WO2021139422A1

WO2021139422A1 - Hydrodynamic radial bearing and power device

Info

Publication number: WO2021139422A1
Application number: PCT/CN2020/131086
Authority: WO
Inventors: 刘华; 张治平; 雷连冬; 李宏波; 陈玉辉
Original assignee: 珠海格力电器股份有限公司
Priority date: 2020-01-09
Filing date: 2020-11-24
Publication date: 2021-07-15
Also published as: CN113090643A

Abstract

A hydrodynamic radial bearing and a power device. The hydrodynamic radial bearing comprises: a housing (1) comprising a shaft hole (1-9) having a central axis, the shaft hole (1-9) comprising at least one hole section (1-9A, 1-9B), the hole wall of the hole section (1-9A, 1-9B) comprising a plurality of curved surfaces (1-6, 1-8) sequentially arranged along the circumferential direction of the central axis of the shaft hole (1-9), and the distances from the curved surfaces (1-6, 1-8) in the radial direction of the shaft hole (1-9) to the central axis of the shaft hole (1-9) gradually decreasing along a first rotation direction (RD) about the central axis of the shaft hole (1-9); and at least one elastic support structure, corresponding to the at least one hole section (1-9A, 1-9B), the elastic support structure comprising a plurality of foil sheet groups, the plurality of foil sheet groups being provided on the plurality of corresponding curved surfaces (1-6, 1-8) of the hole wall of the shaft hole (1-9), the foil sheet groups comprising top foil sheets (5, 9) and elastic support foil sheets (3, 7) provided between corresponding curved surfaces (1-6, 1-8) and the top foil sheets (5, 9), and the distances from the top foil sheets (5, 9) to the central axis of the shaft hole (1-9) in the radial direction of the shaft hole (1-9) gradually decreasing along the first rotation direction (RD). The present structure facilitates the improvement of the hydrodynamic effect of the hydrodynamic radial bearing.

Description

Hydrodynamic gas radial bearings and power equipment

Cross-references to related applications

This disclosure is based on the Chinese patent application with the application number 202010022411.6, the filing date of January 9, 2020, and the invention titled "Dynamic Pressure Gas Radial Bearing and Power Equipment", and claims its priority. The Chinese patent application The disclosure of is hereby incorporated into this disclosure as a whole.

Technical field

The present disclosure relates to the technical field of bearings, in particular to a dynamic pressure gas radial bearing and power equipment.

Background technique

With a series of advantages such as low friction loss, good stability, low vibration, and oil-free lubrication, air bearing has a very broad application prospect in the fields of high-speed turbine, machine tool manufacturing and space technology. Air bearing is divided into static pressure gas bearing and dynamic pressure gas radial bearing according to the different generation mechanism of lubricating gas film.

The corrugated foil type dynamic pressure gas radial bearing is a kind of dynamic pressure gas radial bearing. It generally includes a flat foil and an elastic foil as the top foil. The flat foil provides a lubricating surface for the rotor, and the elastic foil is The bearing provides support stiffness and damping.

Summary of the invention

The first aspect of the present disclosure provides a dynamic pressure gas radial bearing, including:

The housing includes a shaft hole with a central axis, the shaft hole includes at least one hole section, and the hole wall of the hole section includes a plurality of curved surfaces sequentially arranged along the circumferential direction of the central axis of the shaft hole, each of the curved surfaces The distance from the central axis of the shaft hole in the radial direction of the shaft hole gradually decreases along the first rotation direction that revolves around the central axis of the shaft hole; and

At least one elastic support structure is provided corresponding to the at least one hole section, the elastic support structure includes a plurality of foil groups, and the plurality of foil groups are arranged in the plurality of holes of the corresponding shaft hole. On a curved surface, the foil set includes a top layer foil and an elastic support foil disposed between the corresponding curved surface and the top layer foil, and the top layer foil is in the radial direction of the shaft hole. The distance from the central axis of the shaft hole gradually decreases along the first rotation direction.

In some embodiments, the distance between the surface of the top layer foil close to the central axis and the corresponding curved surface in the radial direction of the shaft hole and the central axis of the shaft hole is along the The first rotation direction remains unchanged.

In some embodiments, the foil set further includes an intermediate foil disposed between the top foil and the elastic support foil.

In some embodiments, the top foil and the middle foil are both curved plate-shaped foils.

