JPS5923138A - Inertia vibro-isolator with accelerator - Google Patents

Abstract

PURPOSE:To vary the vibro-isolating effect according to low or high rate of variation in the speed of displacement by converting linear motion into rotary motion by dint of a ball screw and mounting an inertia element on the shaft thereof via planetary gears. CONSTITUTION:In case displacement occurs at low acceleration because of thermal deformation or other reasons, a main case 1 and a sub-case 2 make relatively reciprocating motion in the axial direction so that a ball nut 3 turns a screw shaft 4. Planetary gears 6 then make revolution, slowly turning an internal gear 7 along with them. A sun gear 3 also turns, making a rotary shaft 9 turn together with an inertia element 10. In this case, an accelerator mechanism will not operate. In another case, where relative displacement occurs at a high acceleration because of earthquake or other reasons, the internal gear 7 cannot follow highly accelerated revolution of the planetary gear 6 due to the inertia force so that relative turn is produced between them. The planetary gear 6 tends to make the rotary shaft 9 make intense accelerated turn, however, cannot follow the turn because of the intertia of the inertia element 10. The inertia therefore acts as a great resistance against the turn to isolate vibration.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is installed between equipment such as piping systems and structures in power plants, chemical plants, etc., and allows low acceleration displacement due to thermal expansion between the two. This invention relates to an improved inertial damping device that suppresses high-acceleration displacements caused by earthquakes, etc.

Conventionally, this type of vibration damping device converts the relative axial direction back motion during vibration between two supporting members connected to the damping target and the structure into the rotational motion of a rotating body, and is installed on this rotating body. In other words, the inertia of the inertial body is utilized, such as by operating the braking body by the direct inertia of the inertial body or by differential rotation between the inertial body and the inertial body caused by the inertia, and bringing it into frictional engagement with one of the supporting members 4. It is known that vibration damping devices suppress the rotation of a rotating body by doing so, and a speed increaser is incorporated between the rotating body and the inertial body of these vibration damping devices to cope with low cycle vibrations. It has been proposed to reduce the size of the inertial body and to reduce the size of the inertial body.

However, in such a vibration damping device with a speed increasing mechanism of a subordinate effect, the resistance is proportional to the multiplier of the speed increasing mechanism even for the slow displacement that should be allowed between the structure and the damped object. There is a problem that it gets old.

The present invention has been made by focusing on the problems of such conventional vibration damping devices.A planetary gear is attached to a rotating body, and a sun gear is attached directly or indirectly to an inertial body, and this is connected to a planetary gear. Further, an internal gear is rotatably provided on the outside of these gears, and speed-up operation is caused by relative rotation between the rotating body and the internal gear due to inertia when the rotating body rotates at high acceleration. The aim is to solve the above problems.

Embodiments of the invention will be described below with reference to the figures. The cylindrical main case 1, which is the first support member, is composed of a large diameter portion 1a and a small diameter portion 1b. A handle 1d is provided on the outside of the main case large-diameter outer end lid 1c, through which it is connected to a vibration damping object such as a structure or piping system. The main case small diameter portion 1b is
The inner side of the cylindrical sub-case 2, which is a second support member, is freely received in and out in the axial direction.

The sub-case 2 can be connected to a vibration damping object or structure via a handle 2a at its outer end, and is provided with a ball nut 3 at its inner end.

The threaded rod 4, which is a rotating body, is rotatably supported by the intermediate wall 1c inside the main case 1 at the intermediate portion, and is supported by the nut 3 at the outside.
It is received in the sub case 2 so as to be able to move in and out in the axial direction. The threaded rod 4 has a mounting plate 5 at the end inside the main case large diameter part 1a, and three planetary gears 6 are mounted on this mounting plate 5.
It is supported on concentric circles.

The planetary gear 6 meshes with an internal gear 7 rotatably provided in the large diameter portion 1a of the main case on the outside, and meshes with a sun gear 8 fixed to one end of the rotating shaft 9 on the inside.

