JP2001233296A - Vibration damping device for helicopter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obviate maintenance work of a vibration damping device for a helicopter, to simplify the constitution, to inexpensively manufacture the vibration damping device, and to minimize the occupying space and a weight increase. SOLUTION: This vibration damping device is provided with a vibration damper vessel 6 being integrally fixed to a rotor head 3b of the helicopter and having a fluid housing chamber 5 inside and fluid 7 housed in the fluid housing chamber of the vibration damper vessel as a vibration damper and smaller in a quantity than the volume of the fluid housing chamber, and an inner peripheral wall surface 8 of the fluid housing chamber forms a cylindrical shape having the axis coincident with the axis of the rotor head.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a helicopter vibration damping device for reducing vibration generated by rotation of a helicopter rotor.

[0002]

BACKGROUND OF THE INVENTION Helicopter rotor systems generally include a plurality of rotor blades and a rotor head that supports the proximal end of the rotor blades about their longitudinal axis so that the pitch angle can be changed. A rotor that is coupled to the upper end of a protruding rotor shaft and that is rotationally driven by the engine; and that the pitch angle of each rotor blade is continuously changed during rotation of the rotor in accordance with a change in the rotational direction position of the rotor blade with respect to the fuselage. The rotor system generates vibration in a direction intersecting the rotation axis of the rotor during rotation of the rotor due to imbalance of the rotor due to imbalance of the centrifugal force of the rotor blade or the like. At the same time, vibration caused by aerodynamic excitation of the rotor blades Other by, during rotation of the rotor to generate a vibration in the extending direction of the rotation axis thereof.

[0003] Such vibrations, as they are, impair the ride comfort of the helicopter and give the occupants discomfort.
Helicopters are often provided with vibration damping devices that reduce the vibration of the rotor, and such vibration damping devices have been conventionally used, for example, by the Japan Aviation Technology Association in May 1993.
The pendulum that acts as a damper mass at the base end of the rotor blade can be swung up and down as described in Chapter 8 “Vibration and anti-vibration equipment” of the new aeronautical engineering course 5 “Helicopter” 2nd edition issued on the 10th A dynamic damper-type vibration damping device that is mounted on the rotor head and supports a star-shaped weight that becomes a damper mass on the rotor head so that it can move in the direction that intersects the rotor axis direction, and supports the lower end of the rotor shaft and A nodal beam type, which supports a rotationally driven transmission such that it can move up and down and swings with multiple beams and connects those beams to the aircraft at the nodes of vibration to reduce vibration transmitted to the aircraft. Devices are known, and other active damping systems that vibrate vibrating parts by using an actuator in the direction opposite to the vibration direction to cancel the vibration. Location also has been studied.

[0004]

However, the above-mentioned conventional vibration damping device is a dynamic damper type in which a pendulum or a weight serving as a damper mass is swingably or movably supported on a rotor blade or a rotor head. There is a problem that the maintenance work of the mechanism that supports the pendulum and the weight movably takes time, and it is not easy to adjust the weight of the pendulum and the weight to effectively reduce the vibration. Nodal beam type devices and active type vibration damping devices are complicated in structure and costly to manufacture, and require time and effort for maintenance. In addition, the size of the device increases the occupied space and weight. There was a problem.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a vibration damping device that advantageously solves the above-mentioned problems, and a helicopter vibration damping device according to the present invention is: A damping body container which is integrally fixed to a rotor head of a helicopter and has a fluid accommodating chamber therein, and a volume of the fluid accommodating chamber accommodated in the fluid accommodating chamber of the damping body container as a damping body. A small amount of fluid, and the inner peripheral wall surface of the fluid storage chamber,
The rotor head has a cylindrical shape having a center axis coinciding with the center axis of the rotor head.

In such a vibration damping device, when the rotor head of the helicopter rotates and the vibration damping container integrally fixed to the rotor head rotates, the fluid in the fluid storage chamber of the vibration damping container rotates. Is urged in the circumferential direction of the inner wall surface by contact with the inner wall surface of the fluid storage chamber and rotates together with the damping body container, and the centrifugal force applied to the fluid causes the center of the rotor head of the fluid storage chamber to rotate. It is pressed against a cylindrical inner peripheral wall surface having a central axis coinciding with the axis, and extends along the inner peripheral wall surface.

