Redundant system propulsion device and electric aircraft

Abstract

The present invention provides a redundant system propulsion device and an electric aircraft capable of appropriately cooling a plurality of electric motors without increasing the size of a nacelle. In a redundant system propulsion device (20) having a propeller (21) and a plurality of electric motors (23) driving the propeller (21), the plurality of electric motors (23) are arranged around the propeller shaft (21a) at a plurality of positions in the extending direction of the propeller shaft (21a) of the propeller (21), at least one each, and when viewed from the side of the propeller (21) in the direction along the propeller shaft (21a), the plurality of electric motors (23) are respectively arranged at positions where each output shaft (23a) of the plurality of electric motors (23) does not overlap with any of the output shafts (23a) of other electric motors (23).

Description

Technical Field

[0001] The present invention relates to a redundant system propulsion device that utilizes multiple electric motors to drive propellers and an electric aircraft equipped with the device. Background Art

[0002] In an electric aircraft that obtains propulsion force from a propeller driven by an electric motor, it is easy to use a plurality of electric motors.

[0003] Therefore, it is possible to relatively easily configure a propulsion device having redundancy by providing a plurality of electric motors for driving the propellers (hereinafter referred to as a redundant system propulsion device).

[0004] As a method of pluralizing electric motors, for example, as described in Patent Documents 1 and 2, there is known a method of arranging a plurality of electric motors in parallel in the circumferential direction around an output shaft (hereinafter referred to as radial arrangement).

[0005] There is also a method of arranging a plurality of electric motors in series and in parallel (hereinafter referred to as axial arrangement).

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 2010-41747

[0009] Patent Document 2: Japanese Patent Application Laid-Open No. 2007-325479 Summary of the Invention

[0010] Technical issues

[0011] However, for example, if the above radial configuration is applied to the configuration of multiple electric motors in a redundant system propulsion device of an electric aircraft, such as Figure 10 As shown, a plurality of electric motors 102 are arranged around the propeller shaft 101 of the propeller 100 .

[0012] Moreover, when the plurality of electric motors 102 are arranged radially in this manner, if the plurality of electric motors 102 are arranged radially in such a manner that the first gear 104 respectively mounted on the output shaft of each electric motor 102 is meshed with the second gear 105 mounted at a position in the extension direction of the propeller shaft 101, then many electric motors 102 must be arranged around the propeller shaft 101, and the diameter of the circumscribed circle of the plurality of electric motors 102 becomes larger.

[0013] Therefore, the size of the pod 103 that houses the electric motor 102 and the like increases. However, as the size of the pod 103 increases, the air resistance caused by the pod 103 increases accordingly, and the resistance to the electric aircraft increases.

[0014] On the other hand, if the above axial configuration is applied to the configuration of multiple electric motors in a redundant system propulsion device of an electric aircraft, such as Figure 11 As shown, the electric motor 102 on the rear side (i.e., the side away from the propeller 100) is directly subjected to the heat of the electric motor 102 on the front side (i.e., the side close to the propeller 100) flowing along with the air flow generated by the rotation of the propeller 100, so the cooling efficiency of the electric motor 102 on the rear side is reduced.

[0015] Therefore, the rear electric motor 102 may suffer from reduced driving performance or burn out depending on circumstances.

[0016] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a redundant system propulsion device capable of appropriately cooling a plurality of electric motors without increasing the size of a nacelle, and an electric aircraft equipped with the same.

[0017] Technical Solution

[0018] In order to solve the above-mentioned problem, the first aspect of the invention is a redundant system propulsion device, characterized in that:

[0019] The redundant system propulsion device includes a propeller and a plurality of electric motors for driving the propeller.

[0020] The plurality of electric motors are arranged around the propeller shaft at a plurality of positions in the direction in which the propeller shaft extends, with at least one electric motor disposed therearound.

[0021] Furthermore, when viewed in a direction along the propeller shaft from the propeller side, the plurality of electric motors are arranged at positions where the output shafts of the plurality of electric motors do not overlap with the output shafts of other electric motors.

