CN111365258A

CN111365258A - Compressor and air conditioning unit

Info

Publication number: CN111365258A
Application number: CN201811595101.2A
Authority: CN
Inventors: 刘华; 张治平; 李宏波; 陈玉辉; 刘胜; 叶文腾; 亓静利
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2018-12-25
Filing date: 2018-12-25
Publication date: 2020-07-03

Abstract

The invention relates to a compressor and an air conditioning unit, wherein the compressor comprises: a housing (4); a rotor (14) rotatably disposed within the housing (4) and including a first shaft section and a second shaft section, the first shaft section having a diameter greater than the second shaft section; an electromagnetic bearing (18) for supporting the rotor (14); and a gas bearing (17) for supporting the rotor (14) and disposed radially outward of the first shaft section. The air conditioning unit includes a compressor. The invention can effectively avoid abrasion between the rotor and the bearing, protect the surface of the rotor, improve the capacity of bearing high temperature and high pressure and prevent the rotor from deforming.

Description

Compressor and air conditioning unit

Technical Field

The invention relates to the technical field of air conditioners, in particular to a compressor and an air conditioning unit.

Background

A refrigerated centrifuge is generally used in various commercial buildings, and is a compressor that performs a compression function by using a centrifugal force, and is classified into several types, in which a centrifugal compressor structure using an electromagnetic bearing as a bearing support has many advantages, such as no friction loss and lower energy consumption; the lubricating oil is not used, the refrigerant and the lubricating oil can be prevented from being mixed, and the unit efficiency is high; the noise is low, the ultra-low noise operation can be realized, and the like, and the method has great application prospect in the field of commercial central air conditioners.

Because the centrifugal compressor may have abnormal working states such as overload, power failure, electromagnetic bearing failure and the like in the working process, and under the abnormal working states, the electromagnetic bearing cannot provide normal suspension force, the high-speed rotor is likely to directly fall on some important parts in the centrifugal machine such as the electromagnetic bearing, the sensor and the like, so that the damage of the parts or the damage of the rotor is caused, the service life and the use stability of the centrifugal machine are affected, and therefore, the rotor and the shaft are supported by adopting the protective bearing at this time.

At present, in a centrifugal compressor, rolling bearings are mainly installed at cantilevers at two ends of a rotor to serve as protection bearings, and the protection bearings firstly play a supporting role under the condition that the centrifugal compressor works abnormally or the rotor floats abnormally, so that damage caused by direct contact of the rotor of the centrifugal compressor with an electromagnetic bearing of the centrifugal compressor, a sensor, an electrical element and the like is prevented.

However, since the centrifugal compressor using the electromagnetic bearing as the support bearing is an oil-free compressor, and the rolling bearing can only fully exert its capacity under the action of oil lubrication, when the centrifugal machine is not normally operated and the protection bearing is used for supporting, there is very large friction between the rotor and the protection bearing, which results in damage to the rotor surface and the strength of the rotor, and also results in backfire or gluing damage of the rolling elements of the rolling bearing, which affects the service life of the centrifugal compressor and the protection bearing.

In addition, the impact load of the rotor on the rolling bearing is large when the rotor rotates at a high speed, and the bearing capacity of the rolling bearing has a certain limit at a high temperature and a high speed; moreover, the rolling bearing is usually installed at the cantilever of the rotor, the cantilever of the rotor has small size and low strength, deformation is easy to generate, and the fit clearance between the rolling bearing and the rotor is small.

It is noted that the information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information constitutes prior art already known to a person skilled in the art.

Disclosure of Invention

The invention aims to provide a compressor and an air conditioning unit, and aims to solve the problems that in the prior art, when a rolling bearing is used as a protective bearing, the surface of a rotor is easy to rub against the rotor to damage, a rolling shaft bears high-temperature and high-pressure impact, and the rotor is easy to deform due to the fact that the rolling bearing is arranged at a rotor cantilever.

To achieve the above object, the present invention provides a compressor comprising:

a housing;

the rotor is rotatably arranged in the shell and comprises a first shaft section and a second shaft section, and the diameter of the first shaft section is larger than that of the second shaft section;

an electromagnetic bearing for supporting the rotor; and

and the gas bearing is used for supporting the rotor and is arranged on the radial outer side of the first shaft section.

