CN215567251U

CN215567251U - Gas thrust bearing, bearing assembly, compressor, air conditioner and automobile

Info

Publication number: CN215567251U
Application number: CN202121880163.5U
Authority: CN
Inventors: 钟瑞兴; 雷连冬; 刘华; 张治平; 陈玉辉; 杨玉明
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2021-08-12
Filing date: 2021-08-12
Publication date: 2022-01-18
Anticipated expiration: 2031-08-12

Abstract

The disclosure relates to a gas thrust bearing, a bearing assembly, a compressor, an air conditioner and an automobile. The bearing assembly includes: a rotor having a thrust disc; the bearing shell is positioned on one side of the thrust disc along the axial direction of the rotor; and a plurality of foil sets arranged along a circumferential direction of the bearing housing, wherein the foil sets include: a bump foil on a side of the bearing housing adjacent the thrust disc; and a top foil located on a side of the bump foil remote from the bearing housing, wherein the top foil comprises a first top foil segment and at least two second top foil segments, the first top foil segment being parallel to the surface of the thrust disc, the at least two second top foil segments being at an oblique angle relative to the surface of the thrust disc; the first top foil segment is located downstream of the at least two second top foil segments, and the angle of inclination of the upstream second top foil segment with respect to the surface of the thrust disc is larger than the angle of inclination of the downstream second top foil segment with respect to the surface of the thrust disc, depending on the direction of rotation of the rotor during operation. The embodiment of the disclosure can quickly form a stable dynamic pressure gas film.

Description

Gas thrust bearing, bearing assembly, compressor, air conditioner and automobile

Technical Field

The disclosure relates to the field of bearings, in particular to a gas thrust bearing, a bearing assembly, a compressor, an air conditioner and an automobile.

Background

The hydrogen fuel cell automobile is a new energy automobile in the 21 st century, has a strategic breakthrough and has the advantages of high dynamic performance, quick hydrogenation, long endurance and the like. The air compressor provides a high-pressure air source for the fuel cell system, and a centrifugal air compressor, a screw air compressor, a scroll air compressor and the like are commonly used. Compared with screw type and vortex type air compressors, the centrifugal type air compressor has higher rotating speed and energy efficiency, and can provide an air source with higher pressure ratio, thereby obviously improving the power density and the overall performance of the electric pile.

The foil dynamic pressure gas thrust bearing belongs to one kind of dynamic pressure sliding bearing, has the advantages of small friction loss, high rotation speed, good high temperature stability, no need of lubricating oil and the like, and is very suitable for being applied to a high-rotation-speed centrifugal air compressor. In the related art, a typical structure of a foil hydrodynamic gas thrust bearing includes a bearing housing, a bump foil, and a top foil to provide axial stiffness and damping to a rotor system.

Like the pads of lube thrust bearings, the top foil of foil hydrodynamic gas thrust bearings is typically designed in a fan shape to act as a pad. For uniform stress, the top foil is evenly distributed in the circumferential direction. The corrugated foil on the underside of the top foil has a corrugated structure, which serves as an elastic support and is the main source of stiffness and damping for the thrust bearing. One end of the wave foil and one end of the top foil are both fixed on the bearing seat, the other end of the wave foil and the other end of the top foil are both free ends, a wedge-shaped convergence included angle exists between the front end of the top foil and the bearing shell, the rear end of the top foil is parallel to the bearing shell, and when the rotor rotates at a high speed, a dynamic pressure gas film is formed under the action of the wedge-shaped convergence included angle to support the rotor.

Disclosure of Invention

The inventor has found that the operation of the foil dynamical pressure gas thrust bearing is key to forming a dynamical pressure gas film supporting rotor, but when the bearing is used on a hydrogen fuel cell automobile, the following technical problems are faced: the automobile needs to be started frequently, which means that an air compressor for providing a high-pressure air source to the fuel cell system is started frequently along with the automobile, and a foil dynamic pressure gas thrust bearing is used as one of dynamic pressure bearings, and an air film is not formed in the starting stage. In order to reduce the bearing wear, the related art increases the wedge-shaped convergence angle of the bearing to improve the dynamic pressure effect and quickly form the air film, but the overlarge wedge-shaped convergence angle causes large pressure gradient of the air film, uneven pressure distribution of the air film, and is not favorable for the bearing stability.

In view of the above, embodiments of the present disclosure provide a gas thrust bearing, a bearing assembly, a compressor, an air conditioner, and an automobile, which can quickly form a stable dynamic pressure film.

