Method of fabricating rotary equipment for a rotary wing, provided with a deicer, said rotary equipment, and a drone provided with said rotary equipment

Abstract

A piece of rotary equipment for a drone, the rotary equipment having a rotary assembly including at least one blade. The rotary assembly includes at least one furrow that extends in a skin from a first end to a second end, the at least one furrow being at least arranged over the blade, the at least one furrow presenting at least one change of direction on the blade, the rotary assembly including at least one deicer having an electrically conductive track that extends in the at least one furrow, the electrically conductive track extending from a first terminal to a second terminal, the first terminal being present at the first end and the second terminal being present at the second end, the deicer including a protective layer covering the electrically conductive track.

Claims

1. A method of fabricating a piece of rotary equipment for a drone, the rotary equipment comprising a rotary assembly provided with a deicer, the rotary assembly comprising at least one blade, wherein the method comprises fabricating the rotary equipment by a laser direct structuring method by performing the following steps: fabricating the rotary assembly, the rotary assembly having a skin, the skin comprising a composite material provided with an organic metal; using a laser to make at least one furrow in an outside face of the skin, the at least one furrow extending from a first end to a second end, the at least one furrow being formed at least over the blade, the at least one furrow presenting at least one change of direction on the blade; making an electrically conductive track of the deicer in the at least one furrow by dipping the rotary assembly in a bath containing a metal, the electrically conductive track extending from a first terminal to a second terminal, the first terminal being present at the first end and the second terminal being present at the second end; and covering the electrically conductive track with a protective layer.

2. The method according to claim 1, wherein the fabrication of the rotary assembly includes a step of making a central core and a step of covering the central core with the skin.

3. The method according to claim 1, wherein the electrically conductive track extends over a length from the first terminal to the second terminal, the electrically conductive track extending in a thickness direction from a bottom face in contact with a bottom of the at least one furrow to a top face, the electrically conductive track extending in a width direction between two sides respectively in contact with two flanks of the at least one furrow, the thickness and the width each lying in the range 30 μm to 60 μm.

4. The method according to claim 1, wherein the rotary assembly comprises at least two blades and a hub, the at least two blades being carried by the hub, and the at least two blades and the hub forming a single piece.

5. The method according to claim 4, wherein the electrically conductive track extends over the hub and over at least one blade, the first end and the second end together with the first terminal and the second terminal being present on the hub.

6. A piece of rotary equipment provided with a rotary assembly for a drone, the rotary assembly being provided with at least one blade and including a skin with at least one furrow extending in an outside face of the skin from a first end to a second end, the at least one furrow being formed at least in the blade, the at least one furrow presenting at least one change of direction in the blade, the rotary equipment including at least one deicer, the deicer comprising an electrically conductive track extending in the at least one furrow, the electrically conductive track extending from a first terminal to a second terminal, the first terminal being present at the first end and the second terminal being present at the second end, the deicer having a protective layer covering the electrically conductive track.

7. The piece of rotary equipment according to claim 6, wherein the rotary equipment includes a central core arranged inside the skin.

8. The piece of rotary equipment according to claim 6, wherein the electrically conductive track extends over a length from the first terminal to the second terminal, the electrically conductive track extending in a thickness direction from a bottom face in contact with a bottom of the at least one furrow to a top face, the electrically conductive track extending in a width direction between two sides respectively in contact with two flanks of the at least one furrow, the thickness and the width each lying in the range 30 μm to 60 μm.

9. The piece of rotary equipment according to claim 6, wherein the rotary assembly comprises at least two blades and a hub, the at least two blades being carried by the hub, and the at least two blades and the hub forming a single piece.

10. The piece of rotary equipment according to claim 9, wherein the electrically conductive track extends over the hub and over at least two blades, the first end and the second end together with the first terminal and the second terminal being present on the hub.

11. The piece of rotary equipment according to claim 6, wherein the protective layer comprises a polyurethane varnish.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention and its advantages appear in greater detail from the context of the following description of examples given by way of illustration and with reference to the accompanying figures, in which:

(2) FIG. 1 is a diagram of a piece of rotary equipment of the invention;

(3) FIGS. 2 to 4 are diagrams showing the steps of the method of the invention;

(4) FIG. 5 is a diagram of a drone of the invention; and

(5) FIG. 6 is a diagram showing a piece of rotary equipment of said drone.

DETAILED DESCRIPTION OF THE INVENTION

(6) Elements present in more than one of the figures are given the same reference in each of them.

(7) FIG. 1 shows a piece of rotary equipment for a drone of the invention.

(8) This piece of rotary equipment comprises an aerodynamic rotary assembly 10 that is provided with at least one blade 11. By way of example, the rotary assembly 10 has a plurality of blades 11 that are optionally rigidly secured to a hub 12. The hub 12 may then be fastened to a rotor mast of a drone.

(9) Where appropriate, the hub 12 and the blades 11 may form a single piece, unlike rotors provided with blades that are pinned to a hub, for example.

(10) Furthermore, the rotary assembly 10 presents a skin 13. Depending on the variant, the rotary assembly 10 may comprise one or more central cores covered by the skin 13, or it may comprise a single optionally-solid structure 13 that defines the skin 13.

