Propeller fan

Abstract

A propeller fan and a drive system with reduced noise emissions are disclosed. The propeller fan includes a blade fan having a plurality of blades. The blade may include a dual pin root design to secure the blade fan to a hub and to a shroud located at the tip of the blade. The blade may include one or more blade seals protruding from a surface of the shroud.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 356,852, filed on June 29, 2022, which is incorporated herein by reference in its entirety. Background Art Technical Field

[0003] The present disclosure relates generally to propeller fans and drive systems, and more particularly to tension blade fans having one or more knife edge seals. Background Art

[0005] Conventional propeller fans typically include an open rotor and a propeller. These types of conventional propeller fans have reached their acoustic limits. Conventional propellers have blades that are supported on a single end, thereby limiting the number of blades to five or fewer blades. In order to make the frequency of the sound emitted by conventional propellers less detectable to the human ear, the speed of the fan must be increased. However, since it is supported only by a single end structure, conventional propellers cannot be driven at higher speeds. In addition, because conventional propeller fans are only supported at a single end, the angle of the fan blades may change as the blade fan rotates faster, resulting in a change in tone that is audible to the human ear. Therefore, noise pollution is increased. As conventional propeller fans are integrated into an array of multiple conventional propeller fans, noise pollution is further increased.

[0006] In addition, conventional fan designs incorporated into conventional propeller fans are targeted at medium to high fan pressure ratio (PR) applications (1.3PR to 1.75PR). Generally, the lower the fan PR, the lower the fan aspect ratio (AR). Therefore, high aspect ratio blades with high pressure ratio fans are made of titanium (or a stronger material). For structural reasons, these conventional fan designs include one or two partial span shrouds to control the vibration modes of the fan blades. This results in reduced fan performance (if one partial span shroud is required, the performance loss is approximately 1%; if two partial span shrouds are required, the performance loss is approximately doubled). For example, the open tip clearance used in conventional fan designs further impairs fan performance because conventional fan designs are designed so that their wear-resistant materials wear over time due to action, hard landings, and erosion. Summary of the invention

[0007] A propeller fan with reduced noise emission is disclosed. The propeller fan includes a blade fan having a plurality of blades. The plurality of blades have an interlocking blade tip shroud design to limit airfoil angle of attack movement and enhance the structural rigidity of the airfoil at high revolutions per minute (RPM).

[0008] In one embodiment, an interlocking tip design is used to tension the blade tips of a blade fan so that the pitch of the blades during thrust generation is substantially the same as the pitch of the blades when stationary. Each blade includes a shroud segment that is configured to connect to the shroud segments of other blades. The connected shroud segments together form the tip shroud around the circumference of the blade fan and tension the tip of the blade. By tensioning the tip of the blade, the same shape and twist of the blade is maintained during thrust generation and at rest, thereby reducing noise that may be generated due to changes in the angle of the blade.

[0009] In one embodiment, each blade may also include a plurality of blade segments protruding from the upper surface of the shroud segment of the blade. The blade segment of each blade is configured to be connected to the blade segments of other blades. The connected blade segments together form one or more blade seals around the circumference of the blade tip shroud. The blade seal improves the control of blade tip leakage and provides an improved fan blade gap span ratio to enhance performance and retention.

[0010] In one embodiment, each blade includes a pin root structure to connect the blade to the hub. The pin root structure may include a plurality of mounting tabs offset from one another. The mounting tab of each blade is inserted into the hub and connected to the hub using a plurality of fasteners. Due to the offset of the mounting tabs of each blade, a plurality of fasteners are used to connect each blade to the hub, wherein each fastener connects a plurality of blades to the hub. By tensioning the root of the blade, the same shape and twist of the blade is maintained during thrust generation and at rest, thereby reducing noise that may be generated due to changes in the angle of the blade. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is a perspective view of a propeller fan according to one embodiment.

[0012] Figure 2A is a first exploded view of a propeller fan according to one embodiment.

[0013] Figure 2B is a second exploded view of a propeller fan according to one embodiment.

[0014] Figure 3A , Figure 3B , Figure 3C and Figure 3D A perspective view, a front view, a side view, and a cross-sectional view are respectively illustrated of a duct lip of a propeller fan according to one embodiment.

[0015] Figure 4A , Figure 4B , Figure 4C and Figure 4DA perspective view, a front view, a cross-sectional view, and a cross-sectional perspective view of a nose cone of a propeller fan according to one embodiment are respectively illustrated.

[0016] Figure 5A and Figure 5B A front view and a side view of a hub of a propeller fan according to a second embodiment are respectively illustrated.

[0017] Fig. 6A and Figure 6B A perspective view and a front view of a blade fan of a propeller fan according to one embodiment are respectively illustrated.

[0018] Fig. 7A , Figure 7B , Figure 7C and Fig.7D The first embodiment is respectively illustrated. Fig. 6A and Figure 6B A perspective view, a front view, a side view and a top view of the blades included in the blade fan are shown.

[0019] Fig. 8A , Figure 8B and Figure 8C A perspective view, a front view, and a side view are respectively illustrated of a locking ring of a propeller fan according to one embodiment.

[0020] Fig.9A and Fig. 9B A perspective view and a side view, respectively, of a tension ring of a propeller fan according to one embodiment are illustrated.

[0021] Fig. 10A , Fig. 10B and Fig. 10C A perspective view, a front view, and a side view are respectively illustrated of an inner duct body housing of a propeller fan according to one embodiment.

[0022] Fig.11A , Fig. 11B , Fig. 11C and Fig.11D A perspective view, a front view, a side view, and a cross-sectional view of a stator of a propeller fan according to one embodiment are respectively illustrated.

[0023] Fig. 12A , Fig. 12B , Fig. 12C and Fig.12D A perspective view, a front view, a side view, and a cross-sectional view of a tail cone of a thruster fan according to one embodiment are respectively illustrated.

[0024] Fig.13A , Fig. 13B and Fig. 13C A perspective view, a front view, and a side view are respectively illustrated of a circumferential drive system of a propeller fan according to one embodiment.

[0025] Fig.14 A circumferential drive system for a propeller fan according to another embodiment is illustrated.

[0026] Fig.15A and Fig. 15B A front view and a perspective view, respectively, of a thruster fan array according to one embodiment are illustrated.

[0027] Fig.16 An example application of a thruster fan array according to one embodiment is illustrated.

[0028] Fig.17A , Fig. 17B and Fig. 17C A front view, a side view, and a top view of a hovering drone including a thruster fan array according to one embodiment are illustrated, respectively.

[0029] Fig.18A , Fig.18B and Fig.18C A front view, a side view, and a top view of a cinema drone including a thruster fan array according to one embodiment are respectively illustrated.

[0030] Fig.19A , Fig.19B and Fig.19C A front view, a side view, and a top view are respectively illustrated of a transport aircraft including a pusher fan array according to one embodiment.

[0031] Fig. 20A , Fig. 20B and Fig. 20C A front view, a side view, and a top view are respectively illustrated of a vertical take-off and landing (VTOL) aircraft including a thruster fan array according to one embodiment.

[0032] Fig.21A , Fig. 21B and Fig. 21C A front view, a side view, and a top view are respectively illustrated of a delivery drone including a thruster fan array according to one embodiment.

[0033] Fig.22A , Fig. 22B and Fig. 22C A front view, a side view and a top view of a blade with a double pin root according to a second embodiment are illustrated, respectively.

[0034] Fig.23A According to the second embodiment, FIG. 22A to FIG. 22C A perspective view of a blade with a double pin root is shown.

[0035] Fig. 23B According to the second embodiment, FIG. 22A to FIG. 22CA perspective view of a shroud segment of a blade with a double pin root is shown.

[0036] Fig.23C According to the second embodiment FIG. 22A to FIG. 22C A perspective view of the root of a double pin is shown.

[0037] Fig.24A , Fig. 24B and Fig.24C A front view, a side view, and a perspective view, respectively, of a plurality of interconnected blades forming part of a tip shroud according to a second embodiment are illustrated, wherein each blade includes a double pin root.

[0038] Fig.25A and Fig.25B A front view and a perspective view, respectively, are illustrated of a plurality of blade segments on a shroud segment of a blade according to one embodiment.

[0039] Fig.26A A front view of multiple blade segments on a shroud segment having blades of different heights is illustrated according to one embodiment.

[0040] Fig.26B A front view of a single blade segment on a shroud of a blade is illustrated according to one embodiment.

[0041] Fig.27A and Fig.27B A front view and a side view of a hub according to a second embodiment are illustrated, respectively.

[0042] Fig.28A and Fig.28B The second embodiment of the present invention is respectively illustrated. Fig.27A and Fig.27B Shown is a perspective view of a first end of the hub and a perspective view of a second end of the hub.

[0043] Fig.29 According to the second embodiment, Fig.27B Cross-sectional view of the hub along line AA'.

[0044] Fig. 30A , Fig. 30B and Fig. 30C The embodiments of the present invention are respectively exemplified as follows: Fig.28A and Fig.28B Front, side and perspective views of the blade at the root of the hub with double pin holes.

[0045] Fig.31A and Fig.31B The embodiments of the present invention are respectively exemplified as follows: Fig.28A and Fig.28B Perspective and side views of multiple interconnected blades at the root of a dual pin hole of a hub.

[0046] Fig.32A and Fig.32B The first end of the hub according to one embodiment is respectively illustrated. Fig.31A Detailed perspective view of area A and the second end of the hub Fig.31A A detailed perspective view of area A of a wheel hub, wherein the first end has a plurality of interconnected blades connected to the hub using a plurality of fasteners and the second end has a plurality of interconnected blades connected to the hub using a plurality of fasteners.

[0047] Fig.33 is a wireframe diagram of a plurality of interconnected blades with a double pin root connected to a hub using a plurality of fasteners according to one embodiment.

[0048] Fig.34A , Fig.34B and Fig.34C A front view, a side view, and a perspective view are respectively illustrated of a blade fan with a tip shroud according to one embodiment, the blade fan using a blade with a double pin hole root.

[0049] Fig.35A , Fig.35B and Fig.35C A front view, a side view, and a perspective view are respectively illustrated of a blade fan having a tip shroud and a plurality of knife edge seals according to one embodiment, the blade fan using a blade having a double pin hole root.

[0050] Fig.36 A perspective view of a blade fan having a tip shroud and a single knife edge seal is illustrated according to one embodiment.

[0051] Fig.37A and Fig.37B A side view and a perspective view, respectively, of a blade having multiple blade segments and a single pin hole root according to a third embodiment are illustrated.

[0052] Fig.38 A front view of a blade fan having a single pin hole root and multiple knife edge seals is illustrated according to one embodiment. DETAILED DESCRIPTION

[0053] The accompanying drawings (figures) and the following description describe certain embodiments by way of example only. Those skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles described herein. Reference will now be made in detail to several embodiments, examples of which are illustrated in the accompanying drawings. It should be noted that, where feasible, similar or similar reference numerals may be used in the drawings and may indicate similar or similar functionality.

[0054] Propulsion fans and drive systems

[0055] In one embodiment, a propeller fan and drive system are disclosed. Generally speaking, the propeller fan and drive system are configured to generate thrust. The propeller fan and drive system can generate thrust for a variety of applications ranging from aircraft to hand tools (such as leaf blowers). However, the applications of the propeller fan and drive system are not limited to those described herein.

[0056] Figure 1 A perspective view of a propeller fan 100 according to one embodiment is illustrated. Generally speaking, the propeller fan 100 includes a plurality of components that collectively reduce the noise emitted by the propeller fan 100 during thrust generation. Therefore, the propeller fan 100 reduces noise pollution. For example, the propeller fan 100 includes a tensioning blade fan that includes a plurality of fan blades. With the tensioning blade fan, the angle of the fan blades remains substantially the same regardless of whether the propeller fan is generating maximum thrust or is not running (e.g., at rest). Therefore, compared to conventional propeller fans, noise pollution is reduced and thrust efficiency is improved. Considering that the angle of the fan blades is maintained within a predetermined tolerance range, the propeller fan 100 reduces noise pollution. For example, the noise emitted by the propeller fan 100 at 300 feet sideline / 5,000lbf is less than 65dBA.

[0057] Figure 2A A first exploded view of a propeller fan 100 according to one embodiment is illustrated, and Figure 2B A second exploded view of a propeller fan 100 according to one embodiment is illustrated. The propeller fan 100 includes a number of different components, such as Figure 2A and Figure 2B In one embodiment, the propeller fan 100 includes a duct lip 201, a nose cone 203, a hub 205, a blade fan 209, a locking ring 210 (in FIG. 8A to FIG. 8C ), a tension ring 211, a motor 215, a main body housing 217, a plurality of housings 213A and 213B, a stator 219, and a tail cone 221. Other embodiments of the propeller fan 100 may include Figure 2A and Figure 2B In one embodiment, the duct lip 201, the housing 213, and a portion of the stator 219 (e.g., 219C) together form a circulation duct that accommodates components of the propeller fan, such as Figure 1 shown.

[0058] Figure 3A , Figure 3B , Figure 3C and Figure 3DA perspective view, a front view, a side view, and a cross-sectional view of a duct lip 201 of a propeller fan 100 according to an embodiment are illustrated respectively. In one embodiment, the duct lip 201 is configured to provide clean air inflow to the propeller fan 100. In one embodiment, the duct lip 201 is configured to be connected to the main body housing 217. The duct lip 201 may include a plurality of mounting holes 223 located on a rear surface of the duct lip 201, such as Figure 2B Fasteners (eg, nuts and bolts, rivets, etc.) are placed in mounting holes 223 to connect duct lip 201 to first end 1001 of body housing 217, as will be further described below.

[0059] The duct lip 201 may include a plurality of panels that together form the duct lip 201. For example, the duct lip 201 may include a first plurality of panels that together form an inner surface 309 of the duct lip 201, and a second plurality of panels that together form an outer surface 307 of the duct lip 201, so that the duct lip 201 has a hollow center through which air is directed to the blade fan 209. The first plurality of panels and the second plurality of panels may be connected to each other via various fastening components, such as fasteners (e.g., screws, nuts, bolts) or via welding. The first plurality of panels and the second plurality of panels may be made of metal, such as aluminum or titanium, or a composite material, such as carbon fiber. Alternatively, the duct lip 201 may be made of a single piece of material, and may be 3D printed, for example.