In one aspect of the present disclosure, there is provided a bearing assembly including: the rotor is provided with a rotating shaft and a thrust disc fixedly connected with or integrally formed with the rotating shaft; the bearing shell is sleeved on the rotating shaft and is positioned on one side of the thrust disc along the axial direction of the rotor; and a plurality of foil groups mounted on one side of the bearing housing adjacent to the thrust disk and arranged along a circumferential direction of the bearing housing, wherein at least one of the plurality of foil groups includes: the bump foil is positioned on one side, adjacent to the thrust disc, of the bearing shell, and one end of the bump foil is connected with the bearing shell; and a top foil located on a side of the bump foil remote from the bearing housing and having one end connected to the bearing housing, wherein the top foil comprises a first top foil segment parallel to the surface of the thrust disk and at least two second top foil segments at an oblique angle relative to the surface of the thrust disk; the first top foil segment is located downstream of the at least two second top foil segments, and an inclination angle of an upstream one of the at least two second top foil segments with respect to the surface of the thrust disk is larger than an inclination angle of a downstream one of the at least two second top foil segments with respect to the surface of the thrust disk, depending on a rotation direction of the rotor in operation.

In some embodiments, the first top foil segment and the at least two second top foil segments are connected in series along a circumference of the bearing housing.

In some embodiments, the top foil further comprises: a third top foil segment parallel to the surface of the thrust disk and spaced further from the surface of the thrust disk than the first top foil segment, wherein the third top foil segment is located upstream of the at least two second top foil segments and connected to the upstream second top foil segment of the at least two second top foil segments, depending on the direction of rotation of the rotor during operation.

In some embodiments, the angle of inclination of the at least two second top foil segments with respect to the surface of the thrust disc is both greater than 0 ° and both less than 15 °.

In some embodiments, a projected length of an upstream one of the at least two second top foil segments on the surface of the thrust disc is less than a projected length of a downstream one of the at least two second top foil segments on the surface of the thrust disc.

In some embodiments, each of the plurality of foil groups is identical in structure and size.

In some embodiments, the number of the plurality of foil sheet sets is an even number greater than 0.

In some embodiments, the bearing housing supports the axial end faces of the plurality of foil packs parallel to the surface of the thrust disk.

In some embodiments, the wave foil comprises a first wave foil section located between the first top foil section and the bearing housing, the first wave foil section comprising a plurality of first corrugations and a plurality of second corrugations, the first corrugations being stiffer than the second corrugations.

In some embodiments, the height of the first corrugations is less than the height of the second corrugations.

In some embodiments, the first corrugations have a span that is less than a span of the second corrugations.

In some embodiments, at least one of said first corrugations and at least one of said second corrugations are alternately arranged along the extension direction of said first top foil segment with respect to said at least two second top foil segments.

In some embodiments, a first number of the first corrugations and a second number of the second corrugations alternate, the first number being the same as the second number, or being less than the second number, or being greater than the second number.

In some embodiments, the wave foil further comprises a second wave foil section located between the at least two second top foil sections and the bearing housing and connected to the first wave foil section, the second wave foil section comprising a plurality of third corrugations, the height of the plurality of third corrugations increasing gradually in the direction of rotation of the rotor in operation.

In one aspect of the present disclosure, there is provided a gas thrust bearing comprising: the bearing comprises a bearing shell, a bearing shell and a bearing seat, wherein the bearing shell is provided with an axial end face and a shaft hole which penetrates through the bearing shell along the axial direction, and the axis of the shaft hole is perpendicular to the axial end face of the bearing shell; and a plurality of foil groups mounted on an axial end surface of the bearing housing and arranged along a circumferential direction of the bearing housing, wherein at least one of the plurality of foil groups includes: the bump foil is abutted against the axial end face of the bearing shell, and one end of the bump foil is connected with the bearing shell; the top foil is positioned on one side, far away from the bearing shell, of the bump foil, and one end of the top foil is connected with the bearing shell, wherein the top foil comprises a first top foil section and at least two second top foil sections, the first top foil section is parallel to the axial end face of the bearing shell, and the at least two second top foil sections form an inclined angle relative to the axial end face of the bearing shell; the first top foil segment is located downstream of the at least two second top foil segments according to a rotational direction of the rotor relative to the bearing housing when in operation, and an inclination angle of an upstream one of the at least two second top foil segments relative to the axial end face of the bearing housing is larger than an inclination angle of a downstream one of the at least two second top foil segments relative to the axial end face of the bearing housing.

In some embodiments, the angle of inclination of the at least two second top foil segments with respect to the axial end face of the bearing housing is each greater than 0 °, and each less than 15 °.

In some embodiments, a projected length of an upstream one of the at least two second top foil segments on the axial end face of the bearing housing is smaller than a projected length of a downstream one of the at least two second top foil segments on the axial end face of the bearing housing.

In one aspect of the present disclosure, there is provided a compressor including: the aforementioned bearing assembly, or the aforementioned gas thrust bearing.

In one aspect of the present disclosure, there is provided an air conditioner including: the aforementioned compressor, or the aforementioned bearing assembly, or the aforementioned gas thrust bearing.

In one aspect of the present disclosure, there is provided an automobile including: the aforementioned compressor, or the aforementioned bearing assembly, or the aforementioned gas thrust bearing.

