JPS60196426A - Damping device for rotor - Google Patents

Abstract

PURPOSE:To make a stable thrust bearing supportable, by setting up an annular retainer, having plural notch parts being fitted in each spherical body, in position around the concave part projectingly installed in the lower surface of a movable body in a state that a part of the spherical body is projected to the inside of an inner circumferential edge part. CONSTITUTION:A thrust rolling bearing 21 consists of plural spherical bodies 22 and a retainer 23. And, this retainer is provided with plural circular notch parts 26 where these spherical bodies 22 are fitted in the side of in an inner side face 25 of an annular body 24. These notch parts are set up in such dimensions and relational positions so as to cause a part of these spherical bodies is situated in more in an inner side than the inner side face of the annular body and each spherical body is rollable and that so as not to slip down in a radial direction. Therefore, each spherical body is no longer restrained, thus a stable thrust bearing supportable.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an improvement in an allocation device mainly used for a vertical rotating body.

[Technical background of the invention and its problems]

Conventionally, vibration damping devices for suppressing the vibrations of vertical rotating bodies include
Various methods have been considered, including one that utilizes the shear resistance of the liquid film as a damping force. This liquid film shear type vibration damping device is designed to perform a damping action using the reaction force when the liquid film is forcibly sheared.
It is characterized by excellent responsiveness.

By the way, such a conventional vibration damping device for a rotating body is generally constructed as shown in FIG.

That is, numeral 1 in the figure is an oil tank whose upper surface is open and which stores lubricating oil P inside. A disk-shaped fixing plate 3 is fixed to the inner surface of the bottom wall of the oil [1] so as to cover the entire inner surface. The upper surface of this fixing plate 3 is formed to be highly accurate and flat so that its peripheral portion serves as the base surface 4, and a shallow recess 5 is formed in the central portion, and furthermore, a four portion 6 is formed in the center portion of the bottom surface of the four portions 5. is formed.

A movable body 7 is disposed within the oil tank 1 so as to face the upper surface of the fixed plate 3.

The movable body 7 is formed into a disk shape as a whole, and is provided with a convex portion 8 extending downward at the center of its lower surface. A thrust bearing 10 is fixed to the center of the upper surface of the movable body 7 to support a lower shaft 9 of a vertical rotating body (not shown).

A thrust load is applied to the movable body 7 with a minute gap Q provided between the movable body 7 and the bottom inner surface of the recess 5 of the fixed plate 3. A rolling bearing is provided to support the movable body 7 so as to be movable in a direction perpendicular to the shaft core. As shown in FIG. 2, the rolling bearing removal unit is composed of a plurality of spheres 2 and a retainer 13 that regulates the relative positional relationship of these spheres 12 in the circumferential direction and the radial direction. The retainer 13 is configured by providing a plurality of holes 14 in an annular plate into which the spheres 12 are fitted, and is arranged so as to slide on the curved surfaces of the four parts 5 of the fixed plate 3 as the spheres 12 roll. On the other hand, the convex portion 8 of the movable body 7
A means for automatically returning the movable body 7 to its home position at all times, such as a spring 15, is stretched between the movable body 7 and the inner surface of the four parts 6 of the fixed plate 3.

This device exhibits a vibration damping function in the following manner. That is, when the vertical rotating body attempts to pass through a critical speed or a twisting force is generated in the vertical rotating body, the vibration of the lower shaft 9 increases, and as a result, the movable body 7
also tries to vibrate horizontally. In this case, the minute gap Q
An oil film is formed inside the movable body 7, so when the movable body 7 vibrates as described above, the oil film is sheared, and the energy consumed during this shearing absorbs vibration energy and exerts a damping effect. ing. In addition, at this time, the spring 15
prevents the movable body 70 from rotating and applies mental force to the movable body 7.

However, the conventional vibration damping device configured as described above has the following problems. That is, since the thrust rolling bearing 11 is in a loose state with respect to the movable body 7 and the fixed plate 3, as the movable body 7 vibrates, the thrust rolling bearing 11 moves against the fixed plate 3.
move above. At that time, for example, as shown in Figure 3,
When the inner surface of the retainer 13 of the rolling bearing 11 and the outer surface of the convex part 8 of the movable body 7 come into close contact, the retainer 13 and the convex part 8 become difficult to separate due to the action of the lubricating oil P, and as a result, the spherical body There was a problem in that the movement of 12 was restricted and whirling force was generated in the rotating body, resulting in a lack of reliability as an allocation device.

[Purpose of the invention]

The present invention was made based on the above circumstances, and its purpose is to prevent the occurrence of a phenomenon in which a thrust rolling bearing comes into close contact with a part of a movable body and its movement is restricted. The object of the present invention is to provide a vibration damping device for a rotating body that can improve reliability.

