AU2021282486B2 - Propulsion device for vertical take-off and landing rotary-wing aerodyne, and aerodyne comprising at least one such propulsion device - Google Patents

Abstract

The invention relates to a propulsion device (1) for a vertical take-off and landing rotary-wing aerodyne, by means 5 of coaxial contra-rotating propellers. This device includes a hollow frame (5) and two propellers (2, 3) each having a blade carrier ring (6) carrying the fixed pitch blades (4). Drive means (14) drive in rotation each propeller about its axis of rotation, and tilt control means (22) tilt the propellers about 10 the roll axis (A2) and the pitch axis (A3). The blade carrier ring (6) of each propeller is connected to the drive means (14) by a pin spherical joint (13) connection and the drive means include, for each propeller, a torque motor (14), the rotor (14a) of which is secured to a cage (10) on which is 15 secured the spherical joint (13) on which the blade carrier ring (6) of the respective propeller pivots, the stator (14b) of the torque motor (14) being secured to the frame (5). 1/7 [Fig. 1] AlA 2 6 A3 4 4 4 6 4 3 A2 Fig. 1 [Fig. 2] 13 Al1 15 13 10 16a A 1540 1 8 6 7 39a 7 16 27 26 - 25 28 51 43 4 24 1 14b 1417 | a 313 pca N8 31 24..03 34 b 29 21 31 ---7 31 414a 5b 414b 12b s1 25 2\ A2n A'3 \ 16b . . 39b 7 39a 8 13 - 15 j 40 1 2 6 116a Fig. 2

Description

1/7

[Fig. 1]

AlA 2 6 A3 4 4

4 6 4 3 A2 Fig. 1

[Fig. 2]

13 13 Al 15 10 16a A 1 1540 1 8 6 7 39a 7

16 27 26 - 25 28 51 43 4 24

1 14b 1417 | a 313 pca N8 31 24..03 34 b

29 21 31 7 --- 31

414a 5b 414b 12b s1 25

2\ A2n A'3 \ 16b . .

39b 7 39a

8 13 - 15 j 40 1 2 6 116a Fig. 2

Propulsion device for vertical take-off and landing rotary wing aerodyne, and aerodyne comprising at least one such propulsion device

The technical field of the invention is that of

vertical take-off and landing rotary-wing aerodynes, and more

specifically that of aerodynes propelled by coaxial contra

rotating propellers (rotors).

In particular, the present invention relates to a

coaxial contra-rotating propeller propulsion device and a

drone-type aerodyne comprising at least one such propulsion

device.

In this application, the term "propulsion" includes

aerodyne lift, translational flight propulsion in the

vertical, longitudinal and lateral directions, and yaw, roll

and pitch attitude control.

Patent FR3095189 discloses an aerodyne propulsion

device with coaxial contra-rotating propellers that offers

improved maneuverability compared to previous devices (in

particular those known from patent FR2980117), while retaining

the advantage of simplicity provided by the absence of

collective and cyclic systems for varying the pitch of the

blades.

This device includes mounting each propeller on a

frame in such a way that only the propellers are moved about

the yaw, roll and pitch axes, by the use of a pin spherical

joint connection, which is hollow, to connect each propeller

to a rotary part which is located within the frame.

The pin spherical joint connection thus makes it

possible to rotate only the associated propeller about the

roll and pitch axes, while the rest of the propulsion device

remains stationary relative to these axes.

However, this device has the disadvantage that it has many parts, which leads to difficulties in the assembly and disassembly and makes maintenance difficult. In addition, the architecture described in patent FR3095189 includes many control rods to ensure the inclination of the propellers abound the roll and pitch axes: motorized rods associated with so-called mirror rods to balance the forces and guide rods to ensure the parallelism of the propellers. This architecture is also very complex and leads to running clearances that are detrimental to the reliability of the control. It is the purpose of the invention to propose a propulsion device for rotary-wing aerodyne that does not have these disadvantages. Thus the propulsion device according to the invention is simple in design, compact and facilitates the disassembly and maintenance of the aerodyne. Thus, the invention relates to a propulsion device for vertical take-off and landing rotary-wing aerodyne, by means of coaxial contra-rotating propellers that can move in yaw, roll and pitch, the propulsion device including: - a hollow frame having a longitudinal axis which, in use, is coaxial with the yaw axis, - an upper propeller and a lower propeller each having a blade carrier ring to the periphery of which fixed pitch blades are secured or intended to be secured, the propellers being spaced apart one above the other along the yaw axis, each propeller defining a propeller disc and being adapted to be driven in rotation about an axis of rotation that is perpendicular to the propeller disc and to be tilted about the roll axis and the pitch axis, - drive means for driving in rotation each propeller about its axis of rotation, and

