• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    The subject of the invention is a rotorcraft rotor comprising a hub (2) formed of a monolithic body (14) made of composite materials derived from a stack of successive layers of carbon fiber fabrics powdered with a thermoplastic resin and compressed. hot. The hub (2) is provided with branches (9) on which blades are respectively mounted by means of articulated systems each comprising a frame (12) bearing a radial support against a branch (9) considered. The reinforcements (12) are individually housed in defined manufacturing cavities (13) in accordance with the formation of a radial bearing seat (16) with a cylindrical bearing surface of the reinforcements (12) against the branches (9) under the effect rotating the rotor at a predefined operating speed, said radial support seats then being of complementary shape with a cylindrical bearing surface of the armature (12).
    公开号:FR3031497A1
    申请号:FR1500021
    申请日:2015-01-08
    公开日:2016-07-15
    发明作者:Matthieu Ferrant；Stephane Mazet
    申请人:Airbus Helicopters SAS；
    IPC主号:
    专利说明:

    [0001] The present invention is in the field of rotorcraft and more specifically relates to a rotorcraft rotor having a hub made of composite materials on which a rotorcraft rotor comprising a hub made of composite materials derived from thermoplastic resin-coated carbon fiber fabrics. the blades of the rotary wing of said rotor are mounted. Rotorcraft are rotary wing aircraft having at least one rotor, at least one main rotor having a substantially vertical axis providing at least the lift of the rotorcraft. In the specific context of a helicopter, said at least one main rotor provides not only the lift of the rotorcraft, but also its propulsion in any directions of progression. The flight attitude of the helicopter can also be modified by a pilot of the rotorcraft operating a cyclic and / or collective variation of the pitch of the blades composing the rotary wing of the main rotor. The rotorcraft are also equipped with an anti-torque device providing their guidance in yaw, such as in particular at least one rotor 20 appendix substantially horizontal axis. Such an auxiliary rotor is for example a rear rotor or may be formed of a propeller propeller in the context of a helicopter at high propulsion speeds. The blades of a rotorcraft rotor are conventionally mounted on a hub for their rotational drive. The hub is mounted on a rotating shaft, such as a mast with respect to a main rotor, rotated by a drive unit providing the mechanical power necessary for the operation of the rotorcraft. In addition, the blades are individually mounted to move on the hub at least around a pitch variation axis, in order to allow a pilot of the rotorcraft to vary their pitch at least collectively if not also cyclically to modify the attitude. in flight of the rotorcraft. More particularly with respect to a main rotor, the blades are not only pivotally mounted about their pitch variation axis, but are also commonly mounted movable in drag and beat. More particularly in this case, the blades are movably mounted on the hub not only around their axis of variation of pitch, but also around a beat axis oriented parallel to the general plane of a given blade, or mainly perpendicular to the orientation of the plane of rotation 15 of the hub, and around a drag axis oriented perpendicularly to the general plane of a blade considered, is mainly parallel to the orientation of the axis of rotation of the hub. With regard to the orientations of the beat axis and the drag axis, the main orientations indicated with respect to the orientation of the axis of rotation of the hub are typically to be appreciated in view of the mobility of the blade in its general plan around its different axes of mobility compared to the hub. In this context, the mechanical strength of the hub of a rotorcraft rotor is obviously adapted to the forces that it must withstand in operation. Such forces result in particular not only from the centrifugal force generated by the rotational drive of the rotor, but also from the mobility of the blades on the hub, at least about their axis of variation of pitch, if not also as far as possible. relates to a main rotor about their beat axis and about their drag axis. Traditionally, the hub of a rotorcraft rotor is formed of a piece of metal. However, such a metal structure of the hub tends to give it a large mass that should be limited in the field of aeronautics. In addition, a metal hub must be machined to adequately receive the various bodies providing the hub connection to the rotating shaft on the one hand and the junction mobile blades on the hub on the other hand. It appears that such a metal hub, although satisfactory in terms of its function and in particular its robustness, however, has the disadvantages of being weighed at given volume and expensive to obtain. Such disadvantages may be limited in the specific context of a hub having flexible legs on which the blades are mounted to provide mobility on the hub. Indeed, in this context, it is known to make a rotor hub of a rotorcraft made of composite materials formed by stacking layers of mineral fiber fabrics impregnated with a thermosetting resin. Thus documents EP 2 234 880 (BELL HELICOPTER TEXTRON INC) and US Pat. No. 8,147,198 (BELL HELICOPTER TEXTRON INC) disclose a stirrup made of composite materials forming the hub of a rotorcraft rotor and its method of manufacture. Said stirrup is made from layers of fiberglass cloth impregnated with a thermosetting resin and comprises branches respectively carrying blades. The composite materials from which the stirrup is derived are used to preserve the mobility of the blades in flapping. More particularly, a localized weakening of the branches of the stirrup 30 gives the branches a flapping flexibility. It has also been proposed by document EP 0 221 678 (WESTLAND GROUP PLC), to make the hub of a rotorcraft rotor according to which flexible branches connecting the blades to the hub are formed of a resin in which are embedded in the reinforcing plates from composite materials. The composite materials used to form the flexible branches, or even the entire hub, are more specifically formed from layers of carbon fiber fabrics impregnated with a thermosetting resin.
