A servo finger seal

Abstract

The application discloses a kind of follow-up fingertip sealing devices, it is related to aero-engine sealing technical field, including front baffle, back baffle and follow-up component, front baffle is connected with back baffle by rivet two, follow-up component includes fingertip sealing sheet, rivet one, spacer and gasket, gasket is arranged between front baffle and fingertip sealing sheet, fingertip sealing sheet is arranged between gasket and back baffle, fingertip sealing sheet is provided with fingertip sealing sheet positioning hole, fingertip beam and fingertip shoe, both sides of fingertip beam are provided with beam gap.The application uses the follow-up fingertip sealing device described above, the elasticity of gasket one and gasket two is used to realize that follow-up component follows the radial displacement and automatic reset of rotor runout, to further reduce the wear and tear and delay leakage of fingertip sealing device, back baffle is provided with antifriction groove, back baffle graphite strip and graphite ring to further reduce the delay leakage of fingertip sealing device, with the advantages of low wear, low delay and long service life.

Description

Technical Field

[0001] This invention relates to the field of aero-engine sealing technology, and in particular to a follow-up fingertip sealing device. Background Technology

[0002] As a crucial component of aero engines, the sealing performance of sealing devices has a significant impact on the reliability, fuel economy, and thrust-to-weight ratio of aero engines.

[0003] Finger-tip seals, as an advanced sealing technology, have advantages over toothed seals and brush seals in terms of lower leakage and manufacturing cost, and therefore have good application prospects in secondary flow sealing of aero-engine air systems.

[0004] Finger seals form a contact-type finger seal through an interference fit between the finger shoe and the rotor. A certain contact pressure always exists between the finger shoe and the rotor surface, and the resulting friction and wear will affect the sealing characteristics and service life of the finger seal. Under high-speed rotation, the rotor will inevitably experience radial runout, which further increases the contact pressure, thus exacerbating the friction and wear between the finger shoe and the rotor surface.

[0005] Finger-tip seals, as a novel flexible sealing method, are characterized by their ability to radially displace the fingertip beam structure to accommodate the radial runout of the rotor. However, this characteristic can lead to hysteretic leakage. Hysteretic leakage occurs when the rotor resets due to radial runout, but the fingertip beam, which has undergone radial displacement with the rotor, cannot fully reset due to frictional damping between the fingertip seals and between the fingertip seals and the rear baffle. This results in a gap between the fingertip shoe and the rotor, and the resulting leakage is called hysteretic leakage.

[0006] Generally, changing the radial stiffness of the fingertip beam can reduce wear or hysteresis leakage, but frictional wear and hysteresis leakage in fingertip seals are always contradictory. That is, reducing the radial stiffness of the fingertip beam is beneficial to reducing frictional wear, but at the same time it will exacerbate hysteresis leakage; while increasing the radial stiffness of the fingertip beam is beneficial to reducing hysteresis leakage, but it will exacerbate the wear between the fingertip shoe and the rotor surface.

[0007] Therefore, it is necessary to provide a follow-up fingertip sealing device to solve the above problems. Summary of the Invention

[0008] The purpose of this invention is to provide a follow-up fingertip sealing device, which utilizes the elasticity of gasket one and gasket two to enable the follow-up component to follow the rotor's jump and undergo radial displacement and automatic reset, thereby reducing the wear and hysteresis leakage of the fingertip sealing device. The rear baffle is provided with anti-friction groove, rear baffle graphite strip and graphite ring to further reduce the hysteresis leakage of the fingertip sealing device, and has the advantages of low wear, low hysteresis and long service life.

[0009] To achieve the above objectives, the present invention provides a follower-type fingertip sealing device, comprising a sealing device disposed on a rotor. The sealing device includes a front baffle, a rear baffle, and a follower component. The front baffle and the rear baffle are connected by a second rivet. The follower component includes a fingertip sealing sheet, a first rivet, a spacer, and a gasket. The gasket is disposed between the front baffle and the fingertip sealing sheet, and the fingertip sealing sheet is disposed between the gasket and the rear baffle. The fingertip sealing sheet is provided with a fingertip sealing sheet positioning hole, a fingertip beam, and a fingertip shoe. Beam gaps are provided on both sides of the fingertip beam.

