CN216812507U

CN216812507U - Thrust foil gas bearing

Info

Publication number: CN216812507U
Application number: CN202220518180.2U
Authority: CN
Inventors: 朱建军; 欧玉书
Original assignee: Dongguan Qingrui Technology Co ltd
Current assignee: Dongguan Qingrui Technology Co ltd
Priority date: 2022-03-09
Filing date: 2022-03-09
Publication date: 2022-06-24
Anticipated expiration: 2032-03-09

Abstract

The application discloses thrust foil gas bearing, thrust foil gas bearing includes: the first module comprises a top foil, and the top foil is formed by integrally forming a single piece; and the second module comprises a bottom plate and a supporting corrugated foil, wherein the supporting corrugated foil is connected to the bottom plate, and the bottom plate is connected to the top foil. According to the thrust foil gas bearing, the top foil integrally formed by the single piece is connected to the bottom plate, so that the use of a plurality of combined and independently fixed foils is avoided, the forming consistency of the top foil is improved, the processing quality and efficiency of the thrust foil gas bearing are improved, meanwhile, the continuity and integrity of a lubricating gas film in the circumferential direction are also ensured by the single-piece integral top foil structure, the bearing characteristic of the bearing is improved, and the running stability of a high-speed rotor is enhanced.

Description

Thrust foil gas bearing

Technical Field

The disclosure belongs to the field of gas bearings, and particularly relates to a thrust foil gas bearing.

Background

The thrust foil gas bearing is a self-acting dynamic pressure gas bearing adopting an elastic supporting structure, and structurally mainly comprises a bottom plate, a supporting bump foil and a top foil. The bearing belongs to a passive adjusting type bearing because air is adopted as a lubricating medium and is fused with an elastic supporting structure, and compared with the traditional oil film bearing and a rolling bearing, the bearing has the advantages of strong adaptability, cleanness, no pollution, high rotating speed, small friction power consumption, strong anti-vibration capability, wide use temperature range, low maintenance cost and the like, and is widely applied to the fields of high-speed rotating machinery such as hydrogen fuel cell air compressors, refrigeration compressors, air suspension centrifugal blowers, micro gas turbines, turbine generators, airplane environmental control systems and the like.

The thrust foil gas bearing supports the rotor to run at high speed by utilizing the compression effect of a wedge-shaped gap gas film between a top foil and a thrust disc, and in order to ensure the stable running of the rotor under a certain axial load, a stable wedge-shaped compression gas film must be ensured.

At present, a top foil of a traditional thrust foil gas bearing generally consists of 4-12 independent foils, and each foil is independently welded on a bearing bottom plate, so that the complexity of a manufacturing process and the processing cost are increased, and the processing consistency of the bearing is reduced; meanwhile, when the bearing operates, the difference of air films between each top layer foil and the thrust disc can weaken the operation stability of the rotor and reduce the service life of the bearing.

SUMMERY OF THE UTILITY MODEL

In view of the above, there is a need to provide a thrust foil gas bearing with an improved consistency of the top foil of the thrust foil gas bearing.

To this end, the present disclosure provides a thrust foil gas bearing comprising:

the first module comprises a top foil, and the top foil is formed by integrally forming a single piece;

and the second module comprises a bottom plate and a supporting corrugated foil, wherein the supporting corrugated foil is connected to the bottom plate, and the bottom plate is connected to the top foil.

Preferably, the top foil is formed by one-time stamping through a die.

Preferably, the first die set further comprises a ring, the top foil is coaxially connected to the ring, the bottom plate is connected to the ring, and the supporting bump foil is located in the ring and between the top foil and the bottom plate.

Preferably, the first die set further comprises a force receiving claw extending from the top foil in a radial direction of the top foil and connected to an end surface of the circular ring.

Preferably, the stress claw and the top foil have a preset inclination angle in the radial direction, and the stress claw is connected with the top foil and the ring along the preset inclination angle.

Preferably, the top foil comprises a plurality of end-to-end working areas, each working area comprises a curved surface section and a bearing section, the section of each curved surface section is a wedge-shaped curved surface inclined along the circumferential direction, and each bearing section is a plane.

Preferably, the working areas are evenly distributed in the circumferential direction on the top foil.

