An intermeshing cycloidal propeller

Abstract

The present application provides a staggered cycloidal propeller, comprising a main shaft and propeller blades, the number of propeller blades is 2n, wherein the number of propeller blades in each group on one side is n. The present application adopts staggered cycloidal propeller, the number of half-side cycloidal propeller blades is half of that of the traditional cycloidal propeller, which improves the efficiency, and the vibration level is the same as that of the traditional cycloidal propeller. Under the same vibration level, the blade area is halved, so that the weight of the blade structure is halved, and the tip vortex of the propeller blade can be located in the center of the propeller disc, the first group of propeller blades induces relative upwash on the second group of propeller blades, significantly reduces the downwash in the propeller disc, thereby effectively improves the efficiency of the cycloidal propeller, according to the CFD calculation, compared with the traditional cycloidal propeller, the hovering efficiency of the staggered cycloidal propeller can be improved by at least 6%.

Description

Technical Field

[0001] This invention relates to the field of cycloidal propeller technology, specifically to an interlaced cycloidal propeller. Background Technology

[0002] As a special type of propulsion device, the cycloidal propeller's blades revolve around the cycloidal propeller axis while also oscillating around the hinge. It provides lift by periodically changing the angle of attack of the blades at different positions in the rotating blade system. By controlling the phase angle of the periodic pitch change of the cycloidal propeller blades, the direction of the net vector thrust can be changed. It is a propulsion device that can provide adjustable omnidirectional vector thrust instantaneously. It has the characteristics of high efficiency and rapid change of vector thrust.

[0003] Currently, most cycloidal propulsion devices use four-bladed propellers, as illustrated in the applicant's earlier Chinese patent application, "A Cycloidal Propeller," publication number CN102582830B. However, in practical use, it has been found that cycloidal propellers with fewer blades are more efficient, but also have higher vibration levels. To reduce the vibration level of the cycloidal propeller, more blades must be used, typically four blades. However, increasing the number of blades in a cycloidal propeller leads to the problem of increasing the internal shroud of the propeller disk, thus reducing the propulsion efficiency. Moreover, increasing the number of blades also increases the blade area, thereby increasing the structural weight. Summary of the Invention

[0004] To address the contradiction in existing cycloidal propeller designs where increasing the number of blades reduces vibration levels but also lowers propulsion efficiency and increases structural weight, this invention provides a staggered cycloidal propeller. This innovative design uses staggered blades, with half the number of blades on each side of the propeller. This improves efficiency while maintaining the same vibration level as the traditional propeller. At the same vibration level, the blade area is halved, resulting in a halved blade structural weight. Furthermore, it allows the blade tip vortex to be located in the center of the propeller disk. The first set of blades induces relative upwash on the second set, significantly reducing downwash within the propeller disk, thereby effectively improving propeller efficiency. According to CFD calculations, the staggered cycloidal propeller can improve hovering efficiency by at least 6% compared to the traditional cycloidal propeller.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] The staggered cycloidal propeller includes a main shaft and blades, with 2n blades, wherein each group of blades on one side has n blades.

[0007] The first blade support, the second blade support, and the third blade support are fixedly installed on the main shaft along the axial direction in sequence.

[0008] The second blade support is a 2n-arm structure composed of n sets of straight arms with their centers overlapping; the center of the second blade support is fixedly connected to the main shaft and can rotate synchronously with the main shaft; both the first and third blade supports have n arms, wherein the planar layout of the n arms of the first blade support is consistent with and parallel to the planar layout of the n arms spaced apart in the second blade support, and the planar layout of the n arms of the third blade support is consistent with and parallel to the planar layout of the other n arms spaced apart in the second blade support; the centers of the first and third blade supports are fixedly connected to the main shaft and can rotate synchronously with the main shaft.

[0009] A first set of blades is installed between the first blade support and the second blade support, and a second set of blades is installed between the third blade support and the second blade support. All blades point in the same clockwise direction and can rotate freely around the axis of rotation to change the angle of attack.

[0010] An eccentric ring is also fitted on the main shaft. The eccentric ring is located on one side of the second blade support, and 2n hinge blocks are arranged on the side of the eccentric ring. The direction of the 2n hinge blocks in the circumferential direction of the eccentric ring is the same as the direction of the 2n arms in the second blade support in the circumferential direction.

