Rotor assembly and single machine two-stage high-pressure screw compressor comprising a rotor assembly

Abstract

The utility model provides a rotor assembly and contain single machine two -stage high pressure screw compressor of rotor assembly, including including one -stage compression mechanism and two -stage compression mechanism, one -stage compression mechanism includes the one -stage male rotor and one -stage female rotor of conjugate operation, two -stage compression mechanism includes the two -stage male rotor and two -stage female rotor of conjugate operation, the tooth number of one -stage male rotor, one -stage female rotor, two -stage male rotor and two -stage female rotor is different, and the outside of one -stage female rotor, two -stage male rotor and two -stage female rotor is provided with the shaft section of driving its rotation. The device is convenient to operate, simple structure, under the condition of not increasing rotor core quantity, will two -stage compression's rotor integration to one rotor core, simplifies the layout of rotor, reduces processing difficulty.

Description

Technical Field

[0001] This utility model relates to the field of compressor equipment, specifically to rotor assemblies and single-unit two-stage high-pressure screw compressors containing rotor assemblies. Background Technology

[0002] Since its invention in the 1930s, the screw compressor has evolved from oil-lubricated to oil-free designs. Early screw compressors were primarily used in fields with low requirements for air cleanliness, employing oil lubrication for sealing, cooling, and lubrication. However, with industrial development, industries with extremely high compressed air quality requirements, such as food, pharmaceuticals, and electronics, found that traditional oil-lubricated screw compressors could not meet their needs due to oil contamination issues, leading to the development of oil-free screw compressors.

[0003] Patent CN 205638922 U discloses a cryogenic twin-screw compressor, including a fixed cover, a cryogenic drive chamber, and a screw housing. The fixed cover is located on the left side of the cryogenic drive chamber and is fixed to the cryogenic drive chamber. A rubber coupling is provided inside the cryogenic drive chamber, and a metal coupling is connected to the right end of the rubber coupling. A drive wheel is provided at the right end of the metal coupling. The screw housing is located on the right side of the cryogenic drive chamber. A female screw and a male screw are provided inside the screw housing and are meshed. A driven wheel is provided at the left end of the male screw and is meshed with the drive wheel. A bearing cover is provided at the right end of the screw housing and is fixed to the screw housing.

[0004] However, the device also has the following problems: when facing high-pressure application scenarios, it is often necessary to use two independent compressors connected in series or to integrate two compressors into one housing, resulting in a large number of components, large equipment size, high manufacturing cost, and complex maintenance. Utility Model Content

[0005] To address the problems existing in the prior art, a rotor assembly and a single-unit two-stage high-pressure screw compressor containing the rotor assembly are provided to solve the problems mentioned in the above-mentioned technical background.

[0006] The technical solution adopted by this utility model to solve its technical problem is:

[0007] This utility model proposes a rotor assembly, including a primary compression mechanism and a secondary compression mechanism. The primary compression mechanism includes a primary male rotor and a primary female rotor that operate in conjugate motion, and the secondary compression mechanism includes a secondary male rotor and a secondary female rotor that operate in conjugate motion. The primary male rotor, the primary female rotor, the secondary male rotor, and the secondary female rotor have different numbers of teeth, and the outer side of the primary female rotor, the secondary male rotor, and the secondary female rotor are all provided with shaft segments that drive their rotation.

[0008] Preferably, the rotation direction of the primary male rotor and the secondary female rotor is right-handed, the rotation direction of the secondary male rotor and the primary female rotor is left-handed, the tooth ratio of the primary male rotor to the primary female rotor is 3:4, and the tooth ratio of the secondary male rotor to the secondary female rotor is 3:4.

[0009] Preferably, the primary male rotor and the primary female rotor have 3 and 4 teeth respectively, and the secondary male rotor and the secondary female rotor have 6 and 8 teeth respectively.

[0010] A single-unit two-stage high-pressure screw compressor uses the above-mentioned rotor assembly. The compressor includes a cylinder, and a primary cavity for accommodating a primary compression mechanism is opened on one side of the cylinder, and a secondary cavity for accommodating a secondary compression mechanism is opened on the other side.

