JPH0719241A - Bearing unit - Google Patents

Abstract

PURPOSE:To make a spring constant in a bearing supporting part able to be set and changed optionally extending over a wide range, although it is so simple as merely using those of inexpensive elastic supporting members including a commercial O-ring or the like, and such one as being small in an axial required space. CONSTITUTION:In this bearing unit, a bearing supporting position of a sleeve 3 supporting a bearing 2 and a sleeve supporting position of an O-ring 4 for elastically supporting this sleeve 3 on a housing 5 both are displaced in the axial direction, and a spring constant is made variable by means of the displacement as its constitution.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing device used, for example, when a rotary shaft of a gas turbine engine is rotatably supported by a housing. More specifically, the setting of the spring constant of the bearing support portion is changed. The present invention relates to a bearing device that absorbs and relaxes the vibration of the rotating shaft.

[0002]

2. Description of the Related Art As a bearing device having this type of vibration absorbing function, conventionally, as shown in FIG. 3, a radial bearing 12 for rotatably supporting a rotary shaft 11 and a cage-shaped bearing as shown in FIG. A cylindrical sleeve that holds a radial bearing 12 that rotatably supports a rotating shaft 11 as shown in FIG. 5, as shown in FIG. No. 15 is supported by the housing 14 via elastic O-rings 16, 16 on both sides of the bearing 12 in the axial direction (see Japanese Utility Model Laid-Open No. 54-10141, etc.), or as shown in FIG. A sealing ring 17 is interposed between a cylindrical sleeve 15 that holds a radial bearing 12 that rotatably supports the rotating shaft 11 and a housing 14 outside the cylindrical sleeve 15. In addition, as shown in FIG. 7 or 8, the sleeve 15 is concentrically supported by the housing 14 by using an elastic support plate 18 made of a leaf spring having a shape having an outward protruding piece 18a. Things (Actual Kai 51-4
No. 5547), and the like are known.

[0003]

Among the conventional bearing devices described above, in the case of the configuration shown in FIGS. 3 and 4, by changing the cage shape of the bearing support 13,
Although the spring constant can be changed over a relatively wide range, use of such a cage-shaped bearing support 13 requires a large space along the axial direction, and the entire bearing device becomes large. In addition to being easy, the shape of the bearing support 13 is complicated and the cost required for its fabrication is high.

In the case of the structure shown in FIG. 5, the space and cost required in the axial direction are small, but the spring constant K of the supporting portion is K = 2k and the elasticity is O, as shown in FIG.
It is largely governed by the rubber elasticity k of the ring 16, and therefore it is difficult to arbitrarily set the spring constant over a wide range. In particular, the spring constant cannot be reduced.

Further, in the case of the configuration shown in FIG. 6, the elastic support plate 18 made of a leaf spring having a special shape as shown in FIGS. 7 and 8.
Not only is it necessary to use the spring constant, but the spring constant of the supporting portion is governed by the material and shape of the leaf spring, making it difficult to change the setting of the spring constant over a wide range.

The present invention has been made in view of the above-mentioned circumstances. It is not necessary to use a member having a special shape, a commercially available inexpensive O-ring or the like is used, and the space in the axial direction is reduced. However, over a wide range of spring constants,
It is an object of the present invention to provide a bearing device that can be set and changed in a particularly small direction.

[0007]

In order to achieve the above object, a bearing device according to the present invention comprises a sleeve for supporting a bearing for rotatably supporting a rotary shaft, and an elastic support for the sleeve on a housing outside thereof. And a ring-shaped elastic supporting member for displacing the bearing supporting position of the bearing and the housing supporting position of the sleeve in the axial direction of the rotating shaft.

[0008]

According to the present invention, a commercially available rubber O-ring is used as the ring-shaped elastic supporting member by displacing the bearing supporting position of the sleeve and the supporting position of the sleeve of the housing in the axial direction of the rotary shaft. Even if you do that
The spring constant, which is uniquely determined by the material and size of the ring, can be arbitrarily changed, that is, reduced, to soften the bearing by the principle of leverage.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view of a main part showing a bearing device according to an embodiment of the present invention. In FIG. 1, reference numeral 1 is a rotary shaft of a gas turbine engine, and 2 is a radial bearing for rotatably supporting the rotary shaft 1. It is a bearing. Reference numeral 3 is a cylindrical sleeve, and the radial bearing 2 is provided on one end side in the axial direction of the sleeve.
The outer race 2a is fitted to support the bearing 2, and two ring grooves 3a, 3a are formed on the outer peripheral surface on the other end side in the axial direction at appropriate intervals in the axial direction. ing.

4, 4 are ring grooves 3a of the sleeve 3,
An O-ring as a ring-shaped elastic support member fitted in 3a. By elastically contacting the O-rings 4 and 4 with the inner peripheral surface of the housing 5, the sleeve 3 is elastically supported by the housing 5. With the above configuration, the supporting position of the bearing 2 with respect to the sleeve 3 and the housing 5 of the sleeve 3
And the supporting position with respect to are displaced in the axial direction of the rotating shaft 1.

In the bearing device having the above-described structure, the spring constant K of the bearing supporting portion is, as shown in FIG. 2, the axial direction between the supporting position of the bearing 2 with respect to the sleeve 3 and the supporting position of the sleeve 3 with respect to the housing 5. Distance is Lb, two O
The axial distance between the rings 4 and 4 is Lo, and each O ring 4 is
When the spring coefficient of 4 is k, K = k · Lo ² / {Lb ² + (Lo + Lb) ² }, and a large amount of change of the bearing support portion with respect to the load F can be obtained by the principle of leverage. Also, here, Lb and Lo
By changing, the spring constant K can be adjusted arbitrarily.

[0012]

As described above, according to the present invention, by displacing the bearing supporting position of the sleeve and the supporting position of the sleeve of the housing in the axial direction of the rotary shaft, the bearing is utilized by utilizing the principle of leverage. Since the spring constant of the support part can be lowered, and the set value of the spring constant can be adjusted by changing the displacement amount in the axial direction,
It is not necessary to use a special shape such as a cage as the sleeve or a special shape made of leaf springs as the elastic support member, and use a commercially available elastic O-ring etc. to simplify the structure. In addition, it is possible to improve the vibration absorbing performance by arbitrarily setting the spring constant over a wide range at a low cost and by reducing the required space in the axial direction to reduce the size as a whole.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a main part of a bearing device according to an embodiment of the present invention.

FIG. 2 is a schematic diagram for explaining a spring constant in the bearing device.

FIG. 3 is a vertical cross-sectional view of a main part showing an example of a conventional bearing device.

FIG. 4 is a perspective view of a main part of FIG.

FIG. 5 is a vertical cross-sectional view of a main part showing another example of a conventional bearing device.

FIG. 6 is a vertical cross-sectional view of a main part showing another example of a conventional bearing device.

7 is an enlarged perspective view of a main part showing one of the parts in the bearing device of FIG.

8 is an enlarged perspective view of a main part showing another part of the bearing device of FIG.

9 is a schematic diagram for explaining a spring constant in the bearing device of FIG.

[Explanation of symbols]

 1 rotating shaft 2 bearing 3 sleeve 4 O-ring (ring-shaped elastic support member) 5 housing

Claims (1)

[Claims] 1. A sleeve, which supports a bearing that rotatably supports a rotating shaft, and a ring-shaped elastic support member, which elastically supports the sleeve on a housing outside thereof, and a bearing support position of the bearing and a sleeve support position. A bearing device characterized in that the position relative to the housing is displaced in the axial direction of the rotary shaft.