Composite rotor screw vacuum pump

Abstract

A composite rotor screw vacuum pump belongs to the technical field of vacuum pumps. The screw pump specifically comprises a shell, a gas inlet end cover and an exhaust end cover, the gas inlet end cover and the exhaust end cover are arranged at the two ends of the shell respectively, a pair of screw rotors is arranged in a pump cavity of the shell, and the screw rotors convey gas into a screw pump exhaust cavity in the shell. A booster cavity is arranged in the exhaust end cover, the claw type booster device is arranged in the booster cavity, and the booster cavity is communicated with the screw pump exhaust cavity through a booster cavity air inlet. The screw pump has the advantages that the exhaust end of the screw pump is connected with the claw type supercharging device in series, the compression ratio can reach more than 10: 1 or even higher, the energy-saving effect is very obvious, and the problem that the compression ratio of the screw vacuum pump is not high is effectively solved.

Description

Technical Field

[0001] The utility model belongs to the technical field of vacuum pumps, and in particular relates to a composite rotor screw vacuum pump. Background Art

[0002] The screw vacuum pump is an exhaust device that uses a pair of screw rotors to rotate synchronously at high speed in the pump housing to produce suction and exhaust. No lubricating oil is used in its working chamber. It is an updated product of the oil-sealed vacuum pump. It is suitable for occasions where a large amount of water vapor and a small amount of dust need to be extracted. It is widely used in domestic pharmaceutical, chemical, semiconductor and other fields with high requirements for clean vacuum. The screw rotor is divided into two types: equal pitch and variable pitch. When the end profile of the equal pitch screw rotor is unfolded, the lead remains unchanged, and there is no internal compression exhaust method. When the end profile of the variable pitch screw rotor is unfolded, the lead changes, and there is an internal compression exhaust method, and its exhaust temperature and energy consumption are lower. Although the variable pitch screw vacuum pump has a lower temperature and is more energy-efficient than the equal pitch vacuum pump, the design and manufacturing difficulty of the variable pitch screw rotor is relatively high. It is difficult to achieve a compression ratio of more than 5:1, so the energy-saving effect is not very prominent.

[0003] In view of the above-mentioned prior art, it is necessary to reasonably improve the existing screw vacuum pump structure. To this end, the applicant has made a useful design, and the technical solution to be introduced below is produced under this background. Utility Model Content

[0004] The task of the utility model is to provide a composite rotor screw vacuum pump, which has a claw-type booster device connected in series at the exhaust end of the screw pump, and the compression ratio can reach more than 10:1, or even higher, and the energy-saving effect is very obvious.

[0005] The task of the utility model is accomplished in this way. A composite rotor screw vacuum pump comprises a shell, and an air inlet end cover and an exhaust end cover respectively arranged at both ends of the shell. A pair of screw rotors are arranged in the pump chamber of the shell. The screw rotors convey gas to the exhaust chamber of the screw pump in the shell. The utility model is characterized in that: a claw-type boosting device is connected in series to the extension section of the screw rotor, a boosting chamber is arranged in the exhaust end cover, the claw-type boosting device is arranged in the aforementioned boosting chamber, and the boosting chamber and the aforementioned exhaust chamber of the screw pump are connected through the boosting chamber air inlet.

[0006] In a specific embodiment of the present invention, the claw-type supercharging device comprises a pair of claw-type rotors, and the pair of claw-type rotors are respectively mounted on extension sections of a pair of screw rotors.

[0007] In another specific embodiment of the present invention, the screw rotor is specifically a first screw rotor and a second screw rotor, and the claw rotor is specifically a first claw rotor and a second claw rotor. The first claw rotor is fixedly arranged on the shaft extension section of the first screw rotor, and the second claw rotor is fixedly arranged on the shaft extension section of the second screw rotor.

[0008] In another specific embodiment of the present utility model, a partition is provided between the boosting chamber and the exhaust chamber of the screw pump, and the air inlet of the boosting chamber is provided on the partition.

[0009] In another specific embodiment of the present invention, the screw rotor adopts a constant pitch or a variable pitch.

[0010] In another specific embodiment of the utility model, an air inlet is provided above the air inlet end of the shell, an exhaust chamber is provided below the exhaust end of the shell, a check valve is provided below the exhaust chamber, an exhaust port is provided below the check valve, and the screw pump exhaust chamber and the exhaust chamber are connected.

[0011] In another specific embodiment of the present invention, a boost chamber exhaust port is provided in the boost chamber, a first boost exhaust channel and a second boost exhaust channel are provided on the exhaust end cover, and the boost chamber exhaust port, the first boost exhaust channel, the second boost exhaust channel and the exhaust port are connected in sequence.

[0012] In a more specific embodiment of the present invention, a shaft seal assembly, an oil retaining ring, and a bearing are sequentially sleeved on the shaft section of each screw rotor extending from the corresponding claw rotor. The outer ring of the bearing is arranged in the bearing seat, and the outer ring of the bearing seat is installed in cooperation with the exhaust end cover.

