Impeller optimization design method, impeller and compressor

Abstract

The present invention relates to the technical field of compressors, and in particular to an impeller optimization design method, an impeller and a compressor. The impeller optimization design method provided by the present invention comprises: providing an impeller, the impeller comprises a hub, the hub comprises a hub portion and a disc portion, the hub portion is provided with an axial hole for installing a rotating shaft, the disc portion is connected to the hub portion and extends radially outward from the hub portion; the wall thickness of the disc portion is cut from the back to the front. Based on this, the weight of the impeller can be reduced, which is beneficial to improving the working reliability of the compressor and extending the service life of the compressor.

Description

Technical Field

[0001] The invention relates to the technical field of compressors, and in particular to an impeller optimization design method, an impeller and a compressor. Background Art

[0002] In a compressor, the rotor includes a rotating shaft and an impeller mounted on the rotating shaft. The heavier the impeller, the more likely it is that the shaft will break or bend, resulting in lower reliability and shorter service life of the rotating shaft, which affects the reliability and service life of the compressor. In addition, the weight of the impeller affects the critical speed of the rotor. The heavier the impeller, the lower the critical speed of the rotor (i.e., the speed when the frequency is equal to the rotor's natural frequency), which is more likely to cause resonance and also affects the reliability and service life of the compressor.

[0003] It can be seen that the weight of the impeller affects the working reliability and service life of the compressor. It is necessary to optimize the impeller structure to reduce the weight of the impeller, improve the working reliability of the compressor, and extend the service life of the compressor. Summary of the invention

[0004] The embodiments of the present invention provide an impeller optimization design method, an impeller, and a compressor to reduce the weight of the impeller, improve the working reliability of the compressor, and extend the service life of the compressor.

[0005] The impeller optimization design method provided by the embodiment of the present invention includes:

[0006] An impeller is provided, the impeller comprises a hub, the hub comprises a hub portion and a disc portion, the hub portion is provided with an axial hole for mounting a rotating shaft, the disc portion is connected to the hub portion and extends radially outward from the hub portion;

[0007] The wall thickness of the disc is cut from the back to the front.

[0008] In some embodiments, the disc portion includes a first disc segment and a second disc segment, the first disc segment is connected to the hub portion through the second disc segment, along the direction from the radial outer side to the radial inner side, the axial distance between the front end face of the first disc segment and the rear end face of the hub portion is equal, and the axial distance between the front end face of the second disc segment and the rear end face of the hub portion gradually increases, and the wall thickness of the disc portion is cut from the back to the front, including:

[0009] The wall thickness of the disc portion is cut from the back to the front in a manner that the cutting amount of the first disc segment of the disc portion remains unchanged and the cutting amount of the second disc segment of the disc portion gradually increases according to a proportional coefficient K along the direction from the radial outer side to the radial inner side.

[0010] In some embodiments, K=1.2-2.

[0011] In some embodiments, K=1.4.

[0012] In some embodiments, when the wall thickness of the disc portion is cut from the back to the front, the convex portion on the rear end surface of the disc portion is cut off, the convex portion protrudes backward from the rear end surface of the disc portion, and a concave cavity is provided in the convex portion.

[0013] In some embodiments, the impeller optimization design method further includes:

[0014] Providing a groove on the inner wall of the hub; and / or,

[0015] A counterweight hole is provided on the wheel hub.

[0016] In some embodiments, when a groove is formed on the inner wall of the hub, the length L3 of the groove is less than or equal to 70% of the diameter D1 of the shaft hole, and / or the depth L4 of the groove is 2-4 mm.

[0017] In some embodiments, when balancing weight holes are opened on the wheel hub, the number of the balancing weight holes is determined by a multi-objective optimization method.

[0018] In some embodiments, when a counterweight hole is opened on the wheel hub, the transverse center axis of the counterweight hole is parallel to the transverse center axis of the shaft hole.

[0019] In some embodiments, opening a counterweight hole on the wheel hub includes:

[0020] A counterweight hole is provided on the rear end surface of the hub.

[0021] In some embodiments, the counterweight hole is provided on the rear end surface of the hub, including at least one of the following:

[0022] The diameter D2 of the counterweight hole is less than or equal to 30% of the radial wall thickness L7 of the rear end face of the hub;

[0023] The depth L5 of the counterweight hole is less than or equal to 60% of the axial distance L6 between the rear wall of the groove on the inner wall of the hub and the rear end surface of the hub;

[0024] Make the radial distance between the transverse center axis of the counterweight hole and the edge of the shaft hole less than or equal to 1 / 3 of the radial wall thickness L7 of the rear end face of the hub.

[0025] The impeller provided in the embodiment of the present invention is designed by using the impeller optimization design method of each embodiment of the present invention.