In some embodiments, the hole wall of the hole section is provided with a plurality of mounting grooves in sequence around the circumference of the central axis of the shaft hole, and the elastic support structure has all the mounting grooves in one of the two adjacent foil groups. One end of the top layer foil and one end of the middle foil of the other foil group are both installed in the same installation groove, and the other ends are both free ends.

In some embodiments, the curved surface is an arc-shaped cylindrical surface, and the central axis of the arc-shaped cylindrical surface is parallel and eccentrically arranged with the central axis of the shaft hole.

In some embodiments, the housing has more than two hole sections and two or more elastic support structures corresponding to the two or more hole sections, and at least two adjacent holes The curved surface on the hole wall of one hole section and the curved surface on the hole wall of the other hole section are arranged in a staggered manner along the first rotation direction.

In some embodiments, the housing has more than two hole sections and two or more elastic support structures corresponding to the two or more hole sections, and the housing is provided with The outside of the housing and the air inlet hole of the shaft hole, and the outlet of the air inlet hole on the wall of the shaft hole is located between two adjacent hole sections in the axial direction of the shaft hole.

In some embodiments, the shaft hole includes a necking section located between two adjacent hole sections, and the hole wall of the necking section is closer to the shaft relative to the hole wall of the hole section. The center axis of the hole, and the outlet of the air inlet hole is located on the hole wall of the necking section.

In some embodiments, the air inlet hole is arranged such that the flow direction of the fluid entering the shaft hole from the outlet is skewed toward the first rotation direction relative to the radial direction of the outlet on the housing .

A second aspect of the present disclosure provides a power equipment including a rotor and a dynamic pressure gas radial bearing supporting the rotor. The dynamic pressure gas radial bearing is the aforementioned dynamic pressure gas radial bearing. , The rotor rotates along the first rotation direction.

Through the following detailed description of exemplary embodiments of the present disclosure with reference to the accompanying drawings, other features and advantages of the present disclosure will become clear.

Description of the drawings

The drawings described here are used to provide a further understanding of the present disclosure and constitute a part of the present application. The exemplary embodiments and descriptions of the present disclosure are used to explain the present disclosure, and do not constitute an improper limitation of the present disclosure. In the attached picture:

Fig. 1 is a schematic diagram of the partial structure of the dynamic pressure gas radial bearing when matched with the rotor.

FIG. 2 is a schematic diagram of the principle of generating a dynamic pressure gas film when the dynamic pressure gas radial bearing shown in FIG. 1 is matched with a rotor.

FIG. 3 is a schematic structural diagram of the matching structure of the dynamic pressure gas radial bearing and the rotor according to an embodiment of the disclosure.

FIG. 4 is a schematic diagram of the front view of the mating structure shown in FIG. 3.

Fig. 5 is a schematic cross-sectional view of the mating structure shown in Fig. 4 taken along the line A-A.

Fig. 6 is a B-B sectional structural diagram of the mating structure shown in Fig. 4.

Fig. 7 is a C-C cross-sectional structural diagram of the mating structure shown in Fig. 4.

FIG. 8 is a schematic diagram of the D-direction structure of the mating structure shown in FIG. 4.

FIG. 9 is a schematic structural diagram of a casing of a dynamic pressure gas radial bearing according to an embodiment of the disclosure.

Fig. 10 is a left structural diagram of the housing shown in Fig. 9.

Fig. 11 is a right structural diagram of the housing shown in Fig. 9.

Fig. 12 is a schematic longitudinal sectional view of the housing shown in Fig. 9.

Fig. 13 is an E-E sectional view of the structure of the housing shown in Fig. 12.

Fig. 14 is a schematic diagram of force analysis of the mating structure shown in Fig. 3.

Detailed ways

The technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative, and in no way serves as any limitation to the present disclosure and its application or use. Based on the embodiments in the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present disclosure.

Unless specifically stated otherwise, the relative arrangement of components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present disclosure. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to actual proportional relationships. The technologies, methods, and equipment known to those of ordinary skill in the relevant fields may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be regarded as part of the authorization specification. In all examples shown and discussed herein, any specific value should be interpreted as merely exemplary, rather than as a limitation. Therefore, other examples of the exemplary embodiment may have different values. It should be noted that similar reference numerals and letters indicate similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further discussed in the subsequent drawings.

In the description of the present disclosure, it should be understood that the use of terms such as “first” and “second” to define parts is only for the convenience of distinguishing the corresponding parts. Unless otherwise stated, the above terms are not special. Therefore, it cannot be understood as a limitation on the protection scope of the present disclosure.

