WO2016132331A1

WO2016132331A1 - Opening servomechanism for aerospace platforms and mechanical components

Info

Publication number: WO2016132331A1
Application number: PCT/IB2016/050909
Authority: WO
Inventors: Renato AURIGEMMA; Pasquale Dell'aversana; Luciano GRAMICCIA; Francesco PUNZO; Raffaele SAVINO; Giovanni SQUAME; Norberto SALZA
Original assignee: Ali S.C.A.R.L.
Priority date: 2015-02-20
Filing date: 2016-02-19
Publication date: 2016-08-25

Abstract

A braking and thermal protection device (1) for landing bodies, comprising a folding braking shield (3) and an articulated frame (2), to which said folding braking shield (3) is fixed. The articulated frame (2) comprises a central opening actuator (4), consisting of an inner fixed portion (5) and an outer mobile portion (6) that can slide around said inner fixed portion (5), a plurality of telescopically extendable spokes (8), each of which is hinged at its first end (8a) to the outer mobile portion (6) and is fixed at its second end (8b) to an outer edge (3b) of the folding braking shield (3), and a plurality of support cables (12), each having a first end fixed to the inner fixed portion (5) of the actuator assembly (4) and a second end fixed to the second end (8b) of a respective extendable spoke (8). The braking and thermal protection device (1) is movable between a closed configuration and an open configuration.

Description

"OPENING SERVOMECHANISM FOR AEROSPACE PLATFORMS AND MECHANICAL COMPONENTS"

TECHNICAL FIELD

The present invention relates to a braking and thermal protection device for landing bodies.

In particular, the present invention finds advantageous application in the aerospace industry as an opening servomechanism for aerospace platforms to which the following description shall make specific reference, but without any loss of generality.

BACKGROUND ART

There is a need in the aerospace field for a thermal protection system for vehicles, for example capsules, in the re-entry phase to earth. In fact, vehicles lose their kinetic energy in the re-entry phase by converting it into heat, which is transferred to the gases surrounding the vehicle. The fluid tends to be aerodynamically heated by convection, conduction and irradiation through the viscous boundary layer that surrounds the vehicle, giving rise to so-called "aerodynamic heating" . There was awareness of the need to provide a thermal protection system that, in addition to ensuring the above- mentioned protection, also met the requirement of being manufactured with inexpensive materials. The applicant has created a device capable of satisfying the above needs by means of the deployment of a braking shield. It has been shown that in this way, the ballistic coefficient is reduced, resulting in acceptable heat flux, an acceptable mechanical load and an acceptable descent speed. DISCLOSURE OF INVENTION

The subject of the present invention is a braking and thermal protection device for landing bodies, the basic characteristics of which are specified in claim 1, and the preferred and/or auxiliary characteristics of which are specified in claims 2-8.

BRIEF DESCRIPTION OF THE DRAWINGS

Some embodiments are described below, purely by way of non- limitative illustration and with the aid of the accompanying figures, where:

Figures la - lc show the device forming the subject of the present invention in three different configurations;

Figures 2a - 2c show the device in Figures la - lc in the same three different configurations, but from a different perspective and with some parts removed;

Figure 3 is a section of a detail of the device in Figures la - lc;

Figure 4 show a further detail, on an enlarged scale, of the device in Figures la - lc; and

Figure 5 is a section of a further detail of the device in Figures la - lc.

BEST MODE FOR CARRYING OUT THE INVENTION

In Figures la - lc, reference numeral 1 indicates, as a whole, the braking and thermal protection device according to the present invention.

