Vehicle fan installation assembly

Abstract

To provide a fan installation assembly for air distribution onboard a vehicle, such as an aircraft.SOLUTION: A fan installation assembly includes a conduit and an axial fan assembly (100). The conduit is disposed onboard a vehicle and configured to contain airflow that is supplied to or received from an internal cabin of the vehicle. The axial fan assembly is configured to propel the airflow through the conduit. The axial fan assembly includes a case (102), a motor assembly (106), and an impeller (104). The case surrounds the impeller and the motor assembly and is attached to the conduit. The impeller includes a hub (110) and multiple blades (112) mounted on the hub. Each of the blades has a toroidal shape and forms a loop.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001]

[0001] Embodiments of the present disclosure generally relate to a fan installation assembly for air distribution mounted on a vehicle such as an aircraft.

Background Art

[0002]

[0002] Some vehicles include a low-pressure axial fan that propels an airflow regulated throughout one or more interior cabins of the vehicle. The axial fans typically used in these vehicle air distribution applications generate a significant amount of noise within the interior cabin. Typical axial fans have conventional airfoils such as blades resembling fish fins. The noise generated by the fan can be annoying to both passengers and crew. For example, the frequency of the noise generated by the fan can be within a range sensitive to human hearing. Additionally, the noise generated by the fan can combine with engine noise and other noises to result in an excessive amount of cumulative noise within the interior cabin. Excessive cumulative noise can interfere with the ability of passengers and crew to communicate effectively and can prevent maintaining a safe, operable, and comfortable space within the interior cabin.

Summary of the Invention

[0003]

[0003] There is a need for a vehicle fan installation assembly that generates less noise and / or generates noise that is less sensitive to human hearing than known low-pressure axial fan assemblies, and that propels an airflow regulated throughout one or more interior cabins of the vehicle.

[0004]

[0004] Certain embodiments of the present disclosure provide a fan installation assembly that includes a duct and an axial flow fan assembly. The duct is configured to be mounted on a vehicle and accommodate an air flow that is supplied to or received from the interior cabin of the vehicle. The axial flow fan assembly is configured to propel the air flow through the duct. The axial flow fan assembly includes a case, a motor assembly, and an impeller. The case surrounds the impeller and the motor assembly and is attached to the duct. The impeller includes a hub and a plurality of blades attached to the hub. Each of the blades has a toroidal shape and forms a loop.

[0005]

[0005] Certain embodiments of the present disclosure provide an aircraft that includes an air distribution system. The air distribution system has a duct and an axial flow fan assembly. The duct is configured to accommodate an air flow that is supplied to or received from the interior cabin of the aircraft. The axial flow fan assembly is configured to propel the air flow through the duct. The axial flow fan assembly includes a motor assembly, an impeller, and a case. The impeller includes a hub and a plurality of blades attached to the hub. Each of the blades has a toroidal shape that forms a loop. The case is attached to the duct and surrounds the impeller and the motor assembly.

[0006]

[0006] Certain embodiments of the present disclosure provide a fan installation assembly that includes a duct and an axial flow fan assembly. The duct is mounted on a vehicle and configured to accommodate an air flow supplied to or received from the interior cabin of the vehicle. The axial flow fan assembly is configured to propel the air flow through the duct. The axial flow fan assembly includes a case, a motor assembly, and an impeller. The case defines a cavity fluidly connected to the interior space of the duct. The impeller and the motor assembly are disposed within the cavity. The impeller includes a hub and a plurality of blades attached to the hub. Each of the blades has a toroidal shape and forms a loop. Each of the blades includes a first airfoil section attached to the hub, a second airfoil section attached to the hub, and a tip section connecting the first airfoil section and the second airfoil section. The case defines an annular relief channel configured to receive the flow of the captured air flow.

[0007]

[0007] These features, aspects, and advantages of the present disclosure, as well as other features, aspects, and advantages, will be better understood by reading the following detailed description with reference to the accompanying drawings. Throughout the drawings, like features represent like parts.

Brief Description of the Drawings

[0008]

Figure 1

[0008] A perspective view of an axial flow fan assembly according to an embodiment.

Figure 2

[0009] A schematic block diagram of a vehicle including a fan installation assembly according to an embodiment.

Figure 3

[0010] A front elevation view of an impeller of an axial flow fan assembly according to an embodiment.

Figure 4

[0011] A perspective view of the impeller shown in FIG. 3.

Figure 5

[0012] Side view of a fan installation assembly according to one embodiment, with the conduit and case shown in cross-section.

Figure 6

[0013] Side cross-sectional view of a fan installation assembly according to a second embodiment including a modified case.

Figure 7

[0014] Perspective view of an aircraft.

Figure 8

[0015] Perspective view of the impeller of a fan a installation assembly according to one embodiment.

Figure 9

[0016] Flowchart of a method of assembling a fan installation assembly according to one embodiment. **DETAILED DESCRIPTION OF THE INVENTION**

[0009]

[0017] The above summary, as well as the following detailed description of certain specific embodiments, will be better understood when read in conjunction with the accompanying drawings. As used herein, it should be understood that a singular element or step following "a" or "an" does not necessarily exclude a plurality of such elements or steps. Further, reference to "one embodiment" is not intended to be construed as excluding the existence of additional embodiments, and such additional embodiments may also incorporate the described features. Conversely, an embodiment "comprising," "including," or "having" one or more elements having a particular property may include additional elements not having that property, unless expressly stated otherwise.

