Rotary support device for aircraft and rotary drive device for aircraft

Abstract

The present invention provides a rotary support device and a rotary drive device for an aircraft that facilitate ensuring coaxiality between the motor stator and the motor rotor. [Solution] The device comprises a stationary body 7, a rotating body 8, and a plurality of rolling elements 9a and 9b. The stationary body 7 includes a first outer ring 11 on its inner circumferential surface, which has an outer ring raceway 10a on one axial side of a double row of outer ring raceways 10a and 10b, and a second outer ring 12 on its inner circumferential surface, which has an outer ring raceway 10b on the other axial side of a double row of outer ring raceways 10a and 10b. The rotating body 8 includes a shaft member 14 on its outer circumferential surface, which has an inner ring raceway 13a on one axial side of a double row of inner ring raceways 13a and 13b, and an inner ring 15 on its outer circumferential surface, which has an inner ring raceway 13b on the other axial side of a double row of inner ring raceways 13a and 13b, and is fitted onto the shaft member 14.

Description

Technical Field

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

Background Art

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

[0003] As described in Japanese Patent Application Laid-Open No. 2020-072530 and the like, a conventional rotary drive device for a flying object is formed by combining a rotary support device for a flying object including a stationary body, a rotating body, and a plurality of balls, and a drive motor including a motor stator and a motor rotor.

[0004] The stationary body has a double-row outer ring raceway on its inner peripheral surface, and is supported and fixed to the airframe of the flying object with its central axis oriented in the vertical direction. The stationary body includes a first outer ring in which an outer ring raceway on one axial side of the double-row outer ring raceway is formed on the inner peripheral surface, a second outer ring in which an outer ring raceway on the other axial side of the double-row outer ring raceway is formed on the inner peripheral surface, and a housing for fitting and supporting the first outer ring and the second outer ring, and the housing is supported and fixed to the airframe of the flying object.

[0005] The rotating body has a double-row inner ring raceway on its outer peripheral surface, and is arranged coaxially with the stationary body inside the stationary body in the radial direction. The rotating body includes a first inner ring in which an inner ring raceway on one axial side of the double-row inner ring raceway is formed on the outer peripheral surface, a second inner ring in which an inner ring raceway on the other axial side of the double-row inner ring raceway is formed on the outer peripheral surface, and a shaft member for fitting and supporting the first inner ring and the second inner ring.

[0006] Multiple balls are positioned between the double-row outer ring raceways and the double-row inner ring raceways, with several balls in each row. This allows the rotating body to be rotatably supported relative to the stationary body.

[0007] The motor stator is cylindrical in shape and is fitted and fixed to the outer surface of the housing that constitutes the stationary body.

[0008] The motor rotor is positioned around the motor stator, coaxially with the motor stator, and capable of relative rotation to the motor stator. The motor rotor is supported and fixed to the shaft member constituting the rotating body by a cover and a yoke.

[0009] The cover is constructed in the shape of a hollow disc and is fitted and fixed to one axial side of the shaft member. The yoke is constructed in the shape of a cylinder and its axial end is connected and fixed to the radially outer end of the cover. The motor rotor is fitted and fixed to the inner circumferential surface of the yoke.

[0010] The propeller of the aircraft is supported and fixed coaxially with the shaft member at one end of the shaft member on the axial side. [Prior art documents] [Patent Documents]

[0011] [Patent Document 1] Japanese Patent Publication No. 2020-072530 [Overview of the project] [Problems that the invention aims to solve]

[0012] In the conventional structure described in Japanese Patent Publication No. 2020-072530, the rotating body is composed of a first inner ring having one axial inner ring raceway of a double row of inner ring raceways formed on its outer circumference, a second inner ring having the other axial inner ring raceway of the double row of inner ring raceways formed on its outer circumference, and a shaft member into which the first and second inner rings are fitted.

[0013] In such conventional structures, there are tolerances in the diameter of each of the double-row inner ring raceways, the inner diameters of the first and second inner rings, and the outer diameter of the shaft member. As a result, the cumulative tolerances tend to become large when the components constituting the rotating support device for aircraft are assembled. Consequently, the coaxiality between the stationary body and the rotating body, that is, the coaxiality between the motor stator and motor rotor attached to them, tends to be low. Therefore, it becomes difficult to control the radial gap between the motor stator and motor rotor to be kept small.

