advanced propulsion device for rotary-wing aircraft with vertical takeoff and landing and aircraft equipped with such a propulsion device

Abstract

Improved Propulsion Device for Rotary-Wing Aircraft with Vertical Takeoff and Landing and Aircraft Equipped with Such a Propulsion Device. The invention relates to a propulsion device (1) for a rotary-wing aircraft with vertical takeoff and landing and an aircraft equipped with such a device (1). This device (1) comprises a hollow frame and two propellers, each having a blade-carrying ring (6) carrying fixed-pitch blades. Drive means (7) allow each propeller to be driven in rotation about its axis of rotation, and tilt control means allow them to be tilted about the roll axis and the pitch axis (A3). The blade-carrying ring (6) of each propeller is connected to the drive means (7) by a gimbal-type gyroscopic mount (10-13). Figure to be published with the abstract: Figure 7.

Description

Title of the invention: Improved propulsion device for rotary-wing aircraft with vertical takeoff and landing and aircraft equipped with such a propulsion device

[0001] The technical field of the invention is that of rotary-wing aerodynes with vertical takeoff and landing, and more specifically that of aerodynes with propulsion by coaxial counter-rotating propellers (or rotors).

[0002] In particular, the present invention relates to a propulsion device using contra-rotating coaxial propellers and a drone-type aerodyne comprising at least one such propulsion device.

[0003] In the present application, the term "propulsion" includes the lifting of the aircraft, propulsion in flight in translation in the vertical, longitudinal and lateral directions, as well as attitude control in yaw, roll and pitch.

[0004] A contra-rotating coaxial propeller aerodyne propulsion device with known French patent FR3095189B1 offers, compared to previous devices (in particular those known from French patent FR2980117B1), improved maneuverability, while retaining the advantage of simplicity provided by the absence of collective and cyclic systems for varying the pitch of the blades.

[0005] This device includes mounting each propeller on a frame such that only the propellers are moved around the yaw, roll and pitch axes, by the use of a hollow finger ball joint which connects each propeller to a rotating drive part which is located inside the frame.

[0006] The ball joint to finger thus allows the rotation of the associated propeller only around the roll and pitch axes while the rest of the propulsion device remains fixed with respect to these axes.

[0007] However, due to the use of the ball joint to finger connection, this device exhibits functional play and friction which leads to a loss of efficiency on the propulsion chain.

[0008] This device also has the disadvantage of having many parts, which leads to difficulties in assembly and disassembly and complicates maintenance.

[0009] Furthermore, the architecture described by patent FR3095189B1 includes numerous rods to ensure the tilting of the propellers around the roll and pitch axes: motorized rods associated with so-called mirror rods to balance the forces and wear compensation rods to ensure the parallelism of the propellers.

[0010] This architecture is also very complex and it leads to functional games which impair the reliability of the control.

[0011] The aim of the invention is to propose a propulsion device for rotary-wing aircraft with vertical takeoff and landing that does not present such disadvantages and allows for better overall performance.

[0012] Thus the propulsion device according to the invention is of simple, compact, light and efficient design and makes it easier to use, assemble, disassemble and maintain the aerodyne.

[0013] The present invention therefore relates to a propulsion device for a rotary-wing aircraft with vertical takeoff and landing, using coaxial and counter-rotating propellers movable in yaw, roll and pitch, the propulsion device comprising:

[0014] - a hollow chassis having a longitudinal axis which, in use, is coaxial with the axis of lace;

[0015] - an upper propeller and a lower propeller, each having a blade-carrying ring around the periphery of which fixed-pitch blades are fixed or intended to be fixed, the propellers being spaced one above the other along the yaw axis, each propeller defining a propeller disk and being capable of being driven into rotation about an axis of rotation which is perpendicular to the propeller disk and of being inclined about the roll axis and the pitch axis;

[0016] - drive means for rotating each propeller around its axis of rotation; and

