A gas sampling vane pump

Abstract

The present invention discloses a gas sampling vane pump, comprising a pump body and a motor. A rotor chamber is provided on the pump body, a first graphite pad is installed in the rotor chamber, a central shaft is rotatably installed in the rotor chamber, a rotor is fixed on the central shaft, a plurality of blade slots are evenly distributed on the outer circumference of the rotor, and the blades are movably embedded in the blade slots. An air inlet groove and an air outlet groove are provided on the end face of the first graphite pad. An air inlet chamber and an air outlet chamber are provided on the pump body. The air inlet groove connects the rotor chamber with the air inlet chamber, and the air outlet groove connects the rotor chamber with the air outlet chamber. The pump body is provided with an air inlet joint connected to the air inlet chamber and an air outlet joint connected to the air outlet chamber. The gas sampling pump can avoid abnormal wear between the blades and the rotor chamber, thereby ensuring that the sampling pressure of the vane pump is stable during long-term use, the fluctuation of the sampling gas flow is smaller, and the accuracy of quantitative sampling is higher.

Description

Technical Field

[0001] The invention relates to a gas sampling vane pump, belongs to the technical field of gas pumps, and is used for gas sampling in gas particle detection. Background Art

[0002] In the process of gas particulate matter concentration detection, it is necessary to quantitatively sample the gas in the atmosphere, and the power of gas sampling is through the sampling pump. According to the particulate matter concentration detection standard, the sampling pump samples a certain amount of gas, and the gas is discharged after being filtered through the filter membrane. After the dust is filtered by the filter membrane, the weight before and after the filter membrane is weighed by the weighing method, and the dust mass under the volume of gas can be obtained. The dust mass concentration of the gas is obtained by dividing the dust mass by the gas volume; the detection method is also recorded in the application document with patent number CN201910386747.8. The calculation method of the open dust concentration detection is also recorded. In the calculation method, the correctness of the gas volume is directly related to the dust concentration. This directly affects the accuracy of the detection concentration. In the current sampling method, the flow rate of the sampling gas is generally controlled at 16.67L / min, which can ensure that the sampling volume in one hour is 1 cubic meter of gas for easy calculation. At the same time, the cutters for PM2.5 or PM10 are also designed at 16.67L / min. The current gas sampling pumps are mainly diaphragm pumps or piston pumps. This type of sampling pump is limited by its own structure and working principle. The gas flow rate fluctuates greatly during the sampling process. Therefore, the measurement of the sampling gas flow rate is inaccurate, which will result in a large deviation in the calculation of the dust mass concentration and inaccurate detection results. There are other pump structures on the market, such as vane pumps. For example, the application document with patent number 202121430564.0 discloses an improved vane pump, which includes a rotor and vanes mounted on the rotor. The rotor is driven to rotate by a motor, and the rotor drives the vanes to rotate to suck gas from the water inlet and press it out from the water outlet. Although the medium of this vane pump is liquid, it can theoretically also be adapted to gas media. However, since gas sampling requires very high sampling accuracy of gas, the fluctuation of gas sampling must be very small. In the patent document with patent number 202121430564.0, the water inlet and outlet are arranged on the right and left sides of the inner cavity of the pump casing. Therefore, if this structure is applied to gas sampling, the blades will be subjected to a large centrifugal force during the rotation of the blades. The side ends will frequently contact and rub against the cavity wall of the pump casing, and the position where the cavity wall, the water inlet and the water outlet are connected is a through hole with an intersecting line structure. When the outer end of the blade contacts the through hole, the wear will be aggravated, so that the end of the outer end of the blade will wear locally and quickly, and the worn blades will cause the air tightness of the chamber between adjacent blades to decrease, so that the suction force of the sampling pump is reduced, and the air pressure at the air inlet is reduced, the flow rate of the sampling gas will also be reduced and produce vibration, and the accuracy of the sampling gas is very low. It can be seen that the vane pump of this structure is not suitable for gas sampling. In addition, during the assembly process of the vane pump, the gap between the blades, the rotor and the bottom plate of the inner cavity is difficult to control. Over-tight assembly will affect the smoothness of the rotation of the blades and the rotor, and when the assembly is relatively loose, the gap between the blades and the bottom of the inner cavity is larger, which will also reduce the air tightness of the chamber between the blades. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a gas sampling vane pump, which can avoid abnormal wear between the blades and the rotor chamber, thereby ensuring that the sampling pressure of the vane pump is stable during long-term use, the fluctuation of the sampling gas flow is smaller, and the accuracy of quantitative sampling is higher.

