A cantilever-mounted flexible filament sealing weir end face sealing moving ring structure

Abstract

A cantilever installation flexible filament sealing weir end face seal moving ring structure belongs to the technical field of groove type self-adaptive end face seal moving ring structure. One side of the moving ring structure is the high pressure side, and the other side is the low pressure side; it comprises a sealing ring base body, a brush filament compression ring and a flexible filament sealing weir; the end face of the sealing ring base body comprises a slotted area end face and a sealing dam area end face, and there is a height difference between the sealing dam area end face and the slotted area end face; a group of flexible filament sealing weirs are evenly distributed along the circumference of the sealing ring base body, the flexible filament sealing weir comprises a cluster of flexible brush filaments closely arranged along the circumference of the sealing ring base body, the starting end of the flexible brush filament is compressed on the slotted area end face by the brush filament compression ring to form a cantilever structure, and a sealing groove for airflow circulation is formed between the two adjacent flexible filament sealing weirs. The flexible filament sealing weir structure of the sealing ring end face can effectively change according to the change of the operating condition, thereby ensuring that the dry gas seal maintains stable gas film bearing capacity during the start-stop stage and variable operating condition of the equipment, and effectively avoids the generation of the sealing ring rubbing phenomenon.

Description

Technical Field

[0001] This invention belongs to the technical field of groove-type adaptive end-face sealing dynamic ring structure, specifically relating to a cantilever-mounted flexible filamentous sealing weir end-face sealing dynamic ring structure. Background Technology

[0002] Creating various dynamic and static pressure grooves on the sealing end face to enhance the fluid film's load-bearing capacity and rigidity, thus achieving non-contact operation between the sealing pairs, is a common technique in gas or liquid lubricated mechanical seals. A mechanical seal pair consists of a rotating ring that follows the shaft and a mating stationary ring. When the rotating ring rotates, the dynamic pressure grooves on its end face pump the fluid medium from the sealing cavity into the sealing gap. Under the combined action of the medium pressure difference and circumferential shear, the fluid medium flows downstream towards the low-pressure side and the windward side within the grooves, continuously being compressed. This increases the gas film pressure on the windward side and at the groove root, creating a dynamic pressure effect. This results in a gas film several micrometers thick between the sealing end faces, ensuring the sealing pairs operate without contact between their end faces.

[0003] Evaluating the performance of dry gas seals primarily considers parameters such as opening force, leakage rate, and gas film stiffness. The groove shape significantly impacts the hydrodynamic pressure effect and film thickness of the dry gas seal. Traditional dry gas seals, once manufactured, cannot change their groove structure during operation. While their gas film load-bearing capacity and stiffness meet design requirements under certain conditions, they often fail due to insufficient gas film load-bearing capacity and stiffness, and inadequate resistance to external disturbances, leading to end-face rubbing or vibration instability. Therefore, the ability to adaptively change the seal groove shape according to variations in external speed and pressure, maintaining good performance under different operating conditions, is crucial for the successful application of dry gas seals in shaft sealing applications with fluctuating operating conditions and frequent start-stop cycles.

[0004] The classic dry gas seal end face mainly consists of three parts: a dynamic pressure groove, a sealing weir, and a sealing dam. The area between adjacent dynamic pressure grooves circumferentially forms the sealing weir, which blocks the circumferential flow of the sealing medium during the operation of the dry gas seal. The sealing dam blocks the radial flow of the sealing medium. When the rotating ring rotates, the sealing medium is pumped into the sealing gap through the dynamic pressure groove and pressurized due to the flow obstruction effect of the sealing weir and sealing dam, thus forming a significant high-pressure zone near the windward side wall and groove root. Extensive theoretical research and engineering application experience show that the shape of the dynamic pressure groove has a significant impact on the area and peak value of the high-pressure zone on the sealing end face. Moreover, the optimal structure of the dynamic pressure groove designed with the goal of maximizing gas film stiffness and gas film bearing capacity is closely related to operating conditions such as rotational speed and medium pressure. That is, when external operating conditions change, dry gas seals that perform well under design conditions may fail due to excessive leakage or end face wear caused by the disruption of axial force balance. Summary of the Invention

[0005] In view of the above-mentioned problems in the prior art, the purpose of the present invention is to provide a cantilevered flexible filament sealing weir end face sealing dynamic ring structure, which can effectively avoid the occurrence of sealing ring rubbing.

