Gas-liquid sealing structure for gear box and gear box

Abstract

The invention provides a gas-liquid sealing structure for a gear box and the gear box, relates to a sealing structure, and aims to solve the problem that sealing gas of current dry gas sealing easily enters the gear box to cause faults. Due to the fact that sealing gas may leak under the action of pressure, the choke disc can play a role, the choke disc prevents the gas from directly impacting the interior of the gear box by changing the flow direction of the sealing gas and reducing the axial thrust of the sealing gas, meanwhile, the leaked sealing gas can be smoothly discharged through the design of the exhaust hole and the exhaust mixing hole in the end cover, and the service life of the gear box is prolonged. And the pressure is kept consistent with atmospheric pressure, so that the normal operation of the gearbox is ensured to prolong the service life.

Description

Technical Field

[0001] The invention relates to a sealing structure, in particular to a gas-liquid sealing structure for a gear box and a gear box. Background Art

[0002] Gearboxes in the chemical and petroleum industries are often used in conjunction with dry gas seals. Dry gas seals use clean and dry gas (usually nitrogen) to form a gas barrier between the mechanical shaft and the sealing component to prevent liquid or gas leakage. It mainly uses the gas pressure to be higher than the liquid or gas pressure to compress the gas or liquid in the sealing chamber near the shaft seal, thereby effectively preventing leakage. In the chemical industry, it is often necessary to handle some harmful, corrosive or viscous media. Traditional liquid seals are susceptible to damage or leakage under such conditions, while dry gas seals can effectively solve these problems. In the petroleum industry, due to the variety of media, it is often necessary to seal in harsh working environments. Dry gas seals can adapt to harsh environments such as high temperature, high pressure, and corrosion to ensure the normal operation of equipment. For example, dry gas seals are often used in oil and gas sealing systems such as oil pumps, oil well gas production equipment, and pipelines.

[0003] During the use of the gearbox, the sealing gas (usually nitrogen) of the dry gas seal enters the gearbox along the gap of the shaft under the action of pressure, affecting the lubrication of the gearbox bearing, causing the pressure inside the box to increase, and easily causing failures; the Chinese patent (publication number CN 115978171 B) discloses a gearbox oil return seal structure, a gearbox and a gearbox oil return method, including an oil retaining ring, an O-ring, a labyrinth seal ring, an oil return pipe designed to return the oil to the gearbox, an oil return groove and an oil return hole designed for oil return, and an oil hole is opened on the oil retaining ring to allow the oil to return to the oil return groove. However, it only considers the oil return problem in the gearbox, and does not solve the problem that the dry gas seal of the gearbox is prone to cause failures; and the airflow of the dry gas seal enters the gearbox along the gap at the end cover position, which will also destroy the seal at the end cover position of the gearbox, resulting in an adverse effect on the sealing effect at the end cover position of the gearbox. Summary of the invention

[0004] The purpose of the present invention is to provide a gas-liquid sealing structure and a gear box for a gear box in view of the defects of the prior art. A wind-blocking disk is installed on the gear box shaft to change the flow direction of the overflowing sealing gas and reduce the axial thrust of the overflowing sealing gas. An exhaust hole is designed on the end cover, and the sealing gas is discharged to the atmosphere through the exhaust hole to ensure that it is basically consistent with the pressure of the gear box.

[0005] The first object of the present invention is to provide a gas-liquid sealing structure for a gear box, which adopts the following scheme:

[0006] It comprises a dry gas sealing assembly, a choke plate and an end cover which are sequentially sleeved outside the shaft; the end cover is provided with a demixing hole, an exhaust hole and a through hole for the shaft to pass through; one end of the demixing hole is connected to the through hole, and the other end extends away from the axis of the through hole and passes through the end cover; the inner ring of the choke plate fits the outer wall of the shaft; a first opening of the exhaust hole is provided on the end surface of the end cover close to one end of the choke plate; the second opening of the exhaust hole is located between the demixing hole and the choke plate; along the through hole radial direction, the outer ring of the choke plate is located between the first opening and the axis of the through hole.

[0007] Furthermore, a plurality of exhaust holes are provided upwardly along the via ring and are arranged in a ring array.

[0008] Furthermore, the exhaust hole includes a first channel and a second channel, the axis of the first channel is parallel to the axis of the through hole, and one end extends to the end face of the end cover to form a first opening, and the other end is connected to the second channel, and the second channel extends radially along the end cover to the outer peripheral surface of the end cover to form a second opening.

