Compression mechanism
By setting a groove structure and an insertion part between the impeller and the back plate of the steam compressor, combined with a multi-layer sealing structure, the problem of poor sealing effect of the steam compressor is solved, achieving efficient steam sealing and space optimization.
Patent Information
- Application Number
- CN202520078600.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-13
- Publication Date
- 2025-11-11
- Estimated Expiration
- 2035-01-13
AI Technical Summary
During operation, the carbon ring seal device of the steam compressor occupies axial space and is difficult to effectively seal high-pressure steam leakage, resulting in reduced efficiency and safety hazards.
A compression mechanism is designed to increase the contact area and reduce steam leakage by setting a groove structure and an insertion part between the impeller and the back plate, and by using a multi-layer sealing structure to seal the gap.
It improves the sealing performance of the steam compressor, reduces steam leakage, avoids energy waste and safety hazards, and optimizes the utilization of axial space.
Smart Images
Figure CN223536576U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of compressor technology, and more particularly to a compression mechanism. Background Technology
[0002] Steam compressors are core components of common high-temperature heat pump systems. Their function is to pressurize and heat low-pressure and / or low-temperature steam to meet the temperature and pressure requirements of a process or engineering project. During operation, to minimize leakage of high-pressure steam, the clearances on the rotor of a steam compressor need to be sealed. The axial length of the steam compressor's structure is limited by rotor dynamics and should not be too long. However, the carbon ring seals commonly used in steam compressors require a portion of the compressor's axial space to achieve the sealing effect. Utility Model Content
[0003] This application provides a compression mechanism that not only achieves a better sealing effect, but also reduces the axial space occupied by the sealing structure on the compression mechanism.
[0004] This application provides a compression mechanism, including:
[0005] Shaft;
[0006] An impeller is fitted onto the rotating shaft and connected to the rotating shaft;
[0007] The back plate is sleeved on the rotating shaft and arranged along the axial direction of the rotating shaft with the impeller;
[0008] The impeller has a first sealing surface facing the back plate, and the back plate has a second sealing surface facing the impeller. An insertion portion is provided on the second sealing surface, and the insertion portion is arranged around the circumference of the rotating shaft. A groove structure for inserting the insertion portion is provided on the first sealing surface. The insertion portion has a mating surface facing the groove structure. At least one of the inner sidewall of the groove structure and the mating surface is provided with a first sealing structure, which is used to seal the gap between the inner sidewall of the groove structure and the mating surface.
[0009] In some embodiments of this application, the mating surface includes an inner ring surface facing the rotating shaft, the first sealing structure is located on the inner ring surface, and the first sealing structure is provided with a first annular channel on the side facing the impeller. The first annular channel is arranged around the circumference of the rotating shaft and communicates with the outside.
[0010] In some embodiments of this application, the compression mechanism further includes:
[0011] A stator assembly is fitted onto the rotating shaft, and the stator assembly is located on the side of the back plate away from the impeller. An exhaust channel is formed between the stator assembly and the back plate. The exhaust channel connects the first annular channel to the outside, so that the steam in the first annular channel can be discharged through the exhaust channel.
[0012] In some embodiments of this application, the stator assembly has an exhaust groove on the side facing the back plate, and the exhaust groove forms the exhaust channel.
[0013] In some embodiments of this application, a second annular channel is provided on the side of the first sealing structure opposite to the impeller. The second annular channel is arranged around the circumference of the rotating shaft and communicates with the outside.
[0014] In some embodiments of this application, the compression mechanism further includes:
[0015] A stator assembly is sleeved on the rotating shaft, and the stator assembly is located on the side of the back plate away from the impeller. An air inflation channel is formed between the stator assembly and the back plate. The air inflation channel connects the second annular channel to the outside, so that compressed air from the outside can enter the second annular channel through the air inflation channel.
[0016] In some embodiments of this application, an inflation groove is provided on the side of the stator assembly facing the back plate, and the inflation groove forms the inflation channel.
[0017] In some embodiments of this application, the mating surface includes an inner ring surface facing the rotating shaft, and the first sealing structure is provided on both the inner sidewall of the groove structure and the inner ring surface. The first sealing structure on the inner ring surface includes a plurality of first sealing teeth, and the tooth height of the plurality of first sealing teeth increases sequentially from the impeller toward the back plate.
