CN114688165A

CN114688165A - Thrust bearing and air conditioning unit

Info

Publication number: CN114688165A
Application number: CN202011568765.7A
Authority: CN
Inventors: 雷连冬; 钟瑞兴; 陈玉辉
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2020-12-25
Filing date: 2020-12-25
Publication date: 2022-07-01

Abstract

The invention provides a thrust bearing and an air conditioning unit. The thrust bearing includes a bearing disk, a rotor disk, a hydrostatic bearing member and a hydrodynamic bearing member. The rotor disc can rotate relative to the bearing disc, the static pressure bearing piece is arranged on the bearing disc and is positioned between the bearing disc and the rotor disc, the static pressure bearing piece is provided with a static pressure air hole, and the static pressure bearing piece supplies air to the rotor disc through the static pressure air hole to support static pressure. A dynamic pressure bearing member is mounted between the bearing disk and the rotor disk, the dynamic pressure bearing member being for providing dynamic pressure support to the rotor disk. By applying the technical scheme of the invention, when the rotating speed of the rotor disc is low, the static pressure air hole on the static pressure bearing piece is used for supplying air to provide static pressure support for the rotor disc; the rotor disk is provided with a dynamic pressure support by means of a dynamic pressure bearing member at high rotor disk speeds. Therefore, the thrust bearing of the invention can run at high speed and low speed, and the using effect of the thrust bearing is improved.

Description

Thrust bearing and air conditioning unit

Technical Field

The invention relates to the technical field of mechanical parts, in particular to a thrust bearing and an air conditioning unit.

Background

The gas lubrication bearing uses gas as a lubricant, and utilizes the characteristics of gas such as adsorptivity, transmission property, diffusivity, viscosity, heat conductivity, compressibility and the like, and during friction, a gas film is formed under the action of a fluid dynamic pressure effect and a static pressure effect to support load and reduce friction. The gas lubrication technology was first proposed in the middle of the nineteenth century and developed rapidly in the middle of the 20 th century, and its appearance breaks the dominance of the liquid lubrication technology, so that the lubrication technology makes a qualitative leap. The gas bearing is a novel bearing produced based on the high and new lubrication technology, has a series of advantages of small friction loss, good stability, small vibration, oil-free lubrication and the like, and has very wide application prospects in the fields of high-speed turbines, machine tool manufacturing, space technology and the like.

The dynamic pressure gas bearing, the static pressure gas bearing and the extrusion type gas bearing are classified according to the generation mechanism of the lubricating gas film. Among them, the foil type dynamic pressure gas bearing is the most studied in the literature at present, and the small hole throttling hydrostatic bearing and the porous hydrostatic bearing are the most studied hydrostatic gas bearings. The typical wave foil type dynamic pressure gas thrust bearing mainly comprises a bearing disc, a wave foil and a top layer foil, wherein the wave foil and the top layer foil are uniformly distributed in the circumferential direction as fan-shaped thrust pads. The corrugated foil has a special wave-shaped structure, which acts as a spring-like elastic support and is the main source of stiffness and damping of the thrust bearing. The top foil is mounted on top of the bump foil, both constituting the flexible support surface of the foil thrust bearing. The bump foil piece is the same as the top layer foil piece, one end of the bump foil piece is fixed on the bearing seat, and the other end of the bump foil piece can freely slide under the bearing force. A certain included angle is formed between the front end of the top foil and the bearing shell, the rear end of the top foil is parallel to the bearing shell, and an air film is formed through a dynamic pressure principle under the effect of the included angle.

As can be seen from the above description, the wave foil type dynamic pressure gas thrust bearing is actually one of dynamic pressure sliding bearings, and under the dynamic pressure effect, the bearing capacity of the bearing is higher as the rotating speed is higher, but during the starting and stopping process, due to insufficient rotating speed, the gas film cannot be formed by the dynamic pressure principle, and at this time, the top foil of the bearing generates dry friction with the rotor, which affects the service life of the bearing. Therefore, it is necessary to adopt measures to solve the problem of abrasion of the dynamic pressure bearing in the starting and stopping processes.

