Shaft sealing structure and centrifugal compressor

Abstract

The utility model belongs to the technical field of mechanical transmission, and particularly provides a shaft sealing structure and a centrifugal compressor, the shaft sealing structure comprises a rotating shaft with an active rotating action and a shell in a static state, the rotating shaft is sleeved with a comb tooth type shaft sleeve, a sealing body is arranged on the peripheral side of the comb tooth type shaft sleeve, and the sealing body and the shell are relatively fixed; a sealing function layer is arranged on the inner wall of the sealing body and used for being in scraping abrasion with the comb tooth type shaft sleeve. Therefore, effective sealing can be formed between the rotating shaft rotating at a high speed and the static shell, working media such as gas and liquid are prevented from leaking, and normal operation of the centrifugal compressor and safety of the working environment are guaranteed. In addition, according to the shaft sealing structure, the transmission shaft is not prone to being abraded, the replacement frequency of the transmission shaft is reduced, and therefore maintenance cost is reduced. Meanwhile, the shaft sealing structure has low requirements on the precision of the transmission shaft, and the cost and difficulty in the manufacturing and mounting process of the centrifugal compressor are reduced.

Description

Technical Field

[0001] This application belongs to the technical field of mechanical transmission, and particularly relates to a shaft sealing structure and a centrifugal compressor. Background Art

[0002] In many industrial fields, rotary mechanical equipment such as compressors and pumps are widely used. In these devices, the sealing of the shaft is a key issue, which is directly related to the performance, efficiency, and reliability of the device. Traditional shaft sealing methods often have some limitations and cannot well meet the high requirements for sealing performance in modern industry.

[0003] With the continuous progress of industrial technology, the operating speed, working pressure, and working temperature of the equipment are constantly increasing, and the requirements for the shaft sealing structure are becoming more and more stringent. On the one hand, it is necessary for the sealing structure to form an effective seal between the high-speed rotating shaft and the stationary housing to prevent the leakage of working media (such as gases, liquids, etc.) to ensure the normal operation of the equipment and the safety of the working environment. On the other hand, the sealing structure also needs to have good wear resistance, corrosion resistance, and high-temperature resistance to adapt to different working conditions and harsh working environments.

[0004] In the existing shaft sealing technologies, common sealing methods such as packing seals and mechanical seals can, to a certain extent, meet the sealing requirements, but there are also some problems. For example, packing seals are prone to wearing the shaft and require frequent replacement of the packing, resulting in high maintenance costs; mechanical seals have a complex structure, are difficult to install and maintain, and have high requirements for the accuracy of the shaft. Summary of the Utility Model

[0005] Therefore, the technical problem to be solved by this application is to provide a shaft sealing structure and a centrifugal compressor. Through the mutual scraping of the sealing functional layer of the comb-tooth type shaft sleeve and the sealing body, an effective seal can be formed between the high-speed rotating shaft and the stationary housing, and the rotating shaft is not easily worn, reducing the replacement frequency of the transmission shaft, thereby reducing the maintenance cost; at the same time, the accuracy requirements for the transmission shaft are relatively low, reducing the costs and difficulties in the equipment manufacturing and installation processes.

[0006] To solve the above problems, on the one hand, this application provides a shaft sealing structure, including a rotating shaft with an active rotation action and a stationary housing. A comb-tooth type shaft sleeve is sleeved on the rotating shaft, a sealing body is arranged on the outer peripheral side of the comb-tooth type shaft sleeve, the sealing body is relatively fixed to the housing, and a sealing functional layer is arranged on the inner wall of the sealing body. The sealing functional layer is used to scrape against the comb-tooth type shaft sleeve to form the shaft sealing structure.

[0007] Optionally, a first inflation channel is provided on the sealing body, the first inflation channel is communicated with the shaft sealing structure, a second inflation channel is provided on the housing, and the second inflation channel is used to communicate the first inflation channel with an external gas source.

[0008] Optionally, a plurality of first inflation channels are provided, and the plurality of first inflation channels are uniformly arranged along the circumferential direction of the sealing body.

