CN115929679A - Static pressure bearing assembly, compressor and refrigerant circulating system - Google Patents

Abstract

The invention discloses a static pressure bearing assembly, a compressor and a refrigerant circulating system, wherein the static pressure bearing assembly comprises: the bearing comprises a bearing body, a bearing sleeve and a bearing seat, wherein the bearing body is provided with an outer ring surface and an inner ring surface, and a plurality of throttling holes are formed in the bearing body; the outer ring surface is provided with a fluid inlet for introducing external fluid, the fluid inlet is communicated with the inlet of the throttling hole, and the outlet of the throttling hole is arranged on the inner ring surface; a gas line through which gas circulates, the gas line being in communication with the fluid inlet; a liquid line through which liquid flows, the liquid line being in communication with the fluid inlet; and the valve assembly is used for controlling the opening and closing of the gas pipeline and the opening and closing of the liquid pipeline. The static pressure bearing assembly, the compressor and the refrigerant circulating system are simple in structure and low in cost.

Description

Static pressure bearing assembly, compressor and refrigerant circulating system

Technical Field

The invention relates to the technical field of bearings, in particular to a static pressure bearing assembly, a compressor and a refrigerant circulating system.

Background

Traditional centrifugal compressor adopts slide bearing more, need adopt lubricating oil to lubricate the bearing, and lubricating oil can enter into the system, leads to the centrifuge efficiency to reduce. Meanwhile, the lubricating oil needs to be replaced regularly, so that more cost is generated, and the existing environment is easily damaged when the lubricating oil is replaced, so that oil stains are generated. In addition, when the rotation speed is further increased, the friction loss and the temperature rise of the lubricating oil are rapidly increased, and the performance and the reliability of the unit are affected. Therefore, the use of oilless bearings is becoming more and more important. The oilless bearing comprises the following parts:

the magnetic suspension bearing realizes rotor suspension through electromagnetic force without lubricating oil, but the magnetic suspension requires an electromagnetic bearing, a high-precision sensor and a bearing controller, and has complex control, large volume and high cost. In addition, the magnetic suspension bearing has poor reliability under the strong disturbance working condition due to small damping.

The dynamic pressure air-float bearing realizes the suspension of a rotor by utilizing a pressure air film formed by the rotation of the air film, realizes the operation without oil and friction, but has small bearing capacity, friction in the start-stop stage and short service life.

The static pressure gas suspension bearing utilizes external high-pressure gas to form a high-pressure gas film on the working surface through the throttler to support the rotor to suspend, and can realize oil-free and friction-free operation. The bearing has small volume, large bearing capacity, no start-stop friction, long service life and wide application prospect in the centrifugal compressor.

The centrifugal compressor adopts the hydrostatic bearing (static pressure gas suspension bearing), can realize that the unit does not have oil, no friction operation, and the hydrostatic bearing during operation needs high-pressure gas, but before the centrifugal unit was started, the system did not have high-pressure gas, consequently needs a set of solitary air feeder, guarantees the hydrostatic bearing air feed. Due to the low gas density, the gas supply device is also very bulky, which results in high costs. When the parts of the gas supply system are damaged, the pressure of the gas supply system is quickly released, the gas bearing is easily damaged due to abnormal gas supply, and the cost caused by maintenance is higher.

In summary, the air supply device of the hydrostatic bearing in the prior art has a very large volume and a complex structure, which results in high cost.

Disclosure of Invention

The embodiment of the invention provides a hydrostatic bearing assembly, a compressor and a refrigerant circulating system, and aims to solve the problems that a gas supply device of a hydrostatic bearing in the prior art is very large in size, complex in structure and high in cost.

To achieve the above object, the present invention provides a hydrostatic bearing assembly comprising: the bearing comprises a bearing body, a bearing sleeve and a bearing seat, wherein the bearing body is provided with an outer ring surface and an inner ring surface, and a plurality of throttling holes are formed in the bearing body; the outer ring surface is provided with a fluid inlet for introducing external fluid, the fluid inlet is communicated with the inlet of the throttling hole, and the outlet of the throttling hole is arranged on the inner ring surface; a gas line through which gas circulates, the gas line being in communication with the fluid inlet; a liquid line through which liquid flows, the liquid line being in communication with the fluid inlet; and the valve assembly is used for controlling the opening and closing of the gas pipeline and the opening and closing of the liquid pipeline.

Further, the valve assembly comprises: the first valve is arranged on the gas pipeline to control the opening and closing of the gas pipeline; and a second valve provided on the liquid line to control opening and closing of the liquid line.

