Comb tooth sealing structure and compressor

Abstract

The comb tooth sealing structure comprises a shell with a shaft hole, multiple circles of comb tooth grooves are formed in the inner wall of the shaft hole to form the comb tooth sealing structure, and flow blocking pieces are arranged in the comb tooth grooves and used for blocking airflow generated in the circumferential direction when a rotor arranged in the shaft hole in a penetrating mode rotates. The sheet baffles with various heights are arranged in the circumferential direction of the comb tooth sealing component, airflow continuously impacts the baffles when flowing circumferentially, so that the circumferential flowing speed is reduced, the airflow cross stiffness is in direct proportion to the airflow average circumferential speed in comb tooth sealing, the cross stiffness is reduced, and the sealing effect is improved. And the vibration problem caused by circumferential vortex motion of the rotor is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of shaft sealing, and particularly to a labyrinth seal structure and a compressor. Background Art

[0002] Centrifugal compressors are commonly used power sources in rotating machinery and are widely applied in industries such as machinery, automotive, medical, food, power, building materials, petroleum, chemical industry, and military.

[0003] A common structure of a centrifugal compressor is as Figure 1 shown. Generally, it consists of a locking member 1, an impeller 2, a volute 3, a diffuser 4, a cylinder 5, a front radial bearing 6, a first bearing support 7, a front thrust bearing 8, a rotor 9, a rear thrust bearing 10, a stator 11, a rear radial bearing 12, a second bearing support 13, etc. During operation, the rotor 9 drives the impeller 2 to rotate at a high speed. The impeller actively sucks in gas, does work on the gas, and after increasing the pressure energy and kinetic energy of the gas, discharges it from the volute 3. The work capacity of the impeller determines the efficiency of the compressor. Measures to improve the compressor efficiency involve aspects such as motor efficiency, impeller structure, operating speed, gas medium type, and airway seal. Among them, the commonly used structure for airway seal is a labyrinth seal (also known as a honeycomb seal), which is used to seal moving parts and stationary parts to reduce air leakage.

[0004] However, the labyrinth seal may cause airflow excitation, exacerbate the circumferential whirling of the rotor, and reduce the rotor stability. As Figure 3 shown, assume that the rotor 9 rotates counterclockwise during operation. Since the gas (at the impeller outlet) enters the labyrinth teeth 41 driven by the rotor 9, forming Figure 4 the gas 0 (labyrinth teeth) as shown. Obviously, the gas (labyrinth teeth) also rotates counterclockwise, and the airflow distribution formed in the labyrinth teeth 41 is as Figure 6 shown. And the gas 0 (labyrinth teeth) itself has stiffness, and the airflow rotation direction is the same as the rotor rotation direction. Therefore, the gas (labyrinth teeth) 19 forms a tangential acceleration on the rotor, increasing the cross stiffness of the rotor, causing the rotor to generate low-frequency circumferential whirling, making the rotor and bearings bear alternating forces, and in severe cases, fatigue failure occurs. An easily conceivable method is to set a large roughness on the outer surface of the rotor and the inner surface of the labyrinth teeth to increase the frictional loss when the airflow passes through the surface. For the rotor, the way of increasing the surface roughness will affect the stability of the overall shaft dynamic balance quality because the airflow passing through the rough surface of the rotor will cause additional frictional forces. For the labyrinth seal parts, since the labyrinth structure is narrow and a metal machined part, the efficiency of obtaining a stable and ideal roughness through machining methods is not high. Summary of the Invention

[0005] In order to solve the above technical problem in the prior art that using a labyrinth seal increases the cross stiffness of the rotor and reduces the rotor durability, the present invention proposes a labyrinth seal structure and a compressor.

[0006] The technical solution adopted by the present invention is as follows:

[0007] The present invention provides a labyrinth seal structure, including: a housing with a shaft hole, wherein the inner wall of the shaft hole is provided with multiple circles of labyrinth grooves along the axial direction, and a flow blocking member is arranged in the labyrinth groove to block the airflow generated circumferentially when the rotor penetrating the shaft hole rotates.

[0008] Further, a plurality of the flow blocking members are arranged at intervals in each circle of the labyrinth grooves.