[0009] Optionally, a first air release channel is provided on the sealing body, the first air release channel is communicated with the shaft sealing structure, a second air release channel is provided on the housing, and the second air release channel is communicated with the first air release channel.

[0010] Optionally, a plurality of first air release channels are provided, and the plurality of first air release channels are uniformly arranged along the circumferential direction of the sealing body.

[0011] Optionally, when the first inflation channel is provided on the sealing body, the first air release channel is located on a side of the first inflation channel close to the housing.

[0012] Optionally, an oil slinger is provided at an end of the sealing body away from the housing.

[0013] Optionally, oil slinger holes are formed in the oil slinger.

[0014] Optionally, a plurality of comb-shaped members are provided on the outer peripheral surface of the comb-shaped shaft sleeve at equal intervals along the axial direction, the height of the comb-shaped members is 2 mm to 3 mm, and the distance between adjacent two comb-shaped members is 2 mm to 4 mm.

[0015] On the other hand, the present application provides a centrifugal compressor, including the shaft sealing structure as described in any one of the above.

[0016] Beneficial effects

[0017] The embodiments of the present utility model provide a shaft sealing structure and a centrifugal compressor. The shaft sealing structure mutually grinds through the comb-shaped shaft sleeve and the sealing body with a sealing functional layer, can form an effective seal between the rotating shaft rotating at a high speed and the stationary housing, prevent leakage of working media such as gas and liquid, and ensure the normal operation of the centrifugal compressor and the safety of the working environment. In addition, the shaft sealing structure is not easy to wear the transmission shaft, reduces the replacement frequency of the transmission shaft, and thus reduces the maintenance cost. At the same time, the shaft sealing structure has a lower precision requirement for the transmission shaft, and reduces the cost and difficulty in the manufacturing and installation processes of the centrifugal compressor. Description of the drawings

[0018] Figure 1 It is a schematic structural diagram of a centrifugal compressor according to an optional embodiment of the present application;

[0019] Figure 2 is Figure 1 a partial enlarged view at position A in

[0020] Figure 3 is Figure 2 a sectional view taken along line B - B in

[0021] The reference numerals are indicated as:

[0022] 1. Rotating shaft; 2. Housing; 3. Comb - tooth - type bushing; 4. Sealing body; 5. Sealing functional layer; 6. First inflation channel; 7. Second inflation channel; 8. First deflation channel; 9. Second deflation channel; 10. Oil - throwing platform; 11. Oil - throwing hole. Detailed implementation manners

[0023] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. These are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present utility model.

[0024] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present utility model, "a plurality" means two or more unless otherwise specifically defined.

[0025] In the present application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected to", "fixed", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0026] The preferred embodiments of the present utility model are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only for the purpose of illustrating and explaining the present utility model and are not used to limit the present utility model.

[0027] Refer to in combinationFigures 1 to 3 As shown, according to one aspect of the embodiments of the present application, a shaft seal structure is provided, which includes a rotating shaft 1 with an active rotating action and a housing 2 in a stationary state. A comb-tooth type shaft sleeve 3 is sleeved on the rotating shaft 1. A sealing body 4 is arranged on the outer peripheral side of the comb-tooth type shaft sleeve 3. The sealing body 4 is relatively fixed to the housing 2. A sealing functional layer 5 is arranged on the inner wall of the sealing body 4. The sealing functional layer 5 is used for scraping against the comb-tooth type shaft sleeve 3 to form a shaft seal structure.

[0028] In the present application, the shaft seal structure can form an effective seal between the rotating shaft 1 rotating at high speed and the stationary housing 2 by scraping between the comb-tooth type shaft sleeve 3 and the sealing body 4 with the sealing functional layer 5, preventing the leakage of working media such as gas and liquid, and ensuring the normal operation of the equipment and the safety of the working environment. In addition, this shaft seal structure is not easy to wear the transmission shaft, reduces the replacement frequency of the transmission shaft, and thus reduces the maintenance cost. At the same time, this shaft seal structure has a lower precision requirement for the transmission shaft, reducing the cost and difficulty in the equipment manufacturing and installation processes.