The braking and thermal protection device 1 comprises an articulated frame 2, movable between a closed configuration (Figure la) and an open configuration (Figure lc) , and a foldable braking shield 3, fixed to the articulated frame 2 to be folded up when the articulated frame 2 is in its closed configuration (Figure la) and spread out when the articulated frame 2 is in its open configuration (Figure lc) . As is shown in Figures 2a - 2c, the articulated frame 2 comprises a central opening actuator 4, constituted by a fixed cylindrical chamber 5 and an outer cylindrical wall 6 placed around and coaxial (X-axis) to the cylindrical chamber 5. The outer cylindrical wall 6 can move by sliding along the X-axis between a closed configuration (Figure 2a) and an open configuration (Figure 2c) . In the closed configuration, the outer cylindrical wall 6 is in its backward position and placed to completely surround the cylindrical chamber 5, while in the open configuration, the outer cylindrical wall 6 is in its forward position and placed in an offset position with respect to the cylindrical chamber 5. The sliding of the cylindrical wall 6 with respect to the cylindrical chamber 5 takes place by means of three telescopic moving rods 7, each consisting of two tubular portions telescopically coupled to each other and fixed to the cylindrical wall 6 and to the cylindrical chamber 5, respectively. In particular, each one of the three telescopic moving rods 7 internally comprises a coil spring responsible for its extension. Each of the telescopic moving rods 7 further comprises locking elements designed to lock the two portions once the telescopic moving rod has taken its extended position, thus ensuring it remains in that position.

As clearly shown in Figures 2a - 2c, the articulated frame 2 comprises twelve extendible spokes 8, each of which has a first end 8a hinged to an upper edge 9 of the outer cylindrical portion 6. Each of the extendible spokes 8 is composed of three tubular portions telescopically connected to one another. As shown in Figure 3, each of the extendible spokes 8 internally comprises a coil spring 10 responsible for extension of the respective extendable spoke 8. Each of the extendible spokes 8 further comprises locking elements designed to lock the three portions of the respective extendable spoke 8 together when the latter is in its extended position (Figures 2b, 2c, 3b and 3c) . The purpose of the locking elements is to ensure that the extended position of the respective extendable spoke 8 is maintained. A lower support cable 11 and an upper support cable 12 are associated with each extendible spokes 8. Each lower support cables 11 has a first end externally fixed to a second end 8b of the extendable spoke 8 and a second end fixed to a lower edge 13 of the cylindrical wall 6. Each upper support cables 12 has a first end also externally fixed to the second end 8b of the extendable spoke 8 and a second end fixed to a free edge 14 of the cylindrical chamber 5.

As shown in Figures 3 and 5, the articulated frame 2 comprises a damping assembly 15, constituted by a wheel 16 fitted on a rotary damper 17 and a plurality of retaining cables 18. Each of the retaining cables 18 is wound around the wheel 16, and then engages a respective pulley 19 and passes through the inside of a respective extendable spoke 8 where it is internally fixed at its second end 8b. In particular, as shown in Figure 5, a plurality of circumferential conduits are provided on an axial edge of the wheel 16, each of which houses a respective wound retaining cable 18. The extension of an extendable spoke 8 takes place through the rotation of the wheel 16, which unwinds the respective retaining cable 18. Rotation of the wheel 16 takes place in a controlled manner under the action of the rotary damper 17 on which the wheel 16 is fitted.

In other words, during the extension of each one of the extendible spokes 8, the respective retaining cable 18, under the action of the rotary damper 17 and with the participation of the wheel 16, ensures a controlled extending movement of the extendable spoke 8.

As shown in Figure 4, the wheel 16 is fixed to an upper end of the cylindrical chamber 5 and the rotary damper 17 is at least partially housed inside the cylindrical chamber 5. The rotary damper 17 is known and for this reason is not described in detail.

In use, by following the sequence shown in Figures la - lc and 2a - 2c, and starting from a closed position of the articulated frame 2 (Figure 2a) and, therefore, of the braking and thermal protection device 1 (Figure la) , the extension of the twelve extendible spokes 8 is activated (in a known manner and not relevant for the purposes of the present invention) . As described above, the extension of the extendible spokes 8 takes place in a controlled manner under the action of the damping assembly 15. Once the extension of the extendible spokes 8 is complete, these shall be elongated and arranged parallel to one another, as well as parallel to the cylindrical wall 6 (Figures lb and Figure 2b) . At this point, the central opening actuator 4 is activated (in a known manner and not relevant for the purposes of the present invention) and, therefore, the sliding of the cylindrical wall 6 on the cylindrical chamber 5. The presence of the upper support cables 12 ensures that the extendible spokes are obliged to open (Figure 2c) during the above-mentioned sliding, at the same time deploying the braking shield 3 (Figure lc) .

