Front gas filtering device of vacuum pump

Abstract

The invention relates to the technical field of air compressors, and particularly discloses a vacuum pump front air filtering device which comprises a shell and air outlet holes formed in the side walls of the shell, a mounting disc and a motor are fixedly mounted on the side walls of the two sides of the shell correspondingly, and a mounting frame is arranged in the shell; the part, penetrating into the shell and the mounting frame, of a main shaft of the motor is fixedly connected with a rotating shaft, a plurality of rows of fins are distributed on the side wall of the rotating shaft, and the fins are formed by alternating fixed fins and rotating fins which are opposite in direction. The filter cotton is driven to be switched back and forth between two states, so that the density of the filter cotton is increased when the filter cotton is in a compressed state, the filtering precision of the filter cotton is improved, the density of the filter cotton is reduced when the filter cotton is switched to an extended state, the filtering precision of the filter cotton is reduced, and the wind resistance of gas passing through the filter cotton is reduced; and subsequent vacuum extraction or vacuum maintenance is facilitated, and meanwhile, the ultimate vacuum degree of the container after extraction is improved.

Description

Technical Field

[0001] The invention relates to the technical field of air compressors, in particular to a pre-gas filtering device for a vacuum pump. Background Art

[0002] A vacuum pump is a device used to extract gas from a closed container to create and maintain a vacuum. They are widely used in scientific research, industry, medicine and aviation. When the vacuum pump is running, solid particles, dust, liquid droplets and other impurities may enter the vacuum pump, causing wear or damage to the inside of the pump body. Therefore, the gas needs to be filtered in the process of creating or maintaining a vacuum.

[0003] For example, Chinese patent number CN114718875B discloses a vacuum pump pre-gas filter device with component anti-corrosion function. The invention extracts gas through the intake pipe during the rotation of the compression impeller on the driving shaft and the driven shaft. The gas passes through the fixed ring through the intake pipe and enters the upper shell and the lower shell. When the rotating circle rotates, the filter component is driven to rotate through the fixed ring. The gas passes through the through hole inside the fixed ring and is filtered by the filter cotton. In the invention, the filter cotton rotates to share impurities in the gas. While filtering the gas, the rotation of the filter cotton will increase the filtering effect, avoid clogging of the filter cotton, and reduce the frequency of replacing the filter cotton.

[0004] However, when the container is evacuated, due to the different qualities of the gases in the container, the lighter gases (such as hydrogen) will be extracted first, and at the same time, the particles or dust with higher density will be driven through the filter cotton at a higher speed (the lighter gases have better fluidity, and the particles with higher density can be more easily sucked out by overcoming air resistance). Therefore, filter cotton with higher filtration accuracy is needed to filter out impurities to prevent the particles from passing through the filter cotton. As the gas in the container decreases, the vacuum pump's extraction efficiency will decrease, and the remaining gas in the container will be heavier and the remaining particle density will be smaller. At this time, the density of the filter cotton needs to be reduced to reduce wind resistance, increase the vacuum pump's attraction to the gas, and improve the ultimate vacuum degree of the vacuum pump. However, the existing filtering devices and filter cotton cannot meet the needs of different stages. Summary of the invention

[0005] The object of the present invention is to provide a pre-gas filter device for a vacuum pump to solve at least one technical problem existing in the above-mentioned prior art.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a pre-gas filter device for a vacuum pump, comprising a shell and an air outlet hole opened on the side wall of the shell, the side walls of the shell are respectively fixedly installed with a mounting plate and a motor, a mounting frame is provided in the shell, the part of the main shaft of the motor that penetrates into the shell and the mounting frame is fixedly connected with a rotating shaft, a plurality of rows of fins are distributed on the side wall of the rotating shaft, the fins are alternately composed of fixed fins and rotating fins in opposite directions, an air inlet pipe that can be connected to the mounting frame is installed on the side wall of the mounting plate, a filter part for filtering gas is provided in the pipeline between the air inlet pipe and the mounting frame, the filter part includes filter cotton, and the filter cotton has two states, in state one, the filter cotton is in a compressed state, the filtering accuracy is improved and the wind resistance is improved; in state two, the filter cotton is in an extended state, the filtering accuracy is reduced and the wind resistance is reduced.

