Sealing structure of screw blower

Abstract

The sealing structure comprises a machine shell, an air inlet end cover and a rotor installed in the machine shell, the air inlet end cover is installed at the air inlet end of the machine shell, the rotor is provided with a first shaft section extending towards the air inlet end cover, the first shaft section is sleeved with a bearing used for supporting the rotor to rotate, and the first shaft section is provided with a second shaft section extending towards the air inlet end cover. A bearing hole used for containing the bearing is formed in the machine shell, an oil sealing assembly and an air sealing assembly are further installed on the first shaft section, and the bearing, the oil sealing assembly and the air sealing assembly are all located in the bearing hole and are sequentially arranged from outside to inside in the axial direction of the rotor. According to the sealing structure, the oil sealing assembly and the air sealing assembly are combined to seal the air inlet end of the rotor, the sealing effect is good, and the cost is low.

Description

Technical Field

[0001] This application relates to the field of blower technology, and more specifically to a sealing structure for a screw blower. Background Technology

[0002] Screw blowers, as efficient, stable, and energy-saving mechanical equipment, play a vital role in the industrial field. They are widely used in wastewater treatment, cement production, chemical and pharmaceutical industries, textiles, and many other sectors. Their core advantage lies in their ability to provide continuous and stable pressure and flow while maintaining low energy consumption and noise levels. The core component of a screw blower is the screw motor, which mainly consists of a casing, a pair of meshing screw rotors, a gearbox, bearings, and a shaft seal assembly. The screw rotors rotate within the casing, creating a periodically changing working chamber volume during their meshing rotation. This process facilitates the entry, expansion / compression / vacuuming, and discharge of gas, achieving efficient conversion of the working medium. The sealing performance of the shaft seal assembly is particularly important, directly affecting not only the operating efficiency and safety of the screw blower but also the purity of the gas and the maintenance costs of the equipment. The sealing structures of oil-free screw blowers are mainly divided into two types: gas seals and oil seals. Gas seals rely on small-gap throttling and pressure reduction to achieve the sealing function. Due to their simple structure, ease of installation and maintenance, and good economy, they are widely used in process screw compressors. Oil seals are contact seals, which use an oil film to prevent lubricating oil leakage and the intrusion of external contaminants, achieving a seal between the rotor and the housing. They are usually used in applications requiring higher sealing performance. Gas seals and oil seals each have their advantages and limitations, and the choice should be made based on the specific application scenario and requirements. However, existing sealing structures are complex, prone to failure at high temperatures, and cannot completely isolate the medium gas and oil. Furthermore, traditional screw rotor sealing structures have a large number of parts, are complex in structure, and are costly. These factors all limit the performance and reliability of the sealing structure. Summary of the Invention

[0003] The technical problem to be solved by this application is to provide a sealing structure for a screw blower, which combines an oil sealing component and an air sealing component to seal the air inlet end of the rotor, resulting in good sealing effect and low cost.

[0004] This application provides a sealing structure for a screw blower, including a housing, an inlet end cover, and a rotor installed inside the housing. The inlet end cover is installed at the inlet end of the housing. The rotor has a first shaft section extending towards the inlet end cover. A bearing for supporting the rotation of the rotor is fitted on the first shaft section. A bearing hole for accommodating the bearing is provided inside the housing. An oil seal assembly and a gas seal assembly are also installed on the first shaft section. The bearing, oil seal assembly, and gas seal assembly are all located inside the bearing hole and are arranged sequentially from the outside to the inside along the axial direction of the rotor.

[0005] In this technical solution, the sealing structure combines an oil seal assembly and a gas seal assembly to seal the air intake end of the rotor. This dual sealing provides more comprehensive protection under different sealing requirements. The oil seal assembly prevents lubricating oil leakage, while the gas seal assembly prevents gas leakage. The combination of the two improves the reliability of the seal. By combining the oil seal assembly and the gas seal assembly, the cost is reduced while ensuring the sealing effect. Compared with using complex gas seals or oil seals alone, this combined sealing structure simplifies the design and reduces material and maintenance costs. The bearing, oil seal assembly, and gas seal assembly are all located in the bearing bore and are arranged sequentially from the outside to the inside along the rotor's axial direction. This arrangement is conducive to achieving a more efficient sealing effect, and the layout helps to reduce space occupation, making the machine design more compact and easier to install and maintain. Compared with traditional single sealing structures or more complex sealing systems, this integrated composite sealing structure can reduce manufacturing and maintenance costs while ensuring the sealing effect.

