Rotor assembly and working method thereof, compressor and air conditioning equipment

Abstract

The present invention relates to a rotor assembly and a working method thereof, a compressor and an air conditioning device, wherein the rotor assembly comprises: a rotor (2); and a first bearing (5) and a second bearing (7), which are installed on the rotor (2), wherein the first bearing (5) is a dynamic pressure gas bearing, and the radial size of the inner ring (71) of the second bearing (7) relative to the rotor (2) can be adjusted according to the working state of the first bearing (5). This rotor assembly can flexibly adjust the supporting state of the bearing to the rotor under different operating conditions of the rotor, thereby improving the stability of the rotor operation and the bearing load capacity, and reducing the wear of the first bearing.

Description

Technical Field

[0001] The present invention relates to the technical field of air compression equipment, and in particular to a rotor assembly and a working method thereof, a compressor and air conditioning equipment. Background Art

[0002] Bearings are essential basic components in rotating machinery. Their functions include: supporting the continuous rotation of the shaft and its parts, and reducing the friction between the rotor and the supporting parts.

[0003] In the current centrifugal compressor, the commonly used bearings include rolling bearings, sliding bearings and magnetic bearings. Rolling bearings have the advantages of low friction resistance, sensitive starting, high efficiency, etc., and are widely used, but the disadvantage is that they have poor impact resistance and are not suitable for high-speed environments; traditional oil sliding bearings have good adaptability in high-precision, heavy-load, impact and other occasions, but due to structural limitations, they must be equipped with a lubrication system and corresponding sealing, which increases the complexity of the system; magnetic bearings have been widely used in small and medium-sized compressors in recent years, with advantages such as high speed and oil-free, but their bearing clearance is large, which limits performance improvement.

[0004] With the development trend of miniaturization of centrifugal compressors, the industry has put forward higher and higher requirements for bearings, not only requiring them to operate at a higher speed, but also requiring them to have extremely high rotation accuracy. Among them, air bearings have a series of advantages such as low friction loss, almost no friction at extremely high speeds, good high temperature stability, low vibration, and no need for lubricating oil, and are gradually being used in centrifugal compressors.

[0005] Air bearings are divided into static gas bearings and dynamic gas bearings according to the different mechanisms of lubricating gas film generation. Static gas bearings use an external gas source to supply air to the bearing to generate pressure to support the load, while dynamic gas bearings use the pressure gas film generated by the wedge-shaped space between the shaft and the inner surface of the bearing to support the load. Compared with static gas bearings, dynamic gas bearings do not require an external gas source, simplifying the structure, and its dynamic pressure effect will become more obvious as the relative motion speed increases, making it very suitable for high-speed environments.

[0006] However, after applying the hydrodynamic gas bearing to the centrifugal compressor, it was found during use that the rotor operation stability was poor when the compressor was in the starting, stopping or reverse operating conditions. Summary of the invention

[0007] The purpose of the present invention is to provide a rotor assembly and a working method thereof, a compressor and an air-conditioning device, which can improve the stability of the rotor support.

[0008] One aspect of the present invention provides a rotor assembly, comprising:

[0009] a rotor; and

[0010] The first bearing and the second bearing are installed on the rotor. The first bearing is a dynamic pressure gas bearing. The radial size of the inner ring of the second bearing relative to the rotor can be adjusted according to the working state of the first bearing.

[0011] In some embodiments, the rotor assembly further comprises:

[0012] The adjusting component is configured to combine the inner ring with the rotor when the first bearing is in an unstable working state so as to support the rotor through the second bearing; and to disengage the inner ring from the rotor when the first bearing is in a stable working state so as to support the rotor through the first bearing.

[0013] In some embodiments, there is a first gap between the first bearing and the rotor, and when the first bearing is in a stable working state, there is a second gap between the inner ring and the rotor, and the second gap is larger than the first gap.

[0014] In some embodiments, the inner ring includes:

[0015] at least two inner ring segments arranged in a circumferential direction; and

[0016] at least two elastic elements connected between ends of adjacent inner ring segments;

[0017] When the inner ring is combined with the rotor, the ends of adjacent inner ring segments are in contact with each other; when the inner ring is separated from the rotor, a third gap exists between the ends of adjacent inner ring segments.

[0018] In some embodiments, the inner ring is configured to be able to receive radial force exerted by high-pressure gas introduced from the outside;

[0019] The rotor assembly further comprises an adjusting component for adjusting the pressure of the high-pressure gas so as to adjust the radial size of the inner ring.

[0020] In some embodiments, the rotor assembly further comprises:

[0021] A rotation speed detection component, used for detecting the rotation speed of the rotor; and

[0022] The control component is used to increase the gas pressure to a first pressure value when the rotation speed of the rotor is in a first rotation speed range, so that the inner ring and the rotor are combined; and to reduce the gas pressure to a second pressure value when the rotation speed of the rotor is in a second rotation speed range, so that the inner ring and the rotor are disengaged; wherein the first rotation speed range is smaller than the second rotation speed range, and the first pressure value is larger than the second pressure value.

[0023] In some embodiments, the rotor assembly includes a support unit, the support unit is disposed at at least one end of the rotor, and the support unit includes a first bearing and a second bearing.

[0024] In some embodiments, the support unit comprises:

[0025] The support unit includes:

[0026] First bearing;

[0027] Two second bearings are arranged at intervals along the axial direction, and each second bearing is arranged on the same side of the first bearing;

[0028] A second bearing seat, used for supporting the rotor through each second bearing, and the second bearing seat is provided with an air inlet passage for introducing external high-pressure gas; and

[0029] The spacing component is arranged between adjacent second bearings and fixed to the inner ring. A pressure chamber is arranged in the spacing component. The pressure chamber is communicated with the air bleed channel and is configured to allow the high-pressure gas to apply radial force to the inner ring.

[0030] In some embodiments, the support unit includes two second bearings, the inner rings of the two second bearings are integrally formed with the spacer assembly, and the outer rings of the two second bearings are respectively in contact with two side surfaces of the spacer assembly along the axial direction and are slidably arranged.

[0031] In some embodiments, the second bearing in the same support unit is located axially outside the first bearing.

[0032] In some embodiments, the rotor comprises:

[0033] a first shaft section, wherein a first bearing is disposed on the first shaft section;

[0034] a second shaft segment, on which a second bearing is disposed, and the diameter of the second shaft segment is smaller than that of the first shaft segment; and

[0035] The guide portion is arranged at the connection between the first shaft segment and the second shaft segment, and is used to guide the refrigerant on the first shaft segment to the second shaft segment.