[0060] In one embodiment, the duct lip 201 includes a first end 303 (eg, an inlet) and a second end 305 (eg, an outlet). The first end 303 receives air, and the air exits from the second end 305. Figure 3C As shown, the diameter of the first end 303 is smaller than the diameter of the second end 305, but may be the same in other embodiments. The diameters of the first end 303 and the second end 305 of the duct lip 201 depend on the application of the propeller fan 100. For example, for an aircraft application, the diameters of the first end 303 and the second end 305 of the duct lip 201 are larger than those of a leaf blower application.

[0061] Figure 3D According to one embodiment, Figure 3B2. A cross-sectional view of the duct lip 201 of the plane AA' shown. As previously mentioned, the duct lip 201 includes an outer surface 307 and an inner surface 309. Both the outer surface 307 and the inner surface 309 extend from the first end 303 of the duct lip 201 toward the second end 305 of the duct lip 201. Air flows through the inner surface 309 of the duct lip 201. The curvature 311A ​​of the inner surface 309 of the duct lip 201 and the curvature 311B of the outer surface 307 of the duct lip 301 are designed to balance various factors, such as different conditions (e.g., flight conditions, such as cruising, take-off and landing) and Reynolds number. Those skilled in the art will be able to customize the duct lip radius to achieve a favorable pressure gradient across the speed regime and flight mode of interest.

[0062] Figure 4A , Figure 4B , Figure 4C and Figure 4D A perspective view, a front view, a cross-sectional view, and a cross-sectional perspective view of a nose cone 203 of a propeller fan 100 according to one embodiment are illustrated respectively. The nose cone 203 is configured to adjust the oncoming airflow behavior and reduce aerodynamic drag. The nose cone 203 may also be configured with an impeller to help cool the air mass flow without significantly contributing to broadband noise or spectral noise.

[0063] In one embodiment, the nose cone 203 is configured to be connected to the motor 215 using a hub 205 disposed between the nose cone 203 and the motor 215. The nose cone 203 may include a plurality of mounting holes located on the rear surface of the nose cone 203, such as Figure 2B A fastener 207 (e.g., a nut and bolt, a rivet, etc.) is placed in the mounting hole to connect the nose cone 203 to the first end of the hub 205. As will be further described below, the fastener 207 extends through the hub 205 and connects to the first end of the motor 215.

[0064] In one embodiment, the nose cone 203 is conical in shape. However, in other embodiments, the nose cone 203 may have a different shape. FIG. 4A to FIG. 4D As shown, the nose cone 203 includes an opening 403 (e.g., a hole) at a first end of the nose cone 203. When the blade fan 209 rotates, air is drawn through the opening 403 in the nose cone 203 to cool the motor 215. The secondary mass flow required to cool the internal components determines the size of the internal diameter of the opening 403 of the nose cone 203. Those skilled in the art will be able to derive this diameter based on the heat dissipation requirements of different electric motors and the air required to cool the electric motor under the most stringent constraints (usually maximum continuous operation).

[0065] Figure 4C According to one embodiment, Figure 4B2 is a cross-sectional view of the nose cone 203 taken along plane BB' as shown. In one embodiment, the nose cone 203 is not solid and includes a cavity. For example, in one embodiment, the nose cone 203 includes an air passage 405. The air passage 405 extends from an opening 403 in the nose cone 203 to a plurality of openings 407 disposed around a circumference of a second end (e.g., a rear surface) of the nose cone 203. Air flows from the opening 403 through the air passage 405 and exits from the plurality of openings 407 to cool the motor 215. In one embodiment, the air passage 405 is formed between an outer surface 409 of the nose cone 203 and a protrusion 411 formed within the nose cone 211, as shown in FIG. Figure 4C and Figure 4D shown.

[0066] In one embodiment, the protrusion 411 protrudes inward from the second end of the nose cone 203 toward the opening 403 of the nose cone 203. The protrusion 411 may have a similar shape to the nose cone 203. For example, the protrusion 411 is also conical in shape. However, in other embodiments, the protrusion 411 may have a different shape from the nose cone 203.

[0067] Generally, the protrusion 411 has a size and shape adjusted for mass air flow to cool the motor 215. In one embodiment, the protrusion 411 includes an air passage 413 formed through the protrusion 411 through which air flows from an opening 415 of the air passage to an opening 417 located on the second end of the nose cone 203. In one embodiment, the center of the air passage 413 is aligned with the center of the opening 403 in the nose cone 203.

[0068] Figure 5A and Figure 5B A front view and a side view of a hub 205 of a propeller fan 100 according to a first embodiment are illustrated, respectively. The hub 205 is the central portion of the propeller fan 100 and is disposed at the center of the blade fan 209, as will be further described below. In one embodiment, the hub 205 is configured to be connected to the nose cone 203, the locking ring 210, and the motor 215.

[0069] like Figure 5AAs shown in FIG. 5C , in one example, the hub 205 is cylindrical in shape. In one embodiment, the diameter of the first end 507 of the hub 205 matches the diameter of the second end of the nose cone 203. The first end 507 (e.g., the front surface) of the hub 205 includes a plurality of mounting holes 501A to 501F formed through the thickness of the hub 205. The position of the mounting holes 501 is such that when the second end of the nose cone 203 is mated with the first end 507 of the head hub 205, the mounting holes 501 are aligned with the mounting holes of the nose cone 203. The fastener 207 is configured to pass through the mounting holes 501A to 501F and be connected to the first end (e.g., the front surface) of the motor 215. For example, the fastener 207 is screwed into the threaded hole 225 on the first end of the motor 215.

[0070] In one embodiment, the hub 205 also includes a plurality of openings 503, such as openings 503A and 503B, extending through the thickness of the hub 205. The plurality of openings 503 have a shape and size that matches (e.g., is the same as) the openings 407 in the rear surface of the nose cone 203. The openings 503 are configured to align with the openings 407 in the rear surface of the nose cone 203 when the nose cone 203 and the hub 205 are mated with each other. Therefore, air exiting from the openings 407 of the nose cone 203 flows through the openings 503 included in the hub 205. In one embodiment, the plurality of openings 503 included in the hub have different sizes. For example, the opening 503A is smaller than the opening 503B.

[0071] In one embodiment, the hub 205 further includes an opening 505 extending through the thickness of the hub 205. The opening 505 is located at the center of the hub 205. In one embodiment, the center of the opening 205 is configured to align with the center of the air passage 413 of the nose cone 203. Thus, airflow exiting from the air passage 413 of the nose cone 203 flows through the opening 505 in the hub 205 to cool the motor 215.

[0072] In one embodiment, the second end 511 of the hub 205 opposite the first end 507 includes a connection mechanism 509 around the outer circumference of the second end 511 of the hub 205. The connection mechanism 509 is configured to connect the hub 205 to the locking ring 210. In one embodiment, the connection mechanism 509 is a thread such that the hub 205 is screwed into the locking ring 210. Once the hub 205 is connected to the locking ring 210, the locking ring 210 surrounds the outer circumference of the hub 205. The motor 215 is configured to mate with the outer surface of the second end 511 of the hub 211.

[0073] In one embodiment, the hub 205 includes a middle area 511 disposed between a first end 507 and a second end 511 of the hub 205. In one embodiment, the blade fan 209 is configured to be disposed around the circumference of the middle area 511, and the hub 205 is placed to pass through the center of the blade fan 209.

[0074] Fig. 6A and Figure 6B 1 and 2 respectively illustrate a perspective view and a front view of a blade fan 209 of the propeller fan 100 according to the first embodiment. FIG. 6A to FIG. 6B As shown, the blade fan 209 includes a plurality of blades 601. The total number of blades 601 included in the blade fan 209 is significantly greater than the number of blades included in a conventional propeller fan having 2 to 5 blades. In one embodiment, the blade fan 209 may include a series of blades 601 with an upper limit of from 20 blades to 100 to 150 blades, with a hub / tip ratio (H / t) of 0.3 to 0.5. However, any number of blades greater than five may be used. Generally speaking, the total number of blades 601 included in the blade fan 209 depends on the application. In one embodiment, the material of the blades for the multi-blade fan also depends on the type of application of the multi-blade fan. The blades may be made of metal (such as aluminum or titanium) or composite materials (such as carbon fiber).

[0075] In one embodiment, when the blade fan 209 rotates at a low tip speed (about 300 feet per second to 450 feet per second), the blade fan 209 reduces the overall blade noise. As described herein, the tensioning fan blades 209 allow more blades to exist within the mechanical material limitations, and still achieve ultrasonic characteristics and low subsonic tip speeds. In addition, a higher number of blades 601 will increase the tonal noise to ultrasonic frequencies that exceed the upper limit of human hearing (≥16,000 Hz for a typical adult). In addition, the low blade loads caused by the higher number of blades also reduce the severity of vortex collisions that cause broadband noise.

[0076] like Fig. 6A and Figure 6B As shown, a plurality of blades 601 are arranged to form a torus shape having a hollow center, and the hub 205 is disposed in the hollow center. Each blade 601 is positioned so that at least a portion of the leading edge and the trailing edge of the blade 601 overlaps with an adjacent blade 601. For example, the leading edge of a given blade overlaps with the trailing edge of the blade to the left of the given blade, and the trailing edge of a given blade overlaps with the leading edge of the blade to the right of the given blade. The overlapping arrangement of a plurality of blades 601 provides enhanced robustness to perform work on the inflowing air flow. The adjustment of this robustness takes into account local aerodynamic effects, and can be adjusted to take into account the Reynolds number effects that may affect the laminar attachment of the airflow within and between the blades.

[0077] Fig. 7A , Figure 7B , Figure 7C and Fig.7D The first embodiment is respectively illustrated. Fig. 6A and Figure 6B The perspective view, front view, side view and top view of the blade 601 included in the blade fan 209 are shown. In one embodiment, each blade 601 includes a first locking end 605, a second locking end 603 and an airfoil 607 disposed between the first locking end 605 and the second locking end 603. In other embodiments, the blade 601 may include other features in addition to those described herein.

[0078] In one embodiment, the first locking end 605 is located at the tip of the blade 601. The first locking end 605 is configured to be inserted into the tensioning ring 211 and lock the blade 601 into the tensioning ring 211, so that the tip of the blade 601 is tensioned. By tensioning the tip of the blade 601, the pitch (e.g., angle) of the tip of the blade 601 is substantially the same during thrust generation or when the propeller fan 100 is stationary, thereby reducing noise pollution.

[0079] like FIG. 7A to FIG. 7D As shown, the shape of the first locking end 605 is a rectangle with chamfered edges, but other shapes can be used for the first locking end 605. In one embodiment, the first locking end 605 has a width and thickness greater than the width and thickness of the tip of the airfoil 607. However, in other embodiments, the width of the first locking end 605 can be the same as or narrower than the tip of the blade 601. Those skilled in the art should customize the edges, chamfers, surface treatments, and bezels to account for local stresses and strains caused by tensioning.

[0080] In one embodiment, the second locking end 603 is located at the root of the blade 601. The second locking end 606 is configured to be inserted into the locking ring 210 and lock the blade 601 into the locking ring 210. By tensioning the root of the blade 601, the pitch (e.g., angle) of the root of the blade 601 is substantially the same during thrust generation or when the propeller fan 100 is stationary, thereby reducing noise pollution. FIG. 7A to FIG. 7D , the second locking end 603 has a plurality of different surfaces (e.g., a straight surface and a curved surface) to increase the surface area contacting the locking ring 210 to reduce blade deflection. In one embodiment, the second locking end 603 has a width greater than the root of the blade 601 and wider than the width of the first locking end 605. However, in other embodiments, the second locking end 603 may have the same width as the root of the blade 601 or be narrower than it.

[0081] The airfoil 607 is disposed between the first locking end 605 and the second locking end 603. In one embodiment, the airfoil 607 includes a geometric twist 609 in the airfoil 607. The geometric twist 609 is a change in the airfoil incidence angle measured relative to the root of the blade 601. That is, the airfoil 607 includes a plurality of different incidence angles across the length of the airfoil 607 due to the geometric twist 609. For example, the airfoil 607 may be at a first side of the geometric twist 609 (e.g., at 7A to 7C having a first angle of incidence (below the geometric twist 609 in FIG. 1 ), and may be at a second side of the geometric twist 609 (e.g., at 7A to 7C The geometric twist in 609 above) has a second angle of incidence.

[0082] Due to geometric twist 609, when Fig.7D The first locking end 605 and the second locking end 609 are offset from each other when viewed from a top view of the blade 601. In one embodiment, the geometric twist 609 starts at a portion of the airfoil 607 that is closer to the root of the blade 601 than the tip of the blade 601. The geometric twist 609 between the root chord and the tip chord can vary by up to 45 degrees.

[0083] Re-reference Fig. 6A and Figure 6B In one embodiment, the blades 601 are positioned so that the second locking ends 603 are arranged parallel to each other around the circumference, thereby forming a hole at the center of the blade fan 209. Therefore, the first locking ends 605 are also arranged parallel to each other, and due to the geometric twist 609 in the airfoil 607, the airfoil 607 of each blade 601 overlaps with another airfoil of an adjacent blade 601.

[0084] Fig. 8A , Figure 8B and Figure 8C A perspective view, a front view, and a side view of a locking ring 210 of a propeller fan 100 according to one embodiment are illustrated, respectively. Generally speaking, the locking ring 210 is configured to be connected to the blade fan 209 and the hub 205, and advantageously tensions the root of the blade 601. Therefore, the blade 601 of the blade fan 209 is tensioned at both the tip and the root to maintain the angle of the blade 601 during operation. The locking ring 210 can be made of metal (such as aluminum or titanium) or a composite material (such as carbon fiber).

[0085] The locking ring 210 includes a first end 801 and a second end 803. In one embodiment, the first end 801 has a diameter that is smaller than the diameter of the second end 803, thereby forming a conical shape. The customization of this shape is determined by the need for the main internal flow (i.e., not the cooling flow) leading to the fan, and any boundary layer pressure gradient along the center body can also be considered in the presence of the fan. In one embodiment, the first end 801 of the locking ring 210 is configured to directly connect the blade fan 209 to the locking ring 210, thereby locking the blade fan 209 to the locking ring 210. The first end 801 of the locking ring 210 includes a plurality of locking teeth 805. In one embodiment, the locking teeth 805 are protrusions that extend from the body of the locking ring 210 at an angle relative to a reference perpendicular to the second end 803 of the locking ring.

