Propulsion device for generating thrust, braking system and transport vehicles using such a propulsion device

Abstract

Propulsion device for generating thrust, braking system and transport vehicles using such a propulsion device. One aspect of the invention relates to a mechanical propulsion device (100) for generating thrust capable of moving a transport vehicle, comprising: - a trochoidal-shaped casing (110), provided with an air inlet (111) and an air outlet (112) facing each other and forming within it a chamber (130), and - a curvilinear triangular-shaped rotor (120), driven in rotation in the chamber (130) of the casing and generating, by its rotation, a modulation of the internal volume of said chamber with a compression and an acceleration of the air, so that the air at the outlet (112) of the casing is accelerated relative to the air at the inlet (111) of said casing. Another aspect of the invention relates to an aircraft braking system, comprising a propulsion device (100) in which the thrust generated is a reverse thrust.Figure to be published with the abbreviation: Figure 2.

Description

Title of the invention: Propulsion device for generating thrust, braking system and transport vehicles using such a propulsion device TECHNICAL FIELD OF THE INVENTION

[0001] The present invention relates to a mechanical propulsion device for generating thrust capable of moving a transport vehicle such as an air or water vehicle. It also relates to a braking device equipped with such a propulsion device adapted to generate reverse thrust. The invention also relates to a transport vehicle equipped with such a propulsion device.

[0002] The invention finds applications in all fields relating to the mechanical propulsion of a transport vehicle and, in particular, in the field of aeronautics for the propulsion of aerial vehicles such as airplanes, helicopters, VTOL (vertical takeoff and landing aircraft), drones, etc. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0003] There are, particularly in aeronautics, several propulsion techniques for generating thrust enabling the movement of an air vehicle: jet engine propulsion and mechanical propeller propulsion, each of the technologies offering advantages and disadvantages. For example, jet engine aircraft, or turbojets, have the advantage of allowing flight at high altitude and high speed, and in particular at supersonic speed. Chemical propulsion turbojets, however, have the disadvantage of being particularly fuel-intensive and therefore expensive in terms of consumption. Propeller aircraft, an example of which is shown in part A of [Fig.l], have the advantage of being fuel-efficient and therefore allowing relatively inexpensive flights compared to turbojet aircraft.In an era where fuel consumption is a key factor in choosing an air vehicle, propeller engines are often preferred to jet engines.

[0004] Furthermore, propeller propulsion is also used in vehicles other than aircraft, and in particular in nautical vehicles such as boats or ships. Propeller propulsion is also used to propel air vehicles other than aircraft, such as for example in helicopters, VTOLs and drones. Examples of a drone, a helicopter and a VTOL, each equipped with propeller engines are shown, respectively, in parts B, C and D of [Fig.l]. Mechanical propeller propulsion is therefore currently the most widely used propulsion technique for generating thrust enabling the movement of a vehicle.

[0005] A propeller is a mechanical part comprising several blades whose twisted surface transforms, by its rotation, the input power into dynamic thrust. The propeller creates thrust by accelerating the surrounding fluid by pressure difference between its front and rear surfaces. It is therefore of real interest for many applications (for example rotary pump, compressor, waterjet engine, etc.). Different examples of propellers are represented in [Fig.l] by the reference 10.

[0006] In aeronautics, the shape of the section used in the propeller blades of modern aircraft was initiated by the Wright brothers, two American aviation pioneers who flew the world's first powered aircraft. Since the Wright brothers, the shape of propeller blades has changed little. A study by the National Advisory Committee for Aeronautics (NACA) examines the relationships between measurable parameters representing propeller efficiency, thrust developed and power absorbed and lists the different shapes of propeller blades.

