A turbulent flow labyrinth seal structure for an I-shaped arc-ellipse chamber

Abstract

A kind of I-shaped arc-shaped elliptical chamber turbulent type labyrinth seal structure, annular sealing tooth is equipped with annular groove on both axial side surfaces, and the two annular grooves between adjacent annular sealing teeth are matched to form elliptical fluid kinetic energy dissipation cavity for generating vortex turbulent flow;The radial inner surface of annular sealing tooth is provided with annular rib, and the cross-sectional shape of annular sealing tooth under the cooperation of annular rib and annular groove constitutes I-shaped arc;The surface of rotating shaft opposite to annular rib is provided with annular groove, and the annular groove and annular rib form fluid throttling gap.The invention improves the dynamic characteristics of labyrinth seal structure, provides better airflow stiffness and damping, improves the operation stability of the whole rotor system, and can generate high-resistance, high-mixing, high-dissipation vortex turbulent flow in each elliptical fluid kinetic energy dissipation cavity, effectively enhances throttling dissipation, so that the pressure and energy of fluid medium are significantly weakened, and the sealing effect is further improved.

Description

Technical Field

[0001] This invention belongs to the field of labyrinth sealing technology, and in particular relates to an I-shaped arc-shaped elliptical cavity turbulent labyrinth sealing structure. Background Technology

[0002] Labyrinth seals are non-contact dynamic seals widely used in rotating machinery such as aircraft engines, steam turbines, and gas turbines to prevent the leakage of lubricating oil or gas. The basic principle of a labyrinth seal is that fluid passes through a series of throttling gaps and expansion cavities, generating a throttling effect and dissipating kinetic energy, thereby reducing the pressure and flow rate of leaking gas.

[0003] Traditional labyrinth seal structures are generally straight-through labyrinth seal structures, which have a series of continuous annular sealing teeth on the sealing ring, which cooperate with the smooth surface on the shaft.

[0004] However, although the straight-through labyrinth seal structure is simple, its sealing effect is limited. This is because the straight-through annular sealing teeth cause uniform axial disturbance to the fluid, forming a straight jet, which cannot allow each chamber to fully consume the fluid's energy. Therefore, the throttling and dissipation effect on the fluid medium is not ideal. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides an I-shaped arc-shaped elliptical chamber turbulent labyrinth seal structure. Through the innovative I-shaped arc-shaped elliptical chamber turbulent design, the dynamic characteristics of the labyrinth seal structure are effectively improved, providing better airflow stiffness and damping. This helps to suppress the vibration of the rotating shaft, improve the operational stability of the entire rotor system, and better adapt to different working conditions and disturbances. High-resistance, high-mixing, and high-dissipation vortex turbulence can be generated in each elliptical fluid kinetic energy dissipation cavity, effectively enhancing throttling dissipation and significantly weakening the pressure and energy of the fluid medium, further improving the sealing effect.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: an I-shaped arc-shaped elliptical cavity turbulent labyrinth sealing structure, comprising a rotating shaft, a sealing shell, and annular sealing teeth, wherein the sealing shell is coaxially fitted onto the outer side of the sealing section of the rotating shaft; the annular sealing teeth are a plurality of teeth, which are fixedly arranged at equal intervals on the inner surface of the sealing shell; characterized in that: circumferential grooves are provided on the left and right axial side surfaces of the annular sealing teeth, and two circumferential grooves between adjacent annular sealing teeth cooperate to form a fluid kinetic energy dissipation cavity, the cross-sectional shape of which is elliptical, and the fluid kinetic energy dissipation cavity is used to generate vortex turbulence; the radial inner surface of the annular sealing teeth is provided as annular ribs, and the cross-sectional shape of the annular sealing teeth under the cooperation of the circumferential ribs and the circumferential grooves constitutes an I-shaped arc.

[0007] The two circumferential grooves on the left and right axial side surfaces of the annular sealing tooth are distributed in a mirror symmetry, and the mirror symmetry plane is distributed perpendicular to the central axis of the rotation axis.

[0008] The cross-sectional shape of the circumferential groove is arc-shaped.

[0009] The cross-sectional shape of the circumferential rib is arc-shaped, and the radius of the arc of all the circumferential ribs is equal.

[0010] A circumferential groove is provided on the surface of the rotating shaft opposite to the circumferential rib, and a fluid throttling gap is formed between the circumferential groove and the circumferential rib.

[0011] All of the fluid throttling gaps have the same size, and the size range of the fluid throttling gaps is 0.2 mm to 0.4 mm.

[0012] The cross-sectional shape of the circumferential groove is arc-shaped.

[0013] All of the circumferential trenches have the same arc radius.

[0014] The center point of the cross-sectional arc of the circumferential rib coincides with the center point of the cross-sectional arc of the circumferential groove.

[0015] In the axial direction and along the direction of fluid leakage, the extended arc of the front circumferential groove is tangent to the extended arc of the adjacent rear circumferential groove.