[0036] In some embodiments, an outer contour of the guide portion is in the shape of an arc, a slope, or a step in the longitudinal section of the rotor.

[0037] In some embodiments, the rotor assembly further comprises a housing, and the support unit further comprises:

[0038] A first bearing seat connected to the housing and used to support the rotor through a first bearing; and

[0039] The second bearing seat is connected to the first bearing seat and is independent of the housing, and is used to support the rotor through the second bearing.

[0040] In some embodiments, a first stop is provided at one end of the second bearing seat close to the first bearing seat, which is used to limit the freedom of the first bearing seat to move axially toward the second bearing seat and to thrust the first bearing; and / or

[0041] A second stop is provided on the inner side wall of the shell, which is used to limit the freedom of the first bearing seat to move axially away from the second bearing seat.

[0042] In some embodiments, the second bearing comprises an angular contact roller bearing.

[0043] Another aspect of the present invention provides a compressor, comprising the rotor assembly of the above embodiment.

[0044] Another aspect of the present invention provides an air conditioning device, comprising the compressor of the above embodiment.

[0045] Another aspect of the present invention provides a working method of the rotor assembly based on the above embodiment, comprising:

[0046] determining the working state of the first bearing;

[0047] The radial dimension of the inner ring is adjusted according to the working state of the first bearing.

[0048] In some embodiments, the step of adjusting the radial size of the inner ring according to the working state of the first bearing includes:

[0049] When the first bearing is in an unstable working state, the gas pressure is increased to a first pressure value through the adjusting component, so that the inner ring is combined with the rotor to support the rotor through the second bearing;

[0050] When the first bearing is in a stable working state, the gas pressure is reduced to a second pressure value through the adjusting component to disengage the inner ring from the rotor so as to support the rotor through the first bearing. The second pressure value is less than the first pressure value.

[0051] In some embodiments, the step of determining the working state of the first bearing comprises:

[0052] Detect the rotation speed of the rotor;

[0053] Determine the range in which the rotor speed is located. When the rotor speed is in a first speed range, determine that the first bearing is in an unstable working state; when the rotor speed is in a second speed range, determine that the first bearing is in a stable working state, and the first speed range is smaller than the second speed range.

[0054] The rotor assembly of an embodiment of the present invention includes a first bearing and a second bearing for supporting the rotor. The first bearing is a hydrodynamic gas bearing. The radial size of the inner ring of the second bearing relative to the rotor can be adjusted according to the working state of the first bearing when the rotor is in different working conditions, so as to flexibly adjust the supporting state of the bearing for the rotor under different working conditions of the rotor, thereby improving the stability of the rotor operation and the load-bearing capacity of the bearing, and preventing abnormal wear of the first bearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0056] Figure 1 are cross-sectional views of some embodiments of the compressor of the present invention;

[0057] Figure 2 for Figure 1 A schematic structural diagram of a first bearing in the compressor shown;

[0058] Figure 3 for Figure 1 A schematic diagram of the structure of the second bearing in the compressor shown;

[0059] Figure 4 for Figure 3 Schematic diagrams of the structures of some embodiments of the inner ring in the second bearing are shown.

[0060] Description of Reference Numerals

[0061] 1. Housing; 2. Rotor; 3. Stator; 4. First bearing seat; 5. First bearing; 6. Second bearing seat; 7. Second bearing; 9. Spacer assembly; 9', spacer section; 10. Bearing gland; 10', locking nut;

[0062] 11. Refrigerant outlet; 12. Guide groove; 13. Refrigerant inlet; 14. Second stop; 21. First shaft section; 22. Second shaft section; 23. Third shaft section; 24. Guide portion; 31. Hole; 41. First mounting hole; 51. Bearing sleeve; 52. Corrugated foil; 53. Top foil; 61. Second mounting hole; 611. First hole section; 612. Second hole section; 62. First stop; 71. Inner ring; 711. Inner ring section; 712. Elastic element; 713. Mounting groove; 72. Outer ring; 73. Rolling element; 74. Retaining cage; 81. Air duct; 82. Pressure chamber; 82', sub-chamber. DETAILED DESCRIPTION

[0063] The present invention is described in detail below. In the following paragraphs, different aspects of the embodiments are defined in more detail. Each aspect so defined can be combined with any other aspect or aspects, unless explicitly stated not to be combined. In particular, any feature that is considered to be preferred or advantageous can be combined with one or more other features that are considered to be preferred or advantageous.

[0064] The terms "first", "second" and the like appearing in the present invention are only for the convenience of description to distinguish different components with the same name, and do not indicate a priority or primary and secondary relationship.

[0065] The present invention improves the rotor assembly of a centrifugal compressor. In order to facilitate the description of the improvements of the present invention, the overall structure of the centrifugal compressor is described below.

[0066] like Figure 1 As shown, a two-stage centrifugal compressor is taken as an example, which includes a housing 1, a rotor 2 and a stator 3. The rotor 2 and the stator 3 form a motor, which is arranged in the housing 1. The stator 3 is a rotating part, on which a winding is arranged, and is fixed to the housing 1 by a tight fit, so that the rotor 2 can rotate at a high speed by generating a magnetic field. The stator 3 is sleeved outside the rotor 2 and is located in the middle area of ​​the rotor 2 along the axial direction, and the rotor 2 and the stator 3 are clearance-fitted.

[0067] The first volute and the second volute are connected to the two ends of the shell 1 in the axial direction, forming the compressor shell together. The compressor shell is irregular in shape and can be formed by casting, mainly supporting and fixing the stator 3 and the bearing seat. The shell 1 can be a cylindrical structure, the stator 3 is tightly matched with the shell 1, the rotor 2 is arranged at the center of the shell 1, an impeller is arranged at each end of the rotor 2, and a diffuser is arranged at the inner end of the impeller. When the impeller rotates at high speed, the gas rotates with it. Under the action of centrifugal force, the gas is thrown into the rear diffuser for expansion, and the velocity energy of the medium at the impeller outlet is converted into pressure energy. The gas with increased pressure is discharged from the volute.

[0068] The working principle of this compressor is as follows: during the operation of the compressor, the rotor 2 rotates at a high speed, the gas enters the diffuser through the impeller on the left, the gas enters the first volute after the first stage of compression, the exhaust channel on the first volute guides the compressed gas to enter the right impeller, and enters the right diffuser after the centrifugal action of the right impeller, the gas enters the second volute after the second stage of compression, and is discharged from the compressor through the exhaust channel on the second volute.

