A contact-type flexible bite seal structure

Abstract

This invention provides a contact-type flexible bite seal structure, including a retaining ring and a groove. The retaining ring has a bristle bundle at its end, facing the groove. The retaining ring includes a root and an end. The root of the retaining ring has a smooth transition, and a throat exists between the root and the end, which is the narrowest section of the retaining ring. From the throat to the end, the cross-section of the retaining ring gradually increases, and the cross-section changes smoothly from the root to the end. The retaining ring has multiple levels, with each level arranged alternately on both sides to form the bite structure. The retaining ring and the bristle bundle are connected by welding. The surface of the groove has a wear-resistant coating, and the tips of the bristle bundle face the bottom of the groove and abut against the groove surface. This invention can effectively reduce the inter-level gaps and sealing gaps of the retaining rings, increase flow resistance, and improve sealing efficiency. Simultaneously, the flexible bite seal structure can better adapt to the problem of retaining ring collisions caused by radial runout and axial movement of rotors in the field of aero-engines and gas turbines, improving the stability of the structure.

Description

Technical Field

[0001] This invention relates to the field of advanced aero-engine and gas turbine sealing, specifically to a contact-type flexible bite seal structure. Background Technology

[0002] With the improvement of thermal efficiency and the increase in internal temperature and pressure ratio of modern aero engines, improving sealing efficiency is of great significance for reducing air loss in the air system and reducing fuel consumption of aero engines. Gas intrusion is one of the serious problems that aero engines may encounter in the rotor-stationary disk cavity. An unavoidable gap exists between the rotor and stationary disks, allowing high-temperature gas to penetrate deep into the rotor-stationary disk cavity, leading not only to interstage energy loss but also to disk core overheating, disk deformation, and fatigue damage. Aero engine sealing devices are mainly used for: fan blade tip seals, low-pressure compressor blade tip seals, high-pressure compressor blade tip and interstage seals, bearing cavity seals, and turbine blade tip and interstage seals. In disk rim sealing, after the mainstream gas passes through the stationary guide vane, it is affected by the interaction of the high-pressure area at the trailing edge of the stationary guide vane and the high-pressure area at the leading edge of the turbine blade. Generally, alternating high-pressure and low-pressure areas are formed circumferentially in the upper region of the seal outlet. The uneven external pressure and the pumping effect of the rotor exacerbate the disk rim gas intrusion effect in the rotor-stationary disk cavity.

[0003] Traditional disc rim sealing structures use staggered retaining rings at the trailing edges of the turntable and stationary disc. Reducing the gap between the retaining rings can improve sealing efficiency, but it also causes vibration due to the collision of the retaining rings. Summary of the Invention

[0004] Purpose of the invention: The technical problem to be solved by the present invention is to address the shortcomings of the prior art by providing a contact-type flexible bite sealing structure. The bite structure has a bristle bundle at the end of the retaining ring, which can ensure higher sealing efficiency of the retaining ring at the tail edge of the rotating plate, reduce the possibility of gas backflow, and reduce the collision and vibration problems caused by the insufficient gap of the retaining ring.

[0005] This invention provides a contact-type flexible bite seal structure, including a retaining ring and a groove;

[0006] The retaining ring includes a root and an end;

[0007] The end of the retaining ring is provided with a bristle bundle;

[0008] The bristle bundles are aligned with the groove;

[0009] The root of each retaining ring is a smooth transition, and there is a throat between the root and the end. The throat is the narrowest section of the retaining ring. From the throat to the end, the cross-section of the retaining ring gradually increases, and the cross-section of the retaining ring changes smoothly from the root to the end.

[0010] The retaining ring is provided with multiple levels of retaining rings, at least 3 levels. When there are 3 levels, they are respectively referred to as the first level retaining ring, the second level retaining ring, and the third level retaining ring. The first level retaining ring and the third level retaining ring are respectively the preceding and following levels of the second level retaining ring, and the second level retaining ring and the fourth level retaining ring are the preceding and following levels of the third level retaining ring. The retaining rings of each level are arranged alternately on both sides to form a bite structure.

[0011] The throat of the first-stage retaining ring is directly opposite the end of the second-stage retaining ring, and the throat of the second-stage retaining ring is directly opposite the end of the third-stage retaining ring.

[0012] The retaining ring and the bristle bundle are connected by welding.

[0013] The bristle bundle is an elastic circular cross-section metal wire bundle with a certain circumferential tilt angle, the tilt angle being 0 to 50°, and the bristle bundle length being 3 to 8 mm.

