CN113236562A

CN113236562A - Magnetic suspension screw type refrigeration compressor

Info

Publication number: CN113236562A
Application number: CN202110741114.1A
Authority: CN
Inventors: 余金龙
Original assignee: Wuhan Kailong Technology Development Co ltd
Current assignee: Wuhan Kailong Technology Development Co ltd
Priority date: 2021-07-01
Filing date: 2021-07-01
Publication date: 2021-08-10

Abstract

A magnetic suspension screw type refrigeration compressor is characterized in that: at least, constitute a whole by spare parts such as organism part (1), drive rotor (2), driven rotor (3), magnetic coupling (7), radial permanent magnet bearing (8) and two-way permanent magnetism axial thrust bearing (9), its beneficial effect is: the friction power consumption of a rotary moving part of the compressor is eliminated, oil-free lubrication operation is realized, the defects that oil film thermal resistance and a filter screen increase pressure drop are overcome, comprehensive adaptability and zero leakage of a refrigerant are realized, a refrigeration cycle system is simplified, resources are saved, and the performance and reliability of the compressor are greatly improved.

Description

Magnetic suspension screw type refrigeration compressor

Technical Field

The invention relates to a screw type refrigeration compressor in the field of air conditioning and refrigeration, in particular to a magnetic suspension screw type refrigeration compressor.

Background

Screw refrigeration compressors are widely used in the air conditioning and refrigeration fields. Screw refrigeration compressors come in two types: the motor is connected with the compressor through a coupler, the motor is independently connected with the compressor through the coupler and a mechanical seal, the motor is opened, and the motor is directly connected with the compressor through the coupler and the mechanical seal and is closed in the same cavity. The closed type is divided into a detachable semi-closed type and a non-detachable full-closed type.

The opening and closing respectively have the advantages and disadvantages:

1. in terms of airtightness, hermetic screw compressors are produced in order to overcome the mechanical seal leakage defect of open screw compressors.

The screw type refrigeration compressor and the driving motor are independently started and connected through the coupler, and the mechanical seal of the refrigeration compressor requires high reliability due to the air tightness requirement of the refrigerant of the refrigeration compressor. Mechanical seals suffer from the drawback of leakage due to wear and seal aging and the drawback of frictional heat and additional lost work.

The closed screw type refrigeration compressor overcomes the defect that mechanical seal leakage exists when the screw type refrigeration compressor is opened, has extremely high air tightness and achieves zero leakage.

2. In terms of refrigerant compatibility, the closed type and the open type are each suitable.

The screw-type refrigeration compressor is only suitable for single refrigerants such as R717, R22 and the like with lower price, and is not suitable for mixed refrigerants such as R407C and the like with various proportions.

Because R717 has chemical corrosion to the metallic copper wire of the motor winding, the closed screw type refrigeration compressor is suitable for most refrigerants except for R717, and R717 is a natural refrigerant, does not damage the ozone layer, and has no greenhouse effect. The widely used R22 at present has a refrigerant replacement problem.

3. The closed type is more demanding than the open type in terms of quality requirements for the refrigerant and the lubricating oil.

The motor of the closed screw type refrigeration compressor and the refrigerant are in the same cavity, and the requirements on the quality of the refrigerant and the lubricating oil, such as the water content, are extremely high. In the manufacturing process of the closed screw type refrigeration compressor, the motor winding is insulated and dried above the E level, the system is strictly vacuumized, and even if the system is strictly vacuumized, the defect that the motor is burnt due to the water content of a medium and the large deflection of a cantilever of a motor rotor sometimes occurs. Opening does not have this drawback.

4. The closed type is not as open as far as the cooling mode of the driving motor consumes the cooling capacity.

When the screw type refrigeration compressor is started and driven by the motor, the cooling of the driving motor is cooled by ambient air or water, and the refrigeration capacity is not consumed.

The motor of the closed screw type refrigeration compressor and the refrigerant are in the same cavity, the driving motor is cooled by the liquid or low-temperature gas of the refrigerant, and the closed type refrigeration compressor has the defects of increasing the heat load of the system and consuming the refrigeration capacity.

