Rotary support device for flying object

Abstract

To realize a structure of a rotary support device for a flying object in which a stationary fitting portion of a stationary object to which a motor stator is outerly fitted and fixed can be easily formed with high precision.SOLUTION: A rotary support device for a flying object includes a stationary object 6 that has double-row outer ring raceway surfaces 9a, 9b on an inner circumferential surface and can support a motor stator, a rotary object 7 that has double-row inner ring raceway surfaces 10a, 10b on an outer circumferential surface and can support a motor rotor and a propeller, and a plurality of rollers 8a, 8b that are disposed between the double-row outer ring raceway surfaces 9a, 9b and the double-row inner ring raceway surfaces 10a, 10b, and in each of the rows. The stationary object 6 has, at a plurality of positions spaced from each other in the axial direction on the outer circumferential surface, stationary fitting portions 11a, 11b to which the motor stator is outerly fitted by pressure, and further has, at a position between two stationary fitting portions 11a, 11b adjacent to each other in the axial direction on the outer circumferential surface, a relief portion 12 that has an outer diameter smaller than the outer diameter of the stationary fitting portions 11a, 11b.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a rotary support device for an aircraft for supporting a propeller and a drive motor of the aircraft. [Background technology]

[0002] An aircraft such as a drone comprises an aircraft frame, a propeller for generating upward lift, and an aircraft rotation drive device that rotatably supports the propeller relative to the aircraft frame and drives the propeller to rotate.

[0003] As described in JP 2020-072530 A and other publications, a conventional rotary drive device for an aircraft includes a rotary support device for an aircraft that includes a stationary body, a rotating body, and a bearing, and a drive motor that includes a motor stator and a motor rotor.

[0004] The stationary body has an inner peripheral surface and is supported and fixed to the airframe of the aircraft.

[0005] The rotating body has an outer circumferential surface and is supported by the bearing relative to the stationary body so as to be able to rotate freely about a central axis facing in the vertical direction.

[0006] The bearing is composed of a pair of single-row ball bearings arranged axially spaced apart between the inner peripheral surface of the stationary body and the outer peripheral surface of the rotating body. Each of the single-row ball bearings comprises an outer ring, an inner ring, and balls, and is assembled between the stationary body and the rotating body in such a manner that the outer peripheral surface of the outer ring is fitted inside the inner peripheral surface of the stationary body, and the inner peripheral surface of the inner ring is fitted outside the outer peripheral surface of the rotating body.

[0007] The motor stator includes a core made of a magnetic material and a coil wound around the core, and is cylindrical overall, with magnetic poles at multiple equally spaced locations on the outer circumferential surface of the core. The motor stator is fitted and fixed to a stationary fitting portion that is provided on the outer circumferential surface of the stationary body and has a cylindrical surface that is continuous over the entire axial length.

[0008] The motor rotor has an inner peripheral surface that faces radially the outer peripheral surface of the motor stator, and has south and north poles arranged alternately in the circumferential direction at a plurality of equally spaced locations on the inner peripheral surface. The motor rotor is supported and fixed to an end portion on one axial side (upper side) of the rotating body.

[0009] The propeller of the aircraft is supported and fixed at a portion of one axial end of the rotating body that is located axially further to the one axial side than the motor rotor so that its central axis of rotation coincides with the central axis of the rotating body.

[0010] In this state, when the coil of the motor stator is energized, a torque (electromagnetic force) that rotates the motor rotor is generated relative to the motor stator, and the propeller is rotated together with the motor rotor. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] Japanese Patent Publication No. 2020-072530 Summary of the Invention [Problem to be solved by the invention]

[0012] In order to improve various performance characteristics of an aircraft such as a drone, such as flight speed, attitude stability during flight, and maximum payload capacity, it is necessary to increase the output torque of the drive motor. The output torque of the drive motor can be increased by increasing the amount of power supplied from the battery installed in the aircraft. However, due to limitations on the size and weight of the battery that can be installed in an aircraft, the amount of power supplied cannot be increased without limit. Therefore, in order to improve the various performance characteristics of the aircraft, it is necessary to improve the output performance of the drive motor, i.e., the magnitude of the output torque per unit of supplied power. From the perspective of improving the output performance of the drive motor, it is preferable to strengthen the magnetic field of the radial gap (hereinafter referred to as the air gap) existing between the outer circumferential surface of the motor stator and the inner circumferential surface of the motor rotor by minimizing the radial width of the air gap.

[0013] In order to reduce the radial width of the air gap, it is necessary to ensure the coaxiality of the motor stator and the motor rotor. Furthermore, in order to ensure the coaxiality of the motor stator and the motor rotor, it is necessary to form the stationary fitting portion, which is the portion of the stationary body that fits and fixes the motor stator, with high precision.

[0014] In order to form the stationary fitting portion with high precision, specifically, when manufacturing the stationary body, a rough machining process may be carried out in which a metal material is forged and / or cut to obtain an intermediate body having the general shape of the stationary body, and then a precision machining process may be carried out in which the outer peripheral surface of the intermediate body is ground to form the stationary fitting portion on the outer peripheral surface with high precision in outer diameter dimension, coaxiality, and tilt accuracy.

[0015] On the other hand, the output torque of the drive motor increases as the axial width of the air gap increases, and therefore, from the viewpoint of improving the output performance of the drive motor, it is preferable that the axial width of the air gap be as large as possible within the allowable range in terms of the size of the drive motor.

[0016] In order to increase the axial width of the air gap, it is necessary to increase the axial width of each of the motor stator and the motor rotor, which in turn requires an increase in the axial width of the stationary fitting portion.

[0017] However, regardless of the type of processing in the rough processing step, if the axial width of the part where the stationary fitting portion is formed, which is the part that is subjected to grinding in the precision processing step, becomes large, it becomes difficult to process it in one grinding operation using a single grinding wheel, and therefore it becomes difficult to form the stationary fitting portion with high precision by the grinding process.

[0018] The present disclosure aims to realize a structure for a rotation support device for an aircraft that makes it easy to form with high precision the stationary fitting portion of the stationary body onto which the motor stator is fitted and fixed. [Means for solving the problem]

[0019] The rotational support device for an aircraft according to the first aspect of the present disclosure includes: a stationary body having a double row outer ring raceway on its inner circumferential surface and capable of supporting a motor stator; a rotor having a double row inner ring raceway on its outer circumferential surface and capable of supporting a motor rotor and a propeller; The rolling elements are arranged between the double row outer ring raceways and the double row inner ring raceways, with a plurality of rolling elements arranged for each row.