The rotating shaft 9, which is a driven rotating body, has one end rotatably supported by the main case large-diameter lid 1c, and has a sun gear 8 meshing with the planetary gear 6 at the other end.

An inertial body 10 is fixed to an intermediate portion of the rotating shaft 9.

Next, the effect will be explained. This vibration damping device connects either the main case 1 or the sub case 2 to a piping system or other vibration damping target.
The other is used by connecting it to the construct.

Now, due to thermal deformation, there is a slow,
When a displacement with low acceleration occurs, main case 1 and sub case 2
move in and out in the axial direction, and the ball nut 3 is connected to the threaded rod 4.
Rotate. The planetary gear 6 revolves together with the threaded rod 4, and in conjunction with this, the internal gear 7 slowly rotates together.

The sun gear 8 also rotates to rotate the rotating shaft 9 together with the inertial body 10.

In this case, the acceleration mechanism does not operate because the displacement is a low acceleration. In this way, slow relative displacement between the damping target and the structure is easily tolerated.

On the other hand, when a high-acceleration phase displacement occurs between the structure and the damping target due to an earthquake, etc., the internal gear 7 cannot follow the high-acceleration revolution of the planetary gear 6 due to inertia, and the gap between the two phase rotation occurs. As a result, the planetary tooth worm 6 rotates at high speed and attempts to rotate the rotating shaft 9 at an increased speed, but the inertial body 10 cannot follow this rotation due to inertia, resulting in a large resistance to rotation. This inertial resistance provides a damping effect.

The present invention is not limited to the embodiments described above. For example, a conventional vibration damping device of this type can be combined with another speed increaser to increase the speed in two stages. In this case, one of the speed increasers can have a function as an inertial body.

Furthermore, the present invention does not directly fix the inertial body 10 to the rotating shaft 9, but elastically connects the two so that relative rotation occurs during high acceleration rotation, and this relative rotation causes various braking operations. It can be applied to other known vibration damping devices that utilize inertial resistance.

Furthermore, contrary to the illustrated embodiment, the present invention can also be applied to a case where the threaded rod is fixed and the nut is a rotating body.

As explained above, according to the present invention, a differential gear speed increasing mechanism consisting of a planetary gear 6, an internal gear 7, and a sun gear 8 is used as a rotation speed increasing mechanism in a vibration damping device that utilizes inertia. , and has a structure in which the internal gear 7 is rotatably incorporated, so that when there is a slow displacement between the structures and vibration damping objects,
The internal gear 7 rotates integrally with the planetary gear 6 and does not increase speed, so there is little resistance to displacement and no unreasonable force is applied to the vibration damping target. During high-acceleration displacement, the internal gear 7 is relatively fixed due to inertia, causing a speed-increasing action and isostatically increasing the mass of the inertial body 10. As a result, the vibration damping device is small and lightweight, but has a large capacity. This has the effect of being able to obtain the following.

[Brief explanation of drawings]

Fig. 1 is a sectional view, Fig. 2 is a sectional view of Fig. 11-ll,
FIG. 3 is a sectional view of another embodiment. 1... Main case, 2... TJL case, 3... Natsu 1-, 4... Twisting stick, 6... Planet Uchiyama, 7... Uchiro l! l-枦1te, 8 sun tooth city, 9... rotating shaft, 10...
...11′ inertial body.

Claims (1)

[Claims] The reciprocating motion in the direction of the relative axis between one support member connected to the vibration damping target and the other support member supported by the structure is converted into rotational motion of a rotating body, and the rotation of this rotating body is transferred to the driven rotating body. In the inertial vibration damping device, the rotation of the driven rotating body is suppressed by using the inertia of an inertial body directly or indirectly connected to the driven rotating body. A sun gear that meshes with the planetary gear is attached to the rotating body, and an internal gear that meshes with the planetary gear is rotatably provided on the outside of the idler gear, and when the rotating body rotates at high acceleration, the sun gear meshes with the planetary gear. An inertia braking device with a speed increaser, characterized in that the sun gear is rotated at an increased speed by the relative rotation of the gear.