JPH11351243A - Thrust bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent damages such as seizure of a bearing, to improve the reliability of the equipment, and to maintain the normal operation for a long time. SOLUTION: A rotating equipment having a rotary shaft 3 supports a runner 4 to be rotated together with the rotary shaft 3 in an oscillating manner, comprises a plurality of pads 10 arranged with required intervals, a supporting means 5 to support each pad in an oscillating manner, and an oil tank 6 in which the pads 10 and the supporting means 5 are stored in oil, and is provided with an additional deformation suppressing member on the pads 10 for a means to suppress the thermal deformation. The thermal deformation of the pads of the thrust bearing to support the rotary shaft can be controlled, the load capacity during the thermal deformation is prevented from being dropped, and the reliability of the equipment is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thrust bearing, and more particularly to a tilting pad thrust bearing for supporting a rotating shaft of a rotating device, which is suitable for preventing thermal deformation of a pad due to heat generated during operation. About bearings.

[0002]

2. Description of the Related Art Generally, a tilting pad thrust bearing is used as a bearing for supporting a thrust load. In particular, in a thrust bearing to which a high surface pressure acts, a high thrust load during rotation acts on the bearing, and a large amount of heat is generated in the bearing. When this tilting pad is thermally deformed by this heat, the pressure generated between the pad and the runner is reduced, so that the load capacity of the thrust bearing is reduced. As a result, the gap between the tilting pad and the rotating runner is reduced, and in a severe case, the contact is made, so that the rotation cannot be performed while supporting the load, and the performance of the device equipped with the bearing is significantly reduced.

In order to prevent this, conventionally, means for preventing this thermal deformation have been devised. For example, JP-A-50-2
According to Japanese Patent No. 53, the pad has a double structure, a material having good heat conductivity is used in a portion close to the runner surface, and the other is made of a heat insulating member and joined to form a pad in the upper member having good heat conductivity. The temperature distribution is minimized to prevent thermal deformation. This is costly and makes the pad thicker.

[0004]

SUMMARY OF THE INVENTION In order to improve the efficiency of rotating equipment, at present, high speed, high load, etc.
The conditions of use have also become severe. Along with this, the load on the bearing that supports the rotating shaft also increases, and excessive heat is generated. This heat causes thermal deformation of the bearing. In a bearing that has been thermally deformed, particularly a tilting pad, pressure is not generated between the pad and the runner due to the deformation of the pad, and the bearing load capacity is reduced. Due to this reduction, there is a risk that the runner and the tilting pad come into contact with each other, causing damage such as burning of the bearing and causing a problem that the rotating device does not operate normally.

SUMMARY OF THE INVENTION An object of the present invention is to provide a rotating device having a rotating shaft, which controls the thermal deformation of the thrust bearing supporting the rotating shaft, thereby preventing a reduction in the load capacity of the thrust bearing due to the thermal deformation. To provide.

[0006]

Means for Solving the Problems To achieve the above object, the thrust bearing of the present invention employs the following means. The invention as claimed in claim 1, wherein the disk-like runner which rotates together with the rotation shaft is swingably supported, and a plurality of pads arranged at required intervals, respectively, and support means for swingably supporting each of the pads. And a thrust bearing in which the pad and the support means are accommodated in an oil bath, wherein the pad has a larger moment of inertia in the radial direction than a moment of inertia in the circumferential direction.

According to a second aspect of the present invention, in the thrust bearing according to the first aspect, the pad is provided with a reinforcing portion made of the same member as the pad on a surface opposite to a surface facing the runner. Alternatively, it is formed by shaving. The invention according to claim 3 is:
2. The thrust bearing according to claim 1, wherein the pad is provided with a reinforcement made of a dissimilar member having a hardness greater than that of the pad on a surface opposite to a surface facing the runner. 3. According to a fourth aspect of the present invention, in the thrust bearing according to the first aspect, the pad comprises:
The surface opposite to the surface facing the runner is provided with a reinforcement made of a different material having a hardness greater than that of the pad, and the different material is a member having substantially the same linear expansion coefficient as the pad. According to a fifth aspect of the present invention, in the thrust bearing according to the first aspect, a reinforcing member having a hardness greater than that of the pad is inserted into a section of the pad opposite to a surface facing the runner. It is characterized by having. According to a sixth aspect of the present invention, in the thrust bearing according to the first aspect, a reinforcing member having a hardness greater than that of the pad is inserted into the pad in a section of the pad opposite to a surface facing the runner; The reinforcing member is a member having substantially the same linear expansion coefficient as the pad. According to a seventh aspect of the present invention, in the thrust bearing according to the first aspect, a reinforcing member having a hardness greater than that of the pad is inserted into a section of the pad opposite to a surface facing the runner. The shape of the reinforcing member is a round bar or a square bar.

As in the prior art, a mechanism for preventing the thermal deformation of a pad by adding a mechanism for preventing the pad from being thermally deformed has the disadvantage that the cost is increased and the pad becomes thicker. According to the present invention, the pad has a large bearing load capacity by controlling the direction in which the pad is easily deformed and the direction in which the pad is unlikely to be thermally deformed, that is, the direction in which the pad is anisotropic and the direction in which the pad and the runner are easily deformed. Can be prevented.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 show an embodiment of the present invention. FIG. 1 is an overall sectional view of a thrust bearing device.
FIG. 2 is a perspective view of a tilting pad pad (hereinafter referred to as a pad) before thermal deformation, and FIG. 3 is a perspective view of the pad after thermal deformation.

