CN113107966A

CN113107966A - Dynamic pressure gas thrust bearing and assembly

Info

Publication number: CN113107966A
Application number: CN202010021447.2A
Authority: CN
Inventors: 卓明胜; 张治平; 刘华; 雷连冬; 李宏波
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 thrust bearing and a component thereof. The dynamic pressure gas thrust bearing comprises a bearing shell, wherein a plurality of fan-shaped sections distributed along the circumferential direction are arranged on one side matched with the rotor; and the supporting foils are respectively and correspondingly arranged on the fan-shaped sections and comprise wave foils and top foils. The dynamic pressure gas thrust bearing of the invention is provided with a plurality of fan-shaped sections in the circumferential direction, thereby improving the stress uniformity of the bearing.

Description

Dynamic pressure gas thrust bearing and assembly

Technical Field

The invention relates to the technical field of air bearings, in particular to a dynamic pressure gas thrust bearing and a component.

Background

A typical wave foil type dynamic pressure gas thrust bearing 2a includes a bearing housing 21a, a wave foil 22a, and a top foil 23a, as shown in fig. 1. The bump foil 22a and the top foil 23a are uniformly distributed in the circumferential direction as sector-shaped thrust pieces. The bump foil 22a has a corrugated structure, and acts as a spring-like elastic support, which is a main source of stiffness and damping of the thrust bearing. The top foil 23a is mounted on the bump foil 22a, both constituting a flexible support surface for the bump foil type dynamic thrust bearing. The bump foil 22a, like the top foil 23a, is fixed to the bearing housing 21a at one end and can slide freely under load. The friction between the foils and the bearing housing limits their sliding movement and generates energy dissipation in the form of heat, and the damping in the foils is thereby generated. In addition, a certain included angle is formed between the front end of the top foil piece 23a and the bearing housing, the rear end of the top foil piece 23a is parallel to the bearing housing, and a wedge-shaped area is formed under the effect of the included angle, so that a dynamic pressure air film is formed between the thrust disc 12a and the wedge-shaped area.

According to the principle of dynamic pressure gas film formation, the wedge-shaped structure is one of three major factors for forming the gas film. As can be seen from the foregoing description, the wedge-shaped region of the conventional hydrodynamic thrust bearing is mainly formed by the angle between the front end of the top foil 23a and the bearing housing. However, the thickness of the foil is small and generally does not exceed 0.5mm, so on one hand, the foil can deform after being stressed to directly influence the size of an included angle, and further the wedge-shaped area is unstable, which is unfavorable for the balance of the rotor; on the other hand, the small thickness of the foil means that the angle cannot be reduced at will to increase the wedge-shaped space, because the smaller the angle, the larger the span of the wedge-shaped structure, and the easier the foil is to deform.

Disclosure of Invention

The invention aims to provide a dynamic pressure gas thrust bearing and a component thereof, which are used for improving the stress uniformity of the conventional dynamic pressure gas thrust bearing.

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

the bearing shell is provided with a plurality of fan-shaped sections distributed along the circumferential direction on one side matched with the rotor; and

and the supporting foils are respectively and correspondingly arranged on the fan-shaped sections and comprise wave foils and top foils. In some embodiments, the first end to the second end of the segment is arranged obliquely in the circumferential direction.

In some embodiments, the distance between the segment and the bottom surface of the bearing housing is gradually greater in the direction of rotation of the rotor.

In some embodiments, the sector is angled relative to the bearing housing in a range of 0.1 to 1.5 degrees.

In some embodiments, a first portion of the plurality of segments surrounds to form a first annular region and a second portion of the plurality of segments surrounds to form a second annular region, the first and second annular regions being coaxial and radially distributed.

In some embodiments, adjacent segments of the first and second annular regions in the radial direction are offset.

In some embodiments, the plurality of support foils comprises a first support foil mounted to the first annular region and a second support foil mounted to the second annular region, the first annular region being located radially inward, the first support foil having a stiffness less than a stiffness of the second support foil.

In some embodiments, the stiffness of the bump foil of the first support foil is less than the stiffness of the bump foil of the second support foil; and/or the stiffness of the top foil of the first support foil is less than the stiffness of the top foil of the second support foil.

