Rotary support device for flying object

Abstract

To provide a rotary support device for a flying object in which stress concentration on a surface of a root part of a rotary flange is unlikely to occur, and bearing load capacities in both rows are easily ensured.SOLUTION: A rotation-side support member 11 includes a rotary flange 13 which projects radially outward from a portion located on one axial-direction side with respect to a stationary object 6 and to which a motor rotor and a propeller are connected, and an annular groove 14 that is disposed on a portion, of an outer circumferential surface, adjoining to the other axial-direction side of the rotary flange 13, and further includes an inclined part 15 that is disposed on a radially inner end of a side surface on the other axial-direction side of the rotary flange 13 and extends to be closer to the other axial-direction side toward the radially inner side, and mount holes 16 that, at a plurality of circumferential-direction positions radially outside the inclined part 15, pass through the rotary flange in the axial direction.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 apart between the inner peripheral surface of the stationary body and 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 has magnetic poles at a plurality of equally spaced locations in the circumferential direction on its outer circumferential surface. The motor stator is supported and fixed to the stationary body.

[0008] The motor rotor has a plurality of magnets in a portion radially facing the outer peripheral surface of the motor stator, and is supported and fixed to an end portion on one axial side (upper side) of the rotating body. From the viewpoint of increasing the output of the drive motor, it is preferable that the radial gap between the motor stator and motor rotor is as small as possible.

[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, an electromagnetic force is generated relative to the motor stator to rotate the motor rotor, 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 the conventional structure described in JP 2020-072530 A, each single-row ball bearing constituting the pair of single-row ball bearings has 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.

[0013] In this conventional structure, there is a tolerance in the radial width of the single-row ball bearing, i.e., 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.

[0014] FIG. 4 shows an aircraft rotation support device 100 that the inventors have previously devised in view of the above circumstances, and which makes it easy to ensure coaxiality between the motor stator and the motor rotor.

[0015] The rotary support device 100 for an aircraft comprises a stationary body 101 having double-row outer ring raceways 104a, 104b on its inner peripheral surface and capable of supporting a motor stator 113, a rotating body 102 having double-row inner ring raceways 105a, 105b on its outer peripheral surface and capable of supporting a motor rotor 114 and a propeller 115, and rolling elements 103a, 103b arranged in multiples in each row between the double-row outer ring raceways 104a, 104b and the double-row inner ring raceways 105a, 105b.

[0016] The rotating body 102 includes a rotating-side support member 107 and an inner ring 108 fitted onto the rotating-side support member 107. Therefore, the outer peripheral surface of the rotating body 102 includes the outer peripheral surface of the rotating-side support member 107 and the outer peripheral surface of the inner ring 108. Of the double-row inner ring raceways 105a, 105b, the inner ring raceway 105a on one axial side (upper side) is formed directly on the outer peripheral surface of the rotating-side support member 107, while the inner ring raceway 105b on the other axial side (lower side) is formed on the outer peripheral surface of the inner ring 108. This aircraft rotary support device 100 can omit one inner ring compared to conventional structures, minimizing the buildup of tolerances when the components constituting the aircraft rotary support device 100 are assembled. Therefore, it is easier to ensure the coaxiality between the stationary body 101 and the rotating body 102, i.e., the coaxiality between the motor stator 113 and the motor rotor 114.

[0017] The stationary body 101 is composed only of a circular stationary-side support member 106. Double-row outer ring raceways 104a, 104b are formed on the inner peripheral surface of the stationary-side support member 106. In this type of aircraft rotary support device 100, two outer rings can be omitted compared to conventional structures, and therefore the accumulation of tolerances when the parts that make up the aircraft rotary support device 100 are assembled can be kept small. Therefore, from this point of view as well, it is easy to ensure coaxiality between the stationary body 101 and the rotating body 102, i.e., coaxiality between the motor stator 113 and the motor rotor 114.

[0018] In aircraft rotation support device 100, rotating-side support member 107 has rotating flange 110 that protrudes radially outward from a portion located on one axial side of stationary body 101 and is coupled to motor rotor 114 and propeller 115. Rotating flange 110 has mounting holes 111 formed by threaded holes that penetrate axially at multiple locations around the circumference. Of motor rotor 114 and propeller 115, at least motor rotor 114 is coupled and fixed to rotating flange 110 by bolts that are threaded into mounting holes 111.

