Air to air refuelling system and method for powering devices of the system thereof

Abstract

The present invention belongs to the field of air to air refuelling for aircraft, in particular to the field of systems for generating electrical power at the end of the hose. More particular, the invention provides a system for an air to air refuelling operation which intends to take advantage of the airflow action at the end of the hose in a refuelling operation for generating electrical power needed to supply devices located at the end of the hose.

Description

[0001] AIR TO AIR REFUELLING SYSTEM AND METHOD FOR POWERING DEVICES OF THE SYSTEM THEREOF

[0002] DESCRIPTION

[0003] TECHNICAL FIELD OF THE INVENTION

[0004] The present invention belongs to the field of air to air refuelling for aircraft, in particular to the field of systems for generating electrical power at the end of the hose. More particular, the invention provides a system for an air to air refuelling operation which intends to take advantage of the airflow action at the end of the hose in a refuelling operation for generating electrical power needed to supply devices located at the end of the hose.

[0005] BACKGROUND OF THE INVENTION

[0006] Air to air refuelling is a well-known manoeuvre in the field of aircraft where a tanker aircraft operates to provide in-flight fuel to a second aircraft called receiver aircraft. One of the most used operating system nowadays is based on a hose & drogue system. These systems are mainly used in a passive way relying on the skills of the receiver aircraft pilot which cause a high ratio of unsuccessful contacts. Those failed contacts can have operational and / or safety consequences.

[0007] In current air to air refuelling methods, the drogue is stored in the tanker aircraft and the system is turned off while the tanker aircraft pilot stabilizes the aircraft at air to air refuelling altitude. Then, the drogue is still stored in the tanker aircraft and the system is turned on while a second aircraft called receiver aircraft waits for further instructions from the tanker aircraft for initiating the refuelling operation.

[0008] Next, the drogue is extended from the tanker aircraft and the hose is deployed till reaching a stand-by position while the receiver aircraft is still waiting. Then, the receiver performs an approach to face the drogue with a receiver probe. While the receiver aircraft tries to make contact with the drogue it creates a phenomenon called Bow Effect which moves the drogue from its balance position. This specific step of approaching completely relies on the skills of the receiver aircraft pilot and its capacity to anticipate the drogue movements.

[0009] Once the receiver aircraft succeeds to make contact with the drogue, it pushes the drogue with the receiver probe to complete contact between the system of the tanker aircraft and the receiver aircraft. While the receiver aircraft pushes the drogue, a phenomenon called Whipping can appear on the contact area which is caused by the impact of the receiver probe transmitted to the hose in a wave form.

[0010] Then, the fuel starts to be dispensed from the tanker aircraft but the drogue is still submitted to radial loads transmitted by the receiver aircraft which means that risk of damage is not eliminated until full disconnection of the receiver aircraft from the drogue. Finally, the receiver aircraft goes backward and starts to disconnect the receiver probe from the drogue. If needed, the operation can be repeated more than once with the same tanker aircraft.

[0011] The actual air to air refuelling methods used for air to air refuelling between two aircrafts are commonly known as Boom system, when rigid connexion is used, and refuelling Pod system, when a flexible connexion is used. When sensors and actuators are required to be implemented at the end of the hose in order to perform different activities, such as parameters monitoring, close to the aircraft receptor, that is at the extreme mobile part of both systems (Boom or POD), these systems require to provide electrical power to the sensors and actuators from the mobile part to the central computer place located in the fixed part of system. However, the present philosophy implies a complex wiring installation and fuel isolating systems in order to perform all these activities in a secure way.

[0012] Most of the air to air refuelling methods are carried out passively and very few are actively performed. Some methods are known for incorporating an active control of the hose-end and its position, however, none of these methods have progressed to a self-sufficient and automated electric generating solution due to the drawbacks above mentioned.

[0013] Therefore, the present invention provides an improvement of the air to air refuelling operation by implementing a system optimizing the response provided to the receiving aircraft when contact approaches but also automatizing maintenance tasks while exploiting the airflow created at the end of the hose, where the contact with the receiver probe happens. So that the air to air refuelling system is able to self-generate electrical power with the aim of powering sensors and actuators implemented at the end of the hose in order to automatize the stability of the hose during operation. Furthermore, the air to air active refuelling system provided by the present invention reduces tanker aircraft and / or receiver aircraft damages, increases safety during the refuelling operation and mission reliability.

[0014] SUMMARY OF THE INVENTION

[0015] The present invention provides an air to air refuelling system for a tanker aircraft according to claim 1 , a tanker aircraft according to claim 17 and a method for powering devices located on the air to air refuelling system according to claim 18. Advantageous embodiments are defined in the dependent claims.

[0016] In a first inventive aspect, the invention provides an air to air refuelling system fora tanker aircraft, the system comprising: a hose suitable for driving fuel inside, the hose having a first end configured to be connected to the tanker aircraft and a second end , a coupling arranged at the second end of the hose, the coupling comprising a drogue configured to be coupled to a probe of a receiver aircraft in a refuelling operation, first sensing means configured to measure the relative position between the first sensing means location and the probe of the receiver aircraft, and actuating means connected to the second end of the hose and configured for adapting the positioning of the drogue during the refuelling operation; wherein the coupling further comprises: a ring located around the second end of the hose and supporting a plurality of blades radially arranged around the second end of the hose, the plurality of blades being fixed to the ring, an airflow passage configured to allow airflow to pass through the ring and reach the plurality of blades so that the ring is configured for rotating around the hose due to airflow action through the plurality of blades in the refuelling operation; braking means configured for braking the rotation of the ring , and an electrical power generator connected to the ring, to the first sensing means and to the actuating means, the electrical power generator being configured for extracting electrical power generated by the braking of the ring to then provide said electrical power to at least the first sensing means and the actuating means.

