Hydrodynamic gas thrust bearings and components

Abstract

The present invention discloses a dynamic pressure gas thrust bearing and its components. The dynamic pressure gas thrust bearing comprises a bearing housing, on one side of which the rotor is matched, a plurality of fan-shaped segments distributed along the circumferential direction are arranged; and a plurality of supporting foils are respectively mounted on the plurality of fan-shaped segments and the supporting foils comprise a corrugated foil and a top foil. The dynamic pressure gas thrust bearing of the present invention distributes a plurality of fan-shaped segments in the circumferential direction so as to improve the force uniformity of the bearing.

Description

Technical Field

[0001] The invention relates to the technical field of air bearings, and in particular to a dynamic pressure gas thrust bearing and a component thereof. Background Art

[0002] The structure of a typical corrugated foil type hydrodynamic gas thrust bearing is as follows: Figure 1 As shown, the wave foil type dynamic pressure gas thrust bearing 2a includes a bearing housing 21a, a wave foil 22a and a top foil 23a. The wave foil 22a and the top foil 23a are evenly distributed in the circumferential direction as fan-shaped thrust blocks. The wave foil 22a has a corrugated structure, acts as an elastic support similar to a spring, and is the main source of stiffness and damping of the thrust bearing. The top foil 23a is installed on the wave foil 22a, and the two constitute the flexible support surface of the wave foil type dynamic pressure thrust bearing. Like the top foil 23a, the wave foil 22a is fixed on the bearing housing 21a at one end, and the other end can slide freely under the action of the bearing force. The friction between the foils and between the foils and the bearing housing will have a certain limiting effect on their sliding and generate energy dissipation in the form of heat, and the damping in the foil is generated from this. In addition, a certain angle is formed between the front end of the top foil 23a and the bearing housing, and the rear end of the top foil 23a is parallel to the bearing housing. Under the effect of the above angle, a wedge-shaped area is formed and then a dynamic pressure air film is formed between the top foil 23a and the thrust plate 12a.

[0003] It can be seen from the formation principle of the dynamic pressure gas film that the wedge structure is one of the three major factors in the formation of the gas film. As can be seen from the previous description, the wedge area of ​​the existing dynamic pressure gas thrust bearing is mainly formed by the angle between the front end of the top foil 23a and the bearing housing. However, due to the small thickness of the foil, which generally does not exceed 0.5mm, on the one hand, the foil will deform after being subjected to force, which directly affects the size of the angle, and then causes the wedge area to be unstable, which is not conducive to the balance of the rotor; on the other hand, the small thickness of the foil means that the above angle cannot be arbitrarily reduced to achieve the purpose of increasing the wedge space, because the smaller the angle, the larger the span of the wedge structure, and the easier the foil is to deform. Summary of the invention

[0004] The object of the present invention is to provide a dynamic pressure gas thrust bearing and an assembly thereof, so as to improve the force uniformity of the existing dynamic pressure gas thrust bearing.

[0005] A first aspect of the present invention provides a hydrodynamic gas thrust bearing, comprising:

[0006] A bearing housing is provided with a plurality of sector segments distributed along the circumferential direction on one side cooperating with the rotor; and

[0007] A plurality of supporting foils are respectively mounted on a plurality of sector segments and the supporting foils include corrugated foils and top foils. In some embodiments, the sector segments are inclined from the first end to the second end in the circumferential direction.

[0008] In some embodiments, in the rotation direction of the rotor, the distance between the sector and the bottom surface of the bearing housing gradually increases.

[0009] In some embodiments, the angle between the sector and the bearing housing ranges from 0.1° to 1.5°.

[0010] In some embodiments, the first partial sectors of the plurality of sectors are surrounded to form a first annular area, and the second partial sectors are surrounded to form a second annular area. The first annular area and the second annular area are coaxial and distributed in the radial direction.

[0011] In some embodiments, adjacent sectors of the first annular region and the second annular region in the radial direction are staggered.

[0012] In some embodiments, the plurality of support foils include a first support foil installed in a first annular area and a second support foil installed in a second annular area, the first annular area is located radially inward, and the stiffness of the first support foil is smaller than that of the second support foil.

[0013] In some embodiments, the stiffness of the bump foil of the first supporting foil is smaller than the stiffness of the bump foil of the second supporting foil; and / or the stiffness of the top foil of the first supporting foil is smaller than the stiffness of the top foil of the second supporting foil.

[0014] In some embodiments, the sector is provided with a plurality of vent holes for introducing cooling gas and arranged at intervals in the radial direction.