[0018] The first sealing structure on the inner wall of the groove structure includes a plurality of first mating teeth, the tooth height of the plurality of first mating teeth decreasing sequentially from the impeller toward the back plate, and the first mating teeth meshing with the first sealing teeth.
[0019] In some embodiments of this application, the mating surface includes an inner ring surface and a first side surface. The inner ring surface faces the rotating shaft and is parallel to the axis of the rotating shaft. The first side surface connects the inner ring surface and the second sealing surface. The first side surface and the second sealing surface are arranged at an angle. The cross-sectional shape of the insertion part and the groove structure along the axis of the rotating shaft is a right triangle. The first sealing structure is provided on both the inner ring surface and the first side surface.
[0020] In some embodiments of this application, the mating surface includes an inner ring surface, a first side surface, and a second side surface. The inner ring surface, the first side surface, and the second side surface are connected in sequence. The inner ring surface faces the rotating shaft. The inner ring surface and the second side surface are both parallel to the axis of the rotating shaft. The first side surface is set at an angle to the inner ring surface and the second side surface. The cross-sectional shape of the insertion part and the groove structure along the axis of the rotating shaft is trapezoidal. The first sealing structure is provided on the inner ring surface, the first side surface, and the second side surface.
[0021] In some embodiments of this application, the first sealing structure on the second side includes a plurality of second sealing teeth, the tooth height of the plurality of second sealing teeth increasing sequentially from the impeller toward the back plate; the first sealing structure is also provided on the inner sidewall of the groove structure, the first sealing structure including a plurality of second mating teeth, the tooth height of the plurality of second mating teeth decreasing sequentially from the impeller toward the back plate, and the second mating teeth meshing with the second sealing teeth.
[0022] In some embodiments of this application, at least one of the first sealing surface and the second sealing surface is provided with a second sealing structure, the second sealing structure being used to seal the gap between the first sealing surface and the second sealing surface.
[0023] In some embodiments of this application, a plurality of second sealing structures are provided on both the first sealing surface and the second sealing surface, and the second sealing structures on the first sealing surface and the second sealing structures on the second sealing surface are alternately arranged.
[0024] In some embodiments of this application, both the first sealing surface and the second sealing surface are perpendicular to the axis of the rotating shaft; the second sealing structure has a flow-facing surface facing away from the direction of the rotating shaft, and the flow-facing surface is parallel to the axis of the rotating shaft.
[0025] In some embodiments of this application, the groove structure has an annular cross-sectional shape along the direction perpendicular to the axis of rotation, and the inner diameter of the groove structure is less than or equal to the outer diameter of the rotation shaft.
[0026] Based on the compression mechanism in this application embodiment, this application embodiment increases the contact area between the back plate and the impeller by opening a groove structure on the side of the impeller facing the back plate and providing an insertion part of the groove structure on the back plate, thereby improving the sealing performance between the back plate and the impeller. At the same time, the insertion part on the back plate extends into the groove structure of the impeller, so that part of the solid space of the impeller along the axis of rotation becomes a groove structure and is provided for the back plate to use, thereby reducing the space occupied by the back plate in the axis of rotation. That is, this embodiment uses part of the space of the impeller along the axis of rotation to increase the sealing space between the back plate and the impeller. Attached Figure Description
[0027] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0028] Figure 1 This is a schematic cross-sectional view of a portion of the compression mechanism along the axis of rotation in one embodiment of this application;
[0029] Figure 2 for Figure 1 Enlarged structural diagram at point A;
[0030] Figure 3 This is a schematic cross-sectional view of a portion of the impeller in one embodiment of this application;
[0031] Figure 4 This is a cross-sectional structural diagram of a portion of the backplate in one embodiment of this application;
[0032] Figure 5 This is a schematic cross-sectional view of a portion of the compression mechanism along the axis perpendicular to the rotating shaft in one embodiment of this application.
[0033] Figure label:
[0034] 10. Shaft;
[0035] 20. Impeller; 21. First sealing surface; 22. Groove structure;
[0036] 30. Back plate; 31. Second sealing surface; 32. Insertion part; 321. Mutation surface; 3211. Inner ring surface; 3212. First side surface; 3213. Second side surface;
[0037] 40. First sealing structure; 41. First sealing tooth; 42. First mating tooth; 43. Second sealing tooth; 44. Second mating tooth; 45. Sealing point;
[0038] 51. First annular channel; 52. Exhaust channel; 53. Second annular channel; 54. Inflation channel;
[0039] 60. Stator assembly;
[0040] 70. Second sealing structure; 71. Frontal surface. Detailed Implementation
[0041] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, a clear and complete description will be provided below with reference to the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.