(11) Independently of the presence or the absence of a central core within the skin 13, the rotary assembly 10 includes at least one deicer 30.

(12) Thus, the rotary assembly 10 has at least one furrow 20 formed in the skin 13, and in particular in an outside face 14 of the skin 13 facing an outside medium EXT situated outside the rotary assembly 10. The furrow 20 is substantially defined by a bottom and by flanks forming a U-shape so that the furrow is open towards the outside medium EXT.

(13) The furrow 20 extends from a first end 21 to a second end 22. The furrow 20 follows a sinuous path over the outside face 14 of the skin 13 going from its first end to its second end, and running along at least one blade 11. Furthermore, the furrow 20 presents at least one change of direction 23 on the blade 11 in order to enter and leave an aerodynamic segment of the blade. For example, at least one furrow 20 runs along and/or in the immediate proximity of the leading edge 16 of the blade 11.

(14) By way of example, a single furrow runs along a plurality of blades 11, or indeed over all of the blades 11 and also over the hub.

(15) Furthermore, each piece of rotary equipment includes at least one deicer 30.

(16) Under such circumstances, each deicer 30 of a piece of rotary equipment 10 has an electrically conductive track 31 arranged in a furrow 20. The deicer is thus integrated in the rotary assembly, with the deicer and the rotary assembly forming an inseparable whole. The electrically conductive track 31 thus extends lengthwise from a first electrical terminal 32 to a second electrical terminal 33. The first terminal 32 is arranged at the first end 21 of a furrow 20, with the second terminal 33 being arranged at the second end 22 of the furrow.

(17) Where appropriate, a single electrically conductive track 31 extends over the hub 12 and over at least one blade 11, or indeed at least two blades 11. The first end 21 and the second end 22 of a furrow, together with said first terminal 32 and said second terminal 33 of the electrically conductive track arranged in the furrow are present on the hub 12.

(18) An electrically conductive track 31 may present thickness and width that are small relative to the voltage present between the first terminal 32 and the second terminal 33 of the electrically conductive track 31. For example, the thickness and the width may lie in the range 30 μm to 60 μm, with said voltage lying in the range 12 V to 14 V.

(19) Furthermore, the deicer 30 may include at least one protective layer 35 that covers at least one electrically conductive track 31.

(20) FIGS. 2 to 4 show a method of the invention for fabricating such a rotary assembly 10 provided with an integrated deicer 30.

(21) With reference to FIG. 2, the method includes a step of fabricating the rotary assembly 10.

(22) FIG. 2 shows a rotary assembly 10 comprising for convenience only one blade 11 in order to illustrate the invention. Nevertheless, the rotary assembly 10 may further comprise a hub, and possibly a plurality of blades together forming a single piece.

(23) During this fabrication step, a rotary assembly 10 that has a skin 13 is fabricated. In particular, the skin 13 is made out of at least one material that is provided with an organic metal, e.g. a copper-filled composite material.

(24) Optionally, the rotary assembly 10 may be made by performing a molding method, an injection molding method, a 3D printing method, . . . .

(25) Optionally, the fabrication step may include a substep of fabricating one or more central cores 15, followed by a substep of covering each central core 15 with said skin 13.

(26) At the end of the fabrication step, the rotary assembly 10 is thus obtained. This rotary assembly 10 comprises at least a skin 13 having an outside face 14.

(27) Under such circumstances, and with reference to FIG. 3, the method includes a step of using a laser to make at least one furrow 20 in the outside face 14 by the laser direct structuring method. At least one furrow extending from a first end 21 to a second end 22 is dug by a laser in the skin 13, the furrow 20 presenting at least one change of direction on a blade 11.

(28) Subsequently, and with reference to FIG. 4, the method includes a step of making an electrically conductive track 31 of a deicer 30.

(29) The electrically conductive track 31 is formed in each furrow 20 by dipping the rotary assembly 10 in a bath containing a metal, e.g. using a method of metal-plating by electrolysis. Each electrically conductive track 31 thus extends from a first terminal 32 to a second terminal 33.

(30) Optionally, at least one electrically conductive track 31 extends over the hub 12 and over at least one blade 11, the first end 21 and the second end 22 together with the first terminal 32 and the second terminal 33 being present on said hub 12.

(31) Thereafter, the method includes a step of covering one or each electrically conductive track 31 with a protective layer 35. For example, a polyurethane varnish is sprayed onto each electrically conductive track 31.

(32) The laser may be designed so as to obtain electrically conductive tracks 31 that present particular dimensions.

(33) By construction, each electrically conductive track 31 extends over a length between the first terminal 32 and the second terminal 33 of the electrically conductive track 31. Furthermore, the electrically conductive track extends in its thickness direction 36 from a bottom face 44 in contact with a bottom 41 of said at least one furrow 20 to a top face 38 covered in the protective layer 35. In addition, the electrically conductive track 31 extends in its width direction 37 between two sides 39 and 40 that are respectively in contact with two flanks 42 and 43 of the furrow receiving the track. The laser may then be designed so that the thickness 36 and the width 37 each lie in the range 30 μm to 60 μm.