[0015] In some embodiments, an axis of the vent hole forms an acute angle with an axis of the bearing housing.

[0016] In some embodiments, a plurality of cooling grooves are disposed on the corrugated foil corresponding to the plurality of ventilation holes.

[0017] In some embodiments, the cooling groove includes an arc segment extending in a circumferential direction and a straight inclined segment connected to the arc segment, and a substantially obtuse angle is formed between the straight inclined segment and a tangent line of the arc segment.

[0018] In some embodiments, a first portion of the sector segments among the plurality of sector segments surrounds a first annular area, and a second portion of the sector segments surrounds a second annular area, and the first annular area is located radially inward, wherein the bearing housing further comprises a first blocking ring disposed between the first annular area and the second annular area, and the first blocking ring is used to block the cooling gas entering the first annular area from flowing to the second annular area; and / or, the bearing housing further comprises a second blocking ring disposed radially outward of the second annular area, and the second blocking ring is used to block the cooling gas entering the second annular area from flowing to the outside of the bearing housing.

[0019] A second aspect of the present invention provides a hydrodynamic gas thrust bearing assembly, comprising a rotor and the hydrodynamic gas thrust bearing provided by the first aspect of the present invention.

[0020] Based on the dynamic pressure gas thrust bearing and its components provided by the present invention, the dynamic pressure gas thrust bearing includes a bearing housing, a plurality of fan-shaped segments distributed along the circumferential direction are arranged on one side cooperating with the rotor; and a plurality of supporting foils, which are respectively installed on the plurality of fan-shaped segments and the supporting foils include a corrugated foil and a top foil. The dynamic pressure gas thrust bearing of the present invention distributes a plurality of fan-shaped segments in the circumferential direction to improve the force uniformity of the bearing.

[0021] Further features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0023] Figure 1 A schematic diagram of the structure of a dynamic pressure gas thrust bearing of the related art;

[0024] Figure 2 for Figure 1 The schematic diagram of the cross-sectional structure in the direction of G shown;

[0025] Figure 3 It is a schematic diagram of the shaft side structure of a dynamic pressure gas thrust bearing assembly according to an embodiment of the present invention;

[0026] Figure 4 for Figure 3 The front structural schematic diagram of the dynamic pressure gas thrust bearing assembly shown;

[0027] Figure 5 for Figure 4 AA cross-sectional structure diagram in;

[0028] Figure 6 for Figure 5 The enlarged structural diagram of part Ⅰ in FIG.

[0029] Figure 7 for Figure 4 BB cross-sectional structure diagram in FIG.

[0030] Figure 8 for Figure 7 The enlarged structural diagram of part II in FIG.

[0031] Fig. 9 for Figure 4 Schematic diagram of CC cross-sectional structure;

[0032] Fig.10 for Fig. 9 An enlarged structural diagram of part III in FIG.

[0033] Fig.11 It is a schematic diagram of the shaft side structure of a dynamic pressure gas thrust bearing according to an embodiment of the present invention;

[0034] Fig.12 for Fig.11 The schematic diagram of the main structure of the dynamic pressure gas thrust bearing shown;

[0035] Fig.13 for Fig.11 The schematic diagram of the shaft side structure of the dynamic pressure gas thrust bearing without the top foil is shown;

[0036] Fig.14 for Fig.13 The schematic diagram of the front view of the dynamic pressure gas thrust bearing without the top foil is shown;

[0037] Fig.15 for Fig.14 An enlarged structural diagram of part IV in FIG.

[0038] Fig.16 for Fig.14 Schematic diagram of the enlarged structure of part V in FIG.

[0039] Fig.17 is a schematic diagram of the three-dimensional structure of a bearing housing according to an embodiment of the present invention;

[0040] Fig.18 for Fig.18 The front view structural diagram of the bearing housing shown;

[0041] Fig.19 for Fig.18 DD cross-sectional structure diagram in;

[0042] Fig. 20 for Fig.18 EE cross-sectional structure diagram in FIG.

[0043] Fig.21 for Fig. 20 An enlarged structural diagram of part VI in FIG.

[0044] Fig. 22 for Fig.18 FF cross-sectional structure diagram in;

[0045] Fig.23 for Fig. 20 Schematic diagram of the enlarged structure of part VII. DETAILED DESCRIPTION

[0046] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0048] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0049] According to the following Figures 3 to 23 The structure of a dynamic pressure gas thrust bearing assembly according to a specific embodiment of the present invention is described in detail.

