KR100760629B1 - Tilting-foil journal bearing - Google Patents

Abstract

A tilting-foil journal bearing is provided to improve a damping effect by overlapping a tilting pad with a foil, and to reduce vibration by improving the adapting ability to a load supporting ability and a misalignment. A tilting-foil journal bearing includes a bearing housing(1), more than one tilting pad(2), and a foil(3). The bearing housing has more than one pivot groove(11) at an inner wall of a shaft hole penetrating inside thereof. The tilting pad is rotatably installed at the pivot groove formed inside the bearing housing, and has an inclined surface. The foil has one end fixed to an inner surface of each tilting pad, and has the rotary shaft inside thereof. The foil includes a foil plate(31) of a plate shape with the same curvature as that of the tilting pad, and a bumper(32) having the same curvature as that of the foil plate. The bumper has a plurality of wrinkles(322) formed along a circumference.

Description

Tilting Foil Journal Bearings {TILTING-FOIL JOURNAL BEARING}

1 is a perspective view showing another example of a tilting-foil journal bearing according to the present invention;

FIG. 2 is a cross sectional view of the tilting-foil journal bearing shown in FIG.

3 is a cross-sectional view of another example of a tilting-foil journal bearing according to the invention,

4 is a perspective view of an example of a foil plate and a bumper provided in a tilting-foil journal bearing according to the present invention;

5 is a perspective view of another example of a foil plate and a bumper provided in the tilting-foil journal bearing according to the present invention;

6 is another example of the bumper provided in the tilting-foil journal bearing according to the present invention;

  6A shows the state of the bumper when the load is small;

  6B shows the state of the bumper when the load is large,

7 is a cross-sectional view of another example of a tilting-foil journal bearing according to the invention,

8 is a cross-sectional view showing a state in which the rotating shaft is tilted to one side in the tilting-foil journal bearing according to the present invention;

9 is a sectional view of an example of a conventional foil bearing,

10 is a sectional view of an example of a conventional tilting bearing.

<Description of the symbols for the main parts of the drawings>

1: bearing housing

   11: Pivot Groove

2: tilting pad

   21: pivot axis

   22: slope

3: pump foil

   31: foil plate

      311: fixing hole

   32: bumper

      321: fixing hole

      322 folds

The present invention relates to a bearing, and more particularly, to a journal bearing for supporting rotatably horizontally with a rotating shaft.

In particular, while supporting the rotating shaft horizontally, the tilting pad and the air foil is provided to provide a double damping effect, and the load supporting ability and the adaptation to the misalignment is improved, thereby supporting the rotating shaft more stably, The present invention relates to a tilting foil journal bearing having improved rotational stability by effectively reducing vibration and the like.

In general, the bearing is a means for supporting the axis of rotational movement and the axis of reciprocating movement to keep the movement smoothly. These types of bearings can be classified into sliding bearings and rolling bearings according to the contact types of the shafts and bearings, and are classified into journal bearings and thrust bearings according to the load direction of the shafts.

The sliding bearing is a sliding friction bearing in which a thin oil film or a pressure gas is interposed between the shaft and the bearing metal to perform relative sliding movements. Bearing.

Such a journal bearing has a shaft hole formed in the center thereof, and is pressed and mounted in the bearing housing. In the journal bearing mounted on the bearing housing, a shaft is inserted into and mounted in a shaft hole formed in a longitudinal direction, wherein a proper gap is maintained between an inner surface of the shaft hole and an outer surface of the shaft, and a through hole formed in the bearing housing is formed in the gap between the shaft hole and the shaft. The oil supplied through the hole is applied to the inner circumferential surface of the journal bearing to form an oil film, and the formation of the oil film supports rotation without directly contacting the shaft hole and the shaft. However, for the high efficiency and light weight of industrial machinery, the rotational speed of industrial machinery is gradually developing at high speed. As a result, conventional journal bearings require bearings with improved misalignment or attenuation at high speed. Air foil bearings (hereinafter, abbreviated as 'foil bearings') have been developed and used.

As shown in FIG. 9, the air foil bearing has a sleeve 120 having a hollow portion 120a therein, and the sleeve 120 and the rotation shaft so that the rotation shaft 110 is accommodated and rotated. A plurality of airfoils 130 are disposed in the hollow portion 120a between the 110.

The air foils 130 are each formed in an arc shape and have an elastic force, and are arranged along the circumferential direction of the sleeve 120. That is, one end of the air foil 130 is fixed to the inner surface of the sleeve 120, the other end is installed in a state overlapping or spaced apart from the adjacent air foil (130). At this time, the fixing between the sleeve 120 and the air foil 130 is fixed to one end of the air foil 130 is inserted into the slot formed on the inner surface of the sleeve 120.

In the foil bearing configured as described above, when the rotating shaft 110 slowly rotates in the hollow portion of the sleeve 120, a high-pressure air layer is formed between the rotating shaft 110 and the air foil 130. As a result of the floating shaft 110, the rotating shaft 110 rotates while maintaining a constant distance from the air foil 130. In this case, the air foil 130 serves as a bumper for supporting the rotating shaft 110. Do it.