[0011] The primary cavity has a primary intake port on the side near the primary male rotor and a primary exhaust port on the end near the primary female rotor. The secondary cavity has a secondary intake port on the side near the secondary male rotor and a secondary exhaust port on the end near the secondary female rotor. The primary exhaust port is connected to the secondary intake port.

[0012] Preferably, the inner sides of the first-stage male rotor and the inner sides of the second-stage male rotor are coaxially fixed to form a male rotor through a connecting section; the inner sides of the first-stage female rotor and the inner sides of the second-stage female rotor are coaxially fixed to form a female rotor through a connecting section.

[0013] Preferably, the male rotor and the female rotor are connected by a baffle, which is formed by two identical locking blocks joined together, and the locking blocks are provided with semi-circular locking grooves for locking the connecting sections on the male rotor and the female rotor respectively.

[0014] Preferably, one end of the primary cavity of the cylinder is detachably connected to an intake seat, and an intake end cap is detachably connected to the intake seat; one end of the secondary cavity of the cylinder is detachably connected to an exhaust seat, and an exhaust end cap is detachably connected to the exhaust seat.

[0015] Preferably, the outer shaft segments of the primary male rotor and the primary female rotor are rotatably connected to the exhaust seat via bearing assemblies, and the outer shaft segments of the secondary male rotor and the secondary female rotor are rotatably connected to the intake seat via bearing assemblies.

[0016] Preferably, a comb-tooth seal, a main seal assembly, a bearing assembly, and a balance disc are sequentially installed on the shaft segment away from the direction of the primary male rotor; a comb-tooth seal, a main seal assembly, and a bearing assembly are sequentially installed on the shaft segment away from the direction of the primary female rotor.

[0017] On the shaft section away from the secondary male rotor, a comb seal, a main seal assembly, a bearing assembly, a pinion, and a skeleton seal are installed in sequence; on the shaft section away from the secondary female rotor, a comb seal, a main seal assembly, a bearing assembly, and a large gear are installed in sequence.

[0018] Preferably, the shaft end of the secondary male rotor extends through the exhaust end cover to form a drive shaft.

[0019] Compared with the prior art, the beneficial effects of this utility model are:

[0020] 1. The rotor assembly of this utility model includes a primary male rotor, a secondary male rotor, a primary female rotor, and a secondary female rotor. The primary male rotor and the secondary male rotor are connected in series on the same axis, and the primary female rotor and the secondary female rotor are connected in series on the same axis. Without increasing the number of rotor cores, the two-stage compression rotors are integrated onto a single shaft, simplifying the rotor layout and reducing the processing difficulty.

[0021] 2. The rotor assembly of this utility model is installed inside the cylinder. Gas enters from the first-stage intake port, is compressed in the first stage, is discharged from the first-stage exhaust port, and then enters the second-stage intake port. After being compressed in the second stage, it is discharged from the second-stage exhaust port. The two-stage design in series can reduce leakage between stages in the cylinder and improve compression efficiency, making it suitable for high-pressure demand scenarios (such as 20-40 bar). At the same time, the first-stage compression can reduce the stress on the second-stage compression, reducing the bearing stress index of conventional single-stage high-pressure machines with the same pressure difference. In addition, the elimination of the internal high-pressure stage seal can reduce the design index of the seal and bearing, thereby reducing the design and production costs of the seal and bearing and extending their service life.

[0022] 3. This utility model uses a single shaft to connect two-stage rotors in series, which reduces the number of rotors, bearings, and seals to a certain extent when installed in the cylinder. The structure is compact, integrates dual-stage compression, saves equipment space, and is easy to install and maintain. At the same time, after integrating dual-stage compression in a single unit, it can be adapted to existing screw compressor housings and drive systems, which is convenient for industrial promotion. Attached Figure Description

[0023] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0024] Figure 1 This is a schematic diagram of the overall structure of this utility model (vertical orientation);

[0025] Figure 2 This is a front view of the present invention;