    [0002] However, the operating conditions of such composite materials for making the hub of a rotorcraft rotor having flexible branches participating in the mobility of the blades on the hub, are limited in particular to light-duty rotorcraft. Indeed, for heavier-weight rotorcraft for which the rotors withstand forces considered to be substantial, the blades are preferably mounted on a robust and rigid hub via an articulated system, such as a ball joint providing multidirectional mobility of the blades on the hub. Such a ball joint is for example made using a body of laminated elastomer incorporating metal blades, commonly referred to as "spherical abutment" or "spherical bearing" in English. Such an elastomer / metal laminate body is integrated with an assembly reinforcement between the hub and the blade root of a blade considered, being placed in abutment against the hub to provide deformation of the blade mobility on the hub. It follows that in such a context of mounting the blades on the hub through an articulated system, the material of the hub traditionally chosen is the metal.
    [0003] Indeed, using composite materials to form such a hub commonly involves having to strengthen the hub against its deformation under operating conditions. Such reinforcement of the hub is commonly performed by a metal belt of the hub having mainly the disadvantage of inducing a heavier hub and to make it more complex to obtain it. In addition the volume of the hub must be increased to provide the desired robust mounting of the blades in relative mobility on the hub through said articulated systems. Such an increase in volume results from a necessary extension of the hub not only in thickness, considered in the direction of axial extension of the hub, but also according to its diameter to give the hub its robustness with respect to the forces 15 it supports in operation and vis-à-vis its terms of junction with the rotating shaft on the one hand and with the blades on the other hand. In this context, the object of the present invention is to propose a rotorcraft rotor comprising a hub made of composite materials, the arrangement of which is suitable for mounting in relative mobility between the blades and the hub by means of articulated systems. . It is more particularly sought such hub composites that can be obtained at lower costs, being in particular of an axial extension as diametric as small as possible, avoiding having to strengthen against its deformation in operation, such as by belting in particular, and restricting as far as possible the machining operations to be performed at the manufacturing output by molding.
    [0004] The composite materials constituting the hub must be chosen not only because of the advantages that can be provided by the manufacturing techniques of such composite materials, but also by seeking ways of using such composite materials to structure at lower cost the hub. In addition, such a desired structuring of the hub must fall within the framework of the previously stated constraints, in particular avoiding its increase. In this context, it is the choice of the present invention to form the hub from composite materials on the one hand from fiber fabric layers selected carbon and on the other hand exploiting a polymer selected from thermoplastic resins. The choice of such composite materials makes it possible to respond to the functions to be provided by the hub and allows clever and specific arrangements of its structure providing solutions within the framework of all the previously identified and stated constraints. In this context, the rotorcraft rotor of the present invention is primarily rotorcraft rotors having a hub made of composite materials from a stack of successive layers of mineral fiber fabrics impregnated with a resin. The hub is coaxially mounted on a rotating shaft providing for the hub to drive in rotation, said rotating shaft extending through a hub shaft. The hub also comprises a plurality of branches radially extended from the shaft, on which blades are respectively individually mounted blades. Said blades are mounted on the hub by being individually movable at least in pitch variation, or alternatively beat and / or drag particularly with respect to a rotorcraft main rotor.
    [0005] According to the present invention, such a hub is part of the known framework according to which the blades are individually movably mounted on the hub via respective hinged systems. Such articulated systems each comprise a mounting frame 5 respectively on each of the branches of the hub. Said armatures take a radial support against said branches being individually housed at least partially in respective cells of a monolithic body extending in its axial extension direction.
    [0006] Taking into account such a frame in which the hub of the present invention fits, it is chosen to essentially form the hub from a monolithic body of composite materials from a stack of successive layers of fiber fabrics. powder-coated carbon of a thermoplastic resin, advantageously exploiting the technique of hot pressing at high pressure of said layers to compress them. Such composite materials make it possible to form the monolithic body from a manufacturing process according to which the carbon fibers integrated in the fabric layers are powdered with said thermoplastic resin, such as PEEK (according to the acronym of PolyEtherEtherKetone). ), which facilitates during the manufacture of the monolithic body the manipulation of the tissue layers then deemed non-sticky. Such easy handling is particularly useful insofar as obtaining said monolithic body 25 requires a stack of a large number of layers, indicatively between 200 and 400. In addition, the composite materials chosen to obtain said monolithic body by compression of said tissue layers at a pressure of the order of 60 bar and a temperature of the order of 400 ° C.
    [0007] The monolithic body obtained is of a robustness able to withstand the forces to which the hub is subjected during operation. In addition, the composite materials chosen make it possible to solve at lower cost the problems posed by the operation of a hub made of composite materials in the context of mounting the blades on the hub via an independent articulated system. reported on the hub. In addition, it has been found that the composite materials chosen according to the present invention make it possible to form, by molding in the monolithic body, said cells respectively receiving the reinforcements of said articulated systems. It is indeed found that the conformation of such cells can be obtained directly from molding without requiring subsequent and expensive machining operations to form a support engagement 15 adapted blades against the hub. It should also be noted that the thermoplastic resin, PEEK resin in particular, chosen in accordance with the present invention for impregnating the fabrics forming the composite materials from which the hub is derived, has higher mechanical strength characteristics than thermosetting resins, especially epoxy resin. , traditionally used to form a hub made of composite materials. In addition, such a thermoplastic resin has no solvent, with the advantage of being recyclable and best meet the requirements of preservation of the natural environment. However, the choice of such composite materials constituting the monolithic body must take into account the problem specific to the formation of a composite rotorcraft rotor hub, according to which the hub subjected to the centrifugal force generated by the rotor drive. tends to deform.
