Flight body rotation support device

Abstract

The present invention provides a rotating support device for aircraft that can reduce weight while preventing or suppressing an increase in size. [Solution] The rotating support device 1 for an aircraft comprises a housing 7, a shaft member 8, and two rolling bearings 9a and 9b, which are arranged axially spaced apart between the inner circumferential surface of the housing 7 and the outer circumferential surface of the shaft member 8, and each bearing has outer rings 15a and 15b fitted inside the housing 7, inner rings 16a and 16b fitted outside the shaft member 8, and a plurality of rolling elements 17a and 17b arranged to roll freely between the outer rings 15a and 15b and the inner rings 16a and 16b. At least a portion of the housing 7 and / or the shaft member 8 is made of carbon fiber composite material.

Description

Technical Field

[0001] The present disclosure relates to a rotary support device for a flying object for supporting a propeller and a drive motor of the flying object.

Background Art

[0002] A flying object such as a drone includes an airframe, a plurality of propellers each for obtaining an upward lift force, and a rotary drive device for a flying object provided one by one for each propeller, for rotatably supporting the propeller with respect to the airframe and for rotationally driving the propeller.

[0003] As described in Japanese Patent Application Laid-Open No. 2020-072530 and the like, a conventional rotary drive device for a flying object is a combination of a rotary support device for a flying object including a housing, a shaft member (shaft), and a bearing, and a drive motor including a motor stator and a motor rotor.

[0004] The housing has a cylindrical shape and is supported and fixed to the airframe of the flying object with its central axis directed in the vertical direction.

[0005] The shaft member is coaxially arranged with the housing inside the radial direction of the housing and is rotatably supported with respect to the housing by the bearing.

[0006] The bearing is composed of two single-row ball bearings arranged axially spaced between the inner peripheral surface of the housing and the outer peripheral surface of the shaft member. Each of the two single-row ball bearings includes an outer ring fitted inside the housing, an inner ring fitted outside the shaft member, and a plurality of balls arranged to be freely rollable between the outer ring and the inner ring.

[0007] The motor stator includes a core made of a magnetic material having a plurality of teeth and a coil wound around the plurality of teeth, and is configured in a cylindrical shape as a whole.

[0008] The motor rotor is configured in a cylindrical shape, with alternating south poles and north poles on its inner circumferential surface in the circumferential direction. The motor rotor is positioned around the motor stator, coaxially with the motor stator, and capable of relative rotation with respect to the motor stator. The motor rotor is supported and fixed to the shaft member by a yoke.

[0009] The yoke comprises a hollow disc-shaped side plate portion fitted and fixed to one axial side (upper side in the vertical direction) of the shaft member, and a cylindrical portion extending from the radially outer end of the side plate portion toward the other axial side. The motor rotor is fitted and fixed to the inner circumferential surface of the cylindrical portion.

[0010] The propeller of the aircraft is supported and fixed to one end of the shaft member on the axial side such that its rotational axis coincides with the central axis of the shaft member.

[0011] When current is supplied to the coils constituting the motor stator, the multiple teeth of the motor stator become magnetized, and an electromagnetic force is generated between the multiple teeth and the multiple S poles and N poles of the motor rotor, causing the motor rotor to rotate relative to the motor stator. This drives the shaft member and the propeller to rotate. [Prior art documents] [Patent Documents]

[0012] [Patent Document 1] Japanese Patent Publication No. 2020-072530 [Overview of the project] [Problems that the invention aims to solve]

[0013] To extend the flight range of aircraft such as drones, reducing the power consumption of the drive motors is an effective way to reduce the weight of the aircraft's rotating support system.

[0014] On the other hand, Japanese Patent Publication No. 2020-072530 describes that the housing constituting the rotating support device for an aircraft can be made of resin, which is a material with a lower specific gravity than metal.

[0015] However, because resin has lower strength and rigidity than metal, the thickness of the housing needs to be increased to ensure the required strength and rigidity, which can lead to problems such as the need for larger rotating support devices for aircraft.