[0007] Preferably, the filter unit comprises two fixing rings which can be installed in a pipe between the air inlet pipe and the installation frame, a bellows is connected between the two fixing rings, and the filter cotton is fixedly installed between the two fixing rings.

[0008] Preferably, two limit plates are rotatably installed on the inner wall of the shell, and the opposite surfaces of the two limit plates are provided with grooves for inserting fixing rings, and after the fixing ring is inserted into the groove, it is in an inscribed state with the limit plates, and a plurality of elastic telescopic rods are fixedly connected between the two limit plates, and a cylinder fixedly installed on the inner wall of the shell is provided on the side of one of the limit plates, and the end of the driving shaft of the cylinder is abutted against the side wall of the limit plate and can slide on the side wall of the limit plate, and a sliding ring that can slide in the shell is fixedly connected to one side of the limit plate.

[0009] Preferably, a reduction motor is fixedly mounted on the side wall of the mounting plate, a driving gear is fixedly connected to the part of the main shaft of the reduction motor that penetrates into the mounting plate, a transmission gear meshing with the driving gear is fixedly mounted on the outer wall of the limit plate, a side channel for the filter part to slide out is opened on the side wall of the shell, and a door panel is arranged in the side channel;

[0010] A firing part is also provided in the shell body, and when the card slot is rotated to be connected with the side channel, the firing part fires the filter part out of the card slot.

[0011] Preferably, the firing part includes a special-shaped cavity opened in the shell and located on the side of the limit disk, the limit disk is provided with a mounting hole, and a firing pin is slidably installed in the mounting hole, a compression spring is installed between the firing pin and the mounting hole to force the firing pin to move closer to the limit disk, the end of the firing pin extending into the special-shaped cavity is fixedly connected to an elastic pin, and the inner wall of the special-shaped cavity is provided with a sliding groove for the elastic pin to be inserted and slide, the sliding groove is composed of two arc-shaped slideways that are increasingly farther away from the center of the limit disk in the sliding direction of the elastic pin and a slideway that coincides with the radius line of the limit disk, and each section of the slideway gradually becomes shallower in the sliding direction of the elastic pin, and the inner wall of the shell is also provided with a sliding groove for the elastic pin to slide along the extension and contraction direction of the cylinder.

[0012] Preferably, a bottom box is fixedly connected to the bottom of the shell, a top plate is slidably installed in the bottom box, a spring is provided between the top plate and the bottom wall of the bottom box, and the sliding ring is arranged tangent to the limit plate.

[0013] Preferably, a laser transmitter and a laser receiver coinciding with the diameter line of the sliding ring are fixedly installed in the groove on the inner wall of the installation frame, and the laser receiver is connected to the cylinder electrical signal. An elastic net is also fixedly installed on the inner wall of the installation frame, and a light-blocking strip is fixedly installed at the center of the elastic net.

[0014] Preferably, the side wall of the slot is provided with an elastic buckle.

[0015] Preferably, the length of the sliding groove is greater than the sliding distance of the elastic pin.

[0016] Preferably, a plastic grid for limiting the position of the filter cotton is fixedly installed in each of the two fixing rings.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. The present invention drives the filter cotton to switch back and forth between two states, so that the lighter gas in the container drives the particles or dust with higher density in the container to pass through the filter cotton at a faster flow rate. The filter cotton is in a state of compression, so that the gap inside it becomes smaller and the density increases, thereby improving the filtering accuracy of the filter cotton. When the gas in the container is reduced to a certain extent and the suction efficiency of the vacuum pump decreases, the filter cotton is switched to a state of extension, so that the gap inside the filter cotton increases and the density decreases, thereby reducing the filtering accuracy of the filter cotton, reducing the wind resistance of the gas passing through the filter cotton, and reducing the gas extraction resistance of the device, which is more conducive to the subsequent vacuum removal or vacuum maintenance, and at the same time, the vacuum limit of the device is improved. When the filter cotton is switched to the state of extension, the wind resistance is reduced while increasing the attraction of the device to the particles or dust in the container, so that these tiny particles or dust can be discharged from the container, and the filter cotton with lower density is more conducive to high-precision filtration of such dust due to the natural dust storage cavity contained in it, so that the device can maintain high-precision filtration of the inhaled gas and improve the filtering effect of the device.