- tilt control means for tilting the propellers about the

roll axis and the pitch axis,

- the blade carrier ring of each propeller being connected to

the drive means by a pin spherical joint connection, the

centre of which is the intersection of the respective

propeller disc and the yaw axis and the axis of which is

the axis of rotation of the propeller,

the propulsion device being characterized in that the drive

means include motor means including, for each propeller, a

torque motor, the rotor of which is secured to a cage on which

is secured the spherical joint on which the blade carrier ring

of the respective propeller pivots, the stator of the torque

motor being secured to the frame.

Advantageously, the cage may be rotatably mounted on

a tubular support secured to the frame.

In a particular embodiment, the frame may be divided

into two cases that can be assembled together, each case being

associated with a separate propeller, each case carrying a

stator of a torque motor and a tubular support on which a cage

driving a pin spherical joint driving the propeller associated

with that case can rotate.

According to another embodiment of the invention,

the tilt control means may include: - two pairs of control rods, of fixed length, located between

the propellers, all the rods being parallel to the yaw axis

and the two rods of the same pair being arranged

diametrically opposite each other relative to the yaw axis, - each rod being movable in translation by a control device,

parallel to the yaw axis, in both directions, so that each

rod is able to push with one end on a plate that is connected

to the blade carrier ring of a propeller so as to make it

tilt about the roll axis for a first pair or the pitch axis

for a second pair,

- each plate being connected to a blade carrier ring of a propeller by a bearing rotationally disengaging the plate from the blade carrier ring of the respective propeller. Advantageously, the control device of each rod may comprise a nut which is pivotally mounted relative to the frame, the rod carrying a thread and being braked or stopped in rotation relative to the frame. According to one embodiment, the two rods of the same pair may be driven by the same motorization which will rotate the two nuts at the same speed by means of a set of gearwheels, wherein the rotation of the two nuts may be in the same direction with the rods being threaded in opposite directions or the rotation of the two nuts may be in opposite directions with the rods being threaded in the same direction. Advantageously, the sets of gearwheels associated with the two pairs of rods may be secured to the same bottom plate which will form the bottom of a first case and will carry pillars forming pivot pins for the gearwheels, the bottom of the second case having holes receiving the pillars of the first case, the two sets of gearwheels thus being located in a housing delimited by the two cases constituting the frame. The motorizations associated with the two pairs of rods may each be housed in a separate tubular support associated with one of the cases. Advantageously, each plate on which the control rods bear may be connected by return springs to the case carrying the propeller associated with said plate. The invention also relates to a vertical take-off and landing rotary-wing aerodyne, the propulsion of which is provided by a propulsion device according to one of the previously described embodiments. The invention will be better understood upon reading the following description of a particular embodiment, the description being made with reference to the attached drawings in which:

[Fig. 1] shows a side view of a propulsion device according to one embodiment of the invention;

[Fig. 2] is a longitudinal sectional view of a propulsion device according to one embodiment of the invention;

[Fig. 3] is a perspective view of a case carrying the control rods and making it possible to see the sets of gearwheels;

[Fig. 4a] shows a top view of the bottom of a first case carrying a set of gearwheels;

[Fig. 4b] shows a top view of the bottom of a second case carrying a set of gearwheels;

[Fig. 5] is an external perspective view of the propulsion device;

[Fig. 6] is an exploded perspective view showing the two blade carrier rings equipped with the rotor of their motorization and the assembled frame;

[Fig. 7] is an exploded view showing the blade carrier ring and the various parts forming its drive means;

[Fig. 8] is a partial exploded view showing a tubular support and the tilt control motorization;

[Fig. 9] is a partial exploded view showing the two cases and the tilt control rods;

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

Referring to Figure 1, a propulsion device 1 for a vertical take-off and landing rotary-wing aerodyne includes two coaxial contra-rotating propellers 2 and 3. These propellers rotate about a longitudinal axis which in Figure 1 is coincident with the yaw axis Al and each includes two fixed pitch blades 4.

