CN111486108A - Centrifugal compressor and heat pump system - Google Patents

Abstract

The invention discloses a centrifugal compressor, and belongs to the technical field of compressors. This centrifugal compressor includes the electric motor rotor in casing and the casing, and electric motor rotor is supported by the bearing, and electric motor rotor's one end fixedly connected with one or more impeller assembly, and wherein, every impeller assembly includes first centrifugal impeller and the second centrifugal impeller of mirror image installation, first centrifugal impeller and second centrifugal impeller, and the one side that the inlet end is dorsad supports mutually and leans on, and first centrifugal impeller and second centrifugal impeller set up in same compression spiral case. By adopting the embodiment, the stability of the axial stress of the motor rotor is ensured, the influence of the axial force is reduced, and the requirements on the thrust disc and the axial bearing are further reduced.

Description

Centrifugal compressor and heat pump system

Technical Field

The invention relates to the technical field of compressors, in particular to a centrifugal compressor and a heat pump system.

Background

Centrifugal compressors are important components of heat pump systems. The centrifugal compressor drives the impeller to generate pressure through the high-speed rotation of the motor.

When the impeller of the centrifugal compressor rotates at a high speed, an axial deflection force is generated, and at the present stage, the thrust disk is mostly matched with the axial bearing to balance the axial force, so that the thrust disk can play a role in balancing the axial force, but when the rotating speed of the centrifugal compressor is too high, the requirements on the thrust disk and the axial bearing for balancing the axial force are higher.

Disclosure of Invention

The embodiment of the invention provides a centrifugal compressor and a heat pump system. The following presents a simplified summary in order to provide a basic understanding of some aspects of the disclosed embodiments. This summary is not an extensive overview and is intended to neither identify key/critical elements nor delineate the scope of such embodiments. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is presented later.

According to a first aspect of embodiments of the present invention, a centrifugal compressor is provided.

In some optional embodiments, a centrifugal compressor includes a housing and a motor rotor in the housing, the motor rotor is supported by a bearing, one end of the motor rotor is fixedly connected with one or more impeller sets, each impeller set includes a first centrifugal impeller and a second centrifugal impeller which are installed in a mirror image mode, the first centrifugal impeller and the second centrifugal impeller are arranged, the sides, facing away from each other, of air inlet ends abut against each other, and the first centrifugal impeller and the second centrifugal impeller are arranged in the same compression volute.

Adopt this optional embodiment, first centrifugal impeller and second centrifugal impeller of mirror image installation, first centrifugal impeller and second centrifugal impeller, the inlet end one side dorsad support mutually and lean on, admit air from both sides, therefore, first centrifugal impeller and second centrifugal impeller, in the rotation process, along the axial, one produces power that produces left one and produces power to the right, the axial force that makes electric motor rotor receive offsets each other, thereby guarantee the stability of electric motor rotor axial upward atress, reduce the influence of axial force, and then reduce thrust disc and axial bearing requirement.

Optionally, one or more impeller sets are also fixedly connected to the other end of the motor rotor. By adopting the embodiment, because of the balance of the axial force, the axial stress of the motor rotor is very small, and a plurality of impeller sets can be arranged at both ends of the motor rotor, thereby ensuring the stability and improving the flow.

Optionally, a stator capable of driving the motor rotor to rotate is arranged between the housing and the motor rotor. By adopting the embodiment, the stable rotation of the motor rotor is ensured.

Optionally, a thrust disk is arranged on the motor rotor, and the thrust disk is limited by axial bearings on two sides. By adopting the embodiment, the axial movement of the motor rotor can be effectively prevented through the thrust disk, and the axial force is effectively balanced.

Optionally, the bearing and the axial bearing are both pneumatic and pneumatic suspension bearings or both static and pneumatic suspension bearings. By adopting the embodiment, dynamic pressure air suspension bearings or static pressure air suspension bearings are uniformly adopted, so that management and control are facilitated, and the friction force of the motor rotor is reduced.