[0016] This disclosure aims to provide a rotating support device for an aircraft that can reduce weight while preventing or suppressing an increase in size. [Means for solving the problem]

[0017] A rotating support device for an aircraft according to one aspect of the present disclosure is: A housing capable of supporting the motor stator, A shaft member is provided, which is arranged coaxially with the housing on the radially inward side of the housing and is located on one axial side of the housing, capable of supporting the motor rotor and propeller. The device comprises two rolling bearings, each positioned axially separated from the inner surface of the housing and the outer surface of the shaft member, and each bearing having an outer ring fitted into the housing, an inner ring fitted onto the shaft member, and a plurality of rolling elements rotatably arranged between the outer ring and the inner ring. At least a portion of the housing and / or the shaft member is made of carbon fiber reinforced polymer (CFRP).

[0018] In a rotating support device for an aircraft according to one aspect of the present disclosure, the rolling elements of the two rolling bearings can be provided with a back-to-back contact angle and preload.

[0019] In this case, a spacer and / or elastic member may be provided between the outer rings of the two rolling bearings.

[0020] When the spacer is provided, at least a part of the spacer can be composed of a carbon fiber composite material.

[0021] In the rotary support device for an aircraft according to one aspect of the present disclosure, the housing can have an inward flange that suppresses the axial side surface on the opposite side of the other rolling bearing with respect to the axial direction of the outer ring of one of the two rolling bearings.

[0022] The rotary support device for an aircraft according to one aspect of the present disclosure can include a rotary flange for supporting the motor rotor and the propeller, and the rotary flange can be integrally formed with the shaft member or provided in a separate member fixed to the shaft member.

[0023] The rotary support device for an aircraft according to one aspect of the present disclosure can include a restraining member fixed to the shaft member and suppressing the axial side surface on the opposite side of the other rolling bearing with respect to the axial direction of the inner ring of one of the two rolling bearings.

[0024] The rotary support device for an aircraft according to one aspect of the present disclosure can be implemented by appropriately combining the configurations of the above-described respective aspects.

Advantages of the Invention

[0025] According to the rotary support device for an aircraft according to one aspect of the present disclosure, it is possible to reduce the weight while preventing or suppressing an increase in size.

Brief Description of the Drawings

[0026] [Figure 1] FIG. 1 is a cross-sectional view of a rotary drive device for an aircraft including a rotary support device for an aircraft according to an example of an embodiment of the present disclosure. [Figure 2] FIG. 2 is a cross-sectional view of the rotary support device for the aircraft.

Embodiments for Carrying Out the Invention

[0027] An example of a rotating support device for an aircraft according to the embodiments of this disclosure will be described with reference to Figures 1 and 2.

[0028] The aircraft to which the rotating support device for aircraft of this disclosure can be applied is not limited to drones or other aircraft of any particular type, such as unmanned or manned aircraft, or small or large aircraft.

[0029] The rotating support device 1 for the aircraft constitutes a part of the rotating drive device 2 for the aircraft. That is, the rotating drive device 2 for the aircraft comprises the rotating support device 1 for the aircraft and a drive motor 3.

[0030] In this disclosure, unless otherwise specified, the axial, radial, and circumferential directions refer to the axial, radial, and circumferential directions of the rotating support device 1 for the aircraft. The axial, radial, and circumferential directions of the rotating support device 1 for the aircraft coincide with the axial, radial, and circumferential directions of the drive motor 3. Furthermore, one axial side refers to the upper side of Figures 1 and 2, and the other axial side refers to the lower side of Figures 1 and 2.

[0031] The rotating support device 1 for the aircraft rotatably supports the propeller 4 of the aircraft relative to the aircraft's frame. The drive motor 3 is of the outer rotor type and comprises a motor stator 5 and a motor rotor 6 arranged around the motor stator 5, generating rotational force between the motor stator 5 and the motor rotor 6 to rotate the propeller 4.

[0032] The rotating support device 1 for the aircraft comprises a housing 7, a shaft member 8, and two rolling bearings 9a and 9b.

