A fingertip seal static characteristic experiment device for measuring fingertip seal sheet stiffness

Abstract

The application relates to a fingertip seal static characteristic experiment device, which comprises a box body, a measuring device, a rotor (14) and a rotor displacement structure; the rotor displacement structure comprises a worm shaft a (16), a worm shaft b (23), a rotor shaft (15) and a driving part; the worm shaft a (16) and the worm shaft b (23) are rotatably arranged on the box body in the vertical direction; the rotor shaft (15) is fixedly connected with the rotor (14) and the ends of the rotor shaft (15) are respectively engaged with the worm shaft a (16) and the worm shaft b (23); and the driving part drives the worm shaft a (16) and the worm shaft b (23) to rotate; the measuring device comprises an eddy current displacement sensor (11) and a resistance strain gauge (12) for measuring the strain of the rotor (14), and the resistance strain gauge (12) is arranged outside the rotor (14). Compared with the prior art, the device has the advantages of simple operation, reliable structure, long service life and the like.

Description

Technical Field

[0001] This invention relates to the field of mechanical seal technology, and in particular to a test device for measuring the static characteristics of fingertip seals, specifically for measuring the stiffness of fingertip seal plates. Background Technology

[0002] The aerospace industry is a crucial area for measuring a nation's comprehensive strength, and the performance of sealing devices has a decisive impact on the operating performance, lifespan, and stability of aero-engines. Therefore, the development of sealing device technology is of paramount importance to the aerospace field. Seals used in aero-engines generally include labyrinth seals, film seals, and brush seals. Among these, brush seals are characterized by their small size and light weight, but they suffer from hysteresis and wear issues, are prone to wire breakage, and have relatively high manufacturing costs and complex processes. In contrast, fingertip seals, invented based on the brush seal principle, offer lower leakage and longer lifespan compared to other sealing methods, while also reducing manufacturing and operating costs. Therefore, they are widely used and gradually replacing other seal types. Currently, scholars from various countries are using different methods to study the various performance characteristics of fingertip seals.

[0003] However, in the existing technology, there are few testing devices for the static characteristics of fingertip seals, and they are all relatively complex, difficult to operate, and have unstable structures. They also have problems such as high cost, high maintenance cost, and inconvenient installation. Summary of the Invention

[0004] The purpose of this invention is to overcome the defects of the prior art and provide a fingertip sealing static characteristic test device that is structurally reliable, has a long service life, and is easy to operate.

[0005] The objective of this invention can be achieved through the following technical solutions: A static characteristic test device for fingertip seals includes: a housing, a measuring device, and a rotor; the measuring device includes an eddy current displacement sensor and a resistance strain gauge for measuring the strain of the rotor; a rotor displacement structure mounted on the housing and used to drive the rotor to move up and down includes a worm shaft a, a worm shaft b, a rotor shaft fixedly connected to the inner ring of the rotor and whose ends mesh with the worm shaft a and the worm shaft b respectively, and a driving component for driving the worm shaft a and the worm shaft b to rotate.

[0006] Furthermore, the housing includes a lower housing, a housing cover, an upper housing, a bearing cover, and a bearing end cover; the bearing cover and the bearing end cover fix the rotor displacement structure inside the housing; the housing cover is installed above the lower housing, and the upper housing is installed above the housing cover.

[0007] Furthermore, the driving component includes an input shaft, a linkage shaft, a handwheel, a small bevel gear a, a large bevel gear a, a bearing, a small bevel gear b, and a large bevel gear b; the bearing is mounted on the input shaft and the linkage shaft; the input shaft is horizontally arranged, one end of the input shaft is connected to the handwheel, and the other end of the input shaft is connected to the small bevel gear a, and the small bevel gear a on the input shaft meshes with the large bevel gear a at the lower end of the worm shaft a; preferably, the bearing is an angular contact ball bearing.

[0008] Furthermore, an eddy current displacement sensor is arranged below the rotor.

[0009] Furthermore, the upper box body is composed of multiple sets of mutually symmetrical box structures, each set of box structures is connected to each other, and each set of box structures is connected to the box cover and the lower box body; preferably, the connection method is by bolt and nut connection.

[0010] Furthermore, the worm shaft a is arranged vertically, and its lower end is connected to the large bevel gear a; the worm shaft b is arranged vertically, and its lower end is connected to the large bevel gear b. Through the bevel gear and worm structure, the transmission ratio is stable.