Optionally, the bearing is a dynamic pressure air suspension bearing, and the axial bearing is a static pressure air suspension bearing; or the bearing is a static pressure air suspension bearing, and the axial bearing is a dynamic pressure air suspension bearing. By adopting the embodiment, the dynamic pressure air suspension bearing or the static pressure air suspension bearing is respectively adopted according to the different axial and radial stresses, the advantages of the dynamic pressure air suspension bearing and the static pressure air suspension bearing are fully exerted, and the rotation stability of the motor rotor is improved.

Optionally, the air outlet end of the first centrifugal impeller and the air outlet end of the second centrifugal impeller are both communicated with a compression chamber in the compression volute. By adopting the embodiment, the air flow generated by the rotation of the first centrifugal impeller and the second centrifugal impeller is compressed in the same compression cavity, so that the stability of the pressure can be ensured, and the air flow can be increased.

Optionally, the compression volute is provided with a first air suction port and a second air suction port, the first air suction port is communicated with the air inlet end of the first centrifugal impeller, and the second air suction port is communicated with the air inlet end of the second centrifugal impeller. By adopting the embodiment, the directions of the air inlet ends of the first centrifugal impeller and the second centrifugal impeller are opposite, air suction from independent air suction ports is more convenient and faster, and the structural design is simpler.

Optionally, a reserve passage is provided between one of the first suction port and the second suction port, which is close to one side of the casing, and the casing. With this embodiment, a sufficient installation space is provided for the first intake port or the second intake port near the side of the casing, ensuring the amount of intake air.

According to a second aspect of embodiments of the present invention, there is provided a heat pump system.

In some alternative embodiments, the centrifugal compressor of any of the previous alternative embodiments is included.

By adopting the optional embodiment, the quality of the heat pump system is improved and the energy consumption is reduced by adopting the more stable centrifugal compressor.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the invention.

FIG. 1 is a schematic block diagram illustrating an alternate embodiment of a centrifugal compressor in accordance with an exemplary embodiment;

FIG. 2 is a schematic structural view of another alternate embodiment of a centrifugal compressor according to an exemplary embodiment;

FIG. 3 is a schematic block diagram illustrating an alternate embodiment of a centrifugal compressor in accordance with an exemplary embodiment;

FIG. 4 is a schematic block diagram illustrating an alternate embodiment of a centrifugal compressor in accordance with an exemplary embodiment;

FIG. 5 is a schematic block diagram illustrating an alternate embodiment of a centrifugal compressor in accordance with an exemplary embodiment;

FIG. 6 is a schematic structural view of another alternate embodiment of a centrifugal compressor in accordance with an exemplary embodiment;

FIG. 7 is a schematic structural view of an alternative embodiment of an impeller assembly of a centrifugal compressor in accordance with an exemplary embodiment;

FIG. 8 is a schematic structural view of an alternative embodiment of a motor rotor of a centrifugal compressor in accordance with an exemplary embodiment;

FIG. 9 is a schematic diagram illustrating an alternative embodiment of a bracket for a centrifugal compressor according to an exemplary embodiment.

Detailed Description

The following description and the drawings sufficiently illustrate specific embodiments of the invention to enable those skilled in the art to practice them. Other embodiments may incorporate structural, logical, electrical, process, and other changes. The examples merely typify possible variations. Individual components and functions are optional unless explicitly required, and the sequence of operations may vary. Portions and features of some embodiments may be included in or substituted for those of others. The scope of embodiments of the invention encompasses the full ambit of the claims, as well as all available equivalents of the claims. Embodiments may be referred to herein, individually or collectively, by the term "invention" merely for convenience and without intending to voluntarily limit the scope of this application to any single invention or inventive concept if more than one is in fact disclosed. Herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method or device comprising the element. The embodiments are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. As for the methods, products and the like disclosed by the embodiments, the description is simple because the methods correspond to the method parts disclosed by the embodiments, and the related parts can be referred to the method parts for description.

The terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like herein, as used herein, are defined as orientations or positional relationships based on the orientation or positional relationship shown in the drawings, and are used for convenience in describing and simplifying the description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the present invention. In the description herein, unless otherwise specified and limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may include, for example, mechanical or electrical connections, communications between two elements, direct connections, and indirect connections via intermediary media, where the specific meaning of the terms is understood by those skilled in the art as appropriate.

Fig. 1 shows an alternative embodiment of a centrifugal compressor.

In this alternative embodiment, a centrifugal compressor includes a housing 100 and a motor rotor 200 in the housing 100, the motor rotor 200 is supported by a bearing 300, one end of the motor rotor 200 is fixedly connected with a first centrifugal impeller 401, an air inlet end of the first centrifugal impeller 401 faces the other end of the motor rotor 200 and is connected with an air inlet channel 500, an air inlet 501 of the air inlet channel 500 is located on the housing 100 corresponding to the other end of the motor rotor 200, and the air inlet channel 500 passes through the interior of the housing 100.

By adopting the optional embodiment, the first centrifugal impeller 401 is reversely installed, so that the air inlet end of the first centrifugal impeller 401 passes through the air inlet channel 500, the air inlet channel 500 is located between the shell 100 and the motor rotor 200, and the motor rotor 200 part which is easy to generate high temperature when a refrigerant firstly passes through the rotation is ensured to be cooled firstly, so that the cooling efficiency of the motor rotor 200 part is improved, additional cooling treatment is not required, the energy loss is reduced, and the purpose of energy saving and high efficiency is achieved.

Optionally, the bearing 300 is connected to the housing 100 by a bracket 600.

Optionally, a first compressor volute 403 is disposed outside the first centrifugal impeller 401, and an air outlet end of the first centrifugal impeller 401 is communicated with a compression cavity of the first compressor volute 403. With this embodiment, the refrigerant is compressed in the compression chamber in the first compressor volute 403 by the rotation of the first centrifugal impeller 401, thereby generating a high pressure.

Optionally, the first compressor volute 403 is located on one side of the housing 100, and the periphery of the first compressor volute 403 is in sealed connection with the housing 100. With this embodiment, the sealing performance can be maintained when the refrigerant flows into the first compressor volute 403 through the casing 100, and the refrigerant is prevented from leaking.

Optionally, a suction channel 404 is arranged in the first compressor volute 403, one end of the suction channel 404 is communicated with the air inlet end of the first centrifugal impeller 401, the other end of the suction channel 404 is communicated with the air inlet channel 500, the inner wall of the suction channel 404 is smooth, and an arc-shaped chamfer structure is adopted at a corner. By adopting the embodiment, the first centrifugal impeller 401 can be ensured to smoothly suck air from the air inlet channel 500, and the wind resistance is reduced through the smooth inner wall of the air suction channel 404 and the arc-shaped chamfer structure at the corner, so that the first centrifugal impeller 401 can work more smoothly.

Optionally, a stator 700 for driving the motor rotor 200 to rotate is disposed between the housing 100 and the motor rotor 200. With this embodiment, stable rotation of the motor rotor 200 is ensured.

Alternatively, the intake passage 500 includes a gap between the stator 700 and the housing 100, and a gap between the stator 700 and the motor rotor 200. By adopting the embodiment, the refrigerant can pass through the gap between the stator 700 and the shell 100 and the gap between the stator 700 and the motor rotor 200, so that the part which is easy to heat in the rotating process of the motor rotor 200 can be effectively cooled rapidly.

Fig. 2 shows another alternative embodiment of the centrifugal compressor.

