Anti-vibration suspension device for a mechanical element, and an aircraft

Abstract

A suspension device provided with at least one suspension means. The suspension means comprise a tuned mass damper, the damper comprising an inertial mass carried by a mass support. The suspension means include at least a first actuator generating a dynamic force for acting on the swinging motion of the damper. The inertial mass being movable longitudinally in translation relative to the mass support, the suspension device including a second actuator connected to the inertial mass to move the inertial mass longitudinally relative to the mass support.

Claims

1. An anti-vibration suspension device for a mechanical assembly, the suspension device provided with at least one suspension means, the suspension means comprising a tuned mass damper that performs swinging motion, the tuned mass damper comprising a mass support and an inertial mass carried by the mass support, the suspension means including at least a first actuator generating dynamic forces to act on a swinging motion of the tuned mass damper, the suspension device having at least first calculation means controlling the first actuator, the first calculation means connected to a measurement system measuring a vibratory response in order to adjust the swinging motion, wherein the inertial mass is movable longitudinally in translation relative to the mass support, the suspension device including a second actuator that is connected to the inertial mass to move the inertial mass longitudinally relative to the mass support, the suspension device including second calculation means controlling the second actuator in order to adjust a position of the inertial mass relative to the mass support, wherein the first actuator is electromagnetic and comprises at least one magnetized member and at least one electric coil, the at least one magnetized member or the at least one coil secured to the inertial mass, the first actuator is configured to excite the tuned mass damper to cause the swinging motion, wherein the inertial mass comprises at least one solid that is longitudinally slidable along the coil, the solid including the at least one magnetized member, the at least one magnetized member positioned facing the at least one coil, wherein the solid presents at least one opening having a longitudinal segment of the coil pass therethrough, wherein the magnetized member comprises a magnetized face of the inertial mass, and the at least one opening is defined at least in part by the magnetized face.

2. The suspension device according to claim 1, wherein the first actuator comprises a movable member and a stationary member, the movable member integrated in the inertial mass so as to be constrained to move in translation with the inertial mass, the stationary member configured for fastening to components other than the suspension means.

3. The suspension device according to claim 1, wherein the at least one coil describes a closed loop around an empty space, the coil presenting two longitudinal segments connected together by two transverse branches, the solid presenting at least two openings separated transversely by a partition of the solid, the two longitudinal segments passing respectively through the two openings and arranged transversely on either side of the partition.

4. The suspension device according to claim 1, wherein the at least one opening extends in elevation over a minimum height and the at least one coil extends in elevation over a maximum dimension in elevation, the minimum height is greater than the sum of the maximum dimension in elevation plus a predetermined stroke in elevation for the mass support.

5. The suspension device according to claim 1, wherein the at least one opening extends longitudinally over a maximum length and the at least one coil extends longitudinally over a minimum longitudinal dimension, the minimum longitudinal dimension is greater than the sum of the maximum length plus a predetermined longitudinal stroke for the inertial mass.

6. An anti-vibration suspension device for a mechanical assembly, the suspension device provided with at least one suspension means, the suspension means comprising a tuned mass damper that performs swinging motion, the tuned mass damper comprising a mass support and an inertial mass carried by the mass support, the suspension means including at least a first actuator generating dynamic forces to act on a swinging motion of the tuned mass damper, the suspension device having at least first calculation means controlling the first actuator, the first calculation means connected to a measurement system measuring a vibratory response in order to adjust the swinging motion, wherein the inertial mass is movable longitudinally in translation relative to the mass support, the suspension device including a second actuator that is connected to the inertial mass to move the inertial mass longitudinally relative to the mass support, the suspension device including second calculation means controlling the second actuator in order to adjust a position of the inertial mass relative to the mass support, wherein the first actuator comprises at least one magnetized member and at least one electric coil, the at least one magnetized member or the at least one coil secured to the inertial mass, wherein the inertial mass comprises at least one solid that is longitudinally slidable along the coil, the solid including the at least one magnetized member, the at least one magnetized member positioned facing the at least one coil, wherein the solid presents at least one opening having a longitudinal segment of the coil pass therethrough, wherein the magnetized member comprises a magnetized face of the inertial mass, and the at least one opening is defined at least in part by the magnetized face.