[0011] Furthermore, the rotor shaft has flat surfaces at both ends to cooperate with the housing and restrict the rotation of the rotor shaft; the flat surfaces at both ends of the rotor shaft have meshing threads that engage with worm structure a and worm structure b, and the threads on worm structure a and worm structure b are symmetrically arranged, which increases the stability of the device and makes the structure reliable.

[0012] Furthermore, oil retaining rings are provided on the input shaft, linkage shaft, worm shaft a, and worm shaft b.

[0013] Furthermore, the small bevel gear a and the small bevel gear b are connected to a linkage shaft, and the small bevel gear a on the linkage shaft meshes with the large bevel gear a at the lower end of the worm shaft a; the small bevel gear b meshes with the large bevel gear b at the lower end of the worm shaft b.

[0014] Furthermore, the worm structure a and worm structure b are single-start Archimedean cylindrical worms with a straight axial tooth profile, a tooth profile angle θ ranging from 19° to 21°, a module ranging from 4 to 6 mm, and a pitch circle lead angle γ ranging from 2.6° to 2.9°.

[0015] Compared with the prior art, the present invention has the following advantages: (1) Reliable structure: The present invention uses bevel gear and worm gear structure for transmission, the transmission ratio is stable, and the rotor shaft is supported at both ends, which increases the stability of the device and makes the structure reliable.

[0016] (2) Long service life: The shortest service life of the bearing can be obtained by checking and calculating the critical sections of the components. This results in the invention having a long service life.

[0017] (3) Simple operation: The experiment on the static characteristics of the fingertip sealing sheet can be completed by simply controlling the handwheel and calculating the obtained experimental data. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall assembly structure of the present invention; Figure 2 This is a schematic diagram of the box structure of the present invention; Figure 3 This is a schematic diagram of the meshing thread structure at both ends of the rotor shaft of the present invention; Figure 4 This is a schematic diagram of the worm gear structure of the present invention; Figure 5 This is a schematic diagram of the measurement process of the present invention; Explanation of the labels in the diagram: 1-Input shaft, 2-Small bevel gear a, 3-Large bevel gear a, 4-Bearing cover, 5-Linkage shaft, 6-Bearing, 7-Lower housing, 8-Housing cover, 9-Upper housing, 10-Bearing end cover, 11-Eddy current displacement sensor, 12-Resistance strain gauge, 13-Fingert seal, 14-Rotor, 15-Rotor shaft, 16-Worm shaft a, 17-Worm structure a, 18-Oil baffle ring, 19-Handwheel, 20-Worm structure b, 21-Small bevel gear b, 22-Large bevel gear b, 23-Worm shaft b. Detailed Implementation

[0019] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0020] Example 1 like Figure 1As shown, a static characteristic test device for fingertip seals is provided. The structure mainly includes a housing, a measuring device, and a rotor 14. The measuring device includes an eddy current displacement sensor and a resistance strain gauge 12 with a top for measuring the strain of the rotor 14. A rotor displacement structure is mounted on the housing and used to drive the rotor 14 to move up and down. This structure includes a worm shaft a16 rotatably mounted on the housing in the vertical direction, a worm shaft b23, and a worm shaft a16 fixedly connected to the rotor 14 with its ends connected to the worm shaft b23 and the worm shaft a16, respectively. The rotor shaft 15 has 23 meshing phases, and a driving component that drives the worm shaft a16 and worm shaft b23 to rotate; the rotor 14 is connected to the rotor shaft 15, the rotor shaft 15 is arranged horizontally, and both ends of the rotor shaft 15 mesh with the worm structure on the worm shaft a16 and worm shaft b23; the worm shaft a16 is arranged vertically, and the lower end of the worm shaft a16 is connected to the large bevel gear a3; the worm shaft b23 is arranged vertically, and the lower end of the worm shaft b23 is connected to the large bevel gear b22; the input shaft 1 is arranged horizontally, and one end of the input shaft 1 is connected to the handwheel 19. The other end of the input shaft 1 is connected to the small bevel gear a2. The small bevel gear a2 on the input shaft 1 meshes with the large bevel gear a3 at the lower end of the worm shaft a16. The two ends of the linkage shaft 5 are connected to the small bevel gear a2 and the small bevel gear b21 respectively. The small bevel gear a2 on the linkage shaft 5 meshes with the large bevel gear a3 at the lower end of the worm shaft a16, and the small bevel gear b21 meshes with the large bevel gear b22 at the lower end of the worm shaft b23. In this embodiment, the bearing 6 is selected as an angular contact ball bearing. The bearing 6 and the oil retainer ring 18 are installed in a fixed position on the shaft. The housing is installed on the side near the inside of the housing; the housing includes a lower housing 7, a housing cover 8, an upper housing 9, a bearing cover 4, and a bearing end cover 10; the rotor displacement structure is fixed in the housing through the bearing cover 4 and the bearing end cover 10; the eddy current displacement sensor 11 is arranged below the rotor 14 and connected to the housing cover 8 by threads; the resistance strain gauge 12 is attached to the outer ring of the rotor 14; the housing cover 8 is installed above the lower housing 7 and connected by bolts and nuts; the upper housing 9 is installed above the housing cover 8 and connected by bolts and nuts.

