Drone

Abstract

To provide a drone which enables reduction of replacement costs.SOLUTION: A drone includes: an arm; a housing fastened to the arm; a holder fastened to the housing; and a rotor fastened to the holder. A shaft which supports the rotor is rotatably supported by the holder, and the arm and the holder are detachably attached to the housing.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to drones. [Background technology]

[0002] For example, in an unmanned aircraft such as a drone disclosed in Patent Document 1, vibration occurs with the rotation of the propellers. When an unmanned aircraft is used for a long period of time, there are cases where the motor itself needs to be replaced due to its lifespan or the like. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-110413 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the drone described in Patent Document 1, the motor is integrated into the arm. Therefore, replacing the motor requires replacing the entire arm. Such replacement increases costs.

[0005] Therefore, one of the objectives of the present invention is to provide an unmanned vehicle that can reduce replacement costs. [Means for solving the problem]

[0006] An unmanned aircraft according to one embodiment of the present invention comprises an arm, a housing fastened to the arm, a holder fastened to the housing, and a rotor fastened to the holder, wherein a shaft supporting the rotor is rotatably supported in the holder, and the arm and the holder are detachable from the housing. [Brief description of the drawings]

[0007] [Figure 1]1 is an oblique view showing, in outline, the structure of an unmanned vehicle 1 according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view taken along line 2-2 in FIG. [Diagram 3] FIG. 3 is a cross-sectional view taken along line 3-3 in FIG. 2. [Figure 4] FIG. 1 is an exploded oblique view of a drone 1 according to one embodiment of the present invention. [Diagram 5] 1 is an exploded cross-sectional view of an unmanned vehicle 1 according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a perspective view showing a schematic structure of a drone 1 according to an embodiment of the present invention. The drone 1 is a so-called multicopter equipped with a plurality of propulsion devices. The drone 1 includes a main body (not shown), a plurality of arms 2 extending from the main body, and a propulsion device 3 arranged at the tip of each arm 2. FIG. 1 shows a part of the drone 1 including a part of the tip of one arm 2 and the propulsion device 3 arranged at the tip of the arm 2. Note that a control device for controlling the operation of the drone 1, a battery, various sensors, a camera, and other components are incorporated in the main body.

[0009] The propulsion device 3 disposed at the tip of the arm 2 includes a motor 4 and a propeller 5 supported by the motor 4 so as to be rotatable about a rotation axis x. The arm 2 has an arm body 2a forming the main body of the arm 2, and a mounting member, i.e., an attachment 2b, formed integrally, for example, at the tip of the arm body 2a. The motor 4 is fixed to the attachment 2b. A propeller 5 is attached to the motor 4. In this example, the propeller 5 is composed of a pair of blades extending in opposite directions to each other in a direction perpendicular to the rotation axis x of the motor 4. Note that a propeller having a different number of blades may be used for the propeller 5.

[0010] FIG. 2 is a cross-sectional view taken along line 2-2 in FIG. 1, and is a longitudinal cross-sectional view of the drone 1 taken along a virtual plane including the rotation axis x. The arm body 2a of the arm 2 is, for example, a hollow cylindrical member. The tip of the arm body 2a is open. Wiring (not shown) that connects, for example, the drone 1 body and the motor 4 to each other is housed inside the arm body 2a. The attachment 2b is formed, for example, in a flat plate shape extending along a virtual plane perpendicular to the rotation axis x. The motor 4 is fastened to the surface of the attachment 2b. For fastening, a fastening member 2c such as a bolt is used. In this example, for example, four fastening members 2c are used. The arm 2 is integrally formed from, for example, a metal material or a resin material.

[0011] The motor 4 has a housing 10. The housing 10 has a cylindrical base 11 that defines an accommodation space, and a cover 12 that closes the accommodation space of the base 11. The base 11 has, for example, a disk-shaped bottom 13 about the rotation axis x, and a side wall 14 that stands upright upward along the rotation axis x from the outer periphery of the bottom 13 in a radial direction perpendicular to the rotation axis x. The side wall 14 is formed, for example, in a cylindrical shape about the rotation axis x. A screw hole 15 is formed in the bottom surface of the bottom 13. The motor 4 is attached to the surface of the attachment 2b by screwing a fastening member 2c into the screw hole 15 through a through hole 2d formed in the attachment 2b.