[0026] Figure 3 This is a sectional view of section AA of this utility model;

[0027] Figure 4This is a cross-sectional view of the BB section of this utility model;

[0028] Figure 5 This is a perspective view of the male rotor of this utility model;

[0029] Figure 6 This is a main body diagram of the male rotor of this utility model;

[0030] Figure 7 This is a cross-sectional view of the primary male rotor of this utility model;

[0031] Figure 8 This is a cross-sectional view of the secondary male rotor of this utility model;

[0032] Figure 9 This is a main body diagram of the female rotor of this utility model;

[0033] Figure 10 This is a main body diagram of the female rotor of this utility model;

[0034] Figure 11 This is a cross-sectional view of the primary female rotor of this utility model;

[0035] Figure 12 This is a cross-sectional view of the secondary female rotor of this utility model;

[0036] Figure 13 This is a perspective view of the cylinder of this utility model.

[0037] Figure 14 This is a schematic diagram of the rotor assembly meshing according to this utility model.

[0038] Explanation of reference numerals in the attached figures:

[0039] 1. Male rotor; 2. Female rotor; 3. Primary male rotor; 4. Secondary male rotor; 5. Primary female rotor; 6. Secondary female rotor; 7. Connecting section; 8. Primary intake port; 9. Primary exhaust port; 10. Secondary intake port; 11. Secondary exhaust port; 12. Intake seat; 13. Intake end cover; 14. Exhaust seat; 15. Exhaust end cover; 16. Cylinder; 17. Baffle; 18. Bearing assembly; 19. Comb seal; 20. Main seal; 21. Pinion; 22. Skeleton seal; 23. Large gear; 24. Balance disc. Detailed Implementation

[0040] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0041] Example 1

[0042] refer to Figures 1-14 As shown, this embodiment proposes a rotor assembly, including a primary compression mechanism and a secondary compression mechanism. The primary compression mechanism includes a primary male rotor 3 and a primary female rotor 5 that operate in conjugate. The secondary compression mechanism includes a secondary male rotor 4 and a secondary female rotor 6 that operate in conjugate. The primary male rotor 3, the primary female rotor 5, the secondary male rotor 4, and the secondary female rotor 6 have different numbers of teeth, and the outer sides of the primary female rotor 5, the secondary male rotor 4, and the secondary female rotor 6 are all provided with shaft segments that drive their rotation.

[0043] The primary male rotor 3 and the secondary female rotor 6 rotate in a right-hand direction, while the secondary male rotor 4 and the primary female rotor 5 rotate in a left-hand direction. The tooth ratio of the primary male rotor 3 to the primary female rotor 5 is 3:4, and the tooth ratio of the secondary male rotor 4 to the secondary female rotor 6 is 3:4.

[0044] The primary male rotor 3 and the primary female rotor 5 have 3 and 4 teeth respectively, and the secondary male rotor 4 and the secondary female rotor 6 have 6 and 8 teeth respectively.

[0045] The outer side of the first-stage male rotor 3 is coaxially fixed with a male intake shaft section that drives its rotation; the outer side of the second-stage male rotor 4 is coaxially fixed with a male exhaust shaft section that drives its rotation; the outer side of the first-stage female rotor 5 is coaxially fixed with a female intake shaft section that drives its rotation; and the outer side of the second-stage female rotor 6 is coaxially fixed with a female exhaust shaft section that drives its rotation.

[0046] Example 2

[0047] Reference Appendix Figure 1 -Appendix Figure 14 This embodiment proposes a single-unit two-stage high-pressure screw compressor, which uses the rotor assembly described above.

[0048] The compressor includes a cylinder 16, with a primary cavity on one side to accommodate a primary compression mechanism and a secondary cavity on the other side to accommodate a secondary compression mechanism.

[0049] A primary air intake port 8 is provided on the side of the primary male rotor 3, and a primary exhaust port 9 is provided on the side of the primary female rotor 5. A secondary air intake port 10 is provided on the side of the secondary male rotor 4, and a secondary exhaust port 11 is provided on the side of the secondary female rotor 6. The primary exhaust port 9 is connected to the secondary air intake port 10.