[0042] In related technologies, the compression principle of a steam compressor is to increase the kinetic energy of the compressed medium by rotating the impeller, which is then converted into static pressure energy in the diffuser, thus achieving compression. High-temperature heat pumps typically use positive pressure steam compressors, where the medium pressure is greater than atmospheric pressure. During compression, under the influence of the internal and external pressure difference, the medium may leak along the rotor gaps towards the lower pressure area. This leakage not only reduces the efficiency of the steam compressor, resulting in energy waste, but more importantly, the leaked steam may pose safety hazards to the equipment and the environment. For magnetic levitation direct-drive steam compressors, high-pressure steam leaking along the shaft to the magnetic bearings and motor may directly cause a short circuit in the motor, creating a safety hazard. Therefore, during the use of steam compressors, to reduce the leakage of internal high-pressure steam, the gaps on the rotor need to be sealed. The length of the axial structure of the steam compressor is limited by rotor dynamics and should not be too long. However, the carbon ring sealing devices commonly used in steam compressors require a portion of the axial space on the steam compressor to achieve the sealing effect.
[0043] For the above situation, please refer to Figures 1-2 This application proposes a compression mechanism, which includes a rotating shaft 10, an impeller 20, and a back plate 30. Both the impeller 20 and the back plate 30 are sleeved on the rotating shaft 10 and connected to it. The back plate 30 and the impeller 20 are arranged axially along the rotating shaft 10. The rotating shaft 10 drives the impeller 20 to rotate, increasing the kinetic energy of the compressed medium. A bushing is sleeved on the rotating shaft 10, and the rotating shaft 10 rotates relative to the bushing. The back plate 30 is sleeved on the bushing of the rotating shaft 10. The compression mechanism can be a steam compressor, and the compressed medium can be steam.
[0044] like Figures 3-4As shown, the impeller 20 has a first sealing surface 21 facing the back plate 30, and the back plate 30 has a second sealing surface 31 facing the impeller 20. An insertion part 32 is provided on the second sealing surface 31. The insertion part 32 is arranged around the periphery of the rotating shaft 10. A groove structure 22 for the insertion part 32 to be inserted is provided on the first sealing surface 21. The insertion part 32 has a mating surface 321 facing the groove structure 22. A first sealing structure 40 is provided on at least one of the inner sidewall of the groove structure 22 and the mating surface 321. The first sealing structure 40 is used to seal the gap between the inner sidewall of the groove structure 22 and the mating surface 321.
[0045] Specifically, taking the axis of the rotating shaft 10 as the first direction L1 and the direction perpendicular to the axis of the rotating shaft 10 as the second direction L2, the cross-sectional shape of the insertion part 32 and the groove structure 22 along the second direction L2 are both annular. Because the impeller 20 itself needs to rotate, there is a clearance fit between the outer periphery of the impeller 20 and the back plate 30. The compressed medium will leak along the gap between the impeller 20 and the back plate 30. The insertion part 32 extends into the groove structure 22. At this time, the insertion part 32 and the groove structure 22 are sealed by the first sealing structure 40 to achieve a seal between the impeller 20 and the back plate 30.
[0046] It should be noted that, in this embodiment, a groove structure 22 is provided on the side of the impeller 20 facing the back plate 30, and an insertion part 32 for the groove structure 22 is provided on the back plate 30. This increases the contact area between the back plate 30 and the impeller 20, and improves the sealing performance between the back plate 30 and the impeller 20. At the same time, the insertion part 32 on the back plate 30 extends into the groove structure 22 of the impeller 20, so that part of the solid space of the impeller 20 along the first direction L1 becomes the groove structure 22 and is provided for the back plate 30 to use. This reduces the space occupied by the back plate 30 in the first direction L1. That is, this embodiment uses part of the space of the impeller 20 along the first direction L1 to increase the sealing space between the back plate 30 and the impeller 20.
[0047] In some embodiments of the application, the cross-sectional shape of the groove structure 22 along the second direction L2 is annular, such as... Figure 1 As shown, the inner diameter length d1 of the groove structure 22 is less than or equal to the outer diameter length d2 of the rotating shaft 10, i.e., d1≤d2. In other words, after the impeller 20 is installed on the rotating shaft 10, the inner ring of the groove structure 22 on the impeller 20 is flush with the circumference of the rotating shaft 10, or the inner diameter of the groove structure 22 is less than the outer diameter of the rotating shaft 10. This can reduce the gap space between the impeller 20 and the back plate 30, thereby reducing the leakage of steam in the compression mechanism.