[0014] The purpose of this disclosure is to provide a rotary support device and a rotary drive device for an aircraft that facilitate ensuring coaxiality between the motor stator and the motor rotor. [Means for solving the problem]

[0015] A rotating support device for an aircraft according to a first aspect of this disclosure is A stationary body having a double row of outer ring raceways on its inner circumference, which does not rotate when combined with the motor stator during use, A rotating body having double rows of inner ring raceways on its outer circumference, which, when used, is combined with a motor rotor and propeller and rotates together with the motor rotor and propeller, Between the double-row outer ring raceway and the double-row inner ring raceway, there are multiple rolling elements arranged in each row.

[0016] The stationary body includes a first outer ring on which one of the double-row outer ring raceways is formed on its inner circumferential surface, and a second outer ring on which the other of the double-row outer ring raceways is formed on its inner circumferential surface.

[0017] The rotating body includes a shaft member on which one of the two rows of inner ring raceways in the axial direction is formed, and an inner ring on which the other of the two rows of inner ring raceways in the axial direction is formed, and which is fitted onto the shaft member.

[0018] In the rotary support device for an aircraft according to the second aspect of the present disclosure, in the rotary support device for an aircraft according to the first aspect of the present disclosure, the shaft member has a rotary flange for supporting the propeller at a portion located on one axial side of the stationary body.

[0019] In the rotary support device for an aircraft according to the third aspect of the present disclosure, in the rotary support device for an aircraft according to the first aspect or the second aspect of the present disclosure, the shaft member has a central hole extending in the axial direction at the radially central portion within an axial range including the axial positions where the respective double-row inner ring raceways are present. Further, among the central holes, the inner diameter of the portion that radially overlaps with the minimum diameter portion of the inner ring raceway on one axial side is larger than the inner diameter of the portion that radially overlaps with the minimum diameter portion of the inner ring raceway on the other axial side.

[0020] In the rotary support device for an aircraft according to the fourth aspect of the present disclosure, in the rotary support device for an aircraft according to any one of the first to third aspects of the present disclosure, a back combination type contact angle and preload are applied to the rolling elements in each row.

[0021] The rotary support device for an aircraft according to the fifth aspect of the present disclosure is the rotary support device for an aircraft according to the fourth aspect of the present disclosure, and includes a spacer and / or an elastic member disposed between the first outer ring and the second outer ring.

[0022] In the rotary support device for an aircraft according to the sixth aspect of the present disclosure, in the rotary support device for an aircraft according to any one of the first to fifth aspects of the present disclosure, the stationary body further includes a housing that fits and supports the first outer ring and the second outer ring.

[0023] The rotary drive device for an aircraft according to the seventh aspect of the present disclosure includes a motor stator, a motor rotor, and a rotary support device for an aircraft, and the rotary support device for an aircraft is constituted by the rotary support device for an aircraft according to any one of the first to sixth aspects of the present disclosure.

[0024] The rotary drive device for a flying object according to the eighth aspect of the present disclosure includes a motor stator, a motor rotor, and a rotary support device for a flying object, and the rotary support device for a flying object is constituted by the rotary support device for a flying object according to any one of the first to fourth aspects of the present disclosure. Further, the first outer ring and the second outer ring are fitted and supported in the motor stator in a state of being axially spaced apart. Furthermore, the motor rotor is externally fitted and supported on the rotating body and is disposed radially inward of a portion of the motor stator that is located between the first outer ring and the second outer ring in the axial direction.

Effects of the Invention

[0025] According to the rotary support device for a flying object and the rotary drive device for a flying object according to one aspect of the present disclosure, it is easy to ensure the coaxiality between the motor stator and the motor rotor.

Brief Description of the Drawings

[0026] [Figure 1] FIG. 1 is a cross-sectional view of a rotary drive device for a flying object according to a first example of an embodiment of the present disclosure. [Figure 2] FIG. 2 is a cross-sectional view of a rotary drive device for a flying object according to a second example of an embodiment of the present disclosure. [Figure 3] FIG. 3 is a cross-sectional view of a rotary drive device for a flying object according to a third example of an embodiment of the present disclosure.

Modes for Carrying Out the Invention

[0027] [First Example] A first example of an embodiment of the present disclosure will be described with reference to FIG. 1.

[0028] Regarding a flying object such as a drone to which the rotary support device for a flying object of the present disclosure is applicable, there is no particular limitation on the type such as unmanned or manned, or the type such as small or large.

[0029] The rotating support device 1 for the aircraft constitutes a part of the rotating drive device 2 for the aircraft. That is, the rotating drive device 2 for the aircraft comprises the rotating support device 1 and a drive motor 3 which includes a motor stator 5 and a motor rotor 6.

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

[0031] The rotating support device 1 for the aircraft rotatably supports the propeller 4 of the aircraft relative to the aircraft frame.

