Oil injection screw air compressor

Abstract

The utility model discloses an oil injection screw air compressor which comprises a shell, a main shaft and a screw rotor set are installed in the shell, the main shaft is in gear transmission connection with the screw rotor set, the shell is provided with an opening matched with the main shaft, one end of the main shaft penetrates through the opening and extends out to be in transmission connection with a motor output shaft, and the other end of the main shaft is in gear transmission connection with the motor output shaft. A bearing is sleeved on the main shaft, a magnetic coupling is arranged between the main shaft and the motor output shaft, the magnetic coupling comprises an outer magnet, an isolation sleeve and an inner magnet which are sequentially sleeved, the outer magnet is connected with the motor output shaft, the inner magnet is sleeved on the main shaft, the isolation sleeve is connected with the shell to seal the opening, and the outer magnet is connected with the motor output shaft. And a sealing cavity for accommodating the main shaft and the inner magnet is formed in the isolation sleeve. The sealing structure has the advantages of better sealing property, good lubricating and cooling effects, lower requirement on production precision and the like.

Description

Technical Field

[0001] The utility model relates to the technical field of air compressors, and more specifically to an oil-injected screw air compressor. Background Art

[0002] A twin-screw air compressor is a mechanical device used to compress gas to increase gas pressure or transport gas. It has the advantages of high reliability, easy operation and maintenance, good power balance, and strong adaptability. Therefore, it can be widely used in production scenarios such as material transportation, gas purging, instrument gas, and process gas. A pair of mutually meshing screw-shaped rotors are arranged in parallel in the body of a twin-screw air compressor. The two screw-shaped rotors are continuously meshed to compress the incoming gas so that high-pressure gas can be discharged. During the continuous meshing process of the two screw-shaped rotors, the temperature of the compressed gas continues to rise, and hard friction will occur between the two rotors. Long-term hard friction requires greater input power to support the normal operation of the air compressor. Therefore, most air compressors currently use lubricating oil to lubricate and cool the high-speed rotors, reduce hard friction, and reduce thermal damage. Oil injection can greatly improve the energy efficiency of the air compressor, but it also brings problems such as lubricating oil leakage. At present, air compressors generally use shaft seals, shaft sleeves and shaft seal end covers on the extended shaft to seal the lubricating oil inside the main engine, and prevent lubricating oil leakage by the cooperation of the shaft seal and the shaft sleeve. However, the installation and positioning of the shaft seal requires special tooling, and the production and assembly are relatively complicated and time-consuming. In addition, the eccentricity of the shaft seal with the rotor shaft must not be too large after installation. Too large eccentricity can easily cause uneven contact between the shaft seal lip and the shaft sleeve, which can easily cause lubricating oil leakage. Therefore, the assembly accuracy of the shaft seal is required to be high, and the shaft seal is a wearing part. Wear of the shaft seal lip can cause lubricating oil leakage. The shaft seal needs to be replaced frequently, which reduces the continuous operation time of the air compressor and increases the operating cost of the air compressor. On the other hand, a shaft shoulder that matches the shaft sleeve needs to be made on the main shaft, and the shaft sleeve is installed on the shaft shoulder. A seal needs to be set between the shaft sleeve and the shaft shoulder. If the shaft sleeve and the shaft shoulder are not assembled in place or the shaft shoulder is not processed in place, there will be an oil leakage gap between the shaft shoulder and the shaft sleeve, and there is a risk of lubricating oil leakage. Utility Model Content

[0003] The technical problem to be solved by the utility model is to provide an oil-injected screw air compressor, which uses a magnetic coupling to seal the inside of the main engine to prevent lubricating oil leakage, and has the advantages of better sealing, good lubrication and cooling effect, and lower production precision requirements.

