Contact type flexible mouthpiece sealing structure

Abstract

The invention provides a contact type flexible mouthpiece sealing structure. The contact type flexible mouthpiece sealing structure comprises a baffle ring and a groove. A bristle bundle is arranged at the end part of the baffle ring; the bristle bundle is opposite to the groove; the baffle ring comprises a root part and an end part; the root part of the baffle ring is in smooth transition, a throat part exists between the root part and the end part, the throat part is the narrowest section of the baffle ring, the section of the baffle ring is gradually increased from the throat part to the end part, and the section of the baffle ring is smoothly changed from the root part to the end part; multiple stages of baffle rings are arranged, and the two sides of each stage of baffle ring are arranged in a staggered mode to form a mouthpiece structure; the baffle ring and the bristle bundle are connected through welding, a wear-resistant coating is arranged on the surface of the groove, and the tip end of the bristle bundle right faces the bottom of the groove and abuts against the surface of the groove. According to the invention, the inter-stage gap and the sealing gap of the baffle ring can be effectively reduced, the flow resistance is increased, and the sealing efficiency is improved; meanwhile, the flexible mouthpiece sealing structure can better adapt to the problem of baffle ring collision caused by radial run-out and axial play of the rotor in the field of aero-engines and gas turbines, and the stability of the structure is improved.

Description

Technical Field

[0001] The invention relates to the field of advanced aero-engine and gas turbine sealing, and in particular to a contact-type flexible mouthpiece sealing structure. Background Art

[0002] With the improvement of thermal efficiency of modern aircraft engines, the increase of temperature and pressure ratio in the engine, improving sealing efficiency is of great significance to reducing air loss in the air system and reducing fuel consumption of aircraft engines. Gas intrusion is one of the serious problems that may be encountered in the rotor and stator cavity of aircraft engines. There is inevitably a gap between the rotor and the stator, and the high-temperature gas penetrates into the rotor and stator cavity, which not only causes energy loss between engine stages, but also causes overheating of the disk core, deformation of the wheel and fatigue damage. Aircraft engine sealing devices are mainly used for: fan tip seals, low-pressure compressor tip seals, high-pressure compressor tip and interstage seals, bearing cavity seals, and turbine tip and interstage seals. In the disk edge seal, after the mainstream gas passes through the stationary guide vane, it is affected by 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. In general, alternating high-pressure and low-pressure areas are formed in the circumferential direction of the upper area of ​​the seal outlet. The rotor and stator cavity is aggravated by the uneven external pressure and the pumping effect of the turntable. The gas intrusion effect of the disk edge.

[0003] The traditional disk edge sealing structure has staggered baffle rings at the trailing edges of the rotating disk and the stationary disk. Reducing the baffle ring gap can improve the sealing efficiency, but this is accompanied by the problem of vibration caused by the collision of the baffle rings. Summary of the invention

[0004] Purpose of the invention: The technical problem to be solved by the present invention is to provide a contact-type flexible mouthpiece sealing structure in view of the deficiencies in the prior art. A brush bundle is provided at the end of the baffle ring of the mouthpiece structure, which can ensure a higher sealing efficiency of the baffle ring at the trailing edge of the rotor and stator, reduce the possibility of gas backflow, and reduce the collision vibration problem caused by too small a gap in the baffle ring.

[0005] The present invention provides a contact-type flexible mouthpiece sealing structure, comprising a retaining ring and a groove;

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

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

[0008] The bristle bundle faces the groove;

[0009] The root of the retaining ring is smoothly transitioned, there is a throat between the root and the end, the throat is the narrowest section of the retaining ring, the cross section of the retaining ring gradually increases from the throat to the end, and the cross section of the retaining ring changes smoothly from the root to the end;

[0010] The retaining ring is provided with multiple stages of retaining rings, at least 3 stages. When there are 3 stages, they are respectively recorded as the first stage retaining ring, the second stage retaining ring, and the third stage retaining ring. The first stage retaining ring and the third stage retaining ring are respectively the front stage and the rear stage of the second stage retaining ring, and the second stage retaining ring and the fourth stage retaining ring are respectively the front stage and the rear stage of the third stage retaining ring. The retaining rings of each stage are arranged alternately on both sides to form a mouthpiece structure.

[0011] The throat of the first-stage baffle ring faces the end of the second-stage baffle ring, and the throat of the second-stage baffle ring faces the end of the third-stage baffle ring.

[0012] The baffle 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 inclination angle, the inclination angle is 0-50 degrees, and the length of the bristle bundle is 3-8 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 the baffle rings at each level 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 baffle ring, and the length b of the bristle bundle is greater than 1 / 5 of the length of the baffle 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 the present invention are as follows: the present invention proposes a contact-type flexible mouthpiece sealing structure, and a brush bundle is arranged at the end of the baffle ring of the mouthpiece structure, which can ensure that the sealing efficiency of the baffle ring at the trailing edge of the rotor and stator is higher, reduce the possibility of gas backflow, and reduce the collision vibration problem caused by the small gap of the baffle ring. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0021] Figure 1 Schematic diagram of the contact-type flexible mouthpiece seal.

[0022] Figure 2 Schematic diagram of the axial flow turbine disk rim seal.

[0023] Figure 3 Schematic diagram of the contact-type flexible mouthpiece rim sealing structure.

[0024] Figure 4 Schematic diagram of sealing fluid flow.