[0010] Preferably, the front baffle is configured as an annular disc structure, the rear baffle is configured as an annular plate structure, the gasket is configured as an annular sheet structure, and the fingertip sealing sheet is configured as an annular structure.

[0011] Preferably, the front baffle includes an inner end face, a connecting surface, and a first stepped surface. A graphite strip is provided on the inner end face, and the inner end face includes a mounting groove and a stepped hole. A rivet hole is provided on the connecting surface.

[0012] Preferably, the rear baffle includes an inner end face, a connecting surface, and a first stepped surface. A graphite strip and a graphite ring are provided on the inner end face of the rear baffle. The graphite ring is circular and has a width and thickness of not less than 1.51 mm. The inner end face of the rear baffle includes a mounting groove, a stepped hole, and a friction-reducing groove. A rivet hole is provided on the connecting surface. The friction-reducing groove has a width of not less than 5 mm and a depth range of 1.51 mm to 2.99 mm.

[0013] Preferably, both the front baffle graphite strip and the rear baffle graphite strip are configured with an arc-shaped structure. The depth of both the front baffle mounting groove and the rear baffle mounting groove is not less than 2 mm. A second washer is provided between the front baffle mounting groove and the rear baffle mounting groove. The thickness of the second washer is in the range of 2 mm to 5 mm. A first washer is provided in the stepped hole of the front baffle and the stepped hole of the rear baffle. The wall thickness of the first washer is not less than 1 mm. Both the first washer and the second washer are made of high-temperature resistant rubber.

[0014] Preferably, the spacer has a T-shaped structure and is axially fixed inside the washer by a rivet.

[0015] Preferably, a plurality of the fingertip sealing sheets are staggered and stacked through the positioning holes of the fingertip sealing sheets, the fingertip beams cover the gaps between adjacent beams and form end face seals, and the fingertip boots and the rotor are interference-fitted to form a contact dynamic seal.

[0016] Preferably, the axial clearance between the lower surface of the spacer and the first stepped surface of the front baffle and the first stepped surface of the rear baffle is in the range of 0.2mm to 0.499mm.

[0017] Therefore, the present invention employs the above-mentioned follow-up fingertip sealing device, which has the following beneficial effects:

[0018] (1) The present invention utilizes the elasticity of gasket one and gasket two to enable the follower component to follow the rotor's jump and undergo radial displacement and automatic reset, which can reduce the contact pressure between the fingertip shoe and the rotor surface, effectively reduce wear and frictional heat, and at the same time reduce the radial displacement of the fingertip beam, thereby effectively reducing the hysteresis leakage of the fingertip sealing device.

[0019] (2) The inner end face of the rear baffle of the present invention is not only provided with friction-reducing groove to reduce the contact area between the fingertip sealing sheet and the rear baffle, but also with graphite strip and graphite ring of the rear baffle. By utilizing the good lubrication properties of graphite, the friction coefficient between the fingertip sealing sheet and the rear baffle is reduced. This measure can effectively reduce the friction damping effect of the rear baffle on the fingertip beam after radial displacement and reset, and further reduce the hysteresis leakage of the fingertip sealing device.

[0020] (3) The present invention has the advantages of low wear, low hysteresis and long life.

[0021] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0022] Figure 1 This is a flowchart of a follow-up fingertip sealing device according to the present invention;

[0023] Figure 2 This is a front view of the front baffle in this invention;

[0024] Figure 3 This is a side view of the front baffle in this invention;

[0025] Figure 4 This is a schematic diagram of the structure of the fingertip sealing sheet in this invention;

[0026] Figure 5 This is an enlarged view of the structure of area I of the fingertip sealing sheet in this invention;

[0027] Figure 6 This is a front view of the rear baffle in this invention;

[0028] Figure 7 This is a side view of the rear baffle in this invention;

[0029] Figure 8 This is an enlarged view of the structure of area I of the rear baffle in this invention;

[0030] Figure 9This is a schematic diagram of the spacer structure in this invention;