[0004] The utility model provides an oil-injected screw air compressor, comprising a shell, a main shaft and a screw rotor group are installed in the shell, the main shaft is connected to the screw rotor group by gear transmission, the shell is provided with an opening adapted to the main shaft, one end of the main shaft extends through the opening to be connected to a motor output shaft by transmission, a bearing is sleeved on the main shaft, a magnetic coupling is arranged between the main shaft and the motor output shaft, the magnetic coupling comprises an outer magnet, a spacer sleeve and an inner magnet which are sleeved in sequence, the outer magnet is connected to the motor output shaft, the inner magnet is sleeved on the main shaft, the spacer sleeve is connected to the shell to seal the opening, and a sealing cavity for accommodating the main shaft and the inner magnet is formed inside the spacer sleeve.

[0005] In this technical solution, the main shaft extends through the opening so as to be able to connect to an external power source. The main shaft is connected to the motor through the motor output shaft. The motor can drive the main shaft to rotate through the motor output shaft, thereby driving the screw rotor group to rotate and engage the compressed gas through the main shaft. The main shaft is equipped with bearings, which support the main shaft. However, the bearings will gradually heat up during rotation, affecting the rotation efficiency. At present, lubricating oil is mostly used to lubricate and cool the bearings to extend the service life of the bearings. This solution sets a magnetic coupling between the main shaft and the motor output shaft, and replaces the conventional shaft seal, shaft sleeve and shaft seal end cover with the magnetic coupling. The main shaft and the motor output shaft are connected through a magnetic coupling transmission. The magnetic coupling principle is used to realize the transmission of force and torque between the main shaft and the motor output shaft without direct contact, and the dynamic seal is converted into a static seal to achieve zero leakage. The inner magnet of the magnetic coupling is set on the shaft section of the main shaft extending through the opening of the shell, and the outer magnet of the magnetic coupling is connected to the motor output shaft. The body, isolation sleeve and inner magnet are sleeved in sequence, the outer magnet is sleeved on the outer periphery of the isolation sleeve and the isolation sleeve is sleeved on the outer periphery of the inner magnet, there is no contact between the inner magnet and the outer magnet, reducing the risk of motor blocking or burning due to sudden increase in torque of the air compressor, the isolation sleeve is connected to the shell to form a sealed cavity connected to the inner cavity of the shell, the isolation sleeve seals the opening through the sealed cavity, the shaft section of the main shaft extending out of the shell and the inner magnet are both accommodated in the sealed cavity, which can prevent the lubricating oil at the bearing from leaking through the opening, and improve the sealing efficiency. The prior art requires that a shaft shoulder matching the shaft sleeve be made on the main shaft for installing the shaft seal, while the magnetic coupling in the present invention is installed by means of a sleeve, and the main shaft does not need to be provided with an assembly structure corresponding to the magnetic coupling, reducing the installation of the shaft sleeve and the processing technology of the shaft shoulder, and the production precision requirements are low and the assembly is simple and labor-saving. On the other hand, the sealed cavity can accommodate more lubricating oil, which can make the lubricating oil lubricate and cool the bearing more fully, reduce hard friction and thermal damage, and improve the operating efficiency of the whole machine.

[0006] As an improvement, the inner wall of the opening is provided with an oil return hole, and the sealing chamber is connected to the oil return hole. In this technical solution, the bearing is installed on the shaft section of the main shaft located in the housing. By providing the oil return hole on the inner wall of the opening, the lubricating oil lubricates the bearing and is thrown onto the inner wall of the housing by the bearing and discharged through the oil return hole, thereby realizing the reuse of the lubricating oil and improving the efficiency of lubrication and heat dissipation. In this solution, the isolation cover is connected to the housing to seal the opening, and a sealing chamber is formed between the isolation cover and the housing. Part of the lubricating oil will enter the sealing chamber, and the sealing chamber is provided to be connected to the oil return hole. The internal magnet is located in the sealing chamber. During the operation of the machine body, the rotation of the internal magnet will cause the lubricating oil in the sealing chamber to be discharged more quickly through the oil return hole, thereby improving the oil discharge efficiency.