In some embodiments, the segment is provided with a plurality of ventilation holes for the passage of cooling gas and arranged at radial intervals.

In some embodiments, the axis of the vent hole is at an acute angle to the axis of the bearing housing.

In some embodiments, the bump foil is provided with a plurality of cooling grooves provided corresponding to the plurality of vent holes.

In some embodiments, the cooling slot includes an arcuate segment extending in a circumferential direction and a linearly inclined segment in communication with the arcuate segment, the linearly inclined segment being at a substantially obtuse angle with respect to a tangent of the arcuate segment.

In some embodiments, a first portion of the plurality of segments surrounds to form a first annular region and a second portion of the plurality of segments surrounds to form a second annular region, the first annular region being located radially inward, wherein the bearing housing further comprises a first blocker ring disposed between the first annular region and the second annular region, the first blocker ring for blocking a flow of cooling gas entering the first annular region to the second annular region; and/or the bearing shell further comprises a second blocking ring arranged on the radial outer side of the second annular area, and the second blocking ring is used for blocking the cooling gas entering the second annular area from flowing to the outer side of the bearing shell.

In a second aspect the invention provides a dynamic gas thrust bearing assembly comprising a rotor and a dynamic gas thrust bearing as provided in the first aspect of the invention.

Based on the dynamic pressure gas thrust bearing and the assembly thereof provided by the invention, the dynamic pressure gas thrust bearing comprises a bearing shell, wherein a plurality of fan-shaped sections distributed along the circumferential direction are arranged on one side matched with a rotor; and the supporting foils are respectively and correspondingly arranged on the fan-shaped sections and comprise wave foils and top foils. The dynamic pressure gas thrust bearing of the invention is provided with a plurality of fan-shaped sections in the circumferential direction, thereby improving the stress uniformity of the bearing.

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 dynamic pressure gas thrust bearing of the related art;

FIG. 2 is a schematic sectional view of the structure of FIG. 1 along the direction G;

FIG. 3 is a schematic axial side view of a hydrodynamic thrust bearing assembly in accordance with an embodiment of the present invention;

FIG. 4 is a front view of the hydrodynamic gas thrust bearing assembly shown in FIG. 3;

FIG. 5 is a schematic sectional view A-A of FIG. 4;

FIG. 6 is an enlarged view of section I in FIG. 5;

FIG. 7 is a schematic cross-sectional view of B-B of FIG. 4;

FIG. 8 is an enlarged view of section II of FIG. 7;

FIG. 9 is a schematic cross-sectional view of C-C of FIG. 4;

fig. 10 is an enlarged schematic view of part iii of fig. 9;

FIG. 11 is a schematic axial side view of a dynamic pressure gas thrust bearing according to an embodiment of the present invention;

FIG. 12 is a schematic front view of the hydrodynamic gas thrust bearing shown in FIG. 11;

FIG. 13 is a schematic axial view of the thrust gas dynamic bearing of FIG. 11 with the top foil removed;

FIG. 14 is a schematic front view of the aerodynamic thrust bearing of FIG. 13 with the top foil removed;

FIG. 15 is an enlarged schematic view of the portion IV of FIG. 14;

FIG. 16 is an enlarged view of the portion V in FIG. 14;

FIG. 17 is a schematic perspective view of a bearing housing according to an embodiment of the present invention;

FIG. 18 is a front view of the bearing housing of FIG. 18;

FIG. 19 is a schematic cross-sectional view of D-D of FIG. 18;

FIG. 20 is a schematic cross-sectional view of E-E of FIG. 18;

FIG. 21 is an enlarged view of the VI portion of FIG. 20;

FIG. 22 is a schematic cross-sectional view of F-F of FIG. 18;

fig. 23 is an enlarged schematic view of the vii portion in fig. 20.

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.

The structure of a dynamic pressure gas thrust bearing assembly according to an embodiment of the present invention will be described in detail with reference to fig. 3 to 23.

As shown in fig. 3, the dynamic pressure gas thrust bearing assembly of the embodiment of the present invention includes a rotor 1 and a dynamic pressure gas thrust bearing 2. Wherein, rotor 1 includes pivot 11 and thrust disc 12.

