A floating surface textured end cylinder combined air film sealing structure

Abstract

The present invention discloses a floating surface textured end cylinder combined air film sealing structure, including a sleeve and an end column floating ring mounted on a main shaft, the end column floating ring including an end plate and a cylinder, the front end of the cylinder is connected to the end plate, the front end of the end plate is provided with a sleeve, the end plate and the cylinder are provided with a channel from the front end to the rear end, the main shaft passes through the channel, a plurality of surface texture grooves are provided on the front end of the end plate and the inner wall of the cylinder, the front end of the end column floating ring is a low pressure side, the rear end of the end column floating ring is a high pressure side, the gas enters the sealing gap formed by the main shaft and the inner wall of the cylinder from the high pressure side, and passes through the sealing gap formed between the end plate and the sleeve; the surface texture grooves provided on the end and cylinder of the present invention can realize a more reliable fluid dynamic pressure effect and reduce the leakage of fluid seal. At the same time, the unique spring structure can ensure that the floating ring floats within a certain controllable range to prevent the collision between the end column floating ring and the sleeve and the main shaft when the rotor vibrates.

Description

Technical Field

[0001] The present invention relates to the field of fluid sealing at the dynamic and static interfaces of high-speed rotating parts of gas turbines (including ground gas turbines and aircraft engines) and rocket engines, and in particular to a floating surface textured end cylinder combined air film sealing structure. Background Art

[0002] Gas turbines are currently widely used in aerospace, shipbuilding, power generation and other industrial fields due to their small size, fast response speed, high efficiency and high power. Rocket engines are widely used in aerospace, missiles and other fields due to their high specific impulse. Improving the sealing technology of high-speed rotating parts of gas turbines and rocket engines is one of the key technologies to improve the performance of gas turbines and rocket engines. With the continuous increase in demand for modern gas turbines and rocket engines and the continuous deterioration of the working environment, the requirements for reducing leakage flow are getting higher and higher, and the demand for advanced sealing technology is becoming more and more urgent.

[0003] As a key technology for fluid sealing of gas turbines and rocket engines, air film sealing is used. When the sleeve rotates at high speed, the gas on the high-pressure side will be brought into the groove. The gas is continuously compressed and generates air film pressure, forming a dynamic pressure effect, so that a thin film with small thickness and large rigidity is formed between the floating ring and the sleeve, thereby blocking the main leakage channel; at the same time, the sleeve and the end column floating ring are installed eccentrically to form a convergent wedge-shaped space with different air film thicknesses, which further enhances the dynamic pressure effect of the seal and greatly improves the air film bearing capacity. The two end surfaces that were originally in contact between the dynamic and static are separated by the fluid film formed by the flow of the fluid medium, avoiding direct contact and wear between the sealing end faces, thereby realizing non-contact operation of the seal. The air film seal has low power loss, simple auxiliary system, high reliability, and is very suitable for the high parameter requirements of gas turbines and rocket engines. This technology has been used in the sealing of high-speed rotating parts of the domestic "Spey" aircraft engine and a certain type of rocket engine turbine pump. Summary of the invention

[0004] In order to further improve the sealing performance of the end cylinder combined air film seal, increase the air film stiffness and reduce leakage, and overcome the limitations of the existing end cylinder combined air film sealing structure, the present invention proposes a floating surface textured end cylinder combined air film sealing structure. The main feature of this structure is that surface texture grooves are opened on the floating ring end and the cylindrical surface, and the outer side of the floating ring is connected to the stator with a spring.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] A floating surface textured end cylinder combined air film sealing structure comprises a sleeve 2 and an end column floating ring 5 which are sequentially mounted on a main shaft 3, the end column floating ring 5 comprising an end plate 10 and a column 9, the front end of the column 9 is connected to the end plate 10, the front end of the end plate 10 is provided with a sleeve 2, a passage from the front end to the rear end is provided on the end plate 10 and the column 9, the main shaft 3 passes through the passage, a plurality of surface textured grooves 8 are provided on the front end of the end plate 10 and the inner wall of the column 9, the front end of the end column floating ring 5 is a low pressure side, and the rear end of the end column floating ring 5 is a high pressure side, the gas enters the sealing gap formed by the main shaft 3 and the inner wall of the column 9 from the high pressure side, and passes through the sealing gap formed between the end plate 10 and the sleeve 2.

[0007] Furthermore, a plurality of springs 4 are also provided on the rear side of the end plate 10 and on the outer wall of the column 9, and the springs 4 are connected to the casing 1 outside the sleeve 2 and the end column floating ring 5; the springs 4 between the end plate 10 and the casing 1 are arranged in two rows in the radial direction and are evenly distributed in the circumferential direction, with four springs per circumference; the springs 4 between the column 9 and the casing 1 are arranged in three rows in the axial direction and are evenly distributed in the circumferential direction, with four springs per circumference.