    [0008] In such a context taking into account a deformation of the cells under the effect of the rotation of the rotor, the conformation of the cells is defined manufacturing in accordance with the formation of a cylindrical abutment bearing cylindrical bearing surfaces. armatures against the branches under the effect of rotating the rotor at a predefined operating speed. Said cylindrical scope is defined in particular by a base oriented orthogonally to the radial direction of support of the armatures against the branches, generally arcuate conformation such as for example indifferently shaped arc or elliptical arc. Said radial bearing seat cylindrical range extends in particular along a generatrix oriented in the direction of axial extension of the hub being of complementary shape with a cylindrical bearing surface surface of the armature. Of course, the notion of "manufacturing" means taking into consideration the state of the monolithic body as manufactured, that is to say out of context of its placing under stress as a result of its operation in operation aboard the rotorcraft and in particular as a result of rotating the rotor and / or moving the blades on the hub. It emerges that in order to obviate the deformation of said cells under the effect of the centrifugal force applied to the hub in operation, the manufacturing configuration of the cells advantageously takes into account such deformation of the cells in order to protect the said surface against the cell. 'support, unusually cylindrical scope. Such a cylindrical surface of said bearing surface provides a robust radial support of the armature against the cell when the rotor 30 is in the operating phase.
    [0009] Thanks to these arrangements, the radial extension of the branches can then be advantageously reduced without affecting the maintaining robust mobility of the blades and without having to strengthen the conformation of the hub, such as according to the known technique of s selt metal of the hub avoiding its deformation in operation but having the disadvantage of being heavy. Moreover, it is then possible to make the choice to gradually reduce the thickness of the hub from its axial zone of junction with the rotating shaft towards its periphery, in order to reduce at best its mass and its bulk while maintaining a robust maintenance of the blades on the hub. Indeed, wedges can be easily reported to compensate for the slope of the end faces of the hub against which in particular supports the armature. Indeed, the reversible nature of the polymerization of the thermoplastic resin can be exploited to integrate such wedges with the monolithic body by molding and more particularly by overmolding. According to an embodiment promoting the passage of the conformation of the manufacturing cells to the conformation of the cells in the operating phase of the rotor, the profile of the cells in the diametral plane of the hub is of oblong general conformation, the smallest dimension d such an oblong conformation extending in particular in the direction of radial extension of the monolithic body.
    [0010] Such an oblong general conformation of the profile of the cells is in particular conferred on the cells from a conformation of their profile in the diametral plane of the hub defined by a plurality of successively tangential circular arcs, at least four in particular, two successive arcs of circle having different radii of curvature.
    [0011] Such a profile of the cells defines in the diametral plane of the hub a circular arc forming the surface portions of the cells forming said radial support seats reinforcements against the branches. A first radius of said defined machining arc is larger than a second radius imparted to said arc of a circle under the effect of rotating the rotor at said predefined operating speed, said second radius defining in operating condition rotor said radial bearing seat cylindrical bearing armatures against the branches.
    [0012] By way of indication for defining the first radius of said defined manufacturing arc, it is verified in particular that, in the rotor operating situation, the pressure exerted between the monolithic body and the armature is less than a permissible pressure, for example example defined by tests on specimens. It has been found that the cylindrical bearing surface of said radial support pad advantageously makes it possible to optimize the distribution of said pressure. Indeed, when the rotor stops, the radius of the part of the armature taking radial support against the branches is smaller than the radius of the arc of the cell defining manufacturing said radial support seat cylindrical range of the armature against the branches. Under the effect of the centrifugal force produced by the rotation of the rotor, the hub is deformed and the radius of the arc of the cell decreases to match then the radius of the cylindrical bearing surface of the barrel. armature against the branches, providing the desired pressure distribution. To reinforce the axial extent of the cylindrical bearing surface of the radial bearing of the reinforcements against the branches, it is alternatively proposed to exempt the monolithic body from demolding bodies along the surface portions of the cells 30 forming the bases of the radial support of the armatures against the branches.
    [0013] The bodies required for demolding the monolithic body are then formed on the surface portions of the cells complementary to the surface portions of the cells forming said radial support seats reinforcements against the branches. The monolithic body of the present invention is adapted to be operated in the known frame according to which said frames are each equipped with a laminated elastomer / metal body providing a multidirectional mobility of the blades on the hub. Such reinforcements are typically respectively placed in radial support against the branches. In this case, it is proposed to unusually conform the bearing surface of the reinforcements against the cylindrical surface surface branches defined by a generatrix oriented in the axial direction of extension of the hub. In the preferred case where at least one of the axial end faces of said monolithic body is at least partially inclined relative to the plane of rotation of the hub, the monolithic body is advantageously provided with shims as previously referred to. Such wedges are wedges for compensation of the slope resulting from the inclination of said at least one axial end face of the monolithic body, said wedges providing on the hub axial support seats reinforcements armatures against the branches. As previously referred to, the thermoplastic resin is used to integrally mold said shims to the monolithic body, avoiding having to damage the monolithic body by the use of fasteners, such as by screwing for example , to provide mounting on the monolithic body compensation wedges a slope imparted to its axial end faces.