[0010]

[0018] Certain specific embodiments of the present disclosure provide a fan installation assembly. The fan installation assembly can be implemented on a vehicle such as an aircraft. The fan installation assembly is used to propel an air flow through a duct. The air flow propelled by the fan installation assembly can be supplied to or received from the interior cabin of the vehicle. For example, the air flow can be conditioned air supplied to the interior cabin for the comfort of passengers and / or crew within the interior cabin. The duct can be part of an air distribution system mounted on the vehicle. The fan installation assembly includes an axial flow fan assembly. The axial flow fan assembly can be within or attached to the duct to propel an air flow through the duct.

[0011]

[0019] The axial flow fan assembly includes an impeller having a hub and a plurality of blades attached to the hub. The blades of the axial flow fan assembly are toroidal blades. Each of the toroidal blades has a toroidal shape forming a loop. For example, a toroidal blade has a body having a first end and a second end connected to the hub. The body traces a loop along the length of the body from the first end to the second end. The body defines a lateral opening between a first airfoil section of the blade and a second airfoil section of the blade. The opening can extend radially from the hub to a tip section of the blade connecting the first airfoil section and the second airfoil section. The toroidal blade may be twisted along the length of the body.

[0012]

[0020] The fan installation assembly described herein includes an axial fan assembly having toroidal blades used to propel an air stream through an air distribution system. The axial fan assembly can propel an air stream for supply to an interior cabin and / or recirculation to an air conditioning system. The fan installation assembly can have several beneficial technical effects. The designed shape of the toroidal fan blades can reduce the generation of broadband noise compared to conventional low-pressure axial fans. For example, the design of the toroidal blades can reduce the generation of broadband noise by reducing vortex shedding turbulence. The toroidal blades can flow air from the blades more smoothly than conventional fin-shaped rotor blades and can reduce the slip from the tip vortices. When the noise in the interior cabin is reduced, the benefit of improved comfort experienced by the passengers and crew of the vehicle in which the fan installation assembly is implemented can be obtained. For example, a quieter cabin may be felt to be more enjoyable and may also make it possible to more reliably communicate between passengers and crew. Further, the axial fan assembly described herein having toroidal blades can generate noise within a frequency range that is more acceptable to the human ear than conventional axial fans. For example, the axial fan assembly described herein can generate noise at a lower frequency than conventional axial fans.

[0013]

[0021] The design of a toroidal fan blade can improve efficiency more than a conventional axial fan. This is because the toroidal blade can increase the speed of air passing through the duct. Improving the efficiency of the axial fan assembly may be possible to improve the efficiency of some vehicles. For example, the axial fan assembly can reduce power consumption and save energy. In another embodiment, the axial fan assembly can have a reduced size and / or weight compared to a conventional axial fan without reducing the output. Thereby, energy can be saved through weight savings and / or the space occupied on the vehicle can be saved. Further, various design aspects of the fan installation assembly can be adjusted to meet specific requirements, constraints, or goals specified by the user regarding noise, power consumption, pressure rise, flow rate, etc., while still maintaining broadband noise reduction compared to known low-pressure axial fans.

[0014]

[0022] In one or more embodiments described herein, the fan installation assembly is installed within a vehicle. The vehicle including the fan installation assembly can be an aircraft. In one embodiment, the aircraft can be a commercial airliner. The fan installation assembly can also be implemented in other types of aircraft and non-aircraft vehicles. Other types of aircraft can include electric aircraft, autonomous aircraft, etc. Other suitable types of vehicles for the fan installation assembly can include trains (e.g., locomotives), automobiles, trucks, buses, mining vehicles, agricultural vehicles, etc. Further, the fan installation assembly described herein can be installed within a stationary building. For example, the fan installation assembly can be part of a building's heating, ventilation, and air conditioning (HVAC) system.

[0015]

[0023] Next, referring to the drawings, FIG. 1 is a perspective view of an axial flow fan assembly 100 according to one embodiment. The axial flow fan assembly 100 includes a case 102, an impeller 104, and a motor assembly 106. The case 102 surrounds the impeller 104 and the motor assembly 106. For example, the case 102 defines a cavity 108 for containing and guiding the airflow passing through the case 102. The impeller 104 and the motor assembly 106 can be disposed within the cavity 108 that is exposed to the airflow. The case 102 also ensures safety by preventing external objects from contacting the impeller 104 during operation and reduces the risk of damage to the impeller 104. The impeller 104 includes a hub 110 and a plurality of blades 112 attached to the hub 110. The blades 112 are circumferentially spaced along the outer periphery of the hub 110. The impeller 104 (e.g., the hub 110 and the blades 112) is designed to rotate about a hub axis 114 that extends through the center of the hub 110. The impeller 104 has seven blades 112 in one illustrated embodiment, but in another embodiment, it may have eight or more blades 112 or six or fewer blades 112. The blades 112 can be equally spaced around the outer periphery of the hub 110 for the propulsion of a uniform airflow.