In the description of the present disclosure, it needs to be understood that the orientation words are only used to facilitate the description of the present disclosure and simplify the description. Unless otherwise stated, these orientation words do not indicate or imply that the device or element referred to must have The specific orientation or the construction and operation in a specific orientation cannot be understood as a limitation of the protection scope of the present disclosure; the orientation word "inside and outside" refers to the inside and outside relative to the contour of each component itself.

The working principle of the dynamic pressure gas radial bearing is shown in Figure 1 and Figure 2. Fig. 1 is a schematic diagram of the partial structure of the dynamic pressure gas radial bearing when matched with the rotor. FIG. 2 is a schematic diagram of the principle of generating a dynamic pressure gas film when the dynamic pressure gas radial bearing shown in FIG. 1 is matched with a rotor. When the rotor 1'runs at high speed, due to the force (such as gravity) of the rotor 1', the center of the rotor 1'and the center of the dynamic pressure gas radial bearing 2'are eccentric, and the top foil and the dynamic pressure gas radial bearing 2' A wedge-shaped structure is formed between the rotors 1'. Due to the viscosity of the gas, when the rotor 1'drives the gas to move, the gas is compressed in the wedge-shaped structure to form a dynamic pressure gas film 3'to support the operation of the rotor 1'.

As shown in FIGS. 3 to 13, an embodiment of the present disclosure provides a dynamic pressure gas radial bearing, which includes a housing 1 and at least one elastic support structure.

The housing 1 includes a shaft hole 1-9 having a central axis. The shaft hole 1-9 includes at least one hole section. The hole wall of the hole section includes a plurality of curved surfaces arranged in sequence along the circumferential direction of the central axis of the shaft hole 1-9, and each curved surface is wound along the distance from the central axis of the shaft hole 1-9 in the radial direction of the shaft hole 1-9. The first rotation direction RD in which the central axis of the shaft hole 1-9 rotates gradually decreases. At least one elastic support structure is arranged corresponding to the at least one hole section. The elastic support structure includes a plurality of foil groups. A plurality of foil groups are arranged on a plurality of curved surfaces of the hole wall of the corresponding shaft hole 1-9. The foil set includes a top foil and an elastic support foil arranged between the corresponding curved surface and the top foil. The distance between the top foil in the radial direction of the shaft hole 1-9 and the central axis of the shaft hole 1-9 gradually decreases along the first rotation direction RD.

In the dynamic pressure gas radial bearing of the embodiment of the present disclosure, curved surfaces are provided on the hole wall of the shaft hole, and the distance between each curved surface and the central axis of the shaft hole in the radial direction of the shaft hole gradually decreases along the first rotation direction. , And the distance between the top foil in the radial direction of the shaft hole 1-9 and the central axis of the shaft hole gradually decreases along the first rotation direction, which realizes the forced distribution of the wedge-shaped area of the dynamic pressure gas radial bearing, which is beneficial to solve the problem. The problem of instability in the wedge-shaped convergence area caused by the eccentricity of the rotor is beneficial to improve the dynamic pressure effect of the dynamic pressure gas radial bearing.

In the embodiments shown in Figs. 3 to 13, the shaft hole 1-9 of the housing 1 includes two hole sections and two elastic support structures corresponding to the two hole sections. In an embodiment not shown, it may include one hole segment and one corresponding elastic support structure, or it may include more than three hole segments and more than three corresponding elastic support structures.

As shown in Figures 3 to 13, the shaft hole 1-9 of the housing 1 includes a first hole section 1-9A. The hole wall of the first hole section 1-9A includes a plurality of first curved surfaces 1-6 sequentially arranged around the circumference of the central axis of the shaft hole 1-9. In the radial direction of the shaft hole 1-9, the distance between each first curved surface 1-6 and the central axis of the shaft hole 1-9 gradually decreases along the first rotation direction RD that revolves around the central axis of the shaft hole 1-9 . Wherein, the first rotation direction RD is the same as the rotation direction of the rotating shaft 2 supported by the dynamic pressure gas radial bearing.

As shown in FIGS. 3 to 13, the elastic support structure corresponding to the first hole section 1-9A includes a plurality of first foil groups, and the plurality of first foil groups are correspondingly arranged on the plurality of first curved surfaces 1-6 . The first foil group includes a first top foil 5 and a first elastic support foil 3 arranged between the corresponding first curved surface 1-6 and the first top foil 5. In the radial direction of the shaft hole 1-9, the distance between the first top layer foil 5 and the central axis of the shaft hole 1-9 gradually decreases along the first rotation direction RD.