[0017] The present invention provides an air to air refuelling system which is to be implemented in a tanker aircraft and is configured for generating electrical power thanks to the airflow action at the end of the hose in refuelling operation. In particular, the present invention includes a coupling which is arranged at the second end of the hose, which is the end of the hose furthest from the tanker aircraft when fuel is brought to a receiver aircraft. This coupling comprises a drogue configured to be coupled to a probe of a receiver aircraft while in operating mode. The coupling of the invention further comprises a ring located around the second end of the hose and housing a plurality of blades radially arranged. Also, the plurality of blades is fixed to the ring. During a refuelling operation, the ring, and by extension the plurality of blades, freely rotates around the second end of the hose so that the air to air refuelling system of the invention takes advantage of the airflow action for generating electrical power when the hose is deployed. Specifically, the ring and the blades rotates together as one body.

[0018] Throughout the present description, when the hose is extended, deployed or “tensed”, it will be understood that the hose is extended along a longitudinal axis X-X’ that runs from one end of the hose to the other end, that is, from the first end to the second end. The expression “tensed” will be understood as the position in which the hose is arranged with its entire structure being coaxial to such longitudinal axis. Therefore, it is understood that the ring rotates around the longitudinal axis X-X’.

[0019] The invention also includes actuating means connected to the second end of the hose and configured for adapting the positioning of the drogue during the refuelling operation. The actuating means helps in positioning the drogue in an optimal manner during the whole refuelling operation.

[0020] Also, the invention comprises braking means which are configured for braking the rotation of the ring. Said braking means helps slowing down in an active and controlled manner the rotational speed of the ring.

[0021] Furthermore, the system of the first inventive aspect of the invention also comprises an electrical power generator which is connected to the ring. The electrical power generator is also connected to the braking means and allows extracting electrical power from the braking of the ring. The more force is applied on the ring by means of the braking means, the more electrical power is to be extracted from it by the electrical power generator.

[0022] The system also includes first sensing means to which the electrical power generated by the electrical power generator are provided, that is thanks to the braking of the ring. The first sensing means are able, once powered by power extracted by means of the electrical power generator, to measure the relative position between the first sensing means location and the probe of the receiver aircraft approaching. This facilitates the manoeuver of the receiver aircraft and further the pairing of the drogue of the system with the probe of the receiver.

[0023] The coupling of the invention also comprises an airflow passage configured to allow the airflow to pass through the ring and reach the plurality of blades so that the ring is able to rotate around the hose due to airflow action passing through the plurality of blades during the refuelling operation. The ring, and by extension the plurality of blades, rotates in an uncontrolled manner due to the airflow action that takes places around the second end of the hose. In order to generate electrical power, the ring is slowed down by means of the braking means so that the rotational speed of the ring is reduced. Said reduction of the rotation of the ring allows the electrical power generator to extract electrical power as a result of the braking operation. In other words, the more the ring is slowed down, the more power is extracted by the electrical power generator.

[0024] In an embodiment, the electrical power extracted from the braking means is equal to the power required to run the first sensing means and the actuating means in an optimal condition. In other embodiments, when more electrical power is extracted than it is necessary to run the first sensing means and the actuating means, the quantity of electrical power that is not required is further dissipated.

[0025] Thus, the present invention provides a system which is automated and self-sufficient since the functioning of its elements, such as the first sensing means and actuating means, is only based on those elements implemented inside the coupling of the invention and located at the second end of the hose. In particular, the power required for those elements to optimally function only depends on the electrical power generated by the braking of the ring and extracted by the electrical power generator. All these elements are called self-sufficient since they are independent from the power generated in the tanker aircraft that is from any additional generator located at the first end of the hose and proceeding from the tanker aircraft.

[0026] Additionally, the present invention provides an improvement of the air to air refuelling system and operation by implementing a coupling optimizing the positioning response provided to the receiving aircraft when contact approaches with the receiver probe.

[0027] Therefore, the air to air refuelling system of the invention is able to self-generate electrical power with the aim of powering at least the sensing means, for example the first sensing means and the actuating means implemented at the second end of the hose in order to automatize and improve stability of the hose during refuelling operation. Furthermore, the air to air active refuelling system provided by the present invention reduces tanker aircraft and / or receiver aircraft risk of damages, increases safety during the refuelling operation and also mission reliability. The present system configuration also avoids providing the hose with communications means along the entire length of the hose in order to supply electrical power to the end of the hose.

[0028] In an embodiment, a parachute is attached to the coupling and said parachute is configured for stabilizing the second-end of the hose while the hose is deployed.

[0029] The ring of the present invention can reach a maximum rotational speed which corresponds with the maximum tanker aircraft speed condition and, thus, ensures the integrity of the overall system and refuelling operation with respect to any type of flight condition.

[0030] Also, in case of failure, the ring is intended to achieve a maximum rotational speed, preferably lower than 6000 rpm, which helps securing the system during the refuelling operation and avoid adding any uncontrollable parameter, such as the maximum rotational speed of the ring, during said operation. This maximum rotational speed in passive mode does not compromise the mechanical integrity of the coupling or the ring with blades which could lead to detachment of any blade or part of the same.

[0031] Advantageously, implementing the ring, the plurality of blades, the braking means and the electrical power generator in the coupling which allows the system of the invention to be self-sufficient avoids the drawbacks known of the solutions from the state of the art. In particular, known solutions of the state of the art are used to provide power from the first end of the hose that is from the tanker aircraft, towards the second end of the hose which limits the maximum quantity of electrical power which the system is able to send. Also, these known solutions relies on high density of wiring arranged along the hose in order to provide said electrical from the first end to the second end of the hose.