Further, the valve assembly comprises a three-way valve, a first port of the three-way valve is communicated with the gas pipeline, a second port of the three-way valve is communicated with the liquid pipeline, and a third port of the three-way valve is communicated with the fluid inlet; the three-way valve has a first state communicating the first port with the third port, and the three-way valve has a second state communicating the second port with the third port.

Further, still include: and the liquid pump is arranged on the liquid pipeline and used for pressurizing the liquid and pumping the liquid to the fluid inlet.

Further, the viscosity of the gas in the gas line is less than 0.01Pa · s; the viscosity of the liquid in the liquid pipeline is less than 0.01Pa s.

Further, the hole depth to hole diameter ratio of the orifice is less than or equal to 20.

According to another aspect of the invention, there is provided a compressor comprising the hydrostatic bearing assembly described above.

Further, the compressor is a centrifugal compressor.

Further, the compressor includes a shaft that mates with the hydrostatic bearing assembly, with a working clearance between the shaft and the inner annular surface that is less than 0.02mm.

Further, a fluid channel is arranged on the compressor, and a first end of the fluid channel is communicated with the fluid inlet; the gas pipeline and the liquid pipeline are connected in parallel and then communicated with the second end of the fluid channel.

According to another aspect of the present invention, a refrigerant circulation system is provided, which includes a compressor, and the compressor is the above-mentioned compressor.

Further, the device also comprises a condenser; a first end of the gas pipeline is communicated with the condenser, and a second end of the gas pipeline is communicated with the fluid inlet; a first end of the liquid line is communicated with the condenser, and a second end of the liquid line is communicated with the fluid inlet; the gas of the condenser enters the gas pipeline, and the liquid of the condenser enters the liquid pipeline.

The static pressure bearing assembly can be filled with general gas or liquid to achieve the bearing supporting effect. When the machine is just started, the gas pipeline is closed, the liquid pipeline is opened, fluid is provided for the bearing body through the liquid pipeline by the liquid supply device, the size of the liquid supply device is very small, the structure is relatively simple, and the cost is reduced to the maximum extent. After the starting operation, one end time later, open the gas pipeline and close the liquid pipeline simultaneously, provide fluid for the bearing body through gas pipeline through gas supply arrangement, because the gas tightness is low, so gas supply arrangement can last the pressurization in long-time, need not to reach the predetermined pressure in the short time, consequently need not bulky gas supply arrangement, and the structure is simpler, the maximize reduce cost. The hydrostatic bearing assembly can switch between liquid and gas, and has the advantages of simple structure, convenient maintenance and low maintenance cost. Therefore, compared with the hydrostatic bearing in the prior art, the hydrostatic bearing assembly is smaller in size, simple in structure and lower in cost.

Drawings

FIG. 1 is a perspective view of a bearing body of a hydrostatic bearing assembly in accordance with an embodiment of the present invention;

FIG. 2 is a cross-sectional schematic view of a bearing body of a hydrostatic bearing assembly in accordance with an embodiment of the present invention;

FIG. 3 is a schematic illustration of a portion of a bearing body of a hydrostatic bearing assembly in accordance with an embodiment of the present invention;

fig. 4 is a system diagram of a refrigerant circulation system according to an embodiment of the present invention.

Detailed Description

The invention is described in further detail below with reference to the figures and the examples, but without limiting the invention.

Referring to fig. 1 to 4, according to an embodiment of the present invention, there is provided a hydrostatic bearing assembly including a bearing body 10, the bearing body 10 having an outer annular surface 11 and an inner annular surface 12, the bearing body 10 being provided with a plurality of orifices 20; the outer annular surface 11 is provided with a fluid inlet 31 for introducing an external fluid, the fluid inlet 31 communicating with an inlet of the orifice 20, and an outlet of the orifice 20 being provided on the inner annular surface 12. The hydrostatic bearing assembly further comprises a gas line 51, a liquid line 52, and a valve assembly, the gas line 51 being in fluid communication with the fluid inlet 31; a liquid line 52 is in fluid communication with the fluid inlet 31, and the liquid line 52 is in fluid communication with the fluid inlet; the valve assembly is used for controlling the opening and closing of the gas line 51 and the opening and closing of the liquid line 52.

The outer annular surface is typically secured to the housing of the bearing block or machine and serves to support the bearing body. The inner annular surface typically fits over the shaft (typically a journal) with a working gap between the inner annular surface and the shaft for bearing support. The static pressure bearing assembly is provided with an orifice and a fluid inlet on a bearing body, external high-pressure fluid flows in from the fluid inlet on the bearing body and flows out from the orifice, and a high-pressure fluid film is formed on the surface of an orifice outlet, namely the high-pressure fluid film is formed on the surface of an inner annular surface, so that the supporting capacity is formed, and the function of the bearing is achieved.

