Adjustable Pitch Propeller with Bionic Structure of Fish Scales

Abstract

The present invention provides an adjustable pitch propeller applying a fish scale bionic structure, which includes blade, bionic structure slider, propeller hub, fixed bracket, blade rotation mechanism and bionic structure slider angle adjustment mechanism; the fixed bracket is fixedly connected with the propeller hub; the blade is rotatably connected to the outer periphery of the propeller hub; the blade rotation mechanism is connected inside the propeller hub and is in transmission connection with the blade; a plurality of bionic structure sliders are arranged on the surface of each blade; one end of the bionic structure slider is rotatably connected to the blade, and the middle part of the bionic structure slider is connected to the fixed bracket through the bionic structure slider angle adjustment mechanism. The present invention is an adjustable pitch propeller applying a fish scale bionic structure. By setting the bionic structure slider and relying on the design of the mechanical structure, it is realized that while changing the pitch of the adjustable pitch propeller, the arrangement angle of the bionic structure slider is changed, so that the drag reduction grooves can be parallel to the streamline of the blade surface in a large area at various advance speeds, giving play to the characteristics of reducing friction and drag, and making the propeller work more energy-efficient and efficient.

Description

Technical Field

[0001] The present invention relates to the technical field of propellers, and particularly to an adjustable pitch propeller applying a fish scale bionic structure. Background Art

[0002] Fish skin has good hydrodynamic performance, which can help fish swim quickly in water. Existing research shows that there are widely distributed shield-shaped scales on the surface of shark skin. This structure can achieve the effects of friction reduction, anti-friction, shock absorption and anti-adhesion, and has been applied in high-performance swimsuits, aerospace, medicine and other fields. The research in the naval field is currently more focused on applying the friction and drag reduction characteristics of shark skin imitation to reduce the hull navigation resistance. However, this method has too high preparation costs and small benefits, and cannot be applied on a large scale in practice. The existing method of processing fixed pitch propellers using shark skin imitation surface treatment does not follow the principle of hydrodynamics: the grooves processed on the shark skin imitation need to be parallel to the water flow direction to show the characteristics of friction and drag reduction. In the case of non-parallel, the resistance of the propeller will increase. Most propellers have multiple rotational speeds and speeds during operation, the angle of attack of the oncoming flow is variable, and the streamline on the blade surface is also variable. This leads to the negligible or even counterproductive effect of drag reduction of the fixed pitch propeller processed through the shark skin imitation structure surface.

[0003] The literature (Wang, Li, Han, & Hao, 2022) and the calculation results obtained by using Fluent software for hydrodynamic numerical simulation show that the streamlines on the blade surface are parallel in most areas; and when the advance coefficient changes, with the change of the angle of attack of the oncoming flow, most of the streamlines on the blade surface produce the same angular change, that is, the angle between the streamline and the chord line changes regularly with the angle of attack of the oncoming flow. On variable pitch propellers, the change of pitch at different speeds also causes a change in the water flow angle of attack, resulting in a similar phenomenon. The fixed-angle grooves processed by the existing shark skin drag reduction technology are often unable to be parallel to the water flow when directly applied to the propeller, making it have little effect or even having a counterproductive effect. Summary of the Invention

[0004] In view of the above deficiencies in the prior art, the present invention provides an adjustable pitch propeller applying a fish scale bionic structure. Shark skin drag reduction grooves are locally arranged on the surface of the propeller blade, and through the design of the mechanical structure, while changing the pitch of the adjustable pitch propeller, the arrangement angle of the drag reduction grooves on the blade surface is changed, so that the drag reduction grooves are parallel to the oncoming flow over a large area at various advance speeds, thereby exerting its characteristics of friction and drag reduction, and making the propeller work more energy-efficiently.

[0005] To achieve the above object, the present invention provides an adjustable pitch propeller applying a fish scale bionic structure, which includes a plurality of blades, a plurality of bionic structure sliders, a propeller hub, a fixed bracket, a blade rotation mechanism and a bionic structure slider angle adjustment mechanism; the fixed bracket is fixedly connected to the propeller hub; the blades are rotatably connected to the outer periphery of the propeller hub; the blade rotation mechanism is connected inside the propeller hub and is in transmission connection with the blades; a plurality of the bionic structure sliders are arranged on the surface of each blade; one end of the bionic structure slider is rotatably connected to the blade, and the middle part of the bionic structure slider is connected to the fixed bracket through the bionic structure slider angle adjustment mechanism.

[0006] Preferably, a plurality of fish skin bionic structure grooves are formed on the surface of the bionic structure slider.

[0007] Preferably, the blade rotation mechanism includes a plurality of bottom blade spiral gears and a spiral gear inside the hub; a bottom blade spiral gear is connected to one end of each blade adjacent to the propeller hub; the spiral gear inside the hub is arranged inside the propeller hub and meshes with each of the bottom blade spiral gears.