[0022] The second aspect of the invention is a redundant system propulsion device, characterized in that:

[0023] The redundant system propulsion device includes a propeller and a plurality of electric motors for driving the propeller.

[0024] The plurality of electric motors are arranged at a plurality of positions relative to the propeller shaft of the propeller in the extending direction thereof, at one position of the plurality of positions, one electric motor is directly connected to the propeller shaft of the propeller, and at the other positions, at least one electric motor is arranged around the propeller shaft.

[0025] Furthermore, when viewed in a direction along the propeller shaft from the propeller side, the plurality of electric motors are arranged at positions where the output shafts of the plurality of electric motors do not overlap with the output shafts of other electric motors.

[0026] The invention according to a third aspect is the redundant system propulsion device according to the first aspect or the second aspect, wherein the plurality of positions are two positions.

[0027] The invention of a fourth aspect is the redundant system propulsion device according to the third aspect, wherein the number of the electric motors on the side close to the propeller is greater than the number of the electric motors on the side far from the propeller.

[0028] The invention of the fifth aspect is characterized in that, in addition to the redundant system propulsion device according to the first aspect or the second aspect,

[0029] The multiple positions are three or more positions,

[0030] The redundant system propulsion device is configured such that the closer to the propeller, the greater the number of the electric motors.

[0031] The invention of the sixth aspect is characterized in that, in addition to the redundant system propulsion device according to the second aspect,

[0032] The multiple positions are two or more positions,

[0033] When viewed in a direction along the propeller shaft from the propeller side, the electric motor on the side farthest from the propeller is provided as one of the electric motors directly connected to the propeller shaft of the propeller.

[0034] The invention of the seventh aspect is characterized in that, in the redundant system propulsion device according to any one of the first to sixth aspects,

[0035] The plurality of electric motors are housed in the pod,

[0036] An air guide plate for guiding air flowing in from an air inlet to each of the electric motors is provided in the nacelle.

[0037] An eighth aspect of the invention is an electric aircraft characterized in that:

[0038] The electric aircraft includes the redundant system propulsion device according to any one of the first to seventh aspects.

[0039] Effects of the Invention

[0040] According to the present invention, in a redundant system propulsion device and an electric aircraft equipped with the same, a plurality of electric motors can be appropriately cooled without increasing the size of the nacelle. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is a perspective view showing the appearance of an example of an electric aircraft.

[0042] Figure 2A 1 is a perspective view showing a configuration example of a redundant system propulsion device according to this embodiment. Figure 2B This is a front view showing a configuration example of a redundant system propulsion device according to this embodiment.

[0043] Figure 3 (A) is a perspective view showing another structural example of the redundant system propulsion device of this embodiment, Figure 3 (B) is a front view showing a configuration example of a redundant system propulsion device according to this embodiment.

[0044] Figure 4 (A) is a perspective view showing another structural example of the redundant system propulsion device of this embodiment, Figure 4 (B) is a front view showing another configuration example of the redundant system propulsion device according to the present embodiment.

[0045] Figure 5 (A) is a perspective view showing another structural example of the redundant system propulsion device of this embodiment, Figure 5 (B) is a front view showing another configuration example of the redundant system propulsion device according to the present embodiment.

[0046] Figure 6 (A) is a perspective view showing another configuration example of the redundant system propulsion device of this embodiment. Figure 6 (B) is a front view showing another configuration example of the redundant system propulsion device according to the present embodiment.

[0047] Figure 7 This is a front view showing a structural example of an air inlet or a wind deflector provided in a pod of a redundant system propulsion device.

[0048] Figure 8 It is a perspective view showing another configuration example of the redundant system propulsion device according to the present embodiment.

[0049] Figure 9 (A) Figure 9(B) is a diagram for explaining the degree of curvature of the air guide plate.

[0050] Figure 10 This is a diagram showing a state where a plurality of electric motors are radially arranged around the propeller shaft.

[0051] Figure 11 This is a diagram showing a state where a plurality of electric motors are arranged in the axial direction along the propeller shaft.

