Automatic compensation fingertip seal for compressors

Abstract

The utility model relates to a kind of automatic compensation fingertip seal for compressor, belong to sealing technical field, sealing matrix and sealing tooth, sealing matrix inner hole is processed with several annular grooves, each annular groove is embedded with sealing tooth;The inner hole side of the sealing tooth is arc fingertip type.The fingertip end of the arc fingertip of the inner hole side of the sealing tooth is raised, and the tip end is towards sealed gas;The back of the gas face of sealing tooth is provided with concave arc;Wherein the bottom arc of the tip end part of the arc fingertip of part of sealing tooth is tangent to the outer circle of shaft sleeve.The utility model changes the flat tooth with inner hole with bevel angle to arc fingertip type sealing tooth, and the sealing tooth is made of polyether ether ketone, polytetrafluoroethylene and other non-metallic materials, which can be suspended in the outer circle of rotor, and automatically compensate for the wear of sealing tooth tip, so that the gap between the outer circle of rotor is minimized, and the sealing performance is better.

Description

Technical Field

[0001] This utility model belongs to the field of sealing technology, and in particular relates to an automatic compensating fingertip seal for compressors. Background Technology

[0002] Because there is a gap between the sealing teeth of the labyrinth seal and the outer circumference of the rotor, there is no solid contact, no lubrication is required, and thermal expansion is allowed. Therefore, labyrinth seals are suitable for high-temperature, high-pressure, and high-rotation-frequency applications. This type of seal is widely used as a pre-seal for shaft end and interstage sealing or other dynamic seals in steam turbines, gas turbines, compressors, blowers.

[0003] With technological advancements, the demands on compressor efficiency are increasing. Commonly used labyrinth seals have a relatively large gap between the seal and the rotor, resulting in significant leakage and hindering efficiency improvements. Reducing this gap causes the rotor to vibrate during operation, resulting in intermittent contact and friction between the rotor and the labyrinth seal's sealing teeth. This rapid wear of the teeth leads to further widening of the gap. Furthermore, existing labyrinth seals cannot automatically compensate for worn sealing teeth, further increasing leakage. Therefore, improving the sealing performance of labyrinth seals while retaining their inherent advantages is a pressing issue. Utility Model Content

[0004] To address the shortcomings of existing technologies, this utility model provides an automatic compensating fingertip seal for compressors. The commonly used flat teeth with beveled inner holes are replaced with arc-shaped fingertip sealing teeth. These sealing teeth are made of non-metallic materials such as PEEK and polytetrafluoroethylene. They can float on the outer circle of the rotor and automatically compensate as the tips of the sealing teeth wear down, minimizing the gap with the outer circle of the rotor and improving the sealing performance.

[0005] An automatic compensating fingertip seal for a compressor includes a sealing substrate and sealing teeth. The inner hole of the sealing substrate is machined with several annular grooves, and a sealing tooth is embedded in each annular groove. The inner hole side of the sealing tooth is arc-shaped fingertip, and the fingertip tip of the arc-shaped fingertip is raised with the tip pointing towards the gas being sealed.

[0006] Both the sealing substrate and the sealing teeth are annular structures.

[0007] The sealing substrate is made of stainless steel or aluminum alloy.

[0008] The sealing teeth are made of polyetheretherketone or polytetrafluoroethylene.

[0009] The outer circle of the axial section of the sealing tooth, as well as the front and rear clamping surfaces, fit tightly with the annular groove.

[0010] The back of the air-facing surface of the sealing tooth is provided with a concave arc. The distance between the midpoint of the arc's chord and the tooth root reference surface in the tooth height direction is d1, and the distance between the midpoint of the arc's chord and the tooth tip in the tooth height direction is d2.

[0011] The air-facing surface of the arc-shaped fingertip on the inner hole side of the sealing tooth forms an angle of 10° to 15° with the front clamping surface, and the back of the air-facing surface forms an angle of 10° to 15° with the air-facing surface.

[0012] The sealing teeth include a first sealing tooth and a second sealing tooth with different tooth heights but the same structure, wherein the tooth height of the first sealing tooth is greater than that of the second sealing tooth.

[0013] The first sealing tooth is 1 mm higher than the second sealing tooth, and the second sealing tooth has a sealing gap with the outer circle of the rotor.

[0014] The bottom arc of the tip of the first sealing tooth is tangent to the outer circle of the rotor. The distance between the tangent point and the front clamping surface is 1 mm, and the distance between the tip and the tip is 1 mm.

[0015] By employing the above technical solution, this utility model application has at least the following beneficial effects:

[0016] 1. The sealing teeth are made of non-metallic materials such as PEEK and polytetrafluoroethylene. At the same time, the axial cross-section of the sealing teeth is wide at the root and thin at the tip. The sealing teeth are rounded on the inner side of the hole, which makes them better in terms of stress. This ensures both the strength and flexibility of the entire sealing teeth.