Therefore, according to the embodiment of the present disclosure, at least two second top foil segments are provided in the top foil upstream of the first top foil segment of the dynamic pressure bearing region in the direction of rotation of the rotor during operation, such that the at least two second top foil segments are at an inclination angle (i.e., wedge convergence angle) with respect to the surface of the thrust disk, and the inclination angle of the second top foil segment located upstream with respect to the surface of the thrust disk is larger than the inclination angle of the second top foil segment located downstream with respect to the surface of the thrust disk, so that the dynamic pressure gas enters the dynamic pressure bearing region after flowing through the wedge gap having a wedge convergence angle from large to small. Because the wedge-shaped convergence angle corresponding to the upstream second top foil section is larger, a large-area abrupt wedge-shaped convergence region can be formed to improve the dynamic pressure effect of the bearing, so that a dynamic pressure air film can be quickly formed in the starting process of the compressor, and the bearing abrasion is reduced. And the wedge-shaped convergence angle corresponding to the downstream second top foil section is smaller, the area of the formed wedge-shaped convergence area is slightly gradually changed, so that the pressure gradient mutation is smaller, the fluctuation of the air film is reduced, the movable air film is more stable, and the vibration of the rotor is reduced.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description, serve to explain the principles of the disclosure.

The present disclosure may be more clearly understood from the following detailed description, taken with reference to the accompanying drawings, in which:

FIG. 1 is a schematic structural view of some embodiments of a bearing assembly according to the present disclosure;

FIG. 2 is a schematic structural view in an axial perspective of some embodiments of a bearing assembly according to the present disclosure;

FIG. 3 is a schematic view of the AA cross-section of FIG. 2;

FIG. 4 is an enlarged schematic view of region B of FIG. 3;

FIG. 5 is a schematic view of the placement of the top foil in each of the foil groups in some embodiments of a bearing assembly according to the present disclosure;

FIG. 6 is a schematic view of an arrangement of bump foils in each foil set in some embodiments of a bearing assembly according to the present disclosure.

It should be understood that the dimensions of the various parts shown in the figures are not drawn to scale. Further, the same or similar reference numerals denote the same or similar components.

Detailed Description

Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The description of the exemplary embodiments is merely illustrative and is in no way intended to limit the disclosure, its application, or uses. The present disclosure may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. It should be noted that: the relative arrangement of parts and steps, the composition of materials, numerical expressions and numerical values set forth in these embodiments are to be construed as merely illustrative, and not as limitative, unless specifically stated otherwise.

The use of "first," "second," and similar terms in this disclosure is not intended to indicate any order, quantity, or importance, but rather are used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that the element preceding the word covers the element listed after the word, and does not exclude the possibility that other elements are also covered. "upper", "lower", "left", "right", and the like are used merely to indicate relative positional relationships, and when the absolute position of the object being described is changed, the relative positional relationships may also be changed accordingly.

In the present disclosure, when a specific device is described as being located between a first device and a second device, there may or may not be intervening devices between the specific device and the first device or the second device. When a particular device is described as being coupled to other devices, that particular device may be directly coupled to the other devices without intervening devices or may be directly coupled to the other devices with intervening devices.

All terms (including technical or scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs unless specifically defined otherwise. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

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.

Referring to fig. 1-6, in some embodiments, a bearing assembly includes: a rotor 10, a bearing housing 21 and a plurality of foil sets. The rotor 10 has a rotating shaft 12 and a thrust disk 11 fixedly connected to or integrally formed with the rotating shaft 12. The rotor 10 is configured to rotate about an axis 13. The bearing housing 21 is sleeved on the rotating shaft 12, and is located on one side of the thrust disc 11 along the axial direction of the rotor 10. The bearing housing 21 may be an annular thin plate-shaped member. A plurality of foil sets are mounted on the bearing housing 21 on a side adjacent to the thrust disk 11 and arranged along the circumferential direction of the bearing housing 21.

The overall shape of the foil set here may be fan-ring shaped and may therefore also be referred to as a tile. The number of the plurality of foil groups may be an even number larger than 0, such as 4, 6, 8, etc., to improve the bearing capacity and stability of the bearing. Referring to fig. 5 and 6, the bearing assembly may include 6 foil sets, the 6 foil sets being uniformly arranged in a circumferential direction on the surface of the bearing housing 21. In other embodiments, the number of foil groups may also be odd.

In some embodiments, each of the plurality of foil sets is of the same configuration and size to provide a more uniform dynamic pressure film at various locations around the circumference of the bearing. In other embodiments, the foil sets in the plurality of foil sets may be different in structure and size.

At least one of the plurality of foil sets includes a bump foil and a top foil. The bump foil is located on the side of the bearing housing 21 adjacent to the thrust disk 11, and has one end connected to the bearing housing 21. The top foil is located on the side of the bump foil away from the bearing housing 21, and one end is connected to the bearing housing 21.