[0009] Furthermore, an inner wall of the through hole is provided with demixing grooves distributed in the circumferential direction, and one end of the demixing hole close to the through hole is connected to the demixing groove and connected to the through hole through the demixing groove.

[0010] Furthermore, along the through-hole axis, a sealing groove is provided on the side of the demixing groove away from the exhaust hole, and a felt sealing ring is installed in the sealing groove.

[0011] Furthermore, along the through hole axis, an oil return hole is provided in the end cover on the side of the mixing hole away from the exhaust hole, one end of the oil return hole is connected to the through hole, and the other end extends to the end surface of the end cover away from the wind blocking disk.

[0012] Furthermore, an inner wall of the through hole is provided with an oil return groove distributed in a circumferential direction, and one end of the oil return hole is connected to the through hole through the oil return groove.

[0013] Furthermore, the oil return holes are provided in plurality, the plurality of oil return holes are connected to one end of the through hole and are spaced apart from each other, and the plurality of oil return holes extend together to one end of the end surface of the end cover.

[0014] A second object of the present invention is to provide a gear box using the gas-liquid sealing structure for the gear box as described in the first object.

[0015] Furthermore, the shaft of the gear box is equipped with a gas-liquid sealing structure for the gear box, the positive pressure gas source is connected to the dry gas sealing component, and the negative pressure gas source is connected to the demixing hole and the exhaust hole.

[0016] Compared with the prior art, the present invention has the following advantages and positive effects:

[0017] (1) In view of the problem that the sealing gas of the current dry gas seal can easily enter the gear box and cause failures, when the gear box is running, the dry gas seal assembly first plays a sealing role to prevent external gas and impurities from entering the gear box. Since the sealing gas may leak under the action of pressure, the air choke disk will come into play at this time. The air choke disk changes the flow direction of the sealing gas, reduces its axial thrust, and prevents the gas from directly impacting the inside of the gear box. At the same time, the exhaust hole and mixing hole design on the end cover can ensure that the leaked sealing gas can be discharged smoothly and keep it consistent with the atmospheric pressure, ensuring the normal operation of the gear box and increasing its service life.

[0018] (2) Along the through-hole axis, a sealing groove is provided on the side of the demixing groove away from the exhaust hole. A felt sealing ring is installed in the sealing groove. The felt sealing ring installed in the sealing groove can effectively prevent external impurities and moisture from entering the gearbox. At the same time, the felt sealing ring also has a certain elasticity and can adapt to the slight vibration of the shaft during operation. The sealing performance of the gearbox can be improved by the sealing groove and the felt sealing ring. It not only helps to prevent external impurities and moisture from damaging the gearbox, but also improves the reliability and durability of the gearbox. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0020] Figure 1 Schematic diagram of the gas-liquid sealing structure for the gearbox in Examples 1 and 2 of the present invention.

[0021] Among them, 1. dry gas sealing assembly; 2. wind blocking disc; 3. exhaust hole; 4. demixing hole; 5. first oil return hole; 6. second oil return hole; 7. felt sealing ring; 8. shaft; 9. end cover. DETAILED DESCRIPTION

[0022] Example 1

[0023] In a typical embodiment of the present invention, Figure 1 As shown, a gas-liquid sealing structure for a gear box is provided.

[0024] The main problem faced by existing gearboxes during use is that the sealing gas (usually nitrogen) of the dry gas seal enters the interior of the gearbox along the gap of the shaft 8 under pressure. This not only affects the lubrication of the gearbox bearings, causing the internal pressure of the box to increase, which is easy to cause failures, but also destroys the seal at the position of the gearbox end cover 9, resulting in an adverse effect on the sealing effect. Although the prior art discloses a gearbox oil return seal structure that solves the oil return problem in the gearbox, it does not solve the problem of failure caused by the dry gas seal. Based on this, the present embodiment provides a gas-liquid seal structure for a gearbox, which aims to reduce the axial thrust of the overflowing sealing gas by changing its flow direction, and discharge the sealing gas to the atmosphere through the exhaust hole 3 on the end cover 9 to ensure that it is basically consistent with the gearbox pressure.