[0011] Each hinge block is equipped with a transmission rod. One end of the transmission rod is rotatably connected to the hinge block via a pin, and the axis of the pin is parallel to the axis of the main shaft. The other end of the transmission rod is connected to the blade via a connecting shaft, and the axis of the connecting shaft is parallel to the axis of the main shaft.

[0012] When the external power system drives the main shaft to rotate, the main shaft drives the first blade support, the second blade support, and the third blade support to rotate, which in turn drives the first set of blades and the second set of blades to rotate synchronously. When the first set of blades and the second set of blades rotate, they drive the eccentric ring to move through the transmission rod. The central axis of the eccentric ring has a set eccentricity relative to the main shaft, which makes the first set of blades and the second set of blades perform periodic pitching motion, generating tension.

[0013] Furthermore, when the number of blades on one side, n, is 2, the second blade support is a four-arm structure composed of two sets of straight arms that overlap at the center. The four-arm structure adopts a cross-shaped layout, while the first blade support and the third blade support are in a straight line shape.

[0014] Furthermore, when the number of blades on one side, n, is 2, the second blade support is a four-arm structure composed of two sets of straight arms that overlap at the center, and the included angle between the two sets of straight arms in the four-arm structure is set to an arbitrary angle.

[0015] Further, when the number n of blades on one side is 3, the second blade support is a six-arm structure formed by three sets of straight arms in a center-coincident manner, the six-arm structure adopts a circumferentially uniformly distributed "asterisk" layout, and the first blade support and the third blade support adopt a "Y-shaped" layout.

[0016] Further, each blade in the first set of blades is mounted at the ends of the first blade support and the second blade support via a first rotating shaft, and the axis of the first rotating shaft penetrates through the center of gravity of the blade and is parallel to the main shaft; each blade in the second set of blades is mounted at the ends of the third blade support and the second blade support via a second rotating shaft, and the axis of the second rotating shaft penetrates through the center of gravity of the blade and is parallel to the main shaft.

[0017] Further, the first rotating shaft and the second rotating shaft respectively adopt a manner that a single shaft penetrates through the entire blade along the spanwise direction, or a manner that coaxial rotating shafts are respectively arranged at two ends of the blade.

[0018] Further, for each blade in the first set of blades, a first connecting shaft is provided on the end face of the blade facing the second blade support, the axial direction of the first connecting shaft is parallel to the main shaft, one end of the first transmission rod is in rotating fit with the first connecting shaft, and the other end is rotatably connected with the hinge block via a pin shaft; for each blade in the second set of blades, a second connecting shaft is provided on the end face of the blade facing the second blade support, the axial direction of the second connecting shaft is parallel to the main shaft, one end of the second transmission rod is in rotating fit with the second connecting shaft, and the other end is rotatably connected with the hinge block via a pin; the second transmission rod is in rotating fit with the second connecting shaft inside the blade of the second set of blades.

[0019] Beneficial effects:

[0020] In the staggered cycloidal propeller provided by the present invention, the number of blades on one half side is half of that of the traditional cycloidal propeller, which not only improves the efficiency, but also has the same vibration level as the traditional cycloidal propeller: at the same vibration level, the blade area is halved, so that the structural weight of the blades is halved, and the blade tip vortices of the blades can be located at the center of the propeller disk, the first set of blades induces a relative upwash on the second set of blades, which significantly reduces the downwash in the propeller disk, thereby effectively improving the efficiency of the cycloidal propeller. According to CFD calculation, compared with the traditional cycloidal propeller, the hovering efficiency of the staggered cycloidal propeller can be increased by at least 6%. Brief Description of the Drawings

[0021] Figure 1 is a perspective view of the staggered cycloidal propeller (four-blade propeller);

[0022] Figure 2 is a front view of the staggered cycloidal propeller (four-blade propeller);

[0023] Figure 3 is a schematic structural view of the main shaft part of the staggered cycloidal propeller (four-blade propeller);

[0024] Figure 4 This is a schematic diagram of the first transmission rod section.

[0025] Figure 5 This is a schematic diagram of the second transmission rod section.

[0026] Figure 6 This is a schematic diagram of the eccentric ring and hinge block structure.