[0007] As an improvement, the inner diameter of the opening is greater than or equal to the outer diameter of the bearing. In this technical solution, the size of the opening is set larger than the size of the bearing, and the bearing can pass through the opening and be directly mounted on the main shaft. The larger the opening, the easier it is to install the bearing, and the easier and more labor-saving it is to assemble the bearing.

[0008] As an improvement, the outer edge of the isolation sleeve is provided with a mounting seat adapted to the opening, and the mounting seat is connected to the shell to seal the opening. In this technical solution, the isolation sleeve is connected to the shell to seal the opening, and a mounting seat is provided on the outer edge of the isolation sleeve, and the mounting seat is formed by extending from the outer edge of the isolation sleeve, and the isolation sleeve and the isolation sleeve are an integrated structure. The mounting seat is adapted to the size of the opening, and the mounting seat is engaged with the outer wall of the shell to seal the opening, thereby improving the sealing efficiency and simplifying the assembly and saving labor.

[0009] As an improvement, the shell is provided with a mounting groove adapted to the mounting seat, and the mounting seat is connected to the mounting groove. In this technical solution, a mounting groove whose size is adapted to the mounting seat is provided on the shell, and the mounting seat is installed in the mounting groove so that the isolation sleeve is connected to the shell and limited, and the isolation sleeve is installed and positioned through the mounting groove, so that the installation position is more accurate and the installation efficiency is higher.

[0010] As an improvement, a fastener is provided between the mounting seat and the mounting groove, and the isolation sleeve is limited on the housing by the fastener. In this technical solution, the mounting seat is installed in the mounting groove and limited by the fastener, the fastener is preferably a bolt, and the isolation sleeve is limited on the housing by the fastener, and the mounting structure is simple and reliable.

[0011] As an improvement, one end of the external magnet is provided with a first connection hole adapted to the isolation sleeve, and the external magnet is sleeved on the outer periphery of the isolation sleeve through the first connection hole. In this technical solution, the external magnet is sleeved with the isolation sleeve, and the first connection hole is provided at one end of the external magnet close to the isolation sleeve, and the external magnet is sleeved on the outer periphery of the isolation sleeve through the first connection hole. There is a gap between the inner wall of the first connection hole and the outer wall of the isolation sleeve, which is simple to assemble and has efficient transmission.

[0012] As an improvement, the other end of the external magnet is provided with a second connection hole adapted to the motor output shaft, and the external magnet is sleeved on the outer periphery of the motor output shaft through the second connection hole. In this technical solution, the magnetic coupling is connected to the motor output shaft through the external magnet, and the second connection hole is provided at one end of the external magnet close to the motor output shaft, and the external magnet is sleeved on the end of the motor output shaft through the second connection hole to complete the installation, which is simple to assemble and has efficient transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the three-dimensional structure of the air compressor disclosed in the present invention.

[0014] Figure 2 For this disclosure Figure 1 Schematic cross-sectional view of the structure shown.

[0015] Figure 3 It is a schematic diagram of the exploded structure of the magnetic coupling disclosed in the present invention.

[0016] Figure 4 It is a schematic diagram of the three-dimensional structure of the air compressor disclosed in the present invention without installing a magnetic coupling.

[0017] Figure 5 For this disclosure Figure 4 A local enlarged schematic diagram of point A in the middle.

[0018] As shown in the figure: 1. Shell; 11. Opening; 12. Oil return hole; 13. Mounting groove; 2. Main shaft; 3. Screw rotor group; 4. Bearing; 5. Magnetic coupling; 51. External magnet; 511. First connecting hole; 512. Second connecting hole; 52. Isolation sleeve; 521. Sealing chamber; 522. Mounting seat; 53. Internal magnet. DETAILED DESCRIPTION

[0019] In order to better understand the present application, a more detailed description of various aspects of the present application will be made with reference to the accompanying drawings. It should be understood that these detailed descriptions are only descriptions of exemplary embodiments of the present application, and do not limit the scope of the present application in any way. Throughout the specification, the same figure numerals refer to the same elements.