[0012] An upper open end of the side wall 14 along the rotation axis x is partially closed by the cover 12. The cover 12 has a disk-shaped portion (hereinafter referred to as the "disk portion") 16 and a cylindrical portion (hereinafter referred to as the "cylindrical portion") 17. The disk portion 16 is fitted at its outer periphery to an inner circumferential surface 14a of the side wall 14 of the base 11. The cylindrical portion 17 extends downward along the rotation axis x from the inner circumferential edge of the disk portion 16. In the storage space of the housing 10, a cylindrical space S is formed on the inner circumferential side of an inner circumferential surface 12a of the cover 12, which is defined by the inner circumferential surface of the disk portion 16 and the inner circumferential surface of the cylindrical portion 17. The base 11 and the cover 12 of the housing 10 are formed of, for example, a resin material or a metal material.

[0013] FIG. 3 is a cross-sectional view taken along line 3-3 in FIG. 2, and is a cross-sectional view of the drone 1 taken along a virtual plane perpendicular to the rotation axis x. Referring to both FIG. 2 and FIG. 3, a stator 20 is attached to the inner peripheral surface 14a of the side wall 14. The stator 20 has a stator core 21, a plurality of coils 22, and an insulator 23. The stator core 21 is formed of a laminated body of a magnetic material such as silicon steel plate. The stator core 21 functions as a yoke of the stator 20. The coil 22 is wound around the stator core 21. The insulator 23 insulates the stator core 21 and the coil 22 from each other. The stator core 21 is fitted to the inner peripheral surface 14a of the side wall 14.

[0014] As shown in FIG. 3, the stator core 21 has a cylindrical portion (hereinafter referred to as the "cylindrical portion") 24 and a plurality of (e.g., 12) teeth 25 extending from the inner peripheral surface of the cylindrical portion 24 to the inner peripheral side. Each tooth 25 has a spoke 26 connected at its outer peripheral end to the inner peripheral surface of the cylindrical portion 24, and a magnetic pole portion 27 continuing to the inner peripheral end of the spoke 26. A coil 22 is wound around each spoke 26. The magnetic pole portions 27 are arranged at equal intervals around the rotation axis x. The inner peripheral surfaces of the plurality of magnetic pole portions 27 are continuous with gaps between them, thereby forming a cylindrical surface 27a around the rotation axis x. The cylindrical surface 27a is, for example, defined flush with the inner peripheral surface 12a of the cover 12. The aforementioned space S is defined by the inner peripheral surface 12a and the cylindrical surface 27a.

[0015] FIG. 4 is an exploded perspective view of the drone 1 according to one embodiment of the present invention. FIG. 5 is an exploded cross-sectional view of the drone 1 according to one embodiment of the present invention. The cross section of FIG. 5 corresponds to the cross section of FIG. 3. Referring to FIGS. 2 to 5 together, a holder 30 is accommodated in a space S in the housing 10. The holder 30 has a cylindrical tube 31 around the rotation axis x and a flange 32 formed on the outer circumferential surface 31a of the tube 31. The upper and lower ends of the tube 31 are open. The flange 32 protrudes in an annular shape from the outer circumferential surface 31a of the tube 31 to the outer circumferential side. In this example, the flange 32 is provided at a middle position of the tube 31 along the rotation axis x. Through holes 33 are formed in the flange 32, for example, at equal intervals around the rotation axis x. The through holes 33 are formed parallel to the rotation axis x. In this example, for example, four through holes 33 are arranged at equal intervals.

