CN111365293A - Compressor rotor, compressor and air conditioning equipment - Google Patents

Abstract

The present invention relates to a compressor rotor, a compressor and an air conditioning apparatus, wherein the compressor rotor includes: the end part of the main shaft is provided with a cavity (111) so as to form a shaft core (112) at the center of the main shaft, and the end part of the shaft core (112) extends out of the end part of the main shaft; the impeller (14) is sleeved at the outer end of the shaft core (112) and is axially positioned through the end part of the outer ring of the main shaft; and a locking member configured to lock the impeller (14) to the shaft core (112). The compressor rotor can reduce the impeller dismounting difficulty, simplify the impeller assembling process and required equipment, and improve the assembling efficiency and the operability of dismounting work and maintenance; moreover, the installation mode can ensure the strength of the impeller and avoid generating stress concentration, thereby improving the compression capacity of the compressor.

Description

Compressor rotor, compressor and air conditioning equipment

Technical Field

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

Background

The centrifugal compressor impeller applies work to the gas to improve the energy of the gas, and the energy increased by the gas is positively correlated with the rotating speed of the impeller. According to different pressure ratios, the rotating speed of the impeller can reach thousands of revolutions per minute, and when the pressure ratio is high, even more than ten thousand revolutions. Therefore, the compressor rotor plays an important role in ensuring the reliability and safety of the impeller during operation.

The common impeller locking modes of the centrifugal compressor in the prior art comprise shrink fit locking, key fit locking and the like. When the thermal sleeve is matched, the impeller is heated to about 100 ℃ to expand and then is rapidly assembled with the main shaft, and the locking purpose is achieved by utilizing the assembly interference magnitude generated after the impeller is cooled. The thermal deformation locking structure is simple, does not need to add other parts, but needs heating equipment, is not beneficial to disassembly, and has strict requirements on an assembly process. Traditional key cooperation locking relies on the cooperation of keyway and key to retrain impeller displacement and transmission moment, but the key is the standard component, and its inherent right angle structure causes the stress concentration of keyway tip great, reduces impeller intensity. Accordingly, there is a need for an improved compressor rotor.

Disclosure of Invention

The invention aims to provide a compressor rotor, a compressor and air conditioning equipment, which can reduce the assembly difficulty of the compressor rotor.

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

the end part of the main shaft is provided with a cavity so as to form a shaft core at the center of the main shaft, and the end part of the shaft core extends out of the end part of the main shaft;

the impeller is sleeved at the outer end of the shaft core and is axially positioned through the end part of the outer ring of the main shaft; and

and a locking member configured to lock the impeller to the shaft core.

Further, the cavity is centrosymmetric with respect to the axis of the main shaft.

Further, the cavity is a ring groove concentric with the main shaft; or the cavity may comprise a plurality of discrete holes, each hole being centrally symmetrical with respect to the axis of the main shaft.

Further, the inner of impeller is equipped with location portion, and the lateral wall of location portion cooperates with the inside wall of cavity to carry out radial positioning to the impeller, the inside wall of location portion has the clearance with the inside wall of cavity.

Furthermore, the outer end of the shaft core is a threaded section, the locking component comprises a locking nut, and the locking nut is screwed on the outer end of the shaft core to lock the impeller.

Further, the outer end of the shaft core exceeds the outer end of the locking nut.

Furthermore, a stepped hole with the diameter gradually reduced from inside to outside is arranged on the impeller, the outer end of the shaft core is a stepped shaft with the diameter gradually reduced from inside to outside, and a hole section with the minimum diameter of the stepped hole is matched with a shaft section with the minimum diameter of the stepped shaft.

Further, the main shaft is of a sectional type structure and comprises a first shaft section, a second shaft section and a third shaft section which are sequentially installed along the axial direction, the second shaft section is a permanent magnet, cavities are formed in the outer ends of the first shaft section and the third shaft section, and impellers are installed on corresponding shaft cores.

Further, the main shaft further comprises a connecting piece for connecting the first shaft section, the second shaft section and the third shaft section.