The propulsion device 1 includes a hollow frame 5

which has a longitudinal axis which, in use, is coaxial with

the yaw axis Al.

Each propeller 2 and 3 has a blade carrier ring 6 to

the periphery of which the blades 4 are attached.

The two propellers 2 and 3 are spaced one above the

other along the yaw axis Al. Each propeller 2 or 3 defines a

propeller disc, which corresponds to the geometric plane in

which each propeller rotates, and driven in rotation about an

axis of rotation that is perpendicular to the propeller disc.

Each propeller 2 and 3 may also be tilted about the roll axis

A2 and the pitch axis A3 to enable movement of the aerodyne.

The propulsion device 1 includes drive means for

driving in rotation each propeller 2 and 3 about its axis of

rotation.

It also includes tilt control means for tilting the

two propellers 2 and 3, in a parallel manner, and about the

roll axis A2 and/or the pitch axis A3.

Figure 2 shows a cross-section of the propulsion

device 1 according to one embodiment of the invention.

In this figure the blades 4 have been removed. It

can be seen that in this figure the two blade carrier rings 6

are oriented identically. Thus, for each blade carrier ring 6,

the two arms 7 which make it possible to attach the blades to

the blade carrier ring 6 can be seen.

It can be noted that each blade carrier ring 6 of

each propeller includes a cylindrical housing inside which a

spherical seat 8 is secured, for example by force fitting,

which is intended to receive a portion of sphere 9. It would

also be possible to make the blade carrier ring 6 and the

spherical seat 8 in one piece.

The portion of sphere 9 is itself fitted onto a cage

10 and furthermore a pin 11 passes through both the cage 10 and the portion of sphere 9 and runs in a groove 12 provided in the spherical seat 8. This mounting: portion of sphere 9, spherical seat 8, pin 11 and groove 12 constitute a pin spherical joint 13 connection which connects the blade carrier ring 6 to a drive means 14. Driving a propeller by means of a pin spherical joint connection is already described in patent FR3095189. The pin 11 ensures the rotational connection of the blade carrier ring 6 and the cage 10. The blade carrier ring 6 can oscillate about the axis A'3 of the pin 11, which is parallel to the pitch axis A3. Thanks to the groove 12, the blade carrier ring 6 can also pivot about an axis A'2 that is parallel to the roll axis A2 (perpendicular to the yaw axis Al and the pitch axis A3). Of course, the spherical joint 13 connection immobilizes the blade carrier ring 6 and the cage 10 in translation. As the inclinations of each spherical joint 13 connection about its axes A'2 and A'3 are synchronized, the roll axis A2 and pitch axis A3 of the propulsion device 1 are parallel to the axes A'2 and A'3 and pass through the centre of the device 1 (middle of the straight line connecting the centres 0 of the spherical joint connections). The centre 0 of each pin spherical joint 13 connection is the intersection of the propeller disc of the respective propeller and the yaw axis Al, and the axis of the spherical joint 13 connection is here the yaw axis Al coincident with the axis of the cage 10. In accordance with the invention, the drive means 14 includes motor means that include, for each propeller 2 and 3, a torque motor 14 (a ring-shaped motor for which the rotor directly drives the shaft on which it is mounted), the rotor 14a of which is secured to the cage 10 to which the spherical joint 13 is secured, the stator 14b of the torque motor being secured to the frame 5. Torque motors are well known to the person skilled in the art. They have the advantage of providing a high torque with a small footprint. They combine a rotor made of a material forming a permanent magnet and a stator carrying the windings. The rotor can be separated from the stator to facilitate assembly. As can be seen in Figure 2 (and Figure 9), the frame 5 has a cavity 51 in which the stator 14b is positioned. Within this cavity 51 there is also a tubular support 15 which is attached to the frame 5 by, for example, axial screws (not shown). The tubular support 15 carries a ball bearing 16a, on the outer ring of which the cage 10 carrying the rotor 14a is positioned. In addition, the tubular support 15 carries a second ball bearing 16b on the outer ring of which the cage 10 is also positioned. The bearings 16a and 16b are held by stops 39a and 39b, one of which (39a) is secured in translation to the cage 10 and the other (39b) is secured in translation to the tubular support 15. It can be seen in Figure 2 that a third bearing 16c is positioned outside the cage 10 and its outer ring is fitted on a bearing surface 17 of the frame 5. Figures 7 to 9 show the different parts as they are assembled. It is particularly noticeable that the cage 10 includes a reduced diameter bearing surface 10b on which the rotor 14a and the bearing 16c are positioned. As can be seen in Figure 2, the cage 10 is in abutment thanks to a shoulder 40 of the tubular support 15 against the bearing 16a and is also applied against the inner ring of the bearing 16c via the rotor 14a and a spacer 41. The rotor 14a is clamped between the spacer 41 and the shoulder of the cage 10 that separates the bearing surfaces 10a and 10b.