[0016] The beneficial effects of this invention are: The I-shaped arc-shaped elliptical chamber turbulent labyrinth seal structure of this invention, through its innovative I-shaped arc-shaped elliptical chamber turbulent design, effectively improves the dynamic characteristics of the labyrinth seal structure, provides better airflow stiffness and damping, helps to suppress the vibration of the rotating shaft, improves the operational stability of the entire rotor system, and can better adapt to different working conditions and disturbances. High-resistance, high-mixing, and high-dissipation vortex turbulence can be generated in each elliptical fluid kinetic energy dissipation cavity, effectively enhancing throttling dissipation, significantly weakening the pressure and energy of the fluid medium, and further improving the sealing effect. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the I-shaped arc-shaped elliptical cavity turbulent labyrinth sealing structure of the present invention; Figure 2 This is a schematic diagram of the fluid medium flow in the I-shaped arc-shaped elliptical cavity turbulent labyrinth sealing structure of the present invention; In the figure, 1—rotating shaft, 2—sealing shell, 3—annular sealing tooth, 4—annular groove, 5—fluid kinetic energy dissipation cavity, 6—annular rib, 7—annular groove, 8—fluid throttling gap. Detailed Implementation

[0018] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0019] like Figure 1 , 2 As shown, an I-shaped arc-shaped elliptical cavity turbulent labyrinth seal structure includes a rotating shaft 1, a sealing shell 2, and annular sealing teeth 3. The sealing shell 2 is coaxially fitted onto the outer side of the sealing section of the rotating shaft 1. A plurality of annular sealing teeth 3 are fixedly arranged at equal intervals on the inner surface of the sealing shell 2. The structure is characterized by: circumferential grooves 4 provided on the left and right axial side surfaces of each annular sealing tooth 3; two annular grooves 4 between adjacent annular sealing teeth 3 cooperate to form a fluid kinetic energy dissipation cavity 5; the cross-sectional shape of the fluid kinetic energy dissipation cavity 5 is elliptical; the fluid kinetic energy dissipation cavity 5 is used to generate vortex turbulence; the radial inner surface of each annular sealing tooth 3 is provided with annular ribs 6; the cross-sectional shape of the annular sealing tooth 3 under the cooperation of the annular ribs 6 and the annular grooves 4 forms an I-shaped arc.

[0020] The two circumferential grooves 4 on the left and right axial side surfaces of the annular sealing tooth 3 are distributed in a mirror symmetry, and the mirror symmetry plane is distributed perpendicular to the central axis of the rotation shaft 1.

[0021] The cross-sectional shape of the circumferential groove 4 is arc-shaped.

[0022] The cross-sectional shape of the circumferential rib 6 is arc-shaped, and the radius of the arc of all the circumferential ribs 6 is equal.

[0023] A circumferential groove 7 is provided on the surface of the rotating shaft 1 opposite to the circumferential rib 6, and a fluid throttling gap 8 is formed between the circumferential groove 7 and the circumferential rib 6.

[0024] All of the fluid throttling gaps 8 have the same size, and the size range of the fluid throttling gaps 8 is 0.2 mm to 0.4 mm.

[0025] The cross-sectional shape of the circumferential groove 7 is arc-shaped.

[0026] All of the circumferential grooves 7 have the same arc radius.

[0027] The center point of the cross-sectional arc of the circumferential rib 6 coincides with the center point of the cross-sectional arc of the circumferential groove 7.

[0028] In the axial direction and along the direction of fluid medium leakage, the arc extension line of the front circumferential groove 7 is tangent to the arc extension line of the adjacent rear circumferential groove 4.

[0029] The following description, in conjunction with the accompanying drawings, illustrates the usage of this invention: In this embodiment, the number of annular sealing teeth 3 is set to five, which are sequentially referred to as the first sealing tooth, the second sealing tooth, the third sealing tooth, the fourth sealing tooth, and the fifth sealing tooth. The fluid kinetic energy dissipation cavity 5 between the first sealing tooth and the second sealing tooth is referred to as the first chamber, the fluid kinetic energy dissipation cavity 5 between the second sealing tooth and the third sealing tooth is referred to as the second chamber, the fluid kinetic energy dissipation cavity 5 between the third sealing tooth and the fourth sealing tooth is referred to as the third chamber, and the fluid kinetic energy dissipation cavity 5 between the fourth sealing tooth and the fifth sealing tooth is referred to as the fourth chamber. The circumferential rib of the first sealing tooth is... The fluid throttling gap 8 formed between the 6 and its corresponding circumferential groove 7 is denoted as the first gap; the fluid throttling gap 8 formed between the circumferential rib 6 of the second sealing tooth and its corresponding circumferential groove 7 is denoted as the second gap; the fluid throttling gap 8 formed between the circumferential rib 6 of the third sealing tooth and its corresponding circumferential groove 7 is denoted as the third gap; the fluid throttling gap 8 formed between the circumferential rib 6 of the fourth sealing tooth and its corresponding circumferential groove 7 is denoted as the fourth gap; and the fluid throttling gap 8 formed between the circumferential rib 6 of the fifth sealing tooth and its corresponding circumferential groove 7 is denoted as the fifth gap.