[0007] While the fluid is rotating together with the damping body container, the center axis of the rotor head is unbalanced with respect to the actual rotation axis due to the unbalance of the rotating system such as the rotor. Eccentric in the opposite direction, when the damping body container moves in a direction intersecting the center axis of the rotor head, the liquid balancer known in the art as being provided in a dewatering basket of a washing machine is completely different from the present invention. As described above, the fluid in the fluid storage chamber collects in the same direction as the movement direction of the damping body container due to centrifugal force or the like. As a result, the mass of the unbalance of the entire rotation system such as the rotor with respect to the actual rotation axis is reduced, and the vibration of the rotor in the direction intersecting with the center axis of the rotor head is damped.

When the damper container moves in the direction in which the center axis of the rotor head extends while the fluid is rotating together with the damper container, the inner peripheral wall surface of the fluid storage chamber of the damper container is moved. Fluid moves along the inner peripheral wall surface of the fluid storage chamber with inertia in a direction opposite to the moving direction of the damping body container, and induces a wave on the surface. The light is reflected on the axial end wall surface of the fluid storage chamber. Accordingly, when the damping body container vibrates in the direction in which the center axis of the rotor head extends, the fluid vibrates and acts as a damping mass serving as a damper mass of the dynamic damper. And the vibration of the rotor in the direction in which the central axis of the rotor head extends is damped.

Therefore, according to the vibration damping device of the present invention, both the vibration of the rotor in the direction intersecting with the center axis of the rotor head and the vibration of the rotor in the direction in which the center axis of the rotor head extends can be effectively controlled. According to the vibration damping device of the present invention, since the structure is such that the fluid serving as the vibration damper is accommodated in the fluid storage chamber of the vibration damper container and movably supported, a mechanical operation requiring maintenance work is required. Because there are no major parts, maintenance is not troublesome, maintaining long-term reliability, and adjusting the vibration damping body to effectively reduce vibration requires adjusting the amount of fluid stored in the fluid storage chamber. By increasing or decreasing the specific gravity of the fluid, or by changing the specific gravity of the fluid.

According to the vibration damping device of the present invention, since the fluid as the vibration damper is accommodated in the fluid chamber of the vibration damper container and supported movably as described above, it is inexpensive. Since the apparatus can be manufactured and the apparatus is made compact, an occupied space and an increase in weight can be reduced.

In the present invention, the fluid storage chamber may have a convex portion protruding inward from the inner peripheral wall surface. According to the convex portion, the fluid is stored in the fluid storage chamber. Can be effectively urged in the circumferential direction of the inner peripheral wall of the
Even if the rotational speed of the vibration damping container changes suddenly, the fluid can be reliably rotated around the vibration damping container, and when the vibration damping container moves in a direction intersecting the center axis of the rotor head. The fluid collects in the direction of movement of the damping body container while avoiding the convex portion, and when the damping body container moves in the direction in which the center axis of the rotor head extends, the movement direction of the damping body container is Since the wave on the fluid surface moves in the opposite direction while contacting the convex portion, self-excited vibration of the fluid can be suppressed, and the vibration damping action of the device can be made more effective.

Further, in the present invention, the convex portion is
The partition wall may extend in the radial direction with respect to the center axis of the inner peripheral wall surface in parallel with the center axis and may have one or a plurality of through-holes. Is more reliably generated, so that the vibration damping action of the device can be made more effective.

Further, in the present invention, the fluid may be:
A non-volatile liquid having a higher specific gravity than water may be used.If such a liquid is used, the non-volatile liquid has a higher specific gravity than water. It can be obtained stably and reliably. However, the fluid in the present invention is not limited to this, and may be, for example, an aggregate of granular materials as long as it has a mass enough to be a vibration damper.

Further, in the present invention, a plurality of the fluid storage chambers may be provided in a radial direction with respect to a center axis of the rotor head. According to the plurality of fluid storage chambers, the fluid storage chambers of the respective layers may be provided. Since the chamber has a vibration damping effect, the vibration of the rotor in a direction intersecting with the center axis of the rotor head can be more effectively damped.