[0019] 2. The present invention can quickly knock the discarded filter part out of the shell by the sliding of the elastic pin in the slide groove and the rotation of the limit plate, so that the filter cotton can be quickly removed and replaced after excessive particles or dust accumulates on it, avoiding the blockage of airflow caused by the use of the filter cotton for too long, causing the device to be stuck in idling.

[0020] 3. In the present invention, after the striker hits the fixed ring in the limit disk and knocks the filter part out of the shell, the reduction motor drives the active gear to drive the transmission gear and the limit disk to reset. At this time, the spring in the bottom box pushes the top plate to drive the filter part in the bottom box to move up to the limit disk, completing the automatic replacement of the filter part and realizing the rapid replacement of the filter cotton, solving the pain points of the current replacement of the filter cotton, reducing the number and duration of shutdown maintenance of the device, and reducing the use cost of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention;

[0022] Figure 2 is a side cross-sectional view of the present invention;

[0023] Figure 3 is a cross-sectional view of the three-dimensional structure of the present invention;

[0024] Figure 4 It is a three-dimensional structural schematic diagram of the internal structure of the present invention;

[0025] Figure 5 is a cross-sectional view of the mounting plate of the present invention;

[0026] Figure 6 is a cross-sectional view of the firing portion of the present invention;

[0027] Figure 7 It is an exploded view of the three-dimensional structure of the filter part in the present invention;

[0028] Figure 8 For the present invention Figure 3 A in the enlarged view;

[0029] Fig. 9 For the present invention Figure 3 The enlarged view of point B in the figure;

[0030] Fig.10 It is a cross-sectional schematic diagram of the filter part after compression in the present invention;

[0031] Fig.11 It is a cross-sectional schematic diagram of the filter portion after extension in the present invention.

[0032] In the figure: 1. shell; 2. mounting plate; 3. motor; 4. rotating shaft; 5. fin; 6. mounting frame; 7. cylinder; 8. sliding ring; 9. limiting plate; 10. slot; 11. transmission gear; 12. elastic telescopic rod; 13. bellows; 14. fixing ring; 15. filter cotton; 16. striker; 17. elastic pin; 18. compression spring; 19. special-shaped cavity; 20. slide groove; 21. door panel; 22. driving gear; 23. top plate; 24. spring; 25. air inlet pipe; 26. elastic net; 27. laser transmitter; 28. laser receiver; 29. ​​light-blocking strip; 30. sliding groove; 31. reduction motor; 32. bottom box. DETAILED DESCRIPTION

[0033] 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.

[0034] See also Figures 1 to 11The present invention provides a technical solution: a pre-gas filter device for a vacuum pump, comprising a shell 1 and an air outlet hole opened on the side wall of the shell 1, a mounting plate 2 and a motor 3 are fixedly installed on the side walls of the shell 1, a mounting frame 6 is arranged in the shell 1, a main shaft of the motor 3 penetrates into the shell 1 and the mounting frame 6 and is fixedly connected with a rotating shaft 4, a plurality of rows of fins 5 are distributed on the side wall of the rotating shaft 4, the fins 5 are alternately composed of fixed fins and rotating fins in opposite directions, an air inlet pipe 25 which can be connected with the mounting frame 6 is arranged on the side wall of the mounting plate 2, a filter part for filtering gas is arranged in the pipeline between the air inlet pipe 25 and the mounting frame 6, the filter part comprises filter cotton 15, and the filter cotton 15 has two states, in state one, the filter cotton 15 is in a compressed state, the filtering accuracy is improved and the wind resistance is improved; in state two, the filter cotton 15 is in an extended state, the filtering accuracy is reduced and the wind resistance is reduced.