[0069] In order to cool the stator 3 during the operation of the compressor, a refrigerant inlet 13 and a refrigerant outlet 11 are provided on the side wall of the housing 1, and a spiral guide groove 12 is provided on the inner wall of the housing 1 to guide the refrigerant from the motor cavity on the first side of the stator 3 to the motor cavity on the second side, thereby cooling the stator 3 during the flow process. The gaseous refrigerant formed after cooling the stator 3 returns from the gap between the stator 3 and the rotor 2 to cool the rotor 2. The liquid refrigerant that is not completely gasified after cooling the stator 3 returns to the motor cavity on the first side through the hole 31 provided on the stator 3 along the axial direction, and is discharged from the motor cavity through the refrigerant outlet 11.

[0070] In order to support the rotor 2, first bearings 5 ​​are installed at both ends of the rotor 2 for bearing the radial force exerted on the rotor 2 during operation. The first bearing 5 is a radial bearing. The first bearing 5 adopts a hydrodynamic gas bearing and is supported by a first bearing seat 4. The first bearing seat 4 can be fixed to the housing 1. The stator 3 is axially located between the two first bearings 5.

[0071] like Figure 2 As shown, the dynamic pressure gas bearing includes from the outside to the inside: a bearing sleeve 51, an elastic corrugated foil 52 and a top foil 53. A dynamic pressure gas film will be formed between the top foil 53 and the rotor 2. When a wedge-shaped structure is formed between the top foil 53 and the high-speed rotating rotor 2, due to the viscosity of the gas, the rotor 2 drives the gas to move, compresses the gas in the wedge-shaped area, forms a gas film high pressure, and supports the stable operation of the rotor 2. When the dynamic pressure gas film is formed, the rotation direction of the rotor 2 points from the non-fixed end of the corrugated foil 52 and the top foil 53 to the fixed end, so that the gas enters from the large cross section and exits from the small cross section, as shown by the arrow θ.

[0072] When the compressor control program is abnormal or the compressor stops abnormally, causing the exhaust pressure to recoil, there is a possibility that the rotor 2 will rotate in the opposite direction. At this time, it is difficult to form a stable air film, and the hydrodynamic gas bearing fails. Moreover, during the startup and shutdown of the compressor, since the air film of the hydrodynamic gas bearing is not formed, the inner surface of the top foil 53 and the rotor 2 are in dry friction contact. During frequent starts and stops, the wear of the first bearing 5 is further aggravated, which will reduce its service life. In addition, since the hydrodynamic gas bearing is oil-free, it means that the lubricating oil medium is changed from oil to refrigerant gas, and the viscosity of the gas is only one thousandth of the viscosity of the oil, resulting in a small support stiffness and low load-bearing capacity of the hydrodynamic gas bearing. When the rotor 2 is working at a low speed, the air film load-bearing capacity is low, resulting in low bearing capacity of the bearing and instability of the shaft system.

[0073] When the first bearing 5 is in the various unstable working states mentioned above, in order to improve the working stability of the rotor 2, the rotor assembly of the present invention includes a first bearing 5 and a second bearing 7, both of which are installed on the rotor 2. Among them, the first bearing 5 is a gas dynamic pressure bearing, and the second bearing 7 can be a rolling bearing, such as Figure 3 As shown, it includes an inner ring 71, an outer ring 72 and a rolling body 73 disposed between the inner ring 71 and the outer ring 72. The radial size of the inner ring 71 is adjustable, specifically, it can be adjusted according to the operating conditions of the rotor 2. Figure 3 As shown, the rolling element 73 can be arranged on the cage 74. The rolling bearing is a contact bearing, which has sensitive starting, high load-bearing capacity, stable rigidity, can make the shaft system run stably at low speed, and has simple setting and low cost.

[0074] like Figure 1As shown, the rotor assembly may further include a second bearing seat 6, which is fixedly arranged to support the rotor 2 through a second bearing 7. The outer ring 72 of the second bearing 7 is tightly fitted with the second bearing seat 6, for example, the interference is 40-60 μm.

[0075] This embodiment can flexibly adjust the support state of the bearing for the rotor under different operating conditions of the rotor, thereby improving the stability of the rotor operation and the bearing capacity of the bearing, preventing abnormal wear of the first bearing, and avoiding dry friction between the inner surface of the top foil 53 of the hydrodynamic gas bearing and the rotor 2.

[0076] Furthermore, the rotor assembly of the present invention may also include an adjusting component for combining the inner ring 71 with the rotor 2 when the rotor 2 is in a starting, stopping, reversing or low speed working condition, so that the first bearing 5 is in an unstable working state. For example, a tight fit is formed between the inner ring 71 and the rotor 2 to support the rotor 2 through the second bearing 7. At this time, the characteristics of the rolling bearing such as sensitive starting, high load-bearing capacity and stable stiffness are utilized to prevent the rotor 2 from becoming unstable; and when the rotor 2 is in a high speed working condition and the first bearing 5 is in a stable working state, the inner ring 71 is disengaged from the rotor 2 to support the rotor 2 through the first bearing 5. At this time, the friction loss is small, the rotation accuracy is high and the rotor stability is good.

[0077] This rotor assembly can flexibly adjust the support state of the bearing on the rotor 2 under different operating conditions of the rotor 2, thereby improving the stability of the operation of the rotor 2 and the bearing capacity of the bearing. The distinction between high speed and low speed is the speed at which the first bearing 5 can establish a stable air film, or the speed at which the rotor 2 can be suspended.

[0078] When the first bearing 5 is in an unstable working state, such as during the start-up of the compressor, a stable gas film is not established between the first bearing 5 and the rotor 2. At this time, since the inner ring 71 of the second bearing 7 is connected to the rotor 2, and the outer ring 72 and the second bearing seat 6 are tightly matched, the second bearing 7 plays a priority and sole supporting role for the rotor 2, which can solve the problem of low load-bearing capacity of the dynamic pressure gas bearing at low speed. When the first bearing 5 is in a stable working state, the inner ring 71 of the second bearing 7 is disengaged from the rotor 2, and the first bearing 5 plays a major supporting role for the rotor 2. Moreover, due to the superiority of the dynamic pressure gas bearing in positioning accuracy, the amplitude of the rotor 2 is very small, which can improve the stability of the rotor operation.

[0079] like Figure 1As shown, there is a first gap between the first bearing 5 and the rotor 2. When the first bearing 5 is in a stable working state, there is a second gap between the inner ring 71 and the rotor 2, and the second gap is larger than the first gap. In this way, the rotor 2 can be independently supported by the first bearing 5 under high speed conditions to prevent the second bearing 7 from participating in the support due to precision error, and fully utilize the advantages of the dynamic pressure gas bearing with low friction loss, high rotation accuracy and good rotor stability.