As shown in Figures 3 to 13, the shaft hole 1-9 of the housing 1 further includes a second hole section 1-9B coaxial with the first hole section 1-9A. The hole wall of the second hole section 1-9B includes a plurality of second curved surfaces 1-8 sequentially arranged around the circumference of the central axis of the shaft hole 1-9. In the radial direction of the shaft hole 1-9, the distance between each second curved surface 1-8 and the central axis of the shaft hole 1-9 gradually decreases along the first rotation direction RD.

As shown in FIGS. 3-13, the elastic support structure corresponding to the first hole section 1-9A includes a plurality of second foil groups. The plurality of second foil groups are correspondingly arranged on the plurality of second curved surfaces 1-8. The second foil group includes a second top foil 9 and a second elastic support foil 7 arranged between the second curved surface 1-8 and the second top foil 9. In the radial direction of the shaft hole 1-9, the distance between the second top layer foil 9 and the central axis of the shaft hole 1-9 gradually decreases along the first rotation direction RD.

In the embodiments shown in FIGS. 3 to 13, each foil group includes an elastic supporting foil. In an embodiment not shown, the foil group may include a double-layer elastic supporting foil.

In the dynamic pressure gas radial bearing of some embodiments, the distance between the surface of the top layer foil near the central axis and the corresponding curved surface in the radial direction of the shaft hole 1-9 and the central axis of the shaft hole 1-9 It is unchanged along the first rotation direction RD.

As shown in Figures 3 to 13, the surface of the first top layer foil 5 close to the central axis of the shaft hole 1-9 and the corresponding first curved surface 1-6 is in the radial direction of the shaft hole 1-9. The distance of the central axis of the shaft hole 1-9 is constant along the first rotation direction RD.

As shown in Figures 3 to 13, the surface of the second top layer foil 9 close to the central axis of the shaft hole 1-9 and the corresponding second curved surface 1-8 is in the radial direction of the shaft hole 1-9. The distance from the central axis of the shaft hole 1-9 is constant along the first rotation direction RD.

In the dynamic pressure gas radial bearing of some embodiments, the foil group further includes an intermediate foil disposed between the top foil and the elastic support foil.

As shown in FIGS. 3 to 13, the first foil group further includes a first intermediate foil 4 arranged between the first top foil 5 and the first elastic supporting foil 3.

As shown in FIGS. 3 to 13, the second foil group also includes a second intermediate foil 8 arranged between the second top foil 9 and the second elastic support foil 7.

In the dynamic pressure gas radial bearing of some embodiments, the top foil and the middle foil are both bent plate-shaped foils.

In the dynamic pressure gas radial bearing of some embodiments, the hole wall of the hole section is sequentially provided with a plurality of mounting grooves around the circumference of the central axis of the shaft hole 1-9, and one of the two adjacent foil groups of the elastic support structure One end of the top foil piece of the sheet group and one end of the middle foil piece of the other foil group are both installed in the same mounting groove, and the other ends are both free ends.

As shown in Figures 3 to 13, the hole wall of the first hole section 1-9A is sequentially provided with a plurality of first mounting grooves 1-3 around the circumference of the central axis of the shaft hole 1-9, two adjacent first foils One end of the first top foil 5 of the first foil group in the group and one end of the first middle foil 4 of the other first foil group are both installed in the same first mounting groove 1-3, and the other end Both are free ends.

As shown in Figures 3 to 13, the hole wall of the second hole section 1-9B is sequentially provided with a plurality of second mounting grooves 1-4 around the circumference of the central axis of the shaft hole 1-9, and two adjacent second foils One end of the second top foil 9 of one second foil group in the group and one end of the second middle foil 8 of the other second foil group are both installed in the same second mounting groove 1-4, and the other end Both are free ends.

In the dynamic pressure gas radial bearing of some embodiments, the curved surface is an arc cylindrical surface, and the central axis of the arc cylindrical surface is parallel and eccentrically arranged with the central axis of the shaft hole 1-9.

As shown in FIGS. 3 to 13, the first curved surface 1-6 is a first arc-shaped cylindrical surface, and the central axis of the first arc-shaped cylindrical surface is parallel and eccentrically arranged with the central axis of the shaft hole 1-9.

As shown in FIGS. 3 to 13, the second curved surface 1-8 is a second arc-shaped cylindrical surface, and the central axis of the second arc-shaped cylindrical surface is parallel and eccentrically arranged with the central axis of the shaft hole 1-9.

