A mechanical sealing device with a graphite ring structure

Abstract

The present invention discloses a mechanical sealing device with a graphite ring structure, which is characterized in that it comprises a gland assembly (1), a clamping ring (2), a graphite ring (3) and a wave spring (4); the graphite ring (3) is located in the center hole of the gland assembly (1) and the inner bottom surface of the graphite ring (3) is tightly attached to the inner bottom surface of the center hole of the gland assembly (1); the graphite ring (3) adopts a multi-segment splicing structure along the circumference and the outer wall is clamped by an elastic structure to form a circular ring; the inner bottom surface of the center hole of the gland assembly (1) is provided with a circle of fluid dynamic pressure spiral grooves (13) arranged along the circumferential direction; the device divides the graphite rings into multiple groups and then positions them by an elastic device, and at the same time adopts a wave spring as a compensation part, saves installation space, effectively reduces the axial length, and at the same time adds a circle of fluid dynamic pressure spiral grooves on the sealing end surface of the dynamic ring, thereby improving the bearing capacity of the seal, reducing the friction and wear of the sealing end surface, and reducing the temperature of the sealing end surface.

Description

Technical Field

[0001] The invention relates to the technical field of mechanical seals, in particular to a mechanical seal device with a graphite ring structure. Background Art

[0002] The dynamic seal device at the turbine end of the starter is installed on the turbine shaft at the power end of the starter and is used for sealing the turbine end. The lubricating oil medium is 4106 or 4050 synthetic aviation lubricating oil for aviation turbine engines, and the environmental medium is air. The starter has two stable speed working conditions, one is the overrunning condition, and the other is the cold running condition. Both of them continue to work after the speed increases from 0 to the specified speed. Under normal working conditions, the maximum pressure difference is 0.03MPa, and under abnormal conditions, the limit pressure difference is 0.13MPa. The working environment temperature is: -40℃~150℃, and the gas medium temperature is: -54℃~250℃; under extreme conditions, oil mist will form on the sliding oil side, and the dynamic seal device can also be immersed in the instantaneous oil flow. At present, conventional mechanical seals cannot effectively seal for a long time when used.

[0003] At present, there is a disclosed double-end mechanical seal device for a graphite pump, comprising a graphite pump body, a first end face is welded to the upper left end of the graphite pump body, and a second end face is welded to the left end of the graphite pump body, a static ring seat is welded to the upper outer surface of the first end face, and a connecting piece is connected through the inside of the first end face, a dynamic ring seat is connected to the lower outer surface of the connecting piece, and the lower end of the dynamic ring seat is welded to the first connecting block, the lower end of the dynamic ring seat is welded to the inner side of the dynamic ring seat, and the upper left and right sides of the dynamic ring seat are movably connected with extrusion blocks, the inner end of the extrusion block is fixedly connected with a spring, and the inner end of the spring is fixedly connected with a connecting plate, the inner end of the connecting plate is fixedly connected with a mother rod, and the inner end of the mother rod is movably connected with a sub-rod, the outer end of the spring is fixedly connected with a first reinforcement block, and a screw is connected through the inside of the first reinforcement block, grooves are opened on the left and right sides of the middle of the connecting piece, and the second reinforcement block is connected inside the groove, and a fixed block is tightly fitted below the second reinforcement block. When the mechanical sealing device of the above structure is used in the field of aircraft engine sealing, the fluid equipment shaft end seal is prone to leakage under the harsh working conditions of high speed (60000r / min) and high temperature (temperature ≥300℃). Moreover, when the aircraft engine is accelerating to boost liftoff or operating in multiple postures, the seal will be subjected to the impact and vibration brought by the operation of the whole machine, and the seal will leak due to the strong impact. In addition, a large amount of radial leakage will be generated under load fluctuation conditions. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a mechanical sealing device with a graphite ring structure, which divides graphite rings into multiple groups and then positions them through elastic devices, while using wave springs as compensation parts, saving installation space, effectively reducing the axial length, and adding a circle of fluid dynamic pressure spiral grooves on the sealing end face of the dynamic ring, thereby improving the bearing capacity of the seal, reducing the friction and wear of the sealing end face, and reducing the temperature of the sealing end face.