[0033] The housing 7 is capable of supporting the motor stator 5.

[0034] On the inner circumferential surface of the housing 7, the outer rings 15a and 15b of two rolling bearings 9a and 9b, which rotatably support the shaft member 8 radially inward of the housing 7, are fitted without radial play. The housing 7 is supported and fixed to the aircraft frame and does not rotate even when the propeller 4 rotates.

[0035] The housing 7 may have an inward flange 10 that restrains the axial side of the outer ring of one of the two rolling bearings 9a, 9b, on the side opposite to the other rolling bearing 9a, 9b in axial terms.

[0036] In this example, the housing 7 has an inward-facing flange 10 that restrains one axial side of the outer ring 15a of the axially-facing rolling bearing 9a, one of the two rolling bearings 9a, 9b. The inward-facing flange 10 protrudes radially inward from one axial end of the housing 7, and its other axial side restrains one axial side of the outer ring 15a of the axially-facing rolling bearing 9a. This enables axial positioning of the outer ring 15a of the axially-facing rolling bearing 9a.

[0037] Furthermore, the housing 7 may have a stationary flange projecting radially outward from the other axial end for supporting and fixing the housing 7 to the aircraft frame. For example, the stationary flange may have multiple flange-side support holes that penetrate axially at multiple locations in the circumferential direction. In this case, the housing is supported and fixed to the aircraft frame by inserting the connecting member, the support bolt, through the frame-side support hole provided in the aircraft frame and screwing it into the flange-side support hole, or by screwing the support bolt inserted through the flange-side support hole into the frame-side support hole provided in the aircraft frame.

[0038] In this example, the housing 7 does not have a stationary flange. In this example, the housing 7 is supported and fixed to the aircraft frame by having its other axial end fitted and fixed into a support hole provided in the aircraft frame.

[0039] The housing 7 can have any shape as long as it can perform its function. However, if at least a portion of the housing 7 is made of carbon fiber reinforced polymer (CFRP), the portion made of carbon fiber reinforced polymer is preferably cylindrical. In this example, the housing 7 is entirely made of carbon fiber reinforced polymer and has a substantially cylindrical shape. More specifically, the outer circumferential surface of the housing 7 is made of a cylindrical surface whose outer diameter does not change with respect to the axial direction. The inner circumferential surface of the housing 7 is made of a cylindrical surface whose inner diameter does not change with respect to the axial direction, except for the axial end on one side where the inward flange 10 is provided.

[0040] The shaft member 8 is positioned coaxially with the housing 7, radially inward, and is capable of supporting the motor rotor 6 and propeller 4 in the portion located axially to one side of the housing 7.

[0041] The shaft member 8 can have any shape as long as it can perform its function. However, if at least a portion of the shaft member 8 is made of carbon fiber composite material, it is preferable that the portion made of carbon fiber composite material be cylindrical. In this example, the shaft member 8 is entirely made of carbon fiber composite material and has a cylindrical shape. Specifically, the outer circumferential surface of the shaft member 8 is made of a cylindrical surface whose outer diameter does not change with respect to the axial direction. The inner circumferential surface of the shaft member 8 is made of a cylindrical surface whose inner diameter does not change with respect to the axial direction.

[0042] In the rotating support device 1 for an aircraft according to this disclosure, at least a portion of the housing 7 and / or the shaft member 8 is made of carbon fiber reinforced polymer (CFRP). That is, part or all of the housing 7 is made of carbon fiber reinforced polymer. Additionally or alternatively, part or all of the shaft member 8 is made of carbon fiber reinforced polymer.

[0043] The types and content of synthetic resins, carbon fibers, and additives constituting the carbon fiber composite material are not particularly limited, as long as they can ensure the required strength and rigidity of the housing 7 and / or shaft member 8. Examples of carbon fibers that can be included in the carbon fiber composite material include "Torayca" manufactured by Toray Industries, Inc., "Pyrophil" manufactured by Mitsubishi Chemical Corporation, and "Tenax" manufactured by Teijin Limited.