[0080] Optionally, the second gap may also be no larger than the first gap. Due to the superiority of the hydrodynamic gas bearing in positioning accuracy, the amplitude of the rotor 2 is very small, which is smaller than the internal gap of the rolling bearing, so the rolling bearing is equivalent to being in a suspended state, and the first bearing 5 plays a major supporting role for the rotor 2.

[0081] like Figure 4 As shown, the inner ring 71 includes: at least two inner ring segments 711 and at least two elastic elements 712, such as springs, arranged along the circumferential direction, and the elastic elements 712 are connected between the ends of adjacent inner ring segments 711. When the inner ring 71 is combined with the rotor 2, the ends of adjacent inner ring segments 711 are in contact with each other, and the contact surface is K, so that the inner ring 71 and the rotor 2 form a tight fit, and the clamping force of each inner ring segment 711 on the rotor 2 is increased; when the inner ring 71 is disengaged from the rotor 2, there is a third gap between the ends of adjacent inner ring segments 711, so that each inner ring segment 711 expands to increase the radial size, so that there is a second gap between the inner ring 71 and the rotor 2.

[0082] For example, in Figure 4 In the embodiment, the inner ring 71 includes two inner ring segments 711 and two elastic elements 712. A mounting groove 713 is provided on the two end surfaces of each inner ring segment 711. The two ends of the elastic element 712 are respectively connected to the bottom surfaces of the mounting grooves 713 of the two inner ring segments 711 that are close to each other. When the inner ring 71 is combined with the rotor 2, the elastic element 712 is in a compressed state. When the inner ring 71 is disengaged from the rotor 2, the elastic element 712 is in a free state.

[0083] like Figure 3 As shown, the inner ring 71 is configured to receive radial force exerted by high-pressure gas introduced from the outside; for example, high-pressure gas outside the second bearing seat 6 or outside the housing 1, and the regulating component is used to adjust the pressure of the high-pressure gas to adjust the radial size of the inner ring 71. For example, the regulating component may include a pressure regulating valve, etc., and the regulating component may receive a control signal from the control component to automatically adjust, or may be manually adjusted.

[0084] This embodiment is easy to actively adjust the radial size of the inner ring 71 by controlling the air pressure, which can achieve precise adjustment, and can provide a stable connection force when the inner ring 71 is combined with the rotor 2 to prevent slippage between the rotor 2 and the inner ring 71. Alternatively, the radial size of the inner ring 71 can also be adjusted by high-pressure oil or a mechanical adjustment mechanism.

[0085] Furthermore, the rotor assembly of the present invention may also include: a speed detection component for detecting the speed of the rotor 2; and a control component for causing the regulating component to increase the gas pressure to a first pressure value when the speed of the rotor 2 is in a first speed range so that the inner ring 71 is combined with the rotor 2; and causing the regulating component to reduce the gas pressure to a second pressure value when the speed of the rotor 2 is in a second speed range so that the inner ring 71 is disengaged from the rotor 2; wherein the first speed range is smaller than the second speed range, and the first pressure value is greater than the second pressure value.

[0086] This embodiment can objectively reflect the working state of the first bearing 5 by detecting the rotation speed of the rotor 2 , so as to accurately determine the timing for adjusting the radial dimension of the inner ring 71 of the second bearing 7 .

[0087] like Figure 1 As shown, the rotor assembly includes a support unit, which is arranged at at least one end of the rotor 2 . The support unit includes a first bearing 5 and a second bearing 7 , that is, each first bearing 5 is correspondingly provided with a second bearing 7 .

[0088] This structure can keep the original support mode of the rotor 2 as much as possible when the rotor 2 rotates under low-speed conditions, and can improve the stability of the rotor during the transition between low-speed and high-speed conditions. For the structure in which support units are arranged at both ends of the rotor 2, the support mode of the support at both ends of the rotor 2 can be always maintained, and the working stability of the rotor 2 and the bearing capacity of the bearing can be improved. Preferably, the support units at both ends can be arranged symmetrically to improve the working stability of the rotor 2.

[0089] like Figure 1 and Figure 3 As shown, the support unit includes: a first bearing 5; two second bearings 7 arranged at intervals along the axial direction, each second bearing 7 is arranged on the same side of the first bearing 5; a second bearing seat 6, used to support the rotor 2 through each second bearing 7, and the second bearing seat 6 is provided with an air inlet channel 81 for introducing external high-pressure gas; and a spacing component 9, which is arranged between adjacent second bearings 7 and fixed to the inner ring 71, and a pressure chamber 82 is provided in the spacing component 9, and the pressure chamber 82 is connected to the air inlet channel 81, and is configured to enable the high-pressure gas to apply a radial force to the inner ring 71.

[0090] In this structure, the high-pressure gas introduced from the outside of the second bearing seat 6 can act on the spacing component 9 so as to simultaneously apply radial force to the two second bearings 7 in the same support unit, which can simplify the air bleed structure. Moreover, since the spacing component 9 is located in the middle position between the two second bearings 7, the gas force acting on the two second bearings 7 in the same support unit can be consistent, thereby ensuring the synchronization and dimensional consistency of the adjustment of the inner rings 71 of the two second bearings 7, so that when the first bearing 5 is in an unstable working state, each second bearing 7 can simultaneously support the rotor 2, so that the force on each part of the rotor 2 is balanced; when the first bearing 5 is in a stable working state, each second bearing 7 can be disengaged from the rotor 2 at the same time to avoid affecting the operation of the first bearing 5.

[0091] like Figure 3 As shown, the support unit includes two second bearings 7, the inner rings 71 of the two second bearings 7 are integrally formed with the spacer assembly 9, and the outer rings 72 of the two second bearings 7 are respectively in contact with the two side surfaces of the spacer assembly 9 along the axial direction and are slidably arranged. Since the second bearings 7 work when the rotor 2 is at a low speed, the wear between the outer ring 72 and the spacer assembly 9 can be reduced. Since the spacer assembly 9 is in a rotating state with the inner ring 71, in order to facilitate the supply of air to the pressure chamber 82, the pressure chamber 82 can be designed as an annular groove, and the air inlet channel 81 can be designed as a hole. The cooperation of the hole and the annular groove can realize the supply of air from the fixed second bearing seat 6 to the rotating spacer assembly 9.

