A Roots screw vacuum unit

Abstract

The present invention discloses a Roots screw vacuum unit, which specifically relates to the field of vacuum pumps, including a vacuum unit, wherein one end of the vacuum unit is provided with an air inlet and outlet port 1, and one end of the vacuum unit away from the air inlet and outlet port 1 is provided with an air inlet and outlet port 2, and one end of the air inlet and outlet port 2 is provided with a plurality of unit-type blades, wherein the plurality of unit-type blades are arranged in a circular shape and equidistantly distributed in sequence, and a central positioning bolt is fixedly installed in the middle of the plurality of unit-type blades by bolts, and the central positioning bolt is arranged in a rod-shaped structure. The vacuum unit is operated in the direction of the air inlet and outlet port 1, so the vacuum unit needs to be air-intaked, and the air inlet of the vacuum unit is also the position of the air inlet and outlet port 2, which drives the plurality of unit-type blades to rotate during the air intake of the vacuum unit, and when the unit-type blades are rotating, the blade edges of the unit-type blades scrape to the edge of the protective external frame arm 1, and scrape larger particles to the outside, thereby achieving the effect of air inlet filtering.

Description

Technical Field

[0001] The present invention relates to the technical field of vacuum pumps, and more specifically to a Roots screw vacuum unit. Background Art

[0002] The water ring vacuum unit is composed of Roots pump as the main pump and water ring pump as the fore-stage pump in series. The water ring vacuum unit uses a water ring pump as the fore-stage pump, which is more advantageous than other vacuum pumps, because it not only overcomes the disadvantages of the limit pressure difference when a single water ring pump is used and the low pumping rate under a certain pressure, but also retains the advantages of the Roots pump that it can work quickly and has a relatively large pumping rate. It can adapt to the extraction of a large amount of condensable steam, especially when the gas-ballast oil-sealed mechanical vacuum pump is not capable of removing condensable steam, or the solvent used can deteriorate the pump oil and thus affect the performance, or the vacuum system does not allow oil pollution. If it is equipped with explosion-proof motors and electrical appliances and complies with the corresponding safety regulations, it can also extract flammable and explosive gases;

[0003] Patent No. CN217632943U discloses a Roots screw vacuum unit, including a machine, a vacuum unit and an air inlet pipe, and also includes a pre-filter mechanism and a side-mounted mechanism, wherein the pre-filter mechanism is composed of a filter tube, a flange, an inner ring, a pressure ring, a middle tube and a filter mesh. The vacuum unit is installed on the top of the machine, and a pre-filter mechanism is arranged at the air inlet pipe of the vacuum unit. A flange is provided below the filter tube of the pre-filter mechanism, which is threadedly connected with the top plate of the air inlet pipe by means of bolts. At this time, the middle tube can be downwardly embedded in the inner ring in the filter tube, and the middle tube can be hung on the inner ring by means of a larger pressure ring after passing through the annular hole of the inner ring. When the vacuum unit is working and pumping air, the gas enters the middle tube along the filter tube, and the double-group sheet body of the filter mesh in the middle tube can intercept larger particle impurities in the gas, and the pre-filtered air can be introduced into the vacuum unit, thereby realizing simple and effective filtration at the air inlet pipe above the vacuum unit;

[0004] However, this filtering method does not take into account the gas filtration at the air inlet and the heat dissipation circulation port of the group, and only realizes simple filtration of the gas in the pipeline. Therefore, a vacuum unit with synchronous filtration at the air inlet and outlet is needed for practical use. Summary of the invention

[0005] In order to overcome the above-mentioned defects of the prior art, an embodiment of the present invention provides a Roots screw vacuum unit, which works in the direction of air inlet and outlet one through the vacuum unit, so the vacuum unit needs to take in air, and the air inlet of the vacuum unit is also the position of air inlet and outlet two. During the air intake of the vacuum unit, multiple unit-type blades are driven to rotate. When the unit-type blades are rotating, the blade edges of the unit-type blades scrape to the edge of the protective external frame arm one, and scrape larger particles to the outside, thereby achieving the effect of air inlet filtering to solve the problems raised in the above-mentioned background technology.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a Roots screw vacuum unit, comprising a vacuum unit, one end of the vacuum unit is provided with an air inlet and outlet port 1, and one end of the vacuum unit away from the air inlet and outlet port 1 is provided with an air inlet and outlet port 2, one end of the air inlet and outlet port 2 is provided with a plurality of unit-type blades, the plurality of unit-type blades are arranged in a circular shape and equidistantly in sequence, a central positioning bolt is fixedly installed in the middle of the plurality of unit-type blades by bolts, the central positioning bolt is arranged in a rod-shaped structure, the central positioning bolt is rotatably connected to the middle of the air inlet and outlet port 2 through a bearing, a plurality of protective external frame arms 1 are fixedly installed at the outer edge of the air inlet and outlet port 2, and the plurality of protective external frame arms 1 are arranged in a circular shape and equidistantly in sequence;