[0086] A plurality of slots 807 are formed between the locking teeth 805. For example, slots 807 are formed between a pair of locking teeth including locking teeth 805A and locking teeth 805B. The slots 807 have a width and depth that match the size of the second locking end 603 of the blade fan 209. The slots 807 partially extend through the thickness of the locking ring 210 (e.g., such as ¾ of the thickness of the locking ring 210).

[0087] In one embodiment, each of the plurality of slots 807 is configured to be connected to a corresponding one of the plurality of blades 601 of the blade fan 209. Specifically, the second locking end 603 of each blade 601 is inserted into one of the slots 807, thereby fixing the blade 601 to the locking ring 210 through direct contact between the surface of the second locking end 603 and the locking teeth 805 forming the slot. In one embodiment, a fastener (such as epoxy) is also applied to the second locking end 603 of each blade 601 to further strengthen the connection between the blade 601 and the locking ring 210. By locking the second locking end 603 of the blade 601 to the locking ring 210, the pitch of the root of the blade 601 remains substantially the same during thrust generation or at rest, thereby reducing audible noise emitted from the propeller fan 100 (because the change in pitch can be detected by the human ear).

[0088] In one embodiment, the second end 803 of the locking ring 210 includes a connection mechanism 809 located at the inner circumference of the second end 803 of the locking ring 210. For example, the connection mechanism 809 is configured to connect the locking ring 210 to the connection mechanism 509 of the hub 205. In one embodiment, the connection mechanism 809 is a thread that matches the thread of the connection mechanism 509 of the hub 205, thereby allowing the hub 205 to be screwed into the locking ring 210. Because the motor 215 is connected to the hub 205, the hub 205 rotates, causing the locking ring 210 and the blade fan 209 to also rotate.

[0089] Fig.9A and Fig. 9B A perspective view and a side view of a tension ring 211 of a propeller fan 100 according to one embodiment are illustrated, respectively. The tension ring 211 is configured to be connected to a blade fan 209 by being placed around the circumference of the blade fan 209. More specifically, the tension ring 211 is configured to be connected to all first locking ends 605 of the blade fan 209 according to one embodiment. By locking the first locking end 605 of the blade 601 to the tension ring 211, the pitch of the tip of the blade 601 remains substantially the same during thrust generation and at rest, thereby reducing the audible noise emitted from the propeller fan 100 (because the change in pitch can be detected by the human ear). Therefore, pre-tensioning the blade 601 using the tension ring 211 reduces inefficiencies caused by tip gaps. In one embodiment, the tension ring 211 is made of metal (such as aluminum or titanium) or a composite material (such as carbon fiber). However, other materials may be used in other embodiments.

[0090] like Fig.9A and Fig. 9B , the tensioning ring 211 includes a first end 903 and a second end 905. In one embodiment, the first end 903 has a diameter that is substantially the same as a diameter of the second end 905. A body 909 of the tensioning ring 211 is disposed between the first end 903 and the second end 905.

[0091] In one embodiment, the body 909 of the tension ring 211 includes a plurality of openings (e.g., slots) 907 extending through the entire thickness of the tension ring 211. Each opening 907 is configured to connect to the first locking end 605 of one of the plurality of blades 601. Thus, there is a one-to-one relationship between each opening 907 of the tension ring 211 and the blade 601. In one embodiment, a fastener (such as epoxy) is also applied to the first locking end 605 of each blade 601 to further strengthen the connection between the blade 601 and the tension ring 211.

[0092] In one embodiment, a plurality of openings 907 are formed at an angle relative to a reference that is perpendicular to the first end 903 or the second end 905. The angle at which the openings 907 are formed matches the pitch of the first locking end 605 of the blade 601. The size of the openings 907 substantially matches the size of the first locking end 605, so that once the first locking end 605 is inserted into the openings 907 of the tensioning ring 211 and the first locking end 605 is in direct contact with the tensioning ring 211, the first locking end 605 is locked to the tensioning ring 211.

[0093] Fig. 10A , Fig. 10B and Fig. 10CA perspective view, a front view, and a side view of an internal duct body housing 217 (hereinafter referred to as a "body housing") of a propeller fan 100 according to one embodiment are respectively illustrated. In one embodiment, the body housing 217 is configured to accommodate (e.g., partially surround) components of the propeller fan 100. For example, in one embodiment, the blade fan 209, the hub 205, the tensioning ring 211, the locking ring 210, and the motor 215 are accommodated in the body housing 217. In other embodiments, other components of the propeller fan 100 may be included in the body housing 217. In one embodiment, the body housing 217 is made of metal (such as aluminum or titanium) or a composite material (such as carbon fiber). However, other materials may be used in different embodiments.

[0094] In one embodiment, the body housing 217 is cylindrical in shape and includes a first end 1001 (e.g., an inlet) and a second end 1003 (e.g., an outlet). In one embodiment, the first end 1001 has a diameter that is greater than the diameter of the second end 1003. The first end 1001 includes a plurality of mounting holes 1005 formed around the circumference of the first end 1001 of the body housing 217. In one embodiment, the first end 1001 of the body housing 217 is configured to be connected to the second end 305 of the duct lip 201 such that the mounting holes 223 in the duct lip 201 are aligned with the mounting holes 1005 of the body housing 217. As previously mentioned above, the fastener 207 can be used to secure the duct lip 201 to the first end 1001 of the duct body housing 217.

[0095] In one embodiment, the second end 1003 of the main body housing 217 includes a plurality of mounting holes 1007 formed around the circumference of the second end 1003 of the main body housing 217. In one embodiment, the second end 1003 of the main body housing 217 is configured to be connected to a first end (e.g., an inlet) of the stator 219. When the second end 1003 of the main body housing 217 is connected to the first end of the stator 219, the mounting holes 1007 in the second end 1003 of the main body housing 217 are aligned with the mounting holes on the first end of the stator 219. Fasteners (e.g., nuts, bolts, rivets) may be used to secure the second end 1003 of the main body housing 217 to the first end of the stator 219.

[0096] In one embodiment, the main body housing 217 includes a plurality of intermediate portions 1009, each of which is configured to accommodate different components of the propeller fan. The plurality of intermediate portions 1009 include a first intermediate portion 1009A extending from the first end 1001 and a second intermediate portion 1009B extending from the second end 1003. The intermediate portion 1009 of the main body housing 217 is disposed between the first end 1001 and the second end 1003 of the main body housing 217.

[0097] like Fig. 10C As shown, the first middle portion 1009A has a diameter different from the diameter of the second middle portion 1009B. For example, the diameter of the first middle portion 1000A is greater than the diameter of the second middle portion 1000B. In addition, the first middle portion 1009A has a smaller diameter than the first end portion 1001, and the second middle portion 1009B has a smaller diameter than the second end portion 1003.

[0098] In one embodiment, the first middle portion 1009A is configured to accommodate the hub 205, the blade fan 209, the locking ring 210, and the tension ring 211. Because the tension ring 211 has the largest diameter of the components accommodated in the first middle portion 1009A, the diameter 1009A of the first middle portion 1009A is based on the diameter of the tension ring 211. In one embodiment, the diameter of the first middle portion 1009A is substantially the same as the diameter of the tension ring 211, thereby allowing the tension ring 211 to be securely fastened within the first middle portion 1000A due to a press fit, for example.

[0099] In one embodiment, the second intermediate portion 1009B is configured to accommodate a portion of the motor 215 and the stator 219. The length of the second intermediate portion 1009B is based on the length of the motor 215 and the length of a portion of the stator 219 contained therein. The second intermediate portion 1009B has a length at least as long as a portion of the motor 215 and the stator 219 so as to contain the portion of the motor 215 and the stator 219 in the second intermediate portion 1009B. In one embodiment, the diameter of the second intermediate portion 1009B is based on the mass air flow rate of air entering and exiting the stator 219. Those skilled in the art will be able to customize the diameter so as to produce a favorable pressure gradient across a plurality of design speeds of interest to minimize flow separation or vortices. The internal cavity of the second portion 1009B may also be adjusted to reduce noise.

[0100] Fig.11A , Fig. 11B , Fig. 11C and Fig.11D The perspective view, front view, side view, and cross-sectional view of the stator 219 of the propeller fan 100 according to one embodiment are respectively illustrated. In one embodiment, the stator 219 includes a plurality of stator blades 219A, a motor housing 219B, and a stator housing 219C. In other embodiments, the stator 219 may include FIG. 11A to FIG. 11D other components than those shown.

[0101] In one embodiment, the motor housing 219B is cylindrical in shape and includes a first end 1101 and a second end 1103. Fig.11D shown. Fig.11D An example is shown along the Fig. 11B A cross-sectional view of the stator 219 along the plane CC' in FIG. Fig.11D As shown, the motor housing 219B includes a cavity 1105 disposed between the first end 1101 and the second end 1103. The cavity 1105 may extend from the first end 1101 toward the second end 1103, but does not extend to the second end 1103. In one embodiment, the cavity 1105 is configured to accommodate the motor 215. That is, the motor 215 is placed in the cavity 1105 of the motor housing 219B. Therefore, the shape and size of the cavity 1105 depends on the shape and size of the motor 215. Because the motor 215 is placed in the cavity 1105 and the motor 215 is indirectly connected to the hub 205, the stator 219 also serves as a structural component to support the hub 205 and other components of the propeller 100.

[0102] In one embodiment, the motor housing 219B includes a hole 1113 through the center of the motor housing 219B, such as Fig. 11B and Fig.11D The diameter of hole 1113 is smaller than the diameter of motor 215 to prevent motor 215 from falling through hole 1113. Hole 1113 is placed in motor housing 219B to help dissipate heat and thus cool motor 215.

[0103] refer to Fig. 11B , the stator 219 includes a plurality of stator blades 219A. The stator blades 219A extend radially from the motor housing 219B. That is, the root of each blade 219A is connected to the motor housing 219B, and the airfoil of the stator blade 219 extends outwardly away from the electric motor housing 219B. In one embodiment, each blade 219A extends away from the motor housing 219B at an angle measured relative to a reference line extending vertically from a point on the motor housing 219B from which the stator blade 219A extends.

[0104] In one embodiment, the stator blades 219 conduct heat away from the motor 215. Because the blades 219 contact the motor housing 219B that houses the motor 215, the air passing through the blades 219 dissipates the heat generated by the motor 215. In one embodiment, the arrangement of the blades 219 also reduces the noise generated by the blade fan 209 and controls the thrust generated by the propeller fan 100. The number of blades of the stator blades 219 can be selected so that the harmonics of the stator cancel the harmonics of the blade fan 209. For ultrasonic fans, due to the local low Reynolds number along the blades, those skilled in the art will see that the blade fan 209 can carry a plurality of blades 601, the number of which (e.g., total number) is higher than the stator blades 219 to achieve a favorable acoustic effect. For a particular set of design tones, this can vary in the range of 50% to 200% more blades.

[0105] In one embodiment, the stator housing 219C is configured to house the stator blades 219 and the motor housing 219B. That is, the stator blades 219 are placed within the stator housing 219C such that the stator housing 219C surrounds the circumference of the blades 219. In one embodiment, the stator housing 219C includes a first end 1107 (e.g., an inlet) and a second end 1109 (e.g., an outlet). Fig. 11C As shown, the first end 1107 has a diameter greater than the diameter of the second end 1109. Therefore, the stator housing 219C can have a conical shape. However, in other embodiments, the stator housing 219C can have other shapes.

[0106] refer to Fig.11D In one embodiment, the blade tip of the blade 219A contacts the inner surface 1111 of the stator housing 219C. Therefore, the blades 219A of the stator are stationary. By making the blades 219A contact the inner surface 1111 of the stator housing 219C, the position of each blade 219A is stationary.

[0107] Fig. 12A , Fig. 12B , Fig. 12C and Fig.12D A perspective view, a front view, a side view, and a cross-sectional view of a tail cone 221 of a propeller fan 100 according to one embodiment are illustrated, respectively. In one embodiment, the tail cone 221 is configured to produce the correct change in area of ​​the stator housing 219C through which air exits the propeller fan 100. The tail cone 221 may be made of metal, such as aluminum or titanium, or may be made of a composite material, such as carbon fiber.

[0108] Tail cone 221 includes a first end 1201 (eg, an inlet) and a second end 1203 (eg, an outlet). In one embodiment, first end 1201 includes a diameter that is greater than a diameter of second end 1203. In one embodiment, the diameter of tail cone 221 varies across the length of tail cone 221. Fig. 12C As shown, the diameter of the tail cone 221 decreases from the first end 1201 toward the second end 1203 until reaching the midpoint 1205. From the midpoint 1205 to the second end 1203, the diameter of the tail cone 221 is relatively constant.

[0109] In one embodiment, the first end 1201 of the tail cone 221 is configured to be connected to the second end 1103 of the motor housing 219B of the stator 219. Therefore, the diameter of the second end 1201 of the tail cone 221 substantially matches the diameter of the second end 1103 of the motor housing 219B of the stator 219. In one embodiment, the first end 1201 of the tail cone 221 includes a mounting surface 1209 that mates with (e.g., contacts) the second end 1103 of the motor housing 219B. The mounting surface 1209 can be attached to the motor housing 219B using, for example, fasteners. However, other attachment mechanisms can be used in other embodiments.

[0110] refer to Fig.12D , showing that along Fig. 12B A cross-sectional view of the tail cone 221 in plane D-D' is shown. In one embodiment, the tail cone 221 includes a cavity 1207 formed by the length of the tail cone 221 starting from the first end 1201 of the tail cone to the second end 1203 of the tail cone. The shaping of the rear end of the tail cone 221 is controlled by the secondary flow discharged from the inside of the tail cone 221 relative to the expansion of the jet following the blade disk and / or the stator.

[0111] In one embodiment, the propeller fan 100 includes a central hub drive motor 215. That is, in one embodiment, a single motor 215 is used to drive the propeller fan 100. An example motor for the propeller fan 100 is an electric motor. However, in other embodiments, other types of motors, such as a gas engine or a jet turbine, may be used in the propeller fan 100. In general, different motor types and sizes may be used, depending on the application of the propeller fan 100.