A static pressure gas bearing means that gas with a certain pressure is supplied through an external gas supply system, and then the gas is delivered to a gap between a bearing and a rotor through a bearing restrictor, so that a gas film is formed at the gap to support an external load. The air film pressure of the bearing gap can be adjusted by the bearing restrictor and the air supply system. According to the difference of the throttler, a static pressure gas bearing with a small hole and a static pressure gas bearing with a porous hole are common. The hydrostatic bearing has the advantages of large bearing capacity, stable work, long service life and the like, and the bearing capacity is positively correlated with the pressure of an air supply system, but when the speed of a rotor is higher, the hydrostatic bearing cannot effectively absorb and inhibit the vibration of the rotor due to the lack of a damping mechanism, such as a wave structure of a dynamic pressure bearing.

Disclosure of Invention

The embodiment of the invention provides a thrust bearing and an air conditioning unit, and aims to solve the technical problem that the thrust bearing in the prior art is poor in compatibility between high-speed operation and low-speed operation.

An embodiment of the present invention provides a thrust bearing, including: a bearing disk; a rotor disc rotatable relative to the bearing disc; the static pressure bearing piece is arranged on the bearing disc and positioned between the bearing disc and the rotor disc, a static pressure air hole is formed in the static pressure bearing piece, and the static pressure bearing piece supplies air to the rotor disc through the static pressure air hole to support the rotor disc in a static pressure mode; and the dynamic pressure bearing piece is arranged between the bearing disk and the rotor disk and is used for providing dynamic pressure support for the rotor disk.

In one embodiment, the hydrostatic bearing elements are arcuate in shape.

In one embodiment, the hydrostatic bearing elements are annularly disposed.

In one embodiment, the hydrostatic bearing elements comprise an inner ring hydrostatic bearing element and an outer ring hydrostatic bearing element, the inner and outer ring hydrostatic bearing elements being concentrically arranged, the outer ring hydrostatic bearing element having a diameter greater than the diameter of the inner ring hydrostatic bearing element.

In one embodiment, the dynamic pressure bearing member is disposed between the inner and outer ring static pressure bearing members.

In one embodiment, an air storage cavity is formed in the bearing disc, an air inlet communicated with the air storage cavity is formed in the bearing disc, and the air storage cavity is communicated with the static pressure air hole and used for supplying air to the static pressure air hole.

In one embodiment, the dynamic pressure bearing member: the bump foil is arranged on the bearing disc; a top foil mounted on the bump foil; the bearing disc is also provided with dynamic pressure air holes communicated with the air storage cavity, and the dynamic pressure air holes supply air to provide supporting force for the corrugated foil.

In one embodiment, the bump foil includes wave structures and straight structures connected between the wave structures, the dynamic pressure air holes correspond to the straight structures, and the dynamic pressure air holes provide supporting force for the straight structures.

In one embodiment, the hydrodynamic gas holes correspond to the middle of the straight edge structure.

In one embodiment, the air reservoir chambers are distributed in the form of sectors or circular rings in the bearing disk.

In one embodiment, the bearing disc comprises a disc body and a base, the air reservoir being formed between the disc body and the base, and the air inlet opening in the base.

In one embodiment, a sealing member is disposed between the tray body and the base.

The invention also provides an air conditioning unit, which comprises the thrust bearing.

In the embodiment, the static pressure air holes on the static pressure bearing pieces are used for supplying air to provide static pressure support for the rotor disc so as to avoid dry friction during the starting, stopping and low-speed stages of the rotor disc; at high rotor disk speeds, the rotor disk is provided with dynamic pressure support by the dynamic pressure bearing member to provide greater stiffness and damping. Therefore, the thrust bearing of the invention can run at high speed and low speed, and the using effect of the thrust bearing is improved.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 is a front view and a perspective cross-sectional structural schematic view of an embodiment of a thrust bearing according to the present invention;

FIG. 2 is a cross-sectional view taken at A-A of the thrust bearing of FIG. 1 and an enlarged schematic view thereof;

FIG. 3 is a schematic cross-sectional view at B-B of the thrust bearing of FIG. 1;

FIG. 4 is a schematic cross-sectional view at C-C of the thrust bearing of FIG. 3;

fig. 5 is a partial perspective view of the thrust bearing of fig. 4.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the following embodiments and accompanying drawings. The exemplary embodiments and descriptions of the present invention are provided to explain the present invention, but not to limit the present invention.