In this alternative embodiment, one end of the motor rotor 200 is fixedly connected with one or more first centrifugal impellers 401, and the first centrifugal impellers 401 are connected in series, that is, the air outlet end of one first centrifugal impeller 401 is connected with the air inlet end of another first centrifugal impeller 401. With this embodiment, a multistage centrifugal compression can be formed by connecting a plurality of first centrifugal impellers 401 in series, thereby increasing the pressure of the centrifugal compressor.

Fig. 3 shows another alternative embodiment of the centrifugal compressor.

In this alternative embodiment, a centrifugal compressor includes a housing 100 and a motor rotor 200 in the housing 100, the motor rotor 200 is supported by a bearing 300, one end of the motor rotor 200 is fixedly connected with a first centrifugal impeller 401, the other end of the motor rotor 200 is fixedly connected with a second centrifugal impeller 402, air inlet ends of the first centrifugal impeller 401 and the second centrifugal impeller 402 are opposite and are both connected with an air inlet channel 500, an air inlet 501 of the air inlet channel 500 is located on the housing 100, and the air inlet channel 500 penetrates through the interior of the housing 100 and is located between the housing 100 and the motor rotor 200.

By adopting the optional embodiment, the air inlet end of the first centrifugal impeller 401 and the air inlet end of the second centrifugal impeller 402 both penetrate through the air inlet channel 500, so that the refrigerant firstly passes through the motor rotor 200 part to cool the motor rotor 200 part, the cooling efficiency of the motor rotor 200 part is improved, and no additional cooling treatment is needed, and the energy loss can be reduced.

Alternatively, the air inlet 501 is provided at a middle portion on the housing 100. By adopting the embodiment, the refrigerant enters from the middle part of the shell 100 and then flows out from the two ends, so that the refrigerant is more uniform and stable, and the cooling effect of the refrigerant is better exerted.

Optionally, a second compressor volute 405 is disposed outside the second centrifugal impeller 402, and an air outlet end of the second centrifugal impeller 402 is communicated with a compression chamber of the second compressor volute 405. With this embodiment, the refrigerant is compressed in the compression chamber in the first compressor volute 403 by the rotation of the first centrifugal impeller 401, and the refrigerant is compressed in the compression chamber in the second compressor volute 405 by the rotation of the second centrifugal impeller 402, thereby generating high pressure from both ends.

Optionally, first compressor volute 403 is located on one side of housing 100, second compressor volute 405 is located on the other side of housing 100, and the peripheries of first compressor volute 403 and second compressor volute 405 are in sealed connection with housing 100. With the embodiment, when the refrigerant flows into the first compressor volute 403 and the second compressor volute 405 through the casing 100, the sealing performance can be maintained, and the refrigerant is prevented from leaking.

Optionally, first compressor volute 403 and second compressor volute 405 are identical in structure. With this embodiment, the two ends of the casing 100 are strictly symmetrical, and the stability of the operation of the whole centrifugal compressor is maintained.

Alternatively, the compression chamber is a volute groove provided in first and second compression volutes 403 and 405, and the airflow circulates from the large end to the small end for compression.

Fig. 4 shows another alternative embodiment of the centrifugal compressor.

In this alternative embodiment, a centrifugal compressor includes a housing 100 and a motor rotor 200 in the housing 100, the motor rotor 200 is supported by a bearing 300, one end of the motor rotor 200 is fixedly connected with a first centrifugal impeller 401, the other end of the motor rotor 200 is fixedly connected with a second centrifugal impeller 402, an air inlet end of the first centrifugal impeller 401 faces an air outlet end of the second centrifugal impeller 402, an air inlet end of the first centrifugal impeller 401 and an air outlet end of the second centrifugal impeller 402 are connected through an air inlet channel 500, and the air inlet channel 500 penetrates through the interior of the housing 100 and is located between the housing 100 and the motor rotor 200.