[0035] When the device is in use, the air inlet pipe 25 is first sealed and connected to the container whose vacuum needs to be extracted or maintained, and then the motor 3 is started to drive the rotating shaft 4 to drive the part of the fin 5 that is fixedly connected to the rotating shaft 4, and the fixed fins and rotating fins that are alternately arranged are used to generate suction inside the shell 1, and the inhaled gas is filtered through the filter part, and then the filtered gas is discharged outside the shell 1 through the air outlet opened on the outer wall of the shell 1, thereby completing the extraction of the gas inside the container or maintaining the vacuum state in the container.

[0036] During the vacuuming process, the filter cotton 15 is driven to switch back and forth between the two states, so that the lighter gas in the container drives the denser particles or dust in the container to pass through the filter cotton 15 at a faster flow rate. The filter cotton 15 is in a state of compression. Fig.10 At this time, the filter cotton 15 is compressed, so that the gap inside it becomes smaller and the density increases, thereby improving the filtering accuracy of the filter cotton 15, and preventing particles with small volume but large mass from passing through the filter cotton 15 under the action of high-speed airflow, thereby improving the filtering effect of the inhaled gas. When the gas in the container is reduced to a certain extent and the suction efficiency of the vacuum pump decreases, the filter cotton 15 is switched to the second state of extension. For details, see Fig.11 As the filter cotton 15 is stretched, the internal gap of the filter cotton 15 increases and the density decreases, which reduces the filtering accuracy of the filter cotton 15, reduces the wind resistance encountered by the gas passing through the filter cotton 15, and reduces the device's resistance to gas extraction, which is more conducive to subsequent vacuum removal or vacuum maintenance, and also improves the vacuum limit of the device.

[0037] It is worth mentioning that after the gas in the container is reduced to a certain level, the remaining gas in the container is heavier, and most of the gas inside is particles or dust with small density and volume. These particles or dust cannot easily break through the air resistance and therefore move irregularly in the container. When the filter cotton 15 is switched to the second state, the extended state, the wind resistance is reduced while the device increases the attraction of the particles or dust in the container, so that these tiny particles or dust can be discharged from the container. The filter cotton 15 with lower density has a natural dust storage cavity contained inside, which is more conducive to high-precision filtration of this type of dust, thereby enabling the device to maintain high-precision filtration of the inhaled gas and improving the filtration effect of the device.

[0038] Furthermore, the filter unit includes two fixing rings 14 that can be installed in the pipeline between the air inlet pipe 25 and the installation frame 6 , a bellows 13 is connected between the two fixing rings 14 , and the filter cotton 15 is fixedly installed between the two fixing rings 14 .

[0039] According to the above embodiment, a specific embodiment of the filter unit is provided. Figure 7 Since the filter cotton 15 is arranged in the bellows 13, when the fixing rings 14 on both sides are pushed closer to or away from each other, the filter cotton 15 inside the bellows 13 is compressed or stretched, thereby completing the switching of the filter cotton 15 between the two states mentioned above. The bellows 13 is made of elastic material, which can be adjusted in compression or stretching along the axial direction.

[0040] Furthermore, two limit plates 9 are rotatably installed on the inner wall of the shell 1, and the opposite surfaces of the two limit plates 9 are provided with a slot 10 for inserting a fixing ring 14, and after the fixing ring 14 is inserted into the slot 10, it is in an inscribed state with the limit plate 9, and a plurality of elastic telescopic rods 12 are fixedly connected between the two limit plates 9. A cylinder 7 fixedly installed on the inner wall of the shell 1 is provided on the side of one of the limit plates 9, and the end of the driving shaft of the cylinder 7 is against the side wall of the limit plate 9 and can slide on the side wall of the limit plate 9, and a sliding ring 8 that can slide in the shell 1 is fixedly connected to one side of the limit plate 9.