[0016]

[0024] Blade 112 has a toroidal shape and forms respective loops extending from hub 110. For example, each blade 112 has a first airfoil section 116 attached to hub 110, a second airfoil section 118 attached to hub 110, and a tip section 120 connecting the first airfoil section 116 and the second airfoil section 118. The tip section 120 forms a distal end on blade 112 that is farthest from hub 110. The blade 112 is loop-shaped such that the first airfoil section 116, the tip section 120, and the second airfoil section 118 define an opening 122 that extends through the thickness of the blade 112. The opening 122 is radially elongated and may extend from hub 110 to tip section 120. The loop may be a closed loop. For example, the opening is laterally enclosed between the first airfoil section 116 and the second airfoil section 118 and is radially enclosed between hub 110 and tip section 120.

[0017]

[0025] The toroidal shape of blade 112 may generate significantly less noise than an axial fan having a conventional rotor (e.g., a fin or blade-shaped rotor) at least at audible frequencies perceptible to humans. For example, axial fan assembly 100 may be significantly quieter than a conventional axial fan between 20 Hz and 20 kHz. For example, the toroidal blade design can disperse the vortices generated by impeller 104 not only at the tips but also along the entire radial length of blade 112, thereby attenuating the generated noise. Axial fan assembly 100 may generate equivalent and / or increased fluid propulsion force compared to a conventional propeller.

[0018]

[0026] The impeller 104 is driven to rotate by a motor assembly 106 to propel the airflow through the case 102. The impeller 104 can propel the airflow in a guiding direction parallel to the hub axis 114 (for example, the rotation axis of the blade 112). The axial flow fan assembly 100 can be a low-pressure fan. For example, the axial flow fan assembly 100 may not compress air to a pressure level used to generate thrust for propelling the vehicle. In one embodiment, the axial flow fan assembly 100 is used to circulate air through one or more interior cabins of the vehicle.

[0019]

[0027] Figure 2 is a schematic block diagram of a vehicle 200 including a fan installation assembly 202 according to one embodiment. The vehicle 200 has two fan installation assemblies 202A and 202B in one illustrated embodiment, but may have only one or three or more fan installation assemblies 202 in other embodiments. Each fan installation assembly 202 includes a conduit 204 mounted on the vehicle 200 and an axial flow fan assembly 100, as shown in FIG. 1. The conduit 204 accommodates the airflow supplied to or received from the interior cabin 206 of the vehicle 200. The interior cabin 206 in FIG. 2 includes seats 208 for passengers and / or crew of the vehicle 200.

[0020]

[0028] In one embodiment, the fan installation assemblies 202A, 202B are incorporated into the air distribution system 210 mounted on the vehicle 200. The air distribution system 210 circulates air between the interior cabin 206 and the air conditioning (AC) system 212. The AC system 212 modifies air parameters such as temperature and humidity to generate a conditioned airflow. The air distribution system 210 can direct and distribute the conditioned airflow from the AC system 212 to the interior cabin 206 and optionally to other interior cabins mounted on the vehicle 200. The air distribution system 210 can also collect the airflow from the interior cabin 206 and optionally other interior cabins and return the collected airflow to the AC system 212. The AC system 212 can be a heating, ventilation, and air conditioning (HVAC) system. For example, the AC system 212 can include a compressor, an expansion device, an evaporator, and a condenser, as well as refrigerant lines, an air temperature sensor, an air filter, and other associated components. In one embodiment, the vehicle 200 is an aircraft and the AC system 212 is part of the environmental control system mounted on the aircraft. For example, the AC system 212 can be an AC pack of a commercial aircraft. A commercial aircraft can include multiple AC packs. For example, a first AC pack can be associated with the left side of the aircraft and a second AC pack can be associated with the right side of the aircraft.

[0021]

[0029] In one embodiment, the conduit 204A of the first fan installation assembly 202A is an output conduit 204A that supplies an adjusted airflow from the AC system 212 to the internal cabin 206. The conduit 204B of the second fan installation assembly 202B can be a return conduit 204B that receives the airflow from the internal cabin 206 and propels the airflow to the AC system 212. The conduits 204A, 204B can be closed air passages such as ducts. The first axial fan assembly 100A can propel the airflow in a first guiding direction 214 through the output conduit 204A toward the internal cabin 206. The second axial fan assembly 100B can propel the airflow in a second guiding direction 216 through the return conduit 204B toward the AC system 212. In one embodiment, the axial fan assemblies 100A, 100B can be disposed within the corresponding conduits 204A, 204B. In another embodiment, the axial fan assemblies 100A, 100B can be disposed at the ends of the corresponding conduits 204A, 204B. In any of the embodiments, the axial fan assemblies 100A, 100B are fluidly connected to the internal spaces of the conduits 204A, 204B to drive the airflow through the conduits 204A, 204B. The axial fan assemblies 100A, 100B are duct fans. Thereby, the airflow propelled by the fans 100A, 100B is contained within the conduits 204A, 204B. The axial fan assemblies 100A, 100B are shown within the conduits 204A, 204B of the air distribution system 210 in one of the illustrated embodiments, and the axial fan assemblies 100A, 100B can be considered components of the AC system 212. For example, the axial fan assemblies 100A, 100B can be fans that propel the airflow to cover the evaporator and condenser coils of the AC system 212.

