Self-cleaning roots vacuum pump

Abstract

The invention discloses a self-cleaning Roots vacuum pump which comprises a pump shell, end plates are installed at the two ends of the pump shell, two mutually-meshed Roots rotors are arranged in the pump shell, rotating shafts at the two ends of each Roots rotor are rotationally installed on the two end plates, and air gaps are formed between the two ends of each Roots rotor and the end plates. A first pipeline is arranged in the middle of the Roots rotor and extends into the rotating shaft, a plurality of second air inlet holes are formed in the position, located on the outer side of the first pipeline, of the rotating shaft at equal intervals, first air inlet holes are formed in the end plates, and when the Roots rotor rotates till the second air inlet holes correspond to the first air inlet holes, the second air inlet holes are communicated with the first air inlet holes. The first air inlet holes and the corresponding second air inlet holes are of a communicating structure. Second pipelines are arranged on the roots rotor and located on the two sides of the first pipeline, and a plurality of third pipelines are arranged between the first pipeline and the second pipelines. According to the invention, the service life of the improved roots pump is obviously prolonged, and the roots pump is kept in high-vacuum, high-pumping-speed and clean operation.

Description

Technical Field

[0001] The present invention relates to the technical field of Roots vacuum pumps, and specifically to a self-cleaning Roots vacuum pump. Background Art

[0002] A Roots vacuum pump (abbreviation: Roots pump) refers to a positive-displacement vacuum pump in which two leaf-shaped Roots rotors that rotate synchronously in opposite directions are installed inside the pump, and there are small gaps between the Roots rotors and between the Roots rotors and the inner wall of the pump housing without contacting each other.

[0003] A Roots vacuum pump disclosed in the existing publication number CN114645848B includes a pump housing. A Roots cavity and a gear cavity are formed inside the pump housing. A circulating water cooling device is detachably connected to the pump housing. A water cooling spiral channel is formed inside the pump housing, and the water cooling spiral channel wraps the Roots cavity and the gear cavity. An inlet water pipe and an outlet water pipe that extend out of the pump housing are respectively fixed at both ends of the water cooling spiral channel. The circulating water cooling device is used to input the water in the container into the inlet water pipe in a cycle and suck it out from the outlet water pipe. An operator uses the circulating water cooling device to connect the inlet water pipe and the outlet water pipe. The water cooling device inputs the water in the container into the inlet water pipe in a cycle and sucks it out from the outlet water pipe. The water sucked out from the outlet water pipe is cooled and then enters from the inlet water pipe, so as to realize the continuous circulation of water, and the water cools the Roots vacuum pump, thereby reducing the probability of the Roots vacuum pump malfunctioning during operation.

[0004] Disadvantages / Deficiencies of the Existing Technology: After the Roots pump is used for a period of time, a large amount of products or dust will remain inside the Roots pump. In particular, there is a lot of dust in the holes of the Roots rotors, which cannot be cleaned, and it is easy to cause the machine to jam. If it needs to be cleaned, the entire pump body, cavity, and Roots rotors need to be disassembled for cleaning, resulting in very inconvenient cleaning. Summary of the Invention

[0005] The purpose of the present invention is to provide a self-cleaning Roots vacuum pump to solve the problems in the existing technology.

[0006] To achieve the above object, the present invention provides the following technical solution: A self-cleaning Roots vacuum pump, comprising a pump housing, end plates are installed at both ends of the pump housing, two meshing Roots rotors are arranged inside the pump housing, the two Roots rotors rotate synchronously and reversely, the rotating shafts at both ends of the Roots rotors are rotatably installed on the two end plates, the Roots rotors and the rotating shafts are of an integral structure, and an air gap is formed between both ends of the Roots rotors and the end plates; a first pipeline is opened in the middle of the Roots rotor, the first pipeline extends into the rotating shaft, and a plurality of second air inlet holes are equidistantly opened on the outer side of the rotating shaft where the first pipeline is located, a first air inlet hole is opened on the end plate, when the Roots rotor rotates to make the second air inlet hole correspond to the first air inlet hole, the first air inlet hole and the corresponding second air inlet hole are in a communicating structure; second pipelines are arranged on both sides of the first pipeline of the Roots rotor, and a plurality of third pipelines are arranged between the first pipeline and the second pipelines, and both ends of the third pipeline are respectively communicated with the first pipeline and the second pipeline.

[0007] Preferably, a gas sealing structure for sealing gas is arranged between the rotating shaft of the Roots rotor and the end plate.

