Thrust generator

Abstract

To suppress noise of a cruise rotor.SOLUTION: A propulsion force generation device comprises a propeller section 30 which has a propeller 34 and a duct 38 covering a periphery of the propeller 34. The duct 38 is made up of a cylinder 50 arranged around the propeller 34, a hub 52 arranged inside the cylinder 50, and a plurality of duct stators 54 radially extended from the hub 52 to the cylinder 50. The hub 52 and each duct stator 54 are arranged posterior to the propeller 34.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a thrust generating device including a propeller and a duct surrounding the propeller. [Background technology]

[0002] Patent Document 1 discloses a VTOL aircraft equipped with multiple VTOL rotors and multiple cruise rotors. The cruise rotor has a motor, a propeller, and a duct. The duct has a cylinder, a hub, and multiple stators. The cylinder is arranged around the propeller. The hub is arranged inside the cylinder. Each stator extends radially from the hub to the cylinder. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2022 / 130501 Summary of the Invention [Problem to be solved by the invention]

[0004] In the VTOL aircraft of Patent Document 1, the stators of each duct are positioned in front of the propeller. In this structure, the stators obstruct the flow of air drawn into the propeller, which disrupts the flow of air drawn into the propeller and generates noise.

[0005] The present invention aims to solve the above-mentioned problems. [Means for solving the problem]

[0006] An aspect of the present invention is a thrust generating device having one or more propellers that generate thrust for propelling an aircraft forward, the thrust generating device comprising a propeller section having the propeller and a duct surrounding the propeller, the duct having a cylinder arranged around the propeller, a hub arranged inside the cylinder, and a plurality of stators extending radially from the hub to the cylinder, the hub and each of the stators being arranged rearward of the propeller. [Effects of the Invention]

[0007] According to the present invention, noise from the cruise rotor can be suppressed. [Brief explanation of the drawings]

[0008] [Figure 1] Figure 1 is an external view of a VTOL aircraft. [Figure 2] FIG. 2 is a schematic diagram showing a simplified structure of the cruise rotor of the thrust generating device according to the first embodiment. [Figure 3] FIG. 3 is a simplified schematic diagram of the mounting structure of the duct hub to the shaft member. [Figure 4] FIG. 4 is a rear view of the thrust generating device. [Figure 5] FIG. 5 is a rear view of a thrust generating device having a different structure from that shown in FIG. [Figure 6] FIG. 6 is a schematic diagram showing a simplified structure of a cruise rotor of a thrust generating device according to a second embodiment. [Figure 7] FIG. 7 is a schematic diagram showing a simplified structure of a cruise rotor of a thrust generating device according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] [1 VTOL aircraft 10 configuration] 1 is an external view of a VTOL aircraft 10. The VTOL aircraft 10 is, for example, an electric vertical take-off and landing aircraft, or so-called eVTOL aircraft. The VTOL aircraft 10 includes a fuselage 12, a front wing 14, a rear wing 16, two booms 18, eight VTOL rotors 20, and two cruise rotors 22.

[0010] In this specification, the direction in which the VTOL aircraft 10 flies when cruising is referred to as "forward," and the opposite direction of "forward" is referred to as "rearward." Furthermore, flying the VTOL aircraft 10 forward is referred to as "forward movement."

[0011] The front wings 14 are connected to the front of the fuselage 12. The rear wings 16 are connected to the rear of the fuselage 12. The front wings 14 and the rear wings 16 generate lift as the VTOL aircraft 10 moves forward.

[0012] Of the two booms 18, the boom 18R is disposed on the right side of the fuselage 12. Of the two booms 18, the boom 18L is disposed on the left side of the fuselage 12. Each boom 18 extends in the front-to-rear direction.

[0013] Four VTOL rotors 20 are arranged on the boom 18L in sequence toward the rear. Similarly, four VTOL rotors 20 are arranged on the boom 18R in sequence toward the rear. Each VTOL rotor 20 is used in the takeoff process, the vertical ascent process, the transition from the ascent process to cruising, the transition from cruising to descent process, the vertical descent process, the landing process, and the hovering flight process. Each VTOL rotor 20 generates vertical thrust.

