Comb tooth sealing structure and compressor

Abstract

The comb tooth sealing structure comprises a shell with a shaft hole, a plurality of 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, so that airflow continuously impacts the baffles when flowing circumferentially, the circumferential flowing speed is reduced, the airflow cross stiffness is in direct proportion to the average circumferential speed of the airflow in comb tooth sealing, the cross stiffness is reduced, and the sealing performance of the comb tooth sealing component is improved. And the vibration problem caused by circumferential vortex motion of the rotor is improved.

Description

Technical Field

[0001] This utility model relates to the field of shaft sealing technology, specifically a comb-tooth sealing structure and a compressor. Background Technology

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

[0003] A common structure of a centrifugal compressor is as follows: Figure 1 As shown, a compressor typically consists of a locking element 1, impeller 2, volute 3, diffuser 4, cylinder 5, front radial bearing 6, primary bearing support 7, front thrust bearing 8, rotor 9, rear thrust bearing 10, stator 11, rear radial bearing 12, and secondary bearing support 13. During operation, rotor 9 drives impeller 2 to rotate at high speed. The impeller actively draws in gas and performs work on it, increasing its pressure and kinetic energy before discharging it from the volute 3. The impeller's work capacity determines the compressor's efficiency. Measures to improve compressor efficiency involve motor efficiency, impeller structure, operating speed, gas medium type, and gas passage sealing, among other aspects. A commonly used gas passage seal is the comb seal (also known as a labyrinth seal), used to seal the moving and stationary parts, reducing airflow leakage.

[0004] However, labyrinth seals can cause airflow excitation, exacerbating circumferential vortexing of the rotor and reducing rotor stability. For example... Figure 3 As shown, assuming that rotor 9 rotates counterclockwise during operation, the gas (impeller outlet) enters the comb teeth 41 under the drive of rotor 9, forming... Figure 4 The gas 0 (comb teeth) shown clearly rotates counterclockwise, and the airflow distribution formed in the comb teeth 41 is as follows. Figure 6 As shown. The gas 0 (comb teeth) itself possesses rigidity, and the airflow rotation direction is the same as the rotor's rotation direction. Therefore, the gas (comb teeth) 19 creates tangential acceleration on the rotor, increasing the rotor's cross stiffness and causing low-frequency circumferential vortices. This results in the rotor and bearings experiencing alternating forces, potentially leading to fatigue failure in severe cases. An easy approach is to increase the roughness of the rotor's outer surface and the inner surface of the comb teeth to increase frictional losses as the airflow passes over these surfaces. However, increasing surface roughness affects the stability of the rotor's overall dynamic balance quality because the airflow over the rough rotor surface generates additional friction. For the comb tooth sealing components, due to the small size of the comb teeth and their machined metal structure, achieving a stable and ideal roughness through machining is inefficient. Utility Model Content

[0005] In order to solve the technical problem that the use of comb-tooth seals in the prior art increases the cross stiffness of the rotor, resulting in a decrease in rotor durability, this utility model proposes a comb-tooth seal structure and a compressor.

[0006] The technical solution adopted in this utility model is:

[0007] This utility model proposes a comb-tooth sealing structure, including: a housing with a shaft hole, the inner wall of the shaft hole being provided with multiple comb-tooth grooves along the axial direction, and a baffle being provided in the comb-tooth grooves to block the airflow generated circumferentially by the rotor passing through the shaft hole when it rotates.

[0008] Furthermore, each of the comb tooth grooves is provided with a plurality of flow-blocking elements at intervals.

[0009] Furthermore, the multiple flow-blocking elements in the multi-ring comb grooves are evenly spaced along the circumferential direction, and the flow-blocking elements at the same circumferential position are arranged in a single row along the axial direction.

[0010] Furthermore, the multiple flow-blocking elements within each ring of the comb groove are divided into multiple groups of flow-blocking elements with different extension lengths.

[0011] Furthermore, the flow-blocking component is divided into a first flow-blocking component and a second flow-blocking component, and the length of the first flow-blocking component is greater than the length of the second flow-blocking component.

[0012] Furthermore, the first baffle and the second baffle are alternately arranged in each ring of the comb groove.