7. The suspension device according to claim 6, wherein the second actuator comprises a motor connected by a screw-and-nut system to the inertial mass.

8. The suspension device according to claim 6, wherein the second calculation means are connected to a measurement unit, the measurement unit transmitting at least one data value to the second actuator that represents a speed of rotation of a rotor that excites the mechanical assembly.

9. The suspension device according to claim 6, wherein the first calculation means is configured to apply a minimizing algorithm, the vibratory response is injected into the minimizing algorithm, and the minimizing algorithm delivering a first control signal for controlling the first actuator.

10. The suspension device according to claim 6, wherein the second calculation means is configured to apply an algorithm delivering a second control signal for the second actuator as a function of a speed of rotation of a rotor that excites the mechanical assembly.

11. An aircraft provided with a carrier structure and a mechanical assembly comprising a rotor and a main power transmission gearbox driving the rotor in rotation, the mechanical assembly including at least one suspension bar extending from a high end hinged to the main power transmission gearbox (MGB) to a low end, wherein the aircraft includes a suspension device according to claim 6, at least one low end of a suspension bar is hinged to suspension means of the suspension device.

12. The aircraft according to claim 11, wherein each suspension bar is hinged to suspension means that are specific thereto.

13. An anti-vibration suspension device for a mechanical assembly, the suspension device provided with at least one suspension means, the suspension means comprising a tuned mass damper that performs swinging motion, the tuned mass damper comprising a mass support and an inertial mass carried by the mass support, the suspension means including at least a first actuator generating dynamic forces to act on a swinging motion of the tuned mass damper, the suspension device having at least first calculation means controlling the first actuator, the first calculation means connected to a measurement system measuring a vibratory response in order to adjust the swinging motion, wherein the inertial mass is movable longitudinally in translation relative to the mass support, the suspension device including a second actuator that is connected to the inertial mass to move the inertial mass longitudinally relative to the mass support, the suspension device including second calculation means controlling the second actuator in order to adjust a position of the inertial mass relative to the mass support, wherein the first actuator comprises at least one magnetized member and at least one electric coil, the at least one magnetized member or the at least one coil secured to the inertial mass, wherein the inertial mass comprises at least one solid that is longitudinally slidable along the coil, the solid including the at least one magnetized member, the at least one magnetized member positioned facing the at least one coil, wherein the solid presents at least one opening having a longitudinal segment of the coil pass therethrough, wherein the at least one coil describes a closed loop around an empty space, the coil presenting two longitudinal segments connected together by two transverse branches, the solid presenting at least two openings separated transversely by a partition of the solid, the two longitudinal segments passing respectively through the two openings and arranged transversely on either side of the partition.

14. The suspension device according to claim 13, wherein the first actuator comprises a movable member and a stationary member, the movable member integrated in the inertial mass so as to be constrained to move in translation with the inertial mass, the stationary member configured for fastening to components other than the suspension means.

15. The suspension device according to claim 6, wherein the inertial mass comprises two solids co-operating respectively with two coils of the first actuator.

16. The suspension device according to claim 6, wherein the first actuator comprises a movable member and a stationary member, the movable member integrated in the inertial mass so as to be constrained to move in translation with the inertial mass, the stationary member configured for fastening to components other than the suspension means.

17. The suspension device according to claim 6, wherein the first actuator does not displace a mass.

18. The suspension device according to claim 6, wherein the at least one coil describes a closed loop around an empty space, the coil presenting two longitudinal segments connected together by two transverse branches, the solid presenting at least two openings separated transversely by a partition of the solid, the two longitudinal segments passing respectively through the two openings and arranged transversely on either side of the partition.

19. The suspension device according to claim 6, wherein the at least one opening extends in elevation over a minimum height and the at least one coil extends in elevation over a maximum dimension in elevation, the minimum height is greater than the sum of the maximum dimension in elevation plus a predetermined stroke in elevation for the mass support.