[0027] Figure 7 A three-dimensional view of an interlaced cycloidal propeller (six-bladed propeller);

[0028] Figure 8 A three-dimensional view of an interlaced cycloidal propeller (non-orthogonal four-bladed propeller);

[0029] Figure 9 Comparison of the swishing speed inside the propeller disk of the same size cycloidal propeller; (a) staggered two-bladed cycloidal propeller (single side), (b) conventional four-bladed cycloidal propeller (half-mold);

[0030] Figure 10 The thrust variation curves of a two-bladed staggered cycloidal propeller and a conventional four-bladed cycloidal propeller within one cycle are shown; (a) staggered two-bladed cycloidal propeller, (b) conventional four-bladed cycloidal propeller.

[0031] The components are as follows: 1. Main shaft; 2. First blade support; 3. First rotating shaft; 4. First set of blades; 5. Second blade support; 6. Second rotating shaft; 7. Second set of blades; 8. Third blade support; 9. Eccentric ring; 10. Inner plate of eccentric ring; 11. Hinge block; 12. Pin; 13. First transmission rod; 14. First connecting shaft; 15. Second transmission rod; 16. Second connecting shaft. Detailed Implementation

[0032] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] The present invention provides an interlaced cycloidal propeller, including a main shaft 1, on which a first blade support 2, a second blade support 5 and a third blade support 8 are fixedly mounted in sequence along the axial direction. The first blade support 2, the second blade support 5 and the third blade support 8 can rotate synchronously with the main shaft 1.

[0034] The staggered cycloidal propeller proposed in this invention has 2n blades, of which n are blades on one side. Therefore, the second blade support 5 is a 2n-arm structure composed of n sets of straight arms with their centers overlapping; the center of the second blade support 5 is fixedly connected to the main shaft 1, and the second blade support 5 can rotate synchronously with the main shaft 1.

[0035] Each of the first blade support 2 and the third blade support 8 has n arms, wherein the planar layout of the n arms of the first blade support 2 is consistent with the planar layout of the n arms distributed at intervals on the second blade support 5, and the planar layout of the n arms of the third blade support 8 is consistent with the planar layout of the other n arms distributed at intervals on the second blade support 5; the centers of the first blade support 2 and the third blade support 8 are fixedly connected to the main shaft 1, and can rotate synchronously with the main shaft 1.

[0036] After the first blade support 2, the second blade support 5 and the third blade support 8 are all fixed to the main shaft 1, the n arms of the first blade support 2 are correspondingly parallel to the n arms distributed at intervals on the second blade support 5, and the n arms of the third blade support 8 are correspondingly parallel to the other n arms distributed at intervals on the second blade support 5.

[0037] Figures 1-3 The figure shows a staggered four-blade propeller, the number of blades on one side n is 2, so the second blade support 5 is a four-arm structure formed by two sets of straight arms in a center-coincident manner. This four-arm structure adopts a "cross" shape. Certainly, the included angle between the two sets of straight arms can also be set to other angles, such as Figure 8 as shown in the figure. The planar layout of the 2 arms distributed at intervals in the four-arm structure is a "one" shape, therefore, the first blade support 2 and the third blade support 8 are of "one" shape, the first blade support 2 is parallel to one set of straight arms in the second blade support 5, and the third blade support 8 is parallel to the other set of straight arms in the second blade support 5.

[0038] Figure 7 The figure shows a staggered six-blade propeller, the number of blades on one side n is 3, so the second blade support 5 is a six-arm structure formed by three sets of straight arms in a center-coincident manner. This six-arm structure adopts a circumferentially uniformly distributed "asterisk" shape, the planar layout of the 3 arms distributed at intervals in the six-arm structure is a circumferentially uniformly distributed "Upsilon" shape, then the first blade support 2 and the third blade support 8 are also of "Upsilon" shape, the 3 arms of the first blade support 2 are correspondingly parallel to the 3 arms distributed at intervals on the second blade support 5, and the 3 arms of the third blade support 8 are correspondingly parallel to the other 3 arms distributed at intervals on the second blade support 5.

[0039] A first set of blades 4 is installed between the first blade support 2 and the second blade support 5, and a second set of blades 7 is installed between the third blade support 8 and the second blade support 5. For all the blades, the blades point in the same clockwise direction.

