Combined non-contact fingertip sealing device with rear baffle provided with reed

Abstract

The invention discloses a combined non-contact fingertip sealing device with a reed on a rear baffle plate. The combined non-contact fingertip sealing device comprises a front baffle plate; the high-pressure fingertip piece is located behind the front baffle, and the high-pressure fingertip piece is provided with a plurality of first fingertip beams; the low-pressure fingertip piece is located behind the high-pressure fingertip piece, and the low-pressure fingertip piece is provided with a plurality of second fingertip beams; the plurality of lift boots extend backwards from the inner ends of the plurality of second fingertip beams respectively; the rear baffle is located behind the low-pressure fingertip piece; the outer edge of each reed is connected with the inner circumferential face of the rear baffle, the multiple reeds are all located on the outer side of the lifting boot, the multiple reeds are arranged in the circumferential direction of the rear baffle at intervals, and each reed obliquely extends backwards and inwards from the front edge of the inner circumferential face of the rear baffle. The combined non-contact fingertip sealing device with the rear baffle provided with the reed has the advantages of being small in hysteresis effect, good in sealing effect and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of turbine mechanical seal, in particular to a combined non-contact finger seal device with spring leaf behind the back plate. BACKGROUND

[0002] The non-contact finger seal is to keep the finger seal leaf and the rotor apart by the dynamic and static pressure effect of the sealing fluid. The rotor will produce radial deviation due to vibration, load change and other factors. In the ideal state, the non-contact finger seal should have good dynamic response ability, and can automatically adjust the sealing gap with the deflection of the rotor, so as to maintain the sealing performance.

[0003] In the related art, the finger seal device has friction between the finger leaf and the back plate. When the finger leaf adjusts dynamically with the rotor, even if the rotor returns to the original position, the friction will hinder the reset of the finger leaf, causing the sealing gap to expand and the leakage to increase. This phenomenon is called "hysteresis effect". SUMMARY

[0004] The present application aims to solve at least one of the technical problems in the prior art. To this end, the present application provides a combined non-contact finger seal device with spring leaf behind the back plate, which has the advantages of small hysteresis effect, good sealing effect and the like.

[0005] To achieve the above-mentioned purpose, according to the embodiment of the present application, a combined non-contact finger seal device with spring leaf behind the back plate is provided, which comprises: a front baffle; a high-pressure finger leaf located behind the front baffle and attached to the front baffle, the high-pressure finger leaf has a plurality of first finger beams, the first finger beams extend in an arc shape from outside to inside; a low-pressure finger leaf located behind the high-pressure finger leaf and attached to the high-pressure finger leaf, the low-pressure finger leaf has a plurality of second finger beams, the second finger beams extend in an arc shape from outside to inside; a plurality of lift boots, the plurality of lift boots respectively extend backward from the inner ends of the plurality of second finger beams; a back plate located behind the low-pressure finger leaf and attached to the low-pressure finger leaf; a plurality of spring leaves, the outer edge of each spring leaf is connected to the inner circumferential surface of the back plate, the plurality of spring leaves are located outside the lift boots, the spring leaves are a plurality of and are arranged in the circumferential direction of the back plate, and each spring leaf extends backward and inward from the front edge of the inner circumferential surface of the back plate.

[0006] The combined non-contact finger seal device with spring leaf behind the back plate according to the embodiment of the present application has the advantages of small hysteresis effect, good sealing effect and the like.

[0007] In addition, the combined non-contact fingertip sealing device with a reed on the tailgate according to the above embodiment of the present invention may also have the following additional technical features: According to one embodiment of the present invention, the spring plate is a memory alloy and has a high temperature state and a low temperature state. In the high temperature state, the inscribed circle diameter of the inner edge of the spring plate is equal to the circumscribed circle diameter of the outer surface of the lift boot. In the low temperature state, the inscribed circle diameter of the inner edge of the spring plate is greater than the circumscribed circle diameter of the outer surface of the lift boot.