Further, in the present invention, the fluid storage chamber may be provided in a plurality of stages in the extending direction of the central axis of the rotor head. Since the accommodating chamber achieves the vibration damping effect, the vibration of the rotor in the extending direction of the center axis of the rotor head can be more effectively damped. Here, the heights of the fluid storage chambers of the plurality of stages may be different from each other, and according to the fluid storage chambers having different heights, the vibration of the rotor in the extending direction of the center axis of the rotor head is wider. Vibration can be effectively suppressed over a range of frequencies.

Further, another vibration damping device for a helicopter according to the present invention comprises a vibration damping container integrally fixed to a rotor head of a helicopter and having a hard sphere accommodating chamber therein; And two or more rigid balls rotatably accommodated in the rigid ball accommodating chamber of the vibration damping container, wherein the rigid ball accommodating chamber has a center that coincides with a central axis of the rotor head. It has an annular shape with an axis.

In such a vibration damping device, when the rotor head of the helicopter rotates and the vibration damping container integrally fixed to the rotor head rotates, the two of the vibration damping container in the rigid ball storage chamber are rotated. One or more hard spheres are urged in the circumferential direction of the inner wall surface by direct contact with the inner wall surface of the hard sphere housing chamber and contact with viscous fluid in contact with the inner wall surface of the hard sphere housing chamber. It rotates together with the vibration container. In the meantime, the center axis of the rotor head is eccentric with respect to the actual rotation axis in the direction opposite to the unbalance mass due to the unbalance of the rotating system such as the rotor, and the damping body container is shifted to the center axis of the rotor head. When moving in a direction intersecting with the ball, two or more hard spheres in the hard sphere accommodating chamber are controlled by centrifugal force or the like, as in a ball-type balancer which is completely different from the present application but is provided in a centrifuge. They gather in the same direction as the swinging container. As a result, the mass of the unbalance as a whole rotation system such as a rotor with respect to the actual rotation axis decreases,
Vibration of the rotor in a direction intersecting with the center axis of the rotor head is damped.

Therefore, according to the vibration damping device of the present invention, the vibration of the rotor in the direction intersecting with the center axis of the rotor head can be effectively damped, and the rigid ball as the vibration damping member is used. Since the structure is such that the container is housed in the container of the hard sphere and rollably supported, there is no mechanical part requiring maintenance work, so that long-term reliability can be maintained without any trouble in maintenance work. . Further, as described above, the simple structure in which the rigid sphere is accommodated in the rigid sphere accommodating chamber of the damping body container and supported in a freely rolling manner can be manufactured at a low cost, and the apparatus is made compact, so that the occupied space and weight increase. Can be done with only a small amount.

In the present invention, the hard-sphere housing chamber of the above invention may be provided inside the vibration-damping container of the above-mentioned invention together with the fluid storage chamber. Vibration of the rotor in a direction intersecting with the center axis of the head can be more effectively damped.
Here, the hard sphere storage chamber may be provided radially outward or radially inward with respect to the fluid storage chamber, or may be provided side by side in the axial direction.

Further, in the present invention, the damping body container may be provided, for example, housed inside the rotor head, but is formed separately from the rotor head and has a convex upper surface. According to such a vibration damping container, since it is formed separately from the rotor head, it can be easily installed on the rotor head of an existing helicopter and Because the outer shape is a disk with a convex upper surface, the damper container itself can be easily manufactured in a well-balanced manner, and the airflow during the flight of the helicopter on the rotor head can be rectified. Can bring effects.

[0021]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Here, FIG. 1 is a perspective view showing an embodiment of the helicopter vibration damping device of the present invention in a partially cut-away state together with a helicopter rotor, and FIGS. 2 (a) and 2 (b).
1 is a plan view and a side view showing a state in which the damping device of the embodiment is mounted on a helicopter. In the figure, reference numeral 1 denotes a helicopter body, 2 denotes a rotor shaft protruding upward from the helicopter body 1, 3 Is a rotor coupled to the upper end of the rotor shaft 2 and is rotationally driven by an engine (not shown), and 4 is the vibration damping device of the above embodiment, respectively, and the rotor 3 is three rotor blades 3a and 3 , Those rotor blades
Rotor head 3b that supports the base end of 3a around the longitudinal axis of those rotor blades 3a so that the pitch angle can be changed.
have.