[0050] like Figure 3 As shown, the hydrodynamic gas thrust bearing assembly of the embodiment of the present invention comprises a rotor 1 and a hydrodynamic gas thrust bearing 2. The rotor 1 comprises a rotating shaft 11 and a thrust plate 12.

[0051] The dynamic pressure gas thrust bearing of this embodiment includes:

[0052] like Fig.17 As shown, the bearing housing 21 is provided with a plurality of sector segments distributed along the circumferential direction on one side cooperating with the rotor 1, and the sector segments are inclinedly arranged from the first end to the second end in the circumferential direction; and

[0053] A plurality of supporting foils are respectively mounted on a plurality of sector segments and the supporting foils include corrugated foils and top foils.

[0054] The dynamic pressure gas thrust bearing of the embodiment of the present invention forms a forced convergence structure by tilting the sector segment, which improves the stability of the dynamic pressure convergence area compared with the prior art that only relies on foil to form a convergence angle. In this embodiment, in the rotation direction of the rotor 1, the distance between the sector segment and the bottom surface of the bearing housing 21 gradually increases. And the tilt angle of the sector segment of this embodiment is guaranteed by machining, so its machining accuracy is higher.

[0055] In this embodiment, the angle between the sector segment and the bearing housing 21 ranges from 0.1 to 1.5°.

[0056] like Figures 11 to 17 As shown, in order to ensure uniform force on the bearing, the first part of the multiple sector segments in this embodiment surrounds the first annular area, and the second part of the sector segments surrounds the second annular area. The first annular area and the second annular area are coaxial and distributed radially.

[0057] Preferably, the number of sector segments of the first annular area and the second annular area in this embodiment is an even number.

[0058] like Figures 11 to 17 As shown, the adjacent sectors of the first annular area and the second annular area are staggered. In the circumferential direction, the adjacent sectors are staggered at angles to achieve multi-directional load bearing.

[0059] like Fig.11 As shown, the plurality of support foils include a first support foil installed in a first annular area and a second support foil installed in a second annular area. The first annular area is located radially inward, and the stiffness of the first support foil is less than the stiffness of the second support foil. This arrangement makes the stiffness of the bearing in the radial direction different. Specifically, Fig.10As shown, in the radial direction, the matching clearance between the bearing and the rotor forms a low-rigidity wedge-shaped area P and a high-rigidity wedge-shaped area Q. Among them, the clearance of the low-rigidity wedge-shaped area P is L2, and the clearance of the high-rigidity wedge-shaped area Q is L1, and L2>L1. During operation, the rotor 1 has a low rotation speed and a small required rigidity. Since L2>L1, the low-rigidity wedge-shaped area P takes precedence at this time, and the support is mainly provided by the first support foil; when the rotor speed is high, the required rigidity increases. At this time, the support force provided by the first support foil is insufficient, and deformation occurs, and L2 becomes smaller. When it is reduced to less than L1, the high-rigidity wedge-shaped area Q begins to work, and the first support foil and the second support foil provide support together. The thrust bearing of this embodiment improves the bearing capacity and load-bearing adaptability of the bearing by arranging wedge-shaped areas of different rigidity in the radial direction to adapt to different rotation speed changes of the rotor.

[0060] To achieve the support of foils with different stiffness, the stiffness of the corrugated foil of the first supporting foil is smaller than the stiffness of the corrugated foil of the second supporting foil. The stiffness of the top foil of the first supporting foil is smaller than the stiffness of the top foil of the second supporting foil.

[0061] Specifically in this embodiment, Fig.10 As shown, the first support foil comprises a low-rigidity bump foil 25 and a low-rigidity top foil 26. The second support foil comprises a high-rigidity bump foil 22 and a high-rigidity top foil 23.

[0062] To effectively control the bearing temperature, Fig.17 and Fig.18 As shown, the sector segment of this embodiment is provided with a plurality of vent holes 213 for introducing cooling gas and arranged at intervals in the radial direction.

[0063] like Fig.15 and 16 As shown, the corrugated foil of this embodiment is provided with a cooling groove, which includes an arc segment, and the vent hole is connected to the arc segment. When the cooling gas flows in through the vent hole 213, it flows in a circular manner along the rotation direction of the rotor through the arc segment to cool the bearing and finally flows to the next supporting foil.