The static pressure bearing assembly can be filled with general gas or liquid to achieve the bearing supporting effect. When the machine is just started, the gas pipeline is closed, the liquid pipeline is opened, fluid is provided for the bearing body through the liquid pipeline by the liquid supply device, the size of the liquid supply device is very small, the structure is relatively simple, and the cost is reduced to the maximum extent. After the starting operation, one end time later, open the gas pipeline and close the liquid pipeline simultaneously, provide fluid for the bearing body through gas pipeline through gas supply arrangement, because the gas tightness is low, so gas supply arrangement can last the pressurization in long-time, need not to reach the predetermined pressure in the short time, consequently need not bulky gas supply arrangement, and the structure is simpler, the maximize reduce cost. The static pressure bearing assembly can switch between liquid and gas, and has the advantages of simple structure, convenient maintenance and low maintenance cost. Therefore, compared with the hydrostatic bearing in the prior art, the hydrostatic bearing assembly is smaller in size, simple in structure and lower in cost.

The gas pipeline and the liquid pipeline can respectively correspond to a gas supply device and a liquid supply device, and through the matching of the gas pipeline, the liquid pipeline and the hydrostatic bearing, the hydrostatic bearing can work as an independent hydrostatic bearing, can also work as an independent aerostatic bearing, and can also switch between liquid and gas. The two fluid media can be selected according to the situation, and the requirements on the air supply device and the liquid supply device are lower, the volume is smaller, and the cost can be reduced.

In the present embodiment, the valve assembly includes a first valve 61 and a second valve 62, the first valve 61 is disposed on the gas line 51 to control the opening and closing of the gas line 51; a second valve 62 is provided on the liquid line 52 to control the opening and closing of the liquid line 52. In an embodiment not shown in the figures, the valve assembly comprises a three-way valve, a first port of which communicates with the gas line 51, a second port of which communicates with the liquid line 52, and a third port of which communicates with the fluid inlet 31; the three-way valve has a first state communicating the first port with the third port, and the three-way valve has a second state communicating the second port with the third port. The three-way valve can control the opening and closing of the gas pipeline and the liquid pipeline.

Preferably, the hydrostatic bearing assembly further comprises a liquid pump 70, the liquid pump 70 being disposed on the liquid line 52, the liquid pump 70 being adapted to pump the pressurized liquid to the fluid inlet 31. The liquid pump 70 can make up for the problem of insufficient liquid pressure in the liquid supply device and ensure the fluid pressure of the hydrostatic bearing.

To further optimize the stability and reliability of the hydrostatic bearing assembly, in this embodiment, the viscosity of the gas in the gas line 51 is less than 0.01Pa · s; the viscosity of the liquid in the liquid line 52 is less than 0.01Pa · s. When the fluid viscosity is too high, the blockage is easy to cause, and the bearing cannot work normally, so that the static pressure bearing can stably run by adopting the fluid with low viscosity.

Referring to fig. 3, the hole depth h to the hole diameter d of the orifice 20 has a value less than or equal to 20. If the above ratio is larger than 20, the cost of the orifice machining increases and the quality decreases. Therefore, the improvement can reduce the processing cost and ensure that the bearing quality is more stable.

Preferably, the aperture d of the orifice 20 is between 0.05mm and 0.2 mm. The high-pressure fluid membrane supporting capacity is closely related to the size of the throttling hole, and the aperture d of the throttling hole is 0.05 mm-0.2 mm in size. When the aperture of the throttling hole is smaller than 0.05mm, the bearing capacity of the fluid after passing through the throttling hole is greatly reduced, and meanwhile, the processing difficulty of the hole is increased. When the pore diameter is greater than 0.2mm, the stability of the fluid film may be deteriorated, reducing the reliability of the bearing.

The number of the fluid inlets 31 is plural, and the fluid inlets 31 are provided in one-to-one correspondence with the orifices 20. The bearing body 10 is provided with a plurality of overflow holes 32, the overflow holes 32 are provided in one-to-one correspondence with the orifices 20, and the inlet of the orifice 20 communicates with the fluid inlet 31 through the overflow holes 32. The arrangement mode of the throttling holes 20 is uniformly distributed according to the annular surface of the bearing body, and the distribution mode can be selected according to the bearing capacity.

In this embodiment, the orifice 20, the fluid inlet 31 and the flowbore 32 are coaxial. The structure enables the bearing body to be lower in processing difficulty and lower in production cost.

According to an embodiment of the present invention, there is provided a compressor including the hydrostatic bearing assembly of the above-described embodiment.

