Hydrodynamic bearings and air conditioning units

Abstract

The present invention provides a hydrodynamic bearing and an air-conditioning unit. A rotating cavity is formed in the middle of the bearing body, and a rotor is installed in the rotating cavity. The hydrodynamic bearing component is installed in the rotating cavity and is located between the rotor and the bearing body. The rotor disk is fixedly installed at both ends of the rotor to rotate with the rotor and is opposite to the two end faces of the bearing body. The static pressure bearing components are respectively installed on the two end faces of the bearing body and are located between the rotor disk and the bearing body. In the radial direction, the static pressure bearing component is located on the outside of the hydrodynamic bearing component. By applying the technical solution of this embodiment, through the structural arrangement of the above-mentioned static pressure bearing component, the static pressure bearing component can play a bearing support role in the axial direction, and at the same time, the static pressure bearing component can also seal the gap on the outside of the hydrodynamic bearing component, reduce the problem of air film end leakage, and improve the bearing capacity of the hydrodynamic bearing.

Description

Technical Field

[0001] The present invention relates to the technical field of bearings, and in particular to a hydrodynamic bearing and an air conditioning unit. Background Art

[0002] Gas lubrication technology was first proposed in the middle of the 19th century and developed rapidly in the middle of the 20th century. Its emergence broke the dominant position of liquid lubrication technology and brought about a qualitative leap in lubrication technology. Gas bearings are new bearings based on this high-tech lubrication technology. They have a series of advantages such as low friction loss, good stability, low vibration, and oil-free lubrication. They have very broad application prospects in the fields of high-speed turbine machine tool manufacturing and space technology.

[0003] Gas bearings use gas as a lubricant and utilize the gas's adsorption, transport (diffusivity, viscosity and thermal conductivity) and compressibility characteristics. During friction, under the action of fluid dynamic pressure effect, static pressure effect and extrusion effect, a gas film is formed to support the load and reduce friction. According to the different formation mechanisms of the lubricating gas film, they are divided into dynamic pressure gas bearings, static pressure gas bearings and extrusion type gas bearings. Among them, the corrugated foil type dynamic pressure gas bearing is the dynamic pressure gas bearing with the most research literature available, and the small hole throttling static pressure bearing and porous static pressure bearing are the static pressure gas bearings that have been studied more.

[0004] The foil dynamic pressure gas radial bearing is generally composed of a bearing shell, a top foil, and a corrugated foil. Among them, the corrugated foil is an elastic foil with a special waveform. When working, it generates a supporting force through the elastic change of the waveform, providing the main stiffness and partial damping for the bearing. The top foil is a long cylindrical foil. In the radial direction, one side of the top foil is evenly overlapped on the top of each corrugation of the corrugated foil. The friction generated by the contact with the corrugated foil provides another part of the damping for the bearing; the other side of the top foil cooperates with the rotor gap to form the air film space required for the dynamic pressure effect. The working principle of the foil dynamic pressure gas bearing is that the rotating shaft is eccentric relative to the bearing under the action of gravity, and then forms a wedge-shaped gap with the inner surface of the bearing. When the rotating shaft is rotating at high speed, it continuously brings gas with a certain viscosity into the wedge-shaped gap, and the continuous entry of gas causes the air film to generate a certain pressure. When the air film force is sufficient to balance the load of the rotating shaft, the shaft and the bearing are completely separated. The process of generating the above-mentioned air film is called the dynamic pressure effect.

[0005] According to the above description, the wave foil type hydrodynamic gas hydrodynamic bearing is actually a type of hydrodynamic sliding bearing. Under the hydrodynamic effect, the higher the speed, the higher the bearing's load capacity. However, during the start-up and stop process, due to insufficient speed, the gas film cannot be formed through the hydrodynamic principle. At this time, the top foil of the bearing and the rotor will have dry friction, affecting the bearing life. Therefore, it is necessary to take measures to solve the wear problem of the hydrodynamic bearing during the start-up and stop process. In addition, due to the need for air intake and exhaust, there is no sealing structure at both ends of the hydrodynamic bearing, so the formed gas film can leak from both ends of the bearing, resulting in end leakage problems, resulting in a decrease in the bearing's load capacity. Summary of the invention

[0006] The embodiments of the present invention provide a hydrodynamic bearing and an air conditioning unit to solve the technical problem of easy leakage of air film in the hydrodynamic bearing in the prior art.