[0013] Furthermore, the housing is annular in shape with the shaft hole in the middle. The comb groove is provided with a mounting groove that leads to the outer wall of the housing. The flow-blocking member is inserted into the mounting groove from the outer wall of the housing.

[0014] Furthermore, the depth of the mounting groove is consistent with the length of the flow deflector, and a fitting gap is left between the groove and the flow deflector.

[0015] Preferably, the fitting clearance between the flow deflector and the mounting groove includes a clearance L1 on both axial sides and a clearance L2 on both circumferential sides; the value of L1 ranges from 0.01 to 0.1 mm, and the value of L2 ranges from 0.01 to 0.2 mm.

[0016] Furthermore, a sealing ring groove is provided on the outer wall surface of the housing near the edge, and a sealing ring protruding from the sealing ring groove is installed in the sealing ring groove.

[0017] Furthermore, the baffle is provided with multiple air holes.

[0018] This utility model also proposes a compressor, including the above-mentioned comb-tooth sealing structure.

[0019] Furthermore, the comb-tooth sealing structure is mounted on the diffuser of the compressor.

[0020] Furthermore, the compressor includes: a cylinder, the diffuser, a rotor, a stator, and an impeller; the diffuser is installed at one end of the cylinder to seal the cylinder, the cylinder is provided with a stator and a bearing assembly supporting the rotor, the rotor cooperates with the stator and bearing assembly in the cylinder and passes through the shaft hole of the comb-tooth sealing 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 flow deflector is embedded in the internal space of the comb tooth groove. When the rotor rotates at high speed, the spiral airflow generated in its circumference continuously impacts the surface of the flow deflector, causing the kinetic energy of the mainstream airflow to be weakened step by step, and the originally continuous vortex motion state is forcibly interrupted. Since the airflow cross stiffness is positively correlated with the average circumferential velocity in the comb tooth sealing cavity, the low-speed airflow modulated by the flow deflector significantly reduces the overall dynamic coupling effect of the system and effectively suppresses the self-excited vibration phenomenon caused by rotor vortex.

[0023] 2. The flow-blocking component adopts a thin baffle plate, which is inserted into the groove reserved on the comb teeth. The baffle plate and the groove are fitted with a small clearance. The baffle plate is allowed to move slightly in the groove. During operation, part of the kinetic energy of the airflow hitting the baffle plate can be consumed by the vibration of the baffle plate itself, thereby improving the baffle plate's ability to impede 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 resistance effect. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this utility model, 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 utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

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

[0027] Figure 2 yes Figure 1 A magnified view of a portion of the image;

[0028] Figure 3 yes Figure 1 AA section diagram;

[0029] Figure 4 yes Figure 3 A magnified view of a portion of the image;

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

[0031] Figure 6 yes Figure 5 A magnified view of a portion of the image;

[0032] Figure 7 This is a cross-sectional schematic diagram of a specific embodiment of the present utility model;

[0033] Figure 8 yes Figure 7 A magnified view of a portion of the image;

[0034] Figure 9 yes Figure 7 BB section diagram;

[0035] Figure 10 yes Figure 9 A magnified view of a portion of the image;

[0036] Figure 11 This is a three-dimensional cross-sectional schematic diagram of the comb-tooth sealing structure in a specific embodiment of this utility model;

[0037] Figure 12 This is a side view of the comb-tooth sealing structure in a specific embodiment of this utility model;

[0038] Figure 13 yes Figure 11 A magnified view of a portion of the image;

[0039] Figure 14 This is a three-dimensional schematic diagram of the comb-tooth sealing structure in a specific embodiment of this utility model;

[0040] Figure 15 This is a front view of a specific embodiment of this utility model;

[0041] Figure 16 This is a three-dimensional schematic diagram of the first flow-blocking component in a specific embodiment of this utility model;

[0042] Figure 17 This is a three-dimensional schematic diagram of the second flow-blocking component in a specific embodiment of this utility model;

[0043] 1. Locking element; 2. Impeller; 3. Volute; 4. Diffuser; 41. Comb 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. Comb tooth sealing structure;

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

[0045] 163. First flow-blocking component; 164. Second flow-blocking component; 165. Air hole. Detailed Implementation

[0046] To make the technical problem to be solved, the technical solution, and the beneficial effects of this utility model clearer, the present utility model 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 merely illustrative of the present utility model and are not intended to limit the present utility model.