[0007] To produce high thrust with a fixed propeller diameter, a propeller with a large number of blades, called a fan, is generally used. However, even with a fan, mechanical propulsion by propeller has a number of limitations, notably because its use is limited to subsonic speeds. Indeed, a propeller-driven aircraft can only fly at subsonic speeds because, above a speed of approximately 770 km / h, the speed of the local airflow at the tips of the propeller blades is close to, or even exceeds, the speed of sound. However, this locally supersonic airflow causes a supersonic shock, which generally results in increased drag, deafening noise and / or a structural problem with the propeller's stability. Consequently, the diameter and rotational speed of the propeller are strictly limited. There is therefore a power limitation which is incompatible with large commercial aircraft.Additionally, when a propeller is operated at low (subsonic) speed, the air mass passing through the propeller causes a large tangential airflow. The energy of this tangential airflow caused by the propeller wastes engine power.

[0008] In response to the issue of efficiency loss due to subsonic operation, a ducted fan can be used to increase thrust. The ducted fan design is typically used in a turbofan engine system. This system was developed to improve flight speed and engine performance. As air enters the duct, the air speed decreases and its pressure and temperature increase. If the aircraft is at a high speed (but still subsonic), this creates two advantages: the air enters the propeller at a lower speed and the high temperature increases the local speed of sound. This allows the propeller to maintain efficiency even at high speeds, where the efficiency of conventional propellers decreases significantly with speed. The reduced fairing also noise. However, the fairing adds weight, increases the cost and complexity of the system, and generates additional drag, which limits its use to turbofans. This is because the maximum fan diameter is still limited by the fact that the air speed at the fan blade tips cannot exceed the speed of sound, to avoid supersonic air shock.

[0009] To date, there is no mechanical propulsion solution for use at supersonic speeds. The only solution for supersonic speeds is the use of a jet engine, with all the disadvantages mentioned above.

[0010] For ecological reasons, it seems that the aircraft of the future will be an electric aircraft. Indeed, in order to limit and even avoid fuel consumption, aircraft manufacturers plan, for the aircraft of the future, to use engines with mechanical propulsion by propeller. However, as explained previously, the speed of propeller engines is limited to subsonic speeds, which in fact limits the speed of aircraft of the future to subsonic speeds, creating a significant limitation for this future aircraft in accessing high speeds.

[0011] There is therefore a real need for a mechanical propulsion device capable of generating supersonic thrust, without generating supersonic shock, and thus enabling an aerial vehicle to fly at supersonic speeds. Summary of the invention

[0012] To address the problems mentioned above of limiting the speed of mechanical propeller-driven engines, the applicant proposes a mechanical propulsion device in which a triangular rotor rotating within a trochoidal-shaped casing generates a thrust greater than that produced by a propeller without generating any locally supersonic air flow.

[0013] According to a first aspect, the invention relates to a mechanical propulsion device for generating thrust capable of moving a transport vehicle, comprising: • a trochoidal-shaped casing, provided with an air inlet and an air outlet facing each other and forming a chamber within it, and • a rotor of curvilinear triangular shape, driven in rotation in the chamber of the casing and generating, by its rotation, a modulation of the internal volume of said chamber (130) with a compression and an acceleration of the air, so that the air at the outlet of the casing is accelerated relative to the air at the inlet of said casing.

[0014] This mechanical propulsion device has the advantage not only of generating greater thrust than a propeller but also of offering a bladeless design which maximizes safety and minimizes noise and aerodynamic shock, particularly at supersonic speeds.

[0015] In addition to the characteristics which have just been mentioned in the preceding paragraph, the mechanical propulsion device according to one aspect of the invention may have one or more complementary characteristics among the following, considered individually or according to all technically possible combinations: • the rotor has sides whose dimension is substantially equal to a length (L) of the casing. • it has a drive motor to drive the rotor into rotation. • the drive motor is mounted outside the housing. • the drive motor is a Wankel type rotary motor, mounted parallel to the casing, around the same transmission shaft. • the drive motor is an electric motor. • the drive motor is mounted inside the housing. • the drive motor has permanent magnets distributed over the rotor and electric coils mounted in the housing chamber to ensure the rotation of the rotor. • It has an air supply duct opening into the air inlet of the crankcase and an air exhaust duct opening from the air outlet of the crankcase.

