CN211398266U - Dynamic pressure gas radial bearing and power equipment - Google Patents

Abstract

The present disclosure provides a dynamic pressure gas radial bearing and a power device. The hydrodynamic gas radial bearing includes: the shell comprises a shaft hole with a central axis, the shaft hole comprises at least one hole section, the hole wall of the hole section comprises a plurality of curved surfaces which are sequentially arranged along the circumferential direction of the central axis 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 a first rotary direction rotating around the central axis of the shaft hole; and at least one elastic supporting structure, correspond the setting with at least one hole section, elastic supporting structure includes a plurality of foil sheet groups, a plurality of foil sheet groups set up on a plurality of curved surfaces of the pore wall in corresponding shaft hole, foil sheet group includes top layer foil sheet and sets up the elastic supporting foil sheet between curved surface and the top layer foil sheet that corresponds, the top layer foil sheet reduces along first direction of gyration gradually with the distance of the central axis in shaft hole in the radial direction in shaft hole. The technical scheme disclosed facilitates improving the dynamic pressure effect of the dynamic pressure gas radial bearing.

Description

Dynamic pressure gas radial bearing and power equipment

Technical Field

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

Background

The air bearing has a series of advantages of small friction loss, good stability, small vibration, oil-free lubrication and the like, and has a very wide application prospect in the fields of high-speed turbines, machine tool manufacturing, space technology and the like. The air bearings are classified into static pressure gas bearings and dynamic pressure gas radial bearings according to the difference in the mechanism of generation of a lubricating gas film.

The bump foil type dynamic pressure gas radial bearing is one of the dynamic pressure gas radial bearings, and generally includes a flat foil as a top foil, which provides a lubrication surface for a rotor, and an elastic foil, which provides support rigidity and damping for the bearing.

SUMMERY OF THE UTILITY MODEL

A first aspect of the present disclosure provides a hydrodynamic gas radial bearing, including:

the shell comprises a shaft hole with a central axis, the shaft hole comprises at least one hole section, the hole wall of the hole section comprises a plurality of curved surfaces which are sequentially arranged along the circumferential direction of the central axis 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 a first rotary direction rotating around the central axis of the shaft hole; and

at least one elastic support structure, with at least one the hole section corresponds the setting, elastic support structure includes a plurality of foil sheet groups, a plurality of foil sheet groups set up in the pore wall in corresponding shaft hole on a plurality of curved surfaces, foil sheet group includes top layer foil sheet and sets up in corresponding the curved surface with the elastic support foil sheet between the top layer foil sheet, the top layer foil sheet is in the radial direction in shaft hole with the central axis's in shaft hole distance is followed first direction of gyration reduces gradually.

In some embodiments, a distance between a surface of the top foil near the central axis and the corresponding curved surface in a radial direction of the shaft hole from the central axis of the shaft hole is constant along the first revolution direction.

In some embodiments, the set of foils further comprises an intermediate foil disposed between the top foil and the flexible support foil.

In some embodiments, the top foil and the middle foil are both bent plate foils.

In 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, one end of the top foil of one of the two adjacent foil groups of the elastic support structure and one end of the middle foil of the other foil group are both mounted in the same mounting 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 to the central axis of the shaft hole and is eccentrically arranged.

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

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

In some embodiments, the axial bore includes a reduced section between two adjacent bore sections, the bore wall of the reduced section is closer to the central axis of the axial bore than the bore wall of the bore section, and the outlet of the air intake hole is located on the bore wall of the reduced section.

In some embodiments, the air intake hole is provided so that a flow direction of the fluid entering the shaft hole from the outlet is inclined toward the first rotation direction with respect to a radial direction of the outlet on the housing.

A second aspect of the present disclosure provides a power device, including a rotor and a dynamic pressure gas radial bearing supporting the rotor, where the dynamic pressure gas radial bearing is the aforementioned dynamic pressure gas radial bearing, and when the power device is in operation, the rotor rotates in the first rotation direction.