The compressor of the present embodiment is a centrifugal compressor. The refrigeration centrifugal compressor adopts a hydrostatic bearing, and can realize oil-free and friction-free operation of the unit. The air supply system or the liquid supply system of the compressor has smaller volume, lower cost and more stable operation.

Referring to figure 3, the compressor comprises a shaft fitted with a hydrostatic bearing assembly, the shaft having a working clearance S between it and the inner annular surface 12 of the hydrostatic bearing assembly, the working clearance S being less than 0.02mm. The working clearance S is less than 0.02mm to ensure the rigidity of the bearing, and the rigidity of the bearing is rapidly reduced due to an overlarge clearance, so that the support performance of the bearing is influenced.

The compressor is provided with a fluid channel 41, and a first end of the fluid channel 41 is communicated with the fluid inlet 31 of the hydrostatic bearing; the gas line 51 and the liquid line 52 are connected in parallel and communicate with the second end of the fluid passage 41. The fluid passage 41 is a structure provided to fit the hydrostatic bearing assembly.

Referring to fig. 4, according to an embodiment of the present invention, a refrigerant circulation system is provided, which includes a compressor 40, the compressor 40 includes the compressor of the above embodiment, and the bearing body 10 of the hydrostatic bearing is mounted on a support structure inside the compressor.

The gas pipeline and the liquid pipeline can respectively correspond to a gas supply device and a liquid supply device, and through the matching of the gas pipeline, the liquid pipeline and the hydrostatic bearing, the hydrostatic bearing can work as an independent hydrostatic bearing, can also work as an independent aerostatic bearing, and can also switch between liquid and gas. The two fluid media can be used alternatively, so that the requirements on the gas supply device and the liquid supply device are low, the volume of the liquid supply device is smaller, the structures of the gas supply device and the liquid supply device are simple, the maintenance cost is low, and the cost can be reduced.

Preferably, the coolant circulation system further includes a liquid pump 70, the liquid pump 70 is disposed on the liquid line 52, and the liquid pump 70 is used for pressurizing and pumping the liquid to the fluid inlet 31. The liquid pump 70 can make up for the problem of insufficient liquid pressure in the liquid supply device and ensure the fluid pressure of the hydrostatic bearing.

In the refrigerant circulating system, a compressor 40 is provided with a fluid channel 41, and a first end of the fluid channel 41 is communicated with a fluid inlet 31 of the hydrostatic bearing; the gas line 51 and the liquid line 52 are connected in parallel and communicate with the second end of the fluid passage 41. Fluid passage 41 is a structure provided to fit the hydrostatic bearing assembly.

To further optimize the stability and reliability of the hydrostatic bearing assembly, in this embodiment, the viscosity of the gas in the gas line 51 is less than 0.01Pa · s; the viscosity of the liquid in the liquid line 52 is less than 0.01Pa · s. When the fluid viscosity is too high, the blockage is easy to cause, and the bearing cannot work normally, so that the static pressure bearing can stably run by adopting the fluid with low viscosity.

The present embodiment is to reduce the volume of the air supply device or the liquid supply device to the maximum and to utilize the various structures of the refrigerant circulation system to the maximum. In the present embodiment, the refrigerant circulation system further includes a condenser 80; a first end of the gas line 51 communicates with the condenser 80, and a second end of the gas line 51 communicates with the fluid inlet 31 of the hydrostatic bearing; a first end of liquid line 52 is in communication with condenser 80, and a second end of liquid line 52 is in communication with fluid inlet 31 of the hydrostatic bearing; the gas from condenser 80 enters gas line 51 and the liquid from condenser 80 enters liquid line 52. The first end of gas line 51 is connected at a location (condenser upper) such that the gas line receives condenser gas portion 80a and the first end of liquid line 52 is connected at a location (condenser bottom) such that the liquid line receives condenser liquid portion 80b.

Before the refrigerant circulating system is started, the pressure of each position of the system is the same, and at the moment, gas cannot flow freely. Opening the liquid line 52 via the second valve 62, while closing the gas line 51; after the liquid pump pressurizes the liquid at the bottom of the condenser, the liquid is provided to a hydrostatic bearing inside the compressor to support the rotor to operate. After the compressor is operated, the system pressure is raised, the condenser pressure is higher than the pressure inside the compressor and the evaporator, when the pressure difference between the condenser pressure and the pressure inside the compressor reaches the working condition of the hydrostatic bearing, the gas pipeline 51 is opened through the first valve 61, the liquid pipeline 52 is closed, and the high-pressure liquid of the condenser enters the hydrostatic bearing inside the compressor to support the rotor in the compressor to operate.