[0041] According to the above embodiment, it can be known that when the cylinder 7 drives the limit plates 9 to approach each other, it will drive the elastic telescopic rod 12 to compress. When the cylinder 7 retracts the active shaft, the elastic telescopic rod 12 can drive the two limit plates 9 to move away from each other, completing the above-mentioned driving of the filter cotton 15 to switch back and forth between the two states. The end of the active shaft of the cylinder 7 is against the side wall of the limit plate 9 and can slide on the side wall of the limit plate 9, so that the limit plate 9 can maintain contact with the limit plate 9 without disengaging even when it rotates eccentrically with the cylinder 7. Since the limit plate 9 is tangent to the fixing ring 14 inserted into the slot 10, the fixing ring 14 is easier to be removed from the slot 10, which is convenient for subsequent replacement of the filter part. Moreover, since one side of the limit plate 9 is fixedly connected with a sliding ring 8 that can slide in the shell 1, the limit plate 9 can still maintain the sealing of the air flow channel through the sliding ring 8 during the process of approaching each other, so that the filtered gas will not enter the interior of the shell 1, thereby ensuring the sealing effect of the pipeline.

[0042] Furthermore, a reduction motor 31 is fixedly mounted on the side wall of the mounting plate 2, a driving gear 22 is fixedly connected to the part of the main shaft of the reduction motor 31 that penetrates into the mounting plate 2, a transmission gear 11 meshing with the driving gear 22 is fixedly mounted on the outer wall of the limiting plate 9, a side channel for the filter part to slide out is opened on the side wall of the housing 1, and a door panel 21 is arranged in the side channel;

[0043] A firing part is also provided in the housing 1 , and when the slot 10 is rotated to be connected with the side channel, the firing part fires the filter part out of the slot 10 .

[0044] According to the above embodiment, when the reduction motor 31 drives the driving gear 22 to drive the limit plate 9 and the transmission gear 11 to rotate together, Figure 6 , when the notch of the card slot 10 is aligned with the door panel 21, that is, when the filter part is in the side channel opened on the side wall of the shell 1 for the filter part to slide out, the firing part knocks the filter part out of the card slot 10, so that the removed filter part moves along the side channel and passes through the door panel 21 to the outside of the shell 1, thereby completing the removal of the discarded filter part.

[0045] In this way, by cooperating with the rotation of the limit plate 9, the filter part and the filter cotton 15 that are contaminated with too much dirt can be quickly disassembled and discharged from the shell 1, which facilitates the replacement of the filter part.

[0046] Furthermore, the firing part includes a special-shaped cavity 19 opened in the shell 1 and located on the side of the limit disk 9, the limit disk 9 is provided with a mounting hole, and a firing pin 16 is slidably installed in the mounting hole, a compression spring 18 is installed between the firing pin 16 and the mounting hole to force the firing pin 16 to move closer to the limit disk 9, one end of the firing pin 16 extending into the special-shaped cavity 19 is fixedly connected with an elastic pin 17, and the inner wall of the special-shaped cavity 19 is provided with a slide groove 20 for the elastic pin 17 to be inserted and slide, the slide groove 20 is composed of two arc-shaped slideways that are increasingly farther away from the center of the limit disk 9 in the sliding direction of the elastic pin 17 and a slideway that coincides with the radius line of the limit disk 9, and each section of the slideway gradually becomes shallower in the sliding direction of the elastic pin 17, and the inner wall of the shell 1 is also provided with a sliding groove 30 for the elastic pin 17 to slide along the telescopic direction of the cylinder 7.