Optionally, the gas bearing is arranged axially inside or outside the electromagnetic bearing.

Optionally, the compressor further comprises a barrier, the barrier being disposed between the electromagnetic bearing and the gas bearing.

Optionally, the barrier comprises a first gasket.

Optionally, the electromagnetic bearing and the gas bearing are both arranged in a radial direction of the rotor.

Optionally, the compressor further comprises an impeller assembly connected with the second shaft section.

Optionally, the compressor further comprises a motor assembly connected with the first shaft section.

Optionally, the compressor further comprises a first end cap disposed within the housing and configured to secure the electromagnetic bearing and the gas bearing.

Optionally, the compressor further comprises a fixing sleeve disposed between the impeller assembly and the first end cap, the fixing sleeve being for axially positioning the impeller assembly.

Optionally, the compressor further comprises a seal member cooperating with the fixed sleeve to effect a seal between the chamber in which the impeller assembly is located and the chamber in which the motor assembly is located.

Optionally, the first end cap is in interference fit with the housing, and the electromagnetic bearing and the gas bearing are in interference fit with the first end cap.

Optionally, the compressor further comprises a gas supply channel for supplying gas for gas suspension to the gas bearing.

Optionally, the gas supply channel is arranged on the housing and the first end cover, the housing is provided with a gas inlet, and the gas inlet is communicated with the gas supply channel.

Optionally, the compressor further comprises a suction device for sucking the suspension gas.

Optionally, the compressor further comprises a thrust bearing disposed at an end of the rotor for axially positioning the rotor.

In order to achieve the purpose, the invention further provides an air conditioning unit which comprises the compressor.

Based on the technical scheme, the gas bearing is arranged, so that the suspension force can be provided together with the electromagnetic bearing at the initial stage of rotor suspension, a better supporting effect on the rotor is realized, the gas bearing can be used as a protective bearing to continuously provide a supporting effect when the supporting effect of the electromagnetic bearing fails, no friction loss exists, and the rotor and the bearing are effectively protected; the gas bearing is arranged on the radial outer side of the first shaft section with the larger diameter, so that the second shaft section with the smaller diameter can be prevented from deforming, and the service life of the rotor is prolonged.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the invention without limiting the invention. In the drawings:

fig. 1 is a schematic view showing an internal structure of one embodiment of a compressor according to the present invention.

In the figure:

1. a housing; 2. sealing a first-stage impeller; 3. a first-stage impeller diffuser; 4. a housing; 5. a first stage diffuser; 6. a reflux device; 7. a secondary diffuser; 8. a first end cap; 9. a motor assembly; 10. a thrust bearing; 11. a bearing support; 12. a third end cap; 13. a first gasket; 14. a rotor; 15. an air supply flow channel; 16. a gas inlet; 17. a gas bearing; 18. an electromagnetic bearing; 19. a seal member; 20. fixing a sleeve; 21. a second gasket; 22. sealing the secondary impeller; 23. interstage sealing; 24. a third gasket; 25. locking the nut; 26. an impeller assembly; 27. a sleeve.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments. It is to be understood that the described embodiments are merely a few embodiments of the invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it is to be understood that the terms "central," "lateral," "longitudinal," "front," "rear," "left," "right," "upper," "lower," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in the orientation or positional relationship indicated in the drawings for convenience in describing the invention and for simplicity in description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the scope of the invention.

As shown in fig. 1, in one embodiment of the compressor provided by the present invention, the compressor comprises a housing 4, a rotor 14, an electromagnetic bearing 18 and a gas bearing 17, wherein the rotor 14 is rotatably disposed in the housing 4, the rotor 14 comprises a first shaft section and a second shaft section, the diameter of the first shaft section is larger than that of the second shaft section, the electromagnetic bearing 18 and the gas bearing 17 are used for supporting the rotor 14, and the gas bearing 17 is disposed radially outside the first shaft section.