[0044] The method for fabricating at least a portion of the housing 7 and / or shaft member 8 from carbon fiber composite material is not particularly limited, but for example, a method can be employed in which prepreg is wrapped around a core material, heat-cured, and then the core material is removed.

[0045] Furthermore, the parts of the housing 7 and / or shaft member 8 other than those made of carbon fiber composite material may be made of any material such as metal or synthetic resin, as long as the necessary strength and rigidity of the housing 7 and / or shaft member 8 can be ensured.

[0046] When a portion of the housing 7 and / or shaft member 8 is made of carbon fiber composite material, and the remaining portion is made of other material, for example, a two-layer structure can be adopted in which the outer diameter portion is made of carbon fiber composite material and the inner diameter portion is made of other material. In this case, the outer diameter portion can be made by wrapping prepreg around a core material and heat-curing it, and this core material can be used as the inner diameter portion. That is, the process of removing the core material (inner diameter portion) from the inside of the outer diameter portion after it has been made can be omitted.

[0047] In this example, the entire housing 7 and the entire shaft member 8 are made of carbon fiber composite material.

[0048] According to the rotating support device 1 for aircraft of this disclosure, compared to the case in which the entire housing 7 and the entire shaft member 8 are made of metal material, the weight of the housing 7 and / or shaft member 8 can be reduced, and compared to the case in which the entire housing 7 and the entire shaft member 8 are made of synthetic resin, high strength and high rigidity can be achieved, so the radial dimensions of the housing 7 and / or shaft member 8 can be kept small. In other words, the rotating support device 1 for aircraft can be made lighter while preventing or suppressing an increase in size.

[0049] The rotating support device 1 for the aircraft may optionally include a rotating flange 11 for supporting the motor rotor 6 and the propeller 4. The rotating flange 11 may be manufactured integrally with the shaft member 8, or it may be provided on a separate member 12 fixed to the shaft member 8.

[0050] In this example, the rotating support device 1 for the aircraft includes a rotating flange 11 provided on a separate member 12 fixed to the shaft member 8.

[0051] The separate component 12 can be made of any material, such as metal or synthetic resin, as long as the necessary strength and rigidity can be ensured. In this example, the separate component 12 is made of metal.

[0052] In this example, the separate component 12 has a cylindrical portion 13 and a rotating flange 11 that protrudes radially outward from one axial end of the cylindrical portion 13.

[0053] The separate component 12 is fixed to the shaft member 8 in a way that prevents relative rotation and relative axial displacement, by press-fitting and / or bonding the cylindrical portion 13 onto the axial end of the shaft member 8, which protrudes axially from the housing 7.

[0054] Furthermore, the other end face of the cylindrical portion 13 on the axial side can also be used as a abutment surface for abutting the axial side of the inner ring 16a of the rolling bearing 9a on the axial side.

[0055] In this example, the rotating flange 11 is configured as a hollow circular flat plate. The rotating flange 11 has mounting holes 14 that penetrate axially at multiple locations in the circumferential direction.

[0056] Of the yoke 25 and propeller 4, which support and fix the motor rotor 6 to the shaft member 8, at least the yoke 25 is coupled and fixed to the rotating flange 11 using the mounting holes 14.

[0057] The mounting hole 14 is composed of a threaded hole or a press-fit hole. If the mounting hole 14 is composed of a threaded hole, the yoke 25 is joined and fixed to the rotating flange 11 by screwing a bolt, which is inserted through through holes provided at multiple circumferential locations on its radially inner side, into the mounting hole 14 from one axial side. If the mounting hole 14 is composed of a press-fit hole, a stud is press-fitted into the mounting hole 14 from the other axial side. The yoke 25 is joined and fixed to the rotating flange 11 by inserting the stud through through holes provided at multiple circumferential locations on its radially inner side and screwing a nut onto the tip of the stud. In this example, the mounting hole 14 is composed of a threaded hole.