20. The suspension device according to claim 6, wherein the at least one opening extends longitudinally over a maximum length and the at least one coil extends longitudinally over a minimum longitudinal dimension, the minimum longitudinal dimension is greater than the sum of the maximum length plus a predetermined longitudinal stroke for the inertial mass.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

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

(2) FIG. 1 is a diagram showing an aircraft provided with a suspension device;

(3) FIG. 2 is a diagram showing suspension means of a suspension device;

(4) FIGS. 3 and 4 are views showing a first actuator of electromagnetic type;

(5) FIGS. 5 and 7 are views showing at least part of the suspension means in three dimensions;

(6) FIG. 6 is a plan view of the FIG. 5 mass support; and

(7) FIG. 8 is a view showing a coil fastened to a blade.

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

DETAILED DESCRIPTION OF THE INVENTION

(9) FIG. 1 shows an aircraft 1 having a carrier structure 2. For example, the carrier structure 2 may be in the form of a platform.

(10) Furthermore, the aircraft 1 has a mechanical assembly 3 fastened to the carrier structure 2 in particular for the purpose of contributing to providing the aircraft 1 with lift.

(11) The mechanical assembly 3 includes a rotor 5 contributing at least in part to providing the aircraft with lift and/or propulsion. The mechanical assembly 3 may also include a main power transmission gearbox (MGB) 4 that is interposed between the rotor 5 and a power plant that is not shown in the figures.

(12) Specifically, the aircraft is shown in the figures in deliberately incomplete manner in order to avoid pointlessly overcrowding the figures.

(13) The MGB 4, and in particular its bottom 4 may be connected to the carrier structure 2 by a diaphragm 300. Such a diaphragm 300 may be made of metal, for example, and allows the MGB to move vertically and also to pivot about point of the diaphragm 300.

(14) The aircraft 1 has a suspension device 10 that seeks firstly to reduce the vibration transmitted by the mechanical assembly 3 to the carrier structure 2, and secondly to connect the mechanical assembly 3 to the carrier structure 2.

(15) The mechanical assembly 3 includes at least one suspension bar 15, and indeed at least three suspension bars 15 for fastening it to the carrier structure. Each suspension bar then extends from a top end 16 to a bottom end 17. Each top end 16 is hinged to the MGB 4, e.g. to a high portion of the MGB 4. Each bottom end 17 is connected indirectly to the carrier structure 2.

(16) Under such circumstances, the suspension device 10 has at least one suspension means 20 interfaced between a suspension bar 15 and the carrier structure 2. For example, the suspension device comprises respective suspension means for each suspension bar hinged both to the carrier structure and also to the bottom end 17 of the corresponding suspension bar.

(17) Each suspension means 20 includes a tuned mass damper 21. The damper 21 has a mass support 25 that caries an inertial mass 30, and indeed the bottom end 17 of a suspension bar. The mass support 25 may comprise at least one lever, at least one bar, . . . .

(18) The mass support 25 then extends longitudinally from a proximal segment 27 towards a distal segment 26. The distal segment 26 may form a free end. The inertial mass is then carried by the distal segment 26 of the damper.

(19) Furthermore, the proximal segment 27 may be hinged to the suspension bar and to the carrier structure 2. For rotorcraft, the suspension means are provided with a first hinge 35 for hinging the mass support 25 to the carrier structure 2.

(20) With reference to FIG. 2, the first hinge 35 optionally includes a pivot connection enabling the mass support, and thus the inertial mass 30, to pivot about a first direction AX1. Consequently, the first hinge may comprise a fitting 37 suitable for fastening to the carrier structure 2. A first pivot pin 36 of the first hinge can then pass transversely through at least one cheek 61 of the fitting 37.

(21) In addition, the suspension means may comprise a second hinge 40 for hinging a suspension bar 15 to the mass support 25, optionally in the proximity of the first hinge 35. For example, the second hinge 40 is arranged in the proximal segment.

(22) This second hinge 40 may include at least a pivot connection, and possibly a ball-joint connection. The second hinge may optionally be provided with a second connection pin 42. The second connection pin 42 may pass through the mass support 25 and the suspension bar 15. The second connection pin 42 is directed along a second direction AX2 that is optionally parallel to the first direction AX1.