[0025] like Figure 1 As shown, the gas-liquid sealing structure for the gearbox includes a dry gas sealing assembly 1, a choke plate 2 and an end cover 9, which are arranged in sequence along the axial direction of the gearbox shaft 8. The dry gas sealing assembly 1 is located at the outermost layer of the shaft 8 and is the first line of defense to prevent leakage of the sealing gas. Through the dry gas sealing technology, it effectively prevents external gases (such as air, dust, etc.) from entering the interior of the gearbox, and prevents the internal oil of the gearbox from leaking out. The choke plate 2 is located between the dry gas sealing assembly 1 and the end cover 9, close to the outer wall of the shaft 8. The main function of the choke plate 2 is to change the flow direction of the overflowing sealing gas. When the sealing gas tries to enter the gearbox along the gap of the shaft 8 under the action of pressure, the choke plate 2 will guide the gas to change direction so that the airflow can flow radially outward along the choke plate 2, reducing its axial thrust, thereby preventing the gas from directly impacting the interior of the gearbox.

[0026] The end cover 9 is located at the outermost layer of the entire sealing structure and is used to seal one end of the gearbox. The end cover 9 is provided with a mixing hole 4, an exhaust hole 3 and a through hole for the shaft 8 to pass through. The through hole is located at the center of the end cover 9 and adopts a through hole structure, and can achieve clearance fit with the shaft 8 of the gearbox. One end of the mixing hole 4 is connected to the through hole, and the other end extends away from the through hole axis and passes through the end cover 9.

[0027] The main function of the demixing hole 4 is to discharge the processed sealing gas and prevent external impurities from entering the gearbox. The lubricating oil is sealed through the non-contact gap between the end cover 9 and the shaft 8 of the gearbox, and the sealing effect is guaranteed by the tension of the oil film. The excess oil is returned to the gearbox through the oil return hole. The first opening of the exhaust hole 3 is located on the end face of the end cover 9 close to the air-blocking disk 2, and the second opening is provided on the end cover 9 between the demixing hole 4 and the air-blocking disk 2, which can ensure that the sealing gas can smoothly enter the exhaust hole 3 after passing through the air-blocking disk 2, and be discharged to the atmosphere through the demixing hole 4.

[0028] The outer ring of the air choke disk 2 is located between the first opening of the exhaust hole 3 and the through-hole axis, which can ensure that the sealing gas can smoothly enter the exhaust hole 3 and be discharged after passing through the air choke disk 2. Under the action of pressure, the sealing gas would originally enter the interior of the gearbox along the gap of the shaft 8, but due to the existence of the air choke disk 2, its flow direction is changed. The sealing gas discharged from the dry gas seal assembly 1 enters from the first opening of the exhaust hole 3, passes through the space between the outer ring of the air choke disk 2 and the first opening, and then is discharged from the second opening, and finally discharged to the atmosphere through the demixing hole 4.

[0029] By adjusting the structure of the air blocking plate 2 and the end cover 9, the possibility of the sealing gas entering the gear box is reduced, thereby avoiding the problem of the internal pressure of the gear box rising and the lubrication being affected. The problem of the dry gas seal airflow entering the gear box along the gap at the end cover 9 position and destroying the seal at the end cover 9 position is solved. The sealing performance of the gear box is improved, the occurrence of failures is reduced, and the internal pressure of the gear box is ensured to be basically consistent with the atmospheric pressure, which is conducive to the normal operation of the gear box.

[0030] like Figure 1 As shown, multiple exhaust holes 3 are arranged upward along the through-hole ring and arranged in an annular array, ensuring that the sealing gas can be evenly distributed in the axial direction and effectively guided to the exhaust holes 3. The annular array arrangement not only improves the exhaust efficiency, but also, compared with increasing the size of the first opening of a single exhaust hole 3, using multiple exhaust holes 3 distributed in multiple positions can reduce the adverse effect on the structural strength of the end cover 9, so that the end cover 9 can better withstand the axial and radial forces from the shaft 8 and the gearbox.

[0031] In addition, the evenly distributed exhaust holes 3 can avoid problems such as gas leakage or deformation of the end cover 9 caused by excessive local gas pressure, which helps to improve the overall stability and operating efficiency of the gearbox.