[0026] The impeller provided in the embodiment of the present invention comprises:

[0027] The wheel hub comprises a hub portion and a disc portion, wherein the hub portion is provided with an axial hole for mounting a rotating shaft, the disc portion is connected to the hub portion and extends radially outward from the hub portion, the disc portion comprises a first disc segment and a second disc segment, the first disc segment is connected to the hub portion through the second disc segment, and along the direction from the radial outward to the radial inward, the axial distance between the front end face of the first disc segment and the rear end face of the hub portion is equal, and the axial distance between the front end face of the second disc segment and the rear end face of the hub portion gradually increases;

[0028] Among them, along the direction from the radial outer side to the radial inner side, the axial distance between the rear end face of the first disc segment and the rear end face of the hub remains unchanged, and the axial distance between the rear end face of the second disc segment and the rear end face of the hub gradually increases according to the proportional coefficient K.

[0029] In some embodiments, K=1.2-2.

[0030] In some embodiments, K=1.4.

[0031] In some embodiments, a groove is provided on the inner wall of the hub; and / or a counterweight hole is provided on the hub.

[0032] In some embodiments, the length L3 of the groove is less than or equal to 70% of the diameter D1 of the shaft hole, and / or the depth L4 of the groove is 2-4 mm.

[0033] In some embodiments, the weight hole is configured as at least one of the following:

[0034] The transverse center axis of the counterweight hole is parallel to the transverse center axis of the shaft hole;

[0035] The number of counterweight holes is at least two;

[0036] At least two counterweight holes are evenly distributed along the circumference of the shaft hole;

[0037] The number of counterweight holes is 8.

[0038] In some embodiments, the counterweight hole is disposed on the rear end surface of the hub.

[0039] In some embodiments, the weight hole is configured as at least one of the following:

[0040] The diameter D2 of the counterweight hole is 30% of the radial wall thickness L7 of the rear end face of the hub;

[0041] The depth L5 of the counterweight hole is 60% of the axial distance L6 between the rear wall of the groove on the inner wall of the hub and the rear end surface of the hub;

[0042] The radial distance between the transverse central axis of the counterweight hole and the edge of the shaft hole is less than or equal to 1 / 3 of the radial wall thickness L7 of the rear end face of the hub.

[0043] The compressor provided by the present invention comprises the impeller of each embodiment of the present invention.

[0044] By cutting the wall thickness of the impeller disk from the back to the front, the weight of the impeller can be reduced, which is beneficial to improving the working reliability of the compressor and extending the service life of the compressor.

[0045] Other features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0047] Figure 1 A partial structural schematic diagram of a compressor before optimization in an embodiment of the present invention is shown.

[0048] Figure 2 A partial structural schematic diagram of the compressor after optimization in an embodiment of the present invention is shown.

[0049] Figure 3 A schematic diagram showing the distribution of counterweight holes on the wheel hub in an embodiment of the present invention is shown.

[0050] Figure 4 A schematic flow chart of an impeller optimization design method according to an embodiment of the present invention is shown.

[0051] Description of reference numerals:

[0052] 100, compressor; 10, impeller; 20, rotating shaft; 30, supporting sleeve; 40, positioning member;

[0053] 1. wheel hub; 11. hub portion; 11a. shaft hole; 11b. counterweight hole; 11c. groove; 12. disc portion; 12a. first disc section; 12b. second disc section; 13. convex portion; 13a. concave cavity;

[0054] 2. Leaves;

[0055] 3. Wheel cover. DETAILED DESCRIPTION

[0056] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without carrying out creative work are within the scope of protection of the present invention.

[0057] Technologies, methods, and apparatus known to ordinary technicians in the relevant field may not be discussed in detail, but where appropriate, such technologies, methods, and apparatus should be considered part of the authorization specification.

[0058] In the description of the present invention, it should be understood that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0059] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0060] Figure 1 and Figure 2-3 The application of the impeller in the compressor before and after optimization in the embodiment of the present invention is respectively shown.

[0061] Figure 1 and Figure 2 It mainly shows the rotor structure of the compressor 100. The rotor mainly performs work on the gas by rotating. Generally, the rotor will be balanced before use, but it is still inevitable that there will be extremely small deviations due to objective conditions. In addition, due to its own weight, the rotor will inevitably have a certain deflection between the bearings. These two reasons make it impossible for the center of gravity of the rotor to completely coincide with the axis of rotation of the rotor, and then when rotating, a periodically changing centrifugal force will be generated. When the frequency of change of the periodically changing centrifugal force is equal to the natural frequency of the rotor, the compressor 100 will vibrate strongly and form resonance.

[0062] Reference Figure 1-2 In some embodiments of the compressor 100, the rotor includes an impeller 10 and a rotating shaft 20. The impeller 10 is mounted on the rotating shaft 20 and rotates driven by the rotating shaft 20 to compress the gas and perform work. The axial, radial and circumferential directions of the impeller 10 are consistent with the axial, radial and circumferential directions of the rotating shaft 20, forming the axial, radial and circumferential directions of the rotor.

[0063] For the convenience of subsequent description, the axial, radial and circumferential directions of the impeller 10 are referred to as axial, radial and circumferential directions respectively, and the front and back and the inside and outside are defined based on the axial and radial directions of the impeller 10, wherein the side along the axial direction of the impeller 10 where the airflow flows in is called the "front" or "upstream", and the side where the airflow flows out is called the "back" or "downstream", and the side along the radial direction of the impeller 10 away from the center of the impeller 10 is called the "outside" or "radial outside", and the side close to the center of the impeller 10 is called the "inside" or "radial inside".