Thus, when the tubular support 15 is secured to the

frame 5 (case 5a or 5b) by screws (not shown) passing through

its front face 15a (Figures 7 and 8), the cage 10 is also

connected in translation to the tubular support 15.

A shim 18 is interposed between the inner ring of

the bearing 16c and the frame 5. This shim fills the gaps

between the rotor 14a and the bearing 16c. Thus, securing the

tubular support 15 to the frame 5 will remove any clearances.

As can be seen in Figure 2, the torque motors 14 to

drive the two spherical joint 13 connections are mounted

identically.

In this embodiment of the invention, the frame 5 is

thus divided into two cases 5a and 5b, which can be assembled

to each other by screws 42 evenly distributed around the

periphery (screws visible in particular in Figures 5 and 9).

Each case 5a or 5b is associated with a separate propeller 2

or 3.

Thus each case 5a, 5b carries a stator 14a of a

torque motor 14 and a tubular support 15 on which a cage 10

can rotate, driving a pin spherical joint 13 connection, which

drives the propeller associated with said case 5a or 5b.

This symmetry of the cases 5a and 5b simplifies

manufacturing as the parts are virtually identical in each

case. The assembly is also simplified because each case 5a or

5b can be individually equipped with its pin spherical joint

13 connection and its motorization 14. The assembly of the two

cases will complete the integration of the device 1.

It is also worth noting that the compact structure

of the torque motors 14 makes it possible to define a space

saving device for which the internal volume of the tubular

supports 15 remains available.

As can be seen in particular in Figure 3, the

propulsion device includes tilt control means 22.

These means include two pairs 23a and 23b of control

rods 24, of fixed length. As can be seen in Figure 2, these

control rods 24 are located between the propellers 2 and 3 and

all rods 24 are parallel to the yaw axis Al.

The two rods 24 of the same pair 23a or 23b are

arranged diametrically opposite each other relative to the yaw

axis Al (Figure 3).

Each rod 24 can be moved in translation by a control

device, parallel to the yaw axis Al, in both directions, so

that each rod 24 is able to push, by each end, on a plate 25

that is secured in translation to the blade carrier ring 6 of

a propeller 2 or 3 so as to make it tilt about the roll axis

A2, for a first pair 23a, or the pitch axis A3, for a second

pair 23b.

This configuration therefore differs in a major way

from that described in patent application FR3095189 in that

there are now only four rods and each rod acts on the blade

carrier rings 6. There is therefore no longer a drive rod and

a mirror rod, intended to balance the forces of the drive rod,

as well as guide rods, but only two drive rods for each pair,

both of which act on the blade carrier rings 6.

In order to avoid wear of the ends of the rods 24 by

friction on the blade carrier rings 6, each plate 25 is

connected to a blade carrier ring 6 of a propeller by a bearing

26 (Figure 2) which rotationally disengage the plate 25 and

the blade carrier ring 6 of the respective propeller.

