JPS6091014A - Vibro-isolating device for rotary unit - Google Patents

Abstract

PURPOSE:To decrease frictional contact resistance between a retainer and spacers so as to prevent a decrease of vibro-isolating action, by arranging ball members between the retainer and the spacer brought into contact with this retainer. CONSTITUTION:An annular disc-shaped retainer 12 provides on a concentric circle three opening holes 21 spacing an equal distance, and the first ball members 11 are respectively arranged in these opening holes 21. The retainer 12 arranges on its upper and bottom surfaces a pair of annular disc-shaped spacers 9, 10 to be opposed interposing the ball members 11 therebetween. While the retainer 12 provides on its bottom surface three hollowed parts 22 on a concentric circle, and the second ball members 23 are respectively arranged in these hollowed parts 22. Then this ball member 23 is arranged so as to separate the retainer 12 from the spacer 10 in the lower side. In this way, the retainer 12 enables its free movement only through rolling friction due to the second ball members 23 without causing direct contact with the spacer 10.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an improvement of a vibration damping device used mainly 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, but among them there is one that uses 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, and 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.

In other words, 1 in the figure is an oil tank with an open top surface and containing lubricating oil P inside. A portion 2 located at the peripheral edge of the inner surface of the bottom wall of this oil tank 1 also serves as a base and has a height of 1q. Precisely formed flat.

A recess 3 is formed in the center of the inner surface of the bottom wall of the oil tank 1.

A movable body 4 is disposed within the oil tank 1 so as to face the inner surface of the bottom wall of the oil tank 1.

The movable body 4 is formed into a disk shape as a whole, and a convex portion 5 that enters the recess 3 is formed at the center of its lower surface, and a vertical rotating body (not shown) is formed at the center of its upper surface. A positive one bearing 7 supporting the lower shaft 6 is fixed. C1: A small gap Q is provided between the movable body 4 and the bottom inner surface of the recess 3 to support the thrust load applied to the movable body 4, and to support the thrust load applied to the movable body 4. A thrust rolling bearing β- is provided to support the movable body 4 so as to be movable in a direction orthogonal to the axis. The rolling bearing stop includes a first annular spacer 9 fixed to the lower surface of the movable body 4, a second annular spacer 10 fixed to the inner surface of the bottom of the recess 3, and these first and second spacers. It is composed of a plurality of spheres 11 interposed between spacers 9 and 10, and a retainer 12 that keeps the relative positional relationship of these spheres 11 in the circumferential direction always constant. The above retainer 2 is
It is constructed by providing a hole in an annular plate into which the sphere 11 is inserted, and is arranged so as to slide on the upper surface of the second spacer 10 as the sphere 11 rolls. On the other hand, between the convex portion 5 of the movable body 4 and the inner surface of the concave portion 3, a means for automatically returning the movable body 4 to the home position at all times, such as a spring 13, is stretched.

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 when a whirling force is generated in the vertical rotating body, the vibration of the lower shaft 6 increases, and as a result, the movable body 4 also tries to vibrate in the horizontal direction. do. In this case, since an oil film is formed within the minute gap Q, the movable body 4
When it vibrates, the oil film is sheared, and the energy consumed during this shearing absorbs the vibration energy and exerts a vibration damping function. In addition, at this time, the spring 13 is
Rotation of the movable body 4 is prevented and mental force is applied to the movable body 4.

However, the conventional allocation device configured as described above has the following problems.

That is, the retainer 12 and the lower second spacer 10
The frictional force exerted at the contact portion between the retainer 12 and the spheres 11 is large, and the movement of the spheres 11 is restricted at the portions where the retainer 12 and the spheres 11 come into contact. In this case, smooth radial movement of the movable body 4 is hindered, leading to a decrease in damping force. Therefore, there was a problem in that the vibration damping effect deteriorated and the reliability as a vibration damping device was lacking.

[Purpose of the invention]

The present invention was made in view of the above circumstances, and its purpose is to prevent the movement of the spheres from being restricted due to the contact friction resistance between the retainer and the spacer, which constitute a part of the thrust rolling bearing. It is an object of the present invention to provide a highly reliable vibration damping device for a rotating body that can prevent the vibrations from occurring and always generate a sufficient damping force.

[Summary of the Invention] The gist of the present invention is to arrange a sphere between a retainer and a spacer that contacts the retainer to reduce the contact frictional resistance between the retainer and the spacer.