[0019] The rotating flange 110 has an inclined portion 112 on the radially inner side of its side surface on the other axial direction, which extends radially inward and toward the other axial direction. The inclined portion 112 is inclined in a curved line, i.e., curved, and specifically configured by a corner R portion having an arc-shaped cross section. The end portion on the other axial direction of the inclined portion 112 is connected to the end portion on one axial direction side of a cylindrical shoulder portion 109 provided on the outer peripheral surface of the rotation-side support member 107, adjacent to one axial side of the inner ring raceway 105a on one axial direction. The presence of this inclined portion 112 relieves stress acting on the base portion (radially inner end portion) of the rotating flange 110.

[0020] The motor rotor 114 is fixed to the rotating flange 110 by threading bolts, which are inserted through holes provided at multiple locations around the circumference of the radially inner portion of the motor rotor 114, into the mounting holes 111 from one axial side. The pitch circle diameter of the through holes in the motor rotor 114 is set to a predetermined size according to the specifications of the motor manufacturer. The pitch circle diameter D of the mounting holes 111 in the rotating flange 110 is A It is necessary to set the pitch diameter of the through hole of the motor rotor 114 to the same size (the predetermined size).

[0021] Therefore, when the outer diameter of the inner ring raceway 105a on one axial side, the outer diameter of the shoulder portion 109, and the radius of curvature of the inclined portion 112 are set to ensure sufficient load capacity, taking into account the load applied to the drive motor including the motor stator 113 and the motor rotor 114, the outer diameter of the inclined portion 112 becomes larger than the diameter of an imaginary circle centered on the central axis of the rotating side support member 107 and tangent to the radially inner end of the mounting hole 111, and the end of the mounting hole 111 on the other axial side may open into the inclined portion 112, as shown in Figure 4.

[0022] During flight, aircraft rotation support device 100, which supports propeller 115, is subjected to a moment load due to external forces such as wind. At this time, a rotating bending load, which is a repeated load, is applied to inclined portion 112, which is the surface of the base of rotating flange 110. For this reason, if the other axial end of mounting hole 111 opens into inclined portion 112, stress due to the rotating bending load is likely to concentrate on the peripheral edge of the opening, which may make it difficult to ensure durability.

[0023] One possible solution to this problem is to reduce the pitch circle diameter (particularly the outer diameter of the inner ring raceway 105a) of the rolling elements 103a in at least one row on one axial side of the two rows of rolling elements 103a, 103b, and reduce the outer diameter of the shoulder portion 109, thereby making the outer diameter of the inclined portion 112 smaller than the diameter of the virtual circle, and opening the end of the mounting hole 111 on the other axial side at a position located radially outward from the inclined portion 112.

[0024] However, if the pitch circle diameter of the rolling elements 103a in at least one row on the axial side of the two rows of rolling elements 103a, 103b is reduced, it may become difficult to ensure sufficient bearing load capacity for the row with the reduced pitch circle diameter.

[0025] The present disclosure aims to provide a rotational support device for an aircraft that is less likely to experience stress concentration on the surface of the base of the rotating flange and that makes it easy to ensure the bearing load capacity of both rows. [Means for solving the problem]

[0026] 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.

[0027] The rotating body includes a rotating side support member having an inner ring raceway on one axial side of the double-row inner ring raceway directly formed on its outer surface, and an inner ring having an inner ring raceway on the other axial side of the double-row inner ring raceway directly formed on its outer surface and fitted onto the rotating side support member.

[0028] The rotating side support member protrudes radially outward from a portion located on one axial side of the stationary body, and has a rotating flange to which the motor rotor and the propeller are connected, and an annular groove provided on a portion of its outer surface adjacent to the other axial side of the rotating flange, and also has an inclined portion provided on the radially inner end of the side surface on the other axial side of the rotating flange, which extends radially inward toward the other axial side, and mounting holes that axially penetrate the rotating flange at multiple circumferential locations radially outward of the inclined portion.

[0029] A second aspect of the present disclosure provides a rotary support device for an aircraft, comprising: a one-side seal that closes an opening on one axial side of a rolling element installation space that exists between the inner peripheral surface of the stationary body and the outer peripheral surface of the rotating body, The rotating-side support member has an outer circumferential surface, at a portion thereof located on the other axial side of the annular groove, that has a sealing circumferential surface to which the one-side seal is disposed adjacently and radially outward.