[0048] Please see Figures 3-4In some embodiments of this application, at least one of the first sealing surface 21 and the second sealing surface 31 is provided with a second sealing structure 70, which is used to seal the gap between the first sealing surface 21 and the second sealing surface 31.
[0049] It is easy to understand that the insertion part 32 and the groove structure 22 can also be sealed by the second sealing structure 70 to further achieve the seal between the impeller 20 and the back plate 30. For example, the second sealing structure 70 is located on the side of the insertion part 32 / groove structure 22 away from the rotating shaft 10. If the steam in the compression mechanism leaks along the gap between the impeller 20 and the back plate 30, the leaked steam will pass through the second sealing structure 70 and the first sealing structure 40 in sequence. The combined action of multiple sealing structures can improve the sealing performance between the impeller 20 and the back plate 30.
[0050] Further reading is available upon request. Figures 3-4 In some embodiments of this application, a plurality of second sealing structures 70 are provided on both the first sealing surface 21 and the second sealing surface 31, and the second sealing structures 70 on the first sealing surface 21 and the second sealing surface 31 are alternately arranged.
[0051] For example, the second sealing structure 70 can be a sealing comb group, each sealing comb group having 3 to 5 comb teeth. The first sealing surface 21 is provided with 3 groups of sealing comb groups, and the second sealing surface 31 is provided with 3 groups of sealing comb groups. The sealing comb groups on the first sealing surface 21 and the sealing comb groups on the second sealing surface 31 are arranged alternately to form an interlaced tooth pattern.
[0052] Furthermore, please continue to see Figures 3-4 In some embodiments of this application, the first sealing surface 21 and the second sealing surface 31 are both perpendicular to the axis of the rotating shaft 10. That is, the inlet gap between the first sealing surface 21 and the second sealing surface 31 extends along the second direction L2. The second sealing structure 70 has a flow-facing surface 71 that is away from the direction of the rotating shaft 10 and is parallel to the axis of the rotating shaft 10.
[0053] It is easy to understand that the flow-facing surface 71 of the second sealing structure 70 is perpendicular to the inlet gap between the first sealing surface 21 and the second sealing surface 31. That is, the second sealing structure 70 forms a radial seal. Steam leaking from the inlet gap between the impeller 20 and the back plate 30 first contacts the flow-facing surface 71, increasing the resistance to steam leakage. The second sealing structure 70 can be a sealing comb, and the cross-sectional shape of the sealing comb along the first direction L1 can be trapezoidal, rectangular, or triangular.
[0054] Please see Figure 2In some embodiments of this application, the mating surface 321 includes an inner ring surface 3211 facing the rotating shaft 10, the first sealing structure 40 is located on the inner ring surface 3211, and the first sealing structure 40 is provided with a first annular channel 51 on the side facing the impeller 20. The first annular channel 51 is arranged around the periphery of the rotating shaft 10 and communicates with the outside.
[0055] Specifically, the first annular channel 51 can be formed by the first sealing structure 40, the inner ring surface 3211, and the inner sidewall of the groove structure 22. The first annular channel 51 is formed around the circumference of the rotating shaft 10, and can ensure uniform steam flow within it. The inner ring surface 3211 can be parallel to the first direction L1 to form an axial seal between the impeller 20 and the back plate 30. If steam leaks from the compression mechanism along the gap between the impeller 20 and the back plate 30, some of the leaked steam will reach the first annular channel 51 and be discharged to the outside from the first annular channel 51, reducing steam leakage into the interior of the compression mechanism.
[0056] Further, please see Figure 1 In some embodiments of this application, the compression mechanism further includes a stator assembly 60, which is sleeved on the rotating shaft 10 and located on the side of the back plate 30 away from the impeller 20. An exhaust channel 52 is formed between the stator assembly 60 and the back plate 30. The exhaust channel 52 connects the first annular channel 51 to the outside, so that the steam in the first annular channel 51 can be discharged through the exhaust channel 52.
[0057] It is understandable that the stator assembly 60 is sleeved on the bushing of the rotating shaft 10, and the stator assembly 60 and the back plate 30 are spaced apart. The exhaust channel 52 can be formed by the gap between the stator assembly 60 and the back plate 30, so there is no need to open a channel on the back plate 30 to discharge the steam in the first annular channel 51, thus reducing the volume of the back plate 30.