[0020] The stationary body has stationary fitting portions at multiple axially spaced locations on its outer peripheral surface, into which the motor stator is externally fitted by press-fitting, and has a recess portion on the outer peripheral surface located between two axially adjacent stationary fitting portions, the recess portion having an outer diameter smaller than the outer diameter of the stationary fitting portion.

[0021] In a second aspect of the rotary support device for an aircraft of the present disclosure, in the first aspect of the rotary support device for an aircraft of the present disclosure, at least one of the double-row outer ring raceways is formed directly on the inner surface of the stationary body, and / or at least one of the double-row inner ring raceways is formed directly on the outer surface of the rotating body.

[0022] A rotational support device for an aircraft according to a third aspect of the present disclosure is a rotational support device for an aircraft according to the first or second aspect of the present disclosure, the double-row outer ring raceway is formed directly on the inner circumferential surface of the stationary body, The diameter of the minimum diameter portion of the relief portion is larger than the diameter of the maximum diameter portion of the double row outer ring raceway.

[0023] A fourth aspect of the present disclosure provides a rotary support device for an aircraft, wherein the rotary support device for an aircraft according to any one of the first to third aspects of the present disclosure comprises: the double-row outer ring raceway is formed directly on the inner circumferential surface of the stationary body, The minimum diameter portions of the recesses are disposed only at positions axially deviated from the maximum diameter portions of the double row outer ring raceways.

[0024] A fifth aspect of the present disclosure provides a rotary support device for an aircraft, wherein the rotary support device for an aircraft according to any one of the first to fourth aspects of the present disclosure comprises: the double-row outer ring raceway is formed directly on the inner circumferential surface of the stationary body, the stationary fitting portion includes a first stationary fitting portion and a second stationary fitting portion that are adjacent to each other in the axial direction and are on one side in the axial direction, The recess portion located between the first stationary fitting portion and the second stationary fitting portion is arranged to overlap radially with the inter-row portion, which is the portion of the inner surface of the stationary body located between the double-row outer ring raceways.

[0025] In a sixth aspect of the rotary support device for an aircraft according to the fifth aspect of the present disclosure, the axial width of the recessed portion is equal to or greater than the axial width of the inter-row portion, and the entire inter-row portion overlaps the recessed portion in the radial direction. In this case, for example, a configuration can be employed in which an end portion on one axial side of the recessed portion is disposed so as to overlap radially with the outer ring raceway on the one axial side, and an end portion on the other axial side of the recessed portion is disposed so as to overlap radially with the outer ring raceway on the other axial side.

[0026] In the seventh aspect of the rotary support device for an aircraft of the present disclosure, in the fifth or sixth aspect of the rotary support device for an aircraft of the present disclosure, at least a portion of the outer ring orbit on one axial side of the double-row outer ring orbit is arranged radially overlapping with the first stationary fitting portion, and at least a portion of the outer ring orbit on the other axial side of the double-row outer ring orbit is arranged radially overlapping with the second stationary fitting portion.

[0027] In the eighth aspect of the rotary support device for an aircraft of the present disclosure, in a rotary support device for an aircraft of any of the fifth to seventh aspects of the present disclosure, the minimum diameter portion of the recess is positioned axially on the other side of the maximum diameter portion of the outer ring raceway on one axial side of the double-row outer ring raceway, and axially on the one side of the maximum diameter portion of the outer ring raceway on the other axial side of the double-row outer ring raceway.

[0028] A ninth aspect of the present disclosure provides a rotary support device for an aircraft, wherein in the rotary support device for an aircraft according to any one of the first to eighth aspects of the present disclosure, the rotating body has a rotating flange that protrudes radially outward from a portion located on one axial side of the stationary body, and to which the motor rotor and the propeller are coupled, The outer diameter of the rotating flange is smaller than the outer diameter of each of the stationary fitting portions.

[0029] In a rotary support device for an aircraft of a tenth aspect of the present disclosure, in a rotary support device for an aircraft of any of the first to ninth aspects of the present disclosure, the stationary body has a stationary flange that protrudes radially outward at a portion located on the other axial side of each of the stationary fitting portions. [Effects of the Invention]

[0030] According to the rotational support device for an aircraft according to one aspect of the present disclosure, it is easy to form with high precision the stationary fitting portion of the stationary body onto which the motor stator is fitted and fixed. [Brief explanation of the drawings]

[0031] [Figure 1] FIG. 1 is a cross-sectional view of a rotary drive device including a rotary support device for an aircraft according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a cross-sectional view of the rotary support device for an aircraft. [Figure 3] FIG. 3 is a cross-sectional view showing a part of the stationary body (stationary-side support member) that constitutes the rotary support device for an aircraft. DETAILED DESCRIPTION OF THE INVENTION

[0032] A rotary support device for an aircraft according to an embodiment of the present disclosure will be described with reference to FIGS. 1 to 3. FIG.

[0033] An aircraft to which the aircraft rotation support device of the present disclosure can be applied includes an aircraft frame, a propeller for generating upward lift, and an aircraft rotation drive device that rotatably supports the propeller on the aircraft frame and drives the propeller to rotate. The aircraft may be a large aircraft such as a helicopter, or a small aircraft such as a drone. The aircraft rotation support device of the present disclosure can be particularly well suited to logistics drones used for small-lot deliveries.

[0034] As shown in FIG. 1, the rotary drive device for an aircraft is composed of an aircraft rotation support device 1 and a drive motor 2.

[0035] The aircraft rotation support device 1 supports a drive motor 2 and a propeller 3 on the aircraft frame (not shown).

[0036] The drive motor 2 is an outer rotor brushless motor. The drive motor 2 includes a motor stator 4 and a motor rotor 5, and generates a rotational force for driving the propeller 3 to rotate.

[0037] The motor stator 4 includes a core made of a magnetic material and a coil wound around the core, and is configured cylindrically as a whole, with magnetic poles at multiple equally spaced locations on the outer circumferential surface of the core. The motor stator 4 is fitted and fixed around the stationary body 6 of the aircraft rotation support device 1 so as to prevent relative rotation with respect to the stationary body 6.

[0038] The motor rotor 5 has an inner peripheral surface that faces radially the outer peripheral surface of the motor stator 4, and has south and north poles arranged alternately in the circumferential direction at multiple equally spaced locations on the inner peripheral surface. The motor rotor 5 is supported and fixed to the rotating body 7 of the aircraft rotation support device 1 so as to rotate integrally with the rotating body 7.

[0039] The aircraft rotation support device 1 includes a stationary body 6, a rotating body 7, and a plurality of rolling bodies 8a and 8b.

