CN113107961A

CN113107961A - Dynamic pressure gas radial bearing, assembling method thereof and power equipment

Info

Publication number: CN113107961A
Application number: CN202010021442.XA
Authority: CN
Inventors: 刘华; 张治平; 叶文腾; 钟瑞兴; 陈玉辉; 雷连冬; 刘胜
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2020-01-09
Filing date: 2020-01-09
Publication date: 2021-07-13

Abstract

The invention discloses a dynamic pressure gas radial bearing, an assembling method thereof and power equipment. The hydrodynamic gas radial bearing comprises a bearing body with a shaft hole; and the elastic supporting structure comprises a bottom gasket, a supporting bump foil and a top foil which are sequentially arranged along the radial direction, and the bottom gasket, the supporting bump foil and the top foil are mutually independent and are arranged in a split manner. The bottom gasket of the hydrodynamic gas radial bearing is independent and separated from the supporting bump foil and the top foil, so that the bottom gasket can be embedded between the supporting bump foil and the bearing body after the supporting bump foil and the top foil are assembled, and the gap between the top foil and the rotating shaft can be adjusted.

Description

Dynamic pressure gas radial bearing, assembling method thereof and power equipment

Technical Field

The invention relates to the technical field of gas bearings, in particular to a dynamic pressure gas radial bearing, an assembling method thereof and power equipment.

Background

The foil air bearing is a self-acting dynamic pressure air bearing adopting an elastic supporting structure and mainly comprises a bearing seat, the elastic supporting structure and a top layer foil. As gas is adopted as a lubricating medium, compared with the traditional rolling bearing and oil bearing, the gas-oil bearing has the advantages of high rotating speed, low friction power consumption, no need of lubrication, strong shock resistance, capability of working in severe environments such as high temperature and low temperature, low maintenance cost and the like, and is widely applied to high-speed rotating equipment such as blowers, compressors, micro gas turbines, electronic turbochargers, auxiliary power systems and the like.

The foil air bearing supports the rotor to run at a high speed by utilizing the compression effect of a wedge-shaped gap air film between the top foil and the rotor, so that a stable wedge-shaped compressed air film is formed, on one hand, a reasonable air film gap is required between the top foil and the rotor, on the other hand, a supporting wave foil sheet at the bottom of the bearing is required to have good consistency, and meanwhile, the rotor is required to stably run in a small-amplitude vibration mode under a heavy load or impact working load, and the bearing has good damping performance. At present, the gas film gap between the top foil of the radial foil gas bearing and the rotor is generally designed to be 0.04-0.08 mm, but the gas film gap is influenced by the bending deformation of the top foil during hot processing, and the rotor needs to be polished and adjusted.

Disclosure of Invention

The invention aims to provide a dynamic pressure gas radial bearing, an assembling method thereof and power equipment, so as to better meet the requirement of a gap between a rotor and the bearing.

A first aspect of the present invention provides a dynamic pressure gas radial bearing comprising:

a bearing body having a shaft hole; and

the elastic supporting structure comprises a bottom gasket, a supporting bump foil and a top foil which are sequentially arranged along the radial direction, wherein the bottom gasket, the supporting bump foil and the top foil are mutually independent and are arranged in a split manner.

In some embodiments, the resilient support structure comprises at least two sub-gaskets distributed circumferentially.

In some embodiments, adjacent ones of the at least two bottom gaskets have a void therebetween.

In some embodiments, the base gasket is formed by bending a square foil.

In some embodiments, the sub-layer pad has a thickness of 0.05 to 0.1 mm.

In some embodiments, the bearing body is provided with mounting holes penetrating through two axial ends of the bearing body, and the mounting holes are arranged at intervals with the shaft hole and communicated through the communication seam and are used for mounting the top foil.

In some embodiments, the top foil is of cylindrical sleeve construction and is provided at one end with a top foil bend (21), said top foil bend (21) being embedded in the communication seam.

