CN218894871U

CN218894871U - Radial foil gas bearing structure

Info

Publication number: CN218894871U
Application number: CN202320167015.1U
Authority: CN
Inventors: 唐茂; 李响; 甘露; 常海兵; 左成艺
Original assignee: Cssc Southwest Equipment Research Institute Co ltd
Current assignee: Cssc Southwest Equipment Research Institute Co ltd
Priority date: 2023-02-09
Filing date: 2023-02-09
Publication date: 2023-04-21
Anticipated expiration: 2033-02-09

Abstract

The utility model discloses a radial foil gas bearing structure which comprises a top layer flat foil, a bottom layer arch foil and a bearing seat, wherein the bottom layer arch foil is assembled on the inner surface of the bearing seat, the top layer flat foil is positioned on the inner side of the bottom layer arch foil, and fixed ends of the bottom layer arch foil and the top layer flat foil are fixedly connected with the bearing seat; the top layer flat foil and the bottom layer arch foil are respectively provided with at least one baffle strip along the two axial sides, the baffle strips and the top layer flat foil or the bottom layer arch foil are integrally formed, the baffle strips are perpendicular to the top layer flat foil or the bottom layer arch foil, and the baffle strips on the top layer flat foil and the bottom layer arch foil are arranged in a staggered mode. The foil gas bearing structure realizes the axial limit of the free end of the foil of the gas bearing, and ensures that the free end of the foil of the bearing cannot deform and move along the axial direction in the rotor installation process and the equipment operation process.

Description

Radial foil gas bearing structure

Technical Field

The utility model relates to the technical field of gas bearings, in particular to a radial foil gas bearing structure.

Background

The dynamic pressure gas bearing utilizes the gas dynamic pressure effect, and the rotor is suspended by means of a high-pressure gas film formed between the rotor rotating at high speed and the inner surface of the bearing, so that the dynamic pressure gas bearing has the characteristic advantages of small friction, oil-free lubrication, no maintenance, high rotating speed, low power consumption, wide applicable temperature range, compact structure, long service life, high reliability and the like. In addition to the advantages, the flexible foil brings the elastic foil gas bearing with good self-adaptability.

The conventional foil gas bearing is characterized in that a top flat foil, a bottom arch foil and a middle foil are all arranged in a manner of fixing one end and freely fixing the other end, wherein the conventional foil gas bearing is of a whole circumference type or a multi-tile type. Such an arrangement ensures that the foil is able to deform towards the free end after being stressed to achieve its self-adapting bearing properties. However, because the gap between the foil gas bearing and the rotor is extremely small, even no gap exists to increase the pretightening force, the rotor is inserted into the bearing inner hole along the axial direction of the bearing in the rotor installation process, the free end of the bearing foil is easy to eject out along the axial direction, so that the free ends of the top layer flat foil, the bottom layer arch foil and the middle layer foil of the bearing are possibly stretched out along the axial dislocation, the distribution of the air film is influenced in the operation process, the performance is influenced, and even the bearing failure fault is caused in serious cases. Therefore, a special structure is designed to limit the movement of the free end of the bearing foil in the axial direction, and meanwhile, the deformation and the movement of the bearing foil in other directions are avoided, so that the bearing foil is significant for the installation of a bearing rotor system and the stable operation of a bearing.

Disclosure of Invention

To the defects of the prior art, the technical problem to be solved by the application is how to provide a radial foil gas bearing structure, so that the axial limit of the foil free end of the gas bearing is realized, and the free end of the foil of the bearing is ensured not to deform and move along the axial direction in the rotor installation process and the equipment operation process.

In order to solve the technical problems, the utility model adopts the following technical scheme:

the radial foil gas bearing structure comprises a top layer flat foil, a bottom layer flat foil and a bearing seat, wherein the bottom layer flat foil is assembled on the inner surface of the bearing seat, the top layer flat foil is positioned on the inner side of the bottom layer flat foil, and fixed ends of the bottom layer flat foil and the top layer flat foil are fixedly connected with the bearing seat;

the top layer flat foil and the bottom layer arch foil are respectively provided with at least one baffle strip along the two axial sides, the baffle strips and the top layer flat foil or the bottom layer arch foil are integrally formed, the baffle strips are perpendicular to the top layer flat foil or the bottom layer arch foil, and the baffle strips on the top layer flat foil and the bottom layer arch foil are arranged in a staggered mode.

The middle-layer foil is arranged between the top-layer flat foil and the bottom-layer arch foil, the fixed end of the middle-layer foil is fixedly connected with the bearing seat, at least one stop strip is arranged on two sides of the middle-layer foil along the axial direction, and the stop strips arranged on the middle-layer foil are arranged in a staggered manner with the stop strips arranged on the top-layer flat foil and the bottom-layer arch foil.