[0020] In the drawings, the thickness, size and shape of objects have been slightly exaggerated for ease of explanation. The drawings are only examples and are not drawn strictly to scale.

[0021] It should also be understood that the terms “comprises,” “including,” “has,” “contains,” and “comprising,” when used in this specification, indicate the presence of the described features, integers, steps, operations, elements, and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts, and / or combinations thereof.

[0022] like Figures 1 to 5 As shown, the present application discloses an oil-injected screw air compressor, comprising a housing 1, in which a main shaft 2 and a screw rotor group 3 are installed, the main shaft 2 is connected to the screw rotor group 3 through gear transmission, the housing 1 is provided with an opening 11 adapted to the main shaft 2, one end of the main shaft 2 extends through the opening 11 to be connected to a motor output shaft, the main shaft 2 extends through the opening 11 to be able to be connected to an external power source, the main shaft 2 is connected to the motor through the motor output shaft, the motor can drive the main shaft 2 to rotate through the motor output shaft, thereby driving the screw rotor group 3 to rotate and engage the compressed gas through the main shaft 2, and a bearing 4 is sleeved on the main shaft 2, and the bearing 4 supports the main shaft 2;

[0023] A bearing 4 is sleeved on the main shaft 2, and a magnetic coupling 5 is arranged between the main shaft 2 and the motor output shaft. The magnetic coupling 5 includes an outer magnet 51, an isolation sleeve 52 and an inner magnet 53 which are sleeved in sequence. The outer magnet 51 is connected to the motor output shaft, and the inner magnet 53 is sleeved on the main shaft 2. The isolation sleeve 52 is connected to the housing 1 to seal the opening 11. The bearing 4 will gradually heat up during the rotation process, affecting the rotation efficiency. At present, the bearing 4 is lubricated and cooled by lubricating oil to extend the service life of the bearing 4. In this solution, a magnetic coupling 5 is arranged between the main shaft 2 and the motor output shaft, and the conventional shaft seal, shaft sleeve and shaft seal end cover are replaced by the magnetic coupling 5. The main shaft 2 and the motor output shaft are connected by a magnetic coupling 5. The transmission connection is through the magnetic coupling 5, and the magnetic coupling principle is adopted to realize the transmission of force and torque between the main shaft 2 and the motor output shaft without direct contact, and the dynamic seal is converted into a static seal to achieve zero leakage. The inner magnet 53 of the magnetic coupling 5 is sleeved on the shaft section of the main shaft 2 that passes through the opening 11 and extends out of the housing 1, and the outer magnet 51 of the magnetic coupling 5 is connected to the motor output shaft. The outer magnet 51, the isolation sleeve 52 and the inner magnet 53 are arranged to be sleeved in sequence, and the outer magnet 51 is sleeved on the outer periphery of the isolation sleeve 52 and the isolation sleeve 52 is sleeved on the outer periphery of the inner magnet 53. There is no contact between the inner magnet 53 and the outer magnet 51, thereby reducing the risk of motor stalling or burning due to sudden increase in torque of the air compressor;

[0024] The isolation sleeve 52 is connected to the shell 1 to form a sealing cavity 521 that is connected to the inner cavity of the shell 1. The isolation sleeve 52 seals the opening 11 through the sealing cavity 521. The shaft section of the main shaft 2 extending out of the shell 1 and the internal magnet 53 are both accommodated in the sealing cavity 521, which can prevent the lubricating oil at the bearing 4 from leaking through the opening 11, thereby improving the sealing efficiency. The prior art requires that a shaft shoulder that matches the shaft sleeve be made on the main shaft 2 for installing the shaft seal, while the magnetic coupling 5 in the present invention is installed in a set manner, and the main shaft 2 does not need to be provided with an assembly structure corresponding to the magnetic coupling 5, thereby reducing the installation of the shaft sleeve and the processing technology of the shaft shoulder, and the production precision requirements are low and the assembly is simple and labor-saving. On the other hand, the sealing cavity 521 can accommodate more lubricating oil, which can make the lubricating oil lubricate and cool the bearing 4 more fully, reduce hard friction and thermal damage, and improve the operating efficiency of the whole machine.