[0052] Explanation of symbols

[0053] 10 Electric aircraft

[0054] 20 Redundant propulsion system

[0055] 21 Propeller

[0056] 21a Propeller shaft

[0057] 22 pods

[0058] 22a Air inlet

[0059] 22b Air deflector

[0060] 23 Electric Motor

[0061] 23a Output shaft DETAILED DESCRIPTION

[0062] Hereinafter, embodiments of a redundant system propulsion device and an electric aircraft according to the present invention will be described with reference to the accompanying drawings.

[0063] In the following description, the nose side of the electric aircraft is referred to as the front side, and the tail side is referred to as the rear side.

[0064] Figure 1 This is a perspective view showing the appearance of an example of an electric aircraft.

[0065] The electric aircraft 10 is configured such that a redundant system propulsion device 20 including a propeller 21, a pod 22, and a plurality of electric motors 23 described later is mounted on a wing 11, and the propeller 21 is driven by the plurality of electric motors 23 to obtain propulsion force. Figure 1 The redundant system propulsion device 20 is shown as being mounted on a fixed wing, but the present invention is not limited thereto. For example, the redundant system propulsion device 20 may be mounted on a folding wing or a movable wing such as a tilt wing. Furthermore, the electric aircraft 10 may be a drone.

[0066] Figure 2A and 2B 1 is a diagram showing a configuration example of a redundant system propulsion device according to this embodiment. Figure 2AIt's a stereogram. Figure 2B It is the main view.

[0067] In the redundant system propulsion device 20 of the present embodiment, the electric motors 23 for driving the propellers 21 are arranged as a redundant system motor arrangement, and the propellers 21 are driven by the plurality of electric motors 23A to 23E.

[0068] Specifically, in this configuration example, three electric motors 23A to 23C are located forwardly within the pod 22 of the redundant system propulsion unit 20, and two electric motors 23D and 23E are located aft. Furthermore, each electric motor 23 is arranged so that a first gear 24 attached to an output shaft 23a of each electric motor 23 meshes with a second gear 25 fixed to the forward and aft sides of the propeller shaft 21a, respectively.

[0069] Thus, in this configuration example, the plurality of electric motors 23 are disposed around the propeller shaft 21 a at a plurality of positions in the extending direction (ie, the front-rear direction) of the propeller shaft 21 a of the propeller 21 .

[0070] In addition, instead of arranging a plurality of electric motors 23 at a plurality of positions in the extending direction of the propeller shaft 21a of the propeller 21 as in the above-mentioned configuration example, for example Figure 3 As shown in (A), although a plurality of electric motors 23 are arranged at a plurality of positions in the extending direction relative to the propeller shaft 21a of the propeller 21, it is also possible to configure each electric motor 23 to be only one (at Figure 3 In (A), it is the electric motor 23D).

[0071] It should be noted that although Figure 3 (A) shows the case where there are four electric motors 23, but the same applies to cases other than four. Figure 3 (A) shows a case where one electric motor 23 is arranged at one of a plurality of positions in the extending direction of the propeller shaft 21 a , but a configuration in which one electric motor 23 is arranged at each of a plurality of positions is also possible.

[0072] Thus, in the redundant system propulsion device 20 of this embodiment, the plurality of electric motors 23 are arranged around the propeller shaft 21a at least one each at a plurality of positions in the extending direction (ie, the front-rear direction) of the propeller shaft 21a of the propeller 21.

[0073] Furthermore, the electric motors 23 are driven by respective controllers (not shown). The propeller shaft 21 a is rotated by driving the electric motors 23 , thereby driving the propeller 21 to rotate around the propeller shaft 21 a .

[0074] In addition, if Figure 2B and Figure 3 As shown in (B), in the redundant system propulsion device 20 of the present embodiment, when viewed from the side of the propeller 21 along the propeller shaft 21a (i.e., when viewed from the front to the rear), the plurality of electric motors 23 are respectively arranged at positions where the output shafts 23a of the plurality of electric motors 23 do not overlap with any of the output shafts 23a of other electric motors 23.

[0075] Next, the effects of the redundant system propulsion device 20 of this embodiment and the electric aircraft 10 equipped with the redundant system propulsion device 20 will be described. Figure 2A 、 Figure 2B The structural example shown is explained, but the following Figure 3 (A) Figure 3 The structural example shown in (B) is described in the same manner.