[0064] The cooling groove also includes a straight inclined section connected to the arc section, and the straight inclined section and the tangent of the arc section are roughly at an obtuse angle. The cooling gas flows along the arc section and then flows to the next supporting foil through the straight inclined section. The setting of the obtuse angle can reduce the energy loss caused by the formation of vortices due to the change of the flow channel of the cooling gas. In addition, the end of the arc section of the cooling groove of this embodiment is rounded, which further reduces energy loss. Fig.17 and 18 As shown, in order to prevent the cooling gas from flowing radially and causing uneven cooling of the bearing, the bearing housing 21 of this embodiment further includes a first blocking ring 214 disposed between the first annular area and the second annular area. Fig.15As shown, the first blocking ring 214 is used to block the cooling gas entering the first annular area from flowing to the second annular area; and / or, the bearing housing 21 also includes a second blocking ring 215 arranged radially outside the second annular area, and the second blocking ring 215 is used to block the cooling gas entering the second annular area from flowing to the outside of the bearing housing 21.

[0065] Preferably, in order to ensure that the cooling gas flows into the vent hole 213 in the same direction as the rotor rotation direction, the vent hole 213 is pre-rotated so that the axis of the vent hole 213 forms an acute angle with the horizontal line.

[0066] According to the following Figures 3 to 22 The structure of a dynamic pressure gas thrust bearing assembly according to a specific embodiment of the present invention is described in detail.

[0067] like Figure 3 As shown in the figure, the hydrodynamic gas thrust bearing assembly of this embodiment includes a rotor 1 and a hydrodynamic gas thrust bearing 2. The rotor 1 includes a rotating shaft 11 and a thrust plate 12. The rotation direction of the rotor 1 is shown by the arrow in the figure. Fig.10 As shown, the dynamic pressure gas thrust bearing 1 of this 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 matching clearance between the thrust plate 12 and the dynamic pressure gas thrust bearing 2 forms a low-rigidity wedge-shaped area P and a high-rigidity wedge-shaped area Q. When working, the rotor 1 rotates at a high speed under the action of the electromagnetic field. When the set speed is reached, a dynamic pressure gas film is formed in the low-rigidity wedge-shaped area P and the high-rigidity wedge-shaped area Q to support the operation of the rotor 1.

[0068] like Fig.17 and Fig.18 As shown, the bearing housing 21 of this embodiment is an annular hollow part. It supports and fixes the supporting foil. The bearing housing 21 of this embodiment has 8 fan-shaped segments evenly distributed along the circumference. Each fan-shaped segment is tilted on the circumference along the rotation direction to form a forced wedge-shaped convergence structure. The formed wedge-shaped convergence structure is as shown in FIG. Figures 6 to 8 As shown, Figure 6 As shown, for the high-rigidity wedge-shaped region Q, in the rotation direction R, the wedge-shaped gap θ1 is larger than θ2. Figure 7 and Figure 8 As shown, for the low-rigidity wedge-shaped area P, in the rotation direction, the wedge-shaped gap θ3 is greater than θ4. Therefore, the bearing of this embodiment has a wedge shape in both the radial direction and the circumference, thus forming a dynamic pressure gas bearing with a multi-wedge area change-direction design, thereby reducing the vibration of the shaft system and improving the stability of the shaft system.

[0069] Specifically, to achieve the above forced convergence structure, such as Fig.17 As shown, the fan-shaped segments of this embodiment are arranged obliquely. Specifically, as Fig.21As shown in FIG. 1 , the gap θ7 is larger than θ8 in terms of size. Fig.23 As shown, the gap θ9 is greater than θ10. In this embodiment, the inclination of the above-mentioned sector segments is ensured by machining, and compared with the existing wedge-shaped convergence angle, its structure is stable and the machining accuracy is high.

[0070] Moreover, the sector-shaped area of ​​the present embodiment is formed by digging grooves on the surface of the bearing housing.

[0071] like Fig.17 As shown, the bearing housing 21 of this embodiment includes a first annular area and a second annular area distributed in the radial direction. The first annular area includes at least two first sector segments 211. The second annular area includes at least two second sector segments 212. Support foils are installed on both the first sector segment 211 and the second sector segment 212 to form multiple supports for the rotor system, thereby improving the force uniformity of the bearing.

[0072] like Fig.17 As shown, the adjacent first sector segments 211 and the second sector segments 212 of this embodiment are staggered. In the circumferential direction, the adjacent sector segments along the radial direction are staggered at an angle to achieve multi-directional load bearing.