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

[0048] The working principle of comb-tooth seal: Figure 2 As shown, due to the small radial gap between the inner diameter of the comb tooth 41 and the outer diameter of the rotor 9, the gas 0 (impeller outlet) from the impeller back cavity 15, when flowing through the aforementioned radial gap, experiences a sudden drop in flow area, approximating an ideal throttling process. Its pressure and temperature decrease, while its velocity increases, transforming into gas (comb tooth slit) 17. When the gas (comb tooth slit) 17 enters the cavity of the annular tooth, the flow area suddenly increases, forming a strong vortex. The pressure remains constant, but the velocity almost completely disappears, continuing to flow to the next comb tooth 41. By repeating this throttling process, as the gas flows through more gaps and annular cavities, the gas accumulated in the later comb teeth 41 increases, the gas pressure rises, forming back pressure, thereby reducing the flow of gas (impeller outlet) 16 to the bearing cavity 14, which helps reduce impeller leakage losses and improves compressor efficiency. However, the labyrinth seal may cause airflow excitation, exacerbating rotor circumferential vortexing and reducing rotor stability. Figure 3 As shown in view AA, assuming that rotor 9 rotates counterclockwise during operation, gas 0 (impeller outlet) enters comb teeth 41 under the drive of rotor 9, forming... Figure 4 The gas 0 (comb teeth) shown is obviously also rotating counterclockwise, and the airflow distribution formed in the comb teeth 41 is as follows. Figure 6 As shown. The gas 0 (comb teeth) itself possesses stiffness, and the airflow rotation direction is the same as the rotor's rotation direction. Therefore, the gas 0 (comb teeth) creates tangential acceleration on the rotor, increasing the rotor's cross stiffness. This causes the rotor to generate low-frequency circumferential vortices, subjecting the rotor and bearings to alternating forces, which can lead to fatigue failure in severe cases. The airflow cross stiffness caused by the comb tooth seal is proportional to the average circumferential velocity of the airflow within the comb tooth seal. Therefore, reducing the circumferential flow velocity of the airflow is beneficial for improving rotor stability.

[0049] In this regard, such as Figure 11 As shown, this utility model proposes a comb-tooth sealing structure 16, which is mainly used in centrifugal compressors, but can also be used in other components with shaft holes and rotors, taking centrifugal compressors as an example.

[0050] The comb-tooth sealing structure 16 specifically includes a housing 162; the housing 162 is an annular component 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 limiting and sealing support. The inner wall of the shaft hole is provided with multiple rings of comb-tooth grooves along the axial direction to form a labyrinth-type sealing structure. The comb-tooth groove (specifically the groove between two comb teeth) maintains a set gap with the rotor surface through which it passes, forming a fluid damping channel to ensure that the rotor does not directly contact the housing 162 when rotating.

[0051] The baffle is embedded within the comb-tooth groove. When the rotor rotates at high speed, the spiral airflow generated circumferentially continuously impacts the surface of the baffle, gradually weakening the kinetic energy of the mainstream airflow and forcibly interrupting the originally continuous vortex motion. Since the airflow cross stiffness is positively correlated with the average circumferential velocity within the comb-tooth sealing 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 vortexing. This sealing structure, by adding mechanical flow-disrupting elements within the traditional comb-tooth groove, achieves active control of the flow field characteristics within the cavity without altering the original sealing gap. Compared to conventional comb-tooth seals, the new structure maintains the same sealing performance while significantly improving the operational stability of the rotor system, making it particularly suitable for centrifugal compressor units operating at high speeds.

[0052] In specific embodiments, such as Figure 9 As shown, the baffles of the comb-tooth sealing structure 16 are distributed circumferentially within each comb tooth groove. Multiple baffles are arranged in a dispersed manner circumferentially, with a certain distance maintained between adjacent baffles. This cuts the continuous circumferential airflow into several independent flow regions, achieving asymmetric suppression of vortex motion through the phase difference between adjacent baffles. When the rotor rotates, it drives the medium inside the cavity to generate circumferential flow, which can uniformly disperse the airflow impact energy and simultaneously disrupt the spatiotemporal continuity of the vortex structure, causing the originally spiral-shaped fluid kinetic energy to be converted into heat energy dissipation during multiple collisions.