[0017] - tilt control means for tilting the propellers around the axis of roll and pitch axis;

[0018] the propulsion device being characterized by the fact that the blade-carrying ring of each propeller is connected to the drive means by a gyroscopic type gimbal assembly comprising two concentric gimbals, namely an inner gimbal mounted for rotation around a first pivot axis by a first pair of bearings connecting the inner gimbal to the drive means, and an outer gimbal fixed to the blade-carrying ring and mounted for rotation, relative to the inner gimbal, around a second pivot axis by a second pair of bearings connecting the outer gimbal to the inner gimbal, the second pivot axis being perpendicular to the first pivot axis, the first and second pivot axes being perpendicular to the longitudinal axis of the frame.

[0019] The use of such a gyroscopic gimbal-type assembly eliminates the play and friction that might be present with the use of another assembly, such as one using a ball joint. In particular, the use of this gyroscopic-type assembly allows for a gain of approximately 30%. efficiency on the device's drive chain compared with the use of a ball joint to finger connection.

[0020] In a particular embodiment, each blade carrier ring carries blade supports, each blade support being pivotally mounted relative to the blade carrier ring between a folded position in which the blade support, and where applicable the blade attached to said blade support, on the one hand, and the blade carrier ring carrying said blade support, on the other hand, are not located in the same plane, and an unfolded position in which the blade support, and where applicable the blade attached to said blade support, on the one hand, and the blade carrier ring carrying said blade support, on the other hand, are located in the same plane, each blade support being subjected to the effect of an elastic return element which forces it towards said unfolded position and of a locking element configured and arranged to lock the blade support in its unfolded position.

[0021] This movable blade support assembly allows the blades to be positioned in a folded position, in which the blades are folded downwards to extend, for example, globally parallel to the yaw axis. This allows the propulsion system, and therefore a drone equipped with this system, to be slid into a launch tube. The presence of the return mechanism allows the blade support to be automatically returned to the unfolded position upon ejection from the launch tube.

[0022] Preferably, the return element is formed by a spiral torsion spring arranged coaxially around the axis of rotation of the blade support.

[0023] Preferably, the axis of rotation of the blade support is defined by a screw.

[0024] Preferably, the locking member comprises a locking latch movably mounted between a retracted position in which the latch is retracted to allow the blade support to move freely from its folded to its unfolded position, and an extended position in which the latch engages in a groove in the blade support, under the action of an elastic return element, when the blade support is in the unfolded position. Thus, the blade support is reliably and automatically immobilized in the unfolded position after ejection from the launch tube.

[0025] The elastic return element can be a simple spring.

[0026] In a particular embodiment, the blade-carrying ring of the upper propeller carries an upper plate and the blade-carrying ring of the lower propeller carries a lower plate, the two plates being located between the propellers and each plate being connected to the respective blade-carrying ring by a bearing allowing the plate and the respective blade-carrying ring to be rotationally separated around the axis of rotation of the blade-carrying ring, the tilt control means comprising at least two guide rods of fixed length parallel to the yaw axis, each rod of the guide being articulated to the upper plate by a first ball joint and being articulated to the lower plate by a second ball joint, the tilt control means further comprising two control devices, namely a roll control device and a pitch control device, arranged such that the roll control device is able to control the tilting of one of the two plates, in particular the lower plate, around the roll axis and that the pitch control device is able to control the tilting of this same plate around the pitch axis, the movement of the control devices being controlled by drive means, locking means being provided to prevent the rotation of the plates relative to the drive means.

[0027] Such tilt control means make it possible to motorize only one of the two plates in pitch and roll, the forces being transmitted by the guide rods to the other plate. This has the effect of reducing the overall backlash.

[0028] For example, each ball joint comprises a ball joint cage integral with the end of the guide rod and a ball joint rod integral with the plate.

[0029] Preferably, there are four guide rods, each angularly offset from the others.