[0006] As an improvement, the bearing is a grease-lubricated bearing. In this technical solution, the bearing is set to use grease lubrication. Grease lubrication has advantages such as good adhesion and low flowability, and is less prone to leakage problems. Therefore, it helps to reduce the sealing performance requirements of the rotor intake end, and can reduce manufacturing and maintenance costs.

[0007] As an improvement, a pressure differential balancing hole is provided between the oil sealing assembly and the gas sealing assembly. In this technical solution, the main function of the pressure differential balancing hole is to control the pressure difference between the oil sealing assembly and the gas sealing assembly, preventing negative pressure from forming between them. The pressure differential balancing hole prevents lubricating grease from leaking from the oil sealing assembly to the gas sealing assembly due to negative pressure, thereby protecting the lubricating grease and maintaining its proper lubrication and sealing functions. The pressure differential balancing hole also helps improve the overall sealing effect.

[0008] As an improvement, the oil sealing assembly includes a stationary sealing ring and a rotating sealing ring. The rotating sealing ring is fitted onto the first shaft segment, and the stationary sealing ring is fitted onto the rotating sealing ring. In this technical solution, the oil sealing assembly consists of a stationary sealing ring and a rotating sealing ring. The rotating sealing ring is directly fitted onto the first shaft segment of the rotor and rotates synchronously with the rotor through the first shaft segment. The stationary sealing ring is fitted onto the rotating sealing ring and remains stationary, which helps to form a stable sealing surface, reduce leakage, and improve sealing efficiency. This allows the oil sealing assembly to fit tightly with the first shaft segment for effective sealing. Since the bearing is lubricated with grease, the requirements for the sealing performance at the intake end are reduced, thus allowing for a simplified design of the oil sealing assembly, reducing its complexity, and lowering manufacturing costs.

[0009] As an improvement, the outer diameter of the sealing stationary ring is clearance-fitted with the inner diameter of the bearing bore. In this technical solution, the outer diameter of the sealing stationary ring and the inner diameter of the bearing bore are fitted with a clearance fit. This precise fit ensures the correct axial and radial positioning of the sealing stationary ring, preventing it from deviating or moving, thereby guaranteeing the sealing effect, improving sealing reliability, and reducing the risk of seal failure due to improper installation or component misalignment during operation.

[0010] As an improvement, a retaining ring is also installed on the first shaft section. The retaining ring is located between the oil seal assembly and the gas seal assembly, and it cooperates with the bearing to limit the position of the oil seal assembly. In this technical solution, the retaining ring between the oil seal assembly and the gas seal assembly, used in conjunction with the bearing, effectively restricts the position of the oil seal assembly, ensuring its correct axial and radial positioning, preventing displacement of the oil seal assembly, thereby improving sealing performance, preventing lubricating grease leakage, enhancing the reliability of the sealing system, reducing axial and radial wobble of the oil seal assembly, reducing wear, and extending the service life of the oil seal assembly and the bearing.

[0011] As an improvement, the gas-tight assembly includes a gas seal seat with multiple sealing grooves. In this technical solution, the gas seal seat has multiple sealing grooves to form a labyrinth seal. Due to its complex channel structure, the labyrinth seal causes leaking fluid or gas to undergo multiple radial turns and velocity changes in the channel, thereby reducing leakage and improving the sealing effect by increasing the resistance to fluid flow.