By adopting the optional embodiment, the air inlet end of the first centrifugal impeller 401 and the air outlet of the second centrifugal impeller 402 both penetrate through the air inlet channel 500, the second centrifugal impeller 402 firstly inputs the refrigerant into the air inlet channel 500, so that the refrigerant firstly passes through the motor rotor 200 part to cool the motor rotor 200 part, and then is sucked and compressed by the first centrifugal impeller 401, thereby improving the cooling efficiency of the motor rotor 200 part, avoiding the need of extra cooling treatment and reducing the energy loss.

Alternatively, the first centrifugal impeller 401 and the second centrifugal impeller 402 are identical in shape and structure and size. By adopting the embodiment, the same flow rate of the first centrifugal impeller 401 and the second centrifugal impeller 402 is ensured, and the phenomenon that the pressure in the air inlet channel 500 is too high or too low, and further the motor rotor 200 rotates abnormally or is damaged is prevented.

Optionally, a first compressor volute 403 is disposed outside the first centrifugal impeller 401, an air outlet end of the first centrifugal impeller 401 is communicated with a compression cavity of the first compressor volute 403, a third compressor volute 406 is disposed outside the second centrifugal impeller 402, an air outlet end of the second centrifugal impeller 402 is communicated with a compression cavity of the third compressor volute 406, and a compression cavity of the third compressor volute 406 is communicated with the air inlet channel 500. By adopting the embodiment, the third compressor volute 406 is directly communicated with the air inlet channel 500 in an open manner, so that the compression cavity of the third compressor volute does not have the capacity of compressing the refrigerant to form high pressure, the refrigerant is conveyed into the air inlet channel 500, the first centrifugal impeller 401 compresses the refrigerant in the compression cavity of the first compressor volute 403 to generate high pressure, and the compression process is more stable.

Optionally, the first compressor volute 403 is located on one side of the housing 100, the third compressor volute 406 is located on the other side of the housing 100, and the peripheries of the first compressor volute 403 and the third compressor volute 406 are in sealing connection with the housing 100. By adopting the embodiment, the refrigerant flows into the casing 100 through the third compressor volute 406, and the refrigerant can be kept in a sealing state when flowing into the first compressor volute 403 through the casing 100, so that the refrigerant is prevented from leaking.

Fig. 5 and 6 show another alternative embodiment of the centrifugal compressor.

In this alternative embodiment, a centrifugal compressor includes a housing 100 and a motor rotor 200 in the housing 100, the motor rotor 200 is supported by a bearing 300, one end of the motor rotor 200 is fixedly connected with one or more impeller sets 400, wherein each impeller set 400 includes a first centrifugal impeller 401 and a second centrifugal impeller 402 which are installed in a mirror image manner, the first centrifugal impeller 401 and the second centrifugal impeller 402 are installed in a mirror image manner, the sides of the air inlet ends, which face away from each other, abut against each other, and the first centrifugal impeller 401 and the second centrifugal impeller 402 are disposed in the same compression volute 800.

With this alternative embodiment, the first centrifugal impeller 401 and the second centrifugal impeller 402 are installed in a mirror image manner, so that axial forces applied to the first centrifugal impeller 401 and the second centrifugal impeller 402 during rotation are mutually offset, thereby ensuring axial stability of the motor rotor 200 and reducing influence of the axial forces.

Optionally, the air outlet end of the first centrifugal impeller 401 and the air outlet end of the second centrifugal impeller 402 are both communicated with the compression chamber in the compression volute 800. With this embodiment, the air flows generated by the rotation of the first centrifugal impeller 401 and the second centrifugal impeller 402 are compressed in the same compression chamber, so that the pressure can be stabilized and the air flow can be increased.

Alternatively, the compression scroll 800 is provided with a first suction port 801 and a second suction port 802, the first suction port 801 communicating with the intake end of the first centrifugal impeller 401, and the second suction port 802 communicating with the intake end of the second centrifugal impeller 402. With the adoption of the embodiment, the directions of the air inlet ends of the first centrifugal impeller 401 and the second centrifugal impeller 402 are opposite, air suction from the independent air suction ports is more convenient and faster, and the structural design is simpler.