[0009] Further, a plurality of the flow blocking members in multiple circles of the labyrinth grooves are uniformly arranged at intervals in the circumferential direction, and the flow blocking members at the same circumferential position are arranged in a single row structure in sequence along the axial direction.

[0010] Further, the plurality of flow blocking members in each circle of the labyrinth grooves are divided into multiple groups of flow blocking members with different protruding lengths.

[0011] Further, the flow blocking members are divided into a first flow blocking member and a second flow blocking member, and the length of the first flow blocking member is greater than that of the second flow blocking member.

[0012] Further, the first flow blocking members and the second flow blocking members in each circle of the labyrinth grooves are arranged alternately.

[0013] Further, the housing is in an annular shape, with the shaft hole in the middle, and an installation groove leading to the outer wall surface of the housing is arranged in the labyrinth groove, and the flow blocking member is inserted into the installation groove from the outer wall surface of the housing.

[0014] Further, the depth of the installation groove is consistent with the length of the flow blocking member, and a fitting gap is left between the installation groove and the flow blocking member.

[0015] Preferably, the fitting gap between the flow blocking member and the installation groove includes a gap L1 on both axial sides and a gap L2 on both circumferential sides; the value range of L1 is 0.01 to 0.1 mm, and the value range of L2 is 0.01 to 0.2 mm.

[0016] Further, a sealing ring groove is arranged at a position close to the edge of the outer wall surface of the housing, and a sealing ring protruding from the sealing ring groove is installed in the sealing ring groove.

[0017] Further, a plurality of air holes are arranged on the flow blocking member.

[0018] The present invention also provides a compressor, including the above-mentioned labyrinth seal structure.

[0019] Further, the labyrinth seal structure is installed on the diffuser of the compressor.

[0020] Further, the compressor includes: a cylinder body, the diffuser, a rotor, a stator, and an impeller; the diffuser is installed at one end of the cylinder body to seal the cylinder body, a stator and a bearing group for supporting the rotor are provided inside the cylinder body, the rotor cooperates with the stator and the bearing group inside the cylinder body, and passes through the shaft hole of the comb seal structure on the diffuser, and the impeller is installed at the outer end of the rotor.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] 1. The baffle is embedded in the internal space of the comb slot. When the rotor rotates at a high speed, the spiral airflow generated circumferentially continuously impacts the surface of the baffle, so that the kinetic energy of the mainstream airflow is gradually weakened, and the original continuous vortex motion state is forcibly interrupted. Since the cross stiffness of the airflow is positively correlated with the average circumferential velocity in the comb seal cavity, the low-speed airflow modulated by the baffle significantly reduces the overall dynamic coupling effect of the system and effectively suppresses the self-excited vibration phenomenon caused by the rotor whirling.

[0023] 2. The baffle is a thin plate baffle, which is inserted into the reserved slot on the comb. The baffle and the slot are in a small clearance fit, and the baffle is allowed to shift slightly in the slot. During operation, part of the kinetic energy of the airflow impacting the baffle can be consumed through the self-vibration of the baffle, improving the function of the baffle to hinder the circumferential flow velocity of the airflow.

[0024] 3. The baffle structure is arranged in multiple layers along the axial direction to further improve the flow blocking effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0026] Figure 1 is a cross-sectional schematic view of the prior art;

[0027] Figure 2 is Figure 1 a partial enlarged view of

[0028] Figure 3 is Figure 1 the A-A cross-sectional view of

[0029] Figure 4 is Figure 3 a partial enlarged view of

[0030] Figure 5 is a three-dimensional cross-sectional schematic view of the prior art diffuser;

[0031] Figure 6 is Figure 5 a partially enlarged view of;

[0032] Figure 7 is a schematic cross-sectional view in a specific embodiment of the present invention;

[0033] Figure 8 is Figure 7 a partially enlarged view of;

[0034] Figure 9 is Figure 7 the cross-sectional view B-B in;

[0035] Figure 10 is Figure 9 a partially enlarged view of;

[0036] Figure 11 is a three-dimensional cross-sectional schematic view of the labyrinth seal structure in a specific embodiment of the present invention;

[0037] Figure 12 is a side view of the labyrinth seal structure in a specific embodiment of the present invention;

[0038] Figure 13 is Figure 11 a partially enlarged view of;

[0039] Figure 14 is a three-dimensional schematic view of the labyrinth seal structure in a specific embodiment of the present invention;