[0030] In a rotary support device for an aircraft of a third aspect of the present disclosure, in the rotary support device for an aircraft of the second aspect of the present disclosure, the outer diameter of the sealing peripheral surface is greater than or equal to the diameter of an imaginary circle centered on the central axis of the aircraft and tangent to the radially inner end of the mounting hole.

[0031] 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 stationary body has, on its outer circumferential surface, a stationary fitting portion into which the motor stator is fitted, The outer diameter of the rotating flange is smaller than the outer diameter of the stationary fitting portion. [Effects of the Invention]

[0032] According to the rotational support device for an aircraft of one aspect of the present disclosure, stress concentration is unlikely to occur on the surface of the base portion of the rotational flange, and it is easy to ensure the bearing load capacity of both rows. [Brief explanation of the drawings]

[0033] [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 first example of the rotation support device for an aircraft. [Figure 3] FIG. 3 is an enlarged view of the upper end portion of FIG. [Figure 4] FIG. 4 is a cross-sectional view of a rotary support device for an aircraft previously conceived by the present inventors. DETAILED DESCRIPTION OF THE INVENTION

[0034] 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.

[0035] 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.

[0036] 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.

[0037] The aircraft rotation support device 1 supports a drive motor 2 and a propeller 3 on the aircraft frame (not shown).

[0038] 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.

[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 to 3, and the other axial side is the side opposite the propeller, which is the lower side in Figures 1 to 3.

[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 rotating body 7 is configured to include a rotating side support member 11 on whose outer surface the inner ring raceway 10a on one axial side of the double row inner ring raceways 10a, 10b is directly formed, and an inner ring 12 on whose outer surface the inner ring raceway 10b on the other axial side of the double row inner ring raceways 10a, 10b is directly formed and is externally fitted onto the rotating side support member 11.

[0045] 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.

[0046] That is, in the aircraft rotation support device 1 of this example, the inner ring raceway 10a on one axial side of the double-row inner ring raceways 10a, 10b is formed directly on the outer peripheral surface of the rotating body 7. Specifically, the rotating body 7 includes a rotating-side support member 11 and an inner ring 12 fitted onto the rotating-side support member 11. The outer peripheral surface of the rotating body 7 includes the outer peripheral surface of the rotating-side support member 11 and the outer peripheral surface of the inner ring 12. The inner ring raceway 10a on one axial side is formed directly on the outer peripheral surface of the rotating-side support member 11, and the inner ring raceway 10b on the other axial side is formed directly on the outer peripheral surface of the inner ring 12. Compared to conventional structures, the aircraft rotation support device 1 of this example can omit one inner ring, thereby minimizing the buildup of tolerances when the components constituting the aircraft rotation support device 1 are assembled. 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.

[0047] In the aircraft rotation support device 1 of this example, the rotating-side support member 11 has a rotating flange 13 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, and an annular groove 14 provided on the outer circumferential surface at a portion adjacent to the other axial side of the rotating flange 13. The rotating-side support member 11 also has an inclined portion 15 provided at the radially inner end of the side surface on the other axial side of the rotating flange 13, extending radially inward toward the other axial side, and mounting holes 16 that axially penetrate the rotating flange 13 at multiple locations radially outward of the inclined portion 15 along the circumference. The inclined portion 15 can have any shape as long as it extends radially inward toward the other axial side, and the inclination may be curved or linear. That is, the generatrix shape of the inclined portion 15 can be curved, linear, or a combination of curved and linear shapes. In this example, the inclined portion 15 is configured by a corner R portion having an arc-shaped cross section.

[0048] During flight of the aircraft, a moment load due to external forces such as wind is applied to aircraft rotation support device 1, which supports propeller 3, and a rotating bending load, which is a repeated load, is applied to the base portion (radially inner end) of rotatable flange 13. Inclined portion 15 is provided to relieve stress due to the rotating bending load that acts on the surface of the base portion of rotatable flange 13 on the other axial side.

