JP2019158097A - Spherical joint and attenuation device utilizing the same - Google Patents

Abstract

【Task】
It is possible to easily connect a damping device using a ball screw device to a structure, and to provide a spherical joint that is advantageous in terms of strength in transmitting a huge rotational torque.
[Solution]
An anti-rotation member 25 is provided between the spherical part 21 to which one end of the shaft member is fixed and a holder 22 that wraps the spherical part. The anti-rotation member is orthogonal to the axis of the axial member and A first support shaft 26 and a second support shaft 27 exist on a plane passing through the center of rotation. The first support shaft and the second support shaft are provided along the radial direction of the spherical body portion 21 and the axes are orthogonal to each other. The first support shaft is a first locking hole 28 provided in the holder. The second support shaft is fitted in a second locking hole 29 provided in the spherical body portion. Then, according to the precession movement of the shaft member, the rotation preventing member 25 is centered on the first support shaft with respect to the holder 22, and the spherical portion is centered on the second support shaft with respect to the rotation stopping member. Swing.
[Selection] Figure 3

Description

  The present invention relates to a spherical joint used when a damping device such as a rotary inertia mass damper is attached to a structure such as a building.

  As a damping device for quickly converging vibrations acting on a structure, a device using a ball screw device is known as disclosed in Patent Document 1. The damping device includes a rod having a helical male screw and one end coupled to the structure, a nut member screwed to the rod, and a nut member rotatably supported and fixed to the structure. A cylinder and a rotating weight that is rotated by the nut member are provided. The rod and the nut member constitute a ball screw device. When the rod advances and retracts in the axial direction, the nut member rotates around the rod.

  In such a damping device, when relative vibration generated in the structure due to an earthquake or the like is input between the rod and the holding cylinder, axial relative acceleration is generated in the rod along with the vibration, and the shaft Directional relative acceleration is converted into angular acceleration of the nut member screwed onto the rod. The nut member and the rotating weight together constitute a rotating body, and the rotational torque generated in the rotating body is represented by the product of the moment of inertia of the rotating body and the angular acceleration. This rotational torque is inversely converted by the nut member and the rod each time the axial relative acceleration of the rod is reversed, and acts on the rod as an axial reaction force.

  In order to allow a change in the posture (mounting angle) of the damping device with respect to the structure, a spherical joint (ball joint) is provided at one end of the rod, and the damping device is connected to the structure through the spherical joint. Has been. The spherical joint includes a sphere portion provided at an end of the rod, and a bracket that rotatably holds the sphere portion and is fixed to the structure.

  Further, in order to prevent the rod from being rotated by the rotational torque acting on the nut member, the spherical joint is allowed to rotate around the axial direction while allowing the rod to precess. A stop mechanism is provided. The detent mechanism is composed of a long hole formed in the spherical surface of the sphere along the axial direction of the rod, and a restriction bolt having a tip inserted through the bracket and inserted into the long hole. ing.

JP 2017-26074 A

  However, the anti-rotation mechanism of the spherical joint disclosed in Patent Document 1 allows the rod to precess by moving the tip of the restriction bolt in a long hole formed in the sphere. The tip of the regulation bolt needs to be loosely fitted into the elongated hole, and it is difficult to eliminate the gap between the elongated hole and the regulation bolt in the rotation direction of the rod. For this reason, every time the rotation direction of the nut member changes, the restriction bolt collides with the inner wall of the elongated hole, which is disadvantageous in terms of strength. In addition, since a long hole into which the tip of the restriction bolt is inserted is provided in the spherical body portion, this is also disadvantageous in terms of strength.

  Further, when the restriction bolt collides with the inner wall of the elongated hole, a sudden pulse-like change in angular acceleration occurs with respect to the rotation of the rotating body every time the collision occurs, and accordingly, the rotational torque of the rotating body Will fluctuate. Due to this sudden change in rotational torque, a sudden axial reaction force acts on the rod, and there is a problem that vibration generated in the structure cannot be damped smoothly.

  The present invention has been made in view of such a problem, and an object of the present invention is to easily connect an attenuation device using a ball screw device to a structure, An object of the present invention is to provide a spherical joint which is advantageous in terms of strength in transmitting rotational torque.