[0014] Two cruise rotors 22 are arranged side by side on the rear wing 16. Each cruise rotor 22 is used during the cruise phase, the transition from ascent to cruise, and the transition from cruise to descent. Each cruise rotor 22 generates horizontal thrust. The one or more cruise rotors 22 provided on the VTOL aircraft 10 are referred to as a thrust generating unit 24.

[0015] The thrust generating device 24 causes air to flow from the front to the rear, thereby generating thrust for flying the VTOL aircraft 10 in a substantially horizontal direction.

[0016] [2 First embodiment of thrust generating device 24] Figure 2 is a schematic diagram illustrating a simplified structure of the cruise rotor 22 of the thrust generating device 24 according to the first embodiment. The schematic diagram in Figure 2 shows the cruise rotor 22 viewed from above, with the cylinder 50 of the duct 38 cut into upper and lower halves. The cruise rotor 22 has one or more support members 26, a motor 28, and a propeller unit 30. The propeller unit 30 has a propeller 34, a shaft member 36, and a duct 38.

[0017] The propeller section 30 is supported by the rear wing 16 via a support member 26 and a motor 28. The axis of the motor 28, the axis of the propeller 34 (axis of the blade hub 46), the axis of the shaft member 36, and the axis of the duct 38 (axis of the cylinder 50 and the duct hub 52) are all the same.

[0018] The motor 28 is supported by the support member 26. The motor 28 is connected to the rear end of the support member 26. The support member 26 is, for example, a pipe-shaped shaft. The support member 26 extends in the front-to-rear direction. The support member 26 is housed inside the rear wing 16 and supported by a member inside the rear wing 16. In other words, the motor 28 is supported by the rear wing 16 via the support member 26. A rotation shaft 40 of the motor 28 extends rearward.

[0019] A harness 42 for supplying power is connected to the motor 28. The harness 42 runs from a power source (not shown) through the inside of the rear wing 16 and the support member 26, and is connected to the motor 28.

[0020] The propeller 34 has a blade hub 46 and a plurality of blades 48. The propeller 34 is disposed rearward of the rear wing 16 and the motor 28. The blade hub 46 is disposed at the center of the propeller 34. The blade hub 46 is connected to the rear end of the rotary shaft 40 of the motor 28. Each blade 48 extends radially from the blade hub 46. Each blade 48 is connected to the outer circumferential surface of the blade hub 46.

[0021] The shaft member 36 is disposed rearward of the propeller 34. The shaft member 36 has, for example, a pipe-shaped shaft portion. The shaft member 36 is connected to the blade hub 46 and extends rearward from the blade hub 46. Details of the shaft member 36 will be described later.

[0022] The duct 38 has a cylinder 50, a duct hub 52, and multiple duct stators 54. The cylinder 50 is open at the front and rear. The cylinder 50 is disposed around the propeller 34. Specifically, the cylinder 50 is disposed so as to intersect with the direction in which each blade 48 extends. The cylinder 50 covers the periphery of the propeller 34 and the space behind the propeller 34. The duct hub 52 is disposed inside the cylinder 50 and behind the propeller 34. The duct hub 52 is connected to the shaft member 36. Each duct stator 54 extends radially from the duct hub 52 to the cylinder 50. Each duct stator 54 is connected to the outer circumferential surface of the duct hub 52 and the inner circumferential surface of the cylinder 50. Each duct stator 54 is disposed behind the propeller 34.

[0023] 3 is a simplified schematic diagram of the mounting structure of the duct hub 52 to the shaft member 36. The duct stator 54 is omitted from FIG. 3. The duct hub 52 is connected to the shaft member 36 via a front bearing 66 and a rear bearing 68. The front bearing 66 is disposed forward of the rear bearing 68. The outer diameter of the front bearing 66 is larger than the outer diameter of the rear bearing 68.