[0006] This invention provides the following technical solution:

[0007] A cantilever-mounted flexible filamentous sealing weir end face sealing dynamic ring structure, with one side of the dynamic ring structure being a high-pressure side and the other side being a low-pressure side; comprising a sealing ring base, a brush wire clamping ring, and flexible filamentous sealing weirs; the end face of the sealing ring base includes a slotted area end face and a sealing dam area end face, with a height difference between the sealing dam area end face and the slotted area end face; a set of flexible filamentous sealing weirs are evenly distributed along the circumference of the sealing ring base; the flexible filamentous sealing weirs include a cluster of flexible brush wires tightly arranged along the circumference of the sealing ring base; the starting end of the flexible brush wires is pressed against the slotted area end face by the brush wire clamping ring to form a cantilever structure; a sealing groove is formed between two adjacent flexible filamentous sealing weirs to allow airflow.

[0008] Furthermore, the flexible filamentous sealing weir deforms under the airflow pressure in two adjacent sealing grooves and forms the boundary of the sealing groove.

[0009] Furthermore, the end face of the sealed dam area is higher than the end face of the slotted area, with a height difference of 1 to 100 μm, and the diameter of the flexible brush bristles is not greater than this height difference.

[0010] Furthermore, multiple circumferentially distributed arc-shaped shallow grooves are provided at the boundary radius between the end face of the sealed dam area and the end face of the slotted area. The bottom end face of the arc-shaped shallow groove is flush with the end face of the slotted area, and the end of the flexible brush bristles is placed in the arc-shaped shallow groove for positioning.

[0011] Furthermore, the bristle clamping ring is provided with a mounting groove through which flexible bristles can pass.

[0012] Furthermore, the mounting groove is an inclined groove structure, and the angle between the center line of the mounting groove and the radial line of the sealing ring base is 5 to 85°.

[0013] Furthermore, the number of sealing grooves is 4 to 30.

[0014] Furthermore, the shape of the flexible bristles is either a curve or a straight line.

[0015] By employing the above-described technology, the beneficial effects of the present invention compared to the prior art are as follows:

[0016] 1) The flexible filamentous sealing weir structure on the end face of the sealing ring of the present invention can effectively change according to the changes in operating conditions, thereby ensuring that the dry gas seal maintains a stable gas film bearing capacity during equipment start-up and shutdown and operation under changing conditions, and effectively avoids the occurrence of sealing ring rubbing phenomenon.

[0017] 2) The arrangement of flexible bristles can be adjusted according to the groove structure. By designing reasonable sealing grooves, sealing weirs and sealing dams, and applying reasonable constraints, the dry gas seal can adapt to different media and working conditions. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the cantilevered flexible filament sealing weir end face sealing dynamic ring structure in Embodiment 1 of the present invention;

[0019] Figure 2 This is a left view of the cantilevered flexible filament sealing weir end face sealing dynamic ring structure of Embodiment 1 of the present invention;

[0020] Figure 3 This is a partial cross-sectional view of the flexible brush bristles fixed by the brush bristle clamping ring in Embodiment 1 of the present invention;

[0021] Figure 4 This is a schematic diagram of the pairing of the dynamic and static ring friction pairs in Embodiment 1 of the present invention;

[0022] Figure 5 This is a schematic diagram of the brush bristle clamping ring and mounting groove structure in Embodiment 1 of the present invention;

[0023] Figure 6 This is a diagram showing the relationship between the sealing groove and the sealing weir in Embodiment 1 of the present invention;

[0024] Figure 7 This is a schematic diagram of the force analysis of the flexible brush bristles in Embodiment 1 of the present invention;

[0025] Figure 8 This is a schematic diagram illustrating the deformation principle of the sealing groove at high speed in Embodiment 1 of the present invention.

[0026] Figure 9 This is a schematic diagram illustrating the deformation principle of the sealing groove at low speed in Embodiment 1 of the present invention.

[0027] Figure 10 This is a schematic diagram of the cantilevered flexible filamentous sealing weir end face sealing dynamic ring structure in Embodiment 2 of the present invention. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the 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 merely illustrative and not intended to limit the invention.

[0029] Conversely, this invention encompasses any substitutions, modifications, equivalent methods, and solutions made within the spirit and scope of the invention as defined in the claims. Furthermore, to provide a better understanding of the invention, certain specific details are described in detail below. However, those skilled in the art will fully understand the invention even without these detailed descriptions.