(23) The second hinge 40 is offset relative to the first hinge 35, thus enabling the movement of the inertial mass 30 as caused by relative movement between the carrier structure 2 and the MGB 4 and by a first actuator that is described below to be amplified dynamically.

(24) In addition, the suspension device may include one resilient element 200 for each suspension means that provides the stiffness needed to take up a fraction of the static forces passing through the suspension bars 15. This resilient element 200 is shown in FIG. 2 as a blade that operates in bending, being secured to the damper and resting at its end against the bottom 4 of the MGB. Optionally, the blade may be fastened to the mass support and hinged to the MGB. The blade and the mass support may form two portions of a single mechanical part, the blade presenting bending stiffness that is smaller than the bending stiffness of the mass support.

(25) In other variants, the element 200 may be constituted by a torsion tube mounted in the first hinge 35 between the fitting 37 and the damper 21, or indeed by means of a spring arranged between the damper 21 and the carrier structure, for example.

(26) In a variant, a blade 200 has firstly a first end zone hinged to the carrier structure and to the suspension bar, and secondly a second end zone hinged to the MGB. The mass support is then secured to the blade between these two end zones.

(27) In another aspect, suspension means may comprise at least a first actuator 60 for generating dynamic forces on the damper 21, e.g. in order to control the amplitude and the phase of the oscillatory motion of the damper 21. The first actuator 60 excites the damper 21.

(28) With reference to FIG. 1, the suspension device 10 may include a first actuator 60 integrated in each suspension means. The first actuator 60 may be an actuator that is hydraulic, pneumatic, electromechanical, electromagnetic, or indeed piezoelectric.

(29) The suspension device 10 also includes at least a first calculation means 51. By way of example, the first calculation means may comprise at least a processor, an integrated circuit, a programmable system, a logic circuit, these examples not limiting the scope to be given to the term first calculation means.

(30) The first calculation means 51 are connected to a measurement system 53 measuring a vibratory response. The measurement system 53 can measure the vibratory response of the carrier structure, or of any other structure, e.g. a structure of a cabin. The vibratory response represents the vibration of the carrier structure and may in particular be in the form of accelerations and/or deformations and/or forces. Under such circumstances, the measurement system 53 may optionally be provided with accelerometers, with force sensors, and/or with strain gauge deformation sensors. For example, accelerometers may be secured to the carrier structure 2.

(31) Each first actuator 60 then communicates with the first calculation means 51, the first calculation means 51 actively controlling the amplitude and the phase of the motion of the damper by generating a first control signal delivered to the first actuator 60, the first control signal being a function of at least one measurement signal coming from the measurement system 53.

(32) For example, the first calculation means 51 apply a minimizing algorithm that receives as input the vibratory response to be minimized as provided by the measurement system 53. As output, the first calculation means 51 deliver a first control signal for controlling a power amplifier 400. Depending on the order it receives, the power amplifier 400 delivers a particular electric current to at least one member of the first actuator 60. Consequently, the first actuator vibrates the damper 21.

(33) The suspension device may include respective first calculation means for each first actuator 60, or indeed single first calculation means 51 controlling all of the first actuators 60 of the suspension device 10.

(34) Furthermore, the inertial mass 30 is movable longitudinally in translation relative to the mass support 25. Under such circumstances, the inertial mass can slide parallel to a direction in which the mass support 25 extends. This extension direction extends from the proximal segment to the distal segment.

(35) In order to move the inertial mass 30, the suspension device 10 has a second actuator 70. The second actuator 70 is connected to the inertial mass 30 in order to move the inertial mass 30 longitudinally relative to the mass support 25. For example, the second actuator 70 comprises a motor 90 connected by a screw-and-nut system 92 to the inertial mass 30.

(36) Furthermore, the suspension device 10 has second calculation means 52 controlling the second actuator 70 for adjusting the position of the inertial mass 30 relative to the mass support 25 by moving the inertial mass towards or away from an end of the mass support 25. By way of example, the second calculation means 52 may comprise at least a processor, an integrated circuit, a programmable system, a logic circuit, these examples not limiting the scope to be given to the term second calculation means.