  That is, the spherical joint of the present invention includes a spherical portion to which one end of the shaft member is fixed, a holder having a concave spherical surface that is fixed to the structure and slidably contacts the spherical surface of the spherical portion, and encloses the spherical portion. An anti-rotation member that is disposed between the spherical body portion and the holder and locks the rotation of the spherical body portion about the axis of the shaft member. The anti-rotation member has a first support shaft and a second support shaft that exist on a plane orthogonal to the axis of the shaft member and passing through the rotation center of the spherical body portion. The first support shaft and the second support shaft are provided along the radial direction of the spherical body portion, and the axes are orthogonal to each other. The first support shaft is fitted in a first locking hole provided in the holder. On the other hand, the second support shaft is fitted in a second locking hole provided in the spherical body portion. Then, in response to the precession of the shaft member around the sphere, the detent member swings relative to the holder around the first support shaft, while the sphere is supported by the second support. Swinging with respect to the detent member about an axis

  According to the spherical joint of the present invention, the anti-rotation member and the spherical portion swing with respect to the holder with the first and second support shafts whose axes are orthogonal to each other as the rotation center. The rotational motion around the axis of the shaft member can be locked while allowing the differential motion, and a damping device using a ball screw device can be easily connected to the structure.

  The first support shaft is fitted in the first locking hole of the holder, while the second support shaft is fitted in the second locking hole of the sphere portion, and these holder and sphere portion are supported by these support shafts. Since there is no need to provide a long hole in which the shaft loosely fits, it is advantageous in terms of strength in transmitting a huge rotational torque.

It is the schematic which shows the example of attachment of the attenuation device using the spherical joint of this invention. It is a perspective view which shows 1st embodiment of the attenuation device attached using the spherical joint of this invention. It is a perspective view which shows an example of embodiment of the spherical coupling of this invention. It is a perspective view which shows an example of the rotation prevention member provided between the spherical body part and the holder. It is a figure which shows the detail of the 1st locking hole provided in the holder. It is a fragmentary sectional view which shows the state which the rotation prevention member rock | fluctuated with respect to the holder. It is a fragmentary sectional view which shows the state which the spherical body part rock | fluctuated with respect to the rotation preventing member. It is a perspective view which shows the 2nd example of the rotation prevention member provided between the spherical body part and the holder. It is a perspective view which shows the 3rd example of the rotation prevention member provided between the spherical body part and the holder. It is the schematic which shows 2nd embodiment of the attenuation device attached using the spherical joint of this invention.

  Hereinafter, the spherical joint of the present invention will be described in detail with reference to the accompanying drawings, and a damping device that can be attached to a structure using the spherical joint will be described in detail.

  FIG. 1 shows an example of attachment of an attenuation device using a spherical joint of the present invention to a structure. The attenuation device includes, for example, a first connecting part 10 and a first connecting part 10 fixed to different parts (first structure S1 and second structure S2) in a system including structures such as buildings, towers, and bridges. And two connecting portions 11. The system including the structure is intended to include the foundation ground to which the structure is fixed. For example, the first connecting portion 10 is formed in the structure outside the case where the damping device is disposed inside the structure. The 2nd connection part 11 includes the case where it fixes to a foundation ground.

  A spherical joint 2 is provided in each of the first connecting part 10 fixed to the first structure S1 and the second connecting part 11 fixed to the second structure S2. Thereby, the attenuation device 1 can freely adjust the connection angle with respect to the first structure S1 and the second structure S2, and the first structure S1 and the second structure S2. When relative vibration acts between the first structure S1 and the second structure S2, the damping device 1 expands and contracts according to the vibration. In FIG. 1, a pair of spherical joints 2 are provided at both ends in the longitudinal direction of the attenuation device 1. For example, when both structures are not relatively displaced in the direction perpendicular to the axis of the attenuation device 1, The spherical joint 2 may be provided only at one end, and the other end may be directly fixed to the first structure S1 or the second structure S2.

  FIG. 2 is a perspective view showing a first embodiment of the damping device that can be attached to a structure using the spherical joint of the present invention, and is drawn with a part cut away so that the internal structure can be grasped. The damping device 1 is a so-called rotary inertia mass damper, and includes a fixed cylinder 12 having a hollow portion and formed in a cylindrical shape, and a helical screw groove inserted into the hollow portion of the fixed cylinder 12. The formed rod 13, the nut member 14 screwed into the thread groove of the rod 13 through a large number of balls, and the nut member 14 are rotatably supported with respect to the fixed cylinder 12 and coupled to the nut member 14. A cylindrical bearing housing 15, a cylindrical flywheel 16 fixed to the bearing housing 15, and a rotor member rotatably supported with respect to the fixed cylinder 12 and coupled to the flywheel 16 17. The rod 13 and the fixed cylinder 12 are connected to the structure via the spherical joint 2 and are restricted from rotating about the axis.