As shown in FIG. 1, the vibration damping device 4 of this embodiment has a substantially disk-shaped damping body container 6 having a substantially spherically projecting upper surface and having a fluid storage chamber 5 therein.
A non-volatile liquid (for example, silicone oil) having a specific gravity higher than that of water as a fluid contained in the fluid storage chamber 5 inside the vibration damping container 6 and having a smaller volume than the volume of the fluid storage chamber 5 2), and the damping body container 6 is formed separately from the rotor head 3b and disposed on the rotor head 3b, as shown in FIG. It is integrally fixed to the rotor head 3b by a member. In addition, such a damping body container 6
Can be formed by, for example, cutting or casting of a light alloy material, and the fluid damping vessel 6 contains a liquid 7 in an appropriate position such as the center of the upper surface thereof, although not shown. An inlet for injecting into the chamber 5, a detachable lid for closing the inlet in a liquid-tight manner, and a pressure regulating valve provided on the lid for keeping the pressure in the fluid storage chamber 5 at an appropriate pressure. Is provided.

As shown in FIG. 1, the fluid storage chamber 5 inside the vibration damping container 6 has an inner wall surface 8, which is aligned with the center axis C of the rotor shaft 2 and the rotor head 3b. It has a cylindrical inner peripheral wall surface 8a having a coincident central axis (indicated here by the same symbol C for convenience). Also,
The fluid accommodating chamber 5 has a convex portion that protrudes inward from the inner peripheral wall surface 8a and the upper and lower end surfaces of the inner wall surface 8 and extends radially with respect to the central axis C along the extending direction of the central axis C. The rib-shaped partition walls 9 are radially arranged at equal intervals in the circumferential direction,
In the illustrated example, there are six, and a plurality of small through holes 9a are formed in each partition wall 9.

FIG. 3 is a perspective view schematically showing the inside of the vibration damping container 6 of the vibration damping device 4 of the above embodiment in a state where the vibration damping container 6 is rotating, and FIG. Example vibration suppression device 4
Is an explanatory view showing an operation principle when damping the vibration of the rotor 3 in a direction intersecting with the center axis of the rotor head 3b. In FIG. 4, a point O1 indicates an actual position of the rotation center axis of the rotor head 3b, The point O2 indicates the position of the center axis of the rotor head 3b and thus the inner peripheral wall 8a of the fluid storage chamber 5, M indicates an unbalanced weight, and the four springs 10 and dampers 11 of the fluid storage chamber 5
1 schematically shows a suspension structure for supporting a lower end portion of FIG.

In the vibration damping device 4 of the above embodiment, when the rotor head 3b of the helicopter rotates and the vibration damping container 6 integrally fixed to the rotor head 3b rotates, as shown in FIG. As described above, the liquid 7 in the fluid storage chamber 5 of the damping body container 6 comes into contact with the inner wall surface 8 of the fluid storage chamber 5 and projects inward from the inner wall surface 8 so that the central axis of the inner wall surface 8 extends. C is rotated in the circumferential direction of the inner wall surface 8 by contact with the six partition walls 9 extending in the radial direction along the extending direction of C, and rotates together with the vibration-damping container 6. Is pressed against the cylindrical inner peripheral wall surface 8a having the central axis C of the fluid storage chamber 5 by the centrifugal force applied thereto, and extends in a layered manner along the inner peripheral wall surface 8a.

Thus, as shown in FIG. 4, the liquid 7 rotates together with the vibration damping container 6 at a higher rotational frequency than the natural frequency of the suspension structure supporting the lower end of the rotor shaft 2. In the meantime, the center axis C (position is indicated by a point O2) of the rotor head 3b is unbalanced weight M with respect to the actual rotation axis (position is indicated by a point O1) due to the unbalance of the rotating system such as the rotor 3. When the damping body container 6 moves in a direction intersecting the center axis C of the rotor head 3b eccentrically in a direction opposite to the above, it is known to be provided in a dewatering basket of a washing machine although the technical field is completely different from the present application. As in the liquid balancer, the fluid 7 in the fluid storage chamber 5 is moved by centrifugal force or the like in the same direction as the moving direction of the damping body container 6 so as to move the partition 9.
, That is, while climbing over the partition 9 or passing through the through hole 9a. As a result, the mass of the unbalance of the entire rotation system such as the rotor 3 with respect to the actual rotation axis is reduced, and the vibration of the rotor 3 in the direction intersecting with the center axis of the rotor head is damped.
Since the principle of the liquid balancer is known (for example, see "Vibration Control" translated by Yoichi Kobori, published by Corona Co., Ltd., Aug. 20, 1967, published by McDuff and Callery). The mechanical details are omitted.