[0064] According to the needs, one, two or more impellers 10 can be installed on the rotating shaft 20, which are respectively called single-stage, double-stage or multi-stage impellers. When a single-stage impeller structure is adopted, the rotation speed requirement of the impeller 10 is generally high, the centrifugal force on the impeller 10 is large, and the reliability of the rotating shaft 20 is low. When a double-stage or multi-stage impeller structure is adopted, although the requirement for the rotation speed of the impeller 10 can be reduced to a certain extent, due to the increase in the number of impellers 10, the weight of the rotor cantilever end will be increased, and the length of the rotating shaft 20 will be increased, resulting in an increase in the deflection of the rotating shaft 20, a decrease in the rigidity, and an increase in the risk of the rotating shaft 20 breaking or bending and deforming, affecting the working reliability and service life of the rotating shaft 20. In addition, the increase in the weight of the cantilever end and the increase in the shaft length will also lead to a decrease in the critical speed of the rotating shaft 20. If the rotor runs at the critical speed for a long time, it will cause severe vibration or even resonance, and will cause the bending of the rotating shaft 20 to increase significantly, and even cause the rotating shaft to be severely bent and deformed, or even break. Among them, the critical speed refers to the speed when the frequency is equal to the natural frequency of the rotor. Factors that affect the critical speed include shaft diameter, shaft length, material, rotor mass and support form.

[0065] Figure 1 and Figure 2 Two impellers 10 are shown mounted on a rotating shaft 20. Figure 1-2 As shown, the two impellers 10 are arranged at intervals along the axial direction of the rotating shaft 20, and a support sleeve 30 is provided between the two impellers 10. The support sleeve 30 is sleeved on the rotating shaft 20 and supported between two adjacent impellers 10 to limit the axial displacement of the impellers 10.

[0066] In addition, if Figure 1 and Figure 2 As shown, the rotor further includes a positioning member 40 for positioning the impeller 10. In some embodiments, the positioning member 40 abuts against the front end surface of an impeller 10 located most upstream to position the impeller 10. Specifically, the positioning member 40 may be a locking nut.

[0067] In the rotor, the impeller 10 is a key component for achieving the function of performing work on the gas. The structure of the impeller 10 will be described in detail below.

[0068] See also Figure 1 and Figure 2 The impeller 10 includes a hub 1 and blades 2. The hub 1 is mounted on the rotating shaft 20. The blades 2 are arranged on the hub 1. Figure 1 and Figure 2 As shown, in some embodiments, in addition to the hub 1 and the blades 2, the impeller 10 further includes a wheel cover 3. The wheel cover 3 is disposed on the blades 2.

[0069] Specifically, see Figure 1 and Figure 2 The hub 1 includes a hub portion 11 and a disk portion 12. An axial hole 11a for mounting the rotating shaft 20 is provided in the hub portion 11. The axial, radial and circumferential directions of the axial hole 11a are consistent with the axial, radial and circumferential directions of the impeller 10. The front end face and the rear end face of the hub portion 11 are the axial end faces of the hub portion 11 facing and away from the airflow inflow direction, respectively. The disk portion 12 is connected to the hub portion 11 and extends radially outward from the hub portion 11. The blades 2 are arranged on the disk portion 12, and specifically on the front end face of the disk portion 12. In other words, the front end face of the disk portion 12 is the end face for arranging the blades 2. The rear end face of the disk portion 12 is the end face of the disk portion 12 away from the blades 2. The front end face and the rear end face of the disk portion 12 are opposite to each other in the axial direction.

[0070] Among them, see Figure 1-2 In some embodiments, the disc portion 12 includes a first disc segment 12a and a second disc segment 12b. The first disc segment 12a is connected to the hub portion 11 through the second disc segment 12b, that is, the first disc segment 12a and the second disc segment 12b are two parts of the disc portion 12 arranged in sequence from the radial outer side to the radial inner side, and the two are connected in sequence from the radial outer side to the radial inner side. The main difference between the first disc segment 12a and the second disc segment 12b is that the shapes of the first disc segment 12a and the second disc segment 12b are not consistent. Among them, as Figure 1 and Figure 2 As shown in the figure, along the direction from the radial outer side to the radial inner side, the axial distance between the front end face of the first disc segment 12a and the rear end face of the hub 11 is equal, while the axial distance between the front end face of the second disc segment 12b and the rear end face of the hub 11 gradually increases. Specifically, the rear end face of the hub 11 is a plane perpendicular to the transverse central axis of the shaft hole 11a. The front end face of the first disc segment 12a is substantially parallel to the rear end face of the hub 11. The front end face of the second disc segment 12b is an arc surface concave toward the rear side.