[0047] According to the above embodiment, a specific embodiment of a firing part is provided. Figure 6 and Fig. 9 When the reduction motor 31 drives the driving gear 22 to drive the limit plate 9 and the transmission gear 11 to rotate together, it will drive the elastic pin 17 to slide in the outermost arc-shaped slideway and compress the compression spring 18. When the limit plate 9 rotates 90 degrees counterclockwise, that is, when the slot 10 rotates to communicate with the side channel, the elastic pin 17 moves to the slideway that coincides with the radius line of the limit plate 9, and quickly approaches the fixing ring 14 under the action of the compression spring 18 until the striker 16 hits the fixing ring 14 and knocks the filter part out of the slot 10. Then the reduction motor 31 drives the driving gear 22 to drive the limit plate 9 and the transmission gear 11 to rotate 90 degrees in the opposite direction to reset, and at the same time drives the elastic pin 17 to slide and reset along the arc-shaped slideway close to the fixing ring 14, and the striker 16 is pulled back to Figure 6 state, and the compression spring 18 also begins to be gradually compressed to prevent the firing pin 16 from blocking the fixing ring 14 that is subsequently installed in the slot 10 or preventing it from being completely inserted. Finally, the new filter part (i.e., the fixing ring 14) is reinstalled into the slot 10 to complete the rapid disassembly and installation of the filter part in the limit plate 9.

[0048] In this way, through the sliding of the elastic pin 17 in the slide groove 20 and the rotation of the limit plate 9, the discarded filter part can be quickly knocked out of the shell 1, so that after too many particles or dust accumulate on the filter cotton 15, it can be quickly disassembled and replaced, avoiding the filter cotton 15 from being used for too long and causing blockage of airflow, causing the device to idle and get stuck.

[0049] It is worth mentioning that since each slide section in the slide groove 20 gradually becomes shallower in the sliding direction of the elastic pin 17, the elastic pin 17 can only slide in one direction in the slide groove 20, avoiding the sliding reverse change of the elastic pin 17 so that the striker 16 cannot knock the discarded filter part out of the shell 1.

[0050] Furthermore, a bottom box 32 is fixedly connected to the bottom of the shell 1, a top plate 23 is slidably installed in the bottom box 32, a spring 24 is provided between the top plate 23 and the bottom wall of the bottom box 32, and the sliding ring 8 is tangent to the limit plate 9.

[0051] According to the above embodiment, it can be known that when the striker 16 knocks the fixing ring 14 in the limit disk 9 to knock the filter part out of the shell 1, the reduction motor 31 drives the active gear 22 to drive the transmission gear 11 and the limit disk 9 to reset. At this time, the spring 24 in the bottom box 32 pushes the top plate 23 to drive the filter part in the bottom box 32 to move up to the limit disk 9, completing the automatic replacement of the filter part and realizing the rapid replacement of the filter cotton 15, solving the pain points of replacing the filter cotton 15 at this stage, reducing the number and duration of shutdown maintenance of the device, and reducing the use cost of the device.

[0052] It is worth mentioning that since the sliding ring 8 is arranged tangentially to the limit plate 9, when the sliding ring 8 follows the limit plate 9 to slide in the shell 1, the sliding ring 8 can replace the fixed ring 14 in the limit plate 9 to limit the filter part below, thereby preventing the fixed ring 14 on one side of the lower filter part from losing its upward limit and being tilted by the thrust of the lower top plate 23, thereby hindering the resetting of the limit plate 9.

[0053] Furthermore, a laser transmitter 27 and a laser receiver 28 coinciding with the diameter line of the sliding ring 8 are fixedly installed in the groove on the inner wall of the mounting frame 6, and the laser receiver 28 is connected to the cylinder 7 via electrical signals. An elastic net 26 is also fixedly installed on the inner wall of the mounting frame 6, and a light-blocking strip 29 is fixedly installed at the center of the elastic net 26.

[0054] According to the above embodiment, when the filter cotton 15 is in state 1, the gas filtered by the filter cotton 15 will enter the installation frame 6 through the sliding ring 8. At this time, the elastic net 26 fixed on the inner wall of the installation frame 6 will expand toward the installation frame 6 under the influence of the air flow. Figure 8 At this time, the light-blocking strip 29 cannot prevent the laser receiver 28 from receiving the laser signal from the laser transmitter 27. As the gas in the container decreases to a certain level, the gas passing through the filter cotton 15 gradually decreases, causing the elastic net 26 to expand less, causing the light-blocking strip 29 to move toward the laser receiver 28. When the laser receiver 28 cannot receive the laser signal from the laser transmitter 27, the cylinder 7 is driven through the telecommunication connection to switch the filter cotton 15 to state two.