[0032] Specifically, the exhaust hole 3 includes a first channel and a second channel. The axis of the first channel is parallel to the axis of the through hole, and one end extends to the end face of the end cover 9 to form a first opening, which is convenient for cooperating with the wind-blocking disk 2 to guide the sealed gas to change the flow direction; the other end of the first channel is connected to the second channel, and the second channel extends radially along the end cover 9 to the outer peripheral surface of the end cover 9 to form a second opening to ensure that the sealed gas can be discharged smoothly. The second opening can also be configured with a corresponding docking structure, such as a thread, a card interface, a card joint, etc., so as to facilitate docking with an external negative pressure gas source to achieve smooth gas discharge. The exhaust efficiency is improved, and the accumulation and vortex phenomenon of the sealed gas inside the end cover 9 are reduced. At the same time, the size and shape of the first channel and the second channel can be adjusted according to demand to optimize the exhaust performance and meet the needs under different working conditions.

[0033] The inner wall of the through hole is provided with a mixing removal groove distributed along the annular direction, and the mixing removal hole 4 is connected to the mixing removal groove at one end close to the through hole, and is connected to the through hole through the mixing removal groove; Figure 1As shown, a demixing groove is configured to collect the oil-gas mixture discharged from the gear box. After being circumferentially distributed, the collection range can be enlarged to improve the efficiency of discharging the oil-gas mixture. The gas from the direction of the wind-blocking disk 2 can also be discharged, thereby collecting and mixing the sealing gases in different flow directions to prevent the gas from forming vortices or dead corners inside the end cover 9.

[0034] Along the through-hole axis, a sealing groove is provided on the side of the demixing groove away from the exhaust hole 3, and a felt sealing ring 7 is installed in the sealing groove. The felt sealing ring 7 installed in the sealing groove can effectively prevent external impurities and moisture from entering the gearbox. At the same time, the felt sealing ring 7 also has a certain elasticity and can adapt to the slight vibration of the shaft 8 during operation. The sealing performance of the gearbox can be improved by the sealing groove and the felt sealing ring 7. It not only helps to prevent external impurities and moisture from damaging the gearbox, but also improves the reliability and durability of the gearbox.

[0035] like Figure 1 As shown, along the through-hole axis, an oil return hole is provided in the end cover 9 on the side of the mixing hole 4 away from the exhaust hole 3, one end of the oil return hole is connected to the through-hole, and the other end extends to the end face of the end cover 9 away from the wind-blocking plate 2; the lubricating oil is sealed through the non-contact gap between the gear box end cover 9 and the shaft 8, and the sealing effect is ensured by the tension of the oil film, and the excess oil is returned to the gear box through the oil return hole, which can also balance the oil pressure inside the gear box.

[0036] The inner wall of the through hole is provided with an oil return groove distributed along the annular direction, and one end of the oil return hole is connected to the through hole through the oil return groove. The oil return groove increases the oil collection range and improves the oil return efficiency. At the same time, the oil return groove can also play the role of distributing the oil.

[0037] There are multiple oil return holes, which are spaced apart and connected to one end of the through hole. The multiple oil return holes extend together to one end of the end face of the end cover 9, so that the oil can be collected and refluxed multiple times during the reflux process, thereby improving the reliability and stability of the oil return.

[0038] In this embodiment, there is a gap of 0.15-0.25 mm between the end cover 9 and the shaft 8. The gearbox lubricating oil is sealed by the tension of the oil film. The oil leaked through the gap flows back to the gearbox through the first oil return hole 5 and the second oil return hole 6. A very small amount of oil and gas is sealed by the felt sealing ring 7, and the remaining trace amount of leaked oil and gas is discharged through the demixing hole 4.

[0039] The exhaust hole 3, the mixing hole 4 and the oil return hole on the end cover 9 not only improve the sealing performance and lubrication effect of the gearbox, but also enhance the structural strength and durability of the end cover 9. Various working conditions and requirements of the gearbox in the actual operation process are taken into consideration to ensure that the gearbox can operate stably in various complex environments.

[0040] Example 2

[0041] In another typical embodiment of the present invention, Figure 1 As shown, a gear box is provided, which utilizes the gas-liquid sealing structure for the gear box as in Example 1.

[0042] A gearbox includes a shaft 8 on which a gear is mounted, and a dry gas seal assembly 1, a choke plate 2, and an end cover 9 are sequentially sleeved on the shaft 8. The gearbox incorporates the optimized features of the sealing structure in Example 1 in terms of design and function, aiming to improve the sealing performance, lubrication effect, and operating stability of the gearbox.