[0005] The technical solution of the present invention is to provide a mechanical sealing device with a graphite ring structure having the following structure, including a gland assembly, a clamping ring, a graphite ring and a wave spring; the graphite ring is located in the center hole of the gland assembly and the inner bottom surface of the graphite ring is tightly attached to the inner bottom surface of the center hole of the gland assembly; a gasket is provided on the inner side of the opening of the center hole of the gland assembly, the wave spring is located on the inner side of the gasket, and pushes one end surface of the clamping ring to be tightly attached to the outer end surface of the graphite ring; the clamping ring, the graphite ring, the wave spring and the gasket are all located in the hole of the gland assembly; the graphite ring adopts a multi-section splicing structure along the circumference and the outer side wall is clamped by an elastic structure to form a circular ring; the inner bottom surface of the center hole of the gland assembly is provided with a circle of fluid dynamic pressure spiral grooves arranged along the circumferential direction; a part of each fluid dynamic pressure spiral groove is tightly attached to the inner bottom surface of the graphite ring to form a dynamic seal.

[0006] The gland assembly comprises a gland and a plurality of brake pins, one end of each brake pin is fixed on the gland, and the other end is fixed in a clamping ring, so that the gland and the clamping ring are circumferentially limited.

[0007] The inner bottom surface of the center hole of the gland includes an inner ring end surface and an outer ring end surface, the outer ring end surface is lower than the inner ring end surface, and the fluid dynamic pressure spiral grooves are evenly distributed on the inner ring end surface, with a spacing between two adjacent ones.

[0008] The clamping ring includes a pressing ring and a plurality of positioning pins. One end face of the pressing ring is in close contact with the end face of the graphite ring. Each positioning pin is axially embedded in the pressing ring and the graphite ring. Each section of the graphite ring is embedded with a positioning pin for circumferential positioning.

[0009] A spring groove is formed between the washer and the clamping ring, and the wave spring is assembled in the spring groove.

[0010] The graphite ring adopts a multi-segment structure along the circumference, and an annular groove is arranged on the outer wall. The elastic structure is an annular spring, and the annular spring is sleeved in the annular groove.

[0011] The connection of the multi-section graphite ring structure adopts a snap-fit ​​structure.

[0012] After adopting the above structure, the present invention has the following advantages:

[0013] 1. The compensation part is changed from a small spring to a wave spring: it saves installation space, reduces installation difficulty, has more uniform force and longer service life.

[0014] 2. Improve the gasket to a stamping part to facilitate installation and reduce costs.

[0015] 3. The radial multi-petal seal adopts a multi-segment graphite ring structure to improve the displacement of the sealing surface caused by heat and force deformation, which is greater than the thickness of the sealing gap and the structural limitation of the sealing position; at the same time, the auxiliary sealing ring is omitted, so that this type of seal can better adapt to high-temperature conditions; at the same time, the dynamic pressure effect of the radial multi-petal seal is particularly obvious due to the eccentric effect. With the increase of the speed, the membrane pressure gradually increases, and the two interfaces that keep in contact are separated for a long time and in a stable non-contact state, which can better adapt to high-speed conditions. Therefore, the radial multi-petal seal has become a key component in the field of sealing of the new generation of aircraft engines, which can solve the problem of easy leakage of the shaft end seal of fluid equipment under harsh conditions of high speed (60000r / min) and high temperature (temperature ≥300℃).

[0016] 4. With a multi-segment graphite ring structure, the seal will be subjected to the impact and vibration caused by the operation of the whole machine during the acceleration and boosting or multi-attitude operation of the aircraft engine. Since the radial seal is mainly composed of a multi-petal ring and a flexible cylindrical spring, it is different from the traditional integrally mounted floating ring. The multi-petal ring has multiple degrees of freedom to autonomously adjust and adapt to the radial floating, and can adapt to the movement changes caused by the vibration of the rotor. It also resists the axial displacement or radial displacement of the aircraft engine through eccentricity and flexible wave spring force, reducing the "rubbing" and "shaft-holding" phenomena of the sealing pair, thereby greatly improving the reliability of the seal and avoiding leakage caused by strong impact on the seal.

[0017] 5. The radial graphite petal seal is composed of multiple petals connected end to end, and the two ends of the arc are respectively provided with a buckle interface structure with a certain shape function, which can realize adaptive compensation. When the upstream and downstream ends of the seal are subjected to radial pressure difference, the petal ring can play a floating adjustment, automatically adjust the gap between the petal ring buckles, realize the repeated iterative process of tightening and relaxing, and reduce the radial leakage under load fluctuations, with high reliability and long service life.

[0018] 6. Add a circle of fluid dynamic pressure spiral grooves on the sealing end face of the dynamic ring, and use relative rotation to generate fluid dynamic pressure effect, so that a very thin liquid film is formed between the sealing end faces. This liquid film has fluid dynamic pressure and static pressure, plays a role in lubrication and pressure balance, and prevents medium leakage, thereby improving the bearing capacity of the seal; reducing friction and wear of the sealing end face; and reducing the temperature of the sealing end face. It reduces leakage and prolongs service life.