As shown in these figures, the thrust bearing device swings and supports a rotating shaft 3 and a flat runner 4 rotating with the rotating body, and a plurality of pads arranged at a certain interval. 10, a pivot (supporting means) 5 for swingably supporting the pad 10 and an oil tank 6 for accommodating the pad 10 and the supporting means in a lubricating oil 7.

As shown in FIGS. 3 and 2, the pad 10 is provided with a deformation suppressing member 20 in a direction perpendicular to the deformation direction so as to be deformed only in an optimum circumferential direction during rotation. Has been added. That is, the pad is provided with a direction that is easy to bend and a direction that is difficult to bend. This member 20
A reinforcing member having a higher hardness than the member of the pad 10 or having a similar hardness and a similar linear expansion coefficient to the pad 10
Shall be inserted. The shape of the reinforcing member to be inserted is preferably a round bar or a square bar.

As a result, when the pad is thermally deformed, as shown in FIG. 3, the pad is deformed only in a direction perpendicular to the restraining member 20. At present, the insertion direction of the restraining member is the pad radial direction, but the optimum direction changes depending on the number of rotations, load, and the like. Here, the optimal direction indicates a direction in which the load capacity becomes larger than the other directions. Therefore, by estimating the number of rotations and load that are most likely to be in contact by analysis, etc., and inserting it in that direction, the bearing can have great reliability when there is a concern about contact between the runner and the pad. .

In the conventional pad without such a reinforcing member, the thermal deformation becomes three-dimensional, and the bearing load capacity becomes extremely small. However, when the thermal deformation is limited to a certain direction as in the present invention, the load capacity becomes larger than the load capacity at the time of the three-dimensional deformation, and further, there is a maximum value and a minimum value depending on the direction. This direction changes with the number of rotations as described above.
The present invention uses this feature to ensure the reliability of the bearing.

Next, another embodiment of the present invention will be described with reference to FIGS. FIG. 4 is a perspective view of the pad, and FIG. 5 is a perspective view when the pad of FIG. 4 is thermally deformed. In the pad 11 shown in FIGS. 4 and 5, a deformation suppressing means 21 is added to the pad cross section in a direction perpendicular to the deformation direction so as to deform only in an optimum direction during rotation. It is assumed that the means 21 is the same as or different from the pad 11 member and has a high hardness and a similar linear expansion coefficient. In addition, it is desirable that the cross-sectional shape of the reinforcing member be a semicircle, a quadrilateral, or a triangle because of good workability.

Further, in order to create this cross section, it is possible to realize the cross section as shown in FIGS. 4 and 5, instead of adding a reinforcing member. As a result, when the pad is thermally deformed, as shown in FIG. 5, the pad is deformed only in a direction perpendicular to the direction in which the suppressing means 21 is formed. At present, the direction in which the suppression member is formed is the radial direction of the pad, but the optimal direction varies depending on the number of rotations, load, and the like. Therefore, by estimating the number of rotations and load at which contact is most likely to occur by analysis or the like, and inserting the load in that direction, the reliability of the bearing can be improved.

[0016]

According to the present invention, in a rotating device having a rotating shaft, the thermal deformation of the thrust bearing supporting the rotating shaft can be controlled, so that the load capacity of the thrust bearing due to the thermal deformation can be prevented. Therefore, the normal operation of the rotating device is maintained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a thrust bearing structure according to an embodiment of the present invention.

FIG. 2 is a perspective view of the tilting pad bearing shown in FIG.

FIG. 3 is a perspective view of the tilting pad bearing shown in FIG. 2 when thermally deformed.

FIG. 4 is a perspective view of a tilting pad bearing according to another embodiment of the present invention.

FIG. 5 is a perspective view of the tilting pad bearing shown in FIG. 4 when thermally deformed.

[Explanation of symbols]

 Reference Signs List 3 rotating shaft 4 runner 5 pivot (supporting means) 6 oil tank 7 lubricating oil 10, 11 tilting pad 20 deformation suppressing member 21 deformation suppressing means

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masanori Katayama 603, Kandachicho, Tsuchiura-shi, Ibaraki Pref.

Claims (7)

[Claims] 1. A plurality of pads which swingably support a disk-shaped runner which rotates together with a rotation shaft, and are arranged at required intervals, and a support means for swingably supporting each of the pads. A thrust bearing in which the pad and the support means are accommodated in an oil bath, wherein the pad has a radial second moment of area larger than a circumferential second moment of the pad. 2. The thrust bearing according to claim 1, wherein the pad is formed by adding or shaving a reinforcing portion made of the same member as the pad on a surface opposite to a surface facing the runner. A thrust bearing. 3. The thrust bearing according to claim 1, wherein the pad has a reinforcing portion made of a dissimilar member having a hardness greater than that of the pad on a surface opposite to a surface facing the runner. A characteristic thrust bearing. 4. The thrust bearing according to claim 1, wherein the pad has a reinforcing portion made of a dissimilar member having a hardness greater than that of the pad on a surface opposite to a surface facing the runner. Is a member having a coefficient of linear expansion substantially the same as that of the pad. 5. The thrust bearing according to claim 1, wherein a reinforcing member having a hardness greater than that of the pad is inserted into a section of the pad opposite to a surface facing the runner. And thrust bearing. 6. The thrust bearing according to claim 1, wherein a reinforcing member having a hardness greater than that of the pad is inserted in a section of the pad opposite to a surface facing the runner. A thrust bearing wherein the linear expansion coefficient is substantially the same as that of the pad. 7. The thrust bearing according to claim 1, wherein a reinforcing member having a hardness greater than that of the pad is inserted into a section of the pad opposite to a surface facing the runner. A thrust bearing characterized in that the shape is a round bar or a square bar.