In a liquid balancer using such a fluid storage chamber 5, the vibration damping effect increases as the density of the liquid 7 and thus the specific gravity × the volume of the fluid storage chamber 5 increases, so that the specific gravity of the liquid 7 and the fluid storage chamber 5 Increasing at least one of the volumes is effective for improving the vibration damping effect.

FIG. 5 is an explanatory view showing the operation principle when the vibration damping device 4 of the above embodiment damps the vibration of the rotor 3 in the direction in which the center axis of the rotor head 3b extends.
Reference numeral 12 denotes a rotating system including the rotor shaft 2 and the rotor 3, and a spring 10 and a damper 11 below the rotating system 12.
1 schematically shows a suspension structure for supporting the lower end of the rotor shaft 2.

As shown in FIG. 5, the liquid 7 is
When the damper container 6 moves in the direction in which the center axis C of the rotor head 3b extends as shown by the double-headed arrow in the drawing, the inside of the fluid storage chamber 5 of the damper container 6 is rotated. Perimeter wall 8a
Is moved by inertia along the inner peripheral wall surface 8a of the fluid storage chamber 5 in the direction opposite to the moving direction of the vibration damping container 6, and the wave W is applied to the surface. Induce the wave W
Is the axial end wall surface of the fluid storage chamber 5 (the upper and lower end wall surfaces in the figure)
Is reflected by As a result, when the vibration damping container 6 vibrates in the direction in which the center axis C of the rotor head 3b extends, the liquid 7 vibrates and acts as a damping mass serving as a damper mass of the dynamic damper. 6 is damped, and thus the vibration of the rotor 3 in the direction in which the central axis C of the rotor head 3b extends is damped. Since the principle of such a liquid dynamic damper is known (for example, the Transactions of the Japan Society of Mechanical Engineers in 1988 (C))
Vol. 54, No. 504, pp. 1629-1636, by Yuichi Sato, "Dynamic vibration absorber using hollow rotating body containing liquid", the mechanical details of which are omitted here.

In the liquid dynamic damper using the fluid storage chamber 5, the vibration is controlled so as to correspond to the vibration of the target vibration frequency ratio (axial vibration frequency / rotor rotation frequency).
Setting at least one of the height of the fluid storage chamber 5 and the type and amount of the liquid 7 is effective for improving the vibration damping effect.

Therefore, according to the vibration damping device 4 of the above embodiment, both the vibration of the rotor 3 in the direction intersecting with the central axis C and the vibration in the extending direction of the central axis C are effectively damped. In addition, according to the vibration damping device of the above embodiment, since the structure is such that the liquid 7 serving as the vibration damper is accommodated in the fluid storage chamber 5 of the vibration damper container 6 and movably supported, the maintenance work is performed. Since there is no mechanical part requiring maintenance, the maintenance of the maintenance work is not troublesome, the reliability is maintained for a long time, and the adjustment of the vibration damping body for effectively reducing the vibration is performed in the fluid storage chamber 5. Increase or decrease the amount of liquid 7 contained in
The specific gravity can be easily changed.

According to the vibration damping device of the above embodiment, the liquid 7 serving as a vibration damper is simply accommodated in the fluid storage chamber 5 of the vibration damper container 6 and movably supported as described above. Due to the structure, the device can be manufactured at low cost and the device can be made compact, so that the space occupied and the increase in weight can be reduced.