[0013] In yet another specific embodiment of the present invention, a pair of synchronous gears are provided at the ends of the screw rotors extending out of the bearings. The synchronous gears are specifically a first gear and a second gear. The first gear is fixedly arranged at the end of the shaft extension section of the first screw rotor, and the second gear is fixedly arranged at the end of the shaft extension section of the second screw rotor.

[0014] Due to the adoption of the above structure, the utility model has the following beneficial effects: first, the scheme connects a claw-type booster device in series at the exhaust end of the screw pump to form a compound rotor screw vacuum pump, and the suction capacity of the claw-type booster device can be set according to the required compression ratio, and its compression ratio can easily reach 10:1 or more, or even higher, which effectively solves the problem of low compression ratio of the screw vacuum pump, and the energy-saving effect is very obvious; second, the compound rotor screw vacuum pump described in this scheme greatly improves the suction efficiency at low pressure, and the exhaust temperature is lower. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the structure of the composite rotor screw vacuum pump of the utility model;

[0016] Figure 2 for Figure 1 AA section view;

[0017] Figure 3 for Figure 1 BB cross-sectional view.

[0018] In the figure: 1. Inlet end cover; 2. Shell; 3. Exhaust end cover; 4. Partition; 5. Screw pump exhaust chamber; 6. First boost exhaust channel; 7. Second boost exhaust channel; 8. Exhaust chamber; 9. Exhaust port; 10. Check valve; 11. Inlet port; 12. First screw rotor; 13. Second screw rotor; 14. Bearing seat; 15. Bearing; 16. First gear; 17. Second gear; 18. Oil retaining ring; 19. Shaft seal assembly; 20. First claw rotor; 21. Second claw rotor; 22. Inlet port of boost chamber; 23. Exhaust port of boost chamber; 24. Boost chamber. DETAILED DESCRIPTION

[0019] The specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings, but the description of the embodiments is not a limitation of the technical solution. Any changes in form rather than substance based on the concept of the present invention should be regarded as the protection scope of the present invention.

[0020] In the following description, all concepts related to directionality or orientation such as up, down, left, right, front and back are based on the positions shown in the corresponding drawings. They are only used to facilitate the description of the technical solution provided by the utility model and simplify the description in conjunction with the drawings, and therefore cannot be understood as a special limitation on the technical solution provided by the utility model.

[0021] See also Figures 1 to 3 The utility model relates to a composite rotor screw vacuum pump, comprising a housing 2, and an inlet end cover 1 and an exhaust end cover 3 respectively arranged at both ends of the housing 2, wherein a pair of screw rotors are arranged in the pump chamber of the housing 2. The screw rotors adopt a constant pitch or a variable pitch. The screw rotors are specifically a first screw rotor 12 and a second screw rotor 13, and the screw rotors convey gas to the exhaust chamber 5 of the screw pump in the housing 2.

[0022] An air inlet 11 is provided above the air inlet end of the housing 2, an exhaust chamber 8 is provided below the exhaust end of the housing 2, a check valve 10 is provided below the exhaust chamber 8, and an exhaust port 9 is provided below the check valve 10. The exhaust chamber 5 of the screw pump is connected to the exhaust chamber 8.

[0023] A claw-type supercharging device is connected in series on the extension section of the screw rotor, and the claw-type supercharging device includes a pair of claw-type rotors, and the pair of claw-type rotors are respectively installed on the extension sections of a pair of screw rotors. More specifically, a supercharging chamber 24 is provided in the exhaust end cover 3, and a pair of claw-type rotors are arranged in the supercharging chamber 24. The supercharging chamber 24 and the exhaust chamber 5 of the screw pump are connected through the supercharging chamber air inlet 22. The claw-type rotors are specifically a first claw-type rotor 20 and a second claw-type rotor 21. The first claw-type rotor 20 is fixedly arranged on the shaft extension section of the first screw rotor 12, and the second claw-type rotor 21 is fixedly arranged on the shaft extension section of the second screw rotor 13.

[0024] Specifically, a partition 4 is provided between the boost chamber 24 and the screw pump exhaust chamber 5 to separate the two chambers, and the boost chamber air inlet 22 is provided on the partition 4. A boost chamber exhaust port 23 is provided in the boost chamber 24, and a first boost exhaust channel 6 and a second boost exhaust channel 7 are provided on the exhaust end cover 3. The boost chamber exhaust port 23, the first boost exhaust channel 6, the second boost exhaust channel 7 and the exhaust port 9 are connected in sequence.