[0016] A second aspect of the invention relates to a braking system for an aircraft comprising a propulsion device as defined above, in which the thrust generated by said propulsion device is reverse thrust.

[0017] This braking system may have one or more additional characteristics among the following, considered individually or according to all technically possible combinations: • the propulsion device is coupled to a friction braking device or a regenerative braking mechanism. • It is mounted in each of the wheels of an aircraft.

[0018] A third aspect of the invention relates to a transport vehicle comprising at least one propulsion device as defined above, ensuring its propulsion in the air, in water or in a tube. BRIEF DESCRIPTION OF THE FIGURES

[0019] Other advantages and characteristics of the invention will appear on reading the following description, illustrated by the figures in which:

[0020] [Fig.l], already described, represents schematic examples of airplanes, drones, helicopters and VTOLs equipped with propeller engines;

[0021] [Fig.2] represents a schematic sectional view of a mechanical propulsion device according to the invention;

[0022] [Fig. 3] schematically represents different positions of the rotor in the casing of the mechanical propulsion device of the invention;

[0023] [Fig.4] schematically represents the evolution of the air pressure within the mechanical propulsion device of [Fig.2];

[0024] [Fig. 5] represents schematic views, in perspective and in section, of the mechanical propulsion device according to a passive embodiment of the invention;

[0025] [Fig.6] represents schematic sectional views of the mechanical propulsion device according to an active embodiment of the invention;

[0026] [Fig.7] represents, in a table, different examples of thrusts obtained with the mechanical propulsion device according to the invention, compared to the thrusts obtained with conventional propulsion devices;

[0027] [Fig. 8] represents a schematic view of an aircraft equipped with a mechanical propulsion device used, according to one embodiment of the invention, as a braking system;

[0028] [Fig.9] represents schematic views of different examples of vehicles equipped with the mechanical propulsion device according to the invention. DETAILED DESCRIPTION

[0029] An exemplary embodiment of a mechanical propulsion device, configured so as not to generate a locally supersonic air flow, is described in detail below, with reference to the accompanying drawings. This example illustrates the characteristics and advantages of the invention. It is however recalled that the invention is not limited to this example.

[0030] In the figures, identical elements are identified by identical references. For reasons of readability of the figures, the size scales between elements represented are not respected.

[0031] An example of a mechanical propulsion device 100 according to the invention is shown in [Fig. 2]. This mechanical propulsion device 100 comprises a casing 110 of trochoidal, or cycloidal, shape, inside which rotates a rotor 120 of curvilinear triangular shape. The casing 110 comprises an enclosure 115 of approximately oval section and two flat side walls (not visible in the figure) which close the enclosure, thus forming a chamber 130 inside the casing 110. The chamber 130 has an internal volume directly dependent on the length L (also called size) of the enclosure, defined along the X axis of the orthonormal reference frame XYZ, and its depth w (not visible in [Fig. 3]) defined along the Z direction of the XYZ reference frame.

[0032] The rotor 120 has a section in the shape of a substantially triangle whose sides are curved in a slightly convex manner and a thickness substantially equal to the depth w of the enclosure 115. The rotor 120 is engaged in the casing 110, around a transmission shaft 125 extending along the axis of rotation R.

[0033] In other words, the casing 110 and the rotor 120 have substantially the shape, respectively, of a casing and a rotor of a Wankel-type rotary engine. As in a Wankel engine, the rotor 120 rotates inside the chamber 130 and, by its rotation, causes a modulation of the internal volume of said chamber 130. The comparison between a Wankel engine and the mechanical propulsion device of the invention is limited to a simple similarity of structure of the casing 110 and the rotor 120 and of operation of the rotor within the casing. Unlike a Wankel engine, the chamber 130 located within the casing 110 receives air and only air. For this, the casing 110 comprises an air inlet 111 and an air outlet 112, facing each other. The air inlet 111 allows the introduction of an air flow 200 into the chamber 130 and the air outlet 112 allows the evacuation of this air flow 200 from said chamber 130.An air supply duct, not shown in [Fig. 2], may open into the air inlet 111 to allow the introduction of air into the chamber 130. An air exhaust duct, not shown in [Fig. 2], may open from the air outlet 112 to evacuate air from the chamber 130.