Further, according to the vibration damping device 4 of the above embodiment,
Since a plurality of partition walls 9 having a plurality of through-holes 9 a are provided as the convex portions, the liquid 7 is supplied to the inner wall surface 8 of the fluid storage chamber 5.
Can be effectively urged in the circumferential direction, and even if the rotational speed of the damping body container 6 changes suddenly, the liquid 7 can be reliably rotated around the damping body container 6. When the body container 6 moves in a direction intersecting with the center axis C of the rotor head 3b, the liquid 7 collects in the moving direction of the damping body 6 through the plurality of through holes 9a of the partition wall 9, and When the body container 6 moves in the direction in which the central axis C of the rotor head 3b extends, the body container 6 moves in a direction opposite to the moving direction of the damping body container 6 while being in contact with the partition wall 9, so that the liquid 7 is self-excited. Vibration can be suppressed,
The damping action of the damping device can be made more effective.

Further, according to the vibration damping device 4 of the above embodiment,
As the fluid, a non-volatile liquid having a specific gravity higher than that of water (for example, silicone oil having a viscosity higher than that of water) 7
Is used, the vibration damping action can be more stably and reliably obtained as compared with the case where water is used for the fluid, and
As compared with the case where water is used as the fluid, the vibration damping action can be made effective with a smaller vibration damping body container.

Further, according to the vibration damping device 4 of the above embodiment,
The damping body container 6 is formed separately from the rotor head 3b,
Since the upper surface has a convex disk shape, the damper container 6 is formed separately from the rotor head 3b, so that it can be easily installed on the rotor head of an existing helicopter. Since the versatility can be improved, and the outer shape of the damping body container 6 is a disk having a convex upper surface, the damping body container itself can be easily manufactured in a well-balanced manner. , The air flow rectification effect during the flight of the helicopter.

FIGS. 6 to 9 show the inside of the damping body container 6 in a modified example of the vibration damping device 4 of the above embodiment in a state where the vibration damping vessel 6 is rotating. In the example shown in (1), two layers of fluid accommodation chambers 5 are provided in the vibration damping body 6 in the radial direction with respect to the center axis C of the rotor head 3b. According to the two-layer fluid storage chamber 5, the fluid storage chambers 5 of each layer exert a vibration damping effect, so that the vibration of the rotor 3 in a direction intersecting with the central axis C of the rotor head 3b can be more effectively damped. can do.

In the example shown in FIG. 7, two fluid storage chambers 5 are provided in the vibration damping container 6 at the same height in the direction in which the center axis C of the rotor head 3b extends. According to such a two-stage fluid storage chamber 5, since the fluid storage chambers 5 in each stage exert a vibration damping effect, the vibration of the rotor 3 in the direction in which the central axis C of the rotor head 3b extends can be more effectively controlled. Can be shaken.

In the example shown in FIG. 8, two fluid storage chambers 5 are provided in the vibration damping container 6 in the direction in which the center axis C of the rotor head 3b extends. Are different from each other. According to the fluid storage chambers 5 having different heights, the vibration of the rotor 3 in the extending direction of the center axis C of the rotor head 3b can be effectively damped over a wider frequency range.

The example shown in FIG. 9 is a combination of the example having two layers of fluid storage chambers 5 shown in FIG. 6 and the example having two levels of fluid storage chambers 5 having different heights as shown in FIG. In this way, a larger vibration damping effect can be obtained over a wider frequency range.

FIG. 10 is an explanatory view showing the principle of operation of another embodiment of the helicopter vibration damping device of the present invention when damping the vibration of the rotor 3 in a direction intersecting the center axis of the rotor head 3b. The vibration damping device of this embodiment has a rigid ball storage chamber 13 instead of the fluid storage chamber 5 in a damping body container 6 having a disk-like outer shape with a convex upper surface similar to the previous embodiment. The hard ball housing chamber 13 has an annular shape having a central axis coinciding with the central axis C of the rotor head 3b. In the hard sphere housing chamber 13, two hard spheres 14, for example, made of steel, for example, made of steel as vibration dampers are housed together with a viscous fluid such as silicon oil. In addition,
4, point O1 is the position of the actual rotation center axis of the rotor head 3b, and point O2 is the rotor head 3b in FIG.
Consequently, the position of the central axis C of the rigid housing chamber 13 is shown, M represents an unbalanced weight, and the four springs 10 and the dampers 11 of the rigid housing chamber 13 are connected to the rotor shaft 2.
1 schematically shows a suspension structure for supporting a lower end portion of FIG.