[0016] For example, two bearings 34, 35 are attached to the inner peripheral surface 31b of the tube 31. The bearings 34, 35 are, for example, press-fitted into the inner peripheral surface 31b. In this way, the bearings 34, 35 are housed in the tube 31. The bearings 34, 35 are, for example, ball bearings. The holder 30 is received by the flange 32 on the bottom 13 of the base 11. In this example, the tube 31 of the holder 30 is housed in a recess 36 formed in the upper surface of the bottom 13. Meanwhile, a fastening member 37 such as a bolt is screwed through a through hole 33 of the flange 32 into a screw hole 18 formed in the upper surface of the bottom 13, thereby fastening the holder 30 to the base 11. The tube 31 and flange 32 of the holder 30 are, for example, integrally formed from a metal material.

[0017] The bearings 34, 35 rotatably support the shaft 40. The shaft 40 is fixed to the bearings 34, 35 by, for example, press-fitting or adhesive. The shaft 40 has a cylindrical main body 41 and an annular outer peripheral portion 42 extending radially from the outer peripheral surface of the main body 41 toward the outer periphery. The main body 41 is rotatably supported by the bearings 34, 35. In this example, the outer peripheral portion 42 is disposed adjacent to the upper side of the tube 31 of the holder 30. The size (outer diameter) of the outer peripheral portion 42 may be the same as the size (outer diameter) of the outer shape of the tube 31. The outer peripheral portion 42 is formed with one or more screw holes 43 at equal intervals, for example, around the rotation axis x. The screw holes 43 extend parallel to the rotation axis x. Here, four screw holes 43 are formed. The main body 41 and the outer peripheral portion 42 of the shaft 40 are integrally formed from, for example, a metal material.

[0018] A rotor 50 is fastened to the shaft 40. The rotor 50 has a cylinder 51 and a magnet 52. The cylinder 51 is fastened to the shaft 40. The cylinder 51 has a cylindrical side wall 53 and an upper wall 54 that closes the upper end of the side wall 53. As is clear from FIG. 2, most of the cylinder 51 is accommodated in a space S. The lower end of the side wall 53 is open. The side wall 53 defines a cylindrical outer peripheral surface 53a around the rotation axis x. A magnet 52 is fixed to the outer peripheral surface 53a of the side wall 53. The magnet 52 is attached to the outer peripheral surface 53a by, for example, an adhesive. The magnet 52 is a permanent magnet including, for example, a rare earth magnet. In the magnet 52, an S-pole region magnetized to an S pole and an N-pole region magnetized to an N pole are alternately arranged in the circumferential direction. The outer peripheral surface of the magnet 52 faces the magnetic pole portion 27 of the stator core 21 with a predetermined magnetic gap.

[0019] The upper wall 54 of the cylinder 51 has a hole (through hole) 55 formed along the rotation axis x, and one or more holes (through holes) 56 (four holes in this example) formed around the through hole 55. The through hole 55 receives the main body 41 of the shaft 40. The main body 41 of the shaft 40 protrudes partially upward from the through hole 55. In this example, four through holes 56 are formed at positions corresponding to the screw holes 43 of the outer periphery 42 of the shaft 40. The upper wall 54 is received on the outer periphery 42 of the shaft 40 at its lower surface. The cylinder 51 is fastened to the shaft 40 by screwing a fastening member 57 such as a bolt into the screw hole 43 of the outer periphery 42 through the through hole 55 of the upper wall 54.

[0020] As shown in FIG. 4, one or more screw holes 58 are formed in the upper wall 54 around the rotation axis x. In this example, four screw holes 58 are formed, for example, at equal intervals around the rotation axis x. Meanwhile, one or more holes (through holes) 59 are formed in the propeller 5 around the rotation axis x. In this example, four through holes 59 are formed at equal intervals around the rotation axis x in correspondence with the positions of the screw holes 58. A fastening member 60 such as a bolt is screwed through the through hole 59 of the propeller 5 into the screw hole 58 in the upper wall 54, whereby the propeller 5 is directly fastened to the tube 51, i.e., the rotor 50. The shaft 40 is accommodated in the through hole 61 of the propeller 5. The propeller 5 may be indirectly fastened to the rotor 50 via another member (not shown).

