Compressor rotor, compressor and air conditioning equipment

Abstract

The present invention relates to a compressor rotor, a compressor and an air-conditioning device, wherein the compressor rotor comprises: a main shaft, a cavity (111) is provided at the end of the main shaft to form a shaft core (112) at the center of the main shaft, and the end of the shaft core (112) extends out of the end of the main shaft; an impeller (14) is sleeved on the outer end of the shaft core (112) and axially positioned by the end of the main shaft outer ring; and a locking component configured to lock the impeller (14) on the shaft core (112). This compressor rotor can reduce the difficulty of disassembling and assembling the impeller, simplify the assembly process and required equipment of the impeller, improve assembly efficiency and the operability of disassembly and maintenance; moreover, this installation method can ensure the strength of the impeller, avoid stress concentration, and thus improve the compression capacity of the compressor.

Description

Technical Field

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

[0002] The centrifugal compressor impeller performs work on the gas, increasing its energy. This energy increase is positively correlated with the impeller's rotational speed. Depending on the compression ratio, the impeller's speed can reach several thousand revolutions per minute, and at high compression ratios, even exceeding 10,000 revolutions per minute. Therefore, the compressor rotor plays a crucial role in ensuring the impeller's reliability and safety during operation.

[0003] Common impeller locking methods used in centrifugal compressors in the prior art include shrink fit locking and key fit locking. Among them, when shrink fit is used, the impeller is heated to about 100°C so that it expands due to the heat and is quickly assembled with the main shaft. The assembly interference generated after the impeller cools is used to achieve the locking purpose. The thermal deformation locking structure is simple and does not require the addition of other parts, but it requires heating equipment, is not conducive to disassembly, and has strict requirements on the assembly process. Traditional key fit locking relies on the fit between the keyway and the key to constrain the impeller displacement and transmit torque, but the key is a standard part, and its inherent right-angle structure causes greater stress concentration at the end of the keyway, reducing the strength of the impeller. Therefore, it is necessary to improve the compressor rotor. Summary of the Invention

[0004] The purpose of the present invention is to provide a compressor rotor, a compressor and an air-conditioning device, which can reduce the difficulty of assembling the compressor rotor.

[0005] According to a first aspect of the present invention, a compressor rotor is provided, comprising:

[0006] A main shaft, wherein the end of the main shaft is provided with a cavity to form a shaft core at the center of the main shaft, and the end of the shaft core extends out of the end of the main shaft;

[0007] An impeller is sleeved on the outer end of the shaft core and is axially positioned by the end of the main shaft outer ring; and

[0008] The locking component is configured to lock the impeller on the shaft core.

[0009] Furthermore, the cavity is centrally symmetrical with respect to the axis of the main shaft.

[0010] Furthermore, the cavity is an annular groove concentric with the main shaft; or the cavity includes a plurality of discrete holes, and each hole is symmetrical with respect to the axis of the main shaft.

[0011] Furthermore, a positioning portion is provided at the inner end of the impeller, the outer side wall of the positioning portion cooperates with the inner side wall of the cavity to radially position the impeller, and a gap is formed between the inner side wall of the positioning portion and the inner side wall of the cavity.

[0012] Furthermore, the outer end of the shaft core is a threaded section, and the locking component includes a locking nut, which is screwed onto the outer end of the shaft core to lock the impeller.

[0013] Furthermore, the outer end of the shaft core exceeds the outer end of the locking nut.

[0014] Furthermore, the impeller is provided with a stepped hole with a diameter gradually decreasing from the inside to the outside, the outer end of the shaft core is a stepped shaft with a diameter gradually decreasing from the inside to the outside, and the hole section with the smallest diameter of the stepped hole cooperates with the shaft section with the smallest diameter of the stepped shaft.

[0015] Furthermore, the main shaft is a segmented structure, including a first shaft segment, a second shaft segment and a third shaft segment installed in sequence along the axial direction, the second shaft segment is a permanent magnet, the outer ends of the first shaft segment and the third shaft segment are provided with cavities, and impellers are installed on the corresponding shaft cores.