Referring to fig. 3 and 4, the top foil comprises a first top foil segment 22 and at least two second top foil segments. The first top foil segment 22 is parallel to the surface of the thrust disc 11 and the at least two second top foil segments are at an oblique angle with respect to the surface of the thrust disc 11. In fig. 4, the at least two second top foil segments comprise second

top foil segments

231 and 232, wherein the second top foil segment 231 is located upstream and the second top foil segment 232 is located downstream in the direction of rotation of the rotor 10 in operation.

Depending on the direction of rotation ω of the rotor 10 in operation, the first top foil segment 22 is located downstream of the at least two second top foil segments, and the angle of inclination θ 1 of the upstream one of the at least two second top foil segments (e.g. second top foil segment 231 in fig. 4) with respect to the surface of the thrust disk 11 is larger than the angle of inclination θ 2 of the downstream one of the at least two second top foil segments (e.g. second top foil segment 232 in fig. 4) with respect to the surface of the thrust disk 11.

According to the dynamic pressure effect principle, a wedge-shaped gap is formed between the working surface of the top foil and the working surface of the thrust disc in order to form a dynamic pressure gas film. The two working surfaces are filled with gas with certain viscosity, such as air or gaseous refrigerant, and relative sliding speed exists between the two working surfaces. The gas flows in from the section with larger area of the wedge-shaped gap and flows out from the section with smaller area.

In this embodiment, the first top foil segment 22, which is parallel to the surface of the thrust disc 11, forms with the thrust disc 11 a bearing area a1, which bearing area a1 is the main bearing area of the bearing. The at least two second top foil segments are inclined with respect to the surface of the thrust disc 11 (i.e. at a wedge-shaped convergence angle) such that when the thrust disc 11 is rotated at high speed with respect to the bearing housing 21 and the plurality of foil sets, a certain amount of viscous hydrodynamic gas is entrained to flow through the wedge-shaped gap formed between the at least two second top foil segments and the thrust disc 11 and enter the bearing area a 1. The high-pressure gas film formed in the bearing area a1 can support the thrust disk 11.

Because the wedge-shaped convergence angle (namely the inclination angle theta 1) corresponding to the upstream second top foil section is larger, a large-area and abrupt wedge-shaped convergence area A2 can be formed to improve the dynamic pressure effect of the bearing, so that a dynamic pressure gas film can be quickly formed in the starting process of the compressor, and the bearing abrasion is reduced. And the wedge-shaped convergence angle (namely the inclination angle theta 2) corresponding to the downstream second top foil section is smaller, and the area of the formed wedge-shaped convergence area A3 is slightly gradually changed, so that the sudden change of the pressure gradient is smaller, the adverse effect on the stability of the air film due to the too fast sudden change of the pressure gradient is avoided, the fluctuation of the air film is reduced, the air film is more stable, and the vibration of the rotor is reduced. This can satisfy the requirements of the bearing life and the operational stability of the vehicle including the air compressor of the present embodiment, which are frequently started, to a greater extent.

Referring to fig. 4 and 5, in some embodiments, the top foil further comprises a third top foil segment 24. The third top foil segment 24 is parallel to the surface of the thrust disk 11 and is spaced further from the surface of the thrust disk 11 than the first top foil segment 22 is spaced from the surface of the thrust disk 11. The third top foil segment 24 is located upstream of the at least two second top foil segments, depending on the direction of rotation omega of the rotor 10 in operation, and is connected to the upstream one of the at least two second top foil segments, e.g. the second top foil segment 231 in fig. 4.

The third top foil segment 24 may be lapped over the bump foil and fixedly attached to the bearing housing 21 by welding or other fastening means. The third top foil section 24 forms an air flow inlet with the thrust disc 11. When the thrust disc 11 rotates at high speed relative to the top foil, it entrains the air flow from the wider air flow inlet and then through the wedge-shaped convergence areas a2 and A3 into the load-bearing area a 1.

The first top foil segment 22 and the at least two second top foil segments are connected in series in the circumferential direction of the bearing housing 21. In fig. 5, the third top foil segment 24 is in the form of a strip extending in the radial direction of the rotor 10, and the connecting lines of the first top foil segment 22 and the second top foil segment, the connecting lines of adjacent ones of the plurality of second top foil segments and the connecting lines of the second top foil segment and the third top foil segment 24 are all parallel. The first top foil segment 22, the plurality of second top foil segments and the third top foil segment together form a top foil in the shape of a sector ring.

The inclination angle of the second top foil segment with respect to the surface of the thrust disc 11 can be determined comprehensively from parameters such as bearing load, rotor speed, gas temperature, gas viscosity, etc. In some embodiments, the angle of inclination of at least two second top foil segments with respect to the surface of said thrust disc 11 is both greater than 0 ° and both less than 15 °.