    [0014] More particularly, the shims are advantageously integrated into the monolithic body by overmoulding, the shims being advantageously derived from composite materials incorporating mineral fibers, such as glass and / or carbon fibers for example, embedded in a thermoplastic resin. According to various variants, the shims can be formed from composite materials. These composite materials may be formed by stacking layers of mineral fiber fabrics embedded in a thermoplastic resin or may be formed from an agglomerate of mineral fibers embedded in a thermoplastic resin. In the case in particular of a main rotor, the blades are capable of being further mounted movably dragging on the hub at least around a drag axis. In this case, the peripheral end faces 15 of the branches are preferably each provided with a protective member, such as a protective member formed of a wear part or even formed of a limiting abutment member. the individual race in drag of the blades. To reinforce the mounting of such protective members, they are preferably each equipped with fixing lugs respectively bearing against the axial end faces of the monolithic body. Such fixing lugs, for example each arranged in a stirrup bearing against one and the other of the axial end faces of the monolithic body, can be fixed to the peripheral end of the branches by first fasteners, such as for example screws or bolts, respectively extending through first passages in the monolithic body in its axial direction of extension.
    [0015] It should be taken into account that the composite materials chosen to form the hub advantageously make it possible to conform the monolithic body according to the following provisions, considered alone or in combination: 5 -) said monolithic body is of a gradually decreasing thickness since a axially central zone, in which is formed at least the barrel, to the outer edge of a peripheral zone of the monolithic body integrating the branches. Such a conformation of the hub gives it a suitable robustness without weakening the connection in relative mobility between the blades and the hub. -) said monolithic body is symmetrical on either side of an axially central diametral plane, which avoids irregular distortions of shape of the hub in operation. -) the branches are projecting towards the periphery of the monolithic body 15, the projecting parts of the branches being of a dimension of radial extension advantageously reduced, as an indication between 0.2 and 0.3 times the overall size of the monolithic body. In this context and considering a given branch, the separation distance between the peripheral end of the branches and the radial support base of the armatures against the branches is reduced, being indicative of the order between 0, 1 and 0.15 times the clutter diameter of the monolithic body. Such provisions relating to the reduced radial extension of the projecting parts of the branches, allow the branches to be reinforced against their deformation while limiting the diametral size and the mass of the hub. The limitation of the radial extension of the branches also makes it possible to reduce the extension, radially at the hub, of the blade roots through which the blades are mounted on the limbs of the hub, with the advantage of reinforcing the robustness of the blade. mounting the blades on the hub.
    [0016] It will be noted that such compactness of the monolithic body obtained by limiting the radial extension of the branches is made possible by the aforementioned consideration of the deformation of the cells during the rotation of the hub.
    [0017] More particularly according to a specific embodiment of the hub, said monolithic body comprises: -) said axially central zone of a constant thickness in which are formed at least the barrel and second passages oriented in the axial direction of extension of the hub by being distributed around the curb. Said second passages receive second fastening members, such as for example formed of screws or bolts, fixing the hub to at least one plate of the rotating shaft disposed opposite one of the faces of axial end of the hub. 15 -) said peripheral zone formed in radial extension of said central zone progressively decreasing in thickness towards its periphery from the thickness of said axially central zone. Said peripheral zone comprises at least partly each of said respective receiving cavities of the armatures and third passages oriented in the direction of axial extension of the hub. Such third passages receive third fasteners, such as screws or bolts for example, fixing the armatures to the hub. Such third passages are formed in particular by passing, if appropriate, said wedges 25 against which the reinforcements axially bear. More particularly, the cells are preferably formed in a first portion in said axially central zone and in a second portion in said peripheral zone of the monolithic body.
    [0018] In this context, said second portion then comprises the surface portions of the cells forming said radial support seats reinforcements against the branches, being specified if necessary that the radial support taken by the armatures against the branches is oriented 5 to the periphery of the hub. The choice of composite materials forming the monolithic body, and alternatively its preferred manufacturing methods previously referred to, make possible an arrangement of the hub according to which: the thickness of the monolithic body considered at its periphery is of the order of between % and 40% of the thickness of the monolithic body considered in its axially central zone, and -) the overall size of the monolithic body is of the order between 6 and 10 times the thickness of the monolithic body 15 considered in said axially central zone. It should be noted that as a result of the molding conditions of the monolithic body from the composite materials chosen and the secondary arrangements proposed by the invention, considered alone or in combination, the machining operations carried out on the monolithic body after its molding can be significantly limited. Indeed, such machining operations can be restricted to the machining of molding reserves through the thickness of the monolithic body, such reserves forming said first passages, said second passages and / or said third passages. As a result of their machining, said reserves can then be advantageously provided with reinforcement rings reported and integrated into the monolithic body, particularly by sealing.
    [0019] Alternatively, said machining operations may be restricted to machining the inner recess of such reinforcement rings previously installed within said reserves. In this case, the reinforcing rings can advantageously be integrated into the monolithic body by overmoulding by exploiting the reversible nature of the polymerization of the thermoplastic resin. Such reserves are notably formed in conjunction with the eventual formation of the cells, by exploiting in particular the technique of stacking thermoplastic resin powdered carbon fiber cloth layers on cores respectively sparing said reserves and / or cells through the monolithic body. . As a result, the reversible nature of the polymerization of the thermoplastic resin is thus potentially exploited to provide said reinforcing rings with either said first passages and / or said second passages and / or said third passages, said reinforcing rings being advantageously integrated into the monolithic body by overmolding.