[0016] Furthermore, the main shaft also includes a connecting piece for connecting the first shaft segment, the second shaft segment and the third shaft segment.

[0017] Furthermore, the connecting member includes a first cylinder, which is coaxially arranged on the first shaft segment near one end of the second shaft segment, and the entire second shaft segment and at least part of the length of the third shaft segment are located in the first cylinder.

[0018] Furthermore, the diameter of the portion of the third shaft segment located inside the first cylinder is reduced so that the side surface of the first cylinder and the portion of the third shaft segment located outside the first cylinder are flush.

[0019] Furthermore, an exhaust hole is provided at the bottom of the first shaft section corresponding to the cavity along the axial direction.

[0020] Furthermore, the connecting member includes a second cylinder, and the second cylinder is integrally sleeved on the side walls of the first shaft segment, the second shaft segment and the third shaft segment.

[0021] Furthermore, both ends of the second cylinder are flush with outer edges of the contact surfaces of the first shaft segment and the third shaft segment respectively.

[0022] Furthermore, a limiting portion is provided at the outer end of the contact surface between the first shaft segment or the third shaft segment and the second cylinder, for limiting the axial position of the second cylinder.

[0023] According to a second aspect of the present invention, a compressor is provided, comprising the compressor rotor according to the above embodiment.

[0024] Furthermore, the compressor is a centrifugal compressor.

[0025] According to a third aspect of the present invention, an air-conditioning device is provided, comprising the compressor according to the above embodiment.

[0026] Based on the above technical solution, the compressor rotor of an embodiment of the present invention forms a shaft core at the center of the main shaft by providing a cavity at the end of the main shaft, sleeves an impeller on the end of the shaft core, and locks the impeller to the shaft core using a locking component. This compressor rotor can reduce the difficulty of impeller assembly and disassembly, simplify the impeller assembly process and required equipment, improve assembly efficiency, and facilitate disassembly, inspection, and maintenance. Furthermore, this installation method ensures impeller strength and avoids stress concentration, thereby improving the compressor's compression capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] 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:

[0028] Figure 1 It is a structural schematic diagram of an embodiment of a centrifugal compressor of the present invention;

[0029] Figure 2 Schematic diagram of the structure of a compressor rotor according to an embodiment of the present invention;

[0030] Figure 3 This is a schematic structural diagram of another embodiment of a compressor rotor of the present invention.

[0031] Description of Reference Numerals

[0032] 1. Compressor rotor; 2. First volute; 3. Diffuser; 4. Thrust plate; 5. Bearing support; 6. Intermediate housing; 7. Stator assembly; 8. Second volute;

[0033] 11. First shaft section; 12. Second shaft section; 13. Third shaft section; 14. Impeller; 15. First cylinder; 16. Locking nut; 17. Second cylinder;

[0034] 111, cavity; 112, shaft core; 113, size reduction portion; 141, positioning portion;

[0035] 1121. First shaft portion; 1122. Second shaft portion; 1123. Third shaft portion. DETAILED DESCRIPTION

[0036] The present invention is described in detail below. In the following paragraphs, various aspects of the embodiments are defined in more detail. Each aspect defined in this manner may be combined with any other aspect or aspects unless expressly stated not to be combinable. In particular, any feature considered to be preferred or advantageous may be combined with one or more other features considered to be preferred or advantageous.

[0037] The terms "first" and "second" 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.

[0038] The present invention provides a compressor rotor, combined with Figures 1 to 3 In one exemplary embodiment, the main shaft comprises a main shaft, an impeller 14, and a locking component. A cavity 111 is provided at the end of the main shaft to form a shaft core 112 at its center. The end of the shaft core 112 extends beyond the end of the main shaft to accommodate the impeller 14. The shaft core 112 serves as a support for the impeller 14. The impeller 14 is sleeved onto the outer end of the shaft core 112 and axially positioned by the end of the main shaft outer ring. The locking component is used to lock the impeller 14 to the shaft core 112. The impeller 14 can be mounted on only one end of the main shaft, or on both ends.