[0019] 7. The outer side wall of the spring seat and the annular groove is provided with at least one group of circumferentially symmetrical positioning blocks, and the outer wall of the sealing static ring is provided with at least one group of circumferentially symmetrical positioning grooves, each positioning block is embedded in a corresponding positioning groove for circumferential positioning; in addition, during processing and measurement, the distance between the two opposite positioning grooves can be directly measured, which well guarantees the processing size of the sealing ring and makes the force on the end face of the mechanical seal more uniform. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The figure is a cross-sectional schematic diagram of a mechanical sealing device with a graphite ring structure according to the present invention.

[0021] Figure 2 for Figure 1 A magnified schematic diagram of part A.

[0022] Figure 3 It is a cross-sectional schematic diagram of the gland assembly of the present invention.

[0023] Figure 4 It is the front view of the gland of the present invention.

[0024] Figure 5 It is a cross-sectional view of the connection between the graphite ring and the annular spring of the present invention.

[0025] Figure 6 It is a front view of the graphite ring of the present invention.

[0026] Figure 7 It is a cross-sectional view of the clamping ring of the present invention.

[0027] Figure 8 Schematic diagram of the gasket of the present invention.

[0028] As shown in the figure: 1. gland assembly, 2. clamping ring, 3. graphite ring, 4. wave spring, 5. gasket, 11. gland, 12. brake pin, 1.3. fluid dynamic pressure spiral groove, 1.4. inner ring end face, 1.5. outer ring end face, 21. pressure ring, 22. positioning pin, 31. annular spring. DETAILED DESCRIPTION

[0029] The present invention will be further described below in conjunction with the accompanying drawings.

[0030] like Figure 1-8 As shown, a mechanical sealing device with a graphite ring structure of the present invention comprises a gland assembly 1, a clamping ring 2, a graphite ring 3, and a wave spring 4.

[0031] The gland assembly 1 comprises a gland 11 and a plurality of brake pins 12. The gland 11 is an annular structure. Figure 3 and Figure 4As shown, one end of each brake pin 12 is fixed on the gland 11, and the other end is fixed in the clamping ring 2, so that the gland 11 and the clamping ring 2 are circumferentially limited. The gland 11 and the clamping ring 2 are provided with a plurality of holes, and the brake pins 12 are respectively embedded in the corresponding holes on the gland 11 and the holes on the clamping ring 2. The inner bottom surface of the center hole of the gland 11 includes an inner ring end face 14 and an outer ring end face 15, and the outer ring end face 15 is lower than the inner ring end face 14. The fluid dynamic pressure spiral grooves 13 are evenly distributed on the inner ring end face 14, and there is a spacing between two adjacent ones.

[0032] like Figure 5 and Figure 6 As shown, the graphite ring 3 is located in the center hole of the gland assembly 1 and the inner bottom surface of the graphite ring 3 is tightly attached to the inner bottom surface of the center hole of the gland assembly 1; the graphite ring 3 adopts a multi-segment splicing structure along the circumference and the outer wall is clamped by an elastic structure to form a circular ring, that is, the graphite ring 3 is formed by the graphite ring 3 adopting a multi-segment structure along the circumference and the outer side is clamped by an elastic structure to form a circular ring. The graphite ring 3 adopts a multi-segment structure along the circumference, and an annular groove is provided on the outer wall. The elastic structure is an annular spring 31, and the annular spring 31 is sleeved in the annular groove. The two ports of the arc are respectively provided with a buckle interface structure with a certain shape function, and the structure can realize adaptive compensation. When the upstream and downstream ends of the seal are subjected to radial pressure difference, the petal ring can play a floating adjustment, automatically adjust the gap of the petal ring buckle, realize the repeated iterative process of tightening-relaxing, and reduce the radial leakage under load fluctuations, with high reliability and long service life.

[0033] The clamping ring 2, graphite ring 3, wave spring 4 and gasket 5 are all located in the hole of the gland assembly 1, so that these components become a whole, which is convenient for installation.

[0034] A gasket 5 is provided inside the opening of the center hole of the gland assembly 1, and the wave spring 4 is located inside the gasket 5, and pushes one end face of the clamping ring 2 to be tightly attached to the outer end face of the graphite ring 3 to seal. The gasket is improved to a stamping part, which is easy to install and reduces costs.