[0008] Furthermore, the tail end of the column 9 is connected to the casing 1 through a plurality of positioning pins 6. The tail end of the column 9 is connected to the casing 1 through a rubber gasket 7. The rubber gasket 7 is a circular ring, and the plurality of positioning pins 6 are located outside the circular ring. There are four positioning pins 6, which are evenly distributed along the circumference of the tail end of the column 9.

[0009] Furthermore, the column 9 is a cylindrical tube with a channel arranged along its central axis, the end plate 10 is a disc with a circular hole in the middle, the diameter of the channel is the same as the diameter of the circular hole, the front end of the cylindrical tube is connected to the disc, and the disc and the cylindrical tube are perpendicular to each other. The column 9 and the end plate 10 are integrated.

[0010] Furthermore, the surface texture grooves 8 are circular grooves with a radius of 3-5 mm and a depth of 0.2-1 mm, and the size and depth of each circular groove are the same.

[0011] Furthermore, the surface texture grooves 8 opened on the end plate 10 are evenly distributed in several circles along the circumference thereof, and the surface texture grooves 8 opened on the inner wall of the column 9 are evenly distributed in several circles along the axial and circumferential directions thereof.

[0012] Furthermore, the central axis of the surface texture groove 8 opened in front of the end plate 10 is parallel to the central axis of the main shaft 3, and several circles of surface texture grooves 8 are equidistant and concentrically arranged, and their centers are all the center of the end plate 10, and the spacing is twice the radius of the surface texture groove 8, and several circles of surface texture grooves 8 are arranged in sequence or in a cross-array; the central axis of the surface texture groove 8 opened on the inner wall of the column 9 is perpendicular to the central axis of the main shaft 3, and several circles of surface texture grooves 8 are equidistant and concentrically arranged, and their centers are all on the central axis of the column 9, and the spacing is twice the radius of the surface texture groove 8, and several circles of surface texture grooves 8 are arranged in sequence or in a cross-array.

[0013] Furthermore, the shaft sleeve 2 and the main shaft 3 are interference fit and are concentrically installed.

[0014] Furthermore, the end column floating ring 5 is eccentrically installed with respect to the main shaft 3, and the eccentricity is 0.2-0.8.

[0015] Furthermore, the outer diameter of the shaft sleeve 2 is the same as the outer diameter of the end plate 10 .

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] Compared with the traditional end-cylinder combined air film seal structure, the surface texture grooves opened on the end and cylinder can achieve a more reliable fluid dynamic pressure effect and reduce fluid seal leakage. At the same time, the unique spring structure can ensure that the floating ring floats within a certain controllable range to prevent the end column floating ring from colliding with the shaft sleeve and the main shaft when the rotor vibrates. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of the present invention;

[0019] Figure 2 is a schematic diagram of the sequential arrangement of the surface texture grooves on the end face of the present invention;

[0020] Figure 3 is a schematic diagram of a forked row of surface texture grooves on an end face of the present invention;

[0021] Figure 4 It is the use assembly diagram of the present invention;

[0022] Figure 5 is a cross-sectional view of the present invention;

[0023] Figure 6 It is a schematic diagram of the gas flow of the present invention;

[0024] Among them: 1-receiving, 2-sleeve, 3-main shaft, 4-spring, 5-end column floating ring, 6-locating pin, 7-rubber gasket, 8-surface texture groove, 9-column, 10-end plate. DETAILED DESCRIPTION

[0025] The present invention will be further described below in conjunction with embodiments.

[0026] like Figure 1-6 As shown, a floating surface textured end cylinder combined air film sealing structure comprises a sleeve 2 and an end column floating ring 5 which are sequentially mounted on a main shaft 3, the end column floating ring 5 comprising an end plate 10 and a column 9, the front end of the column 9 is connected to the end plate 10, the front of the end plate 10 is provided with a sleeve 2, the end plate 10 and the column 9 are provided with a channel from the front end to the rear end, the main shaft 3 passes through the channel, the front of the end plate 10 and the inner wall of the column 9 are provided with a plurality of surface texture grooves 8, the front of the end column floating ring 5 The end is the low-pressure side, and the rear end of the end column floating ring 5 is the high-pressure side. The gas enters the sealing gap formed by the main shaft 3 and the inner wall of the column 9 from the high-pressure side, and passes through the sealing gap formed between the end plate 10 and the sleeve 2; specifically, the column 9 is a cylindrical tube with a channel arranged along its central axis, and the end plate 10 is a disc with a circular hole in the middle, the diameter of the channel is the same as the diameter of the circular hole, the front end of the cylindrical tube is connected to the disc, and the disc and the cylindrical tube are perpendicular to each other. Preferably, the column 9 and the end plate 10 are integrated.