[0034] The air inlet 111 is housed in one of the rectilinear portions 115d of the enclosure 115 of the casing 110 and the air outlet 112 is housed in the other of the rectilinear portions 115b of the enclosure of the casing. The portions 115b and 115d of the enclosure 115 are called "rectilinear portions" as opposed to the portions 115a and 115c in the shape of an arc of a circle of said enclosure 115, said rectilinear portions being more rectilinear than the portions in the shape of an arc of a circle even if these so-called rectilinear portions comprise a boss 116 as shown in [Fig.2]. The air inlet 111 and the air outlet 112 are opposite each other, that is to say located along the same direction A of a plane XZ parallel to the plane containing the axis of rotation R of the rotor 120.

[0035] Thus, in the mechanical propulsion device 100 of the invention, the rotation of the rotor 120 makes it possible to suck in a flow of ambient air through the air inlet 111 and to evacuate this flow of air through the air outlet 112 after it has been compressed and accelerated in the chamber 130, as explained below. The acceleration of the flow of air evacuated from the casing generates mechanical propulsion.

[0036] [Fig. 3] schematically represents the mechanical propulsion device 100 of the invention during its three operating phases. In phase 1, the air flow 200 in the vicinity of the air inlet 111 is sucked into the chamber 130 by the rotation of the rotor 120. In phase 2, the air inlet 111 is closed by the rotor 111 which, by rotating, compresses the air flow 200 in the center of the chamber 130 and, at the same time, accelerates it. In phase 3, the accelerated air flow is discharged through the air outlet 112, generating propulsion power.

[0037] By its substantially triangular shape, the rotor 120 allows at least three partial sessions of compression and acceleration of the air per rotation cycle. In other words, it allows the introduction of an air flow simultaneously with the evacuation of another air flow. An example of these three sessions of compression and acceleration of the mechanical propulsion device 100 is shown in [Fig. 4]. In this [Fig. 4], the chamber 130 of the casing 110 is referenced C1 during a first session, C2 and C3 the same chamber 130 during, respectively, a second and a third session. This [Fig. 4] shows that, while a first air flow 201 is introduced inside the chamber C1 (admission phase of session 1), a second air flow 202 is evacuated from the chamber C2 (evacuation phase of session 2). When the second air flow 202 is completely evacuated, the first air flow 201 passes through the chamber Cl from one side to the other.When this first air flow 201 finishes being evacuated through the air outlet 112 (evacuation phase of session 1), a third air flow 203 begins its admission into the chamber C3 through the air inlet 111 (admission phase of session 3). Thus, an admission session of an air flow takes place at the same time as an evacuation session of the previous air flow. A complete session (admission and evacuation) and two partial sessions (admission for one and evacuation for the other) are therefore carried out during the duration of a rotation cycle of the mechanical propulsion device. A complete session, which corresponds to the duration of stay of an air flow inside the mechanical propulsion device 100, is therefore equal to a half-cycle of rotation of the rotor 120.

[0038] The performance, i.e. the thrust, of the mechanical propulsion device according to the invention can be estimated by the general method for calculating the performance of propulsion devices proposed by NASA. This method consists of applying the following formula: F ~ H!? X Ve — riU X Vn °ù m is 'c mass flow rate, Ve is the air velocity in outlet and Vo the air velocity at the inlet. In the mechanical propulsion device, the mass flow rate and the air velocity can be estimated, respectively, the size (or length) of the chamber and the rotational speed in revolutions per minute (RPM) of the rotor. Note that the outlet velocity is assumed to be the same as the air velocity flowing between the air inlet 111 and the air outlet 112 of the casing, which directly depends on the length L (also called size) between said air inlet and outlet and the duration of a session, namely a half-cycle. Therefore, the velocity Ve can be calculated by the following equation: where 2 is the cycle to session ratio. Fe (m / s) ~ £ (???)