[0040] Figure 15 is a front view in a specific embodiment of the present invention;

[0041] Figure 16 is a three-dimensional schematic view of the first baffle in a specific embodiment of the present invention;

[0042] Figure 17 is a three-dimensional schematic view of the second baffle in a specific embodiment of the present invention;

[0043] 1. Locking member; 2. Impeller; 3. Volute; 4. Diffuser; 41. Labyrinth teeth; 5. Cylinder; 6. Front radial bearing; 7. Primary bearing support; 8. Front thrust bearing; 9. Rotor; 10. Rear thrust bearing; 11. Stator; 12. Rear radial bearing; 13. Secondary bearing support; 14. Bearing cavity; 15. Impeller back cavity; 16. Labyrinth seal structure;

[0044] 161. Sealing ring; 162. Housing; 1621. First mounting groove; 1622. Second mounting groove;

[0045] 163. First baffle; 164. Second baffle; 165. Air hole. Detailed implementation manners

[0046] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clear and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0047] The principle and structure of the present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0048] Working principle of labyrinth seal: As Figure 2 shown, since there is a tiny radial clearance between the inner diameter of the labyrinth teeth 41 and the outer diameter of the rotor 9, the gas 0 (from the impeller outlet) at the impeller back cavity 15, when flowing through the above-mentioned radial clearance, due to the sudden drop in the flow area, is approximately an ideal throttling process, its pressure and temperature drop, the speed increases, and it becomes gas (labyrinth slit) 17; when the gas (labyrinth slit) 17 enters the cavity of the annular teeth, due to the sudden increase in the flow area, the gas forms a strong vortex, the pressure remains unchanged but the speed almost completely disappears, and it continues to flow to the next labyrinth teeth 41. By repeating the above throttling process, as the number of gaps and annular cavities passed through increases, the gas accumulated by the subsequent labyrinth teeth 41 increases, the gas pressure rises, forming a back pressure, thereby reducing the flow of gas (impeller outlet) 16 to the bearing cavity 14, which is beneficial to reducing the impeller leakage loss and improving the compressor efficiency. However, the labyrinth seal may cause gas flow-induced vibration, exacerbate the circumferential whirling of the rotor, and reduce the rotor stability. As Figure 3 shown, when viewed from view A-A, assuming that the rotor 9 rotates counterclockwise during operation, since the gas 0 (impeller outlet) is driven by the rotor 9 into the labyrinth teeth 41, forming Figure 4 the gas 0 (labyrinth teeth) as shown, obviously the gas 0 (labyrinth teeth) also rotates counterclockwise, and the gas flow distribution formed in the labyrinth teeth 41 is as Figure 6 shown. And the gas 0 (labyrinth teeth) itself has stiffness, and the gas flow rotation direction is the same as the rotation direction of the rotor, so the gas 0 (labyrinth teeth) forms a tangential acceleration on the rotor, increasing the cross stiffness of the rotor, causing the rotor to generate low-frequency circumferential whirling, making the rotor and bearings bear alternating forces, and in severe cases, fatigue failure occurs. The gas flow cross stiffness caused by the labyrinth seal is proportional to the average circumferential velocity of the gas flow in the labyrinth seal, so reducing the circumferential flow velocity of the gas flow is beneficial to improving the rotor stability.

[0049] In this regard, as Figure 11 shown, the present invention proposes a labyrinth seal structure 16, which is mainly used for centrifugal compressors and can also be used in other components with shaft holes and rotors. Taking the centrifugal compressor as an example.

[0050] The comb tooth seal structure 16 specifically includes a housing 162; the housing 162 is an annular member with a shaft hole, and its installation position is fixed at the through hole of the compressor diffuser 4, mainly undertaking the functions of radial limit and sealing support. A multi-turn comb tooth groove is arranged axially along the inner wall of the shaft hole to form a labyrinth seal structure. The comb tooth groove (specifically, the groove between two comb teeth) retains a set amount of clearance from the surface of the rotor passing through it, constituting a fluid damping channel to ensure that the rotor does not directly contact the housing 162 during rotation.