However, the conventional foil bearing configured as described above has a problem in that misalignment permitting ability, rigidity control, and damping function are excellent, but stability at high speed is difficult to obtain.

In addition, a tilting pad bearing (Tilting Pad Bearing) has been developed and used to supplement the disadvantages of the conventional journal bearing as described above.

As shown in FIG. 10, the tilting pad bearing (hereinafter, referred to as a 'tilting bearing') has a plurality of tilting pads therein in the circumferential direction in the shaft hole 220 formed through the inside of the bearing housing 210. 230 is provided. The tilting pad 230 has the same curvature as that of the bearing housing 210 to form an inner circumferential surface of the bearing housing 210, and a plurality of oil supply holes extending to the tilting pad 230 are provided in the bearing housing 210. The oil is supplied to the contact surface of the tilting pad 230 with the rotating shaft, and the tilting pad 230 flows in the centrifugal direction so as to be spaced apart from each other by a predetermined distance so as to smoothly rotate the rotating shaft. It is installed.

In addition, the tilting pad 230 is installed such that the outer peripheral center portion of the tilting pad 230 is supported by the pivot 230a so that one end thereof does not touch the inner surface of the bearing housing 210 or swing beyond a predetermined range.

However, the above-mentioned tilting bearing has excellent stability at high speed but has a problem of weak alignment or thermal expansion.

The present invention is to solve the above problems, not only can support the rotating shaft more stably, but also the damping performance, load bearing capacity and the ability to adapt to the misalignment is improved to support the rotating shaft more stably while shaking or vibration An object of the present invention is to provide a tilting foil journal bearing having improved rotational stability by effectively reducing the back.

In particular, an object of the present invention is to provide a tilting foil journal bearing having an air foil and a tilting pad, which can obtain both the effects of the air foil and the tilting pad.

The present invention for achieving the above object is a bearing housing formed with at least one pivot groove in the inner wall of the shaft hole formed through the inside; At least one tilting pad rotatably installed in a pivot groove formed in the bearing housing; One end portion is fixedly installed on the inner surface of each of the tilting pads, and a rotation shaft is inserted into the inner side.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily understand and reproduce.

1 is a perspective view showing an example of a tilting-foil journal bearing according to the present invention, and FIG. 2 is a cross-sectional view of the tilting-foil journal bearing shown in FIG.

As shown, the tilting-foil journal bearing according to the present invention is provided with both a tilting bed 2 and a foil 3 inside the bearing housing 1.

As shown in FIG. 1, the bearing housing 1 has a ring-shaped groove along the inner circumferential surface of a groove in which the following parts are installed in the middle portion of the groove, and a plurality of pivot grooves are formed in the center portion of the groove. (11) is formed.

The tilting pad 2 is rotatably installed in the pivot groove 11 formed in the bearing housing 1.

The tilting pad 2 is an arc-shaped plate that is bent at the same curvature as the inner curvature of the bearing housing 1, and a pivot shaft 21 is formed on an outer circumferential surface of the tilting pad facing the bearing housing 1. Is coupled to the pivot groove 11 is rotated in the circumferential direction.

The tilting pad 2 may be provided in plural as shown in the drawing, and is provided to be spaced apart from each other by a predetermined distance so as not to hit each other when rotated. In addition, the tilting pad 2 cuts both ends facing outward as shown in FIG. 3 to form an inclined surface 22 thinner than other portions to increase the range in which the tilting pad 2 can be rotated. .

In addition, since the pivot shaft 21 of the tilting pad 2 has an outer diameter smaller than the inner diameter of the pivot groove 11, the pivot shaft 21 may flow in the pivot groove 11 to obtain a pumping effect. Can be.

As described above, the foil 3 is provided on the inner facing surface of each of the tilting pads 2 rotatably fixed to the inner circumferential surface of the bearing housing 1.

The foil 3 elastically supports the rotating shaft 110 to absorb the load applied to the rotating shaft 110 and to enable the smooth rotation of the rotating shaft 110. One end of the foil is tilted. It is fixed to the end of the pad (2) by fixing means such as rivets or screws, and the other end is freely prevented to support the rotating shaft 110 elastically around the fixing portion.

The foil 3 may be configured by combining the foil plate 31 and the bumper 32 as shown.

The foil 3 is to increase the damping effect by installing a bumper 32 on one side of the foil plate (31).

The bumper 32 may have a structure capable of simply supporting a part of the foil plate 31 as a means for enhancing the damping effect by reinforcing the elastic force of the foil plate 31, but as shown in FIG. By using the 322 formed along the circumferential surface, the foil plate 31 can be evenly supported.

One end of the bumper 32 is fixed to one end of the tilting pad 2 together with the fixing part of the foil plate 31 and the fixing means is as described above. The bumper 32 is installed at a position between the foil plate 31 and the tilting pad 2 as shown, and the unfixed end is left free to allow the foil plate 31 to be loaded by the rotating shaft 110. As a result, the wrinkles 322 are expanded and contracted to buffer the load that is erased on the foil plate 31.