[0007] An embodiment of the present invention provides a hydrodynamic bearing, comprising: a bearing body, a rotating cavity formed in the middle of the bearing body; a rotor, installed in the rotating cavity; a hydrodynamic bearing member, installed in the rotating cavity and located between the rotor and the bearing body, the hydrodynamic bearing member is used to provide hydrodynamic support for the rotor; the hydrodynamic bearing also includes: a rotor disk, fixedly installed at both ends of the rotor to rotate with the rotor and opposite to the two end faces of the bearing body in the axial direction; a static pressure bearing member, respectively installed on the two end faces of the bearing body and located between the rotor disk and the bearing body, in the radial direction, the static pressure bearing member is located on the outside of the hydrodynamic bearing member.

[0008] In one embodiment, an air inlet hole is opened on the bearing body, an air inlet passage connected to the air inlet hole is formed in the bearing body, and the air inlet passage is connected to the static pressure bearing component.

[0009] In one embodiment, the air inlet passage comprises a main airway and a lateral airway, the main airway is connected to the air inlet hole, a first end of the lateral airway is connected to the main airway, and a second end of the lateral airway is connected to the static pressure bearing member.

[0010] In one embodiment, an air outlet hole is opened on the bearing body, and an air outlet channel connected to the air outlet hole is formed in the bearing body, and the air outlet channel is connected to the rotating cavity.

[0011] In one embodiment, an annular groove is formed on the hydrostatic bearing component, and an annular protrusion matched with the annular groove is formed on the rotor disk.

[0012] In one embodiment, there are a plurality of annular grooves, which are spaced apart and concentrically arranged, and there are a plurality of annular protrusions, each of which is arranged corresponding to an annular groove.

[0013] In one embodiment, a plurality of annular grooves cooperate with a plurality of annular protrusions to form an annular corrugated air barrier passage or a comb-teeth sealed air barrier passage.

[0014] In one embodiment, a wedge-shaped groove is formed on the side wall of the annular groove.

[0015] In one embodiment, wedge-shaped grooves are formed on both side walls of the annular groove.

[0016] In one embodiment, there are a plurality of wedge-shaped grooves, and the plurality of wedge-shaped grooves are sequentially spaced apart along the radial direction of the annular groove.

[0017] In one embodiment, the hydrodynamic bearing member comprises: at least one layer of corrugated foil disposed on the inner wall of the rotating cavity; and at least one layer of top foil mounted on the corrugated foil.

[0018] In one embodiment, there are at least two top foils, and the at least two top foils are stacked along the radial direction of the bearing body.

[0019] In one embodiment, the bump foil and the top foil are fixed to the inner wall of the rotating cavity by pins.

[0020] The present invention also provides an air conditioning unit, comprising a hydrodynamic bearing, wherein the hydrodynamic bearing is the above-mentioned hydrodynamic bearing.

[0021] In the above embodiment, through the structural setting of the above-mentioned static pressure bearing component, the static pressure bearing component can not only play a bearing support role in the axial direction, but also allow the static pressure bearing component to seal the gap on the outside of the dynamic pressure bearing component, reduce the problem of air film end leakage, and improve the bearing capacity of the dynamic pressure bearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. 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 accompanying drawings:

[0023] Figure 1 is a schematic diagram of the three-dimensional structure of an embodiment of a hydrodynamic bearing according to the present invention;

[0024] Figure 2 yes Figure 1 A schematic cross-sectional structure diagram of a hydrodynamic bearing and a schematic partial enlarged structure diagram thereof;

[0025] Figure 3 yes Figure 2 A schematic cross-sectional structure diagram of the hydrodynamic bearing from an AA perspective and a schematic partial enlarged structure diagram;

[0026] Figure 4 yes Figure 2 BB perspective cross-sectional structural diagram of the hydrodynamic bearing and its partially enlarged structural diagram. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments and the accompanying drawings. Here, the illustrative embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention.