  A bearing (not shown) is provided between the fixed cylinder 12 and the bearing housing 15, and the bearing housing 15 is rotatably supported with respect to the fixed cylinder 12. The nut member 14 is fixed to one end of the bearing housing 15 in the axial direction. When the nut member 14 rotates, the bearing housing 15 rotates with the nut member 14 with respect to the fixed cylinder 12. It is configured.

  The rod 13 and the nut member 14 constitute a so-called ball screw device. The nut member 14 has an infinite circulation path for the plurality of balls, and these balls roll in a spiral thread groove formed in the rod 13. Thereby, between the rod 13 and the nut member 14, it is possible to mutually convert an axial linear motion and a rotational motion around the rod 13. When a linear motion is applied, the nut member 14 generates a rotational motion around the rod 13, while when the nut member 14 is applied with a rotational motion, the rod 13 generates a linear motion in the axial direction.

  A cylindrical flywheel 16 is provided outside the bearing housing 15. The flywheel 16 is fixed to the bearing housing 15 and is configured to rotate integrally with the nut member 14 and the bearing housing 15. Further, since the bearing housing 15 can freely rotate with respect to the fixed cylinder 12, the flywheel 16 can also rotate freely with respect to the fixed cylinder 12.

  On the other hand, the rotor member 17 is provided around the fixed cylinder 12. The rotor member 17 is supported on the outer peripheral surface of the fixed cylinder 12 through a rotary bearing, and is coupled to the flywheel 16 through an end plate 18, and the fixed cylinder is rotated as the flywheel 16 rotates. 12 is configured to rotate around 12. The inner peripheral surface of the rotor member 17 is opposed to the outer peripheral surface of the fixed cylinder 12 through a slight gap, and this gap is a sealed space for viscous fluid. For this reason, when the rotor member 17 rotates, a shear resistance force acts from the viscous fluid between the outer peripheral surface of the fixed cylinder and the inner peripheral surface of the rotor member, and the energy of the rotational motion of the rotor member 17 is attenuated. It is like that.

  In the damping device 1 of the first embodiment, when relative vibration acts between the first structure S1 and the second structure S2, the rod 13 is pivoted with respect to the fixed cylinder 12. The attenuating device 1 expands and contracts in the direction, and the flywheel 16 and the rotor member 17 are repeatedly reversed around the fixed cylinder 12. When the flywheel 16 reverses, a large rotational torque is generated by the rotational inertia of the flywheel 16, and this rotational torque acts as a reaction force against the axial movement of the rod 13. Further, a shear resistance force acts on the rotation of the rotor member 17 from a viscous fluid, and this shear resistance force also acts as a reaction force on the axial movement of the rod 13. As a result, the vibration acting between the first structure S1 and the second structure S2 is damped by the rotary inertia mass damper.

  FIG. 3 is an exploded perspective view showing an example of a spherical joint to which the present invention is applied, and is partially cut away to show the internal structure.

  The spherical joint 2 includes a spherical part 21 having a through-hole 20 into which a shaft member (not shown) is fitted, and the spherical surface of the spherical part 21 and the first structure S1 or the second structure by a fixing bolt. And a holder 22 fastened to a structure such as the body S2. The holder 22 includes a base member 23 having a bolt mounting hole 23 a and a lid member 24 that is fixed to the base member 23 and covers the spherical body portion 21. An opening 24 a is provided at the center of the lid member, and the shaft member is inserted through the opening 24 a and is fitted in the through hole 20 of the sphere 21. The opening 24a limits the swing range of the shaft member relative to the structure. The lid member 24 is fastened to the base member 23 using a fixing bolt (not shown), whereby the holder 22 is completed. The means for integrating the lid member 24 and the base member 23 is bolt fastening. It is not restricted but welding etc. can also be used.

  In this embodiment, the through hole 20 for fixing the shaft member to the sphere portion 21 is provided, but the sphere portion and the shaft member are integrally formed without providing the through hole 20. A ball stud may be provided, and the sphere portion of the ball stud may be wrapped with a holder.

  Each of the base member 23 and the lid member 24 is provided with concave spherical surfaces 23b and 24b with which the spherical surface of the spherical body portion 21 comes into sliding contact. When the base member 23 and the lid member 24 are integrated with a coupling bolt (not shown), the spherical portion 21 is sandwiched between the concave spherical surface 23b of the base member 23 and the concave spherical surface 24b of the lid member 24, and the spherical portion 21 is The holder 22 is wrapped around and can freely rotate with respect to the holder 22.