5. The closed type is not as open as to the diversity of the driving motor loading power.

The screw type refrigeration compressor and the driving machine are started to be independent respectively, and the loading power of the driving machine can be selected and matched with the driving machine according to different power requirements under different operating conditions.

The closed screw type refrigeration compressor generally selects the loading power of a driving motor according to the maximum working condition of an air conditioner, the working condition is changed, the loading power cannot be changed, and the defect of a large horse-drawn trolley exists.

6. Closed type is inferior to open type in terms of driver diversity.

The open screw refrigeration compressor can be driven by an electric motor, a gas engine and an oil engine, while the closed screw refrigeration compressor can only be driven by an electric motor.

The screw compressor uses a pair of driving rotor 2 and driven rotor 3 having specific male and female tooth profiles engaged with each other in a housing 102 to generate a periodic volume change upon rotation to achieve the effect of sucking, compressing and discharging a gas medium.

Referring to fig. 1 and 3, the hermetic screw type refrigeration compressor comprises at least a body 102, a discharge end seat 103, a discharge end cover 104, an end cover 105, a motor end cover 107, a driving rotor 2, a driving rotor suction end radial rolling bearing 21, a driving rotor suction end shaft sleeve 22, a driving rotor discharge end shaft sleeve 23, a driving rotor discharge end radial rolling bearing 24, a driving rotor discharge end gap adjusting ring 25, a driving rotor discharge end axial thrust bearing 26, a driving rotor discharge end bearing cover 27, a driving rotor discharge end belleville spring 28, a driving rotor discharge end lock nut 29, a driven rotor 3, a driven rotor suction end radial rolling bearing 31, a driven rotor suction end shaft sleeve 32, a driven rotor discharge end shaft sleeve 33, a driven rotor discharge end radial rolling bearing 34, a driven rotor discharge end gap adjusting ring 35, a driven rotor discharge end axial thrust bearing 36, The bearing gland 37 of the exhaust end of the driven rotor, the belleville spring 38 of the exhaust end of the driven rotor, the locknut 39 of the exhaust end of the driven rotor, the oil separator part 4, the semi-closed motor 5 and other parts.

The oil separator 4 is composed of at least a cylinder 401 and a stainless steel wire filter screen 402;

the semi-closed motor 5 is composed of a motor stator 501 and a motor rotor 502.

Referring to fig. 2 and 3, the open-screw refrigeration compressor comprises at least a body 102, a discharge end seat 103, a discharge end cover 104, an end cover 105, a pointer seat 106, a suction end seat 108, a suction end cover 109, a shaft seal seat 110, a mechanical seal 6, a drive rotor 2, a drive rotor suction end radial rolling bearing 21, a drive rotor suction end shaft sleeve 22, a drive rotor discharge end shaft sleeve 23, a drive rotor discharge end radial rolling bearing 24, a drive rotor discharge end gap adjustment ring 25, a drive rotor discharge end axial thrust bearing 26, a drive rotor discharge end bearing cap 27, a drive rotor discharge end belleville spring 28, a drive rotor discharge end lock nut 29, a driven rotor 3, a driven rotor suction end radial rolling bearing 31, a driven rotor suction end shaft sleeve 32, a driven rotor discharge end shaft sleeve 33, a driven rotor discharge end radial rolling bearing 34, a driven rotor discharge end gap adjustment ring 35, a pointer seat 106, a pointer seat for a pointer, a mechanical seal for a screw, and a mechanical seal for a screw for a mechanical seal for a screw for a mechanical seal for a screw for a mechanical seal for a screw for a mechanical seal for a screw for a mechanical seal for a screw, The exhaust end axial thrust bearing 36 of the driven rotor, the exhaust end bearing cover 37 of the driven rotor, the exhaust end belleville spring 38 of the driven rotor, the exhaust end locking nut 39 of the driven rotor and other parts.