[0055] In this way, the laser receiver 28 and the light-blocking strip 29 can be used to detect the amount of remaining gas in the container, so that when the suction force of the device is reduced, the state of the filter cotton 15 can be automatically switched to meet the different requirements of gas filtration in different suction stages, thereby improving the filtering effect and vacuum limit of the device.

[0056] Furthermore, a side wall of the slot 10 is provided with an elastic buckle.

[0057] According to the above embodiment, when the transmission gear 11 drives the limit plate 9 to rotate, the fixing ring 14 in the slot 10 provides support force close to the filter part and the top plate 23 below. Figure 7 During the rotation, the upper fixed filter part and the lower filter part will be out of contact, so that the filter part in the slot 10 will have escaped from the slot 10 before the striker 16 hits the fixed ring 14, and enter the side channel opened in the side wall of the shell 1 for the filter part to slide out, so that the striker 16 cannot knock the filter part out of the shell 1, which will hinder the next replacement of the filter part.

[0058] Furthermore, the length of the sliding slot 30 is greater than the sliding distance of the elastic pin 17 .

[0059] According to the above embodiment, since the cylinder 7 will push the fixing ring 14 and the elastic pin 17 in the fixing ring 14 to slide together, in order to avoid the elastic pin 17 hindering the sliding of the fixing ring 14, so that the compression of the filter cotton 15 cannot be completed normally, causing the device to get stuck and reducing the filtering accuracy of the filter cotton 15, the present invention sets the length of the sliding groove 30 to be greater than the sliding distance of the elastic pin 17 to meet the sliding requirements of the fixing ring 14.

[0060] Furthermore, plastic grids for limiting the position of the filter cotton 15 are fixedly installed in the two fixing rings 14 .

[0061] According to the above embodiment, it can be known that as the cylinder 7 compresses the filter cotton 15 when pushing the fixed ring 14 to slide, the filter cotton 15 may expand to both sides. By fixing the plastic grids on both sides of the fixed ring 14, the filter cotton 15 is limited to prevent the filter cotton 15 from expanding to both sides, resulting in insufficient density of the compressed filter cotton 15, which cannot intercept high-density particles or dust in a high-speed state, resulting in reduced filtering accuracy.

[0062] The standard parts used in this embodiment can be purchased directly from the market, and the non-standard structural components recorded in the specification and the drawings can also be directly processed according to the existing technical common sense without any doubt. At the same time, the connection method of each component adopts the mature conventional means in the prior art, and the machinery, parts and equipment all adopt the conventional models in the prior art, so no specific description will be given here.

[0063] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A vacuum pump pre-gas filtering device, comprising a housing (1) and a gas outlet hole provided on a side wall of the housing (1), Features: The side walls of the housing (1) are respectively fixedly mounted with a mounting plate (2) and a motor (3); a mounting frame (6) is provided inside the housing (1); a portion of the main shaft of the motor (3) that penetrates into the housing (1) and the mounting frame (6) is fixedly connected with a rotating shaft (4); a plurality of rows of fins (5) are distributed on the side walls of the rotating shaft (4); the fins (5) are alternately composed of fixed fins and rotating fins in opposite directions; an air intake pipe (25) that can communicate with the mounting frame (6) is installed on the side walls of the mounting plate (2); a filter portion for filtering gas is provided in the pipeline between the air intake pipe (25) and the mounting frame (6); the filter portion comprises filter cotton (15); the filter cotton (15) has two states: in state one, the filter cotton (15) is in a compressed state, thereby improving the filtering accuracy and the wind resistance; in state two, the filter cotton (15) is in an extended state, thereby reducing the filtering accuracy and the wind resistance.

2. The vacuum pump pre-gas filter device according to claim 1, Features: The filter unit comprises two fixing rings (14) which can be installed in a pipe between an air inlet pipe (25) and a mounting frame (6); a corrugated pipe (13) is connected between the two fixing rings (14); and the filter cotton (15) is fixedly installed between the two fixing rings (14).