[0012] As an improvement, the outer diameter of the gas seal seat is clearance-fitted with the inner diameter of the bearing bore. In this technical solution, setting the outer diameter of the gas seal seat and the inner diameter of the bearing bore through a clearance fit ensures the correct positioning of the gas seal seat within the bearing bore. This simplifies the installation and disassembly of the gas seal seat, helps maintain its stability, and ensures that it will not shift or deviate during equipment operation. The clearance fit also helps form a good seal between the gas seal seat and the bearing bore, preventing gas or liquid leakage.

[0013] As an improvement, the bearing is sequentially connected with a pressure block and a pressure ring, the pressure block and the pressure ring cooperating to confine the bearing on the first shaft segment. In this technical solution, the cooperation of the pressure block and the pressure ring ensures that the bearing is confined on the first shaft segment, guaranteeing a fixed position of the bearing on the shaft and preventing bearing damage or equipment operation from axial displacement. The cooperation of the pressure block and the pressure ring provides additional stability, preventing bearing misalignment, thereby protecting the bearing from damage and extending its service life. Attached Figure Description

[0014] Figure 1 This is a cross-sectional schematic diagram of the sealing structure of a screw blower according to this application.

[0015] Figure 2 For this application Figure 1 A magnified view of a portion of point A in the middle.

[0016] Figure 3 This is a cross-sectional schematic diagram of the oil sealing assembly in this application.

[0017] The figure shows: 1. Housing; 11. Bearing hole; 2. Inlet end cover; 3. Rotor; 31. First shaft section; 4. Bearing; 5. Oil seal assembly; 51. Sealing stationary ring; 52. Sealing moving ring; 6. Gas seal seat; 61. Sealing groove; 7. Retaining ring; 8. Pressure block; 9. Pressure ring; 10. Differential pressure balance hole. Detailed Implementation

[0018] To better understand this application, various aspects of this application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of exemplary embodiments of this application and are not intended to limit the scope of this application in any way. Throughout the specification, the same reference numerals refer to the same elements.

[0019] In the accompanying drawings, the thickness, size, and shape of the objects have been slightly exaggerated for illustrative purposes. The drawings are for illustrative purposes only and are not drawn to scale.

[0020] It should also be understood that the terms "comprising," "including," "having," "containing," and "including," when used in this specification, indicate the presence of the stated features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or combinations thereof. The terms "first," "second," etc., are primarily used to distinguish different devices, elements, or components (the specific types and constructions may be the same or different), and are not intended to indicate or imply the relative importance or quantity of the indicated devices, elements, or components. Unless otherwise stated, "a plurality of" means two or more.

[0021] Furthermore, it should be noted that the terms "installation," "setting," "equipped with," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, elements, or components; they can refer to a direct installation on another component or the possible presence of another intermediate component. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0022] like Figures 1 to 3 As shown, this application discloses a sealing structure for a screw blower, including a housing 1, an inlet end cover 2, and a rotor 3 installed inside the housing 1. The inlet end cover 2 is installed at the inlet end of the housing 1. The rotor 3 has a first shaft section 31 extending towards the inlet end cover 2. A bearing 4 for supporting the rotation of the rotor 3 is fitted on the first shaft section 31. The housing 1 has a bearing hole 11 for accommodating the bearing 4. An oil seal assembly 5 and a gas seal assembly are also installed on the first shaft section 31. The bearing 4, the oil seal assembly 5, and the gas seal assembly are all located within the bearing hole 11 and are arranged sequentially from the outside to the inside along the axial direction of the rotor 3. The sealing structure combines the oil seal assembly 5 and the gas seal assembly to seal the inlet end of the rotor 3. The double seal ensures more comprehensive protection under different sealing requirements. The oil seal assembly 5 is responsible for preventing... The lubricating oil leaks while the gas seal assembly prevents gas leakage. The combination of the two improves the reliability of the seal. By combining the oil seal assembly 5 with the gas seal assembly, the sealing effect is guaranteed while the cost is reduced. Compared with the use of complex gas seals or oil seals alone, this combined sealing structure simplifies the design and reduces material and maintenance costs. The bearing 4, the oil seal assembly 5 and the gas seal assembly are all located in the bearing hole 11 and are arranged sequentially from the outside to the inside along the axial direction of the rotor 3. This arrangement is conducive to achieving a more efficient sealing effect, and the layout helps to reduce space occupation, making the machine design more compact and easy to install and maintain. Compared with traditional single sealing structures or more complex sealing systems, this integrated composite sealing structure can reduce manufacturing and maintenance costs while ensuring the sealing effect.