The mechanical seal 6 is composed of a hard alloy static ring 601, a static ring seal ring 602, a graphite moving ring 603, a moving ring seal ring 604, a spring 605 and a moving ring seat 606, friction power consumption exists between the moving ring and the static ring, and oil injection, lubrication and cooling are needed.

The existing screw type refrigeration compressors are provided with radial rolling bearings and axial thrust bearings, and have friction power consumption and need oil injection, lubrication and cooling. The oil circuit circulation system is complex, the number of components is large, if an oil separator, an oil cooler, a circulating oil pump and the like need to be arranged in the system, oil return is difficult, and if a flooded evaporator in the system exists, the defects that oil-gas separation is not sufficient, oil film thermal resistance is increased in a condenser and the evaporator, and pressure drop is increased by a filter screen exist.

Disclosure of Invention

In order to overcome the defects of an open screw type refrigeration compressor and a closed screw type refrigeration compressor in the prior art and improve and develop the advantages of the open screw type refrigeration compressor and the closed screw type refrigeration compressor, the invention provides a magnetic suspension screw type refrigeration compressor.

When the screw type refrigeration (air-conditioning) compressor operates under different working conditions, the radial force and the axial force applied to the driving rotor 2 and the driven rotor 3 are different in magnitude and direction.

The technical scheme adopted by the invention for solving the technical problems is as follows: at least, constitute a whole by spare parts such as organism part 1, drive rotor 2, driven rotor 3, magnetic coupling 7, radial permanent magnet bearing 8 and two-way permanent magnet axial thrust bearing 9, characterized by:

the connecting body 101, the machine body 102, the exhaust end seat 103, the exhaust end cover 104, the end cover 105 and the silencer 111 are connected into a machine body part through screws;

the driving rotor component is formed by assembling a driving rotor 2, a driving rotor air suction end radial permanent magnetic bearing 201, a driving rotor air suction end shaft sleeve 22, a driving rotor exhaust end shaft sleeve 23, a driving rotor exhaust end radial permanent magnetic bearing 202, a driving rotor exhaust end clearance adjusting ring 203, a driving rotor exhaust end bidirectional permanent magnetic axial thrust bearing 204, a driving rotor exhaust end bearing cover 27, a driving rotor exhaust end belleville spring 28 and a driving rotor exhaust end locking nut 29;

the driven rotor part is formed by assembling a driven rotor 3, a driven rotor air suction end radial permanent magnet bearing 301, a driven rotor air suction end shaft sleeve 32, a driven rotor air discharge end shaft sleeve 33, a driven rotor air discharge end radial permanent magnet bearing 302, a driven rotor air discharge end clearance adjusting ring 303, a driven rotor air discharge end bidirectional permanent magnet axial thrust bearing 304, a driven rotor air discharge end bearing cover 37, a driven rotor air discharge end belleville spring 38 and a driven rotor air discharge end locking nut 39;

the drive coupling 701, the shield case 702, the outer rotor 703, the outer magnetic shoe 704, the inner rotor 705 and the inner magnetic shoe 706 are combined to form a magnetic coupling;

the outer ring body 801, the outer magnetic ring 802, the outer magnetic ring pressing ring 803, the inner ring body 804, the inner magnetic ring 805 and the inner magnetic ring pressing ring 806 form a radial permanent magnet bearing;

the outer ring body 901, the static magnetic ring 902, the outer ring body 903, the inner ring body 904, the thrust magnetic ring 905 and the inner pressure ring body 906 form a bidirectional permanent magnet axial thrust bearing in a combined mode.

The drive rotor 2 is suspended by the magnetic forces of the drive rotor suction end radial permanent magnet bearing 201 and the drive rotor discharge end radial permanent magnet bearing 202.

The driven rotor 3 is levitated by the magnetic forces of the driven rotor suction end radial permanent magnet bearing 301 and the driven rotor discharge end radial permanent magnet bearing 302.

Under the combined action of the bidirectional permanent magnet axial thrust bearing 204 at the exhaust end of the drive rotor, the bearing cover 27 at the exhaust end of the drive rotor, the belleville spring 28 at the exhaust end of the drive rotor and the lock nut 29 at the exhaust end of the drive rotor, the drive rotor 2 realizes the balance of bidirectional axial force.