Alternatively, a reserve passage is provided between one of the first suction port 801 and the second suction port 802, which is adjacent to one side of the casing 100, and the casing 100. With this embodiment, a sufficient installation space is provided for the first intake port 801 or the second intake port 802 on the side close to the casing 100, ensuring the amount of intake air.

Fig. 7 shows an alternative embodiment of the impeller assembly.

In this alternative embodiment, the impeller assembly 400 includes a first centrifugal impeller 401 and a second centrifugal impeller 402 which are mirror-mounted, the first centrifugal impeller 401 and the second centrifugal impeller 402 having their inlet ends facing away from each other.

Alternatively, the first centrifugal impeller 401 and the second centrifugal impeller 402 are identical in shape, structure and size.

Optionally, the air inlet angle of the first centrifugal impeller 401 and the second centrifugal impeller 402 is perpendicular to the air outlet angle.

Optionally, one or more impeller assemblies 400 are also fixedly connected to the other end of the motor rotor 200. With this embodiment, because of the balance of the axial force, the axial force of the motor rotor 200 is small, and a plurality of impeller sets 400 can be installed at both ends of the motor rotor 200, thereby ensuring stability and improving flow rate.

Fig. 8 shows an alternative embodiment of the rotor of the electrical machine.

In this alternative embodiment, motor rotor 200 is provided with thrust disk 201, and axial bearings 202 limit both sides of thrust disk 201. By adopting the embodiment, the thrust disc 201 can effectively prevent the motor rotor 200 from moving axially, and axial force can be effectively balanced.

Alternatively, the bearing 300 and the axial bearing 202 may be conventional oil lubricated bearings.

Optionally, the thrust disk 201 is in a circular disk shape, the center of the circular disk is hollow, and the thrust disk is sleeved outside the motor rotor 200 and fixedly connected to the outside of the motor rotor 200 by welding or casting.

Optionally, the bearing 300 and the axial bearing 202 are both pneumatic and pneumatic suspension bearings or both static and pneumatic suspension bearings. By adopting the embodiment, the dynamic pressure air suspension bearing or the static pressure air suspension bearing is uniformly adopted, so that the management and the control are convenient, and the friction force of the motor rotor 200 is reduced.

Alternatively, the bearing 300 is a dynamic pressure gas suspension bearing and the axial bearing 202 is a static pressure gas suspension bearing; alternatively, the bearing 300 may be a static pressure air bearing and the axial bearing 202 may be a dynamic pressure air bearing. By adopting the embodiment, the dynamic pressure air suspension bearing or the static pressure air suspension bearing is respectively adopted according to the different stress in the axial direction and the radial direction, the points of the dynamic pressure air suspension bearing and the static pressure air suspension bearing are fully exerted, and the rotating stability of the motor rotor 200 is improved.

The existing centrifugal compressor mostly adopts an oil lubrication bearing, the rotating speed is limited, and the oil lubrication bearing and the power consumption of a speed increasing system are very large when the rotating speed is high; meanwhile, the existence of oil adversely affects the energy efficiency of the compressor and the system. In the centrifugal compressor provided by the embodiment of the invention, the motor rotor 200 is supported by the radial dynamic pressure air suspension bearing, the axial dynamic pressure air suspension bearings are arranged on two sides of the thrust disc 201 of the motor rotor 200, the existing oil lubrication bearing is replaced by the air suspension bearings, the rotating speed is not limited, and higher rotating speed can be achieved; the energy consumption of the air suspension bearing adopted by the embodiment of the invention is lower, and the energy consumption of a speed increasing system is reduced; and gas lubrication is adopted to replace oil lubrication, so that the system where the compressor is located cannot be influenced. Compared with the existing magnetic suspension type compressor, the air suspension bearing provided by the embodiment of the invention is used as the supporting part of the electronic rotor, so that the cost of the centrifugal compressor is reduced.

