Efficient and durable graphite sealing device and method

Abstract

The invention relates to the technical field of graphite sealing, in particular to an efficient and durable graphite sealing device. According to the technical scheme, the sealing device comprises a graphite sealing assembly and a friction ring, the graphite sealing assembly comprises a sealing shell, a wave spring is arranged in the sealing shell, a gasket is arranged at the position, located in the sealing shell, of one side of the wave spring, and a graphite ring assembly is installed on the side, away from the wave spring, of the gasket; and one side of the friction ring is tightly attached to one side of the graphite ring assembly, and two sets of stop blocks are symmetrically installed on the inner wall of the sealing shell. The sides, close to each other, of the graphite sealing assembly and the friction ring are ground, so that the graphite sealing assembly and the friction ring are in a sealed state, meanwhile, the graphite sealing assembly is simple in overall structure and convenient to disassemble, assemble and replace, and the service life of the graphite sealing assembly can be prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of graphite sealing, and in particular to a highly efficient and durable graphite sealing device and method. Background Art

[0002] As the aviation industry develops rapidly, the quality of aviation products needs to be improved to ensure that they meet the requirements of high performance and high reliability. When parts are out of tolerance, or there is a pressure difference or vibration in the working environment, small gaps will inevitably appear between parts, and the working medium (such as lubricating oil) will leak through the gaps. In order to ensure that parts can operate safely and reliably for a long time at high efficiency, it is necessary to pay attention to the development of sealing technology to prevent and solve leakage problems.

[0003] In the aspect of mechanical seal of aircraft engine or aircraft auxiliary power, it is necessary to invent a sealing device which can achieve long service life and good sealing effect. To this end, we specially propose a highly efficient and durable graphite sealing device and method. Summary of the invention

[0004] The purpose of the present invention is to provide a highly efficient and durable graphite sealing device and method in view of the problems existing in the background technology.

[0005] The technical solution of the present invention is: an efficient and durable graphite sealing device, including a graphite sealing assembly and a friction ring, the graphite sealing assembly including a sealing shell, a wave spring is arranged in the sealing shell, a gasket is arranged on one side of the wave spring located in the sealing shell, a graphite ring assembly is installed on the side of the gasket away from the wave spring, one side of the friction ring is tightly fitted with one side of the graphite ring assembly, and two sets of stop blocks are symmetrically installed on the inner wall of the sealing shell.

[0006] Preferably, the sealing shell is arranged in a circular ring shape, an inner cavity is opened on one side of the sealing shell, the wave spring is installed corresponding to the inner wall of the inner cavity of the sealing shell, and the material of the wave spring is 0Cr17Ni7Al.

[0007] Preferably, the inner ring of the gasket is arranged in a convex shape, and the convex side of the gasket is in contact with the wave spring, and the material of the gasket is rubber FX-17.

[0008] Preferably, the graphite ring assembly comprises a graphite ring, the inner ring of the graphite ring is in contact with the inner wall of the inner cavity of the sealing shell, an O-ring for auxiliary sealing is arranged between the graphite ring and the sealing shell, and grooves are provided on both sides of the graphite ring.

[0009] Preferably, the material of the graphite ring is pure carbon graphite ZC7-3, the material of the friction ring is 9Cr18, and the graphite ring and the friction ring are ground on the side close to each other, with a grinding roughness of 0.063 and a flatness of 0.0006.

[0010] Preferably, the two groups of stop blocks are connected to the sealing shell by resistance welding, and the sealing shell and the stop blocks are both made of 0Cr18Ni9.

[0011] Preferably, a shallow groove is provided on one side of the grinding surface of the friction ring, and the shallow groove is arranged in a spiral shape.

[0012] A highly efficient and durable graphite seal assembly method comprises the following steps:

[0013] Step 1: Clean all parts. There should be no dirt on the surface. Check whether there are scratches or dents on the surface of the parts. Focus on the end face of the graphite ring that fits the friction ring and the end face of the friction ring that fits the graphite ring.

[0014] Step 2: Perform resistance welding according to GB / T19867.5-2008 "Resistance Welding Process Specification" to weld two sets of stop blocks to both sides of the inner ring of the sealing housing, so that the stop blocks and the sealing housing are integrated, i.e., the sealing housing assembly;

[0015] Step 3: Install the O-ring in the groove of the graphite ring to form a graphite ring assembly;

[0016] Step 4: Place the seal housing assembly on the workbench with the opening facing upward, and install the wave spring, washer and graphite ring assembly into the seal housing assembly in sequence;

[0017] When installing the gasket, the convex side of the gasket faces the inner side of the sealing housing assembly;