[0076] For example, in Figure 2A In the example of the structure shown, three electric motors 23 and two electric motors 23 are respectively dispersed in the front and back and radially arranged. In addition, when three (or two) electric motors 23 are arranged in the radial direction, the same as in the example Figure 10 Compared with the case where five electric motors 102 are radially arranged at one position in the extending direction of the propeller shaft 101 as shown, even if the diameter of the second gear 25 is reduced, the electric motors 23 do not interfere with each other, so the diameter of the second gear 25 can be reduced.

[0077] Therefore, since the diameter of the circumscribed circle of the three (or two) electric motors 23 arranged around the second gear 25 can be reduced, the size of the pod 22 that accommodates these electric motors 23 and the like can be kept small.

[0078] Thus, in the redundant system propulsion device 20 and the electric aircraft 10 of the present embodiment, it is possible to prevent the size of the nacelle 22 that houses the electric motor 23 and the like from increasing.

[0079] Furthermore, in the redundant system propulsion unit 20 and the electric aircraft 10 of the present embodiment, as described above, the plurality of electric motors 23 of the redundant system propulsion unit 20 are arranged at positions where the output shafts 23 a of each of the plurality of electric motors 23 do not overlap with the output shafts 23 a of any of the other electric motors 23 when viewed from the propeller 21 side in the direction along the propeller shaft 21 a.

[0080] Therefore, even if the heat of the front electric motor 23 flows rearward along with the air flow generated by the rotation of the propeller 21 , the rear electric motor 23 is not directly exposed to the heat.

[0081] That is, the rear electric motor 23 is not subjected to the heat of the front electric motor 23 , or even if subjected to the heat, it is subjected to only a part of the heat.

[0082] Therefore, the airflow generated by the rotation of the propeller 21 can sufficiently cool not only the front electric motor 23 but also the rear electric motor 23 , and thus the plurality of electric motors 23 can be appropriately cooled.

[0083] As described above, the redundant system propulsion device 20 and the electric aircraft 10 equipped with the same according to the present invention can appropriately cool the plurality of electric motors 23 driving the propellers 21 by the airflow generated by the rotation of the propellers 21 without increasing the size of the nacelle 22 .

[0084] Therefore, while each electric motor 23 can be sufficiently cooled, the air resistance caused by the nacelle 22 can be suppressed to a lower level, and thus an increase in the resistance to the electric aircraft 10 can be reliably prevented.

[0085] It should be explained that Figure 2A 、 Figure 2B In the illustrated configuration example, the redundant system propulsion device 20 is described as having five electric motors 23. Figure 3 (A) and Figure 3 In the configuration example shown in (B), the redundant system propulsion device 20 is described as including four electric motors 23 . However, the optimum number of electric motors 23 in the redundant system propulsion device 20 can be determined, for example, as follows.

[0086] That is, assuming that the ratio of the motor output at the short-time rating to the motor output at the continuous rating of the electric motor 23 is a, the number of electric motors 23 at the short-time rating is calculated by 1 / (a-1).

[0087] Furthermore, by adding the number of electric motors 23 that have failed and stopped, 1, to this value, the optimal number of electric motors 23 in the redundant system propulsion unit 20 can be determined. Note that, if the number of electric motors 23 that have failed is allowed to be two, 2 is added to 1 / (a-1).

[0088] For example, if the ratio a is 1.25, then 1 / (a-1)=4. Assuming the number of electric motors 23 that stop due to failure is 1, the most appropriate number of electric motors 23 in the redundant system propulsion device 20 is 4+1=5.

[0089] Therefore, the number of electric motors 23 in the redundant propulsion device 20 can be determined by the ratio a of the motor output under the short-term rating to the motor output under the continuous rating of the electric motor 23 used for the redundant propulsion device 20 .

[0090] Therefore, although the number of electric motors 23 in the redundant system propulsion device 20 is also determined by the performance of the electric motor 23, that is, the above-mentioned ratio a, etc. Figure 2A 、 Figure 2B The five or Figure 3 (A) Figure 3 Although the number is four as shown in (B), it may be a number other than four or five.