[0112] Multi-motor drive system

[0113] In another embodiment, the propeller fan 100 may be driven by multiple motors rather than just the single motor 215 described above. Fig.13A , Fig. 13B and Fig. 13C A perspective view, a front view, and a side view are respectively illustrated of a circumferential multi-motor drive system of a propeller fan 100 according to one embodiment.

[0114] Instead of using a single motor 215 to drive thrust, multiple auxiliary motors 1301A, 1301B, 1301C, and 1301D are placed within the main body housing 217 to drive the blade fan 209 via a ring gear 1303. In one embodiment, the multiple auxiliary motors 1303 may be electric motors. However, other types of motors may be used.

[0115] In one embodiment, the ring gear 1303 may be connected to the tension ring 211. The auxiliary motor 1303 may replace the motor 215 described above, or may be used in conjunction with the motor 215. Multi-motor redundancy allows the propeller fan 100 system to achieve excellent fault tolerance. For example, with four auxiliary motors 1303, the loss of a single auxiliary motor has little to do with the normal operation of the propeller. Even with the loss of another motor, the remaining auxiliary motor 1303 can be overspeeded to generate sufficient thrust.

[0116] like FIG. 13A to FIG. 13C As shown, the auxiliary motors 1301A to 1301D are radially dispersed around the circumference of the propeller 100, rather than all being located at the hub 205 of the propeller. The end of each auxiliary motor 1301 includes a gear connected to the ring gear 1303. The radial arrangement does not have to be limited to equiangular intervals. For example, the fan can be driven by three motors offset toward the quarter area of ​​the lower part of the duct. In addition, the propeller can use the duct structure itself to handle the motor and its load, without the need for the stator 219 to support the hub 205 to support the motor 215 accommodated centrally. In addition to eliminating weight and resistance, this also makes the broadband noise usually caused by the stator flow interaction smaller. In one embodiment, the auxiliary motor 1303 is more at a high speed of 20,000RPM, at which high speed, the auxiliary motor can produce a 15kW / kg specific power that is superior to the heavier and lower speed motor of 5kW / kg specific power. The auxiliary motors 1303 drive the ring gear 1303 together to eliminate (axial and radial) gear slip. This low bearing results in lower gear noise.

[0117] Fig.14 Another embodiment of a circumferential drive system of a propeller fan 100 according to another embodiment is illustrated. Fig.14 The embodiment shown is similar to the example described in FIG13. However, Fig.14 The drive system shown omits the central drive motor 215 and relies on the auxiliary motor 1303 to generate thrust.

[0118] Thruster array

[0119] Fig.15A and Fig. 15B 1 and 2 illustrate a front view and a perspective view of a propeller fan array 1500 according to one embodiment. In one embodiment, the propeller fan array 1500 includes a plurality of propeller fans 100 arranged transversely to form a row of propeller fans. Fig.15A and Fig. 15BIn the example shown, the propeller fan array 1500 includes a first propeller fan 100A, a second propeller fan 100B, and a third propeller fan 100C. Each propeller fan in the plurality of propeller fans 100A to 100C includes the propeller fan structure described herein. Although three propeller fans 100 are included in the propeller fan array 1500, the array may include any number of propeller fans greater than two.

[0120] Fig.16 An example application of a propeller fan array 1600 according to one embodiment is illustrated. Fig.16 As shown, propeller fan array 1600 includes multiple propeller fans as described herein. In one embodiment, propeller fan array 1600 is integrated into a ducted wing 1603 of an aircraft 1605. Multiple propeller fans can be combined laterally to form ducted wing 1603. Ducted wing 1603 can be shaped to create a passive lift biplane, wherein the stagger, sweep angle, taper and dihedral of the biplane can be added as needed. The total number of propeller fans and the size of the propeller fans to be included in array 1600 depend on the requirements of the aircraft, such as, for example, the number of passengers who will be riding the aircraft, the speed requirements of the aircraft 1605, and the altitude requirements.

[0121] The combination of thruster fans into an array creates several control and thrust vectoring opportunities. Thrust can be simply varied between each individual thruster fan 100 to induce yaw, roll or pitch moments. The relative spanwise pitch differences between the thruster fans can be used to facilitate faster climbs and descents. This can be further enhanced by additional control surfaces mounted at the trailing edge.

[0122] The spanwise combination of ducts makes it ideal for integration along a wing, or even as a biplane wing itself. The array can be arranged and extended as a biplane-type wing, with sweep angles, stagger, anhedral angles, and tapers to meet system requirements. The choice of integrating the pusher fan array into a complete biplane-type wing depends on the amount of thrust (negative drag) required and the relative size of the pusher fans.

[0123] Propulsion fan applications

[0124] Fig.17A , Fig. 17B and Fig. 17C 100A and 100B are diagrams illustrating a front view, a side view, and a top view of a hovering drone 1700 according to an embodiment. The hovering drone 1700 includes a propeller fan array, which includes a first propeller fan 100A, a second propeller fan 100B, and a third propeller fan 100C. Although only three propeller fans are included in the hovering drone 1700, the hovering drone 1700 may include more than 100 fans. FIG. 17A to FIG. 17CMore thruster fans or fewer thruster fans are shown.

[0125] The hovering drone 1700 is a quiet electric vertical take-off and landing (VTOL) drone that includes a propeller fan array as described herein. The hovering drone 1700 can be used for close range, such as in an urban environment. The hovering drone 1700 can have a 360-degree camera and sensors and can be used for hovering flight times of greater than 15 minutes, for example. In one example, the propeller fans 100A to 100C can each have a 1 ft diameter with an enhanced rotor load of 6.4 lb / ft 2 The hover drone 1700 may have a maximum takeoff weight of 30 pounds.

[0126] exist Fig.17A In the example shown, each propeller fan 100A to 100C includes a hub-driven centrally located motor 215 and the auxiliary motor 1301 previously described above. However, the hovering drone 1700 may omit the auxiliary motor 1301 and include only the centrally located motor 215, or may omit the centrally located motor 215 and include only the auxiliary motor 1301.

[0127] Fig.18A , Fig.18B and Fig.18C The front view, side view, and top view of a cinema drone 1800 including a propeller fan array according to one embodiment are illustrated respectively. Generally speaking, the cinema drone 1800 is a quiet deflection slipstream VTOL drone for meeting the needs of theaters. The cinema drone 1800 can be fully electric or hybrid. The cinema drone 1800 can have a gimbaled payload (e.g., a main camera) of up to 35 pounds, for example. The cinema drone 1800 can have auxiliary cameras and sensors. The cinema drone 1800 can be used for a hovering flight time of greater than 20 minutes. In one embodiment, the cinema drone may have a maximum cruising speed of greater than 50mph.

[0128] In one embodiment, the cinema drone 1800 is a biplane and has a neutral stagger. Fig.18AAs shown, the cinema drone 1800 includes a first wing 1801 and a second wing 1803. Each of the first wing 1801 and the second wing 1803 includes a propeller fan array, which includes a plurality of propeller fans. For example, the propeller fan array included in the wing 1801 includes propeller fans 100A, 100B, 100C, and 100D, and the propeller fan array included in the wing 1803 includes propeller fans 100E, 100F, 100G, and 100H. Therefore, half of the propeller fans are located at the first side of the fuselage 1805, and the remaining half of the propeller fans are located at the second side of the fuselage 1805. 18A to 18C In the example shown, the thruster array includes eight thrusters, but any number of thrusters may be used.

[0129] 18A to 18C Each wing 1801, 1803 of the illustrated cinema drone 1800 has an angled sweep formed between the two wings toward the front of the fuselage 1805. Fig.18C In the example shown, wings 1801 and 1803 may have a 20 degree anhedral angle and a 30 degree wing sweep angle. However, other angles may be used in different embodiments.

[0130] In one embodiment, in one example, 18A to 18C The illustrated cinema drone 1800 has a maximum takeoff weight of 75 lbs and a target maximum payload weight of 30 lbs. For example, each propeller fan 100 may have a fan diameter of 1 ft and a 6.0 lb / ft 2 The fuselage 1805 of the cinema drone 1800 may have a length of 5.5 ft and a width of 0.6 ft. For example, the wingspan of the cinema drone 1800 may be 8.8 ft and the wing area may be 17.4 ft. 2 , wing loading is 4.3 lb / ft 2 .

[0131] Fig.19A , Fig.19B and Fig.19C A front view, a side view, and a top view of a transport aircraft 1900 including a propulsor fan array according to one embodiment are illustrated, respectively. The transport aircraft 1900 is an optionally manned VTOL aircraft. The transport aircraft 1900 can be hybrid or fully electric. For example, the transport aircraft 1900 can have a range of 20 nautical miles to 60 nautical miles, a cruising speed of 130 knots to 250 knots, and an operating altitude of 1,000 feet to 2,000 feet.

[0132] In one embodiment, transport aircraft 1900 is a biplane and has a slight negative stagger. Transport aircraft 1900 includes a first wing 1901 and a second wing 1903. An angle is formed between the two wings 1901 and 1903 toward the front of the fuselage 1905. FIG. 19A to FIG. 19C In the example shown, the wing may have a 5 degree anhedral angle and a -25 degree wing sweep angle. However, other angles may be used in different embodiments.

[0133] In one embodiment, a propeller fan array is integrated into each wing 1901 and 1903. A first propeller fan array is located at a first side of the fuselage 1905 and is integrated into the wing 1901, and a second propeller fan array is located at a second side of the fuselage 1905 and is integrated into the wing 1903. For example, the propeller fan array included in the wing 1901 includes propeller fans 100A, 100B, 100C, and 100D, while the propeller fan array included in the wing 1903 includes propeller fans 100E, 100F, 100G, and 100H. Thus, half of the propeller fans are located at the first side of the fuselage 1905, while the remaining half of the propeller fans are located at the second side of the fuselage 1905. FIG. 19A to FIG. 19C In the example shown, the thruster array includes eight thruster fans, but any number of thruster fans may be used.

[0134] In one embodiment, in one example, transport aircraft 1900 has a maximum takeoff weight of 1,000 lbs and a target maximum payload weight of 220 lbs. Each propeller fan 100 may have a fan diameter of 3 ft and a 6.0 lb / ft 2 The fuselage 1905 of the transport aircraft 1900 may have a length of 9.2 ft and a width of 3.75 ft. The wingspan of the transport aircraft 1900 may be 28.7 ft and the wing area may be 106.3 ft. 2 , wing loading is 9.4 lb / ft 2 .

[0135] Fig. 20A , Fig. 20B and Fig. 20C A front view, a side view, and a top view of a vertical take-off and landing (VTOL) aircraft 2000 including a thruster fan array according to one embodiment are illustrated, respectively. The VTOL aircraft 2000 is an optionally manned VTOL aircraft. The VTOL aircraft 2000 can be hybrid or fully electric. The VTOL aircraft 2000 can have a range of 20 nautical miles to 400 nautical miles, a cruising speed of 130 knots to 250 knots, and an operating altitude of 1,000 feet to 2,000 feet. In one embodiment, the VTOL aircraft 2000 is capable of hovering.

[0136] exist FIG. 20A to FIG. 20C In the example shown, the VTOL aircraft 2000 is a biplane and has a slight negative stagger. The VTOL aircraft 2000 includes a first wing 2001 and a second wing 2003. In one embodiment, an angle is formed between the two wings 2001 and 2003 toward the front of the fuselage 2005. The wings 2001, 2003 may have a wing dihedral angle of 5 degrees and a wing sweep angle of -25 degrees. However, other angles may be used in different embodiments.

[0137] In one embodiment, a propeller fan array is integrated into each wing 2001 and 2003. A first propeller fan array is located at a first side of the fuselage 2005 and is integrated into the wing 2001, and a second propeller fan array is located at a second side of the fuselage 2005 and is integrated into the wing 2003. For example, the propeller fan array included in the wing 2001 includes propeller fans 100A, 100B, 100C, and 100D, while the propeller fan array included in the wing 2003 includes propeller fans 100E, 100F, 100G, and 100H. Thus, half of the propeller fans are located at the first side of the fuselage 2005, while the remaining half of the propeller fans are located at the second side of the fuselage 2005. FIG. 20A to FIG. 20C In the example shown, the thruster array includes eight thruster fans, but any number of thruster fans may be used.

[0138] In one example, the VTOL aircraft 2000 has a maximum takeoff weight of 5,000 lbs and a target maximum payload weight of 1,000 lbs (eg, 3-4 passengers). Each thruster fan 100 may have a fan diameter of 5 ft and a thrust of 11.0 lb / ft 2 For example, the fuselage 2005 of the VTOL aircraft 2000 may have a length of 24.7 ft and a width of 5 ft. For example, the wingspan of the VTOL aircraft 2000 may be 49 ft and the wing area may be 300 ft. 2 , wing loading is 16.7 lb / ft 2 .

[0139] Fig.21A , Fig. 21B and Fig. 21C The front view, side view, and top view of a delivery drone 2100 including a thruster fan array according to one embodiment are illustrated, respectively. The delivery drone 2100 may have a 360-degree camera and sensors and may be used for a hovering flight time greater than 20 minutes. In one embodiment, the delivery drone 2100 may have a maximum cruising speed greater than 50 mph.

[0140] Delivery drone 2100 is an example of an electric tail-sitter VTOL drone configured to deliver an interior package. In the example shown, delivery drone 2100 is a biplane and has a neutral stagger. In one embodiment, delivery drone 2100 includes a first wing 2101 and a second wing 2103, forming an angled sweep between the two wings toward the rear of fuselage 2105.

[0141] In one embodiment, a propeller fan array is integrated into each wing 2101 and 2103. A first propeller fan array is located at a first side of the fuselage 2105 and is integrated into the wing 2101, and a second propeller fan array is located at a second side of the fuselage 2105 and is integrated into the wing 2103. For example, the propeller fan array included in the wing 2101 includes propeller fans 100A, 100B, and 100C, while the propeller fan array included in the wing 2103 includes propeller fans 100D, 100E, and 100F. Thus, half of the propeller fans are located at the first side of the fuselage 2105, while the remaining half of the propeller fans are located at the second side of the fuselage 2105. FIG. 21A to FIG. 21C In the example shown, the thruster array includes six thruster fans, but any number of thruster fans may be used.