[0004] In order to solve the above technical problems, the technical solution of the present invention is: a gas sampling vane pump, comprising a pump body, a rotor, a blade and a first end cover, the pump body is provided with a rotor chamber with a circular cross section, a first graphite pad is installed in the rotor chamber, a motor is fixed on the pump body, a central shaft is rotatably installed in the rotor chamber, the central shaft is transmission-connected to the output shaft of the motor, the rotor is fixed on the central shaft, the center of the rotor is eccentrically arranged with the center of the rotor chamber, a plurality of blade slots are evenly distributed on the outer circumference of the rotor, and the rotor is fixed on the central shaft. The blades are movably embedded in the blade grooves, and the outer ends of the blades cooperate with the inner walls of the rotor chamber. An air inlet groove and an air outlet groove are provided on the end face of the first graphite pad. An air inlet chamber and an air outlet chamber are provided on the pump body on the outside of the rotor chamber. The air inlet groove connects the rotor chamber with the air inlet chamber, and the air outlet groove connects the rotor chamber with the air outlet chamber. The first end cover is detachably fixed to the pump body to seal the rotor chamber. The pump body is provided with an air inlet joint connected to the air inlet chamber and an air outlet joint connected to the air outlet chamber.

[0005] As a preferred solution, a second graphite pad is further provided between the first end cover and the rotor.

[0006] As a preferred solution, the outer contour of the rotor is inscribed in the wall of the rotor chamber, and the air inlet sink groove and the air outlet sink groove are respectively located on both sides of the inscribed point.

[0007] As a preferred solution, the air inlet trough and the air outlet trough both include a first strip groove segment and a second strip groove segment, the width of the first strip groove segment is smaller than the width of the second strip groove segment, the first strip groove segment and the second strip groove segment both extend in a circular arc, and the second strip groove segment is closer to the inscribed point than the first strip groove segment.

[0008] As a preferred solution, the pump body includes a second end cover, an intermediate pump body and a stator cylinder, the second end cover is provided with a mounting groove, the intermediate pump body is provided with a mounting chamber, the stator cylinder is installed in the mounting chamber, the inner cavity of the stator cylinder forms the rotor chamber, the air inlet chamber and the air outlet chamber are both provided on the intermediate pump body, the first graphite pad is installed in the mounting groove, the first end cover and the second end cover are detachably fixed by a locking bolt, and the locking bolt passes through the first graphite pad, the intermediate pump body and the second graphite pad.

[0009] As a preferred solution, a radial screw hole is provided on the rotor, a tightening plane corresponding to the position of the radial screw hole is provided on the central axis, a tightening screw is installed in the radial screw hole, and the end face of the tightening screw is tightly matched with the tightening plane.

[0010] As a preferred solution, the second end cover serves as the motor end cover of the motor.

[0011] As a preferred solution, an obtuse-angle contact portion is provided at the outer end of the blade.

[0012] As a preferred solution, the intermediate pump body is provided with two air inlets, the two air inlets being provided on different sides of the intermediate pump body and being connected to the air inlet chamber via an air inlet passage, one of the air inlets being provided with the air inlet connector, and the other being provided with a plug.

[0013] After adopting the above technical scheme, the effect of the present invention is as follows: a gas sampling vane pump comprises a pump body, a rotor, blades and a first end cover, the pump body is provided with a rotor chamber with a circular cross section, the rotor chamber is installed with a first graphite pad, the pump body is fixed with a motor, a central shaft is rotatably installed in the rotor chamber, the central shaft is transmission-connected to the output shaft of the motor, the rotor is fixed on the central shaft, the center of the rotor is eccentrically arranged with the center of the rotor chamber, the outer circumference of the rotor is evenly distributed with a plurality of blade grooves, the blades are movably embedded in the blade grooves, the outer ends of the blades cooperate with the inner wall of the rotor chamber, the end surface of the first graphite pad is provided with an air inlet groove and an air outlet groove, the pump body is provided with an air inlet chamber and an air outlet chamber on the outer side of the rotor chamber, the air inlet groove connects the rotor chamber with the air inlet chamber, and the air outlet groove connects the rotor chamber with the air outlet chamber. The first end cover is detachably fixed to the pump body to seal the rotor chamber, and the pump body is provided with an air inlet connector connected to the air inlet chamber and an air outlet connector connected to the air outlet chamber. Therefore, since a first graphite pad is provided, an air inlet groove and an air outlet groove are provided on the first graphite pad, and an air inlet chamber and an air outlet chamber are provided on the outside of the rotor chamber on the pump body, so that the outer end of the blade will be reliably matched with the inner wall of the rotor chamber, and the outer end of the blade will not suffer abnormal wear. In this way, the air tightness of the chamber between adjacent blades is better and more stable, so that the pressure at the air inlet of the vane pump is more stable when working, and the flow rate of the sampled gas is also more stable. At the same time, since the blades are continuously driven to rotate by the motor, the chamber between the blades will continuously draw gas in from the air inlet connector and discharge it from the air outlet connector, and the flow fluctuation is also smaller, so that the flow regulation is more accurate, the amount of sampled gas is more accurate, and the error is smaller when the dust concentration is finally calculated.