[0029] It can be understood that the shaft seal structure can be applied to compressors, pumps, stirring equipment, reaction kettles, gas turbines, wind turbine generators, or paper-making machinery, etc. For example, when the shaft seal structure is applied to a compressor, it can ensure that the compressed gas does not leak, improving the efficiency and reliability of the equipment; when the shaft seal structure is applied to a pump, it can prevent the leakage of the conveyed liquid, ensuring the normal operation of the pump and the safety of the working environment; when the shaft seal structure is applied to stirring equipment, it can prevent the leakage of the stirring medium and at the same time adapt to high-speed rotation and different working conditions; when the shaft seal structure is applied to a reaction kettle, it can ensure that the substances in the reaction kettle do not leak due to shaft seal problems during the reaction process, meeting the requirements of harsh working environments such as high temperature and high pressure; when the shaft seal structure is applied to a gas turbine, it can prevent the leakage of gas, improving the energy utilization efficiency and the safety of the equipment; when the shaft seal structure is applied to a wind turbine generator, it can ensure the sealing performance of the fan main shaft, preventing external dust, moisture, etc. from entering the equipment interior and extending the service life of the equipment; when the shaft seal structure is applied to paper-making machinery, it can prevent the leakage of pulp, ensuring the continuity of production and the quality of paper.

[0030] Among them, taking the application of the shaft seal structure to a compressor as an example, the shaft seal structure can be installed at the shaft end part of the compressor. During the operation of the compressor, when the gas or liquid inside the compressor tries to leak towards the shaft end under the action of pressure, the shaft seal structure can effectively block its leakage path.

[0031] Among them, the shaft seal structure includes a rotating shaft 1 and a housing 2. The rotating shaft 1 is specifically the drive shaft of the compressor impeller. One end of the drive shaft of the compressor impeller is connected to the gearbox, and the other end is connected to the impeller. The gearbox is used to drive the rotation of the drive shaft of the compressor impeller, thereby driving the impeller to rotate. The housing 2 is specifically a volute. The impeller is located inside the volute. The rotation of the impeller generates centrifugal force, thereby compressing gas or liquid.

[0032] Specifically, the housing 2 is provided with a shaft hole passing through the rotating shaft 1, and the shaft hole is located at the axial center position of the housing 2.

[0033] Among them, a sealing body 4 is fixed on the inner wall of the shaft hole. The inner wall of the sealing body 4 is closely attached to the comb-shaped shaft sleeve 3. The comb-shaped shaft sleeve 3 is firmly sleeved on the rotating shaft 1.

[0034] Specifically, a sealing functional layer 5 is provided on the inner wall of the sealing body 4. The sealing functional layer 5 can be a wear-resistant coating made of aluminum-silicon polyphenyl ester. When the rotating shaft 1 rotates at a high speed, the comb-shaped shaft sleeve 3 sleeved on it rotates synchronously. The sealing functional layer 5 on the inner wall of the sealing body 4, which is relatively fixed to the housing 2, is in close contact with the comb-shaped shaft sleeve 3 and generates a scraping effect, forming an effective sealing area to prevent the working medium (such as gas, liquid, etc.) from leaking from the shaft hole.

[0035] In the above embodiment, a number of comb-shaped members are arranged at equal intervals along the axial direction on the outer peripheral surface of the comb-shaped shaft sleeve 3. The height of the comb-shaped members is 2 mm to 3 mm, and the interval distance between two adjacent comb-shaped members is 2 mm to 4 mm.

[0036] It can be understood that the number of comb-shaped members arranged at equal intervals cooperate with the sealing functional layer 5 of the sealing body 4, increasing the contact area and complexity of the seal. When the working medium attempts to leak, it needs to pass through the tortuous paths between a number of comb-shaped members, greatly increasing the difficulty of leakage, thereby enhancing the sealing effect.

[0037] Among them, the number of comb-shaped members can be raised portions distributed at equal intervals along the axial direction on the outer periphery of the comb-shaped shaft sleeve 3, and their shapes are similar to the teeth of a comb.