[0018] There are grooves on both sides of the graphite ring. During assembly, the grooves are aligned with the stop blocks on both sides of the sealing housing assembly. After the graphite ring is placed in the sealing housing assembly, the sealing housing is rotated clockwise until the graphite ring is locked by the stop blocks, thereby preventing the graphite ring from being disengaged, and then the graphite sealing assembly is assembled;

[0019] Step 5: Apply a certain pressure evenly to the end face of the assembled graphite ring to check whether the springback of the graphite ring meets the requirements;

[0020] If the requirements are met, the graphite seal assembly is qualified;

[0021] If the requirements are not met, disassemble the graphite seal assembly, rotate the graphite ring counterclockwise until the groove on the graphite ring is aligned with the stop block, and then take out the graphite ring. The O-ring, wave spring and gasket can also be easily taken out. Check each part, and then repeat steps 3, 4 and 5 until the requirements are met.

[0022] Step 6: Use appropriate tooling to conduct a static sealing test on the assembled graphite sealing assembly and friction ring to check the sealing performance. If the test is qualified, they are successfully paired to form a graphite sealing device;

[0023] Step 7: When the graphite sealing device is installed and used, the graphite sealing assembly is a stationary part, installed in the hole of the casing with a slight interference fit, and the friction ring is a rotating part, installed on the rotating shaft with a slight clearance fit.

[0024] Compared with the prior art, the present invention has the following beneficial technical effects:

[0025] The present invention grinds the graphite sealing assembly and the friction ring on one side close to each other, so that the graphite sealing assembly and the friction ring are in a sealed state, and then the O-ring is set to perform auxiliary sealing, so as to prevent the lubricating oil from leaking to the outside. At the same time, the shallow groove is set so that the friction ring can absorb the lubricating oil into the shallow groove when rotating. After the friction ring rotates at a high speed, the lubricating oil in the shallow groove is compressed, so that the graphite sealing assembly and the friction ring are separated from the tightly fitting state, and an air film is formed between the graphite sealing assembly and the friction ring, thereby reducing the friction between the graphite sealing assembly and the friction ring, thereby extending the service life of the sealing device. At the same time, the overall structure of the graphite sealing assembly is simple, which is convenient for disassembly and replacement, and can also extend the service life of the graphite sealing assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a cross-sectional view of the present invention;

[0027] Figure 2 It is a schematic diagram of the structure of the friction ring and the shallow groove in the present invention;

[0028] Figure 3 It is a schematic diagram of the structure of the graphite ring assembly in the present invention;

[0029] Figure 4 It is a schematic diagram of the structure of the stop block in the present invention;

[0030] Figure 5 It is an assembly diagram of the sealing housing and the stop block in the present invention;

[0031] Figure 6 It is a schematic diagram of the structure of the graphite ring in the present invention;

[0032] Figure 7It is a schematic diagram of the explosion structure of the present invention.

[0033] Figure numerals: 1. graphite sealing assembly; 11. sealing housing; 12. wave spring; 13. gasket; 14. graphite ring assembly; 141. graphite ring; 142. O-ring; 15. stop block; 2. friction ring; 3. shallow groove. DETAILED DESCRIPTION