Wherein, the bottom arch foil, the top flat foil, the middle foil and the bearing seat are fixed by welding or slotting clamping.

The fixing ends of the top layer flat foil, the middle layer foil and the bottom layer arch foil are respectively provided with a right-angle bending structure, the bearing seat is provided with a slot, and the right-angle bending structures are positioned in the slot.

The bottom arch foil is provided with a plurality of arch bulges, flat sections are arranged between adjacent arch bulges, and the stop bars are arranged at the flat sections of the bottom arch foil.

Wherein, the inner surface of the top layer flat foil is sprayed with a self-lubricating coating with the thickness of 20-30 microns.

In summary, according to the radial foil gas bearing structure, through arranging the baffle strips on two sides of each layer of foil, the axial limit of the free end of the foil bearing is realized, and the free end of the foil bearing is prevented from deforming and moving along the axial direction in the installation process of the matched rotor and the operation process of equipment on the premise of not affecting the normal operation and the normal performance of the foil bearing. The risk of damage to the radial foil bearing caused by the installation process is reduced, and the problem that the free end of the bearing foil is axially shifted or deformed due to various reasons in the running process of equipment carrying the foil bearing, so that the performance of the bearing is reduced or the bearing is damaged due to failure is avoided.

Drawings

Fig. 1 is a schematic structural diagram of a radial foil gas bearing structure according to the present utility model, where the fixed ends of the foils are on the same side and the free ends are on the same side, and the foil structure may be a full circumference.

Fig. 2 is a front view of fig. 1.

Fig. 3 is an enlarged view at a in fig. 2.

Fig. 4 is a schematic structural view of a radial foil gas bearing structure according to the present utility model, where the foil has a fixed end on the opposite side and a free end on the opposite side, and the foil structure may be entirely circumferential.

Fig. 5 is a front view of fig. 1.

Fig. 6 is an enlarged view at B in fig. 5.

Fig. 7 is a schematic structural diagram of a radial foil gas bearing structure according to the present utility model in fig. 1, where the fixed ends of the foils are on the same side and the free ends are on the same side, and the foil structure may be a multi-watt overlap joint type.

Fig. 8 is a front view of fig. 7.

Fig. 9 is a schematic view of fig. 1 with the bearing housing removed.

Fig. 10 is an exploded view of fig. 1.

Fig. 11 is an exploded view of fig. 9.

Fig. 12 is a side view of fig. 1.

Fig. 13 is an enlarged view of fig. 12 at C.

Fig. 14 is a schematic view of another orientation of fig. 1.

Fig. 15 is an enlarged view of D in fig. 14.

Detailed Description

The present utility model will be described in further detail with reference to the accompanying drawings. In the description of the present utility model, it should be understood that the azimuth or positional relationship indicated by the azimuth words such as "upper, lower" and "top, bottom", etc. are generally based on the azimuth or positional relationship shown in the drawings, and are merely for convenience of description and simplification of the description, and these azimuth words do not indicate or imply that the apparatus or element to be referred to must have a specific azimuth or be constructed and operated in a specific azimuth, without limiting the scope of protection of the present utility model; the orientation word "inner and outer" refers to inner and outer relative to the contour of the respective component itself.

As shown in figures 1-15, a radial foil gas bearing structure comprises a top layer flat foil 1, a bottom layer arch foil 2 and a bearing seat 3, wherein a middle layer foil 4 is arranged between the top layer flat foil and the bottom layer arch foil, the bottom layer arch foil is assembled on the inner surface of the bearing seat, the middle layer foil is assembled on the inner surface of the bottom layer arch foil, the top layer flat foil is assembled on the inner surface of the middle layer foil, fixed ends of the bottom layer arch foil, the middle layer foil and the top layer flat foil are fixedly connected with the bearing seat, one ends of the bottom layer arch foil, the middle layer foil and the top layer flat foil are fixed ends, the other ends are free ends, the foils are mutually overlapped, the fixed ends of the bottom layer arch foil, the middle layer foil and the top layer flat foil can be in the same direction, the opposite directions, the foil structure can be whole circumference, and the multi-tile overlapped connection mode.

The top layer flat foil, the middle layer foil and the bottom layer arch foil are respectively provided with at least one baffle strip along the two axial sides, the baffle strips 11 arranged on the top layer flat sheet, the baffle strips 41 arranged on the middle layer foil and the baffle strips 21 arranged on the bottom layer arch foil, the baffle strips and the top layer flat foil, the middle layer foil or the bottom layer arch foil are integrally formed, the baffle strips and the top layer flat foil, the middle layer foil or the bottom layer arch foil are vertically arranged, and the baffle strips on the top layer flat foil, the middle layer foil and the bottom layer arch foil are arranged in a staggered mode.

Specifically, the stop bar is of an elongated strip structure.