[0024] The shaft member 36 has an attachment portion 60, a large diameter portion 62, and a small diameter portion 64. The attachment portion 60 is connected to the rear end of the blade hub 46. The large diameter portion 62 and the small diameter portion 64 are pipe-shaped shafts. The large diameter portion 62 extends rearward from the rear end of the attachment portion 60. The small diameter portion 64 extends rearward from the rear end of the large diameter portion 62. The outer diameter of the large diameter portion 62 is larger than the outer diameter of the small diameter portion 64.

[0025] The small diameter portion 64 is press-fitted into the inner ring 66a of the front bearing 66 and the inner ring 68a of the rear bearing 68. The small diameter portion 64 is also inserted through a front collar 70 and a rear collar 72. A nut 74 is attached to the rear end of the small diameter portion 64. The inner ring 66a of the front bearing 66 abuts against the rear end of the large diameter portion 62, thereby positioning the front bearing 66. The front collar 70 is interposed between the inner ring 66a of the front bearing 66 and the inner ring 68a of the rear bearing 68. The front collar 70 abuts against the rear end of the inner ring 66a of the front bearing 66 and the front end of the inner ring 68a of the rear bearing 68. The inner ring 68a of the rear bearing 68 abuts against the rear end of the front collar 70, thereby positioning the rear bearing 68. The rear collar 72 is interposed between the rear bearing 68 and the nut 74. The rear collar 72 abuts against the rear end of the inner ring 68a of the rear bearing 68 and the front end of the nut 74. The nut 74 is positioned by abutting against the rear end of the rear collar 72.

[0026] A through hole 80 is formed in the duct hub 52, penetrating in the front-to-rear direction. The through hole 80 has a large diameter hole 82 and a small diameter hole 84. The inner diameter of the large diameter hole 82 is larger than the inner diameter of the small diameter hole 84. A step 86 is formed at the boundary between the large diameter hole 82 and the small diameter hole 84.

[0027] The front bearing 66 and the rear bearing 68 are attached to the shaft member 36 in advance. This shaft member 36 is inserted into the through-hole 80 from the front. Then, the rear bearing 68 is press-fitted into the small diameter hole 84. Furthermore, the front bearing 66 is press-fitted into the large diameter hole 82. The rear end of the front bearing 66 abuts against the step 86, thereby positioning the duct hub 52 with respect to the shaft member 36. Furthermore, a snap ring 78 that abuts against the front end of the front bearing 66 is fitted into the duct hub 52.

[0028] With the above structure, the duct 38 is connected to the rear wing 16 via two bearings (the front bearing 66 and the rear bearing 68), the shaft member 36, the propeller 34, the motor 28, and the support member 26. In other words, the duct 38 is supported by the rear wing 16.

[0029] FIG. 4 is a rear view of the thrust generating unit 24. A fairing 88 is attached to the rear end of the shaft member 36 of each cruise rotor 22 (the rear end of the small diameter portion 64). The cylinder 50L of the left cruise rotor 22L and the cylinder 50R of the right cruise rotor 22R are connected to each other by a connector 90. The connector 90 has a left connector 90L and a right connector 90R. The left connector 90L is connected to the right end of the outer circumferential surface of the cylinder 50L and protrudes to the right. The right connector 90R is connected to the left end of the outer circumferential surface of the cylinder 50R and protrudes to the left. The left connector 90L and the right connector 90R are connected to each other. The cylinders 50L and 50R may be connected directly without the connector 90.

[0030] As described above, the duct 38 is connected to the shaft member 36 via two bearings (the front bearing 66 and the rear bearing 68). If the duct 38 were not connected to any part other than the shaft member 36, the duct 38 would be rotatable relative to the shaft member 36. In this embodiment, as shown in FIG. 4, two ducts 38, one on the left and one on the right, are connected to each other. With this structure, each duct 38 does not rotate.

[0031] As shown in Figure 4, the duct 38 preferably has four duct stators 54. The four duct stators 54 are arranged at equal intervals (90-degree intervals) around the periphery of the duct hub 52. Duct stator 54a extends leftward from the duct hub 52 toward the cylinder 50. Duct stator 54b extends rightward from the duct hub 52 toward the cylinder 50. Duct stator 54c extends upward from the duct hub 52 toward the cylinder 50. Duct stator 54d extends downward from the duct hub 52 toward the cylinder 50.