[0008] According to one embodiment of the present invention, the spring is made of piezoelectric material or magnetostrictive material and has a first state and a second state. When the spring is in the first state, the inscribed circle diameter of the inner edge is equal to the circumscribed circle diameter of the outer surface of the lift shoe. When the spring is in the second state, the inscribed circle diameter of the inner edge is greater than the circumscribed circle diameter of the outer surface of the lift shoe.

[0009] According to one embodiment of the present invention, the spring is trapezoidal and the length of the outer base is smaller than the length of the inner base.

[0010] According to one embodiment of the present invention, the angle between the spring and the front-back direction is 30-60 degrees.

[0011] According to one embodiment of the present invention, the first fingertip beam and the second fingertip beam have the same rotation direction.

[0012] According to one embodiment of the present invention, the first fingertip beam and the second fingertip beam have the same linear shape.

[0013] According to one embodiment of the present invention, there is a first gap between every two adjacent first fingertip beams, and there is a second gap between every two adjacent second fingertip beams, and multiple first gaps and multiple second gaps do not overlap in the front-to-back direction.

[0014] According to one embodiment of the present invention, the axial dimension of the reed is 1-8 mm and the thickness is 0.1-0.5 mm, the axial dimension of the rear baffle is greater than or equal to the axial dimension of the reed, the axial dimension of the lift boot is greater than or equal to the axial dimension of the reed, and the gap between the inner end of the reed and the lift boot is less than or equal to 0.15 mm.

[0015] According to one embodiment of the present invention, the lift boot and the low-pressure fingertip sheet are integrally formed.

[0016] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which: Figure 1 2 is a partial cross-sectional view of a combined non-contact fingertip seal device with a spring for a tailgate according to an embodiment of the present invention.

[0018] Figure 2 1 is a schematic structural diagram of a rear baffle and a reed of a combined non-contact fingertip sealing device with a rear baffle and a reed according to an embodiment of the present invention.

[0019] Figure 3 1 is a partial structural diagram of a combined non-contact fingertip sealing device with a reed on a rear baffle according to an embodiment of the present invention.

[0020] Figure 4 2 is a partial cross-sectional view of a combined non-contact fingertip seal device with a spring for a tailgate according to an embodiment of the present invention.

[0021] Figure numerals: combined non-contact fingertip sealing device 1 with reed on the rear baffle, front baffle 10, high-pressure fingertip sheet 20, first fingertip beam 21, first gap 22, low-pressure fingertip sheet 30, second fingertip beam 31, second gap 32, lift boot 40, rear baffle 50, reed 60, rotor 2. DETAILED DESCRIPTION

[0022] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0023] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, features defined as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, "multiple" means two or more. In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0024] The following describes a combined non-contact fingertip sealing device 1 with a spring for a tailgate according to an embodiment of the present invention with reference to the accompanying drawings.

[0025] like Figures 1-4 As shown, the combined non-contact fingertip sealing device 1 with reeds for the tailgate according to an embodiment of the present invention includes a front tailgate 10, a high-pressure fingertip sheet 20, a low-pressure fingertip sheet 30, a plurality of lift boots 40, a tailgate 50 and a plurality of reeds 60 (the front-to-back and inside-outside directions are indicated by the arrows in the figure).

[0026] The high-pressure fingertip 20 is located behind the front fender 10 and is in contact with the front fender 10. The high-pressure fingertip 20 has a plurality of first fingertip beams 21 that extend in an arc from the outside to the inside. The low-pressure fingertip 30 is located behind the high-pressure fingertip 20 and is in contact with the high-pressure fingertip 20. The low-pressure fingertip 30 has a plurality of second fingertip beams 31 that extend in an arc from the outside to the inside. A plurality of lift boots 40 extend rearward from the inner ends of the plurality of second fingertip beams 31. The rear fender 50 is located behind the low-pressure fingertip 30 and is in contact with the low-pressure fingertip 30. The outer edge of each reed 60 is connected to the inner circumference of the rear fender 50. The plurality of reeds 60 are located outside the lift boots 40. There are multiple reeds 60 and they are spaced apart along the circumference of the rear fender 50. Each reed 60 extends rearward and inward from the front edge of the inner circumference of the rear fender 50.