[0071] Before being optimized, see Figure 1 In some embodiments, the rear end surfaces of the first disk segment 12 a and the second disk segment 12 b are flush with the rear end surface of the hub 11 , that is, the entire rear end surface of the disk 12 is flush with the rear end surface of the hub 11 .

[0072] In addition, if Figure 1As shown, in some embodiments, before being optimized, there is a convex portion 13 on the rear end surface of the disc portion 12, the convex portion 13 protrudes backward from the rear end surface of the disc portion 12, and a concave cavity 13a is provided in the convex portion 13. The convex portion 13 is generally a product defect caused by extrusion during the processing and fixing process of the hub 1.

[0073] Figure 1 The impeller 10 shown is relatively heavy, which affects the working reliability and service life of the compressor 100.

[0074] For the above situation, see Figure 4 , an embodiment of the present invention provides an optimization design method, which includes:

[0075] S100, provide an impeller 10. The impeller 10 comprises a hub 1, the hub 1 comprises a hub portion 11 and a disc portion 12, the hub portion 11 is provided with an axial hole 11a for mounting a rotating shaft 20, and the disc portion 12 is connected to the hub portion 11 and extends radially outward from the hub portion 11.

[0076] S200, the wall thickness of the disc portion 12 is cut from the back to the front. That is, in step S200, the rear end surface of the disc portion 12 is cut to reduce the thickness of the disc portion 12 (ie, the dimension along the axial direction).

[0077] By cutting the wall thickness of the disc 12 from the back to the front, the weight of the impeller 10 can be reduced. This helps reduce the risk of breakage or bending deformation of the shaft 20, increases the natural frequency of the rotor, increases the critical speed of the rotor, and reduces the risk of resonance. Therefore, it helps to improve the working reliability of the compressor 100 and extend the service life of the compressor 100.

[0078] Furthermore, the wall thickness of the disk 12 is cut from the back to the front without changing the structure of the front end face of the disk 12 or other parts such as the blades 2. Therefore, the blade shape and the flow channel are not affected, and the impact on the aerodynamic performance is relatively small. The lightweight design of the impeller 10 can be achieved without affecting the aerodynamic performance too much.

[0079] In addition, comparison Figure 1 and Figure 2 It can be seen that when the aforementioned convex portion 13 is provided on the rear end face of the disk portion 12, when step S200 is executed and the wall thickness of the disk portion 12 is cut from the back to the front, the convex portion 13 on the rear end face of the disk portion 12 can be cut off, which can not only further reduce the weight of the impeller 10, but also reduce the loss of the concave cavity 13a in the convex portion 13 to the airflow.

[0080] When the impeller 10 provided in step S100 has a disk portion 12 as described above, including a first disk segment 12a and a second disk segment 12b, the first disk segment 12a is connected to the hub 11 through the second disk segment 12b, and the axial distance between the front end surface of the first disk segment 12a and the rear end surface of the hub 11 is equal along the direction from the radial outer side to the radial inner side, and the axial distance between the front end surface of the second disk segment 12b and the rear end surface of the hub 11 gradually increases, see Figure 2 In some embodiments, step S200 of cutting the wall thickness of the disk portion 12 from the back to the front includes:

[0081] The wall thickness of the disk portion 12 is cut from the back to the front in such a manner that the cutting amount of the first disk segment 12a of the disk portion 12 remains unchanged and the cutting amount of the second disk segment 12b of the disk portion 12 gradually increases according to the proportional coefficient K along the direction from the radial outside to the radial inside.

[0082] K may be within the range of 1.2 to 2, that is, K may be greater than or equal to 1.2 and less than or equal to 2, which is expressed by the formula 1.2≤K≤2, or K=1.2 to 2. For example, in some embodiments, K=1.4.

[0083] When the wall thickness of the disk portion 12 is removed from the back to the front by using the above-mentioned method of removing according to the linear ratio K, it can be regarded as a process of offsetting and removing the rear end face of the disk portion 12 with a certain proportional coefficient according to the line shape of the front end face of the disk portion 12. Figure 2 The shape of the rear end face of the disk 12 of the optimized impeller 10 is similar to that of the front end face, which is beneficial to reduce the weight while making the hub 1 still have high strength and good aerodynamic performance, so as to further improve the working reliability of the compressor 100 and extend the service life of the compressor 100. Figure 2 As shown, after cutting, the rear end face of the second disc segment 12b is no longer a plane perpendicular to the transverse central axis of the axial hole 11a, but becomes an arcuate surface convex backwards, that is, the line shape of the rear end face of the second disc segment 12b is no longer a straight line, but becomes an arcuate line. Compared with the case where the line shape of the rear end face of the second disc segment 12b is still a straight line after cutting, not only is the weight reduction effect better, but also the airflow channel can be optimized and the energy efficiency can be improved.

[0084] For example, see Figure 2 After the cutting, the wall thickness L2 of the root of the second disc segment 12b (i.e., the connection portion between the second disc segment 12b and the hub 11) is still greater than the wall thickness L1 of the first disc segment 12a. This helps prevent the disc 12 from being brittlely damaged and fractured due to stress concentration at the root when the impeller 10 is running at a high speed, thereby helping to improve the working reliability of the compressor 100 and extend the service life of the compressor 100.