[0030] During the rotation of the rotating shaft 1, the high-pressure leaking fluid medium first impacts the circumferential groove 4 on the left axial side surface of the first sealing tooth at a certain speed. The arc-shaped cross-section of the circumferential groove 4 causes part of the fluid medium to swirl, while the other part of the fluid medium enters the first gap. According to the Bernoulli equation, under the same medium conditions, the smaller the flow area, the faster the speed and the lower the pressure. Therefore, after the fluid medium flows through the first gap, it will form a jet and rush into the first chamber at high speed. At this time, the high-speed injected fluid medium will have a significant velocity gradient with the stationary gas in the first chamber, thus forming a free shear layer and eventually generating vortex turbulence. The "internal friction" based on vortex turbulence will irreversibly convert the macroscopic jet kinetic energy into heat energy. This process dissipates energy quickly, causing the pressure to drop further.

[0031] Subsequently, the vortex and entrained gas in the first chamber enter the second gap, where the pressure of the fluid medium continues to decrease and its velocity continues to increase. The resulting jet continues to form vortices in the second chamber, further dissipating energy. This process continues, with energy dissipation occurring through the jet in the third gap and the vortex in the third chamber, and then through the jet in the fourth gap and the vortex in the fourth chamber. Ultimately, most of the fluid medium's kinetic energy is irreversibly converted into heat energy. Only a small portion of the fluid medium can leak out through the fifth gap, and the pressure of the fluid medium also decreases, thus achieving the goal of reducing leakage.

[0032] The solutions in the embodiments are not intended to limit the scope of protection of the present invention. All equivalent implementations or modifications that do not depart from the present invention are included in the scope of protection of the present invention.

Claims

1. A T-shaped arc-shaped elliptical cavity turbulent labyrinth seal structure, comprising a rotating shaft, a sealing shell, and annular sealing teeth, wherein the sealing shell is coaxially fitted onto the outer side of the sealing section of the rotating shaft; the annular sealing teeth are a plurality of teeth, which are fixedly arranged at equal intervals on the inner surface of the sealing shell; characterized in that: Circular grooves are provided on both the left and right axial side surfaces of the annular sealing teeth. The two annular grooves between adjacent annular sealing teeth cooperate to form a fluid kinetic energy dissipation cavity. The cross-sectional shape of the fluid kinetic energy dissipation cavity is elliptical. The fluid kinetic energy dissipation cavity is used to generate vortex turbulence. The radial inner surface of the annular sealing teeth is set as an annular rib. The cross-sectional shape of the annular sealing teeth under the cooperation of the annular rib and the annular groove forms an I-shaped arc.

2. The I-shaped arc-shaped elliptical cavity turbulent labyrinth sealing structure according to claim 1, characterized in that: The two circumferential grooves on the left and right axial side surfaces of the annular sealing tooth are distributed in a mirror symmetry, and the mirror symmetry plane is distributed perpendicular to the central axis of the rotation axis.

3. The I-shaped arc-shaped elliptical cavity turbulent labyrinth sealing structure according to claim 1, characterized in that: The cross-sectional shape of the circumferential groove is arc-shaped.

4. The I-shaped arc-shaped elliptical cavity turbulent labyrinth sealing structure according to claim 1, characterized in that: The cross-sectional shape of the circumferential rib is arc-shaped, and the radius of the arc of all the circumferential ribs is equal.

5. The I-shaped arc-shaped elliptical cavity turbulent labyrinth sealing structure according to claim 1, characterized in that: A circumferential groove is provided on the surface of the rotating shaft opposite to the circumferential rib, and a fluid throttling gap is formed between the circumferential groove and the circumferential rib.

6. The I-shaped arc-shaped elliptical cavity turbulent labyrinth sealing structure according to claim 5, characterized in that: All of the fluid throttling gaps have the same size, and the size range of the fluid throttling gaps is 0.2 mm to 0.4 mm.

7. The I-shaped arc-shaped elliptical cavity turbulent labyrinth sealing structure according to claim 6, characterized in that: The cross-sectional shape of the circumferential groove is arc-shaped.

8. The I-shaped arc-shaped elliptical cavity turbulent labyrinth sealing structure according to claim 7, characterized in that: All of the circumferential trenches have the same arc radius.

9. The I-shaped arc-shaped elliptical cavity turbulent labyrinth sealing structure according to claim 7, characterized in that: The center point of the cross-sectional arc of the circumferential rib coincides with the center point of the cross-sectional arc of the circumferential groove.

10. The I-shaped arc-shaped elliptical cavity turbulent labyrinth sealing structure according to claim 7, characterized in that: In the axial direction and along the direction of fluid leakage, the extended arc of the front circumferential groove is tangent to the extended arc of the adjacent rear circumferential groove.

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