Under the combined action of the driven rotor exhaust end bidirectional permanent magnet axial thrust bearing 304, the driven rotor exhaust end bearing pressure cover 37, the driven rotor exhaust end belleville spring 38 and the driven rotor exhaust end locking nut 39, the driven rotor 3 realizes the balance of bidirectional axial force.

Under the isolation of the shield 702, the screw refrigeration compressor achieves zero leakage of static seal and full adaptability of refrigerant.

The invention has the beneficial effects that: the friction power consumption of a rotary moving part of the compressor is eliminated, oil-free lubrication operation is realized, the defects that oil film thermal resistance and a filter screen increase pressure drop are overcome, comprehensive adaptability and zero leakage of a refrigerant are realized, a refrigeration cycle system is simplified, resources are saved, and the performance and reliability of the compressor are greatly improved.

Drawings

The invention is further illustrated with reference to the following figures and examples.

Fig. 1 is a horizontal sectional view of an example of a semi-hermetic screw refrigeration (air conditioning) compressor of the prior art.

Fig. 2 is a horizontal sectional view of an example of an open screw refrigeration (air conditioning) compressor of the prior art.

Figure 3 is a horizontal cross-sectional view of an example of a rotor component of a screw refrigeration (air conditioning) compressor of the prior art.

Fig. 4 is a horizontal sectional view of an embodiment of a magnetically levitated screw refrigeration (air conditioning) compressor of the present invention.

Figure 5 is a horizontal cross-sectional view of an embodiment of the rotor components of a magnetically levitated screw refrigeration (air conditioning) compressor of the present invention.

Fig. 6 is an axial cross-sectional view of an embodiment of the magnetic coupling of a magnetically levitated screw refrigeration (air conditioning) compressor of the present invention.

Fig. 7 shows an embodiment of the radial permanent magnet bearing of a maglev screw refrigeration (air conditioning) compressor of the present invention.

Fig. 8 shows an embodiment of the bidirectional permanent magnet axial thrust bearing of a maglev screw refrigeration (air conditioning) compressor of the present invention.

Fig. 9 shows another embodiment of the radial permanent magnet bearing of a maglev screw refrigeration (air conditioning) compressor of the present invention.

Fig. 10 is another embodiment of the bidirectional permanent magnet axial thrust bearing of a maglev screw refrigeration (air conditioning) compressor of the present invention.

In the figure: 1. the device comprises a machine body part, 2 driving rotors, 3 driven rotors, 4 oil separator parts, 5 semi-closed motors, 6 mechanical seals, 7 magnetic couplings, 8 radial permanent magnetic bearings and 9 bidirectional permanent magnetic axial thrust bearings;

21. the driving rotor air suction end radial rolling bearing 22, the driving rotor air suction end shaft sleeve 23, the driving rotor air discharge end shaft sleeve 24, the driving rotor air discharge end radial rolling bearing 25, the driving rotor air discharge end gap adjusting ring 26, the driving rotor air discharge end axial thrust bearing 27, the driving rotor air discharge end bearing gland 28, the driving rotor air discharge end belleville spring 29 and the driving rotor air discharge end locking nut 29;

31. the device comprises a driven rotor air suction end radial rolling bearing, a driven rotor air suction end shaft sleeve, a driven rotor air discharge end radial rolling bearing, a driven rotor air discharge end gap adjusting ring, a driven rotor air discharge end axial thrust bearing, a driven rotor air discharge end bearing cover, a driven rotor air discharge end butterfly spring, a driven rotor air discharge end locking nut, a driven rotor air discharge end shaft sleeve, a driven rotor air discharge end radial rolling bearing, a driven rotor air discharge end gap adjusting ring, a driven rotor air discharge end axial thrust bearing, a driven rotor air discharge end shaft sleeve, a driven rotor air discharge end locking nut, a driven rotor air discharge end shaft, a driven rotor air discharge end locking nut, a driven rotor air locking nut, a driven rotor air;