  Between the spherical body portion 21 and the holder 22, an anti-rotation member 25 formed in an annular shape is provided. The anti-rotation member 25 is overlapped on a plane perpendicular to the axis of the shaft member (indicated by a one-dot chain line in FIG. 3) that fits into the through hole 20 of the sphere 21 and passing through the center of the sphere 21. It is provided and covers the vicinity of the equator of the sphere 21, that is, the maximum outer diameter of the sphere 21 from the outside. Further, the inner diameter of the anti-rotation member 25 is slightly larger than the maximum outer diameter of the spherical portion 21, and a slight gap is formed between the inner peripheral surface of the anti-rotation member 25 and the spherical surface of the spherical portion 21. Is provided.

  FIG. 4 is a perspective view showing the rotation preventing member 25. As shown in the figure, the anti-rotation member 25 is a metal flat plate formed into an annular shape, and a pair of first support shafts 26 are provided on the outer peripheral surface, while a pair of inner support surfaces are provided on the inner peripheral surface. A second support shaft 27 is provided. The pair of first support shafts 26 and the pair of second support shafts 27 are provided along the radial direction of the spherical portion 21, and the axis line of the first support shaft 26 and the axis line of the second support shaft 27 are They are orthogonal to each other. The first support shaft 26 and the second support shaft 27 may be formed integrally with the anti-rotation member 25, or may be integrated with the anti-rotation member by screwing or welding.

  The holder 22 is provided with a first locking hole 28 into which the first support shaft 26 is fitted, and the anti-rotation member 25 swings with respect to the holder 22 with the first support shaft 26 as a rotation center. It is free to move. The spherical body portion 21 is provided with a second locking hole 29 into which the second support shaft 27 is fitted. The spherical body portion 21 has the rotation preventing member 25 with the second support shaft 27 as a rotation center. It can rotate freely.

  FIG. 5 is a diagram showing details of the first locking hole 28 provided in the holder 22. The first locking hole 28 is formed in a long hole shape with respect to the lid member 24 of the holder 22, and the first locking hole 28 is fixed by fixing the lid member 24 to the base member 23. 28 is closed and the spacer 28 a and the first support shaft 26 are enclosed in the first locking hole 28. The spacer 28a, together with the first locking hole 28, encloses the first support shaft 26, whereby the first support shaft 26 is held in the first locking hole 28 in a rotatable state. Instead of providing the spacer 28a, the split surfaces of the base member 23 and the lid member 24 of the holder 22 are aligned with the axial center of the first support shaft 26 so that both the base member 23 and the lid member 24 are aligned. A semi-cylindrical first locking hole may be provided.

  FIG. 6 is a cross-sectional view depicting the rocking member 25 swinging about the first support shaft 26 as a rotation center. As shown in the figure, the holder 22 is provided with an annular groove 30 for accommodating the detent member 25. The annular groove 30 exists between the concave spherical surface of the base member 23 and the concave spherical surface of the lid member 24, and the groove width is formed wider than the width of the anti-rotation member 25. When the anti-rotation member 25 swings with respect to the holder 22 about the first support shaft 26, the anti-rotation member 25 moves in the annular groove 30. That is, the groove width of the annular groove 30 limits the swing range of the rotation preventing member 25 with respect to the holder 22.

  On the other hand, FIG. 7 is a cross-sectional view depicting the swinging of the spherical portion 21 with the second support shaft 26 as the center of rotation. As shown in the figure, the spherical portion 21 swings with respect to the detent member 25 about the second support shaft 27 as a rotation center. The swing of the spherical body portion 21 occurs regardless of the swing of the detent member 25 with the first support shaft 26 as the center of rotation.

  Therefore, as shown in FIG. 3, the axial direction of the through hole 20 of the spherical body portion 21 is the Z direction, the axial direction of the first support shaft 26 is the X direction, and the axial direction of the second support shaft 27 is the Y direction. In this case, the anti-rotation member 25 swings with respect to the holder 22 with the X direction as the center of rotation, while the spherical body 21 swings with respect to the anti-rotation member 25 with the Y direction as the center of rotation. Then, by superimposing the movements of the anti-rotation member 25 and the sphere part 21, the sphere part 21 can swing freely in the X direction and the Y direction with respect to the holder 22. It is possible to connect the shaft member to the structure while allowing the precession of the shaft member fitted in the through-hole 20. At this time, since the spherical surface of the spherical portion 21 is in sliding contact with the concave spherical surfaces 23 b and 24 b provided on the holder, the load acting on the spherical portion 21 is directly applied by the holder 22 without passing through the anti-rotation member 25. Is loaded.