[0032] On the contrary, the present invention localizes all the elements and the respective required wiring at the second end of the hose. The present invention also allows the refuelling system to be self-sufficient and increases the electrical power quantity available for the plurality of elements of the system of the present invention, such as the first sensing means or other devices located at the coupling such as the actuating means.

[0033] In an embodiment, the coupling comprises a leading edge and a trailing edge opposite to the leading edge, the leading edge being an edge of the coupling nearest to the first end of the hose, and wherein the airflow passage is arranged between both leading edge and trailing edge.

[0034] Advantageously, the airflow passage allows airflow to pass through during the refuelling operation so that said airflow enters at the leading edge of the coupling and comes out at the trailing edge of the same. Specifically, part of the airflow entering into the coupling pass through the ring achieving the blades housed in the ring. That is, said airflow is carried towards the plurality of blades before exiting the coupling.

[0035] In an embodiment, the airflow passage comprises a plurality of channels configured to inject the airflow towards the plurality of blades with a predefined orientation.

[0036] Advantageously, the plurality of channels helps orienting the airflow coming from the leading edge towards the trailing edge and, thus, in providing the airflow towards the plurality of blades before said airflow is ejected out of the coupling. In addition, the channels are provided to inject airflow to the blades with a specific orientation. That is, these channels allow the airflow to be injected with an orientation that benefits the rotation of the ring.

[0037] In an embodiment, the airflow passage comprises one channel for each blade comprised in the ring.

[0038] In an embodiment, the channels are extended from the leading edge to the trailing edge of the coupling passing through the ring.

[0039] In an embodiment, the channels are interposed between the leading edge and the trailing edge of the coupling, extending a length less than the length between leading edge and trailing edge.

[0040] In an embodiment, the system further comprises second sensing means connected to the electrical power generator, the second sensing means being configured for monitoring temperature and for being powered by the electrical power generator.

[0041] In an embodiment, the second sensing means comprise at least one sensor for measuring the temperature in the coupling, that is, around the second end of the hose.

[0042] Advantageously, this at least one sensor helps monitoring the temperature of the elements located outside the hose, i.e. around the second end of the hose.

[0043] In an embodiment, the second sensing means comprise at least one sensor for measuring the temperature inside the hose at the second end of the hose. Advantageously, this at least one sensor helps monitoring the temperature of the fuel running inside the hose.

[0044] In an embodiment, the second sensing means are connected to the tanker aircraft in order to process information regarding data monitored at the second end of the hose.

[0045] In an embodiment, the electrical power extracted from the braking of the ring is equal to the power required to run the actuating means, the first sensing means and the second sensing means in an optimal condition.

[0046] In an embodiment, the system further comprises third sensing means connected to the electrical power generator, the third sensing means being configured for monitoring pressure and for being powered by the electrical power generator. Advantageously, the third sensing means help monitoring the pressure of the fuel running inside the hose.

[0047] In an embodiment, the third sensing means are connected to the tanker aircraft in order to process information regarding data monitored at the second end of the hose.

[0048] In an embodiment, the electrical power extracted from the braking of the ring is equal to the power required to run the actuating means, the first sensing means, the second sensing means and the third sensing means in an optimal condition.

[0049] In an embodiment, the electrical power extracted from the braking of the ring is equal to the power required to run any combination of the first, second and third sensing means and, additionally, any other device included in the coupling of the invention run by electrical power, such as the actuating means.

[0050] In an embodiment, the coupling comprises a support structure around the second end of the hose; and the ring is attached to the support structure allowing the ring to rotate relative to the support structure, i.e. around the second end of the hose, by means of a plurality of rolling bearings.

[0051] Advantageously, the ring comprises a plurality of rolling bearings in order to provide active control of said ring thanks to the support structure arranged around the second end of the hose.

[0052] In an embodiment, the plurality of blades is distributed in a ring-shape around the hose.

[0053] In an embodiment, the plurality of blades are distributed radially around the second end of the hose inside the ring. Each blade is arranged within the ring in a single part. That is, the ring with the blades is manufactured as a single part.

[0054] In an embodiment, the plurality of blades are distributed equidistantly, one with respect to the other, in a radial manner around the second end of the hose inside the ring.

[0055] In an embodiment, the braking means are aligned with the electrical power generator according to an alignment direction. In an embodiment, the alignment direction is parallel to the longitudinal axis X-X’.

[0056] Advantageously, the braking means are aligned with the electrical power generator so that the extraction of electrical power is optimal.

[0057] In an embodiment, each blade of the plurality of blades further comprises one braking mean.

[0058] In an embodiment, the braking means are arranged on the ring. In a particular embodiment, the braking means are arranged over the whole surface of the ring.

[0059] In an embodiment, the braking means are at least one magnet located on the ring and configured for interacting with the electrical power generator. The at least one magnet is arranged or distributed on each one of the blades of the plurality of blades respectively and, said plurality of magnets are configured for interacting with an opposed magnetic field of the electrical power generator which helps in braking the ring and its plurality of blades and further generating and extracting electrical power.

[0060] In an embodiment, the braking means located on the ring is one continuous magnet arranged over a portion of the external surface of the ring surrounding the hose.

[0061] In an embodiment, the braking means are at least two magnets located on the ring and configured for interacting with the electrical power generator.

[0062] In a particular embodiment, the at least two magnets are pairs of magnets of opposite polarization.