[0022]

[0030] FIG. 3 is a front elevation view of the impeller 104 of the axial flow fan assembly 100 according to one embodiment. FIG. 4 is a perspective view of the impeller 104 shown in FIG. 3. In one illustrated embodiment, each of the blades 112 has a toroidal shape that forms a loop. For example, each blade 112 has a body 302 having a first end 304 and a second end 306. The blade 112 extends from the first end 304 and the second end 306. Both the first end 304 and the second end 306 can be connected to the hub 110. The body 302 draws a loop along the length of the body from the first end 304 to the second end 306. The first airfoil section 116 of the blade 112 extends from the first end 304 to the tip section 120. The second airfoil section 118 extends from the tip section 120 to the second end 306. The body 302 defines a lateral opening 122 between the first airfoil section 116 and the second airfoil section 118. The opening 122 can extend radially from the hub 110 to the tip section 120 of the blade 112.

[0023]

[0031] The first airfoil section 116 can be the intake portion of the blade 112, and the second airfoil section 118 can be the exhaust portion of the blade 112. For example, as shown in FIG. 4, the first airfoil section 116 can be upstream of at least a majority of the second airfoil section 118 along the direction of guiding the airflow through the case 102 (shown in FIG. 1) and the conduit 204 (FIG. 2). The direction of guiding the airflow represents the direction in which the axial flow fan assembly 100 propels the airflow through the case 102 and the conduit 204 (such as the first and second guiding directions 214, 216 shown in FIG. 2). The first airfoil section 116 of the blade 112 can generally draw the airflow into the opening 122 and provide an intake function. The second airfoil section 118 can generally push the airflow downstream in the direction of guiding the airflow and provide an exhaust function. In one embodiment, the first airfoil section 116 (e.g., the first end 304 of the main body 302) is connected to the hub 110 at respective first positions 312, and the second airfoil section 118 (e.g., the second end 306 of the main body 302) is connected to the hub 110 at respective second positions 314. The first and second positions 312, 314 are spaced apart along the hub axis 114 of the hub 110. For example, the first position 312 can be between the tip 316 of the hub 110 and the second position 314 along the hub axis 114. Thus, the first position 312 can be upstream of the second position 314 with respect to the direction of guiding the airflow.

[0024]

[0032] Blade 112 may be twisted along the length of each body 302. For example, blade 112 (e.g., body 302 of blade 112) has a first side 308 and a second side 310 opposite the first side 308. The first and second sides 308, 310 can be wide surfaces extending between the first and second lateral edges of body 302. Blade 112 may be twisted such that the first side 308 of blade 112 along the first airfoil section 116 faces a different direction than the first side 308 of blade 112 along the second airfoil section 118. For example, the first side 308 of blade 112 along the first airfoil section 116 can generally face upstream in accordance with the direction of the airflow through case 102 and conduit 204. The first side 308 of blade 112 along the second airfoil section 118 can generally face downstream in accordance with the direction of the airflow.

[0025]

[0033] In one embodiment, body 302 of blade 112 can be a monolithic (e.g., one-piece) body. That body 302 is monolithic indicates that different sections are integrally and seamlessly connected to each other. For example, blade 112 will likely have no seams along the length of body 302. Body 302 can be formed by shaping (e.g., molding, casting, laminating) a single structural building part into the twisted toroidal shape shown in FIGS. 1, 3, and 4.

[0026]

[0034] In one embodiment, hub 110 has a narrow portion 318 and a wide portion 320 extending from narrow portion 318. Blade 112 is attached to narrow portion 318 of hub 110. Motor assembly 106 (shown in FIG. 1) is attached to wide portion 320. In one embodiment, narrow portion 318 of hub 110 can have a cylindrical shape and wide portion 320 can have a conical shape. The conical shape has a diameter that gradually increases as the distance from narrow portion 318 increases. The internal space within the cavity of case 102 through which the airflow is propelled by impeller 104 gradually decreases along the length of conical wide portion 320.

[0027]

[0035] FIG. 5 is a side view of a fan installation assembly 202 according to an embodiment, in which the conduit 204 and the case 102 are shown in cross section. The impeller 104 and the motor assembly 106 are disposed within the cavity 108 of the case 102. The cavity 108 is fluidly connected to the internal space 502 of the conduit 204. The case 102 may be mechanically coupled to the conduit 204. For example, the case 102 may be attached between two sections of the conduit 204 and / or disposed within the internal space 502 of the conduit 204.

[0028]

[0036] In one embodiment, the case 102 may define an annular relief channel 504 designed to receive the flow of the captured airflow. For example, the case 102 may include a radially projecting portion 506 (also shown in FIG. 1) that defines the annular relief channel 504. The radially projecting portion 506 is a section of the case 102 that bulges outward in the radial direction. The annular relief channel 504 has a diameter larger than that of the portion of the case 102 adjacent to the annular relief channel 504 (e.g., the portions immediately upstream and downstream of the annular relief channel 504). The annular relief channel 504 may be aligned with the blades 112 of the impeller 104. The tip section 120 of the blade 112 may be aligned with the annular relief channel along the hub axis 114 of the hub. For example, the plane through which the blade 112 rotates may intersect the annular relief channel 504.