[0040] Each blade in the first set of blades 4 is mounted at the end of the first blade support 2 and the second blade support 5 via a first rotating shaft 3. The axis of the first rotating shaft 3 passes through the center of gravity of the blade and is parallel to the main shaft 1. Here, the first rotating shaft 3 can be a single shaft running longitudinally through the entire blade, or coaxial rotating shafts can be arranged at both ends of the blade. The blade can rotate freely around the first rotating shaft 3, thereby changing the angle of attack.

[0041] Each blade in the second set of blades 7 is mounted at the end of the third blade support 8 and the second blade support 5 via a second rotating shaft 6. The axis of the second rotating shaft 6 passes through the center of gravity of the blade and is parallel to the main shaft 1. Here, the second rotating shaft 6 can also be a single shaft running longitudinally through the entire blade, or coaxial rotating shafts can be arranged at both ends of the blade. The blade can rotate freely around the second rotating shaft 6, thereby changing the angle of attack.

[0042] An eccentric ring 9 is also fitted on the main shaft 1. The eccentric ring 9 is located on one side of the second blade support 5, and 2n hinge blocks 11 are arranged on the side of the eccentric ring 9. The 2n hinge blocks 11 point in the circumferential direction of the eccentric ring 9 and point in the circumferential direction of the 2n arms in the second blade support 5.

[0043] Each hinge block 11 is equipped with a transmission rod, one end of which is rotatably connected to the hinge block via a pin 12, and the axial direction of the pin 12 is parallel to the axial direction of the main shaft 1.

[0044] For each blade in the first set of blades 4, a first connecting shaft 14 is provided on the blade end face facing the second blade support 5. The axial direction of the first connecting shaft 14 is parallel to the main shaft 1. One end of the first transmission rod 13 is rotatably engaged with the first connecting shaft 14, and the other end is rotatably connected to the hinge block through the pin 12.

[0045] For each blade in the second set of blades 7, a second connecting shaft 16 is provided on the blade end face facing the second blade support 5. The axial direction of the second connecting shaft 16 is parallel to the main shaft 1. One end of the second transmission rod 15 is rotatably engaged with the second connecting shaft 16, and the other end is rotatably connected to the hinge block through a pin 12. Due to the installation position limitation of the eccentric ring 9, the second transmission rod 15 is rotatably engaged with the second connecting shaft 16 inside the blade of the second set of blades 7.

[0046] When the external power system drives the main shaft 1 to rotate, the main shaft 1 drives the first blade support 2, the second blade support 5 and the third blade support 8 to rotate, which in turn drives the first set of blades 4 and the second set of blades 7 to rotate synchronously. When the first set of blades 4 and the second set of blades 7 rotate, they drive the eccentric ring to move through the transmission rod. Since the central axis of the eccentric ring has a set eccentricity relative to the main shaft 1, the first set of blades 4 and the second set of blades 7 make periodic pitching motion, thereby generating tension.

[0047] The staggered cycloidal propeller proposed in this invention halves the blade area and thus halves the blade structural weight under the same vibration level. More importantly, by arranging the blades in a staggered configuration on both sides, the blade tip vortex is positioned in the center of the propeller disk. The first set of blades (leading blades) induces relative upward washing on the second set of blades (rearing blades), thereby significantly reducing downward washing within the propeller disk and effectively improving the cycloidal propeller efficiency. Figure 9 As shown, the rinsing speed inside the disk of a conventional cycloidal propeller is much lower than that of a conventional cycloidal propeller. And... Figure 10 The figures show the thrust variation curves of a two-bladed staggered cycloidal propeller and a conventional four-bladed cycloidal propeller within one cycle. S, W, N, and E represent the blades initially located in the south, west, north, and east, respectively. As can be seen from the figures, both the two-bladed staggered cycloidal propeller and the conventional four-bladed cycloidal propeller have four peaks within one cycle. They have the same aerodynamic fluctuation frequency. However, under the same vibration level, the blade area of ​​the two-bladed staggered cycloidal propeller is halved, which results in a halved blade structural weight.