[0030] Example 1:

[0031] Please see Figure 1-10 A cantilevered flexible filamentous sealing weir end face sealing dynamic ring structure is disclosed. The inner diameter side of the sealing ring base 1 is the low-pressure side, and the outer diameter side is the high-pressure side. The end face of the sealing ring base 1 consists of a slotted area end face 11 and a sealing dam area end face 12, with the sealing dam area end face 12 being higher than the slotted area end face 11. The flexible filamentous sealing weir 3 is formed by a cluster of flexible brush filaments 31 arranged tightly along the circumference and evenly distributed along the circumference on the end face of the sealing ring base 1. This arrangement, based on a typical end face sealing structure, naturally presents the structure and shape of the sealing weir and sealing groove. The starting end 311 of the flexible brush filaments passes through the mounting groove 21 provided on the brush filament clamping ring 2 and is pressed by the brush filament clamping ring 2 onto the slotted area end face 11 to form a cantilever structure. A sealing groove that allows airflow is formed between two adjacent flexible filamentous sealing weirs 3 in the circumference. Under the condition that both ends are constrained, the middle section of the flexible brush filaments 31 can deform with changes in working conditions.

[0032] Reference Figure 4 The dynamic ring and stationary ring 5, which consist of a sealing ring base 1, a brush bristle clamping ring 2 and a flexible filamentous sealing weir 3, form a pair of friction pairs. When the dry gas seal is working, a dynamic pressure effect is generated between the end face of the stationary ring 5 and the end face of the dynamic ring, forming a gas film with a thickness of several micrometers.

[0033] The boundary shape of the sealing groove 4 is determined by two adjacent flexible filamentous sealing weirs 3, and the number of sealing grooves 4 is 10. The flexible filamentous sealing weirs 3 can deform under the airflow pressure in the first sealing groove 41 and the adjacent second sealing groove 42. When the rotation speed increases or decreases, the angle at which the fluid medium is pumped into the sealing groove 4 changes. The degree of deformation of the flexible filamentous sealing weirs 3 is affected by the rotation speed, so that the shape and inlet angle of the sealing groove 4 always respond to the change in the medium flow rate.

[0034] To prevent radial leakage of the sealing medium flowing through the sealing dam, the end face 12 of the sealing dam area must be higher than the end face of the slotted area, with a protrusion height of 10 μm. Multiple circumferentially distributed arc-shaped shallow grooves 111 are provided at the boundary radius between the end face 12 of the sealing dam area and the end face 11 of the slotted area. The slotting direction of the arc-shaped shallow grooves 111 is consistent with the rotation direction of the sealing groove, and the bottom end face is flush with the end face 11 of the slotted area. The flexible brush bristle ends 312 are positioned within the arc-shaped shallow grooves 111. The diameter of the flexible brush bristles 31 is 10 μm. The shape of the flexible brush bristles 31 is curved.

[0035] The contact surface between the brush bristle clamping ring 2 and the end face of the sealing ring base 1 is provided with multiple circumferentially distributed inclined grooves 21. The flexible brush bristles 31 pass through the mounting grooves 21 and are pressed against the end face 11 of the grooved area. The angle α between the center line of the mounting groove 21 and the radial line of the sealing ring is 25°. The mounting groove 21 not only serves to fix the flexible brush bristles 31, but also ensures that the sealing groove formed by the flexible filamentous sealing weir 3 forms a certain angle at the inlet, which is conducive to the pumping in of the sealing medium.

[0036] Reference Figure 7 This section primarily explains the stress and constraint conditions of individual flexible brush filaments 31 that make up the flexible filamentous sealing weir 3. The starting end 311 of the flexible brush filament is fixed by the brush filament clamping ring 2, and the ending end 312 of the flexible brush filament is positioned within the arc-shaped shallow groove 111. The flexible brush filament response section 313 is located between two constraints and can deform circumferentially. When sealing gas flows into the gap between the flexible brush filaments 31 from the outer diameter side, a pressure difference is formed on both sides of the flexible brush filament 31. Under the action of the pressure difference, the load F1 on the windward side of the flexible brush filament response section 313 is greater than the load F2 on the leeward side, causing the flexible brush filament response section 313 to bend and deform in the leeward direction. When the responses of a cluster of brush filaments are combined, they form the overall deformation of the flexible filamentous sealing weir 3, thereby changing the boundary shape of the sealing groove 4 to adapt to changes in operating conditions.

[0037] Reference Figure 8 and 9 This mainly explains the change in medium inlet velocity under different rotation speeds, as well as the adaptive deformation principle of the flexible brush bristles 31 and the mechanism for changing the groove structure.