[0008] Preferably, the fixed bracket includes a propeller hub fixed bracket and a plurality of inner blade threaded rods; the propeller hub fixed bracket is fixed inside the propeller hub; an inner blade threaded rod is penetrated through each blade; the inner blade threaded rod is fixedly welded to the propeller hub fixed bracket.

[0009] Preferably, the bionic structure slider angle adjustment mechanism includes a plurality of threaded grooves and a plurality of ball column sliding control bolts; a plurality of the threaded grooves are formed side by side on each inner blade threaded rod; the ball column sliding control bolt includes a connecting rod and a spherical ball formed at the first end of the connecting rod, the spherical ball is slidably arranged in the corresponding threaded groove along the threaded groove and the threaded groove limits the spherical ball; the inner side surface of the bionic structure slider is connected to the second end of the corresponding connecting rod.

[0010] Preferably, the fish skin bionic structure grooves on the surface of the bionic structure slider are always parallel to the surface streamline of the blade.

[0011] Due to the adoption of the above technical solutions, the present invention has the following beneficial effects:

[0012] 1. A plurality of fish skin bionic structure grooves are formed on the surface of the bionic structure slider. Compared with the surface of the propeller with smooth treatment, the hydrodynamic performance of the propeller can be effectively improved, the resistance during operation can be reduced, and the anti-friction, anti-friction and anti-adhesion capabilities of the blade surface can be enhanced.

[0013] 2. During the entire process of the propeller's operation, various water speeds and rotational speeds under different working conditions impose various hydrodynamic requirements on the propeller. Compared with the existing propellers with sharkskin-like surface treatment, which only have a fixed groove angle and cannot adapt to the complex hydrodynamic environment of the propeller. Through the cooperation of the blade rotation mechanism and the bionic structure slider angle adjustment mechanism in this solution, various corresponding pitches and the angles of the bionic structure sliders can be adjusted, corresponding to a variety of pre-calculated working speeds and states, and ensuring that the propeller has the best hydrodynamic performance under various different working states. Therefore, the propeller design in this solution has good economy and applicability.

[0014] 3. The anti-wear, anti-seismic and anti-adhesion effects of the fish-scale bionic structure of the bionic structure slider can better resist seawater corrosion, cavitation corrosion, vibration noise and biological fouling compared with traditional propellers, effectively extending the service life of the propeller. Brief Description of the Drawings

[0015] Figure 1 It is the front elevation sectional view of the adjustable pitch propeller applying the fish-scale bionic structure in the embodiment of the present invention;

[0016] Figure 2 It is the side elevation sectional view of the adjustable pitch propeller applying the fish-scale bionic structure in the embodiment of the present invention;

[0017] Figure 3 It is the top elevation sectional view of the adjustable pitch propeller applying the fish-scale bionic structure in the embodiment of the present invention;

[0018] Figure 4 and Figure 5 It is the working state diagram of the propeller under the design working conditions in the embodiment of the present invention;

[0019] Figure 6 and Figure 7 It is the working state diagram of the propeller when the pitch increases in the embodiment of the present invention;

[0020] Figure 8 and Figure 9 It is the working state diagram of the propeller when the pitch decreases in the embodiment of the present invention. Detailed Embodiment

[0021] Next, according to the drawings Figures 1 to 9 , the preferred embodiment of the present invention is given and described in detail to better understand the functions and features of the present invention.

[0022] Please refer to Figures 1 to 9An adjustable pitch propeller using a fish scale bionic structure according to an embodiment of the present invention comprises a plurality of blades 1, a plurality of bionic structure sliders 4, a hub 7, a fixed bracket 6, a blade rotation mechanism and a bionic structure slider angle adjustment mechanism; the fixed bracket 6 is fixedly connected to the hub 7; the blade 1 is rotatably connected to the outer periphery of the hub 7; the blade rotation mechanism is connected inside the hub 7 and is transmission-connected to the blade 1; a plurality of bionic structure sliders 4 are arranged on the surface of each blade 1; one end of the bionic structure slider 4 is rotatably connected to the blade 1 through a fixed rivet 2, and the middle part of the bionic structure slider 4 is connected to the fixed bracket 6 through the bionic structure slider angle adjustment mechanism.

[0023] In this embodiment, a plurality of fish skin bionic structure grooves are formed on the surface of the bionic structure slider 4 .

[0024] The blade rotation mechanism includes a plurality of blade bottom helical gears 8 and a hub inner helical gear 9; one end of each blade 1 adjacent to the hub 7 is connected to the blade bottom helical gear 8; the hub inner helical gear 9 is arranged in the hub 7 and meshes with each blade bottom helical gear 8.

[0025] The fixing bracket 6 comprises a hub fixing bracket and a plurality of blade internal thread rods; the hub fixing bracket is fixed in the hub 7; a blade internal thread rod is penetrated in each blade 1; the blade internal thread rod is fixed to the hub fixing bracket by welding.

[0026] The bionic structure slider angle adjustment mechanism includes multiple thread grooves 5 and multiple ball-column sliding control bolts 3; the threaded rod in each leaf forms multiple parallel thread grooves 5; the ball-column sliding control bolt 3 includes a connecting rod and a ball formed at the first end of the connecting rod, the ball can be slidably arranged in the corresponding thread groove 5 along the thread groove 5 and the thread groove 5 limits the ball; the inner side surface of the bionic structure slider 4 is connected to the second end of the corresponding connecting rod.