Preferably, the side of the top foil far away from the supporting bump foil is provided with a wear-resistant coating, and the wear-resistant coating is formed by spraying at least one of molybdenum disulfide or polytetrafluoroethylene on the side of the top foil far away from the supporting bump foil.

Preferably, the support bump foil includes a connection section connected to the base plate and a support section including a plurality of support portions protruding toward the top foil in an axial direction, a top of the support portions being in contact with the top foil and a bottom thereof being in contact with the base plate.

Preferably, the second module further comprises a support sheet connected between the support bump foil and the top foil, and the support sheet has a height lower than the support portion.

Compared with the prior art, the thrust foil gas bearing has the advantages that the top foil integrally formed by the single piece is connected to the bottom plate, multiple pieces of combined and independently fixed foils are avoided, the forming consistency of the top foil is improved, the processing quality and efficiency of the thrust foil gas bearing are improved, meanwhile, the continuity and integrity of a lubricating gas film in the circumferential direction are guaranteed due to the single-piece integral top foil structure, the bearing characteristic of the bearing is improved, and the running stability of a high-speed rotor is enhanced.

Drawings

In order to illustrate the embodiments more clearly, the drawings that will be needed in the description of the embodiments will be briefly described below, it being apparent that the drawings in the following description are some examples of the disclosure, and that other drawings may be derived from those drawings by a person skilled in the art without inventive effort.

FIG. 1 is a schematic view of a thrust foil gas bearing.

FIG. 2 is a schematic view of a thrust foil gas bearing in an exploded condition.

Fig. 3 is a schematic view of the structure of the top foil.

Fig. 4 is a schematic sectional view of a-a in fig. 3.

Fig. 5 is a schematic view of the structure of the supporting bump foil.

Fig. 6 is a schematic side view of a supporting bump foil.

Fig. 7 is a schematic diagram of a gas film pressure distribution.

Description of the main elements

The following detailed description will further illustrate the disclosure in conjunction with the above-described figures.

Detailed Description

In order that the above objects, features and advantages of the present disclosure can be more clearly understood, a detailed description of the present disclosure will be given below with reference to the accompanying drawings and detailed description. In addition, the embodiments and features of the embodiments of the present application may be combined with each other without conflict. In the following description, numerous specific details are set forth to provide a thorough understanding of the present disclosure, and the described embodiments are merely a subset of the embodiments of the present disclosure, rather than a complete embodiment. All other embodiments, which can be derived by one of ordinary skill in the art from the embodiments disclosed herein without making any creative effort, shall fall within the protection scope of the present disclosure.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terminology used in the description herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure.

In various embodiments, for convenience in description and not limitation of the disclosure, the term "coupled" as used in the specification and claims of the present disclosure is not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "upper", "lower", "below", "left", "right", and the like are used merely to indicate relative positional relationships, and when the absolute position of the object to be described is changed, the relative positional relationships are changed accordingly.

Fig. 1 is a schematic structural view of a thrust foil gas bearing, and fig. 2 is a schematic structural view of the thrust foil gas bearing in a disassembled state. As shown in fig. 1 and 2, the thrust foil gas bearing comprises a first module and a second module, and the thrust foil gas bearing is formed by connecting the first module to the second module in a combined manner, so that the thrust foil gas bearing has the advantages of simplicity and convenience in installation and good consistency.

The first module comprises a top foil 10 and a ring 20, wherein the top foil 10 is connected to the ring 20, and a pressurized air film can be formed between the rotor and the thrust disc.

Fig. 3 is a schematic structural diagram of the top foil 10, and as shown in fig. 1 to 3, the top foil 10 is formed by integrally molding a single piece of the top foil 10, preferably, the top foil 10 is formed by one-step punch forming through a die, and has high processing precision, good dimensional consistency, and effectively improved production efficiency, and is very suitable for mass production of products in the later period. In some embodiments, the thickness of the top foil 10 may be 0.08mm to 0.5mm, preferably 0.1 mm.