[0032] The drive motor 3 comprises a motor stator 5 and a motor rotor 6, and generates rotational force to drive the propeller 4. The drive motor 3 can be either a radial gap type, in which the motor stator 5 and motor rotor 6 are opposed radially, or an axial gap type, in which the motor stator and motor rotor are opposed axially. In this example, the drive motor 3 is a radial gap type, and more specifically, an outer rotor type, in which the motor rotor 6 is positioned radially outside the motor stator 5.

[0033] The rotating support device 1 for the aircraft comprises a stationary body 7, a rotating body 8, and a plurality of rolling elements 9a, 9b.

[0034] The stationary body 7 has double rows of outer ring raceways 10a and 10b on its inner circumferential surface and does not rotate when combined with the motor stator 5 during use. The stationary body 7 is supported and fixed to the machine frame directly or via other members. In this example, the stationary body 7 is supported and fixed to the machine frame via the motor stator 5.

[0035] The stationary body 7 includes a first outer ring 11 on which one of the double-row outer ring raceways 10a and 10b, specifically the outer ring raceway 10a on one axial side, is formed on its inner circumferential surface, and a second outer ring 12 on which the other of the double-row outer ring raceways 10a and 10b, specifically the outer ring raceway 10b, is formed on its inner circumferential surface.

[0036] Each of the outer ring raceways 10a and 10b has a generatrix shape corresponding to the shape of the multiple rolling elements 9a and 9b. When the multiple rolling elements 9a and 9b are composed of balls, each of the outer ring raceways 10a and 10b has an arc-shaped generatrix, and when the multiple rolling elements 9a and 9b are composed of cone-shaped rollers, the outer ring raceways 10a and 10b have a linear generatrix shape inclined with respect to the central axis of the stationary body 7. In this example, the multiple rolling elements 9a and 9b are composed of balls. Therefore, each of the outer ring raceways 10a and 10b has an arc-shaped generatrix.

[0037] Each of the first outer ring 11 and the second outer ring 12 is constructed in a cylindrical shape from a hard metal such as medium carbon steel. The outer ring raceway 10a on one axial side is formed in the axial middle portion of the inner circumferential surface of the first outer ring 11. The outer ring raceway 10b on the other axial side is formed in the axial middle portion of the inner circumferential surface of the second outer ring 12. In this example, the first outer ring 11 and the second outer ring 12 are arranged spaced apart in the axial direction.

[0038] The rotating body 8 has double rows of inner ring raceways 13a and 13b on its outer circumference, and when in use, it is combined with the motor rotor 6 and propeller 4 and rotates together with the motor rotor 6 and propeller 4.

[0039] The rotating body 8 includes a shaft member 14 on which one of the two rows of inner ring raceways 13a and 13b, specifically the inner ring raceway 13a on the axial side, is formed on its outer circumferential surface, and an inner ring 15 on which the other of the two rows of inner ring raceways 13a and 13b, specifically the inner ring raceway 13b, is formed on its outer circumferential surface and is fitted onto the shaft member 14.

[0040] Each of the inner ring raceways 13a and 13b has a generatrix shape corresponding to the shape of the multiple rolling elements 9a and 9b. When the multiple rolling elements 9a and 9b are composed of balls, each of the inner ring raceways 13a and 13b has an arc-shaped generatrix, and when the multiple rolling elements 9a and 9b are composed of cone-shaped rollers, the inner ring raceways 13a and 13b have a linear generatrix shape inclined with respect to the central axis of the rotating body 8. In this example, the multiple rolling elements 9a and 9b are composed of balls. Therefore, each of the inner ring raceways 13a and 13b has an arc-shaped generatrix.

[0041] The shaft member 14 is made of a hard metal such as an iron alloy. In this example, the inner ring raceway 13a on one axial side is formed on the outer circumferential surface of the axial intermediate portion of the shaft member 14.

[0042] The portion of the shaft member 14 that supports the propeller 4 can adopt any structure as long as it can support the propeller 4. For example, the portion of the shaft member 14 located on one axial side of the stationary body 7 can be configured to externally fit the cylindrical portion of the propeller 4 so that it cannot rotate relative to it, or it can be configured to internally fit the shaft portion of the propeller 4 so that it can rotate relative to it, or the portion located on one axial side of the stationary body 7 can be configured to have a rotating flange for supporting the propeller 4.

[0043] In this example, the shaft member 14 has a rotating flange 16 for supporting the propeller 4 at a portion located axially to one side of the stationary body 7. In this example, in addition to the propeller 4, the motor rotor 6 is also supported by the rotating flange 16.