[0008] Preferably, four second air inlet holes are opened on the rotating shafts at both ends of the Roots rotor; the distance between adjacent third pipelines is the same.

[0009] Preferably, the Roots rotor adopts an 8-shaped Roots rotor.

[0010] Preferably, the rotating shafts at both ends of the Roots rotor both extend to the outside of the end plate, a first gear and a second gear are respectively installed on the rotating shafts of the two Roots rotors, the first gear and the second gear mesh with each other, a first protective cover and a second protective cover are respectively installed on the outside of the two end plates, and a driving assembly for driving one of the rotating shafts to rotate is installed on the outside of the first protective cover.

[0011] Preferably, the first protective cover and the second protective cover are both provided with oil injection holes for filling lubricating oil into the gears.

[0012] Preferably, an air inlet is opened at the top of the pump housing, an air outlet is opened at the bottom of the pump housing, heat dissipation fins are arranged on the outside of the pump housing, and the pump housing is installed on a base.

[0013] Preferably, the end plate includes a plate body, two shaft holes are opened in the plate body, reinforcing ribs are arranged on the outside of the plate body, and the plate body and the reinforcing ribs are of an integral structure.

[0014] Preferably, second arc structures are symmetrically arranged at both ends of the Roots rotor, first arc structures are symmetrically arranged on both sides of the Roots rotor, first arc-shaped structures are arranged at both ends of the Roots rotor located at the first arc structures, and second arc-shaped structures are arranged between the first arc-shaped structures and the second arc structures; when one Roots rotor and another Roots rotor rotate, the first arc structure of one Roots rotor contacts the second arc structure of the other Roots rotor, the second arc structure of one Roots rotor contacts the first arc structure of the other Roots rotor, the first arc-shaped structure of one Roots rotor contacts the second arc-shaped structure of the other Roots rotor, and the second arc-shaped structure of one Roots rotor contacts the first arc-shaped structure of the other Roots rotor; the distance between the axes of the two rotating shafts is L, the radius of the first arc structure is R1, the radius of the second arc structure is R2, and L = R1 + R2.

[0015] Preferably, it further includes a nitrogen purging device, and the nitrogen purging device is connected to the first air inlet hole of the end plate through a gas pipe.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] 1. A certain amount of nitrogen is blown in from the outside of the two end plates (the blowing amount is controlled to be able to purge cleanly without affecting the vacuum degree and pumping speed requirements). The nitrogen enters the hollow shaft from the end plate, and then enters the two-end hollow Roots rotor through the shaft hole, forming an air flow that purges towards the cavity end plate inside the middle-hole Roots rotor, so that the gas and dust in the entire cavity are discharged together with the lower pump. The service life of the Roots pump is significantly improved through the improved Roots pump, and various costs such as time, labor, and repair costs (due to dust in the pump that requires shutdown and production suspension) are saved, and the Roots pump maintains high vacuum, large pumping speed, and clean operation.

[0018] 2. An automatic timing and constant-pressure nitrogen purging device is adopted to make nitrogen enter from the two end plates. The end plate air groove is tightly connected to the Roots rotor shaft. There are 4 second air inlet holes at each end of the shaft. The middle of the shaft is the first pipeline. The 4 second air inlet holes are tightly connected to the first pipeline. The two ends of the shaft are sealed by special devices, and gas cannot be blown into the oil cavity. The shaft and the 8-shaped Roots rotor are integrally cast. The two arcs of the 8-shaped Roots rotor are hollow. There are multiple blowing holes at different parts inside the shaft and the hollow arc (the outside of the 8-shaped arc is sealed and has no holes). When the Roots rotor rotates at high speed, nitrogen is blown into the end plate hole groove from the nitrogen port, and then purges towards both ends through the shaft center hole into the arc holes of the 8-shaped Roots rotor. There is a certain air gap at both ends of the end plate. Nitrogen purges a certain air pressure and air volume into the cavity from the air gaps at both ends. Through the compression between the cavity and the Roots rotor, the nitrogen products and fine dust are discharged together from the outlet, and this process is repeated to achieve the self-cleaning effect during the working process. Description of the Drawings

[0019] The accompanying drawings are used to provide a further understanding of the present invention and form a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation to the present invention. In the drawings:

[0020] Figure 1 is a schematic structural diagram of the present invention;

[0021] Figure 2 is a cross-sectional view of the Roots rotor and the pump housing of the present invention;

[0022] Figure 3 is a schematic structural diagram of the end plate of the present invention;

[0023] Figure 4 is a schematic structural diagram of the engagement of the first gear and the second gear of the present invention;

[0024] Figure 5 is a schematic structural diagram of the engagement of the Roots rotors of the present invention.