[0030] Preferably, each control device comprises a control rod fixed at one end to a connecting rod via a ball joint and fixed at the other end to one of the two plates, in particular the lower plate, via a ball joint. The end of the connecting rod opposite the first end of the control rod is rotationally fixed to a rotating output shaft of the drive means. Such a control device constitutes a reliable and simple means of transmitting the motion of the drive means to one of the plates.

[0031] Preferably, the locking means comprise at least one lever arm attached to the driving means by a first end at a pivot joint and attached to one of the guide rods by a second end at a pivot joint, a linear bearing being mounted on the guide rod and being connected to the lever arm via a bearing interposed between the linear bearing and the second end, and a bearing being interposed between the first end and the driving means.

[0032] Since the two plates are joined by the guide rods, they must be locked by these locking means to prevent them from rotating due to the torque induced by the drive means. These locking means thus allow the guide rod to move as it shifts with the angle of incidence of the plate. Such locking means have the advantage of not causing vibrations.

[0033] Advantageously, the drive means used to control the movement of the control devices are located outside the chassis. Installing the drive means outside the chassis increases the space available inside the chassis for the propulsion device. This facilitates the installation of all the electronics required for the propulsion device, such as motor control boards, a satellite positioning system, and sensors. Once equipped with all its electronics, the propulsion device according to the invention is then ready to be installed on any aircraft, requiring only an external power supply.

[0034] Preferably, the drive means comprise, for each control device, a servomotor. The use of servomotors saves space, thereby freeing up room to house all the onboard electronics. This also reduces weight, allowing for an increased payload capacity for a drone equipped with this device, as well as improved flight time.

[0035] Preferably, the drive means comprise, for each propeller, a permanent magnet motor whose magnetized rotor has a plurality of magnets and is integral with a gyroscopic rotor on which is fixed the gimbal gyroscopic type assembly on which pivots the blade-carrying ring of said propeller, and whose stator surrounds the rotor.

[0036] The present invention also relates to a rotary-wing aerodyne with vertical takeoff and landing, the propulsion of which is ensured by a propulsion device, characterized by the fact that the propulsion device is as defined above.

[0037] The aerodyne can be a manned aerodyne, for example a helicopter, or an unmanned aerodyne, for example a drone.

[0038] It is emphasized here that the configuration of the means for driving the rotation of the propellers described above is independent of the configuration of the means for controlling their inclinations.

[0039] To better illustrate the object of the present invention, a particular embodiment thereof will be described below, with reference to the accompanying drawings. In these drawings:

[0040] [Fig.1] is an overview of a propulsion device according to a particular embodiment of the present invention, the blades being in their unfolded position;

[0041] [Fig.2] is a view analogous to that of [Fig.1], with the blades in their folded position;

[0042] [Fig.3] is a perspective view of the propulsion device, with the blades omitted;

[0043] [Fig.4A] is a side view of the propulsion device as shown in [Fig.3];

[0044] [Fig.4B] is another side view of the propulsion device as shown in [Fig.3];

[0045] [Fig.4C] is yet another side view of the propulsion device as shown in [Fig.3];

[0046] [Fig.5] is a side view analogous to that of [Fig.4B], the propellers being inclined around the roll axis and the pitch axis;

[0047] [Fig.6] is a top view of the propulsion device as shown on the [Fig.3];

[0048] [Fig.7] is a vertical cross-sectional view of the propulsion device, along a cutting plane passing through the guide rod equipped with means for locking the plates in rotation;

[0049] [Fig.8] is an exploded perspective view of a propeller, showing the bearing ring blades, its drive means and the gyroscopic type mounting with gimbals;

[0050] [Fig.9] is a top perspective view of the propulsion device showing the blade supports; and

[0051] [Fig. 10] is a schematic side view of a drone according to the present invention.

[0052] If we refer first to Figures 1 and 2, we can see that a device of propulsion 1 for rotary-wing aerodyne with vertical takeoff and landing comprises two coaxial and counter-rotating propellers 2 and 3.