Based on this gaseous journal bearing of dynamic pressure that this disclosure provided, through set up the curved surface on the pore wall in shaft hole, and each curved surface reduces along first direction of revolution gradually with the central axis's in shaft hole distance in the radial direction in shaft hole to and top layer foil reduces along first direction of revolution gradually with the central axis's in shaft hole distance in the radial direction in shaft hole, realized the gaseous journal bearing wedge region of dynamic pressure and forced the distribution, do benefit to and solve the unstable problem of the wedge convergence region that only relies on rotor off-centre to bring, thereby do benefit to the dynamic pressure effect that improves gaseous journal bearing of dynamic pressure.

The power equipment provided by the present disclosure has the advantages of the above hydrodynamic gas radial bearing provided by the present disclosure.

Other features of the present disclosure 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 disclosure and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the disclosure and together with the description serve to explain the disclosure and not to limit the disclosure. In the drawings:

fig. 1 is a schematic view of a partial structure of a hydrodynamic gas radial bearing in cooperation with a rotor.

Fig. 2 is a schematic view showing a principle of generating a dynamic pressure gas film when the dynamic pressure gas radial bearing shown in fig. 1 is engaged with a rotor.

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

Fig. 4 is a front view of the mating structure shown in fig. 3.

Fig. 5 is a schematic sectional view of the fitting structure shown in fig. 4 from the direction of a-a.

Fig. 6 is a schematic sectional view of the fitting structure shown in fig. 4 from the direction B-B.

Fig. 7 is a schematic cross-sectional view of the mating structure of fig. 4 taken along the direction C-C.

Fig. 8 is a schematic view of the structure of the mating structure shown in fig. 4 in the direction D.

Fig. 9 is a schematic structural view of a housing of a dynamic pressure gas radial bearing according to an embodiment of the present disclosure.

Fig. 10 is a left side view of the housing shown in fig. 9.

Fig. 11 is a right-side structural view of the housing shown in fig. 9.

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

Fig. 13 is a schematic sectional view of the housing shown in fig. 12 taken along direction E-E.

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

Detailed Description

The technical solutions in the embodiments of the present disclosure will be clearly and completely described below with reference to the drawings in the embodiments of the present disclosure, and it is obvious that the described embodiments are only a part of the embodiments of the present disclosure, 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 disclosure, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments disclosed herein without making any creative effort, shall fall within the protection scope of the present disclosure.

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 disclosure 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.

In the description of the present disclosure, it should be understood that the terms "first", "second", etc. are used to define the components, and are used only for convenience of distinguishing the corresponding components, and if not otherwise stated, the terms have no special meaning, and thus, should not be construed as limiting the scope of the present disclosure.

In the description of the present disclosure, it is to be understood that the directional terms are merely used for convenience in describing the present disclosure and for simplicity in description, and in the absence of any indication to the contrary, these directional terms are not intended to indicate and imply that the referenced device or element must have a particular orientation or be constructed and operated in a particular orientation, and therefore should not be taken as limiting the scope of the present disclosure; the terms "inner and outer" refer to the inner and outer relative to the profile of the respective component itself.

The working principle of the hydrodynamic gas radial bearing is shown in fig. 1 and 2. Fig. 1 is a schematic view of a partial structure of a hydrodynamic gas radial bearing in cooperation with a rotor. Fig. 2 is a schematic view showing a principle of generating a dynamic pressure gas film when the dynamic pressure gas radial bearing shown in fig. 1 is engaged with a rotor. When the rotor 1 'runs at high speed, the center of the rotor 1' is eccentric to the center of the dynamic pressure gas radial bearing 2 'due to the stress (such as gravity) applied to the rotor 1', and a wedge-shaped structure is formed between the top foil of the dynamic pressure gas radial bearing 2 'and the rotor 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, and a dynamic pressure gas film 3 ' is formed to support the rotor 1 ' to operate.