In this embodiment, when the coil is energized, electromagnetic levitation force is generated to support the rotor 14, and the rotor 14 is not in contact with the electromagnetic bearing 18, so that friction loss is not generated, energy consumption is low, and noise is low; the gas bearing 17 supports the rotor 14 by forming a supporting force by the supplied gas, and the gas bearing 17 can protect the bearing and support the rotor 14 during the operation of the compressor, such as the occurrence of abnormal operation conditions, such as power failure, overload, or failure of the electromagnetic bearing 18. Compared with a rolling bearing, the gas bearing 17 is adopted as a protection bearing, the gas bearing has the advantages of small mass, high reliability, large design freedom degree and the like, almost no friction exists at high rotating speed, the friction between the rotor 14 and the bearing is effectively avoided, the surface of the rotor is effectively protected, the strength of the rotor is improved, and the service life of the rotor is prolonged; meanwhile, the protection of the gas bearing 17 is facilitated, the supplied gas also has a certain cooling effect, and the bearing capacity of the gas bearing 17 in a high-temperature and high-pressure environment is improved.

In addition, compared with the case that the protective bearing is arranged at the cantilever of the rotor, the gas bearing 17 is arranged at the radial outer side of the first shaft section with a larger diameter, so that the second shaft section with a smaller diameter can be effectively prevented from deforming, and the service life of the rotor is prolonged; meanwhile, when the first shaft section is used for being connected with a motor assembly, the space at the position is large, and the fit clearance between the gas bearing 17 and the rotor 14 can be increased, so that the size of the gas bearing 17 is increased, and a better supporting effect is realized.

An embodiment of a compressor provided by the present invention will be described below.

As shown in fig. 1, the compressor includes a housing 1, a first-stage impeller seal 2, a first-stage impeller diffuser 3, a casing 4, a first-stage diffuser 5, a backflow device 6, a second-stage diffuser 7, a first end cover 8, a motor assembly 9, a thrust bearing 10, a bearing support 11, a third end cover 12, a first gasket 13, a rotor 14, a supply air flow passage 15, an air inlet 16, an air bearing 17, an electromagnetic bearing 18, a sealing member 19, a fixing sleeve 20, a second gasket 21, a second-stage impeller seal 22, an inter-stage seal 23, a third gasket 24, a lock nut 25, an impeller assembly 26, and a sleeve 27.

The housing 1 and the casing 4 are mounted at the outer end of the centrifugal compressor and are fixed by bolts. The impeller assembly 26 is locked to the rotor 14 by a lock nut 25. The impeller assembly 26 includes a primary impeller and a secondary impeller. The first-stage impeller seal 2 is arranged at the top end of the first-stage impeller and is fixed through a bolt. A sleeve 27 is assembled between the first-stage impeller and the second-stage impeller, the sleeve 27 is installed on the rotor 14 and is connected through clearance fit, and the sleeve 27 mainly functions to transmit the locking force of the locking nut 25 so as to press other parts at a shaft shoulder to realize axial fixation. A third gasket 24 is arranged between the primary impeller and the sleeve 27. An interstage seal 23 is also arranged between the two stages of impellers.

One-level impeller diffuser 3 is fixed with the backward flow ware 6 through one-level impeller seal 2, and one-level diffuser 5 is connected with the backward flow ware 6 through the bolt, and second grade impeller seal 22 is fixed through backward flow ware 6 and second grade impeller interconnect and the mode that adopts the bolt to compress tightly, and its main function is in order to carry out the sealed between one-level compression cavity and the second grade compression cavity, prevents that the air current from circulating between one-level compression cavity and second grade compression cavity. The reflux device 6 is connected with the shell 4 through interference fit, the right end of the reflux device is tightly pressed on the second-stage diffuser 7 through a screw, the second-stage diffuser 7 is connected with the shell 4 through interference fit, and axial positioning and fixing are carried out through the first end cover 8.

The gas bearing 17 may be disposed on the axially inner side of the electromagnetic bearing 18, or may be disposed on the axially outer side of the electromagnetic bearing 18.

In this embodiment, the gas bearings 17 include two and the electromagnetic bearings 18 include two, and for convenience of arrangement, the gas bearing 17 on the left side is located on the right side (i.e., axially inward) of the electromagnetic bearing 18 on the left side, and the gas bearing 17 on the right side is located on the right side (i.e., axially outward) of the electromagnetic bearing 18 on the right side.

A barrier is provided between the electromagnetic bearing 18 and the gas bearing 17, and is used for separating the electromagnetic bearing 18 and the gas bearing 17 and preventing the electromagnetic bearing 18 and the gas bearing 17 from contacting each other and influencing each other. The barrier may employ the first gasket 13 or the like.