[0040] In the description of this example of the rotary support device 1 for an aircraft, one axial side is the side on which the propeller is positioned when the aircraft is assembled, which is the upper side in Figures 1 and 2, and the other axial side is the side opposite the propeller, which is the lower side in Figures 1 and 2.

[0041] The stationary body 6 has double-row outer ring raceways 9a, 9b on its inner circumferential surface and is capable of supporting the motor stator 4. The stationary body 6 is supported and fixed to the aircraft frame, and does not rotate even when the propeller 3 rotates.

[0042] The rotor 7 has double-row inner ring raceways 10a, 10b on its outer circumferential surface, and is capable of supporting the motor rotor 5 and the propeller 3.

[0043] The rolling elements 8a, 8b are arranged in multiple rows between double-row outer ring raceways 9a, 9b and double-row inner ring raceways 10a, 10b, so that the rotating element 7 is rotatably supported radially inside the stationary element 6.

[0044] The stationary body 6 has stationary fitting portions 11a, 11b at multiple axially spaced locations on its outer peripheral surface, onto which the motor stator 4 is press-fitted, and also has a recess 12 with an outer diameter smaller than that of the stationary fitting portions 11a, 11b in a portion of the outer peripheral surface located between two axially adjacent stationary fitting portions 11a, 11b. In other words, the motor stator 4 is supported and fixed to the stationary body 6 by being press-fitted onto each of the stationary fitting portions 11a, 11b. The recess 12 is a portion that does not come into contact with the inner peripheral surface of the motor stator 4 when the motor stator 4 is supported and fixed to the stationary body 6.

[0045] In this example, the stationary body 6 has stationary fitting portions 11a, 11b at two positions spaced apart in the axial direction on its outer peripheral surface, and also has one relief portion 12 in a portion of the outer peripheral surface located between the two stationary fitting portions 11a, 11b. Specifically, the stationary fitting portions 11a, 11b are configured to include a first stationary fitting portion 11a on one axial side and a second stationary fitting portion 11b on the other axial side, which are arranged adjacent to each other in the axial direction.

[0046] The first stationary fitting portion 11a and the second stationary fitting portion 11b are each formed of a cylindrical surface whose outer diameter does not change in the axial direction, and are arranged coaxially with each other and have the same outer diameter D 11 The relationship between the axial widths of the first stationary fitting portion 11a and the second stationary fitting portion 11b can be set arbitrarily. In this example, the axial width W 11a is the axial width W of the first stationary fitting portion 11a 11b greater than (W 11a >W 11b ).

[0047] In this example, the end portion on one axial side of the first stationary fitting portion 11a is positioned at the end portion on one axial side of the outer peripheral surface of the stationary body 6, and the end portion on the other axial side of the second stationary fitting portion 11b is positioned at a portion adjacent to one axial side of the stationary flange 21 described later.

[0048] In the aircraft rotation support device 1, the multiple stationary fitting portions 11a, 11b are arranged spaced apart in the axial direction. Therefore, from the viewpoint of improving the output performance of the drive motor 2, the axial width W of the radial gap portion (hereinafter referred to as air gap G) existing between the outer peripheral surface of the motor stator 4 and the inner peripheral surface of the motor rotor 5 is set to be 1 / 2. G Even when the axial widths of the motor stator 4 and the motor rotor 5 are increased to increase the size of the stationary body, the axial width of the multiple stationary fitting portions 11a, 11b can be kept small compared to the conventional structure in which the portion of the outer surface of the stationary body onto which the motor stator is fitted is composed of a continuous stationary fitting portion over the entire axial length.

[0049] When manufacturing the stationary body 6, a rough machining step is performed in which a metal material is forged and / or cut to obtain an intermediate body having the general shape of the stationary body 6 (including the plurality of stationary fitting portions 11a, 11b and the relief portion 12), and then a precision machining step is performed in which portions of the outer circumferential surface of the intermediate body where the plurality of stationary fitting portions 11a, 11b are to be formed are ground to form the plurality of stationary fitting portions 11a, 11b in those portions with high precision in terms of outer diameter, coaxiality, and inclination accuracy. When forging is performed as the rough machining step, either die forging or free forging can be used.

[0050] In the aircraft rotation support device 1, the axial width of the multiple stationary fitting portions 11a, 11b can be kept small, making it easy to form each of the stationary fitting portions 11a, 11b with high precision during the precision machining process. As a result, it becomes easier to ensure coaxiality between the motor stator 4 and the motor rotor 5, and it becomes easier to keep the radial width of the gap portion G small, making it easier to further improve the output performance of the drive motor 2.

[0051] In this example, at least one of the double-row outer ring raceways 9a, 9b is formed directly on the inner surface of the stationary body 6, and / or at least one of the double-row inner ring raceways 10a, 10b is formed directly on the outer surface of the rotating body 7.

[0052] More specifically, in this example, the double-row outer ring raceways 9a, 9b are formed directly on the inner peripheral surface of the stationary body 6. In other words, the stationary body 6 is composed only of the annular stationary-side support member 13, and the double-row outer ring raceways 9a, 9b are formed on the inner peripheral surface of the stationary-side support member 13.

[0053] Furthermore, of the double-row inner ring raceways 10a, 10b, the inner ring raceway 10a on one axial side is formed directly on the outer peripheral surface of the rotating body 7. More specifically, the rotating body 7 is composed of a rotating-side support member 14 and an inner ring 15 fitted onto the rotating-side support member 14, and the outer peripheral surface of the rotating body 7 includes the outer peripheral surface of the rotating-side support member 14 and the outer peripheral surface of the inner ring 15, with the inner ring raceway 10a on one axial side being formed on the outer peripheral surface of the rotating-side support member 14 and the inner ring raceway 10b on the other axial side being formed on the outer peripheral surface of the inner ring 15.

[0054] In the aircraft rotation support device 1 of this example, the outer surfaces of the outer rings of a pair of single-row ball bearings arranged axially spaced apart are fitted inside the inner surface of a stationary body, and the inner surfaces of the inner rings of the pair of single-row ball bearings are fitted outside the outer surface of a rotating body, making it easier to ensure concentricity between the motor stator 4 and the motor rotor 5.

[0055] In other words, in the conventional structure, there is a tolerance in the radial width of the single-row ball bearing, which is the difference between the outer diameter of the outer ring and the inner diameter of the inner ring, and there is also a tolerance in the radial width of the portion between the inner peripheral surface of the stationary body and the outer peripheral surface of the rotating body where the single-row ball bearing is located. This results in a large accumulation of tolerances when the components that make up the aircraft rotation support device are assembled, which tends to reduce the coaxiality between the stationary body and the rotating body, i.e., the coaxiality between the motor stator and motor rotor attached to them. This makes it difficult to maintain a small radial gap between the motor stator and motor rotor.