[0027] It should be understood that the "high" and "low" of the high-pressure fingertip 20 and the low-pressure fingertip 30 are relative. Since the fluid flows from the high-pressure side to the low-pressure side, the fingertip relatively close to the high-pressure side is called the high-pressure fingertip 20, and the fingertip relatively close to the low-pressure side is called the low-pressure fingertip 30. The figure shows an embodiment in which the fluid flows from front to back. The direction of fluid flow is as follows: Figure 1 Indicated by the hollow arrow.

[0028] Specifically, the high-pressure fingertip sheet 20 includes a first outer ring and multiple first fingertip beams 21, the low-pressure fingertip sheet 30 includes a second outer ring and multiple second fingertip beams 31, the front baffle 10 is fitted with the first outer ring, and the rear baffle 50 is fitted with the second outer ring.

[0029] The reed 60 is capable of radial deformation. After the lift boot 40 is deformed by the hydrostatic and dynamic effects of the fluid, the low-pressure fingertip 30 is deformed. When the lift boot 40 strikes the inner end of the reed 60, the reed 60 can further deform radially. Simultaneously, the overall radial deformation stiffness of the low-pressure fingertip 30, lift boot 40, and reed 60 changes.

[0030] According to the combined non-contact fingertip sealing device 1 with a reed on the rear baffle according to an embodiment of the present invention, a plurality of reeds 60 are provided, and the outer edges of the reeds 60 are connected to the inner circumference of the rear baffle 50. Each reed 60 extends backward and inward from the front edge of the inner circumference of the rear baffle 50. Compared with the rear baffle structure in the related art that is in overall contact with the fingertip sheet, the reed 60 is not in direct contact with the low-pressure fingertip sheet 30 or is in limited contact with the edge only, which can slow down the hysteresis effect caused by friction and avoid the increase in leakage caused by the increase in the gap due to the hysteresis effect, thereby improving the sealing performance and reducing the leakage.

[0031] Furthermore, since each reed 60 extends backward and inward from the front edge of the inner circumferential surface of the rear baffle 50, the reed 60 has the ability to deform radially. When the rotor 2 undergoes radial runout, the sealing gap between the rotor 2 and the lift boot 40 is adaptively adjusted along with the rotor 2, thereby facilitating the follow-up of the low-pressure fingertip 30 and the lift boot 40 when the rotor 2 undergoes radial runout, thereby eliminating unnecessary friction and wear.

[0032] Furthermore, by providing the elastic hollow layer 60, compared with the technical solution of providing a retaining ring between the rear baffle and the low-pressure fingertip sheet in the related art, not only the retaining ring can be eliminated, but also the contact area and sliding friction can be reduced, thereby more effectively reducing the hysteresis effect.

[0033] Therefore, the combined non-contact fingertip sealing device 1 with a reed for the tailgate according to the embodiment of the present invention has the advantages of small hysteresis effect and good sealing effect.

[0034] The following describes a combined non-contact fingertip sealing device 1 with a spring for a tailgate according to a specific embodiment of the present invention with reference to the accompanying drawings.

[0035] In some specific embodiments of the present invention, Figures 1-4 As shown, the combined non-contact fingertip sealing device 1 with reeds for the tailgate according to an embodiment of the present invention includes a front tailgate 10 , a high-pressure fingertip sheet 20 , a low-pressure fingertip sheet 30 , a plurality of lift boots 40 , a tailgate 50 and a plurality of reeds 60 .

[0036] The deformation of the reed 60 can have a large inner diameter state and a small inner diameter state. In the small inner diameter state, the inscribed circle diameter of the inner edge of the reed 60 is equal to the circumscribed circle diameter of the outer surface of the lift boot 40. In the second state, the inscribed circle diameter of the inner edge of the reed 60 is greater than the circumscribed circle diameter of the outer surface of the lift boot 40.

[0037] In some embodiments, the reed 60 is made of a memory alloy and has a high-temperature state and a low-temperature state. In the high-temperature state, the inscribed diameter of the inner edge of the reed 60 is equal to the circumscribed diameter of the outer surface of the lift shoe 40. In the low-temperature state, the inscribed diameter of the inner edge of the reed 60 is greater than the circumscribed diameter of the outer surface of the lift shoe 40. This allows the inscribed diameter of the inner edge of the reed 60 to be adjusted under different operating temperatures to adjust the support capacity of the reed 60 for the lift shoe 40, reduce leakage variations caused by thermal effects such as thermal expansion, and provide better sealing capabilities under different temperature environments.