[0025] In the figure: 1, base; 2, pump housing; 3, drive assembly; 4, first protective cover; 5, end plate; 6, heat dissipation fins; 7, oil injection hole; 8, second protective cover; 9, first gear; 10, second gear; 11, Roots rotor; 12, first air inlet hole; 13, second air inlet hole; 14, air gap; 15, first pipeline; 16, second pipeline; 17, third pipeline; 51, plate body; 52, reinforcing rib; 53, shaft hole; 111, first arc structure; 112, first arc-shaped structure; 113, second arc-shaped structure; 114, second arc structure. Detailed Embodiments

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention.

[0027] Please refer to Figures 1-5, in the embodiment of the present invention, a self-cleaning Roots vacuum pump includes a pump housing 2. An air inlet is provided at the top of the pump housing 2, and an air outlet is provided at the bottom of the pump housing 2. Heat dissipation fins 6 are arranged on the outer side of the pump housing 2, and the pump housing 2 is installed on a base 1. End plates 5 are installed at both ends of the pump housing 2. Two meshing Roots rotors 11 are arranged inside the pump housing 2, and the two Roots rotors 11 rotate synchronously and in opposite directions. The Roots rotor 11 adopts an 8-shaped Roots rotor. The rotating shafts at both ends of the Roots rotor 11 are rotatably installed on the two end plates 5. A gas sealing structure for sealing gas is arranged between the rotating shaft of the Roots rotor 11 and the end plate 5. The Roots rotor 11 and the rotating shaft are of an integral structure. An air gap 14 is formed between both ends of the Roots rotor 11 and the end plate 5. A first pipeline 15 is provided in the middle of the Roots rotor 11, and the first pipeline 15 extends into the rotating shaft. A plurality of second air inlet holes 13 are equidistantly arranged on the outer side of the rotating shaft where the first pipeline 15 is located. A first air inlet hole 12 is provided on the end plate 5. When the Roots rotor 11 rotates to make the second air inlet hole 13 correspond to the first air inlet hole 12, the first air inlet hole 12 and the corresponding second air inlet hole 13 are in a communicating structure. Second pipelines 16 are arranged on both sides of the Roots rotor 11 where the first pipeline 15 is located. A plurality of third pipelines 17 are arranged between the first pipeline 15 and the second pipelines 16, and both ends of the third pipeline 17 are respectively communicated with the first pipeline 15 and the second pipelines 16. Four second air inlet holes 13 are provided on the rotating shafts at both ends of the Roots rotor 11. The distance between adjacent third pipelines 17 is the same. An automatic timing and constant pressure nitrogen purging device is used to introduce nitrogen from both end plates. The end plate air grooves are tightly connected to the Roots rotor shaft. There are 4 second air inlet holes at each end of the shaft. The middle of the shaft is the first pipeline 15. The 4 second air inlet holes are tightly communicated with the first pipeline 15. Both ends of the shaft are sealed by a special device, and gas cannot be blown into the oil chamber. The shaft and the 8-shaped Roots rotor are integrally cast. The two arcs of the 8-shaped Roots rotor are hollow. There are multiple blow holes at different parts in the shaft and the hollow arc (the outside of the 8-shaped arc is sealed and has no holes). When the Roots rotor rotates at high speed, nitrogen is blown into the end plate hole grooves from the nitrogen port, and then passes through the central hole of the shaft and blows towards both ends into the arc holes of the 8-shaped Roots rotor. There is a certain air gap at both ends of the end plates. Nitrogen is blown into the cavity from the air gaps at both ends with a certain air pressure and air volume. Through the compression between the cavity and the Roots rotor, the nitrogen products and fine dust are discharged together from the outlet. This process is repeated to achieve the self-cleaning effect during the working process. Nitrogen is blown into a certain amount from the outside of both end plates (the blowing volume is controlled to be able to purge cleanly without affecting the vacuum degree and pumping speed requirements). Nitrogen enters the hollow shaft from the end plate, and then enters the two hollow 8-shaped Roots rotors at both ends through the shaft holes, forming an air flow blowing towards the cavity end plates inside the middle-hole Roots rotor, so that the gas and dust in the entire cavity are discharged together with the lower pump.The service life is significantly increased by the improved Roots pump, and various costs such as time, labor, and repair costs (due to dust in the pump that requires shutdown and production suspension) are saved, keeping the Roots pump operating at high vacuum, high pumping speed, and cleanly.