The dynamic pressure gas thrust bearing of the embodiment comprises:

as shown in fig. 17, the bearing housing 21 is provided with a plurality of segments distributed in the circumferential direction on the side fitted to the rotor 1, and the first end to the second end of the segments are arranged obliquely in the circumferential direction; and

and the supporting foils are respectively and correspondingly arranged on the fan-shaped sections and comprise wave foils and top foils.

The dynamic pressure gas thrust bearing of the embodiment of the invention forms a forced convergence structure by obliquely arranging the fan-shaped sections, and improves the stability of a dynamic pressure convergence area compared with the prior art which only depends on a foil to form a convergence included angle. In the present embodiment, the distance between the segment and the bottom surface of the bearing housing 21 becomes gradually larger in the rotational direction of the rotor 1. And the inclination angle of the fan-shaped section of this embodiment is guaranteed by machining, so its machining precision is higher.

The included angle between the sector section and the bearing shell 21 of the embodiment ranges from 0.1 to 1.5 degrees.

As shown in fig. 11 to 17, in order to ensure uniform bearing stress, a first partial segment of the plurality of segments of the present embodiment forms a first annular region and a second partial segment forms a second annular region, and the first annular region and the second annular region are coaxial and radially distributed.

Preferably, the number of segments of the first annular zone and the second annular zone of the present embodiment is an even number.

As shown in fig. 11 to 17, adjacent segments of the first and second annular regions are offset. In the circumferential direction, adjacent fan-shaped sections are staggered by an angle to realize multidirectional bearing stress.

As shown in fig. 11, the plurality of support foils comprises a first support foil mounted to the first annular region and a second support foil mounted to the second annular region, the first annular region being located radially inward, the first support foil having a stiffness less than a stiffness of the second support foil. This arrangement is such that the bearing has different stiffnesses in the radial direction, specifically, as shown in fig. 10, the fit clearance between the bearing and the rotor in the radial direction forms a low stiffness wedge region P and a high stiffness wedge region Q. Wherein the clearance of the wedge-shaped region P with low rigidity is L2, the clearance of the wedge-shaped region Q with high rigidity is L1, and L2 is more than L1. When the rotor 1 works, the rotating speed is low, the required rigidity is low, and since L2 is greater than L1, the low-rigidity wedge-shaped region P is preferentially acted and is mainly supported by the first supporting foil; when the rotor speed is high, the required rigidity is increased, the supporting force provided by the first supporting foil is insufficient, deformation occurs, L2 is reduced, and when the required rigidity is reduced to be less than L1, the high rigidity wedge-shaped area Q starts to act, and the first supporting foil and the second supporting foil together provide support. The thrust bearing of the embodiment is provided with the wedge-shaped areas with different rigidities in the radial direction to adapt to different rotating speed changes of the rotor, so that the bearing capacity and the bearing adaptability of the bearing are improved.

To achieve support of foils of different stiffness, the stiffness of the bump foil of the first support foil is smaller than the stiffness of the bump foil of the second support foil. The stiffness of the top foil of the first support foil is smaller than the stiffness of the top foil of the second support foil.

In the present embodiment in particular, as shown in fig. 10, the first support foil includes a low-rigidity bump foil 25 and a low-rigidity top foil 26. The second support foil comprises a high stiffness bump foil 22 and a high stiffness top foil 23.

In order to effectively control the bearing temperature, as shown in fig. 17 and 18, the segment of the present embodiment is provided with a plurality of ventilation holes 213 for introducing cooling gas and arranged at intervals in the radial direction.

As shown in fig. 15 and 16, the corrugated foil of the present embodiment is provided with a cooling groove including an arc-shaped section, and the vent hole communicates with the arc-shaped section. When the cooling gas flows in through the ventilation holes 213, it takes a circumferential flow in the rotor rotation direction through the arc-shaped section to cool the bearing and finally flows toward the next support foil.