[0044] In this example, the rotating flange 16 protrudes radially outward from one axial end of the shaft member 14 and is configured as a hollow circular flat plate. The rotating flange 16 has mounting holes 17 that penetrate axially through multiple locations in the circumferential direction in the radial middle section.

[0045] In this example, the motor rotor 6 is supported by the rotating flange 16 via a yoke 24. The yoke 24 is coupled and fixed to the rotating flange 16 using mounting holes 17.

[0046] The mounting hole 17 is composed of a threaded hole or a press-fit hole. If the mounting hole 17 is composed of a threaded hole, the yoke 24 is joined and fixed to the rotating flange 16 by screwing a bolt, which is inserted through through holes provided at multiple circumferential locations on its radially inner side, into the mounting hole 17 from one axial side. If the mounting hole 17 is composed of a press-fit hole, a stud is press-fitted into the mounting hole 17 from the other axial side. The yoke 24 is joined and fixed to the rotating flange 16 by inserting the stud through through holes provided at multiple circumferential locations on its radially inner side and screwing a nut onto the tip of the stud. In this example, the mounting hole 17 is composed of a threaded hole.

[0047] In this example, the shaft member 14 has a small-diameter stepped portion 18 on its outer circumferential surface, located on the axial side of the inner ring raceway 13a on one axial side, with a smaller outer diameter than the portion adjacent to it on one axial side, into which the inner ring 15 is fitted. The shaft member 14 has a stepped surface 19 facing the axial side at the axial end of the small-diameter stepped portion 18.

[0048] The shaft member 14 may optionally have a central hole extending axially at its radial center. The central hole may be a through hole penetrating the shaft member 14 axially, or it may be a bottomed hole opening only on one axial side or the other axial side of the shaft member 14. The shaft member may also have a solid structure without a central hole.

[0049] In this example, the shaft member 14 has a central hole 20 that extends axially in the radial center within the axial range that includes the axial positions where each of the two rows of inner ring raceways 13a and 13b exists. The central hole 20 is composed of a through hole that penetrates the shaft member 14 in the axial direction. The inner diameter d1 of the central hole 20 that radially overlaps with the minimum diameter portion of the inner ring raceway 13a on one axial side (the groove bottom in this example) is larger than the inner diameter d2 of the portion that radially overlaps with the minimum diameter portion of the inner ring raceway 13b on the other axial side (the groove bottom in this example) (d1 > d2).

[0050] The inner ring 15 is constructed in a cylindrical shape from a hard metal such as an iron alloy. The inner ring raceway 13b on the other axial side is formed on the outer circumferential surface of the axial intermediate portion of the inner ring 15.

[0051] The rotating body 8 is constructed by fitting the inner ring 15 onto the small-diameter stepped portion 18 of the shaft member 14, and by bringing one axial end face of the inner ring 15 into contact with the stepped surface 19 of the shaft member 14, thereby joining and fixing the shaft member 14 and the inner ring 15. In this example, the joining and fixing of the shaft member 14 and the inner ring 15 is performed by press-fitting (tight-fitting) the inner ring 15 onto the small-diameter stepped portion 18, and / or by bonding the shaft member 14 and the inner ring 15 together.

[0052] In implementing this disclosure, the rotating body may be configured such that the inner ring is fitted onto the small-diameter stepped portion of the shaft member, and the inner ring is clamped from both axial sides between the stepped surface of the shaft member and a nut screwed onto the other axial end of the shaft member, thereby joining and fixing the shaft member and the inner ring. Alternatively, the rotating body may be configured such that the inner ring is fitted onto the small-diameter stepped portion of the shaft member, and the inner ring is clamped from both axial sides between the stepped surface of the shaft member and a crimped portion formed by plastically deforming the other axial end of the shaft member, thereby joining and fixing the shaft member and the inner ring.

[0053] Multiple rolling elements 9a and 9b are positioned between the double-row outer ring raceways 10a and 10b and the double-row inner ring raceways 13a and 13b, in each row. As a result, the rotating body 8 is rotatably supported radially inward of the stationary body 7.

[0054] The rolling elements 9a and 9b are made of hard metals such as bearing steel, or ceramics. Furthermore, the rolling elements 9a and 9b are composed of balls or tapered rollers. In this example, the rolling elements 9a and 9b are composed of balls. The rolling elements 9a and 9b in each row are held rotatably by a cage (not shown).

[0055] In this example, the rolling elements 9a and 9b in each row are provided with a back-to-back combination type (DB type) contact angle and preload.

[0056] The rotating support device 1 for the aircraft may optionally include a spacer 21 and / or an elastic member 22 positioned between the first outer ring 11 and the second outer ring 12.