3. The vacuum pump pre-gas filter device according to claim 2, Features: Two limiting plates (9) are rotatably mounted on the inner wall of the housing (1). The opposing surfaces of the two limiting plates (9) are provided with a slot (10) for inserting a fixing ring (14). After the fixing ring (14) is inserted into the slot (10), it is in an inscribed state with the limiting plates (9). A plurality of elastic telescopic rods (12) are fixedly connected between the two limiting plates (9). A cylinder (7) fixedly mounted on the inner wall of the housing (1) is provided on the side of one of the limiting plates (9). The end of the driving shaft of the cylinder (7) abuts against the side wall of the limiting plate (9) and can slide on the side wall of the limiting plate (9). A sliding ring (8) capable of sliding in the housing (1) is fixedly connected to one side of the limiting plate (9).

4. The vacuum pump pre-gas filter device according to claim 3, Features: A reduction motor (31) is fixedly mounted on the side wall of the mounting plate (2); a portion of the main shaft of the reduction motor (31) that penetrates into the mounting plate (2) is fixedly connected to a driving gear (22); a transmission gear (11) that meshes with the driving gear (22) is fixedly mounted on the outer wall of the limiting plate (9); a side channel for the filter part to slide out is provided on the side wall of the housing (1), and a door panel (21) is provided in the side channel; A firing portion is also provided in the housing (1), and when the slot (10) is rotated to communicate with the side channel, the firing portion fires the filter portion out of the slot (10).

5. The vacuum pump pre-gas filter device according to claim 4, Features: The firing portion comprises a special-shaped cavity (19) which is opened in the housing (1) and is located on the side of the limiting disk (9); a mounting hole is opened in the limiting disk (9), and a firing pin (16) is slidably mounted in the mounting hole; a compression spring (18) is installed between the firing pin (16) and the mounting hole to apply pressure to the firing pin (16) to move closer to the limiting disk (9); one end of the firing pin (16) extending into the special-shaped cavity (19) is fixedly connected to an elastic pin (17); and the firing pin (16) is provided with a spring (18) which is arranged in the special-shaped cavity (19). The wall is provided with a slide groove (20) for the elastic pin (17) to be inserted and slide. The slide groove (20) is composed of two arc-shaped slideways that are increasingly far away from the center of the limit plate (9) in the sliding direction of the elastic pin (17) and a slideway that coincides with the radius line of the limit plate (9) connected end to end, and each section of the slideway gradually becomes shallower in the sliding direction of the elastic pin (17). The inner wall of the housing (1) is also provided with a slide groove (30) for the elastic pin (17) to slide along the extension and contraction direction of the cylinder (7).

6. The vacuum pump pre-gas filter device according to claim 5, Features: The bottom of the housing (1) is fixedly connected to a bottom box (32), a top plate (23) is slidably mounted inside the bottom box (32), a spring (24) is provided between the top plate (23) and the bottom wall of the bottom box (32), and the sliding ring (8) is tangentially arranged with the limiting plate (9).

7. The vacuum pump pre-gas filter device according to claim 6, Features: A laser transmitter (27) and a laser receiver (28) which coincide with the diameter line of the sliding ring (8) are fixedly installed in the groove of the inner wall of the installation frame (6), and the laser receiver (28) is connected to the cylinder (7) by electrical signals. An elastic net (26) is also fixedly installed on the inner wall of the installation frame (6), and a light blocking strip (29) is fixedly installed at the center of the elastic net (26).

8. The vacuum pump pre-gas filter device according to claim 3, Features: The side wall of the clamping slot (10) is provided with an elastic clamping buckle.

9. The vacuum pump pre-gas filter device according to claim 5, Features: The length of the sliding groove (30) is greater than the sliding distance of the elastic pin (17).

10. The vacuum pump pre-gas filter device according to claim 2, Features: Plastic grids for limiting the position of the filter cotton (15) are fixedly installed in the two fixing rings (14).

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