[0051] The baffle is embedded in the internal space of the comb tooth groove. When the rotor rotates at high speed, the spiral airflow generated circumferentially continuously impacts the surface of the baffle, causing the kinetic energy of the mainstream airflow to be gradually weakened, and the originally continuous vortex motion state to be forcibly interrupted. Since the cross-flow stiffness of the airflow is positively correlated with the average circumferential velocity in the comb tooth seal cavity, the low-speed airflow modulated by the baffle significantly reduces the overall dynamic coupling effect of the system, effectively suppressing the self-excited vibration phenomenon caused by rotor whirling. By adding a mechanical turbulence element in the traditional comb tooth groove, this seal structure realizes the active regulation of the flow field characteristics in the cavity without changing the original seal clearance. Compared with the conventional comb tooth seal, the new structure can maintain the same sealing performance while significantly improving the operating stability of the rotor system, and is particularly suitable for centrifugal compressor units under high-speed operating conditions.

[0052] In a specific embodiment, as Figure 9 shown, the baffles of the comb tooth seal structure 16 are circumferentially spaced and distributed inside each turn of the comb tooth groove. The multiple baffles are distributed in a decentralized layout circumferentially, and a certain distance is maintained between adjacent baffles. The continuous circumferential airflow is cut into several independent flow regions, and the asymmetric suppression of the vortex motion is achieved through the phase difference between adjacent baffles. When the rotor rotates to drive the medium in the cavity to generate circumferential flow, the impact energy of the airflow can be evenly dispersed, and at the same time, the spatio-temporal continuity of the vortex structure is destroyed, so that the fluid kinetic energy originally developing in a spiral shape is converted into heat energy and dissipated during multiple collisions.

[0053] In a further embodiment, as Figure 9 、 11, as shown in Figures 12 and 14, the baffle members in the multi-turn comb-shaped grooves are evenly distributed in the circumferential direction and arranged in multiple rows axially, that is, the baffle members are coaxially aligned. Preferably, 8 baffle members can be arranged on one axis to form 8 layers of baffle rings. This single-row arrangement with axial alignment makes the baffle members at corresponding positions in each turn of the comb-shaped grooves form a continuous channel of vertical superposition. When the air flow flows axially, it needs to pass through multiple baffle members in this channel in sequence. By constructing an axially continuous barrier layer, the air flow is forced to continuously collide with multiple-stage baffle members during the traversing process, further dissipating kinetic energy and reducing the average circumferential velocity of the air flow. Compared with the multi-row structure with axial misalignment distribution, this alignment arrangement is more suitable for scenarios that require strengthening the axial sealing ability. Through the axial cumulative effect, the concentrated suppression of the air flow disturbance energy is realized, so as to effectively weaken the dynamic response risk caused by the circumferential vortex of the rotor while maintaining a high sealing efficiency, and it is also more convenient for installation.

[0054] In a specific embodiment, the baffle members in each turn of the comb-shaped grooves are divided into multiple groups according to the extension length. Each group of baffle members extends vertically towards the rotor surface. Specifically, the baffle members evenly distributed in the circumferential direction are divided into two to three height levels, and a progressive extension length difference is formed between each level according to a preset ratio. By introducing a non-uniform local resistance gradient, the air flow is forced to deflect refractionally in the horizontal direction instead of flowing in a straight line in a single direction. The longer baffle members can directly cut off the main channel of the high-speed air flow, while the shorter baffle members are used to capture the remaining vortex air flow. The two work together to form a multi-stage energy dissipation mechanism. The air flow continuously experiences dynamic pressure fluctuations during the traversing process, so as to more thoroughly weaken its circumferential momentum accumulation ability, further reduce the cross stiffness and enhance the suppression of the rotor vortex vibration.

[0055] Furthermore, as Figure 11 , 16 , as shown in Figures 16 and 17, the baffle members are divided into two types: the first baffle member 163 and the second baffle member 164. Among them, the radial extension length of the first baffle member 163 is greater than that of the second baffle member 164, and the two are alternately embedded in the same axial row in the circumferential direction. When the air flow passes through multiple rows of baffle members axially in sequence, it will continuously encounter alternating long and short barrier surfaces. The longer first baffle member 163 can preferentially cut off the high-speed main air flow, forcing the air flow to deflect violently and form local vortices; the shorter second baffle member 164 is used to capture the remaining rotating air flow and further dissipate its kinetic energy through secondary collisions.