[0053] In a further embodiment, such as Figure 9 , 11As shown in Figures 12 and 14, the baffles within the multi-ring comb grooves are uniformly distributed circumferentially and arranged in multiple rows axially, meaning the baffles are coaxially aligned. Preferably, eight baffles can be arranged on one axis, forming eight layers of baffle rings. This axially aligned single-row arrangement allows the baffles at corresponding positions in each ring of comb grooves to form a vertically superimposed continuous channel. When the airflow flows axially, it must pass through multiple baffles within this channel sequentially. By constructing an axially continuous barrier layer, the airflow is forced to continuously collide with the multi-stage baffles during its passage, further dissipating kinetic energy and reducing the average circumferential velocity of the airflow. Compared to the axially staggered multi-row structure, this aligned arrangement is more suitable for scenarios requiring enhanced axial sealing capabilities. It achieves concentrated suppression of airflow disturbance energy through axial cumulative effects, thereby maintaining high sealing efficiency while effectively reducing the dynamic response risk caused by circumferential vortexing of the rotor, and also facilitating installation.

[0054] In a specific embodiment, the baffles within each ring of comb grooves are divided into multiple groups according to their extension length. Each group of baffles extends vertically toward the rotor surface. Specifically, the baffles evenly distributed along the circumference are divided into two to three height levels, with a progressive difference in extension length between each level according to a preset ratio. By introducing a non-uniform local resistance gradient, the airflow is forced to undergo a refractory deflection in the horizontal direction, rather than a straight flow in a single direction. Longer baffles can directly cut off the main channel of high-speed airflow, while shorter baffles are used to capture residual vortex airflow. The two work together to form a multi-stage energy dissipation mechanism. This causes the airflow to continuously experience dynamic pressure fluctuations during its passage, thereby more thoroughly weakening its circumferential momentum accumulation ability, further reducing cross stiffness and improving the suppression of rotor vortex vibration.

[0055] Furthermore, such as Figure 11 , 16 As shown in Figure 17, the flow deflectors are of two types: a first flow deflector 163 and a second flow deflector 164. The radial extension length of the first flow deflector 163 is greater than that of the second flow deflector 164. The two are alternately embedded in the same axial row along the circumferential direction. When the airflow passes through multiple rows of flow deflectors in sequence along the axial direction, it will continuously encounter obstruction surfaces of alternating lengths. The longer first flow deflector 163 can preferentially cut off the high-speed main airflow, forcing the airflow to deflect violently and form a local vortex; the shorter second flow deflector 164 is used to capture the residual rotating airflow and further dissipate its kinetic energy through secondary collisions.

[0056] By employing the synergistic effect of axially spaced long and short baffles, a dynamic disturbance mechanism is introduced on top of the existing axial continuous obstruction, causing asymmetric pressure fluctuations in the vertical direction of the airflow. This layered energy dissipation strategy significantly improves the efficiency of weakening the circumferential momentum of the airflow while reducing the risk of resonance that may be caused by the axial continuous channel, thereby achieving better rotor dynamic stability control while maintaining 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 airflow. For example... Figure 8 , 10 As shown, the gas in front of the first baffle rotates counterclockwise under the action of the motor rotor 9. A portion of the gas in front of the first baffle 163 collides with the first baffle, reducing its flow velocity. To prevent all the gas from impacting the first baffle 163 and causing excessive baffle vibration, multiple air holes 165 are opened on the first baffle 163, through which a small amount of gas passes. The gas that slows down after the collision, as well as the gas that did not collide, flows along the gap C1. Due to the presence of the first baffle 163, some gas experiences a throttling effect as described in the background when flowing through the gap C1, which to some extent improves the comb-tooth seal's ability to prevent airflow leakage. The airflow continues counterclockwise to the next stage, where it approaches the second baffle. Similarly, some gas collides with the second baffle 164, reducing its flow velocity. Similarly, multiple air holes are opened on the second baffle 164. After a small amount of gas passes through the air holes, the gas that is decelerated after collision and the gas that is not collided flow along the gap C2. At this time, due to the presence of the second baffle 164, some gas flows through the gap C2 and the throttling effect described in the background occurs, which to a certain extent improves the function of the comb seal in preventing airflow leakage. Therefore, in the circumferential direction, through the action of the alternating first baffle 163 and second baffle 164, the airflow circulates and impacts the baffle, thereby reducing the circumferential flow velocity of the airflow. The cross stiffness of the airflow is proportional to the average circumferential velocity of the airflow in the comb seal, thereby reducing the cross stiffness and improving the vibration problem caused by the circumferential vortex of the rotor.