[0028] Figure 1 and Figure 2 The embodiment of the hydrodynamic bearing of the present invention is shown, and the hydrodynamic bearing comprises a bearing body 10, a rotor 20, a hydrodynamic bearing component 30, a static pressure bearing component 40 and a rotor disk 50. A rotating cavity 11 is formed in the middle of the bearing body 10, and the rotor 20 is installed in the rotating cavity 11. The hydrodynamic bearing component 30 is installed in the rotating cavity 11 and is located between the rotor 20 and the bearing body 10. The hydrodynamic bearing component 30 is used to provide hydrodynamic support for the rotor 20. The rotor disk 50 is fixedly installed at both ends of the rotor 20 and rotates with the rotor 20, and is opposite to the two end faces of the bearing body 10 in the axial direction. The static pressure bearing component 40 is respectively installed on the two end faces of the bearing body 10 and is located between the rotor disk 50 and the bearing body 10. In the radial direction, the static pressure bearing component 40 is located on the outside of the hydrodynamic bearing component 30.

[0029] By applying the technical solution of this embodiment, through the structural setting of the above-mentioned hydrostatic bearing component 40, the hydrostatic bearing component 40 can not only play a bearing support role in the axial direction, but also seal the gap on the outside of the hydrodynamic bearing component 30, reduce the air film end leakage problem, and improve the bearing capacity of the hydrodynamic bearing.

[0030] It should be noted that in the technical solution of this embodiment, Figure 1 As shown, mounting grooves are formed on the two end faces of the bearing body 10, and the hydrostatic bearing component 40 is installed in the mounting grooves. As another optional embodiment, mounting structures can also be formed on the bearing body 10 and the rotor disk 50 at the same time, and the hydrostatic bearing component 40 can be installed by means of the mounting structures on the bearing body 10 and the rotor disk 50. As another optional embodiment, the mounting structure can also be formed only on the rotor disk 50, and it is also feasible to install the hydrostatic bearing component 40 in the mounting structure on the rotor disk 50.

[0031] Preferably, in the radial direction, the rotor disk 50 and the rotor 20 are generally in an interference fit, and rotate at a high speed along with the rotor 20 during operation.

[0032] Preferably, the hydrostatic bearing member 40 is made of a porous material. Optionally, the hydrostatic bearing member 40 is fixed to both ends of the bearing body 10 by high temperature glue.

[0033] like Figure 2As shown, an air inlet hole 12 is provided on the bearing body 10, and an air inlet channel 13 connected to the air inlet hole 12 is formed in the bearing body 10, and the air inlet channel 13 is connected to the hydrostatic bearing component 40. A high-pressure air source is provided to the hydrostatic bearing component 40 through the air inlet hole 12 and the air inlet channel 13, so that an air film is generated on the surface of the hydrostatic bearing component 40, which plays a role of hydrostatic support for the rotor disk 50. It should be noted that the hydrostatic bearing component 40 is a porous workpiece, and air is supplied to the hydrostatic bearing component 40, and an air film can be generated on the surface of the hydrostatic bearing component 40 opposite to the rotor disk 50 for support. Optionally, the air inlet channel 13 includes a main airway and a branch airway, the main airway is connected to the air inlet hole, the first end of the branch airway is connected to the main airway, and the second end of the branch airway is connected to the hydrostatic bearing component 40.

[0034] like Figure 2 As shown, the bearing body 10 is provided with an air outlet hole 14, and the bearing body 10 is provided with an air outlet channel 15 connected to the air outlet hole 14, and the air outlet channel 15 is connected to the rotating cavity 11. The air pressure in the rotating cavity 11 can be balanced through the air outlet channel 15 and the air outlet hole 14 to prevent the air pressure from continuously increasing. In order to prevent the gas from being drawn out too quickly and affecting the stability of the bearing air film, the diameter of the air outlet hole 14 should be less than one-fourth of the diameter of the air inlet hole 12.