101. the device comprises a connecting body, a machine body, a 103 exhaust end seat, a 104 exhaust end cover, a 105 end cover, a 106 pointer seat, a 107 motor end cover, a 108 suction end seat, a 109 suction end cover, a 110 shaft seal seat and a 111 silencer;

201. the driving rotor air suction end radial permanent magnetic bearing 202, the driving rotor air exhaust end radial permanent magnetic bearing 203, the driving rotor air exhaust end gap adjusting ring 204, the driving rotor air exhaust end bidirectional permanent magnetic axial thrust bearing;

301. the axial thrust bearing comprises a driven rotor air suction end radial permanent magnetic bearing 302, a driven rotor air exhaust end radial permanent magnetic bearing 303, a driven rotor air exhaust end gap adjusting ring 304, a driven rotor air exhaust end bidirectional permanent magnetic axial thrust bearing;

401. barrel 402 stainless steel wire filter screen;

501. a motor stator, 502. a motor rotor;

601. the device comprises a hard alloy static ring, 602, a static ring sealing ring, 603, a graphite moving ring, 604, a moving ring sealing ring, 605, a spring, 606 and a moving ring seat;

701. a driving coupling, 702, a shielding cover, 703, an outer rotating body, 704, an outer magnetic shoe, 705, an inner rotating body, 706, an inner magnetic shoe;

801. the outer ring body, 802. the outer magnetic ring, 803. the outer magnetic ring pressing ring, 804. the inner ring body, 805. the inner magnetic ring, 806. the inner magnetic ring pressing ring;

901. outer ring body, 902 static magnetic ring, 903 external pressure ring body, 904 internal ring body, 905 thrust magnetic ring, 906 internal pressure ring body,

A. And B, perforating a spray hole and perforating an economizer steam supplementing hole.

Detailed Description

In the embodiment of a magnetic levitation screw refrigeration (air-conditioning) compressor shown in fig. 4, 5, 6, 7 and 8, at least the machine body part 1, the driving rotor 2, the driven rotor 3, the magnetic coupling 7, the radial permanent magnet bearing 8, the bidirectional permanent magnet axial thrust bearing 9 and other parts form a whole.

The body 102 is characterized in that: the compression cavity of the machine body 102 is provided with a liquid spraying opening A or an economizer steam supplementing opening B at the same time.

Magnetic coupling 7, characterized by: the driving coupling 701 is connected with the outer rotor 703, the outer magnetic shoe 704 is embedded in the outer rotor 703, the inner rotor 705 is connected with the driving rotor 2, the inner magnetic shoe 706 is embedded in the inner rotor 705, and the outer rotor 703 and the inner rotor 705 are isolated by the shielding case 702 and connected with the connecting body 101; the outer magnetic shoe 704 and the inner magnetic shoe 706 are arranged in even number pairs in the circumferential direction, and are magnetized in the radial direction, and the magnetic lines of force of adjacent magnetic rows are opposite in direction.

Radial permanent magnet bearing 8, characterized by: the outer ring body 801, the outer magnetic ring 802 and the outer magnetic ring pressing ring 803 are combined into a whole, the inner ring body 804, the inner magnetic ring 805 and the inner magnetic ring pressing ring 806 are combined into a whole, and can be separately installed in pairs; the outer magnetic rings 802 and the inner magnetic rings 805 are axially arranged in even number pairs, and are axially magnetized, and the magnetism between the magnetic rings connected with each other is repelled, or is radially magnetized, and the magnetism between the inner magnetic ring and the outer magnetic ring is repelled.

Two-way permanent magnetism axial thrust bearing 9, characterized by: the static magnetic rings 902 are embedded on the outer ring body 901 and the outer ring body 903 respectively, the thrust magnetic ring 905 is embedded between the inner ring body 904 and the inner ring body 906, and the thrust magnetic ring 905 is positioned between the two static magnetic rings 902; the magnetic repulsion between the thrust magnetic ring 905 and the static magnetic ring 902.