[0017] 2. The tips of the sealing teeth are arc-shaped and finger-tip type, with the tips facing the gas being sealed. When the equipment is running, high-pressure gas leaks outward. The high-pressure gas will exert pressure on the sealing teeth, forcing the tooth tips to move towards the outer circle of the rotor, thereby reducing the sealing gap and minimizing the leakage.

[0018] 3. The tip of the sealing tooth is raised, and the arc of the sealing tooth is in linear contact with the rotor. The small contact area can reduce the friction between the sealing tooth and the main shaft, thereby reducing the heat generated at the friction point, reducing the amount of thermal deformation of the rotor, and preventing the sealing tooth from losing strength and aging too quickly at high temperatures.

[0019] 4. The air-facing surface of the sealing tooth forms a 10° angle with the front clamping surface, and the contact point with the rotor is an arc. The front end of the sealing tooth is raised. After the equipment is running, the high-pressure gas enters the bottom of the arc and can generate a buoyancy effect on the sealing tooth. This buoyancy force is balanced with the closing force generated by the high-pressure gas on the sealing tooth, ensuring that the tip of the sealing tooth floats on the outer circle of the rotor. When the shaft and the housing are eccentric, it ensures that the lip has a suitable following ability while preventing the sealing tooth from being tightly pressed against the rotor under the action of high-pressure gas, resulting in excessive friction and premature wear of the sealing tooth.

[0020] 5. The sealing tooth tip not only has a sealing function but also a compensation function. As the equipment operates for a long time, the arc of the sealing tooth is worn due to prolonged contact with the shaft. The tip of the tooth tip is raised and automatically compensated by the pressure of the sealed gas inside the equipment, thus ensuring that the sealing tooth still maintains a minimum clearance with the shaft after wear.

[0021] 6. Due to the high hardness and poor responsiveness of the sealing tooth material, an arc is set on the back of the air-facing side of the sealing tooth to thin and weaken the cross-section of the sealing tooth. The arc forms a flexible hinge, and the arc is set closer to the tooth root, which ensures that the sealing tooth is more easily deformed under the pressure of gas inside the equipment, thereby ensuring sealing performance. Attached Figure Description

[0022] Figure 1 An axial cross-sectional view of the automatic compensating fingertip seal for compressors provided by this utility model;

[0023] Figure 2 A radial view of the automatic compensation fingertip seal for a compressor provided by this utility model;

[0024] Figure 3 This is a tooth profile diagram of the sealing tooth in this utility model;

[0025] In the picture:

[0026] 1001-Sealing tooth, 1011-First sealing tooth, 1012-Second sealing tooth, 1002-Sealing substrate, 1003-Front clamping surface, 1004-Rear clamping surface, 1005-Air-facing surface, 1006-Back side of air-facing surface. Detailed Implementation

[0027] To better explain and facilitate understanding of this utility model, the technical solution and effects of this utility model will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] like Figures 1-3 As shown, this embodiment provides an automatic compensation fingertip seal for a compressor, including a sealing base 1002 and sealing teeth 1001.

[0029] The sealing substrate 1002 is made of stainless steel or aluminum alloy and is fixedly installed inside the equipment cavity, specifically on the outside of the sealing cavity of the equipment housing. The inner hole of the sealing substrate 1002 is machined with several annular grooves, and each groove is fitted with a sealing tooth 1001.

[0030] Both the sealing substrate 1002 and the sealing teeth 1001 are annular structures.

[0031] The sealing tooth 1001 is made of non-metallic materials, including but not limited to polyetheretherketone (PEEK) or polytetrafluoroethylene. The outer circle of the axial cross-section of the sealing tooth 1001, the front clamping surface 1003, and the rear clamping surface 1004 are tightly fitted with an annular groove. The inner hole side of the sealing tooth 1001 is an arc-shaped fingertip, with the tip of the arc-shaped fingertip curving upwards and facing the sealed gas. The back surface 1006 of the air-facing side of the sealing tooth 1001 has a concave arc to reduce the strength of the sealing tooth 1001, ensuring that the tooth tip of the sealing tooth 1001 is more easily deformed under the pressure of the gas inside the equipment, thereby ensuring that it can automatically compensate for spindle runout. The distance between the midpoint of the chord of the arc and the tooth root reference surface in the tooth height direction is d1, and the distance between the midpoint of the chord of the arc and the tooth tip in the tooth height direction is d2.

[0032] The air-facing surface 1005 of the arc-shaped fingertip forms a 10° angle with the front clamping surface 1003, and the back of the air-facing surface forms a 10° angle with the air-facing surface 1005.