[0038] In other embodiments, the reed 60 is made of a piezoelectric or magnetostrictive material and has a first state and a second state. In the first state, the inscribed diameter of the inner edge of the reed 60 is equal to the circumscribed diameter of the outer surface of the lift shoe 40. In the second state, the inscribed diameter of the inner edge of the reed 60 is greater than the circumscribed diameter of the outer surface of the lift shoe 40. Specifically, the reed 60 can switch between the first and second states under the influence of an electric field and / or a magnetic field. For example, during the startup phase of the rotor 2, the reed 60 switches to the second state. Under high temperature, high pressure, and high speed conditions, the reed 60 switches to the first state. This allows the inscribed diameter of the inner edge of the reed 60 to be adjusted under different operating conditions of temperature, pressure differential, and speed to adjust the support capacity of the reed 60 for the lift shoe 40, reduce leakage variations caused by thermal effects such as thermal expansion, and achieve better sealing capabilities under different temperature environments.

[0039] Specifically, if Figure 2 and Figure 3 As shown, the reed 60 is trapezoidal and the length of the outer bottom side is less than the length of the inner bottom side. This makes it easier for the reed 60 to deform and support the lifting shoe 40.

[0040] More specifically, the angle between the reed 60 and the front-rear direction is 30-60 degrees, which makes it easier for the reed 60 to deform and support the lifting shoe 40.

[0041] Advantageously, the first fingertip beam 21 and the second fingertip beam 31 have the same rotational direction. Specifically, the rotational directions of the first fingertip beam 21 and the second fingertip beam 31 are both in the same direction as the rotational direction of the rotor 2. For example, when viewed from the same direction, if the rotor 2 rotates clockwise, the first fingertip beam 21 and the second fingertip beam 31 both extend in an arc shape from outward to inward in a clockwise direction. This allows the fluid interaction and deformation modes of the first fingertip beam 21 and the second fingertip beam 31 to be more similar, facilitating smooth rotation of the rotor 2.

[0042] Advantageously, the first fingertip beam 21 and the second fingertip beam 31 have the same linear shape. Specifically, the linear shapes of the first fingertip beam 21 and the second fingertip beam 31 can be arc-shaped, involute-shaped, or spiral-shaped. This allows the fluid interaction and deformation modes of the first fingertip beam 21 and the second fingertip beam 31 to be more similar, and avoids leakage caused by overlapping gaps.

[0043] Furthermore, if Figure 4 As shown, a first gap 22 is defined between each pair of adjacent first fingertip beams 21, and a second gap 32 is defined between each pair of adjacent second fingertip beams 31. The plurality of first gaps 22 and the plurality of second gaps 32 do not overlap in the front-to-back direction. Specifically, the projection of the second gaps 32 onto a plane perpendicular to the front-to-back direction lies within the first fingertip beams 21, and the projection of the first gaps 22 onto a plane perpendicular to the front-to-back direction lies within the second fingertip beams 31. This reduces leakage caused by gaps at the fingertips of the fingertip beams, further improving the sealing effect.

[0044] Optionally, the reed 60 has an axial dimension of 1-8 mm and a thickness of 0.1-0.5 mm, the rear baffle 50 has an axial dimension greater than or equal to the axial dimension of the reed 60, the lift shoe 40 has an axial dimension greater than or equal to the axial dimension of the reed 60, and the dimension difference is less than or equal to 0.75 mm, and the gap between the inner end of the reed 60 and the lift shoe 40 is less than or equal to 0.15 mm. This ensures that the reed 60 has a reasonable size, improves the supporting effect of the reed 60, and facilitates deformation of the reed 60.