In the dynamic pressure gas radial bearing of some embodiments, the housing 1 has more than two hole sections and two or more elastic support structures corresponding to the two or more hole sections, and one hole in at least two adjacent hole sections The curved surface on the hole wall of one segment and the curved surface on the hole wall of the other hole segment are arranged in a staggered arrangement along the first rotation direction RD.

As shown in Figures 3 to 13, the first curved surface 1-6 on the hole wall of the first hole section 1-9A and the second curved surface 1-8 on the hole wall of the second hole section 1-9B rotate along the first The direction RD is staggered.

In the dynamic pressure gas radial bearing of some embodiments, the housing 1 has more than two hole sections and two or more elastic support structures corresponding to the two or more hole sections. The housing 1 is provided with an air inlet 1-2 connecting the outside of the housing 1 and the shaft hole 1-9. The outlet of the air inlet hole 1-2 on the hole wall of the shaft hole 1-9 is located between two adjacent hole sections in the axial direction of the shaft hole 1-9.

As shown in Figures 3 to 13, the outlet of the air inlet hole 1-2 on the hole wall of the shaft hole 1-9 is located in the first hole section 1-9A and the second hole section in the axial direction of the shaft hole 1-9 Between 1-9B.

In the dynamic pressure gas radial bearing of some embodiments, the shaft hole 1-9 includes a necked section 1-9C located between two adjacent hole sections. The hole wall of the necking section 1-9C is closer to the central axis of the shaft hole 1-9 relative to the hole wall of the hole section. The outlet of the air inlet hole 1-2 is located on the hole wall of the necking section 1-9C. As shown in Figures 7, 9 and 12, the necking section 1-9C is located between the first hole section 1-9A and the second hole section 1-9B.

As shown in FIG. 13, in the dynamic pressure gas radial bearing of some embodiments, the air inlet hole 1-2 is arranged so that the flow direction of the fluid entering the shaft hole 1-9 from the outlet is relative to the outlet on the housing 1. The radial direction is skewed toward the first turning direction RD.

The dynamic pressure gas radial bearing of the embodiment of the present disclosure will be further described below with reference to FIGS. 3 to 13.

The dynamic pressure gas radial bearing of the embodiment of the present disclosure is used to support the rotor 2. The rotor 2 is installed in the bearing hole of the dynamic pressure gas radial bearing. The rotor 2 is a shaft-like, solid part. During operation, the rotor 2 performs high-speed rotation under the action of an electromagnetic field.

The dynamic pressure gas radial bearing includes a housing 1, a first elastic support foil 3, a first intermediate foil 4, a first top layer foil 5, a second elastic support foil 7, a second intermediate foil 8 and a first Two top layer foil 9.

The first elastic support foil 3 and the second elastic support foil 7 are foils with an elastic support function, which provide rigidity and damping for the dynamic pressure gas radial bearing. The first elastic support foil 3 connects the corresponding first curved surface 1-6 and the first intermediate foil 4. The second elastic support foil 7 connects the corresponding second curved surface 1-8 and the second intermediate foil 1-8. In this embodiment, the first elastic supporting foil 3 and the second elastic supporting foil 7 are both corrugated foils.

In this embodiment, in order to facilitate the uniform force of the dynamic pressure gas radial bearing, the wave structure of the first elastic support foil 3 and the second elastic support foil 7 are the same. In the non-illustrated embodiment, if there is a special requirement, the wave structure of the first elastic support foil and the second elastic support foil can be designed to be different according to the actual situation.

In addition, the elastic support foils in each foil group can also be designed as two layers.

As shown in Figs. 3 to 13, the first top foil 5, the first intermediate foil 4, the second top foil 9 and the second intermediate foil 8 are all curved plate-shaped foils. Among them, the middle foil connects the elastic support foil and the top foil to provide additional damping, and the top foil cooperates with the rotor 2 to form a dynamic pressure film.

As shown in Figures 5, 6 and 8, when the central axis of the rotating shaft 2 coincides with the central axis of the dynamic pressure gas radial bearing, a first foil group is formed between the first top layer foil 5 and the rotating shaft 2. A plurality of first wedge-shaped regions 6 corresponding to the number forms a plurality of second wedge-shaped regions 10 corresponding to the number of the second foil groups between the second top layer foil 9 and the rotating shaft 2. The plurality of first wedge-shaped regions 6 and the plurality of second wedge-shaped regions 10 are convergent regions formed between the dynamic pressure gas radial bearing and the rotor 2 and are the key to forming a dynamic pressure gas film.