[0007] A circular flat panel is fixedly installed between the multiple protective external frame arms, a connecting type positioning panel is fixedly installed in the middle of the circular flat panel, a circular hole is opened in the middle of the connecting type positioning panel, the central positioning bolt is arranged in the circular hole, and an annular connecting frame is fixedly installed between the multiple protective external frame arms.

[0008] In a preferred embodiment, the outer wall of the protective external frame arm one is clamped with a semicircular clamping block, the number of the semicircular clamping blocks is consistent with the number of the protective external frame arm one, one end of the semicircular clamping block is fixedly installed with a protective external frame arm three, the end of the protective external frame arm three away from the semicircular clamping block is fixedly installed with a protective external frame arm two, and an annular connecting arm is fixedly installed between the multiple protective external frame arms three.

[0009] In a preferred embodiment, an end of the protective external frame arm two away from the protective external frame arm three is fixed with an upward convex support arm by bolts, and the upward convex support arm is stuck on the outside of the protective external frame arm one, and the upward convex support arm is arranged in an upward shape.

[0010] In a preferred embodiment, a spherical limit block is installed in the middle part of the protective external frame arm 2 by bolts, and drainage type blade 1, drainage type blade 2 and drainage type blade 3 are respectively installed in the middle part of the protective external frame arm 2 by bolts, and the adjacent drainage type blade 1, drainage type blade 2 and drainage type blade 3 are arranged in a stacked state.

[0011] In a preferred embodiment, both ends of the drainage blade one, the drainage blade two and the drainage blade three are provided with through-shaped ventilation circular holes, and the outer walls of the protective external frame arm two and the protective external frame arm three are installed with multiple peripheral support guard plates by bolts.

[0012] In a preferred embodiment, the outer supporting guard plate is arranged in the shape of a flat straight blade, the drainage type blade one, the drainage type blade two and the drainage type blade three are arranged in the shape of a twisted inclined blade, and the adjacent drainage type blade one, the drainage type blade two and the drainage type blade three are arranged in a one-to-one correspondence.

[0013] In a preferred embodiment, a pre-filter pipe for doing work is installed in a connected state at one end of the air inlet and outlet away from the vacuum unit, and an anti-clogging chute is provided at the bottom of the pre-filter pipe. The number of the anti-clogging chute is set to multiple, and the multiple anti-clogging chute is distributed in sequence in a circular shape with equal distances.

[0014] In a preferred embodiment, a convex ring is installed on the inner wall of the inner cavity of the pre-filter pipe, and an annular positioning cylinder 1 is clamped at both ends of the convex ring, and an annular positioning cylinder 2 is fixedly installed in the middle of the annular positioning cylinder 1. The number of the annular positioning cylinders 1 is set to two, and the number of the annular positioning cylinders 1 and 2 is set to be the same, and an elastic pull rope is connected between the two annular positioning cylinders 2.

[0015] In a preferred embodiment, the number of the elastic pull ropes is set to multiple, and the elastic pull ropes are arranged in an obliquely suspended state. The multiple elastic pull ropes are arranged in a ring-shaped and equidistant manner in sequence. An annular limit groove is opened inside the convex ring, and the inner cavity of the annular limit groove is slidably connected with multiple obliquely suspended sliders. A drainage-type obliquely suspended blade is fixedly installed on one side of the obliquely suspended slider. The number of the obliquely suspended sliders is set to multiple, and the multiple obliquely suspended sliders are connected by sheet elastic bands.

[0016] In a preferred embodiment, a plurality of the protective external frame arms 2 and 3 are externally clamped with a protective cover, an extension ring is installed on one side of the protective cover, a gap is reserved between the protective cover and the extension ring, a roller for clamping the upper convex support arm is installed in the gap, and a positioning external frame bolt is installed on the outer wall of the vacuum unit.