    [0020] Furthermore, said second passages open in particular to one and the other of the axial end faces of the hub, the second fasteners preferably extending through the hub and potentially cooperating with a pair of plates of the hub. Turning shaft disposed respectively opposite each other of the axial end faces of the hub to increase the strength of the junction of the hub with the rotating shaft. An exemplary embodiment of the present invention will be described with reference to the figures of the accompanying drawings, in which: FIG. 1 is a perspective illustration of a rotorcraft rotor according to an exemplary embodiment of the present invention FIGS. 2 and 3 are illustrations of an exemplary embodiment of a monolithic body essentially forming a hub of the rotor shown in FIG. 1, respectively in perspective and in axial section, FIG. 4 is composed of two diagrams (a) and (b) partially illustrating in its general plane the monolithic body shown in fig.2 and fig.3. In FIG. 1, a rotorcraft rotor comprises blades 1 (only one partially illustrated blade) mounted on a hub 2. For its driving in rotation, the hub 2 is mounted on a coaxial rotating shaft 3 extending through a shaft 4 of the hub. Such a rotating shaft 3 comprises in particular a mast in the illustrated case of a main rotor of a rotorcraft. For this purpose, the hub 2 comprises second passages 5 formed around and at the edge of the barrel 4 for the reception of second fastening members 6, such as screws or bolts, providing the fixing of the hub 2 to at least one plate 7 of the rotating shaft 3. The blades 1 are movably mounted on the hub 2 at least in step variation, or even in drag and beat as in the illustrated embodiment. For this purpose, the blades 1 are conventionally each provided with a blade root 8 for their assembly on respective branches 9 of the hub 2. According to a current embodiment, the mobility of the blades 1 on the hub 2 is provided by through an articulated system 10 interposed between a given blade root 8 and the hub 2.
    [0021] In the exemplary embodiment illustrated in FIGS. 1 and 4, such an articulated system 10 is of the type employing an elastomer / metal 11 laminate body incorporating metal blades and elastomer layers, commonly referred to as a "spherical stop". The laminated elastomer / metal body 11 is integrated with an armature 12 through which the articulated system 10 is mounted interposed between a given blade root 8 and the hub 2. For this purpose, the hub 2 comprises cells 13 respectively housing the armatures 12. A given armature 12 connects by bolting a blade root 8 to the hub 2, by axially bearing against the axial end faces of the hub 2. As illustrated in FIG. armature 12 is for example of the type comprising at least one said elastomer / metal laminated body 11 interposed between two reinforcing elements 12 ', 12 ". The laminated elastomer / metal body 11 is compressed between the reinforcing elements 12 ', 12 ", an externally qualified reinforcing member 12" radially bearing against the branches 9. As a result, the laminated elastomer / metal body 11, radially bearing against the hub 2 via the element armature 12 "outside, 20 provides by deformation a relative mobility between the hub 2 and the blade root 8. Note now that the concept of" axial ", and therefore the concepts of" diametral "and / or" radial " ", Are to be considered along the axis of rotation A of the hub 2. In this context, it is understood that the thickness of the hub 2 is considered in its direction of axial extension. The hub 2 essentially consists of a monolithic body 14 formed by molding a stack of layers of fabrics of carbon fibers powdered with a thermoplastic resin, said layers of fabrics being stacked inside a mold and then being hot compressed at high pressures.
    [0022] In fig.1, fig.2 and fig.3, the monolithic body 14 comprises an axially central zone 15 in which are formed the barrel 4 and said second passages 5. Said axially central zone 15 is diametrically extended by a zone peripheral device comprising at least partially the branches 9. More particularly visible in FIG. 3, the monolithic body 14 is symmetrical on both sides of an axially medial diametrical plane P. The axially central zone 15 of the monolithic body 4 is of a constant thickness El favoring the bearing of the hub against the plate or plates fitted to the rotating shaft. The peripheral zone of the monolithic body has a thickness E2 progressively decreasing towards its periphery from the axially central zone 15. The thickness E2 of the monolithic body 14 considered at its periphery is of the order of 30% to 40% of its volume. thickness E1 considered in its axially central zone 15. More particularly visible in FIG. 3, the overall diameter D of the monolithic body 14 is of the order of eight times its thickness E1 considered in the axially median zone 15. Moreover, in FIGS. 1 to 4, the cells 13 provide a radial support seat 16 with a cylindrical bearing surface of the reinforcements 12 against the branches 9, in particular by means of the elastomer / metal 11 laminated bodies of which they are equipped . As illustrated in FIG. 1, the dimension d1 of radial extension of the projections 26 of the branches 9 towards the periphery of the monolithic body 14 is of the order of 0.2 to 0.3 times the diameter of the space D of the monolithic body 14, for a separation distance d2 between the peripheral end of the branches 9 and the radial support base 16 of the armatures 12 against the branches 9 of the order included, for a given branch 9, between 0.1 and 0.15 times the overall diameter D of the monolithic body 14.
    [0023] As illustrated in FIG. 2, the cells 13 are of generally oblong conformation by defining a circular arc CA providing the surface portions of the cells 13 forming said radial support seats 16 of the frames 12 against the branches 9. .
    [0024] However, as illustrated in FIG. 4, the cells 13 tend to deform under the effect of the centrifugal force during the rotation of the rotor. More particularly in the diagram (a) the monolithic body 14 is shown stationary station of the hub and in the diagram (b) the monolithic body 14 is shown in a rotating position of the hub. As a result of the deformation of the cells 13, the defined initial radius of manufacture of said arc of circle, as illustrated in the diagram (a), tends to be reduced to match the radius of the surface of the armature 12 taking radially support against branches 9, as shown in diagram (b).