Further, the connecting piece comprises a first barrel, the first barrel is coaxially arranged at one end, close to the second shaft section, of the first shaft section, and the second shaft section is integrally arranged in the first barrel with at least part of the length of the third shaft section.

Further, the diameter of the part of the third shaft section located in the first cylinder is reduced, so that the first cylinder is flush with the side surface of the part of the third shaft section located outside the first cylinder.

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

Further, the connecting piece includes the second barrel, and the second barrel is whole to be established at the lateral wall of first shaft part, second shaft part and third shaft part.

Furthermore, two ends of the second cylinder are flush with the outer edges of the contact surfaces of the first shaft section and the third shaft section respectively.

Furthermore, the outer end of the contact surface of the first shaft section or the third shaft section and the second cylinder body is provided with a limiting part for limiting the axial position of the second cylinder body.

According to a second aspect of the present invention, a compressor is proposed, comprising the compressor rotor of the above-described embodiment.

Further, the compressor is a centrifugal compressor.

According to a third aspect of the present invention, an air conditioning apparatus is provided, which includes the compressor of the above-described embodiment.

Based on the technical scheme, the compressor rotor provided by the embodiment of the invention has the advantages that the cavity is formed at the end part of the main shaft to form the shaft core at the center of the main shaft, the impeller is sleeved at the end part of the shaft core, and the impeller is locked on the shaft core through the locking component. The compressor rotor can reduce the impeller dismounting difficulty, simplify the impeller assembling process and required equipment, and improve the assembling efficiency and the operability of dismounting work and maintenance; moreover, the installation mode can ensure the strength of the impeller and avoid generating stress concentration, thereby improving the compression capacity of the compressor.

Drawings

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

FIG. 1 is a schematic structural view of one embodiment of a centrifugal compressor of the present invention;

FIG. 2 is a schematic structural view of one embodiment of a compressor rotor of the present invention;

fig. 3 is a schematic structural view of another embodiment of the rotor of the compressor of the present invention.

Description of the reference numerals

1. A compressor rotor; 2. a first volute; 3. a diffuser; 4. a thrust disc; 5. a bearing support; 6. a middle housing; 7. a stator assembly; 8. a second volute;

11. a first shaft section; 12. a second shaft section; 13. a third shaft section; 14. an impeller; 15. a first cylinder; 16. locking the nut; 17. a second cylinder;

111. a cavity; 112. a shaft core; 113. a size reducing portion; 141. a positioning part;

1121. a first shaft portion; 1122. a second shaft portion; 1123. a third shaft portion.

Detailed Description

The present invention is described in detail below. In the following paragraphs, different aspects of the embodiments are defined in more detail. Aspects so defined may be combined with any other aspect or aspects unless clearly indicated to the contrary. 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.

The terms "first", "second", and the like in the present invention are merely for convenience of description to distinguish different constituent elements having the same name, and do not denote a sequential or primary-secondary relationship.

The present invention provides a compressor rotor, which, in conjunction with fig. 1-3, in one exemplary embodiment, includes a main shaft, an impeller 14, and a locking assembly. Wherein, the end of the main shaft is provided with a cavity 111 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 to install the impeller 14, and the shaft core 112 is used as a supporting part of the impeller 14; the impeller 14 is sleeved at the outer end of the shaft core 112 and is axially positioned by the end part of the outer ring of the main shaft; the locking means is used to lock the impeller 14 to the hub 112. The impeller 14 may be mounted at only one end of the main shaft, or at both ends.

This embodiment has at least one of the following advantages:

(1) the impeller and the main shaft are fixed through the locking part, so that the impeller is detachably arranged relative to the main shaft, the impeller dismounting difficulty can be reduced, the assembly process and required equipment of the impeller are simplified, and the assembly efficiency and the operability of dismounting work and maintenance are improved.

(2) Compared with a hot sleeve or key groove connection mode, the installation mode can prevent the main shaft or the impeller from deforming, can also ensure the installation strength of the impeller, and avoids stress concentration, thereby improving the compression capacity of the compressor.