[0058] Furthermore, please continue to see Figure 1 The stator assembly 60 has an exhaust groove on the side facing the back plate 30, which forms an exhaust channel 52. Specifically, the exhaust groove and the surface of the back plate 30 together form the exhaust channel 52. By providing an exhaust groove on the stator assembly 60, the distance between the stator assembly 60 and the back plate 30 can be reduced, that is, the stator assembly 60 and the back plate 30 can contact each other. The exhaust channel 52 is formed by the exhaust groove, thereby reducing the space occupied by the back plate 30 and the stator assembly 60 in the first direction L1.
[0059] Please continue reading Figure 1 In some embodiments of this application, a second annular channel 53 is provided on the side of the first sealing structure 40 away from the impeller 20. The second annular channel 53 is arranged around the periphery of the rotating shaft 10 and communicates with the outside.
[0060] Specifically, the second annular channel 53 can be formed by the first sealing structure 40, the inner ring surface 3211, and the first sealing surface 21. The second annular channel 53 is formed around the periphery of the rotating shaft 10, allowing compressed air from the outside to enter the second annular channel 53. The second annular channel 53 and the first annular channel 51 are located on opposite sides of the first sealing structure 40. If steam in the compression mechanism leaks along the gap between the impeller 20 and the back plate 30, some of the leaked steam will reach the first annular channel 51. At this time, compressed air can be injected into the second annular channel 53 to increase the air pressure in the second annular channel 53, thereby preventing steam from leaking from the first annular channel 51 into the second annular channel 53.
[0061] Further reading is available upon request. Figure 1 In some embodiments of this application, the compression mechanism further includes a stator assembly 60, which is sleeved on the rotating shaft 10 and located on the side of the back plate 30 away from the impeller 20. An inflation channel 54 is formed between the stator assembly 60 and the back plate 30. The inflation channel 54 connects the second annular channel 53 to the outside, so that compressed air from the outside can enter the second annular channel 53 through the inflation channel 54.
[0062] It is understandable that the stator assembly 60 is sleeved on the bushing of the rotating shaft 10, and the stator assembly 60 and the back plate 30 are spaced apart. The air filling channel 54 can be formed by the gap between the stator assembly 60 and the back plate 30. Therefore, it is not necessary to open a channel on the back plate 30 for filling compressed air from the outside into the second annular channel 53, thus reducing the volume of the back plate 30.
[0063] Furthermore, please continue to see Figure 1 An inflation groove is provided on the side of the stator assembly 60 facing the back plate 30, forming an inflation channel 54. Specifically, the inflation groove and the surface of the back plate 30 together form the inflation channel 54. By providing an inflation groove on the stator assembly 60, the distance between the stator assembly 60 and the back plate 30 can be reduced, that is, the stator assembly 60 and the back plate 30 can contact each other. The inflation channel 54 is formed by the inflation groove, thereby reducing the space occupied by the back plate 30 and the stator assembly 60 in the first direction L1.
[0064] It should be noted that both the exhaust channel 52 and the inflation channel 54 are located between the back plate 30 and the stator assembly 60, which can prevent the exhaust channel 52 and the inflation channel 54 from interfering with the seal between the impeller 20 and the back plate 30. Preferably, the exhaust channel 52 is located below the rotating shaft 10 and extends vertically so that the steam leaking into the first annular channel 51 can flow to the exhaust channel 52 under the action of gravity; the inflation channel 54 can be located above the rotating shaft 10 to prevent interference between the inflation channel 54 and the exhaust channel 52. In addition, the larger the flow area of the exhaust channel 52, the smaller the exhaust resistance and the smoother the flow. Figure 1 and Figure 5 As shown, to save space in the first direction L1, the width of the exhaust channel 52 can extend along the axis perpendicular to the rotation shaft 10. To ensure the inflation pressure of the inflation channel 54 and effectively prevent steam from leaking from the first annular channel 51 into the second annular channel 53, the flow area of the inflation channel 54 near the inflation point should not be too large. At the same time, the flow area of the inflation channel 54 should not be too small, as this would increase the inflation resistance.