[0038] Specifically, when the comb-shaped bushing 3 is sleeved on the rotating shaft 1 and rotates therewith, the sealing functional layer 5 of the seal body 4 is in close contact with the outer peripheral surface of the comb-shaped bushing 3. Since a number of comb-shaped members are arranged at equal intervals along the axial direction on the outer peripheral surface of the comb-shaped bushing 3, the presence of these comb-shaped members makes the contact between the sealing functional layer 5 and the bushing no longer a smooth surface. Each comb-shaped member has a certain height and width, and an interval space is formed between adjacent comb-shaped members. When the working medium attempts to leak from the shaft sealing structure, it must pass through these interval spaces. After the working medium enters the gap between the first comb-shaped member and the sealing functional layer 5, it will be blocked and diverted by the comb teeth. Due to the presence of the comb-shaped members, the flow direction of the working medium is forced to change and cannot pass straight through. Then, the working medium needs to bypass the first comb tooth and enter the gap between the next comb-shaped member and the sealing functional layer 5. During this process, the flow path of the working medium changes again, forming a tortuous route. As the working medium passes through the gaps between multiple comb-shaped members in sequence, its flow path is continuously changed by the comb teeth, thus forming a complex tortuous path. The generation of this tortuous path increases the difficulty of working medium leakage. The working medium needs to overcome the blocking, friction of multiple comb-shaped members, and the energy loss caused by multiple changes in the flow direction before it can finally leak out. Therefore, the tortuous path between multiple comb-shaped members effectively improves the sealing performance of the shaft sealing structure.

[0039] Among them, the height of a number of comb-shaped members can be 2 mm to 3 mm. For example, the height of the comb-shaped member is 2.0 mm, or 2.1 mm, or 2.2 mm, or 2.3 mm, or 2.4 mm, or 2.5 mm, or 2.6 mm, or 2.7 mm, or 2.8 mm, or 2.9 mm, or 3.0 mm. It should be noted that the height of a number of comb-shaped members can also be other values outside the above values, as long as the height range of a number of comb-shaped members is 2 mm to 3 mm. When the comb-shaped members with a height of 2 mm to 3 mm are abraded against the sealing functional layer 5, an appropriate sealing pressure can be generated to ensure the tightness of the seal. At the same time, this height range can also avoid excessive wear on the sealing functional layer 5 while ensuring the sealing effect.

[0040] Among them, the spacing distance between two adjacent comb-shaped members can be 2 mm to 4 mm. For example, the spacing distance between two adjacent comb-shaped members is 2.0 mm, or 2.1 mm, or 2.2 mm, or 2.3 mm, or 2.4 mm, or 2.5 mm, or 2.6 mm, or 2.7 mm, or 2.8 mm, or 2.9 mm, or 3.0 mm, or 3.1 mm, or 3.2 mm, or 3.3 mm, or 3.4 mm, or 3.5 mm, or 3.6 mm, or 3.7 mm, or 3.8 mm, or 3.9 mm, or 4.0 mm. It should be noted that the spacing distance between two adjacent comb-shaped members can also be other values outside the above-mentioned values, as long as the spacing distance range between two adjacent comb-shaped members is 2 mm to 4 mm. This spacing range enables the comb-shaped bushing 3 to adapt to different working pressures and flow rates. In the case of high pressure, the spacing can play a certain buffering role to prevent the sealing structure from being damaged by the instantaneous high pressure; in the case of low flow rate, it can ensure the effectiveness of the seal and prevent the working medium from slowly penetrating.

[0041] In some possible embodiments disclosed in the present application, referring to Figure 2 As shown, a first inflation channel 6 is provided on the sealing body 4, the first inflation channel 6 is communicated with the shaft sealing structure, and a second inflation channel 7 is provided on the housing 2, and the second inflation channel 7 is used to communicate the first inflation channel 6 with an external gas source.

[0042] It can be understood that in the present application, the external gas source inflates the shaft sealing structure through the second inflation channel 7 and the first inflation channel 6, and a positive pressure environment can be formed in the sealing area. When the working medium attempts to leak, the positive pressure gas can form an additional blocking force on it, further reducing the possibility of leakage and significantly enhancing the sealing performance.

