sleeve 12 is in the reciprocating stroke, the outer peripheral wall of the sliding sleeve 12 always covers and seals the communication area between the groove 101 and the interior of the shell 11. In other words, although the groove 101 forms a slot on the outer peripheral wall of the shell 11, the external medium cannot enter the interior of the shell 11 through the groove 101 because the sleeve 12 always fits against the inner peripheral wall of the shell 11 and covers the entire opening area of ​​the groove 101.

[0042] exist Figure 6 In one embodiment shown, the hub 1 further includes a shaft 13 and a bushing 14 to drive the sliding sleeve 12 to move.

[0043] The shaft 13 is disposed inside the shell 11 and rotates axially relative to the shell 11. The shaft 13 is coaxially arranged with the shell 11, and the axis of the shaft 13 coincides with the axis of rotation of the propeller hub 1.

[0044] The bushing 14 is connected to the inner circumferential wall of the sliding sleeve 12. The bushing 14 and the sliding sleeve 12 can be fixed by key connection, spline connection, or integral molding to ensure that the bushing 14 can drive the sliding sleeve 12 to move synchronously when it moves axially along the shaft 13. The bushing 14 is set inside the shell 11 and sleeved on the shaft 13, and the bushing 14 is threadedly connected to the shaft 13. When the shaft 13 rotates, due to the circumferential constraint of the sliding groove 101, the shell 11, the sliding sleeve 12, and the movable seat 4, or other components, the bushing 14 will not rotate circumferentially synchronously with the shaft 13, but will instead move axially along the thread of the shaft 13. The bushing 14 drives the connected sliding sleeve 12 to move synchronously along the axial direction of the shaft 13, thereby driving the movable seat 4 and the second blade 3 to move along the slide groove 101. By controlling the rotation direction of the shaft 13, the movement direction of the bushing 14 and the sliding sleeve 12 can be controlled, thereby enabling the second blade 3 to move from the first position to the second position or move in the opposite direction. By controlling the number of rotations of the shaft 13, the axial displacement of the second blade 3 can be precisely controlled, thereby adjusting the spacing between the front and rear blades to adapt to the propulsion requirements of different media.

[0045] exist Figure 6In one embodiment shown, the propeller hub 1 further includes a positioning sleeve 15 for positioning and supporting the shaft 13.

[0046] Two positioning sleeves 15 are disposed inside the housing 11 and respectively at both ends of the shaft 13. Both positioning sleeves 15 are connected to the inner wall of the housing 11, for example, by means of brackets, interference fits, screw connections, or integral molding. The two positioning sleeves 15 are respectively fitted onto both ends of the shaft 13, which rotates relative to the two positioning sleeves 15. A sliding bearing is typically used between the positioning sleeves 15 and the shaft 13; that is, a friction-reducing bushing is provided in the inner hole of the positioning sleeve 15, or smooth surfaces are directly machined at both ends of the shaft 13 to reduce the frictional resistance during shaft rotation and maintain the coaxiality between the shaft 13 and the housing 11. Through the constraint of the two positioning sleeves 15, the shaft 13 is accurately confined to the axis of rotation within the housing 11, preventing wobbling or vibration of the shaft 13 during high-speed rotation, thereby ensuring the smoothness and reliability of the entire threaded transmission mechanism. Axial limiting structures, such as retaining rings or shoulders, can be further provided at both ends of the shaft 13 to limit the axial displacement of the shaft 13 relative to the positioning sleeve 15, so as to ensure that the shaft 13 will not move axially during rotation.

[0047] exist Figure 7 In one embodiment shown, the propeller hub 1 further includes a gear ring 16, a gear 17, and a drive mechanism 18 in order to drive the shaft 13 to rotate.

[0048] The gear ring 16 is sleeved on one end of the shaft 13 and rotates synchronously with the shaft 13; the gear ring 16 can be fixed to the end of the shaft 13 by means of key connection, spline connection or set screw.

[0049] Gear 17 engages with gear ring 16 and drives gear ring 16 to rotate; typically, a small gear drives a large gear ring to achieve high displacement resolution.

[0050] The drive mechanism 18 is housed inside the housing 11 and connected to the gear 17 to drive the gear 17 to rotate. The drive mechanism 18 can be an actuator such as a micro servo motor, a stepper motor, or a rotary electromagnet. In this embodiment, a micro servo motor is preferred because it has advantages such as small size, high control precision, and stable torque output. Since the drive mechanism 18 is located inside the housing 11, and the housing 11 itself rotates together with the propeller hub 1, the power supply and control signals of the drive mechanism 18 need to be introduced from the outside through slip rings or wireless transmission.

[0051] When the drive mechanism 18 receives a control signal, the drive gear 17 rotates, transmitting torque to the gear ring 16. The gear ring 16 drives the shaft 13 to rotate, thereby driving the bushing 14 to move axially. By controlling the rotation direction and rotation angle of the drive mechanism 18, the movement direction and displacement of the second blade 3 can be controlled.