[0053] The propellers 2 and 3 rotate about a longitudinal axis which, in [Fig. 1], coincides with the yaw axis A1 and each comprises two fixed-pitch blades 4 arranged at 180 degrees to each other. Each propeller may, of course, have any number of blades, which together define a propeller disk.

[0054] The propulsion device 1 comprises a hollow chassis 5 which has a longitudinal axis which, in use ([Fig. 1]), is coaxial with the yaw axis AL

[0055] Each of the propellers 2 and 3 has a blade carrier ring 6 around the periphery of which the blades 4 are fixed.

[0056] In [Fig. 1], it can be seen that the two propellers 2 and 3 are spaced one above the other along the yaw axis A1, one of the propellers being called the upper propeller 2 and the other the lower propeller 3. Each propeller 2 and 3 defines a propeller disk which corresponds to the geometric plane in which each propeller rotates and is driven in rotation about an axis of rotation which is perpendicular to the propeller disk. Each propeller 2 and 3 can also be tilted ([Fig. 5]) about the roll axis A2 and / or the pitch axis A3 to allow the movement of the aircraft.

[0057] The propulsion device 1 includes drive means 7 for rotating each propeller 2 and 3 about its axis of rotation. It also includes tilt control means 8 for tilting the two propellers 2 and 3, in a parallel manner, about the roll axis A2 and / or the pitch axis A3.

[0058] Reference is now also made to Figures 3 to 5, in which the blades 4 have been removed. It can be seen that, in these Figures, the two blade-carrying rings 6 are oriented identically. Thus, for each blade-carrying ring 6, we see the two blade supports 9 which allow the blades 4 to be fixed to the blade-carrying ring 6. These two blade supports 9 are diametrically opposed to each other.

[0059] Each blade support 9 is pivotally mounted on the blade carrier ring 6 so as to allow the blade 4 attached to it to be foldable, and thus to be able to be folded ([Fig.2]) in view of the introduction of the device 1 into a launch tube (not shown) and unfolded (Figures 1 and 10) once the device 1 has been ejected out of the launch tube.

[0060] As can be seen in Figures 8 and 9, each blade support 9 is rotatably mounted about the axis of a screw 90 passing through two wings 60 located on the periphery of the blade carrier ring 6. These wings 60 are arranged opposite each other and spaced apart. The head of the screw 90 bears against one of the wings 60, the heads of the screws 90 of the two blade supports 9 of the same blade carrier ring 6 being opposite each other. Each screw 90 also passes through two lugs 91 of the blade support 9, which lugs 91 are spaced apart along the shank of the screw 90 and are positioned between the two wings 60. The axis of the screws 90 is perpendicular to the longitudinal axis of the frame 5, so as to allow pivoting of the blade support 9 between a folded position ([Fig.2]), in which the blade support 9 is inclined downwards (considering the orientation of the [Fig.l]) relative to the plane of the blade carrier ring 6 which supports it, and an unfolded position (Figures 1 and 10), in which the blade support 9 extends in the same plane as the blade carrier ring 6 which supports it. Each tab 91 is shaped so as to allow the blade support 9 to tilt downwards and to prevent it from tilting upwards.

[0061] Each blade support 9 is continuously forced towards the unfolded position by a return element 92, thus allowing the blade support 9 to automatically move into its unfolded position as soon as it is no longer constrained by the walls of the launch tube. In the embodiment shown, the return element 92 is a spiral torsion spring mounted around the shaft of the screw 90, between the two lugs 91.

[0062] As can be seen more particularly in [Fig. 9], each blade support 9 in the unfolded position is automatically locked in this unfolded position by a locking member 93, 94. The locking member 93, 94 comprises a locking latch 93 actuated by a return spring (not visible), such that the The latch 93 is mounted movably between a retracted position in the blade carrier ring 6 and an extended position out of the ring 6. In the extended position, towards which the latch 93 is forced by the return spring, the latch 93 is housed in a groove 94 formed in the corresponding lug 91 of the blade support 9. This is a U-shaped groove 94 opening upwards in the unfolded position.