As shown in Figures 9 to 13, the housing 1 is an annular hollow part, including a base 1-1 and an air inlet 1-2 provided on the base 1-1, a first mounting groove 1-3, and a second mounting Slots 1-4, first curved surfaces 1-6, second curved surfaces 1-8, shaft holes 1-9, and so on.

As mentioned above, the first elastic support foil 3, the first intermediate foil 4 and the first top foil 5 are supported and fixed by the first mounting groove 1-3 provided on the base 1-1. Similarly, the second elastic support foil 7, the second middle foil 8, and the second top foil 9 are supported and fixed by the second mounting groove 1-4 provided on the base 1-1 thereon.

As shown in Figures 5 and 10, three first curved surfaces 1-6 are provided on the hole wall of the first hole section 1-9A of the shaft hole 1-9 of the housing 1, and the three first curved surfaces 6 are connected to the three The first foil group is matched. Each first curved surface 1-6 is matched with the first elastic support foil 3, the first middle foil 4, the first top foil 5 and the rotor 2 of the corresponding first foil group to forcibly form a first wedge-shaped area 6. The formed first wedge region 6 gradually transitions from the wedge angle θ1 to the wedge angle θ2 smaller than the wedge angle θ1 in the circumferential direction along the first rotation direction, so that the first wedge region 6 presents a convergence trend when the rotor 2 rotates.

R in FIG. 5 represents the radius of the first curved surface 1-6, and the value of R can be set according to the requirements of the first wedge-shaped area 6, for example, the radius R1 in FIG.

The size and accuracy of the first curved surface 1-6 can be guaranteed by machining. As shown in FIG. 10, in this embodiment, each of the first curved surfaces 1-6 is an arc-shaped cylindrical surface (corresponding to the first arc-shaped cylindrical surface) with a radius of R1. In this embodiment, the outer surface of the base 1-1 is a cylindrical surface with the central axis of the shaft hole 1-9 as the central axis and the radius R2. The three arc cylindrical surfaces as the first curved surface 1-6 are evenly distributed around the central axis of the shaft hole 1-9.

The number of the first curved surface 1-6 and the corresponding foil group is determined by the actual force environment in which the dynamic pressure gas radial bearing is located. Within the load range of the dynamic pressure gas radial bearing, the first curved surface 1-6 and the corresponding The greater the number of foil groups, the more first wedge-shaped regions 6 that can be formed, and the smaller the shaft amplitude.

In order to improve the dynamic pressure effect, the central axis 1-7 of the multi-section first curved surface 1-6 is parallel and eccentrically arranged with the central axis of the shaft hole 1-9. In the embodiment shown in FIG. 10, both are deviated by L4 in the vertical direction and L5 in the horizontal direction in size. This arrangement is beneficial to effectively avoid the situation that the central axis of the dynamic pressure gas radial bearing (that is, the central axis of the shaft hole) coincides with the central axis of the rotor 2, and is beneficial to form a wedge-shaped area at all times to form a dynamic pressure gas film.

As shown in Figures 7 and 12, the first hole section 1-9A and the second hole section 1-9B are axially separated by the hole wall of the necking section 1-9C with the inner diameter D1 and the width L1. The hole wall of the second hole section 1-9B includes three sections of second curved surfaces 1-8 sequentially arranged in the circumferential direction. The setting method of the second curved surface 1-8 is similar to the setting method of the first curved surface 1-6. It is an arc cylindrical surface with a radius of R3 and a central axis parallel to the central axis of the shaft hole 1-9 and eccentrically arranged (corresponding to the second Arc cylindrical surface). In Figure 7, L2 is the axial length of the first hole section 1-9A, and L3 is the axial length of the second hole section 1-9B.

As shown in Figure 11, the angle between the starting point of the arc cylindrical surface of a second curved surface 1-8 at the bottom and the horizontal line is from the horizontal line downward θ4; as shown in Figure 10, the three sections of the first curved surface 1-6 The angle between the starting point of the arc cylindrical surface of the first curved surface 1-6 closest to the bottom and the horizontal line is θ3 upward from the horizontal line. Therefore, the first curved surface 1-6 on the hole wall of the first hole section 1-9A and the second curved surface 1-8 on the hole wall of the second hole section 1-9B form a staggered arrangement along the first rotation direction RD.

In order to realize that the second curved surface 1-8 and the first curved surface 1-6 are evenly distributed after fitting, θ3+θ4=360/(n1+n2), where n1 is the number of the second curved surfaces 1-8, n2 is the number of the first curved surface 1-6.