[0043] The gearbox shaft 8 is closely matched with the gearbox gas-liquid seal structure, ensuring the stability and reliability of the seal structure, preventing external gas and impurities from entering the gearbox, and effectively preventing the leakage of the gearbox oil. The gearbox gas-liquid seal structure can keep a stable sealing effect during the operation of the gearbox, which helps to reduce the wear and vibration of the shaft 8 and improve the overall operation efficiency and stability of the gearbox.

[0044] The positive pressure gas source is connected to the dry gas seal assembly 1, and the negative pressure gas source is connected to the demixing hole 4 and the exhaust hole 3. The positive pressure gas source is introduced into the dry gas seal assembly 1 to provide sufficient sealing pressure to prevent external gas and impurities from entering the gearbox. At the same time, the negative pressure gas source is introduced into the demixing hole 4 and the exhaust hole 3 to form a negative pressure environment to promote the discharge of the sealing gas and the reflux of the oil-gas mixture. The positive pressure gas source ensures the sealing effect of the dry gas seal assembly 1, while the negative pressure gas source helps to promote the discharge of the sealing gas and the reflux of the oil, thereby further improving the sealing performance and lubrication effect of the gearbox, reducing the leakage and pollution of the gearbox, and improving the reliability and durability of the gearbox.

[0045] This embodiment can ensure the stable operation of the gearbox under complex working conditions, reduce leakage and pollution, and improve reliability and durability.

[0046] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A gas-liquid sealing structure for a gear box, characterized in that: It comprises a dry gas sealing assembly, a choke plate and an end cover which are sequentially sleeved outside the shaft; the end cover is provided with a demixing hole, an exhaust hole and a through hole for the shaft to pass through; one end of the demixing hole is connected to the through hole, and the other end extends away from the axis of the through hole and passes through the end cover; the inner ring of the choke plate fits the outer wall of the shaft; a first opening of the exhaust hole is provided on the end surface of the end cover close to one end of the choke plate; the second opening of the exhaust hole is located between the demixing hole and the choke plate; along the through hole radial direction, the outer ring of the choke plate is located between the first opening and the axis of the through hole.

2. The gas-liquid sealing structure for a gear box according to claim 1, characterized in that: A plurality of exhaust holes are arranged upwardly along the via ring and are arranged in a ring array.

3. The gas-liquid sealing structure for a gear box according to claim 2, characterized in that: The exhaust hole includes a first channel and a second channel. The axis of the first channel is parallel to the axis of the through hole, and one end extends to the end surface of the end cover to form a first opening, and the other end is connected to the second channel. The second channel extends radially along the end cover to the outer peripheral surface of the end cover to form a second opening.

4. The gas-liquid sealing structure for a gear box according to claim 1, characterized in that: The inner wall of the through hole is provided with demixing grooves distributed in the circumferential direction, and one end of the demixing hole close to the through hole is connected to the demixing groove and connected to the through hole through the demixing groove.

5. The gas-liquid sealing structure for a gear box according to claim 1 or 4, characterized in that: Along the through-hole axis, a sealing groove is provided on the side of the demixing groove away from the exhaust hole, and a felt sealing ring is installed in the sealing groove.

6. The gas-liquid sealing structure for a gear box according to claim 1, characterized in that: Along the through hole axis, an oil return hole is provided in the end cover on the side of the mixing hole away from the exhaust hole, one end of the oil return hole is connected to the through hole, and the other end extends to the end surface of the end cover away from the wind blocking disk.

7. The gas-liquid sealing structure for a gear box according to claim 6, characterized in that: An oil return groove distributed along the circumferential direction is arranged on the inner wall of the through hole, and one end of the oil return hole is connected to the through hole through the oil return groove.

8. The gas-liquid sealing structure for a gear box according to claim 6 or 7, characterized in that: The oil return holes are provided in plurality, and the plurality of oil return holes are connected to one end of the through hole and are distributed at intervals, and the plurality of oil return holes extend together to one end of the end surface of the end cover.

9. A gear box, using the gas-liquid sealing structure for a gear box as claimed in any one of claims 1 to 8.

10. The gearbox according to claim 9, characterized in that The shaft of the gear box is equipped with a gas-liquid sealing structure for the gear box, the positive pressure gas source is connected to the dry gas sealing component, and the negative pressure gas source is connected to the demixing hole and the exhaust hole.

Images