[0091] And, for example Figure 4 (A) Figure 4 As shown in (B), when the number of electric motors 23 in the redundant system propulsion device 20 is six, the multiple electric motors 23A to 23F can be arranged around the propeller shaft 21a at multiple positions in the extension direction relative to the propeller shaft 21a of the propeller 21, and when viewed from the side of the propeller 21 along the propeller shaft 21a, the multiple electric motors 23A to 23F can be respectively arranged at positions where the output shafts 23a of the multiple electric motors 23 do not overlap with any of the output shafts 23a of other electric motors 23.

[0092] Therefore, in this case, also with Figure 2A 、 Figure 2B 、 Figure 3 (A) and Figure 3 Similarly to the case of each configuration example shown in (B), the plurality of electric motors 23 that drive the propellers 21 can be appropriately cooled without increasing the size of the nacelle 22 .

[0093] In addition, even when the number of the electric motors 23 in the redundant system propulsion device 20 is, for example, four as described above, Figure 5 (A) Figure 5 As shown in (B), the plurality of electric motors 23A to 23D can be arranged around the propeller shaft 21a at a plurality of positions in the extension direction relative to the propeller shaft 21a of the propeller 21, and, when viewed from the side of the propeller 21 in the direction along the propeller shaft 21a, the plurality of electric motors 23A to 23D can be respectively arranged at positions where the output shafts 23a of the plurality of electric motors 23 do not overlap with any of the output shafts 23a of other electric motors 23.

[0094] Therefore, in this case as well, similarly to the above-described case, the plurality of electric motors 23 that drive the propellers 21 can be appropriately cooled without increasing the size of the nacelle 22 .

[0095] On the other hand, in the case where the number of the electric motors 23 in the redundant system propulsion device 20 is, for example, four, for example, Figure 6 (A) Figure 6 As shown in (B), it is also possible to configure the electric motor 23D on the rear side to be one, etc., and to connect the output shaft 23a of one electric motor 23D to the propeller shaft 21a directly (i.e., not through the first gear 24 or the second gear 24) via a joint 26, etc., only at one position among multiple positions in the extension direction of the propeller shaft 21a.

[0096] Even with such a configuration, when viewed from the side of the propeller 21 in the direction along the propeller shaft 21a, since the output shaft 23a of the electric motor 23D does not overlap with any of the output shafts 23a of the other electric motors 23A to 23C, similarly to the above-mentioned cases, in the redundant system propulsion device 20, the multiple electric motors 23 that drive the propeller 21 can be appropriately cooled without increasing the size of the pod 22.

[0097] It should be noted that although Figure 6 (A) Figure 6 (B) shows the case where there are four electric motors 23 , but the same applies to cases other than the number of the four electric motors 23 .

[0098] In addition, although Figure 2A 、 Figure 2B 、 Figure 3 (A) Figure 3 (B) Figure 6 (A) Figure 6 (B) shows a situation where the number of electric motors 23 on the front side of the pod 22 of the redundant system propulsion device 20 is greater than the number of electric motors 23 on the rear side, but it is also possible to configure the number of electric motors 23 on the rear side to be greater than the number of electric motors 23 on the front side.

[0099] Furthermore, in the above-described embodiment, a case has been described in which the airflow generated by the rotation of the propeller 21 flows into the nacelle 22 and blows air toward the plurality of electric motors 23 .

[0100] However, for example, a configuration may be adopted in which an air guide plate for guiding the air flowing in from the air inlet to each of the electric motors 23 is provided in the nacelle 22 that houses the plurality of electric motors 23 .

[0101] Hereinafter, the wind deflector and the like provided in the nacelle 22 of the redundant system propulsion unit 20 will be described in detail.

[0102] It should be noted that, hereinafter, the plurality of electric motors 23 of the redundant system propulsion device 20 are set as follows Figure 2A and Figure 2B The case where the electric motor 23 is arranged as shown will be described, but the case where the electric motor 23 is arranged in another manner will be described in the same manner.