In order to ensure the uniform force of the bearing, in general, n1=n2, R1=R2.

Three first curved surfaces 1-6 are matched with the first elastic support foil 3, the first intermediate foil 4, the first top foil 5, and the rotor 2 to force the formation of three first wedge-shaped areas 6, and three second curved surfaces. After 1-8 are matched with the second elastic support foil 7, the second intermediate foil 8, the second top foil 9, and the rotor 2, three second wedge-shaped regions 10 are forcibly formed. Similar to the first wedge-shaped area 6, the direction of the second wedge-shaped area 10 on the circumference needs to satisfy that when the rotor 2 rotates, the second wedge-shaped area 10 shows a trend of convergence.

In order to reduce the risk of airflow loss and accumulation of impurities along the way, as shown in Figure 12 and Figure 13, a plurality of air inlet holes 1-2 are opened at the necking section 1-9C of the middle part of the shell 1, so that a dynamic pressure air film is formed. The required gas enters the shaft hole 1-9 of the housing 1 from the air inlet 1-2, and finally flows out from both ends of the housing 1. Compared with the air supply mode of the end face, the gas flow is reduced by half.

In order to improve the uniformity of the bearing inlet flow field, as shown in Figure 13, the 8 inlet holes 1-2 with a diameter of D2 are evenly distributed on the circumference to achieve uniform air inlet.

In order to reduce the impact loss of intake air, the embodiment of the present disclosure also performs preset rotation processing on the intake air flow. As shown in Fig. 13, the center line of the air inlet hole 1-2 is arranged at an angle of θ5 to the horizontal line, so that the air inlet hole 1-2 is set so that the flow direction of the fluid entering the shaft hole 1-9 from the outlet is at The radial direction on the housing 1 is skewed toward the first rotation direction RD, so that the intake air flow direction ID follows the rotation direction of the rotor 2 to intake air.

As shown in FIG. 8, since the three first curved surfaces 1-6 and the three second curved surfaces 1-8 are arranged in a staggered manner in the first rotation direction RD, the three first wedge-shaped regions 6 and the three second wedge-shaped regions 10 make The dynamic pressure gas radial bearing presents six wedge-shaped areas in the circumferential direction, and in the axial direction, every three wedge-shaped areas are distributed in two sections along the axial direction. The six-wedge-shaped areas are uniformly distributed along the circumference. After the six-wedge-shaped areas are fitted, the effect of the dynamic pressure air film formed is shown in Figure 14. Compared with the single-wedge convergent bearing in the related art, the multi-wedge-shaped area dynamic pressure gas radial bearing in the embodiment of the present disclosure exhibits the characteristics of uniform force over 360°, which is beneficial to reduce the rotor amplitude and improve the stability of the shafting.

In Figure 14, X and Y respectively represent the horizontal direction and the vertical direction under the illustrated force state, and W represents the direction of gravity borne by the rotor.

The embodiment of the present disclosure also provides a power equipment, including a rotor 2 and a dynamic pressure gas radial bearing supporting the rotor 2. The dynamic pressure gas radial bearing is the aforementioned dynamic pressure gas radial bearing. When the power equipment is running, the rotor 2 is Rotate in the first rotation direction RD.

The power equipment of the embodiment of the present disclosure has the same advantages as the aforementioned dynamic pressure gas radial bearing.

According to the above description, the dynamic pressure gas radial bearing of the embodiment of the present disclosure has at least one of the following advantages:

By arranging curved surfaces on the wall of the shaft hole, and the distance between each curved surface and the central axis of the shaft hole in the radial direction of the shaft hole is gradually reduced along the first rotation direction, and the top layer foil is in the radial direction of the shaft hole The distance between the upper part and the central axis of the shaft hole gradually decreases along the first rotation direction, which realizes the forced distribution of the wedge-shaped area of the hydrodynamic gas radial bearing, which is beneficial to solve the problem of the instability of the wedge-shaped convergence area caused by the eccentricity of the rotor, thereby helping Improve the dynamic pressure effect of the dynamic pressure gas radial bearing.

Propose a multi-wedge changeable design in the radial direction and segmental design in the axial direction of the wedge-shaped area, which is helpful to solve the problem that the small bearing space is not enough to design the multi-wedge structure, thereby helping to reduce the vibration of the shaft system and improve the stability of the shaft system .