The electromagnetic bearing 18 and the gas bearing 17 are arranged in the radial direction of the rotor 14, thereby providing radial support to the rotor 14.

The impeller assembly 26 is connected to the second shaft section of the rotor 14. It can be seen that the electromagnetic bearing 18 and the gas bearing 17 are disposed on a portion of the rotor 14 remote from the impeller assembly 26.

A first shaft section of the rotor 14 is connected to the motor assembly 9. The motor assembly 9 is attached substantially centrally to the central axis of the rotor 14, the impeller assembly 26 is attached to the end of the rotor 14 remote from the motor assembly 9, and the gas bearing 17 is disposed adjacent the motor assembly 9. The arrangement can realize better support, is beneficial to balancing the whole stress of the rotor 14 and prevents the rotor 14 from deforming.

The first end cap 8 is arranged in the housing 4 and serves to fix the electromagnetic bearing 18 and the gas bearing 17. Optionally, the first end cap 8 is in interference fit with the housing 4, and the electromagnetic bearing 18 and the gas bearing 17 are in interference fit with the first end cap 8.

A retaining sleeve 20 is provided between the impeller assembly 26 and the first end cap 8, the retaining sleeve 20 being used to axially locate the impeller assembly 26 (primarily the secondary impeller).

The seal 19 cooperates with the retaining sleeve 20 to effect a seal between the chamber in which the impeller assembly 26 is located and the chamber in which the motor assembly 9 is located. The seal 19 may be a gasket or the like. Specifically, the sealing member 19 is fixed to the second-stage diffuser 7 by bolts, is connected and positioned by interference fit with a fixing sleeve 20, and is axially positioned by a second gasket 21.

The compressor further comprises a gas supply channel 15 for supplying gas for gas suspension to the gas bearing 17. The gas supply passage 15 communicates with a chamber in which the gas bearing 17 is located, and gas is supplied through the gas supply passage 15 to form a gas levitation force to support the rotor 14.

Specifically, the gas supply flow passage 15 may be provided on the housing 4 and the first end cover 8, the housing 4 being provided with a gas inlet 16, the gas inlet 16 being communicated with the gas supply flow passage 15. The compressor also comprises a suction device, by means of which the suspension gas can be sucked off.

When the supporting function of the electromagnetic bearing 18 fails, the gas bearing 17 serves as a protective bearing of the compressor, gas enters through the gas inlet 16, then enters the gas bearing 17 through the gas supply channel 15 to continue to provide a suspension force, and then the gas is exhausted through the air suction device of the compressor.

Optionally, a third shaft section is further provided on the right side of the first shaft section, and the diameter of the third shaft section is smaller than that of the first shaft section. The third shaft section is connected with the positioning structure. The positioning structure comprises a bearing support 11 and a third end cap 12.

The compressor further comprises a thrust bearing 10, the thrust bearing 10 being arranged at an end of the first shaft section of the rotor 14 for axially positioning the rotor 14 and preventing axial play of the rotor 14. The thrust bearing 10 is installed on a bearing support 11, the thrust bearing 10 is fixedly connected with the first end cover 8 on the right side through screws, and the bearing support 11 is axially positioned through a third end cover 12. The third end cap 12 is mounted on the end of the rotor 14 and is fixed by bolts so that the various components on the rotor 14 can be axially compressed and fixed.

The thrust bearing 10 can also adopt an electromagnetic bearing, and a sensor can be arranged near the thrust bearing 10 and used for detecting the axial displacement of the thrust bearing 10 so as to adjust the size of the electromagnetic force according to a detection result, further adjust the axial displacement and realize a better positioning effect.

The compressor may also include a controller for adjusting the through-flow rate of the gas inlet 16 to adjust the magnitude of the supply gas flow rate as desired. For example, in an initial stage, the gas inlet 16 may be opened so that the gas bearing 17, together with the electromagnetic bearing 18, provides support for the rotor 14; alternatively, the gas inlet 16 can be opened only when the electromagnetic bearing 18 is out of service or has failed, and the rotor 14 is protected by the gas bearing 17.