The cooling tank also comprises a straight line inclined section communicated with the arc-shaped section, and an obtuse angle is formed between the straight line inclined section and a tangent line of the arc-shaped section. Cooling gas flows to the next supporting foil piece through the straight line inclined section after flowing along the arc-shaped section, and the obtuse angle arrangement can reduce energy loss caused by vortex formed by the change of the flow channel of the cooling gas. And the end part of the arc-shaped section of the cooling groove of the embodiment is a round angle, so that the energy loss is further reduced. As shown in fig. 17 and 18, in order to prevent the cooling gas from flowing in the radial direction to cause uneven cooling of the bearing, the bearing housing 21 of the present embodiment further includes a first blocking ring 214 disposed between the first annular region and the second annular region, and as shown in fig. 15, the first blocking ring 214 is used to block the flow of the cooling gas entering the first annular region to the second annular region; and/or, the bearing housing 21 further includes a second blocking ring 215 disposed radially outside the second annular region, the second blocking ring 215 being configured to block the flow of the cooling gas entering the second annular region to the outside of the bearing housing 21.

Preferably, in order to realize that the cooling gas flows in the same direction as the rotation direction of the rotor after flowing in from the vent hole 213, the vent hole 213 is rotated in advance, and the axis of the vent hole 213 forms an acute angle with the horizontal line.

The structure of a dynamic pressure gas thrust bearing assembly according to an embodiment of the present invention will be described in detail with reference to fig. 3 to 22.

As shown in fig. 3, the dynamic pressure gas thrust bearing assembly of the present embodiment includes a rotor 1 and a dynamic pressure gas thrust bearing 2. Wherein, rotor 1 includes pivot 11 and thrust disc 12. The direction of rotation of the rotor 1 is indicated by the arrows in the figure. As shown in fig. 10, the dynamic pressure gas thrust bearing 1 of the present embodiment includes a bearing housing 21, a high-rigidity wave foil 22, a high-rigidity top foil 23, a low-rigidity wave foil 25, and a low-rigidity top foil 26. The fit clearance of the thrust disk 12 and the dynamic pressure gas thrust bearing 2 forms a low rigidity wedge region P and a high rigidity wedge region Q. When the high-rigidity wedge-shaped air film generator works, the rotor 1 rotates at a high speed under the action of an electromagnetic field, and when the set rotating speed is reached, dynamic air films are formed in the low-rigidity wedge-shaped area P and the high-rigidity wedge-shaped area Q to support the rotor 1 to rotate.

As shown in fig. 17 and 18, the bearing housing 21 of the present embodiment is an annular hollow member. The supporting foil is supported and fixed. The bearing housing 21 of the present embodiment has 8 sectors evenly distributed along the circumference. And each segment is arranged circumferentially inclined in the direction of rotation to form a forced wedge convergence. The wedge-shaped convergence structure is formed as shown in fig. 6 to 8, and as shown in fig. 6, for the high rigidity wedge region Q, the wedge gap θ 1 is larger than θ 2 in the rotational direction R. As shown in fig. 7 and 8, for the low rigidity wedge region P, the wedge gap θ 3 is larger than θ 4 in the rotational direction. Therefore, the bearing of the embodiment has wedge shapes in the radial direction and the circumference, so that the dynamic pressure gas bearing with multi-wedge area turning design is formed, the vibration of a shafting is reduced, and the stability of the shafting is improved.

Specifically, to realize the above-described forced convergence structure, as shown in fig. 17, the segments of the present embodiment are arranged obliquely. Specifically, as shown in fig. 21, it is dimensionally represented that the gap θ 7 is larger than θ 8. As shown in fig. 23, the gap θ 9 is larger than θ 10. In this embodiment, the inclination of the above-mentioned segment is guaranteed by machining, compares with current wedge convergence contained angle, and its stable in structure, machining precision are high.

Also, the sectors of this embodiment are formed by grooving the surface of the bearing housing.

As shown in fig. 17, the bearing housing 21 of the present embodiment includes a first annular region and a second annular region that are distributed in the radial direction. The first annular region includes at least two first segments 211. The second annular region includes at least two second segments 212. The first segment 211 and the second segment 212 are respectively provided with a supporting foil, so that a plurality of supports are formed for the rotor system, and the stress uniformity of the bearing is improved.

As shown in fig. 17, the adjacent first segment 211 and second segment 212 of the present embodiment are arranged in a staggered manner. In the circumferential direction, the adjacent fan-shaped sections along the radial direction are staggered by an angle to realize multidirectional bearing stress.