(3) The axle core is through directly forming when processing the cavity, makes the axle core and the processing of the rest of main shaft form an organic whole, need not additionally to install the axle core in the cavity of main shaft, can further reduce the assembly degree of difficulty, increases the joint strength of axle core and main shaft, still can guarantee the position precision of axle core, effectively solves the problem of beating of rotor front end, reduces cantilever end length to improve the job stabilization nature and the reliability of compressor.

(4) The cavity is arranged on the main shaft, so that the weight of the rotor can be reduced, the critical rotating speed of the rotor is improved, and the ultimate working capacity of the compressor is further improved.

In some embodiments, the cavity 111 is centered symmetrically with respect to the axis of the spindle. When the rotor works, the weight of the main shaft is uniformly distributed, and unbalanced force applied to the rotor in the high-speed rotation process can be reduced.

For example, the cavity 111 may be a ring groove concentric with the main shaft, and the ring groove is disposed along the entire circumference of the main shaft, so that the shaft core 112 is easy to form after machining, and the impeller 14 is easy to mount and position. Or the cavity 111 comprises a plurality of discrete holes, each hole is centrosymmetric relative to the axis of the main shaft, and the holes can be circular holes, linear or arc-shaped long round holes and the like, so that the rigidity of the main shaft can be improved, and the processing is easy.

As shown in fig. 2, the inner end of the impeller 14 is provided with a positioning portion 141, the positioning portion 141 extends into the cavity 111, an outer side wall of the positioning portion 141 is matched with an inner side wall of the cavity 111 to radially position the impeller 14, and a gap is formed between the inner side wall of the positioning portion 141 and the inner side wall of the cavity 111. In order to better solve the radial run-out of the impeller 14 at the front end, the length of the positioning portion 141 inserted into the cavity 111 may be a predetermined length, for example, 20mm or more.

The embodiment facilitates ensuring the radial installation accuracy of the impeller 14 in the assembly process by radially positioning the impeller 14; moreover, a gap is formed between the inner side wall of the positioning part 141 and the inner side wall of the cavity 111, so that the impeller 14 can be prevented from being positioned excessively; in addition, the installation mode that the inner end of the impeller 14 extends into the main shaft can improve the overall strength of the compressor rotor, reduce the deflection deformation of the end part of the rotor and improve the stability of the rotation of the rotor.

In order to reduce the problem of front end deflection caused by overlong shaft core 112, the radial width of cavity 111 should be the same as the positioning radial thickness of impeller positioning portion 141, and the radial width should be precisely controlled in terms of precision, for example, a gap of 0.01-0.02mm can be ensured. In the structure, the positioning among the shaft core 112, the impeller 14 and the main shaft is limited, so that the integral rigidity of the structure can be improved.

For the embodiment in which the cavity 111 is a ring groove, the positioning portion 141 is a positioning ring, the positioning ring extends into the ring groove, an outer sidewall of the positioning portion 141 is engaged with an inner sidewall of the ring groove to radially position the impeller 14, and an inner sidewall of the positioning portion 141 has a gap with an inner sidewall of the ring groove (i.e., an outer sidewall of the shaft core).

As shown in fig. 2, the outer end of the shaft core 112 is a threaded section, and the locking component includes a locking nut 16, and the locking nut 16 is screwed on the outer end of the shaft core 112 to lock the impeller 14. The locking nut 16 is easy to disassemble, and the locking reliability can be ensured. Alternatively, the locking component may also be locked by a structure such as a snap.

Further, the outer end of the shaft core 112 exceeds the outer end of the lock nut 16, preventing the lock nut 16 from being withdrawn outward after a long period of use, so as to ensure the locking reliability when the impeller 14 rotates at high speed. The extended length of the shaft core 112 should satisfy the total length of the impeller locking thread section, the impeller positioning smooth section and the safety margin.