[0058] In specific embodiments, such as Figure 14 , 15 As shown, the housing 162 adopts an overall annular structure design, with a through-hole forming a central area to accommodate the rotor. Within each ring of comb grooves, a mounting groove extending radially to the outer wall of the housing 162 is formed. This mounting groove is a through-channel and communicates with the internal space of the comb grooves. The baffle is inserted into the mounting groove through an opening on the outer wall of the housing 162. One end of the baffle is embedded in the bottom of the comb groove and fixedly connected to the housing 162, while the other end extends to the vicinity of the rotor, forming an airflow barrier surface. This insert structure allows the baffle to be assembled without disassembling the entire sealing assembly; functional positioning is achieved simply by pushing it in from the outside of the housing 162. Simultaneously, the mounting groove provides stable support for the baffle, preventing it from shifting or falling off during operation due to airflow impact. This design enhances the maintainability of the sealing structure through modular installation. When the baffle wears or requires adjustment, it can be quickly replaced or reconfigured, thereby extending the service life of the overall sealing system and reducing maintenance costs.

[0059] The depth of the mounting groove matches the radial extension length of the baffle, forming a fitted structure. For example, the depth of the first mounting groove 1621 for installing the first baffle 163 is greater than the depth of the second mounting groove 1622 for installing 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 airflow path position formed on the rotor surface, achieving spatial positioning of the obstruction surface. Furthermore, a clearance is left between the mounting groove and the baffle around its perimeter, allowing the baffle to have a slight displacement capability during operation. When high-speed airflow impacts the surface of the baffle, the resulting impact force can drive the baffle to undergo instantaneous deformation and rebound vibration within the clearance range. This vibration process converts some of the airflow kinetic energy into the mechanical vibration energy of the baffle, which is dissipated through internal material friction and air resistance. In addition, the consistency of depth and length allows the baffle to be disassembled without additional measuring tools; it can be replaced simply by pulling it out axially, further simplifying the maintenance process and reducing operational difficulty.

[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 ranges from 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 ranges from 0.9 to 0.99 mm.

[0061] like Figure 13 As shown, the axial clearance L1 between the baffle and the mounting groove on both sides (i.e., the left and right clearances L in the figure) 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 axial clearance (which can be the same or different) together form a clearance fit, enabling the baffle to have a slight displacement capability during operation. Specifically, L1 ranges from 0.01 to 0.1 mm, and L2 ranges from 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 fixing. The circumferential clearance L2 provides the baffle with a circumferential positioning tolerance, allowing a certain angular offset during installation, while compensating for the slight sway that may occur when the rotor rotates at high speed.

[0062] In specific embodiments, such as Figure 14As shown, the outer wall surface of the housing 162 is provided with sealing ring grooves at both axial edge regions. These sealing ring grooves extend circumferentially, and an outwardly protruding sealing ring 161 is embedded inside the sealing ring groove. Its outline extends beyond the original outer wall surface of the housing 162, forming a close-fitting sealing interface with the inner wall of the diffuser 4 through hole. When the housing 162 is assembled to the through hole position of the diffuser 4, the protruding sealing ring 161 elastically deforms and tightly adheres to the inner wall surface of the through hole, achieving a dynamic sealing effect by utilizing the material's own resilience. This sealing structure, through the axial double-end sealing ring groove design, ensures that the gas flow path between the housing 162 and the diffuser 4 in the axial direction is completely blocked, preventing a decrease in sealing performance due to airflow leakage during operation.