[0033] In this embodiment, the sealing teeth 1001 include a first sealing tooth 1011 and a second sealing tooth 1012 with different tooth heights but the same structure. The first sealing teeth 1011 and the second sealing teeth 1012 are arranged alternately on the sealing substrate 1002. The tooth height of the first sealing tooth 1011 is greater than the tooth height of the second sealing tooth 1012. Preferably, the first sealing tooth 1011 is 1 mm higher than the second sealing tooth 1012. Specifically, the bottom arc of the tip of the arc-shaped fingertip of the first sealing tooth 1011 is tangent to the outer circle of the rotor. The tangency point is 1 mm away from the front clamping surface 1003 and 1 mm away from the tip. The second sealing tooth 1012 has a sealing gap with the outer circle of the rotor. The second sealing tooth 1012 has the same structure as the first sealing tooth 1011, that is, the lowest point of the bottom arc of the tip of the arc-shaped fingertip of the second sealing tooth 1012 is 1 mm away from the front clamping surface 1003 and 1 mm away from the tip.

[0034] The working process of the automatic compensation fingertip seal for the above-mentioned compressor is as follows:

[0035] The compressor described above uses an automatically compensating fingertip seal installed on the outside of the sealing cavity of the equipment housing. The air-facing surface 1005 of the sealing tooth 1001 faces the gas being sealed. When the equipment is running, the gas inside the equipment flows towards the atmosphere. Because the air-facing surface 1005 of the sealing tooth 1001 forms a 10° angle with the front clamping surface 1003, the high-pressure gas exerts a downward force on the air-facing surface 1005 after the equipment starts running, forcing the first sealing tooth 1011 to fit against the outer circle of the shaft, thereby preventing gas leakage inside the equipment. Since the contact point between the first sealing tooth 1011 and the rotor is a rounded bottom, and the sealing tooth 1001... The tip of the first sealing tooth 1001 is raised, and some high-pressure gas enters the bottom of the arc through the raised part of the front end of the first sealing tooth 1011, which can generate a buoyancy effect on the first sealing tooth 1011. This buoyancy force and the closing force generated by the high-pressure gas on the first sealing tooth 1011 form a dynamic balance, ensuring that the tip of the first sealing tooth 1011 floats on the outer circle of the rotor. When there is eccentricity between the shaft and the housing, it ensures that the lip has a suitable following ability, while preventing the first sealing tooth 1011 from being tightly attached to the rotor under the action of high-pressure gas, which would cause excessive friction and cause the sealing tooth 1001 to wear too quickly. At the same time, because the material of the sealing tooth 1001 has high hardness and poor following ability, a concave arc is provided on the back side 1006 of the air-facing side of the sealing tooth 1001. The cross-section of the sealing tooth 1001 is thinned and weakened, which can reduce the strength of the sealing tooth 1001 and ensure that the tip of the sealing tooth 1001 is more easily deformed under the action of gas pressure inside the equipment, thereby ensuring the sealing performance of this type of seal.

Claims

1. An automatically compensating fingertip seal for a compressor, characterized in that: It includes a sealing substrate and sealing teeth. The inner hole of the sealing substrate is machined with several annular grooves, and each annular groove is fitted with a sealing tooth. The inner hole side of the sealing tooth is arc-shaped fingertip, and the fingertip of the arc-shaped fingertip is raised with the tip pointing towards the gas being sealed.

2. The compressor automatic compensating fingertip seal according to claim 1, characterized in that: Both the sealing substrate and the sealing teeth are annular structures.

3. The compressor automatic compensating fingertip seal according to claim 1, characterized in that: The sealing substrate is made of stainless steel or aluminum alloy.

4. The compressor automatic compensating fingertip seal according to claim 1, characterized in that: The sealing teeth are made of polyetheretherketone or polytetrafluoroethylene.

5. The automatic compensating fingertip seal for a compressor according to claim 1, characterized in that: The outer circle of the axial section of the sealing tooth, as well as the front and rear clamping surfaces, fit tightly with the annular groove.

6. The compressor automatic compensating fingertip seal according to claim 1, characterized in that: The back of the air-facing surface of the sealing tooth is provided with a concave arc. The distance between the midpoint of the arc's chord and the tooth root reference surface in the tooth height direction is d1, and the distance between the midpoint of the arc's chord and the tooth tip in the tooth height direction is d2.

7. The compressor automatic compensating fingertip seal according to claim 1, characterized in that: The air-facing surface of the arc-shaped fingertip on the inner hole side of the sealing tooth forms an angle of 10° to 15° with the front clamping surface, and the back of the air-facing surface forms an angle of 10° to 15° with the air-facing surface.

8. The compressor automatic compensating fingertip seal according to claim 1, characterized in that: The sealing teeth include a first sealing tooth and a second sealing tooth with different tooth heights but the same structure, wherein the tooth height of the first sealing tooth is greater than that of the second sealing tooth.

9. The compressor automatic compensating fingertip seal according to claim 8, characterized in that: The first sealing tooth is 1 mm higher than the second sealing tooth, and the second sealing tooth has a sealing gap with the outer circle of the rotor.

10. The compressor automatic compensating fingertip seal according to claim 9, characterized in that: The bottom arc of the tip of the first sealing tooth is tangent to the outer circle of the rotor. The distance between the tangent point and the front clamping surface is 1 mm, and the distance between the tip and the tip is 1 mm.

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