    [0025] In this context, a first radius R1 of said arc AC is defined larger than a second radius R2 of said circular arc AC identified under conditions of rotation of the rotor at its nominal operating speed. Said first radius R1 of the arc of circle AC is identified, in particular by tests, according to a deformation of the cells 13 conferring on said arc of circle AC the second radius R2 equal, at least substantially, to the radius of the cylindrical surface of support of the elastomer / metal laminated bodies 11 against the branches 9 via the armature 12.
    [0026] Moreover, as particularly visible in FIGS. 1 and 2, it appears that, in order to optimize the support surfaces of the armatures 12 against the branches 9, both radially and axially, it is proposed to exempt from spoils the surface portions of the cells 13 respectively defining said radial support seats 16 of the frames 12 against the branches 9.
    [0027] As particularly visible in FIG. 3, the end faces of the monolithic body 14 are preferably inclined, as previously referred to, to reduce the thickness of the branches 9 at the periphery of the hub.
    [0028] In this context and as shown in Fig.1 to Fig.4, the axial end faces of the monolithic body 14 are provided with wedges 17 to compensate for their slope to strengthen the axial seat taken by the frames 12 against the hub 2. Such wedges 17 are derived from composite materials incorporating a thermoplastic resin for implanting wedges 17 by integration with the monolithic body 14, during a molding operation in particular. In FIGS. 1 to 3, the monolithic body 14 has third passages 18 formed axially through the monolithic body 14 while passing through the wedges 17. Third fasteners 19, as arranged in bolts, extend through the third passages 18 to fix the reinforcements 12 on the monolithic body 14, by means of said outer frame members 12 "connecting the blade roots 8 to the hub 2.
    [0029] The blades are further movably mounted on the hub. In this context, the peripheral end faces of the branches 9 are provided with protection members 20, such as consisting of wear parts and / or stop members limiting the drag stroke of the blades. Such protection members 20 comprise, for example, fastening tabs 21 respectively bearing against the axial end faces of the monolithic body 14.
    [0030] The protective members 20 are fixed to the monolithic body 14 by first fixing members 22, such as bolts for example, extending through first passages 23 formed through the branches 9 at the edge of their periphery according to the 5 direction of axial extension of the hub. Adjacent shims 24 are potentially interposed between the fastening lugs 21 and the axial end faces of the monolithic body 14, to compensate for the slope of the axial end faces of the branches 9. Such auxiliary shims 24 are potentially integrated with the molding. monolithic body 14, and more particularly by overmoulding, by integrating a thermoplastic resin such as for wedges 17 against which the armatures 12 axially bear against the monolithic body 14.
    [0031] The additional shims 24 may for example still each be formed of a flexible mass, in particular elastomer, more or less compressed by the first fastening members 22 during the installation of the protection members 20 on the branches 9. Such Flexible masses are potentially integrated in the monolithic body 14 and / or the protective member 20. The different passages 5, 18, 23 are formed by providing reserves in the monolithic body 14 during its molding and by housing rings of reinforcement inside said reserves, such as reinforcement rings similar to the reinforcement rings 27 illustrated in diagrams (a) and (b) of FIG. 4 and housed inside the third passages 18. The operations machining of the monolithic body 14 are then potentially limited to the machining of said reserves prior to the installation by sealing reinforcing rings such as 27 inside the reserves.
    [0032] According to an advantageous variant, the reinforcing rings such as 27 are potentially integrated into the hub by overmoulding and the machining operations of the monolithic body 14 are then potentially limited to the machining of the internal recess of said reinforcement rings such as 27. There will also be noted in FIG. 2 the presence of a polarizer 25 allowing an operator to mount the hub 2 on the rotor in a predefined orientation of its end axial faces facing the fixing plate or plates. 7 equipping the rotating shaft 3. 10
    权利要求:
    Claims (18)
    [0001]
    REVENDICATIONS1. Rotorcraft rotor comprising a hub (2) made of composite materials resulting from a stack of successive layers of mineral fiber fabrics impregnated with a resin, the hub (2) being coaxially mounted on a rotating shaft (3). ) extending through a shaft (4) of the hub (2) and on the other hand having a plurality of branches (9) radially extended from the shaft (4), on which branches (9) are respectively individually mounted blades (1), said blades (1) being mounted individually movable on the hub at least in pitch variation, characterized in that the hub (2) is essentially formed of a monolithic body (14) made of composite materials from a stack of successive layers of carbon fiber fabrics powdered with a thermoplastic resin and hot-compressed, in that the blades (1) are individually mounted to move on the hub (2) via articulated systems ( 10) respective each of them having a mounting armature (12) respectively on each of the branches (9), said armatures (12) taking radial abutment against the limbs (9) being individually housed at least partially in respective cells (13) of the body monolithic (14) extending in its axial direction of extension, and in that said cells (13) being deformable under the effect of the rotation of the rotor, the conformation of the cells (13) is defined manufacturing in accordance with the formation of a radial bearing seat (16) with a cylindrical bearing surface of the reinforcements (12) against the branches (9) under the effect of the rotation of the rotor at a predefined operating speed, said seat of radial support (16) to a cylindrical bearing extending along a generatrix oriented in the direction of axial extension of the hub (2) and being of complementary shape with a given cylindrical surface area of the armature (12).