Still referring to fig. 2, the impeller 14 is provided with a stepped hole having a diameter gradually decreasing from the inside to the outside, the outer end of the shaft core 112 is a stepped shaft having a diameter gradually decreasing from the inside to the outside, and the hole section having the smallest diameter of the stepped hole is matched with the shaft section having the smallest diameter of the stepped shaft. The shaft core 112 is designed into a stepped shaft, so that weight reduction can be realized on the basis of ensuring the structural strength, and the shaft diameter is reduced to the size matched with the mounting hole of the impeller 14, so that the stress on the shaft core 112 can be reduced.

In fig. 2, the stepped shaft includes a first shaft portion 1121, a second shaft portion 1122, and a third shaft portion 1123, which are gradually reduced in size, in order from inside to outside, the impeller 14 is mounted on the third shaft portion 1123, an inner end of the third shaft portion 1123 is an optical axis, and an outer end of the third shaft portion 1123 is provided with a screw thread to mount the lock nut 16.

As shown in fig. 2, the main shaft is a sectional structure, and includes 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 are structurally independent, and the second shaft segment 12 is located between the first shaft segment 11 and the third shaft segment 13. The second shaft section 12 is a permanent magnet and serves as magnetic steel, and the sectional type main shaft is beneficial to arranging the magnetic steel in the middle. The outer ends of the first shaft section 11 and the third shaft section 13 are both provided with cavities 111, and the impellers 14 are mounted on the corresponding shaft cores 112, and can be used in a two-stage compressor. The inner ends of the first shaft section 11 and the third shaft section 13 are in a solid structure, and the thickness of the solid structure directly influences the flexibility and the stability of the front end of the shaft core 112, so that the solid structure cannot be too thin, and the machining size can be more than 30 mm.

Further, the main shaft further comprises a connecting member for connecting the first shaft section 11, the second shaft section 12 and the third shaft section 13. The connecting piece can be of a cylindrical structure, so that the connecting strength of the rotor can be improved, the magnetic steel can be protected, and the problem of jumping at the front end of the rotor can be reduced.

In the configuration shown in fig. 2, the connecting member comprises a first cylinder 15, the first cylinder 15 is coaxially arranged at one end of the first shaft segment 11 close to the second shaft segment 12, and the second shaft segment 12 and at least part of the length of the third shaft segment 13 are arranged in the first cylinder 15. The first barrel 15 can be sleeved on the second shaft section 12 and the third shaft section 13 in a heating state, so that connection of three parts is realized, and the connection is reliable.

Further, the diameter of the part of the third shaft section 13 located in the first cylinder 15 is reduced to form a stepped shaft, so that the first cylinder 15 and the side surface of the part of the third shaft section 13 located outside the first cylinder 15 are flush, and the dynamic balance of the rotor during operation can be effectively ensured. Furthermore, the first barrel 15 can be axially positioned by means of the shoulder of the third shaft section 13.

Further, the first shaft segment 11 is provided with an exhaust hole corresponding to the bottom of the cavity 111 along the axial direction. Because the end of the first shaft section 11 close to the first cylinder 15 is of a solid structure, when the second shaft section 12 and the third shaft section 13 are installed in the first cylinder 15, the gas in the closed area formed by the second shaft section 12 and the first cylinder 15 can be released, so that the installation is facilitated.

As shown in fig. 3, the connecting member includes a second cylinder 17, and the second cylinder 17 is integrally fitted over the side walls of the first shaft section 11, the second shaft section 12, and the third shaft section 13. The outer surface of the main shaft adopts an integral cylinder body, the integral continuity of the outer surface of the rotor can be ensured, gaps are prevented from being generated between the cylinder body and part of the shaft section, and a better protection effect is achieved. With this arrangement, the shaft segments can also be shrink-fitted into the second cylinder 17.

Further, 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, respectively. Referring to fig. 1 and 2, in order to match the thrust disc 4 with the main shaft, the end of the main shaft may be provided with a size reduction portion 113, the size reduction portion 113 forms a shoulder on the main shaft, and the second cylinder 17 only needs to extend to the position of the shoulder.