[0049] Of the motor rotor 5 and the propeller 3, at least the motor rotor 5 is coupled and fixed to the rotating flange 13 by using the mounting holes 16. That is, the mounting holes 16 are configured as threaded holes or press-fit holes. When the mounting holes 16 are configured as threaded holes, the motor rotor 5 is coupled and fixed to the rotating flange 13 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 16 from one axial side. When the mounting holes 16 are configured as press-fit holes, studs are press-fit into the mounting holes 16 from the other axial side. The motor rotor 5 is coupled and fixed to the rotating flange 13 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 16 are configured as threaded holes.

[0050] In the aircraft rotation support device 1 of this example, mounting holes 16 are provided so as to axially penetrate the rotating flange 13 at multiple locations in the circumferential direction radially outward of the inclined portion 15. In other words, the other axial end of mounting hole 16 does not open into inclined portion 15. For this reason, stress concentration due to a rotational bending load is unlikely to occur on inclined portion 15, which is the surface of the base of the rotating flange.

[0051] The pitch circle diameter of the through hole of the motor rotor 5 is set to a predetermined size according to the specifications of the motor manufacturer. A It is necessary to set the size to be the same as the pitch circle diameter of the through hole of the motor rotor 5 (the predetermined size).

[0052] In this regard, in the aircraft rotation support device 1 of this example, the pitch circle diameter D A Even when the size of the annular groove 14 is set to be the same as the pitch circle diameter of the through hole of the motor rotor 5 (the specified size), the presence of the annular groove 14 provided in the portion adjacent to the other axial side of the rotating flange 13 makes it easy to position the inclined portion 15 radially inward of the end portion on the other axial side of the mounting hole 16.

[0053] That is, in the case of a structure in which the portion adjacent to the other axial side of the rotating flange 110 is not provided with an annular groove, as in the structure of the prior art shown in FIG. 4, the pitch circle diameter D A In order to position the inclined portion 112 radially inward from the other axial end of the mounting hole 111 while setting the pitch circle diameter of the inclined portion 112 to the same size as the pitch circle diameter of the through hole of the motor rotor 114, it is necessary to reduce the pitch circle diameter (particularly the outer diameter of the inner ring raceway 105a) of at least the rolling element 103a in the row on one axial side of the two rows of rolling elements 103a, 103b, and to reduce the outer diameter of the shoulder portion 109.

[0054] In contrast, in the aircraft rotation support device 1 of this example, by adjusting the radial depth of the annular groove 14 without reducing the pitch circle diameters of the rolling elements 8a, 8b in both rows (particularly the outer diameters of the inner ring raceways 10a, 10b), it is possible to position the inclined portion 15 radially inward relative to the other axial end of the mounting hole 16. This makes it possible to prevent the other axial end of the mounting hole 111 from opening into the inclined portion 112, as in the structure of the prior invention shown in Figure 4. This makes it less likely that stress will concentrate on the side surface on the other axial side of the base of the rotating flange 13, and makes it easier to ensure the bearing load capacity of both rows.

[0055] The rotary support device for an aircraft of the present disclosure is not limited to the structure of this example, but has the following specific structure in this example.

[0056] In the stationary body 6, the outer ring raceways 9a, 9b can be formed directly on the inner peripheral surface of the stationary body 6, or can be formed via separate outer rings.

[0057] In this example, the 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 an annular stationary-side support member 17, and the outer ring raceways 9a, 9b are formed on the inner peripheral surface of the stationary-side support member 17. The stationary-side support member 17 is made of a hard metal such as an iron alloy.

[0058] In the aircraft rotation support device 1 of this example, compared to a conventional structure in which the outer peripheral surfaces of the outer rings of a pair of single-row ball bearings arranged axially apart are fitted inside the inner peripheral surface of a stationary body and the inner peripheral surfaces of the inner rings of the pair of single-row ball bearings are fitted outside the outer peripheral surface of a rotating body, it is possible to omit two outer rings, thereby minimizing the accumulation of tolerances when assembling the parts 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., coaxiality between the motor stator 4 and the motor rotor 5.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] In this example, the stationary body 6 has a cylindrical shoulder 18a on its inner circumferential surface in a portion adjacent to the other axial side of the outer ring raceway 9a on one axial side, and a cylindrical shoulder 18b on its inner circumferential surface in a portion adjacent to one axial side of the outer ring raceway 9b on the other axial side. In this example, an axially intermediate portion of the inner circumferential surface of the stationary body 6, 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 shoulder 18a, 18b is formed by both axial end portions of the cylindrical surface.