[0023] More specifically, bearing 4 is a grease-lubricated bearing 4. The bearing 4 is set to use grease lubrication. Grease lubrication has the advantages of good adhesion and low flow, and is not prone to leakage problems. Therefore, it is beneficial to reduce the sealing performance requirements of the air inlet end of rotor 3, and can reduce manufacturing and maintenance costs.

[0024] More specifically, such as Figure 2 As shown, a pressure differential balance hole 10 is provided between the oil sealing assembly 5 and the gas sealing assembly. The main function of the pressure differential balance hole 10 is to control the pressure difference between the oil sealing assembly 5 and the gas sealing assembly, and to prevent negative pressure from being generated between the oil sealing assembly 5 and the gas sealing assembly. The pressure differential balance hole 10 can prevent lubricating grease from leaking from the oil sealing assembly 5 to the gas sealing assembly side due to negative pressure, thereby protecting the lubricating grease and maintaining its proper lubrication and sealing functions. The pressure differential balance hole 10 helps to improve the overall sealing effect.

[0025] More specifically, such as Figure 2 and Figure 3 As shown, the oil sealing assembly 5 includes a stationary sealing ring 51 and a rotating sealing ring 52. The rotating sealing ring 52 is fitted onto the first shaft segment 31, and the stationary sealing ring 51 is fitted onto the rotating sealing ring 52. The oil sealing assembly 5 is composed of the stationary sealing ring 51 and the rotating sealing ring 52. The rotating sealing ring 52 is directly fitted onto the first shaft segment 31 of the rotor 3 and rotates synchronously with the rotor 3 through the first shaft segment 31. The stationary sealing ring 51 is fitted onto the rotating sealing ring 52 and remains stationary, which helps to form a stable sealing surface, reduce leakage, and improve sealing efficiency. This allows the oil sealing assembly 5 to fit tightly with the first shaft segment 31 and effectively seal. Since the bearing 4 uses grease lubrication, the requirements for the sealing performance of the air inlet end are reduced, which allows for a simplified design of the oil sealing assembly 5, reduces the complexity of the oil sealing assembly 5, and also reduces manufacturing costs.

[0026] More specifically, such as Figure 2 As shown, the outer diameter of the sealing stationary ring 51 is clearance-fitted with the inner diameter of the bearing hole 11. This precise fit ensures the correct axial and radial positioning of the sealing stationary ring 51, preventing it from deviating or moving, thus guaranteeing the sealing effect, improving the reliability of the seal, and reducing the risk of seal failure due to improper installation or component misalignment during operation.

[0027] More specifically, such as Figure 2As shown, a retaining ring 7 is also installed on the first shaft section 31. The retaining ring 7 is located between the oil seal assembly 5 and the gas seal assembly. The retaining ring 7 cooperates with the bearing 4 to limit the oil seal assembly 5. The retaining ring 7 is set between the oil seal assembly 5 and the gas seal assembly. The retaining ring 7 cooperates with the bearing 4 to effectively limit the position of the oil seal assembly 5, ensure its correct positioning in the axial and radial directions, prevent the oil seal assembly 5 from being displaced, thereby improving the sealing performance, preventing lubricating grease leakage, enhancing the reliability of the sealing system, reducing the axial and radial wobble of the oil seal assembly 5, reducing wear, and extending the service life of the oil seal assembly 5 and the bearing 4.

[0028] More specifically, such as Figure 2 As shown, the gas seal assembly includes a gas seal seat 6, on which multiple sealing grooves 61 are provided. The gas seal seat 6 is provided with multiple sealing grooves 61 to form a labyrinth seal. Due to its complex channel structure, the labyrinth seal causes the leaking fluid or gas to undergo multiple radial turns and velocity changes in the channel, thereby reducing leakage and improving the sealing effect by increasing the resistance to fluid flow.