In order to improve the wear resistance of the top foil 10, reduce the friction torque when the rotor is started and improve the service life of the gas bearing, the side (i.e., the outer side) of the top foil 10 away from the supporting bump foil 40 is provided with a wear-resistant coating. The wear-resistant coating is preferably formed by spraying at least one of molybdenum disulfide or polytetrafluoroethylene on the outer side surface of the top foil 10, but those skilled in the art may also arrange other materials or other processes on the outer side surface of the top foil 10 as required. The wear-resistant coating can effectively reduce the friction coefficient of a gas bearing in a start-stop stage and can prevent a rotor and the bearing from being burnt down when the rotor and the bearing are subjected to short-time collision and grinding, and the thickness of the wear-resistant coating is generally controlled to be 0.01-0.05 mm.

The top foil 10 is integrally connected to the ring 20, preferably coaxially connected to the ring 20, as a one-piece construction. In some embodiments, the top foil 10 may be welded to the ring 20 by one or more welds, or may be attached to the ring 20 by other means, such as connectors or super glue. In this embodiment, the first die set may further include a force receiving claw 11, and the force receiving claw 11 extends from the top foil 10 in a radial direction of the top foil 10 and is connected to an end surface of the circular ring 20. In the process of starting, stopping and running the rotor, the thrust foil gas bearing bears not only axial acting force but also certain circumferential friction torque, and particularly in the dry friction state of the starting and stopping stage, the circumferential acting force of the rotor on the thrust foil gas bearing is large. The top foil 10 is of an integral structure, the top foil 10 and the bottom plate 30 are not directly welded together, in order to prevent circumferential dislocation of the top foil 10, the top foil 10 is connected to the ring 20 through the stress claw 11, and circumferential acting force applied to the top foil 10 is effectively transmitted to the ring 20, so that stable operation of the gas bearing can be ensured.

In some preferred embodiments, the force-bearing claw 11 has a preset inclination angle with respect to the radial direction of the top foil 10, and the force-bearing claw 11 connects the top foil 10 and the ring 20 along the preset inclination angle. Specifically, the stressed claws 11 extend from the top foil 10 in the radial direction and at a certain inclination angle with the radial direction, and the outer end (i.e. the end opposite to the top foil 10) has a disc structure which is fixedly connected to the end surface of the ring 20 by laser welding or bonding, so as to fixedly connect the top foil 10 to the ring 20. Meanwhile, the length and the width of the stress claw 11 can be flexibly adjusted according to the use condition of the gas bearing, and the use requirement of the bearing is guaranteed to be met. Thus, the top foil 10 is coaxially connected to the ring 20, and the top foil 10 is located inside the ring 20 and substantially covers the end surface of the through hole of the ring 20.

Fig. 4 is a schematic sectional view of a-a in fig. 3. As shown in fig. 3 and 4, the top foil 10 includes a plurality of working areas 12 connected end to end, for example, 4 to 12 working areas 12, the working areas 12 are uniformly distributed on the top foil 10 along the circumferential direction, and the shape and size of each working area 12 are identical. For example, fig. 3 shows an embodiment in which the top foil 10 has 6 working areas 12 arranged in the circumferential direction. As shown in fig. 4, the working area 12 includes a curved surface section 121 and a bearing section 122. The curved section 121 has a longitudinal section of a wedge-shaped curved surface inclined in the circumferential direction, which is substantially in a "√" structure, one end of which is concave downward with a large arc, and then is inclined upward and obliquely from the bottom 432 of the concave area with a small inclination until being connected to the bearing section 122. The inclined wedge-shaped curvature of the curved surface segment 121 may provide an effective air film compression effect when the rotor is operating at high speeds. The bearing section 122 is a plane extending in the horizontal direction for bearing the air film pressure, and is used for ensuring that a sufficient effective bearing area is formed at the bearing section 122 when the rotor rotates at a high speed. Compared with the existing gas bearing with a plurality of top foil pieces 10 combined, 4-12 independent wedge-shaped compressions exist on the surface of the whole gas bearing during operation, the gas bearing provided by the embodiment adopts an integral top foil piece 10 structure, so that a plurality of independent working gas films are changed into a complete continuous gas film, the area of an effective bearing area of the gas film is increased, and the performance of the gas bearing is further improved.

The second module comprises a base plate 30, a supporting bump foil 40 and a supporting sheet 50. The supporting bump foil 40 is attached to the inner side (i.e., the side opposite to the outer side) of the bottom plate 30, and the bottom plate 30 is attached to the top foil 10. The supporting bump foil 40 is located in the ring 20 and between the top foil 10 and the bottom plate 30 for supporting the top foil 10. The support sheet 50 is attached to the support end and has a top lower than the support portion 43, and may be welded to the support bump foil 40 by laser welding, for example.