For effective control of the bearing temperature, as shown in fig. 17, a plurality of vent holes 213 for letting in cooling gas are arranged in the radial direction on the bearing housing 21. In order to cooperate with the vent holes 213, as shown in fig. 15 and 16, a plurality of cooling grooves are arranged on the high stiffness bump foil 22 and the low stiffness bump foil 25. The cooling channels cooperate with the vent holes 213. Specifically, as shown in fig. 15, the high-rigidity wave foil 22 is provided with a plurality of first cooling grooves 221. As shown in fig. 16, the low-rigidity wave foil 25 is provided with a plurality of second cooling grooves 251.

In order to prevent the cooling airflow from flowing in the radial direction to cause uneven cooling of the bearing, as shown in fig. 17, the bearing housing 21 of the present embodiment further includes a first blocking ring 214 located between the first annular region and the second annular region, and a second blocking ring 215 disposed radially outside the second annular region. The blocking ring is arranged to block radial air flow.

The bearing housing 21 of the present embodiment further includes an inner ring disposed radially inward of the first annular region, and the inner ring functions to both block the flow of the cooling gas toward the rotating shaft and to support the rotor.

As shown in fig. 19, in order to realize that the cooling gas flows in from the vent hole 213 and then flows in the same direction as the rotor rotation direction, a preset rotation process is performed on the vent hole 213. The axis of the vent hole 213 is arranged at an angle θ 6 to the horizontal.

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 thrust bearing, comprising:

the bearing shell (21) is provided with a plurality of fan-shaped sections distributed along the circumferential direction on one side matched with the rotor (1); and

2. The thrust gas bearing according to claim 1, wherein said segments are arranged with a first end to a second end thereof inclined in a circumferential direction.

3. Thrust gas bearing according to claim 2, characterized in that the distance between the sectors and the bottom surface of the bearing housing (21) in the direction of rotation of the rotor (1) is progressively greater.

4. Thrust gas bearing according to claim 2, wherein the angle between the segments and the bearing housing (21) is in the range of 0.1 to 1.5 °.

5. The thrust gas bearing of claim 1, wherein a first portion of said plurality of segments define a first annular region and a second portion of said plurality of segments define a second annular region, said first and second annular regions being coaxial and radially distributed.

6. The thrust gas bearing according to claim 5, wherein adjacent segments of said first and second annular regions in the radial direction are offset.

7. The thrust hydrodynamic gas bearing according to claim 5, wherein said plurality of support foils comprises a first support foil mounted to said first annular region and a second support foil mounted to said second annular region, said first annular region being radially inward, said first support foil having a stiffness less than a stiffness of said second support foil.

8. The thrust hydrodynamic gas bearing according to claim 7, wherein the stiffness of the bump foil of the first support foil is less than the stiffness of the bump foil of the second support foil; and/or the stiffness of the top foil of the first support foil is less than the stiffness of the top foil of the second support foil.

9. Hydrodynamic gas thrust bearing according to any of claims 1 to 8, characterized in that the sectors are provided with a plurality of ventilation holes (213) for the passage of cooling gas and arranged at radial intervals.

10. Hydrodynamic gas thrust bearing according to claim 9, characterized in that the axis of the ventilation hole (213) is at an acute angle to the axis of the bearing housing (21).

11. The thrust gas bearing according to claim 9, wherein said bump foil is provided with a plurality of cooling grooves corresponding to said plurality of vent holes (213).

12. The thrust gas bearing of claim 11, wherein said cooling groove includes an arcuate segment extending in a circumferential direction and a linearly inclined segment communicating with said arcuate segment, said linearly inclined segment being substantially obtuse from a tangent to said arcuate segment.

13. The thrust gas bearing of claim 9, wherein a first portion of said plurality of segments define a first annular region and a second portion of said plurality of segments define a second annular region, said first annular region being radially inward, wherein said bearing housing further comprises a first blocker ring disposed between said first annular region and said second annular region, said first blocker ring for blocking the flow of cooling gas entering said first annular region to said second annular region; and/or the bearing shell further comprises a second blocking ring arranged on the radial outer side of the second annular area, and the second blocking ring is used for blocking the cooling gas entering the second annular area from flowing to the outer side of the bearing shell.

14. A dynamic gas thrust bearing assembly, characterized by comprising a rotor (1) and a dynamic gas thrust bearing according to any of claims 1 to 13.