[0014] The groove is an annular groove.

[0015] The free end of the bristle bundle is arc-shaped, and the tip of the bristle bundle abuts against the groove.

[0016] The spacing 'a' between each level of retaining rings is greater than the width 'd' of the bristle bundle, the length 'b' of the bristle bundle is less than the length 'c' of the retaining ring, and the length 'b' of the bristle bundle is greater than 1 / 5 of the length of the retaining ring.

[0017] The surface of the groove is coated with a wear-resistant coating.

[0018] The curvature of the free end of the bristle bundle is greater than the curvature of the groove.

[0019] The beneficial effects of this invention are as follows: This invention proposes a contact-type flexible bite sealing structure. The end of the retaining ring of the bite structure is provided with a bristle bundle, which can ensure higher sealing efficiency of the retaining ring at the tail edge of the rotating stationary disc, reduce the possibility of gas backflow, and reduce the collision and vibration problems caused by the excessively small gap of the retaining ring. Attached Figure Description

[0020] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, and the advantages of the present invention in the above and / or other aspects will become clearer.

[0021] Figure 1 This is a schematic diagram of a contact-type flexible bite seal.

[0022] Figure 2 This is a schematic diagram of the edge seal of an axial flow turbine disk.

[0023] Figure 3 This is a schematic diagram of the contact-type flexible bite plate edge sealing structure.

[0024] Figure 4 This is a schematic diagram of the fluid flow in the sealing zone.

[0025] The numbers in the diagram are: 1. retaining ring; 2. bristle bundle; 3. groove; 4. stationary guide vane; 5. main gas flow channel; 6. turbine blade; 7. stationary disc; 8. rotating and stationary disc cavity; 9. turbine disc; 11. throat; 12. root; 13. end. Detailed Implementation

[0026] like Figure 1 As shown, this embodiment of the invention proposes a contact-type flexible bite seal structure, including a retaining ring 1 and a groove 3;

[0027] The retaining ring 1 includes a root portion 12 and an end portion 13;

[0028] The end 13 of the retaining ring 1 is provided with a bristle bundle 2;

[0029] The bristle bundle 2 is directly opposite the groove 3;

[0030] The root 12 of the retaining ring 1 is a smooth transition. There is a throat 11 between the root 12 and the end 13. The throat 11 is the narrowest section of the retaining ring 1. From the throat 11 to the end 13, the cross section of the retaining ring 1 gradually increases, and the cross section of the retaining ring 1 changes smoothly from the root 12 to the end 13.

[0031] The retaining ring 1 is provided with multiple levels of retaining rings, at least 3 levels, namely a first-level retaining ring, a second-level retaining ring, a third-level retaining ring, and a fourth-level retaining ring, etc. The first-level retaining ring and the third-level retaining ring are respectively the preceding and following levels of the second-level retaining ring, and the second-level retaining ring and the fourth-level retaining ring are the preceding and following levels of the third-level retaining ring. The retaining rings of each level are arranged alternately on both sides to form a bite structure.

[0032] The throat 11 of the first-stage retaining ring is directly opposite the end 13 of the second-stage retaining ring, and the throat 11 of the second-stage retaining ring is directly opposite the end of the third-stage retaining ring. And so on.

[0033] The retaining ring 1 and the bristle bundle 2 are connected by welding.

[0034] The bristle bundle 2 is an elastic circular cross-section metal wire bundle with a certain circumferential tilt angle, the tilt angle being 0 to 50°, and the length of the bristle bundle 2 being 3 to 8 mm.

[0035] The groove 3 is an annular groove.

[0036] The free end of the bristle bundle 2 is arc-shaped, and the tip of the bristle bundle 2 abuts against the groove 3.

[0037] The spacing 'a' between each level of retaining rings is greater than the width 'd' of the bristle bundle 2, the length 'b' of the bristle bundle 2 is less than the length 'c' of the retaining ring, and the length 'b' of the bristle bundle 2 is greater than 1 / 5 of the length of the retaining ring.

[0038] The surface of the groove 3 is coated with a wear-resistant coating to reduce frictional wear between the bristle bundle 2 and the groove 3.

[0039] The free end of the bristle bundle 2 comes into contact with and rubs against the groove 3; the curvature of the free end of the bristle bundle 2 is greater than the curvature of the groove 3.