[0063] Alternatively, the blades 4 can of course be fixed to their blade-carrying ring 6 without the interposition of the pivotally mounted blade supports 9, in a known manner. In this case, the blades would then not be folding blades.

[0064] Each blade-carrying ring 6 is connected to the drive means 7 by an assembly of the gyroscopic type with gimbals 10-13. As can be seen in [Fig.8], this assembly 10-13 includes an inner gimbal 10, an outer gimbal 11, a first pair of bearings 12 and a second pair of bearings 13.

[0065] More specifically, as shown in Figures 6 and 7, the inner 10 and outer 11 universal joints each comprise an annular frame, the outer diameter of the inner universal joint 10's frame being smaller than the inner diameter of the outer universal joint 11's frame. The inner universal joint 10 is rotatably mounted relative to the drive means 7 by a pivot joint located between the inner universal joint 10 and the drive means 7, defining a first pivot axis. The outer universal joint 11 is fixed to the blade-carrying ring 6 and is rotatably mounted around the inner universal joint 10 by a pivot joint located between the inner universal joint 10 and the outer universal joint 11, defining a second pivot axis.The first pivot axis is defined by the first pair of bearings 12 and the second pivot axis is defined by the second pair of bearings 13, the two bearings of the same pair being diametrically opposed and the bearing of one pair being angularly offset by 90 degrees with respect to the bearings of the other pair. In other words, the first and second pivot axes are perpendicular to each other and are located in the same plane orthogonal to the longitudinal axis of the chassis 5.

[0066] This mechanical assembly, of the type with two degrees of rotational freedom, with two concentric and orthogonally coupled gimbals 10, 11, is therefore designed to allow the blade carrier ring 6 to oscillate around the first pivot axis and around the second pivot axis. In other words, this assembly 10-13 allows the blade carrier ring 6 to pivot around an axis parallel to the pitch axis A3 and also around an axis parallel to the roll axis A2, thus perpendicular to the yaw axis A1 and the pitch axis A3. Naturally, this gyroscopic assembly 10-13 prevents the blade carrier ring 6 from moving in translation.

[0067] According to the present invention, as shown in Figures 7 and 8, the drive means 7 comprise, for each propeller 2 and 3, a permanent magnet motor 70 of annular shape and a hollow gyroscopic rotor 71. The motor 70 has a hollow magnetized rotor 70a comprising a plurality of magnets and a hollow stator 70b mounted around the magnetized rotor 70a. The magnetized rotor 70a is integral with the gyroscopic rotor 71 and is mounted around it. The stator 70b is therefore external to the magnetized rotor 70a and the gyroscopic rotor 71 and is fixed to the frame 5. Each permanent magnet motor 70 is positioned such that the axis of rotation of the magnetized rotor 70a, and of the gyroscopic rotor 71, is coaxial with the yaw axis AL. The inner gimbal 10 is rotatably mounted on the gyroscopic rotor 71. In particular, the first pair of bearings 12 is connected to an enlarged portion 71a of the gyroscopic rotor 71, while the magnetized rotor 70a is fixed to a narrow portion 71b of this gyroscopic rotor 71. As a result, the enlarged portions 71a of the gyroscopic rotors 71 of the two propellers 2 and 3 are opposite each other.The enlarged part 71a is a tubular part with the same internal diameter as the narrow part 71b, but with a larger external diameter than the narrow part 71b, the external diameter of the narrow part 71b corresponding to the internal diameter of the magnetized rotor 70a.

[0068] Thus, the cardan joint assembly 70-13 being connected to the enlarged part 71a of the gyroscopic rotor 71, it will be easily understood that a rotation of the magnetized rotor 70a causes a rotation of the gyroscopic rotor 71, and consequently of the cardan joint assembly 10-13 and of the blade carrier ring 6 carried by this assembly 10-13, around the yaw axis AL. As can be seen in [Fig.7], the mounting of the permanent magnet motors 70 is identical for the drive of the two cardan joint assemblies 10-13.