[0014] Furthermore, since a second graphite pad is provided between the first end cover and the rotor, the first graphite pad and the second graphite pad can be more wear-resistant and reduce friction.

[0015] Since the outer contour of the rotor is inscribed inwardly with the wall of the rotor chamber, the air inlet trough and the air outlet trough are respectively located on both sides of the inscription point. Therefore, the rotor is inscribed inwardly with the wall of the rotor chamber. In this way, when the blade passes through the inscription point, the gas in the air inlet trough can be completely discharged into the air outlet trough, so that the gas in the chamber of the adjacent blade can be completely discharged. In this way, by controlling the speed of the motor, the speed of the blade can be very accurately controlled, and then the suction volume can be accurately controlled to meet the requirements of quantitative gas sampling.

[0016] Furthermore, since the air inlet sink groove and the air outlet sink groove both include a first strip groove segment and a second strip groove segment, the width of the first strip groove segment is smaller than the width of the second strip groove segment, the first strip groove segment and the second strip groove segment both extend in a circular arc, and the second strip groove segment is closer to the inscribed point than the first strip groove segment. Since the width of the first strip groove segment is smaller than the width of the second strip groove segment, the second strip groove segment can be connected with the air inlet chamber and the air outlet chamber to a greater extent, and the width of the first strip groove segment is smaller, which can reduce the contact friction between the blade and the segment as much as possible, reduce the wear of the blade, and ensure the stability of the flow of the vane pump.

[0017] The pump body includes a second end cover, an intermediate pump body and a stator cylinder, the second end cover is provided with a mounting groove, the intermediate pump body is provided with a mounting chamber, the stator cylinder is installed in the mounting chamber, the inner cavity of the stator cylinder forms the rotor chamber, the air inlet chamber and the air outlet chamber are both provided on the intermediate pump body, the first graphite pad is installed in the mounting groove, the first end cover and the second end cover are detachably fixed by a locking bolt, and the locking bolt passes through the first graphite pad, the intermediate pump body and the second graphite pad. The above structure can first reduce the processing cost, and the intermediate pump body and the stator cylinder can be processed separately. In particular, since the stator cylinder needs to cooperate with the rotor and blades, the smoothness of the inner wall of the stator cylinder is required to be higher. Separating the stator cylinder from the intermediate pump body has lower processing difficulty and processing cost, and is easier to ensure processing accuracy. Secondly, the pump body can be more convenient to assemble and adjust the angular position of the first graphite pad.

[0018] Furthermore, since radial screw holes are provided on the rotor, a tightening plane corresponding to the position of the radial screw holes is provided on the central axis, and a tightening screw is installed in the radial screw hole, and the end face of the tightening screw is tightly matched with the tightening plane, therefore, after adopting the above structure, the gap between the rotor and the first graphite pad can be adjusted better and faster. During assembly, the first graphite pad is first installed in the installation groove provided on the second end cover, and the angle of the first graphite pad is adjusted so that the air inlet groove and the air outlet groove correspond to the positions of the air inlet chamber and the air outlet chamber on the intermediate pump body. Then place a thin sheet on the first graphite pad. The thickness of the thin sheet is the assembly gap between the rotor and the first graphite pad. Then, when the rotor is put on the center shaft, the bottom of the rotor will be supported by the thin sheet, thus ensuring that the gap between the bottom of the rotor and the first graphite pad meets the assembly requirements. Then, tighten the tightening screw to complete the fixation of the rotor. Finally, fix the first end cover and the second end cover together with the locking bolts that pass through the first graphite pad, the middle pump body, and the second graphite pad. The entire assembly process is very simple, and the assembly accuracy can be better controlled.