[0063] In a preferred embodiment, such as Figure 16 , 17 As shown, multiple vents 165 are radially formed on the surface of the baffle, penetrating the thickness of the baffle and forming a permeable structure. When high-speed airflow impacts the baffle, some airflow enters the internal space of the baffle through the vents 165, creating a local pressure release effect. This design, by introducing a controllable gas pressure relief channel, weakens the concentrated impact force of the airflow on the surface of the baffle, thereby reducing the risk of severe vibration caused by instantaneous high pressure. The distribution of the vents 165 optimizes the pressure difference of the airflow on both sides of the baffle, transforming the original unilateral force into multi-point diversion under dynamic equilibrium, further suppressing the overall resonance tendency of the baffle. While maintaining the original barrier function, this structure effectively controls the vibration amplitude of the baffle by actively regulating the airflow distribution characteristics, extending 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 with a rectangular cross-section and an overall thin plate design. This thin plate structure increases structural flexibility by reducing material thickness, enabling the baffle to generate controllable local vibrations when impacted by airflow. When high-speed airflow strikes the surface of the baffle, the thin plate deforms rapidly due to its lightweight material. During this vibration, some of the airflow kinetic energy can be converted into mechanical vibration energy, and the energy is dissipated through internal material damping and air resistance.

[0065] like Figure 7 As shown, this utility model also proposes a centrifugal compressor that uses the aforementioned comb-tooth seal structure 16 as a sealing component. This structure is embedded in the through-hole area of ​​the compressor diffuser 4 and works in conjunction with the rotor shaft system. Through the placement of the baffles within the comb-tooth grooves, the compressor can effectively weaken the dynamic disturbances caused by the circumferential flow of airflow during high-speed operation, thereby significantly reducing the vibration amplitude caused by rotor whirl. This sealing scheme, while maintaining the function of a traditional labyrinth seal, optimizes the damping characteristics of the gas seal system by introducing an airflow energy dissipation mechanism, enabling the compressor to maintain a stable operating state over a wide range of operating conditions.

[0066] Specifically, the centrifugal compressor includes: a cylinder 5, a diffuser 4, a rotor 9, a stator 11, an impeller 2, and a volute 3. The cylinder 5 serves as the basic frame of the entire unit, with its internal space housing the stator assembly and the bearing assembly supporting the rotor. The diffuser 4 is fixedly installed at one end of the cylinder 5, sealing that end face. Its through-hole area is fitted with the aforementioned comb-tooth sealing structure 16, forming a rotor passageway. The rotor is supported by the bearing assembly inside the cylinder 5 and cooperates with the stator to form a motor drive unit. Its axially extending end passes through the shaft holes of the comb-tooth sealing structure 16 in the cylinder 5 and diffuser 4, and is then locked to the impeller 2. The impeller 2 is fixed to the outer end of the rotor by a locking element 1 (such as a screw), rotating synchronously with the rotor at high speed to achieve the gas compression function. The volute 3 is installed around the outer side of the diffuser 4, with its inlet connecting to the outlet of the diffuser 4, used to collect and guide the compressed gas flow to subsequent systems. The structure uses a modular component layout to enable dynamic air sealing of the rotor through the comb-tooth sealing structure 16 when it exits the diffuser 4. At the same time, the spatial matching design between the volute 3 and the diffuser 4 optimizes the airflow outlet path, reduces energy loss and improves the overall compression efficiency.

[0067] Specifically, as shown in the figure, the bearing assembly includes: a front radial bearing 6, a primary bearing support 7, a front thrust bearing 8, a rear thrust bearing 10, a rear radial bearing 12, and a secondary bearing support 13.

[0068] In a specific embodiment, the centrifugal compressor generally includes: a locking component 1, an impeller 2, a volute 3, a diffuser 4, a cylinder 5, a front radial bearing 6, a primary 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 secondary bearing support 13, a bearing cavity 14, an impeller back cavity 15, and a comb-tooth sealing structure 16.

[0069] As described above, the locking element 1 and the impeller 2 are part of the rotor and rotate together with the rotor 9 during operation. The locking element 1 fixes the impeller 2 to the rotor 9 through a threaded joint, so that when the motor is working, it drives the impeller to do work on the gas.

[0070] As mentioned above, the volute 3 and diffuser 4 are rotating hollow parts, with the volute generally being cast. The diffuser 4 and the volute 3 form a channel to diffuse the gas from the impeller outlet, reducing its velocity and increasing its pressure. The function of the volute 3 is to lead the gas out of the compressor.

[0071] As described above, the cylinder 5 is a rotating hollow part, generally cast. The function of the cylinder 5 is to provide support and fixation for parts such as the primary bearing support 7, stator 11, secondary bearing support 13, and volute 3.