[0039] This embodiment has at least one of the following advantages:

[0040] (1) The impeller and the main shaft are fixed by a locking component, so that the impeller can be detachably arranged relative to the main shaft, which can reduce the difficulty of disassembling and assembling the impeller, simplify the assembly process of the impeller and the required equipment, and improve the assembly efficiency and the operability of the disassembly and maintenance work.

[0041] (2) Compared with the shrink sleeve or keyway connection method, this installation method can not only prevent the main shaft or impeller from deformation, but also ensure the installation strength of the impeller, avoid stress concentration, and thus improve the compression capacity of the compressor.

[0042] (3) The shaft core is directly formed when the cavity is machined, so that the shaft core and the rest of the main shaft are machined into one piece. There is no need to install the shaft core in the cavity of the main shaft. This can further reduce the difficulty of assembly, increase the connection strength between the shaft core and the main shaft, and ensure the position accuracy of the shaft core. It can also effectively solve the problem of the vibration of the front end of the rotor and reduce the length of the cantilever end, thereby improving the working stability and reliability of the compressor.

[0043] (4) By setting a cavity on the main shaft, the weight of the rotor can be reduced, the critical speed of the rotor can be increased, and the ultimate working capacity of the compressor can be further improved.

[0044] In some embodiments, the cavity 111 is symmetrical with respect to the axis of the main shaft. When the rotor is working, the weight of the main shaft is evenly distributed, which can reduce the unbalanced force on the rotor during high-speed rotation.

[0045] For example, cavity 111 may be an annular groove concentric with the main shaft, extending along the entire circumference of the main shaft. This provides excellent weight reduction, facilitates forming shaft core 112 after machining, and facilitates installation and positioning of impeller 14. Alternatively, cavity 111 may include multiple discrete holes, each symmetrical about the main shaft axis. The holes may be circular, linear, or arc-shaped oblong holes. This structure can improve the rigidity of the main shaft and facilitate machining.

[0046] like Figure 2 As shown, a positioning portion 141 is provided at the inner end of the impeller 14. The positioning portion 141 extends into the cavity 111. The outer wall of the positioning portion 141 cooperates with the inner wall of the cavity 111 to radially position the impeller 14. A gap exists between the inner wall of the positioning portion 141 and the inner wall of the cavity 111. To better prevent radial runout at the front end of the impeller 14, the length of the positioning portion 141 embedded in the cavity 111 can be set to a predetermined length, for example, more than 20 mm.

[0047] This embodiment radially positions the impeller 14, thereby ensuring the radial installation accuracy of the impeller 14 during the assembly process; moreover, there is a gap between the inner wall of the positioning portion 141 and the inner wall of the cavity 111, which can avoid over-positioning of the impeller 14; in addition, the installation method in which the inner end of the impeller 14 extends into the main shaft can improve the overall strength of the compressor rotor, reduce the deflection and deformation of the rotor end, and improve the stability of the rotor rotation.

[0048] To reduce the front-end deflection caused by an excessively long shaft core 112, the radial width of cavity 111 should be the same as the radial thickness of impeller positioning portion 141, with precise control to ensure a clearance of, for example, 0.01-0.02mm. This structure allows for mutual positioning constraints between shaft core 112, impeller 14, and main shaft, improving the overall rigidity of the structure.

[0049] For the embodiment in which the cavity 111 is an annular groove, the positioning portion 141 is a positioning ring, which extends into the annular groove. The outer wall of the positioning portion 141 cooperates with the inner wall of the annular groove to radially position the impeller 14. There is a gap between the inner wall of the positioning portion 141 and the inner wall of the annular groove (i.e., the outer wall of the shaft core).

[0050] like Figure 2 As shown, the outer end of shaft core 112 is a threaded section, and the locking component includes a locking nut 16, which is screwed onto the outer end of shaft core 112 to lock impeller 14. The use of locking nut 16 facilitates disassembly and ensures reliable locking. Alternatively, the locking component can also use a snap-fit ​​structure or other locking structure.

[0051] Furthermore, the outer end of the shaft core 112 extends beyond the outer end of the locking nut 16 to prevent the locking nut 16 from moving outward after long-term use, thereby ensuring reliable locking during high-speed rotation of the impeller 14. The outward extension of the shaft core 112 should meet the total length of the impeller locking thread section, the impeller positioning smooth section, and the safety margin.