[0039] The air mass flow rate can be calculated from the air density (p=1.2 kg / m3) and of the air inlet and outlet section, this section depending on the size (or length) L of the chamber 130 and the depth w of said chamber 130. Thus, the mass flow rate of the air can be calculated by the following equation: m = 4 x Ve xp = 0.4 x L xwx Ve xp where the section A is equal to 0.4 x L x w. It will be noted that the constant equal to 0.4 is an order of magnitude of the ratio between the length of the air inlet / outlet and the length L of the chamber, obtained from the geometry of said chamber, the depth w of the chamber 130 being a design parameter making it possible to control the mass flow rate of air.

[0040] Finally, the performance of the mechanical propulsion device can be described as a thrust (F) by the following equation, when the input speed Vo is assumed to be zero: 0.4 F ~ wr x W ~ 0.4 x F xwx W x ™ — x t4 xm? x FFM xp '30*

[0041] Examples of estimated performances of the mechanical propulsion device, as a function of the dimensions L and w of the chamber and the rotational speed of the rotor shaft, are indicated in the table in [Fig.7]. These performances, or thrusts, are determined in kilonewtons (kN) for a mechanical propulsion device whose chamber is relatively large (i.e. with a length of the order of a meter), which is the usual unit of measurement for the thrust of jet engines, and in kilograms (kg) for a mechanical propulsion device whose chamber is relatively small (i.e. with a length of the order of a decimeter) which is the usual unit of measurement for the thrust of drone engines.

[0042] This table in [Fig.7] incorporates examples of dimensions and thrusts for several commercial jet engines and drone engines, for comparison. In the case of commercial jet engines, the length and diameter of the engine are entered in the columns relating to the size (or length) and the depth of the chamber, respectively. In the case of drone engines, the diameter of the propeller and the rotational speed of the engine in revolutions per minute are entered in the columns relating to the depth of the chamber and the rotational speed of the shaft, respectively. The diameter of the engine and the diameter of the propeller are design parameters for determining the air mass flow rate as the chamber depth (w) in the mechanical propulsion device of the invention.

[0043] The table in [Fig.7] shows that the mechanical propulsion device according to the invention is capable of providing a thrust of between approximately 20 and 1700 kN, which is comparable to, or even superior to, the best performances of commercial jet engines (between approximately 10 and 500 kN), the main reason being that the device The mechanical propulsion device of the invention generates an extremely high exit velocity (above or even significantly above 300 m / s) while typical commercial jet engines operate with an exit velocity not exceeding 250 to 300 m / s. For comparison, the mechanical propulsion device of the invention, with a size L of 2 m, a depth w of 1 m and a rotational speed of 20,000 cycles / minute, provides 1700 kN of thrust, which exceeds by about 500 kN the performance of the best jet engine, the "High Power Turbofan", which is 8 m in size and has a depth (or diameter) of 3 m.

[0044] When the size of the mechanical propulsion device is reduced to the scale of about ten cm, it has a performance capable of replacing the engines and propellers marketed for drones. Indeed, the mechanical propulsion device of the invention, with a size L of 0.3 m, a depth w of 0.3 m and a rotation speed of 7,500 cycles / minute provides almost 25 kg of thrust, which exceeds the 14 kg of performance provided by a drone whose propeller diameter is 0.7 m and the rotation speed of 6,000 cycles / minute.

[0045] Those skilled in the art will understand that the performance of the mechanical propulsion device according to the invention can be improved simply by increasing the depth w and the size L of the chamber 130 and / or by increasing the rotational speed. For example, doubling the size L of the chamber 130 allows for eight times greater thrust and doubling the rotational speed allows for four times greater thrust. It should be noted that increasing the rotational speed does not pose any aerodynamic problems (such as a supersonic shock) because the triangular rotor rotates in a chamber, i.e. a closed enclosure, which insulates against aerodynamic shocks, unlike a propeller.