As can be seen in particular in Figure 2, the plate

25 has a flange 27 that delimits the housing of the bearing 26

which can be press-fitted or glued. The inner ring of the

bearing 26 is positioned on a bearing surface of the blade

carrier ring 6 where it is press-fitted or glued.

Magnetized discs 28 are positioned on each plate 25,

facing the ends of the rods 24 (Figures 3 and 7).

These discs 28 complete the action of the bearing

26. The frictional forces of the bearing could indeed lead to

a residual rotation of the plate 25. The magnetized discs 28

are attracted by the rods 24 and prevent this rotation, thus

reducing the relative friction between the rods 24 and the

plates 25.

Furthermore, as can be seen in Figures 3 and 5, each

plate 25 on which the control rods 24 bear is connected by

return springs 19 (tension springs) to the case 5a or 5b

carrying the propeller associated with said plate. These

springs 19 prevent the plates 25 from bouncing off the rods

24. They press the plates 25 against the ends of the rods 24

and reduce vibration. The parts 25 and 26 are also visible in

Figure 7.

The control device of each rod 24 comprises a nut 29

which is pivotally mounted relative to the frame 5.

As can be seen in Figure 2, each case 5a and 5b of

the frame 5 has four peripheral bores 30 in which the nuts 29

are pivotally mounted. The mounting is on small bearings 31.

There are two bearings 31 for each rod 24, with one bearing 31

positioned at each end of the associated nut 29.

Each rod 24 has a thread and is braked or rather

stopped in rotation relative to the frame 5 by at least one

flat 43 which cooperates with a hole 44 carrying a flat (see

Figure 2).

According to another feature of the invention, the

two rods 24 of the same pair 23a or 23b are driven by the same

motorization 32a or 32b. As can be seen in Figure 2, each

motorization associated with a pair of rods is housed in a

separate tubular support 15.

Thus, the motorization 32a that controls the pair of

rods 23a is housed in the tubular support 15 of the case 5a, while the motorization 32b that controls the pair of rods 23b is arranged in the tubular support 15 of the case 5b. Mechanical means are provided so that one and the same motorization 32a or 32b causes the two rods of the same pair 23a or 23b to translate in opposite directions. One can choose to: - Use rods 24 threaded in the same direction and rotate the two associated nuts 29 in opposite directions and at the same speed using a suitable set of gearwheels; - Rotate the two associated nuts 29 in the same direction and at the same speed using a suitable set of gearwheels and associate them with rods 24 which are threaded in the opposite direction. In all cases, the sets of gearwheels associated with the two pairs of rods 23a and 23b are secured to the same bottom plate, which is formed by the bottom 38a of a first case 5a or 5b (here 5a) and which carries pillars 45 constituting pivot pins for the gearwheels (Figure 9), said pillars 45 being intended to penetrate holes 46 provided in the bottom 38b of the second case (here 5b). The two sets of gearwheels are thus arranged in a housing 21 which is delimited by the two cases 5a and 5b forming the frame 5. Figure 3 as well as Figures 4a and 4b provide a better understanding of how the sets of gearwheels are arranged. Figure 4a shows the front view of the bottom 38a of the first case 5a on which only a first set of gearwheels, for driving the rods 24 of the first pair of rods 23a, has been positioned. This first set of gearwheels is driven by a driving gearwheel 34a secured to the output shaft of the motorization 32a. Figure 4b shows a front view of the bottom 38b of the second case 5b on which only a second set of gearwheels, for driving the rods 24 of the second pair of rods 23b, has been positioned. This second set of gearwheels is driven by a driving gearwheel 34b secured to the output shaft of the motorization 32b. Figure 3 shows a perspective view of the second case 5b with respect to which all the gearwheels except the first driving gearwheel 34a are positioned. In this figure 3, it can be seen that each nut 29 is integral with a driven gearwheel 33 (33a or 33b respectively, depending on the pair considered). A driving gearwheel 34a or 34b is secured to an output shaft of the motorization 32a or 32b. These two driving gearwheels 34a and 34b are one above the other in Figure 2. Also shown in Figure 3 is one of the bearings 31 on each nut 29. Referring to Figures 3 and 4a, it can be seen that the gearwheel 34a drives one of the driven gearwheel 33a via a gearwheel 35a and the other driven gearwheel 33a via two gearwheels 36a and 37a. It is to be noted that the nuts 29 will then turn in opposite directions. The threads will therefore be in the same direction on each rod 24 of the pair 23a. Referring to Figures 3 and 4b, it can be seen that the gearwheel 34b drives one of the driven gearwheels 33b via a gearwheel 35b and the other driven gearwheel 33b via two gearwheels 36b and 37b. It is to be noted that, again, the nuts 29 rotate in opposite directions. The threads will therefore be in the same direction on each rod 24 of the pair 23b. It is clear that, depending on the constraints of space and torque to be transmitted, it will be possible to provide gearwheels on the bottom plate 38a that turn the nuts in the same direction in a pair.