[0072] As described above, the front radial bearing 6 and the rear radial bearing 12 in centrifugal compressors are commonly oil-lubricated bearings, gas bearings, or magnetic bearings. They are fixed on the primary bearing support 7 and the secondary bearing support 13, respectively, and mainly bear radial loads to provide radial support for the rotor.

[0073] As mentioned above, the front thrust bearing 8 and the rear thrust bearing 10 in centrifugal compressors are commonly oil-lubricated bearings, gas bearings, or magnetic bearings, mainly bearing axial loads and providing axial support for the rotor.

[0074] As described above, the stator 11 is a rotating part, mainly composed of a stator core and stator windings. During operation, the stator 11 generates a magnetic field, and the rotor 9 rotates at high speed under the influence of the electromagnetic field.

[0075] It should be noted that the terminology used above is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this utility model. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0076] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0077] In the description of this utility model, it should be understood that the directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this utility model. The directional terms "inner" and "outer" refer to the inner and outer contours of each component itself.

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

[0079] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, these terms have no special meaning and therefore should not be construed as limiting the scope of protection of this utility model. The above description is only a preferred embodiment of this utility model and is not intended to limit this utility model. For those skilled in the art, this utility model can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A comb seal structure, comprising: A housing with a shaft hole, wherein the inner wall of the shaft hole is provided with multiple rings of comb grooves along the axial direction, characterized in that a baffle is provided in the comb grooves to block the airflow generated circumferentially by the rotor passing through the shaft hole when it rotates.

2. The comb seal structure of claim 1, wherein, Multiple flow-blocking elements are spaced apart within each of the comb tooth grooves.

3. The comb seal structure of claim 2, wherein, Multiple flow-blocking elements in the multi-ring comb groove are evenly spaced along the circumferential direction, and the flow-blocking elements at the same circumferential position are arranged in a single row along the axial direction.

4. The comb-tooth sealing structure as described in claim 1, characterized in that, The multiple flow-blocking elements within each ring of the comb groove are divided into multiple groups of flow-blocking elements with different extension lengths.

5. The comb seal structure of claim 1, wherein, The flow-blocking component is divided into a first flow-blocking component and a second flow-blocking component, and the length of the first flow-blocking component is greater than the length of the second flow-blocking component.

6. The comb seal structure of claim 5, wherein, The first and second flow-blocking elements are alternately arranged in each rotation of the comb teeth.

7. The comb seal structure of any one of claims 1 to 6, wherein, The housing is annular in shape, with the shaft hole in the middle. The comb groove is provided with a mounting groove that leads to the outer wall of the housing. The flow-blocking member is inserted into the mounting groove from the outer wall of the housing.

8. The comb seal structure of claim 7, wherein, The depth of the mounting groove is the same as the length of the flow deflector, and a fitting gap is left between the groove and the flow deflector.

9. The comb seal structure of claim 7, wherein, The fitting clearance between the flow deflector and the mounting groove includes a clearance L1 on both sides of the axial direction and a clearance L2 on both sides of the circumferential direction; the value of L1 ranges from 0.01 to 0.1 mm, and the value of L2 ranges from 0.01 to 0.2 mm.

10. The comb seal structure of claim 7, wherein, The outer wall surface of the housing is provided with a sealing ring groove near the edge, and a sealing ring protruding from the sealing ring groove is installed in the sealing ring groove.

11. The comb seal structure of any one of claims 1 to 6, wherein, The flow-blocking component is provided with multiple air holes.

12. A compressor characterized by, Includes the comb-tooth sealing structure as described in any one of claims 1 to 11.

13. The compressor of claim 12, wherein, The comb-tooth sealing structure is installed on the diffuser of the compressor.

14. The compressor of claim 13, wherein, The compressor includes: The cylinder, the diffuser, the rotor, the stator, and the impeller; the diffuser is installed at one end of the cylinder to seal the cylinder, the cylinder is provided with a stator and a bearing assembly supporting the rotor, the rotor cooperates with the stator and bearing assembly inside the cylinder and passes through the shaft hole of the comb-tooth sealing structure on the diffuser, and the impeller is installed at the outer end of the rotor.

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