[0056] Through the cooperation of the long and short baffle members in the axial row, a dynamic disturbance mechanism is introduced on the basis of the original axial continuous barrier, so that the air flow generates asymmetric pressure fluctuations in the vertical direction. This hierarchical energy dissipation strategy significantly improves the weakening efficiency of the circumferential momentum of the air flow, and at the same time reduces the resonance risk that may be caused by the axial continuous channel, so as to achieve better rotor dynamic stability control while maintaining the sealing performance.

[0057] Specifically, due to the presence of the first baffle 163 and the second baffle 164, alternating impacts occur to reduce the circumferential velocity of the air flow. As Figure 8 、 10 shown, the gas in front of the first baffle rotates counterclockwise in a circle under the action of the motor rotor 9. Part of the gas in front of the first baffle collides with the first baffle 163, and the flow velocity decreases. To prevent all the gas from impacting the first baffle 163 and causing excessive vibration of the baffle, multiple air holes 165 are provided on the first baffle 163, and a small amount of the gas in front of the first baffle passes through the air holes 165; the gas whose velocity has decreased after the collision and the gas that has not collided flow along the gap C1. At this time, due to the presence of the first baffle 163, part of the gas undergoes the throttling effect described in the background when flowing through the gap C1, which to a certain extent improves the effect of the labyrinth seal in preventing air leakage; the air flow continues to flow counterclockwise to the next stage, and at this time the air flow approaches the second baffle. Similarly, part of the gas collides with the second baffle 164, and the flow velocity decreases. Similarly, multiple air holes are provided on the second baffle 164, and a small amount of gas passes through the air holes; the gas whose velocity has decreased after the collision and the gas that has not collided flow along the gap C2. At this time, due to the presence of the second baffle 164, part of the gas undergoes the throttling effect described in the background when flowing through the gap C2, which to a certain extent improves the effect of the labyrinth seal in preventing air leakage. Therefore, in the circumferential direction, through the action of the alternately distributed first baffle 163 and second baffle 164 above, the air flow circulates and impacts the baffle, thereby reducing the circumferential flow velocity of the air flow. And the cross stiffness of the air flow is proportional to the average circumferential velocity of the air flow in the labyrinth seal, achieving a reduction in cross stiffness and improving the vibration problem caused by the circumferential whirling of the rotor.

[0058] In a specific embodiment, as Figure 14 、 15 shown, the housing 162 is integrally designed in a circular ring structure, and a through shaft hole is formed in its central region to accommodate the rotor to pass through. In each circle of labyrinth grooves, mounting grooves extending to the outer wall surface of the housing 162 are radially provided. The mounting grooves are through channels and are communicated with the internal space of the labyrinth grooves. The baffle is inserted into the mounting groove through the opening on the outer wall surface of the housing 162. One end of it is embedded in the bottom of the labyrinth groove and fixedly connected to the housing 162, and the other end extends near the rotor to form an air flow blocking surface. This insertion structure enables the assembly process of the baffle without disassembling the entire sealing assembly, and only requires a push-in installation from the outside of the housing 162 to achieve functional positioning. At the same time, the presence of the mounting groove provides stable support for the baffle, preventing it from shifting or falling off due to air flow impact during operation. This design enhances the maintainability of the sealing structure through a modular installation method. When the baffle is worn or needs to be adjusted, it can be quickly replaced or reconfigured, thereby extending the service life of the overall sealing system and reducing the maintenance cost.

[0059] The depth of the mounting groove matches the radial extension length of the baffle, and the two form a chimeric matching structure. For example, the depth of the first mounting groove 1621 for mounting the first baffle 163 is greater than the depth of the second mounting groove 1622 for mounting the second baffle 164. When the baffle is fully embedded in the mounting groove to the set depth, its end can be precisely aligned with the position of the airflow path formed on the rotor surface to achieve spatial positioning of the blocking surface. In addition, a matching gap is left around the mounting groove and the baffle, so that the baffle has the ability to move slightly during operation. When the high-speed airflow hits the surface of the baffle, the impact force generated can drive the baffle to undergo instantaneous deformation and rebound vibration within the gap range. This vibration process converts part of the kinetic energy of the airflow into the mechanical vibration energy of the baffle, and dissipates the energy through internal friction and air resistance of the material. In addition, the consistency of depth and length makes it unnecessary to assist in the disassembly process of the baffle with the assistance of additional measuring tools. It can be replaced by simply pulling it out axially, further simplifying the maintenance process and reducing the difficulty of operation.