[0019] Furthermore, since the outer end of the blade is provided with an obtuse-angle contact portion, the obtuse-angle contact portion can better stably contact the inner wall of the rotor chamber to ensure air tightness.

[0020] Furthermore, the intermediate pump body is provided with two air inlets, located on different sides of the intermediate pump body. The two air inlets are connected to the air inlet chamber via an air inlet passage. One of the air inlets is provided with the air inlet connector, while the other is provided with a plug. This facilitates the placement of the air outlet connector and facilitates connection to on-site pipelines. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention will be further described below with reference to the accompanying drawings and examples.

[0022] Figure 1 is a schematic diagram of the three-dimensional structure of Example 1 of the present invention;

[0023] Figure 2 is a schematic end view of Example 1 of the present invention;

[0024] Figure 3 yes Figure 2 Cross-sectional view at AA;

[0025] Figure 4 This is a schematic diagram of the end face after the first end cover and the second graphite pad are hidden;

[0026] Figure 5 is a perspective view of the installation positions of the rotor, the first graphite pad, and the blades of Example 1;

[0027] Figure 6It is a structural stereogram of the middle body;

[0028] Figure 7 is a perspective view of Example 2;

[0029] Figure 8 is a schematic end view of Example 2;

[0030] Figure 9 yes Figure 8 Cross-sectional view at BB;

[0031] In the accompanying drawings: 1. Pump body; 2. Motor; 3. Intermediate pump body; 31. Installation chamber; 32. Air inlet chamber; 33. Air outlet chamber; 34. Air inlet; 4. First end cover; 5. Air inlet joint; 6. Air outlet joint; 7. Second end cover; 8. First graphite pad; 9. Second graphite pad; 10. Center axis; 11. Tightening screw; 12. Rotor; 121. Blade groove; 13. Stator cylinder; 14. Blade; 141. Obtuse angle contact portion; 15. Locking bolt; 16. Air outlet trough; 161. First strip groove section; 162. Second strip groove section; 17. Air inlet trough; 18. Sealing head; 19. Tightening plane; 20. Rotor chamber. DETAILED DESCRIPTION

[0032] The present invention is further described in detail below through specific examples.

[0033] Example 1

[0034] like Figures 1 to 6 As shown, a gas sampling vane pump includes a pump body 1, a rotor 12, blades 14 and a first end cover 4. The pump body 1 is provided with a rotor chamber 20 with a circular cross section, and a first graphite pad 8 is installed in the rotor chamber 20. A motor 2 is fixed to the pump body 1, and a central shaft 10 is rotatably installed in the rotor chamber 20. The central shaft 10 is transmission-connected to the output shaft of the motor 2.

[0035] The rotor 12 is fixed to the central shaft 10, with the center of the rotor 12 eccentrically positioned relative to the center of the rotor chamber 20. A second graphite pad 9 is also disposed between the first end cap 4 and the rotor 12. The first and second graphite pads 8 and 9 are made of graphite, which is wear-resistant and has very low friction, facilitating the rotation of the blades 14 and the rotor 12. In this embodiment, the pump body 1 includes a second end cap 7, an intermediate pump body 3, and a stator barrel 13. The second end cap 7 is provided with a mounting groove, the intermediate pump body 3 is provided with a mounting chamber 31, the stator barrel 13 is installed in the mounting chamber 31, and the inner cavity of the stator barrel 13 forms the rotor chamber 20. The air inlet chamber 32 and the air outlet chamber 33 are both provided on the intermediate pump body 3. The first graphite pad 8 is installed in the mounting groove. The first end cap 4 and the second end cap 7 are detachably fixed by a locking bolt 15, which passes through the first graphite pad 8, the intermediate pump body 3, and the second graphite pad 9. The second end cap 7 serves as the motor 2 end cap of the motor 2. The central shaft 10 directly uses the output shaft of the motor 2. The rotor 12 is provided with a radial screw hole, and the central shaft 10 is provided with a tightening plane 19 corresponding to the position of the radial screw hole. A tightening screw 11 is installed in the radial screw hole, and the end face of the tightening screw 11 is tightly fitted with the tightening plane 19.

