Resonator, and an aircraft provided with the resonator

Abstract

A resonator provided with a heavy member comprising a casing fastened a spring blade. The heavy member comprises a set of masses that is movable in translation in said casing along a longitudinal direction. A wormscrew driven by drive means is engaged in a slider nut of said set of masses. The set of masses comprises two masses that are slidable respectively in two cylindrical spaces of the casing. Each mass presents at least two presser means interposed between the mass and the casing, each presser means comprising a groove formed in a circumference of a mass, each presser means comprising at least one resilient member arranged in said groove and a split ring pressed against the casing by said at least one resilient member of the presser means.

Claims

1. A resonator having a heavy member and a spring blade, the heavy member comprising a casing fastened to the spring blade, the heavy member further comprising a set of masses that is movable in translation inside the casing along a longitudinal direction, the resonator including a wormscrew engaged in a slider nut of the set of masses, the resonator including drive means suitable for driving the wormscrew in rotation so that rotation of the wormscrew drives the movement in translation, wherein the casing presents an inside face defining in part at least two cylindrical spaces each presenting a generator line parallel to the longitudinal direction, the two cylindrical spaces being arranged outside a central space, the wormscrew being arranged in the central space, the set of masses comprising two masses slidable respectively in the two cylindrical spaces, the set of masses including a support carrying the slider nut, each mass comprising at least one heavy element fastened to the support, each mass presenting at least two presser means interposed between the mass and the inside face, each presser means comprising a groove formed in a circumference of a mass and contained in a plane perpendicular to the longitudinal direction, each groove describing a closed curve, each presser means comprising at least one resilient member arranged in the groove and a split ring pressed against the inside face by the at least one resilient member of the presser means, the split ring projecting in part from the groove.

2. The resonator according to claim 1, wherein the two masses are identical and arranged transversely in symmetrical manner on either side of a plane of symmetry containing the longitudinal direction.

3. The resonator according to claim 1, wherein at least one presser means comprises two resilient members exerting force on a single split ring.

4. The resonator according to claim 1, wherein at least one split ring extends between two ends that are circumferentially separated by a slot, the slot extending in a direction that is not parallel to the longitudinal direction.

5. The resonator according to claim 1, wherein the support includes a central portion carrying the slider nut and two side branches extending transversely on either side of the central portion, the two masses being fastened respectively to the two side branches.

6. The resonator according to claim 5, wherein the central portion extends transversely between two side faces, the two side faces respectively facing the two masses, each presser means of a mass being arranged facing a side face, each side face defining part of one of the cylindrical spaces.

7. The resonator according to claim 1, wherein at least one cylindrical space is in the shape of a cylinder of circular base.

8. The resonator according to claim 1, wherein at least one mass comprises two distinct heavy elements, the two heavy elements being fastened longitudinally on either side of a side branch of the support, each heavy element carrying respective presser means.

9. The resonator according to claim 8, wherein the two heavy elements are identical.

10. The resonator according to claim 8, wherein the two heavy elements are different, the two heavy elements extending longitudinally over two respective distances that are different.

11. The resonator according to claim 1, wherein the casing is made out of a material presenting density that is less than the density of a material forming the set of masses.

12. The resonator according to claim 1, wherein at least one resilient member is a gasket constrained by the groove to exert a force in radial directions against the corresponding split ring.

13. The resonator according to claim 12, wherein the groove presents an inner space containing the gasket, the inner space extending longitudinally over a groove length and radially over a groove depth, the gasket extending longitudinally over a gasket length and radially over a gasket thickness, and the gasket thickness is greater than the groove depth.

14. The resonator according to claim 1, wherein the groove presents an inner space containing the gasket, the inner space extending longitudinally over a groove length and radially over a groove depth, the gasket extending longitudinally over a gasket length and radially over a gasket thickness, and the gasket length at rest is less than the groove length.

15. The resonator according to claim 1, wherein the inside face is covered in lubricant.

16. The resonator according to claim 1, wherein the groove presents an inner space containing the gasket and an outer space, the outer space surrounding the inner space and containing the split ring in part, the inner space extending longitudinally along an inner length that is less than an outer length along which the outer space extends.