[0103] like Figure 7 As shown, an air inlet 22 a for sucking air generated by the rotation of the propeller 21 into the nacelle 22 is provided on the front surface portion of the nacelle 22 of the redundant system propulsion device 20 .

[0104] Furthermore, an air guide plate 22 b is provided in the nacelle 22 to guide the air flowing in from the air inlet 22 a to the respective electric motors 23A to 23E.

[0105] The air guide plate 22b guides air drawn from the upper side of the air inlet 22a on the left side of the figure to the electric motor 23A, and guides air drawn from the lower side of the air inlet 22a on the left side of the figure to the electric motor 23D.

[0106] Likewise, the air guide plate 22b guides air drawn in from above the right air inlet 22a in the figure to the electric motor 23B, and guides air drawn in from below the right air inlet 22a in the figure to the electric motor 23E.

[0107] Furthermore, the air drawn in from the air inlet 22a on the lower side in the figure is guided to the electric motor 23C by the air guide plate 22b.

[0108] Thus, by configuring so that the air flowing in from the air inlet port 22a is guided to each of the electric motors 23A to 23E by the air guide plate 22b, each of the electric motors 23A to 23E can be reliably cooled.

[0109] Furthermore, when a wind deflector 22b is provided in the pod 22 of the redundant system propulsion device 20, for example Figure 9 As shown in (A), when viewed from the front to the rear, if the front and rear electric motors 23α and 23β are arranged at positions where their output shafts 23a overlap, in order to prevent the rear electric motor 23β from being subjected to the heat of the front electric motor 23α, the air guide plate 22b must be bent significantly.

[0110] However, with such a configuration, the greatly curved air guide plate 22 b may hinder smooth air flow in the nacelle 22 , and the air resistance in the nacelle 22 may increase, thereby increasing the resistance to the electric aircraft 10 .

[0111] In this regard, Figure 9 As in the present embodiment shown in (B), when observing the rear from the front, if the front and rear electric motors 23α and 23β are arranged at positions where the output shafts 23a of each other do not overlap, even if the air guide plate 22b is not bent that much, a state can be achieved in which the electric motor 23β on the rear side does not bear the heat of the electric motor 23α on the front side.

[0112] Therefore, in this embodiment, since the air flows smoothly in the nacelle 22 along the air guide plate 22b, the air resistance in the nacelle 22 is reduced. Therefore, it is possible to accurately prevent the increase in the resistance to the electric aircraft 10.

[0113] Of course, the present invention is not limited to the above-described embodiment and the like, and can be appropriately modified without departing from the gist of the present invention.

[0114] For example, in the above embodiment, the redundant system propulsion device 20 is described as being mounted on the wing 11 of the electric aircraft 10 (see Figure 1 ), but the redundant system propulsion device 20 can also be configured at the nose of the electric aircraft 10, etc.

[0115] In addition, for example, in the above-mentioned embodiment, the case is described in which the multiple electric motors 23 are respectively arranged at two positions, one side close to the propeller 21 (i.e., the front side) and the other side away from the propeller 21 (i.e., the rear side) when viewed from the side of the propeller 21 along the propeller shaft 21a, but they can also be arranged at more than three positions.

[0116] At this time, for example Figure 8 As shown, a plurality of electric motors 23 are arranged at three or more positions in the extending direction of the propeller shaft 21 a of the propeller 21 , and the number of electric motors 23 may be increased as the position is closer to the propeller 21 .

[0117] It should be noted that although Figure 8 The case of three positions is shown in the figure, but four or more positions may be possible.

[0118] In addition, Figure 8 In the figure, although the electric motor 23 on the side farthest from the propeller 21 is shown as a single electric motor 23 directly connected to the propeller shaft 21a of the propeller 21 (i.e., not via the first gear 24 or the second gear 25), it can also be configured as follows, for example Figure 3 This electric motor 23 is attached to the propeller shaft 21 a via a first gear 24 and a second gear 25 , like the rear electric motor 23D shown in FIG. 1 (B).

[0119] Furthermore, even when the plurality of electric motors 23 are arranged at three locations in the extending direction of the propeller shaft 21 a , the number of the electric motors 23 on the rear side may be greater than the number of the electric motors 23 on the front side.