[0043] Among them, the first inflation channel 6 extends along the radial direction of the sealing body 4 and penetrates the sealing body 4 to be communicated with the shaft sealing structure, so that external gas can be introduced into the sealing area of the shaft sealing structure. In this embodiment, the sealing area of the shaft sealing structure is the area where the comb-shaped bushing 3 is in close contact with the sealing functional layer 5 of the sealing body 4 and rubs against each other.

[0044] Among them, the first inflation channel 6 is also communicated with the second inflation channel 7, and the second inflation channel 7 is used to penetrate the housing 2 to communicate with the external gas source. In this embodiment, the second inflation channel 7 guides the gas provided by the external gas source to the first inflation channel 6 on the sealing body 4, and is guided by the first inflation channel 6 into the sealing area of the shaft sealing structure.

[0045] In some specific examples, the second inflation channel 7 is a linear structure. The second inflation channel 7 extends along the radial direction of the housing 2 and penetrates the housing 2 to be communicated with the external gas source and the first inflation channel 6.

[0046] In some other specific examples, the second inflation channel 7 is a multi-segment bent structure. The second inflation channel 7 includes a first segment and a second segment extending in the radial direction of the housing 2. The first segment communicates with the first inflation channel 6, and the second segment communicates with an external gas source. The second inflation channel 7 includes a third segment extending in the axial direction of the housing 2. The third segment is disposed between the first segment and the second segment, and the third segment is used to connect the first segment and the second segment.

[0047] Specifically, in this embodiment, the second inflation channel 7 is a multi-segment bent structure, which can slow down the gas flow rate, so that the air flow is more smoothly and evenly transported into the sealing area of the shaft sealing structure, helping to form a more stable air flow barrier.

[0048] It should be noted that the high-pressure air flow barrier formed by inflation in the sealing area of the shaft sealing structure can, on the one hand, prevent the working medium in the housing 2 from leaking from the shaft sealing structure, and on the other hand, prevent the lubricating oil in the gearbox from leaking from the shaft sealing structure.

[0049] In the above embodiment, a plurality of first inflation channels 6 are provided, and the plurality of first inflation channels 6 are uniformly arranged along the circumferential direction of the seal body 4.

[0050] It can be understood that the plurality of first inflation channels 6 are uniformly arranged along the circumferential direction of the seal body 4, which can ensure that external gas is evenly introduced into the sealing area of the shaft sealing structure. This can make the pressure at each part of the sealing area more balanced, avoid the situation of too high or too low local pressure, and thus improve the overall uniformity of the seal. At the same time, the setting of the plurality of first inflation channels 6 increases the redundancy of the sealing system. Even if one or several of the first inflation channels 6 are blocked or malfunction, the other channels can still supply gas to the sealing area and maintain a certain sealing pressure, thereby improving the stability and reliability of the shaft sealing structure.

[0051] Among them, when a plurality of first inflation channels 6 are provided, only one second inflation channel 7 can be provided.

[0052] Specifically, a first annular distribution cavity is provided at the connection part between the seal body 4 and the housing 2. The second inflation channel 7 transports the gas from the external gas source to the first annular distribution cavity. The first annular distribution cavity is arranged along the outer periphery of the seal body 4, and first connection ports are respectively opened at positions corresponding to each of the first inflation channels 6 in the radial direction. So that after the external gas enters the first annular distribution cavity from the second inflation channel 7, it can be evenly distributed into each of the first inflation channels 6 through the first connection ports.

[0053] It should be noted that by setting the first annular distribution cavity, the gas from the external gas source can be preliminarily diffused and balanced in a relatively large space. When the gas enters the first annular distribution cavity from the second inflation channel 7, since the first annular distribution cavity is arranged along the outer periphery of the sealing body 4, the gas has sufficient space to flow and adjust the pressure in the circumferential direction, so that the air pressure at each first connection port is more uniform, avoiding the problem of unstable sealing performance caused by insufficient local air supply or too high pressure.