[0142] In one example, the delivery drone 2100 has a maximum takeoff weight of 55 lbs and a target maximum payload weight of 5.5 lbs. Each propeller fan 100 may have a fan diameter of 1 ft and a 6.0 lb / ft 2 The fuselage 2105 of the delivery drone 2100 may have a length of 6.7 ft and a width of 1.3 ft. For example, the wingspan of the delivery drone 2100 may be 8.8 ft and the wing area may be 21.9 ft. 2 , wing loading is 2.5 lb / ft 2 .

[0143] Free blade

[0144] Because the propeller fan 100 described herein has a higher speed capability of more than 150 mph, it is desirable to provide improved propulsion efficiency through blade angle variability or mass flow throttling. As described above, the propeller fan 100 includes a significantly higher number of blades than conventional propellers. From a mechanical complexity perspective, implementing a typical variable pitch propeller mechanism is overburdened.

[0145] In one embodiment, a free-wing blade structure is used to incorporate the propeller fan array described above into an aircraft. For example, the free-wing blade structure can be implemented in any of the aircraft described above in Figures 17 to 21. Free-wing blades are propeller fans that can rotate freely along their radial axes due to the mass balance in front of the aerodynamic center of each blade. That is, the blade fan 209 can rotate freely along its radial axis due to the mass balance in front of the aerodynamic center of each blade. Free-wing blades combine airfoil design, wing mass balance, and wing pivot to achieve a capability in which the wing pivots freely at a constant CL under all flight conditions as the wing self-adjusts to zero pitch moment.

[0146] The combination of the free blade structure and the propeller fan 100 creates a passive system for achieving blade angle of attack (AoA) variability while maintaining constant blade loading. This can provide a unique synergy for the electric motor driven propeller fan 100 because the electric motor can operate at high efficiency over a wide rpm range. The electric motor can operate at higher or lower radial speeds across different inflow velocities, with the blades "floating" to align their AoA, thereby maintaining the same adjusted lift coefficient (CL). This capability can also provide the value of achieving lower noise as a way to avoid blade stall, which results in high noise generation under different flight conditions and turbulence levels.

[0147] There are many benefits to using free blades. For example, by increasing the leading edge blade mass, the free blade achieves pitch balance to always be at an AoA close to its L / Dmax CL (typically 0.5 to 1.0). This ensures that the blade AoA is always matched to align with the inflow and there is never a separated flow. In addition, because the propeller fan 100 is rim-driven, it is possible for the propeller fan to achieve mass balance when the internal hub area is empty, thereby providing volume in front of the blade to achieve the lightest mass balance weight (and not exposed to the flow). This allows the propeller fan 100 to change its rpm by the order of about 50% during different flight segments, so that the blades can always be close to their optimal advance speed ratio. Because electric motors have a wide rpm range with high efficiency, unlike turbines or IC engines, the use of free blades in combination with electric motors provides specific benefits. Therefore, a turbine or IC engine needs to run at a fixed speed at a given power, while an electric motor does not. This allows the propeller to change its rpm by the order of about 50% during different flight segments, so that the blades can always be close to their optimal advance speed ratio. Finally, free blades also facilitate larger VTOL integration due to wider AoA variations and thrust requirements.

[0148] Circulation pipe control

[0149] In one embodiment, the circulation control mechanism is placed at the duct lip 201. The circulation control mechanism is configured to blow an air jet at the duct lip 201. By applying air to the duct lip 201, the amount of lip suction that the duct lip 201 can achieve is enhanced. In one embodiment, an electric motor combined with a centrifugal compressor or an axial compressor will be embedded in the remaining duct volume to increase the circulation control blowing and / or suction at the duct lip 201. By applying distributed electric propulsion (DEP) for internal circulation control blowing at the duct lip 201, static and low-speed thrust enhancement can be achieved at a lower power than providing additional power to the propeller. This internal application of DEP maximizes the aviation integration advantages at both the propeller fan 100 and the aircraft integration level. For example, applying circulation control at the duct lip 201 results in an increase of up to 40% in static thrust at the same fan power.

[0150] In one embodiment, the emergency power ram air turbine has a high PR and an inlet velocity that requires a high cycle controlled jet blowing velocity (i.e., a noisy jet that approaches the speed of sound). A quiet low velocity jet (about 300 ft / sec) can be used and can be powered by a small internal duct electric centrifugal blower.

[0151] For the thruster, a lower velocity circulation control jet has an equivalent effect in terms of thrust enhancement, given the much lower PR and static duct inflow velocity. The circulation control effect is based on Vjet / Vintake. Another attractive aspect of circulation control duct lip blowing is the avoidance of duct inner lip separation at high angles of attack (i.e. during transition). For ducted eVTOLs, this is an important consideration - if the inlet flow separates at the duct lip, the noise consequences are significantly increased as the fan blades experience oscillatory flow conditions that result in cyclic blade loading.

[0152] By applying cyclic controlled blowing at the duct lip 201 where the jet velocity is about 300 feet per second, the suction force of the duct lip can be increased, accounting for about 75% of the total static thrust. Blowing air at the duct lip 201 effectively provides aerodynamic shape deformation on the duct lip to entrain additional ambient air. With the blowing turned on, the inflowing air "sees" a much larger bell-mouth duct lip, which is required under static conditions. At cruise, the actual bell-mouth duct inlet will cause significant resistance. During cruise flight, when the blowing is relatively ineffective, the duct cyclic controlled blowing can be turned off. The compact high-speed centrifugal blower runs at a supersonic blade passing frequency to provide internal blowing. Although cyclic controlled blowing is most effective at high nozzle jet velocities (near sonic speed is optimal), our nozzle jets are designed for lower jet velocities to achieve low noise (jet noise varies to the 10th power of the nozzle velocity). Through this application to the leading edge of the duct, the goal is to maximize the inflow turning angle and prevent the leading edge duct lip from stalling.

[0153] In one embodiment, a circulation control duct may be applied to the duct lip 201 in any of the aircraft embodiments discussed herein.

[0154] Blade fan with pin root attachment, blade tip shroud and knife edge seal

[0155] In one embodiment, the blade fan used in the propeller fan 100 described above includes blades having a pin root to attach the blade to the hub, rather than about Fig. 7A , Figure 7B and Figure 7C The locking end previously described above. Fig.22A , Fig. 22B and Fig. 22C A front view, a side view, and a top view of a blade 2200 having a double pin hole root according to a second embodiment are illustrated, respectively. Fig.23A , Fig. 23B and Fig.23C A perspective view of a blade 2200 with a double pin root according to a second embodiment, a perspective view of a shroud segment 2207 of the blade 2200 , and a perspective view of a double pin root of the blade 2200 are respectively illustrated.

[0156] In one embodiment, each blade 2200 includes a first end 2201, a second end 2203 located opposite the first end 2201, and an airfoil 2205 located between the first end 2201 and the second locking end 2203 of the blade 2200. In other embodiments, the blade 2200 may include other features in addition to those described herein. The first end 2201 is located at the tip of the blade 2200.

[0157] In one embodiment, the first end 2201 of each blade 2200 includes a shroud segment (e.g., shroud portion) 2207. Each shroud segment 2207 of the blade 2200 is configured to be connected to a plurality of other shroud segments 2207 of other blades 2200 included in the blade fan. The shroud segments 2207 interlock with each other to form an interlocking blade tip shroud together. As will be described in further detail below, a blade tip shroud is provided along the circumference of the blade fan.

[0158] By interlocking the first end 2201 (e.g., the tip) of the blade 2200 with the shroud segment 2207, the first end 2201 of the blade 2200 is tensioned so that the pitch of the first end 2201 of the blade 2200 during thrust generation is substantially the same as the pitch of the first end 2201 of the blade 2200 when stationary, thereby reducing noise that may be generated due to angular changes of the blade. Therefore, due to the interlocking shroud segment 2207, the blade 2200 does not require a locking ring 211 to tension the tip of the blade 2200 (as described in the embodiment of FIG. 7).

[0159] In one embodiment, each shroud segment 2207 is integrated into a blade 2200 including the shroud segment 2207. The shroud segment 2207 may extend from the end of the airfoil 2205 of the blade 2200 that is farthest from the second end 2203 of the blade 2200. The shroud segment 2207 has a width that is wider than the width of the end of the airfoil 2205. In one embodiment, Fig. 22C In the top view of the shield segment 2207 shown, the shield segment 2207 is a quadrilateral shape (e.g., a parallelogram, a rectangle, or a square). Fig.22A and Fig. 22B The shroud segments 2207 are also shown with curvature in the upper and lower surfaces. The shroud segments 2207 are curved to form an annular blade tip shroud around the circumference of the blade fan, while the shroud segments 2207 of the blade 2200 are interlocked together.

[0160] In one embodiment, each shroud segment 2207 includes a connection mechanism to connect the shroud segment 2207 of the blade 2200 to another shroud segment 2207 of another blade 2200. In one embodiment, the connection mechanism includes a protrusion 2209 located at a first side of the shroud segment 2207 and a recess 2210 located at a second side of the shroud segment 2207 opposite the first side of the shroud segment 2207. In one embodiment, the second side is parallel to the first side of the shroud segment 2207. The remaining sides of the shroud segment 2209 do not include the protrusion 2209 and the recess 2210.

[0161] Generally speaking, the protrusion 2209 of a given shroud segment 2207 is configured to be inserted into the recess 2210 of another shroud segment 2207, and the recess 2211 of a given shroud segment 2207 is configured to receive the protrusion 2209 of another shroud segment 2207 to secure the shroud segments 2207 together. For example, the protrusion 2209 of the shroud segment 2207 of the first blade 2200 is configured to be inserted into the recess 2210 of the second shroud segment 2207 of the second blade 2200. The protrusion 2209 contacts a portion of the second shroud segment 2207 (the portion defining the recess 2210 of the second shroud segment), thereby causing the second side of the shroud segment 2207 of the first blade 2200 to contact the first side of the shroud segment 2207 of the second blade 2200. Similarly, the recess 2210 of the shroud segment 2207 of the first blade 2200 is configured to receive the protrusion 2209 of the shroud segment 2207 of the third blade 2200, so that the protrusion 2209 contacts a portion of the shroud segment 2207 of the first blade 2200 that defines the recess 2210 of the first shroud segment. Thus, the second side of the shroud segment 2207 of the first blade contacts the first side of the shroud segment 2207 of the third blade 2200.

[0162] The second end 2203 of the blade 2200 is located at the root of the blade 2200. In one embodiment, the second end 2203 has a pin root design to fix the second end 2203 of the blade 2200 to the Fig.27A and Fig.27B Hub 2700 is shown. In one embodiment, blade 2200 includes a double pin root design, as will be further described below.

[0163] In one embodiment, the second end portion 2203 includes a base 2211 and a plurality of mounting tabs 2213 (eg, mounting portions, mounting pins, or pin roots) extending vertically away from a lower surface of the base 2211. Fig.23C As shown, the base 2211 extends from the end of the airfoil 2205 farthest from the first end 2201 of the blade, so that a radius is formed between the surface of the base 2211 and the end of the airfoil 2205. The radius is formed to enhance the strength of the blade 2200, thereby reducing the possibility of blade cracking at the interface between the base 2211 and the airfoil 2205.

[0164] In one embodiment, the base 2211 is bent along the length of the base 2211. More specifically, the base 2211 includes a first end and a second end opposite the first end. A portion of the base 2211 between the first end of the base 2211 and the second end of the base 2211 is bent so that the first end and the second end of the base are misaligned with each other (e.g., offset from each other). The base 2211 includes a connecting surface 2219 (e.g., an edge) located on the right side (e.g., the left side) of the base and a connecting surface 2219 located on the second side (e.g., the left side) of the base 2211, wherein each of the connecting surfaces 2219 follows the curvature of the base 2211. The connecting surface 2219 of the blade 2200 is configured to connect to (e.g., contact) the connecting surface 2219 of another blade 2200. In one embodiment, the base 2211 is inclined upward from the first end of the base 2211 to the second end of the base 2211, such as Fig. 22B shown.

[0165] In one embodiment, the mounting fins 2213 are configured to attach the blade 2200 to the hub 2700. The mounting fins 2213 include a first mounting fin 2213A and a second mounting fin 2213B. In one embodiment, the first mounting fin 2213A extends vertically from the lower surface of the first end of the base 2211, and the second mounting fin 2213B extends vertically from the lower surface of the second end of the base 2211 opposite to the first end of the base 2211.

[0166] Due to the curvature of the base 2211 from the first end of the base 2211 to the second end of the base 2211, the first mounting fin 2213A and the second mounting fin 2213B are offset from each other, so that the second mounting fin 2213 is offset from the first mounting fin 2213 in the horizontal direction, as shown in FIG. Fig.22A 2200 is shown in a front view. In one embodiment, the width of the first mounting tab 2213A is the same as the width of the second mounting tab 2213B and is offset to equal the matching width.

[0167] In addition, the length of the first mounting fin 2213A may be different from the length of the second mounting fin 2213B. In one embodiment, since the base 2211 is inclined upward from the first end of the base 2211 to the second end of the base 2211, the length of the second mounting fin 2213B is greater than the length of the first mounting fin 2213A. Fig. 22B Although the first mounting fin 2213A and the second mounting fin 2213B have different lengths, the lowest point of the first mounting fin 2213A is aligned with the lowest point of the second mounting fin 2213B, as shown in FIG. Fig. 22B shown.

[0168] Finally, the thickness of the mounting tab 2213 may vary, e.g. Fig. 22B 2200 in a side view. In one embodiment, the thickness of the second mounting fin 2213B is thicker than the thickness of the first mounting fin 2213A. However, in other embodiments, the first mounting fin 2213A and the second mounting fin 2213B have the same thickness.

[0169] In one embodiment, each of the mounting tabs 2213 includes a corresponding hole in the mounting tab. For example, the first mounting tab 2213A includes a first hole 2215A, and the second mounting tab 2213B includes a second hole 2215B. Fig.22A The front view of the blade 2200 shown illustrates the misalignment of the mounting tab 2213, with the center of the first hole 2215A and the center of the second hole 2215B misaligned (eg, offset) from each other.