As is evident from Figure lc, the braking shield 3 has a circular edge of smaller diameter 3a fixed to the cylindrical chamber 5 of the central opening actuator 4 and a circular edge of larger diameter 3b fixed in a discrete manner to the individual ends 8b of the extendible spokes 8. In this way, when deployed (Figure lc) , the braking shield 3 will only rest against the upper support cables 12. In other words, when deployed, the braking shield 3 does not touch the extendible spokes except at their ends to which it is fixed.

It is evident from the foregoing description how the device forming the subject of the present invention enables overcoming the problem regarding landing bodies overheating in an efficacious and, above all, simple manner. The simplicity of the device forming the subject of the present invention also reflects in the low cost of its parts. In fact, the central opening actuator 4 can be made of aluminium, the moving rods 7 and the extendible spokes 8 can be made with a titanium alloy and the braking shield can be made of NEXTEL®. The material with which the braking shield is made is such as to also provide thermal protection for the underlying components.

As may appear immediate to an expert in the field, the braking device forming the subject of the present invention can be applied to any body that requires a braking action during reentry/landing, such as microsatellites for example.

Claims

1. A braking and thermal protection device (1) for landing bodies, characterized in that it comprises a folding braking shield (3) and an articulated frame (2), to which said folding braking shield (3) is fixed; said articulated frame (2) comprising a central opening actuator (4), consisting of an inner fixed portion (5) and an outer mobile portion (6) that can slide around said inner fixed portion (5), a plurality of telescopically extendable spokes (8), each of which is hinged at its first end (8a) to said outer mobile portion (6) and fixed at its second end (8b) to an outer edge (3b) of said folding braking shield (3), and a plurality of support cables (12), each having a first end fixed to said inner fixed portion (5) of the actuator assembly (4) and a second end fixed to said second end (8b) of a respective extendable spoke (8); said braking and thermal protection device (1) being movable between

- a closed configuration, wherein: the spokes (8) are arranged parallel to one another, said outer mobile portion (6) is in a backward position, and the folding braking shield (3) is in a folded position, and

an open configuration, wherein: the spokes (8) are in a mutually radial arrangement, said outer mobile portion (6) is in a forward position, and the folding braking shield (3) is in an unfolded position.

2. A braking and thermal protection device according to claim 1, characterized in that when in said open configuration, said folding braking shield (3) rests against by said support cables ( 12 ) .

3. A braking and thermal protection device according to claim 1 or 2, characterized in that said articulated frame (2) comprises a second plurality of support cables (11), each of which has a first end fixed to said outer mobile portion (5), and a second end fixed to said second end (8b) of a respective extendable spoke (8) .

4. A braking and thermal protection device according to any of the previous claims, characterized in that it comprises a damping assembly (15) comprising a wheel (16) fitted to a rotary damper (17) and coaxial to said outer portion (6), and a plurality of retaining cables (18), each of which is fixed to said wheel (16) so as to be reversibly wound around it and pass through the inside of a respective extendable spoke (8), to which it is fixed at said second end (8b) .

5. A braking and thermal protection device according to claim 4, characterized in that said wheel (16) of said damping assembly (15) is fixed to said inner fixed portion (5) .

6. A braking and thermal protection device according to any of the previous claims, characterized in that said rotary damper (17) is at least partially housed in said inner fixed portion (5) .

7. A braking and thermal protection device according to any of the previous claims, characterized in that said central opening actuator (4) comprises a plurality of telescopic moving rods (7), each consisting of two tubular portions telescopically coupled to each other and fixed to the inner fixed portion (5) and to the outer mobile portion (6), respectively .

8. A braking and thermal protection device according to any of the previous claims, characterized in that each one of said extendable spokes (8) internally comprises a helical spring (10) designed to achieve its telescopic extension.