As shown in fig. 3 to 13, the disclosed embodiment provides a dynamic pressure gas radial bearing including 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 bore 1-9 includes at least one bore section. The hole wall of the hole section comprises a plurality of curved surfaces which are sequentially arranged along the circumferential direction of the central axis of the shaft hole 1-9, and the distance between each curved surface and the central axis of the shaft hole 1-9 in the radial direction of the shaft hole 1-9 is gradually reduced along the first rotation direction RD rotating around the central axis of the shaft hole 1-9. And the at least one elastic supporting structure is arranged corresponding to the at least one hole section. The resilient support structure comprises a plurality of foil groups. The plurality of foil sets are arranged on the plurality of curved surfaces of the hole walls of the corresponding shaft holes 1-9. The foil group comprises a top layer foil and an elastic supporting foil arranged between the corresponding curved surface and the top layer foil. The distance between the top foil and the central axis of the shaft hole 1-9 in the radial direction of the shaft hole 1-9 is gradually reduced along the first rotation direction RD.

In the dynamic pressure gas radial bearing of the embodiment of the disclosure, the curved surfaces are arranged on the hole wall of the shaft hole, 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 distance between the top foil and the central axis of the shaft hole in the radial direction of the shaft holes 1 to 9 is gradually reduced along the first rotation direction, so that the wedge-shaped area of the dynamic pressure gas radial bearing is forcibly distributed, the problem of unstable wedge-shaped convergence area caused by the eccentricity of a rotor is solved, and the dynamic pressure effect of the dynamic pressure gas radial bearing is improved.

In the embodiment shown in fig. 3 to 13, the shaft hole 1-9 of the housing 1 comprises two hole sections and two elastic support structures arranged corresponding to the two hole sections. In an embodiment not shown, one hole segment and one corresponding resilient support structure may be included, or more than three hole segments and more than three corresponding resilient support structures may be included.

As shown in fig. 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 comprises a plurality of first curved surfaces 1-6 which are sequentially arranged in the circumferential direction 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 is gradually reduced along the first revolution direction RD revolving around the central axis of the shaft hole 1-9. 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 fig. 3 to 13, the elastic support structure corresponding to the first hole segment 1-9A includes a plurality of first foil sets, and the plurality of first foil sets are correspondingly disposed on the plurality of first curved surfaces 1-6. The first foil group comprises a first top foil 5 and a first elastic supporting 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 foil 5 and the central axis of the shaft hole 1-9 gradually decreases along the first rotation direction RD.

As shown in fig. 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 comprises a plurality of second curved surfaces 1-8 which are sequentially arranged in the circumferential direction 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 is gradually reduced along the first rotation direction RD.

As shown in fig. 3-13, the resilient support structure corresponding to the first hole segments 1-9A comprises a plurality of second foil groups. The plurality of second foil sets are correspondingly arranged on the plurality of second curved surfaces 1-8. The second foil group comprises 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 holes 1-9, the distance between the second top foil 9 and the central axis of the shaft holes 1-9 gradually decreases along the first rotation direction RD.

In the embodiments shown in fig. 3-13, each foil set comprises one elastic support foil, and in a non-illustrated embodiment, the foil set may comprise a double layer of elastic support foil.

In the hydrodynamic gas radial bearing of some embodiments, the distance between the surface of the top foil near the central axis and the corresponding curved surface in the radial direction of the shaft hole 1-9 from the central axis of the shaft hole 1-9 is constant in the first rotating direction RD.

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

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

In some embodiments of the hydrodynamic gas radial bearing, the foil set further comprises an intermediate foil disposed between the top foil and the elastic support foil.

As shown in fig. 3 to 13, the first foil group further comprises a first intermediate foil 4 disposed between the first top foil 5 and the first elastic support foil 3.

As shown in fig. 3 to 13, the second foil set further comprises a second intermediate foil 8 arranged between the second top foil 9 and the second elastic support foil 7.

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

In 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, one end of the top foil of one of the two adjacent foil sets of the elastic support structure and one end of the middle foil of the other foil set are both mounted in the same mounting groove, and the other ends are both free ends.

As shown in fig. 3 to 13, the hole walls of the first hole sections 1 to 9A are sequentially provided with a plurality of first mounting grooves 1 to 3 around the circumferential direction of the central axis of the shaft holes 1 to 9, one end of the first top foil 5 of one first foil group and one end of the first middle foil 4 of the other first foil group in two adjacent first foil groups are both mounted in the same first mounting groove 1 to 3, and the other ends are both free ends.