  On the other hand, the first support shaft 26 and the second support shaft 27 are provided along the radial direction of the spherical body portion 21 and surround the axis of the shaft member (dashed line in FIG. 3). The rotation of the spherical portion 21 around the axis is locked by the first support shaft 26 and the second support shaft 27. That is, even if rotational torque acts on the shaft member connected to the spherical body portion 21, the rotational torque is loaded by the first support shaft 26 and the second support shaft 27, and the shaft member rotates around the Z axis. It is connected to the holder 22 without any movement.

  Further, the first support shaft 26 is fitted to a first locking hole 28 provided in the holder 22 without moving with respect to the holder 22, while the second support shaft 27 is fitted to the spherical body portion 21. Since it is fitted in the second locking hole 29 provided in the spherical body portion 21 without moving, the first support shaft 26 and The holder 22, the second support shaft 27 and the sphere portion 21 do not repeatedly collide, and the bearing proof stress is increased and the strength is increased as compared with the conventional spherical joint in which the sphere portion 21 is formed with a long hole. This is advantageous.

  When the damping device 1 is installed between the first structure S1 and the second structure S2 using the spherical joint 2 configured in this way, the shaft end of the rod 13 or the fixed cylinder 12 is provided. Are fitted into the through holes of the sphere.

  As shown in FIG. 1, when the above-described attenuation device 1 is installed between the first structure S1 and the second structure S2 using a pair of spherical joints 2, the first structure S1 and the first structure When relative vibration acts between the two structures S2, the rod 13 translates in the axial direction with respect to the fixed cylinder 12. With this translational movement, a rotational torque acts on the nut member 14 screwed to the rod 13, and as a reaction, the rotational torque acting on the nut member 14 is the same as that on the rod 13. Rotational torque in the opposite direction acts.

  At this time, since the spherical joint 2 allows the precession movement of the rod 13 or the fixed cylinder 12, the spherical member 2 stops the rotation of the rod 13 or the fixed cylinder 12 around the axis. The rotation according to the movement amount by the translational movement of the rod is generated. As a result, in the damping device 1, rotation is transmitted from the nut member 14 to the flywheel 16 and the rotor member 17, and the vibration of the second structure S2 with respect to the first structure S1 is forcibly damped.

  In this spherical joint, in order to allow the precession of the rod 13 or the fixed cylinder 12, it is necessary to form a long hole in the spherical portion 21 or the holder 22 as in the conventional spherical joint. Therefore, it is advantageous in terms of strength in transmitting a huge rotational torque.

  FIG. 8 is a perspective view showing a second example of the detent member, and FIG. 8 is a perspective view showing a third example of the detent member. If the anti-rotation member has the first support shaft 26 and the second support shaft 27, the anti-rotation member does not need to be formed in an annular shape like the anti-rotation member 25 shown in FIG. The anti-rotation member 25A shown in FIG. 8 has a pair of first support shafts 26 and a pair of second support shafts 27, and is formed in a substantially C shape. Further, the anti-rotation member 25B shown in FIG. 9 has one first support shaft and one second support shaft, and a pair of the anti-rotation members 25B are arranged so as to sandwich the spherical body portion. In short, if the first support shaft 26 is the center of rotation of the anti-rotation members 25A and 25B relative to the holder 22, and the second support shaft 27 is the center of rotation of the spherical portion 21 relative to the anti-rotation members 25A and 25B. The shapes of the anti-rotation members 25, 25A, 25B that support the first support shaft 26 and the second support shaft 27 can be arbitrarily changed.

  FIG. 10 is a sectional view showing a second embodiment of the damping device that can be attached to a structure using the spherical joint of the present invention.

  The damping device 3 is a damping device that uses a ball screw device in the same manner as the damping device 1 shown in FIG. 2, but does not include the flywheel 16 as described above, and only has a shear resistance force caused by a viscous fluid. The vibration acting between the one structure S1 and the second structure S2 is attenuated. The damping device 3 has a male thread on the outer peripheral surface and one end in the axial direction is connected to the first structure S1 via the spherical joint 2 and has a hollow portion and is formed in a cylindrical shape. The fixed cylinder 32 connected to the second structure S2 through the spherical joint, and is screwed into the male thread of the rod 31 through a large number of balls and is rotatably supported with respect to the fixed cylinder. A nut member 33; and a cylindrical rotor member 34 which is accommodated in a hollow portion of the device fixing cylinder 32 and has the nut member 33 fixed to one end in the axial direction.