[0063] In an embodiment, the system further comprises connecting means configured for connecting the electrical power generator to any of the actuating means and / or sensing means such as at least the first sensing means. In an embodiment, the electrical power generator is further connected through the connecting means to the second sensing means and / or third sensing means.

[0064] In an embodiment, the system further comprises a controller configured for:

[0065] - providing continuous monitoring of the voltage received by the connecting means, and / or operating the braking means for regulating the reduction of the rotational speed of the ring.

[0066] The present invention allows the rotational speed of the ring to be controlled (by braking) to extract the right amount of electrical power for the operation of the actuators (i.e., actuating means and / or sensors) at any given moment. That is, the invention provides a control loop to brake the ring more or less depending on the need for movement or operation of the actuators. If the actuators do not move or are not operated, the present system does not generate electrical power, and any energy that is left over is burned as heat. This configuration of the present invention advantageously eliminates the necessity for energy storage. This is a significant advantage, given that energy storage is most problematic aspects of aeronautical battery certification.

[0067] In an embodiment, the system further comprising a busbar configured for connecting the electrical power generator to any of the actuating means, first sensing means, the second sensing means and / or third sensing means. In an embodiment, the busbar is the connecting means already described above.

[0068] Advantageously, the busbar facilitates electrical power distribution from the electrical power generator to the actuating means and / or the first sensing means and / or the second sensing means and / or the third sensing means. Specifically, the busbar helps circulating the electric power with greater ease and flexibility with respect to more permanent forms of installation and distribution known in the art.

[0069] In an embodiment, the busbar is a DC busbar.

[0070] In particular, the electrical power generator is connected to the DC busbar in order to use the power in an appropriate manner so that the system runs in its optimal conditions. Furthermore, active control of the electrical power is requested in order to keep the voltage of busbar in an optimal range of operation.

[0071] In an embodiment, the busbar comprises a capacitor configured for stabilizing the voltage of the electrical power generated by the braking of the ring. The DC busbar, where electrical power generated is delivered, integrates a busbar capacitor to stabilize the voltage generated.

[0072] Advantageously, the electrical power generated by the electrical power generator either goes in the capacitor, which will increase the voltage of busbar capacitor or the electrical power connected to the busbar consumes electrical power from the busbar capacitor. This specific consumption of electrical power decreases the voltage of the busbar capacitor.

[0073] In an embodiment, the air to air refuelling system comprises at least four blades.

[0074] In a particular embodiment, the at least four blades are equidistantly distributed around the second end of the hose.

[0075] In an embodiment, the electrical power generator is an axial flux brushless generator.

[0076] Advantageously, an axial flux brushless generator is implemented in the system of the invention in order to optimize the space available in the coupling due to the size and the positioning of the hose in the coupling.

[0077] In an embodiment, the electrical power generator is a three phase brushless generator which is used to extract power from braking the motion of the ring. The elements implemented inside the electrical power generator helps controlling gradually the motion of said ring in order to optimize the functioning of the electrical power generator. In that sense, the braking means slow down the ring consequently, such as by means of a magnetic flux located inside the generator, and helps reducing its rotational speed. This speed reduction is provided in order to generate electrical power that could be used to power any device part of the air to air refuelling system of the invention, such as the actuating means, the first sensing means, the second sensing means and / or the third sensing means.

[0078] In an embodiment, the system further comprises a controller configured for: providing continuous monitoring of the voltage received by the busbar, and / or operating the braking means for regulating the reduction of the rotation speed of the ring. The controller according to any of the above embodiments is implemented in the system of the invention in order to provide active control of the electrical power generator speed. Said active control is performed so that the extraction of electrical power by the electrical power generator corresponds to the electrical power demand of the other devices that are part of the system of the invention, such as the first sensing means and / or other sensing means and / or the actuating means.

[0079] Also, a continuous control of the voltage is requested in order to avoid either power storage or continuous heat-dissipation inside the coupling. When the sensing means and / or the actuating means require a higher electrical power, the controller is able to regulate the reduction of the speed of the ring in a higher proportion, that is by actuating on the braking means, so that more electrical power is extracted by the electrical power generator. When the sensing means and / or the actuators requires a lower power, the controller is able to regulate the reduction of the speed of the ring but allowing a higher rotational speed to said ring. That is, by reducing the force applied by the braking means on said ring, a lower proportion of electrical power is extracted by the electrical power generator.

[0080] In a second inventive aspect, the present invention provides a tanker aircraft comprising an air to air refuelling system according to any embodiment of the first inventive aspect.

[0081] In a third inventive aspect, the present invention provides a method for powering devices located on the air to air refuelling system according to any embodiment of the first inventive aspect, devices such as at least the first sensing means and the actuating means of the air to air refuelling system of the first inventive aspect of the invention, the method comprising the steps of: a) braking the rotation of ring supporting the plurality of blades, b) extracting power by means of the electrical power generator from the braking of the ring; and c) providing the extracted electrical power to at least the actuating means and the first sensing means by the electrical power generator.

[0082] In an embodiment, step a) is performed by means of braking means, more preferably by means of a plurality of magnets located on the ring. In an embodiment, between step b) and c) of the method of the second inventive aspect of the invention, a controller is configured for actuating the braking means and adapt the rotational speed of the ring.

[0083] In particular, the electrical power generator extracts electrical power when applying an initial braking force on the ring. When the electrical power required by other elements of any of the embodiments of the first inventive aspect, the braking means are controlled so that a higher braking force, with respect to the initial braking force, is applied on the ring. On the contrary, when the electrical power required by other elements of any of the embodiments of the first inventive aspect, the braking means are controlled so that a lower braking force, with respect to the initial braking force, is applied on the ring.