17. An aircraft, wherein the aircraft includes the resonator according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention and its advantages appear in greater detail from the context of the following description of embodiments given by way of illustration and with reference to the accompanying figures, in which:

(2) FIG. 1 is a diagram showing a resonator of the invention arranged on an aircraft;

(3) FIG. 2 is a diagram showing a heavy member of a resonator of the invention;

(4) FIG. 3 is an exploded view showing a set of masses of the heavy member;

(5) FIG. 4 is a section view through the set of masses;

(6) FIG. 5 is a side view showing a beveled split ring; and

(7) FIGS. 6 to 8 are diagrams showing pressure means comprising a split ring and a gasket.

(8) Elements present in more than one of the figures are given the same references in each of them.

DETAILED DESCRIPTION OF THE INVENTION

(9) Three mutually orthogonal directions X, Y, and Z are shown in some of the figures.

(10) The first direction X is said to be longitudinal. The term longitudinal relates to any direction parallel to the first direction X.

(11) The second direction Y is said to be transverse. The term transverse relates to any direction parallel to the second direction Y.

(12) Finally, the third direction Z is said to be in elevation. The term in elevation relates to any direction parallel to the third direction Z.

(13) Directions present in a Y,Z plane are also said to be radial relative to the longitudinal direction.

(14) FIG. 1 shows an aircraft 1 having at least one resonator 10 of the invention.

(15) In particular, the aircraft 1 may have an MGB 3 with a rotor mast 4. The rotor mast 4 is constrained to rotate with a rotor 5. The rotor 5 may contribute to providing the aircraft with lift and/or propulsion and/or control. By way of example, the aircraft 1 is a rotorcraft, with the rotor 4 being a rotary wing of the rotorcraft.

(16) The MGB is connected to at least one engine (not shown). The engine drives the MGB 3, which in turn drives rotation of the rotor mast 4 and consequently rotation of the rotor 5.

(17) The MGB 3 is fastened to a support platform 2 by various elements. For example, a first system 7 attaches the bottom of the MGB to the platform 2.

(18) Furthermore, suspension bars 6 are hinged to a top of the MGB 3. Under such circumstances, each bar may be attached to the platform 2 by a resonator 10 of the invention.

(19) The resonator 10 includes a flexible blade 11. The blade 11 extends longitudinally along its axis of extension from a root 12 to a free end 15.

(20) Under such circumstances, the root 12 may be hinged via a first conventional hinge 13 to a suspension bar 6, and via a second conventional hinge 14 to the platform 2. The first hinge 13 is arranged longitudinally between the second hinge 14 and the free end 15 as shown in FIG. 1.

(21) In addition, a flexible blade 100 may extend from the blade 11 to the MGB 3.

(22) Furthermore, the resonator includes a heavy member 20 fastened to the blade 11.

(23) In particular, the heavy member 20 presents an outer casing 25 that is fastened to the free end 15 of the blade 11. The outer casing 25 receives internally a set of masses 40 that is movable in translation along a wormscrew 80 that is driven in rotation by drive means 90. For this purpose, the set of masses includes a nut referred to as a slider nut that is in screw engagement on the wormscrew 80.

(24) The drive means 90 may be controlled by a conventional processor unit (not shown), and/or by a button operated by a pilot. By way of example, the processor unit may comprise a processor, an integrated circuit, a programmable system, a logic circuit, these examples not limiting the scope to be given to the term processor unit.

(25) In another aspect, the casing 25 may be made out of a material having lower density than the material forming the set of masses 40.

(26) FIG. 2 shows a heavy member of the invention.

(27) This heavy member thus comprises a casing 25. The casing 25 may be fastened by conventional means to the blade 11, such as screw fastener means, e.g. studs 29.

(28) The casing 25 may have various members that are fastened to one another. For example, the casing 25 may include a central enclosure 26 extending longitudinally between two openings that are closed by end plates 27. Each end plate 27 may be attached to the central enclosure 26, e.g. by means of screws 28 or bolts.

(29) The casing 25 presents an inside face 34 that defines a volume referred to as the inside volume.

(30) The inside volume may comprise at least two cylindrical spaces 31 away from a central space 32 and possibly separated transversely by the central space 32. For example, the inside volume may comprise only two cylindrical spaces 31 arranged outside the central space 32, or separated transversely by a central space 32. For example, the two cylindrical spaces are arranged symmetrically on either side of a plane of symmetry P1 passing through the central space 32.