[0052] Still refer to Figure 2 Impeller 14 is provided with a stepped hole with a gradually decreasing diameter from the inside to the outside. The outer end of shaft core 112 is a stepped shaft with a gradually decreasing diameter from the inside to the outside. The smallest diameter section of the stepped hole mates with the smallest diameter section of the stepped shaft. Designing shaft core 112 as a stepped shaft reduces weight while maintaining structural strength. By gradually reducing the shaft diameter to a size that matches the mounting hole of impeller 14, stress on shaft core 112 is reduced.

[0053] exist Figure 2 In the figure, the stepped shaft includes, from the inside to the outside, a first shaft portion 1121, a second shaft portion 1122 and a third shaft portion 1123 of gradually decreasing sizes. The impeller 14 is mounted on the third shaft portion 1123. The inner end of the third shaft portion 1123 is a smooth axis, and the outer end is provided with a thread for mounting a locking nut 16.

[0054] like Figure 2 As shown, the main shaft has a segmented structure, including a first shaft segment 11, a second shaft segment 12 and a third shaft segment 13 which are installed in sequence along the axial direction and have independent structures. The second shaft segment 12 is located between the first shaft segment 11 and the third shaft segment 13. Among them, the second shaft segment 12 is a permanent magnet. As a magnetic steel, the segmented main shaft is conducive to the arrangement of the magnetic steel in the middle. The outer ends of the first shaft segment 11 and the third shaft segment 13 are both provided with a cavity 111, and an impeller 14 is installed on the corresponding shaft core 112, which can be used in a two-stage compressor. The inner ends of the first shaft segment 11 and the third shaft segment 13 are solid structures, and their thickness directly affects the deflection and stability of the front end of the shaft core 112. Therefore, they cannot be too thin, and the processing size can be above 30 mm.

[0055] Furthermore, the main shaft also includes a connector for connecting the first shaft segment 11, the second shaft segment 12, and the third shaft segment 13. The connector can be a cylindrical structure, which can not only improve the connection strength of the rotor, but also protect the magnetic steel and reduce the vibration problem of the rotor front end.

[0056] like Figure 2 In the structure shown, the connector includes a first barrel 15, which is coaxially disposed on the first shaft segment 11 near one end of the second shaft segment 12. The entire second shaft segment 12 and at least part of the length of the third shaft segment 13 are located within the first barrel 15. The first barrel 15 can be shrink-fitted onto the second shaft segment 12 and the third shaft segment 13 while heated, achieving a reliable connection between the three parts.

[0057] Furthermore, the diameter of the portion of the third shaft segment 13 located within the first barrel 15 is reduced, forming a stepped shaft. This allows the sides of the first barrel 15 and the portion of the third shaft segment 13 located outside the first barrel 15 to be flush, effectively ensuring the dynamic balance of the rotor during operation. Furthermore, the shoulder of the third shaft segment 13 can be used to axially position the first barrel 15.

[0058] Furthermore, a vent hole is provided at the axial bottom of the first shaft segment 11 corresponding to the cavity 111. Since the end of the first shaft segment 11 close to the first cylinder 15 is a solid structure, when the second shaft segment 12 and the third shaft segment 13 are installed into the first cylinder 15, the gas in the enclosed area formed by the second shaft segment 12 and the first cylinder 15 can be released, facilitating smooth installation.

[0059] like Figure 3 As shown, the connector includes a second barrel 17, which is integrally sleeved around the sidewalls of the first, second, and third shaft segments 11, 12, and 13. The outer surface of the main shaft is a monolithic barrel, ensuring the overall continuity of the rotor's outer surface and avoiding gaps between the barrel and some shaft segments, resulting in better protection. With this structure, the shaft segments can also be installed within the second barrel 17 via shrink fit.