[0056] In contrast, in the aircraft rotation support device 1 of this embodiment, at least one of the double-row outer ring raceways 9a, 9b (in this embodiment, both of the double-row outer ring raceways 9a, 9b) is formed directly on the inner peripheral surface of the stationary body 6, and at least one of the double-row inner ring raceways 10a, 10b (in this embodiment, the inner ring raceway 10a on one axial side) is formed directly on the outer peripheral surface of the rotating body 7. Compared to conventional structures, the aircraft rotation support device 1 of this embodiment can omit at least one outer ring (in this embodiment, two outer rings) and at least one inner ring (in this embodiment, one inner ring), thereby minimizing the buildup of tolerances when assembling the components that make up the aircraft rotation support device 1. This makes it easier to ensure coaxiality between the stationary body 6 and the rotating body 7, i.e., between the motor stator 4 and the motor rotor 5. This allows for a smaller air gap G, improving the output performance of the drive motor 2.

[0057] Furthermore, in the aircraft rotation support device 1 of this example, at least one outer ring (two outer rings in this example) and / or at least one inner ring (one inner ring in this example) can be omitted, which makes it possible to reduce the weight of the stationary body 6 and the rotating body 7 and to keep the outer diameter of the stationary body 6 small compared to conventional structures. In other words, it is easy to make the aircraft rotation support device 1 small and lightweight.

[0058] However, when implementing the aircraft rotation support device of the present disclosure, a configuration can also be adopted in which the stationary body includes an annular stationary support member and two outer rings fitted into the stationary support member, and the double-row outer ring raceways are formed on the inner circumferential surfaces of the two outer rings. Alternatively, a configuration can also be adopted in which the stationary body includes an annular stationary support member and one outer ring fitted into the stationary support member, and one of the double-row outer ring raceways is formed on the inner circumferential surface of the stationary support member, and the other of the double-row outer ring raceways is formed on the inner circumferential surface of the one outer ring.

[0059] Furthermore, when implementing the aircraft rotation support device of the present disclosure, the rotating body may include a rotating-side support member and two inner rings fitted onto the rotating-side support member, with the double-row inner ring tracks formed on the outer peripheral surfaces of the two inner rings. Alternatively, the rotating body may be configured only with a rotating-side support member, with the double-row inner ring tracks formed on the outer peripheral surface of the rotating-side support member.

[0060] In the stationary body 6, the stationary side support member 13 is made of a hard metal such as an iron alloy.

[0061] Each of the outer ring raceways 9a, 9b has a generatrix shape that corresponds to the shape of the multiple rolling elements 8a, 8b. When the multiple rolling elements 8a, 8b are balls, each of the outer ring raceways 9a, 9b has an arc-shaped generatrix shape, and when the multiple rolling elements 8a, 8b are tapered rollers, each of the outer ring raceways 9a, 9b has a linear generatrix shape that is inclined with respect to the central axis of the stationary body 6.

[0062] In this example, the rolling elements 8a, 8b are made up of balls, and therefore each of the outer ring raceways 9a, 9b has an arc-shaped generatrix.

[0063] In this example, the bearing portion of the aircraft rotary support device 1 has a uniform PCD structure in which the pitch circle diameters of the rolling elements 8a, 8b arranged in double rows are equal. Therefore, the radii of curvature and groove bottom diameters of the double row outer ring raceways 9a, 9b are equal. However, the present disclosure can also be applied to aircraft rotary support devices in which the bearing portion has a variable PCD structure in which the pitch circle diameters of the rolling elements arranged in double rows are different. In this case, the radii of curvature and / or groove bottom diameters of the double row outer ring raceways can be different.

[0064] In this example, the stationary body 6 has a cylindrical shoulder 16a on a portion of its inner circumferential surface adjacent to the other axial side of the outer ring raceway 9a on one axial side, and a cylindrical shoulder 16b on a portion of its inner circumferential surface adjacent to one axial side of the outer ring raceway 9b on the other axial side. In this example, the inter-row portion 38 of the inner circumferential surface of the stationary body 6, which is located between the double-row outer ring raceways 9a, 9b, is formed by a cylindrical surface whose inner diameter does not change in the axial direction, and each of the shoulders 16a, 16b is formed by both axial end portions of the cylindrical surface.

[0065] In this example, the stationary body 6 has a cylindrical counterbore portion 17a on its inner circumferential surface adjacent to one axial side of the outer ring raceway 9a on one axial side, and a cylindrical counterbore portion 17b on its inner circumferential surface adjacent to the other axial side of the outer ring raceway 9b on the other axial side. The inner diameter of the counterbore portion 17a on one axial side is the same as or slightly smaller than the groove bottom diameter of the outer ring raceway 9a on one axial side. The inner diameter of the counterbore portion 17b on the other axial side is the same as or slightly smaller than the groove bottom diameter of the outer ring raceway 9b on the other axial side.

[0066] The number, axial positions, and axial width W of the stationary fitting portions 11a, 11b arranged axially apart on the outer peripheral surface of the stationary body 6 (stationary side support member 13) 11a , W 11b can be set arbitrarily as long as the motor stator 4 can be appropriately supported relative to the stationary body 6.

[0067] Number, axial position, and axial width W of the recessed portions 12 12 indicates the number, axial positions, and axial width W of the stationary fitting portions 11a and 11b provided on the outer peripheral surface of the stationary body 6. 11a , W 11b It is determined by the relationship.

[0068] Diameter D of the smallest diameter part 12m, which is the deepest part of the relief part 12 12m can be set arbitrarily as long as the strength required for the stationary body 6 can be secured. In this example, the diameter D12m of the minimum diameter portion 12m of the relief portion 12 is set equal to the diameter D12m of the maximum diameter portions 9aM and 9bM of the double row outer ring raceways 9a and 9b. 9aM , D 9bM greater than (D 12m >D 9aM , D 12m >D 9bM ) Therefore, it is easy to ensure a wall thickness that ensures the strength required for the stationary body 6. In this example, the maximum diameter portions 9aM and 9bM of the double row outer ring raceways 9a and 9b are the groove bottoms of the outer ring raceways 9a and 9b. As is clear from the above explanation, these diameters D 9aM , D 9bM The size relationship between these diameters D 9aM , D 9bM are equal to each other.