[0050] Because the gas will heat up during the compression process, the increased temperature will reduce the compression efficiency. The gas can be discharged through the first-stage exhaust port 9 and then enter the cooler for cooling before entering the second-stage intake port 10. The cooled gas has a higher density, and the gas mass per unit volume is greater during the second-stage compression, which further reduces energy consumption.

[0051] The cooler can be either air-cooled or water-cooled.

[0052] The tandem two-stage rotor design reduces interstage leakage within the cylinder, improving compression efficiency and making it suitable for high-pressure applications (such as 20-40 bar). Simultaneously, the first-stage compression reduces the stress on the second-stage compression, lowering the bearing stress index of conventional single-stage high-pressure machines with the same pressure differential.

[0053] At the same time, eliminating the internal high-pressure stage seal allows for lower design specifications for the seal and bearing, thereby reducing the design and production costs of the seal and bearing and extending their service life.

[0054] The primary and secondary cavities can be arranged vertically or horizontally. When arranged vertically, the outer shaft segment of the primary male rotor 3 or primary female rotor 5 is connected to the power mechanism, and then the other rotor is driven to rotate through two gears sleeved on the two shaft segments. The outer shaft segment of the secondary male rotor 4 or secondary female rotor 6 is connected to the power mechanism, and then the other rotor is driven to rotate through two gears sleeved on the two shaft segments, thereby realizing the vertical arrangement of the primary and secondary cavities.

[0055] When set to left and right, the inner sides of the primary male rotor 3 and the secondary male rotor 4 are coaxially fixed to form the male rotor 1 through the connecting section 7; the inner sides of the primary female rotor 5 and the secondary female rotor 6 are coaxially fixed to form the female rotor 2 through the connecting section 7.

[0056] The inner side of the primary male rotor 3 and the secondary male rotor 4 are coaxially fixed through the connecting section 7, and the inner side of the primary female rotor 5 and the secondary female rotor 6 are coaxially fixed through the connecting section 7, thereby realizing the left-right series design of the primary cavity and the secondary cavity.

[0057] The male rotor 1 and the female rotor 2 are connected by a baffle 17. The baffle is formed by two identical locking blocks joined together. The locking blocks are provided with semi-circular locking grooves for locking the connecting sections 7 on the male rotor 1 and the female rotor 2 respectively.

[0058] There is a gap between the baffle 17 and the male rotor 1 and the female rotor 2. The baffle has a groove along the axial direction of the male rotor 1 and the female rotor 2, which serves to block the airflow between the primary cavity and the secondary cavity.

[0059] One end of the primary cavity of cylinder 16 is detachably connected to an intake seat 12, and an intake end cap 13 is detachably connected to the intake seat 12; one end of the secondary cavity of cylinder 16 is detachably connected to an exhaust seat 14, and an exhaust end cap 15 is detachably connected to the exhaust seat 14.

[0060] The cylinder 16 is connected to the intake seat 12 by a flange and fastened with bolts; the intake seat 12 is connected to the intake end cover 13 by a flange and fastened with bolts.

[0061] The cylinder 16 is connected to the exhaust seat 14 by a flange and fastened with bolts; the exhaust seat 14 is connected to the exhaust end cover 115 by a flange and fastened with bolts.

[0062] The outer shaft segments of the first-stage male rotor 3 and the first-stage female rotor 5, namely the male intake shaft segment and the female intake shaft segment, are rotatably connected to the exhaust seat 14 through the bearing assembly 18. The outer shaft segments of the second-stage male rotor 4 and the second-stage female rotor 6, namely the male exhaust shaft segment and the female exhaust shaft segment, are rotatably connected to the intake seat 12 through the bearing assembly 18.

[0063] On the shaft section away from the primary male rotor 3, that is, the male intake shaft section, a comb seal 19, a main seal assembly 20, a bearing assembly 18, and a balance disc 24 are installed in sequence; on the shaft section away from the primary female rotor 5, that is, the female intake shaft section, a comb seal 19, a main seal assembly 20, and a bearing assembly 18 are installed in sequence.