[0063] In this example, the stationary body 6 has a cylindrical counterbore portion 19a 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 19b 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 19a 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 19b 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.

[0064] The stationary body 6 is not limited in terms of the position or shape of the portion supporting the motor stator 4, as long as it is configured to be able to support the motor stator 4. In this example, the stationary body 6 has a stationary fitting portion 20 on its outer circumferential surface for fitting the motor stator 4 onto the outside. In this example, the stationary fitting portion 20 is provided on the outer circumferential surface of the stationary body 6 except for the end portion on the other axial side, and is configured as a cylindrical surface whose outer diameter does not change in the axial direction.

[0065] 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.

[0066] In this example, the stationary body 6 is directly supported and fixed to the aircraft frame by a connecting member. For this purpose, the stationary body 6 has a stationary flange 21 that protrudes radially outward at the other axial end. The stationary flange 21 has flange-side support holes 22 that penetrate in the axial direction at multiple locations circumferentially in the radial middle part.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] The rotating side support member 11 is made of a hard metal such as an iron alloy.

[0071] 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 11. The rotation-side support member 11 has a cylindrical shoulder 23a that forms a sealing peripheral surface in a portion of its outer peripheral surface that is adjacent to one axial side of the inner ring raceway 10a on one axial side. In this example, a side plate 38a that is part of the one-side seal 35 described below is in sliding contact with the shoulder 23a.

[0072] In this example, the outer diameter D23 of the shoulder 23a is equal to or larger than the diameter D16 of an imaginary circle that is centered on the central axis of the rotating body 7 and that is tangent to the radially inner end of the mounting hole 16. However, the diameter D16 of the imaginary circle may also be made larger than the outer diameter D23 of the shoulder 23a.

[0073] In this example, the rotation flange 13 is provided at one axial end of the rotation side support member 11 .

[0074] The outer diameter of the rotating flange 13 is not particularly limited, and can be, for example, equal to or greater than the outer diameter of the stationary fitting portion 20, or can be smaller than the outer diameter of the stationary fitting portion 20. In this example, the outer diameter of the rotating flange 13 is smaller than the outer diameter of the stationary fitting portion 20 of the stationary body 6. Therefore, after assembling the aircraft rotation support device 1, the motor stator 4 can be fitted onto the stationary fitting portion 20 from one axial side.

[0075] In this example, the rotating flange 13 is configured as a hollow circular flat plate. Specifically, in this example, one axial side of the rotating flange 13 is configured as a flat surface perpendicular to the central axis of the rotor 7. The other axial side of the rotating flange 13 is configured as a flat surface perpendicular to the central axis of the rotor 7, except for an inclined portion 15 provided at the radially inner end portion, which is the base portion. The outer peripheral surface of the rotating flange 13 is configured as a cylindrical surface whose outer diameter does not change in the axial direction.

[0076] In this example, the annular groove 14 is provided in a portion sandwiched between the rotary flange 13 and the shoulder portion 23a in the axial direction.

[0077] Although not limited thereto, in this example, the annular groove 14 has a substantially rectangular cross-sectional shape. In addition to the inclined portion 15, the inner surface of the annular groove 14 includes a first inner surface 24 which is the inner surface on one axial side, a second inner surface 25 which is the inner surface on the other axial side, and a bottom surface 26.

[0078] The first inner surface 24 faces the other axial side and is formed by a plane perpendicular to the central axis of the rotor 7. The first inner surface 24 forms the radially inner portion of the side surface of the rotating flange 13 on the other axial side.

[0079] The second inner surface 25 is configured as a plane that faces one axial side and is perpendicular to the central axis of the rotor 7. The radially outer end of the second inner surface 25 and the axial end of the shoulder 23a are connected by a chamfered portion 27 configured as an R-chamfered portion.

[0080] The bottom surface 26 is disposed between the first inner surface 24 and the second inner surface 25 in the axial direction, and is configured as a cylindrical surface whose outer diameter does not change in the axial direction.

[0081] An end portion on one axial side of the bottom surface 26 and an end portion on the radially inner side of the first inner surface 24 are connected by an inclined portion 15 .