[0065] Please see Figure 2 In some embodiments of this application, the mating surface 321 includes an inner ring surface 3211 facing the rotating shaft 10. A first sealing structure 40 is provided on the inner sidewall of the groove structure 22 and the inner ring surface 3211. The first sealing structure 40 on the inner ring surface 3211 includes a plurality of first sealing teeth 41. The tooth height of the plurality of first sealing teeth 41 increases sequentially from the impeller 20 toward the back plate 30. The first sealing structure 40 on the inner sidewall of the groove structure 22 includes a plurality of first mating teeth 42. The tooth height of the plurality of first mating teeth 42 decreases sequentially from the impeller 20 toward the back plate 30. The first mating teeth 42 mesh with the first sealing teeth 41.
[0066] Specifically, both the first sealing tooth 41 and the first mating tooth 42 are stepped teeth. Because the sealing effect of stepped teeth is better than that of flat teeth, the first sealing structure 40 on the inner ring surface 3211 is set as stepped teeth to improve the sealing performance of the first sealing structure 40 on the inner ring surface 3211.
[0067] It should be noted that, as Figure 2As shown, the first sealing tooth 41 meshes with the first mating tooth 42, forming a sealing point 45 at the inner ring surface 3211. The first annular channel 51 and the second annular channel 53 can be located on opposite sides of the sealing point 45. The first annular channel 51 is located on the side of the sealing point 45 facing the impeller 20. After the leaked steam passes through the gap between the impeller 20 and the back plate 30, it will reach the first annular channel 51. The sealing point 45 can prevent the steam from flowing from the first annular channel 51 to the second annular channel 53. At the same time, compressed air is injected into the air filling channel 54 to increase the air pressure in the second annular channel 53, which can further prevent the low-pressure steam from flowing from the first annular channel 51 to the high-pressure second annular channel 53.
[0068] In some embodiments of this application, the mating surface 321 includes an inner ring surface 3211 and a first side surface 3212. The inner ring surface 3211 faces the rotating shaft 10 and is parallel to the axis of the rotating shaft 10. The first side surface 3212 is connected between the inner ring surface 3211 and the second sealing surface 31. The first side surface 3212 and the second sealing surface 31 are arranged at an angle. The cross-sectional shape of the insertion part 32 and the groove structure 22 along the axis L1 of the rotating shaft 10 is a right triangle (not shown in the figure).
[0069] It is understandable that the insertion part 32 and the groove structure 22 have the same cross-sectional shape, which is beneficial to the sealing between the insertion part 32 and the groove structure 22. The inner ring surface 3211 is perpendicular to the second sealing surface 31. In the cross-section along the first direction L1, the inner ring surface 3211 and the second sealing surface 31 can form two right-angled sides of a right triangle, and the first side surface 3212 forms the hypotenuse of the right triangle. The groove structure 22 with a right-angled triangular cross-section on the impeller 20 makes the thickness of the impeller 20 more uniform, thereby ensuring better strength of the impeller 20.
[0070] The inner ring surface 3211 and the first side surface 3212 are both provided with a first sealing structure 40. That is, each side surface of the insertion part 32 can form a seal with the inner side wall of the groove structure 22. The first sealing structure 40 on the inner ring surface 3211 can form a first seal between the impeller 20 and the back plate 30 in the axial direction. The first sealing structure 40 on the first side surface 3212 can form a second seal between the impeller 20 and the back plate 30 on the inclined side, so as to improve the sealing performance between the impeller 20 and the back plate 30.
[0071] Alternatively, please see Figure 4In some embodiments of this application, the mating surface 321 includes an inner ring surface 3211, a first side surface 3212, and a second side surface 3213. The inner ring surface 3211, the first side surface 3212, and the second side surface 3213 are connected in sequence. The inner ring surface 3211 faces the rotating shaft 10. The inner ring surface 3211 and the second side surface 3213 are both parallel to the axis of the rotating shaft 10. The first side surface 3212 is set at an angle to the inner ring surface 3211 and the second side surface 3213. The cross-sectional shape of the insertion part 32 and the groove structure 22 along the axis L1 of the rotating shaft 10 is trapezoidal.
[0072] It is understandable that the insertion part 32 and the groove structure 22 have the same cross-sectional shape, which is beneficial to the sealing between the insertion part 32 and the groove structure 22. The inner ring surface 3211 and the second side surface 3213 are both perpendicular to the second sealing surface 31. In the cross-section along the first direction L1, the cross-sectional shape of the insertion part 32 is a right trapezoid. The inner ring surface 3211 and the second side surface 3213 can form two parallel sides of the right trapezoid, and the first side surface 3212 forms the hypotenuse of the right trapezoid. The groove structure 22 with a trapezoidal cross-section on the impeller 20 can increase the sealing position between the impeller 20 and the back plate 30 in the axial direction, thereby improving the sealing performance between the impeller 20 and the back plate 30.