[0058] The outer diameter of the rotating flange 11 is not particularly limited; for example, it can be greater than or equal to the outer diameter of the housing 7, or it can be smaller than the outer diameter of the housing 7. In this example, the outer diameter of the rotating flange 11 is smaller than the outer diameter of the housing 7. Therefore, after assembling the rotating support device 1 for the aircraft, the motor stator 5 can be fitted onto the housing 7 from one side in the axial direction.

[0059] The two rolling bearings 9a and 9b are positioned axially separated between the inner circumferential surface of the housing 7 and the outer circumferential surface of the shaft member 8, and each has an outer ring 15a, 15b fitted inside the housing 7, an inner ring 16a, 16b fitted outside the shaft member 8, and a plurality of rolling elements 17a, 17b arranged to roll freely between the outer rings 15a, 15b and the inner rings 16a, 16b. The shaft member 8 is rotatably supported radially inward of the housing 7 by the two rolling bearings 9a and 9b.

[0060] Each of the outer rings 15a and 15b is constructed in a cylindrical shape from a hard metal such as medium carbon steel. Each of the outer rings 15a and 15b has outer ring raceways 18a and 18b on its inner circumferential surface. Each of the outer ring raceways 18a and 18b has a generatrix shape corresponding to the shape of the multiple rolling elements 17a and 17b. That is, when the multiple rolling elements 17a and 17b are composed of balls, each of the outer ring raceways 18a and 18b has an arc-shaped generatrix, whereas when the multiple rolling elements 17a and 17b are composed of cone-shaped rollers, each of the outer ring raceways 18a and 18b has a linear generatrix inclined with respect to the central axis of the outer rings 15a and 15b. In this example, since the multiple rolling elements 17a and 17b are composed of balls, each of the outer ring raceways 18a and 18b has an arc-shaped generatrix.

[0061] Each of the inner rings 16a and 16b is cylindrical and made of a hard metal such as medium carbon steel. Each of the inner rings 16a and 16b has inner raceways 19a and 19b on its outer surface. Each of the inner raceways 19a and 19b has a generatrix shape corresponding to the shape of the multiple rolling elements 17a and 17b. That is, when the multiple rolling elements 17a and 17b are made of balls, each of the inner raceways 19a and 19b has an arc-shaped generatrix, whereas when the multiple rolling elements 17a and 17b are made of cone-shaped rollers, each of the inner raceways 19a and 19b has a linear generatrix inclined with respect to the central axis of the inner rings 16a and 16b. In this example, since the multiple rolling elements 17a and 17b are made of balls, each of the inner raceways 19a and 19b has an arc-shaped generatrix.

[0062] The rolling elements 17a and 17b are made of hard metals such as bearing steel, or ceramics. Furthermore, the rolling elements 17a and 17b are made of balls or tapered rollers. In this example, the rolling elements 17a and 17b are made of balls.

[0063] Multiple rolling elements 17a and 17b are arranged to roll freely between the outer ring raceways 18a and 18b and the inner ring raceways 19a and 19b. In this example, the multiple rolling elements 17a and 17b are arranged to roll freely at equal intervals in the circumferential direction between the outer ring raceways 18a and 18b and the inner ring raceways 19a and 19b, while being held by a retainer (not shown).

[0064] In this example, the rolling elements 17a and 17b of the two rolling bearings 9a and 9b are provided with a back-to-back (DB) type contact angle and preload.

[0065] In other words, the two rolling bearings 9a and 9b are each composed of angular contact ball bearings. Specifically, in the rolling bearing 9a on one axial side, the outer ring raceway 18a has a roughly quarter-circular arc cross-sectional shape in which the inner diameter decreases as it moves toward the other axial side, and the inner ring raceway 19a has a roughly quarter-circular arc cross-sectional shape in which the outer diameter increases as it moves toward the one axial side. Similarly, in the rolling bearing 9b on the other axial side, the outer ring raceway 18b has a roughly quarter-circular arc cross-sectional shape in which the inner diameter decreases as it moves toward the one axial side, and the inner ring raceway 19b has a roughly quarter-circular arc cross-sectional shape in which the outer diameter increases as it moves toward the other axial side.