[0069] It is also noted that the internal volume of the gyroscopic rotors 71 remains available. Such a volume makes it possible to equip the device 1 with all the desired electronics, for example sensors or a satellite positioning receiver, with mounting means using spacers 50 being provided for their attachment within the internal volume.

[0070] We will now describe the tilt control means 8 with reference to Figures 3 to 7.

[0071] These means 8 comprise two swashplates 80 and 81, namely an upper swashplate 80 and a lower swashplate 81, at least two guide rods 82 connecting the upper swashplate 80 and lower swashplate 81, two control devices 83 and 84, namely a roll control device 83 and a pitch control device 84, drive means 85 for the control devices 83 and 84 and means for locking the rotation 86 of the swashplates 80 and 81.

[0072] Each plate 80 and 81 is connected to a blade carrier ring 6 of a propeller by a bearing 61 which allows the plate and the blade carrier ring 6 to be separated in rotation from the propeller in question.

[0073] In the embodiment shown in Figures 3 to 5, four guide rods 82, of fixed length, are located between the helices 2 and 3 and are all parallel to the yaw axis A1. The longitudinal axes of consecutive rods 82 are angularly offset on the periphery of the plates 80 and 81. Each rod 82 has a first end connected to the upper plate 80 and a second end connected to the lower plate 81. The connection between each longitudinal end of the guide rod 82 and the respective plate is a ball joint 820. More particularly, each ball joint 820 comprises a ball joint cage 820a integral with the end of the guide rod 82 and a ball joint rod 820b integral with the plate 80, 81.Because of these first and second ball joint links 820, articulating the guide rod 82 between the two plates 80 and 81, the tilting of one of the plates 80 or 81 can be transmitted, in a synchronized manner, to the other plate 81 or 80.

[0074] In the embodiment shown, only the lower plate 81 is connected to the control devices 83, 84 and is controlled in movement by them. As can be seen in Figures 3 and 4C, each control device 83 and 84 comprises a control rod 830, 840, of fixed length, articulated on the lower plate 81 and a connecting rod 831, 841 connected to the drive means 85.

[0075] More specifically, in the same way as the guide rods 82, the control rod 830, 840 is articulated at its two longitudinal ends by ball joints 832, 842. In other words, a ball joint 832, 842 connects one end of the control rod 830, 840 to one end of the connecting rod 831, 841 and another ball joint 832, 842 connects the second end of the control rod 830, 840 to the lower plate 81. The other end 833, 843 of the connecting rod 831, 841 is connected to the drive means 85, at the center of the chassis 5 considering the longitudinal direction of the chassis 5, so as to rotate together with a rotating output shaft of the respective drive means 85, around a pivot axis. The two pivot axes of the two connecting rods 831, 841 belong to the same plane, transverse to the yaw axis Al, and form an angle of 90 degrees with each other.Thus, the two control devices 83 and 84 are arranged such that one of the control devices is able to control the tilting of the lower plate 81 around the roll axis A2 and the other control device is able to control the tilting of the lower plate 81 around the pitch axis A3.

[0076] The movement of each control device 83 and 84 is controlled by the drive means 85, which are located outside the internal volume of the hollow chassis 5. These drive means 85 comprise two servomotors 85, namely one servomotor 85 connected to each control device 83 and 84, as can be seen in Figures 3 and 4C.

[0077] Mechanical locking means 86 for the platters 80 and 81 are provided to prevent rotation of the platters 80 and 81 relative to the frame 5. An example of such locking means 86 is shown in Figures 4A, 4B, 5 and 7.