[0085] If the rear end surface of the front disc portion 12 is optimized as Figure 1 As shown, the rear end surface of the hub 11 is flush with the rear end surface of the hub 11. Then, the wall thickness of the disc 12 is removed from the back to the front by removing the wall thickness according to the linear ratio K mentioned above. Figure 2 , along the direction from the radial outer side to the radial inner side, the axial distance between the rear end face of the first disc segment 12a and the rear end face of the hub portion 11 remains unchanged, and the axial distance between the rear end face of the second disc segment 12b and the rear end face of the hub portion 11 gradually increases according to the proportional coefficient K. At this time, the rear end face of the disc portion 12 is no longer a plane perpendicular to the transverse central axis of the shaft hole 11a, but becomes a curved surface with a direction substantially the same as that of the front end face.

[0086] Continue to see Figure 2 After completing the cutting step, the connection between the rear end surface of the disk portion 12 and the hub portion 11 can be rounded so that the connection between the rear end surface of the disk portion 12 and the hub portion 11 has a rounded corner, so as to make the transition between the disk portion 12 and the hub portion 11 smoother and reduce stress concentration.

[0087] The material removal process of the above-mentioned embodiments can be completed in finite element software such as ANSYS, and the removal trajectory can be constructed based on the finite element analysis method and numerical calculation method, and the removal can be performed and simulation analysis can be performed.

[0088] Back to Figure 4 In some embodiments, the impeller optimization design method further includes:

[0089] S300, forming a groove 11c on the inner wall of the hub 11; and / or,

[0090] S400 , opening a counterweight hole 11 b on the wheel hub 1 .

[0091] Steps S300 and S400 may occur before or after step S200. For example, in some embodiments, steps S300 and S400 are performed after step S200, that is, after the material of the disc portion 12 is cut from the back to the front, the groove 11c and / or the counterweight hole 11b are opened. When steps S300 and S400 are included at the same time, step S400 may be performed after step S300, that is, the groove 11c may be opened on the inner wall of the hub portion 11 first, and then the counterweight hole 11b may be opened on the hub 1.

[0092] Whether the groove 11c or the counterweight hole 11b is opened, the weight of the impeller 10 can be further reduced, thereby further reducing the risk of breakage or bending deformation of the shaft 20, and further increasing the natural frequency of the rotor, increasing the critical speed of the rotor, and reducing the risk of resonance, thereby further improving the working reliability of the compressor 100 and extending the service life of the compressor 100.

[0093] The groove 11 c is formed on the inner wall of the hub 11 , which has the advantage of not affecting the positioning function of the positioning member 40 .

[0094] See also Figure 2 In some embodiments, when the groove 11c is formed on the inner wall of the hub 11, the length L3 of the groove 11c is less than or equal to 70% of the diameter D1 of the shaft hole 11a, and / or the depth L4 of the groove 11c is 2 to 4 mm.

[0095] The groove length L3 of the groove 11c satisfies L3≤70%D1, which can prevent the thickness of the positioning end surface of the impeller 10 from being too thin, and facilitate the impeller 10 to contact the positioning member 40 more fully, thereby achieving a more stable and reliable positioning effect.

[0096] By making the groove depth L4 of the groove 11c satisfy 2mm≤L4≤4mm, the radial edge of the groove 11c can be made not to exceed the outer diameter of the positioning member 40, thereby preventing plastic deformation of the positioning end face due to excessive groove depth, which makes it easier for the positioning member 40 to achieve more precise positioning of the impeller 10.

[0097] It can be seen that by providing the groove 11 c on the inner wall of the hub 11 and controlling the depth and length of the groove 11 c , a lightweight design of the impeller 10 can be achieved without affecting the positioning effect of the end face of the impeller 10 .

[0098] The shape of the groove 11 c is not particularly limited, and may be, for example, rectangular, wedge-shaped, drum-shaped, or elliptical.

[0099] The counterweight hole 11b is opened on the hub 1, which can not only reduce the weight of the impeller 10, but also facilitate the dynamic balancing of the impeller 10, reduce the centrifugal load borne by the impeller 10, and reduce the stress on the impeller 10, which is conducive to further improving the working reliability of the impeller 10 and the compressor 100 and extending the service life of the impeller 10 and the compressor 100.

[0100] See also Figure 2 In some embodiments, when the counterweight hole 11b is opened on the wheel hub 1, the transverse center axis of the counterweight hole 11b is parallel to the transverse center axis of the shaft hole 11a. At this time, the counterweight hole 11b extends along the axial direction.

[0101] Continue to see Figure 2 In some embodiments, the counterweight hole 11 b is opened on the rear end surface of the hub 11 . At this time, step S400 of opening the counterweight hole 11 b on the wheel hub 1 includes: opening the counterweight hole 11 b on the rear end surface of the hub 11 .

[0102] When the counterweight hole 11 b is opened on the rear end surface of the hub 11 , the size and position of the counterweight hole 11 b can be restricted.