[0073] The inner ring surface 3211, the first side surface 3212, and the second side surface 3213 are all provided with a first sealing structure 40. That is, each side surface of the insertion part 32 can form a seal with the inner side wall of the groove structure 22. The first sealing structure 40 on the second side surface 3213 can form a first axial seal between the impeller 20 and the back plate 30 in the axial direction. The first sealing structure 40 on the first side surface 3212 can form a second inclined surface seal between the impeller 20 and the back plate 30 on the inclined side. The first sealing structure 40 on the inner ring surface 3211 can form a third axial seal between the impeller 20 and the back plate 30 in the axial direction, so as to further improve the sealing performance between the impeller 20 and the back plate 30.
[0074] In summary, such as Figure 1 and Figure 4As shown, taking the cross-sectional shape of both the insertion part 32 and the groove structure 22 along the axis L1 of the rotating shaft 10 as an example, if the steam in the compression mechanism leaks along the gap between the impeller 20 and the back plate 30, the leaked steam will first pass through the second sealing structure 70 between the first sealing surface 21 and the second sealing surface 31. At this time, the pressure of the leaked steam is initially reduced. Then, it passes through the first axial seal, the second inclined surface seal, and the third axial seal between the insertion part 32 and the groove structure 22 to further reduce the pressure and reduce steam leakage. Finally, the unintercepted steam will be discharged through the first annular channel 51 and the exhaust channel 52. At the same time, compressed air is injected into the second annular channel 53 through the air filling channel 54 to increase the air pressure in the second annular channel 53 and prevent low-pressure steam from leaking from the first annular channel 51 to the high-pressure second annular channel 53.
[0075] Further, please see Figures 3-4 In some embodiments of this application, the first sealing structure 40 of the second side 3213 includes a plurality of second sealing teeth 43, the tooth height of the plurality of second sealing teeth 43 increasing sequentially from the impeller 20 toward the back plate 30; the inner sidewall of the groove structure 22 is also provided with a first sealing structure 40, the first sealing structure 40 including a plurality of second mating teeth 44, the tooth height of the plurality of second mating teeth 44 decreasing sequentially from the impeller 20 toward the back plate 30, and the second mating teeth 44 meshing with the second sealing teeth 43.
[0076] Specifically, both the second sealing tooth 43 and the second mating tooth 44 have a stepped tooth shape. Because the sealing effect of stepped teeth is better than that of flat teeth, the first sealing structure 40 on the second side surface 3213 is set as a stepped tooth to improve the sealing performance of the first sealing structure 40 on the second side surface 3213. At the same time, since it is more difficult to process the sealing teeth on the inclined surface, flat teeth are set on the first side surface 3212 of the insertion part 32. At this time, the first sealing structure 40 is not set on the inner wall of the groove structure 22 corresponding to the first side surface 3212, and the first side surface 3212 of the insertion part 32 and the inner wall of the groove structure 22 are sealed by the flat teeth.
[0077] In the accompanying drawings of this embodiment, the same or similar reference numerals correspond to the same or similar components. In the description of this application, it should be understood that if terms such as "upper," "lower," "left," and "right" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the components or elements referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this application. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.
[0078] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. A compression mechanism, characterized in that, include: Shaft; An impeller is fitted onto the rotating shaft and connected to the rotating shaft; The back plate is sleeved on the rotating shaft and arranged along the axial direction of the rotating shaft with the impeller; The impeller has a first sealing surface facing the back plate, and the back plate has a second sealing surface facing the impeller. An insertion portion is provided on the second sealing surface, and the insertion portion is arranged around the circumference of the rotating shaft. A groove structure for inserting the insertion portion is provided on the first sealing surface. The insertion portion has a mating surface facing the groove structure. At least one of the inner sidewall of the groove structure and the mating surface is provided with a first sealing structure, which is used to seal the gap between the inner sidewall of the groove structure and the mating surface.
2. The compression mechanism according to claim 1, characterized in that, The mating surface includes an inner ring surface facing the rotating shaft. The first sealing structure is located on the inner ring surface. The first sealing structure has a first annular channel on the side facing the impeller. The first annular channel is arranged around the circumference of the rotating shaft and communicates with the outside.