[0060] Preferably, the height H3 (or length) of the first baffle 163 is the same as the depth H1 of the first mounting groove 1621, and the value range is 0.9 to 0.99 mm; the height H4 (or length) of the second baffle 164 is the same as the depth H2 of the second mounting groove 1622, and the value range is also 0.9 to 0.99 mm.

[0061] like Figure 13 As shown, the axial gap L1 between the baffle and the mounting groove on both sides (i.e., the left and right gaps L 左 , L 左 , the left and right gaps may be the same or different) and the circumferential gap L2 (i.e. the front and rear gaps L in the figure 前 , L 后 , the front and rear clearances may be the same or different) together constitute a clearance fit, so that the baffle has a slight displacement capability during operation. Specifically, the value range of L1 is 0.01 to 0.1 mm, and the value range of L2 is 0.01 to 0.2 mm. The axial clearance L1 allows the baffle to have a slight floating capability in the axial direction, which can buffer the relative deformation between the housing 162 and the rotor caused by temperature changes, and avoid stress concentration problems caused by rigid fixation. The circumferential clearance L2 provides a positioning tolerance in the circumferential direction for the baffle, allowing a certain angular deviation during the installation process, while compensating for the slight shaking that may occur when the rotor rotates at high speed.

[0062] In a specific embodiment, Figure 14As shown, sealing ring grooves are respectively provided at the axial two-end edge regions of the outer wall surface of the housing 162. The sealing ring grooves extend in the circumferential direction. An outwardly protruding sealing ring 161 is embedded inside the sealing ring grooves. Its outer contour exceeds the original outer wall surface of the housing 162 and is used to form a fitting sealing interface with the inner wall of the through hole of the diffuser 4. When the housing 162 is assembled to the through hole position of the diffuser 4, the protruding sealing ring 161 tightly adheres to the inner wall surface of the through hole through elastic deformation, and the dynamic sealing effect is achieved by using the rebound characteristic of the material itself. Through the design of the sealing ring grooves at both axial ends, this sealing structure ensures that the gas flow path between the housing 162 and the diffuser 4 in the axial direction is completely blocked, preventing the sealing performance from decreasing due to air leakage during operation.

[0063] In a preferred embodiment, as Figure 16 , 17 shown, a plurality of air holes 165 are provided on the surface of the baffle along the radial direction. The air holes 165 penetrate through the thickness of the baffle and form a through structure. When the high-speed air flow impacts the baffle, part of the air flow enters the internal space of the baffle through the air holes 165, forming a local pressure release effect. Through the introduction of a controllable gas pressure relief channel, this design weakens the concentrated impact force of the air flow on the surface of the baffle, thereby reducing the risk of severe vibration caused by instantaneous high pressure. The distribution of the air holes 165 can optimize the pressure difference of the air flow on both sides of the baffle, converting the original single-sided force into multi-point diversion under the dynamic balance state, and further suppressing the overall resonance tendency of the baffle. While maintaining the original blocking function, this structure effectively controls the vibration amplitude of the baffle by actively regulating the air flow distribution characteristics, prolonging its service life and enhancing the long-term reliability of the sealing system.

[0064] In a preferred embodiment, the baffle adopts a square plate structure. Its cross-section is rectangular and the overall design is in the form of a thin plate. This thin plate structure improves the structural flexibility by reducing the material thickness, enabling the baffle to generate controllable local vibration when impacted by the air flow. When the high-speed air flow impacts the surface of the baffle, the thin plate deforms rapidly due to its light weight. During its vibration process, part of the air flow kinetic energy can be converted into mechanical vibration energy, and energy dissipation is achieved through internal damping of the material and air resistance.

[0065] As Figure 7 shown, the present invention also proposes a centrifugal compressor, which adopts the above-mentioned comb tooth sealing structure 16 as a sealing component. This structure is embedded in the through hole area of the compressor diffuser 4 and works in cooperation with the rotor shafting. By arranging the baffle in the comb tooth groove, when the compressor operates at high speed, the dynamic disturbance caused by the circumferential flow of the air flow can be effectively weakened, thereby significantly reducing the vibration amplitude caused by rotor whirl. On the basis of maintaining the function of the traditional labyrinth seal, this sealing solution optimizes the damping characteristics of the air seal system by introducing an air flow energy dissipation mechanism, enabling the compressor to maintain a stable operating state within a wide operating condition range.