[0029]

[0037] The annular relief channel 504 can receive the captured airflow resulting from vortex shedding. The annular relief channel 504 can enable separation of the turbulent blade tip flow (e.g., vortex shedding) from the core (e.g., main) airflow passing through the axial fan assembly 100 and the conduit 204. Due to the annular relief channel 504, the captured flow released from the tip section 120 of the blade 112 can be disposed radially outward of the impeller 104 to avoid significant constriction (e.g., choking) of the core airflow. As a result, more core airflow can be achieved when the annular relief channel 504 is present than when the case 102 does not include the annular relief channel 504. The captured flow can be recombined with the core airflow downstream of the annular relief channel 504.

[0030]

[0038] The blades 112 of the axial fan assembly 100 can be relatively long to enhance the interaction between the blades 112 and the air. In one embodiment, the diameter of the impeller 104 is at least 75% of the first inner diameter of the case 102. The first inner diameter of the case 102 can be disposed in a segment of the case 102 adjacent to the annular relief channel 504. In one embodiment, the diameter of the impeller is not greater than the first inner diameter of the case 102. For example, the tip section 120 of the blade 112 may not extend into the annular relief channel 504. Thus, the annular relief channel 504 can receive the captured flow without receiving a portion of the blade 112. In another embodiment, the tip section 120 of the blade 112 can extend into the annular relief channel 504 at least slightly beyond the first inner diameter.

[0031]

[0039] The fan installation assembly 202 may include a corrective vane 508 attached to the housing 510 of the motor 106. The housing 510 of the motor assembly 106 is connected to the wide portion 320 of the hub 110. The housing 510 may include a motor that drives the rotation of the blades 112 of the impeller 104. The housing 510 may also include a power source that supplies power to the motor. The corrective vanes 508 may be circumferentially spaced along the outer periphery of the housing 510 as shown in FIG. 1. The corrective vanes 508 control the direction of the air flow through the cavity 108 of the case 102 downstream of the impeller 104. For example, the corrective vanes may be arranged to straighten the core air flow by reducing the variation in the air flow direction downstream of the impeller 104 and the annular relief channel 504.

[0032]

[0040] FIG. 6 is a side cross-sectional view of the fan installation assembly 202 according to a second embodiment in which the case 102 is modified with respect to the case 102 shown in FIGS. 1 and 3 to 5. In one embodiment shown, the fan installation assembly 202 may include a flow conditioner 602 within the case 102. The flow conditioner 602 may be disposed upstream of the impeller 104 in accordance with the guiding direction of the air flow 604 through the conduit 204. For example, the flow conditioner 602 may be upstream of the blades 112 and the annular relief channel 504. The flow conditioner 602 may have an annular shape and project into the cavity 108 of the case 102 to restrict the flow by reducing the diameter of the cavity 108. For example, the air flow entering the case 102 is restricted or choked by the flow conditioner 602. Thereby, the pressure and / or the flow velocity of the air flow exiting the flow conditioner 602 before reaching the impeller 104 increases. The flow conditioner 602 may help to direct the incoming air flow in the guiding direction 604.

[0033]

[0041] FIG. 7 is a perspective view of an aircraft 700. In one embodiment, the aircraft 700 represents a vehicle on which a fan installation assembly 202 is installed. The aircraft 700 includes a fuselage 706 extending from a nose section 712 to a tail 714 or a tail section. The aircraft 700 includes a pair of main wings 702, 704 extending from the fuselage 706. The main wings 702, 704 may include movable wing surfaces such as ailerons, flaps, and / or spoilers. One or more propulsion systems 708, 710 propel the aircraft 700. The propulsion systems 708, 710 are supported by the main wings 702, 704 in the illustrated embodiment, but may be attached to the fuselage 706 or the tail 714 in other types of aircraft. The tail 714 may include horizontal stabilizers 716, 718 and a vertical stabilizer 720. The fuselage 706 may define a plurality of internal cabins along the length of the fuselage 706 from the nose section 712 to the tail 714. The fuselage 706 is oriented about a longitudinal axis 722. In one embodiment, the fan installation assembly 202 may be part of an air conditioning system (e.g., an environmental control system) mounted on the aircraft 700 for adjusting the temperature, humidity, and pressure of the air supplied into the internal cabin of the fuselage 706.

[0034]

[0042] FIG. 8 is a perspective view of an impeller 104 of a fan a installation assembly 202 according to one embodiment. The impeller 104 of FIG. 8 has intersecting blades 802. For example, the blade 802 has a toroidal shape defining a loop extending from a hub 110 similar to the blade 112 shown in FIGS. 3 and 4. The adjacent blades 112 in FIGS. 3 and 4 are spaced from each other and are individually attached to the hub 110. In FIG. 8, the adjacent blades 802 intersect each other in the vicinity of the hub 110. For example, a first airfoil section of each blade 802 may define a slot 804 through which a second airfoil section of an adjacent blade 802 is received. This overlapping design may enable a compressed axial flow fan that shortens the axial length of the impeller 104 along the hub axis 114. This overlapping design may be less efficient than the design shown in FIGS. 3 and 4 having separated blades 112.