(31) Under such circumstances, each cylindrical space is physically defined in part by the inside face 34. Furthermore, this cylindrical space is locally open to the central space 32.

(32) Specifically, each cylindrical space presents a generator line 33 that is shown diagrammatically in FIG. 2. This generator line is in the form of a line segment parallel to the longitudinal direction D1. Furthermore, each cylindrical space may have a space that is circular.

(33) Under such circumstances, the inside volume is substantially binocular shaped.

(34) The wormscrew 80 then extends inside the inside volume along the longitudinal direction D1. This longitudinal direction D1 may be contained in the plane of symmetry P1.

(35) More particularly, the wormscrew is arranged in the central space 32.

(36) The drive means 90 may thus comprise a motor 91 carried by the casing and connected to the wormscrew 80. For example, such a motor 91 is carried by an end plate 27 and is situated outside the inside volume.

(37) Furthermore, the set of masses 40 is engaged around the wormscrew 80, the slider nut that is carried by the set of masses being in screw engagement on the wormscrew 80.

(38) The set of masses 40 extends transversely in each cylindrical space 31 and in the central space 32.

(39) Specifically, the set of masses 40 comprises a support 41 that extends at least within the central space 32. The support 41 carries the slider nut that is in screw engagement on the wormscrew.

(40) Furthermore, the set of masses 40 has one mass for each cylindrical space, i.e. two masses 50 in the example shown.

(41) Each mass 50 is constrained to move in translation with the support 41. Under such circumstances, when the wormscrew 80 causes the support 41 to move in translation, each mass 50 is constrained to move in translation within a respective one of the cylindrical spaces.

(42) FIG. 3 is an exploded view of a set of masses 40.

(43) The support 41 presents a central portion 43 that carries the slider nut 85. The slider nut 85 is shown diagrammatically in FIG. 3 with dashed lines. This central portion 43 has an orifice 470 passing longitudinally through it along the longitudinal direction D1. The wormscrew 80 passes through this orifice so as to reach the slider nut 85.

(44) The central portion 43 then slides in the central space of the casing.

(45) Furthermore, the support 41 may include at least one branch for carrying the masses 50.

(46) For example, the support 41 has one branch per mass. Under such circumstances, the support 41 shown has two side branches 42 that extend transversely on either side of the central portion 43. Each side branch 42 extends longitudinally over a length that is shorter than the length over which the central portion extends. Under such circumstances, the central portion projects longitudinally from the side branches 42, and by way of example it projects on either side of the side branches 42.

(47) Furthermore, each branch extends in a cylindrical space and matches the shape of that cylindrical space.

(48) Under such circumstances, each mass 50 is fastened to a side branch. For example, each side branch 42 has a longitudinal orifice 460 and each mass 50 has a longitudinal orifice 55. Under such circumstances, each mass can be fastened to a side branch by screw fastener means 52. The screw fastener means include a bolt 53 passing through the longitudinal orifice 55 of the mass and the longitudinal orifice 460 of the branch in order to be screwed into a fastener nut 54.

(49) The two masses 50 may be identical. In another aspect, the two masses 50 may be arranged transversely in symmetrical manner on either side of the plane of symmetry P1 containing the longitudinal direction D1.

(50) Furthermore, each mass 50 includes at least two presser means 60 interposed between the mass 50 and the inside face 34, and possibly also between the mass 50 and the central portion 43.

(51) Each presser means 60 is thus arranged at least in part in a groove 61 arranged in the mass 50. Such a groove 61 opens out to the inside volume of the casing 25. A groove 61 may describe a closed curve, e.g. being an annular groove. Furthermore, a groove 61 may be contained in a plane perpendicular to the longitudinal direction D1.

(52) FIG. 4 is a section view of the set of masses 40 on such a plane perpendicular to the longitudinal direction D1.

(53) Each presser means 60 has at least one resilient member 65 arranged in the bottom of a groove 61. Furthermore, the processor means 60 are provided with a split ring 70 that surrounds the resilient member 65.

(54) Under such circumstances, the resilient member exerts radial forces on the split ring in order to press the split ring 70 against the inside face 34 that surrounds the mass 50. The split ring 70 then projects in part outside the groove 61 in order to provide clearance between the casing 25, and thus the inside surface 34 and the mass 50.