[0017] Technical effects and advantages of the present invention:

[0018] 1. The vacuum unit works in the direction of the air inlet and outlet 1, so the vacuum unit needs to take in air. The air inlet of the vacuum unit is also the position of the air inlet and outlet 2. During the air intake of the vacuum unit, multiple unit-type blades are driven to rotate. When the unit-type blades are rotating, the blade edges of the unit-type blades scrape to the edge of the protective external frame arm 1, scraping larger particles to the outside, thereby achieving the effect of air inlet filtration;

[0019] 2. When the protective external frame arm three, the protective external frame arm two and the upper convex support arm are installed on the outside of the protective external frame arm one through the semicircular clamping block, since the air flow of the intake moves from the position of the protective external frame arm three to the position of the vacuum unit, the drainage blade one, the drainage blade two and the drainage blade three make left and right swinging motion with the spherical limit block as the center point, and the left and right swinging motion is used to clamp larger impurities between the drainage blade one, the drainage blade two and the drainage blade three, and smaller impurities are adsorbed in the filter materials of the drainage blade one, the drainage blade two and the drainage blade three, thereby achieving the filtering effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0021] Figure 2 It is a partial structural exploded view of the present invention.

[0022] Figure 3 For the present invention Figure 2 A-section structure enlarged view.

[0023] Figure 4 It is a partial structural exploded view of the present invention.

[0024] Figure 5 It is a structural schematic diagram of the upward convex support arm, the spherical limit block and the drainage blade of the present invention.

[0025] Figure 6 For the present invention Figure 5 Enlarged view of the structure of part B.

[0026] Figure 7 It is a structural cross-sectional view of the pre-filtration pipeline of the present invention.

[0027] Figure 8 For the present invention Figure 7 Enlarged view of the C structure.

[0028] The accompanying drawings are marked as: 1 vacuum unit, 2 air inlet and outlet 1, 3 air inlet and outlet 2, 4 unit-type blades, 5 central positioning bolts, 6 circular flat panels, 7 connecting-type positioning panels, 8 protective external frame arm 1, 9 annular connecting frame, 10 protective external frame arm 2, 11 protective external frame arm 3, 12 semicircular blocks, 13 annular connecting arms, 14 upper convex support arms, 15 spherical limit blocks, 16 drainage blade 1, 17 drainage blade 2, 18 drainage blade 3, 19 ventilation circular holes, 20 outer supporting guard plates, 21 pre-filter pipes, 22 anti-clogging inclined grooves, 23 annular positioning cylinder 1, 24 annular positioning cylinder 2, 25 elastic pull ropes, 26 annular limiting card slots, 27 obliquely suspended sliders, 28 drainage obliquely suspended blades, 29 sheet elastic bands, 30 protective sealing covers, 31 extension rings, 32 rollers, and 33 positioning-type external frame bolts. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] Refer to the instruction manual Figure 1-8 In one embodiment of the present invention, a Roots screw vacuum unit includes a vacuum unit 1, an air inlet and outlet 1 2 is provided at one end of the vacuum unit 1, an air inlet and outlet 2 is provided at one end of the vacuum unit 1 away from the air inlet and outlet 1 2, a plurality of unit-type blades 4 are installed at one end of the air inlet and outlet 2 3, the plurality of unit-type blades 4 are arranged in a circular shape and are distributed in sequence at equal intervals, a central positioning bolt 5 is fixedly installed in the middle of the plurality of unit-type blades 4 by bolts, the central positioning bolt 5 is arranged in a rod-shaped structure, and the central positioning bolt 5 is rotatably connected to the middle of the air inlet and outlet 2 3 through a bearing. A plurality of protective external frame arms 8 are fixedly installed at the outer edge of the air inlet and outlet 3, and the plurality of protective external frame arms 8 are arranged in a circular shape and equidistantly in sequence. The air inlet of the vacuum unit 1 is also the position of the air inlet and outlet 3, and drives the plurality of unit-type blades 4 to rotate during the air intake of the vacuum unit 1. When the unit-type blades 4 are rotating, the blade edges of the unit-type blades 4 scrape to the edge of the protective external frame arm 8, and scrape larger particles to the outside, thereby achieving the effect of air inlet filtering;

[0031] A circular flat panel 6 is fixedly installed between multiple protective external frame arms 8, a connecting type positioning panel 7 is fixedly installed in the middle of the circular flat panel 6, a circular hole is opened in the middle of the connecting type positioning panel 7, and a central positioning bolt 5 is arranged in the circular hole, and a ring-shaped connecting frame 9 is fixedly installed between multiple protective external frame arms 8.