The length of each second top foil segment may be designed such that a projected length L1 of an upstream one of the at least two second top foil segments (e.g. second top foil segment 231) on the surface of the thrust disc 11 is smaller than a projected length L2 of a downstream one of the at least two second top foil segments (e.g. second top foil segment 232) on the surface of the thrust disc 11. This helps the shorter, larger wedge convergence angle second top foil segment 231 to quickly form a dynamic pressure film at the compressor start-up stage, reducing bearing wear, and helps the longer, smaller wedge convergence angle second top foil segment 232 to reduce pressure gradients and reduce film fluctuations.

The inventor finds that the road condition is complex when the automobile runs, and the automobile is accelerated and decelerated frequently, so that the air compressor is required to provide air sources with different pressures to the fuel cell system through variable rotating speed. As the speed of the air compressor changes, the load stiffness required of the rotor system also changes, generally increasing with increasing speed. However, in the foil dynamic pressure gas thrust bearing, the bearing capacity of a single bump foil structure after the bearing is assembled is determined, the formed gas film has limited strength adaptability, and the problem that the bearing rigidity is not matched with the variable rotating speed exists.

Referring to fig. 4 and 6, in some embodiments, the wave foil comprises a first wave foil segment 25. The first bump foil segment 25 is located between the first top foil segment 22 and the bearing housing 21. The first wave foil segment 25 comprises a plurality of first corrugations 251 and a plurality of second corrugations 252, the first corrugations 251 being stiffer than the second corrugations 252. The second corrugation 252 with lower rigidity is used for meeting the requirement on the rigidity of the bearing at low rotating speed, the first corrugation 251 with higher rigidity is used for meeting the requirement on the rigidity of the bearing at high rotating speed, and the bearing capacity and the bearing adaptability of the bearing can be effectively improved by carrying out dynamic pressure gas film bearing through the first corrugated foil sections of the corrugated structures with different rigidities.

For a corrugated foil formed of the same material, the smaller the span, the smaller the corrugation height, the greater the stiffness, and conversely, the larger the span, the greater the corrugation height, the less the stiffness. Referring to fig. 4, in some embodiments, the height H1 of the first corrugation 251 is less than the height H2 of the second corrugation 252. When the rotor speed is low, the required bearing force is small, and because H2> H1, the second corrugation 252 with lower rigidity contacts the top foil first and provides rigidity support; as the rotational speed is gradually increased, the required bearing capacity of the rotor is increased, and the height H2 of the second corrugation 252 is reduced in compression to provide greater bearing rigidity; when the rotational speed is raised to a certain degree, the height H2 of the second corrugation 252 is compressed to be equal to the height H1 of the first corrugation 251, at which point the first corrugation 251 and the second corrugation 252 start to jointly support the top foil, providing a greater bearing stiffness.

To achieve a greater stiffness difference between the different corrugations, referring to fig. 4 and 6, in some embodiments, the span S1 of the first corrugation 251 may be made smaller than the span S2 of the second corrugation 252, thereby further accommodating the variable speed bearing requirements of the rotor. In other embodiments, the first corrugations 251 and the second corrugations 252 may have equal spans, based on the stiffness of the first corrugations 251 being higher than the stiffness of the second corrugations 252.

In order to make the load distribution more uniform, in fig. 4 and 6, at least one first corrugation 251 and at least one second corrugation 252 are arranged alternately along the extension of the first top foil section 22 with respect to the at least two second top foil sections 2, so that the formed high pressure gas film is kept stable.

In order to further improve the load distribution uniformity of the load bearing area a1 and to stabilize the formed high pressure gas film, in some embodiments, a first number of the first corrugations and a second number of the second corrugations are alternately arranged, the first number being the same as the second number. For example, one first corrugation and one second corrugation are alternately arranged, or two first corrugations and two second corrugations are alternately arranged, i.e., arranged as two first corrugations, two second corrugations, two first corrugations, two second corrugations … ….

In other embodiments, the number of first corrugations and the number of second corrugations arranged alternately may be different. For example, the first number (e.g., 2 or 3) is greater than the second number (e.g., 1), which may increase the overall stiffness of the bearing, facilitating the bearing to accommodate high rotor speed conditions. Also for example, the first number (e.g., 1) is less than the second number (e.g., 2 or 3), which may reduce the overall stiffness of the bearing, facilitating the bearing to accommodate low rotor speeds.

Referring to fig. 4 and 6, in some embodiments, the wave foil further comprises a second wave foil segment 26. The second bump foil segment 26 is located between the at least two second top foil segments and the bearing housing 21 and is connected to the first bump foil segment 25. That is, second bump foil segment 26 corresponds to wedge-shaped convergence area A2, the shape of which also varies with the angle of inclination of the second bump foil segment. In fig. 4, the second bump foil segment 26 comprises a plurality of third ripples, the height of which gradually increases in the direction of rotation ω of the rotor 10 during operation, in order to support the obliquely arranged second bump foil segment.