(55) Furthermore, the central portion 43 of the support 41 may extend transversely between two side faces 46 and 47. These two side faces 46 and 47 face two respective masses 50. Each side face 46, 47 thus defines part of a cylindrical space 31. In the context of a cylindrical space of circular base, each side face describes a circular arc situated in the extension of the circular arc described by the casing around the corresponding cylindrical space. Each side face 46, 47 thus extends an inside surface 34.

(56) In the presence of cylindrical spaces of circular base, a mass 50 can be free to rotate about the screw fastener means 52. There is therefore no need to seek to prevent such rotation, unlike prior art column devices.

(57) Under such circumstances, each presser means 60 may be arranged facing a side face 46, 47 so as to tend to press the split ring 70 against a side face 46, 47.

(58) FIG. 4 also shows the slider nut 85 in screw engagement on the wormscrew. Nevertheless, such a slider nut could be located in a segment that is not in register with presser means, e.g. a segment that is in register with lateral branches of the support.

(59) Furthermore, and with reference to FIG. 5, a split ring 70 extends between two ends 71 and 72. These two ends are spaced apart circumferentially by a slot 73. Advantageously, said slot 73 extends in a direction D2 of symmetry that is not parallel to the longitudinal direction D1 so as to prevent contact between the resilient member and the casing.

(60) In another aspect, and with reference once more to FIG. 3, each mass 50 includes at least one heavy element 51 fastened to the support 41.

(61) For example, a mass 50 may comprise two distinct heavy elements 51. Under such circumstances, the two heavy elements 51 may be fastened longitudinally on either side of a side branch 42 of said support 41.

(62) Under such circumstances, each heavy element 51 may carry respective presser means 60.

(63) The two heavy elements 51 may be identical.

(64) Nevertheless, and as shown in FIG. 3, the two heavy elements 51 may be different. Consequently, the two heavy elements 51 extend longitudinally over two respective distances 101 and 102 that are different.

(65) Furthermore, the inside face 34 may be covered in lubricant 200.

(66) With reference to FIG. 6, and independently of the number of heavy elements 51 in a mass 50, a resilient member 65 may be a gasket 66 constrained by the groove 61 to exert a force in radial directions D3 against the corresponding split ring 70.

(67) For example, the groove 61 presents an inner space 62 and an outer space 63 surrounding the inner space 62. The inner space 62 may extend longitudinally over an inner length 105 that is shorter than an outer length 107 over which the outer space 63 extends.

(68) The gasket is then arranged in the inner space, while the split ring 70 is arranged in the outer space 63.

(69) Each inner space 62 extends longitudinally over a length referred to as the groove length 105, and radially over a depth referred to as the groove depth 106.

(70) When the gasket 66 is not arranged in a groove, the gasket 66 is at rest and it extends longitudinally over a length referred to as the gasket length, and radially over a thickness referred to as the gasket thickness.

(71) The gasket thickness is greater than the groove depth 106 and the gasket length is shorter than the groove length 105. When the gasket is arranged in the resonator, the gasket is compressed, at least radially.

(72) In FIG. 6, the difference between the groove length 105 and the gasket length can be small. Under such circumstances, and in the assembled position, the gasket is flattened radially and pressed longitudinally against the walls that define the groove longitudinally.

(73) Under such circumstances, the groove also compresses the gasket 66 longitudinally and tends to cause the gasket to move out from the inner space 62 in order to exert a considerable force against the split ring 70.

(74) In FIG. 7, the difference between the groove length 105 and the gasket length can be considerable in order to avoid the groove exerting forces longitudinally on the gasket.

(75) In order to obtain a considerable radial force that is exerted by the gasket against the split ring, it is preferable to use the variant of FIG. 6.

(76) In another aspect, and with reference to FIG. 8, presser means 60 may comprise two resilient members 65 exerting force on a single split ring 70.

(77) Naturally, the present invention may be subjected to numerous variations as to its implementation. Although several embodiments are described, it will readily be understood that it is not conceivable to identify exhaustively all possible embodiments. It is naturally possible to envisage replacing any of the means described by equivalent means without going beyond the ambit of the present invention.