[0032] like Figure 4-5 As shown, the outer wall of the protective external frame arm 1 8 is connected with a semicircular block 12, the number of the semicircular blocks 12 is consistent with the number of the protective external frame arms 1 8, one end of the semicircular block 12 is fixedly installed with a protective external frame arm 3 11, and the end of the protective external frame arm 3 11 away from the semicircular block 12 is fixedly installed with a protective external frame arm 2 10, and a plurality of protective external frame arms 3 11 are fixedly installed with an annular connecting arm 13; the protective external frame arm 2 10 is away from the protective external frame arm 3 11. An upper convex support arm 14 is fixedly installed at one end by bolts, and the upper convex support arm 14 is stuck on the outside of the protective external frame arm 8, and the upper convex support arm 14 is arranged in an upward shape; a spherical limit block 15 is installed at the middle part of the protective external frame arm 10 by bolts, and a drainage type blade 16, a drainage type blade 2 17 and a drainage type blade 3 18 are respectively installed at the middle part of the protective external frame arm 10 by bolts, and the adjacent drainage type blade 16, drainage type blade 2 17 and drainage type blade 3 18 are arranged in a stacked state.

[0033] Among them, the two ends of the drainage blade 16, the drainage blade 2 17 and the drainage blade 3 18 are provided with through-shaped ventilation circular holes 19, and the outer walls of the protective external frame arm 2 10 and the protective external frame arm 3 11 are installed with multiple peripheral support guard plates 20 by bolts; the peripheral support guard plates 20 are arranged in the shape of flat straight blades, and the drainage blade 1 16, the drainage blade 2 17 and the drainage blade 3 18 are arranged in the shape of twisted inclined blades, and the adjacent drainage blades The first 16, the second 17 and the third 18 are arranged in a one-to-one correspondence state. The airflow passes through the first 16, the second 17 and the third 18 at the same time. The first 16, the second 17 and the third 18 of the drainage type are oscillating left and right with the spherical limit block 15 as the center point. The material of the drainage blade 16, the second 17 and the third 18 of the drainage type is a filter material. The larger impurities are clamped between the drainage blade 1 16, the drainage blade 2 17 and the drainage blade 3 18, and the smaller impurities are adsorbed in the filtering materials of the drainage blade 16, the drainage blade 2 17 and the drainage blade 3 18, so as to achieve the filtering effect; the end of the air inlet and outlet 1 2 away from the vacuum unit 1 is connected with a pre-filter pipe 21 for doing work, and an anti-blocking inclined groove 22 is provided at the bottom of the pre-filter pipe 21. The number of the anti-blocking inclined grooves 22 is set to be multiple, and the multiple anti-blocking inclined grooves 22 are arranged in a circular shape and equidistantly in sequence; a convex ring is installed on the inner wall of the inner cavity of the pre-filter pipe 21, and an annular positioning cylinder 1 23 is clamped at both ends of the convex ring. An annular positioning cylinder 24 is fixedly installed in the middle of the annular positioning cylinder 1 23, and the number of the annular positioning cylinder 1 23 is set to two, and the number of the annular positioning cylinder 1 23 and the annular positioning cylinder 24 is set to be consistent, and an elastic pull rope 25 is connected between the two annular positioning cylinders 24.

[0034] As a further solution, the number of elastic pull ropes 25 is set to multiple, the elastic pull ropes 25 are set in an oblique hanging shape, and the multiple elastic pull ropes 25 are arranged in a ring-shaped equidistant order. An annular limiting groove 26 is opened inside the convex ring, and the inner cavity of the annular limiting groove 26 is slidably connected with multiple obliquely suspended sliders 27. A drainage-type obliquely suspended blade 28 is fixedly installed on one side of the obliquely suspended slider 27. The number of the obliquely suspended sliders 27 is set to multiple, and the multiple obliquely suspended sliders 27 are connected by a sheet elastic band 29. The multiple drainage-type obliquely suspended blades 28 rotate in the inner cavity of the annular limiting groove 26 with the obliquely suspended slider 27 and the sheet elastic band 29, so that the multiple obliquely suspended elastic pull ropes 25 make opening and closing movements, and the opening and closing movements are up and down. During the process, since the material of the drainage type obliquely suspended blades 28 is a filtering material, the drainage type obliquely suspended blades 28 form the first filtering channel. In addition, the annular positioning cylinder 1 23 and the annular positioning cylinder 24 make a slight rotational movement when opened and closed by the elastic pull rope 25, so that the airflow in the pre-filtration pipe 21 is retained for a longer time; a plurality of protective external frame arms 2 10 and the external part of the protective external frame arm 3 11 are clamped with a protective cover 30, an extension ring 31 is installed on one side of the protective cover 30, and a gap is reserved between the protective cover 30 and the extension ring 31, and a roller 32 for clamping the upper convex support arm 14 is installed in the gap, and a positioning external frame bolt 33 is installed on the outer wall of the vacuum unit 1.