[Summary of the invention]

The vibration damping device for a rotating body according to the present invention is characterized by a thrust rolling bearing. That is, the thrust rolling bearing incorporated in the device of the present invention has a plurality of spheres arranged between the movable body and the stationary part around a convex part protruding from the lower surface of the movable body, and a plurality of spheres arranged on the inner peripheral edge. The device is provided with an annular retainer having a plurality of notches that fit into each of the spheres so that a portion of each of the spheres always protrudes inward.

〔Effect of the invention〕

With the above configuration, even if the convex part of the movable body makes contact with the rolling bearing, a part of the sphere is always located at the innermost part of the rolling bearing, so the rolling bearing and the convex part always make small contact. becomes. Therefore, even if the movable body and the rolling bearing are in close contact with each other, the contact area is extremely small compared to the conventional art, and the two can be easily separated. Therefore, it is possible to prevent the occurrence of the NIJZ that restrains the sphere as described above, thereby providing a highly reliable device.

[Embodiments of the invention]

Hereinafter, details of the present invention will be explained based on illustrated embodiments.

FIG. 4 shows an embodiment of the present invention, and the same parts as in FIG. 1 are designated by the same reference numerals.

Therefore, detailed explanations of the overlapping parts will be omitted.

The difference between this embodiment and the conventional one shown in Fig. 1 is as follows.
The thrust is on a rolling bearing.

That is, the thrust roller bearing used in this embodiment is composed of a plurality of spheres 22 and a retainer 23 that regulates the circumferential and radial positions of these spheres.
In particular, the shape of the retainer 23 has some drawbacks. As shown in FIG.
The j425 side has a plurality of circular notches 26 into which the spheres 22 fit. Then, when the spheres 22 are fitted into the notch portion 26, a portion of each sphere 22 is located further inside than the inner surface 25 of the annular body 24, and the spheres 22 The dimensions and relative positions are set so that it can roll and not fall off in the radial direction.

With such a configuration, even if the thrust rolling bearing comes into contact with the protrusion 8 of the movable body 7 due to the vibration of the movable body 7, as shown in FIG. It is always the sphere 22 that makes contact on the two sides. Therefore, the contact portion becomes a point contact, and the adhesion is extremely low, so that the rolling bearing 21 and the convex portion 8 are easily separated. Therefore, the sphere 22 is not restricted as in the conventional case.

Therefore, the above-mentioned effects can be achieved.

Note that the present invention is not limited to the above embodiments,
For example, the lower surface of the retainer 23 may be edge-shaped to reduce the contact area between the retainer 23 and the fixed plate 3, and further improve the effectiveness of preventing the phenomenon of spherical restraint.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional view of a conventional vibration damping device for a rotating body that utilizes shearing of a liquid film, Figure 2 is a perspective view showing a thrust rolling bearing in the same device, and Figure 3 is the restraint of a sphere that occurs in the device. Figure 4 is a longitudinal sectional view of a vibration damping device for a rotating body according to an embodiment of the present invention, Figure 5 is a perspective view showing a thrust rolling bearing of the same device, and Figure 6 is a diagram for explaining the phenomenon. FIG. 3 is a diagram for explaining the operation of the device. 1...Oil tank, 3...Fixing plate, 4...Pace surface, 5
゜6...concavity, 7...movable body, 8...! Convex portion, 9.
...Lower shaft, 10...Thrust bearing, 11.21...
・Rolling bearing, 12.22...Spherical, 13.23・
...retainer, 14...hole, 15...spring, 24...
... Annular body, 25 ... Inner surface, 26 ... Notch part,
P...@lubricating oil, Q...minor gap. Figure 1 Figure 2 Figure 4 Figure 2

Claims (1)

[Claims] An oil tank containing lubricating oil, a base installed in a stationary state within the oil tank, and a thrust bearing placed on the base so as to be immersed in the lubricating oil, and a thrust bearing for supporting the vertical rotating body on the upper surface. a movable body that supports the movable body and has a convex portion on its lower surface; a thrust rolling bearing that is movable in a direction orthogonal to the movable body and supported while maintaining a minute gap between the movable body and the base to form an oil film extending only in the horizontal direction; N equipped with means for automatically returning
In the vibration damping device for a rolling body, the thrust rolling bearing includes a plurality of spheres arranged on the lower surface of the movable body between the convex part and the stationary part, and one of the spheres on the inner peripheral edge. 1. A vibration damping device for a rotating body, comprising: an annular retainer having a plurality of notches that fit into each of the spheres so that the retainer always projects inward.