[0103] For example, see Figure 2 In some embodiments, the diameter D2 of the counterweight hole 11b is less than or equal to 30% of the radial wall thickness L7 of the rear end face of the hub 11, that is, D2≤30%*L7, where L7 is the radial wall thickness of the rear end face of the hub 11. In this way, it is possible to prevent the front and rear end faces of the impeller 10 from having a large quality difference due to the excessive diameter of the counterweight hole 11b, which may cause the front end face of the wheel cover 3 to be polished too much during the dynamic balancing test, affecting the flatness of the front end face of the wheel cover 3 and causing the loss of airflow power.

[0104] For another example, see Figure 2 In some embodiments, the hole depth L5 of the counterweight hole 11b is less than or equal to 60% of the axial distance L6 between the rear wall of the groove 11c located on the inner wall of the hub 11 and the rear end face of the hub 11, that is, L5≤L6*60%, L6 is the axial distance between the rear wall of the groove 11c and the rear end face of the hub 11. At this time, it can prevent the wall thickness between the counterweight hole 11b and the groove 11c from being too thin, so as to avoid puncturing the groove wall during drilling or causing deformation and damage to the inner wall of the hub 11.

[0105] For example, see Figure 2 In some embodiments, the radial distance between the transverse central axis of the counterweight hole 11b and the edge of the shaft hole 11a is less than or equal to 1 / 3 of the radial wall thickness L7 of the rear end surface of the hub 11. In this way, the transverse central axis of the counterweight hole 11b is at or below 1 / 3 of L7, and the height is relatively low, which is beneficial to improving the uneven distribution of rotor mass, reducing stress concentration, and improving the connection strength between the impeller 10 and the rotating shaft 20, thereby improving the operating reliability of the rotor.

[0106] It can be seen that by controlling the hole diameter, hole depth and opening position of the counterweight hole 11b, the impeller 10 and the rotor can maintain greater strength and operational reliability while achieving a lightweight design of the impeller 10.

[0107] The number of the counterweight holes 11 b is not limited to 1. When the number of the counterweight holes 11 b is at least two, the at least two counterweight holes 11 b can be evenly distributed along the circumference of the shaft hole 11 a.

[0108] In some embodiments, when the counterweight holes 11b are provided on the hub 1, the number of the counterweight holes 11b is determined by a multi-objective optimization method. For example, in some embodiments, the objective is to minimize the mass of the impeller 10 and minimize the stress concentration factor at the highest speed, and the number of the counterweight holes 11b is used as a design variable to establish a multi-objective optimization function mathematical model, and calculate and determine the optimal value of the number of the counterweight holes 11b.

[0109] Specifically, when establishing a multi-objective optimization function mathematical model, the objective function is min[M,K], and the design variable is X=[x 1 ,x2 …x n ] T , the constraint is σ s ≤σ. Wherein, M is the impeller mass; K is the stress concentration factor at the highest speed of the impeller; X is the design variable, that is, the number of counterweight holes 11b; n is the number of design variables; σ s is the maximum equivalent stress of the impeller; σ is the yield strength of the impeller. Based on these conditions, the β method is used for calculation, and the target evaluation function is established for evaluation. The target evaluation function is Among them, Z is the target evaluation factor, M * is the ideal value of the impeller mass M, K * is the ideal value of stress concentration factor K at the highest speed, p is an index, w 1 and w 2 is the weighting factor of the objective function. Generally, the minimum value of the evaluation factor is selected from all evaluation factors as the optimal result Z min , and then according to Z min Select the corresponding design variables as the final optimization design variable results. The corresponding calculation and evaluation process can be completed by ANSYS. ANSYS obtains multiple sets of design variables that consider and do not consider the stress concentration factor, substitutes them into the target evaluation function, and finally obtains the optimal design variable value, that is, the optimal value of the number of counterweight holes 11b.

[0110] In some embodiments, based on a multi-objective optimization method, the number of the counterweight holes 11b is determined to be 8. Figure 2 In some embodiments, eight counterweight holes 11b are disposed on the rear end surface of the hub 11 and are evenly distributed along the circumference of the shaft hole 11a.

[0111] In addition to reducing the weight of the impeller 10 by optimizing the structure of the impeller 10, the weight of the impeller 10 can also be reduced by changing the material of the impeller 10. For example, in some embodiments, the material of the impeller 10 is changed from aluminum to carbon fiber with lower density.

[0112] It can be seen that, under the condition that the impeller 10 meets the requirements of strength, rigidity and reliability, by utilizing the finite element analysis method, performing material removal on the hub 1 and optimizing the design by providing grooves 11c and / or counterweight holes 11b, a lightweight design of the impeller 10 can be achieved, thereby improving the reliability and service life of the rotating shaft 20 and the components on the shaft, and further improving the reliability and service life of the compressor 100.

[0113] The present invention further provides an impeller 10, which is designed using the impeller optimization design method of an embodiment of the present invention.