The working process of the magnetic suspension screw type refrigeration (air-conditioning) compressor is as follows:

under the action of an external driving force (such as a motor and a fuel engine), the driving coupling 701 drives the outer rotating body 703 to rotate, and the outer magnetic shoe 704 embedded in the outer rotating body 703 drives the inner magnetic shoe 706 embedded in the inner rotating body 705 through magnetic force, so that the inner rotating body 705 synchronously rotates. In this process, the outer magnetic shoe 704 is not in contact with the inner magnetic shoe 706, and there is no frictional power dissipation.

The inner rotor 705 is connected to the driving rotor 2, and when the inner rotor 705 is driven to rotate, the driving rotor 2 is also driven to rotate synchronously.

The driving rotor 2 and the driven rotor 3 are a pair of screw rotors with specific concave-convex tooth shapes meshed with each other, and are both arranged in the cavity of the machine body 102, and as the driving rotor 2 rotates, the elementary volume of the driving rotor 2 and the driven rotor 3 changes periodically from expansion to reduction, so that the refrigerant gas is sucked, compressed and discharged in the compressor cavity, and the state of the refrigerant gas changes: temperature rise, pressure rise and volume reduction. After the refrigerant gas with high temperature and high pressure is discharged out of the compressor, the refrigerant gas enters the condenser, heat is emitted through heat exchange and condensed into liquid, the liquid enters the evaporator through pressure reduction and throttling, the heat is absorbed through the heat exchange and evaporated into the refrigerant gas with low temperature and low pressure, and the state of the refrigerant gas is changed again: temperature reduction, pressure reduction, volume enlargement. The refrigerant gas is sucked by the compressor again, thereby completing the refrigeration cycle.

The liquid medium has the characteristics of large latent heat of vaporization and certain viscosity, and a certain amount of refrigerant liquid is sprayed into the compressor cavity to absorb compression heat, reduce the adiabatic index of the medium, make the compression process tend to an isothermal process, reduce power consumption and simultaneously absorb noise in the vaporization process of the medium. The compression cavity of the body 102 is provided with a liquid spraying opening A for cooling and reducing noise. A certain amount of refrigerant liquid is sprayed into the cavity of the compressor, comes from a branch of a condenser in the refrigeration system, enters the cavity of the compressor through the liquid spraying opening A, is mixed with refrigerant gas sucked by the compressor, absorbs heat for vaporization, is discharged into the condenser together, and is cooled into liquid, so that liquid spraying circulation is completed.

The periodic change of the element volume of the driving rotor 2 and the driven rotor 3 from expansion to reduction to re-steam supplement provides possibility, so that the screw compressor realizes quasi-two-stage compression, namely an economizer, and the low-temperature performance of the compressor is greatly improved. The economizer steam supplementing opening B is opened.

The magnetic suspension screw type refrigeration (air-conditioning) compressor has the advantages that the screw type refrigeration (air-conditioning) compressor in the prior art cannot achieve: the friction power consumption of a rotary moving part of the compressor is eliminated, oil-free lubrication operation is realized, the defects that oil film thermal resistance and a filter screen increase pressure drop are overcome, comprehensive adaptability and zero leakage of a refrigerant are realized, a refrigeration cycle system is simplified, resources are saved, and the performance and reliability of the compressor are greatly improved.

The difference between fig. 9 and fig. 7 is: the inner and outer magnetic rings of fig. 9 are radially magnetized and fig. 7 is axially magnetized.

The difference between fig. 10 and fig. 8 is: the thrust magnetic ring of fig. 10 is composed of two identical magnetic rings which repel each other, and fig. 8 is a magnetic ring. In both fig. 10 and fig. 8, the magnetic force between the thrust magnetic ring and the static magnetic ring is repulsive.