The centrifugal compressor of the refrigerant circulating system adopts a hydrostatic bearing, and oil-free and friction-free operation of the unit can be realized. Before the refrigerant circulating system is started, the pressure of all parts of the system is the same, and high-pressure fluid required by a bearing does not exist, so that a fluid pressurizing device needs to be added, at the moment, liquid is adopted as a working medium, the volume and the cost of the pressurizing device can be reduced, when the refrigerant circulating system normally works, the system has high-pressure liquid and high-pressure gas, at the moment, the high-pressure fluid of the refrigerant circulating system can be adopted to work, the fluid pressurizing device is closed, and the system efficiency and the service life of the fluid pressurizing device are improved.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular is intended to include the plural unless the context clearly dictates otherwise, and it should be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of features, steps, operations, devices, components, and/or combinations thereof.

It should be noted that the terms "first," "second," and the like in the description and claims of this application and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the application described herein are capable of operation in other sequences than those illustrated or described herein.

Of course, the above is a preferred embodiment of the present invention. It should be noted that, for a person skilled in the art, several modifications and refinements can be made without departing from the basic principle of the invention, and these modifications and refinements are also considered to be within the protective scope of the invention.

Claims (12)

1. A hydrostatic bearing assembly, comprising:

the bearing comprises a bearing body (10), wherein the bearing body (10) is provided with an outer annular surface (11) and an inner annular surface (12), and a plurality of throttling holes (20) are formed in the bearing body (10); a fluid inlet (31) for introducing external fluid is arranged on the outer annular surface (11), the fluid inlet (31) is communicated with an inlet of the throttling hole (20), and an outlet of the throttling hole (20) is arranged on the inner annular surface (12);

a gas line (51) through which gas flows in the gas line (51), the gas line (51) being in communication with the fluid inlet (31);

a liquid line (52), the liquid line (52) circulating a liquid therein, the liquid line (52) communicating with the fluid inlet (31);

a valve assembly for controlling the opening and closing of the gas line (51) and the opening and closing of the liquid line (52).

2. The hydrostatic bearing assembly of claim 1, wherein the valve assembly comprises:

a first valve (61) provided on the gas line (51) to control opening and closing of the gas line (51);

and a second valve (62) provided in the liquid line (52) to control opening and closing of the liquid line (52).

3. The hydrostatic bearing assembly of claim 1, wherein the valve assembly comprises a three-way valve, a first port of the three-way valve being in communication with the gas line (51), a second port of the three-way valve being in communication with the liquid line (52), and a third port of the three-way valve being in communication with the fluid inlet (31);

the three-way valve has a first state communicating the first port with the third port, and the three-way valve has a second state communicating the second port with the third port.

4. The hydrostatic bearing assembly of claim 1, further comprising:

a liquid pump (70), the liquid pump (70) is arranged on the liquid pipeline (52), and the liquid pump (70) is used for pressurizing and pumping the liquid to the fluid inlet (31).

5. The hydrostatic bearing assembly of claim 1,

the viscosity of the gas in the gas pipeline (51) is less than 0.01Pa · s;

the viscosity of the liquid in the liquid pipeline (52) is less than 0.01Pa · s.

6. The hydrostatic bearing assembly of claim 1,

the ratio of the hole depth (h) to the hole diameter (d) of the throttle hole (20) is less than or equal to 20.

7. A compressor comprising the hydrostatic bearing assembly of any of claims 1-6.

8. The compressor of claim 7, wherein the compressor is a centrifugal compressor.

9. A compressor according to claim 7, characterized in that it comprises a shaft cooperating with the hydrostatic bearing assembly, said shaft having a working clearance (S) with the inner annular surface (12), said working clearance (S) being less than 0.02mm.

10. A compressor according to claim 7, characterized in that a fluid channel (41) is provided on the compressor, a first end of the fluid channel (41) communicating with the fluid inlet (31);

the gas pipeline (51) and the liquid pipeline (52) are connected in parallel and then are communicated with the second end of the fluid channel (41).

11. A refrigerant circulation system comprising a compressor (40), wherein the compressor (40) is a compressor according to any one of claims 7 to 10.

12. The refrigerant circulation system as claimed in claim 11, further comprising a condenser (80);

a first end of the gas line (51) is in communication with the condenser (80), and a second end of the gas line (51) is in communication with the fluid inlet (31);

a first end of the liquid line (52) is in communication with the condenser (80), and a second end of the liquid line (52) is in communication with the fluid inlet (31);

the gas of the condenser (80) enters the gas line (51), and the liquid of the condenser (80) enters the liquid line (52).

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