[0036] like Figure 6 As shown, the intermediate pump body 3 is provided with two air inlets 34, which are arranged on different sides of the intermediate pump body 3. The two air inlets 34 are connected to the air inlet chamber 32 through the air inlet channel. One of the air inlet ports 34 is installed with the air inlet connector 5, and the other air inlet port 34 is installed with the plug 18. Since there are two air inlets 34 and they are located on different sides, the installation position of the air inlet connector 5 can be flexibly selected, which is convenient for docking with the sampling tube. In addition, the intermediate pump body 3 can also be provided with a flow meter to monitor the flow of the sampled gas. Therefore, the other air inlet port 34 can be connected to the flow meter.

[0037] like Figures 3 to 5 As shown, the outer circumference of the rotor 12 is evenly distributed with a plurality of blade 14 grooves 121. In this embodiment, the number of blade 14 grooves 121 is 5. The blade 14 is movably embedded in the blade 14 groove 121. The outer end of the blade 14 cooperates with the inner wall of the rotor chamber 20. The blade 14 can slide in the blade 14 groove 121. The extension direction of the blade 14 in this embodiment is not a radial direction. Since the cross section of the rotor chamber 20 is circular, the contact point between the outer end of the blade 14 and the inner wall of the rotor chamber 20 will have a tangent passing through the contact point. The intersection angle between the extension line of the blade 14 extending from the outer end to the inner end and the tangent is an acute angle.

[0038] An air inlet groove 17 and an air outlet groove 16 are provided on the end face of the first graphite pad 8, and an air inlet chamber 32 and an air outlet chamber 33 are provided on the pump body 1 on the outside of the rotor chamber 20. The air inlet groove 17 connects the rotor chamber 20 with the air inlet chamber 32, and the air outlet groove 16 connects the rotor chamber 20 with the air outlet chamber 33. The first end cover 4 is detachably fixed to the pump body 1 to seal the rotor chamber 20. The pump body 1 is provided with an air inlet joint 5 connected to the air inlet chamber 32 and an air outlet joint 6 connected to the air outlet chamber 33.

[0039] The motor 2 of the vane pump of this embodiment is a servo motor 2, which can accurately control the speed. Figure 4 As shown, Figure 4 The working state of the middle rotor 12 is clockwise rotation. The motor 2 drives the rotor 12 to rotate clockwise. The outer contour of the rotor 12 is inscribed in the wall of the rotor chamber 20. The air inlet groove 17 and the air outlet groove 16 are respectively located on both sides of the inscribed point. The air inlet groove 17 and the air outlet groove 16 each include a first strip groove segment 161 and a second strip groove segment 162. The width of the first strip groove segment 161 is smaller than the width of the second strip groove segment 162. The first strip groove segment 161 and the second strip groove segment 162 both extend in a circular arc. The second strip groove segment 162 is closer to the inscribed point than the first strip groove segment 161. The outer end of the blade 14 is provided with an obtuse-angle contact portion 141, which can better and reliably contact the inner wall of the rotor chamber 20. Figure 4 The three blades 14 near the introjection point are marked as blade I1, blade I2 and blade I3 respectively. When blade 14 rotates, the chamber between blade I1 and blade I2 will gradually increase. Due to the increase in volume and the decrease in pressure, the gas is sucked in from the air inlet 34, passes through the air inlet chamber 32 and the air inlet trough 17, and enters the chamber between blade I1 and blade I2. At the same time, blade I3 will continue to approach the introjection point, so the chamber between blade I3 and blade I2 will gradually become smaller, so that the gas in the chamber between blade I3 and blade I2 is pressed out. Since the rotor 12 continues to rotate, the whole process of air intake and exhaust is continuous and the gas flow rate is very small. In this way, the flow monitoring of the sampled gas is very accurate, and the detection result of the dust concentration is also accurate. The sampling pump fully meets the needs of gas sampling.

[0040] Example 2

[0041] like Figures 7 to 9As shown, the structure of this embodiment is basically the same as that of embodiment 1, except that in this embodiment, the second end cover 7 does not serve as the end cover of the motor 2, and the central shaft 10 is also a separate central shaft 10. One end of the central shaft 10 passes through the second end cover 7 and is exposed. The central shaft 10 is rotatably installed between the second end cover 7 and the first end cover 4 through a bearing, and the motor 2 is fixed on the second end cover 7 and is connected to the central shaft 10 through a coupling, and the rotation of the rotor 12 can also be realized. The size of the rotor 12 and the blades 14 of the vane pump with this structure is not limited by the end cover of the motor 2. Therefore, the size is large but the power is also greater, which is convenient for application in different occasions.