Fig. 5 is a schematic structural view of the supporting bump foil 40, and as shown in fig. 5, the supporting bump foil 40 is substantially in a fan-shaped structure, and the number of the supporting bump foils can be 3-10, and the supporting bump foils are arranged on the bottom plate 30 along the circumferential direction. In the present embodiment, the number of the supporting bump foils 40 is 6, and the supporting bump foils are uniformly connected to the bottom plate 30 in the circumferential direction, and form 306 ° support for the top foil 10. Specifically, the supporting bump foil 40 includes a connecting section 41 and a supporting section 42, the connecting section 41 has a substantially rectangular strip-shaped structure, extends in a radial direction of the base plate 30, and is connected to the base plate 30, for example, by laser welding or bonding to a side surface of the base plate 30, so as to prevent the supporting bump foil 40 from moving.

The support section 42 is made of an elastic material for supporting the top foil 10. In some embodiments, the support section 42 may use a corrugated metal sheet or similar structure to achieve elastic support for the top foil 10. In the present embodiment, the supporting segments 42 may be subjected to different slitting processes, for example, slitting processes of the corrugated elastic metal sheet, in the radial direction by the corrugated elastic supporting members, so that the rigidity distribution characteristics of the supporting corrugated foil 40 may be changed. A plurality of supporting sections 42 arranged in the radial direction are formed, each supporting section 42 extending in the circumferential direction and having ends connected to the connecting section 41.

Fig. 6 is a side view schematically showing the structure of the supporting bump foil 40. As shown in fig. 5 and 6, the supporting segment 42 includes a plurality of supporting portions 43 protruding toward the top foil 10 in the axial direction, and the plurality of supporting portions 43 are connected end to end, and may be arranged in the circumferential direction, or may be arranged in a single direction in the horizontal plane, and those skilled in the art may arrange the supporting segments as needed, and the present application is not limited thereto. In the present embodiment, the supporting portions 43 are arc-shaped structures that are arched in the axial direction, each supporting portion 43 has a substantially Ω -shaped longitudinal section, the top portion 431 protrudes toward the top foil 10, and after the supporting bump foil 40 is disposed between the bottom plate 30 and the top supporting foil, the top portion 431 of the supporting portion 43 contacts the top foil 10, and the bottom portion 432 contacts the bottom plate 30. When the top foil 10 presses down the supporting bump foil 40, the top 431 of the supporting portion 43 presses down the bottom 432, so that the supporting portion 43 is deformed and/or the bottom 432 moves outward to both sides to elastically support the top foil 10.

Referring back to fig. 2, the supporting sheet 50 is generally in a strip structure and is connected to the connecting segment 41 of the supporting bump 40, for example, the connecting segment 41 of the supporting bump 40 can be connected by laser welding. After the welding is completed, the side of the support sheet 50 facing the supporting bump foil 40 may be used to support the top foil 10, and the height of the side of the support sheet 50 is lower than the top 431 of the support portion 43, so that the top foil 10 may be prevented from being deformed too much under the air film force, the support sheet 50 may control the maximum deformation amount of the top foil 10 and the supporting bump foil 40 by adding the support sheet 50 below the top foil 10, and when the top foil 10 and the supporting bump foil 40 are deformed to a preset distance, the support sheet 50 may support the top foil 10 and the supporting bump foil 40, so that the problem of permanent failure due to the excessive deformation of the top foil 10 and the supporting bump foil 40 may be prevented.

In the present embodiment, the bottom plate 30 is substantially a disk-shaped structure, and in order to ensure good uniformity of the thickness of the gas bearing, the flatness of the bottom plate 30 is preferably not more than 0.01mm, and the thickness difference is not more than 0.006 mm. In order to facilitate the installation of the gas bearing, in some embodiments, the outer circumference of the ring 20 is evenly distributed with 3 to 12 first fixing holes 21, and the outer circumference of the base plate 30 is evenly distributed with 3 to 12 second fixing holes 31 for fixing to the housing of other equipment using screws or positioning pins. In this embodiment, the bottom plate 30 may be connected to the end surface of the ring 20 by laser welding or bonding, etc., to connect the first and second modules together, and to integrally package the entire gas bearing.