[0170] As will be described in further detail below, a fastening mechanism (such as a fastening pin) is configured to be inserted into a first hole 2215A of one blade 2200 and a second hole 2215B of a second blade to connect the first blade and the second blade to the hub 2700. By using a double pin-hole root design to secure the root of the blade 2200, the pitch (e.g., angle) of the root of the blade 2200 is substantially the same during thrust generation or when the propeller fan 100 is stationary, thereby reducing noise pollution.

[0171] The airfoil 2205 is disposed between the first end 2201 and the second end 2203 of the blade 2200. In one embodiment, the airfoil 2205 includes a geometric twist 2217 in the airfoil 2205. The geometric twist 2217 is a change in the airfoil incidence angle measured relative to the root of the blade 2200. That is, the airfoil 2205 includes a plurality of different incidence angles across the length of the airfoil 2205 due to the geometric twist 2217. For example, the airfoil 2205 may be at a first side of the geometric twist 2217 (e.g., at Fig.22A having a first angle of incidence (below the geometric twist 2217 in FIG. 1 ) and may be at a second side of the geometric twist 2217 (e.g., at Fig.22A The geometric twist in 2217 above) has a second angle of incidence.

[0172] Due to geometric twist 2217, when Fig. 22C The first end 2201 and the second end 2203 are offset from each other when viewed from the top view of the blade 2200 shown. In one embodiment, the geometric twist 2217 begins at a portion of the airfoil 2205 that is closer to the second end (e.g., the root) of the blade 2200 than the first end 2201 (e.g., the tip) of the blade 2200. The geometric twist between the root chord and the tip chord can vary by up to 45 degrees.

[0173] Fig.24A , Fig. 24B and Fig.24C A front view, a side view, and a perspective view of a plurality of interlocking blades 2200 each having a double pin root according to a second embodiment are illustrated, respectively. FIG. 24A to FIG. 24C As shown, the plurality of blades 2200 include a first blade 2200A, a second blade 2200B located at a first side (e.g., right side) of the first blade 2200A, and a third blade 2200C located at a second side (e.g., left side) of the first blade 2200A. The plurality of blades 2200 are connected to each other so that the shroud segments 2207 of the blades 2200 are interlocked with each other to form a portion of a blade tip shroud disposed around the circumference of the blade fan.

[0174] For example, the protrusion 2209 of the first shield 2207A of the first blade 2200A is inserted into the recess 2210 of the second shield 2207B of the second blade 2200B, so that the edge of the first side of the first shield 2207A contacts the edge of the second side of the second shield 2207B, as shown in FIG. FIG. 24A to FIG. 24C Similarly, the protrusion 2209 of the third shield 2207C of the third blade 2200C is inserted into the recess 2210 of the first shield 2207A of the first blade 2200A, so that the edge of the first side of the third shield 2207C contacts the edge of the second side of the first shield 2207A, as shown in FIG. FIG. 24A to FIG. 24C shown.

[0175] In addition, the connection surface 2219 of the base 2211 of each blade 2200 contacts the connection surface 2219 of the base 2211 of the adjacent blade 2200. For example, the connection surface 2219 on the right side of the base 2211 of the first blade 2200A contacts the connection surface 2219 on the left side of the base 2211 of the second blade 2200B. Similarly, the connection surface 2219 on the right side of the base 2211 of the third blade 2200C contacts the connection surface 2219 on the left side of the base 2211 of the first blade 2200A.

[0176] As mentioned above, the mounting tabs 2213 of a given blade 2200 are offset from one another. FIG. 24A to FIG. 24C As shown, when the blades 2200 are connected to each other, the center of the first hole 2215A included in the first mounting fin 2213A of a given blade 2200 is aligned with the center of the second hole 2215B included in the second mounting fin 2213B of another blade 2200. For example, the center of the first hole 2215A in the first mounting fin 2213A of the first blade 2200A is aligned with the center of the second hole 2215B in the second mounting fin 2213B of the third blade 2200C.

[0177] Fig.25A and Fig.25B A front view and a perspective view of a shroud segment 2500 according to another embodiment are illustrated, respectively. The shroud segment 2500 includes the features of the shroud segment 2207 previously described above. In addition, in one embodiment, the shroud segment 2500 includes a plurality of blade segments 2501. The blade segments 2501 improve the control of air tip leakage across the interlocking tip shrouds and provide a favorable fan blade gap span ratio to enhance performance and retention. That is, the blade segments act as a dam to reduce air leakage to the rear region of the blade fan.

[0178] In one embodiment, the plurality of blade segments 2501 include a first blade segment 2501A and a second blade segment 2501B. Each blade segment 2501 is a protrusion protruding from the upper surface of the shroud segment 2500. In one embodiment, each blade segment 2501 extends from a first side of the shroud segment 2500 having a protrusion 2209 to a second side of the shroud segment 2500 having a recess 2210. Fig.25A and Fig.25B In the example shown, the heights of the plurality of blade segments 2501 are the same, that is, the first blade segment 2501A has the same height as the second blade segment 2501B.

[0179] In one embodiment, the side surface of each blade segment 2501 includes a plurality of steps 2503, which increase the surface area of ​​the shroud segment 2500 to further improve the reduction of air leakage across the blade fan. Therefore, the side surface of each blade segment 2501 does not extend linearly from the upper surface of the shroud segment 2500 to the blade tip of the blade segment 2501. Instead, each side surface includes one or more steps in the side surface to increase the surface area of ​​the shroud segment 2500. For example, the first blade segment 2501A includes a first step 2503A located at a first side of the first blade segment 2501A and a second step 2503B located at a second side of the first blade segment 2501A. Similarly, the second blade segment 2501B includes a first step 2503A located at a first side of the second blade segment 2501B and a second step 2503B located at a second side of the second blade segment 2501B.

[0180] In one embodiment, each blade segment 2503 has a plurality of connecting surfaces 2505 that are configured to connect to (e.g., contact) connecting surfaces of other blade segments 2503. Each blade segment 2503 has a first connecting surface 2505 located at a first side of the shroud segment 2500 and a second connecting surface 2505 located at a second side of the shroud segment 2500. The connected blade segments 2503 collectively form one or more blade seals around the circumference of the tip shroud, as further described below.

[0181] Fig.26A FIG. 2 is a front view of a shroud segment 2600 according to another embodiment. The shroud segment 2600 includes Fig.25A and Fig.25B 2500. For example, shroud segment 2600 includes blade segments 2601A and 2601B, each of which includes steps 2503A and 2503B. Fig.26A In the illustrated embodiment, the blade segments 2601 have different heights. For example, the first blade segment 2601A has a height that is less than the height of the second blade segment 2601B. The second blade segment 2601B is closer to the rear end of the blade fan than the first blade segment 2601B and further prevents unwanted air from spreading at the rear of the blade fan.

[0182] Fig.26B 26 is a front view of a shroud segment 2603 according to another embodiment. The shroud segment 2603 includes similar features as the shroud segment 2207, except for a single blade segment 2605. In one embodiment, the single blade segment 2605 is aligned with the recess 2210 and the protrusion 2209, and extends from a first side of the shroud segment 2603 having the protrusion 2209 to a second side of the shroud segment 2603 having the recess 2210. However, in other embodiments, the single blade segment 2605 can be placed at other locations along the upper surface of the shroud segment 2603.

[0183] Fig.27A and Fig.27B A front view and a side view of a hub 2700 according to one embodiment are illustrated, respectively. Fig.28A and Fig.28B A perspective view of a first end 2701 of a hub 2700 and a perspective view of a second end 2703 of the hub 2700 are respectively illustrated in accordance with one embodiment. The hub 2700 is configured to be connected to a blade 2200 having a double pin root as previously described above.

[0184] The hub 2700 is the central part of the blade fan and is disposed at the center of the blade fan, as will be further described below. In one embodiment, the hub 2700 is configured to connect to the nose cone 203 and the motor 215. Due to the different design of the hub 2700 compared to the hub 205 previously described above, the nose cone 203 and the motor 215 modify the connection points according to the connection points of the hub 2700.

[0185] like Fig.27A , Fig.27B , Fig.28A and Fig.28BAs shown, in one example, the hub 2700 is cylindrical in shape. In one embodiment, the diameter of the first end 2701 of the hub 2700 is different from the diameter of the second end of the hub 2700. In one embodiment, the first end 2701 of the hub 2700 has a diameter that matches the diameter of the second end of the nose cone 203, while the second end 2703 of the hub 2700 has a diameter that matches the diameter of the motor 215.

[0186] The hub 2700 may include a raised portion 2707, such as Fig.28A and Fig.28B In one embodiment, the raised portion 2707 has a conical shape extending from the second end 2703 of the hub 2700 toward the first end 2701 of the hub 2700. Fig.27B As shown, the raised portion 2707 extends beyond the first end 2701 of the hub 2700. That is, the end of the raised portion 2707 protrudes beyond the first end 2701 of the hub 2700. Fig.28B As shown, the raised portion 2707 forms a cavity 2709 in the second end 2703 of the hub 2700, in which at least a portion of the motor 215 can be disposed. Because at least a portion of the motor 215 is disposed in the cavity 2709 of the hub 2700, the overall length of the propeller fan 100 can be reduced.

[0187] In one embodiment, nose cone mounting point 2711 is located at the end of raised portion 2707. Nose cone mounting point 2711 is configured to contact nose cone 213. Nose cone mounting point 2711 can be cylindrical in shape with a flat surface. In one embodiment, nose cone mounting point includes opening 2705. Opening 2705 is located at the center of hub 2700 and extends through the thickness of hub 2700. The center of opening 2705 is configured to align with the center of air passage 413 of nose cone 203. Thus, airflow exiting from air passage 413 of nose cone 203 flows through opening 2705 in hub 2700 to cool motor 215.

[0188] In one embodiment, the motor mounting point 2713 is located in the cavity 2709. The motor mounting point 2713 is configured to contact the motor 215. The motor mounting point 2713 can be cylindrical in shape with a flat surface. In one embodiment, the opening 2705 extends through the thickness of the motor mounting point 2713, such as Fig.28B The center of the opening 2705 in the motor mounting point 2713 is aligned with the center of the opening 2705 in the nose cone mounting point 2711.

[0189] In one embodiment, the diameter of the opening 2705 in the nose cone mounting point 2711 is different from the diameter of the opening 2705 in the motor mounting point 2713, such as Fig.28A and Fig.28B As shown. For example, the diameter of the opening 2705 in the motor mounting point 2713 is larger than the opening 2705 in the nose cone mounting point 2711. In one embodiment, the opening 2705 in the motor mounting point 2713 is configured to receive the output shaft of the motor 215. That is, the output shaft of the motor 215 is inserted into the opening 2705 in the motor mounting point 2713. The output shaft of the motor 215 contacts the inner surface of the hub 2700 disposed in the opening 2705 to connect the output shaft of the motor 215 to the hub 2700. As the output shaft of the motor 215 rotates, the hub 2700 also rotates, thereby rotating the blade fan connected to the hub 2700.

[0190] The hub 2700 includes a plurality of blade mounting flanges 2715 configured to connect the blades 2200 to the hub 2700. In one embodiment, the plurality of blade mounting flanges 2715 include a first blade mounting flange 2715A, a second blade mounting flange 2715B, a third blade mounting flange 2715C, and a fourth blade mounting flange 2715D. Each blade mounting flange 2715 is a circular ring extending radially from the outer surface of the hub 2700. The blade mounting flange 2715 is disposed on a portion of the outer surface of the hub that is located between the first end 2701 and the second end 2703 of the hub.

[0191] In one embodiment, the blade mounting flanges 2715 are spaced apart from each other so that a slot 2717 is formed between the blade mounting flanges 2615. Fig.27B As shown. A narrow groove 2717 is formed along the circumference of the hub 2700. For example, a first narrow groove 2717A is formed between the first blade mounting flange 2715A and the second blade mounting flange 2715B. Fig.27B In addition, a second narrow groove 2717B is formed between the third blade mounting flange 2715C and the fourth blade mounting flange 2715D, as shown in FIG. Fig.27B The width of the first slot 2717A matches the thickness of the first mounting tab 2213A, and the width of the second slot 2717B matches the thickness of the second mounting tab 2213B.

[0192] In one embodiment, the blade mounting flange 2715 includes a plurality of holes 2719. Each blade mounting flange 2715A, 2715B, 2715C, and 2715D includes a corresponding set of holes 2719. For example, the first blade mounting flange 2715A includes a plurality of first holes 2719A passing through the entire thickness of the first blade mounting flange 2715A. The first holes 2719A are spaced apart from each other at uniform intervals around the circumference of the first blade mounting flange 2715A. The second blade mounting flange 2715B includes a plurality of second holes 2719B passing through the entire thickness of the second blade mounting flange 2715B. The second holes 2719B are spaced apart from each other at uniform intervals around the circumference of the second blade mounting flange 2715B. The third blade mounting flange 2615C includes a plurality of third holes 2719C passing through the entire thickness of the third blade mounting flange 2715C. The third holes 2719C are spaced apart from each other at uniform intervals around the circumference of the third blade mounting flange 2615C. Finally, the fourth blade mounting flange 2715D includes a plurality of fourth holes 2719D. Unlike the first hole 2719A to the third hole 2719C, the fourth hole 2719D partially extends through the entire thickness of the fourth blade mounting flange 2715D. That is, the fourth hole 2719 does not extend through the entire thickness of the fourth blade mounting flange 2715D. The fourth holes 2719D are spaced apart from each other at uniform intervals around the circumference of the fourth blade mounting flange 2715D.

[0193] In one embodiment, the center of the first hole 2719A, the center of the second hole 2719B, the center of the third hole 2719C, and the center of the fourth hole 2719D are aligned to form a plurality of rows of holes 2719 around the circumference of the hub 2700. That is, the center of each first hole 2719A is aligned with the center of the corresponding second hole 2179B, the center of the corresponding third hole 2719C, and the center of the corresponding fourth hole 2719D, wherein the first hole 2719A, the second hole 2719B, the third hole 2719C, and the third hole 2719D are in the same row of holes. In one embodiment, the slot 2717 and the hole 2719 of the hub 2700 are configured to connect the blade 2200 to the hub 2700, as will be further described below.