[0084] In the specific case when the electrical power generator extracts more power that required by the others elements of the system, said power is dissipated in order to avoid implementing additional power storing devices which would increase the overall weight of the system of the invention.

[0085] Advantageously, the controller helps avoiding over-extracting electrical power which may lead to dissipating more electrical power and overloading the electrical power generator.

[0086] All the features described in this specification (including the claims, description and drawings) and / or all the steps of the described method can be combined in any combination, with the exception of combinations of such mutually exclusive features and / or steps.

[0087] DESCRIPTION OF THE DRAWINGS

[0088] These and other characteristics and advantages of the invention will become clearly understood in view of the detailed description of the invention which becomes apparent from preferred embodiments of the invention, given just as examples and not being limited thereto, with reference to the drawings.

[0089] Figures 1 This figure shows a schematic side view of a tanker aircraft with an air to air refuelling system approaching to a receiver aircraft according to an embodiment of the present invention.

[0090] Figure 2 This figure shows a schematic upper view of the embodiment shown in Figure 1.

[0091] Figure 3 This figure shows a schematic front view of a hose and coupling of an air to air refuelling system according to an embodiment of the present invention.

[0092] Figure 4 This figure shows a schematic cross side view of a hose and coupling of an air to air refuelling system according to an embodiment of the present invention.

[0093] Figure 5 This figure shows a schematic cross side view of a hose and coupling of an air to air refuelling system according to an embodiment of the present invention.

[0094] DETAILED DESCRIPTION OF THE INVENTION

[0095] Once the object of the invention has been outlined, specific non-limitative embodiments are described hereinafter.

[0096] Figures 1 and 2 show a side and an upper view respectively of an air to air refuelling system (1) in a refuelling operation between a tanker aircraft (2) and a receiver aircraft (3).

[0097] In particular, these figures show when the hose (4) of the air to air refuelling system (1) is in an extended position, or tensed position, out of a tanker aircraft (2) and the receiver aircraft is approaching to said hose (4) of the refuelling system (1).

[0098] The air to air refuelling system (1) comprises a hose (4) for driving fuel from a tanker aircraft (2) to a receiver aircraft (3) in a refuelling operation. Said hose (4) has a drogue (5) located at a hose-end (4.2) which is configured for being coupled with a probe (6) of the receiver aircraft (3). The hose (4) also comprises another end, a first end (4.1), opposite to the already mentioned hose-end, the second end (4.2), where the hose (4) is fixed to the tanker aircraft (2).

[0099] In a refuelling operation, the air to air refuelling system (1) installed on the tanker aircraft (2) extends the hose (4) in order to couple the drogue (5) of the second end (4.2) to the probe (6) of the receiver aircraft (3). The receive aircraft (3) flies closer to the tanker aircraft (2) so that the drogue (5) approaches towards the probe (6). Once the coupling between the drogue (5) and the probe (6) is achieved, the fuel starts being driven through the hose (4) from the tanker aircraft (2) towards the receiver aircraft (3). The system further comprises actuating means (10) connected to the second end (4.2) of the hose (4) and configured for adapting the positioning of the drogue (5) during the refuelling operation.

[0100] Figure 3 shows a schematic front view of the hose (4) and the coupling (7) at the second end (4.2) of the hose (4) according to an embodiment of the present invention.

[0101] Figure 3 depicts a hose (4) located at the center of the coupling (7). The coupling (7) is arranged at the second end (4.2) of the hose (4), the coupling surrounding the hose (4), and said coupling (7) comprises the drogue (5) (not shown in this figure). In the embodiment shown in figure 3, said coupling (7) has a leading edge (7.1) and a trailing edge (7.2) opposite to the leading edge (7.1). In particular, the leading edge (7.1) is an edge of the coupling (7) nearest to the first end (4.1) of the hose (4).

[0102] As shown in figure 3, the coupling (7) comprises a ring (R) located around the second end (4.2) of the hose (4) and supporting a plurality of blades (9) radially arranged around the hose (4). Said plurality of blades (9) is fixed to the ring (R) and an airflow passage (15) is defined inside the coupling (7). Said airflow passage (15) is configured to allow airflow (F) to pass through the ring (R) and reach the plurality of blades (9) so that the ring (R) is able to rotate around the hose (4) due to airflow (F) action passing through the plurality of blades (9) during refuelling operation. In the embodiment shown in figure 3, the airflow passage (15) is arranged between both leading edge (7.1) and trailing edge (7.2). Also in the embodiment of figure 3, the airflow passage (15) comprises a plurality of channels (16) configured to inject the airflow (F) towards the plurality of blades (9) with a predefined orientation.

[0103] The coupling (7) depicted in figure 3 also comprises first sensing means (not shown in this figure) which are configured to measure the relative position between the first sensing means location and the probe (6) of the receiver aircraft (3).

[0104] The coupling (7) further includes braking means (not shown) which are configured for braking the rotation of the ring (R). The coupling (7) also comprises an electrical power generator (not shown) connected to the ring (R), to the first sensing means (8.1) and to the actuating means (not shown). The electrical power generator (12) is configured for extracting electrical power generated by the braking of the ring (R) to then provide said electrical power to at least the first sensing means (8.1) and the actuating means (10).

[0105] In an embodiment, as the one shown in figure 3, the plurality of blades (9) is distributed in a ring-shape around the hose (4). In a particular embodiment, the plurality of blades are distributed equidistantly with respect to each other and around the hose (4).