Fig. 7 is a schematic diagram of a gas film pressure distribution. As shown in fig. 7, the top foil 10 is drawn with a solid line in a pre-deformed position, and the top foil 10 is drawn with a dotted line in a deformed position 61 of the top foil 10. The air film pressure 60 to which the top foil 10 is subjected is supported by the support portion 43 supporting the bump foil 40. When the thrust disc on the rotor rotates at high speed in operation, the wedge-shaped air film between the thrust disc and the top foil 10 generates dynamic pressure effect, the pressure rises, and a bearing air film is formed between the top foil 10 and the rotor to support the rotor to rotate at high speed. The gas film pressure 60 applied by the gas film to the top foil 10 is shown in fig. 7, the supporting bump foil 40 and the top foil 10 are elastically deformed, wherein the bottom surfaces of the supporting bump foil 40 and the top foil 10, and the surfaces of the supporting bump foil 40 and the bottom plate 30 generate small sliding friction to generate heat, the friction effect can convert the instability energy of the rotor into the heat of the thrust foil bearing and be taken away by the bearing cooling air, sufficient damping is provided for the high-speed operation of the whole shafting, and the stable operation of the shafting is ensured.

The thrust foil gas bearing is characterized in that the top foil 10 integrally formed by the single piece is connected to the bottom plate 30, the use of a plurality of pieces of foil which are combined and independently fixed is avoided, on one hand, the continuity and the integrity of a gas film of the gas bearing in the circumferential direction are improved, the bearing characteristic of the bearing is further improved, meanwhile, the top foil 10 is formed by one-step forming and processing of a die, the consistency of the size of the foil is improved, the processing quality and the production efficiency of the gas bearing are improved, and the impact load resistance and the running stability of the bearing at a high speed are further improved.

In several embodiments provided in the present disclosure, it will be apparent to those skilled in the art that the present disclosure is not limited to the details of the above-described exemplary embodiments, and can be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the disclosure being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Furthermore, it is obvious that the word "comprising" does not exclude other elements or steps, and the singular does not exclude the plural. The terms first, second, etc. are used to denote names, but not any particular order.

Although the present disclosure has been described in detail with reference to the preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the spirit and scope of the present disclosure.

Claims

1. A thrust foil gas bearing comprising:

2. The thrust foil gas bearing of claim 1, wherein the top foil is a one-shot stamped top foil formed by a die.

3. The thrust foil gas bearing of claim 2, wherein the first die set further comprises a ring, the top foil is coaxially connected to the ring, the bottom plate is connected to the ring, and the supporting bump foil is located within the ring and between the top foil and the bottom plate.

4. The thrust foil gas bearing of claim 3, wherein the first die set further comprises a force claw extending from the top foil in a radial direction of the top foil and connected to an end face of the ring.

5. The thrust foil gas bearing of claim 4, wherein the force-bearing fingers have a predetermined angle of inclination with respect to a radial direction of the top foil, the force-bearing fingers connecting the top foil and the ring along the predetermined angle of inclination.

6. The thrust foil gas bearing of claim 5, wherein the top foil includes a plurality of end-to-end working zones, the working zones including curved sections and load-bearing sections, the curved sections having cross-sections that are wedge-shaped curves that are inclined in a circumferential direction, the load-bearing sections being planar.

7. The thrust foil gas bearing of claim 6, wherein said working areas are evenly distributed circumferentially across said top foil.

8. The thrust foil gas bearing of claim 7, wherein the side of the top foil remote from the supporting bump foil is provided with a wear resistant coating of at least one of molybdenum disulfide or polytetrafluoroethylene sprayed onto the side of the top foil remote from the supporting bump foil.

9. The thrust foil gas bearing of claim 1, wherein the supporting bump foil includes a connecting section and a supporting section, the connecting section being connected to the bottom plate, the supporting section including a plurality of supporting portions protruding in an axial direction toward the top foil, the supporting portions having tops in contact with the top foil and bottoms in contact with the bottom plate.

10. The thrust foil gas bearing of claim 9, wherein the second pattern further comprises a support sheet connected between the support bump foil and the top foil, and wherein the support sheet is lower in height than the support.