[0038] Example 2:

[0039] Reference Figure 1-10 The difference between this embodiment and Embodiment 1 is that the flexible brush bristles 31 are straight in shape, while the rest of the structure and implementation method are the same as in Embodiment 1.

[0040] The working principle of this invention is as follows:

[0041] When the dry gas seal of the present invention is used as a shaft end seal, the medium is pumped into the sealing groove 4 from the outer diameter side and continuously compressed in the sealing groove 4, which causes the air film pressure on the windward side and the root of the groove to increase, thereby creating a pressure difference between the windward side and the leeward side, which acts on the flexible brush filament 31 to cause bending deformation.

[0042] When the equipment operates under stable conditions, the flexible filamentous sealing weir 3 maintains its initial deformation state and is in dynamic equilibrium. When the rotational speed n is greater than the design operating condition, the circumferential velocity v of the medium... θ Increase, while radial velocity v r The change is not significant. The circumferential angle of the medium entering the sealing groove 4 decreases. As the medium is pumped in, the pressure on the wind side of the flexible brush filament 31 increases, and the bending deformation increases. The overall deformation of the flexible filamentous sealing weir 3 leads to a decrease in the circumferential angle β at the inlet of the sealing groove 4. At this time, the change in groove angle is adapted to the change in medium flow velocity, which is conducive to the pumping in of the sealing medium, thereby forming a stable gas film more quickly. Similarly, when the rotational speed n is less than the design condition, the circumferential velocity v of the medium decreases. θ As the speed of the medium entering the sealing groove 4 decreases, the circumferential angle v increases, the bending deformation of the flexible brush filament 31 decreases, and the circumferential angle β at the inlet of the sealing groove 4 increases, which is also beneficial to the pumping of the sealing medium. In this way, no matter whether the speed increases or decreases, the flexible filamentous sealing weir structure at the end face of the sealing ring of the present invention can always adapt to the speed, thereby effectively avoiding adverse phenomena caused by changes in operating conditions.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A cantilever-mounted flexible filamentous sealing weir end face sealing dynamic ring structure, wherein one side of the dynamic ring structure is a high-pressure side and the other side is a low-pressure side; characterized in that: The device includes a sealing ring base, a bristle clamping ring, and flexible filamentous sealing weirs. The end face of the sealing ring base includes a slotted area end face and a sealing dam area end face, with a height difference between the sealing dam area end face and the slotted area end face. A set of flexible filamentous sealing weirs is evenly distributed along the circumference of the sealing ring base. Each flexible filamentous sealing weir includes a cluster of flexible bristles that are tightly arranged along the circumference of the sealing ring base. The starting end of the flexible bristles is pressed against the slotted area end face by the bristle clamping ring to form a cantilever structure. A sealing groove that allows airflow is formed between two adjacent flexible filamentous sealing weirs.

2. The cantilever-mounted flexible filamentous sealing weir end face sealing dynamic ring structure according to claim 1, characterized in that... The flexible filamentous sealing weir deforms under the pressure of the airflow in two adjacent sealing grooves and forms the boundary of the sealing groove.

3. The cantilever-mounted flexible filamentous sealing weir end face sealing dynamic ring structure according to claim 1, characterized in that... The end face of the sealed dam area is higher than the end face of the slotted area, with a height difference of 1 to 100 μm, and the diameter of the flexible brush bristles is not greater than this height difference.

4. The cantilever-mounted flexible filamentous sealing weir end face sealing dynamic ring structure according to claim 1, characterized in that... At the boundary radius between the end face of the sealed dam area and the end face of the slotted area, there are multiple circumferentially distributed arc-shaped shallow grooves. The bottom end face of the arc-shaped shallow groove is flush with the end face of the slotted area, and the end of the flexible brush bristles is placed in the arc-shaped shallow groove for positioning.

5. The cantilever-mounted flexible filamentous sealing weir end face sealing dynamic ring structure according to claim 1, characterized in that... The bristle clamping ring is provided with a mounting groove through which flexible bristles can pass.

6. The cantilever-mounted flexible filamentous sealing weir end face sealing dynamic ring structure according to claim 5, characterized in that... The mounting groove is an inclined groove structure, and the angle between the center line of the mounting groove and the radial line of the sealing ring base is 5 to 85°.

7. The cantilever-mounted flexible filamentous sealing weir end face sealing dynamic ring structure according to claim 1, characterized in that... The number of sealing grooves is 4 to 30.

8. The cantilever-mounted flexible filamentous sealing weir end face sealing dynamic ring structure according to claim 1, characterized in that... The shape of the flexible bristles can be either a curve or a straight line.

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