[0069] In this example, the minimum diameter portions 12m of the recesses 12 are disposed only at positions axially offset from the maximum diameter portions 9aM, 9bM of the double-row outer ring raceways 9a, 9b, respectively, making it easy to ensure a wall thickness sufficient to ensure the strength required for the stationary body 6.

[0070] In addition, when implementing the rotation support device for an aircraft of the present disclosure, if the minimum diameter portion 12m of the relief portion 12 is disposed only at a position deviated from the maximum diameter portions 9aM and 9bM of the double-row outer ring raceways 9a and 9b in the axial direction as in this example, the diameter D12m of the minimum diameter portion 12m of the relief portion 12 is set to the diameter D12m of the maximum diameter portions 9aM and 9bM of the double-row outer ring raceways 9a and 9b. 9aM , D 9bM You can also set it to:

[0071] In this example, the relief portion 12 is disposed so as to overlap in the radial direction with an inter-row portion 38, which is a portion of the inner circumferential surface of the stationary body 6 located between the double-row outer ring raceways 9a, 9b.

[0072] In this example, the axial width W of the recess 12 12 is the axial width W of the inter-row portion 38 38 That's all (W 12 ≧W 38 ), the entire inter-row portion 38 overlaps with the recessed portion 12 in the radial direction. That is, in this example, by adopting such a configuration, the axial width W 12 By setting the width of each of the first and second stationary fitting portions 11a, 11b to be large, the axial widths of the first and second stationary fitting portions 11a, 11b are kept sufficiently small, which makes it easy to form the stationary fitting portions 11a, 11b with high precision by the precision machining process.

[0073] Specifically, in this example, the axial width W of the recess 12 12 is the axial width W of the inter-row portion 38 38 Larger than (W 12 >W 38 ), the end of the relief portion 12 on one axial side is arranged to overlap radially with the outer ring raceway 9a on one axial side, and the end of the relief portion 12 on the other axial side is arranged to overlap radially with the outer ring raceway 9b on the other axial side.

[0074] More specifically, in this example, the end of the relief portion 12 on one axial side is disposed at the same axial position as the maximum diameter portion 9aM of the outer ring raceway 9a on one axial side, and the end of the relief portion 12 on the other axial side is disposed at the same axial position as the maximum diameter portion 9bM of the outer ring raceway 9b on the other axial side. However, when implementing the aircraft rotation support device of the present disclosure, the end of the relief portion 12 on one axial side can be disposed on one axial side or the other axial side of the maximum diameter portion 9aM of the outer ring raceway 9a on one axial side, or the end of the relief portion 12 on the other axial side can be disposed on the other axial side or one axial side of the maximum diameter portion 9bM of the outer ring raceway 9b on the other axial side.

[0075] In this example, at least a portion of the outer ring raceway 9a on one axial side is disposed so as to radially overlap the first stationary fitting portion 11a, and at least a portion of the outer ring raceway 9b on the other axial side is disposed so as to radially overlap the second stationary fitting portion 11b. Specifically, in this example, a portion of the outer ring raceway 9a on one axial side that is located on one axial side of the groove bottom (maximum diameter portion 9aM) is disposed so as to radially overlap the first stationary fitting portion 11a, and a portion of the outer ring raceway 9b on the other axial side that is located on the other axial side of the groove bottom (maximum diameter portion 9bM) is disposed so as to radially overlap the second stationary fitting portion 11b. Therefore, the motor stator 4 can be press-fitted onto the stationary body 6 near the outer diameter sides of the double-row rolling elements 8a, 8b, and deformation of the stationary body 6 can be effectively suppressed by the motor stator 4.

[0076] In addition, when the rotation support device for an aircraft of the present disclosure is implemented, the axial width W of the relief portion 12 12 The axial width W of the inter-row portion 38 38 It can also be made smaller (W 12 >W 38 ).

[0077] In this example, the minimum diameter portion 12m of the recess 12 (axial width: W 12m ) is arranged only on the other axial side of the maximum diameter portion 9aM of the outer ring raceway 9a on one axial side and on one axial side of the maximum diameter portion 9bM of the outer ring raceway 9b on the other axial side. In other words, the minimum diameter portion 12m of the relief portion 12 is located in the axial middle of the axial range (axial width: W9) between the maximum diameter portion 9aM of the outer ring raceway 9a on one axial side and the maximum diameter portion 9bM of the outer ring raceway 9b on the other axial side. This makes it easy to ensure a wall thickness that ensures the strength required for the stationary body 6.

[0078] In this example, the axial width W of the minimum diameter portion 12m of the recess 12 12m The axial width W of the inter-row portion 38 38 (W 12m >W 38However, when implementing the rotation support device for an aircraft of the present disclosure, the axial width W of the minimum diameter portion 12m of the recess 12 12m The axial width W of the inter-row portion 38 38 , and the entire minimum diameter portion 12m of the relief portion 12 can be arranged to overlap radially with the inter-row portion 38. By adopting such a configuration, it becomes easier to ensure the wall thickness required to ensure the strength required for the stationary body 6.

[0079] The recess 12 can have any cross-sectional shape, such as a rectangle, a triangle, a U-shape, or a similar shape, but in this example, it has a trapezoidal cross-sectional shape. The inner surface of the recess 12 has a first inner surface 18 that is the inner surface on one axial side, a second inner surface 19 that is the inner surface on the other axial side, and a bottom surface 20 that forms the minimum diameter portion 12m of the recess 12.

[0080] The first inner surface 18 faces the other axial side and is inclined in a direction toward the other axial side as it extends radially inward. The radially outer end of the first inner surface 18 is connected to the other axial end of the first stationary fitting portion 11 a.

[0081] The second inner surface 19 faces one side in the axial direction and is inclined in a direction toward one axial side as it extends radially inward. A radially outer end of the second inner surface 19 is connected to an end of the second stationary fitting portion 11b on one axial side.

[0082] The bottom surface 20 is disposed between the first inner surface 18 and the second inner surface 19 in the axial direction, and is configured as a cylindrical surface whose outer diameter does not change in the axial direction. One axial end of the bottom surface 20 is connected to a radially inner end of the first inner surface 18, and the other axial end of the bottom surface 20 is connected to a radially inner end of the second inner surface 19.

[0083] In this example, the axial width W of the recess 12 12 The axial width W of each of the first stationary fitting portion 11a and the second stationary fitting portion 11b is 11a , W 11b greater than (W12 >W 11a , W 12 >W 11b In other words, in this example, by adopting such a configuration, the axial width W of the relief portion 12 12 By setting the width of each of the first and second stationary fitting portions 11a, 11b to be large, the axial widths of the first and second stationary fitting portions 11a, 11b are kept sufficiently small, which makes it easy to form the stationary fitting portions 11a, 11b with high precision by the precision machining process.