(37) The second calculation means 52 may be connected to a measurement unit 54. The measurement unit 54 can transmit at least one data value to the second calculation means 52 representing a speed of rotation of a rotor 5. For example, the measurement unit 54 includes a speed sensor generating a signal representing the speed of rotation of the rotor.

(38) Under such circumstances, the second calculation means 52 apply an algorithm, e.g. a closed loop algorithm, that provides a second control signal that is transmitted to the second actuator, the second control signal being a function of the speed of rotation of the rotor 5. It is possible to envisage using an open loop algorithm.

(39) The suspension device may have respective second calculation means for each second actuator 70, or indeed single second calculation means 52 controlling all of the second actuators 70 of the suspension device 10.

(40) In addition, at least one first calculation means and at least one second calculation means may form single common calculation means.

(41) Independently of the embodiment and for a particular speed of rotation of the rotor 5, the second actuator 70 positions the inertial mass in a predetermined position relative to the elongate member 25. In the presence of vibration, the first actuator 60 then excites the damper by generating dynamic forces on the damper in order to minimize the vibratory response measured by the measurement system 53.

(42) In another aspect, the first actuator 60 may include a movable member 75 integrated in the inertial mass 30 so as to be constrained to move in translation with the inertial mass 30. Furthermore, the first actuator may include a stationary member 80 co-operating with the movable member 75, the stationary member 80 being arranged not to be fastened directly to the mass support 25. For example, the stationary member may be fastened to the MGB 4 or to a blade that is distinct from the mass support.

(43) The second actuator 70 thus drives part of the movement of the first actuator 60 longitudinally relative to the mass support 25 with the inertial mass 30. More precisely, the second actuator 70 enables the movable member 75 of the first actuator 60 to be moved.

(44) The first actuator may be in the form of an actuator that is hydraulic, pneumatic, electrical, . . . . The first actuator may act on the damper by acting on the mass support or on the inertial mass.

(45) In particular, the first actuator 60 may be in the form of an actuator that is electromagnetic. Thus, the first actuator 60 may have at least one magnetized member 76 and at least one coil 85, the magnetized member 76 or the coil 85 constituting a movable member secured to the inertial mass 30.

(46) In the example of FIG. 2, the magnetized member is a movable member integrated in the inertial mass 30 and it co-operates with a coil. The coil represents a stationary member that is secured to the MGB 4. The coil is then powered electrically under the control of the associated first calculation means.

(47) In the example of FIG. 8, the coil is fastened by an attachment 800 to a blade 200, e.g. at or near a connection member 201 of the blade 200 that is hinged to the MGB.

(48) With reference to FIG. 3, the mass comprises at least one solid 31.

(49) In the context of a first electromagnetic actuator, the solid 31 may include the magnetized member 76. The magnetized member is positioned within the solid so as to face a coil 85.

(50) Under such circumstances, the solid 31 possesses a degree of freedom to move in translation relative to the mass support. The solid is also free to move in longitudinal translation along at least one coil 85.

(51) In order to achieve this result, the solid 31 may present at least one opening 81 having a longitudinal segment 86, 87 of the coil 85 passing therethrough. Such an opening may be defined by walls that described a closed loop around the coil, or that may form an open U-shape, for example.

(52) In particular, the solid 31 may have four walls defining an opening, such as a left side wall, a right side wall, a top wall, and a bottom wall, with the coil extending between these walls.

(53) Optionally, the coil 85 may also describe an O-shaped closed loop around an empty space 79. Under such circumstances, the coil 85 has two longitudinal segments 86 and 87 that are connected together by two transverse branches 88 and 89. Circumferentially, the coil 85 then has a first longitudinal segment 86, a first transverse branch 88, a second longitudinal segment 87, and a second transverse branch 89 that joins the first longitudinal segment 86.

(54) Under such circumstances, the solid 31 may present at least two openings 81 that are separated transversely by a partition 33 of the solid 31. The solid of FIG. 3 thus has a left side wall 321 and a right side wall 322. In addition, the solid presents a top wall 342 and a bottom wall 341 each extending transversely to the left side wall 321 and to the right side wall 322. Finally, the partition 33 extends in elevation from the bottom wall 341 to the top wall 342, being arranged transversely between the left side wall 321 and the right side wall 322.