As shown in fig. 3 to 13, the hole walls of the second hole sections 1 to 9B are sequentially provided with a plurality of second mounting grooves 1 to 4 around the circumferential direction of the central axis of the shaft holes 1 to 9, one end of the second top foil 9 of one second foil group and one end of the second middle foil 8 of the other second foil group in two adjacent second foil groups are both mounted in the same second mounting groove 1 to 4, and the other ends are both free ends.

In some embodiments, the dynamic pressure gas radial bearing has a curved surface which is an arc-shaped cylindrical surface, and the central axis of the arc-shaped cylindrical surface is eccentrically arranged in parallel with the central axis of the shaft holes 1 to 9.

As shown in fig. 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 to the central axis of the shaft hole 1-9 and is eccentrically arranged.

As shown in fig. 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 to the central axis of the shaft hole 1-9 and is eccentrically arranged.

In the hydrodynamic gas radial bearing of some embodiments, the housing 1 has two or more hole segments and two or more elastic support structures disposed corresponding to the two or more hole segments, and the curved surface on the hole wall of one of the at least two adjacent hole segments is arranged to be offset from the curved surface on the hole wall of the other hole segment along the first rotation direction RD.

As shown in fig. 3 to 13, the first curved surface 1-6 on the hole wall of the first hole segment 1-9A and the second curved surface 1-8 on the hole wall of the second hole segment 1-9B are arranged in a staggered manner along the first rotation direction RD.

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

As shown in FIGS. 3 to 13, the outlet of the intake port 1-2 at the hole wall of the shaft hole 1-9 is located between the first hole section 1-9A and the second hole section 1-9B in the axial direction of the shaft hole 1-9.

In some embodiments of the hydrodynamic gas radial bearing, the axial bore 1-9 includes a reduced diameter section 1-9C between adjacent two bore sections. The bore wall of the throat section 1-9C is closer to the central axis of the axial bore 1-9 than the bore wall of the bore section. The outlet of the air inlet hole 1-2 is positioned on the hole wall of the necking section 1-9C. As shown in fig. 7, 9 and 12, the necked-down section 1-9C is located between the first bore section 1-9A and the second bore section 1-9B.

As shown in fig. 13, in the dynamic pressure gas radial bearing of some embodiments, the gas intake holes 1-2 are arranged such that the flow direction of the fluid entering the shaft hole 1-9 from the outlet is inclined toward the first rotation direction RD with respect to the radial direction of the outlet on the housing 1.

The hydrodynamic gas radial bearing according to the embodiment of the present disclosure is further described below with reference to fig. 3 to 13.

The dynamic pressure gas radial bearing of the disclosed embodiment is used to support the rotor 2. The rotor 2 is mounted in a bearing bore of a dynamic pressure gas radial bearing. The rotor 2 is a shaft type solid part, and when the rotor 2 works, the rotor rotates at a high speed under the action of an electromagnetic field.

The hydrodynamic gas radial bearing includes a housing 1, a first elastic support foil 3, a first middle foil 4, a first top foil 5, a second elastic support foil 7, a second middle foil 8, and a second top foil 9.

The first elastic support foil 3 and the second elastic support foil 7 are foils that function as elastic supports, providing stiffness and damping to the hydrodynamic gas radial bearing. The first elastic support foil 3 connects the corresponding first curved surfaces 1-6 and the first intermediate foil 4. The second elastic supporting foil 7 is connected with the corresponding second curved surface 1-8 and the second middle foil 1-8. In this embodiment both the first 3 and the second 7 elastic support foils are corrugated foils.

In this embodiment, to facilitate uniform stress of the hydrodynamic gas radial bearing, the first elastic support foil 3 and the second elastic support foil 7 have the same waveform structure. In the embodiment not shown, the wave structures of the first elastic support foil and the second elastic support foil may be designed differently according to actual situations, if required.

In addition, the elastic supporting foils in each foil set can also be designed into two layers.

As shown in fig. 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 each bent plate-shaped foils. Wherein the middle foil is connected with the elastic supporting foil and the top foil to provide additional damping, and the top foil is matched with the rotor 2 to form a dynamic pressure air film.