[0027] An adjustable pitch propeller using a fish scale bionic structure according to an embodiment of the present invention changes the angle of a bionic structure slider 4 on the surface of a blade 1 by the cooperation between mechanical structures to make it parallel to the streamline, so as to give full play to the characteristics of the bionic groove in reducing friction and drag.

[0028] The blade 1 is designed to be hollow so that the ball column sliding control bolt 3 and the blade inner thread rod can be placed therein.

[0029] Through structural design, the pitch of the blade 1 and the setting angle of the bionic structure slider 4 can be changed simultaneously only by rotating the helical gear 9 in the hub.

[0030] In terms of propeller hydrodynamics, the fish skin bionic structure grooves on the surface of the bionic structure slider 4 are always parallel to the surface streamlines of the blade 1. This ensures that the bionic structure can always achieve the hydrodynamic characteristics of reducing friction and drag, and achieve the design goal.

[0031] An adjustable pitch propeller applying a fish scale bionic structure according to an embodiment of the present invention has the following working principle:

[0032] When the propeller works, through the rotation of the internal hub helical gear 9, on the one hand, the pitch of the blade 1 can be adjusted to ensure the best hydrodynamic performance of the propeller, and on the other hand, the angle of the bionic structure slider 4 can be adjusted at the same time to make it parallel to the oncoming water flow direction, reducing the frictional resistance of the propeller, reducing corrosion and reducing noise.

[0033] When receiving a command to change the pitch, the internal hub helical gear 9 rotates to drive the bottom blade helical gear 8 to rotate, so that the blade 1 rotates to change the propeller pitch. At the same time, since the fixed bracket 6 is fixed in the propeller hub 7 and remains fixed when the blade 1 rotates, while the ball column sliding control bolt 3 and the bionic structure slider 4 rotate following the blade 1, relative rotation occurs between the two parts of the structure. The ball column sliding control bolt 3 slides in the threaded groove 5, generating a horizontal displacement, driving the change of the angle of the bionic structure slider 4. The variable angle range of the bionic structure slider 4 can be adjusted by adjusting the slope of the threaded groove 5. The above process realizes that the propeller can adjust the best pitch and the angle of the bionic groove under different working conditions to achieve the design goal of high efficiency and energy saving.

[0034] When the propeller pitch changes, the bionic fish scales change with the working state, as shown in Figures 4 to 9 , and the arrow direction in the figure is the oncoming water flow direction.

[0035] The present invention has been described in detail above in conjunction with the embodiments of the accompanying drawings. Those of ordinary skill in the art can make various variations of the present invention according to the above description. Therefore, certain details in the embodiments should not constitute a limitation to the present invention, and the protection scope of the present invention will be defined by the scope of the appended claims.

Claims

1. An adjustable pitch propeller applying the fish scale bionic structure, characterized in that, It includes multiple blades, multiple bionic structure sliders, a hub, a fixed bracket, a blade rotation mechanism, and a bionic structure slider angle adjustment mechanism; the fixed bracket is fixedly connected to the hub; the blades are rotatably connected to the outer periphery of the hub; the blade rotation mechanism is connected inside the hub and is in transmission connection with the blades; a plurality of the bionic structure sliders are arranged on the surface of each blade; one end of the bionic structure slider is rotatably connected to the blade, and the middle part of the bionic structure slider is connected to the fixed bracket through the bionic structure slider angle adjustment mechanism; Several fish-skin bionic structure grooves are formed on the surface of the bionic structure slider; The blade rotation mechanism includes multiple bottom-blade helical gears and an in-hub helical gear; one end of each blade adjacent to the hub is connected with the bottom-blade helical gear; the in-hub helical gear is arranged inside the hub and meshes with each of the bottom-blade helical gears; The fish-skin bionic structure grooves on the surface of the bionic structure slider are always parallel to the surface streamline of the blade.

2. The adjustable pitch propeller applying the fish scale bionic structure according to claim 1, characterized in that, The fixed bracket includes a hub fixed bracket and multiple in-blade threaded rods; the hub fixed bracket is fixed inside the hub; one of the in-blade threaded rods is inserted into each blade; the in-blade threaded rod is fixedly welded to the hub fixed bracket.

3. The adjustable pitch propeller applying the fish scale bionic structure according to claim 2, characterized in that, The bionic structure slider angle adjustment mechanism includes multiple threaded grooves and multiple ball-column sliding control bolts; a plurality of the threaded grooves are formed side by side on each in-blade threaded rod; the ball-column sliding control bolt includes a connecting rod and a spherical ball formed at the first end of the connecting rod, the spherical ball is slidably arranged in the corresponding threaded groove along the threaded groove and the threaded groove limits the spherical ball; the inner side surface of the bionic structure slider is connected to the second end of the corresponding connecting rod.

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