[0021] In the drone 1 as described above, as shown in FIG. 4, for example, the motor 4 includes a first unit A including a housing 10 and a stator 20, a second unit B including a holder 30, bearings 34, 35, and a shaft 40, and a third unit C including a cylinder 51 and a magnet 52. The first unit A, the second unit B, and the third unit C are detachable from each other. That is, the second unit B is detachable from the first unit A. Also, the third unit C is detachable from the second unit B. For example, when it is necessary to replace each of the units A, B, or C, it is possible to individually replace only the first unit A, only the second unit B, or only the third unit C.

[0022] Moreover, the rare earth magnet contained in the magnet 52 is a rare earth metal and is scarce. Therefore, when recovering the rare earth metal for recycling, only the third unit C including the magnet 52 needs to be removed from the motor 4, and recovery is easy. As a result, recyclability can be improved. Moreover, the second unit B and the third unit C are fastened to the first unit A and the second unit B, respectively, by fastening members 37, 57 such as bolts, and therefore can be easily attached and detached from the motor 4 without using special tools. With such an unmanned vehicle 1, replacement costs can be significantly reduced.

[0023] Although the present invention has been described above through the above embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It is clear to those skilled in the art that various modifications or improvements can be made to the above embodiments. It is clear from the claims that such modifications or improvements can also be included in the technical scope of the present invention.

[0024] The above-described embodiments are intended to facilitate understanding of the present invention, and are not intended to limit the present invention. The components of the above-described embodiments, as well as their arrangements, materials, conditions, shapes, sizes, etc., are not limited to those illustrated, and can be modified as appropriate. Furthermore, components shown in different embodiments can be partially substituted or combined with each other within the scope of technical inconsistency. [Explanation of symbols]

[0025] 1 drone, 2 arm, 2a arm body, 2b attachment, 2c fastening member, 2d through hole, 3 propulsion device, 4 motor, 5 propeller, 10 housing, 11 base, 12 cover, 13 bottom, 14 side wall, 14a inner peripheral surface, 15 screw hole, 16 disk portion, 17 cylindrical portion, 18 screw hole, 20 stator, 21 stator core, 22 coil, 23 insulator, 24 cylindrical portion, 25 teeth, 26 spokes, 27 magnetic pole portion, 27a cylindrical surface, 30 holder, 31 tube, 31a outer peripheral surface, 31b inner peripheral surface, 32 flange, 33 through hole, 34 bearing, 35 bearing, 36 recess, 37 fastening member, 40 shaft, 41 body, 42 outer peripheral portion, 43 screw hole, 50 rotor, 51 cylinder, 52 magnet, 53 side wall, 53a outer circumferential surface, 54 upper wall, 55 hole (through hole), 56 hole (through hole), 57 fastening member, 58 screw hole, 59 hole (through hole), 60 fastening member, 61 through hole, A first unit, B second unit, C third unit, S space, x rotation axis

Claims

1. Arm and A housing fastened to the aforementioned arm, A holder fastened to the housing, The holder comprises a rotor fastened to the holder, The holder is rotatably supported by a shaft that supports the rotor. An unmanned aircraft in which the arm and the holder are detachable from the housing.

2. The rotor is rotatably supported by a bearing, The holder comprises a cylinder for housing the bearing and a flange provided on the cylinder. The unmanned aircraft according to claim 1, wherein the flange is fastened to the housing.

3. The rotor comprises a cylinder and a magnet fixed to the outer surface of the cylinder, The unmanned aircraft according to claim 1 or 2, wherein the cylinder is fastened to the outer circumference of the shaft.

4. The unmanned aircraft according to claim 3, wherein the outer circumference of the shaft has an annular shape extending in the radial direction.

5. The unmanned aircraft according to claim 1 or 2, further comprising a propeller directly or indirectly fastened to the rotor.

6. The unmanned aircraft according to claim 1 or 2, comprising a stator housed in the housing.

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