[0021] like Figure 2 As shown, in this embodiment, the upper box 9 consists of two sets of mutually symmetrical box structures. Each set of box structures is connected by bolts and nuts. After connection, each set of box structures is connected to the box cover 8 and the lower box 7 by bolts and nuts.

[0022] like Figure 3 As shown, the two end planes of the rotor shaft 15 are provided with meshing threads that engage with the worm structure a17 and the worm structure b20. The two end sections of the rotor shaft 15 are provided with flat surfaces that cooperate with the housing to restrict the rotation of the rotor shaft 15.

[0023] like Figure 4As shown, the worm structure a17 and worm structure b20 are single-start Archimedean cylindrical worms (ZA worms), with a straight axial tooth profile, a tooth profile angle θ ranging from 19° to 21°, a module ranging from 4 to 6 mm, and a pitch circle lead angle γ ranging from 2.6° to 2.9°.

[0024] In this embodiment, all critical sections have been checked, and the equivalent stress of the input shaft is... The equivalent stress of the worm shaft is The shortest lifespan of the bearing is The tooth surface contact fatigue stress is Less than the allowable stress for tooth surface contact fatigue =208 MPa; Bending fatigue stress at the tooth root Less than the allowable bending stress Mpa Example 2 This embodiment is an experiment to measure the stiffness of a fingertip seal.

[0025] In this embodiment, the stiffness of the fingertip seal is measured using a fingertip seal static characteristic experimental device described in Embodiment 1. Figure 5 As shown, the fingertip seal 13 to be tested is placed between the measuring device and the rotor displacement structure. During use, the input shaft 1 is rotated via the handwheel 19. This, in turn, drives the worm shaft b23 to rotate via the bevel gear transmission between the input shaft 1 and the worm shaft a16. The bevel gear transmission between the worm shaft a16 and the linkage shaft 5 ensures that the worm shafts a16 and b23 rotate in the same phase. The worm structures a17 and b20 on the worm shafts a16 and b23 mesh with the rotor shaft 15 at both ends via threaded transmission, causing the rotor shaft 15 to move vertically. This causes the rotor 14 to simulate an eccentric situation, pressing the fingertip beam of the fingertip seal 13. The distance of the rotor is measured by the eddy current displacement sensor 11 positioned below the rotor 14. s =8 mm, the strain at the bonding point when the rotor contacts the fingertip sealing plate was measured by a resistance strain gauge 12 bonded to the outer ring of the rotor 14. ε =1.955×10 -9 Substitute the measured distance s into the formula. mm, the displacement of the fingertip beam is calculated. δ If the rotor is considered as a beam structure with a hollow circular cross-section, its bending section modulus is... In the formula =d / The stress and strain of the beam are analyzed based on the measured strain ε, and the stress between the rotor and the fingertip beam is calculated. In the formula E The elastic modulus of the rotor material is used to calculate the force between the rotor and the fingertip beam. FFinally, according to the formula for calculating stiffness... K = F / δ The stiffness of the fingertip seal was calculated.

[0026] In the description of this invention, the terms "center," "upper," "lower," "left," "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when placing the invention. They are only used to describe the invention and simplify the description, and therefore should not be construed as limiting the invention.

[0027] The above description of the embodiments is provided to enable those skilled in the art to understand and apply the present invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the embodiments described herein, and any improvements and modifications made to the present invention by those skilled in the art based on the disclosure thereof should be within the scope of protection of the present invention.