In such a vibration damping device, the rotor head 3b of the helicopter rotates to rotate the rotor head 3b.
When the vibration-damping container 6 integrally fixed to the container rotates, the two rigid balls 14 in the rigid-sphere accommodating chamber 13 of the vibration-damping container 6 come into direct contact with the inner wall surface of the rigid-sphere accommodating chamber 13 and the rigid-sphere accommodating. Due to the contact with the viscous fluid that is in contact with the inner wall surface of the chamber 13, it is urged in the circumferential direction of the inner wall surface and rotates together with the vibration damping container 6. In the meantime, the center axis C of the rotor head 3b indicated by the point O2 moves in the direction opposite to the unbalanced weight M with respect to the actual rotation axis indicated by the point O1 due to the imbalance of the rotating system such as the rotor 3. Eccentrically, damping container 6
Moves in a direction intersecting the center axis C of the rotor head 3b, as in a ball-type balancer whose technical field is completely different from that of the present invention but is provided in a centrifugal separator, two balls in a hard-ball accommodation chamber 13 are provided. Hard balls 14 gather in the same direction as the movement direction of the damping body container 6 due to centrifugal force or the like. As a result, the mass of the unbalance of the entire rotation system such as the rotor 3 with respect to the actual rotation axis is reduced, and the vibration of the rotor 3 in the direction intersecting with the center axis C of the rotor head 3b is damped. Since the principle of such a ball-type balancer is known (for example, in addition to "Vibration Control" by MacDuff and Callely, the Journal of the Japan Society of Mechanical Engineers, 1979, Vol. 45, No. 394) No.646-652
(See "Automatic Equilibrium Apparatus" by Junkichi Inoue et al., Page), the details of which are omitted here.

In the ball-type balancer using the hard-ball housing chamber 13, if the hard-ball 14 having a certain mass or more is used, the hard-ball 14 can be perfectly balanced with the unbalanced mass.

Therefore, according to the vibration damping device of the above embodiment,
Vibration of the rotor 3 in a direction intersecting with the center axis C of the rotor head 3b can be effectively damped, and the rigid sphere 14 as a vibration damper is accommodated in the rigid sphere accommodating chamber 13 of the vibration damper container 6. Since it is supported so that it can be rolled freely, there is no mechanical part that requires maintenance work, so that reliability can be maintained for a long time without any trouble in maintenance work. Further, as described above, the hard sphere 14 is moved to the hard sphere accommodation chamber 13 of the vibration damping vessel 6.
Since it has a simple structure of being housed inside and supported in a freely rolling manner, it can be manufactured at a low cost, and the apparatus can be made compact, so that the space occupied and the weight increase can be small.

FIGS. 11 and 12 show the above-described embodiment in which the rigid ball storage chamber 13 of the vibration damping device of the above embodiment is provided together with the fluid storage chamber 5 in the vibration damping container 6 of the vibration damping device of the previous embodiment. FIG. 11 shows a modified example of the vibration damping device of the example. In the example shown in FIG. 11, a rigid ball accommodating chamber 13 is arranged around two-stage fluid accommodation chambers 5 having different heights shown in FIG. Two hard spheres 14 are housed in the housing chamber 13 together with a viscous fluid. In the example shown in FIG. 12, two fluid storage chambers 5 are arranged above and below the middle of the fluid storage chamber 5, and a hard sphere storage chamber 13 is provided around the center of the fluid storage chamber 5. The two rigid spheres 14 are accommodated in the rigid sphere accommodation chamber 13 together with the viscous fluid. According to these configurations, the vibration of the rotor 3 in the direction intersecting with the center axis C of the rotor head 3b can be more effectively damped.

Although the present invention has been described with reference to the illustrated examples, the present invention is not limited to the above examples. For example, as the fluid, for example, an aggregate of liquids other than silicon oil or particulate matter may be used. Further, the damping body container may be accommodated in the rotor head, and as the convex portion, for example, a mountain-shaped ridge may be provided so as to extend in the direction in which the central axis of the fluid containing chamber extends. It may be formed on the inner wall surface or a round mountain-shaped projection may be formed on the inner wall surface of the fluid storage chamber. Further, three or more hard balls may be housed in the hard ball housing chamber.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a helicopter vibration damping device according to an embodiment of the present invention in a partially cut-away state together with a helicopter rotor.