[0029] More specifically, such as Figure 1 and Figure 2 As shown, the outer diameter of the air seal seat 6 is clearance-fitted with the inner diameter of the bearing hole 11. Setting the outer diameter of the air seal seat 6 and the inner diameter of the bearing hole 11 through clearance fit can ensure the correct positioning of the air seal seat 6 in the bearing hole 11. The installation and disassembly of the air seal seat 6 are simpler, which helps to maintain the stability of the air seal seat 6 and ensures that it will not shift or deviate during equipment operation. The clearance fit helps to form a good seal between the air seal seat 6 and the bearing hole 11, preventing gas or liquid leakage.

[0030] More specifically, such as Figure 2 As shown, bearing 4 is sequentially connected with pressure block 8 and pressure ring 9. Pressure block 8 and pressure ring 9 cooperate to limit bearing 4 to the first shaft section 31. Through the cooperation of pressure block 8 and pressure ring 9, bearing 4 is limited to the first shaft section 31, ensuring that the position of bearing 4 on the shaft is fixed, avoiding damage to bearing 4 or affecting equipment operation due to axial displacement. The cooperation of pressure block 8 and pressure ring 9 provides additional stability, preventing bearing 4 from shifting, thereby protecting bearing 4 from damage and extending the service life of bearing 4.

[0031] This application is not limited to the above-described preferred embodiments. Anyone can derive other products in various forms under the guidance of this application. However, regardless of any changes made to their shape or structure, any technical solution that is the same as or similar to that of this application falls within the protection scope of this application.

Claims

1. A sealing structure for a screw blower, characterized in that, The device includes a housing (1), an air inlet cover (2), and a rotor (3) installed inside the housing (1). The air inlet cover (2) is installed at the air inlet end of the housing (1). The rotor (3) has a first shaft section (31) extending toward the air inlet cover (2). A bearing (4) for supporting the rotation of the rotor (3) is fitted on the first shaft section (31). A bearing hole (11) for accommodating the bearing (4) is provided inside the housing (1). An oil seal assembly (5) and a gas seal assembly are also installed on the first shaft section (31). The bearing (4), the oil seal assembly (5), and the gas seal assembly are all located inside the bearing hole (11) and are arranged sequentially from the outside to the inside along the axial direction of the rotor (3).

2. The sealing structure of a screw blower according to claim 1, characterized in that, The bearing (4) is a grease-lubricated bearing (4).

3. The sealing structure of a screw blower according to claim 1 or 2, characterized in that, A differential pressure balancing hole (10) is provided between the oil sealing assembly (5) and the gas sealing assembly.

4. The sealing structure of a screw blower according to claim 1 or 2, characterized in that, The oil sealing assembly (5) includes a stationary sealing ring (51) and a rotating sealing ring (52). The rotating sealing ring (52) is fitted onto the first shaft segment (31), and the stationary sealing ring (51) is fitted onto the rotating sealing ring (52).

5. The sealing structure of a screw blower according to claim 4, characterized in that, The outer diameter of the sealing stationary ring (51) is clearance-fitted with the inner diameter of the bearing hole (11).

6. The sealing structure of a screw blower according to claim 4, characterized in that, A retaining ring (7) is also installed on the first shaft section (31). The retaining ring (7) is located between the oil seal assembly (5) and the gas seal assembly. The retaining ring (7) cooperates with the bearing (4) to limit the oil seal assembly (5).

7. The sealing structure of a screw blower according to claim 1, characterized in that, The gas-tight assembly includes a gas seal seat (6), and the gas seal seat (6) is provided with a plurality of sealing grooves (61).

8. The sealing structure of a screw blower according to claim 7, characterized in that, The outer diameter of the air seal seat (6) is clearance-fitted with the inner diameter of the bearing hole (11).

9. The sealing structure of a screw blower according to claim 1, characterized in that, The bearing (4) is sequentially connected with a pressure block (8) and a pressure ring (9), and the pressure block (8) and the pressure ring (9) cooperate to confine the bearing (4) on the first shaft section (31).

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