[0035] Working principle: In actual use, first, the vacuum unit 1 works in the direction of the air inlet and outlet 2, so the vacuum unit 1 needs to take in air. The air inlet of the vacuum unit 1 is the position of the air inlet and outlet 2 3. During the air intake process of the vacuum unit 1, multiple unit-type blades 4 are driven to rotate. When the unit-type blades 4 are rotating, the blade edges of the unit-type blades 4 scrape to the edge of the protective external frame arm 8, scraping larger particles to the outside, thereby achieving the effect of air inlet filtering;

[0036] When the protective external frame arm three 11, the protective external frame arm two 10 and the upper convex support arm 14 are installed on the outside of the protective external frame arm one 8 through the semicircular clamping block 12, since the airflow of the intake moves from the position of the protective external frame arm three 11 to the position of the vacuum unit 1, the airflow passes through the drainage blade one 16, the drainage blade two 17 and the drainage blade three 18 at the same time, and the drainage blade one 16, the drainage blade two 17 and the drainage blade three 18 make left and right swinging motions with the spherical limit block 15 as the center point, wherein the materials of the drainage blade one 16, the drainage blade two 17 and the drainage blade three 18 are filter materials, and the left and right swinging motions are used to clamp larger impurities between the drainage blade one 16, the drainage blade two 17 and the drainage blade three 18, and smaller impurities are adsorbed in the filter materials of the drainage blade one 16, the drainage blade two 17 and the drainage blade three 18, thereby achieving a filtering effect;

[0037] When the airflow moves in the working pre-filter pipe 21, it drives the multiple drainage type obliquely suspended blades 28 to rotate. The multiple drainage type obliquely suspended blades 28 rotate in the inner cavity of the annular limit groove 26 with the obliquely suspended slider 27 and the sheet elastic band 29, so that the multiple obliquely suspended elastic pull ropes 25 perform opening and closing movements. In the process of opening and closing up and down movements, since the material of the drainage type obliquely suspended blades 28 is a filtering material, the drainage type obliquely suspended blades 28 form a first filtering channel. In addition, the annular positioning cylinder 1 23 and the annular positioning cylinder 2 24 perform a slight rotational movement when opened and closed by the elastic pull rope 25, so that the airflow in the pre-filter pipe 21 retains longer and contacts the drainage type obliquely suspended blades 28 more times, thereby achieving the effect of a second filtering channel.

[0038] Finally, a few points should be explained: First, in the description of this application, it should be noted that, unless otherwise specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, which may refer to mechanical connection or electrical connection, or internal communication between two components, or direct connection. "upper", "lower", "left", "right", etc. are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may change;

[0039] Secondly: In the drawings of the embodiments disclosed in the present invention, only the structures related to the embodiments disclosed in the present invention are involved, and other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of the present invention can be combined with each other;