[0028] The rotating shafts at both ends of the Roots rotor 11 extend to the outside of the end plate 5. A first gear 9 and a second gear 10 are respectively installed on the rotating shafts of the two Roots rotors 11. The first gear 9 and the second gear 10 mesh with each other. A first protective cover 4 and a second protective cover 8 are respectively installed on the outside of the two end plates 5. A driving assembly 3 for driving one of the rotating shafts to rotate is installed on the outside of the first protective cover 4. The first protective cover 4 and the second protective cover 8 are both provided with oil injection holes 7 for lubricating the gears. The oil injection holes 7 are used to inject lubricating oil to lubricate the gears.

[0029] The end plate 5 includes a plate body 51. The plate body 51 is provided with two shaft holes 53. A reinforcing rib 52 is arranged on the outside of the plate body 51. The plate body 51 and the reinforcing rib 52 are of an integral structure, and the reinforcing rib 52 enhances the strength of the end plate 5.

[0030] Second arc structures 114 are symmetrically arranged at both ends of the Roots rotor 11. First arc structures 111 are symmetrically arranged on both sides of the Roots rotor 11. First arc-shaped structures 112 are arranged at both ends of the Roots rotor 11 where the first arc structures 111 are located. A second arc-shaped structure 113 is arranged between the first arc-shaped structure 112 and the second arc structure 114. When one Roots rotor 11 and another Roots rotor 11 rotate, the first arc structure 111 of one Roots rotor 11 contacts the second arc structure 114 of the other Roots rotor 11, the second arc structure 114 of one Roots rotor 11 contacts the first arc structure 111 of the other Roots rotor 11, the first arc-shaped structure 112 of one Roots rotor 11 contacts the second arc-shaped structure 113 of the other Roots rotor 11, and the second arc-shaped structure 113 of one Roots rotor 11 contacts the first arc-shaped structure 112 of the other Roots rotor 11. The distance between the centers of the two rotating shafts is L. The radius of the first arc structure 111 is R1, and the radius of the second arc structure 114 is R2. L = R1 + R2. The above structure has better meshing performance during meshing.

[0031] It also includes a nitrogen purging device which is connected to the first air inlet hole 12 of the end plate through an air pipe; an automatic timing and constant pressure nitrogen purging device is used to introduce nitrogen from both end plates. The end plate air groove is closely connected to the Roots rotor shaft. There are 4 second air inlet holes at both ends of the shaft. The middle of the shaft is the first pipeline 15. The 4 second air inlet holes are closely connected to the first pipeline 15. Both ends of the shaft are sealed by special devices, and gas cannot be blown into the oil cavity. The shaft and the figure-eight Roots rotor are integrally cast. The two arcs of the figure-eight Roots rotor are hollow. There are multiple blow holes at different positions in the shaft and the hollow arc (the outside of the figure-eight arc is sealed and has no holes). When the Roots rotor rotates at high speed, nitrogen is blown into the end plate hole groove from the nitrogen port, then passes through the shaft center hole and blows towards both ends into the arc holes of the figure-eight Roots rotor. There is a certain air gap between the two end plates. Nitrogen is blown into the cavity from the two air gaps with a certain air pressure and air volume. Through the compression between the cavity and the Roots rotor, the nitrogen products and fine dust are discharged together from the outlet, and this cycle is repeated to achieve the self-cleaning effect during the working process.

[0032] The working principle of the present invention is as follows: An automatic timing and constant pressure nitrogen purging device is used to introduce nitrogen from both end plates. The end plate air groove is closely connected to the Roots rotor shaft. There are 4 second air inlet holes at both ends of the shaft. The middle of the shaft is the first pipeline 15. The 4 second air inlet holes are closely connected to the first pipeline 15. Both ends of the shaft are sealed by special devices, and gas cannot be blown into the oil cavity. The shaft and the figure-eight Roots rotor are integrally cast. The two arcs of the figure-eight Roots rotor are hollow. There are multiple blow holes at different positions in the shaft and the hollow arc (the outside of the figure-eight arc is sealed and has no holes). When the Roots rotor rotates at high speed, nitrogen is blown into the end plate hole groove from the nitrogen port, then passes through the shaft center hole and blows towards both ends into the arc holes of the figure-eight Roots rotor. There is a certain air gap between the two end plates. Nitrogen is blown into the cavity from the two air gaps with a certain air pressure and air volume. Through the compression between the cavity and the Roots rotor, the nitrogen products and fine dust are discharged together from the outlet, and this cycle is repeated to achieve the self-cleaning effect during the working process.