[0092] Since the inner rings 71 of the two second bearings 7 are integrally formed with the spacing assembly 9, it is equivalent to increasing the width of the inner ring 71 of the second bearing 7, so that the inner ring 71 is subjected to balanced force when combined with the rotor 2, and is not easily deflected, and the contact length section between the inner ring 71 and the rotor 2 can be increased, thereby improving the bonding force between the inner ring 71 and the rotor 2. In addition, the inner rings 71 of the two second bearings 7 and the spacing assembly 9 form an integral structure, which can improve assembly efficiency. Optionally, the inner ring segment 711 and the spacing assembly 9 can also be fixed by bonding or fasteners.

[0093] In some embodiments, the inner ring 71 includes: at least two inner ring segments 711 and at least two elastic elements 712 arranged along the circumferential direction, and the elastic elements 712 are connected between the ends of adjacent inner ring segments 711. Correspondingly, the spacing component 9 includes at least two arc-shaped spacing segments 9', and the pressure chamber 82 includes at least two sub-chambers 82', each spacing segment 9' is arranged corresponding to each inner ring segment 711 in the circumferential direction, and each spacing segment 9' is provided with a sub-chamber 82'.

[0094] When the ends of adjacent inner ring segments 711 are connected to the ground, each sub-cavity 82' forms an annular groove as a whole, and the gas introduced from the air inlet channel 81 enters the annular groove to apply radial force to each inner ring segment 711 to press the inner ring 71 and the rotor 2. When the air pressure is reduced to form a second gap between the inner ring 71 and the rotor 2, each sub-cavity 82' cannot form a continuous annular groove, and the gap between each sub-cavity 82' can also assist in reducing the air pressure.

[0095] like Figure 1 As shown, the support unit includes at least two second bearings 7 spaced apart in the axial direction, and each second bearing 7 in the same support unit is arranged on the same side of the first bearing 5. This structure can simplify the positioning and support structure of the second bearing 7, and is also conducive to the assembly and lubrication of the second bearing 7.

[0096] like Figure 1 As shown, the second bearing 7 in the same support unit is axially located outside the first bearing 5. In this structure, the first bearing 5 is closer to the motor cooling system, and a proper amount of liquid refrigerant can be used to lubricate and cool the dynamic pressure gas bearing. Moreover, when the second bearing 7 adopts a rolling bearing, it is easy to wear after long-term use. Placing it outside the first bearing 5 is conducive to repairing or replacing the rolling bearing. Optionally, the second bearing 7 in the same support unit is axially located inside the first bearing 5.

[0097] like Figure 1 As shown, the rotor 2 includes: a first shaft segment 21, a second shaft segment 22 and a guide portion 24. The first shaft segment 21 is provided with a first bearing 5, the second shaft segment 22 is provided with a second bearing 7, and the diameter of the second shaft segment 22 is smaller than that of the first shaft segment 21. The guide portion 24 is provided at the connection between the first shaft segment 21 and the second shaft segment 22, and is used to guide the refrigerant on the first shaft segment 21 to the second shaft segment 22.

[0098] When the motor is unevenly cooled, part of the liquid refrigerant does not absorb heat and vaporize, and will accumulate in the motor cavity on the second side. When the rotor 2 rotates at high speed, the dynamic pressure gas bearing will absorb the surrounding refrigerant medium, and the liquid refrigerant will be sucked into the gap between the first bearing 5 and the rotor 2 together with the gaseous refrigerant. An appropriate amount of liquid refrigerant is beneficial for lubricating the bearing and reducing its temperature, but when there is too much liquid refrigerant, liquid will accumulate inside the bearing, occupying space, affecting the formation of the dynamic pressure gas film, and manifested as a larger amplitude of the shaft system.

[0099] By providing the guide portion 24 , the liquid refrigerant between the first bearing 5 and the rotor 2 can be guided to the second bearing 7 , which can not only prevent the liquid refrigerant from accumulating in the first bearing 5 and facilitate the establishment of a stable air film, but also improve the lubrication effect of the second bearing 7 .

[0100] For example, Figure 1As shown, the outer contour of the guide portion 24 is an arc in the longitudinal section of the rotor 2, and its radius is R. The arc can be concave inward or convex outward, and the liquid refrigerant can flow to the second bearing 7 under the guidance of the arc surface. Combined with the high-speed rotation of the rotor 2 during operation, the centrifugal force can be used to accelerate the liquid refrigerant to the second bearing 7. Optionally, the guide portion 24 can also be sloped or stepped.

[0101] When at least two second bearings 7 are axially arranged on the second shaft section 22, the liquid coolant accumulated in the first bearing 5 can flow to each second bearing 7 in sequence. For example, the second bearing 7 is a rolling bearing, and the liquid coolant in the first bearing 5 can continue to flow to the outer rolling bearing through the clearance between the balls after being guided to the inner rolling bearing.

[0102] Still refer to Figure 1 The rotor assembly also includes a shell 1, and the supporting unit may also include: a first bearing seat 4, connected to the shell 1, used to support the rotor 2 through a first bearing 5, the first bearing 5 and the first bearing seat 4 are connected by a tight fit; and a second bearing seat 6, connected to the first bearing seat 4 and independent of the shell 1, used to support the rotor 2 through a second bearing 7.

[0103] This structure directly connects the second bearing seat 6 to the first bearing seat 4, without changing the original structure of the housing 1, and can also reduce the volume of the second bearing seat 6. In addition, the liquid coolant accumulated in the first bearing 5 can enter the second bearing 7 more through the closed cavity formed between the second bearing seat 6 and the rotor 2, preventing the liquid coolant accumulated in the first bearing 5 from flowing to other areas in the housing 1, thereby improving the lubrication effect of the second bearing 7.

[0104] like Figure 1 As shown, the second bearing 7 is arranged outside the first bearing 5, and a first stop 62 is provided at one end of the second bearing seat 6 close to the first bearing seat 4. One end of the first bearing seat 4 is embedded in the first stop 62 and abuts against the bottom surface of the first stop 62, which is used to limit the freedom of the first bearing seat 4 to move axially toward the second bearing seat 6, and at the same time, the first bearing 5 can be thrusted. This structure can make the rotor assembly more compact, and the second bearing seat 6 can support the second bearing 7 while limiting the position of the first bearing seat 4. Furthermore, the second bearing seat 6 can be fixed to the first bearing seat 4 by fasteners.

[0105] Furthermore, a second stop 14 is provided on the inner side wall of the housing 1 to limit the freedom of the first bearing seat 4 to move axially away from the second bearing seat 6. Thus, the freedom of the first bearing seat 4 in both axial directions is limited.

[0106] The first bearing seat 4 and the second bearing seat 6 can be split structures, which are easy to process. Alternatively, the first bearing seat 4 and the second bearing seat 6 are integrally formed, which is easy to assemble and easy to improve the coaxiality of the corresponding mounting holes of the first bearing 5 and the second bearing 7.