[0032] As shown in Figure 4, from left to right, the duct stator 54a (first stator) of the cruise rotor 22L, the duct hub 52 of the cruise rotor 22L, the duct stator 54b (first stator) of the cruise rotor 22L, the connector 90, the duct stator 54a (second stator) of the cruise rotor 22R, the duct hub 52 of the cruise rotor 22R, and the duct stator 54b (second stator) of the cruise rotor 22R are aligned in a straight line. This structure increases the rigidity of each cylinder 50. This structure also reduces the moment acting on the support points (support members 26) of the cruise rotor 22.

[0033] 5, the duct 38 may have three duct stators 54. In this embodiment, it is preferable that, from left to right, the duct hub 52 of the cruise rotor 22L, one duct stator 54 of the cruise rotor 22L, the connector 90, one duct stator 54 of the cruise rotor 22R, and the duct hub 52 of the cruise rotor 22R are aligned in a straight line. This structure reduces the moment acting on the support point (support member 26) of the cruise rotor 22.

[0034] As described above, in the first embodiment, each duct stator 54 is disposed rearward of the propeller 34. Therefore, each duct stator 54 does not obstruct the flow of air drawn into the propeller 34 from the front as the propeller 34 rotates. Therefore, according to the first embodiment, noise caused by the duct stators 54 can be suppressed. Furthermore, according to the first embodiment, it is possible to prevent the amount of air drawn into the propeller 34 from being restricted by the duct stators 54.

[0035] [3 Second embodiment of thrust generating device 24] FIG. 6 is a simplified schematic diagram of the structure of the cruise rotor 22 of the thrust generating device 24 according to the second embodiment. The schematic diagram in FIG. 6 shows the cruise rotor 22, with the cylinder 50 of the duct 38, the blade hub 46, and the motor 94 cut into upper and lower halves, as viewed from above. In the second embodiment, the same components as in the first embodiment are designated by the same reference numerals. The cruise rotor 22 includes one or more support members 92, a motor 94, and a propeller section 30.

[0036] The propeller section 30 has a propeller 34 and a duct 38. The propeller section 30 is supported by the rear wing 16 via a support member 92. As shown in FIG. 6 , the propeller 34 is disposed rearward of the motor 94. The duct hub 52 and each duct stator 54 are disposed rearward of the propeller 34. In the second embodiment, the duct 38 is directly connected to the support member 92.

[0037] The motor 94 is supported by a support member 92. The motor 94 is an outer rotor motor having a rotor 94R outside a stator 94S. The motor 94 is connected to the rear end of the support member 92. The support member 92 has, for example, a pipe-shaped shaft. The support member 92 extends in the fore-and-aft direction. The support member 92 penetrates the centers of the stator 94S, the rotor 94R, the rotating shaft 40, and the propeller 34, and is connected to the duct hub 52. A portion of the support member 92 is housed inside the rear wing 16 and is supported by a member inside the rear wing 16.

[0038] In the second embodiment, each duct stator 54 is disposed rearward of the propeller 34. Therefore, each duct stator 54 does not obstruct the flow of air drawn into the propeller 34 from the front as the propeller 34 rotates. Therefore, according to the second embodiment, noise caused by the duct stators 54 can be suppressed. Furthermore, according to the second embodiment, it is possible to prevent the amount of air drawn into the propeller 34 from being restricted by the duct stators 54.

[0039] In the second embodiment, a connector 90 shown in Fig. 4 may be provided between two ducts 38 arranged side by side. Also, each duct stator 54 may be arranged as shown in Fig. 4 or Fig. 5.

[0040] [4. Third embodiment of thrust generating device 24] FIG. 7 is a simplified schematic diagram of the structure of the cruise rotor 22 of the thrust generating device 24 according to the third embodiment. The schematic diagram in FIG. 7 shows the cruise rotor 22 viewed from above, with the cylinder 50 of the duct 38 and the blade hub 46 cut into upper and lower halves. In the third embodiment, the same components as in the first embodiment are designated by the same reference numerals. The cruise rotor 22 has two support members 96, a motor 28, and a propeller unit 30.