[0033] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A self-cleaning Roots vacuum pump, comprising a pump housing (2), characterized in that: End plates (5) are installed at both ends of the pump housing (2). Two meshing Roots rotors (11) are arranged inside the pump housing (2). The two Roots rotors (11) rotate synchronously and in opposite directions. The rotating shafts at both ends of the Roots rotors (11) are rotatably installed on the two end plates (5). The Roots rotors (11) and the rotating shafts are of an integral structure. An air gap (14) is formed between both ends of the Roots rotors (11) and the end plates (5). A first pipeline (15) is formed in the middle of the Roots rotor (11). The first pipeline (15) extends into the rotating shaft. A plurality of second air inlet holes (13) are equidistantly arranged on the rotating shaft outside the first pipeline (15). A first air inlet hole (12) is formed in the end plate (5). When the Roots rotor (11) rotates to make the second air inlet hole (13) correspond to the first air inlet hole (12), the first air inlet hole (12) and the corresponding second air inlet hole (13) are in a communicating structure. Second pipelines (16) are arranged on both sides of the Roots rotor (11) where the first pipeline (15) is located. A plurality of third pipelines (17) are arranged between the first pipeline (15) and the second pipelines (16). Both ends of the third pipelines (17) are respectively communicated with the first pipeline (15) and the second pipelines (16).

2. The self-cleaning Roots vacuum pump according to claim 1, wherein: A gas sealing structure for sealing gas is arranged between the rotating shaft of the Roots rotor (11) and the end plate (5).

3. The self-cleaning Roots vacuum pump according to claim 1, wherein: Four second air inlet holes (13) are formed on the rotating shafts at both ends of the Roots rotor (11). The distance between adjacent third pipelines (17) is the same.

4. The self-cleaning Roots vacuum pump according to claim 1, wherein: The Roots rotor (11) adopts an 8-shaped Roots rotor.

5. The self-cleaning Roots vacuum pump according to claim 1, characterized in that: The rotating shafts at both ends of the Roots rotor (11) extend outside the end plates (5). A first gear (9) and a second gear (10) are respectively installed on the rotating shafts of the two Roots rotors (11). The first gear (9) and the second gear (10) mesh with each other. A first protective cover (4) and a second protective cover (8) are respectively installed outside the two end plates (5). A driving assembly (3) for driving one of the rotating shafts to rotate is installed outside the first protective cover (4).

6. The self-cleaning Roots vacuum pump according to claim 5, wherein: Both the first protective cover (4) and the second protective cover (8) are provided with oil injection holes (7) for filling lubricating oil into the gears.

7. The self-cleaning Roots vacuum pump according to claim 1, wherein: An air inlet is formed at the top of the pump housing (2), and an air outlet is formed at the bottom of the pump housing (2). Heat dissipation fins (6) are arranged outside the pump housing (2). The pump housing (2) is installed on a base (1).

8. The self-cleaning Roots vacuum pump according to claim 1, characterized in that: The end plate (5) includes a plate body (51). Two shaft holes (53) are formed in the plate body (51). Reinforcing ribs (52) are arranged outside the plate body (51). The plate body (51) and the reinforcing ribs (52) are of an integral structure.

9. The self-cleaning Roots vacuum pump according to claim 1, characterized in that: Both ends of the Roots rotor (11) are symmetrically provided with second arc structures (114), both sides of the Roots rotor (11) are symmetrically provided with first arc structures (111), both ends of the Roots rotor (11) located at the first arc structures (111) are provided with first arc-shaped structures (112), and a second arc-shaped structure (113) is arranged between the first arc-shaped structure (112) and the second arc structure (114); when one Roots rotor (11) and another Roots rotor (11) rotate, the first arc structure (111) of one Roots rotor (11) contacts the second arc structure (114) of the other Roots rotor (11), the second arc structure (114) of one Roots rotor (11) contacts the first arc structure (111) of the other Roots rotor (11), the first arc-shaped structure (112) of one Roots rotor (11) contacts the second arc-shaped structure (113) of the other Roots rotor (11), and the second arc-shaped structure (113) of one Roots rotor (11) contacts the first arc-shaped structure (112) of the other Roots rotor (11); the distance between the axes of the two rotating shafts is L, the radius of the first arc structure (111) is R1, the radius of the second arc structure (114) is R2, and L = R1 + R2.

10. The self-cleaning Roots vacuum pump according to claim 1, characterized in that: It further includes a nitrogen purging device, and the nitrogen purging device is connected to the first air inlet hole (12) of the end plate through a gas pipe.

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