That is, the present invention includes an oil tank containing lubricant, a base stationary in the oil tank, and a vertical rotating body disposed on the base so as to be immersed in the TA lubricant. a movable body supporting a supporting thrust bearing; and a movable body provided between the movable body and a stationary part in the oil tank, the movable body being movable in a direction orthogonal to the axis of the rotating body; A rotating device comprising: a thrust rolling bearing that supports the movable body and the base while maintaining a small gap capable of forming an oil film extending horizontally between the movable body and the base; and means for automatically returning the movable body to a home position. In the body vibration damping device, the thrust rolling bearing is configured to include a plurality of first spheres inserted between the bottom surface of the oil tank and the lower surface of the movable body, a retainer that limits the position of the spheres, and the spheres. and a pair of spacers inserted between the bottom surface of the oil tank and the lower surface of the movable body, and a plurality of second spheres inserted between the retainer and one of the spacers that abuts the retainer. This is how it was done.

〔Effect of the invention〕

According to the present invention, by using rolling resistance as the contact frictional resistance between the retainer and the spacer, the above-mentioned resistance can be extremely reduced by C. For this reason, the retainer becomes very easy to move, and problems such as restricting the movement of the spheres do not occur. Therefore, a sufficient damping force can always be obtained, and a stable and reliable vibration damping effect can be obtained.

[Embodiments of the invention]

Hereinafter, details of the present invention will be explained with reference to illustrated embodiments.

Figures 2(a), (b) and f show the main parts of a vibration damping device according to an embodiment of the present invention, that is, only the rolling bearing part is removed from the thrust 1. ]~A longitudinal sectional view of the rolling bearing, FIG. 2(b) is a view of the retainer and sphere in FIG. 2(a) seen from below. Note that the same parts as in FIG. 1 are indicated by the same reference numerals. In this embodiment, in addition to the configuration shown in FIG. 1 described above, a sphere is disposed between a retainer and a spacer that constitute a part of the thrust rolling bearing.

That is, the annular plate-shaped retainer 12 has the shape shown in FIG. 2(a) (
As shown in b), three openings 21 are provided at equal intervals on a concentric circle, and the first sphere 11 is placed in each of these openings 21. A pair of annular plate-shaped spacers 9 and 10 are arranged on the upper and lower surfaces of the retainer 12 to face each other with the spherical body 11 in between. Furthermore, three recesses 22 are provided on the lower surface of the retainer 12 on a concentric circle, and a second sphere is arranged in each of the recesses 22. This sphere 23 separates the retainer 12 from the spacer 10 on the lower side.

With such a configuration, the retainer 12 is connected to the spacer 10
The retainer 12 moves freely only by the rolling friction caused by the second spheres 23 without making direct contact with the second spheres 23. Here, since the retainer 12 normally has a higher specific gravity than the lubricating oil in the oil tank 1, it goes without saying that it does not come into contact with the upper spacer 9.

Therefore, there is no problem such as the movement of the first sphere 11 being restricted by the retainer 12, and the sphere 11 can move freely. Therefore, a sufficient damping force can always be generated, and a stable vibration damping effect can be obtained.

Note that the present invention is not limited to the embodiments described above. For example, if the specific gravity of the retainer is smaller than that of the lubricating oil in the oil tank, a second sphere may be inserted between the upper part of the retainer and the upper spacer.

In addition, the shape of the retainer and spacer is not limited to the annular plate, and the number of spheres used is also 3fJ.
Of course, there are other things that are not limited to A. In addition, various modifications can be made without departing from the gist of the present invention.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of a conventional vibration damping device for a rotating body that utilizes shearing of a liquid film, and FIG. FIG. 2 is a vertical cross-sectional view and a plan view showing only one part. DESCRIPTION OF SYMBOLS 1... Oil tank, 2... Base part, 3... Recessed part, 4... Movable body, 5... Convex part, 6... Lower shaft,
7... Thrust bearing, L... Thrust rolling bearing, 9... First spacer, 10... Second spacer, 11... First sphere, 12... Retainer, 21...
... Opening hole, 22 ... Recessed part, 23 ... Second sphere, P
...Lubricating oil, Q...Small gap. Applicant's agent Patent attorney Takehiko Suzue Figure 1 22 (a)

Claims (1)

[Claims] An oil tank containing lubricating oil, a base provided in a stationary state within the oil tank, and a thrust bearing disposed on the base so as to be immersed in the lubricating oil and supporting a vertical rotating body. a movable body, and a movable body provided between the movable body and a stationary part in the oil tank, the movable body being movable in a direction perpendicular to the axis of the rotating body, and between the movable body and the base; A vibration damping device for a rotating body, comprising: a thrust rolling bearing that supports the movable body while maintaining a minute gap capable of forming an oil film extending in the horizontal direction; and means for automatically returning the movable body to a fixed position. The thrust rolling bearing includes a plurality of first spheres inserted between the bottom surface of the oil tank and the bottom surface of the movable body, a retainer that limits the position of the spheres, the spheres, the bottom surface of the oil tank, and the bottom surface of the movable body. and a plurality of second spheres inserted between the retainer and one of the spacers that abuts the retainer. Body vibration damping device.