[0031] Attached Figure Captions

[0032] 1. Front baffle; 11. Inner end face of front baffle; 12. Connecting surface of front baffle; 13. Rivet hole of front baffle; 14. Graphite strip of front baffle; 15. Mounting groove of front baffle; 16. Stepped hole of front baffle; 17. First stepped surface of front baffle; 2. Washer one; 3. Rivet one; 4. Spacer; 41. Lower surface of spacer; 5. Gasket; 6. Washer two; 7. Finger tip seal; 71. Finger tip seal 72. Finger tip beam; 73. Beam gap; 74. Finger tip shoe; 8. Rivet 2; 9. Rear baffle; 91. Inner end face of rear baffle; 92. Rear baffle connecting surface; 93. Rear baffle rivet hole; 94. Rear baffle graphite strip; 95. Rear baffle mounting groove; 96. Rear baffle stepped hole; 97. Rear baffle first stepped surface; 98. Friction reduction groove; 99. Graphite ring; 10. Rotor. Detailed Implementation

[0033] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0034] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0035] The terms "comprising" or "including" as used in this invention mean that the element preceding the term encompasses the element listed after the term, and do not exclude the possibility of encompassing other elements. Terms such as "inner," "outer," "upper," and "lower" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. When the absolute position of the described object changes, the relative positional relationship may also change accordingly. In this invention, unless otherwise explicitly specified and limited, the term "attached" and similar terms should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral part; it can refer to a direct connection or an indirect connection through an intermediate medium; it can refer to the internal communication of two elements or the interaction relationship between two elements. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0036] like Figure 1As shown, the present invention provides a follower-type fingertip sealing device, including a sealing device disposed on a rotor 10. The sealing device includes a front baffle 1, a rear baffle 9, and a follower component. The front baffle 1 and the rear baffle 9 are connected by a second rivet 8. The follower component includes a fingertip sealing sheet 7, a first rivet 3, a spacer 4, and a gasket 5. The gasket 5 is disposed between the front baffle 1 and the fingertip sealing sheet 7. Figures 4-5 As shown, the fingertip sealing sheet 7 is disposed between the gasket 5 and the rear baffle 9. The fingertip sealing sheet 7 is provided with a fingertip sealing sheet positioning hole 71, a fingertip beam 72, and a fingertip shoe 74. Beam gaps 73 are provided on both sides of the fingertip beam 72. Several fingertip sealing sheets 7 are staggered and stacked through the fingertip sealing sheet positioning holes 71. The fingertip beam 72 covers the adjacent beam gaps 73 and forms an end face seal. The fingertip shoe 74 and the rotor 10 are interference-fitted to form a contact dynamic seal.

[0037] The front baffle 1 is configured as an annular disc structure, the rear baffle 9 is configured as an annular plate structure, the gasket 5 is configured as an annular sheet structure, and the fingertip sealing sheet 7 is configured as an annular structure.

[0038] like Figures 2-3 As shown, the front baffle 1 includes a front baffle inner end face 11, a front baffle connecting face 12, and a front baffle first stepped face 17. A front baffle graphite strip 14 is provided on the front baffle inner end face 11. The front baffle inner end face 11 includes a front baffle mounting groove 15 and a front baffle stepped hole 16. A front baffle rivet hole 13 is provided on the front baffle connecting face 12.

[0039] like Figures 6-8 As shown, the rear baffle 9 includes an inner end face 91, a connecting surface 92, and a first stepped surface 97. A graphite strip 94 and a graphite ring 99 are provided on the inner end face 91. The graphite ring 99 is circular, and its width and thickness are both no less than 1.51 mm. The inner end face 91 includes a mounting groove 95, a stepped hole 96, and a friction-reducing groove 98. A rivet hole 93 is provided on the connecting surface 92. The friction-reducing groove 98 reduces the contact area between the fingertip sealing piece 7 and the inner end face 91, thereby reducing the frictional damping effect of the inner end face 91 during the fingertip beam 72's repositioning process, thus achieving low hysteresis leakage in the fingertip sealing device. To fully utilize the friction-reducing effect, the width of the friction-reducing groove 98 is no less than 5 mm, and its depth ranges from 1.51 mm to 2.99 mm.