[0082] The other axial end of the bottom surface 26 and the radially inner end of the second inner surface 25 are connected by an anti-flange side inclined portion 28. The anti-flange side inclined portion 28 is configured by a corner R portion having an arc-shaped cross section.

[0083] In addition, when implementing the present disclosure, the cross-sectional shape of the bottom surface of the annular groove can be a concave arc shape or a similar shape, that is, the annular groove can be configured as a U-shaped groove having a U-shaped cross-sectional shape.

[0084] In this example, the rotating-side support member 11 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 29 that has a smaller outer diameter than a portion adjacent to that side in the axial direction and onto which the inner ring 12 is fitted. The rotating-side support member 11 has, at the end on one axial side of the small-diameter stepped portion 29, a step surface 30 facing the other axial side, and has, at a portion adjacent to the other axial side of the small-diameter stepped portion 29, a male threaded portion 31 onto which a nut 32 is screwed.

[0085] The inner ring 12 is made of a hard metal such as an iron alloy.

[0086] In this example, the inner ring 12 has a cylindrical shoulder 23b on the outer peripheral surface of the inner ring raceway 10b on the other axial side, in a portion of the outer peripheral surface that is adjacent to the other axial side of the inner ring raceway 10b. In this example, a side plate 38b, which is part of the other-side seal 36 described below, is in sliding contact with the shoulder 23b.

[0087] The rotating body 7 is constructed by fitting the inner ring 12 onto the small diameter step portion 29 of the rotating side support member 11, and by clamping the inner ring 12 from both axial sides between a step surface 30 of the rotating side support member 11 and one axial side surface of a nut 32 that is threaded onto the male thread portion 31 of the rotating side support member 11, thereby connecting and fixing the rotating side support member 11 and the inner ring 12. 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 11 and the inner ring 12, so that the preload applied to the rolling bodies 8a, 8b can be adjusted to an appropriate magnitude.

[0088] 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.

[0089] 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.

[0090] The rolling elements 8a and 8b are made of metal such as an iron alloy or ceramics.

[0091] In this example, a back-to-back (DB) type 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 33a, 33b.

[0092] 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 12 against the stepped surface 30 of the rotation-side support member 11 and regulating the force pressing down on the end face on the other axial side of the inner ring 12 with the nut 32. 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.

[0093] 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.

[0094] The aircraft rotation support device 1 of this example further includes, as optional elements, a one-side seal 35 that closes an opening on one axial side of the rolling element installation space 34 that exists between the inner circumferential surface of the stationary body 6 and the outer circumferential surface of the rotating body 7, and a other-side seal 36 that closes an opening on the other axial side of the rolling element installation space 34. This prevents or suppresses foreign matter from the external space from entering the rolling element installation space 34 through the openings on both axial sides of the rolling element installation space 34, and the grease sealed in the rolling element installation space 34 from leaking into the external space. However, the one-side seal 35 and / or the other-side seal 36 may be omitted.

[0095] Each of the one-side seal 35 and the other-side seal 36 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, may 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 may be used.

[0096] In this example, each of the one-side seal 35 and the other-side seal 36 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 35 and the other-side seal 36 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.

[0097] The one-side seal 35 comprises a cylindrical fitting tubular portion 37a formed from the core metal, and a conical cylindrical side plate portion 38a formed from the sealing material and extending radially inward and toward the other axial side from one axial end of the fitting tubular portion 37a, and the side plate portion 38a functions as a seal lip.

[0098] The rotating side support member 11 has a cylindrical shoulder portion 23a on its outer surface located on the other axial side of the annular groove 14, which forms a sealing peripheral surface to which the one-side seal 35 is arranged adjacently on the radial outside.

[0099] The one-side seal 35 is supported by the stationary body 6 by tightly fitting the fitting cylindrical portion 37a into the inner peripheral surface of one axial end of the stationary-side support member 17. In this state, the radially inner end of the side plate portion 38a is in sliding contact with the shoulder portion 23a.

[0100] When implementing the present disclosure, if one seal is configured with a combination seal ring, which is a contact seal, the sliding ring can be fitted and fixed to the seal peripheral surface (shoulder 23a in this example). Also, if one seal is configured with a seal ring (shield plate), which is a non-contact seal, the radially inner end of the seal ring can be placed close to and opposite the seal peripheral surface (shoulder 23a in this example).