In some embodiments, the support bump foil includes a plurality of wave-shaped convex sections and a horizontal connecting section disposed between two adjacent wave-shaped convex sections, the horizontal connecting section being in contact with the base gasket.

In some embodiments, the elastic support structure comprises at least two support bump foils distributed along the circumferential direction; and/or the elastic support structure comprises at least two support bump foils distributed along the axial direction.

In some embodiments, the bearing body defines at least two mounting slots for corresponding at least two supporting bump foils.

A second aspect of the present invention provides a method of assembling a dynamic pressure gas radial bearing, comprising:

mounting a top foil and a supporting bump foil on the bearing body;

and inserting a bottom gasket between the supporting bump foil and the bearing body to adjust the gap between the top foil and the rotor.

A third aspect of the present invention provides a power plant comprising a rotor and the hydrodynamic gas radial bearing of the first aspect of the present invention, the rotor comprising a shaft, the shaft being disposed in the shaft hole.

Based on the technical scheme provided by the invention, the dynamic pressure gas radial bearing comprises a bearing body, a bearing body and a bearing seat, wherein the bearing body is provided with a shaft hole; and the elastic supporting structure comprises a bottom gasket, a supporting bump foil and a top foil which are sequentially arranged along the radial direction, and the bottom gasket, the supporting bump foil and the top foil are mutually independent and are arranged in a split manner. The bottom gasket of the hydrodynamic gas radial bearing is independent and separated from the supporting bump foil and the top foil, so that the bottom gasket can be embedded between the supporting bump foil and the bearing body after the supporting bump foil and the top foil are assembled, and the gap between the top foil and the rotating shaft can be adjusted.

Other features of the present invention and advantages thereof will become apparent from the following detailed description of exemplary embodiments thereof, which proceeds with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the invention without limiting the invention. In the drawings:

FIG. 1 is a schematic structural view of a gas radial bearing according to an embodiment of the present invention;

FIG. 2 is a partial enlarged structural view of the M portion in FIG. 1;

FIG. 3 is a schematic view of the bearing body of FIG. 1;

FIG. 4 is a schematic diagram of the top foil of FIG. 1;

FIG. 5 is a schematic structural view of the supporting bump foil of FIG. 1;

FIG. 6 is a schematic view of the structure of the sub-gasket of FIG. 1.

Each reference numeral represents:

1. a bearing body; 11. mounting holes; 12. installing a seam; 13. a communicating seam;

2. a top foil; 21. a top foil bend segment;

3. supporting the corrugated foil; 31. an undulating raised section; 32. a horizontal connecting section; 33. a wave foil bending section;

4. a back-up pad.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate. In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

Spatially relative terms, such as "above … …," "above … …," "above … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial relationship to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is turned over, devices described as "above" or "on" other devices or configurations would then be oriented "below" or "under" the other devices or configurations. Thus, the exemplary term "above … …" can include both an orientation of "above … …" and "below … …". The device may be otherwise variously oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

As shown in fig. 1 to 6, a hydrodynamic gas radial bearing according to an embodiment of the present invention includes:

a bearing body 1 having a shaft hole; and

the elastic supporting structure comprises a bottom gasket 4, a supporting bump foil 3 and a top foil 2 which are sequentially arranged along the radial direction, wherein the bottom gasket 4, the supporting bump foil 3 and the top foil 2 are mutually independent and are arranged in a split mode.

The bottom gasket 4 of the hydrodynamic gas radial bearing is independent and separated from the supporting bump foil 3 and the top foil 2, so that the bottom gasket 4 can be embedded between the supporting bump foil 3 and the bearing body 1 after the supporting bump foil 3 and the top foil 2 are assembled, and the gap between the top foil 2 and the rotating shaft can be adjusted. In addition, because the bottom gasket 4 is additionally arranged between the inner wall of the bearing body 1 and the supporting bump foil 3, the supporting bump foil 3 is stressed by a certain pretightening force due to the fact that the bottom foil 4 is higher than the supporting bump foil 3, the contact area between the supporting bump foil 3 and the top foil 2 is increased, and the deformation quantity exists on the height of the supporting bump foil 3, so that the thickness distribution of the wedge-shaped air film between the top foil 2 and the rotor cannot be influenced even if the height consistency of the supporting bump foil 3 is not too high, and the requirement on the bump foil consistency is reduced.