[0025] The numbers in the figure are: baffle ring 1, bristle bundle 2, groove 3, stationary guide vane 4, mainstream gas flow channel 5, turbine blade 6, stator disk 7, rotor-stator disk cavity 8, turbine disk 9, throat 11, root 12, end 13. DETAILED DESCRIPTION

[0026] like Figure 1 As shown, the embodiment of the present invention provides a contact-type flexible mouthpiece sealing structure, including a retaining ring 1 and a groove 3;

[0027] The retaining ring 1 comprises 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 faces the groove 3;

[0030] The root 12 of the retaining ring 1 is a smooth transition, and 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 from the root 12 to the end 13, the cross section of the retaining ring 1 changes smoothly;

[0031] The retaining ring 1 is provided with multiple stages of retaining rings, at least 3 stages, namely, a first stage retaining ring, a second stage retaining ring, a third stage retaining ring and a fourth stage retaining ring, etc. The first stage retaining ring and the third stage retaining ring are respectively the front stage and the rear stage of the second stage retaining ring, the second stage retaining ring and the fourth stage retaining ring are respectively the front stage and the rear stage of the third stage retaining ring, and the retaining rings of each stage are arranged alternately on both sides to form a mouthpiece structure.

[0032] The throat 11 of the first-stage retaining ring faces the end 13 of the second-stage retaining ring, and the throat 11 of the second-stage retaining ring faces 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 inclination angle, the inclination angle is 0 to 50 degrees, and the length of the bristle bundle 2 is 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 the baffle rings of each level 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 baffle ring, and the length b of the bristle bundle 2 is greater than 1 / 5 of the length of the baffle ring.

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

[0039] The free end of the bristle bundle 2 and the groove 3 are in contact and friction with each other; the curvature of the free end of the bristle bundle 2 is greater than the curvature of the groove 3.

[0040] Figure 2 The diagram is a schematic diagram of the sealing structure of the axial flow turbine disk edge, including a retaining ring 1, a stationary guide vane 4, a mainstream gas flow channel 5, a turbine blade 6, a stator 7, a rotating stator cavity 8, and a turbine disk 9. The stationary guide vane 4 and the stator 7 are fixedly connected and are stationary parts; the turbine blade 6 and the turbine disk 9 are fixedly connected and are rotating parts. The mainstream gas flow channel 5 is between the stationary guide vane 4 and the turbine blade 6. Since there is an inevitable gap between the dynamic and static machinery, the gas will invade downward into the rotating stator cavity. Therefore, a sealing structure is required to effectively prevent the intrusion of gas.

[0041] Figure 3 The schematic diagram of the contact-type flexible mouthpiece disc edge sealing structure includes a retaining ring 1, a bristle bundle 2, a groove 3, a stationary guide vane 4, a mainstream gas flow channel 5, a turbine blade 6, and a rotor-stator disc cavity 8. The sealing fluid flows as follows Figure 4 As shown in the figure, when the mainstream gas flows through the mainstream gas flow channel 5 to the rotating disc cavity 8, it is blocked by the baffle ring 1, forcing the gas to pass through the gap of the bristle bundle 2; when the uniform airflow passes through the bristle bundle 2 with uneven gaps, the flow direction suddenly changes, forming a co-current flow and jet, accompanied by backflow and eddy current, generating turbulent kinetic energy dissipation, effectively preventing the gas from invading along the wall of the rotating disc, and improving the sealing efficiency. The pressure bearing capacity of the single-stage mouthpiece seal is limited, and the disc edge seal requires at least 3 to 5 levels of sealing.

[0042] The present invention provides a contact-type flexible mouthpiece sealing structure. There are many methods and ways to implement the technical solution. The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention. All components not specified in this embodiment can be implemented by existing technologies.

Claims

1. A contact-type flexible mouthpiece sealing structure, characterized in that: It comprises a retaining ring (1) and a groove (3); The retaining ring (1) comprises a root portion (12) and an end portion (13); The end (13) of the retaining ring (1) is provided with a bristle bundle (2); The bristle bundle (2) faces the groove (3); The root (12) of the retaining ring (1) is smoothly transitioned, a throat (11) is present between the root (12) and the end (13), the throat (11) is the narrowest section of the retaining ring (1), the cross section of the retaining ring (1) gradually increases from the throat (11) to the end (13), 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 stages, at least 3 stages. When there are 3 stages, they are respectively recorded as a first stage retaining ring, a second stage retaining ring, and a third stage retaining ring. The first stage retaining ring and the third stage retaining ring are respectively the front stage and the rear stage of the second stage retaining ring. The retaining rings of each stage are arranged alternately on both sides to form a mouthpiece structure.

2. A contact-type flexible mouthpiece sealing structure according to claim 1, characterized in that: The throat (11) of the first-stage retaining ring faces the end (13) of the second-stage retaining ring, and the throat (11) of the second-stage retaining ring faces the end of the third-stage retaining ring.

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

4. A contact-type flexible mouthpiece sealing 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 inclination angle, the inclination angle is 0 to 50 degrees, and the length of the bristle bundle (2) is 3 to 8 mm.

5. A contact-type flexible mouthpiece sealing structure according to claim 4, characterized in that: The groove (3) is an annular groove.

6. A contact-type flexible mouthpiece sealing 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. A contact-type flexible mouthpiece sealing structure according to claim 6, characterized in that: The spacing a between the baffle rings at each level is greater than the width d of the bristle bundle (2).

8. A contact-type flexible mouthpiece sealing structure according to claim 7, characterized in that: The length b of the bristle bundle (2) is smaller than the length c of the baffle ring, and the length b of the bristle bundle (2) is larger than 1 / 5 of the length of the baffle ring.

9. A contact-type flexible mouthpiece sealing structure according to claim 8, characterized in that: The surface of the groove (3) is coated with a wear-resistant coating.

10. A contact-type flexible mouthpiece sealing 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).

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