[0025] More specifically, Figure 2 and Figure 5 As shown, an oil return hole 12 is provided on the inner wall of the opening 11, and the sealing chamber 521 is connected to the oil return hole 12. The bearing 4 is installed on the shaft section of the main shaft 2 located in the shell 1. By setting the oil return hole 12 on the inner wall of the opening 11, the lubricating oil lubricates the bearing 4 and is thrown onto the inner wall of the shell 1 by the bearing 4 and discharged through the oil return hole 12, thereby realizing the reuse of the lubricating oil and improving the efficiency of lubrication and heat dissipation. In this scheme, the isolation cover is connected to the shell 1 to seal the opening 11, and a sealing chamber 521 is formed between the isolation cover and the shell 1. Part of the lubricating oil will enter the sealing chamber 521. The sealing chamber 521 is connected to the oil return hole 12, and the internal magnet 53 is located in the sealing chamber 521. During the operation of the machine body, the rotation of the internal magnet 53 will cause the lubricating oil in the sealing chamber 521 to be discharged more quickly through the oil return hole 12, thereby improving the oil discharge efficiency.

[0026] More specifically, Figure 2 , Figure 4 and Figure 5 As shown, the inner diameter of the opening 11 is greater than or equal to the outer diameter of the bearing 4. The size of the opening 11 is set larger than the size of the bearing 4. The bearing 4 can pass through the opening 11 and be directly mounted on the main shaft 2. The larger the opening 11, the easier it is to install the bearing 4, and the assembly of the bearing 4 is simpler and more labor-saving.

[0027] More specifically, Figures 1 to 3 As shown, the outer edge of the isolation sleeve 52 is provided with a mounting seat 522 adapted to the opening 11, and the mounting seat 522 is connected to the shell 1 to seal the opening 11. The isolation sleeve 52 is connected to the shell 1 to seal the opening 11. The mounting seat 522 is provided on the outer edge of the isolation sleeve 52. The mounting seat 522 is formed by extending from the outer edge of the isolation sleeve 52, and it is an integral structure with the isolation sleeve 52. The mounting seat 522 is adapted to the size of the opening 11, and the mounting seat 522 is engaged with the outer wall of the shell 1 to seal the opening 11, thereby improving the sealing efficiency and simplifying and saving labor when assembling.

[0028] More specifically, Figure 5 As shown, the shell 1 is provided with a mounting groove 13 adapted to the mounting seat 522, and the mounting seat 522 is connected to the mounting groove 13. The mounting groove 13 with a size adapted to the mounting seat 522 is provided on the shell 1. The mounting seat 522 is installed in the mounting groove 13 so that the isolation sleeve 52 is connected to the shell 1 and limited. The isolation sleeve 52 is installed and positioned through the mounting groove 13, so that the installation position is more accurate and the installation efficiency is higher.

[0029] More specifically, Figure 2 As shown, a fastener is provided between the mounting seat 522 and the mounting groove 13, the isolation sleeve 52 is limited on the shell 1 by the fastener, the mounting seat 522 is installed in the mounting groove 13 and limited by the fastener, the fastener is preferably a bolt, the isolation sleeve 52 is limited on the shell 1 by the fastener, and the installation structure is simple and reliable.