[0054] In some possible implementation embodiments disclosed in the present application, as shown in Figure 2 shown, a first air release channel 8 is provided on the sealing body 4, and the first air release channel 8 is communicated with the shaft sealing structure. A second air release channel 9 is provided on the housing 2, and the second air release channel 9 is communicated with the first air release channel 8. Thus, when the internal pressure in the sealing area of the shaft sealing structure is too high, the first air release channel 8 and the second air release channel 9 can timely discharge the excess working medium, preventing the shaft sealing structure from being damaged due to too high pressure. It provides an important guarantee for the safe operation of the compressor and reduces the risk of seal failure or even compressor failure caused by abnormal pressure.

[0055] Among them, the first air release channel 8 extends along the radial direction of the sealing body 4 and penetrates through the sealing body 4 to be communicated with the shaft sealing structure, so that the working medium in the sealing area of the shaft sealing structure can be led out. In this embodiment, the sealing area of the shaft sealing structure is the area where the comb-shaped shaft sleeve 3 is in close contact with the sealing functional layer 5 of the sealing body 4 and rubs against each other.

[0056] Among them, the first air release channel 8 is also communicated with the second air release channel 9, and the second air release channel 9 is used to penetrate through the housing 2. When the internal pressure of the shaft sealing structure is too high, the working medium can quickly flow into the second air release channel 9 through the first air release channel 8. The second air release channel 9 is like a safety channel, guiding these excess working media to a specific collection or treatment area outside the compressor.

[0057] In some specific examples, the second air release channel 9 is a linear structure. The second air release channel 9 extends along the radial direction of the housing 2 and penetrates through the housing 2 to be communicated with the first air release channel 8.

[0058] In other specific examples, the second air release channel 9 is a multi-segment bent structure. The multi-segment bent second air release channel 9 has the same structure as the multi-segment bent second inflation channel 7, which will not be elaborated here.

[0059] In the above embodiment, a plurality of first air release channels 8 are provided, and the plurality of first air release channels 8 are uniformly arranged along the circumferential direction of the sealing body 4.

[0060] It can be understood that a plurality of first air release channels 8 are evenly arranged along the circumferential direction of the seal body 4, which can ensure that the pressure inside the sealed area of the shaft seal structure is evenly released in all directions. When the pressure inside the sealed area increases, the working medium can be discharged simultaneously from multiple positions, avoiding the situation of excessive local pressure, making the pressure of the entire sealed area more balanced, reducing the deformation and damage of the seal body 4 and the comb-tooth type shaft sleeve 3 caused by uneven pressure, and improving the stability and reliability of the shaft seal structure.

[0061] Among them, when a plurality of first air release channels 8 are provided, only one second air release channel 9 can be provided.

[0062] Specifically, a second annular distribution cavity is provided at the connection part between the seal body 4 and the housing 2. The second annular distribution cavity is arranged along the outer circumference of the seal body 4, and second connection ports are respectively opened at positions corresponding to each first air release channel 8 in the radial direction. When the pressure inside the sealed area of the shaft seal structure increases and air needs to be released, the working medium flows out from each first air release channel 8 and enters the second annular distribution cavity through the corresponding second connection port. The second annular distribution cavity plays a role in concentrating and guiding the working medium, converging the working medium from multiple first air release channels 8 together. A single second air release channel 9 is led out from the second annular distribution cavity, and this second air release channel 9 penetrates through the housing 2 to guide the working medium to a safe area outside the equipment for treatment.

[0063] It should be noted that the second annular distribution cavity can conduct preliminary buffering and pressure equalization on the discharged working medium, enabling the working medium to enter the second air release channel 9 more smoothly, reducing the impact and noise of the airflow. At the same time, during the maintenance and overhaul process, by checking the second annular distribution cavity and the second connection ports, the working states of each first air release channel 8 can be quickly judged, improving the efficiency and accuracy of maintenance.

[0064] In some possible implementation embodiments disclosed in the present application, refer to Figure 2 As shown, when a first inflation channel 6 is provided on the seal body 4, the first air release channel 8 is located on the side of the first inflation channel 6 close to the housing 2.