[0073] To effectively control the bearing temperature, Fig.17 As shown, a plurality of vent holes 213 are arranged radially on the bearing housing 21 for introducing cooling gas. Fig.15 and Fig.16 As shown, a plurality of cooling grooves are arranged on the high-rigidity bump foil 22 and the low-rigidity bump foil 25. The cooling grooves cooperate with the vent holes 213. Specifically, as Fig.15 As shown, a plurality of first cooling slots 221 are provided on the high-rigidity corrugated foil 22. Fig.16 As shown, a plurality of second cooling grooves 251 are provided on the low-rigidity corrugated foil 25 .

[0074] In order to prevent the cooling airflow from flowing radially and causing uneven cooling of the bearing, Fig.17 As shown, the bearing housing 21 of this embodiment further includes a first blocking ring 214 located between the first annular area and the second annular area and a second blocking ring 215 arranged radially outside the second annular area. The above blocking rings are arranged to block radial airflow.

[0075] The bearing housing 21 of this embodiment further comprises an inner ring arranged radially inwardly of the first annular region, and the inner ring serves to block the cooling gas from flowing toward the rotating shaft and to support the rotor.

[0076] like Fig.19As shown, in order to achieve that the cooling gas flows in from the vent hole 213 in the same direction as the rotor rotation direction, the vent hole 213 is pre-rotated. The axis of the vent hole 213 is arranged at an angle of θ6 with the horizontal line.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the present invention, which should be included in the scope of the technical solution for protection of the present invention.

Claims

1. A dynamic pressure gas thrust bearing, characterized in that: include: The bearing housing (21) is provided with a plurality of sector segments distributed along the circumferential direction on one side cooperating with the rotor (1); as well as A plurality of supporting foils, respectively mounted on the plurality of sector segments and comprising a corrugated foil and a top foil; The sector segment is provided with a plurality of vent holes (213) for introducing cooling gas and arranged at intervals in a radial direction, wherein the axis of the vent hole (213) forms an acute angle with the axis of the bearing housing (21) so that the cooling gas flows into the vent hole (213) in the same direction as the rotation direction of the rotor; The corrugated foil is provided with a plurality of cooling grooves corresponding to the plurality of vent holes (213), and the cooling groove comprises an arc segment extending in a circumferential direction and a straight inclined segment connected to the arc segment, and a tangent line of the straight inclined segment and the arc segment substantially forms an obtuse angle.

2. The dynamic pressure gas thrust bearing according to claim 1, characterized in that: The sector segments are arranged obliquely from the first end to the second end in the circumferential direction.

3. The dynamic pressure gas thrust bearing according to claim 2, characterized in that: In the rotation direction of the rotor (1), the distance between the sector segment and the bottom surface of the bearing housing (21) gradually increases.

4. The dynamic pressure gas thrust bearing according to claim 2, characterized in that: The angle between the sector segment and the bearing housing (21) ranges from 0.1 to 1.5 degrees.

5. The dynamic pressure gas thrust bearing according to claim 1, characterized in that: Among the plurality of sectors, a first portion of the sectors surrounds a first annular region, and a second portion of the sectors surrounds a second annular region. The first annular region and the second annular region are coaxial and distributed in the radial direction.

6. The dynamic pressure gas thrust bearing according to claim 5, characterized in that: Adjacent sectors of the first annular zone and the second annular zone in the radial direction are arranged offset.

7. The dynamic pressure gas thrust bearing according to claim 5, characterized in that: The plurality of support foils include a first support foil installed in the first annular area and a second support foil installed in the second annular area. The first annular area is located radially inward, and the first support foil has a smaller stiffness than the second support foil.

8. The dynamic pressure gas thrust bearing according to claim 7, characterized in that: The stiffness of the bump foil of the first supporting foil is smaller than the stiffness of the bump foil of the second supporting foil; and / or the stiffness of the top foil of the first supporting foil is smaller than the stiffness of the top foil of the second supporting foil.

9. The dynamic pressure gas thrust bearing according to claim 1, characterized in that: The first part of the sector segments among the multiple sector segments forms a first annular area, and the second part of the sector segments forms a second annular area, and the first annular area is located radially inside, wherein the bearing housing further includes a first blocking ring arranged between the first annular area and the second annular area, and the first blocking ring is used to block the cooling gas entering the first annular area from flowing to the second annular area; and / or, the bearing housing further includes a second blocking ring arranged radially outside the second annular area, and the second blocking ring is used to block the cooling gas entering the second annular area from flowing to the outside of the bearing housing.

10. A dynamic pressure gas thrust bearing assembly, characterized in that: The invention comprises a rotor (1) and a hydrodynamic gas thrust bearing according to any one of claims 1 to 9.

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