[0066] Specifically, the centrifugal compressor specifically includes: a cylinder body 5, a diffuser 4, a rotor 9, a stator 11, an impeller 2, and a volute 3. Among them: The cylinder body 5 serves as the overall machine's basic framework, and its internal space is used to accommodate the stator assembly and the bearing group that supports the rotor. The diffuser 4 is fixedly installed at one end of the cylinder body 5 and closes this end face. The through-hole area thereof is fitted with the above-mentioned labyrinth seal structure 16 to form a passage for the rotor to pass through. The rotor is supported by the bearing group inside the cylinder body 5 and cooperates with the stator to form an electric motor drive unit. After its axially extending end sequentially passes through the shaft holes of the labyrinth seal structure 16 of the cylinder body 5 and the diffuser 4, it is locked and connected to the impeller 2. The impeller 2 is fixed to the outer end of the rotor by a locking member 1 (such as a screw, etc.) and rotates synchronously with the rotor at high speed to achieve the gas compression function. The volute 3 is then circumferentially installed on the outer side of the diffuser 4, and its inlet is docked with the outlet of the diffuser 4, and is used to collect and guide the compressed gas to the subsequent system. Through the modular component layout, this structure enables the rotor to achieve dynamic gas sealing through the labyrinth seal structure 16 when passing through the diffuser 4. At the same time, the spatial matching design of the volute 3 and the diffuser 4 optimizes the gas flow outlet path, reduces energy loss, and improves the overall compression efficiency.

[0067] Specifically, as shown in the figure, the bearing group includes: a front radial bearing 6, a first-stage bearing support 7, a front thrust bearing 8, a rear thrust bearing 10, a rear radial bearing 12, and a second-stage bearing support 13.

[0068] In a specific embodiment, the centrifugal compressor generally includes: a locking member 1, an impeller 2, a volute 3, a diffuser 4, a cylinder body 5, a front radial bearing 6, a first-stage bearing support 7, a front thrust bearing 8, a rotor 9, a rear thrust bearing 10, a stator 11, a rear radial bearing 12, a second-stage bearing support 13, a bearing cavity 14, an impeller back cavity 15, and a labyrinth seal structure 16.

[0069] The locking member 1 and the impeller 2 as described above are part of the rotor and rotate together with the rotor 9 during operation. Among them, the locking member 1 fixes the impeller 2 to the rotor 9 through a thread pair, so that when the electric motor operates, it drives the impeller to do work on the gas.

[0070] The volute 3 and the diffuser 4 as described above are rotary hollow parts, and the volute is generally cast. The diffuser 4 and the volute 3 form a passage to diffuse the gas from the impeller outlet, reduce its speed, and increase its pressure. The function of the volute 3 is to lead the gas out of the compressor.

[0071] The cylinder body 5 as described above is a rotary hollow part and is generally cast. The function of the cylinder body 5 is to provide support and fixation for parts such as the first-stage bearing support 7, the stator 11, the second-stage bearing support 13, and the volute 3.

[0072] The front radial bearing 6 and the rear radial bearing 12 as described above are commonly oil sliding bearings, gas bearings or magnetic levitation bearings in a centrifugal compressor, and are respectively fixed on the first-stage bearing support 7 and the second-stage bearing support 13, mainly bearing radial loads and providing radial support for the rotor.

[0073] The front thrust bearing 8 and the rear thrust bearing 10 as described above are commonly oil sliding bearings, gas bearings or magnetic levitation bearings in a centrifugal compressor, mainly bearing axial loads and providing axial support for the rotor.

[0074] The stator 11 as described above is a rotating part, mainly composed of a stator core and a stator winding. During operation, the stator 11 generates a magnetic field, and the rotor 9 makes a high-speed rotating motion under the action of the electromagnetic field.