Referring to fig. 1-6, the present disclosure also provides a gas thrust bearing comprising: a bearing housing 21 and a plurality of foil sets. The gas thrust bearing may be manufactured and sold separately from the rotor 10. The bearing housing 21 has an axial end face and a shaft hole that penetrates in the axial direction, and the axis of the shaft hole is perpendicular to the axial end face of the bearing housing 21. The axis of the shaft hole coincides with the axis 13 of the rotation shaft of the rotor 10. A plurality of foil sets are mounted on an axial end surface of the bearing housing 21 and arranged along a circumferential direction of the bearing housing 21.

At least one of the plurality of foil sets includes a bump foil and a top foil. The bump foil abuts against an axial end face of the bearing housing 21, and one end is connected to the bearing housing 21. The top foil is located on the side of the bump foil away from the bearing housing 21, and one end is connected to the bearing housing 21.

The top foil comprises a first top foil segment 22 and at least two second top foil segments, said first top foil segment 22 being parallel to an axial end face of said bearing housing 21 and said at least two second top foil segments being at an oblique angle with respect to the axial end face of said bearing housing 21; depending on the direction of rotation ω of the rotor 10 in operation relative to the bearing housing 21, the first top foil segment 22 is located downstream of the at least two second top foil segments, and the angle of inclination of the upstream one of the at least two second top foil segments relative to the axial end face of the bearing housing 21 is larger than the angle of inclination of the downstream one of the at least two second top foil segments relative to the axial end face of the bearing housing 21.

When the gas thrust bearing is mounted, the axial end face of the bearing housing 21 is made parallel to the thrust disk of the rotor 10, and the rotating shaft 12 of the rotor 10 is inserted into the shaft hole of the bearing housing 21. Correspondingly, the angle of inclination of the at least two second top foil segments with respect to the axial end face of the bearing housing 21 is equal to the angle of inclination of the at least two second top foil segments with respect to the surface of the thrust disc 11.

On this basis, the inclination angles of the at least two second top foil segments with respect to the axial end face of the bearing housing 21 may each be greater than 0 ° and each be less than 15 °. The projected length of the upstream one of the at least two second top foil segments on the axial end face of the bearing housing 21 is smaller than the projected length of the downstream one of the at least two second top foil segments on the axial end face of the bearing housing 21.

In some embodiments, the wave foil comprises a first wave foil section 25, the first wave foil section 25 being located between the first top foil section 22 and the bearing housing 21, the first wave foil section 25 comprising a plurality of first corrugations 251 and a plurality of second corrugations 252, the first corrugations 251 being stiffer than the second corrugations 252. The second corrugation 252 with lower rigidity is used for meeting the requirement on the rigidity of the bearing at low rotating speed, the first corrugation 251 with higher rigidity is used for meeting the requirement on the rigidity of the bearing at high rotating speed, and the bearing capacity and the bearing adaptability of the bearing can be effectively improved by carrying out dynamic pressure gas film bearing through the first corrugated foil sections of the corrugated structures with different rigidities.

In some embodiments, the height of the first corrugations 251 is less than the height of the second corrugations 252. When the rotor speed is low, the required bearing force is small, and because H2> H1, the second corrugation 252 with lower rigidity contacts the top foil first and provides rigidity support; as the rotational speed is gradually increased, the required bearing capacity of the rotor is increased, and the height H2 of the second corrugation 252 is reduced in compression to provide greater bearing rigidity; when the rotational speed is raised to a certain degree, the height H2 of the second corrugation 252 is compressed to be equal to the height H1 of the first corrugation 251, at which point the first corrugation 251 and the second corrugation 252 start to jointly support the top foil, providing a greater bearing stiffness. Further, the span of the first corrugations 251 may be smaller than the span of said second corrugations 252. Thereby further accommodating the variable speed bearing requirements of the rotor.

In some embodiments, the at least one first corrugation 251 and the at least one second corrugation 252 are arranged alternately along the extension of said first top foil segment 22 with respect to said at least two second top foil segments to make the load distribution of the load bearing area a1 more uniform and thereby stabilize the formed high pressure gas film.

In some embodiments, the wave foil further comprises a second wave foil section 26, the second wave foil section 26 being located between the at least two second top foil sections and the bearing housing 21 and being connected to the first wave foil section 25, the second wave foil section 26 comprising a plurality of third corrugations, the height of the plurality of third corrugations increasing gradually in the direction of rotation of the rotor 10 in operation relative to the bearing housing 21. That is, second bump foil segment 26 corresponds to wedge-shaped convergence area A2, the shape of which also varies with the angle of inclination of the second bump foil segment. In fig. 4, the second bump foil segment 26 comprises a plurality of third ripples, the height of which gradually increases in the direction of rotation ω of the rotor 10 during operation, in order to support the obliquely arranged second bump foil segment.