[0084] As long as the stationary body 6 can be supported and fixed to the machine frame, there are no limitations on the shape or method of the support and fixing. For example, the stationary body 6 can be supported and fixed directly to the machine frame by a connecting member, or can be supported and fixed to the machine frame via the motor stator 4.

[0085] In this example, the stationary body 6 is directly supported and fixed to the aircraft frame by connecting members. For this purpose, the stationary body 6 has a stationary flange 21 that protrudes radially outward at a portion located on the other axial side of each of the stationary fitting portions 11a and 11b. In this example, the stationary flange 21 protrudes radially outward from the end portion on the other axial side of the stationary body 6. The stationary flange 21 has flange-side support holes 22 that penetrate in the axial direction at multiple locations circumferentially in the radial middle portion.

[0086] The stationary body 6 is directly supported and fixed to the machine frame by inserting support bolts, which are connecting members, into frame-side support holes provided in the machine frame and screwing them into flange-side support holes 22. When implementing the present disclosure, it is also possible to directly support and fix the stationary body 6 to the machine frame by configuring the flange-side support holes 22 as through-holes and screwing the bolts inserted into the flange-side support holes 22 into frame-side support holes provided in the machine frame.

[0087] In the rotating body 7, the inner ring raceways 10a, 10b each have a generatrix shape that corresponds to the shapes of the multiple rolling elements 8a, 8b. When the multiple rolling elements 8a, 8b are balls, the inner ring raceways 10a, 10b each have an arc-shaped generatrix shape, and when the multiple rolling elements 8a, 8b are tapered rollers, the inner ring raceways 10a, 10b each have a linear generatrix shape that is inclined with respect to the central axis of the rotating body 7.

[0088] In this example, the rolling elements 8a and 8b are made up of balls, and therefore each of the inner ring raceways 10a and 10b has a generatrix shape of an arc.

[0089] The rotating side support member 14 is made of a hard metal such as an iron alloy.

[0090] In this example, the inner ring raceway 10a on one axial side is formed on the outer peripheral surface of the axially middle portion of the rotation-side support member 14. The rotation-side support member 14 has a cylindrical shoulder portion 23a on the outer peripheral surface in a portion adjacent to one axial side of the inner ring raceway 10a on one axial side.

[0091] The rotating side support member 14 has a rotating flange 24 that protrudes radially outward from a portion located on one axial side of the stationary body 6 and to which the motor rotor 5 and propeller 3 are coupled. In this example, the rotating flange 24 is provided at one axial end of the rotating side support member 14 and is configured as a hollow circular flat plate. The rotating flange 24 has mounting holes 25 that penetrate the axial direction at multiple locations circumferentially in the radial middle portion.

[0092] Of the motor rotor 5 and the propeller 3, at least the motor rotor 5 is coupled and fixed to the rotating flange 24 using the mounting holes 25. That is, the mounting holes 25 are configured as threaded holes or press-fit holes. When the mounting holes 25 are configured as threaded holes, the motor rotor 5 is coupled and fixed to the rotating flange 24 by threading bolts inserted into through holes provided at multiple locations circumferentially on the radially inner side of the motor rotor 5 into the mounting holes 25 from one axial side. When the mounting holes 25 are configured as press-fit holes, studs are press-fit into the mounting holes 25 from the other axial side. The motor rotor 5 is coupled and fixed to the rotating flange 24 by inserting the studs into through holes provided at multiple locations circumferentially on the radially inner side of the motor rotor 5 and screwing nuts onto the tips of the studs. In this example, the mounting holes 25 are configured as threaded holes.

[0093] Outer diameter D of rotating flange 24 24 is not particularly limited, and for example, the outer diameter D 11 or more, and the outer diameter D 11 In this example, the outer diameter D of the rotating flange 24 can be made smaller than 24 The outer diameter D of the stationary fitting portions 11a and 11b of the stationary body 6 11 (D 24 <D 11 Therefore, after assembling the aircraft rotation support device 1, the motor stator 4 can be externally fitted into the stationary fitting portions 11a and 11b by press-fitting from one axial side.

[0094] In this example, the rotation-side support member 14 has, at a portion located on the other axial side of the inner ring raceway 10a on one axial side, a small-diameter stepped portion 26 that has a smaller outer diameter than a portion adjacent to that side in the axial direction and onto which the inner ring 15 is fitted. The rotation-side support member 14 has, at the end on one axial side of the small-diameter stepped portion 26, a step surface 27 facing the other axial side, and, at a portion adjacent to the other axial side of the small-diameter stepped portion 26, a male threaded portion 28 onto which a nut 29 is threadedly fitted.

[0095] The inner ring 15 is made of a hard metal such as an iron alloy.

[0096] In this example, the inner ring 15 has a cylindrical shoulder portion 23b on the outer peripheral surface at a portion adjacent to the other axial side of the inner ring raceway 10b on the other axial side.

[0097] The rotating body 7 is constructed by fitting the inner ring 15 onto the small diameter step portion 26 of the rotating side support member 14, and by clamping the inner ring 15 from both axial sides between a step surface 27 of the rotating side support member 14 and one axial side surface of a nut 29 that is threaded onto the male thread portion 28 of the rotating side support member 14, thereby connecting and fixing the rotating side support member 14 and the inner ring 15. In the aircraft rotation support device 1 of this example, the rotating body 7 is constructed by connecting and fixing the rotating side support member 14 and the inner ring 15, so that the preload applied to the rolling bodies 8a, 8b can be adjusted to an appropriate magnitude.

[0098] When implementing the present disclosure, instead of a nut, a configuration can be adopted in which a crimped portion is formed by plastically deforming the end portion of the rotating side support member on the other axial side that protrudes from the end face on the other axial side of the inner ring radially outward, and the crimped portion presses down on the end face on the other axial side of the inner ring, thereby connecting and fixing the rotating side support member and the inner ring.

[0099] The types of rolling elements 8a, 8b are determined appropriately depending on the type of rolling bearing composed of double-row outer ring raceways 9a, 9b, double-row inner ring raceways 10a, 10b, and rolling elements 8a, 8b. In this example, rolling elements 8a, 8b are composed of balls. However, tapered rollers can also be used as rolling elements 8a, 8b instead of balls.

[0100] The rolling elements 8a and 8b are made of metal such as an iron alloy or ceramics.