[0064] On the shaft section away from the secondary male rotor 4, that is, the male exhaust shaft section, a comb seal 19, a main seal assembly 20, a bearing assembly 18, a pinion 21, and a skeleton seal 22 are installed in sequence; on the shaft section away from the secondary female rotor 6, that is, the female exhaust shaft section, a comb seal 19, a main seal assembly 20, a bearing assembly 18, and a large gear 23 are installed in sequence.

[0065] During the operation of the compressor, the gas will generate a pressure difference when it is compressed. This pressure difference will generate an axial force on the rotor. An oil injection hole is provided on the suction end cover 13. Pressurized oil is injected through the hole, which can generate a thrust on the balance disc 24. This causes the balance disc 24 to generate a balancing force in the axial direction of the rotor that is opposite to the direction of the axial force, thereby effectively offsetting most of the axial force and enabling the rotor to maintain a stable axial position.

[0066] The small gear 21 meshes with the large gear 23.

[0067] The ratio of the number of teeth of the pinion to the number of teeth of the gear is 3:4.

[0068] The comb seal 19 (also known as a labyrinth seal) is a component that achieves a sealing effect through multi-stage throttling and expansion. The principle is that when gas enters the cavity between the comb teeth, the flow area suddenly expands, the airflow forms a strong vortex, its velocity almost disappears, and kinetic energy is converted into heat energy. The gas temperature rises back to the temperature before the sealing teeth, while the pressure in the cavity remains the same as before the gap. As the gas passes through each comb tooth sequentially, the pressure continuously decreases, thus achieving the purpose of sealing. In this way, the comb seal can effectively reduce gas leakage and achieve a balance between internal and external pressures.

[0069] The main sealing assembly adopts sealing methods such as dry gas seal, mechanical seal, or carbon ring seal, and corresponding components.

[0070] Dry gas seal is a type of contact-type hydrodynamic mechanical seal that uses the gas being sealed as the sealing medium and achieves a seal by forming a gas film between the sealing end faces.

[0071] Mechanical seals prevent fluid leakage by tightly fitting two smooth, parallel sealing surfaces (a rotating ring and a stationary ring). When the equipment is running, the rotating ring rotates with the shaft, while the stationary ring remains stationary, creating a very small gap between them to achieve a seal.

[0072] Carbon ring seals are a type of non-contact seal that achieves its sealing effect primarily through the porosity and elasticity of the carbon ring.

[0073] The end of the male exhaust shaft section extends through the exhaust end cover 15 to form a drive shaft 25.

[0074] The skeleton seal 22 is used to seal the space between the drive shaft 25 and the exhaust end cover 15.

[0075] The principle of skeleton seal is that its sealing lip is in close contact with the rotating shaft to form a radial seal. Under the action of spring force and liquid pressure, the lip maintains close contact with the shaft and prevents media leakage.

[0076] Specific work process:

[0077] Drive shaft 25 is connected to drive device, drive device to drive male rotor 1 to rotate, male rotor 1 in turn drives large gear 23 to rotate through small gear 21, large gear 23 in turn drives female rotor 2 to rotate; gas enters primary cavity from primary intake port 8, primary male rotor 3 and primary female rotor 5 operate in conjugate to compress gas, after primary compression it is discharged from primary exhaust port 9, after discharge it enters cooler, after being cooled down it enters secondary intake port 10 to reach secondary cavity, secondary male rotor 4 and secondary female rotor 6 operate in conjugate to compress gas again, after secondary compression it is discharged from secondary exhaust port 11, completing gas compression.

[0078] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A rotor assembly, characterized in that, It includes a primary compression mechanism and a secondary compression mechanism. The primary compression mechanism includes a primary male rotor (3) and a primary female rotor (5) that operate in conjugate. The secondary compression mechanism includes a secondary male rotor (4) and a secondary female rotor (6) that operate in conjugate. The primary male rotor (3), the primary female rotor (5), the secondary male rotor (4), and the secondary female rotor (6) have different numbers of teeth. The outer side of the primary male rotor (3), the primary female rotor (5), the secondary male rotor (4), and the secondary female rotor (6) is provided with a shaft segment that drives them to rotate.