[0057] When only a spacer 21 is placed between the first outer ring 11 and the second outer ring 12, the rolling elements 9a and 9b are subjected to a fixed-position preload. In contrast, when only an elastic member 22, or both a spacer 21 and an elastic member 22, are placed between the first outer ring 11 and the second outer ring 12, the rolling elements 9a and 9b are subjected to a constant-pressure preload. In this case, the magnitude of the preload applied to the rolling elements 9a and 9b can be adjusted by adjusting the elasticity of the elastic member 22. Whether to apply a constant-pressure preload or a fixed-position preload to the rolling elements 9a and 9b is appropriately selected according to the performance required of the rotating support device 1 for the aircraft.

[0058] The rotating support device 1 for the aircraft in this example includes a spacer 21 and an elastic member 22, which are positioned between the first outer ring 11 and the second outer ring 12. Specifically, the elastic member 22 and the spacer 21 are positioned between the first outer ring 11 and the second outer ring 12, starting from one axial side.

[0059] The spacer 21 can be configured as a cylindrical shape with a continuous circumference or as a partial cylindrical shape with a discontinuity at one point in the circumferential direction. In this example, the spacer 21 is configured as a cylindrical shape with a continuous circumference. The spacer 21 can be made of any material such as metal or synthetic resin, as long as the required strength and rigidity can be ensured.

[0060] In this example, the spacer 21 is fitted into the inner circumferential surface 23 of the motor stator 5 without radial play, and the other end face of the spacer 21 on the axial side is in contact with the side surface on the axial side of the second outer ring 12.

[0061] The elastic member 22 can be made of a spring such as a wave washer, disc spring, or coil spring, or rubber. In this example, the elastic member 22 is made of a wave washer.

[0062] In this example, the elastic member 22 is elastically sandwiched in the axial direction between the other axial side of the first outer ring 11 and the axial end face of the spacer 21. As a result, the first outer ring 11 and the second outer ring 12 are elastically pressed apart from each other in the axial direction, and a constant-pressure preload is applied to the rolling elements 9a and 9b.

[0063] The rotating support device 1 for aircraft in this example has a so-called equal-diameter PCD type structure in which the pitch circle diameter of the rolling elements 9a in one axial row and the pitch circle diameter of the rolling elements 9b in the other axial row are equal to each other. However, the rotating support device for aircraft of this disclosure can also be applied to a so-called different-diameter PCD type structure in which the pitch circle diameters of the rolling elements 9a and 9b in each row are different to each other.

[0064] The motor stator 5 includes a core made of magnetic material having multiple teeth and coils wound around the multiple teeth, and the entire structure is cylindrical.

[0065] In this example, the motor stator 5 is assembled to the stationary body 7 by fitting the outer surfaces of the first outer ring 11 and the second outer ring 12 into the inner surface 23 of the core.

[0066] The inner circumferential surface 23 of the core is composed of a cylindrical surface whose inner diameter does not change in the axial direction. The outer circumferential surface of one of the first outer ring 11 and the second outer ring 12 is fitted and fixed to the inner circumferential surface 23 of the core by press-fitting and / or adhesive bonding. In contrast, the outer circumferential surface of the other of the first outer ring 11 and the second outer ring 12 is fitted to the inner circumferential surface 23 of the core without radial play and allowing axial movement. This allows a constant-pressure preload to be applied to the rolling elements 9a and 9b based on the elasticity of the elastic member 22, and allows the stationary body 7 to be supported and fixed to the machine frame via the motor stator 5. In this example, one of the outer rings is composed of the first outer ring 11, and the other outer ring is composed of the second outer ring 12.

[0067] In this example, the core is connected and fixed to the aircraft frame. That is, in this example, the stationary body 7 is supported and fixed to the aircraft frame via the core. The structure for connecting and fixing the core to the aircraft frame is not limited. In this example, the core has support holes (not shown) at multiple locations in the circumferential direction, which open only on the other axial side. The stationary body 7 is supported and fixed to the aircraft frame by screwing bolts, which are inserted through holes provided in the aircraft frame, into the support holes of the core, which is fitted and fixed to the stationary body 7, from the other axial side.

[0068] The motor rotor 6 is cylindrical in shape, with alternating south and north poles on its inner surface in the circumferential direction. The motor rotor 6 is positioned around the motor stator 5, coaxially with the motor stator 5, and capable of relative rotation with respect to the motor stator 5. The motor rotor 6 is supported and fixed to the shaft member 14 via the yoke 24.

[0069] In this example, the yoke 24 is constructed in the shape of a hollow circular plate, and one axial end of the motor rotor 6 is connected and fixed to its radially outer end.