One could even have a pair of rods driven by nuts turning in opposite directions and another pair of rods driven by nuts turning in the same direction. It can be seen in Figures 3, 4a and 4b that discs 47 of antifriction material are interposed between the gearwheels that are stacked one on top of the other on the same pillar 45, as well as between the gearwheels and the case bottoms 38a and 38b. It should be noted for the understanding of the figures that Figures 4a and 4b show the bottoms of each case 5a or 5b in front view. Therefore, to imagine the relative positioning of all the gearwheels on a single bottom, one of the two cases must be turned upside down and a geometric symmetry of one or the other figure must therefore be made relative to a horizontal line before superimposing the figures. After such symmetry the driving gearwheels 34a and 34b are superimposed and coaxial, as well as the intermediate gearwheels 36a and 36b. This superimposition of the gearwheels 36a and 36b is clearly visible in Figure 3 (as well as in Figure 2). It can therefore be noted that the propulsion device 1 according to the invention is very compact, with all the means for driving the propellers in rotation and the means for controlling the tilt of the propellers about the roll and pitch axes being located between the two propellers. Moreover, the tilt control for the propellers by two pairs of rods, both motorized, ensures a more reliable control than the solution according to the prior art. It avoids mechanical latency during control, reduces clearances and makes it possible to balance the forces between the two rods of the same pair. This results in a simpler, more reliable and more robust control. Thus, as can be seen in Figure 10, where an aerodyne or drone D is shown very schematically, with the body Dl equipped with the propulsion device 1, the overall height of the drone D is not affected by the presence of the propulsion device 1. Thus, the size of the blades can be increased without necessarily increasing the size of the rest of the aerodyne, for both visual and acoustic stealth. The propulsion device 1 according to the invention allows for easy maintenance and repair. In fact, simply disassembling the frame 5 by separating the two cases 5a and 5b gives access to all the gearwheels placed on the bottom plate 38a to allow for example the replacement of gearwheels. Each case 5a or 5b contains its own torque motor 14 which can therefore be easily replaced. Finally, the tubular supports 15 each delimit the housing of a tilt control motor 32a or 32b, which can also be removed without disassembling the rest of the device. It should be noted that the power supply batteries will preferably be housed in the drone D and connected to the various motors by cables not shown. The electrical passage of the housing 21 between the cases 5a and 5b can be made by means of spring-loaded electrical contacts well known to the skilled person, which will be secured to one of the case bottoms. It is understood that the particular embodiment just described is indicative and non-limiting, and that modifications may be made without departing from the present invention.

Claims (1)

1 - A propulsion device (1) for a vertical take-off

and landing rotary-wing aerodyne, by means of coaxial contra

rotating propellers that can move in yaw, roll and pitch, the

propulsion device including:

- a hollow frame (5) having a longitudinal axis which, in

use, is coaxial with a yaw axis (Al),

- an upper propeller (2) and a lower propeller (3) each having

a blade carrier ring (6) to the periphery of which fixed

pitch blades (4) are secured or intended to be secured, the

propellers (2,3) being spaced one above the other along the

yaw axis (Al), each propeller defining a propeller disc and

being adapted to be driven in rotation about an axis of

rotation that is perpendicular to the propeller disc and to

be tilted about a roll axis (A2) and a pitch axis (A3),

- drive means (14) for driving in rotation each propeller

(2,3) about its axis of rotation, and

- tilt control means (22) for tilting the propellers about

the roll axis (A2) and the pitch axis (A3), - the blade carrier ring (6) of each propeller being connected