As shown in fig. 5, 6 and 8, when the central axis of the shaft 2 coincides with the central axis of the hydrodynamic radial bearing, a plurality of first wedge regions 6 corresponding to the number of first foil sets are formed between the first top foil 5 and the shaft 2, and a plurality of second wedge regions 10 corresponding to the number of second foil sets are formed between the second top foil 9 and the shaft 2. The first wedge-shaped regions 6 and the second wedge-shaped regions 10 are convergent regions formed between the hydrodynamic gas radial bearing and the rotor 2, and are critical to forming a hydrodynamic gas film.

As shown in fig. 9 to 13, the housing 1 is an annular hollow part, and includes a base 1-1, an air inlet 1-2 disposed on the base 1-1, a first mounting groove 1-3, a second mounting groove 1-4, a first curved surface 1-6, a second curved surface 1-8, an axle hole 1-9, and the like.

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

As shown in fig. 5 and fig. 10, three first curved surfaces 1-6 are arranged on the hole walls of the first hole sections 1-9A of the shaft holes 1-9 of the shell 1, and the three first curved surfaces 6 are respectively matched with the three first foil groups. Each first curved surface 1-6 is matched with the first elastic supporting foil 3, the first middle foil 4, the first top foil 5 and the rotor 2 of the corresponding first foil set to forcibly form a first wedge-shaped area 6. The first wedge area 6 is formed to gradually transition from the wedge angle θ 1 to a wedge angle θ 2 smaller than the wedge angle θ 1 in the first rotation direction in the circumferential direction so that the first wedge area 6 exhibits a convergence tendency when the rotor 2 rotates.

In fig. 5, R represents the radius of the first curved surface 1-6, and the value of R can be set according to the requirement of the first wedge-shaped area 6, such as the radius R1 in fig. 10.

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

The number of the first curved surfaces 1-6 and the corresponding foil groups is determined by the actual stress environment of the dynamic pressure gas radial bearing, and in the bearing range of the dynamic pressure gas radial bearing, the more the number of the first curved surfaces 1-6 and the corresponding foil groups is, the more the first wedge-shaped areas 6 can be formed, and the smaller the shafting amplitude is.

In order to improve the dynamic pressure effect, the central axis 1-7 of the multi-section first curved surface 1-6 is parallel to the central axis of the shaft hole 1-9 and is eccentrically arranged. In the embodiment shown in fig. 10, the two are offset in size from L4 in the up-down direction and L5 in the horizontal direction. This arrangement facilitates effective avoidance of the situation where the center axis of the dynamic pressure gas radial bearing (i.e., the center axis of the shaft hole) coincides with the center axis of the rotor 2, facilitating the formation of the wedge-shaped region at all times so as to form a dynamic pressure gas film.

As shown in FIGS. 7 and 12, first bore section 1-9A and second bore section 1-9B are axially separated by bore walls having an inner diameter D1 and a reduced section 1-9C of width L1. The hole wall of the second hole section 1-9B comprises three sections of second curved surfaces 1-8 which are sequentially arranged along the circumferential direction. The second curved surface 1-8 is arranged in a similar manner to the first curved surface 1-6, and is an arc-shaped cylindrical surface (corresponding to the second arc-shaped 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. In FIG. 7, L2 is the axial length of the first bore section 1-9A and L3 is the axial length of the second bore section 1-9B.

As shown in fig. 11, the starting point of the arc-shaped cylindrical surface of one of the second curved surfaces 1-8 at the bottom forms an angle θ 4 downward from the horizontal line; as shown in FIG. 10, the angle between the starting point of the arc-shaped cylindrical surface of the first curved surface 1-6 closest to the bottom of the three first curved surfaces 1-6 and the horizontal line is upward theta 3 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 surfaces 1-8 and the first curved surfaces 1-6 are fitted to present a circumferentially uniform state, θ 3+ θ 4 is 360/(n1+ n2), where n1 is the number of the second curved surfaces 1-8 and n2 is the number of the first curved surfaces 1-6.

In order to ensure that the bearing is stressed uniformly, n1 is n2, and R1 is R2.