[0035] like Figure 7 As shown, the clamping ring 2 includes a pressure ring 21 and a plurality of positioning pins 22. One end face of the pressure ring 21 is in close contact with the end face of the graphite ring 3. Each positioning pin 22 is axially embedded in the pressure ring 21 and the graphite ring 3. Each section of the graphite ring 3 is embedded with a positioning pin 22 for circumferential positioning.

[0036] A spring groove is formed between the washer 5 and the clamping ring 2, and the wave spring 4 is assembled in the spring groove. The wave spring is used as a compensating part: it saves installation space, reduces installation difficulty, has more uniform force, and has a longer service life.

[0037] like Figure 3 and4 As shown, the inner bottom surface of the center hole of the gland assembly 1 is provided with a circle of fluid dynamic pressure spiral grooves 13 arranged in the circumferential direction; a part of each fluid dynamic pressure spiral groove 13 is in close contact with the inner bottom surface of the graphite ring 3 to form a dynamic seal. There is a spacing between adjacent fluid dynamic pressure spiral grooves 8 and they are arranged along the circumference of the gland 11, and one circle is in an outward-swinging structure. Adding a circle of fluid dynamic pressure spiral grooves, the fluid dynamic pressure effect is generated by relative rotation, so that an extremely thin liquid film is formed between the sealing end faces. This liquid film has fluid dynamic pressure and static pressure, plays the role of lubrication and pressure balance, and prevents medium leakage at the same time, thereby improving the bearing capacity of the seal; reducing the friction and wear of the sealing end face; and reducing the temperature of the sealing end face. The leakage is reduced and the service life is extended.

Claims

1. A mechanical sealing device with a graphite ring structure, characterized in that: The invention comprises a gland assembly (1), a clamping ring (2), a graphite ring (3) and a wave spring (4); the graphite ring (3) is located in the center hole of the gland assembly (1) and the inner bottom surface of the graphite ring (3) is tightly attached to the inner bottom surface of the center hole of the gland assembly (1); a gasket (5) is provided on the inner side of the opening of the center hole of the gland assembly (1); the wave spring (4) is located on the inner side of the gasket (5) and pushes the end surface of one end of the clamping ring (2) to be tightly attached to the outer end surface of the graphite ring (3) The clamping ring (2), graphite ring (3), wave spring (4) and gasket (5) are all located in the hole of the gland assembly (1); the graphite ring (3) adopts a multi-segment splicing structure along the circumference and the outer wall is clamped by an elastic structure to form a circular ring; the inner bottom surface of the center hole of the gland assembly (1) is provided with a circle of fluid dynamic pressure spiral grooves (13) arranged along the circumferential direction; a part of each fluid dynamic pressure spiral groove (13) is tightly attached to the inner bottom surface of the graphite ring (3) to form a dynamic seal.

2. A mechanical sealing device with a graphite ring structure according to claim 1, characterized in that: The gland assembly (1) comprises a gland (11) and a plurality of brake pins (12), one end of each brake pin (12) being fixed on the gland (11) and the other end being fixed in a clamping ring (2), so that the gland (11) and the clamping ring (2) are circumferentially limited.

3. A mechanical sealing device with a graphite ring structure according to claim 2, characterized in that: The inner bottom surface of the center hole of the pressure cover (11) includes an inner ring end surface (14) and an outer ring end surface (15), the outer ring end surface (15) is lower than the inner ring end surface (14), and the fluid dynamic pressure spiral grooves (13) are evenly distributed on the inner ring end surface (14), and a distance is set between two adjacent ones.

4. A mechanical sealing device with a graphite ring structure according to claim 1, characterized in that: The clamping ring (2) comprises a pressing ring (21) and a plurality of positioning pins (22); one end face of the pressing ring (21) is in close contact with the end face of the graphite ring (3); each positioning pin (22) is axially embedded in the pressing ring (21) and the graphite ring (3); and each section of the graphite ring (3) is embedded with a positioning pin (22) for circumferential positioning.

5. The mechanical sealing device with a graphite ring structure according to claim 1, characterized in that: A spring groove is formed between the washer (5) and the clamping ring (2), and the wave spring (4) is assembled in the spring groove.

6. A mechanical sealing device with a graphite ring structure according to claim 1, characterized in that: The graphite ring (3) adopts a multi-segment structure along the circumference, and an annular groove is provided on the outer wall; the elastic structure is an annular spring (31), and the annular spring (31) is sleeved in the annular groove.

7. A mechanical sealing device with a graphite ring structure according to claim 6, characterized in that: The connection points of the multi-segment structure of the graphite ring (3) adopt a snap-fit ​​structure.

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