A gas supply method for the dynamic pressure gas radial bearing with air inlet in the middle and air outlet at both ends is proposed, which is beneficial to reduce the airflow loss and the accumulation of impurities along the way.

A ring-shaped and pre-rotating bearing air supply technology is proposed, which is beneficial to improve the uniformity of the air inlet flow field of the dynamic pressure gas radial bearing.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure and not to limit it; although the present disclosure has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that: Modifications to the disclosed specific implementations or equivalent replacements of some technical features shall be included in the scope of the technical solutions claimed in the present disclosure.

Claims

A dynamic pressure gas radial bearing, including:

The housing (1) includes a shaft hole (1-9) with a central axis, the shaft hole (1-9) includes at least one hole section, and the hole wall of the hole section includes a hole along the shaft (1- 9) A plurality of curved surfaces arranged sequentially in the circumferential direction of the central axis of the shaft, each of the curved surfaces in the radial direction of the shaft hole (1-9) and the central axis of the shaft hole (1-9) along the distance The first direction of rotation (RD) in which the central axis of the shaft hole (1-9) rotates gradually decreases; and

At least one elastic support structure is arranged corresponding to the at least one hole section, the elastic support structure includes a plurality of foil groups, and the plurality of foil groups are arranged in the holes of the corresponding shaft holes (1-9) On the multiple curved surfaces of the wall, the foil set includes a top foil and an elastic support foil disposed between the corresponding curved surface and the top foil, and the top foil is in the shaft hole The distance from the central axis of the shaft hole (1-9) in the radial direction of (1-9) gradually decreases along the first rotation direction (RD).
The dynamic pressure gas radial bearing according to claim 1, wherein between the surface of the top layer foil close to the central axis and the corresponding curved surface is in the radial direction of the shaft hole (1-9) The distance from the central axis of the shaft hole (1-9) in the direction is constant along the first rotation direction (RD).
The dynamic pressure gas radial bearing according to claim 1, wherein the foil group further comprises an intermediate foil disposed between the top foil and the elastic support foil.
The dynamic pressure gas radial bearing according to claim 3, wherein the top foil and the middle foil are both bent plate-shaped foils.
The dynamic pressure gas radial bearing according to claim 3, wherein the hole wall of the hole section is sequentially provided with a plurality of mounting grooves around the circumference of the central axis of the shaft hole (1-9), and the elastic support structure One end of the top foil of one of the two adjacent foil groups and one end of the middle foil of the other foil group are both installed in the same mounting groove, and the other end Both are free ends.
The hydrodynamic gas radial bearing according to claim 1, wherein the curved surface is an arc cylindrical surface, and the central axis of the arc cylindrical surface is parallel and eccentrically arranged with the central axis of the shaft hole (1-9) .
The dynamic pressure gas radial bearing according to any one of claims 1 to 6, wherein the housing (1) has more than two hole sections and is arranged corresponding to the two or more hole sections Of the two or more elastic support structures, the curved surface on the hole wall of one of the at least two adjacent hole sections and the curved surface on the hole wall of the other hole section are along the first The direction of rotation (RD) is misaligned.
The dynamic pressure gas radial bearing according to any one of claims 1 to 6, wherein the housing (1) has more than two hole sections and is arranged corresponding to the two or more hole sections Two or more elastic support structures, the housing (1) is provided with an air inlet (1-2) connecting the outside of the housing (1) and the shaft hole (1-9), so The outlet of the air inlet hole (1-2) on the hole wall of the shaft hole (1-9) is located between two adjacent hole sections in the axial direction of the shaft hole (1-9).
The dynamic pressure gas radial bearing according to claim 8, wherein the shaft hole (1-9) includes a necking section (1-9C) located between two adjacent hole sections, the The hole wall of the necking section (1-9C) is closer to the central axis of the shaft hole (1-9) relative to the hole wall of the hole section, and the outlet of the air inlet hole (1-2) is located On the hole wall of the necking section (1-9C).
The dynamic pressure gas radial bearing according to claim 8, wherein the air inlet hole (1-2) is arranged such that the flow direction of the fluid entering the shaft hole (1-9) from the outlet is relative to the The radial direction of the outlet on the housing (1) is skewed toward the first turning direction (RD).
A power equipment comprising a rotor (2) and a dynamic pressure gas radial bearing supporting the rotor (2), wherein the dynamic pressure gas radial bearing is according to any one of claims 1-10 With a dynamic pressure gas radial bearing, the rotor (2) rotates along the first rotation direction (RD) when the power equipment is running.