[0066] In this example, the axial side of the inner ring 16a of the axially-oriented rolling bearing 9a is abutted against the axially-oriented end face of the cylindrical portion 13 of another member 12 fixed to the shaft member 8. This prevents the axial displacement of the inner ring 16a of the axially-oriented rolling bearing 9a relative to the shaft member 8. In addition, the axial side of the outer ring 15a of the axially-oriented rolling bearing 9a is abutted against the axially-oriented side of the inward flange 10 of the housing 7. This prevents the axial displacement of the outer ring 15a of the axially-oriented rolling bearing 9a relative to the housing 7.

[0067] With the above configuration, the housing 7 is positioned axially relative to the shaft member 8.

[0068] The rotating support device 1 for the aircraft may optionally include a retaining member 22 fixed to the shaft member 8, which holds the axial side of the inner ring of one of the two rolling bearings 9a and 9b, on the side opposite to the other rolling bearing 9a and 9b in the axial direction. The retaining member 22 is a member that prevents the inner ring of one rolling bearing from being displaced away from the other rolling bearing relative to the shaft member 8.

[0069] Furthermore, if the inner ring of one rolling bearing can be press-fitted and / or bonded to the shaft member 8, or a part of the shaft member 8 can be crimped, thereby preventing the inner ring of one rolling bearing from moving away from the other rolling bearing relative to the shaft member 8, the retaining member 22 can be omitted.

[0070] The rotating support device 1 for the aircraft in this example is fixed to the shaft member 8 and includes a restraining member 22 that restrains the side surface of the inner ring 16b of the rolling bearing 9b on the other axial side. That is, the restraining member 22 prevents the inner ring 16b of the rolling bearing 9b on the other axial side from being displaced in the other axial direction relative to the shaft member 8.

[0071] The retaining member 22 can be composed of a member fixed to the circumferential surface of the shaft member 8 by press-fitting and / or adhesive, a retaining ring that engages with a locking groove provided on the circumferential surface of the shaft member 8, or a screw member that is screwed into a male or female threaded portion provided on the circumferential surface of the shaft member 8. Furthermore, the retaining member 22 can be composed of any material such as metal or synthetic resin, as long as the necessary strength and rigidity can be ensured.

[0072] In this example, the retaining member 22 is constructed of metal in an annular shape and has a cylindrical portion 23 and a hollow circular plate-shaped ring portion 24 that protrudes radially outward from the other axial end of the cylindrical portion 23. The retaining member 22 is fixed to the shaft member 8 by press-fitting and / or adhesively fixing the cylindrical portion 23 to the other axial end of the shaft member 8.

[0073] The rotating support device 1 for the aircraft may optionally include a spacer 20 and / or an elastic member 21 positioned between the outer rings 15a and 15b of two rolling bearings 9a and 9b. The spacer 20 and / or elastic member 21 are members for applying preload to the two rolling bearings 9a and 9b.

[0074] When only a spacer 20 is placed between the two outer rings 15a and 15b, the rolling elements 17a and 17b are subjected to a fixed-position preload. In contrast, when only an elastic member 21, or both a spacer 20 and an elastic member 21, are placed between the two outer rings 15a and 15b, the rolling elements 17a and 17b are subjected to a constant-pressure preload. In this case, the magnitude of the preload applied to the rolling elements 17a and 17b can be adjusted by adjusting the elasticity of the elastic member 21. Whether to apply a constant-pressure preload or a fixed-position preload to the rolling elements 17a and 17b is appropriately selected according to the performance required of the rotating support device 1 for the aircraft.

[0075] The rotating support device 1 for the aircraft in this example includes a spacer 20 and an elastic member 21 positioned between the outer rings 15a and 15b of two rolling bearings 9a and 9b. Specifically, the elastic member 21 and the spacer 20 are positioned between the two outer rings 15a and 15b, starting from one axial side.