[0035] like Figure 2 and Figure 3 As shown, in the technical solution of this embodiment, an annular groove 41 is formed on the static pressure bearing member 40, and an annular protrusion 51 matched with the annular groove 41 is formed on the rotor disk 50. The matching mode of the annular groove 41 and the annular protrusion 51 can make the static pressure bearing member 40 and the rotor disk 50 match more closely, and at the same time, the effect of blocking the end leakage of the gas film of the dynamic pressure bearing member 30 is better. When in use, in the radial direction, during the start and stop and low-speed stages of the rotor 20, the static pressure gas radial bearing is used to achieve support to prevent the dynamic pressure bearing member 30 from dry friction; and in the high-speed stage, the dynamic pressure gas radial bearing of the dynamic pressure bearing member 30 is used to achieve support to provide greater rigidity and damping. In addition, in the axial direction, the static pressure bearing member 40 is used to bear the axial force on the one hand, and to form an end face seal for the dynamic pressure bearing member 30 on the other hand, thereby reducing the end leakage and further improving the bearing capacity of the dynamic pressure gas radial bearing.

[0036] More preferably, there are multiple annular grooves 41, which are spaced and concentrically arranged, and there are multiple annular protrusions 51, each of which is arranged corresponding to the annular groove 41. In this way, the coordination effect between the static pressure bearing component 40 and the rotor disk 50 can be further improved, and the effect of blocking the air film end leakage of the dynamic pressure bearing component 30 can also be further improved.

[0037] like Figure 2As shown, in the technical solution of this embodiment, multiple annular grooves 41 cooperate with multiple annular protrusions 51 to form an annular corrugated air barrier. The annular corrugated air barrier is continuously bent, making it difficult for the air film of the dynamic pressure bearing member 30 to leak, and the barrier effect is better.

[0038] As another optional implementation, a plurality of annular grooves 41 and a plurality of annular protrusions 51 may also cooperate to form a comb-teeth sealed airway barrier.

[0039] like Figure 3 As shown, in the technical solution of the present embodiment, a wedge-shaped groove 411 is provided on the side wall of the annular groove 41. The wedge-shaped groove 411 can generate a dynamic pressure effect when the rotor disk 50 rotates relative to the hydrostatic bearing component 40. When the rotor disk 50 is performing high-speed rotation, gas with a certain viscosity is continuously brought into the wedge-shaped groove 411, and the continuous entry of gas causes the gas film to generate a certain gas film pressure, so the above-mentioned gas film pressure can form a supporting force for the rotor disk 50, thereby improving the radial bearing capacity of the hydrostatic bearing. Even in the high-speed stage, when the hydrostatic bearing component 30 fails, the radial support of the hydrostatic bearing component 40 can also provide secondary protection for the rotor 20. More preferably, wedge-shaped grooves 411 are provided on both side walls of the annular groove 41. In this way, the dynamic pressure effect is better, further enhancing the radial bearing capacity of the rotor disk 50. Preferably, in the technical solution of the present embodiment, Figure 3 As shown, there are a plurality of wedge-shaped grooves 411 , and the plurality of wedge-shaped grooves 411 are sequentially spaced apart along the radial direction of the annular groove 41 .

[0040] like Figure 4 As shown, in the technical solution of this embodiment, the hydrodynamic bearing member 30 includes a bump foil 31, a first top foil 32, and a second top foil 33. The bump foil 31 is arranged on the inner wall of the rotating cavity 11, the first top foil 32 is installed on the bump foil 31, and the second top foil 33 is installed on the first top foil 32. In the high-speed stage, the rotor 20 is radially supported by the hydrodynamic air film, and the cooperation of the bump foil 31, the first top foil 32, and the second top foil 33 provides better rigidity and damping, thereby ensuring the stability of the rotor 20.

[0041] As another optional implementation, the bump foil 31 and the top foil may also be multiple layers, and the bump foil 31 or the top foil may be stacked along the radial direction of the bearing body.

[0042] Optional, such as Figure 4 As shown, in the technical solution of this embodiment, the bump foil 31, the first top foil 32 and the second top foil 33 are fixed to the inner wall of the rotating cavity 11 by pins 34. As other optional implementations, the bump foil 31, the first top foil 32 and the second top foil 33 can also be connected to the inner wall of the rotating cavity 11 by welding.

[0043] It should be noted that, in the technical solution of the present invention, the rotor disks 50 and the static pressure bearings 40 fixedly mounted on both ends of the rotor 20 are symmetrically designed. The rotor 20 mentioned above performs high-speed rotation under the action of the electromagnetic field.