(55) Thus, a first opening 81 is defined transversely by the left side wall 321 and the partition 33 and in elevation by the top wall 342 and the bottom wall 341. In contrast, the first opening 81 is open longitudinally so as to have a first longitudinal segment 86 pass therethrough.

(56) Likewise, a second opening is defined transversely by the right side wall 322 and the partition 33, and in elevation by the top wall 342 and the bottom wall 341. In contrast, the second opening is longitudinally open to have a second longitudinal segment 87 pass therethrough.

(57) The two longitudinal segments 86 and 87 are arranged transversely on either side of the partition 33.

(58) Each opening 81 may be defined at least in part by at least one magnetized face 76 of the inertial mass 30. For example, at least one wall of the inertial mass is provided with a magnet.

(59) Furthermore, at least one opening 81 extends longitudinally over maximum length DIM1. In addition, the coil 85 extends longitudinally over a minimum longitudinal dimension DIM2. Under such circumstances, the minimum longitudinal dimension DIM2 may be greater than the sum of the maximum length DIM1 plus a predetermined longitudinal stroke for the inertial mass 30.

(60) With reference to FIG. 4, at least one opening 81 extends in elevation over a minimum height DIM3, and the coil 85 extends in elevation over a maximum dimension in elevation DIM4. Under such circumstances, the minimum height DIM3 may be greater than the sum of the maximum dimension in elevation DIM4 plus a predetermined stroke in elevation for the mass support 25.

(61) In another aspect, the inertial mass 30 may comprise two solids 31 that co-operate respectively with two coils 85 of the first actuator 60.

(62) FIG. 5 shows an embodiment of this type. The second actuator 70 is shown diagrammatically. The suspension means may also include a fairing (not shown) arranged around the inertial mass in order to protect the inertial mass from various projections.

(63) In FIG. 5, the suspension means comprise a mass support 25 and a resilient blade 200 that forms a single unitary part.

(64) With reference to FIG. 6, the distal segment 26 may have to arms 261 and 262 that extend longitudinally from the proximal segment 27. The blade 200 then extends longitudinally from the proximal segment 27 between the two arms 261 and 262.

(65) Under such circumstances, the mass support 25 includes an upside-down U-shaped bridge 263 that extends from one arm 261 to the other arm 262, passing over the blade 200. The inertial mass is then arranged on the bridge 263, for example in sliding manner.

(66) Furthermore, by way of example, the blade 200 includes a connection member 201 hinged to the MGB in order to connect the blade 200 to the MGB.

(67) The two arms 261 and 262 may be rigid, with the blade 200 being flexible relative to the two arms 261, 262.

(68) FIG. 7 shows suspension means provided with a heavy member arranged on a distal segment of a mass support 25. For example, the heavy member is arranged on a mass support of the type shown in FIGS. 5 and 6, e.g. being fastened to the bridge 263.

(69) This heavy member has a casing 100 that may be fastened by conventional means to the mass support 25, such as screw fastener means, and, by way of example, pins or studs 101. The casing 100 may possess various members that are fastened to one another.

(70) The casing 100 presents an inside face that defines a volume referred to as the inside volume.

(71) This inside volume may have a respective cylindrical space 102 for each solid 31 of the inertial mass 30, e.g. two cylindrical spaces optionally spaced apart transversely by a central space. Under such circumstances, each cylindrical space 102 is physically defined in part by an inside face. Furthermore, the cylindrical space is locally open to the central space.

(72) In addition, the second actuator has a motor 90 fastened to the casing 100. The motor drives a wormscrew 93, e.g. arranged in the central space. A nut 94 is then engaged on the wormscrew 93. The nut 94 is constrained to move in translation and in rotation with each of the solids 31. For example, the nut 94 is arranged in a support 103 that is fastened to the solids 31.

(73) Under such circumstances, when the wormscrew 93 causes the support 103 to move in translation, each solid 31 of the inertial mass is constrained to move in translation within a cylindrical space.

(74) Furthermore, each solid 31 has a coil 85 passing therethrough. Each coil 85 projects outside the casing 100, e.g. so as to be fastened to an MGB.

(75) 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.