In order to solve the technical problem of poor compatibility between the thrust bearing of the prior art and the high-speed operation and the low-speed operation, the thrust bearing of the present invention includes a bearing disk 10, a rotor disk 20, a static pressure bearing member 30 and a dynamic pressure bearing member 40, as shown in fig. 1. The rotor disc 20 is rotatable relative to the bearing disc 10, the static pressure bearing member 30 is disposed on the bearing disc 10 and located between the bearing disc 10 and the rotor disc 20, the static pressure bearing member 30 is provided with a static pressure air hole 31, and the static pressure bearing member 30 provides static pressure support for the rotor disc 20 through air supply of the static pressure air hole 31. A dynamic pressure bearing member 40 is installed between the bearing disk 10 and the rotor disk 20, and the dynamic pressure bearing member 40 serves to provide dynamic pressure support to the rotor disk 20.

By applying the technical scheme of the invention, when the rotor disc 20 is started, stopped and at a low speed stage, the static pressure air holes 31 on the static pressure bearing piece 30 are used for supplying air to provide static pressure support for the rotor disc 20 so as to avoid dry friction; at higher rotor disk 20 speeds, dynamic pressure support is provided to rotor disk 20 by dynamic pressure bearing members 40 to provide greater stiffness and damping. Therefore, the thrust bearing of the invention can run at high speed and low speed, and the using effect of the thrust bearing is improved.

In addition, because the dynamic and static pressure mixed gas thrust bearing of the technical scheme of the invention adopts an integrated design, namely the dynamic pressure gas thrust bearing and the static pressure gas thrust bearing are designed into a bearing, the compact structure of the bearing is effectively improved.

As shown in fig. 3 and 4, in the solution of the present embodiment, the hydrostatic bearing member 30 is provided in an annular shape. In order to allow the static pressure bearing member 30 to support the rotor disk 20 more stably, the static pressure bearing member 30 includes an inner ring static pressure bearing member 30a and an outer ring static pressure bearing member 30b, the inner ring static pressure bearing member 30a and the outer ring static pressure bearing member 30b are concentrically arranged, and the diameter of the outer ring static pressure bearing member 30b is larger than that of the inner ring static pressure bearing member 30 a. By adopting the structure, the rotor disc 20 can be prevented from inclining, and more stable support is realized. As other alternative embodiments, the hydrostatic bearing member 30 may be designed with a greater number of rings. The supporting area of the hydrostatic bearing member 30 can be selected as appropriate according to design requirements.

As other alternative embodiments, the static pressure bearing member 30 may not be disposed in a complete ring shape, and the static pressure bearing member 30 may be disposed in an arc shape. More preferably, the static pressure bearing member 30 having an arc shape may be provided in a plurality of stages, thereby achieving stable support of the rotor disk 20.

As shown in fig. 3, in the solution of the present embodiment, the dynamic pressure bearing member 40 is provided between the inner ring static pressure bearing member 30a and the outer ring static pressure bearing member 30 b. Therefore, the space on the thrust bearing can be fully utilized, and the structure of the thrust bearing is more compact.

As shown in fig. 1 and 3, in the solution of the present embodiment, an air storage cavity c is formed in the bearing disc 10, an air inlet hole c1 communicated with the air storage cavity c is opened on the bearing disc 10, and the air storage cavity c is communicated with the static pressure air hole 31 for supplying air to the static pressure air hole 31. When the air storage cavity c is used, an air source is introduced into the air storage cavity c through the air inlet hole c1, the air storage cavity c supplies air to the static pressure air hole 31, and static pressure support of the rotor disc 20 is achieved. The reason for setting up gas storage chamber c is in order to store some high-pressure gas, avoids appearing the gas condition of cutting off the gas when the static pressure is used. The air inlet hole c1 is connected to an external air supply flow passage and an air supply system when in use, and the air supply flow passage and the air supply system are not described in detail since the patent mainly relates to a bearing structure.

In the present embodiment, the hydrostatic bearing member 30 is a porous hydrostatic bearing made of graphite, and numerous hydrostatic air holes 31 are distributed in the hydrostatic bearing member 30. As shown in fig. 4, the static pressure vents 31 are typically 20-50um in actual diameter. A ring-shaped groove is formed on the surface of the bearing disk 10, and the hydrostatic bearing member 30 is mounted on the bearing disk 10 through the ring-shaped groove, and is generally bonded and sealed to the radial surface using a high-temperature adhesive. During operation, high-pressure gas from the gas storage cavity c enters the static pressure bearing piece 30 along the axial direction through the gas port and flows to the static pressure gas hole 31, and the gas is extruded to further increase the pressure due to the small diameter of the static pressure gas hole 31, so that a gas film is formed, and the rotor is supported. As another alternative embodiment, the hydrostatic bearing member 30 may be a small bore throttling type hydrostatic bearing.