[0076] The spacer 20 can be configured as a cylindrical shape with a continuous circumference or as a partial cylindrical shape with a discontinuity at one point in the circumferential direction. In this example, the spacer 20 is configured as a cylindrical shape with a continuous circumference. The spacer 20 is fitted inside the housing 7 radially without any play, and the other axial end face of the spacer 20 abuts against the axial side of the outer ring 15b of the rolling bearing 9b on the other axial side.

[0077] The spacer 20 can be made of any material, such as metal or synthetic resin, as long as the required strength can be ensured. In this example, at least a portion of the spacer 20 is made of carbon fiber composite material. More specifically, in this example, the entire spacer 20 is made of carbon fiber composite material.

[0078] Therefore, in this example, compared to the case where the entire spacer 20 is made of metal, it is possible to reduce the thickness of the spacer 20 while reducing the weight of the shaft member 8. Consequently, it is easier to reduce the weight of the rotating support device 1 for the aircraft.

[0079] The elastic member 21 can be made of a spring such as a wave washer, disc spring, or coil spring, or rubber. In this example, the elastic member 21 is made of a wave washer.

[0080] In this example, the elastic member 21 is elastically sandwiched in the axial direction between the side surface on the other axial side of the outer ring 15a of the rolling bearing 9a on one axial side and the end face on the one axial side of the spacer 20. As a result, the outer rings 15a and 15b of the two rolling bearings 9a and 9b are elastically pressed apart from each other in the axial direction, and a constant-pressure preload is applied to the rolling elements 17a and 17b of the two rolling bearings 9a and 9b.

[0081] The motor stator 5 includes a core made of magnetic material having multiple teeth and coils wound around the multiple teeth, and the entire structure is cylindrical.

[0082] In this example, the motor stator 5 is supported by the housing 7 by externally fitting and fixing the core to the outer surface of the housing 7, specifically from one end on the axial side to the middle section on the axial side.

[0083] The motor stator 5 can also be supported by the housing 7 via an annular member. That is, the motor stator 5 can also be supported by the housing 7 by externally fitting and fixing the core to an annular member that is externally fitted and fixed to the housing 7. The annular member functions as a base to ensure a large output for the drive motor 3 by increasing the outer diameter of the core while keeping the radial thickness of the core small. The annular member can further function as a heat exchange member (heat dissipation fin) that efficiently receives heat from the adjacent core and efficiently exchanges heat with the surrounding air in order to facilitate cooling of the drive motor 3. In this case, it is preferable that the annular member be made of a light alloy such as an aluminum alloy, which has high thermal conductivity.

[0084] The motor rotor 6 is cylindrical in shape, with alternating south and north poles on its inner surface in the circumferential direction. The motor rotor 6 is positioned around the motor stator 5, coaxially with the motor stator 5, and capable of relative rotation with respect to the motor stator 5. The motor rotor 6 is supported and fixed to the shaft member 8 by a yoke 25.

[0085] In this example, the yoke 25 is constructed in the shape of a hollow circular plate, and one axial end of the motor rotor 6 is connected and fixed to its radially outer end.

[0086] In this example, the motor rotor 6 is arranged coaxially with the shaft member 8, and is fixed to the rotating flange 11 by screwing bolts (not shown), which are inserted through through holes provided at multiple circumferential locations on the radially inner portion of the yoke 25, into mounting holes 14 of the rotating flange 11, with the other axial side of the radially inner portion of the yoke 25 in contact with one axial side of the rotating flange 11. Alternatively, a yoke having a cylindrical portion extending from the radially outer end toward the other axial side can be used, and a structure in which the motor rotor 6 is fitted and fixed inside this cylindrical portion can also be adopted.

[0087] In this example, an outer rotor type motor 3 is used, in which the motor rotor 6 is positioned radially outward of the motor stator 5. However, when implementing this disclosure, an inner rotor type motor 3 is also used, in which the motor rotor is positioned radially inward of the motor stator.

[0088] In this example, the propeller 4 is arranged coaxially with the shaft member 8, and with the other axial side of its radially inner portion in contact with one axial side of the yoke 25, bolts inserted through through holes provided at multiple locations in the circumferential direction of the propeller 4 are screwed into threaded holes provided at multiple locations in the circumferential direction of the yoke 25, thereby connecting and fixing it to the rotating flange 11 via the yoke 25.