[0101] In this example, the pitch circle diameter D of the mounting hole 16 of the rotating flange 13 Ais set to the same size as the pitch circle diameter of the through hole of the motor rotor 5 (the predetermined size), the presence of the annular groove 14 provided in the portion adjacent to the other axial side of the rotating flange 13 makes it easy to arrange the inclined portion 15 radially inward of the mounting hole 16. A Therefore, the inner diameter of the one-side seal 35 and the outer diameter D23 of the shoulder portion 23a can be set without being affected by the above.

[0102] That is, in the case of the structure of the prior art shown in FIG. 4, in which the portion adjacent to the other axial side of the rotating flange 110 is not provided with an annular groove, and the end portion of one axial side of the shoulder portion 109 is connected to the end portion of the other axial side of the inclined portion 112, the pitch circle diameter D A is set to the same size as the pitch circle diameter of the through hole of the motor rotor 114, while positioning the inclined portion 112 radially inward from the other axial end of the mounting hole 111, the outer diameter D109 of the shoulder portion 109 needs to be smaller than the diameter D111 of an imaginary circle that is centered on the central axis of the rotating body 102 and touches the radially inner end of the mounting hole 111.

[0103] In contrast, in the aircraft rotation support device 1 of this example, by adjusting the radial depth of the annular groove 14, the inclined portion 15 can be positioned radially inward from the other axial end of the mounting hole 16. Therefore, the pitch circle diameter D A As in the present example, the outer diameter D23 of the shoulder 23a can be set to a size equal to or larger than the diameter D16 of an imaginary circle that is centered on the central axis of the rotor 7 and that is tangent to the radially inner end of the mounting hole 16. This makes it easy to ensure freedom of design, including the one-side seal 35.

[0104] The other-side seal 36 includes a cylindrical fitting portion 37b made of the core metal and having a cylindrical shape, and a conical side plate portion 38b made of the sealing material and extending radially inward and toward one axial side from the other axial end of the fitting portion 37b, with the side plate portion 38b functioning as a seal lip. The fitting portion 37b is tightly fitted onto the inner circumferential surface of the other axial end of the stationary-side support member 17. The radially inner end of the side plate portion 38b is in sliding contact with the shoulder portion 23b.

[0105] 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 locations equally spaced circumferentially around the outer surface of the core.

[0106] 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 high output 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.

[0107] 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 portion 20. However, when implementing the rotary support device for an aircraft according to the present disclosure, the method of fixing the motor stator fitted into the stationary fitting portion of the stationary body to the stationary body is not limited to the fixing method of this example, and various fixing methods can be used, such as connecting and fixing using bolts, key press-fitting, pin press-fitting, serration press-fitting, and adhesive bonding.

[0108] The motor rotor 5 includes a substantially disk-shaped side plate portion 39 that is an attachment portion to the rotor 7, and a cylindrical tubular portion 40 that extends from the radially outer end of the side plate portion 39 toward the other axial direction. South poles and north poles are alternately arranged in the circumferential direction at a plurality of equally spaced locations (the same number as the magnetic poles of the motor stator 4) on the inner peripheral surface of the tubular portion 40.

[0109] In this example, the motor rotor 5 is arranged coaxially with the rotating body 7, and is coupled and fixed to the rotating flange 13 by threading bolts (not shown) through through holes provided at multiple locations circumferentially on the radially inner portion of the side plate portion 39 into mounting holes 16 of the rotating flange 13, with the other axial side surface of the radially inner portion of the side plate portion 39 abutting against the one axial side surface of the rotating flange 13. In this state, multiple south poles and multiple north poles provided on the inner peripheral surface of the tubular portion 40 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.

[0110] In this example, the propeller 3 is fixed to the rotating body 7 via the motor rotor 5 by aligning the rotational center axis with the center axis of the rotating body 7 and abutting the other axial side of the portion surrounding the rotational center axis against the axial side of one side of the side plate portion 39 of the motor rotor 5, and then 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 39.

[0111] In addition, the propeller 3 can also be connected and fixed to the rotating flange 13 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 39 into the mounting holes 16 of the rotating flange 13.