[0060] Furthermore, both ends of the second cylinder 17 are flush with the outer edges of the contact surfaces of the first shaft segment 11 and the third shaft segment 13. Figure 1 and Figure 2 In order to make the thrust plate 4 cooperate with the main shaft, a size reducing portion 113 can be provided at the end of the main shaft. The size reducing portion 113 forms a shaft shoulder on the main shaft, and the second cylinder 17 only needs to extend to the shaft shoulder position.

[0061] Furthermore, a stopper is provided at the outer end of the contact surface between the first shaft segment 11 or the third shaft segment 13 and the second cylinder 17 to limit the axial position of the second cylinder 17 and facilitate installation and positioning of the second cylinder 17. The stopper may be stepped, and its outer diameter is consistent with the outer diameter of the second cylinder 17.

[0062] The first and second cylinders 15 and 17 serve as magnetic steel sheaths. The thickness should not be too thick to affect the magnetism of the motor, nor too thin to affect the strength of the sheath itself. The thickness range is 3mm to 5mm. Since the magnetic steel sheath has a connecting function, it can be made of high-performance high-temperature alloy steel.

[0063] Secondly, the present invention also provides a compressor, comprising the compressor rotor 1 of each of the above embodiments. Figure 1 As shown, the compressor can be a centrifugal compressor. Alternatively, the compressor can also be a centrifugal refrigeration compressor or a screw refrigeration compressor.

[0064] Since the impeller installation method of the present invention can prevent the deformation of the main shaft or impeller, it can also ensure the installation strength of the impeller and avoid stress concentration, thereby improving the compression capacity of the compressor and being easy to disassemble when maintenance is required; moreover, by arranging a cavity on the main shaft, the weight of the rotor can be reduced, the critical speed of the rotor can be increased, and the ultimate working capacity of the compressor can be further improved; in addition, directly forming the shaft core through processing can increase the connection strength between the shaft core and the main shaft, and ensure the position accuracy of the shaft core, which can effectively solve the problem of the vibration of the front end of the rotor and improve the working stability and reliability of the compressor.

[0065] like Figure 1 The figure shows a two-stage centrifugal compressor comprising a first volute 2, a second volute 8, and an intermediate casing 6. The first and second volutes 2 and 8 are disposed axially at opposite ends of the intermediate casing 6, forming the compressor housing. The compressor rotor 1 is positioned at the center of the compressor housing. An impeller 14 is disposed at each end of the main shaft. A diffuser 3 is disposed at the inner end of the impeller 14. When the impeller 14 rotates at high speed, the gas is drawn into the rear diffuser 3 by centrifugal force for diffusion. The pressurized gas is then discharged from the volute.

[0066] To support the main shaft, radial bearings are provided at both ends of the main shaft. The radial bearings are supported by bearing supports 5, which are connected to the intermediate housing 6. The radial bearings can be hydrodynamic gas bearings. A stator assembly 7 is provided between the main shaft and the intermediate housing 6.

[0067] Because impeller 14 generates axial force during operation, two thrust bearings are installed at one end of the main shaft. These bearings can be fixed to the diffuser 3 and the bearing support 5 at opposite ends, with clearances between the two bearings and both ends of the thrust plate 4 to form a thrust bearing. This structure can simultaneously balance axial forces in both directions. In addition to air bearings, magnetic bearings can also be used for the radial and thrust bearings.

[0068] The working principle of this compressor is as follows: during the operation of the compressor, the compressor rotor 1 rotates at high speed, allowing the gas to enter the diffuser 3 through the impeller 14 on the left. After the first stage of compression, the gas enters the first volute 2. The exhaust channel on the first volute 2 guides the compressed gas to enter the right impeller 14. After the centrifugal action of the right impeller 14, it enters the right diffuser 3. After the second stage of compression, the gas enters the second volute 8 and is discharged from the compressor through the exhaust channel on the second volute 8.

[0069] Finally, the present invention also provides an air-conditioning device comprising the compressor of the above embodiment, thereby enabling the air-conditioning device to have a stable working state and improve stability and reliability during operation.