[0194] Fig.29 According to one embodiment, Fig.27B A cross-sectional view of the hub 2700 taken along line AA' in FIG. Fig.29 As shown, the hub 2700 includes a webbing 2900 extending from the center of the hub 2700 toward the second end 2703 of the hub 2703. The thickness of the webbing 2900 varies along the length of the webbing 2900. Fig.29As shown, the end of the webbing 2900 at the second end 2703 of the hub 2700 is thicker than the middle portion of the webbing 2900 between the second end 2703 of the hub and the end of the webbing 2900 extending from the center of the hub 2703. The end of the webbing 2900 at the second end of the hub 2700 includes a radius portion 2901 to enhance the strength of the hub 2700.

[0195] Fig. 30A , Fig. 30B and Fig. 30C A front view, a side view, and a perspective view of a blade 2200 having a double pin hole root connected to a hub 2700 according to one embodiment are illustrated, respectively. The mounting tabs 2213 of the blade 2200 are configured to be inserted into the slots 2717 of the hub 2700. Specifically, the first mounting tab 2213A of the blade 2200 is inserted into the first slot 2171A formed between the first blade mounting flange 2715A and the second blade mounting flange 2715B. In addition, the second mounting tab 2213B of the blade 2200 is inserted into the second slot 2171B formed between the third blade mounting flange 2715C and the fourth blade mounting flange 2715D.

[0196] When the first mounting tab 2213A is inserted into the first slot 2717A, the center of the first hole 2215A in the first mounting tab 2213A is aligned with the center of the hole 2719A in the first blade mounting flange 2715A and the center of the hole 2719B in the second blade mounting flange 2715A, wherein the centers of the holes 2719A and 2719B in the first blade mounting flange 2715A and the second blade mounting flange are aligned with each other. Similarly, when the second mounting tab 2213B is inserted into the second slot 2717B, the center of the second hole 2215B in the second mounting tab 2213B is aligned with the center of the hole 2719C in the third blade mounting flange 2715C and the center of the hole 2719D in the fourth blade mounting flange 2715D, wherein the centers of the holes 2719C and 2719D in the third blade mounting flange and the fourth blade mounting flange 2715D are aligned with each other. However, due to the offset between the first mounting fin 2213A and the second mounting fin 2213B, the centers of the holes 2719A and 2719B aligned with the center of the first hole 2215A in the first mounting fin 2213A are misaligned with the centers of the holes 2719C and 2719D aligned with the center of the second hole 2215B in the second mounting fin 2213B. This is because the holes 2719A in the first blade mounting flange 2715A and the holes 2719B in the second blade mounting flange 2715B are located in the first row of holes, while the holes 2719B in the third blade mounting flange 2715C and the holes 2719D in the fourth blade mounting flange 2715D are located in the second row of holes adjacent to the first row of holes.

[0197] Fig.31A and Fig.31B A perspective view and a side view, respectively, of a plurality of interconnected blades 2200 having a dual pinhole root connected to a hub 2700, according to one embodiment are illustrated. Fig.31A and Fig.31B , the plurality of blades 2200 are connected to the hub 2700 using a plurality of fasteners 3100. In one embodiment, the fasteners are as follows Fig.31A and Fig.31B Pin fasteners are shown, but other types of fasteners may be used. When multiple blades 2200 are connected to the hub 2700, the shroud segments 2707 of the blades 2200 are interlocked together, and the connecting surfaces 2219 of the bases 2211 of the blades 2200 are connected to each other, as described with respect to FIG. FIG. 24A to FIG. 24C When all blades in the plurality of blades are attached to the hub 2700, an annular tip shroud is formed at the second end of the blade 2200, as will be further described below.

[0198] Fig.32A and Fig.32B The diagrams are respectively illustrated as viewed from the first end 2701 of the hub 2700. Fig.31A Detailed perspective view of region A and from the perspective of the second end 2703 of the hub 2700 Fig.31A Detailed perspective view of area A of , wherein the first end has a plurality of blades 2200 attached to the hub 2700 using fasteners 3100 and the second end has a plurality of blades 2200 attached to the hub 2700 using fasteners 3100. Fig.33 A wireframe diagram of a first end 2701 of a hub 2700 is illustrated, with a plurality of blades 2200 attached to the hub 2700 using fasteners 3100 .

[0199] Due to the offset between the first mounting tab 2213A and the second mounting tab 2213B of each blade, a single fastener 3100 cannot connect the blade 2200 to the hub 2700. Instead, multiple (e.g., two) fasteners 3100 are required to connect each blade 2200 to the hub 2700. The multiple fasteners 3100 used to connect each blade 2200 to the hub 2700 include a first fastener and a second fastener.

[0200] The first fastener is inserted through: 1) a first hole in the blade mounting flange 2715A; 2) a first hole in the second blade mounting flange 2715B aligned with the first hole in the first blade mounting flange 2715A; and 3) a first hole 2215A in the first mounting tab 2213A of the blade 2200 disposed between the first hole in the first blade mounting flange 2715A and the first hole in the second blade mounting flange 2715B to secure the first mounting tab 2213A of the first blade to the hub 2700. The first fastener is also inserted into: 4) a first hole in the third blade mounting flange 2715C; and 5) a first hole in the fourth blade mounting flange 2715D aligned with the first holes in the first blade mounting flange and the second blade mounting flange 2715B; and 6) a second mounting tab 2213B of a first adjacent blade 2200 disposed between the first hole in the third blade mounting flange 2715C and the first hole in the fourth blade mounting flange 2715D, wherein the first adjacent blade 2200 is directly adjacent to the blade 2200 at a first side (e.g., the left side) of the blade 2200.

[0201] Because the second mounting tab 2213B of the blade 2200 is offset from the first mounting tab 2213A of the blade 2200, the second mounting tab 2213B of the blade is not connected to the hub 2700 using the first fastener. Instead, the second mounting tab 2213B of the blade 2200 is connected to the hub 2700 using the second fastener that is used to connect the first mounting tab 2213A of the second adjacent blade 2200 to the hub 2700, wherein the second adjacent blade 2200 is directly adjacent to the second side (e.g., the right side) of the blade 2200.

[0202] The second fastener is inserted through: 1) a second hole in the first blade mounting flange 2715A, which is directly adjacent to the first hole in the first blade mounting flange 2715A; 2) a second hole in the second blade mounting flange 2715B, which is aligned with the second hole in the first blade mounting flange 2715A, wherein the second hole in the second blade mounting flange 2715B is directly adjacent to the first hole in the second blade mounting flange 2715B; and 3) a first hole 2215A in the first mounting wing 2213A of the second adjacent blade 2200, which is located between the second hole in the first blade mounting flange 2715A and the second hole in the second blade mounting flange 2715B to fix the first mounting wing 2213A of the second adjacent blade 2200 to the hub 2700.

[0203] The second fastener is also inserted into: 4) a first hole in the third blade mounting flange 2715C; 5) a first hole in the fourth blade mounting flange 2715D aligned with the first holes in the first blade mounting flange and the second blade mounting flange 2715B; and 6) a second mounting tab 2213B of the blade 2200 disposed between the first hole in the third blade mounting flange 2715C and the first hole in the fourth blade mounting flange 2715D to secure the blade to the hub 2700.

[0204] refer to Fig.33 As an example of how the first blade 2200A is connected to the hub 2700, the first fastener 3100B is inserted through the first hole 2719 of the first blade mounting flange 2715A, the first hole 2719 of the second blade mounting flange 2715B, and the first mounting tab 2213A of the first blade 2200A. However, the first fastener 3100B does not secure the second mounting tab 2213B of the first blade 2200A to the hub 2700. Instead, the second fastener 3100C is used to secure the second mounting tab 2213B of the first blade 2200A to the hub 2700.

[0205] The second fastener 3100C is inserted through: the second hole 2719 of the first blade mounting flange 2715A, which second hole is directly adjacent to the first hole 2719 in the first blade mounting flange 2715A, and the first fastener 3100B is inserted through the first hole; the second hole 2719 of the second blade mounting flange 2715B, which second hole is directly adjacent to the first hole 2719 in the second blade mounting flange 2715B, and the first fastener 3100B is inserted through the first hole; and the first hole of the first mounting wing 2213A of the second blade 2200C, which first hole is adjacent to the first blade 2200A. The second fastener 3100C is also inserted through: the second hole 2719 of the third blade mounting flange 2715C; the second hole 2719 of the fourth blade mounting flange 2715D; and the second hole 2215B in the second mounting fin 2213B of the first blade 2200A (the second mounting fin is inserted between the second hole 2719 of the third blade mounting flange 2715C and the second hole 2719 of the fourth blade mounting flange 2715D) to secure the first blade 2200A to the hub 2700. The remaining blades 2200 are attached to the hub 2700 in this manner to form a blade fan having blades with a double pin root and a blade tip shroud.

[0206] Fig.34A , Fig.34B and Fig.34CA front view, a side view, and a perspective view of a blade fan 3400 having a blade tip shroud 3401 used in a propeller fan 100 according to one embodiment are respectively illustrated. As previously described above, the blade tip shroud 3401 is formed together from the connected shroud segments 2207. The blade fan 3400 includes a blade 2200 having a double pin root as described above. Depending on the application, the blade fan 3400 may have any number of blades 2200. In one embodiment, the material of the blade 2200 used for the blade fan 3400 also depends on the type of application of the blade fan 3400. The blade 2200 may be made of a metal (such as aluminum or titanium) or a composite material (such as carbon fiber). It should be noted that in other embodiments, the blade fan may have a double pin root as previously described above without a blade tip shroud 3401.

[0207] like Fig.34A , Fig.34B and Fig.34C As shown, a plurality of blades 2200 are arranged to form a torus shape having a hollow center, and a hub 2700 is disposed in the hollow center. Each blade 2200 is positioned so that at least a portion of the leading edge and the trailing edge of the blade 2200 overlaps with an adjacent blade 2200. For example, the leading edge of a given blade 2200 overlaps with the trailing edge of the blade 2200 on the left side of the given blade 2200, and the trailing edge of a given blade 2200 overlaps with the leading edge of the blade 2200 on the right side of the given blade 2200. The overlapping arrangement of a plurality of blades 601 provides enhanced robustness to perform work on the inflowing air flow. The adjustment of this robustness takes into account the local aerodynamic effects, and can be adjusted to take into account the Reynolds number effects that may affect the laminar attachment of the airflow within the blade 2200 and between the blades.

[0208] like Fig.34A , Fig.34B and Fig.34C As shown, the shroud segments 2207 of the blade 2200 are interlocked together to tension the tip of the blade 2200 so that the pitch of the blade 2200 during thrust generation is substantially the same as the pitch of the blade 2200 when stationary. That is, by tensioning the tip of the blade 2200, the same shape and twist of the blade is maintained during thrust generation and when stationary, thereby reducing noise that may be generated due to changes in the angle of the blade. The interlocking shroud segments 2207 of the blade 2200 together form a tip shroud that prevents or at least reduces blade vibration at the tip of the blade 2200. Reducing blade vibration enables a high blade count, high aspect ratio fan rotor design.

[0209] Fig.35A , Fig.35B and Fig.35CThe front view, side view and perspective view of the blade fan 3500 of the propeller fan 100 according to one embodiment are respectively illustrated. The blade fan 3500 is similar to the blade fan 3400 except that the blade fan 3500 includes a plurality of blade seals 3501 formed around the circumference of the blade fan 3500 (e.g., around the circumference of the blade tip shroud). In one embodiment, the blade seal 3501 includes a first blade seal 3501A formed around the circumference of the blade fan 3500 and a second blade seal 3501B formed around the circumference of the blade fan 3500. In one embodiment, the first blade seal 3501A and the second blade seal 3501B are spaced apart from each other. The first blade seal 3501A is arranged closer to the first side of the blade fan 3500, which is configured to be connected to the nose cone 203, and the second blade 3501B is arranged closer to the second side of the blade fan 3500, which is configured to be connected to the motor 215.

[0210] The first blade seal 3501A includes a plurality of first blade segments 2501A extending from a plurality of shroud segments 2500 of a plurality of blades 2200. As previously mentioned, each first blade segment 2501A is configured to be connected to other first blade segments 2501A of the plurality of blades 2200. Similarly, the second blade 3501B includes a plurality of second blade segments 2501B extending from a plurality of shroud segments 2500 of a plurality of blades 2200 in the blade fan 3500. As previously mentioned, each second blade segment 2501B is configured to be connected to other second blade segments 2501B of the plurality of blades 2200. The interconnected first blade segments 2501A form the first blade seal 3501A, and the interconnected second blade segments 2501B form the second blade seal 3501B.

[0211] The blade fan 3500 shown in FIG. 35 has a first blade seal 3501A and a second blade seal 3501B. Fig.25A and Fig.25B As described above, the first blade segment 2501A and the second blade segment 2501B have the same height, and the first blade seal and the second blade seal have the same height. Fig.26A and Fig.26B As described, the first blade segment 2601A and the second blade segment 2601B have different heights, and the first blade seal 3501A and the second blade seal 3501B may have different heights.

[0212] Fig.36A perspective view of a blade fan 3600 of a propeller fan 100 according to one embodiment is illustrated. Blade fan 3600 is similar to blade fan 3500, except that blade fan 3600 includes a single blade seal 3601 formed around the circumference of blade fan 3600. Single blade seal 3601 is formed along the center of the blade tip shroud surrounding the blade. Single blade seal 3601 includes multiple single blade segments 2605 (at Fig.26B ), the plurality of blades are included in a blade fan 3600. As previously mentioned, each single blade segment 2605 is configured to be connected to other single blade segments 2605 of the plurality of blades 2200.

[0213] Fig.37A and Fig.37B A side view and a perspective view of a blade 3700 having multiple blade segments and a single pin hole root according to a third embodiment are illustrated, respectively. The blade 3700 includes the same as described above with respect to FIGS. 22 to 23 and Fig.25A and Fig.25B 2200, such as the shroud segment 2500 having blade segments 2501A and 2501B at the first end of the blade 3700, and the base 2211 at the second end of the blade 3700. Therefore, for ease of description, the description of similar features is omitted. In contrast to the blade 2200, the blade 3700 includes a single mounting fin 3701 extending vertically from the lower surface of the base 2211. The single mounting fin 3701 includes a hole 3703 to secure the blade 3700 to the hub 2700.