[0065] It can be understood that arranging the first air release channel 8 on the side of the first inflation channel 6 close to the housing 2 can form a clear pressure partition in the sealed area of the shaft seal structure. When an external air source inflates the sealed area through the first inflation channel 6, a relatively high positive pressure area is formed on the side far from the housing 2, while the pressure on the side close to the housing 2 is relatively low due to the existence of the first air release channel 8. Thus, a damping effect is generated to reduce the leakage amount of the working medium and achieve a better sealing effect.

[0066] In some possible implementation embodiments disclosed in the present application, refer to Figure 2As shown, an oil slinger 10 is provided at one end of the sealing body 4 away from the housing 2.

[0067] It can be understood that in some application scenarios, such as the shaft sealing structure connected to a gearbox, the oil slinger 10 can effectively prevent the lubricating oil in the gearbox from entering the shaft sealing structure along the rotating shaft 1 or leaking to the outside. When the rotating shaft 1 rotates at a high speed, the oil slinger 10 can use centrifugal force to throw off the lubricating oil that may adhere to the rotating shaft 1 from the shaft sealing area, ensuring that the lubricating oil is restricted within a specific area, thereby maintaining the normal lubrication system of the equipment and avoiding problems such as insufficient lubrication and increased equipment wear caused by lubricating oil leakage. At the same time, the presence of the oil slinger 10 can reduce the impact of the lubricating oil on the sealing functional layer 5 and the comb-shaped shaft sleeve 3. If the lubricating oil enters the sealing area, it may reduce the performance of the sealing material and damage the sealing structure. The oil slinger 10 isolates the lubricating oil and the shaft sealing structure to a certain extent, enabling the shaft sealing structure to better play its sealing role and improving the overall sealing performance of the shaft sealing structure.

[0068] Among them, the oil slinger 10 and the sealing body 4 can be integrally formed.

[0069] Specifically, the oil slinger 10 can be an annular protrusion structure, located on the side of the sealing body 4 close to where there may be lubricating oil or other easily leaked liquids. When the rotating shaft 1 rotates at a high speed, due to the action of centrifugal force, the lubricating oil or other liquids that may adhere to the rotating shaft 1 will be blocked by the oil slinger 10 and affected by the centrifugal force when approaching the oil slinger 10. The annular protrusion structure of the oil slinger 10 causes the liquid to be thrown outwards under the action of centrifugal force, away from the core sealing area of the shaft sealing structure.

[0070] In the above embodiment, referring to Figure 3 As shown, an oil drain hole 11 is provided on the oil slinger 10.

[0071] It can be understood that the presence of the oil drain hole 11 further increases the way of draining oil. When the rotating shaft 1 rotates at a high speed, the lubricating oil adhering to the rotating shaft 1 is thrown towards the oil slinger 10 under the action of centrifugal force, and the oil drain hole 11 provides an additional discharge channel for the lubricating oil. The lubricating oil can be thrown out more quickly through the oil drain hole 11, improving the oil draining efficiency, and thus more effectively preventing the lubricating oil from entering the core sealing area of the shaft sealing structure.

[0072] Among them, the oil drain hole 11 can be a hole opened on the annular oil slinger 10.

[0073] Specifically, in this embodiment, the central angle of the oil drain hole 11 is 60°, which can accommodate more lubricating oil to pass through, reduce the accumulation of lubricating oil on the oil slinger 10, and reduce the pressure on the shaft sealing structure caused by the accumulation of lubricating oil, thereby better protecting the sealing functional layer 5 and the comb-shaped shaft sleeve 3.

[0074] On the other hand, an embodiment of the present application provides a centrifugal compressor, including the shaft seal structure as described in any one of the above.