The technical means involved in the embodiments of the bearing assembly can also be applied to the embodiments of the gas thrust bearing of the present disclosure, and the related effects can be referred to the foregoing description, which is not repeated herein.

The present disclosure also provides a compressor including the bearing assembly of any of the foregoing embodiments or the gas thrust bearing of any of the foregoing embodiments. The compressor can be a centrifugal air compressor and can be suitable for hydrogen fuel cell automobiles and the like.

The present disclosure also provides an air conditioner, including: the compressor of any of the preceding embodiments, or the bearing assembly of any of the preceding embodiments, or the gas thrust bearing of any of the preceding embodiments. The present disclosure also provides an air conditioner, including: the compressor of any of the preceding embodiments, or the bearing assembly of any of the preceding embodiments, or the gas thrust bearing of any of the preceding embodiments.

Thus, various embodiments of the present disclosure have been described in detail. Some details that are well known in the art have not been described in order to avoid obscuring the concepts of the present disclosure. It will be fully apparent to those skilled in the art from the foregoing description how to practice the presently disclosed embodiments.

Although some specific embodiments of the present disclosure have been described in detail by way of example, it should be understood by those skilled in the art that the foregoing examples are for purposes of illustration only and are not intended to limit the scope of the present disclosure. It will be understood by those skilled in the art that various changes may be made in the above embodiments or equivalents may be substituted for elements thereof without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is defined by the appended claims.

Claims

1. A bearing assembly, comprising:

a rotor (10) having a rotating shaft (12) and a thrust disc (11) fixedly connected or integrally formed with the rotating shaft (12);

the bearing shell (21) is sleeved on the rotating shaft (12) and is positioned on one side of the thrust disc (11) along the axial direction of the rotor (10); and

a plurality of foil groups mounted on the bearing housing (21) on a side adjacent to the thrust disk (11) and arranged in a circumferential direction of the bearing housing (21),

wherein at least one of the plurality of foil sheet sets comprises:

a bump foil located on the side of the bearing housing (21) adjacent to the thrust disc (11) and having one end connected to the bearing housing (21); and

a top foil located on a side of the bump foil remote from the bearing housing (21) and having one end connected to the bearing housing (21),

wherein the top foil comprises a first top foil segment (22) and at least two second top foil segments (231, 232), the first top foil segment (22) being parallel to the surface of the thrust disc (11), the at least two second top foil segments (231, 232) being at an oblique angle with respect to the surface of the thrust disc (11); the first top foil segment (22) is located downstream of the at least two second top foil segments (231, 232) depending on a direction of rotation of the rotor (10) during operation, and an angle of inclination of an upstream one (231, 232) of the at least two second top foil segments (231, 232) with respect to the surface of the thrust disc (11) is larger than an angle of inclination of a downstream one (231, 232) of the at least two second top foil segments (231, 232) with respect to the surface of the thrust disc (11).

2. A bearing assembly according to claim 1, characterized in that the first top foil segment (22) and the at least two second top foil segments (231, 232) are connected in sequence in the circumferential direction of the bearing housing (21).

3. The bearing assembly of claim 1, wherein the top foil further comprises:

a third top foil section (24) parallel to the surface of the thrust disk (11) and spaced from the surface of the thrust disk (11) by a distance greater than the distance between the first top foil section (22) and the surface of the thrust disk (11),

wherein the third top foil segment (24) is located upstream of the at least two second top foil segments (231, 232) and is connected to the upstream second top foil segment (231, 232) of the at least two second top foil segments (231, 232) depending on the direction of rotation of the rotor (10) during operation.

4. Bearing assembly according to claim 1, wherein the inclination angles of the at least two second top foil segments (231, 232) with respect to the surface of the thrust disc (11) are each greater than 0 ° and each less than 15 °.

5. Bearing assembly according to claim 1, wherein a projected length of an upstream one (231, 232) of the at least two second top foil segments (231, 232) on the surface of the thrust disc (11) is smaller than a projected length of a downstream one (231, 232) of the at least two second top foil segments (231, 232) on the surface of the thrust disc (11).

6. The bearing assembly of claim 1, wherein each of the plurality of foil sets is identical in structure and size.

7. The bearing assembly of claim 1, wherein the number of the plurality of foil sets is an even number greater than 0.

8. Bearing assembly according to claim 1, wherein the axial end faces of the bearing housing (21) supporting the plurality of foil sets are parallel to the surface of the thrust disc (11).

9. A bearing assembly according to any of claims 1 to 8, wherein the wave foil comprises a first wave foil segment (25), the first wave foil segment (25) being located between the first top foil segment (22) and the bearing housing (21), the first wave foil segment (25) comprising a plurality of first corrugations (251) and a plurality of second corrugations (252), the stiffness of the first corrugations (251) being higher than the stiffness of the second corrugations (252).