Further, the outer end of the contact surface of the first shaft section 11 or the third shaft section 13 and the second cylinder 17 is provided with a limiting part for limiting the axial position of the second cylinder 17, so that the second cylinder 17 is easy to install and position. The limiting portion may be stepped, and the outer diameter thereof is identical to the outer diameter of the second cylinder 17.

The first cylinder 15 and the second cylinder 17 are used as magnetic steel sheaths, the thickness of the magnetic steel sheaths cannot be too thick so as not to influence the magnetism of the motor, the thickness of the magnetic steel sheaths cannot be too thin so as not to influence the strength of the sheaths, and the selectable range is 3 mm-5 mm. Because the magnetic steel sheath has the connecting function, the high-temperature alloy steel material with good workability is processed.

Secondly, the invention also provides a compressor, which comprises the compressor rotor 1 of each embodiment. As shown in fig. 1, the compressor may be a centrifugal compressor. Alternatively, the compressor may be a centrifugal refrigeration compressor, a screw refrigeration compressor, or the like.

The impeller mounting mode of the invention can prevent the deformation of the main shaft or the impeller, ensure the mounting strength of the impeller and avoid the stress concentration, thereby improving the compression capacity of the compressor and being easy to disassemble when in need of maintenance; moreover, the cavity is arranged on the main shaft, so that the weight of the rotor can be reduced, the critical rotating speed of the rotor is improved, and the ultimate working capacity of the compressor is further improved; in addition, the shaft core is directly formed through processing, so that the connection strength between the shaft core and the main shaft can be increased, the position precision of the shaft core is ensured, the problem of jumping at the front end of the rotor can be effectively solved, and the working stability and reliability of the compressor are improved.

As shown in fig. 1, the two-stage centrifugal compressor includes a first scroll casing 2, a second scroll casing 8, and an intermediate casing 6, and the first scroll casing 2 and the second scroll casing 8 are respectively disposed at both ends of the intermediate casing 6 in the axial direction, and together form a compressor casing. The compressor rotor 1 is arranged at the center of the compressor shell, two ends of the main shaft are respectively provided with an impeller 14, the inner end of the impeller 14 is provided with a diffuser 3, when the impeller 14 rotates at a high speed, gas is thrown into the rear diffuser 3 to be diffused under the action of centrifugal force along with the rotation, and the gas with improved pressure is discharged from the volute.

For supporting the main shaft, radial bearings are provided at both ends of the main shaft, the radial bearings are supported by bearing supports 5, the bearing supports 5 are connected to the middle housing 6, and the radial bearings may be hydrodynamic gas bearings. A stator component 7 is arranged between the main shaft and the middle shell 6.

Because the impeller 14 can generate axial force in the working process, two thrust bearings are arranged at one end of the main shaft, the two thrust bearings can be respectively fixed at one ends of the diffuser 3 and the bearing support 5, and gaps are formed between the two thrust bearings and two ends of the thrust disc 4 to form the thrust bearings, and the structure can balance the axial force in two directions at the same time. Besides the air suspension bearing, the radial bearing and the thrust bearing can also be magnetic suspension bearings.

The working principle of the compressor is as follows: in the working process of the compressor, the compressor rotor 1 rotates at a high speed, so that gas enters the diffuser 3 through the left impeller 14, the gas enters the first volute 2 after being compressed at a first stage, the compressed gas is guided to enter the right impeller 14 through the exhaust passage on the first volute 2, the gas enters the right diffuser 3 after being subjected to the centrifugal action of the right impeller 14, and the gas enters the second volute 8 after being compressed at a second stage and is discharged out of the compressor through the exhaust passage on the second volute 8.

Finally, the invention also provides air conditioning equipment comprising the compressor of the embodiment. Therefore, the air conditioning equipment can have a stable working state, and the stability and the reliability in the working process are improved.

The compressor rotor, the compressor and the air conditioning equipment provided by the invention are described in detail above. The principles and embodiments of the present invention are explained herein using specific examples, which are presented only to aid in understanding the method and its core concepts. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.