FIGS. 2A and 2B are a plan view and a side view showing a state where the vibration damping device of the above embodiment is mounted on a helicopter.

FIG. 3 is a perspective view schematically showing the inside of the damping body container of the vibration damping device of the embodiment in a state where the vibration damping body container is rotating.

FIG. 4 is an explanatory diagram showing an operation principle when the vibration damping device of the above embodiment damps the vibration of the rotor in a direction intersecting the center axis of the rotor head.

FIG. 5 is an explanatory diagram showing an operation principle when the vibration damping device of the embodiment dampens the vibration of the rotor in the extending direction of the center axis of the rotor head.

FIG. 6 is a perspective view schematically showing a modified example of the vibration damping device of the above embodiment in a state where the vibration damping body container is rotating.

FIG. 7 is a perspective view schematically showing another modified example of the vibration damping device of the embodiment in a state where the vibration damping container is rotating.

FIG. 8 is a perspective view schematically showing still another modified example of the vibration damping device of the embodiment in a state where the vibration damping body container is rotating.

FIG. 9 is a perspective view schematically showing still another modified example of the vibration damping device of the above embodiment in a state where the vibration damping body container is rotating.

FIG. 10 is an explanatory view showing an operation principle when another embodiment of the helicopter vibration damping device of the present invention dampens the vibration of the rotor in a direction intersecting the center axis of the rotor head.

FIG. 11 is a perspective view schematically showing a modified example of the vibration damping device of the above embodiment in combination with the previous embodiment in a state where the damping body container is rotating.

FIG. 12 is a perspective view schematically showing another modified example of the vibration damping device of the above embodiment in combination with the previous embodiment in a state where the damping body container is rotating.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Airframe 2 Rotor shaft 3 Rotor 3a Rotor blade 3b Rotor head 4 Vibration damping device 5 Fluid accommodation room 5 6 Vibration damping container 7 Liquid 8 Inner wall surface 8a Inner peripheral wall surface 9 Partition wall 9a Through hole 10 Spring 11 Damper 12 Rotating system 13 Hard ball Storage room 14 Hard ball C Central axis of rotor head M Unbalance weight

Claims (9)

[Claims] 1. A vibration damping vessel (6) integrally fixed to a rotor head (3b) of a helicopter and having a fluid storage chamber (5) therein, and a fluid in the vibration damping vessel as a vibration damping body. A volume of the fluid (7) contained in the containing chamber smaller than the volume of the fluid containing chamber;
A helicopter vibration damping device, wherein the inner peripheral wall surface (8) of the fluid storage chamber has a cylindrical shape having a center axis coinciding with the center axis of the rotor head. 2. The helicopter vibration damping device according to claim 1, wherein said fluid storage chamber (5) has a projection (9) projecting inward from said inner peripheral wall surface. 3. The projection (9) is a partition (9) extending radially in parallel with the central axis of the inner peripheral wall surface and parallel to the central axis, and having one or more through holes (9a). The vibration damping device for a helicopter according to claim 2. 4. The helicopter vibration damping device according to claim 1, wherein the fluid is a non-volatile liquid having a higher specific gravity than water. 5. The helicopter vibration damping device according to claim 1, wherein a plurality of the fluid storage chambers (5) are provided in a radial direction with respect to a center axis of the rotor head. 6. The fluid storage chamber (5) is provided in a plurality of stages in a direction in which a center axis of the rotor head extends.
A helicopter vibration damping device according to any one of claims 1 to 5. 7. A vibration damping vessel (6) integrally fixed to a rotor head (3b) of a helicopter and having a hard sphere housing chamber (13) therein; And two or more rigid balls (14) rotatably accommodated in a rigid ball accommodating chamber of the body container, wherein the rigid ball accommodating chamber has a central axis coinciding with a central axis of the rotor head. It has an annular shape with
Helicopter vibration control device. 8. The rigid ball storage chamber (13) according to claim 7 is provided inside the vibration damping container (6) according to any one of claims 1 to 6 together with the fluid storage chamber (5). Helicopter vibration control device. 9. The vibration damping body container (6) is formed separately from the rotor head, and has a disk-shaped outer shape with a convex upper surface. The vibration damping device for a helicopter according to the above.