As shown in fig. 2 and 5, in the present embodiment, the dynamic pressure bearing member 40 includes a top foil 41 and a bump foil 42, the bump foil 42 is provided on the bearing disk 10, and the top foil 41 is attached to the bump foil 42. The bearing disc 10 is further provided with a dynamic pressure air hole 11 communicated with the air storage cavity c, and the dynamic pressure air hole 11 supplies air to provide supporting force for the corrugated foil 42. When mounted, the bump foil 42 is typically fixed to the bearing disc 10 by means of spot welding. When the rotor disc 20 is operated at a high speed relative to the bearing disc 10, the air flow is driven to generate an air film between the bearing disc 10 and the top foil 41, so that the dynamic pressure support is realized. A fitting gap, h in fig. 4, is formed between the bottom end of the rotor disc 20 and the top of the top foil 41. In operation, the rotor disc 20 rotates at a high speed, and when the designed rotation speed is reached, a dynamic pressure film is formed in the gap h to support the rotor disc 20 to rotate. In the process, the top foil 41 presses the corrugated foil 42 to enable the corrugated foil 42 to be easily deformed, and the dynamic pressure air holes 11 communicated with the air storage cavity c are formed in the bearing disc 10, so that the dynamic pressure air holes 11 supply air to provide supporting force for the corrugated foil 42, the rigidity of the corrugated foil 42 can be improved, and the dynamic pressure supporting rigidity of the thrust bearing is improved.

As shown in fig. 2, in the solution of the present embodiment, the bump foil 42 includes a waveform structure 421 and a straight structure 422 connected between the waveform structure 421, the dynamic pressure air holes 11 correspond to the straight structure 422, and the dynamic pressure air holes 11 provide a supporting force for the straight structure 422. During operation, the corrugated foil 42 receives a reaction force while forming the gas film support, so that the straight-edge structure 422 is tightly attached to the bearing disc 10, and at the moment, the high-pressure gas from the gas storage cavity c forms high-pressure gas through the throttling action of the dynamic pressure gas hole 11, so that the straight-edge structure 422 is supported, and the reaction force of part of the supporting force is counteracted, so that the corrugated foil 428 can provide greater rigidity.

More preferably, the dynamic pressure air hole 11 corresponds to the middle portion of the straight structure 422. It should be noted that the middle portion of the straight-edge structure 422 is the middle portion of the straight-edge structure 422 in the length direction. Most preferably, the central portion is the central location of the straight edge structure 422. Alternatively, the middle portion may be at other positions along the center line of the straight-edge structure 422.

Optionally, the dynamic pressure air hole 11 is formed by laser drilling, and the diameter of the dynamic pressure air hole 11 is 15-50 um.

It should be noted that, in the technical solution of the present invention, there are a plurality of static pressure air holes 31 and dynamic pressure air holes 11, and the distribution density can be adjusted accordingly according to actual working requirements.

As shown in fig. 2 and 5, in the present embodiment, the top foil 41 has a tile shape, and 8 pieces of top foil are uniformly distributed in the circumferential direction. In order to form the dynamic pressure effect, the top foil 41 includes an inclined plane 411 and a straight plane 412, and the included angle formed between the inclined plane 411 and the straight plane is a supplementary angle theta, and theta is generally 2-8 degrees. Wherein, the inclined plane 411 of the top foil 41 is mainly used for promoting the dynamic pressure effect, and the fit clearance between the straight plane 412 of the top foil 41 and the bottom surface of the rotor disc 20 forms a gas film to play a main supporting role for the rotor disc 20. The wave foil 42 is matched with the top foil 41 in structure, and the dynamic pressure bearing wave foils 42 are in tile shapes and are uniformly distributed in 8 in the circumferential direction. Similarly, in order to form a dynamic pressure effect, and the inclined plane 411 of the top foil 41 and the straight plane 412 of the top foil 41 are matched, as shown in fig. 2, a waveform 421a, a waveform 421b, a waveform 421c, and a waveform structure 421 serving as a main supporting function are provided at different heights, the waveform 421a, the waveform 421b, the waveform 421c are used for supporting the inclined plane 411, and the waveform structure 421 is used for supporting the straight plane 412.