Claims (18)

1. A compressor rotor, comprising:

a main shaft, the end of which is provided with a cavity (111) to form a shaft core (112) at the center of the main shaft, the end of the shaft core (112) extending out of the end of the main shaft;

the impeller (14) is sleeved at the outer end of the shaft core (112) and is axially positioned through the end part of the outer ring of the main shaft; and

a locking component configured to lock the impeller (14) to the shaft core (112).

2. The compressor rotor according to claim 1, characterized in that the cavity (111) is centrosymmetric with respect to the axis of the main shaft.

3. -compressor rotor according to claim 2, characterised in that the cavity (111) is an annular groove concentric with the main shaft; or the cavity (111) comprises a plurality of discrete holes, each hole being centrosymmetric with respect to the axis of the main shaft.

4. The compressor rotor according to claim 1, characterized in that the inner end of the impeller (14) is provided with a positioning portion (141), the outer side wall of the positioning portion (141) cooperating with the inner side wall of the cavity (111) for radially positioning the impeller (14), the inner side wall of the positioning portion (141) having a clearance with the inner side wall of the cavity (111).

5. The compressor rotor as recited in claim 1, wherein an outer end of the shaft core (112) is a threaded section and the locking member includes a lock nut (16), the lock nut (16) being threaded on the outer end of the shaft core (112) to lock the impeller (14).

6. The compressor rotor as recited in claim 5, characterized in that an outer end of the shaft core (112) exceeds an outer end of the lock nut (16).

7. The compressor rotor as claimed in claim 1, wherein the impeller (14) is provided with a stepped bore having a diameter gradually decreasing from an inner diameter to an outer diameter, the outer end of the shaft core (112) is a stepped shaft having a diameter gradually decreasing from an inner diameter to an outer diameter, and the bore section having the smallest diameter of the stepped bore is fitted with the shaft section having the smallest diameter of the stepped shaft.

8. The compressor rotor as recited in claim 1, wherein the main shaft is a segmented structure including a first shaft segment (11), a second shaft segment (12) and a third shaft segment (13) sequentially installed along an axial direction, the second shaft segment (12) is a permanent magnet, the outer ends of the first shaft segment (11) and the third shaft segment (13) are provided with the cavities (111), and the impellers (14) are installed on the corresponding shaft cores (112).

9. The compressor rotor as recited in claim 8, characterized in that the main shaft further comprises a connection for enabling connection of the first shaft section (11), the second shaft section (12) and the third shaft section (13).

10. Compressor rotor according to claim 9, characterized in that the connection comprises a first cylinder (15), the first cylinder (15) being coaxially arranged on the first shaft section (11) near one end of the second shaft section (12), the second shaft section (12) being located within the first cylinder (15) over its entirety and at least part of the length of the third shaft section (13).

11. The compressor rotor as recited in claim 10, characterized in that the portion of the third shaft section (13) located inside the first cylinder (15) is reduced in diameter so that the first cylinder (15) is flush with the side of the portion of the third shaft section (13) located outside the first cylinder (15).

12. Compressor rotor according to claim 10, characterised in that the first shaft section (11) is provided with a venting hole in correspondence of the bottom of the cavity (111) in the axial direction.

13. The compressor rotor as recited in claim 9, wherein the connecting member includes a second cylinder (17), the second cylinder (17) being integrally fitted over the side walls of the first shaft section (11), the second shaft section (12) and the third shaft section (13).

14. Compressor rotor according to claim 13, characterised in that the second cylinder (17) is flush at both ends with the outer edges of the contact surfaces of the first shaft section (11) and the third shaft section (13), respectively.

15. The compressor rotor as recited in claim 13, characterized in that the outer end of the contact surface of the first shaft segment (11) or the third shaft segment (13) and the second cylinder (17) is provided with a limiting portion for limiting the axial position of the second cylinder (17).

16. A compressor, characterized by comprising a compressor rotor (1) according to any one of claims 1 to 15.

17. The compressor of claim 16, wherein the compressor is a centrifugal compressor.

18. An air conditioning apparatus, characterized by comprising the compressor of claim 16 or 17.

Images