The embodiment of the invention also provides an assembling method of the dynamic pressure gas radial bearing, which comprises the following steps:

a top layer foil 2 and a supporting bump foil 3 are arranged on the bearing body 1;

a bottom shim 4 is inserted between the supporting bump foil 3 and the bearing body 1 to adjust the gap between the top foil 2 and the rotor.

After the supporting bump foil 3 and the top foil 2 are assembled, the bottom layer gasket 4 is embedded between the supporting bump foil 3 and the bearing body 1, so that the gap between the top foil 2 and the rotating shaft is adjusted.

The structure of the dynamic pressure gas radial bearing according to the embodiment of the present invention will be described in detail with reference to fig. 1 to 6.

As shown in fig. 1 and 2, the hydrodynamic gas radial bearing of the present embodiment includes a bearing body 1 having a shaft hole, and an elastic support structure including a bottom shim 4, a support bump foil 3, and a top foil 2, which are sequentially arranged in a radial direction.

As shown in fig. 3, the bearing body 1 has an end portion provided with a mounting hole 11. The mounting hole 11 runs through the axial both ends of bearing body 1, and there is certain distance in mounting hole 11 and shaft hole, communicates mounting hole 11 and shaft hole through intercommunication seam 13, conveniently carries out the installation and the fixed of top layer foil 2. As shown in fig. 3, the top foil 2 of this embodiment is a cylindrical sleeve structure, one end of the top foil 2 is provided with a top foil bending section 21 that is tilted upward, and the top foil bending section 21 is used to be embedded into the communication seam 13, so as to ensure that the top foil 2 does not axially slide during the start-stop stage of the rotor.

The width of the communication seam 13 of the embodiment is 0.01-0.02 mm larger than the thickness of the top foil 2, so that the two are in transition fit and have a certain pretightening force. Simultaneously, a cylindrical pin is arranged at the position of the mounting hole 11 for prepressing and fixing, so that axial movement is effectively prevented.

The top foil 2 of this embodiment is provided with a ramp near the top foil bend 21, mainly for forming a gas film and making contact with the non-bent end of the top foil 2. The ramp provided on the top foil 2 of this embodiment is formed by a thin to thick surface coating.

The top foil 2 of the embodiment is provided with a wear-resistant lubricating coating on the inner wall in contact with the rotor so as to ensure that the rotor is less worn when being started and stopped, reduce the starting torque and improve the reliability of the bearing.

As shown in fig. 3, the mounting hole 11 of the present embodiment is a circular hole. And the number of the mounting holes is preferably 2-6, and preferably 3 to ensure uniform stress of the bearing body 1.

As shown in fig. 5, the supporting bump foil 3 of the present embodiment has a curved shape, and includes a plurality of bump segments 31, a horizontal connecting segment 32 disposed between two adjacent bump segments 31, and a bump foil bending segment 33 disposed at one end, wherein the bump segments 31 are in contact with the top foil sheet 2, and the horizontal connecting segment 32 is in contact with the inner surface of the bottom gasket 4.

The corrugated foil bending section 33 is embedded in the mounting seam 12 of the bearing body 1, so that the corrugated foil 3 is supported without circumferential relative sliding when the rotor starts and stops. And the width of the mounting seam 12 is 0.01-0.02 mm larger than the thickness of the corrugated foil, so that the mounting seam and the corrugated foil are in transition fit, have a certain pretightening force and prevent axial movement.

The supporting bump foil of the present embodiment is a non-full circle structure. The elastic support structure of the present embodiment comprises at least two support bump foils 3 distributed in the circumferential direction. The corresponding bearing body 1 is provided with at least two mounting seams 12, and the at least two mounting seams 12 are used for corresponding to the at least two supporting wave foils 3.