    [0002]
    2. rotorcraft rotor according to claim 1, characterized in that the profile of the cells (13) in the diametral plane of the hub (2) is of generally oblong configuration defining a circular arc (AC) leaving the surface portions of the cells (13) forming said radial support seats (16) of the reinforcements (12) against the branches (9), and in that a first radius (R1) of said defined manufacturing arc (AC) is larger a second radius (R2) imparted to said arc of circle (AC) under the effect of the rotation of the rotor at said predetermined operating speed, said second radius (R2) defining in operating situation of the rotor said seat radial bearing (16) with a cylindrical bearing surface of the reinforcements (12) against the branches (9).
    [0003]
    3. rotorcraft rotor according to any one of claims 1 and 2, characterized in that the surface portions of the cells (13) forming the radial support seats (16) of the armatures (12) against the branches (9). ) are free from demolding bodies of the monolithic body (14). 25
    [0004]
    4. rotorcraft rotor according to any one of claims 1 to 3, characterized in that the armatures (12) each being equipped with an elastomer / metal laminate body (11) providing a multidirectional mobility of the blades (1). ) on the hub (2), the armatures (12) are respectively placed in radial support against the branches (9) along a cylindrical bearing surface defined by a generatrix oriented in the axial direction of extension of the hub (2).
    [0005]
    5. Rotorcraft rotor according to any one of claims 1 to 4, characterized in that at least one of the axial end faces of said monolithic body (14) is at least partially inclined relative to the hub plane of rotation. (2), the monolithic body (14) is provided with wedges (17) for compensation of the slope resulting from the inclination of the at least one axial end face of the monolithic body (14), said wedges (17) on the hub (2) axial support seats reinforcements (12) against the branches (9).
    [0006]
    6. rotorcraft rotor according to claim 5, characterized in that said shims (17) are integrally molded to the monolithic body (14).
    [0007]
    7. rotorcraft rotor according to claim 6, characterized in that the wedges (17) are more particularly integrated into the monolithic body (14) by overmoulding, the wedges (17) 20 being derived from composite materials incorporating mineral fibers embedded in a thermoplastic resin.
    [0008]
    8. rotorcraft rotor according to any one of claims 1 to 7, characterized in that the blades (1) being further mounted movably 25 drag on the hub (2), the peripheral end faces of the legs (9). ) are each provided with a protective member (20).
    [0009]
    9. rotorcraft rotor according to claim 8, characterized in that said protective member (20) is formed indifferently of a wear part and / or an abutment member limiting the individual stroke in drag blades (1).
    [0010]
    10. rotorcraft rotor according to any one of claims 8 and 9, characterized in that said protective members (20) are each provided with fastening lugs (21) respectively bearing against the axial end faces of the body monolithic (14) and being fixed to the peripheral end of the branches (9) by first fasteners (22) extending respectively through first passages (23) formed in the monolithic body (14) in its axial direction extension.
    [0011]
    11. rotorcraft rotor according to any one of claims 1 to 10, characterized in that said monolithic body (14) is of a gradually decreasing thickness from an axially central zone (15), in which is provided at least the bole (4), towards the outer edge of a peripheral zone of the monolithic body (14) integrating the branches (9).
    [0012]
    12. rotorcraft rotor according to any one of claims 1 to 11, characterized in that said monolithic body (14) is symmetrical on either side of an axially median diametral plane (P).
    [0013]
    13. rotorcraft rotor according to any one of claims 1 to 12, characterized in that the branches (9) protruding towards the periphery of the monolithic body (14), the protruding parts (26) of the branches (9) are of a dimension (dl) of radial extension between 0.2 and 0.3 times the overall diameter (D) of the monolithic body (14) and, considering a given branch (9), the distance ( d2) between the peripheral end of the branches (9) and the radial bearing seat (16) of the reinforcements (12) against the branches (9) is between 0.1 and 0.15 times the diameter of space (D) of the monolithic body (14).
    [0014]
    14. rotorcraft rotor according to any one of claims 11 to 13, characterized in that said monolithic body (14) comprises: 10 -) said axially central zone (15) of constant thickness (E1) in which are provided at least the barrel (4) and second passages (5) oriented in the axial direction of extension of the hub (2) being distributed in an edge around the barrel (4), said second passages (5) receiving second bodies fixing device (6) fixing the hub (2) to at least one plate (7) of the rotating shaft (3) arranged opposite any axial end faces of the hub (2) , -) said peripheral zone formed in radial extension of said axially central zone (15) gradually decreasing in thickness (E2) towards its periphery from the thickness (E1) of said axially central zone, said peripheral zone comprising at least each of said receiving cells (13) respecti armatures (12) and third passages (18) oriented in the direction of axial extension of the hub (2), said third passages (18) receiving third fasteners (24) securing the reinforcements (12) to the hub (2).
    [0015]
    15. rotorcraft rotor according to any one of claims 12 to 14, 3031497 characterized in that the thickness (E2) of the monolithic body (14) considered at its periphery is of the order of between 30% and 40% the thickness (E1) of the monolithic body (14) considered in its axially central zone (15), and in that the overall diameter (D) of the monolithic body (14) is of the order of between 6 and 10 times the thickness (El) of the monolithic body (14) considered in said axially central zone (15). 10
    [0016]
    16. rotorcraft rotor according to any one of claims 10 to 15, characterized in that indifferently said first passages (23) and / or said second passages (5) and / or said third passages (18) are each provided with reinforcing rings (27). 15
    [0017]
    17. rotorcraft rotor according to claim 16, characterized in that said reinforcing rings (27) are integrated into the monolithic body (14) by sealing.