[0101] In this example, a back-to-back (DB) contact angle θ and a predetermined amount of preload are applied to the rolling elements 8a, 8b in each row. The magnitude of the contact angle θ can be determined arbitrarily within a range that ensures the required bearing rigidity, for example, within a range of 1° to 45°. The magnitude of the contact angle θ is not limited to this, but is preferably 15° to 45°, and more preferably 15° to 42°. In this example, the rolling elements 8a, 8b in each row are held in a freely rollable manner by cages 30a, 30b.

[0102] In this example, a predetermined amount of preload is applied to the rolling elements 8a, 8b in each row by abutting the end face on one axial side of the inner ring 15 against the stepped surface 27 of the rotation-side support member 14 and regulating the force pressing down on the end face on the other axial side of the inner ring 15 with the nut 29. When a structure is adopted in which the end face on the other axial side of the inner ring is pressed down by a crimped portion formed on the end of the rotation-side support member on the other axial side, a predetermined amount of preload can be applied to the rolling elements in each row by regulating the force pressing down on the end face on the other axial side of the inner ring by the crimped portion.

[0103] In the aircraft rotation support device 1 of this example, the diameters of the rolling elements 8a in the row on one axial side and the diameters of the rolling elements 8b in the row on the other axial side are equal to each other, but when implementing the aircraft rotation support device of this disclosure, the diameters of the rolling elements 8a in the row on one axial side and the diameters of the rolling elements 8b in the row on the other axial side can also be made different from each other. Furthermore, the aircraft rotation support device 1 of this example has an equal-diameter PCD structure in which the pitch circle diameters of the rolling elements 8a in the row on one axial side and the pitch circle diameters of the rolling elements 8b in the row on the other axial side are equal to each other. However, the aircraft rotation support device of this disclosure can also be applied to a different-diameter PCD structure in which the pitch circle diameters of the rolling elements 8a, 8b in each row are different from each other.

[0104] The aircraft rotation support device 1 of this example further includes, as optional elements, a one-side seal 32 that closes an opening on one axial side of the rolling element installation space 31 that exists between the inner circumferential surface of the stationary body 6 and the outer circumferential surface of the rotating body 7, and an other-side seal 33 that closes an opening on the other axial side of the rolling element installation space 31. This prevents or suppresses foreign matter from the external space from entering the rolling element installation space 31 through the openings on both axial sides of the rolling element installation space 31, and the grease sealed in the rolling element installation space 31 from leaking into the external space. However, the one-side seal 32 and / or the other-side seal 33 may be omitted.

[0105] Each of the one-side seal 32 and the other-side seal 33 may be a contact-type seal or a non-contact-type seal. As a contact-type seal, for example, a seal ring supported by the stationary body 6 and having a seal lip that slides against the surface of the rotating body 7, or a combination seal ring formed by combining a sliding contact ring fixed to the rotating body 7 with a seal ring supported by the stationary body 6 and having a seal lip that slides against the surface of the sliding contact ring, can be used. Furthermore, as a non-contact-type seal, for example, a seal ring (shield plate) supported by the stationary body 6 and having a portion thereof closely facing the surface of the rotating body 7 can be used.

[0106] In this example, each of the one-side seal 32 and the other-side seal 33 is configured as a seal ring, which is a contact-type seal. Although detailed illustration is omitted, in this example, each of the one-side seal 32 and the other-side seal 33 is configured as a ring by joining a rubber sealing material to a core metal made of a metal plate such as a steel plate.

[0107] The one-side seal 32 includes a cylindrical fitting tubular portion 34a formed from the core metal and having a cylindrical shape, and a conical side plate portion 35a formed from the sealing material and extending radially inward and toward the other axial direction from one axial end of the fitting tubular portion 34a, with the side plate portion 35a functioning as a seal lip. The fitting tubular portion 34a is tightly fitted onto the inner circumferential surface of the one axial end of the stationary-side support member 13. The radially inner end of the side plate portion 35a is in sliding contact with the shoulder portion 23a.

[0108] The other-side seal 33 includes a cylindrical fitting portion 34b made of the core metal and a conical side plate portion 35b made of the sealing material and extending radially inward and toward one axial side from the other axial end of the fitting portion 34b, with the side plate portion 35b functioning as a seal lip. The fitting portion 34b is tightly fitted into the inner circumferential surface of the other axial end of the stationary-side support member 13. The radially inner end of the side plate portion 35b is in sliding contact with the shoulder portion 23b.

[0109] The motor stator 4 includes a core made of a magnetic material and a coil wound around the core, and is cylindrical in shape as a whole. The outer surface of the core has multiple magnetic poles arranged at equal pitch in the circumferential direction.

[0110] The motor stator 4 can also be configured to include an annular member fitted inside the core. The annular member functions as a base to ensure a large output torque of the drive motor 2 by increasing the outer diameter of the core while keeping the radial width of the core small. The annular member can also function as a heat exchanger that efficiently receives heat from the adjacent core and efficiently exchanges heat with the surrounding air, making it easier to cool the drive motor 2. In this case, the annular member is preferably made of a light alloy such as an aluminum alloy, which has high thermal conductivity.

[0111] In this example, the motor stator 4 is supported and fixed to the stationary body 6 by press-fitting the core or the annular member into the stationary fitting portions 11a and 11b, respectively.

[0112] The motor rotor 5 includes a substantially disk-shaped side plate portion 36 that is an attachment portion to the rotor 7, and a cylindrical tubular portion 37 that extends from the radially outer end of the side plate portion 36 toward the other axial direction. South poles and north poles are alternately arranged in the circumferential direction at multiple equally spaced locations on the inner peripheral surface of the tubular portion 37.

[0113] In this example, the motor rotor 5 is arranged coaxially with the rotating body 7, and is fixed to the rotating flange 24 by threading bolts (not shown) through through holes provided at multiple locations around the circumference of the radially inner portion of the side plate 36 into mounting holes 25 of the rotating flange 24, with the other axial side surface of the radially inner portion of the side plate 36 abutting against the one axial side surface of the rotating flange 24. In this state, multiple south poles and multiple north poles provided on the inner peripheral surface of the tubular portion 37 of the motor rotor 5 closely face multiple magnetic poles provided on the outer peripheral surface of the motor stator 4 in the radial direction.

[0114] In this example, the propeller 3 is fixed to the rotating body 7 via the motor rotor 5 by aligning the central axis of rotation with the central axis of the rotating body 7 and abutting the other axial side of the portion surrounding the central axis of rotation against the side of one axial side of the side plate portion 36 of the motor rotor 5, and threading bolts through holes provided at multiple locations around the circumference of the propeller 3 into screw holes provided at multiple locations around the circumference of the side plate portion 36.