[0106] In preferred embodiments, the air to air refuelling system (1) comprises a plurality of blades (9) as shown in the embodiment of figure 3 which depicts 16 blades (9) distributed around the hose (4). Also in preferred embodiments, the system (1) comprises as many channels (16) as blades (9).

[0107] Figure 4 shows a schematic cross side view of a hose (4) and coupling (7) of an air to air refuelling system (1) according to an embodiment of the invention.

[0108] The cross side view depicts an embodiment comprising the same elements as described in the front view of the embodiment of figure 3.

[0109] In particular, figure 4 shows the hose (4) and the distribution of the ring (R) connected to the hose (4) by means a support structure (17) arranged around the second end (4.2) of the hose (4). As shown in this figure, the ring (R) is attached to the support structure (17) allowing the ring (R) to rotate relative to the support structure(17), that is around the second end (4.2) of the hose (4), by means of a plurality of rolling bearings (18). As depicted in this figure, braking means (11) are arranged on the ring (R) and on an electrical power generator (12) from which the electrical power is extracted when the braking means (11) are actuated and the rotational speed of the ring (R) is slowed down.

[0110] In the embodiment of figure 4, the braking means (11) are aligned with the electrical power generator (12).

[0111] Also depicted in figure 4, the air to air refuelling system (1) comprises a busbar (13) configured for connecting the electrical power generator (12) to the actuating means (10) (shown in figures 1 or 2), the first sensor means (8.1) and / or the second sensor means

[0112] (8.2) and / or the third sensor means (8.3). Furthermore, the air to air refuelling system (1) comprises a controller (14) connected to the electrical power generator (12), the actuating means (10) and to the first (8.1), second (8.2) and third (8.3) sensing means via the busbar (13). The controller (14) is configured for providing continuous monitoring of the voltage of the electrical power extracted by the generator (12) and received by the busbar (13) but the controller (14) is also configured for operating the braking means (11) in order to reduce the rotational speed of the ring (R).

[0113] In an embodiment, the second sensing means (8.2) are configured for monitoring temperature and for being powered by the electrical power generator (12).

[0114] In an embodiment, the second sensing means (8.2) comprise at least one sensor for measuring the temperature in the coupling (7), that is, around the second end (4.2) of the hose (4). Advantageously, this at least one sensor (8.2) helps monitoring the temperature of the elements located outside the hose (4), i.e. around the second end

[0115] (4.2) of the hose (4).

[0116] In an embodiment, the second sensing means comprise at least one sensor, not shown in the set of figures, for measuring the temperature inside the hose (4) at the second end

[0117] (4.2) of the hose (4). Advantageously, this at least one sensor helps monitoring the temperature of the fuel running inside the hose (4).

[0118] In an embodiment, the second sensing means (8.2) are connected to the tanker aircraft in order to process information regarding data monitored at the second end of the hose. In an embodiment, the third sensing means (8.3) are configured for monitoring pressure and for being powered by the electrical power generator (12).

[0119] In an embodiment, the third sensing means (8.3) are connected to the tanker aircraft in order to process information regarding data monitored at the second end (4.2) of the hose (4). Advantageously, the third sensing means (8.3) help monitoring the pressure of the fuel running inside the hose (4).

[0120] In an embodiment, the busbar (13) is a DC busbar.

[0121] In further embodiments, the busbar (13) comprises a capacitor configured for stabilizing the voltage of the electrical power generated by the braking of the ring (R).

[0122] In preferred embodiments, the electrical power generator (12) is an axial flux brushless generator.

[0123] Finally, figure 5 depicts a schematic cross side view of a hose (4) and coupling (7) of an air to air refuelling system (1) according to an embodiment of the present invention.

[0124] As depicted in both figures 4 and 5, the electrical power generator (12) is arranged radially around the second end (4.2) of the hose (4) and between the leading edge (7.1) and trailing edge (7.2) of the coupling (7). Figures 4 and 5 also show the airflow passage (15) through which the airflow (F) passes through the coupling (7), from the leading edge (7.1) to the trailing edge (7.2).

[0125] The embodiment of figure 5 includes all the elements previously described in the embodiment of figure 4 and further comprises a parachute (14) preferably attached to the coupling (7) and the second-end of the hose (4)

[0126] Method for powering devices located on the air to air refuelling system

[0127] The present invention also discloses a method for powering devices located on the air to air refuelling system (1) according to any embodiment described regarding figures 1 to 5, devices such as at least the first sensing means (8.1) and the actuating means (10) of the air to air refuelling system (1), the method comprising the steps of: a) braking the rotation of the ring (R) supporting the plurality of blades (9), b) extracting power by means of the electrical power generator (12) from the braking of the ring (R); and c) providing the extracted electrical power to at least the actuating means (10) and the first sensing means (8.1) by the electrical power generator (12).

[0128] In an embodiment, step a) is performed by means of the braking means (11), more preferably by means of a plurality of magnets located the ring (R).

[0129] In an embodiment, the braking means (11) are at least two magnets located on the ring (R) and configured for interacting with the electrical power generator (12). In a particular embodiment, the at least two magnets are pairs of magnets of opposite polarization.

[0130] In an embodiment, between step b) and c) of the method, a controller (14) is configured for actuating the braking means (11) and adapt the rotational speed of the ring (R).

[0131] In particular, the electrical power generator (12) allows the extraction of electrical power when applying an initial braking force on the ring (R). When the electrical power required by other elements of the system (1) of any embodiment of the invention, the braking means (11) are controlled by means of the controller (14) so that a higher braking force, with respect to the initial braking force, is applied on the ring (R). On the contrary, when the electrical power required by other elements of the system (1) of any embodiment of the invention, the braking force is controlled by means of the controller (14) so that a lower braking force, with respect to the initial braking force, is applied on the ring (R).