[0107] The first bearing seat 4 is provided with a first mounting hole 41 along the axial direction for mounting the first bearing 5. The first bearing 5 and the first mounting hole 41 are tightly fitted, such as transition fit or interference fit. When working, the first bearing 5 uses the dynamic pressure gas film to achieve precise support for the rotor 2 and the parts on the shaft, and the radial runout can be less than 5μm. The second bearing seat 6 is provided with a second mounting hole 61 along the axial direction for mounting each second bearing 7 in the same support unit. The outer diameter of the second bearing 7 is D2, and the inner diameter is D1. The outer ring 72 of the second bearing 7 and the second mounting hole 61 are tightly fitted.

[0108] When the support unit includes at least two second bearings 7 , adjacent second bearings 7 can be spaced apart by arranging a spacing component 9 , so that the positioning of the second bearings 7 is more accurate, the support effect is optimized, and mutual influence between adjacent second bearings 7 is prevented.

[0109] like Figure 1 As shown, the second bearing seat 6 is a rotary structure, including a main body and a flange connected to the main body in the axial direction, and a first stop 62 is provided on the end surface of the flange. The second bearing seat 6 is provided with a second mounting hole 61, which is a stepped hole, including a first hole section 611 and a second hole section 612, and a stepped surface is formed at the connection between the first hole section 611 and the second hole section 612. The outer ring of the second bearing 7 located at the innermost side of the same support unit abuts against the stepped surface, and the inner ring abuts against the thrust surface formed by the second shaft section 22 and the guide portion 24.

[0110] The support unit further includes: a bearing cover 10 and a locking nut 10', the rotor 2 further includes a third shaft segment 23, the third shaft segment 23 is connected to the end of the second shaft segment 22 away from the first shaft segment 21, the diameter of the third shaft segment 23 is smaller than the second shaft segment 22, the outer ring of the outermost second bearing 7 in the same support unit is limited by the bearing cover 10, and the inner ring is limited by the locking nut 10'. After the bearing cover 10 and the locking nut 10' are installed, the axial clearance s with the second bearing 7 can be controlled to be 30 to 50 μm.

[0111] Since the outlet pressure is greater than the inlet pressure when the impeller of the compressor works on the refrigerant during operation, the pressure difference will generate axial force and radial force. In order to balance the axial force on the rotor 2, the second bearing 7 can adopt an angular contact rolling bearing. As a result, the thrust plate and gas thrust bearing in the compressor can be omitted, which can simplify the structure, improve the working reliability of the bearing and reduce the cost.

[0112] When a program abnormality or abnormal shutdown causes exhaust pressure recoil, there is a possibility that the rotor 2 rotates in the opposite direction. At this time, the first bearing 5 cannot form an air film and fails. At this time, the second bearing 7 works, and the angular contact rolling bearing can simultaneously bear the axial force and radial force exerted on the rotor 2.

[0113] Angular contact rolling bearings can be arranged in at least one of the following ways:

[0114] First, a support unit is provided at each end of the rotor 2, each support unit includes a first bearing 5 and a second bearing 7, and the second bearings 7 in the support units at both ends are installed in opposite directions. Since the axial force is related to the structure and speed of the rotor 2 and the working condition of the compressor, its direction is uncertain. This structure can balance the axial forces on the rotor 2 in two directions at the same time.

[0115] Secondly, a support unit is provided at each end of the rotor 2, each support unit includes a first bearing 5 and at least two second bearings 7, each second bearing 7 in the same support unit is installed in the same direction, and the second bearings 7 in the support units at both ends are installed in opposite directions. This structure can balance the axial forces on the rotor 2 in two directions, and can also improve the load-bearing capacity by increasing the number of second bearings 7.

[0116] Third, a support unit is provided at each end of the rotor 2, each support unit includes a first bearing 5 and two second bearings 7, and the two second bearings 7 in the same support unit are installed in opposite directions. This structure can balance the axial forces on the rotor 2 in two directions through one support unit, prevent the axial force on one end of the rotor 2 from being transmitted to the other end, and improve the service life of each component in the shaft system.

[0117] In order to improve the installation accuracy of the rotor assembly, in some embodiments, during the processing of the rotor assembly, the first bearing seat 4, the second bearing seat 6 and the shell 1 can be assembled into a combination, and the combination can be positioned and clamped on the processing equipment, and then the first mounting hole 41 and the second mounting hole 61 can be processed to a preset size through one positioning and clamping.

[0118] By processing the first bearing seat 4, the second bearing seat 6 and the housing 1 in a state of being positioned and forming an assembly, the installation accuracy of the bearing can be ensured by the processing accuracy of the assembly, and through one-time positioning and clamping, a unified processing reference can be used to ensure the coaxiality of each first mounting hole 41 and the second mounting hole 61, thereby improving the positioning accuracy and making the rotor 2 work more stably.

[0119] For example, each first mounting hole 41 and each second mounting hole 61 can be processed sequentially to a preset size from one side of the housing 1 along the axial direction. Each first mounting hole 41 and each second mounting hole 61 can be processed by boring, and the processing tool is processed sequentially from one side of the housing 1 through axial feeding, which can improve the processing efficiency, further improve the coaxiality of each first mounting hole 41 and each second mounting hole 61, improve the positioning accuracy, and make the rotor 2 work more stably.

[0120] The steps of assembling the first bearing seat 4, the second bearing seat 6 and the housing 1 into a combination include: matching the first bearing seat 4 with the second bearing seat 6 through the first stop 62, and matching the first bearing seat 4 with the housing 1 through the second stop 14 to perform a first repositioning, and the order of these two matching assembly links is not limited; fixing the first bearing seat 4 with the second bearing seat 6, and the first bearing seat 4 with the housing 1 by fasteners; after fixing by fasteners, pinning between the first bearing seat 4 and the second bearing seat 6, and between the first bearing seat 4 and the housing 1 to perform a second repositioning.

[0121] After the initial positioning through the first stop 62 and the second stop 14, the positional relationship between the first bearing seat 4, the second bearing seat 6 and the housing 1 is constrained by fasteners. On this basis, on the basis of the original pin holes, pin holes are drilled between the first bearing seat 4 and the second bearing seat 6, and between the first bearing seat 4 and the housing 1, and pins are inserted into the pin holes. The pins can prevent the position changes between the components caused by the large cutting force during the processing process, and can also provide accurate positioning for the subsequent product assembly process. By adopting double positioning, the installation accuracy between the first bearing seat 4, the second bearing seat 6 and the housing 1 can be accurately guaranteed, thereby improving the coaxiality of the first bearing 5 and the second bearing 7.