[0034] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0035] Example

[0036] like Figure 1 and Figure 7 As shown, the present invention provides an efficient and durable graphite sealing device, comprising a graphite sealing assembly 1 and a friction ring 2. The graphite sealing assembly 1 comprises a sealing housing 11, and the sealing housing 11 is arranged in a circular ring shape. Figure 4-5 As shown, two groups of stop blocks 15 are symmetrically installed on the inner wall of the sealing housing 11, and the stop blocks 15 are arranged in an ear shape. The two groups of stop blocks 15 are connected to the sealing housing 11 by resistance welding, and the stop blocks 15 are fixedly connected to the sealing housing 11. The materials of the sealing housing 11 and the stop blocks 15 are both 0Cr18Ni9. An inner cavity is opened on one side of the sealing housing 11, and a wave spring 12 is arranged in the sealing housing 11. The wave spring 12 is installed corresponding to the inner wall of the inner cavity of the sealing housing 11. The material of the wave spring 12 is 0Cr17Ni7Al. The wave spring 12 meets the design requirements in a free state, and a durable elastic force test is required. The spring is compressed to a certain height and maintained for 24 hours. The elastic force is not allowed to change. The wave spring The setting of the spring 12 can provide elastic force to the graphite ring 141. The body of the wave spring 12 is evenly bent, so that the graphite ring 141 can move axially. A gasket 13 is arranged on one side of the wave spring 12 in the sealing housing 11. The inner ring of the gasket 13 is arranged in a convex shape. The convex side of the gasket 13 fits with the wave spring 12. The material of the gasket 13 is rubber FX-17. The setting of the gasket 13 can make the graphite ring 141 and the wave spring 12 adapt to each other. A graphite ring assembly 14 is installed on the side of the gasket 13 away from the wave spring 12. The graphite ring assembly 14 includes a graphite ring 141. The inner ring of the graphite ring 141 fits with the inner wall of the inner cavity of the sealing housing 11. The graphite ring 141 is slidably connected to the sealing housing 11, such as Figure 3 As shown, an O-ring 142 for auxiliary sealing is provided between the graphite ring 141 and the sealing housing 11, and the outer ring of the O-ring 142 is tightly fitted with the graphite ring 141 and the sealing housing 11, respectively. Figure 6As shown, grooves are provided on both sides of the graphite ring 141. The setting of the grooves can lock the graphite ring 141 through the stop block 15 when the graphite ring 141 is assembled with the sealing housing 11 to prevent the graphite ring 141 from being disengaged when in the assembled state. One side of the friction ring 2 is tightly fitted with one side of the graphite ring assembly 14. The material of the graphite ring 141 is pure carbon graphite ZC7-3, and the material of the friction ring 2 is 9Cr18. The sides of the graphite ring 141 and the friction ring 2 close to each other are both ground, with a grinding roughness of 0.063 and a flatness of 0.0006. The grinding surfaces of the graphite ring 141 and the friction ring 2 cooperate with each other to play a major sealing role, and at the same time, the O-ring 142 is used for auxiliary sealing, thereby greatly preventing the lubricating oil from flowing out. Figure 2 As shown, a shallow groove 3 is provided on one side of the grinding surface of the friction ring 2, and the shallow groove 3 is arranged in a spiral shape, such as Figure 2 As shown, the area between the two dotted lines is the contact area with the graphite ring 141. When the friction ring 2 is in a stationary state, the graphite ring 141 is tightly fitted with the friction ring 2 under the elastic force of the wave spring 12 to prevent the lubricating oil from leaking to the outside. When the friction ring 2 is in a high-speed rotating state, the lubricating oil is sucked into the shallow groove 3 and moves toward the root of the shallow groove 3. When the lubricating oil reaches the root of the shallow groove 3, the lubricating oil is gradually compressed. When the pressure reaches a certain value, the friction ring 2 and the graphite ring 141 will be out of the tightly fitted state, thereby forming a gap with a thickness of only a few microns, and the gas fills the gap to form an end face air film. This effectively prevents the lubricating oil from leaking to the outside. At the same time, the continuous flow of gas can also cool the side where the friction ring 2 and the graphite ring 141 are in contact with each other, thereby suppressing the thermal deformation of the end faces of the friction ring 2 and the graphite ring 141. The friction ring 2 and the graphite ring 141 can be separated from the contact state to achieve frictionless movement between the two, which can reduce the wear of the end faces of the friction ring 2 and the graphite ring 141 close to each other and extend the service life of the sealing device. In addition, the graphite sealing assembly 1 is easy to install and disassemble, and when a part fails, it can be easily replaced, which can also extend the service life of the graphite sealing assembly.

[0037] In this embodiment, the operator first welds the stop block 15 symmetrically on both sides of the inner wall of the sealing housing 11, so that the stop block 15 and the sealing housing 11 are combined with each other to form a sealing housing assembly, and then installs the O-ring 142 in the graphite ring 141 to form a graphite ring assembly 14, and then successively installs the wave spring 12 and the gasket 13 in the sealing housing assembly, at this time, the convex inner ring of the gasket 13 fits with the inner side of the sealing housing assembly, and then puts the graphite ring assembly 14 into the sealing housing assembly, so that one side of the graphite ring 141 fits with one side of the gasket 13, and at this time, the grooves on both sides of the graphite ring 141 are installed correspondingly with the stop block 15, and then the graphite ring 141 is rotated clockwise to make the stop block 15 buckle the graphite ring 141, thereby forming a graphite sealing assembly 1, and then the graphite sealing assembly 1 is installed correspondingly in the hole of the casing, so that the graphite sealing assembly 1 and the hole of the casing are matched with a small gap, and finally the friction ring 2 is installed on the rotating shaft, so that the friction ring 2 and the rotating shaft are matched with a small gap.

[0038] The above specific embodiment is only a preferred embodiment of the present invention. Based on the technical solution of the present invention and the relevant inspiration of the above embodiment, those skilled in the art can make various alternative improvements and combinations to the above specific embodiment.