[0070] The above describes in detail a compressor rotor, a compressor, and an air-conditioning device provided by the present invention. Specific embodiments are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is intended only to facilitate understanding of the method and core concept of the present invention. It should be noted that, for those skilled in the art, various improvements and modifications may be made to the present invention without departing from the principles of the present invention, and such improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A compressor, characterized in that: The invention comprises a compressor rotor (1), wherein the compressor rotor (1) comprises: A main shaft, wherein a cavity (111) is provided at the end of the main shaft to form a shaft core (112) at the center of the main shaft, the end of the shaft core (112) extends out of the end of the main shaft, and the shaft core (112) is configured to be directly formed when the cavity (111) is machined and to be integrally machined with the rest of the main shaft; An impeller (14) is sleeved on the outer end of the shaft core (112) and is axially positioned by the end of the main shaft outer ring. A positioning portion (141) is provided at the inner end of the impeller (14). The outer side wall of the positioning portion (141) cooperates with the inner side wall of the cavity (111) to radially position the impeller (14). A gap is formed between the inner side wall of the positioning portion (141) and the inner side wall of the cavity (111); and A locking component is configured to lock the impeller (14) on the shaft core (112).

2. The compressor according to claim 1, characterized in that The cavity (111) is centrally symmetrical relative to the axis of the main shaft.

3. The compressor according to claim 2, characterized in that The cavity (111) is an annular groove concentric with the main shaft; or the cavity (111) includes a plurality of discrete holes, each hole being symmetrical relative to the axis of the main shaft.

4. The compressor according to claim 1, characterized in that The outer end of the shaft core (112) is a threaded section, and the locking component includes a locking nut (16). The locking nut (16) is screwed onto the outer end of the shaft core (112) to lock the impeller (14).

5. The compressor according to claim 4, characterized in that The outer end of the shaft core (112) extends beyond the outer end of the locking nut (16).

6. The compressor according to claim 1, characterized in that The impeller (14) is provided with a stepped hole with a diameter gradually decreasing from the inside to the outside, the outer end of the shaft core (112) is a stepped shaft with a diameter gradually decreasing from the inside to the outside, and the hole section with the smallest diameter of the stepped hole cooperates with the shaft section with the smallest diameter of the stepped shaft.

7. The compressor according to claim 1, characterized in that The main shaft is a segmented structure, comprising a first shaft segment (11), a second shaft segment (12), and a third shaft segment (13) sequentially installed along the axial direction, the second shaft segment (12) being a permanent magnet, the outer ends of the first shaft segment (11) and the third shaft segment (13) being provided with the cavity (111), and the impeller (14) being installed on the corresponding shaft core (112).

8. The compressor according to claim 7, characterized in that The main shaft also includes a connecting piece for connecting the first shaft segment (11), the second shaft segment (12) and the third shaft segment (13).

9. The compressor according to claim 8, characterized in that The connecting member comprises a first cylinder (15), wherein the first cylinder (15) is coaxially arranged on the first shaft segment (11) near one end of the second shaft segment (12), and the entire second shaft segment (12) and at least part of the length of the third shaft segment (13) are located within the first cylinder (15).

10. The compressor according to claim 9, characterized in that The diameter of the portion of the third shaft segment (13) located inside the first cylinder (15) is reduced so that the first cylinder (15) is flush with the side surface of the portion of the third shaft segment (13) located outside the first cylinder (15).

11. The compressor according to claim 9, characterized in that An exhaust hole is provided at the bottom of the first shaft section (11) corresponding to the cavity (111) along the axial direction.

12. The compressor according to claim 8, characterized in that The connecting member comprises a second cylinder (17), and the second cylinder (17) is integrally sleeved on the side walls of the first shaft section (11), the second shaft section (12), and the third shaft section (13).

13. The compressor according to claim 12, characterized in that Both ends of the second cylinder (17) are flush with the outer edges of the contact surfaces of the first shaft section (11) and the third shaft section (13).

14. The compressor according to claim 12, characterized in that A limiting portion is provided at the outer end of the contact surface between the first shaft segment (11) or the third shaft segment (13) and the second cylinder (17), for limiting the axial position of the second cylinder (17).

15. The compressor according to claim 1, characterized in that The compressor is a centrifugal compressor.

16. An air conditioning device, characterized in that: Including the compressor according to any one of claims 1 to 15.

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