[0048] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A staggered cycloidal propeller, comprising a main shaft and blades, characterized in that: The number of blades is 2n, wherein the number of blades in each group on one single side is n; A first blade support, a second blade support and a third blade support are fixedly mounted on the main shaft sequentially along the axial direction; The second blade support is a 2n-arm structure formed by n groups of straight arms in a manner of coinciding at the center; The center of the second blade support is fixedly connected with the main shaft and can rotate synchronously with the main shaft; each of the first blade support and the third blade support has n arms, wherein the planar layout of the n arms of the first blade support is consistent with and correspondingly parallel to the planar layout of the n arms distributed at intervals in the second blade support, and the planar layout of the n arms of the third blade support is consistent with and correspondingly parallel to the planar layout of the other n arms distributed at intervals in the second blade support; The centers of the first blade support and the third blade support are fixedly connected with the main shaft and can rotate synchronously with the main shaft; A first group of blades is installed between the first blade support and the second blade support, a second group of blades is installed between the third blade support and the second blade support, all the blades point to the same clock direction, and the blades can rotate freely around the rotating shafts to change the angle of attack; An eccentric circular ring is further sleeved on the main shaft, the eccentric circular ring is located on one side of the second blade support, 2n hinge blocks are arranged on the side surface of the eccentric circular ring, and the pointing directions of the 2n hinge blocks in the circumferential direction of the eccentric circular ring are the same as the pointing directions of the 2n arms in the second blade support in the circumferential direction; One transmission rod is mounted on each hinge block, one end of the transmission rod is rotatably connected with the hinge block through a pin shaft, and the axial direction of the pin shaft is parallel to the axial direction of the main shaft; the other end of the transmission rod is connected with the blade through a connecting shaft, and the axial direction of the connecting shaft is parallel to the axial direction of the main shaft; When an external power system drives the main shaft to rotate, the main shaft drives the first blade support, the second blade support and the third blade support to rotate, and further drives the first group of blades and the second group of blades to rotate synchronously. When the first group of blades and the second group of blades rotate, the eccentric circular ring is driven to move through the transmission rods. The central axis of the eccentric circular ring has a set eccentricity relative to the main shaft, so that the first group of blades and the second group of blades perform periodic pitching motion to generate pulling force.

2. The staggered cycloidal propeller according to claim 1, characterized in that: When the number n of blades on one single side is 2, the second blade support is a four-arm structure formed by two groups of straight arms in a manner of coinciding at the center, the four-arm structure adopts a "cross"-shaped layout, and the first blade support and the third blade support are in a "one"-shaped layout.

3. The staggered cycloidal propeller according to claim 1, characterized in that: When the number n of blades on one single side is 2, the second blade support is a four-arm structure formed by two groups of straight arms in a manner of coinciding at the center, and the included angle between the two groups of straight arms in the four-arm structure is set to any angle.

4. The staggered cycloidal propeller according to claim 1, characterized in that: When the number n of blades on one single side is 3, the second blade support is a six-arm structure formed by three groups of straight arms in a manner of coinciding at the center, the six-arm structure adopts a circumferentially uniformly distributed "asterisk"-shaped layout, and the first blade support and the third blade support are in a "Upsilon"-shaped layout.

5. The staggered cycloidal propeller according to claim 1, characterized in that: Each blade in the first group of blades is mounted at the ends of the first blade support and the second blade support through a first rotating shaft, and the axis of the first rotating shaft penetrates through the center of gravity of the blade and is parallel to the main shaft; each blade in the second group of blades is mounted at the ends of the third blade support and the second blade support through a second rotating shaft, and the axis of the second rotating shaft penetrates through the center of gravity of the blade and is parallel to the main shaft.

6. The staggered cycloidal propeller according to claim 5, characterized in that: The first and second shafts are each arranged in a manner where a single shaft runs through the entire blade along its span, or in a manner where coaxial shafts are arranged at both ends of the blade.

7. The staggered cycloidal propeller according to claim 1, characterized in that: For each blade in the first group of blades, a first connecting shaft is provided on the blade end face facing the second blade support. The axial direction of the first connecting shaft is parallel to the main shaft. One end of the first transmission rod is rotatably engaged with the first connecting shaft, and the other end is rotatably connected to the hinge block via a pin. For each blade in the second group of blades, a second connecting shaft is provided on the blade end face facing the second blade support. The axial direction of the second connecting shaft is parallel to the main shaft. One end of the second transmission rod is rotatably engaged with the second connecting shaft, and the other end is rotatably connected to the hinge block via a pin. The second transmission rod is rotatably engaged with the second connecting shaft inside the blade of the second group of blades.

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