The mounting slit 12 of the present embodiment is provided near the mounting hole 11.

The elastic support structure of the present embodiment comprises at least two support bump foils 3 distributed in the axial direction. So be provided with and do benefit to even atress to support ripples paper tinsel 3 and have the polylith to splice into circularly along the circumferencial direction in the bearing body 1, reserve the segment clearance between two adjacent, can carry out small slip after guaranteeing the atress.

The processing precision and consistency of the protrusions of the elastic corrugated supporting structure supporting the surface of the corrugated foil 3 of the embodiment are mainly ensured by means of a grinding tool. After the elastic corrugation on the surface of the supporting corrugated foil 3 is processed, the elastic corrugation is bent and formed through a heat treatment process, and then the bearing assembly is carried out.

As shown in fig. 1, the elastic support structure of the present embodiment includes at least two base gaskets 4 distributed in the circumferential direction. The shim 4 of this embodiment freely bends along the inner wall of the bearing body 1, splices into a circle, reserves a small space between two adjacent sheets, and allows the shim 4 to slide slightly.

The thickness of the bottom pad 4 is not too thick, and the thickness is preferably selected to be in the range of 0.05-0.1 mm. At least two of the plurality of sub-gaskets 4 have a gap between adjacent ones of the sub-gaskets 4.

As shown in fig. 6, the base gasket 4 of the present embodiment is formed by bending a square foil. The length is designed according to the radius of the shaft hole of the bearing body 1.

To ensure good bending performance, the underlying pad needs to be subjected to a heat treatment process to increase the elasticity of the underlying pad.

The inner wall of the bottom gasket 4 of this embodiment is in close contact with the horizontal connection section 32 supporting the corrugated foil 3, and the outer wall is in contact with the inner wall of the bearing body 1, so that the bottom gasket 4 is prevented from moving axially and circumferentially due to the extrusion pretightening force in the installation process. The shim 4 of this embodiment needs to assemble after bearing and axle assembly, carries out the adjustment of gas film clearance, can guarantee that the rotor shaft need not to carry out the coping, also can guarantee reasonable design clearance. And the supporting bump foil 3 can generate micro elastic stretching deformation under the action of the air film acting force through the force transmission action of the top foil 2, and can generate micro sliding with the top foil 2, the inner wall and the outer wall of the bottom gasket 4 and the inner surface of the bearing body, so that enough damping is provided for the high-speed running of the bearing, and the running stability of the rotor is ensured.

And because the bottom gasket 4 is additionally arranged on the inner wall of the bearing body 1, and the supporting bump foil 3 is heightened by the bottom foil 4, the supporting bump foil 3 is subjected to a certain pretightening force, the contact area between the wavy convex section 31 of the supporting bump foil 3 and the top foil 2 is increased, and the deformation quantity exists on the height of the supporting bump foil 3, so that the thickness distribution of the wedge-shaped air film between the top foil 2 and the rotor cannot be influenced even if the height consistency of the supporting bump foil 3 is not too high, and the requirement on the bump foil consistency is reduced.

The operation of the hydrodynamic gas radial bearing of the present embodiment is as follows:

when the rotor of the embodiment works at a high speed, a certain amount of eccentricity exists between the center of the bearing and the rotor, and a gas film with a certain thickness is formed between the rotor and the top foil 2 to support the rotor. The inner wall of the bearing body 1 is provided with a bottom gasket 4, a supporting wave foil 3 is arranged above the bottom gasket 4, and the supporting wave foil 3 is embedded into the mounting seam of the bearing body 1 through a wave foil bending section 33 for fixing. The horizontal connecting section 32 makes contact with the inner wall of the underlay sheet 4. Meanwhile, a top layer foil 2 is arranged above the supporting bump foil 3, the top foil bending section 21 is embedded into a communication seam of the bearing body mounting hole, and a cylindrical long pin is arranged in the mounting hole for fixing. Because the resilience of the top foil 2 and the support of the bottom gasket 4, the top foil is subjected to certain pretightening force, so that the outer wall of the top foil 2 can be fully contacted with the bulge on the surface of the bump foil, and the bump foil is prevented from being stressed unevenly. Meanwhile, the traditional bearing is not subjected to pretightening force after being assembled, and the consistency of the gap between the rotor and the top foil and the height of the bump foil needs to be ensured by a high-precision grinding tool, so that the process complexity is increased. The bearing of this embodiment is used, the precision of the bump foil grinding tool can be reduced, the tolerance is increased during design, the design clearance adjustment is carried out by adding the bottom gasket after the bearing is assembled, and the design precision and the consistency of the bearing are ensured. Meanwhile, because the air film force acts on the top foil and is transmitted to the supporting bump foil, the supporting bump foil is elastically deformed, micro sliding is generated between the supporting bump foil and the bottom gasket, the structural damping of the bearing can be increased, and because the bottom gasket and the supporting bump foil and the bottom gasket and the bearing body also slide relatively, the friction resistance can be increased, the damping is improved, and the reliability of the bearing is improved.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention and not to limit it; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art will understand that: modifications to the specific embodiments of the invention or equivalent substitutions for parts of the technical features may be made; without departing from the spirit of the present invention, it is intended to cover all aspects of the invention as defined by the appended claims.

Claims

1. A dynamic pressure gas radial bearing, comprising:

a bearing body (1) having a shaft hole; and

the elastic supporting structure comprises a bottom gasket (4), a supporting bump foil (3) and a top foil (2) which are sequentially arranged along the radial direction, wherein the bottom gasket (4), the supporting bump foil (3) and the top foil (2) are mutually independent and are arranged in a split manner.

2. Hydrodynamic gas radial bearing according to claim 1, characterized in that the elastic support structure comprises at least two of the sub-gaskets (4) distributed in the circumferential direction.

3. Hydrodynamic gas radial bearing according to claim 2, characterized in that a gap is present between two adjacent shims (4) of the at least two shims (4).

4. Hydrodynamic gas radial bearing according to claim 1, characterized in that the sub-shim (4) is bent from a square foil.

5. Hydrodynamic gas radial bearing according to claim 1, characterized in that the thickness of the shim (4) is 0.05 to 0.1 mm.

6. The radial hydrodynamic gas bearing according to any one of claims 1 to 5, wherein the bearing body (1) is provided with mounting holes (11) penetrating through both axial ends of the bearing body, and the mounting holes (11) are spaced apart from the axial hole and communicate with the axial hole through a communication slit (13) and are used for mounting the top foil (2).

7. Hydrodynamic gas radial bearing according to claim 6, characterized in that the top foil (2) is of cylindrical sleeve construction and is provided at one end with a top foil bend (21), the top foil bend (21) being embedded in the connecting seam (13).

8. Hydrodynamic gas radial bearing according to any of claims 1 to 5, characterized in that the supporting bump foil (3) comprises a plurality of undulating raised sections (31) and a horizontal connecting section (32) arranged between two adjacent undulating raised sections (31), the horizontal connecting section (32) being in contact with the sub-shim (4).

9. Hydrodynamic gas radial bearing according to any of claims 1 to 5, characterized in that the elastic support structure comprises at least two of the support wave foils (3) distributed in the circumferential direction; and/or the elastic supporting structure comprises at least two supporting wave foils (3) distributed along the axial direction.

10. Hydrodynamic gas radial bearing according to claim 9, characterized in that the bearing body is provided with at least two mounting slots (12), the at least two mounting slots (12) being adapted to correspond to the at least two carrier foils (3).

11. A method of assembling a dynamic pressure gas radial bearing, comprising:

a top layer foil (2) and a supporting bump foil (3) are arranged on the bearing body (1);

and inserting a bottom gasket (4) between the supporting bump foil (3) and the bearing body (1) to adjust the gap between the top foil (2) and the rotor.

12. A power plant comprising a rotor and a hydrodynamic gas radial bearing as claimed in any one of claims 1 to 10, the rotor comprising a shaft disposed within the shaft bore.