[0070] In this example, the motor rotor 6 is arranged coaxially with the shaft member 14, and is fixed to the rotating flange 16 by screwing bolts (not shown), which are inserted through through holes provided at multiple circumferential locations on the radially inner portion of the yoke 24, into mounting holes 17 of the rotating flange 16, with the other axial side of the radially inner portion of the yoke 24 in contact with one axial side of the rotating flange 16. Alternatively, a yoke having a cylindrical portion extending from the radially outer end toward the other axial side can be used, and a structure in which the motor rotor 6 is fitted and fixed inside this cylindrical portion can also be adopted.

[0071] In this example, the propeller 4 is arranged coaxially with the shaft member 14, and with the other axial side of its radially inner portion in contact with one axial side of the yoke 24, bolts inserted through through holes provided at multiple locations in the circumferential direction of the propeller 4 are screwed into threaded holes provided at multiple locations in the circumferential direction of the yoke 24, thereby connecting and fixing it to the rotating flange 16 via the yoke 24.

[0072] Furthermore, the propeller 4 can also be joined and fixed to the rotating flange 16 together with the yoke 24 by screwing bolts, which are inserted through through holes provided at multiple locations in the circumferential direction of the propeller 4 and through holes provided at multiple locations in the circumferential direction of the yoke 24, into the mounting holes 17 of the rotating flange 16.

[0073] Alternatively, the mounting holes 17 of the rotating flange 16 can be configured as press-fit holes, and the yoke 24 and propeller 4 can be joined and fixed to the rotating flange 16 by inserting a stud, which has been press-fitted into the press-fit hole, through the through-hole of the yoke 24 and the through-hole of the propeller 4, and then screwing a nut onto the tip of the stud.

[0074] In any case, with the motor stator 5, motor rotor 6, and propeller 4 attached to the rotating support device 1 for the aircraft in this example, current is supplied to the coils constituting the motor stator 5, causing the multiple teeth of the motor stator 5 to become magnetized. This generates an electromagnetic force between the multiple teeth and the multiple S poles and N poles of the motor rotor 6, causing the motor rotor 6 to rotate relative to the motor stator 5. As a result, the shaft member 14 and the propeller 4 are driven to rotate.

[0075] In the rotating support device 1 for the aircraft in this example, the rotating body 8 is composed of a shaft member 14 having an inner ring raceway 13a on one axial side formed on its outer circumferential surface, and an inner ring 15 having an inner ring raceway 13b on the other axial side formed on its outer circumferential surface and fitted onto the shaft member 14. That is, compared to a conventional structure in which the rotating body comprises a first inner ring having an inner ring raceway on one axial side formed on its outer circumferential surface, a second inner ring having an inner ring raceway on the other axial side formed on its outer circumferential surface, and a shaft member into which the first and second inner rings are fitted, the rotating support device 1 for the aircraft has a structure in which the first inner ring is omitted and the inner ring raceway 13a on one axial side is directly formed on the outer circumferential surface of the shaft member 14.

[0076] In this example of a rotating support device 1 for an aircraft, the first inner ring can be omitted compared to the conventional structure, thereby reducing the cumulative tolerance when combining the components that make up the rotating support device 1 for an aircraft. Consequently, it is easier to ensure coaxiality between the stationary body 7 and the rotating body 8. As a result, it is easier to ensure coaxiality between the motor stator 5 attached to the stationary body 7 and the motor rotor 6 attached to the rotating body 8. Consequently, it becomes easier to manage the radial gap between the motor stator 5 and the motor rotor 6. In addition, it is easier to suppress the rotational runout of the propeller 4 supported by the rotating body 8.

[0077] In the rotating support device 1 for aircraft in this example, the first inner ring can be omitted compared to the conventional structure, which makes it easier to reduce the radial thickness of the rotating body 8 and thus reduce the weight. In other words, it is easier to achieve a lighter rotating support device 1 for aircraft.

[0078] Furthermore, in this example, the inner diameter d1 of the portion of the central hole 20 of the shaft member 14 that radially overlaps with the minimum diameter portion of the inner ring raceway 13a on one axial side is larger than the inner diameter d2 of the portion of the inner ring raceway 13b on the other axial side that radially overlaps with the minimum diameter portion (d1>d2). Therefore, compared to the case where the inner diameter d1 is the same size as the inner diameter d2, it is easier to reduce the weight by keeping the radial thickness of the portion of the rotating body 8 that radially overlaps with the minimum diameter portion of the inner ring raceway 13a on one axial side smaller.