[0044] The hydrodynamic bearing of the present invention uses the hydrostatic bearing member 40 to achieve support during the process of starting, stopping and low speed of the rotor 20 to prevent dry friction of the hydrodynamic bearing member 30; and uses the hydrodynamic bearing member 30 to achieve support in the radial direction at the high speed stage to provide greater rigidity and damping, thereby improving the stability of the rotor 20. In addition, by using the wedge-shaped groove 411 opened on the side wall of the annular groove 41, the radial bearing capacity of the hydrostatic bearing member 40 is improved, and even at the high speed stage, it can play a secondary protection role for the rotor 20 when the hydrodynamic radial bearing fails.

[0045] The present invention further provides an air conditioning unit, which includes the above-mentioned hydrodynamic bearing. The air conditioning unit using the above-mentioned hydrodynamic bearing runs more stably.

[0046] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the embodiments of the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A hydrodynamic bearing, comprising: A bearing body (10), wherein a rotating cavity (11) is formed in the middle of the bearing body (10); A rotor (20) installed in the rotating cavity (11); A dynamic pressure bearing member (30) is installed in the rotating cavity (11) and is located between the rotor (20) and the bearing body (10); Characterized in that the hydrodynamic bearing further comprises: A rotor disk (50) is fixedly mounted at both ends of the rotor (20) to rotate with the rotor (20) and is axially opposite to two end surfaces of the bearing body (10); A static pressure bearing component (40) is respectively mounted on two end surfaces of the bearing body (10) and is located between the rotor disk (50) and the bearing body (10). In the radial direction, the static pressure bearing component (40) is located outside the dynamic pressure bearing component (30); An annular groove (41) is formed on the static pressure bearing member (40), and an annular protrusion (51) matched with the annular groove (41) is formed on the rotor disk (50).

2. The hydrodynamic bearing according to claim 1, characterized in that: An air inlet hole (12) is provided on the bearing body (10), an air inlet passage (13) connected to the air inlet hole (12) is formed in the bearing body (10), and the air inlet passage (13) is connected to the static pressure bearing component (40).

3. The dynamic pressure bearing according to claim 2, characterized in that: The air inlet passage (13) comprises a main airway and a branch airway, the main airway is connected to the air inlet hole (12), the first end of the branch airway is connected to the main airway, and the second end of the branch airway is connected to the static pressure bearing member (40).

4. The dynamic pressure bearing according to claim 2, characterized in that: An air outlet hole (14) is provided on the bearing body (10), an air outlet channel (15) connected to the air outlet hole (14) is formed in the bearing body (10), and the air outlet channel (15) is connected to the rotating cavity (11).

5. The hydrodynamic bearing according to claim 1, characterized in that: There are a plurality of annular grooves (41), which are spaced apart and concentrically arranged. There are also a plurality of annular protrusions (51), and each annular protrusion (51) is arranged corresponding to the annular groove (41).

6. The hydrodynamic bearing according to claim 5, characterized in that: The plurality of annular grooves (41) cooperate with the plurality of annular protrusions (51) to form an annular corrugated air barrier passage or a comb-teeth sealed air barrier passage.

7. The dynamic pressure bearing according to claim 4, characterized in that: A wedge-shaped groove (411) is provided on the side wall of the annular groove (41).

8. The hydrodynamic bearing according to claim 7, characterized in that: The wedge-shaped grooves (411) are formed on both side walls of the annular groove (41).

9. The dynamic pressure bearing according to claim 7, characterized in that: There are a plurality of wedge-shaped grooves (411), and the plurality of wedge-shaped grooves (411) are sequentially spaced apart along the radial direction of the annular groove (41).

10. The hydrodynamic bearing according to claim 1, characterized in that: The dynamic pressure bearing member (30) comprises: At least one layer of corrugated foil (31) is arranged on the inner wall of the rotating cavity (11); At least one top foil is installed on the bump foil (31).

11. The dynamic pressure bearing according to claim 10, characterized in that: There are at least two top foils, and at least two top foils are stacked along the radial direction of the bearing body (10).

12. The hydrodynamic bearing according to claim 11, characterized in that: The corrugated foil (31) and / or the top foil are fixed to the inner wall of the rotating cavity (11) via pins (34).

13. An air conditioning unit, comprising a hydrodynamic bearing, characterized in that: The hydrodynamic bearing is the hydrodynamic bearing according to any one of claims 1 to 12.

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