2. A rotor assembly according to claim 1, characterized in that, The first-stage male rotor (3) and the second-stage female rotor (6) rotate in a right-hand direction, while the second-stage male rotor (4) and the first-stage female rotor (5) rotate in a left-hand direction. The tooth ratio of the first-stage male rotor (3) to the first-stage female rotor (5) is 3:4, and the tooth ratio of the second-stage male rotor (4) to the second-stage female rotor (6) is 3:

4.

3. A rotor assembly according to claim 1, characterized in that, The first-stage male rotor (3) and the first-stage female rotor (5) have 3 teeth and 4 teeth respectively, and the second-stage male rotor (4) and the second-stage female rotor (6) have 6 teeth and 8 teeth respectively.

4. A single-unit, two-stage high-pressure screw compressor, employing the rotor assembly described in any one of claims 1-3, characterized in that, The compressor includes a cylinder (16), and a primary cavity for accommodating a primary compression mechanism is provided on one side of the cylinder (16), and a secondary cavity for accommodating a secondary compression mechanism is provided on the other side. The primary cavity has a primary intake port (8) on the side near the primary male rotor (3) and a primary exhaust port (9) on the end near the primary female rotor (5). The secondary cavity has a secondary intake port (10) on the side near the secondary male rotor (4) and a secondary exhaust port (11) on the end near the secondary female rotor (6). The primary exhaust port (9) is connected to the secondary intake port (10).

5. A single-unit two-stage high-pressure screw compressor according to claim 4, characterized in that, The inner side of the first-stage male rotor (3) and the inner side of the second-stage male rotor (4) are coaxially fixed to form a male rotor (1) through a connecting section (7); the inner side of the first-stage female rotor (5) and the inner side of the second-stage female rotor (6) are coaxially fixed to form a female rotor (2) through a connecting section (7).

6. A single-unit two-stage high-pressure screw compressor according to claim 5, characterized in that, The male rotor (1) and female rotor (2) are connected by a baffle (17), which is formed by two identical locking blocks joined together. The locking blocks are provided with semi-circular slots for locking the connecting sections (7) on the male rotor (1) and female rotor (2) respectively.

7. A single-unit two-stage high-pressure screw compressor according to claim 5, characterized in that, One end of the primary cavity of the cylinder (16) is detachably connected to an intake seat (12), and an intake end cap (13) is detachably connected to the intake seat (12); one end of the secondary cavity of the cylinder (16) is detachably connected to an exhaust seat (14), and an exhaust end cap (15) is detachably connected to the exhaust seat (14).

8. A single-unit two-stage high-pressure screw compressor according to claim 7, characterized in that, The outer shaft segments of the first-stage male rotor (3) and the first-stage female rotor (5) are rotatably connected to the exhaust seat (14) via a bearing assembly (18), and the outer shaft segments of the second-stage male rotor (4) and the second-stage female rotor (6) are rotatably connected to the intake seat (12) via a bearing assembly (18).

9. A single-unit two-stage high-pressure screw compressor according to claim 8, characterized in that, On the shaft segment away from the primary male rotor (3), a comb seal (19), a main seal assembly (20), a bearing assembly (18), and a balance disc (24) are installed in sequence; on the shaft segment away from the primary female rotor (5), a comb seal (19), a main seal assembly (20), and a bearing assembly (18) are installed in sequence. On the shaft segment away from the secondary male rotor (4), a comb seal (19), a main seal assembly (20), a bearing assembly (18), a pinion (21), and a skeleton seal (22) are installed in sequence; on the shaft segment away from the secondary female rotor (6), a comb seal (19), a main seal assembly (20), a bearing assembly (18), and a large gear (23) are installed in sequence.

10. A single-unit two-stage high-pressure screw compressor according to claim 4, characterized in that, The shaft end of the secondary male rotor (4) extends through the exhaust end cover (15) to form a drive shaft (25).

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