[0040] Figure 2 This is a schematic diagram of an axial-flow turbine disk sealing structure, including a retaining ring 1, a stationary guide vane 4, a main gas flow channel 5, turbine blades 6, a stationary disk 7, a rotating-stationary disk cavity 8, and a turbine disk 9. The stationary guide vane 4 and stationary disk 7 are fixedly connected and are stationary components; the turbine blades 6 and turbine disk 9 are fixedly connected and are rotating components. The main gas flow channel 5 is located between the stationary guide vane 4 and the turbine blades 6. Due to the unavoidable gap between the moving and stationary components, gas can flow downwards into the rotating-stationary disk cavity. Therefore, a sealing structure is needed to effectively prevent gas intrusion.

[0041] Figure 3 This is a schematic diagram of a contact-type flexible bite nozzle edge sealing structure, including a retaining ring 1, a bristle bundle 2, a groove 3, a stationary guide vane 4, a main gas flow channel 5, a turbine blade 6, and a rotating and stationary disc cavity 8. The sealing fluid flow is as follows... Figure 4 As shown, when the mainstream gas flows through the mainstream gas flow channel 5 to the rotating disk cavity 8, it is blocked by the baffle ring 1, forcing the gas to pass through the gaps in the bristle bundles 2. When the uniform airflow passes through the non-uniformly spaced bristle bundles 2, the flow direction changes abruptly, forming a co-current flow and jet, accompanied by backflow and eddies, generating turbulent kinetic energy dissipation, effectively preventing the gas from intruding along the rotating disk wall, and improving the sealing efficiency. Single-stage bite seals have limited pressure resistance; disk edge sealing requires at least 3 to 5 stages of sealing.

[0042] This invention provides a contact-type flexible bite seal structure. Many methods and approaches exist for implementing this technical solution; the above description is merely a preferred embodiment of the invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications should also be considered within the scope of protection of this invention. All components not explicitly stated in this embodiment can be implemented using existing technologies.

Claims

1. A contact-type flexible bite seal structure, characterized in that, Includes a retaining ring (1) and a groove (3); The retaining ring (1) includes a root (12) and an end (13); The end (13) of the retaining ring (1) is provided with a bristle bundle (2); The bristle bundle (2) is directly opposite the groove (3); The root (12) of the retaining ring (1) is a smooth transition. There is a throat (11) between the root (12) and the end (13). The throat (11) is the narrowest section of the retaining ring (1). From the throat (11) to the end (13), the cross section of the retaining ring (1) gradually increases, and the cross section of the retaining ring (1) changes smoothly from the root (12) to the end (13). The retaining ring (1) is provided with multiple levels, at least 3 levels. When there are 3 levels, they are respectively called the first level retaining ring, the second level retaining ring, and the third level retaining ring. The first level retaining ring and the third level retaining ring are respectively the front and rear levels of the second level retaining ring. The retaining rings of each level are arranged alternately on both sides to form a bite structure.

2. The contact-type flexible bite seal structure according to claim 1, characterized in that, The throat (11) of the first-stage retaining ring is directly opposite the end (13) of the second-stage retaining ring, and the throat (11) of the second-stage retaining ring is directly opposite the end of the third-stage retaining ring.

3. The contact-type flexible bite seal structure according to claim 2, characterized in that, The retaining ring (1) and the bristle bundle (2) are connected by welding.

4. The contact-type flexible bite seal structure according to claim 3, characterized in that, The bristle bundle (2) is an elastic circular cross-section metal wire bundle with a certain circumferential tilt angle of 0 to 50° and a bristle bundle (2) length of 3 to 8 mm.

5. The contact-type flexible bite seal structure according to claim 4, characterized in that, The groove (3) is an annular groove.

6. The contact-type flexible bite seal structure according to claim 5, characterized in that, The free end of the bristle bundle (2) is arc-shaped, and the tip of the bristle bundle (2) abuts against the groove (3).

7. The contact-type flexible bite seal structure according to claim 6, characterized in that, The spacing a between the various levels of retaining rings is greater than the width d of the bristle bundle (2).

8. The contact-type flexible bite seal structure according to claim 7, characterized in that, The length b of the bristle bundle (2) is less than the length c of the retaining ring, and the length b of the bristle bundle (2) is greater than 1 / 5 of the length of the retaining ring.

9. The contact-type flexible bite seal structure according to claim 8, characterized in that, The groove (3) is coated with a wear-resistant coating.

10. A contact-type flexible bite seal structure according to claim 9, characterized in that, The curvature of the free end of the bristle bundle (2) is greater than the curvature of the groove (3).

Images