[0122] After the processing is completed, the assembly is disassembled so that the first bearing 5 and the second bearing 7 can be installed in a state where the housing 1, the first bearing seat 4 and the second bearing seat 6 are separated. During the assembly process, the assembly accuracy of the first bearing 5 and the second bearing 7 can be ensured by the dual positioning method of the stopper and the pin, thereby improving the stability of the bearing rotor system.

[0123] The rotor assembly of the present invention adopts a multi-bearing cooperation working mode, which can realize high-precision operation of the compressor in both low-speed and high-speed stages. It utilizes the characteristics of rolling bearings with sensitive starting, high load-bearing capacity and stable rigidity, and through the rolling bearings and the rotor 2, it can realize that the rolling bearings support the rotor 2 at low speed, so that the rotation accuracy of the rotor 2 is 10 to 30 μm. At the same time, the four angular contact bearings are used in pairs on one side and arranged symmetrically on both sides, which can improve the bearing load-bearing capacity on the one hand, and effectively balance the axial force generated by the shaft system and the bearing itself on the other hand. When the speed of the compressor is increased, the dynamic pressure effect will become more and more obvious with the increase of speed, and a dynamic pressure gas film will gradually form. The dynamic pressure gas bearing gradually plays a supporting role. When the dynamic pressure gas film is fully formed, due to the high stability of the gas film, the rotor amplitude is less than 5 μm. At this time, the dynamic pressure gas bearing works alone, and the rolling bearing does not work, realizing high-precision operation at high speed.

[0124] The present invention also provides a compressor, such as a centrifugal compressor, comprising the rotor assembly of the above embodiment. Since the rotor assembly of the present invention can improve the stability of the rotor in various working states and the bearing capacity of the bearing, the working performance of the centrifugal compressor can be optimized and the service life can be increased. Moreover, the stable rotation of the rotor can also reduce the noise generated during the operation of the compressor. In addition, the rotor assembly of the present invention can also be used in an electric motor.

[0125] The specific working process of this compressor is as follows:

[0126] When the compressor is stationary, the inner ring 71 of the second bearing 7 is tightly fitted with the rotor 2 due to the effect of gas pressure to ensure the compressor starting conditions. At this time, the rotor 2 is supported by the second bearing 7.

[0127] When the compressor is running at a low speed, the control gas pressure is increased to make the rotor 2 fit tightly with the inner ring 71, so as to support the rotor 2 to run at a low speed through the second bearing 7.

[0128] As the compressor gradually accelerates, the center of gravity of the rotor 2 gradually rises, driving the inner ring 71 to move together. At this time, the control air pressure will be gradually reduced through the adjusting component. The inner ring 71 expands outward under the action of the elastic element 712 and gradually loosens the rotor. When the rotor 2 reaches a certain speed, a rigid air film is formed between the rotor 2 and the first bearing 5, so that the rotor 2 is adaptively suspended, so that the rotor 2 can run at a high speed through the first bearing 5.

[0129] When the compressor suddenly stops or actively slows down during high-speed operation, when the speed gradually approaches the rotor suspension speed, the dynamic pressure effect gradually disappears, causing the control air pressure to gradually increase, such as linearly increase, so that the inner ring 71 gradually approaches the rotor 2. When the speed of the rotor 2 is in the first speed range, that is, lower than the suspension speed, the inner ring 71 holds the rotor 2 under the action of air pressure, and the dynamic pressure gas bearing loses the air film support effect. The rotor 2 runs until it stops with the support of the second bearing 7. So far, during the entire cycle from starting to stopping the compressor, there is no direct contact between the rotor 2 and the first bearing 5, and there is no friction risk, which improves the unit's operating reliability and bearing life.

[0130] Furthermore, this type of compressor can operate with high precision in both low and high speed stages. Among them, by utilizing the characteristics of rolling bearings with sensitive starting, high load-bearing capacity and stable rigidity, the shaft system is supported by rolling bearings at low speed, and the rotation accuracy is 10 to 30 μm. At the same time, four angular contact bearings are used in pairs on one side and arranged symmetrically on both sides. On the one hand, the bearing load can be increased, and on the other hand, the axial force generated by the shaft system and the bearing itself can be effectively balanced. When the speed of the compressor is increased, the dynamic pressure effect will become more and more obvious with the increase of speed, and a dynamic pressure air film will gradually form. The first bearing 5 gradually plays a supporting role. When the dynamic pressure air film is fully formed, due to the high stability of the air film, the amplitude of the rotor 2 is less than 5 μm. At this time, the first bearing 5 works alone, and the second bearing 7 does not work, so as to achieve high-precision operation at high speed.

[0131] The present invention also provides an air conditioning device, comprising the compressor of the above embodiment. Such air conditioning device has high working stability and reliability.

[0132] The present invention further provides a working method of the rotor assembly based on the above embodiment, which in some embodiments includes:

[0133] Step 101, determining the working state of the first bearing 5;

[0134] Step 102 : adjusting the radial dimension of the inner ring 71 according to the working state of the first bearing 5 .

[0135] Wherein, step 101 can be executed by a control component, and step 102 can be executed by controlling the air pressure regulating valve by the control component.

[0136] In some embodiments, the step 101 of determining the working state of the first bearing 5 includes:

[0137] Step 101A, detecting the rotation speed of the rotor 2;

[0138] Step 101B, determine the speed interval of the rotor 2, and when the speed of the rotor 2 is in the first speed interval, determine that the first bearing 5 is in an unstable working state; when the speed of the rotor 2 is in the second speed interval, determine that the first bearing 5 is in a stable working state. The first speed interval is smaller than the second speed interval.

[0139] In some embodiments, step 102 of adjusting the radial dimension of the inner ring 71 according to the working state of the first bearing 5 includes:

[0140] Step 102A, when the first bearing 5 is in an unstable working state, the gas pressure is increased to a first pressure value by means of an adjusting component, so that the inner ring 71 is combined with the rotor 2, so as to support the rotor 2 through the second bearing 7;

[0141] Step 102B: When the first bearing 5 is in a stable working state, the gas pressure is reduced to a second pressure value by adjusting the component, so that the inner ring 71 is disengaged from the rotor 2, so as to support the rotor 2 through the first bearing 5. The first pressure value is greater than the second pressure value.