[0120] In addition, for example, although not shown in the figure, it can be configured so that Figure 2A 、 Figure 2B In the case where the output shaft 23a of the electric motor 23 is provided with the first gear 24, or as shown in FIG. Figure 6 (A) Figure 6 When the output shaft 23a of the electric motor 23 is attached to the propeller shaft 21a as shown in FIG. 2(B), the attachment is performed via a one-way clutch.

[0121] If constructed in this manner, when the electric motor 23 is driven to rotate the propeller 21, the output of the electric motor 23 is reliably transmitted from the output shaft 23a to the first gear 24 and the propeller shaft 21a. However, when the electric motor 23 stops due to a failure, etc., the first gear 24 and / or the propeller shaft 21a become idle relative to the output shaft 23a of the electric motor 23.

[0122] If the first gear 24 and the propeller shaft 21a are fixed to the output shaft 23a of the electric motor 23, the output shaft 23a that stops and does not rotate due to a malfunction of the electric motor 23 may hinder the rotation of the first gear 24 and the propeller shaft 21a, and may reduce the driving efficiency of each electric motor 23. However, if a one-way clutch is provided, even if the electric motor 23 stops due to a malfunction of the electric motor 23 and the output shaft 23a does not rotate, it will idle and will not hinder the rotation of the first gear 24 and the propeller shaft 21a.

[0123] Therefore, even if one (or two, etc.) of the plurality of electric motors 23 fails and stops, it is possible to accurately prevent the driving efficiency of each electric motor 23 from being reduced.

Claims

1. A redundant system propulsion device, characterized in that: The redundant system propulsion device includes a propeller and a plurality of electric motors for driving the propeller. The plurality of electric motors are arranged around the propeller shaft at least one each at a plurality of positions in a direction in which the propeller shaft extends. Furthermore, when viewed in a direction along the propeller shaft from the propeller side, the plurality of electric motors are respectively arranged at positions where the output shafts of the plurality of electric motors do not overlap with any of the output shafts of other electric motors.

2. A redundant system propulsion device, characterized in that: The redundant system propulsion device includes a propeller and a plurality of electric motors for driving the propeller. The plurality of electric motors are arranged at a plurality of positions relative to the propeller shaft of the propeller in the extending direction thereof, one of the plurality of positions is directly connected to the propeller shaft of the propeller, and at the other positions, at least one of the electric motors is arranged around the propeller shaft. Furthermore, when viewed in a direction along the propeller shaft from the propeller side, the plurality of electric motors are respectively arranged at positions where the output shafts of the plurality of electric motors do not overlap with any of the output shafts of other electric motors.

3. The redundant system propulsion device according to claim 1, characterized in that: The plurality of positions is two positions.

4. The redundant system propulsion device according to claim 2, characterized in that: The plurality of positions is two positions.

5. The redundant system propulsion device according to claim 3, characterized in that: The number of the electric motors on the side close to the propeller is greater than the number of the electric motors on the side far from the propeller.

6. The redundant system propulsion device according to claim 4, characterized in that: The number of the electric motors on the side close to the propeller is greater than the number of the electric motors on the side far from the propeller.

7. The redundant system propulsion device according to claim 1, characterized in that: The multiple positions are three or more positions, The redundant system propulsion device is configured such that the closer to the propeller, the greater the number of the electric motors.

8. The redundant system propulsion device according to claim 2, characterized in that: The multiple positions are three or more positions, The redundant system propulsion device is configured such that the closer to the propeller, the greater the number of the electric motors.

9. The redundant system propulsion device according to claim 2, characterized in that: The multiple positions are two or more positions, When viewed from the propeller side in the direction along the propeller shaft, the electric motor on the side farthest from the propeller is provided as one of the electric motors directly connected to the propeller shaft of the propeller.

10. The redundant system propulsion device according to any one of claims 1 to 9, characterized in that: The plurality of electric motors are housed in the pod, An air guide plate for guiding air flowing in from an air inlet to each of the electric motors is provided in the nacelle.

11. An electric aircraft, characterized in that: The electric aircraft includes the redundant system propulsion device according to any one of claims 1 to 9.

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