to the drive means (14) by a pin spherical joint (13)

connection, the centre of which is the intersection of the

respective propeller disc and the yaw axis (Al) and the

axis of which is the axis of rotation of the propeller,

the propulsion device (1) being characterized in that the drive

means (14) include motor means including, for each propeller,

a torque motor (14), the rotor (14a) of which is secured to a

cage (10) on which is secured the spherical joint (13) on which

the blade carrier ring (6) of the respective propeller pivots,

the stator (14b) of the torque motor (14) being secured to the

frame (5).

2 - The propulsion device according to claim 1, characterized in that the cage (10) is rotatably mounted on a tubular support (15) secured to the frame (5). 3 - The propulsion device according to claim 2, characterized in that the frame (5) is divided into two cases (5a,5b) that can be assembled together, each case being associated with a separate propeller, each case (5a,5b) carrying a stator (14b) of a torque motor (14) and a tubular support (15) on which a cage (10) driving a pin spherical joint (13) driving the propeller associated with said case can rotate. 4 - The propulsion device according to any one of claims 1 to 3, characterized in that the tilt control means (22) include: - two pairs (23a, 23b) of control rods (24), of fixed length, located between the propellers, all the rods (24) being parallel to the yaw axis (Al) and the two rods of the same pair (23a,23b) being arranged diametrically opposite each other relative to the yaw axis (Al), - each rod (24) being movable in translation by a control device, parallel to the yaw axis (Al), in both directions, so that each rod (24) is able to push with one end on a plate (25) that is connected to the blade carrier ring (6) of a propeller (2, 3) so as to make it tilt about the roll axis (A2) for a first pair or about the pitch axis (A3) for a second pair, - each plate (25) being connected to a blade carrier ring (6) of a propeller by a bearing (26) rotationally disengaging the plate (25) from the blade carrier ring (6) of the respective propeller. 5 - The propulsion device according to claim 4, characterized in that the control device of each rod (24) comprises a nut (29) which is pivotally mounted relative to the frame (5), the rod (24) carrying a thread and being braked or stopped in rotation relative to the frame (5).

6 - The propulsion device according to claim 5,

characterized in that the two rods (24) of the same pair (23a,

23b) are driven by the same motorization (32a, 32b) which

rotates the two nuts (29) at the same speed by means of a set

of gearwheels, wherein the rotation of the two nuts (29) may

be in the same direction with the rods being threaded in

opposite directions or the rotation of the two nuts (29) may

be in opposite directions with the rods being threaded in the

same direction.

7 - The propulsion device according to claims 3 and

6, characterized in that the sets of gearwheels associated

with the two pairs (23a, 23b) of rods (24) are secured to the

same bottom plate which forms the bottom (38a) of a first case

(5a) and carries pillars (45) forming pivot pins for the

gearwheels, the bottom (38b) of the second case (5b) having

holes (46) receiving the pillars (45) of the first case (5a),

the two sets of gearwheels thus being located in a housing

(21) delimited by the two cases (5a, 5b) constituting the frame

(5).

8 - The propulsion device according to claim 7,

characterized in that the motorizations (32a, 32b) associated

with the two pairs (23a, 23b) of rods (24) are each housed in

a separate tubular support (15) associated with one of the

cases (5a, 5b).

9 - The propulsion device according to claims 3 and

4, characterized in that each plate (25) on which the control

rods (24) bear is connected by return springs (19) to the case

(5a, 5b) carrying the propeller associated with said plate

(25).

10 - A vertical take-off and landing rotary-wing

aerodyne (D), the propulsion of which is provided by a propulsion device (1), characterized in that the propulsion device (1) is as defined in any one of claims 1 to 9.

[Fig. 2]

[Fig. 1] 1/7

[Fig. 3] 2/7

[Fig. 4a] 3/7

[Fig. 4b] 4/7

[Fig. 6]

[Fig. 5] 5/7

[Fig. 8]

[Fig. 7] 6/7

[Fig. 9]

[Fig. 10] 7/7