[0045] Specifically, the reed 60 is welded to the tailgate 50, and the lift boot 40 and low-pressure fingertip 30 are integrally formed. Specifically, the lift boot 40 and low-pressure fingertip 30 can be first machined into an L-shaped structure, and then gaps are machined using electrospark machining to form multiple cantilever beams and lift boots 40. This facilitates the processing and manufacturing of the combined non-contact fingertip seal device 1 for the tailgate with a reed, improving connection strength and reliability.

[0046] Other structures and operations of the combined non-contact fingertip sealing device 1 with a reed for a tailgate according to the embodiment of the present invention are well known to those skilled in the art and will not be described in detail here.

[0047] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative uses of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0048] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

Claims

1. A combined non-contact fingertip sealing device with a reed on the rear baffle, characterized in that: include: front fender; A high-voltage fingertip sheet, located behind the front baffle and in contact with the front baffle, having a plurality of first fingertip beams extending in an arc shape from outside to inside; A low-pressure fingertip sheet, the low-pressure fingertip sheet is located behind the high-pressure fingertip sheet and is in contact with the high-pressure fingertip sheet, the low-pressure fingertip sheet has a plurality of second fingertip beams, and the second fingertip beams extend in an arc shape from outside to inside; a plurality of lift boots, each of the plurality of lift boots extending rearward from an inner end of each of the plurality of second fingertip beams; a rear baffle, the rear baffle being located behind the low-pressure fingertip sheet and being in contact with the low-pressure fingertip sheet; A plurality of reeds, the outer edge of each reed being connected to the inner circumference of the tailgate, the plurality of reeds being located on the outside of the lift boot, the plurality of reeds being spaced apart along the circumference of the tailgate, and each reed extending obliquely backward and inward from the front edge of the inner circumference of the tailgate.

2. The combined non-contact fingertip sealing device with a reed for the tailgate according to claim 1, characterized in that: The spring is a memory alloy and has a high temperature state and a low temperature state. In the high temperature state, the inscribed circle diameter of the inner edge of the spring is equal to the circumscribed circle diameter of the outer surface of the lift boot. In the low temperature state, the inscribed circle diameter of the inner edge of the spring is greater than the circumscribed circle diameter of the outer surface of the lift boot.

3. The combined non-contact fingertip sealing device with a reed for the tailgate according to claim 1, characterized in that: The spring is made of piezoelectric material or magnetostrictive material and has a first state and a second state. When the spring is in the first state, the inscribed circle diameter of the inner edge is equal to the circumscribed circle diameter of the outer surface of the lift shoe. When the spring is in the second state, the inscribed circle diameter of the inner edge is greater than the circumscribed circle diameter of the outer surface of the lift shoe.

4. The combined non-contact fingertip sealing device with a reed for the tailgate according to claim 1, characterized in that: The spring piece is trapezoidal and the length of the outer bottom side is smaller than the length of the inner bottom side.

5. The combined non-contact fingertip sealing device with a reed for the tailgate according to claim 1, characterized in that: The angle between the spring and the front-back direction is 30-60 degrees.

6. The combined non-contact fingertip sealing device with a reed for the tailgate according to claim 1, characterized in that: The first fingertip beam and the second fingertip beam have the same rotation direction.

7. The combined non-contact fingertip sealing device with a reed for the tailgate according to claim 1, characterized in that: The first fingertip beam and the second fingertip beam have the same linear shape.

8. The combined non-contact fingertip sealing device with a reed for the tailgate according to claim 1, characterized in that: There is a first gap between every two adjacent first fingertip beams, and there is a second gap between every two adjacent second fingertip beams. The first gaps and the second gaps do not overlap in the front-to-back direction.

9. The combined non-contact fingertip sealing device with a reed for a tailgate according to claim 1, characterized in that: The axial dimension of the reed is 1-8 mm and the thickness is 0.1-0.5 mm, the axial dimension of the rear baffle is greater than or equal to the axial dimension of the reed, the axial dimension of the lift boot is greater than or equal to the axial dimension of the reed, and the gap between the inner end of the reed and the lift boot is less than or equal to 0.15 mm.

10. The combined non-contact fingertip sealing device with a reed for the tailgate according to claim 1, characterized in that: The lifting boot and the low-pressure fingertip sheet are integrally formed.

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