[0089] Furthermore, the propeller 4 can also be joined and fixed to the rotating flange 11 together with the yoke 25 by screwing bolts, which are inserted through through holes provided at multiple locations in the circumferential direction of the propeller 4 and through holes provided at multiple locations in the circumferential direction of the yoke 25, into the mounting holes 14 of the rotating flange 11.

[0090] Alternatively, the mounting hole 14 of the rotating flange 11 can be configured as a press-fit hole, and a stud that has been press-fitted into the press-fit hole can be inserted through the through-hole of the yoke 25 and the through-hole of the propeller 4, and a nut can be screwed onto the tip of the stud to connect and fix the yoke 25 and the propeller 4 to the rotating flange 11.

[0091] In any case, with the motor stator 5, motor rotor 6, and propeller 4 attached to the rotating support device 1 for the aircraft in this example, current is supplied to the coils constituting the motor stator 5, causing the multiple teeth of the motor stator 5 to become magnetized. This generates an electromagnetic force between the multiple teeth and the multiple S poles and N poles of the motor rotor 6, causing the motor rotor 6 to rotate relative to the motor stator 5. As a result, the shaft member 8 and the propeller 4 are driven to rotate.

[0092] In the rotating support device 1 for the aircraft in this example, the housing 7, shaft member 8, and spacer 20 are all constructed entirely of carbon fiber composite material. Therefore, it is easy to reduce the weight of the rotating support device 1 while preventing it from becoming too large. Consequently, it is easier to ensure the aircraft's flight range. [Explanation of Symbols]

[0093] 1 Rotational support device for aircraft 2. Rotary drive system for aircraft 3. Drive motor 4 propellers 5 Motor Stator 6 Motor Rotor 7 Housing 8 Shaft member 9a, 9b Rolling bearings 10 Inward flange 11 Rotating flange 12 Separate parts 13 Cylindrical section 14 mounting holes 15a, 15b outer ring 16a, 16b inner ring 17a, 17b rolling elements 18a, 18b Outer ring track 19a, 19b Inner ring track 20 Spacers 21 Elastic members 22 Retaining member 23 Cylindrical section 24 Circular part 25 York

Claims

1. A housing capable of supporting the motor stator, A shaft member is provided, which is arranged coaxially with the housing on the radially inward side of the housing and is located on one axial side of the housing, capable of supporting the motor rotor and propeller. The device comprises two rolling bearings, each positioned axially separated from the inner surface of the housing and the outer surface of the shaft member, and each bearing having an outer ring fitted into the housing, an inner ring fitted onto the shaft member, and a plurality of rolling elements rotatably arranged between the outer ring and the inner ring. At least a portion of the housing and / or the shaft member is made of a carbon fiber composite material. Rotation support device for aircraft.

2. The rotating support device for an aircraft according to claim 1, wherein the rolling elements of the two rolling bearings are provided with a back-to-back contact angle and preload.

3. The rotating support device for an aircraft according to claim 2, further comprising a spacer and / or an elastic member disposed between the outer rings of the two rolling bearings.

4. The rotating support device for an aircraft according to claim 3, wherein at least a portion of the spacer is made of a carbon fiber composite material.

5. The rotating support device for an aircraft according to claim 1, wherein the housing has an inward flange that restrains the axial side of the outer ring of one of the two rolling bearings that is opposite to the other of the two rolling bearings in the axial direction.

6. The motor rotor and the propeller are provided with a rotating flange for supporting them. The rotating flange is either integrally manufactured with the shaft member, or provided on a separate member fixed to the shaft member. Rotating support device for an aircraft according to claim 1.

7. The rotating support device for an aircraft according to claim 1, further comprising a retaining member fixed to the shaft member and which restrains the axial side of the inner ring of one of the two rolling bearings that is opposite to the other of the two rolling bearings in terms of axial direction.

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