The barrier strips on two sides of the top layer flat foil are symmetrically distributed on two sides of the foil, the barrier strips are parallel to the foil before installation, and after the top layer flat foil is installed, the barrier strips are bent to enable the barrier strips to be perpendicular to the top layer flat foil. In the rotor installation or bearing working process, once the free end of the foil is axially displaced or deformed, the stop bar is contacted with the bottom arch foil, the middle foil and the bearing seat of the top flat foil and the outer layer, thereby playing a limiting role. When the foil is positioned in the axial center of the bearing seat, a small gap of 0.1-0.5mm is arranged between the baffle strip and the outer edge of the outer foil or the end face of the bearing seat so as to prevent the baffle strip from affecting the deformation and movement of the foil in other directions. The stop bars at two sides of the bottom arch foil, the stop bars at two sides of the middle foil and the top flat foil have the same structure and gaps.

For the arrangement of the stop bars, for small bearings, 1 stop bar is generally axially and symmetrically arranged near the free end of the foil, and for bearings with larger sizes, the number of the stop bars is axially and symmetrically increased between the free end and the fixed end of the foil.

The stop strips of the top layer flat foil, the bottom layer arch foil and the middle layer foil cannot be overlapped after the foils are installed, and the stop strips are required to be staggered for a certain distance (0.5-2 mm, and the distance can be properly increased along with the increase of the size of the bearing) so as to prevent mutual interference, thereby influencing the deformation and movement of the foils.

In this embodiment, the stiff end of top layer flat foil, intermediate level foil and bottom layer hunch foil all is provided with right angle bending structure, the bearing frame is provided with the fluting, right angle bending structure is located the fluting, is convenient for fix on the bearing frame through welding or fluting joint's mode.

In this embodiment, the bottom layer arch foil has a plurality of arch-shaped protrusions, a flat section is provided between adjacent arch-shaped protrusions, and the stop bar is disposed at the flat section position of the bottom layer arch foil. Avoiding being arranged at the arch position so as to prevent the foil from being arch-shaped and deformed by mistake in the bending process of the stop bar. The whole foil may be monolithic and may be slit in the circumferential direction.

In this embodiment, the inner surface of the top flat foil is sprayed with a self-lubricating coating having a thickness of 20-30 micrometers. Plays a role in lubrication and friction reduction.

The method for bending the stop strip comprises the following steps: before the foil is installed, the stop strips on the foil and the foil are in a parallel state, the stop strips and the foil are integrally cut and formed through linear cutting or laser cutting, after the foil is processed in advance, all the foils are installed in a bearing seat through welding or clamping grooves according to the designed internal and external arrangement sequence, after all the foils are installed, cylindrical tools with the diameter identical to the inner diameter of the bearing are inserted into the bearing, then all the foils are adjusted to be integrally positioned in the axial center of the bearing seat, and at the moment, the stop strips are bent by using tools such as tweezers. The cylindrical tool can prevent the foil from deforming in the bending process.

Finally, it should be noted that: various modifications and alterations of this utility model may be made by those skilled in the art without departing from the spirit and scope of this utility model. Thus, it is intended that the present utility model also include such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

Claims

1. The radial foil gas bearing structure is characterized by comprising a top layer flat foil, a bottom layer arch foil and a bearing seat, wherein the bottom layer arch foil is assembled on the inner surface of the bearing seat, the top layer flat foil is positioned on the inner side of the bottom layer arch foil, and fixed ends of the bottom layer arch foil and the top layer flat foil are fixedly connected with the bearing seat;

2. The radial foil gas bearing structure according to claim 1, wherein an intermediate foil is arranged between the top flat foil and the bottom arch foil, a fixed end of the intermediate foil is fixedly connected with the bearing seat, at least one stop strip is arranged on two sides of the intermediate foil along the axial direction, and the stop strip arranged on the intermediate foil is arranged in a staggered manner with the stop strips arranged on the top flat foil and the bottom arch foil.

3. A radial foil gas bearing structure according to claim 2, wherein the bottom layer arch foil, the top layer flat foil, the middle layer foil and the bearing seat are fixed by welding or slot clamping.

4. The radial foil gas bearing structure of claim 2, wherein the fixed ends of the top flat foil, the middle foil and the bottom arch foil are each provided with a right angle bend structure, the bearing housing is provided with a slot, and the right angle bend structures are located in the slots.

5. A radial foil gas bearing structure according to claim 1, wherein the bottom layer arch foil has a plurality of arch-shaped protrusions, and wherein flat sections are provided between adjacent arch-shaped protrusions, and wherein the barrier strips are provided at flat sections of the bottom layer arch foil.

6. A radial foil gas bearing structure according to claim 1, wherein the top flat foil inner surface is sprayed with a self-lubricating coating of 20-30 microns thickness.