[0114] See also Figure 2In some embodiments, the impeller 10 comprises:

[0115] The hub 1 comprises a hub portion 11 and a disc portion 12. The hub portion 11 is provided with an axial hole 11a for mounting a rotating shaft 20. The disc portion 12 is connected to the hub portion 11 and extends radially outward from the hub portion 11. The disc portion 12 comprises a first disc segment 12a and a second disc segment 12b. The first disc segment 12a is connected to the hub portion 11 through the second disc segment 12b. Along the direction from the radial outer side to the radial inner side, the axial distance between the front end face of the first disc segment 12a and the rear end face of the hub portion 11 is equal, and the axial distance between the front end face of the second disc segment 12b and the rear end face of the hub portion 11 gradually increases.

[0116] Among them, along the direction from radially outer side to radially inner side, the axial distance between the rear end face of the first disc segment 12a and the rear end face of the hub 11 remains unchanged, and the axial distance between the rear end face of the second disc segment 12b and the rear end face of the hub 11 gradually increases according to the proportional coefficient K.

[0117] Based on the above arrangement, the rear end surface of the disk 12 is no longer flush with the rear end surface of the hub 11, but is moved forward relative to the rear end surface of the hub 11, creating an axial distance between the rear end surface of the hub 11, so that the wall thickness of the disk 12 becomes smaller, thereby helping to reduce the weight of the impeller 10, thereby improving the working reliability of the compressor 100 and extending the service life of the compressor 100.

[0118] Moreover, based on the above arrangement, the shape of the rear end face of the disc 12 has a certain similarity with the shape of the front end face, which is beneficial for reducing weight while ensuring that the hub 1 still has high strength and good aerodynamic performance, so as to further improve the working reliability of the compressor 100 and extend the service life of the compressor 100.

[0119] In some embodiments, K=1.2-2.

[0120] In some embodiments, K=1.4.

[0121] In some embodiments, a groove 11 c is provided on the inner wall of the hub 11 ; and / or a counterweight hole 11 b is provided on the wheel hub 1 .

[0122] In some embodiments, the length L3 of the groove 11c is less than or equal to 70% of the diameter D1 of the shaft hole 11a, and / or the depth L4 of the groove 11c is 2-4 mm.

[0123] In some embodiments, the weight hole 11b is configured as at least one of the following:

[0124] The transverse center axis of the counterweight hole 11b is parallel to the transverse center axis of the shaft hole 11a;

[0125] The number of the counterweight holes 11b is at least two;

[0126] At least two counterweight holes 11b are evenly distributed along the circumference of the shaft hole 11a;

[0127] The number of the weight holes 11b is eight.

[0128] In some embodiments, the counterweight hole 11 b is disposed on the rear end surface of the hub 11 .

[0129] In some embodiments, the weight hole 11b is configured as at least one of the following:

[0130] The diameter D2 of the counterweight hole 11b is 30% of the radial wall thickness L7 of the rear end surface of the hub 11;

[0131] The hole depth L5 of the counterweight hole 11b is 60% of the axial distance L6 between the rear wall of the groove 11c located on the inner wall of the hub 11 and the rear end surface of the hub 11;

[0132] The radial distance between the transverse central axis of the counterweight hole 11 b and the edge of the shaft hole 11 a is less than or equal to 1 / 3 of the radial wall thickness L7 of the rear end surface of the hub portion 11 .

[0133] In addition, the present invention further provides a compressor 100, which includes the impeller 10 in the embodiment of the present invention. The compressor 100 may be a centrifugal compressor.

[0134] The above description is only an exemplary embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for optimizing the design of an impeller, characterized in that: include: An impeller (10) is provided, the impeller (10) comprising a hub (1), the hub (1) comprising a hub portion (11) and a disc portion (12), the hub portion (11) being provided with an axial hole (11a) for mounting a rotating shaft (20), the disc portion (12) being connected to the hub portion (11) and extending radially outward from the hub portion (11), the disc portion (12) comprising a first disc segment (12a) and a second disc segment (12b), the first disc segment (12a) being connected to the hub portion (11) via the second disc segment (12b), and along the direction from the radial outer side to the radial inner side, the axial distance between the front end surface of the first disc segment (12a) and the rear end surface of the hub portion (11) is equal, and the axial distance between the front end surface of the second disc segment (12b) and the rear end surface of the hub portion (11) gradually increases; The wall thickness of the disc portion (12) is cut from the back to the front, including: the cutting amount of the first disc segment (12a) of the disc portion (12) is kept constant along the direction from the radial outer side to the radial inner side, and the cutting amount of the second disc segment (12b) of the disc portion (12) is gradually increased according to a proportional coefficient K, so that along the direction from the radial outer side to the radial inner side, the axial distance between the rear end face of the first disc segment (12a) and the rear end face of the hub portion (11) is kept constant, and the axial distance between the rear end face of the second disc segment (12b) and the rear end face of the hub portion (11) is gradually increased according to a proportional coefficient K, K=1.2~2.