[0075] It should be noted that the terms used above are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they specify the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0076] Unless otherwise specifically stated, the relative arrangements of components and steps, numerical expressions and values set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that for the convenience of description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationships. Technologies, methods and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the said technologies, methods and devices should be regarded as part of the authorized specification. In all the examples shown and discussed here, any specific value should be interpreted as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0077] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by orientation words such as "front, rear, upper, lower, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description. Without contrary description, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and thus cannot be understood as limiting the protection scope of the present invention; the orientation words "inner, outer" refer to the inside and outside relative to the contour of each component itself.

[0078] For ease of description, spatial relative terms such as "above", "over", "on the upper surface", "upper" etc. can be used herein to describe the spatial positional relationship of a device or feature shown in the figures with other devices or features. It should be understood that the spatial relative terms are intended to encompass different orientations in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figure is inverted, a device described as "above" or "over" other devices or structures will then be positioned "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both the orientations of "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and corresponding interpretations of the spatial relative descriptions used herein will be made accordingly.

[0079] In addition, it should be noted that the use of terms such as "first" and "second" to define components is only for the convenience of differentiating the corresponding components. Without additional statements, these terms have no special meanings, and thus should not be construed as limiting the protection scope of the present invention.

[0080] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and variations. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A comb tooth seal structure, comprising: A housing with a shaft hole, wherein the inner wall of the shaft hole is provided with multiple turns of comb-shaped grooves along the axial direction. It is characterized in that a flow-blocking member is arranged in the comb-shaped groove for blocking the airflow generated circumferentially when the rotor penetrating the shaft hole rotates.

2. The comb-tooth seal structure according to claim 1, characterized in that, A plurality of the flow-blocking members are arranged at intervals in each turn of the comb-shaped groove.

3. The comb-tooth seal structure according to claim 2, wherein, The plurality of flow-blocking members in the multiple turns of the comb-shaped grooves are evenly arranged at intervals in the circumferential direction, and the flow-blocking members at the same circumferential position are arranged in a single-row structure in sequence along the axial direction.

4. The comb tooth seal structure according to claim 1, characterized in that, The multiple flow-blocking members in each turn of the comb-shaped groove are divided into multiple groups of flow-blocking members with different protruding lengths.

5. The comb tooth seal structure according to claim 1, characterized in that, The flow-blocking member is divided into a first flow-blocking member and a second flow-blocking member, and the length of the first flow-blocking member is greater than the length of the second flow-blocking member.

6. The comb seal structure according to claim 5, characterized in that, The first flow-blocking member and the second flow-blocking member in each turn of the comb-shaped groove are arranged alternately.

7. The comb tooth seal structure according to any one of claims 1 to 6, characterized in that, The housing is in a circular ring shape, with the shaft hole in the middle. An installation groove leading to the outer wall surface of the housing is arranged in the comb-shaped groove, and the flow-blocking member is inserted into the installation groove from the outer wall surface of the housing.

8. The comb tooth seal structure according to claim 7, characterized in that, The depth of the installation groove is consistent with the length of the flow-blocking member, and a fitting gap is left between the installation groove and the flow-blocking member.

9. The comb tooth seal structure according to claim 7, wherein, The fitting gap between the flow-blocking member and the installation groove includes a gap L1 on both axial sides and a gap L2 on both circumferential sides; the value range of L1 is 0.01 to 0.1 mm, and the value range of L2 is 0.01 to 0.2 mm.

10. The comb-tooth seal structure according to claim 7, wherein A sealing ring groove is arranged at a position near the edge of the outer wall surface of the housing, and a sealing ring protruding from the sealing ring groove is installed in the sealing ring groove.

11. The comb-tooth seal structure according to any one of claims 1 to 6, characterized in that, A plurality of air holes are arranged on the flow-blocking member.

12. A compressor, characterized in that, It includes the comb-shaped seal structure according to any one of claims 1 to 11.

13. The compressor according to claim 12, wherein, The comb-shaped seal structure is installed on the diffuser of the compressor.

14. The compressor according to claim 13, characterized in that, The compressor includes: A cylinder body, the diffuser, a rotor, a stator, and an impeller; the diffuser is installed at one end of the cylinder body to seal the cylinder body. A stator and a bearing group for supporting the rotor are arranged inside the cylinder body. The rotor cooperates with the stator and the bearing group inside the cylinder body and passes through the shaft hole of the comb-shaped seal structure on the diffuser, and the impeller is installed at the outer end of the rotor.

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