  When the rod 31 advances and retreats in the axial direction with respect to the nut member 33 in accordance with vibration acting between the first structure S1 and the second structure S2 in the previous period, the nut member 33 is moved to the rod. The axial motion of the member 31 is converted into a rotational motion, and the rotor member 34 fixed to the nut member 33 is repeatedly reversed with the rotational motion of the nut member 33.

  A gap between the inner peripheral surface of the fixed cylinder 32 and the outer peripheral surface of the rotor member 34 serves as a viscous fluid containing chamber 35, and when the rotor member 34 rotates, the inner peripheral surface of the fixed cylinder 32 and the A shear resistance acts from the viscous fluid between the outer peripheral surface of the rotor member 34. Since this shear resistance acts as a reaction force against the axial movement of the rod 31, the vibration acting between the first structure S1 and the second structure S2 is damped by the damping device 3. .

  Even in the damping device of the second embodiment, the spherical joint 2 is used to connect to the first structure S1 and the second structure S2, thereby improving the performance of the damping device using the ball screw device. It is possible to fully exhibit and prevent the attenuation device from being damaged by a huge earthquake.

DESCRIPTION OF SYMBOLS 1 ... Damping device, 13 ... Rod, 14 ... Nut member, 2 ... Spherical joint, 21 ... Spherical part, 22 ... Holder, 25 ... Detent member, 26 ... First spindle, 27 ... Second spindle, 28 ... 1st locking hole, 29 ... 2nd locking hole

Claims (6)

A spherical portion to which one end of the shaft member is fixed;
A holder that is fixed to the structure and has a concave spherical surface that slidably contacts the spherical surface of the spherical portion, and encloses the spherical portion;
A detent member disposed between the sphere portion and the holder and locking the rotation of the sphere portion around the axis of the shaft member;
The anti-rotation member is present on a plane orthogonal to the axis of the shaft member and passing through the rotation center of the sphere, and is provided along the radial direction of the sphere, and the first support shafts whose axes are orthogonal to each other And a second spindle,
The first support shaft is fitted in a first locking hole provided in the holder, while the second support shaft is fitted in a second locking hole provided in the spherical body portion,
In response to the precession of the shaft member around the spherical body portion, the detent member swings with respect to the holder about the first support shaft, while the spherical body portion supports the second support shaft. A spherical joint characterized by swinging relative to the detent member as a center. The anti-rotation member is formed in an annular shape surrounding the spherical body portion, and the first support shaft is erected on the outer peripheral surface, while the second support shaft is erected on the inner peripheral surface. Item 5. The spherical joint according to Item 1. The spherical joint according to claim 2, wherein the holder is formed with an annular groove that bisects the concave spherical surface, and the anti-rotation member is accommodated in the annular groove and swings in the annular groove. . The spherical joint according to claim 1, wherein the spherical body portion has a through hole into which the shaft member is fitted. The spherical joint according to claim 1, wherein the spherical body portion is provided integrally with the shaft member to constitute a ball stud. A rod in which a spiral thread groove is formed on the outer peripheral surface and at least one shaft end is connected to the first structure;
A nut member that is rotatably held with respect to the second structure and is screwed into the thread groove of the rod, and reciprocally rotates according to the vibration of the second structure with respect to the first structure;
Attenuating means coupled to the nut member to attenuate the reciprocating rotation of the nut member;
A spherical joint connecting the shaft end of the rod to the first structure,
The spherical joint is
A spherical portion to which one end of the rod is fixed;
A holder that is fixed to the first structure and has a concave spherical surface that slidably contacts the spherical surface of the spherical portion, and that wraps the spherical portion;
A detent member disposed between the sphere part and the holder and locking the rotation of the sphere part around the axis of the rod;
The anti-rotation member is present on a plane perpendicular to the axis of the rod and passing through the rotation center of the sphere, and is provided along the radial direction of the sphere, and the first support shaft and the axes are orthogonal to each other; Having a second spindle,
The first support shaft is fitted in a first locking hole provided in the holder, while the second support shaft is fitted in a second locking hole provided in the spherical body portion,
In response to the precession of the rod around the sphere, the detent member swings with respect to the holder about the first spindle, while the sphere is centered about the second spindle A damping device characterized by swinging with respect to the detent member.

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