2. The impeller optimization design method according to claim 1, characterized in that: K＝1.4。 3. The impeller optimization design method according to claim 1, characterized in that: When the wall thickness of the disk portion (12) is cut from the back to the front, the convex portion (13) on the rear end surface of the disk portion (12) is cut off, the convex portion (13) protrudes backward from the rear end surface of the disk portion (12), and a concave cavity (13a) is provided in the convex portion (13).

4. The impeller optimization design method according to any one of claims 1 to 3, characterized in that: The impeller optimization design method further comprises: A groove (11c) is provided on the inner wall of the hub (11); and / or, A counterweight hole (11b) is provided on the wheel hub (1).

5. The impeller optimization design method according to claim 4, characterized in that: When the groove (11c) is formed on the inner wall of the hub (11), the length L3 of the groove (11c) is less than or equal to 70% of the diameter D1 of the axial hole (11a), and / or the depth L4 of the groove (11c) is 2 to 4 mm.

6. The impeller optimization design method according to claim 4, characterized in that: When the counterweight holes (11b) are opened on the wheel hub (1), the number of the counterweight holes (11b) is determined using a multi-objective optimization method.

7. The impeller optimization design method according to claim 4, characterized in that: When the counterweight hole (11b) is opened on the wheel hub (1), the transverse center axis of the counterweight hole (11b) is parallel to the transverse center axis of the shaft hole (11a).

8. The impeller optimization design method according to claim 4, characterized in that: The step of opening a counterweight hole (11b) on the wheel hub (1) comprises: The counterweight hole (11b) is provided on the rear end surface of the hub (11).

9. The impeller optimization design method according to claim 8, characterized in that: The counterweight hole (11b) opened on the rear end surface of the hub (11) comprises at least one of the following: The diameter D2 of the counterweight hole (11b) is smaller than or equal to 30% of the radial wall thickness L7 of the rear end surface of the hub (11); The hole depth L5 of the counterweight hole (11b) is less than or equal to 60% of the axial distance L6 between the rear wall of the groove (11c) located on the inner wall of the hub (11) and the rear end surface of the hub (11); The radial distance between the transverse central axis of the counterweight hole (11b) and the edge of the shaft hole (11a) is less than or equal to 1 / 3 of the radial wall thickness L7 of the rear end face of the hub (11).

10. An impeller (10), characterized in that: The impeller is designed by using the impeller optimization design method as described in any one of claims 1 to 9.

11. An impeller (10), characterized in that: include: A wheel hub (1) comprises a hub portion (11) and a disc portion (12), wherein the hub portion (11) is provided with an axial hole (11a) for mounting a rotating shaft (20), the disc portion (12) is connected to the hub portion (11) and extends radially outward from the hub portion (11), the disc portion (12) comprises a first disc segment (12a) and a second disc segment (12b), the first disc segment (12a) is connected to the hub portion (11) via the second disc segment (12b), and along the direction from the radial outer side to the radial inner side, the axial distance between the front end surface of the first disc segment (12a) and the rear end surface of the hub portion (11) is equal, and the axial distance between the front end surface of the second disc segment (12b) and the rear end surface of the hub portion (11) gradually increases; Wherein, along the direction from the radial outer side to the radial inner side, the axial distance between the rear end face of the first disc segment (12a) and the rear end face of the hub (11) remains unchanged, and the axial distance between the rear end face of the second disc segment (12b) and the rear end face of the hub (11) gradually increases according to a proportional coefficient K, K=1.2~2.

12. The impeller (10) according to claim 11, characterized in that K＝1.4。 13. The impeller (10) according to any one of claims 11 to 12, characterized in that: A groove (11c) is provided on the inner wall of the hub portion (11); and / or a counterweight hole (11b) is provided on the wheel hub (1).

14. The impeller (10) according to claim 13, characterized in that The length L3 of the groove (11c) is less than or equal to 70% of the diameter D1 of the axial hole (11a), and / or the depth L4 of the groove (11c) is 2 to 4 mm.

15. The impeller (10) according to claim 13, characterized in that The counterweight hole (11b) is configured as at least one of the following: The transverse center axis of the counterweight hole (11b) is parallel to the transverse center axis of the shaft hole (11a); The number of the counterweight holes (11b) is at least two; At least two of the counterweight holes (11b) are evenly distributed along the circumference of the shaft hole (11a); The number of the counterweight holes (11b) is 8.

16. The impeller (10) according to claim 13, characterized in that The counterweight hole (11b) is arranged on the rear end surface of the hub (11).

17. The impeller (10) according to claim 16, characterized in that The counterweight hole (11b) is constructed as at least one of the following: The diameter D2 of the counterweight hole (11b) is 30% of the radial wall thickness L7 of the rear end surface of the hub (11); The hole depth L5 of the counterweight hole (11b) is 60% of the axial distance L6 between the rear wall of the groove (11c) located on the inner wall of the hub (11) and the rear end surface of the hub (11); The radial distance between the transverse central axis of the counterweight hole (11b) and the edge of the shaft hole (11a) is less than or equal to 1 / 3 of the radial wall thickness L7 of the rear end face of the hub (11).

18. A compressor (100), characterized in that: It comprises an impeller (10) as claimed in any one of claims 11 to 17.

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