[0027] A plurality of springs 4 are also provided on the rear side of the end plate 10 and on the outer wall of the column 9, and the springs 4 are connected to the casing 1 outside the sleeve 2 and the end column floating ring 5; preferably, the springs 4 between the end plate 10 and the casing 1 are arranged in two rows in the radial direction and are evenly distributed in the circumferential direction, with four springs per circumference; the springs 4 between the column 9 and the casing 1 are arranged in three rows in the axial direction and are evenly distributed in the circumferential direction, with four springs per circumference.

[0028] As a preferred solution, the tail end of the column 9 is connected to the casing 1 through a plurality of locating pins 6, and the tail end of the column 9 is connected to the casing 1 through a rubber gasket 7, wherein the rubber gasket 7 is a circular ring, and the plurality of locating pins 6 are located outside the circular ring. Preferably, there are 4 locating pins 6, and they are evenly distributed along the circumference of the tail end of the column 9.

[0029] Preferably, the outer diameter of the sleeve 2 is the same as the outer diameter of the end plate 10, the sleeve 2 and the main shaft 3 are interference fit and are installed concentrically, then the sleeve 2 and the main shaft 3 move synchronously, the end column floating ring 5 is eccentrically installed with the main shaft 3, and the eccentricity is 0.2~0.8; specifically, the sleeve 2 and the main shaft 3 are interference fit, the tail end of the column 9 is connected to the casing 1 through the rubber gasket 7, the gas cannot pass between the sleeve 2 and the main shaft 3, the gas cannot pass between the casing 1 and the outer wall of the sleeve 2, the gas can only enter the sealing gap formed by the main shaft 3 and the inner wall of the column 9 from the high pressure side, and pass through the sealing gap formed between the end plate 10 and the sleeve 2.

[0030] Preferably, the surface texture grooves 8 are circular grooves with a radius of 3-5 mm and a depth of 0.2-1 mm, and the size and depth of each circular groove are the same.

[0031] As a preferred solution, the surface texture grooves 8 opened on the end plate 10 are evenly distributed in several circles along the circumference thereof, and the surface texture grooves 8 opened on the inner wall of the column 9 are evenly distributed in several circles along the axial and circumferential directions thereof.

[0032] Specifically, the central axis of the surface texture groove 8 opened on the front of the end plate 10 is parallel to the central axis of the main shaft 3, and several circles of surface texture grooves 8 are equidistant and concentrically arranged, and their centers are all the center of the end plate 10, and the spacing is twice the radius of the surface texture groove 8, and several circles of surface texture grooves 8 are arranged in sequence or in a staggered manner; the central axis of the surface texture groove 8 opened on the inner wall of the column 9 is perpendicular to the central axis of the main shaft 3, and several circles of surface texture grooves 8 are equidistant and concentrically arranged, and their centers are all on the central axis of the column 9, and the spacing is twice the radius of the surface texture groove 8, and several circles of surface texture grooves 8 are arranged in sequence or in a staggered manner.

[0033] The principle of the present invention is as follows: the main shaft and the sleeve adopt an interference fit so that the sleeve and the rotating shaft move synchronously; the end column floating ring is installed on the main shaft, and the end face and the outer side of the cylindrical surface of the end column floating ring are connected to the spring. The spring can determine the radial displacement of the floating ring, that is, to ensure that the floating ring floats within a certain controllable range, and to prevent collision with the casing and the sleeve, thereby extending the service life of the seal. The rear end of the end column floating ring is positioned by the positioning pin of the casing, which limits the circumferential rotational movement of the end column floating ring and keeps it in a relatively stable position in the circumferential direction. With the help of spring force and sealing gas pressure, the end column floating ring can be close to the rubber gasket to prevent the high-pressure end medium from leaking directly to the low-pressure side of the shaft end through this gap, thereby reducing the risk of secondary leakage. The end column floating ring and the sleeve form a narrow micro-scale gap, and at the same time, surface texture micro-grooves are opened on the end face and cylindrical surface of the end column floating ring. When the sleeve rotates at high speed, the gas on the high-pressure side will be brought into the groove, and the gas will be continuously compressed to generate air film pressure, forming a dynamic pressure effect, so that a thin film with small thickness and large rigidity is formed between the end column floating ring and the sleeve and the main shaft, thereby blocking the main leakage channel; at the same time, the end column floating ring is eccentrically installed between the main shaft to form a convergent wedge-shaped space with different air film thicknesses, which further enhances the dynamic pressure effect of the seal and greatly improves the air film bearing capacity.