[0035]

[0043] FIG. 9 is a flowchart 900 of a method of assembling a fan installation assembly according to one embodiment. The fan installation assembly can be the fan installation assembly 202 described herein. The method can optionally include more steps, fewer steps, and / or different steps than those shown in flowchart 900, and / or one or more of the steps can be performed in an order different from that shown and described herein.

[0036]

[0044] In step 902, an axial flow fan assembly 100 is provided that includes a case 102, a motor assembly 106, and an impeller 104. The case 102 surrounds the impeller 104 and the motor assembly 106. The impeller 104 includes a hub 110 and a plurality of blades 112 attached to the hub 110. Each of the blades 112 has a toroidal shape that forms a loop. As an example, the case 102 defines an annular relief channel 504. The annular relief channel 504 can receive the flow of captured air that is propelled by the axial flow fan assembly 100. In one example, the impeller 104 is disposed relative to the case 102. Thereby, the annular relief channel 504 is aligned with the blades 112.

[0037]

[0045] In step 904, the axial flow fan assembly 100 is attached to a duct 204 mounted to the vehicle 200 such that the axial flow fan assembly 100 propels an airflow through the duct 204. The airflow within the duct 204 can be supplied to or received from the interior cabin 206 of the vehicle 200. In one example, the vehicle 200 can be an aircraft 700. The axial flow fan assembly 100 can be mounted within the duct 204, coupled to the duct 204, in series with the duct 204, or serially coupled between two sections of the duct 204.

[0038]

[0046] In one embodiment, the method may include providing a flow conditioner 602 that flows into the case 102 upstream of the impeller 104 in accordance with the guiding direction of the air flow 604 through the conduit 204. In one embodiment, the method may include providing a corrective vane 508 attached to the housing 510 of the motor assembly 106 of the axial fan assembly 100. The corrective vanes 508 may be circumferentially spaced along the outer periphery of the housing 510.

[0039]

[0047] Furthermore, the present disclosure includes a plurality of embodiments according to the following clauses.

[0040]

[0048] Clause 1. A fan installation assembly, mounted on a vehicle and configured to accommodate an air flow supplied to or received from the interior cabin of the vehicle, and a conduit, and An axial fan assembly configured to propel the air flow through the conduit, the axial fan assembly including a case, a motor assembly, and an impeller, the case surrounding the impeller and the motor assembly and attached to the conduit, the impeller including a hub and a plurality of blades attached to the hub, each of the blades having a toroidal shape forming a loop, the fan installation assembly comprising an axial fan assembly.

[0041]

[0049] Clause 2. Each of the blades includes a first airfoil section attached to the hub, a second airfoil section attached to the hub, and a tip section connecting the first airfoil section and the second airfoil section, the first airfoil section, the second airfoil section, and the tip section defining the loop, the fan installation assembly according to clause 1.

[0042]

[0050] Clause 3. The first airfoil section of the blade is connected to the hub at respective first positions, and the second airfoil section of the blade is connected to the hub at respective second positions. The first position is between the tip of the hub and the second position along the hub axis of the hub. The fan installation assembly according to clause 2.

[0043]

[0051] Clause 4. Each of the blades has a monolithic body including a first side and a second side opposite the first side. The monolithic body is twisted along the length of the monolithic body. The fan installation assembly according to clause 2.

[0044]

[0052] Clause 5. The hub has a narrow portion and a wide portion extending from the narrow portion. The blade is attached to the narrow portion, and the motor assembly is attached to the wide portion. The fan installation assembly according to any one of clauses 1 to 4.

[0045]

[0053] Clause 6. The narrow portion of the hub has a cylindrical shape, and the wide portion of the hub has a conical shape. The fan installation assembly according to clause 5.

[0046]

[0054] Clause 7. The impeller and the motor assembly are disposed within the cavity of the case. The cavity is fluidly connected to the internal space of the conduit. The case defines an annular relief channel configured to receive the flow of the captured air stream. The fan installation assembly according to any one of clauses 1 to 6.

[0047]

[0055] Clause 8. The annular relief channel is aligned with the blades of the impeller. The fan installation assembly according to clause 7.

[0048]

[0056] Clause 9. The fan installation assembly according to clause 7, wherein the diameter of the impeller is at least 75% of the diameter of the cavity in the segment of the case adjacent to the annular relief channel.

[0049]

[0057] Clause 10. The fan installation assembly according to any one of clauses 1 to 9, further comprising a flow conditioner disposed upstream of the impeller along the guiding direction of the air flow through the conduit.

[0050]

[0058] Clause 11. The fan installation assembly according to any one of clauses 1 to 10, further comprising a correction vane attached to the housing of the motor assembly, the correction vane being circumferentially spaced along the outer periphery of the housing.

[0051]

[0059] Clause 12. The fan installation assembly according to any one of clauses 1 to 11, wherein the vehicle is an aircraft.

[0052]

[0060] Clause 13. An aircraft, An air distribution system including a conduit and an axial flow fan assembly, the conduit being configured to accommodate an air flow supplied to or received from the interior cabin of the aircraft, the axial flow fan assembly being configured to propel the air flow through the conduit, the axial flow fan assembly comprising A motor assembly, An impeller including a hub and a plurality of blades attached to the hub, each of the blades having a toroidal shape forming a loop, and A case attached to the conduit and surrounding the impeller and the motor assembly.