The dynamic pressure gas suspension bearing and the static pressure gas suspension bearing may be collectively referred to as a gas suspension bearing, an air bearing or a gas bearing, and the gas suspension bearing in the embodiment of the present invention is not particularly limited to the type of the gas lubricant, and may be, for example, a refrigerant gas compressed by a centrifugal refrigeration compressor.

The air supply system of the dynamic pressure bearing in the prior art is complex. The centrifugal compressor provided by the embodiment of the invention adopts the dynamic pressure air suspension bearing, the compression air inlet channel of the centrifugal compressor is communicated with the air supply holes of the radial dynamic pressure air suspension bearing and the axial dynamic pressure air suspension bearing, the air in the compression air inlet channel is used as an air source, an additional complex air supply system is not needed, and the operation flow of the centrifugal compressor is simplified.

The compression air inlet channel is communicated with the air supply holes of the radial dynamic pressure air suspension bearing and the axial dynamic pressure air suspension bearing, and it can be understood that the compression air inlet channel is communicated with the air supply holes of the radial dynamic pressure air suspension bearing, and simultaneously, the compression air inlet channel is communicated with the air supply holes of the axial dynamic pressure air suspension bearing. Alternatively, in an embodiment of the present invention, the air supply hole of the radial aero-levitation bearing and the air supply hole of the axial aero-levitation bearing may be communicated through a certain line, and thus, the compression air supply passage may be simultaneously communicated with the air supply holes of the radial aero-levitation bearing and the axial decompression aero-levitation bearing through the same connecting portion.

In order to further improve the support and wear resistance of the aerostatic bearing, the structure of the radial aerostatic bearing may include: the bearing block, go up the foil to and be located the buffer foil between bearing block and the last foil, buffer foil can be the wave, has improved the support performance of radial pneumatics air suspension bearing. Optionally, a side of the upper foil close to the buffer foil is defined as a first surface, a side close to the rotor is defined as a second surface, and the second surface of the upper foil of the radial hydrodynamic suspension bearing is coated with one or more layers of polytetrafluoroethylene, so that the friction resistance of the radial hydrodynamic suspension bearing of the embodiment is improved.

Similarly, the structure of the aforementioned axial hydrodynamic suspension bearing may also include: the bearing seat, the upper foil and the buffer foil positioned between the bearing seat and the upper foil can be wavy, so that the support performance of the axial dynamic pressure air suspension bearing is improved. Optionally, a side of the upper foil close to the buffer foil is defined as a first surface, a side close to the thrust disk is defined as a second surface, and the second surface of the upper foil of the axial hydrodynamic suspension bearing is coated with one or more layers of polytetrafluoroethylene, so that the friction resistance of the axial hydrodynamic suspension bearing in the embodiment is improved.

Compared with a dynamic pressure air suspension bearing, the bearing capacity of the static pressure air suspension bearing is obviously increased.

In order to further improve the support and wear resistance of the aerostatic bearing, the structure of the radial hydrostatic aerostatic bearing may include: the bearing seat, go up the foil piece to and be located the buffer foil piece between bearing seat and the last foil piece, the buffer foil piece can be the wave, has improved radial static pressure gas suspension bearing's support performance. Optionally, a side of the upper foil close to the buffer foil is defined as a first surface, a side close to the rotor is defined as a second surface, and the second surface of the upper foil of the radial static pressure air suspension bearing is coated with one or more layers of polytetrafluoroethylene, so that the friction resistance of the radial static pressure air suspension bearing of the embodiment is improved.

Similarly, the structure of the aforementioned axial hydrostatic gas suspension bearing may also include: the bearing seat, the upper foil and the buffer foil positioned between the bearing seat and the upper foil can be wavy, so that the support performance of the axial static pressure air suspension bearing is improved. Optionally, a side of the upper foil close to the buffer foil is defined as a first surface, a side close to the thrust disk is defined as a second surface, and the second surface of the upper foil of the axial static pressure air suspension bearing is coated with one or more layers of polytetrafluoroethylene, so that the friction resistance of the axial static pressure air suspension bearing of the embodiment is improved.