[0078] According to this embodiment, the locking means 86 comprise a linear bearing 860, two lever arms 861, and bearings 862. The linear bearing 860 is threaded onto one of the guide rods 82. The two lever arms 861 are arranged on either side of the linear bearing 860, with a bearing 862 interposed between the linear bearing 860 and each lever arm 861. The end of each lever arm 861 opposite the end connected to the linear bearing 860 is rotatably connected to the frame of the drive means 85 via a bearing 862. The bearings 862 are arranged to define pivot joints at each end of the lever arms 861. Thus, these locking means 86 can accommodate the oscillations of the plates 80 and 81 while preventing their rotation around the AL yaw axis

[0079] The tilt control means 8 are thus capable of tilting the two propellers 2 and 3 synchronously around the roll axis A2 or the pitch axis A3 by a positive mechanical control of a single plate, namely the lower plate 81 in the present embodiment.

[0080] It is noted that the propulsion device 1 according to the invention is very compact, the set of drive means 7 in rotation of the blade carrier rings 6 and of control means 8 of the inclination of these blade carrier rings 6 around the roll axis A2 and pitch axis A3 being located between the two blade carrier rings 6.

[0081] Furthermore, the use of a gyroscopic-type linkage based on cardan shafts 10-13 and the connection of the plates 80 and 81 by articulated ball-joint guide rods 82 reduces backlash. This results in a control that is simultaneously simplified, more reliable, more robust and more efficient, as well as a reduction in the overall weight of the device 1.

[0082] Thus, as can be seen in [Fig. 10], where a very schematic representation of an aerodyne or drone D whose body DI is equipped with the propulsion device 1 is shown, the total height of the drone D is not affected by the presence of the propulsion device 1. It is therefore possible to increase the size of the blades 4 without necessarily increasing the size of the rest of the aerodyne, for both visual and acoustic stealth.

[0083] It is understood that the particular embodiment just described has been given by way of example and not limitation, and that modifications may be made without departing from the scope of the present invention.

Claims

1.

2. Demands Propulsion device (1) for a rotary-wing aircraft (D) with vertical takeoff and landing, by means of coaxial and counter-rotating propellers (2, 3) movable in yaw, roll and pitch, the propulsion device (1) comprising: • a hollow chassis (5) having a longitudinal axis which, in use, is coaxial with the yaw axis (Al), • an upper propeller (2) and a lower propeller (3) each having a blade carrier ring (6) around the periphery of which fixed-pitch blades (4) are fixed or intended to be fixed, the propellers (2, 3) being spaced one above the other along the yaw axis (A1), each propeller (2, 3) defining a propeller disk and being capable of being driven into rotation about an axis of rotation which is perpendicular to the propeller disk and of being inclined about the roll axis (A2) and the pitch axis (A3), • drive means (7) for rotating each propeller (2, 3) around its axis of rotation, and • tilt control means (8) for tilting the propellers (2, 3) around the roll axis (A2) and the pitch axis (A3), the propulsion device (1) being characterized in that the blade carrier ring (6) of each propeller (2, 3) is connected to the drive means (7) by a gyroscopic type gimbal assembly (10-13) comprising two concentric gimbals (10, 11), namely an inner gimbal (10) mounted for rotation about a first pivot axis by a first pair of bearings (12) connecting the inner gimbal (10) to the drive means (7), and an outer gimbal (11) fixed to the blade carrier ring (6) and mounted for rotation, relative to the inner gimbal (10), about a second pivot axis by a second pair of bearings (13) connecting the outer gimbal (11) to the inner gimbal (10), the second pivot axis being perpendicular to the first pivot axis, the first and second pivot axes being perpendicular to the longitudinal axis of the frame (5). Propulsion device (1) according to claim 1, characterized in that each blade-carrying ring (6) carries blade supports

3.