[0142] The above is a detailed introduction to a rotor assembly and its working method, compressor and air-conditioning equipment provided by the present invention. Specific embodiments are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A rotor assembly, characterized in that: include: Rotor (2); as well as A first bearing (5) and a second bearing (7) are mounted on the rotor (2), the first bearing (5) being a dynamic pressure gas bearing, and the radial dimension of the inner ring (71) of the second bearing (7) relative to the rotor (2) can be adjusted according to the working state of the first bearing (5); Wherein, the inner ring (71) comprises: At least two inner ring segments (711) arranged along the circumferential direction; and at least two elastic elements (712), the elastic elements (712) being connected between ends of adjacent inner ring segments (711); Wherein, when the inner ring (71) is combined with the rotor (2), the ends of adjacent inner ring segments (711) are in abutment with each other; and when the inner ring (71) is disengaged from the rotor (2), a third gap is provided between the ends of adjacent inner ring segments (711).

2. The rotor assembly according to claim 1, characterized in that Also includes: The adjustment component is configured to, when the first bearing (5) is in an unstable working state, enable the inner ring (71) to be combined with the rotor (2) so as to support the rotor (2) through the second bearing (7); and, when the first bearing (5) is in a stable working state, enable the inner ring (71) to be disengaged from the rotor (2) so as to support the rotor (2) through the first bearing (5).

3. The rotor assembly according to claim 2, characterized in that: There is a first gap between the first bearing (5) and the rotor (2), and when the first bearing (5) is in a stable working state, there is a second gap between the inner ring (71) and the rotor (2), and the second gap is larger than the first gap.

4. The rotor assembly according to claim 1, characterized in that: The inner ring (71) is configured to receive a radial force exerted by high-pressure gas introduced from the outside; The rotor assembly also includes an adjusting component for adjusting the pressure of the high-pressure gas to adjust the radial size of the inner ring (71).

5. The rotor assembly according to claim 4, characterized in that: Also includes: A rotation speed detection component, used to detect the rotation speed of the rotor (2); and A control component is used to cause the regulating component to increase the gas pressure to a first pressure value when the rotation speed of the rotor (2) is in a first rotation speed range, so that the inner ring (71) is combined with the rotor (2); and to cause the regulating component to reduce the gas pressure to a second pressure value when the rotation speed of the rotor (2) is in a second rotation speed range, so that the inner ring (71) is disengaged from the rotor (2); wherein the first rotation speed range is smaller than the second rotation speed range, and the first pressure value is larger than the second pressure value.

6. The rotor assembly according to claim 1, characterized in that It comprises a support unit, the support unit is arranged at at least one end of the rotor (2), and the support unit comprises the first bearing (5) and the second bearing (7).

7. The rotor assembly according to claim 6, characterized in that The support unit comprises: The first bearing (5); two second bearings (7) arranged at intervals in the axial direction, each of the second bearings (7) being arranged on the same side of the first bearing (5); A second bearing seat (6) for supporting the rotor (2) via each of the second bearings (7), the second bearing seat (6) being provided with an air inlet passage (81) for introducing external high-pressure gas; and A spacer assembly (9) is disposed between adjacent second bearings (7) and is fixed to the inner ring (71). A pressure chamber (82) is provided in the spacer assembly (9). The pressure chamber (82) is communicated with the air bleed passage (81) and is configured to allow high-pressure gas to apply a radial force to the inner ring (71).

8. The rotor assembly according to claim 7, characterized in that The inner ring (71) of each of the two second bearings (7) is integrally formed with the spacer assembly (9), and the outer ring (72) of each of the two second bearings (7) is respectively in contact with two side surfaces of the spacer assembly (9) along the axial direction and is slidably arranged.

9. The rotor assembly according to claim 6, characterized in that: The second bearing (7) in the same support unit is located axially outside the first bearing (5).

10. The rotor assembly according to claim 1, characterized in that The rotor (2) comprises: A first shaft section (21), wherein the first bearing (5) is provided on the first shaft section (21); a second shaft segment (22), the second shaft segment (22) being provided with the second bearing (7), the second shaft segment (22) having a smaller diameter than the first shaft segment (21); and The guide portion (24) is provided at the connection between the first shaft segment (21) and the second shaft segment (22), and is used to guide the refrigerant on the first shaft segment (21) to the second shaft segment (22).

11. The rotor assembly according to claim 10, characterized in that The outer contour of the guide portion (24) is in the shape of an arc, a slope or a step in the longitudinal section of the rotor (2).

12. The rotor assembly according to claim 6, characterized in that It also includes a housing (1), and the support unit further includes: a first bearing seat (4) connected to the housing (1) and used to support the rotor (2) via the first bearing (5); and A second bearing seat (6) is connected to the first bearing seat (4) and is independent of the housing (1), and is used to support the rotor (2) via the second bearing (7).

13. The rotor assembly according to claim 12, characterized in that A first stop (62) is provided at one end of the second bearing seat (6) close to the first bearing seat (4), for limiting the freedom of the first bearing seat (4) to move axially toward the second bearing seat (6) and for thrusting the first bearing (5); and / or A second stop (14) is provided on the inner side wall of the housing (1) for limiting the freedom of the first bearing seat (4) to move axially away from the second bearing seat (6).

14. The rotor assembly according to claim 1, characterized in that The second bearing (7) comprises an angular contact rolling bearing.

15. A compressor, characterized in that: Comprising the rotor assembly described in any one of claims 1 to 14.

16. An air conditioning device, characterized in that: Comprising the compressor as claimed in claim 15.

17. A working method of the rotor assembly according to any one of claims 1 to 14, characterized in that: include: Determining the working state of the first bearing (5); The radial dimension of the inner ring (71) is adjusted according to the working state of the first bearing (5).

18. The working method according to claim 17, characterized in that: The step of adjusting the radial dimension of the inner ring (71) according to the working state of the first bearing (5) comprises: When the first bearing (5) is in an unstable working state, the gas pressure is increased to a first pressure value through an adjusting component, so that the inner ring (71) is combined with the rotor (2), so as to support the rotor (2) through the second bearing (7); When the first bearing (5) is in a stable working state, the gas pressure is reduced to a second pressure value through the regulating component, so that the inner ring (71) is disengaged from the rotor (2) to support the rotor (2) through the first bearing (5), and the second pressure value is less than the first pressure value.

19. The working method according to claim 17, characterized in that: The step of determining the working state of the first bearing (5) comprises: Detecting the rotation speed of the rotor (2); The range in which the rotation speed of the rotor (2) is located is determined. When the rotation speed of the rotor (2) is in a first rotation speed range, it is determined that the first bearing (5) is in an unstable working state. When the rotation speed of the rotor (2) is in a second rotation speed range, it is determined that the first bearing (5) is in a stable working state. The first rotation speed range is smaller than the second rotation speed range.

Images