[0079] In the rotating support device 1 for the aircraft in this example, the amount of preload applied to the rolling elements 9a and 9b can be easily adjusted by adjusting the axial dimension of the spacer 21 and / or the elasticity of the elastic member 22. From this perspective, it is also possible to easily suppress the rotational wobble of the propeller 4 supported by the rotating body 8.

[0080] [Example 2] A second example of the embodiment of this disclosure will be described with reference to Figure 2.

[0081] In this example, of the rotating support device 1a and drive motor 3a for the aircraft that constitute the rotating drive device 2a for the aircraft, the drive motor 3a is an inner rotor type in which the motor rotor 6a is positioned radially inward of the motor stator 5a.

[0082] In this example, the portion of the core constituting the motor stator 5a that becomes magnetized when current is supplied to the coils constituting the motor stator 5a is the axial middle portion of the inner circumferential surface 23a. In this example, the motor stator 5a is provided with an inward flange 25 that protrudes radially inward along its entire circumference, on the portion of the inner circumferential surface 23a of the core that is adjacent to the other axial side of the magnetized portion, specifically the portion closer to the other axial side.

[0083] The motor rotor 6a is configured in a cylindrical shape, with S poles and N poles alternately arranged on its outer circumferential surface. The motor rotor 6a is positioned radially inward of the portion of the motor stator 5a located between the first outer ring 11 and the second outer ring 12 in the axial direction, specifically radially inward of the axial intermediate portion of the inner circumferential surface 23a of the core, coaxially with the motor stator 5a and capable of relative rotation with respect to the motor stator 5a. The motor rotor 6a is externally fitted and supported by adhesive or the like on the outer circumferential surface of the shaft member 14 constituting the rotating body 8, on the portion located between the inner ring raceway 13a and the small-diameter stepped portion 18 on one axial side. In other words, the motor rotor 6a is positioned between the rolling elements 9a and 9b of each row in the axial direction.

[0084] Thus, in the rotary drive device 2a for the aircraft in this example, the motor rotor 6a is positioned radially inward rather than around the motor stator 5a, employing an inner rotor type structure. This allows for a smaller outer diameter, making miniaturization easier.

[0085] In the rotary drive device 2a for the aircraft in this example, one axial side of the second outer ring 12 abuts against the other axial side of the inward flange 25. This prevents the second outer ring 12 from being displaced in one axial direction relative to the core. In this example, no spacer or elastic member is placed between the first outer ring 11 and the second outer ring 12.

[0086] In this example, when assembling the rotary drive device 2a for the aircraft, the inner ring 15 is fitted onto the small-diameter stepped portion 18 of the shaft member 14, and with one axial end face of the inner ring 15 in contact with the stepped surface 19 of the shaft member 14, the preload applied to the rolling elements 9a and 9b can be adjusted to an appropriate size.

[0087] In this example, the propeller 4 is arranged coaxially with the shaft member 14, and with the other axial side of its radially inner portion in contact with one axial side of the rotating flange 16, it is joined and fixed to the rotating flange 16 by screwing bolts, which are inserted through through holes provided at multiple locations in the circumferential direction of the propeller 4, into the mounting holes 17 of the rotating flange 16.

[0088] The other components and effects of the second example are the same as those of the first example.

[0089] [Example 3] A third example of the embodiments of this disclosure will be described with reference to Figure 3.

[0090] In the rotary drive device 2b for the aircraft in this example, the stationary body 7a further includes a housing 26 that internally fits and supports the first outer ring 11 and the second outer ring 12.

[0091] The housing 26 can employ any structure as long as it has a portion that internally fits and supports the first outer ring 11 and the second outer ring 12. In this example, the housing 26 has a cylindrical main body portion 27 that internally fits and supports the first outer ring 11 and the second outer ring 12, and a stationary flange 28 that protrudes radially outward from the other axial end of the main body portion 27.

[0092] The main body portion 27 has a cylindrical shape. The outer circumferential surface of the first outer ring 11 is internally fitted and / or bonded to one axial end of the inner circumferential surface of the main body portion 27. The outer circumferential surface of the second outer ring 12 is internally fitted to the other axial end of the inner circumferential surface of the main body portion 27 without radial play and allowing axial movement.

[0093] The inner circumferential surface 23 of the motor stator 5 is externally fitted and fixed to the outer circumferential surface of the main body 27 by press-fitting, adhesive, or other means. The relative sizes of the outer diameter of the main body 27 and the outer diameter of the rotating flange 16 are arbitrary, but in this example, the outer diameter of the rotating flange 16 is smaller than the outer diameter of the main body 27. This allows the inner circumferential surface 23 of the motor stator 5 to be externally fitted to the outer circumferential surface of the main body 27 from one side in the axial direction when the rotating support device 1b for the aircraft is assembled.