[0030] More specifically, Figures 1 to 3 As shown, one end of the external magnet 51 is provided with a first connecting hole 511 adapted to the isolation sleeve 52, and the external magnet 51 is sleeved on the outer periphery of the isolation sleeve 52 through the first connecting hole 511. The external magnet 51 and the isolation sleeve 52 are sleeved. By setting the first connecting hole 511 at one end of the external magnet 51 close to the isolation sleeve 52, the external magnet 51 is sleeved on the outer periphery of the isolation sleeve 52 through the first connecting hole 511, and there is a gap between the inner wall of the first connecting hole 511 and the outer wall of the isolation sleeve 52, the assembly is simple and the transmission is efficient.

[0031] More specifically, Figures 1 to 3 As shown, the other end of the external magnet 51 is provided with a second connecting hole 512 adapted to the motor output shaft. The external magnet 51 is sleeved on the outer periphery of the motor output shaft through the second connecting hole 512. The magnetic coupling 5 is connected to the motor output shaft through the external magnet 51. By setting the second connecting hole 512 at one end of the external magnet 51 close to the motor output shaft, the external magnet 51 is sleeved on the end of the motor output shaft through the second connecting hole 512 to complete the installation, which has simple assembly and efficient transmission.

[0032] The present utility model is not limited to the above-mentioned optimal implementation mode. Anyone can derive other various forms of products under the inspiration of the present utility model. However, no matter what changes are made in the shape or structure, all those having the same or similar technical solutions as the present application fall within the protection scope of the present utility model.

Claims

1. An oil-injected screw air compressor, comprising a housing (1), wherein a main shaft (2) and a screw rotor group (3) are installed in the housing (1), wherein the main shaft (2) and the screw rotor group (3) are connected by gear transmission, wherein the housing (1) is provided with an opening (11) adapted to the main shaft (2), wherein one end of the main shaft (2) extends through the opening (11) to be connected by transmission to a motor output shaft, wherein a bearing (4) is sleeved on the main shaft (2), wherein: A magnetic coupling (5) is arranged between the main shaft (2) and the motor output shaft, and the magnetic coupling (5) comprises an outer magnet (51), an isolation sleeve (52) and an inner magnet (53) which are sleeved in sequence, the outer magnet (51) is connected to the motor output shaft, the inner magnet (53) is sleeved on the main shaft (2), the isolation sleeve (52) is connected to the housing (1) to seal the opening (11), and a sealed cavity (521) for accommodating the main shaft (2) and the inner magnet (53) is formed inside the isolation sleeve (52).

2. The oil-injected screw air compressor according to claim 1, characterized in that: The inner wall of the opening (11) is provided with an oil return hole (12), and the sealing cavity (521) is connected to the oil return hole (12).

3. The oil-injected screw air compressor according to claim 1, characterized in that: The inner diameter of the opening (11) is greater than or equal to the outer diameter of the bearing (4).

4. The oil-injected screw air compressor according to claim 1, characterized in that: The outer edge of the isolation sleeve (52) is provided with a mounting seat (522) adapted to the opening (11), and the mounting seat (522) is connected to the housing (1) to seal the opening (11).

5. The oil-injected screw air compressor according to claim 4, characterized in that: The housing (1) is provided with a mounting groove (13) adapted to the mounting seat (522), and the mounting seat (522) is connected to the mounting groove (13).

6. The oil-injected screw air compressor according to claim 5, characterized in that: A fastener is provided between the mounting seat (522) and the mounting groove (13), and the isolation sleeve (52) is fixed on the housing (1) by the fastener.

7. The oil-injected screw air compressor according to claim 1, characterized in that: One end of the external magnet (51) is provided with a first connection hole (511) adapted to the isolation sleeve (52), and the external magnet (51) is sleeved on the outer circumference of the isolation sleeve (52) through the first connection hole (511).

8. The oil-injected screw air compressor according to claim 1 or 7, characterized in that: The other end of the external magnet (51) is provided with a second connection hole (512) adapted to the motor output shaft, and the external magnet (51) is sleeved on the outer circumference of the motor output shaft through the second connection hole (512).

Images