[0052] exist Figure 6 In one embodiment shown, a main shaft 5 is also included. The shaft 13 is a hollow rod-tube with both ends extending through it. The main shaft 5 passes through the shaft 13 along the axial center of the shell 11, forming a clearance fit or a sliding bearing between them, allowing the main shaft 5 to rotate freely within the shaft 13 without interference. The main shaft 5 drives the propeller hub 1 to rotate axially. One end of the main shaft 5 is connected to the vehicle's drive motor, which is not shown in the accompanying drawings. Both ends of the main shaft 5 are connected to the two ends of the shell 11 and drive the shell 11 to rotate synchronously. Because the main shaft 5 passes inside the shaft 13, the shaft 13 has both axial and circumferential degrees of freedom relative to the shell 11 and the main shaft 5. However, when the drive mechanism 18 is not working, the shaft 13 remains stationary relative to the shell 11. When the shell 11 rotates under the drive of the main shaft 5, the shaft 13 also rotates synchronously. When the drive mechanism 18 is working, the shaft 13 undergoes additional relative rotation with respect to the main shaft 5 and the shell 11, thereby driving the bushing 14 to move and adjusting the position of the second blade 3. In this embodiment, by inserting the main shaft 5 through the hollow structure of the shaft 13, the propeller rotation power and the blade position adjustment power are decoupled, resulting in a compact structure, high space utilization, and avoiding redundant arrangement of the transmission system.

[0053] Working principle: When the vehicle is in the initial stage of flight or water navigation, the second blade 3 is in the first position, all the first blades 2 and the second blade 3 are on the same plane of rotation, and the propeller rotates in the form of a single blade.

[0054] When a vehicle needs to submerge from the air into the water, or more critically, when it needs to rise from underwater to the surface and transition into the air, the vehicle's control system determines that it is about to enter a trans-domain interface. At this stage, the vehicle has not yet entered the water, and the propeller is still in single-layer propeller mode.

[0055] Just before the vehicle enters the cross-domain interface, for example, when the vehicle is at a preset height or depth above the water surface, the control system issues a command to activate the drive mechanism 18. The drive mechanism 18 drives the gear 17 to rotate, the gear 17 drives the gear ring 16 to rotate, and the gear ring 16 drives the shaft 13 to rotate. Since the bushing 14 is threadedly connected to the shaft 13, and the bushing 14 and the sliding sleeve 12 connected to it are circumferentially constrained, the bushing 14 drives the sliding sleeve 12 to move along the axial direction of the shaft 13. The sliding sleeve 12 drives the movable seat 4 to slide along the slide groove 101, thereby driving the second propeller blade 3 connected to the movable seat 4 to move from the first position to the second position along a preset trajectory. At the second position, the first propeller blade 2 and the second propeller blade 3 are located on the front and rear rotation planes respectively, forming a coaxial double-layer propeller structure.

[0056] After the propeller completes its configuration conversion, the vehicle begins to cross the water-air interface. Because the propeller blades are divided into two layers of planes at different heights, each blade is positioned at a different height when the entire propeller crosses the water surface, preventing a single blade from simultaneously crossing both water and air phases. At this point, some blades may still be submerged in water, while others are exposed above the water and in the air. However, because the thrust is distributed across multiple blades and the forces on each blade compensate for each other, the sudden drop in thrust caused by a single blade being simultaneously subjected to forces from both media, as is common with traditional single-layer propellers, is avoided when crossing the water surface. This ensures the continuity of power and stability of the vehicle during the transition phase.

[0057] Once the vehicle has fully submerged or completely detached from the water and entered the air, if the user wishes to revert to a single-propeller configuration for optimal single-medium propulsion efficiency, the drive mechanism 18 can be restarted. This reverses the rotation of the drive shaft 13, causing the sliding sleeve 12 to drive the second blade 3 back from the second position to the first position, returning all blades to the same plane of rotation. In practice, state switching is generally not performed during airborne flight. When navigating in water, the propeller can be stopped first, then the state can be switched and the propeller restarted.

[0058] During the operation of the vehicle, the user can select different fore-and-aft spacings according to the operating conditions. Specifically, by controlling the number of rotations of the drive mechanism 18, the axial movement distance of the bushing 14 along the shaft 13 is controlled, thereby adjusting the axial spacing between the first blade 2 and the second blade 3. For example, in underwater high-thrust demand mode, the spacing between the two rows of blades can be appropriately increased to reduce mutual interference; in underwater high-efficiency cruise mode, a smaller spacing can be used to reduce the length of the rotor hub. Through variable spacing adjustment, the propeller of this invention can adapt to a wider range of underwater operating conditions, further improving propulsion efficiency. Taking a certain type of water-air cross-domain vehicle as an example, this vehicle adopts a single-layer propeller configuration in normal flight, that is, the second blade 3 is in the first position. When the vehicle rises from underwater to about 0.5 m above the water surface, the control system automatically triggers a configuration conversion command, and the second blade 3 completes the movement from the first position to the second position within two seconds, forming a double-layer propeller configuration. Subsequently, the vehicle passed through the water at a speed of approximately 0.8 m / s, with propeller thrust fluctuations of less than 5%, far lower than the performance of traditional single-layer propellers, which experience a thrust drop of more than 30% under the same operating conditions.