[0214] Fig.38 A front view of a blade fan 3800 of a propeller fan 100 according to one embodiment is illustrated. Blade fan 3800 includes features similar to blade fan 3500, such as a plurality of blades 3700 and a plurality of blade seals 3501 located around the circumference of blade fan 3800. Therefore, for ease of description, descriptions of similar features are omitted. In contrast to blade fan 3800, each blade 3700 is attached to hub 2700 using a single fastener 3100, while the blades 2200 included in blade fan 3800 each require a plurality of fasteners 3100 to attach a single blade 2200 to hub 2700, as previously described above.

[0215] In this specification, reference to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic is included in at least one embodiment of the present disclosure. Multiple appearances of the term "in one embodiment" in this specification are not necessarily referring to the same embodiment.

[0216] While the present disclosure has been particularly shown and described with reference to one embodiment and several alternative embodiments, it will be understood by those skilled in the relevant art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.

Claims

1. A propeller fan, comprising: a wheel hub, the wheel hub comprising a first end and a second end; a plurality of blades, each of the plurality of blades comprising a first end of the blade, a second end opposite the first end of the blade, and an airfoil located between the first end of the blade and the second end of the blade, wherein the second end of each blade comprises a first mounting tab and a second mounting tab inserted into the hub; a plurality of fasteners configured to connect the plurality of blades to the hub, wherein each fastener is configured to connect the first mounting tab of a first blade from the plurality of blades to the hub and to connect the second mounting tab of a second blade from the plurality of blades to the hub, the second blade being directly adjacent to the first blade; one or more seals, the one or more seals protruding from upper surfaces of the plurality of first ends of the plurality of blades, each of the one or more seals extending around a circumference of the blade fan; a nose cone connected to the first end of the hub; a motor connected to the second end of the hub; and A duct at least partially surrounds the blade fan, the hub, the nose cone and the motor.

2. A blade fan, comprising: Wheel hub; a plurality of blades, each of the plurality of blades comprising a first end, a second end opposite the first end, and an airfoil located between the first end and the second end, wherein the second end of each blade comprises a first mounting tab and a second mounting tab inserted into the hub; and a plurality of fasteners configured to connect the plurality of blades to the hub, wherein each fastener is configured to connect the first mounting tab of a first blade from the plurality of blades to the hub and to connect the second mounting tab of a second blade from the plurality of blades to the hub, the second blade being directly adjacent to the first blade.

3. The blade fan according to claim 2, wherein the hub comprises: a first end and a second end opposite the first end; a plurality of mounting flanges protruding from an upper surface of the hub, the upper surface being located between the first end of the hub and the second end of the hub, the plurality of mounting flanges comprising a first mounting flange and a second mounting flange toward the first end of the hub, and a third mounting flange and a fourth mounting flange toward the second end of the hub; a plurality of slots around a circumference of the hub, the plurality of slots comprising a first slot between the first mounting flange and the second mounting flange and a second slot between the third mounting flange and the fourth mounting flange; and a plurality of holes in the plurality of mounting flanges, the plurality of holes comprising a first hole in the first mounting flange, a second hole in the second mounting flange, a third hole in the third mounting flange, and a fourth hole in the fourth mounting flange, The center of each of the first holes is aligned with the center of a corresponding one of the second holes, the center of a corresponding one of the third holes, and the center of a corresponding one of the fourth holes. 4 . The blade fan according to claim 4 , wherein each of the first mounting flange, the second mounting flange, the third mounting flange, and the fourth mounting flange extends around a circumference of the hub.

5. A blade fan according to claim 3, wherein the first mounting wing of each of the multiple blades includes a first hole, and the second mounting wing of each of the multiple blades includes a second hole, and the first mounting wing and the second mounting wing of each of the multiple blades are offset from each other so that the center of the first hole in the first mounting wing is misaligned with the center of the second hole in the second mounting wing. 6 . The blade fan according to claim 5 , wherein the first mounting tab of each of the plurality of blades is inserted into the first slot, and the second mounting tab of each of the plurality of blades is inserted into the second slot.

7. The blade fan according to claim 6, wherein the center of the first hole in the first mounting wing of each blade of the plurality of blades is aligned with the center of a first hole in the first holes in the first mounting flange and the center of a second hole in the second mounting flange, and the center of the second hole in the second mounting wing of each blade of the plurality of blades is aligned with the center of a third hole in the third holes in the third mounting flange and the center of a fourth hole in the fourth mounting flange, wherein the center of the one of the first holes and the center of the one of the second holes aligned with the first hole of the first mounting wing of the blade are not aligned with the center of the one of the third holes and the center of the fourth hole aligned with the second hole of the second mounting wing of the blade.

8. A blade fan according to claim 6, wherein each fastener is configured to be inserted into the one first hole in the first hole of the first mounting flange, the first hole in the first mounting wing of the corresponding blade, a second hole in the second holes in the second mounting flange, a third hole in the third holes in the third mounting flange, the second hole in the second mounting wing of another blade adjacent to the corresponding blade, and a fourth hole in the fourth holes in the fourth mounting flange.

9. The blade fan according to claim 2, wherein the second end portion of each blade of the plurality of blades further comprises: A base comprising a lower surface, a first connection surface at a first side of the base, and a second connection surface at a second side of the base opposite the first side of the base, wherein the first mounting tab and the second mounting tab extend vertically away from the lower surface of the base.

10. The blade fan according to claim 9, wherein the first connecting surface of each of the plurality of blades is connected to the second connecting surface of a first adjacent blade at the first side of the blade, and the second connecting surface of each of the plurality of blades is connected to the first connecting surface of a second adjacent blade at the second side of the blade.

11. The blade fan according to claim 2, wherein the first end portion of each of the plurality of blades comprises: A shroud segment is wider than a portion of the airfoil connected to the shroud segment, the shroud segment being configured to be connected to other shroud segments of other blades from the plurality of blades.

12. The blade fan according to claim 11, further comprising: A blade tip shroud is positioned about a circumference of the blade fan, the shroud comprising interconnected shroud segments of the plurality of blades.

13. The blade fan according to claim 12, wherein the shroud segment of each of the plurality of blades comprises a protrusion located at a first side of the shroud segment and a recess located at a second side of the shroud segment opposite to the first side of the shroud segment, wherein the protrusion of each shroud segment is inserted into the recess of another shroud segment to connect the shroud segment to the other shroud segment.

14. The blade fan according to claim 12, wherein the first end portion of each of the plurality of blades further comprises: A plurality of protrusions extend from and away from an upper surface of the shroud segment of the blade.

15. The blade fan of claim 14, wherein each of the plurality of protrusions is connected to other protrusions from other blades of the plurality of blades to collectively form a plurality of seals along the upper surface of the tip shroud and around the circumference of the blade fan. 16 . The blade fan of claim 14 , wherein each of the plurality of protrusions of each shroud segment includes a side surface each having one or more steps. 17 . The blade fan according to claim 14 , wherein each of the plurality of protrusions of each shroud segment includes a first protrusion having a first height and a second protrusion having a second height that is the same as the first height. 18 . The blade fan according to claim 14 , wherein each of the plurality of protrusions of each shroud segment includes a first protrusion having a first height and a second protrusion having a second height different from the first height.

19. A blade fan, comprising: a wheel hub, the wheel hub comprising a first end and a second end opposite the first end; a plurality of blades, the plurality of blades comprising a plurality of first ends, a plurality of second ends, and a plurality of airfoils, the plurality of second ends being opposite the plurality of first ends and attached around a circumference of the hub, and the plurality of airfoils being located between the plurality of first ends and the plurality of second ends; and One or more seals protrude from upper surfaces of the plurality of first ends of the plurality of blades, each of the one or more seals extending around the circumference of the blade fan.

20. The blade fan according to claim 19, wherein the first end portion of each blade of the plurality of blades comprises: A shroud segment is wider than a portion of one of the plurality of airfoils connected to the shroud segment, the shroud segment being configured to be connected to other shroud segments of other blades from the plurality of blades.

21. The blade fan according to claim 20, further comprising: A shroud is positioned around a circumference of the blade fan, the shroud comprising interconnected shroud segments of the plurality of blades.

22. A blade fan according to claim 21, wherein the shroud segment of each of the plurality of blades includes a protrusion located at a first side of the shroud segment and a recess located at a second side of the shroud segment opposite to the first side of the shroud segment, wherein the protrusion of each shroud segment is inserted into the recess of another shroud segment to connect the shroud segment to the other shroud segment.

23. The blade fan of claim 21, wherein the one or more seals protrude from the upper surface of the shroud.

24. The blade fan according to claim 20, wherein the first end portion of each blade of the plurality of blades further comprises: a plurality of protrusions extending from and away from an upper surface of the shroud segment of the blade, Wherein each of the plurality of protrusions of the shroud segment of the blade is configured to connect to other protrusions of other shroud segments from other blades of the plurality of blades to collectively form the one or more seals.

25. The blade fan of claim 24, wherein each of the plurality of protrusions of each shroud segment includes a side surface each having one or more steps. 26 . The blade fan of claim 24 , wherein each of the plurality of protrusions of each shroud segment includes a first protrusion having a first height and a second protrusion having a second height that is the same as the first height. 27 . The blade fan of claim 24 , wherein each of the plurality of protrusions of each shroud segment comprises a first protrusion having a first height and a second protrusion having a second height different from the first height.

28. The blade fan according to claim 19, wherein the hub comprises: a first end and a second end opposite the first end; a plurality of mounting flanges protruding from an upper surface of the hub, the upper surface being located between the first end of the hub and the second end of the hub, the plurality of mounting flanges comprising a first mounting flange and a second mounting flange toward the first end of the hub, and a third mounting flange and a fourth mounting flange toward the second end of the hub; a plurality of slots located around the circumference of the hub, the plurality of slots comprising a first slot located between the first mounting flange and the second mounting flange and a second slot located between the third mounting flange and the fourth mounting flange; and a plurality of holes in the plurality of mounting flanges, the plurality of holes comprising a first hole in the first mounting flange, a second hole in the second mounting flange, a third hole in the third mounting flange, and a fourth hole in the fourth mounting flange, The center of each of the first holes is aligned with the center of a corresponding one of the second holes, the center of a corresponding one of the third holes, and the center of a corresponding one of the fourth holes.

29. The blade fan of claim 28, wherein each of the first mounting flange, the second mounting flange, the third mounting flange, and the fourth mounting flange extends around a circumference of the hub.

30. A blade fan according to claim 28, wherein the second end of each of the plurality of blades includes a first mounting wing and a second mounting wing inserted into the hub, the first mounting wing of each of the plurality of blades includes a first hole, and the second mounting wing of each of the plurality of blades includes a second hole, and the first mounting wing and the second mounting wing of each of the plurality of blades are offset from each other so that the center of the first hole in the first mounting wing is misaligned with the center of the second hole in the second mounting wing.

31. The blade fan according to claim 30, wherein the first mounting tab of each of the plurality of blades is inserted into the first slot, and the second mounting tab of each of the plurality of blades is inserted into the second slot.

32. The blade fan according to claim 31, wherein the center of the first hole in the first mounting wing of each blade of the plurality of blades is aligned with the center of a first hole in the first holes in the first mounting flange and the center of a second hole in the second mounting flange, and the center of the second hole in the second mounting wing of each blade of the plurality of blades is aligned with the center of a third hole in the third holes in the third mounting flange and the center of a fourth hole in the fourth mounting flange, wherein the center of the one of the first holes and the center of the one of the second holes aligned with the first hole of the first mounting wing of the blade are not aligned with the center of the one of the third holes and the center of the fourth hole aligned with the second hole of the second mounting wing of the blade.

33. The blade fan according to claim 31, further comprising: a plurality of fasteners configured to connect the plurality of blades to the hub, wherein each fastener is configured to connect the first mounting tab of a first blade from the plurality of blades to the hub and to connect the second mounting tab of a second blade from the plurality of blades to the hub, the second blade being directly adjacent to the first blade. Each fastener is configured to be inserted into the one of the first holes in the first mounting flange, the first hole in the first mounting tab of the corresponding blade, the one of the second holes in the second mounting flange, the one of the third holes in the third mounting flange, the second hole in the second mounting tab of another blade adjacent to the corresponding blade, and the one of the fourth holes in the fourth mounting flange.

34. The blade fan according to claim 30, wherein the second end portion of each blade of the plurality of blades further comprises: A base comprising a lower surface, a first connection surface at a first side of the base, and a second connection surface at a second side of the base opposite the first side of the base, wherein the first mounting tab and the second mounting tab extend vertically away from the lower surface of the base.

35. A blade fan according to claim 34, wherein the first connecting surface of each of the plurality of blades is connected to the second connecting surface of a first adjacent blade at the first side of the blade, and the second connecting surface of each of the plurality of blades is connected to the first connecting surface of a second adjacent blade at the second side of the blade.

36. A propeller, the propeller being configured to generate thrust, the propeller comprising: a wheel hub, the wheel hub comprising a first end and a second end opposite the first end; A blade fan, the blade fan comprising a plurality of blades arranged in a ring, wherein each blade comprises a first end, a second end opposite to the first end, and an airfoil located between the first end and the second end, wherein the second end of each blade comprises a first mounting wing and a second mounting wing, the first mounting wing and the second mounting wing being inserted into a portion of the hub located between the first end of the hub and the second end of the hub; a plurality of fasteners configured to connect the blade fan to the hub, wherein each fastener is configured to connect the first mounting tab of a corresponding blade from the plurality of blades to the hub and to connect the second mounting tab of another blade from the plurality of blades to the hub, the other blade being directly adjacent to the corresponding blade; a nose cone connected to the first end of the hub; a motor connected to the second end of the hub; and A duct at least partially surrounds the blade fan, the hub, the nose cone and the motor.

37. A propeller, the propeller being configured to generate thrust, the propeller comprising: a wheel hub, the wheel hub comprising a first end and a second end opposite the first end; a blade fan comprising a plurality of blades, the plurality of blades comprising a plurality of first ends, a plurality of second ends, and a plurality of airfoils, the plurality of second ends being opposite to the plurality of first ends and attached around the circumference of the hub, and the plurality of airfoils being located between the plurality of first ends and the plurality of second ends; one or more seals, the one or more seals protruding from upper surfaces of the plurality of first ends of the plurality of blades, each of the one or more seals extending around a circumference of the blade fan; a nose cone connected to the first end of the hub; a motor connected to the second end of the hub; and A duct at least partially surrounds the blade fan, the hub, the nose cone and the motor.

Images