4. (9), each blade support (9) being mounted pivotally relative to the blade carrier ring (6) between a folded position in which the blade support (9), and where applicable the blade (4) attached to said blade support (9), on the one hand, and the blade carrier ring (6) carrying said blade support (9), on the other hand, are not located in the same plane, and an unfolded position in which the blade support (9), and where applicable the blade (4) attached to said blade support (9), on the one hand, and the blade carrier ring (6) carrying said blade support (9), on the other hand, are located in the same plane, each blade support (9) being subjected to the effect of an elastic return member (92) which forces it towards said unfolded position and of a locking member (93, 94) configured and arranged to lock the blade support (9) in its unfolded position. Propulsion device (1) according to claim 2, characterized in that the locking member (93, 94) comprises a locking latch (93) mounted movablely between a retracted position in which the latch (93) is retracted to allow the blade support (9) to move freely from its folded position to its unfolded position, and an extended position in which the latch (93) is lodged in a groove (94) of the blade support (9), under the effect of an elastic return member, when the blade support (9) is in the unfolded position. Propulsion device (1) according to any one of claims 1 to 3, characterized in that the blade-carrying ring (6) of the upper propeller (2) carries an upper plate (80) and the blade-carrying ring (6) of the lower propeller (3) carries a lower plate (81), the two plates (80, 81) being located between the propellers (2, 3) and each plate (80,81) being connected to the respective blade-carrying ring (6) by a bearing (61) allowing the rotational separation, around the axis of rotation of the blade-carrying ring (6), of the plate (80, 81) and the respective blade-carrying ring (6), the tilt control means (8) comprising at least two guide rods (82), of fixed length and parallel to the yaw axis (A1), each guide rod (82) being articulated to the upper plate (80) by a first ball joint (820) and being articulated to the lower plate (81) by a second ball joint (820), the tilt control means (8) further comprising two control devices (83, 84), namely a roll control device (83) and a pitch control device (84), arranged as follows, such that the roll control device (83) is capable of controlling the tilting of one of the two plates, in particular the lower plate (81), around the roll axis (A2) and that the pitch control device (84) is capable of controlling the tilting of this same plate (81) around the pitch axis (A3), the movement of the control devices (83, 84) being controlled by driving means (85), blocking means (86) being provided to prevent the rotation of the plates (80, 81) relative to the driving means (85).

5. Propulsion device (1) according to claim 4, characterized in that each control device (83, 84) comprises a control rod (830, 840) integral with a connecting rod (831, 841) by a first end at the level of a ball joint (832, 842) and integral with one of the two plates, in particular the lower plate (81), by a second end at the level of a ball joint (832, 842), the end (833, 843) of the connecting rod (831, 841) opposite the first end of the control rod (830, 840) being rotationally integral with a rotating output shaft of the drive means (85).

6. Propulsion device (1) according to any one of claims 4 and 5, characterized in that the locking means (86) comprise at least one lever arm (861) attached to the driving means (85) by a first end at a pivot joint and attached to one of the guide rods (82) by a second end at a pivot joint, a linear bearing (860) being mounted on the guide rod (82) and being connected to the lever arm (861) via a bearing (862) interposed between the linear bearing (860) and the second end, and a bearing (862) being interposed between the first end and the driving means (85).

7. Propulsion device (1) according to any one of claims 4 to 6, characterized in that the drive means (85) used to control the movement of the control devices (83, 84) are located outside the chassis (5).

8. Propulsion device (1) according to any one of claims 4 to 7, characterized in that the drive means (85) comprise, for each control device, a servomotor (85).

9. Propulsion device (1) according to any one of claims 1 to 8, characterized in that the drive means (7) comprise, for each propeller (2, 3), a permanent magnet motor (70) whose magnetized rotor (70a) has a plurality of magnets and is integral with a gyroscopic rotor (71) on which is fixed the gimbal gyroscopic type assembly (10-13) on which pivots the blade carrier ring (6) of said propeller (2, 3), and whose stator (70b) surrounds the rotor (70a).

10. Aerodyne (D) with rotary wing and vertical takeoff and landing, the propulsion of which is ensured by a propulsion device (1), characterized in that the propulsion device (1) is as defined in any one of claims 1 to 9.

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