[0059] 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 within the protection scope of the present invention.

Claims

1. A propeller, characterized in that, include: The propeller hub (1) rotates along its own axis; Several first blades (2) are arranged axially around the hub (1); Several second blades (3) are arranged axially around the hub (1) and respectively between two adjacent first blades (2); Among them, a plurality of the second blades (3) move synchronously relative to the hub (1), so that the second blades (3) have a first position and a second position; When all of the second blades (3) are in the first position, all of the first blades (2) and the second blades (3) are located on the same plane of rotation relative to the radial surface of the hub (1); When all of the second blades (3) are in the second position, the radial surfaces of the first blades (2) and the second blades (3) relative to the hub (1) are respectively located on the front and rear rotation planes.

2. A propeller according to claim 1, characterized in that: A number of second blades (3) move synchronously back and forth relative to the hub (1) along the axial direction of the hub (1), or a number of second blades (3) move synchronously back and forth relative to the hub (1) along the axial direction of the hub (1) and simultaneously move synchronously circumferentially around the hub (1).

3. A propeller according to claim 2, characterized in that: The number of first blades (2) and second blades (3) are equal, and the first blades (2) and second blades (3) are arranged alternately around the axial direction of the hub (1); When a number of second blades (3) move synchronously to the second position relative to the hub (1) along the axial direction of the hub (1), a number of first blades (2) and a number of second blades (3) are alternately staggered. When a plurality of second blades (3) move synchronously relative to the hub (1) along the axial direction of the hub (1) and simultaneously move synchronously circumferentially around the hub (1) to the second position, a plurality of first blades (2) and a plurality of second blades (3) are respectively arranged in pairs along the axial direction of the hub (1).

4. A propeller according to claim 2, characterized in that, Also includes: Several movable seats (4) are respectively provided with several second blades (3); The hub (1) has a groove (101) on its outer circumferential surface. The two ends of the groove (101) extend toward the first position and the second position, respectively. The movable seat (4) is set in the groove (101) and moves back and forth along the groove (101).

5. A propeller according to claim 4, characterized in that: The propeller hub (1) includes, The outer peripheral wall of the shell (11) has the groove (101) provided. A sliding sleeve (12) is fitted inside the shell (11) and has several movable seats (4) on its outer peripheral wall. When a plurality of second blades (3) move synchronously to a second position relative to the hub (1) along the axial direction of the hub (1), the sliding sleeve (12) moves relative to the shell (11) along the axial direction of the hub (1). When a plurality of second blades (3) move synchronously relative to the hub (1) along the axial direction of the hub (1) and simultaneously move synchronously around the hub (1) in the circumferential direction to the second position, the sliding sleeve (12) moves relative to the shell (11) along the axial direction of the hub (1) and simultaneously rotates relative to the shell (11).

6. A propeller according to claim 5, characterized in that: The sliding sleeve (12) moves close to the inner peripheral wall of the shell (11). The axial length of the sliding sleeve (12) is greater than the axial length of the sliding groove (101) along the hub (1), so that the sliding sleeve (12) always separates the sliding groove (101) from the interior of the shell (11) during the movement.

7. A propeller according to claim 5, characterized in that: The propeller hub (1) also includes, A shaft (13) is disposed inside the shell (11) and rotates axially relative to the shell (11); A bushing (14) is disposed inside the shell (11) and sleeved on the shaft (13); The bushing (14) is connected to the inner circumferential wall of the sliding sleeve (12), and the bushing (14) is threadedly connected to the shaft (13). When the shaft (13) rotates, the bushing (14) drives the sliding sleeve (12) to move synchronously along the shaft (13).

8. A propeller according to claim 7, characterized in that: The propeller hub (1) also includes, Two positioning sleeves (15) are disposed inside the shell (11) and respectively disposed at both ends of the shaft (13); Both of the positioning sleeves (15) are connected to the inner wall of the shell (11), and the two positioning sleeves (15) are respectively sleeved on both ends of the shaft (13), and the shaft (13) rotates relative to the two positioning sleeves (15).

9. A propeller according to claim 7, characterized in that: The propeller hub (1) also includes, A gear ring (16) is fitted onto one end of the shaft (13) and rotates synchronously with the shaft (13); The gear (17) engages with the gear ring (16) and drives the gear ring (16) to rotate; A drive mechanism (18) is disposed inside the shell (11) and connected to a gear (17) to drive the gear (17) to rotate.

10. A propeller according to claim 7, characterized in that, Also includes: The main shaft (5) is used to drive the propeller hub (1) to rotate axially; The shaft (13) is a hollow rod tube with both ends through it. The main shaft (5) is inserted inside the shaft (13) along the axial center of the shell (11). The two ends of the main shaft (5) are respectively connected to the two ends of the shell (11) and drive the shell (11) to rotate synchronously.

Images