[0040] Both the front baffle graphite strip 14 and the rear baffle graphite strip 94 are designed with an arc-shaped structure. The depth of the front baffle mounting groove 15 and the rear baffle mounting groove 95 is not less than 2mm. A second washer 6 is provided between the front baffle mounting groove 15 and the rear baffle mounting groove 95. To ensure the installation reliability of the second washer 6 and the sealing performance of the fingertip sealing device, the thickness of the second washer 6 is in the range of 2mm to 5mm. A first washer 2 is provided in the stepped hole 16 of the front baffle and the stepped hole 96 of the rear baffle. The wall thickness of the first washer 2 is not less than 1mm. The material of the first washer 2 and the second washer 6 is high-temperature resistant rubber.

[0041] like Figure 9 As shown, the spacer 4 has a T-shaped structure and is axially fixed inside the washer 2 by rivets 3. The axial clearance between the lower surface 41 of the spacer and the first stepped surface 17 of the front baffle and the first stepped surface 97 of the rear baffle is 0.2mm to 0.499mm.

[0042] Therefore, the present invention adopts the above-mentioned follow-up fingertip sealing device, which utilizes the elasticity of gasket one and gasket two to realize the follow-up component to follow the jump of the rotor to generate radial displacement and automatic reset, thereby reducing the wear and hysteresis leakage of the fingertip sealing device. The rear baffle is provided with friction-reducing groove, rear baffle graphite strip and graphite ring to further reduce the hysteresis leakage of the fingertip sealing device, which has the advantages of low wear, low hysteresis and long service life.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A follow-up fingertip sealing device, comprising a sealing device disposed on a rotor, characterized in that: The sealing device includes a front baffle, a rear baffle, and a follower component. The front baffle and the rear baffle are connected by a second rivet. The follower component includes a fingertip sealing sheet, a first rivet, a spacer, and a gasket. The gasket is disposed between the front baffle and the fingertip sealing sheet. The fingertip sealing sheet is disposed between the gasket and the rear baffle. The fingertip sealing sheet is provided with a fingertip sealing sheet positioning hole, a fingertip beam, and a fingertip boot. Beam gaps are provided on both sides of the fingertip beam. The front baffle includes an inner end face, a connecting surface, and a first stepped surface. A graphite strip is provided on the inner end face of the front baffle. The inner end face of the front baffle includes a mounting groove and a stepped hole. A rivet hole is provided on the connecting surface. The rear baffle includes an inner end face, a connecting surface, and a first stepped surface. A graphite strip and a graphite ring are provided on the inner end face of the rear baffle. The width and thickness of the graphite ring are both not less than 1.51 mm, and the graphite ring is circular. The inner end face of the rear baffle includes a rear baffle mounting groove, a stepped hole, and a friction-reducing groove. A rivet hole is provided on the connecting surface of the rear baffle. The width of the friction-reducing groove is not less than 5 mm, and the depth range is 1.51 mm to 2.99 mm. Both the front and rear baffle graphite strips are designed with an arc shape. The depth of both the front and rear baffle mounting grooves is not less than 2 mm. A second washer is provided between the front and rear baffle mounting grooves, and the thickness of the second washer is in the range of 2 mm to 5 mm. A first washer is provided in the stepped hole of the front and rear baffles, and the wall thickness of the first washer is not less than 1 mm. Both the first and second washers are made of high-temperature resistant rubber.

2. The follow-up fingertip sealing device according to claim 1, characterized in that: The front baffle is configured as an annular disc structure, the rear baffle is configured as an annular plate structure, the gasket is configured as an annular sheet structure, and the fingertip sealing sheet is configured as an annular structure.

3. The follow-up fingertip sealing device according to claim 1, characterized in that: The spacer has a T-shaped structure and is axially fixed inside the washer by a rivet.

4. The follow-up fingertip sealing device according to claim 1, characterized in that: Several fingertip sealing sheets are staggered and stacked through the positioning holes of the fingertip sealing sheets, the fingertip beams cover the gaps between adjacent beams and form end face seals, and the fingertip boots and the rotor are interference-fitted to form a contact dynamic seal.

5. A follow-up fingertip sealing device according to claim 3, characterized in that: The axial clearance between the lower surface of the spacer and the first stepped surface of the front baffle and the first stepped surface of the rear baffle is in the range of 0.2mm~0.499mm.

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