Claims

1. The utility model provides a magnetic suspension screw refrigeration compressor, constitutes a whole, characterized by spare parts such as organism part (1), drive rotor (2), driven rotor (3), magnetic coupling (7), radial permanent magnet bearing (8) and two-way permanent magnet axial thrust bearing (9) at least:

the connecting body (101), the machine body (102), the exhaust end seat (103), the exhaust end cover (104), the end cover (105) and the silencer (111) are connected into a machine body component through screws;

the driving rotor component is formed by assembling a driving rotor (2), a driving rotor air suction end radial permanent magnetic bearing (201), a driving rotor air suction end shaft sleeve (22), a driving rotor exhaust end shaft sleeve (23), a driving rotor exhaust end radial permanent magnetic bearing (202), a driving rotor exhaust end clearance adjusting ring (203), a driving rotor exhaust end bidirectional permanent magnetic axial thrust bearing (204), a driving rotor exhaust end bearing cover (27), a driving rotor exhaust end belleville spring (28) and a driving rotor exhaust end locking nut (29);

the driven rotor component is formed by assembling a driven rotor (3), a driven rotor air suction end radial permanent magnetic bearing (301), a driven rotor air suction end shaft sleeve (32), a driven rotor exhaust end shaft sleeve (33), a driven rotor exhaust end radial permanent magnetic bearing (302), a driven rotor exhaust end clearance adjusting ring (303), a driven rotor exhaust end bidirectional permanent magnetic axial thrust bearing (304), a driven rotor exhaust end bearing cover (37), a driven rotor exhaust end belleville spring (38) and a driven rotor exhaust end locking nut (39);

the magnetic coupling is formed by combining a driving coupling (701), a shielding cover (702), an outer rotating body (703), outer magnetic tiles (704), an inner rotating body (705) and inner magnetic tiles (706);

the outer ring body (801), the outer magnetic ring (802), the outer magnetic ring pressing ring (803), the inner ring body (804), the inner magnetic ring (805) and the inner magnetic ring pressing ring (806) are combined to form a radial permanent magnet bearing;

the outer ring body (901), the static magnetic ring (902), the outer ring body (903), the inner ring body (904), the thrust magnetic ring (905) and the inner pressure ring body (906) are combined to form the bidirectional permanent magnet axial thrust bearing.

2. A machine body (102) of a magnetic levitation screw refrigeration compressor as claimed in claim 1, wherein: a compression cavity of the machine body (102) is provided with a liquid spraying opening (A) or an economizer steam supplementing opening (B).

3. Magnetic coupling (7) of a magnetic levitation screw refrigeration compressor according to claim 1, characterized in that: the driving coupling (701) is connected with the outer rotating body (703), the outer magnetic shoe (704) is embedded in the outer rotating body (703), the inner rotating body (705) is connected with the driving rotor (2), the inner magnetic shoe (706) is embedded in the inner rotating body (705), and the outer rotating body (703) and the inner rotating body (705) are isolated by the shielding cover (702) and connected with the connecting body (101); the outer magnetic shoe (704) and the inner magnetic shoe (706) are arranged in even number pairs in the circumferential direction, and are magnetized in the radial direction, and the magnetic lines of force of adjacent magnetic rows are opposite in direction.

4. Radial permanent magnet bearing (8) of a magnetic levitation screw refrigeration compressor according to claim 1, characterized in that: the outer ring body (801), the outer magnetic ring (802) and the outer magnetic ring pressing ring (803) are combined into a whole, and the inner ring body (804), the inner magnetic ring (805) and the inner magnetic ring pressing ring (806) are combined into a whole and can be separately installed in pairs; the outer magnetic rings (802) and the inner magnetic rings (805) are axially arranged in even number pairs, and are axially magnetized, the magnetism between the magnetic rings connected with each other is repelled, or the magnetism between the inner magnetic ring and the outer magnetic ring is repelled radially.

5. The bidirectional permanent magnetic axial thrust bearing (9) of a magnetic levitation screw refrigeration compressor as claimed in claim 1, characterized in that: the static magnetic rings (902) are embedded on the outer ring body (901) and the outer ring body (903) respectively, the thrust magnetic ring (905) is embedded between the inner ring body (904) and the inner ring body (906), and the thrust magnetic ring (905) is positioned between the two static magnetic rings (902); the magnetism between the thrust magnetic ring (905) and the static magnetic ring (902) is repulsive.