Claims

1. A highly efficient and durable graphite sealing device, comprising a graphite sealing assembly (1) and a friction ring (2), characterized in that: The graphite sealing assembly (1) comprises a sealing housing (11), a wave spring (12) is arranged in the sealing housing (11), a gasket (13) is arranged in the sealing housing (11) on one side of the wave spring (12), a graphite ring assembly (14) is installed on the side of the gasket (13) away from the wave spring (12), one side of the friction ring (2) is tightly fitted with one side of the graphite ring assembly (14), and two groups of stop blocks (15) are symmetrically installed on the inner wall of the sealing housing (11).

2. A highly efficient and durable graphite sealing device according to claim 1, characterized in that: The sealing shell (11) is arranged in a circular ring shape, an inner cavity is opened on one side of the sealing shell (11), the wave spring (12) is installed corresponding to the inner wall of the inner cavity of the sealing shell (11), and the material of the wave spring (12) is 0Cr17Ni7Al.

3. A highly efficient and durable graphite sealing device according to claim 2, characterized in that: The inner ring of the washer (13) is arranged in a convex shape, and the convex side of the washer (13) is in contact with the wave spring (12). The material of the washer (13) is rubber FX-17.

4. A highly efficient and durable graphite sealing device according to claim 3, characterized in that: The graphite ring assembly (14) comprises a graphite ring (141), the inner ring of the graphite ring (141) is in contact with the inner wall of the inner cavity of the sealing housing (11), an O-ring (142) for auxiliary sealing is arranged between the graphite ring (141) and the sealing housing (11), and grooves are arranged on both sides of the graphite ring (141).

5. A highly efficient and durable graphite sealing device according to claim 4, characterized in that: The material of the graphite ring (141) is pure carbon graphite ZC7-3, and the material of the friction ring (2) is 9Cr18. The graphite ring (141) and the friction ring (2) are both ground on one side close to each other, with a grinding roughness of 0.063 and a flatness of 0.0006.

6. A highly efficient and durable graphite sealing device according to claim 5, characterized in that: The two groups of stop blocks (15) are connected to the sealing housing (11) by resistance welding, and the sealing housing (11) and the stop blocks (15) are both made of 0Cr18Ni9.

7. A highly efficient and durable graphite sealing device according to claim 6, characterized in that: A shallow groove (3) is provided on one side of the grinding surface of the friction ring (2), and the shallow groove (3) is arranged in a spiral shape.

8. An efficient and durable graphite seal assembly method, characterized in that: The following steps are involved: Step 1: Clean all parts to ensure that there is no dirt on the surface. Check whether there are scratches or dents on the surface of the parts. Focus on checking the end face of the graphite ring (141) that fits the friction ring (2) and the end face of the friction ring (2) that fits the graphite ring (141). Step 2: resistance welding is performed according to GB / T19867.5-2008 "Resistance Welding Process Specification", and two sets of stop blocks (15) are respectively welded to the two sides of the inner ring of the sealing housing (11), so that the stop blocks (15) and the sealing housing (11) are integrated into one body, i.e., the sealing housing assembly; Step 3: Install the O-ring (142) in the groove of the graphite ring (141) to form a graphite ring assembly (14); Step 4: Place the sealing housing assembly on a workbench with the opening facing upward, and install the wave spring (12), gasket (13) and graphite ring assembly (14) in the sealing housing assembly in sequence; When the gasket (13) is installed, the protruding side of the gasket (13) faces the inner side of the sealing housing assembly; The graphite ring (141) has grooves on both sides. During assembly, the grooves are aligned with the stop blocks (15) on both sides of the sealing housing assembly. After the graphite ring (141) is placed in the sealing housing assembly, the sealing housing (11) is rotated clockwise until the graphite ring (141) is locked by the stop blocks (15), thereby preventing the graphite ring (141) from being disengaged, and then the graphite sealing assembly (1) is assembled. Step 5: uniformly apply a certain pressure to the end surface of the assembled graphite ring (141) to check whether the springback of the graphite ring (141) meets the requirements; If the requirements are met, the graphite seal assembly (1) is qualified; If the requirements are not met, the graphite sealing assembly (1) needs to be disassembled, and then the graphite ring (141) is rotated counterclockwise so that the groove on the graphite ring (141) is aligned with the stop block (15), and the graphite ring (141) can be taken out. The O-ring (142), the wave spring (12) and the gasket (13) can also be easily taken out. Check each part, and then repeat steps 3, 4 and 5 until the requirements are met. Step 6: Use appropriate tooling to conduct a static sealing test on the assembled graphite sealing assembly (1) and the friction ring (2) to check the sealing performance. If the test is qualified, the two components are successfully paired to form a graphite sealing device. Step 7: When the graphite sealing device is installed and used, the graphite sealing component (1) is a stationary part, installed in the hole of the casing with a slight interference fit, and the friction ring (2) is a rotating part, installed on the rotating shaft with a slight clearance fit.

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