Three sections of first curved surfaces 1-6 are matched with a first elastic supporting foil 3, a first middle foil 4, a first top layer foil 5 and a rotor 2 to forcibly form three first wedge-shaped areas 6, three sections of second curved surfaces 1-8 are matched with a second elastic supporting foil 7, a second middle foil 8, a second top layer foil 9 and the rotor 2 to forcibly form three sections of second wedge-shaped areas 10. Similar to the first wedge area 6, the second wedge area 10 is circumferentially oriented such that the second wedge area 10 exhibits a converging tendency when the rotor 2 is rotated.

In order to reduce the risk of air flow loss and impurity accumulation along the way, as shown in fig. 12 and 13, a plurality of air inlet holes 1-2 are formed in the necking sections 1-9C in the middle of the shell 1, so that the air required for forming the dynamic pressure air film enters the shaft holes 1-9 of the shell 1 from the air inlet holes 1-2 and finally flows out from the two ends of the shell 1 respectively, and compared with an air supply mode of entering and exiting from the end face, the air flow is reduced by half.

In order to improve the uniformity of the bearing intake air flow field, as shown in fig. 13, 8 intake holes 1-2 with the diameter of D2 are uniformly distributed on the circumference to realize uniform intake.

In order to reduce the intake impact loss, the embodiment of the disclosure also performs preset rotation processing on the intake air flow. As shown in fig. 13, the center lines of the intake ports 1-2 are arranged at an angle θ 5 to the horizontal line to achieve that the intake ports 1-2 are disposed such that the flow direction of the fluid entering the shaft hole 1-9 from the outlet is inclined toward the first rotation direction RD with respect to the radial direction of the outlet on the housing 1 so that the intake flow direction ID is taken in the rotation direction of the rotor 2.

As shown in fig. 8, since the three first curved surfaces 1 to 6 and the three second curved surfaces 1 to 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 cause the hydrodynamic gas radial bearing to exhibit six wedge-shaped regions in the circumferential direction and a characteristic that each 3 wedge-shaped regions are distributed in two stages in the axial direction. Six wedge-shaped areas are uniformly distributed along the circumference, and the dynamic pressure air film effect formed after the six wedge-shaped areas are fitted is shown in figure 14. Compared with a single-wedge convergent bearing in the related art, the multi-wedge area dynamic pressure gas radial bearing disclosed by the embodiment of the disclosure has the characteristic of uniform stress in 360 degrees, and is beneficial to reducing the amplitude of a rotor and improving the stability of a shafting.

In fig. 14, X and Y represent the horizontal direction and the vertical direction, respectively, in the illustrated stressed state, and W represents the direction of gravity borne by the rotor.

The embodiment of the present disclosure further provides a power device, which includes a rotor 2 and a dynamic pressure gas radial bearing supporting the rotor 2, where the dynamic pressure gas radial bearing is the aforementioned dynamic pressure gas radial bearing, and when the power device operates, the rotor 2 rotates in the first rotation direction RD.

The power equipment of the disclosed embodiment has the same advantages as the dynamic pressure gas radial bearing described above.

As can be seen from the above description, the hydrodynamic gas radial bearing of the embodiments of the present disclosure has at least one of the following advantages:

the curved surfaces are arranged on the hole walls of the shaft holes, 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 rotating direction, and the distance between each top foil and the central axis of the shaft hole in the radial direction of the shaft hole is gradually reduced along the first rotating direction, so that the wedge-shaped area forced distribution of the dynamic pressure gas radial bearing is realized, the problem of unstable wedge-shaped convergence area caused by the eccentricity of a rotor is favorably solved, and the dynamic pressure effect of the dynamic pressure gas radial bearing is favorably improved.

The scheme of multi-wedge turning design in the radial direction and sectional design of the wedge-shaped area in the axial direction is provided, so that the problem that the multi-wedge structure cannot be designed in a small bearing space is solved, the shafting vibration is reduced, and the shafting stability is improved.

The gas supply mode of the dynamic pressure gas radial bearing with the middle gas inlet and the two gas outlet ends is provided, and the reduction of the loss of the on-way gas flow and the accumulation of impurities is facilitated.

The annular preset rotating bearing gas supply technology is provided, and the uniformity of the gas inlet field of the dynamic pressure gas radial bearing is improved.