By way of illustration of various embodiments of the compressor of the present invention, it can be seen that embodiments of the compressor of the present invention provide at least one or more of the following advantages:

1. the gas bearing is arranged at the first shaft section with larger diameter of the rotor, so that the second shaft section with smaller diameter can be prevented from deforming, and the service life of the rotor is prolonged;

2. the gas bearings are uniformly arranged on two sides of the motor assembly, so that a more stable supporting effect can be achieved at the two ends;

3. the gas bearing adopts an external gas supply mode to provide suspension pressure, can continuously supply gas, and can still continuously provide suspension force when the compressor has the problems of short circuit, power failure, electromagnetic bearing fault and the like, so that the supporting and protecting functions are realized, and the rotor and the electromagnetic bearing are prevented from being damaged due to friction; in the initial stage of the rotor floating, the gas bearing can also generate a suspension effect, and the gas bearing and the electromagnetic bearing realize a supporting effect together, so that the bearing protection effect is better;

4. the gas bearing is separated from the electromagnetic bearing 18 by a barrier which prevents the two bearings from contacting each other and thus affecting each other;

5. the gas bearing is arranged in a cavity where the motor assembly is located, and the matching gap between the gas bearing and the rotor is larger, so that better support can be realized.

Based on the compressor, the invention further provides an air conditioning unit which comprises the compressor. The positive technical effects of the compressor in the above embodiments are also applicable to the air conditioning unit, and are not described herein again.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention and not to limit it; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art will understand that: modifications to the specific embodiments of the invention or equivalent substitutions for parts of the technical features may be made; without departing from the spirit of the present invention, it is intended to cover all aspects of the invention as defined by the appended claims.

Claims

1. A compressor, comprising:

a housing (4);

a rotor (14) rotatably disposed within the housing (4) and including a first shaft section and a second shaft section, the first shaft section having a diameter greater than the second shaft section;

an electromagnetic bearing (18) for supporting the rotor (14); and

a gas bearing (17) for supporting the rotor (14) and arranged radially outside the first shaft section.

2. Compressor according to claim 1, characterized in that the gas bearing (17) is arranged axially inside or outside the electromagnetic bearing (18).

3. Compressor according to claim 1, characterized in that it further comprises a barrier, which is arranged between the electromagnetic bearing (18) and the gas bearing (17).

4. A compressor according to claim 3, characterized in that the barrier comprises a first gasket (13).

5. Compressor according to claim 1, characterized in that the electromagnetic bearing (18) and the gas bearing (17) are both arranged in the radial direction of the rotor (14).

6. The compressor of claim 1, further comprising an impeller assembly (26), the impeller assembly (26) being connected to the second shaft section.

7. The compressor of claim 6, further comprising a motor assembly (9), the motor assembly (9) being connected with the first shaft section.

8. The compressor of claim 7, further comprising a first end cover (8), the first end cover (8) being disposed within the housing (4) and being configured to secure the electromagnetic bearing (18) and the gas bearing (17).

9. The compressor of claim 8, further comprising a retaining sleeve (20), said retaining sleeve (20) disposed between said impeller assembly (26) and said first end cover (8), said retaining sleeve (20) for axially locating said impeller assembly (26).

10. Compressor according to claim 9, characterized in that it further comprises a seal (19), said seal (19) cooperating with said cover (20) to obtain a seal between the chamber in which said impeller assembly (26) is located and the chamber in which said motor assembly (9) is located.

11. The compressor of claim 8, wherein the first end cover (8) is an interference fit with the housing (4), and the electromagnetic bearing (18) and the gas bearing (17) are each an interference fit with the first end cover (8).

12. The compressor of claim 8, further comprising a gas supply channel (15) for supplying gas for gas suspension to the gas bearing (17).

13. Compressor according to claim 12, characterized in that the gas supply channel (15) is provided on the housing (4) and the first end cover (8), the housing (4) being provided with a gas inlet (16), the gas inlet (16) being in communication with the gas supply channel (15).

14. The compressor of claim 12, further comprising a suction device for drawing a suspension gas.

15. Compressor according to claim 1, characterized in that it further comprises a thrust bearing (10), said thrust bearing (10) being provided at the end of said rotor (14) for axially positioning said rotor (14).

16. An air conditioning assembly comprising a compressor as claimed in any one of claims 1 to 15.