3. The compression mechanism according to claim 2, characterized in that, The compression mechanism further includes: A stator assembly is fitted onto the rotating shaft, and the stator assembly is located on the side of the back plate away from the impeller. An exhaust channel is formed between the stator assembly and the back plate. The exhaust channel connects the first annular channel to the outside, so that the steam in the first annular channel can be discharged through the exhaust channel.
4. The compression mechanism according to claim 3, characterized in that, The stator assembly has an exhaust groove on the side facing the back plate, and the exhaust groove forms the exhaust channel.
5. The compression mechanism according to claim 2, characterized in that, The first sealing structure has a second annular channel on the side opposite to the impeller. The second annular channel is arranged around the circumference of the rotating shaft and communicates with the outside.
6. The compression mechanism according to claim 5, characterized in that, The compression mechanism further includes: A stator assembly is sleeved on the rotating shaft, and the stator assembly is located on the side of the back plate away from the impeller. An air inflation channel is formed between the stator assembly and the back plate. The air inflation channel connects the second annular channel to the outside, so that compressed air from the outside can enter the second annular channel through the air inflation channel.
7. The compression mechanism according to claim 6, characterized in that, An inflation groove is provided on the side of the stator assembly facing the back plate, and the inflation groove forms the inflation channel.
8. The compression mechanism according to claim 1, characterized in that, The mating surface includes an inner ring surface facing the rotating shaft. The inner sidewall of the groove structure and the inner ring surface are both provided with the first sealing structure. The first sealing structure on the inner ring surface includes a plurality of first sealing teeth. The tooth height of the plurality of first sealing teeth increases sequentially from the impeller toward the back plate. The first sealing structure on the inner wall of the groove structure includes a plurality of first mating teeth, the tooth height of the plurality of first mating teeth decreasing sequentially from the impeller toward the back plate, and the first mating teeth meshing with the first sealing teeth.
9. The compression mechanism according to claim 1, characterized in that, The mating surface includes an inner ring surface and a first side surface. The inner ring surface faces the rotating shaft and is parallel to the axis of the rotating shaft. The first side surface is connected between the inner ring surface and the second sealing surface. The first side surface and the second sealing surface are set at an angle. The cross-sectional shape of the insertion part and the groove structure along the axis of the rotating shaft is a right triangle. The first sealing structure is provided on both the inner ring surface and the first side surface.
10. The compression mechanism according to claim 1, characterized in that, The mating surface includes an inner ring surface, a first side surface, and a second side surface. The inner ring surface, the first side surface, and the second side surface are connected in sequence. The inner ring surface faces the rotating shaft. The inner ring surface and the second side surface are both parallel to the axis of the rotating shaft. The first side surface is set at an angle to the inner ring surface and the second side surface. The cross-sectional shape of the insertion part and the groove structure along the axis of the rotating shaft is trapezoidal. The first sealing structure is provided on the inner ring surface, the first side surface, and the second side surface.
11. The compression mechanism according to claim 10, characterized in that, The first sealing structure on the second side includes a plurality of second sealing teeth, the tooth height of which increases sequentially from the impeller toward the back plate; The first sealing structure is also provided on the inner sidewall of the groove structure. The first sealing structure includes a plurality of second mating teeth. The tooth height of the plurality of second mating teeth decreases sequentially from the impeller toward the back plate. The second mating teeth mesh with the second sealing teeth.
12. The compression mechanism according to claim 1, characterized in that, A second sealing structure is provided on at least one of the first sealing surface and the second sealing surface, and the second sealing structure is used to seal the gap between the first sealing surface and the second sealing surface.
13. The compression mechanism according to claim 12, characterized in that, Both the first sealing surface and the second sealing surface are provided with a plurality of second sealing structures arranged at intervals, and the second sealing structures on the first sealing surface and the second sealing structures on the second sealing surface are alternately arranged.
14. The compression mechanism according to claim 13, characterized in that, Both the first sealing surface and the second sealing surface are perpendicular to the axis of the rotating shaft; The second sealing structure has a flow-facing surface facing away from the direction of the rotating shaft, and the flow-facing surface is parallel to the axis of the rotating shaft.
15. The compression mechanism according to claim 1, characterized in that, The groove structure has an annular cross-sectional shape along the direction perpendicular to the axis of rotation, and the inner diameter of the groove structure is less than or equal to the outer diameter of the axis of rotation.