[0046] In addition to these advantageous performances, the mechanical propulsion device according to the invention is a bladeless device, all of whose moving parts are internal to the housing chamber, which makes it possible to maximize safety and minimize noise and aerodynamic shock, even in supersonic regime. Such a mechanical propulsion device can therefore allow an aircraft, and in particular the future electric aircraft, to reach supersonic speed.

[0047] According to certain embodiments, the mechanical propulsion device 100 comprises a power source suitable for driving the rotor 120 in rotation. Indeed, the rotor 120 needs to be driven in order to be able to rotate within the chamber 130. For this, a power source, such as a drive motor 310 or 320, can be housed outside or inside the casing 110.

[0048] When a drive motor 310 is housed outside the casing 110, as in the example shown in [Fig. 5], the mechanical propulsion device 100 is said to be “passive”. This drive motor 310 is a conventional motor; this can be, for example, an electric motor (such as a brushless motor) or a thermal engine (such as a Wankel rotary engine). The rotation from this drive motor 310 is transmitted to the mechanical propulsion device 100 by a shaft such as an eccentric shaft. The rotor 110 of the mechanical propulsion device is then driven like a propeller and generates propulsion as explained previously. With this “passive” drive mode, both the rotor and its drive system are completely isolated from the outside of the chamber. The mechanical propulsion device then has, in addition to high thrust, the advantage of maximizing safety and minimizing noise, including aerodynamic shock at supersonic speed.

[0049] In such a passive drive mode, using a brushless motor as the drive motor allows for a very high rotational speed (up to 100,000 rpm), which has a direct link with the performance offered by the mechanical propulsion device, as explained previously.

[0050] In an alternative, the drive motor 310 is a Wankel rotary engine coupled to the mechanical propulsion device 100. This alternative is shown in [Fig. 5] which shows a device in which the Wankel engine 310 is mounted parallel to the mechanical propulsion device 100, the same transmission shaft 125 then ensuring the rotation of the Wankel engine and the mechanical propulsion device. This coupling of the mechanical propulsion device 100 with a Wankel engine 310 has two advantages. The first advantage is that the Wankel engine makes it possible to achieve a high rotational speed (up to 15,000 rpm), which can be transmitted directly to the rotor 120, without additional transmission or gearing, because their rotations are already coupled by the same eccentric shaft.The second advantage is that the high airflow generated by the mechanical propulsion device 100 is in contact with the hottest part of the Wankel engine, which allows local cooling which can overcome the known problem of the Wankel engine, namely an unbalanced heat distribution.

[0051] In other embodiments, the drive motor 320 is housed inside the casing 110, as in the example shown in [Fig. 6]. The mechanical propulsion device 100 is then called “active” or “CHANGED” (acronym for Cold & Highly Accelerating & No Gas Emitting Engine). In the example of [Fig. 6], a brushless motor 320 is integrated within the mechanical propulsion device 100. In such an active mechanical propulsion device, components suitable for constituting a drive motor are introduced into the casing 110, and in particular into the unused areas of the chamber 130. Indeed, as understood from the preceding description, only a portion 130a of the chamber 130 (approximately half the volume of the chamber) is used for the compression and acceleration of the air flow. The other portion 130b is not used. It is therefore proposed, in this “active” embodiment, to position the components useful for constituting a brushless motor in this portion 130b of the chamber.

[0052] These components of the brushless motor 320 may be, for example, permanent magnets 321 distributed over the rotor 120 and electric coils 322 positioned inside the enclosure 115 of the casing 110, for example on its internal wall. The magnets 321 may, for example, be three in number, each positioned at an angle between two sides of the triangular rotor 120. The coils 322, for example two in number, may be housed in the internal wall of the enclosure 115 of the casing 110, in the unused portion 130b of the chamber 130. Such a configuration, quite similar to a typical brushless motor structure, is capable of rotating the rotor 120 by controlling the activation of the coils 322. Of course, the number and distribution of the magnets 321 and the coils 322 may vary depending in particular on the dimensions of the chamber 130 and the chosen rotation speed.