(34) With reference to FIG. 5, a piece of rotary equipment of the invention may be arranged on a drone 1. The drone 1 may have a body 2 carrying at least one rotor 5, e.g. via an arm 3. The rotor thus includes a piece of rotary equipment of the invention. Optionally, each rotor 5 includes a respective piece of rotary equipment of the invention.

(35) FIG. 6 shows such a rotor 5 having a piece of rotary equipment of the invention. This configuration is optionally reproduced by all of the rotors 5.

(36) In order to rotate the rotary assembly 10 of a piece of rotary equipment of a rotor 5, the drone 1 has an electric motor 50. The electric motor 50 is connected to an electrical energy storage member 75, possibly via a switch 76 or the equivalent. The electric motor 50, or the switch 76, if any, may be remotely controlled by piloting control means 91 forming part of a remote control 90.

(37) The electric motor 50 has a frame 51 carried by an arm 3. The electric motor 50 thus possesses an outlet shaft that projects from the frame 51. The outlet shaft constitutes a rotor mast 52 that is constrained to rotate with the rotary assembly 10. The rotor mast 52 is optionally solid. By way of example, the rotary assembly then comprises a hub 12 fastened to a free end zone of the rotor mast by conventional means, such as for example screw fastening, adhesive, riveting, welding, stapling, . . . means.

(38) Furthermore, the drone 1 has a source of electrical energy 70 for causing electricity to flow in each electrically conductive track 31 of the rotary assembly 10. This electrical energy source 70 may comprise one or more optionally rechargeable batteries . . . . The electrical energy source 70 may for example be located in the body 2. The electrical energy source 70 may deliver electricity at a voltage lying in the range 12 V to 14 V, for example. Furthermore, the electrical energy source 70 and the above-mentioned electrical energy storage member 75 may constitute single electrical energy storage means or two different electrical energy storage means.

(39) The drone is then provided for each rotor with respective electricity transfer means that are electrically interposed between the electrical energy source and the rotary assembly of the rotor in order to transfer electricity from the stationary reference frame of the body 2 to a rotary reference frame of the rotor 5 and the rotary assembly 10, while they are rotating.

(40) Under such circumstances, the electricity transfer means 60 comprise a stationary portion 61 that is electrically connected to a movable portion 63 of the electricity transfer means 60.

(41) The stationary portion 61 is optionally secured to the frame 51 of the electric motor, via a protective casing 67 of the electricity transfer means, if any.

(42) The movable portion 63 is secured to the rotor mast 52, having the rotor mast 52 passing therethrough. By way of example, the movable portion 63 comprises a tube surrounding the rotor mast 52.

(43) Optionally, the movable portion 63 is fastened to a resilient member 64 by conventional means such as screw fastening, adhesive, riveting, welding, staple means. The resilient member 64 is also secured to the rotor mast 52. For example, the resilient member comprises a band with a bead of adhesive fastening the band to the rotor mast 52.

(44) Furthermore, the stationary portion 61 is electrically in communication with the movable portion 63. For example, the electricity transfer means has brushes 62 in contact with slip rings. In one variant, the stationary portion carries the brushes, with the movable portion carrying the slip rings in contact with the brushes. In another variant, the movable portion carries the brushes and the stationary portion carries the slip rings in contact with the brushes. The stationary portion may surround the movable portion. The movable portion may surround the rotor mast locally.

(45) Nevertheless, any type of electricity transfer means could be envisaged.

(46) Furthermore, the stationary portion 61 is electrically connected to the electrical energy source 70 by an electrical connection. This electrical connection may comprise one or more electric wires together with a switch 71 for the equivalent.

(47) Where appropriate, the switch 71 of the electricity transfer means may be remotely controlled using a deicer control 92 carried by a remote control 90. In the presence of a plurality of rotary assemblies that are electrically powered via respective electricity transfer means connected to switches, the deicer control may serve to control all of the switches. Alternatively, an electrical energy source may be connected to a single switch 71, the switch 71 being connected to all of the electricity transfer means of the drone.

(48) Furthermore, the movable portion 63 is electrically connected to the first terminal 32 and to the second terminal 33 of each electrically conductive track of a rotary assembly.

(49) Under such circumstances, at least two wires 65, 66 extend from the movable portion 63 respectively to the first terminal 32 and to the second terminal 33 of an electrically conductive track.

(50) A first wire 65 is thus placed against the first terminal 32 and a second wire 66 is located against the second terminal 33. A heat-shrink sleeve 80 may be arranged around the connection by surrounding the first wire 65 and the second wire 66 together with the first terminal 32 and the second terminal 33.

(51) Such a fastener system may optionally serve to enable the rotary assembly to be disassembled easily.

(52) Naturally, the present invention may be subjected to numerous variations as to its implementation. Although several embodiments are described, it will readily be understood that it is not conceivable to identify exhaustively all possible embodiments. It is naturally possible to envisage replacing any of the means described by equivalent means without going beyond the ambit of the present invention.