The bumper 32 may also be configured by dividing a circular ring having a plurality of corrugations 322 into two or four or more or less or less, such as the foil plate 31, and the length of the foil plate 31. When the wrinkles 322 are increased by being pushed by the load by the rotating shaft 110, the freely left end should be made to a length such that it does not touch the other bumper 32.

The pleats 322 formed on the bumper 32 may be formed in the circumferential direction or may be formed in the longitudinal direction (not shown) of the rotating shaft as shown in FIG. 4 or 5. In addition, the pleats 322 may have a plurality of rows, and the pleats 322 of different rows may be staggered with each other.

As described above, when the foil 3 is divided into several pieces, the tilting pad 2 should be divided in the same manner, and as shown in the drawing, the tilting pad 2 may be divided into two or four portions.

In addition, the foil 3 may be configured to be divided into three, as shown in Figure 7, wherein the tilting pad (2) is also divided into three.

Figure 6 is another example of the bumper 32 constituting the foil (3) provided in the tilting-foil journal bearing according to the invention is composed of two corrugated plate overlap. Thus, by constituting the corrugated plate in duplicate, the rigidity control and damping function is improved.

That is, as shown in Fig. 6A, when the load is small, the rigidity is attenuated by only the internal bumper 32a. When the load is large, the load also affects the external bumper 32b as shown in Fig. 6B. This results in a double damping effect.

Hereinafter, the operation of the tilting-foil journal bearing configured as described above is outlined.

8 illustrates an example when a load eccentrically is applied to one side of the rotating shaft.

As shown in the figure, when the rotating shaft 110 is eccentrically to one side by an external force, the rotating shaft 110 is opposed to the end of the foil plate 31 in the eccentric direction and exerts a force on the end portion of the foil plate 31. The bumper 32 provided between the plate 31 and the tilting pad 2 contracts to absorb the load, and the tilting pad 2 is rotated about the pivot shaft 21 to rotate as shown in FIG. 8. The part which meets 110 is pushed toward the housing 1 side, and the opposite side is pulled to the center.

By doing so, the load of the rotary shaft 110 is absorbed and the rotary shaft 110 can achieve stable rotation.

In addition, when the eccentricity of the rotating shaft 110 or vibration of the rotating shaft occurs in this process, the vibrating rotating shaft hits the foil plate 31 and the tilting pad 2 rotates to rotate the foil plate 31 in the direction of the rotating shaft. ), The bumper 32 and the tilting pad 2 rotate, thereby preventing them from being damaged by the oscillating axis of rotation.

While the invention has been described with reference to the preferred embodiments, many modifications and variations are possible without departing from the scope and spirit of the invention as set forth by the claims below.

As described in detail above, the present invention can increase the damping effect by overlapping the tilting pad and the foil, the load bearing capacity and the ability to adapt to misalignment is improved to support the rotating shaft more stably while generating a vibration phenomenon or vibration There is an effect that can effectively reduce the back.

While the present invention has been described with reference to the accompanying drawings, it will be apparent to those skilled in the art that many various obvious modifications are possible without departing from the scope of the invention from this description. Accordingly, the invention can only be construed limited by the words of the appended claims.

Claims (8)

delete delete delete delete A bearing housing 1 having one or more pivot grooves 11 formed on an inner wall of the shaft hole formed through the inside thereof; One or more tilting pads (2) rotatably installed in the pivot grooves (11) formed in the bearing housing (1), the outer side of both ends of which are inclined surface (22) thinner than the suspension; One end of the foil is fixedly installed on the inner surface of each of the tilting pads 2, and the rotation shaft 110 is inserted into the inside, and includes a foil 3 installed therein. The foil 3 is further provided with a plate-shaped foil plate 31 having the same curvature as the tilting pad 2 and a bumper 32 having the same curvature as the foil plate 31, Tilting foil journal bearing, characterized in that the bumper 32 has a plurality of corrugations (322) formed in the circumferential direction. A bearing housing 1 having one or more pivot grooves 11 formed on an inner wall of the shaft hole formed through the inside thereof; One or more tilting pads (2) rotatably installed in the pivot grooves (11) formed in the bearing housing (1), the outer side of both ends of which are inclined surface (22) thinner than the suspension; One end of the foil is fixedly installed on the inner surface of each of the tilting pads 2, and the rotation shaft 110 is inserted into the inside, and includes a foil 3 installed therein. The foil 3 is further provided with a plate-shaped foil plate 31 having the same curvature as the tilting pad 2 and a bumper 32 having the same curvature as the foil plate 31, Tilting foil journal bearing, characterized in that the bumper 32 has a plurality of corrugations (322) formed in the longitudinal direction of the axis of rotation. The method according to claim 5 or 6, Tilting foil journal bearing, characterized in that the plurality of corrugations (322) formed in the bumper (32) has a plurality of rows, the corrugations (322) of different rows are staggered with each other. The method of claim 7, wherein Tilting foil journal bearing is characterized in that the bumper 32 has a dual structure of the inner pump (32a) and the outer pump (32b).

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