[0053] The “active” type mechanical propulsion device is thus an autonomous electrical mechanism, which can replace a commercial jet engine on its own. Indeed, as shown in the table in [Fig.7], the performance of this mechanical propulsion device is entirely comparable to the performance of commercial jet engines. It can operate in a supersonic speed environment with, in addition, the advantages of producing neither polluting gas nor heat.

[0054] The mechanical propulsion device 100 according to the invention has been described previously in its application to the propulsion of aircraft. It has been, in particular, described in its application to an airplane, as shown in drawing A of [Fig. 9], in which the mechanical propulsion device can be mounted in the same locations as a propeller engine, for example at the front of the airplane or under its wing. It has also been described in its application to drones, as shown in drawing B of [Fig. 9], in which the mechanical propulsion device can be mounted in the same locations as a propeller engine, for example at the end of each wing of the drone.

[0055] However, this mechanical propulsion device can also be applied to aircraft braking. Indeed, the braking of an aircraft is often generated, at least partially, by means of reverse thrust. The mechanical propulsion device according to the invention, depending on its positioning, is capable of generating reverse thrust which, by the very high airflow speed in the direction of advance of the aircraft, ensures the braking of said aircraft. An example of a mechanical propulsion device 100 used as a braking system is shown in [Fig. 8]. In this example, a mechanical propulsion device 100 is housed in the center of each wheel 400 of the aircraft, in a position opposite to that used in propulsion mode. Indeed, in propulsion mode, the mechanical propulsion device is positioned so that the airflow leaving the casing is directed in the opposite direction to the direction of advance of the aircraft. On the contrary, in braking mode, the mechanical propulsion device 100 is positioned so that the airflow leaving the casing is in the direction Da of advance of the aircraft.

[0056] According to one embodiment, the mechanical propulsion device used in braking mode can be coupled with the regenerative braking mechanism of the wheel, this mechanism creating a strong resistance of the rotating wheel, where the rotation of the wheel is converted into rotation of the rotor 120 of the mechanical propulsion device through the transmission shaft 125. It should be noted that the intensity of the resistance can be controlled by the levels of the transmission gear.

[0057] According to another embodiment, the mechanical propulsion device used in braking mode can be coupled with a conventional friction braking device. This coupling offers excellent synergy because the air flow generated by the mechanical propulsion device of the invention in braking mode can also function as a cooling flow for the friction braking system.

[0058] In addition to its applications to aircraft, the mechanical propulsion device according to the invention can be applied to a water transport vehicle, for example a jet ski. Indeed, it can replace a so-called "waterjet" engine. Since the current "waterjet" engine uses a propeller turbine and a transmission shaft, its structure, shown in drawing C of [Fig.9], is relatively complex. In particular, the transmission shaft is long, which can disturb the water flow and reduce its performance. The relatively simple structure of the mechanical propulsion device of the invention can advantageously replace a "waterjet" engine and its high performance is sufficient to ensure the propulsion of the vehicle. A jet ski, or other electric water vehicle, equipped with a mechanical propulsion device according to the invention, can operate with an electrical power supply as long as the battery capacity is sufficient.It should be noted that the passive mode of the mechanical propulsion device of the invention (with a Wankel engine) would be particularly well suited to replacing a “waterjet” engine.