[0094] The stationary flange 28 is used to support and fix the stationary body 7a to the aircraft frame. The stationary flange 28 has multiple flange-side support holes 29 that penetrate axially at multiple locations in the circumferential direction in the radially intermediate part. The flange-side support holes 29 are made up of threaded holes.

[0095] The stationary body 7a is supported and fixed to the aircraft frame by inserting a support bolt, which is a connecting member, through a frame-side support hole provided in the aircraft frame and screwing it into a flange-side support hole 29. In addition, when implementing this disclosure, the flange-side support hole 29 can be configured as a through hole, and the stationary body 7a can also be supported and fixed to the aircraft frame by screwing the bolt inserted through the flange-side support hole 29 into a frame-side support hole provided in the aircraft frame.

[0096] The other components and effects of the third example are the same as those of the first example.

[0097] The rotating support device and rotating drive device for aircraft of this disclosure can be implemented by appropriately combining the configurations of each embodiment described above, to the extent that no inconsistencies arise. [Explanation of Symbols]

[0098] 1, 1a, 1b Rotating support device for aircraft 2, 2a, 2b Rotary drive device for aircraft 3, 3a Drive motor 4 propellers 5. 5a Motor Stator 6, 6a Motor Rotor 7, 7a Stationary body 8. Revolving bodies 9a, 9b rolling elements 10a, 10b Outer ring track 11. First outer ring 12. Second outer ring 13a, 13b Inner ring track 14 Shaft member 15 Inner circle 16 Rotating Flange 17 mounting holes 18 Small diameter stepped section 19 Step surface 20 center hole 21 Spacers 22 Elastic members 23, 23a Inner surface 24 York 25 Inward Flange 26 Housing 27 Main body 28 Static flange 29 Flange-side support holes

Claims

1. A stationary body having a double row of outer ring raceways on its inner circumference, which does not rotate when combined with the motor stator during use, A rotating body having double rows of inner ring raceways on its outer circumference, which, when used, is combined with a motor rotor and propeller and rotates together with the motor rotor and propeller, The system comprises multiple rolling elements arranged between the double-row outer ring raceway and the double-row inner ring raceway, with each row having multiple rolling elements. The stationary body includes a first outer ring on its inner circumferential surface, which has an outer ring raceway on one axial side of the double row of outer ring raceways formed thereon, and a second outer ring on its inner circumferential surface, which has an outer ring raceway on the other axial side of the double row of outer ring raceways formed thereon. The rotating body includes a shaft member on which one of the two rows of inner ring raceways in the axial direction is formed, and an inner ring on which the other of the two rows of inner ring raceways in the axial direction is formed, and which is fitted onto the shaft member. Rotation support device for aircraft.

2. The rotating support device for an aircraft according to claim 1, wherein the shaft member has a rotating flange for supporting the propeller in a portion located axially to one side of the stationary body.

3. The shaft member has a central hole extending in the axial direction at its radial center, within an axial range that includes the axial position where each of the two rows of inner ring raceways exists. Of the central hole, the inner diameter of the portion that radially overlaps with the minimum diameter portion of the inner ring raceway on one axial side is larger than the inner diameter of the portion that radially overlaps with the minimum diameter portion of the inner ring raceway on the other axial side. Rotating support device for an aircraft according to claim 1.

4. The rotating support device for an aircraft according to claim 1, wherein the rolling elements in each row are provided with a back-to-back combination type contact angle and preload.

5. The rotating support device for an aircraft according to claim 4, further comprising a spacer and / or an elastic member disposed between the first outer ring and the second outer ring.

6. The rotating support device for an aircraft according to claim 1, wherein the stationary body further includes a housing that internally fits and supports the first outer ring and the second outer ring.

7. It comprises a motor stator, a motor rotor, and a rotating support device for the aircraft. The aforementioned rotating support device for the aircraft is configured as the rotating support device for the aircraft according to any one of claims 1 to 6. Rotary drive device for aircraft.

8. It comprises a motor stator, a motor rotor, and a rotating support device for the aircraft. The aforementioned rotating support device for the aircraft is configured as the rotating support device for the aircraft described in any one of claims 1 to 4. The first outer ring and the second outer ring are fitted and supported within the motor stator, with the two rings positioned axially separated from each other. The motor rotor is externally supported by the rotating body and is positioned radially inward of the portion of the motor stator located between the first outer ring and the second outer ring in the axial direction. Rotary drive device for aircraft.

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