[0040] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A Roots screw vacuum unit, comprising a vacuum unit (1), wherein one end of the vacuum unit (1) is provided with a first air inlet and outlet (2), and an end of the vacuum unit (1) away from the first air inlet and outlet (2) is provided with a second air inlet and outlet (3), characterized in that: A plurality of unit-type blades (4) are installed at one end of the second air inlet and outlet (3), and the plurality of unit-type blades (4) are arranged in a circular manner and are equidistantly distributed in sequence. A central positioning bolt (5) is fixedly installed in the middle of the plurality of unit-type blades (4) by bolts, and the central positioning bolt (5) is arranged in a rod-shaped structure. The central positioning bolt (5) is rotatably connected to the middle of the second air inlet and outlet (3) through a bearing. A plurality of protective external frame arms are fixedly installed at the outer edge of the second air inlet and outlet (3). One (8), a plurality of the protective external frame arms one (8) are arranged in a circular shape and are equidistant from one another, and a pre-filter pipe (21) for doing work is installed in a connected state at one end of the air inlet and outlet one (2) away from the vacuum unit (1), and an anti-blocking inclined groove (22) is provided at the bottom of the pre-filter pipe (21), and the number of the anti-blocking inclined grooves (22) is set to be multiple, and the plurality of the anti-blocking inclined grooves (22) are arranged in a circular shape and are equidistant from one another, and the inner cavity of the pre-filter pipe (21) is A convex ring is installed on the wall, and an annular positioning tube 1 (23) is clamped at both ends of the convex ring. An annular positioning tube 2 (24) is fixedly installed in the middle of the annular positioning tube 1 (23). The number of the annular positioning tube 1 (23) is set to two, and the number of the annular positioning tube 1 (23) and the annular positioning tube 2 (24) is set to be the same. An elastic pull rope (25) is connected between the two annular positioning tubes 2 (24). The number of the elastic pull ropes (25) is set to be multiple. The elastic pull ropes (25) are arranged in an oblique hanging shape. The multiple elastic pull ropes (25) are arranged in a circular shape and are equidistantly arranged in sequence. An annular limiting groove (26) is opened inside the convex ring. The inner cavity of the annular limiting groove (26) is slidably connected to multiple obliquely suspended sliders (27). A drainage type obliquely suspended blade (28) is fixedly installed on one side of the obliquely suspended slider (27). The number of the obliquely suspended sliders (27) is set to be multiple, and the multiple obliquely suspended sliders (27) are connected by a sheet elastic belt (29); A circular flat panel (6) is fixedly installed between the plurality of the protective external frame arms (8); a connecting type positioning panel (7) is fixedly installed in the middle of the circular flat panel (6); a circular hole is opened in the middle of the connecting type positioning panel (7); the central positioning bolt (5) is arranged in the circular hole; an annular connecting frame (9) is fixedly installed between the plurality of the protective external frame arms (8); a semicircular clamping block (12) is clamped on the outer wall of the protective external frame arm (8); the number of the semicircular clamping blocks (12) is consistent with the number of the protective external frame arms (8); a protective external frame arm (3) (11) is fixedly installed on one end of the semicircular clamping block (12); a protective external frame arm (2) (10) is fixedly installed on the end of the protective external frame arm (3) (11) away from the semicircular clamping block (12); and an annular connecting arm (13) is fixedly installed between the plurality of the protective external frame arms (11).

2. A Roots screw vacuum unit according to claim 1, characterized in that: An end of the protective external frame arm 2 (10) away from the protective external frame arm 3 (11) is fixedly mounted with an upward convex support arm (14) by means of bolts. The upward convex support arm (14) is clamped on the outside of the protective external frame arm 1 (8). The upward convex support arm (14) is arranged in an upwardly tilted shape.

3. A Roots screw vacuum unit according to claim 2, characterized in that: A spherical stopper (15) is installed at the middle of the second protective external frame arm (10) by means of bolts, and a drainage blade (16), a drainage blade (17) and a drainage blade (18) are installed at the middle of the second protective external frame arm (10) by means of bolts, respectively. The adjacent drainage blades (16), drainage blades (17) and drainage blades (18) are arranged in a stacked state.

4. A Roots screw vacuum unit according to claim 3, characterized in that: The two ends of the drainage blade one (16), the drainage blade two (17) and the drainage blade three (18) are provided with through-shaped ventilation circular holes (19), and the outer walls of the protective external frame arm two (10) and the protective external frame arm three (11) are mounted with a plurality of peripheral support guard plates (20) by means of bolts.

5. A Roots screw vacuum unit according to claim 4, characterized in that: The outer supporting guard plate (20) is arranged in the shape of a flat straight blade, the drainage blade one (16), the drainage blade two (17) and the drainage blade three (18) are arranged in the shape of a twisted inclined blade, and the adjacent drainage blades one (16), the drainage blade two (17) and the drainage blade three (18) are arranged in a one-to-one correspondence.

6. A Roots screw vacuum unit according to claim 5, characterized in that: A plurality of protective external frame arms (2) (10) and a plurality of protective external frame arms (11) are externally clamped with protective covers (30), an extension ring (31) is installed on one side of the protective covers (30), a gap is reserved between the protective covers (30) and the extension ring (31), a roller (32) for clamping the upper convex support arm (14) is installed in the gap, and a positioning external frame bolt (33) is installed on the outer wall of the vacuum unit (1).

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