[0041] The propeller section 30 has a propeller 34 and a duct 38. The propeller section 30 is supported by the rear wing 16 via a support member 96. As shown in Figure 7, the propeller 34 is disposed in front of the motor 28. The duct hub 52 and each duct stator 54 are disposed behind the propeller 34.

[0042] The two support members 96 are stays. One support member 96 is connected to the left side of the outer circumferential surface of the cylinder 50. The other support member 96 is connected to the right side of the outer circumferential surface of the cylinder 50. In addition, each support member 96 is connected to the rear wing 16. With this structure, the duct 38 is supported by the rear wing 16 via the two support members 96.

[0043] The motor 28 is housed inside the duct hub 52. The rotating shaft 40 of the motor 28 extends forward. The front end of the rotating shaft 40 is connected to the blade hub 46. The motor 28 is supported by the rear wing 16 via the duct 38 and two support members 96.

[0044] The harness 42 runs from a power source (not shown) through the inside of the rear wing 16 , the support member 96 , the cylinder 50 and the duct hub 52 , and is connected to the motor 28 .

[0045] In the third embodiment, each duct stator 54 is disposed rearward of the propeller 34. Therefore, each duct stator 54 does not obstruct the flow of air drawn into the propeller 34 from the front as the propeller 34 rotates. Therefore, according to the third embodiment, noise caused by the duct stators 54 can be suppressed. Furthermore, according to the third embodiment, it is possible to prevent the amount of air drawn into the propeller 34 from being restricted by the duct stators 54.

[0046] In the third embodiment, a common support member 96 may be provided between two ducts 38 arranged side by side. Also, each duct stator 54 may be arranged as shown in FIG. 4 or FIG. 5.

[0047] [5 Inventions Obtained from the Embodiments] The invention that can be understood from the above embodiment will be described below.

[0048] An aspect of the present invention is a thrust generating device (24) having one or more propellers (34) that generate thrust for propelling an aircraft (10), the thrust generating device (24) comprising a propeller section (30) having the propeller and a duct (38) surrounding the propeller, the duct having a cylinder (50) arranged around the propeller, a hub (52) arranged inside the cylinder, and a plurality of stators (54) extending radially from the hub to the cylinder, the hub and each of the stators being arranged rearward of the propeller.

[0049] According to the above configuration, noise caused by the stator can be suppressed, and the amount of air drawn into the propeller can be prevented from being restricted by the stator.

[0050] In the above aspect, the propeller section may be supported by and positioned aft of a rear wing (16) of the aircraft.

[0051] In the above aspect, the thrust generating device may include a motor (28, 94) having a rotating shaft (40) connected to the propeller and rotating the propeller, the motor being supported by the rear wing, and the propeller section being disposed rearward of the motor.

[0052] In the above aspect, the hub may be connected to the rotating shaft of the motor via bearings (66, 68).

[0053] According to the above configuration, the propeller, which is the vibration source, is located close to the support point of the support member (26), so that vibration of the entire thrust generating device can be suppressed.

[0054] In the above aspect, the propeller portion may have a shaft (36) protruding rearward from the propeller, and the hub may be connected to the shaft via the bearing.

[0055] In the above aspect, the thrust generating device may include an outer rotor motor (94) as the motor, and a shaft (92) that passes through the center of the rotation axis of the outer rotor motor and connects the rear wing and the hub to each other.

[0056] In the above aspect, the thrust generating device may include a motor having a rotating shaft connected to the propeller and rotating the propeller, the duct may be supported by the rear wing, and the motor may be disposed rearward of the propeller section.

[0057] In the above aspect, the duct may be supported by a stay (96) extending from the rear wing, and the motor may be supported by the duct.

[0058] In the above aspect, a harness (42) may be provided to energize the motor, and the harness may pass through the inside of each of the rear wing, the stay, the cylinder, one of the stators, and the hub, and be connected to the motor.