[0053]

[0061] Clause 14. Each of the blades has a monolithic body including a first side and a second side opposite the first side, the monolithic body being twisted along the length of the monolithic body, the aircraft according to clause 13.

[0054]

[0062] Clause 15. The hub has a narrow portion and a wide portion extending from the narrow portion, the blade being attached to the narrow portion, the motor assembly being attached to the wide portion, the aircraft according to clause 13 or 14.

[0055]

[0063] Clause 16. The impeller and the motor assembly are disposed within a cavity of the case, the cavity being fluidly connected to an internal space of the conduit, the case defining an annular relief channel configured to receive a flow of the captured air stream, the aircraft according to any one of clauses 13 to 15.

[0056]

[0064] Clause 17. The air distribution system is part of an air conditioning system of the aircraft, the air distribution system communicating conditioned air as the air stream to passengers within the internal cabin, the aircraft according to any one of clauses 13 to 16.

[0057]

[0065] Clause 18. An axial flow fan assembly, a conduit mounted on a vehicle and configured to contain an air stream supplied to or received from an internal cabin of the vehicle, and an axial flow fan assembly configured to propel an air stream through the conduit, the axial flow fan assembly including a case, a motor assembly, and an impeller, the case defining a cavity fluidly connected to an internal space of the conduit, the impeller and the motor assembly being disposed within the cavity, comprising an axial flow fan assembly, the impeller including a hub and a plurality of blades attached to the hub, Each of the blades has a toroidal shape and forms a loop, Each of the blades includes a first airfoil section attached to the hub, a second airfoil section attached to the hub, and a tip section connecting the first airfoil section and the second airfoil section. The case is a fan installation assembly that defines an annular relief channel configured to receive the flow of the captured air stream.

[0058]

[0066] Clause 19. The first airfoil section of the blade is connected to the hub at respective first positions, the second airfoil section of the blade is connected to the hub at respective second positions, and the first position is between the tip of the hub and the second position along the hub axis of the hub. The fan installation assembly according to Clause 18.

[0059]

[0067] Clause 20. The annular relief channel is aligned with the blades of the impeller. The fan installation assembly according to Clause 18 or 19.

[0060]

[0068] For the description of the embodiments of the present disclosure, various terms related to space and direction such as upper, lower, downward, central, lateral, horizontal, vertical, forward, etc. may be used, but it should be understood that such terms are used only in relation to the orientation shown in the drawings. The orientation may be reversed, rotated, or otherwise changed, such as making the upper part the lower part, or vice versa, or making the horizontal vertical.

[0061]

[0069] As used herein, a structure, limitation, or element “configured to” perform an operation or action is structurally formed, configured, or adapted to correspond to the operation or action in particular. For the sake of clarity and to avoid misunderstanding, an object that can merely be modified to perform an operation or action is not “configured / set to” perform the operation or action herein.

[0062]

[0070] It should be understood that the above description is intended to be illustrative and not limiting. For example, the above-described embodiments (and / or aspects thereof) can be used in combination with each other. Further, many modifications can be made to the teachings of the various embodiments of the present disclosure to adapt to a particular situation or material without departing from the scope of the various embodiments of the present disclosure. The shape dimensions and types of materials described herein are intended to define the parameters of the various embodiments of the present disclosure, but these embodiments are exemplary rather than limiting. By reviewing the above description, many other embodiments will be apparent to those skilled in the art. Accordingly, the scope of the various embodiments of the present disclosure should be determined with reference to the appended claims along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms “including” and “in which” are used as plain synonyms of the terms “comprising” and “wherein” respectively in English. Further, terms such as “first,” “second,” and “third” are used merely as labels and are not intended to impose numerical requirements on their objects. Further, the limitations of the following claims are not described in means-plus-function format and are not intended to be construed under 35 U.S.C. § 112, paragraph (f), unless the limitation of the claim explicitly uses the recitation “means for” followed by a description of a function lacking further structure.

[0063]

[0071] In this specification, various embodiments of the present disclosure, including the best mode, are disclosed using examples, and enable those skilled in the art to implement various embodiments of the present disclosure, including the creation and use of any device or system and the execution of any integrated method. The patentable scope of various embodiments of the present disclosure is defined by the claims and may include other examples that those skilled in the art can conceive. Such other examples are intended to be within the scope of the claims if the examples have structural elements that do not differ from the language of the claims, or if the examples include equivalent structural elements that have only a slight difference from the language of the claims.