    [0018]
    Rotorcraft rotor according to claim 16, characterized in that said reinforcing rings (27) are integrated into the monolithic body (14) by overmolding.
    类似技术:
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    EP2930308B1|2021-07-28|Faceted axial turbomachine housing
    FR2639021A1|1990-05-18|METHOD FOR MANUFACTURING A PROPULSIVE FIN FROM A COMPOSITE MATERIAL OR MULTIPLE COMPOSITE LAYERS, FOR MAINTAINING STRUCTURAL INTEGRITY AND FOR BALANCING THE SAID FIN
    CA1332053C|1994-09-20|Integrated rotor mast and rotary-wing aircraft rotor head comporting same
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    同族专利:
    公开号 | 公开日
    EP3042851B1|2017-06-07|
    US10118694B2|2018-11-06|
    CN105775107B|2018-01-12|
    EP3042851A1|2016-07-13|
    US20160200433A1|2016-07-14|
    FR3031497B1|2017-01-06|
    KR101809700B1|2017-12-15|
    CN105775107A|2016-07-20|
    KR20160085715A|2016-07-18|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    GB2092541A|1981-02-05|1982-08-18|Agusta Aeronaut Costr|A composite hub for a helicopter rotor|
    EP0120803A2|1983-03-22|1984-10-03|United Technologies Corporation|A fiber reinforced/epoxy matrix composite helicopter rotor main hub plate|
    EP0340095A1|1988-04-29|1989-11-02|AEROSPATIALE Société Nationale Industrielle|Rotor head having elastic, internally damped return devices between the blades|
    FR2653405A1|1989-10-20|1991-04-26|Aerospatiale|ROTARY VISCO-ELASTIC DEVICE FOR ELASTIC RECALL AND TRAINING DAMPING FOR ROTOR BLADE OF ROTOR OF ROTOR, AND ROTOR HEAD COMPRISING SAME|
    US5478204A|1991-08-02|1995-12-26|The Boeing Company|Ducted fan and pitch controls for tail rotor of rotary wing aircraft|
    EP0221678B1|1985-10-15|1990-03-07|Westland Group plc|Helicopter rotor|
    US4818179A|1987-07-30|1989-04-04|United Technologies Corporation|Composite helicopter rotor hub|
    CN101583535B|2006-01-13|2013-11-06|贝尔直升机泰克斯特龙公司|Stiff-in-plane gimbaled tiltrotor hub|
    CA2637461C|2006-02-24|2011-04-19|Bell Helicopter Textron Inc.|Helicopter rotor yoke and method of making same|
    CA2712638C|2008-01-31|2015-05-12|Bell Helicopter Textron Inc.|Method of making a rotor yoke and rotor yoke thereof|EP3281869B1|2016-08-11|2019-04-17|AIRBUS HELICOPTERS DEUTSCHLAND GmbH|A control system for controlling at least collective pitch of rotor blades of a multi-blade rotor in a rotary-wing aircraft|
    CN106379523B|2016-09-28|2019-05-31|深圳智航无人机有限公司|A kind of modular transport unmanned plane|
    US10556676B2|2018-01-29|2020-02-11|Bell Helicopter Textron Inc.|Hybrid yoke|
    US10543913B2|2018-01-29|2020-01-28|Bell Helicopter Textron Inc.|Tri-hybrid yoke|
    法律状态:
    2016-01-21| PLFP| Fee payment|Year of fee payment: 2 |
    2016-07-15| PLSC| Publication of the preliminary search report|Effective date: 20160715 |
    2017-01-20| PLFP| Fee payment|Year of fee payment: 3 |
    2018-01-19| PLFP| Fee payment|Year of fee payment: 4 |
    2019-09-27| ST| Notification of lapse|Effective date: 20190906 |
    优先权:
    申请号 | 申请日 | 专利标题
    FR1500021A|FR3031497B1|2015-01-08|2015-01-08|ROTOR OF GIRAVION COMPRISING A HUB IN COMPOSITE MATERIALS FROM CARBON FIBER TISSUES POWDERED WITH A THERMOPLASTIC RESIN|FR1500021A| FR3031497B1|2015-01-08|2015-01-08|ROTOR OF GIRAVION COMPRISING A HUB IN COMPOSITE MATERIALS FROM CARBON FIBER TISSUES POWDERED WITH A THERMOPLASTIC RESIN|
    EP15200898.3A| EP3042851B1|2015-01-08|2015-12-17|A rotorcraft rotor comprising a hub made of composite materials obtained from carbon fiber fabric dusted with a thermoplastic resin|
    US14/989,142| US10118694B2|2015-01-08|2016-01-06|Rotorcraft rotor comprising a hub made of composite materials obtained from carbon fiber fabric dusted in a thermoplastic resin|
    KR1020160002112A| KR101809700B1|2015-01-08|2016-01-07|A rotorcraft rotor comprising a hub made of composite materials obtained from carbon fiber fabric dusted in a thermoplastic resin|
    CN201610010031.4A| CN105775107B|2015-01-08|2016-01-08|Rotary-wing aircraft rotor with hub made of composite|
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