[0112] The propeller 3 can also be connected and fixed to the rotatable flange 13 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 39 into the mounting holes 16 of the rotatable flange 13. 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 rotatable flange 13 are inserted. In this case, some of the multiple mounting holes 16 provided in the rotatable flange 13 are used to connect and fix the motor rotor 5 to the rotatable flange 13, and the remaining mounting holes 16 are used to connect and fix the propeller 3 to the rotatable flange 13.

[0113] Alternatively, the mounting holes 16 of the rotating flange 13 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 39 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 13.

[0114] 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 an electromagnetic force 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, which causes the motor rotor 5 to rotate relative to the motor stator 4, thereby driving the rotating body 7 and propeller 3 to rotate.

[0115] In the aircraft rotation support device 1 of this example, the stationary body 6 consists only of a stationary-side support member 17 on whose inner circumferential surface there are formed double-row outer ring raceways 9a, 9b. Therefore, compared to when the stationary body consists of a stationary-side support member and two inner rings each having an outer ring raceway formed on its inner circumferential surface and fitted into the stationary-side support member, the weight of the stationary body 6 can be reduced and the outer diameter of the stationary body 6 can be kept small.

[0116] In the aircraft rotation support device 1 of this example, the inner ring raceway 10a on one axial side that constitutes the rotating body 7 is formed directly on the outer peripheral surface of the rotating-side support member 11. This allows the weight of the rotating body 7 to be reduced compared to a structure in which the inner ring raceway on one axial side that constitutes the rotating body is formed on the outer peripheral surface of an inner ring that is fitted onto the rotating-side support member. [Explanation of symbols]

[0117] 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 10a, 10b Inner raceway 11 Rotation side support member 12 Inner Circle 13 Rotating flange 14 Annular groove 15 Slope 16 Mounting holes 17 Stationary side support member 18a, 18b Shoulder 19a, 19b Counterbore section 20 Static fitting part 21 Stationary flange 22 Flange side support hole 23a, 23b Shoulder 24 1st inner surface 25 Second inner surface 26 bottom 27 Chamfered part 28 Non-flange side inclined part 29 Small diameter stepped section 30 Step surface 31 Male thread 32 Nut 33a, 33b retainer 34 Rolling element installation space 35 One-side seal 36 Other side seal 37a, 37b Fitting cylinder part 38a, 38b side plate part 39 Side plate part 40 Cylinder part 100 Rotating support device for aircraft 101 Stationary Object 102 Rotating Body 103a, 103b rolling elements 104a, 104b outer raceway 105a, 105b inner raceway 106 Stationary side support member 107 Rotation side support member 108 Inner Circle 109 Shoulder 110 Rotating flange 111 Mounting hole 112 Slope 113 Motor Stator 114 Motor rotor 115 Propeller

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 rotating body includes a rotating-side support member having an outer peripheral surface on which one axially-side inner ring raceway of the double-row inner ring raceways is directly formed, and an inner ring having an outer peripheral surface on which the other axially-side inner ring raceway of the double-row inner ring raceways is directly formed, and is fitted onto the rotating-side support member, the rotating-side support member 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, and an annular groove provided on a portion of its outer peripheral surface adjacent to the other axial side of the rotating flange; and the rotating-side support member has an inclined portion that is provided on a radially inner end of a side surface on the other axial side of the rotating flange, and extends in a direction toward the other axial side as it moves radially inward; and mounting holes that axially penetrate the rotating flange at multiple circumferential positions radially outward of the inclined portion. Rotation support device for aircraft.

2. a one-side seal that closes an opening on one axial side of a rolling element installation space that exists between the inner peripheral surface of the stationary body and the outer peripheral surface of the rotating body, the rotating-side support member has an outer peripheral surface, at a portion thereof located on the other axial side of the annular groove, having a sealing peripheral surface to which the one-side seal is disposed adjacently on the radially outer side; The rotary support device for an aircraft according to claim 1.

3. the outer diameter of the sealing peripheral surface is equal to or larger than the diameter of an imaginary circle that is centered on the central axis of the rotating body and that is tangent to the radially inner end of the mounting hole; 3. The rotary support device for an aircraft according to claim 2.

4. the stationary body has, on its outer circumferential surface, a stationary fitting portion into which the motor stator is fitted, 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.

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