[0115] In addition, the propeller 3 can also be connected and fixed to the rotating flange 24 together with the motor rotor 5 by threading bolts passed through the through holes provided at multiple locations around the circumference of the propeller 3 and the through holes provided at multiple locations around the circumference of the side plate portion 36 into the mounting holes 25 of the rotating flange 24.

[0116] The propeller 3 can also be connected and fixed to the rotating flange 24 by threading bolts that are inserted through through holes provided at multiple locations around the circumference of the propeller 3 and through other through holes provided at multiple locations around the circumference of the side plate portion 36 into the mounting holes 25 of the rotating flange 24. Here, the other through holes refer to through holes that are different from the through holes through which bolts for connecting and fixing the motor rotor 5 to the rotating flange 24 are inserted. In this case, some of the multiple mounting holes 25 provided in the rotating flange 24 are used to connect and fix the motor rotor 5 to the rotating flange 24, and the remaining mounting holes 25 are used to connect and fix the propeller 3 to the rotating flange 24.

[0117] Alternatively, the mounting holes 25 of the rotating flange 24 may be formed as press-fit holes, and a stud may be pressed into the press-fit hole and inserted through the through holes of the side plate portion 36 and the propeller 3, and a nut may be screwed onto the tip of the stud, thereby connecting and fixing the motor rotor 5 and the propeller 3 to the rotating flange 24.

[0118] In any case, with the motor stator 4, motor rotor 5, and propeller 3 attached to the rotational support device 1 for an aircraft in this example, electricity is passed through the coil that makes up the motor stator 4, and a torque (electromagnetic force) that rotates the motor rotor 5 relative to the motor stator 4 is generated between the multiple magnetic poles of the motor stator 4 and the multiple south poles and north poles of the motor rotor 5, thereby driving the rotating body 7 and propeller 3 to rotate.

[0119] According to the aircraft rotation support device 1 of this example, the precision machining process makes it easy to form each of the stationary fitting portions 11a, 11b with high precision. This makes it easy to ensure the coaxiality between the motor stator 4 and the motor rotor 5 and to keep the radial width of the air gap G small, which makes it easy to improve the output performance of the drive motor 2. [Explanation of symbols]

[0120] 1 Rotational support device for aircraft 2. Drive motor 3 propellers 4 Motor stator 5 Motor rotor 6 Stationary Objects 7 Rotating Body 8a, 8b rolling elements 9a, 9b Outer ring raceway 9aM, 9bM Maximum diameter 10a, 10b Inner raceway 11a, 11b Stationary mating part 12 Relief 12m minimum diameter 13 Stationary side support member 14 Rotation side support member 15 Inner Circle 16a, 16b Shoulder 17a, 17b Counterbore 18 1st inner surface 19 Second inner surface 20 bottom 21 Stationary flange 22 Flange side support hole 23a, 23b Shoulder 24 Rotating flange 25 Mounting holes 26 Small diameter stepped section 27 Step surface 28 Male thread 29 Nut 30a, 30b retainer 31 Rolling element installation space 32 One-side seal 33 Other side seal 34a, 34b Fitting cylinder part 35a, 35b side plate part 36 Side plate part 37 Cylinder part 38 Between rows

Claims

1. a stationary body having a double row outer ring raceway on its inner circumferential surface and capable of supporting a motor stator; a rotor having a double row inner ring raceway on its outer circumferential surface and capable of supporting a motor rotor and a propeller; and a plurality of rolling elements arranged in each row between the double row outer ring raceways and the double row inner ring raceways, the stationary body has stationary fitting portions at a plurality of axially spaced locations on its outer peripheral surface, into which the motor stator is press-fitted, and a relief portion having an outer diameter smaller than the outer diameter of the stationary fitting portion, in a portion of the outer peripheral surface located between two axially adjacent stationary fitting portions; Rotation support device for aircraft.

2. 2. A rotary support device for an aircraft as described in claim 1, wherein at least one outer ring raceway of the double row outer ring raceways is formed directly on the inner peripheral surface of the stationary body, and / or at least one inner ring raceway of the double row inner ring raceways is formed directly on the outer peripheral surface of the rotating body.

3. the double-row outer ring raceway is formed directly on the inner circumferential surface of the stationary body, 2. The aircraft rotation support device according to claim 1, wherein the diameter of the minimum diameter portion of the recessed portion is larger than the diameter of the maximum diameter portion of the double-row outer ring raceway.

4. the double-row outer ring raceway is formed directly on the inner circumferential surface of the stationary body, the minimum diameter portion of the relief portion is disposed only at a position deviated from the maximum diameter portion of the double row outer ring raceway in the axial direction; The rotary support device for an aircraft according to claim 1.

5. the double-row outer ring raceway is formed directly on the inner circumferential surface of the stationary body, the stationary fitting portion includes a first stationary fitting portion and a second stationary fitting portion that are adjacent to each other in the axial direction and are on one axial side, the relief portion located between the first stationary fitting portion and the second stationary fitting portion is disposed so as to radially overlap with an inter-row portion, which is a portion of the inner circumferential surface of the stationary body located between the double-row outer ring raceways, The rotary support device for an aircraft according to claim 1.

6. 6. The rotational support device for an aircraft according to claim 5, wherein the axial width of the recessed portion is equal to or greater than the axial width of the inter-row portion, and the entire inter-row portion radially overlaps the recessed portion.

7. 6. A rotational support device for an aircraft as described in claim 5, wherein at least a portion of the outer ring raceway on one axial side of the double-row outer ring raceways is arranged so as to overlap radially with the first stationary fitting portion, and at least a portion of the outer ring raceway on the other axial side of the double-row outer ring raceways is arranged so as to overlap radially with the second stationary fitting portion.

8. 8. The rotational support device for an aircraft according to claim 7, wherein the minimum diameter portion of the relief portion is located on the other axial side of the maximum diameter portion of the outer ring raceway on one axial side of the double-row outer ring raceway, and on the one axial side of the maximum diameter portion of the outer ring raceway on the other axial side of the double-row outer ring raceway.

9. the rotating body has a rotating flange that protrudes radially outward from a portion located on one axial side of the stationary body, and to which the motor rotor and the propeller are coupled, The outer diameter of the rotating flange is smaller than the outer diameter of the stationary fitting portion. The rotary support device for an aircraft according to claim 1.

10. 2. The aircraft rotation support device according to claim 1, wherein the stationary body has a stationary flange that protrudes radially outward at a portion located on the other axial side of the stationary fitting portion.

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