Claims

1. A test apparatus for measuring the static characteristics of fingertip seals, characterized in that, include: The housing, measuring device, rotor (14), and rotor displacement structure are provided. The rotor displacement structure includes a worm shaft a (16), a worm shaft b (23), a rotor shaft (15), and a driving component. The worm shaft a (16) and worm shaft b (23) are rotatably mounted on the housing in the vertical direction. The rotor shaft (15) is fixedly connected to the rotor (14) and its ends are respectively engaged with the worm shaft a (16) and worm shaft b (23). The driving component drives the worm shaft a (16) and worm shaft b (23) to rotate. The measuring device includes an eddy current displacement sensor (11) and a resistance strain gauge (12) for measuring the strain of the rotor (14). The resistance strain gauge (12) is located on the outside of the rotor (14). The fingertip seal (13) to be tested is placed between the measuring device and the rotor displacement structure.

2. The experimental apparatus for measuring the static characteristics of fingertip seals according to claim 1, characterized in that, The housing includes a lower housing (7), a housing cover (8), an upper housing (9), a bearing cover (4), and a bearing end cover (10); the bearing cover (4) and the bearing end cover (10) fix the rotor displacement structure inside the housing; the housing cover (8) is installed above the lower housing (7), and the upper housing (9) is installed above the housing cover (8).

3. The experimental apparatus for measuring the static characteristics of fingertip seals according to claim 1, characterized in that, The drive components include an input shaft (1), a linkage shaft (5), a handwheel (19), a small bevel gear a (2), a large bevel gear a (3), a bearing (6), a small bevel gear b (21), and a large bevel gear b (22); the bearing (6) is mounted on the input shaft (1) and the linkage shaft (5); the input shaft (1) is arranged horizontally, one end of the input shaft (1) is connected to the handwheel (19), and the other end of the input shaft (1) is connected to the small bevel gear a (2), and the small bevel gear a (2) on the input shaft (1) meshes with the large bevel gear a (3) at the lower end of the worm shaft a (16).

4. The experimental apparatus for measuring the static characteristics of fingertip seals according to claim 1, characterized in that, An eddy current displacement sensor (11) is arranged below the rotor (14).

5. The experimental apparatus for measuring the static characteristics of fingertip seals according to claim 2, characterized in that, The upper box (9) is composed of multiple sets of symmetrical box structures. Each set of box structures is connected to each other, and each set of box structures is connected to the box cover (8) and the lower box (7).

6. The experimental apparatus for measuring the static characteristics of fingertip seals according to claim 3, characterized in that, The worm shaft a (16) is arranged vertically, and the lower end of the worm shaft a (16) is connected to the large bevel gear a (3); the worm shaft b (23) is arranged vertically, and the lower end of the worm shaft b (23) is connected to the large bevel gear b (22).

7. The experimental apparatus for measuring the static characteristics of fingertip seals according to claim 3, characterized in that, The rotor shaft (15) has flat surfaces at both ends, which cooperate with the housing to restrict the rotation of the rotor shaft (15); the flat surfaces at both ends of the rotor shaft have meshing threads that mesh with the worm structure a (17) and the worm structure b (20), and the threads on the worm structure a (17) and the worm structure b (20) are symmetrically arranged.

8. The experimental apparatus for measuring the static characteristics of fingertip seals according to claim 3, characterized in that, Oil baffles (18) are provided on the input shaft (1), linkage shaft (5), worm shaft a (16) and worm shaft b (23).

9. The experimental apparatus for measuring the static characteristics of fingertip seals according to claim 3, characterized in that, The small bevel gear a (2) and the small bevel gear b (21) are connected to the linkage shaft (5). The small bevel gear a (2) on the linkage shaft (5) meshes with the large bevel gear a (3) at the lower end of the worm shaft a (16); the small bevel gear b (21) meshes with the large bevel gear b (22) at the lower end of the worm shaft b (23).

10. The experimental apparatus for measuring the static characteristics of fingertip seals according to claim 7, characterized in that, The worm structure a (17) and worm structure b (20) are single-head Archimedean cylindrical worms with straight axial tooth profiles, tooth angle θ ranging from 19° to 21°, module ranging from 4 to 6 mm, and pitch circle lead angle γ ranging from 2.6° to 2.9°.

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