[0059] In the above aspect, the thrust generating device may include a first propeller section and a second propeller section as the propeller sections, and a connector (90) arranged between the first propeller section and the second propeller section and connecting the first propeller section and the second propeller section, wherein the first propeller section has a first duct as the duct, and the second propeller section has a second duct as the duct, the first propeller section and the second propeller section are aligned in the width direction of the aircraft, and the connector connects the first duct and the second duct to each other.

[0060] In the above aspect, the first duct has a first cylinder as the cylinder, a first hub as the hub, and two first stators (54a, 54b) as the stators, the second duct has a second cylinder as the cylinder, a second hub as the hub, and two second stators (54a, 54b) as the stators, the connector connects the first cylinder and the second cylinder to each other, and the connector, the first hub, the two first stators, and the No. 2 The hub and the two second stators may be arranged in a straight line.

[0061] According to the above configuration, the rigidity of each cylinder is increased, and the moment acting on the support points of the cruise rotor is reduced.

[0062] The present invention is not limited to the above disclosure, and various configurations can be adopted without departing from the gist of the present invention. [Explanation of symbols]

[0063] 10...VTOL aircraft (aircraft) 16...rear wing 24...Thrust generating device 28...Motor 30...Propeller section 34...Propeller 36... Shaft member (shaft) 38... Duct 40...Rotating shaft 42...Harness 50...Cylinder (1st cylinder, 2nd cylinder) 52...Duct hub (hub, 1st hub, 1st hub) 54...Duct stator (stator) 54a, 54b...Duct stators (first stator, second stator) 66...Front bearing (bearing) 68...Rear bearing (bearing) 90...Connector 94...Outer rotor motor (motor) 92...Support member (shaft) 96...Support member (stay)

Claims

1. A thrust generating device comprising one or more propellers for generating thrust for propelling an aircraft, a propeller section having the propeller and a duct surrounding the propeller; a motor having a rotary shaft connected to the propeller and rotating the propeller; Equipped with the motor is supported by a rear wing of the aircraft; the propeller unit is disposed rearward of the motor and the rear wing, the duct has a cylinder disposed around the propeller, a hub disposed inside the cylinder, and a plurality of stators extending radially from the hub to the cylinder, the hub and each of the stators are disposed aft of the propeller; The thrust generating device, wherein the hub is connected to the rotating shaft of the motor via a bearing.

2. 2. The thrust generating device according to claim 1, The propeller section is supported by the rear wing of the aircraft.

3. 2. The thrust generating device according to claim 1, The propeller portion has a shaft protruding rearward from the propeller, The hub is connected to the shaft via the bearing.

4. A thrust generating device having one or more propellers that generate thrust for propelling an aircraft forward, a propeller section having the propeller and a duct surrounding the propeller; a motor having a rotary shaft connected to the propeller and rotating the propeller; Equipped with the motor is supported by a rear wing of the aircraft; the propeller unit is disposed rearward of the motor and the rear wing, the duct has a cylinder disposed around the propeller, a hub disposed inside the cylinder, and a plurality of stators extending radially from the hub to the cylinder, the hub and each of the stators are disposed aft of the propeller; Furthermore, an outer rotor type motor as the motor; a shaft that passes through the center of the rotary shaft of the outer rotor motor and connects the rear wing and the hub to each other; A thrust generating device comprising:

5. The thrust generating device according to any one of claims 1 to 4, a first propeller portion and a second propeller portion as the propeller portion; a connector disposed between the first propeller portion and the second propeller portion and connecting the first propeller portion and the second propeller portion; Equipped with The first propeller portion has a first duct as the duct, The second propeller portion has a second duct as the duct, the first propeller section and the second propeller section are aligned in a width direction of the aircraft, The connector connects the first duct and the second duct to each other.

6. 6. The thrust generating device according to claim 5, the first duct includes a first cylinder as the cylinder, a first hub as the hub, and two first stators as the stators, the second duct includes a second cylinder as the cylinder, a second hub as the hub, and two second stators as the stators, the connector connects the first cylinder and the second cylinder to each other, A thrust generating device, wherein the connector, the first hub, the two first stators, the second hub, and the two second stators are arranged on a straight line.

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