[0059] The mechanical propulsion device according to the invention can further be applied to a vactrain. A vactrain, also called a vacuum tube train, consists of a raised double tube in which capsules, or vehicles, transporting passengers and / or goods move. The interior of the tube is under low pressure (they are emptied of most of their air) to limit air friction. The capsules are raised by air cushions or by electromagnetic levitation and are propelled by a magnetic field created by linear induction motors placed at regular intervals inside the tubes. The design of a vactrain generally requires many conditions and devices that are difficult to achieve (a raised double tube, air cushions, linear induction motors, etc.) and, in particular, a very low air pressure state in the tube. An example of a vactrain incorporating the mechanical propulsion device 100 of the invention is shown in part D of [Fig. 9]. This mechanical propulsion device 100 can be implemented to perform a vactrain in a tube 410 under normal pressure (not quasi-vacuum). Indeed, with the mechanical propulsion device 100, the air 200 can be evacuated from the front to the rear of the capsule 420, so as to decrease the pressure at the front of the capsule by reducing air friction and to increase the air pressure at the rear of said capsule. The pressure difference allows the capsule 420 to move forward very quickly.A vacuum tube is therefore not required, nor is an additional propulsion device for acceleration or deceleration of the capsule. Furthermore, with the mechanical propulsion device, the 425 wheels of the capsule are only used for guidance (and not for acceleration or deceleration), which minimizes friction since a strong adhesion between wheels and tube is not required.

[0060] Those skilled in the art will understand that the mechanical propulsion device according to the invention can also be applicable to all devices operating with propellers such as, for example, a rotary pump, a compressor, a fan, a vacuum cleaner, etc.

[0061] Although described through a certain number of examples, variants and embodiments, the mechanical propulsion device according to the invention comprises various variants, modifications and improvements which will be obvious to those skilled in the art, it being understood that these variants, modifications and improvements are part of the scope of the invention.

Claims

Claims

1. Mechanical propulsion device (100) for generating thrust capable of moving a transport vehicle, comprising a casing (110) of trochoidal shape and a rotor (120) of curvilinear triangular shape, characterized in that: - the casing (110) is provided with a single air inlet (111) and a single air outlet (112) facing each other and forms within it a chamber (130), and - the rotor (120) is driven in rotation in the chamber (130) of the casing and generates, by its rotation, a modulation of the internal volume of said chamber with a compression and an acceleration of the air, so that the air at the outlet (112) of the casing is accelerated relative to the air at the inlet (111) of said casing, the introduction of an air flow through the air inlet (111) being simultaneous with the evacuation of a other air flow through the air outlet (112).

2. Propulsion device according to claim 1, characterized in that the rotor (120) has sides whose dimension is substantially equal to a length L of the casing (110).

3. Propulsion device according to any one of claims 1 and 2, characterized in that it comprises a drive motor (310, 320) for driving the rotor (120) in rotation.

4. Propulsion device according to claim 3, characterized in that the drive motor (310) is mounted outside the housing.

5. Propulsion device according to claim 4, characterized in that the drive motor (310) is a Wankel type rotary motor, mounted parallel to the casing (110), around the same transmission shaft (125).

6. Propulsion device according to claim 4, characterized in that the drive motor (310) is an electric motor.

7. Propulsion device according to claim 3, characterized in that the drive motor (320) is mounted inside the housing (110).

8. Propulsion device according to claim 7, characterized in that the drive motor (320) comprises permanent magnets (321) distributed on the rotor (110) and electric coils (322) mounted in the chamber (130) of the casing to ensure the rotation of the rotor.

9. Propulsion device according to any one of claims 1 to 8, characterized in that it comprises an air supply duct opening into the air inlet of the casing and an air discharge duct opening from the air outlet of the casing.

10. Braking system for aircraft, characterized in that it comprises a propulsion device (100) according to any one of claims 1 to 9, in which the thrust generated by said propulsion device is reverse thrust.

11. Braking system according to claim 10, characterized in that the propulsion device (100) is coupled to a friction braking device or a regenerative braking mechanism.

12. Braking system according to claim 10 or 11, characterized in that it is mounted in each of the wheels (400) of an aircraft.

13. Transport vehicle, characterized in that it comprises at least one propulsion device (100) according to any one of claims 1 to 9 ensuring its propulsion in the air, in water or in a tube.

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