[0042] The number of blades 14 in this embodiment is not limited to 5, but can also be 7. When the vane pump in this embodiment is in use, the central axis 10 is in a horizontal state. After the rotor 12 and the blades 14 are assembled, the spacing between the rotor 12, the blades 14 and the first graphite gasket is determined. When the blades 14 are rotated by the rotor 12, they will only be subjected to centrifugal force. In this way, the blades 14 will not rub against the first graphite gasket as much as possible, reducing wear and ensuring airtightness.

[0043] The air circuit system, servo motor, and bolts mentioned in this embodiment are all current conventional technologies. The above-mentioned embodiments are only descriptions of the preferred implementation methods of the present invention and are not intended to limit the scope of the present invention. Various modifications and alterations to the technical solutions of the present invention without departing from the design spirit of the present invention should fall within the scope of protection determined by the claims of the present invention.

Claims

1. A gas sampling vane pump, comprising a pump body, a rotor, vanes and a first end cover, characterized in that: The pump body is provided with a rotor chamber with a circular cross section, a first graphite pad is installed in the rotor chamber, a motor is fixed on the pump body, a center shaft is rotatably installed in the rotor chamber, the center shaft is transmission-connected to the output shaft of the motor, the rotor is fixed on the center shaft, the center of the rotor is eccentrically arranged with the center of the rotor chamber, a plurality of blade grooves are evenly distributed on the outer circumference of the rotor, the blades are movably embedded in the blade grooves, the outer ends of the blades cooperate with the inner walls of the rotor chamber, an air inlet sink groove and an air outlet sink groove are provided on the end surface of the first graphite pad, an air inlet chamber and an air outlet chamber are provided on the pump body outside the rotor chamber, the air inlet sink groove The chamber is connected to the air inlet chamber, and the air outlet sink groove connects the rotor chamber with the air outlet chamber. The first end cover is detachably fixed to the pump body to seal the rotor chamber. The pump body is provided with an air inlet joint connected to the air inlet chamber and an air outlet joint connected to the air outlet chamber; the outer contour of the rotor is inscribed in the chamber wall of the rotor chamber, and the air inlet sink groove and the air outlet sink groove are respectively located on both sides of the inscription point; the air inlet sink groove and the air outlet sink groove both include a first strip groove segment and a second strip groove segment, the width of the first strip groove segment is smaller than the width of the second strip groove segment, the first strip groove segment and the second strip groove segment both extend in a circular arc, and the second strip groove segment is closer to the inscription point than the first strip groove segment.

2. A gas sampling vane pump according to claim 1, characterized in that: A second graphite pad is further provided between the first end cover and the rotor.

3. A gas sampling vane pump according to claim 2, characterized in that: The pump body includes a second end cover, an intermediate pump body and a stator cylinder. The second end cover is provided with a mounting groove, the intermediate pump body is provided with a mounting chamber, the stator cylinder is installed in the mounting chamber, the inner cavity of the stator cylinder forms the rotor chamber, the air inlet chamber and the air outlet chamber are both provided on the intermediate pump body, the first graphite pad is installed in the mounting groove, the first end cover and the second end cover are detachably fixed by a locking bolt, and the locking bolt passes through the first graphite pad, the intermediate pump body and the second graphite pad.

4. A gas sampling vane pump according to claim 3, characterized in that: The rotor is provided with a radial screw hole, the central shaft is provided with a tightening plane corresponding to the position of the radial screw hole, a tightening screw is installed in the radial screw hole, and the end face of the tightening screw is tightly matched with the tightening plane.

5. A gas sampling vane pump according to claim 4, characterized in that: The second end cover serves as a motor end cover of the motor.

6. A gas sampling vane pump according to any one of claims 1 to 5, characterized in that: An obtuse-angle contact portion is provided at the outer end of the blade.

7. A gas sampling vane pump according to claim 3, characterized in that: The intermediate pump body is provided with two air inlets, which are arranged on different sides of the intermediate pump body. The two air inlets are connected to the air inlet chamber through an air inlet channel. One of the air inlets is installed with the air inlet connector, and the other air inlet is installed with a plugging head.

Images