[0034] The present invention is based on the end column air film seal, and a micron-level pit structure is opened on the front of the end plate and the inner wall of the column 9. Compared with the traditional groove-type sealing method, the bearing capacity of the sealing surface is improved, the wear of the mechanical seal is reduced, and its service life and reliability are improved. Each surface texture groove can be considered as a tiny fluid dynamic pressure bearing, which generates additional fluid dynamic pressure during the relative motion process, so that a very thin fluid lubricating film is formed between the friction pairs, and the two surfaces are transformed from a contact state to a non-contact state, which is of great significance for reducing the friction and wear of the mechanical seal. On the other hand, the surface texture groove can also play the role of storing wear debris and lubricating oil.

[0035] 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 scope of protection of the present invention.

Claims

1. A floating surface textured end cylinder combined air film sealing structure, characterized in that: It comprises a sleeve (2) and an end column floating ring (5) which are sequentially sleeved on a main shaft (3), the end column floating ring (5) comprising an end plate (10) and a column (9), the front end of the column (9) being connected to the end plate (10), the front end of the end plate (10) being provided with a sleeve (2), the end plate (10) and the column (9) being provided with a passage from the front end to the rear end, the main shaft (3) passing through the passage, the front end of the end plate (10) and the inner wall of the column (9) being provided with a plurality of surface texture grooves (8), the front end of the end column floating ring (5) being a low-pressure side, the rear end of the end column floating ring (5) being a high-pressure side, the gas entering from the high-pressure side into a sealing gap formed between the main shaft (3) and the inner wall of the column (9), and passing through a sealing gap formed between the end plate (10) and the sleeve (2); A plurality of springs (4) are also provided on the rear side of the end plate (10) and the outer wall of the column (9), and the springs (4) are connected to the casing (1) outside the shaft sleeve (2) and the end column floating ring (5); The column (9) is a cylindrical tube with a channel arranged along its central axis, the end plate (10) is a disc with a circular hole in the middle, the diameter of the channel is the same as the diameter of the circular hole, the front end of the cylindrical tube is connected to the disc, and the disc and the cylindrical tube are perpendicular to each other; The surface texture grooves (8) are circular grooves with a radius of 3 to 5 mm and a depth of 0.2 to 1 mm, and the size and depth of each circular groove are the same.

2. The floating surface textured end cylinder combined air film sealing structure according to claim 1, characterized in that: The rear end of the column (9) is connected to the casing (1) via a plurality of positioning pins (6), and the rear end of the column (9) is connected to the casing (1) via a rubber gasket (7), wherein the rubber gasket (7) is a circular ring, and the plurality of positioning pins (6) are located outside the circular ring.

3. The floating surface textured end cylinder combined air film sealing structure according to claim 1, characterized in that: The surface texture grooves (8) provided on the end plate (10) are evenly distributed in a plurality of circles along its circumference, and the surface texture grooves (8) provided on the inner wall of the column (9) are evenly distributed in a plurality of circles along its axial direction and circumference.

4. The floating surface textured end cylinder combined air film sealing structure according to claim 3 is characterized by: The central axis of the surface texture groove (8) opened on the front of the end plate (10) is parallel to the central axis of the main shaft (3), and a plurality of circles of surface texture grooves (8) are equally spaced and concentrically arranged, and their centers are all the center of the end plate (10), and the spacing is twice the radius of the surface texture groove (8), and a plurality of circles of surface texture grooves (8) are arranged in a straight line or in a cross-line; the central axis of the surface texture groove (8) opened on the inner wall of the column (9) is perpendicular to the central axis of the main shaft (3), and a plurality of circles of surface texture grooves (8) are equally spaced and concentrically arranged, and their centers are all on the central axis of the column (9), and the spacing is twice the radius of the surface texture groove (8), and a plurality of circles of surface texture grooves (8) are arranged in a straight line or in a cross-line.

5. The floating surface textured end cylinder combined air film sealing structure according to claim 1, characterized in that: The shaft sleeve (2) and the main shaft (3) are interference fit and are concentrically installed.

6. The floating surface textured end cylinder combined air film sealing structure according to claim 1, characterized in that: The end column floating ring (5) is eccentrically mounted to the main shaft (3), with an eccentricity of 0.2-0.

8.

7. The floating surface textured end cylinder combined air film sealing structure according to claim 1, characterized in that: The outer diameter of the shaft sleeve (2) is the same as the outer diameter of the end plate (10).

Images