[0075] Wherein, when the shaft seal structure is applied to the centrifugal compressor, the housing 2 in the shaft seal structure is closely connected to the housing of the centrifugal compressor, usually firmly fixed by means such as bolt connection and welding. This connection ensures that the shaft seal structure can stably stay in the correct position during the operation of the centrifugal compressor, and can withstand internal pressure and external interference without displacement. The seal body 4 is located in the shaft hole reserved in the housing 2, and structures such as a first annular distribution cavity and a second annular distribution cavity are provided at the connection part with the housing 2. These structures cooperate with the housing 2, enabling the gas from the external gas source to smoothly enter the first annular distribution cavity through the second inflation channel 7, and then be evenly distributed into each first inflation channel 6, providing a stable positive pressure environment for the shaft seal structure. At the same time, when deflation is required, the first deflation channel 8 on the seal body 4 is communicated with the second deflation channel 9 on the housing 2 to discharge the excess gas in the sealed area, ensuring the internal pressure balance of the shaft seal structure. The comb-tooth type shaft sleeve 3 is firmly sleeved on the rotating shaft 1 of the centrifugal compressor and rotates synchronously with the high-speed rotation of the rotating shaft 1. The comb-shaped members on its outer peripheral surface are in close contact with and abrade against the sealing functional layer 5 on the inner wall of the seal body 4, forming an effective sealed area. This connection method makes the sealing performance between the comb-tooth type shaft sleeve 3 and the seal body 4 directly affect the overall performance of the centrifugal compressor. At the connection part between the centrifugal compressor and the gearbox, an oil slinger 10 is provided at one end of the seal body 4 away from the housing 2, which can prevent the lubricating oil in the gearbox from entering the shaft seal structure and protect the sealed area from being eroded by the lubricating oil.

[0076] It is easy for those skilled in the art to understand that, on the premise of no conflict, the above advantageous ways can be freely combined and superimposed.

[0077] The above are only the preferred embodiments of the present application, and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application. The above is only the preferred implementation manner of the present application. It should be noted that for those of ordinary skill in the art in this technical field, several improvements and modifications can be made without departing from the technical principle of the present application, and these improvements and modifications should also be regarded as the protection scope of the present application.

Claims

1. A shaft seal structure, characterized in that, It includes a rotating shaft (1) with an active rotating action and a stationary housing (2). A comb-shaped bushing (3) is sleeved on the rotating shaft (1). A sealing body (4) is arranged on the outer peripheral side of the comb-shaped bushing (3). The sealing body (4) is relatively fixed to the housing (2). A sealing functional layer (5) is arranged on the inner wall of the sealing body (4). The sealing functional layer (5) is used for scraping against the comb-shaped bushing (3) to form the shaft sealing structure.

2. The shaft seal structure according to claim 1, characterized in that, A first inflation channel (6) is arranged on the sealing body (4). The first inflation channel (6) is communicated with the shaft sealing structure. A second inflation channel (7) is arranged on the housing (2). The second inflation channel (7) is used for communicating the first inflation channel (6) with an external gas source.

3. The shaft seal structure according to claim 2, characterized in that, There are several first inflation channels (6). The several first inflation channels (6) are evenly arranged along the circumferential direction of the sealing body (4).

4. The shaft seal structure according to claim 1, characterized in that, A first air release channel (8) is arranged on the sealing body (4). The first air release channel (8) is communicated with the shaft sealing structure. A second air release channel (9) is arranged on the housing (2). The second air release channel (9) is connected to the first air release channel (8).

5. The shaft seal structure according to claim 4, characterized in that, There are several first air release channels (8). The several first air release channels (8) are evenly arranged along the circumferential direction of the sealing body (4).

6. The shaft seal structure according to claim 4, wherein, When a first inflation channel (6) is arranged on the sealing body (4), the first air release channel (8) is located on the side of the first inflation channel (6) close to the housing (2).

7. The shaft seal structure according to claim 1, characterized in that, An oil slinger (10) is arranged at one end of the sealing body (4) away from the housing (2).

8. The shaft seal structure according to claim 7, characterized in that, An oil slinger hole (11) is formed in the oil slinger (10).

9. The shaft seal structure according to claim 1, characterized in that A number of comb-shaped members are arranged on the outer peripheral surface of the comb-shaped bushing (3) at equal intervals along the axial direction. The height of the comb-shaped members is 2 mm to 3 mm, and the interval distance between two adjacent comb-shaped members is 2 mm to 4 mm.

10. A centrifugal compressor, characterized in that, It includes the shaft sealing structure according to any one of claims 1-9.

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