[0132] In an embodiment, when the electrical power generator (12) extracts more power that required by the others elements of the system (1), said electrical power is dissipated in order to avoid implementing additional power storing devices which would increase the overall weight of the system (1).

[0133] In an embodiment, step c) further comprises providing the extracted electrical power to the actuating means (10), the first sensing means (8.1) and / or the second sensing means (8.2) and / or the third sensing means (8.3) by the electrical power generator (12). Additionally, further aspects and embodiments of the invention are defined in the following clauses:

[0134] Clause 1. Air to air refuelling system (1) for a tanker aircraft (2), the system (1) comprising: a hose (4) suitable for driving fuel inside, the hose (4) having a first end (4.1) configured to be connected to the tanker aircraft (2) and a second end (4.2), a coupling (7) arranged at the second end (4.2) of the hose (4), the coupling (7) comprising a drogue (5) configured to be coupled to a probe (6) of a receiver aircraft (3) in a refuelling operation, first sensing means (8.1) configured to measure the relative position between the first sensing means (8.1) location and the probe (6) of the receiver aircraft (3), and actuating means (10) connected to the second end (4.2) of the hose (4) and configured for adapting the positioning of the drogue (5) during the refuelling operation; wherein the coupling (7) further comprises: a ring (R) located around the second end (4.2) of the hose (4) and supporting a plurality of blades (9) radially arranged, the plurality of blades (9) being fixed to the ring (R), an airflow passage (15) configured to allow airflow (F) to pass through the ring (R) and reach the plurality of blades (9) so that the ring (R) is configured for rotating around the hose (4) due to airflow (F) action through the plurality of blades (9) in the refuelling operation; braking means (11) configured for braking the rotation of the ring (R), and an electrical power generator (12) connected to the ring (R), to the first sensing means (8.1) and to the actuating means (10), the electrical power generator (12) being configured for extracting electrical power generated by the braking of the ring (R) to then provide said electrical power to at least the first sensing means (8.1) and the actuating means (10).

[0135] Clause 2. The air to air refuelling system (1) according to clause 1 , wherein the coupling (7) comprises a leading edge (7.1) and a trailing edge (7.2) opposite to the leading edge (7.1), the leading edge (7.1) being an edge of the coupling (7) nearest to the first end (4.1) of the hose (4), and wherein the airflow passage (15) is arranged between both leading edge (7.1) and trailing edge (7.2).

[0136] Clause s. The air to air refuelling system (1) according to any of the preceding clauses, wherein the airflow passage (15) comprises a plurality of channels (16) configured to inject the airflow (F) towards the plurality of blades (9) with a predefined orientation.

[0137] Clause 4. The air to air refuelling system (1) according to any of the preceding clauses, further comprising second sensing means (8.2) connected to the electrical power generator (12), the second sensing means (8.2) being configured for monitoring temperature and for being powered by the electrical power generator (12).

[0138] Clause 5. The air to air refuelling system (1) according to any of the preceding clauses, further comprising third sensing means (8.3) connected to the electrical power generator (12), the third sensing means (8.3) being configured for monitoring pressure and for being powered by the electrical power generator (12).

[0139] Clause 6. The air to air refuelling system (1) according to any of the preceding clauses, wherein: the coupling (7) comprises a support structure (17) around the second end (4.2) of the hose (4); and the ring (R) is attached to the support structure (17) allowing the ring (R) to rotate relative to the support structure (17), i.e. around the second end (4.2) of the hose (4), by means of a plurality of rolling bearings (18).

[0140] Clause 7. The air to air refuelling system (1) according to any of the preceding clauses, wherein the plurality of blades (9) is distributed in a ring-shape around the hose.

[0141] Clause s. The air to air refuelling system (1) according to any of the preceding clauses, wherein the braking means (11) are aligned with the electrical power generator (12).

[0142] Clause 9. The air to air refuelling system (1) according to any of the preceding clauses, further comprising a busbar (13) configured for connecting the electrical power generator (12) to any of the actuating means (10), the first sensing means (8.1), the second sensing means (8.2) and / or third sensing means (8.3). Clause 10. The air to air refuelling system (1) according to the previous clause, wherein the braking means (11) are at least one magnet located on the ring (R) and configured for interacting with the electrical power generator (12).

[0143] Clause 11. The air to air refuelling system (1) according to any of clauses 9 or 10, wherein the busbar (13) comprises a capacitor configured for stabilizing the voltage of the electrical power generated by the braking of the ring (R).

[0144] Clause 12. The air to air refuelling system (1) according to any of the preceding clauses, wherein the electrical power generator (12) is an axial flux brushless generator.

[0145] Clause 13. The air to air refuelling system (1) according to any of clauses 9 to 12 further comprising a controller (14) configured for: providing continuous monitoring of the voltage received by the busbar (13), and operating the braking means (11) for regulating the reduction of the rotational speed of the ring (R).

[0146] Clause 14. Tanker aircraft (2) comprising an air to air refuelling system (1) according to any of the preceding clauses.

[0147] Clause 15. Method for powering devices located on the air to air refuelling system (1) according to any of clauses 1 to 13, devices such as at least the first sensing means (8.1) and the actuating means (10) of the air to air refuelling system (1), the method comprising the steps of: a) braking the rotation of the ring (R) supporting the plurality of blades (9), b) extracting power by means of the electrical power generator (12) from the braking of the ring (R); and c) providing the extracted electrical power to at least the actuating means (10) and the first sensing means (8.1) by the electrical power generator (12).