Finally, it should be noted that: the above examples are intended only to illustrate the technical solutions of the present disclosure and not to limit them; although the present disclosure has been described in detail with reference to preferred embodiments, those of ordinary skill in the art will understand that: modifications to the embodiments of the disclosure or equivalent replacements of parts of the technical features may be made, which are all covered by the technical solution claimed by the disclosure.

Claims (11)

1. A dynamic pressure gas radial bearing, comprising:

the shell (1) comprises a shaft hole (1-9) with a central axis, the shaft hole (1-9) comprises at least one hole section, the hole wall of the hole section comprises a plurality of curved surfaces which are sequentially arranged along the circumferential direction of the central axis of the shaft hole (1-9), and the distance between each curved surface and the central axis of the shaft hole (1-9) in the radial direction of the shaft hole (1-9) is gradually reduced along a first Revolution Direction (RD) revolving around the central axis of the shaft hole (1-9); and

at least one elastic support structure, with at least one the hole section corresponds the setting, elastic support structure includes a plurality of foil groups, a plurality of foil groups set up in the pore wall of corresponding shaft hole (1-9) on a plurality of curved surfaces, foil group includes top layer foil and sets up in corresponding the curved surface with the elastic support foil between the top layer foil, the top layer foil is in the radial direction in shaft hole (1-9) with the distance of the central axis in shaft hole (1-9) is followed first direction of Revolution (RD) reduces gradually.

2. Hydrodynamic gas radial bearing according to claim 1, characterized in that the distance between the surface of the top foil close to the central axis and the corresponding curved surface in the radial direction of the shaft bore (1-9) from the central axis of the shaft bore (1-9) is constant in the first direction of Revolution (RD).

3. The dynamic pressure gas radial bearing of claim 1, wherein said set of foils further comprises an intermediate foil disposed between said top foil and said flexible support foil.

4. The dynamic pressure gas radial bearing of claim 3, wherein said top foil and said middle foil are both bent plate-like foils.

5. The dynamical 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), one end of the top foil of one of the two adjacent foil sets of the elastic support structure and one end of the middle foil of the other foil set are both mounted in the same mounting groove, and the other ends are both free ends.

6. Hydrodynamic gas radial bearing according to claim 1, characterized in that the curved surface is an arc-shaped cylindrical surface, the central axis of which is eccentrically arranged in parallel with the central axis of the axial bore (1-9).

7. Hydrodynamic gas radial bearing according to any of claims 1 to 6, characterized in that the housing (1) has two or more bore sections and two or more resilient support structures arranged in correspondence with the two or more bore sections, the curved surface on the bore wall of one of the at least two adjacent bore sections being offset from the curved surface on the bore wall of the other bore section in the first direction of Revolution (RD).

8. The dynamic pressure gas radial bearing according to any one of claims 1 to 6, wherein the housing (1) has two or more of the hole sections and two or more of the elastic support structures provided corresponding to the two or more of the hole sections, an air intake hole (1-2) communicating an outside of the housing (1) with the shaft hole (1-9) is provided in the housing (1), and an outlet of the air intake hole (1-2) on a wall of the shaft hole (1-9) is located between the adjacent two hole sections in an axial direction of the shaft hole (1-9).

9. The dynamic pressure gas radial bearing according to claim 8, wherein the shaft hole (1-9) comprises a constricted section (1-9C) between two adjacent hole sections, the hole wall of the constricted section (1-9C) is closer to the central axis of the shaft hole (1-9) than the hole wall of the hole section, and the outlet of the gas inlet hole (1-2) is located on the hole wall of the constricted section (1-9C).

10. Hydrodynamic gas radial bearing according to claim 8, characterized in that the inlet holes (1-2) are arranged such that the flow direction of the fluid entering the shaft hole (1-9) from the outlet is inclined towards the first direction of Rotation (RD) with respect to the radial direction of the outlet on the housing (1).

11. A power plant comprising a rotor (2) and a hydrodynamic gas radial bearing supporting the rotor (2), characterized in that the hydrodynamic gas radial bearing is a hydrodynamic gas radial bearing according to any one of claims 1-10, the rotor (2) rotating in the first direction of Revolution (RD) when the power plant is in operation.

Images