Claims

**Claim 1** A fan installation assembly (202), mounted on a vehicle (200) and configured to accommodate an air flow (604) supplied to or received from the interior cabin (206) of the vehicle, and an axial flow fan assembly (100) configured to propel the air flow through the conduit, the axial flow fan assembly including a case (102), a motor assembly (106), and an impeller (104), the case surrounding the impeller and the motor assembly and being attached to the conduit, the impeller including a hub (110) and a plurality of blades (112) attached to the hub, each of the blades having a toroidal shape forming a loop, the fan installation assembly (202) comprising the axial flow fan assembly. **Claim 2** Each of the blades (112) includes a first airfoil section (116) attached to the hub (110), a second airfoil section (118) attached to the hub, and a tip section (120) connecting the first airfoil section and the second airfoil section, the first airfoil section, the second airfoil section, and the tip section defining the loop, the fan installation assembly (202) according to claim 1. **Claim 3** The first airfoil section (116) of each of the blades (112) connects to the hub (110) at respective first positions (312), the second airfoil section (118) of each of the blades connects to the hub at respective second positions (314), the first position being between the tip (316) of the hub and the second position along the hub axis of the hub, the fan installation assembly (202) according to claim 2. **Claim 4** Each of the blades (112) has a monolithic body (302) including a first side (308) and a second side (310) opposite the first side, the monolithic body being twisted along the length of the monolithic body, the fan installation assembly (202) according to claim 2. **Claim 5** The hub (110) has a narrow portion (318) and a wide portion (320) extending from the narrow portion, the blade (112) is attached to the narrow portion, and the motor assembly (106) is attached to the wide portion. The fan installation assembly (202) according to claim 1.

6. The narrow portion (318) of the hub (110) has a cylindrical shape, and the wide portion (320) of the hub has a conical shape. The fan installation assembly (202) according to claim 5.

7. The impeller (104) and the motor assembly (106) are disposed within a cavity (108) of the case (102), the cavity is fluidly connected to an internal space (502) of the conduit (204), and the case defines an annular relief channel (504) configured to receive a flow of the captured air stream (604). The fan installation assembly (202) according to claim 1.

8. The annular relief channel (504) is aligned with the blade (112) of the impeller (104). The fan installation assembly (202) according to claim 7.

9. The diameter of the impeller (104) is at least 75% of the diameter of the cavity in a segment of the cavity (108) of the case (102) adjacent to the annular relief channel (504). The fan installation assembly (202) according to claim 7.

10. The fan installation assembly (202) according to claim 1, further comprising a flow conditioner (602) disposed upstream of the impeller (104) along a guiding direction (604) of the air stream (604) through the conduit (204).

11. The fan installation assembly (202) according to claim 1, further comprising a correction vane (508) attached to a housing (510) of the motor assembly (106), the correction vane (508) being circumferentially spaced along an outer periphery of the housing (510).

12. The vehicle (200) is an aircraft (700). The fan installation assembly (202) according to claim 1.

13. An aircraft (700), An air distribution system (210) including a duct (204) and an axial flow fan assembly (100), wherein the duct (204) is configured to accommodate an air flow (604) supplied to or received from the interior cabin (206) of the aircraft, and the axial flow fan assembly is configured to propel the air flow through the duct, and the axial flow fan assembly includes a motor assembly (106), an impeller (104) including a hub (110) and a plurality of blades (112) attached to the hub, each of the blades having a toroidal shape forming a loop, and an aircraft (700) including a case (102) attached to the duct and surrounding the impeller and the motor assembly. **Claim 14** The aircraft (700) according to claim 13, wherein each of the blades (112) has a monolithic body (302) including a first side (308) and a second side (310) opposite the first side, and the monolithic body is twisted along the length of the monolithic body. **Claim 15** The aircraft (700) according to claim 13, wherein the hub (110) has a narrow portion (318) and a wide portion (320) extending from the narrow portion, the blade (112) is attached to the narrow portion, and the motor assembly (106) is attached to the wide portion. **Claim 16** The aircraft (700) according to claim 13, wherein the impeller (104) and the motor assembly (106) are disposed within a cavity (108) of the case (102), the cavity is fluidly connected to an internal space (502) of the duct (204), and the case defines an annular relief channel (504) configured to receive a flow of the captured air flow (604). **Claim 17** The aircraft (700) according to claim 13, wherein the air distribution system (210) is part of an air conditioning system of the aircraft, and the air distribution system conveys conditioned air to passengers within the interior cabin (206) as the air flow (604). **Claim 18** A fan installation assembly (202), A duct (204) configured to be mounted on a vehicle (200) and accommodate an air flow (604) supplied to or received from an interior cabin (206) of the vehicle, and An axial fan assembly (100) configured to propel an air flow through the duct, the axial fan assembly including a case (102), a motor assembly (106), and an impeller (104), the case defining a cavity (108) fluidly connected to an internal space (502) of the duct, the impeller and the motor assembly being disposed within the cavity, the axial fan assembly being provided, The impeller includes a hub (110) and a plurality of blades (112) attached to the hub, Each of the blades has a toroidal shape and forms a loop, Each of the blades includes a first airfoil section (116) attached to the hub, a second airfoil section (118) attached to the hub, and a tip section (120) connecting the first airfoil section and the second airfoil section, The case defines an annular relief channel (504) configured to receive a flow of the captured air flow, a fan installation assembly (202).

19. The first airfoil section (116) of the blade (112) is connected to the hub (110) at respective first positions (312), the second airfoil section (118) of the blade is connected to the hub at respective second positions (314), and the first position is between a tip (316) of the hub and the second position along a hub axis of the hub, the fan installation assembly (202) according to claim 18.

20. The annular relief channel (504) is aligned with the blade (112) of the impeller (104), the fan installation assembly (202) according to claim 18.

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