10. A bearing assembly according to claim 9, characterized in that the height of the first corrugations (251) is smaller than the height of the second corrugations (252).

11. A bearing assembly according to claim 10, characterized in that the span of the first corrugations (251) is smaller than the span of the second corrugations (252).

12. A bearing assembly according to claim 9, characterized in that at least one of said first corrugations (251) and at least one of said second corrugations (252) are alternately arranged along the extension direction of the first top foil segment (22) with respect to the at least two second top foil segments (231, 232).

13. Bearing assembly according to claim 12, characterized in that a first number of said first corrugations (251) and a second number of said second corrugations (252) are arranged alternately, said first number being the same as, or smaller than, or larger than said second number.

14. A bearing assembly according to claim 9, characterized in that the wave foil further comprises a second wave foil segment (26), the second wave foil segment (26) being located between the at least two second top foil segments (231, 232) and the bearing housing (21) and being connected with the first wave foil segment (25), the second wave foil segment (26) comprising a plurality of third corrugations, the height of the plurality of third corrugations increasing gradually in the direction of rotation of the rotor (10) in operation.

15. A gas thrust bearing, comprising:

a bearing housing (21) having an axial end surface and a shaft hole that penetrates in the axial direction, and the axis of the shaft hole is perpendicular to the axial end surface of the bearing housing (21); and

a plurality of foil groups mounted on an axial end face of the bearing housing (21) and arranged along a circumferential direction of the bearing housing (21),

wherein at least one of the plurality of foil sheet sets comprises:

the bump foil is abutted against the axial end face of the bearing shell (21), and one end of the bump foil is connected with the bearing shell (21); and

wherein the top foil comprises a first top foil segment (22) and at least two second top foil segments (231, 232), the first top foil segment (22) being parallel to an axial end face of the bearing housing (21), the at least two second top foil segments (231, 232) being at an oblique angle with respect to the axial end face of the bearing housing (21); the first top foil segment (22) is located downstream of the at least two second top foil segments (231, 232) depending on a direction of rotation of the rotor (10) relative to the bearing housing (21) during operation, and an angle of inclination of an upstream one (231, 232) of the at least two second top foil segments (231, 232) relative to an axial end face of the bearing housing (21) is larger than an angle of inclination of a downstream one (231, 232) of the at least two second top foil segments (231, 232) relative to an axial end face of the bearing housing (21).

16. The gaseous thrust bearing according to claim 15, characterized in that the inclination angles of said at least two second top foil segments (231, 232) with respect to the axial end face of the bearing housing (21) are each greater than 0 ° and each less than 15 °.

17. The gaseous thrust bearing of claim 15, wherein a projected length of an upstream one of the at least two second top foil segments (231, 232) onto the axial end face of the bearing housing (21) is smaller than a projected length of a downstream one of the at least two second top foil segments (231, 232) onto the axial end face of the bearing housing (21).

18. Gas thrust bearing according to any of claims 15 to 17, wherein the wave foil comprises a first wave foil section (25), the first wave foil section (25) being located between the first top foil section (22) and the bearing housing (21), the first wave foil section (25) comprising a plurality of first corrugations (251) and a plurality of second corrugations (252), the stiffness of the first corrugations (251) being higher than the stiffness of the second corrugations (252).

19. The gaseous thrust bearing of claim 18, wherein the height of the first corrugations (251) is less than the height of the second corrugations (252).

20. The gaseous thrust bearing according to claim 19, characterized in that the span of said first corrugations (251) is smaller than the span of said second corrugations (252).

21. The gaseous thrust bearing according to claim 18, characterized in that at least one of said first corrugations (251) and at least one of said second corrugations (252) are arranged alternately along the extension direction of said first top foil segment (22) with respect to said at least two second top foil segments (231, 232).

22. The gaseous thrust bearing according to claim 21, characterized in that a first number of said first corrugations (251) and a second number of said second corrugations (252) are arranged alternately, said first number being the same as, or smaller than, or larger than said second number.

23. The gaseous thrust bearing of claim 18, wherein the bump foil further comprises a second bump foil segment (26), the second bump foil segment (26) being located between the at least two second top foil segments (231, 232) and the bearing housing (21) and being connected to the first bump foil segment (25), the second bump foil segment (26) comprising a plurality of third corrugations, the height of the plurality of third corrugations increasing in the direction of rotation of the rotor (10) relative to the bearing housing (21) when in operation.

24. A compressor, comprising:

the bearing assembly of any of claims 1 to 14, or

A gas thrust bearing as claimed in any one of claims 15 to 23.

25. An air conditioner, comprising:

the compressor of claim 24, or

The bearing assembly of any of claims 1 to 14, or

A gas thrust bearing as claimed in any one of claims 15 to 23.

26. An automobile, comprising:

the compressor of claim 24, or

The bearing assembly of any of claims 1 to 14, or

A gas thrust bearing as claimed in any one of claims 15 to 23.