Preferably, in the solution of the present embodiment, the air storage cavities c are distributed in the bearing disc 10 in a circular ring shape. As a further alternative, the air reservoirs c may also be distributed in the form of sectors in the bearing disk 10.

As shown in fig. 1, the bearing plate 10 includes a plate body 12 and a base 13, an air reservoir c is formed between the plate body 12 and the base 13, and an air intake hole c1 is opened in the base 13. In the technical scheme of the embodiment, the air storage cavity c is processed on the base 13, and the tray body 12 covers the base 13. More preferably, a sealing member 14 is provided between the tray 12 and the base 13 in order to ensure the sealing between the tray 12 and the base 13.

As an alternative embodiment, the air reservoir c may be machined into both the tray 12 and the base 13.

The invention also provides an air conditioning unit which comprises the thrust bearing. The air conditioning unit adopting the thrust bearing can ensure better stability when running at low power or high power.

From the above, the technical scheme of the invention realizes the full-speed region friction-free operation of the bearing by providing the dynamic and static pressure mixed high-rigidity gas thrust bearing, and the bearing has compact structure and higher rigidity.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and variations of the embodiment of the present invention may occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A thrust bearing, comprising:

a bearing disc (10);

a rotor disc (20) rotatable relative to the bearing disc (10);

the static pressure bearing piece (30) is arranged on the bearing disc (10) and is positioned between the bearing disc (10) and the rotor disc (20), a static pressure air hole (31) is formed in the static pressure bearing piece (30), and the static pressure bearing piece (30) supplies air to the rotor disc (20) through the static pressure air hole (31) to provide static pressure support;

a dynamic pressure bearing member (40) mounted between the bearing disk (10) and the rotor disk (20), the dynamic pressure bearing member (40) for providing dynamic pressure support to the rotor disk (20).

2. Thrust bearing according to claim 1, characterized in that the hydrostatic bearing member (30) is arc-shaped.

3. Thrust bearing according to claim 1, characterized in that the hydrostatic bearing element (30) is annular.

4. Thrust bearing according to claim 3, characterized in that said hydrostatic bearing elements (30) comprise an inner annular hydrostatic bearing element (30a) and an outer annular hydrostatic bearing element (30b), said inner annular hydrostatic bearing element (30a) and said outer annular hydrostatic bearing element (30b) being arranged concentrically, said outer annular hydrostatic bearing element (30b) having a diameter greater than the diameter of said inner annular hydrostatic bearing element (30 a).

5. Thrust bearing according to claim 4, characterized in that said hydrodynamic bearing member (40) is arranged between said inner annular hydrostatic bearing member (30a) and said outer annular hydrostatic bearing member (30 b).

6. Thrust bearing according to claim 1, characterized in that an air reservoir (c) is formed in said bearing disc (10), said bearing disc (10) being provided with an air inlet opening (c1) communicating with said air reservoir (c), said air reservoir (c) communicating with said static pressure air opening (31) for supplying air to said static pressure air opening (31).

7. Thrust bearing according to claim 6, characterized in that the hydrodynamic bearing member (40):

a bump foil (42) provided on the bearing disk (10);

a top foil (41) mounted on the bump foil (42);

the bearing disc (10) is further provided with a dynamic pressure air hole (11) communicated with the air storage cavity (c), and the dynamic pressure air hole (11) supplies air to provide supporting force for the corrugated foil (42).

8. The thrust bearing according to claim 7, characterized in that said bump foil (42) comprises wave-shaped structures (421) and straight-sided structures (422) connected between said wave-shaped structures (421), said dynamic pressure gas holes (11) corresponding to said straight-sided structures (422), said dynamic pressure gas holes (11) supplying gas to support said straight-sided structures (422).

9. Thrust bearing according to claim 8, characterized in that said dynamic pressure gas hole (11) corresponds to the middle of said straight edge structure (422).

10. Thrust bearing according to claim 6, characterized in that the air reservoir chambers (c) are distributed in the bearing disc (10) in a sector or circular ring shape.

11. Thrust bearing according to claim 6, characterized in that said bearing disc (10) comprises a disc body (12) and a base (13), said air reservoir chamber (c) being formed between said disc body (12) and said base (13), said air intake opening (c1) opening on said base (13).

12. Thrust bearing according to claim 11, characterized in that a sealing member (14) is provided between the disc (12) and the seat (13).

13. An air conditioning assembly comprising a thrust bearing, wherein the thrust bearing is as claimed in any one of claims 1 to 12.