The bearing seats of the radial static pressure air suspension bearing and the axial static pressure air suspension bearing are provided with air vents communicated with the air inlet channel, so that the working environment of the air suspension bearing is formed, meanwhile, air generated by the running of the static pressure air suspension bearing can pass through the air vents to enter the air inlet channel inside the motor, the internal temperature of the motor is reduced, the original external cooling water is omitted, and the structure of the centrifugal compressor and the cooling process of the motor are simplified. The number of the vent holes on the bearing seat of the radial static pressure air suspension bearing and the axial static pressure air suspension bearing is not particularly limited in this embodiment, and may be one or more, for example.

Fig. 9 shows an alternative embodiment of the stent.

In this alternative embodiment, a bearing installation groove 601 is formed in the center of the bracket 600, one or more through holes 602 are formed in the bracket 600, support ribs 603 are formed between the through holes 602, an air passage 604 is formed in the support ribs 603, one end of the air passage 604 is communicated with the bearing installation groove 601, and the other end of the air passage 604 is communicated with the outer side of the bracket 600. By adopting the embodiment, the bearing 300 can be effectively fixed, the space intercommunication at the two sides of the bracket 600 is ensured, the refrigerant smoothly passes through the bracket 600 to circulate, and meanwhile, when the bearing 300 installed and used on the bracket 600 is an air bearing, the air channel 604 arranged in the support rib 603 can supply air to the air bearing, so that the normal use of the air bearing is ensured.

The present invention is not limited to the structures that have been described above and shown in the drawings, and various modifications and changes can be made without departing from the scope thereof. The scope of the invention is limited only by the appended claims.

Claims (10)

1. The centrifugal compressor comprises a shell and a motor rotor in the shell, wherein the motor rotor is supported by a bearing, and the centrifugal compressor is characterized in that one end of the motor rotor is fixedly connected with one or more impeller sets, each impeller set comprises a first centrifugal impeller and a second centrifugal impeller which are installed in a mirror image mode, the first centrifugal impeller and the second centrifugal impeller are mutually abutted to one side, back to the air inlet end, of the first centrifugal impeller and the second centrifugal impeller are arranged in the same compression volute.

2. The centrifugal compressor according to claim 1, wherein one or more of said impeller sets are also fixedly attached to the other end of said motor rotor.

3. The centrifugal compressor according to claim 1, wherein a stator is disposed between the housing and the motor rotor for driving the motor rotor to rotate.

4. A centrifugal compressor as claimed in any one of claims 1 to 3, wherein the motor rotor is provided with a thrust disk, and the thrust disk is limited on both sides by axial bearings.

5. The centrifugal compressor according to claim 4, wherein the bearing and the axial bearing are both pneumatic and pneumatic suspension bearings or both static and pneumatic suspension bearings.

6. The centrifugal compressor according to claim 4, wherein the bearing is a dynamic pressure gas suspension bearing and the axial bearing is a static pressure gas suspension bearing; or the bearing is a static pressure air suspension bearing, and the axial bearing is a dynamic pressure air suspension bearing.

7. The centrifugal compressor according to claim 1, wherein the gas outlet end of the first centrifugal impeller and the gas outlet end of the second centrifugal impeller are both in communication with a compression chamber within the compression volute.

8. The centrifugal compressor according to any one of claims 1 to 7, wherein the compression scroll is provided with a first suction port communicating with the inlet end of the first centrifugal impeller and a second suction port communicating with the inlet end of the second centrifugal impeller.

9. The centrifugal compressor according to claim 8, wherein one of said first suction port and said second suction port adjacent to one side of said housing is provided with a reserve passage with said housing.

10. A heat pump system, characterized in that it comprises a centrifugal compressor according to any one of claims 1 to 9.

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