[0025] like Figure 3 As shown, the shaft section of each screw rotor extending from the corresponding claw rotor is sleeved with a shaft seal assembly 19, an oil retaining ring 18, and a bearing 15 in sequence, and the outer ring of the bearing 15 is arranged in the bearing seat 14, and the outer ring of the bearing seat 14 is mounted in cooperation with the exhaust end cover 3. A pair of synchronous gears are arranged at the ends of a pair of screw rotors extending from the bearing 15, and the synchronous gears are specifically a first gear 16 and a second gear 17. The first gear 16 is fixedly arranged at the end of the shaft extension section of the first screw rotor 12, and the second gear 17 is fixedly arranged at the end of the shaft extension section of the second screw rotor 13.

[0026] Please continue reading Figures 1 to 3 The working principle of a composite rotor screw vacuum pump described in the utility model is: when the composite rotor screw vacuum pump described in the utility model is working, a pair of synchronous gears mesh with each other to drive a pair of screw rotors to rotate in opposite directions, and the gas enters the pump chamber in the shell 2 from the air inlet 11, and is then transported to the exhaust chamber 5 of the screw pump through the screw rotor. If the gas is high-pressure gas at this time, a large amount of high-pressure gas will flow to the exhaust chamber 8 and push the check valve 10, and be discharged to the outside of the pump from the exhaust port 9; if the gas is low-pressure gas at this time, the low-pressure gas cannot push the check valve 10, and thus enters the boosting chamber 24 through the boosting chamber air inlet 22, and the low-pressure gas is compressed by the claw rotor and discharged from the boosting chamber exhaust port 23. The pressurized gas then passes through the first boosting exhaust channel 6 and the second boosting exhaust channel 7, and is finally exhausted from the pump from the exhaust port 9.

Claims

1. A composite rotor screw vacuum pump, comprising a housing (2), and an inlet end cover (1) and an exhaust end cover (3) respectively arranged at both ends of the housing (2), a pair of screw rotors being arranged in a pump chamber of the housing (2), the screw rotors conveying gas to an exhaust chamber (5) of the screw pump in the housing (2), characterized in that: A claw-type boosting device is connected in series to the extended section of the screw rotor, a boosting chamber (24) is provided in the exhaust end cover (3), the claw-type boosting device is arranged in the aforementioned boosting chamber (24), and the boosting chamber (24) and the aforementioned screw pump exhaust chamber (5) are connected via the boosting chamber air inlet (22).

2. A compound rotor screw vacuum pump according to claim 1, characterized in that: The claw-type supercharging device comprises a pair of claw-type rotors, and the pair of claw-type rotors are respectively installed on the extension sections of a pair of screw rotors.

3. A compound rotor screw vacuum pump according to claim 2, characterized in that: The screw rotor is specifically a first screw rotor (12) and a second screw rotor (13), and the claw rotor is specifically a first claw rotor (20) and a second claw rotor (21). The first claw rotor (20) is fixedly arranged on the shaft extension section of the first screw rotor (12), and the second claw rotor (21) is fixedly arranged on the shaft extension section of the second screw rotor (13).

4. A compound rotor screw vacuum pump according to claim 1, characterized in that: A partition plate (4) is provided between the boosting chamber (24) and the exhaust chamber (5) of the screw pump, and the boosting chamber air inlet (22) is provided on the partition plate (4).

5. The compound rotor screw vacuum pump according to claim 1, characterized in that: The screw rotor adopts a constant pitch or a variable pitch.

6. The compound rotor screw vacuum pump according to claim 1, characterized in that: An air inlet (11) is provided above the air inlet end of the shell (2), an exhaust chamber (8) is provided below the exhaust end of the shell (2), a check valve (10) is provided below the exhaust chamber (8), an exhaust port (9) is provided below the check valve (10), and the exhaust chamber (5) of the screw pump is connected to the exhaust chamber (8).

7. A compound rotor screw vacuum pump according to claim 6, characterized in that: The boost chamber (24) is provided with a boost chamber exhaust port (23), the exhaust end cover (3) is provided with a first boost exhaust channel (6) and a second boost exhaust channel (7), and the boost chamber exhaust port (23), the first boost exhaust channel (6), the second boost exhaust channel (7) and the exhaust port (9) are connected in sequence.

8. The compound rotor screw vacuum pump according to claim 3, characterized in that: A shaft seal assembly (19), an oil retaining ring (18), and a bearing (15) are sequentially sleeved on the shaft section of each screw rotor extending from the corresponding claw rotor. The outer ring of the bearing (15) is arranged in a bearing seat (14), and the outer ring of the bearing seat (14) is mounted in cooperation with the exhaust end cover (3).

9. A compound rotor screw vacuum pump according to claim 8, characterized in that: A pair of synchronous gears are provided at the ends of the pair of screw rotors extending out of the bearing (15), wherein the synchronous gears are specifically a first gear (16) and a second gear (17). The first gear (16) is fixedly arranged at the end of the shaft extension section of the first screw rotor (12), and the second gear (17) is fixedly arranged at the end of the shaft extension section of the second screw rotor (13).

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