Claims

CLAIMS1 Air to air refuelling system (1) for a tanker aircraft (2), the system (1) comprising: a hose (4) suitable for driving fuel inside, the hose (4) having a first end (4.1) configured to be connected to the tanker aircraft (2) and a second end (4.2), a coupling (7) arranged at the second end (4.2) of the hose (4), the coupling (7) comprising a drogue (5) configured to be coupled to a probe (6) of a receiver aircraft (3) in a refuelling operation, first sensing means (8.1) configured to measure the relative position between the first sensing means (8.1) location and the probe (6) of the receiver aircraft (3), and actuating means (10) connected to the second end (4.2) of the hose (4) and configured for adapting the positioning of the drogue (5) during the refuelling operation; wherein the coupling (7) further comprises: a ring (R) located around the second end (4.2) of the hose (4) and supporting a plurality of blades (9) radially arranged around the second end (4.2) of the hose (4), the plurality of blades (9) being fixed to the ring (R), an airflow passage (15) configured to allow airflow (F) to pass through the ring (R) and reach the plurality of blades (9) so that the ring (R) is configured for rotating around the hose (4) due to airflow (F) action through the plurality of blades (9) in the refuelling operation; braking means (11) configured for braking the rotation of the ring (R), and an electrical power generator (12) connected to the ring (R), to the first sensing means (8.1) and to the actuating means (10), the electrical power generator (12) being configured for extracting electrical power generated by the braking of the ring (R) to then provide said electrical power to at least the first sensing means (8.1) and the actuating means (10).2.- The air to air refuelling system (1) according to claim 1 , wherein the coupling (7) comprises a leading edge (7.1) and a trailing edge (7.2) opposite to the leading edge(7.1), the leading edge (7.1) being an edge of the coupling (7) nearest to the first end(4.1) of the hose (4), and wherein the airflow passage (15) is arranged between both leading edge (7.1) and trailing edge (7.2).3.- The air to air refuelling system (1) according to any of the preceding claims, wherein the airflow passage (15) comprises a plurality of channels (16) configured to inject the airflow (F) towards the plurality of blades (9) with a predefined orientation.4.- The air to air refuelling system (1) according to any of the preceding claims, further comprising second sensing means (8.2) connected to the electrical power generator (12), the second sensing means (8.2) being configured for monitoring temperature and for being powered by the electrical power generator (12).5.- The air to air refuelling system (1) according to any of the preceding claims, further comprising third sensing means (8.3) connected to the electrical power generator (12), the third sensing means (8.3) being configured for monitoring pressure and for being powered by the electrical power generator (12).6.- The air to air refuelling system (1) according to any of the preceding claims, wherein: the coupling (7) comprises a support structure (17) around the second end (4.2) of the hose (4); and the ring (R) is attached to the support structure (17) allowing the ring (R) to rotate relative to the support structure (17), i.e. around the second end (4.2) of the hose (4), by means of a plurality of rolling bearings (18).7.- The air to air refuelling system (1) according to any of the preceding claims, wherein the blades (9) of the plurality of blades (9) are distributed equidistantly with respect to each other and around the hose (4).8.- The air to air refuelling system (1) according to any of the preceding claims, wherein the braking means (11) are aligned with the electrical power generator (12) according to an alignment direction.9.- The air to air refuelling system (1) according to any one of the preceding claims, further comprising connecting means configured for connecting the electrical power generator (12) to any of the actuating means and / or at least the first sensing means (8.1).10.- The air to air refuelling system (1) according to the preceding claim, wherein the connecting means is also configured for connecting the electrical power generator (12) to the second sensing means (8.2) when depends on claims 4 or 5 depending on claim4 and / or third sensing means (8.3) when depends on claim 5.11.- The air to air refuelling system (1) according to any one of claims 9 to 10, further comprising a controller (14) configured for: providing continuous monitoring of the voltage received by the connecting means, and / or operating the braking means (11) for regulating the reduction of the rotational speed of the ring (R).12.- The air to air refuelling system (1) according to any of the preceding claims 1 to 8, further comprising a busbar (13) configured for connecting the electrical power generator (12) to: the actuating means (10), or the first sensing means (8.1), or the second sensing means (8.2) when depending on claims 4 or 5 depending on claim 4, or third sensing means (8.3) when depending on claim 5, or a combination of the above.13.- The air to air refuelling system (1) according to the previous claim, wherein the braking means (11) are at least one magnet located on the ring (R) and configured for interacting with the electrical power generator (12).14.- The air to air refuelling system (1) according to any of claims 12 or 13, wherein the busbar (13) comprises a capacitor configured for stabilizing the voltage of the electrical power generated by the braking of the ring (R).15.- The air to air refuelling system (1) according to any of the preceding claims, wherein the electrical power generator (12) is an axial flux brushless generator.16.- The air to air refuelling system (1) according to any of claim 12 to 15 further comprising a controller (14) configured for: providing continuous monitoring of the voltage received by the busbar (13), and / or operating the braking means (11) for regulating the reduction of the rotational speed of the ring (R).17.- Tanker aircraft (2) comprising an air to air refuelling system (1) according to any of the preceding claims.18.- Method for powering devices located on the air to air refuelling system (1) according to any of claims 1 to 16, devices such as at least the first sensing means (8.1) and the actuating means (10) of the air to air refuelling system (1), the method comprising the steps of: a) braking the rotation of the ring (R) supporting the plurality of blades (9), b) extracting power by means of the electrical power generator (12) from the braking of the ring (R); and c) providing the extracted electrical power to at least the actuating means (10) and the first sensing means (8.1) by the electrical power generator (12).

Images