阅读说明：本技术 真空泵减压装置和减压真空泵 (Vacuum pump pressure reducing device and pressure reducing vacuum pump ) 是由 不公告发明人 于 2019-09-24 设计创作，主要内容包括：本发明涉及一种真空泵减压装置和减压真空泵,该真空泵减压装置设有进气通道端、排气通道端和减压腔,通过在减压腔设置气体加速模块,使气体加速区内的气体流速大于气体流入区内的气体流速,根据伯努利原理(气体流速越大,压强越小),通过速度变化,使原本压强相近的进气通道端和排气通道端产生正压强差,两端产生的压强差带动进气通道端的气体流速变大。从而缓解了进气通道端的排气阻力,使真空泵的转子转动速率下降,从而预防了真空泵的过度磨损,延长了真空泵的使用寿命。(The invention relates to a vacuum pump pressure reducing device and a pressure reducing vacuum pump, wherein the vacuum pump pressure reducing device is provided with an air inlet channel end, an air outlet channel end and a pressure reducing cavity, a gas accelerating module is arranged in the pressure reducing cavity, so that the gas flow speed in a gas accelerating area is larger than the gas flow speed in a gas inflow area, according to the Bernoulli principle (the larger the gas flow speed is, the smaller the pressure intensity is), the positive pressure difference is generated between the air inlet channel end and the air outlet channel end which are originally similar in pressure intensity through speed change, and the pressure difference generated at the two ends drives the gas flow speed at the air inlet channel end to be increased. Thereby, the exhaust resistance at the end of the air inlet channel is relieved, the rotation speed of the rotor of the vacuum pump is reduced, the excessive abrasion of the vacuum pump is prevented, and the service life of the vacuum pump is prolonged.)

1. Vacuum pump pressure relief device, its characterized in that vacuum pump pressure relief device is equipped with:

an intake passage end;

an exhaust passage end;

the pressure reducing cavity is connected with the air inlet channel end and the air outlet channel end, a preset airflow path is arranged in the pressure reducing cavity, air output by the air inlet channel end enters the air outlet channel end along the preset airflow path, and positive pressure difference exists between the air inlet channel end and the air outlet channel end.

2. A vacuum pump pressure reduction device according to claim 1, wherein a baffle plate is provided in the pressure reduction chamber; the baffle is used for limiting the predetermined gas flow path and dividing the predetermined gas flow path into a gas inflow area close to the end of the gas inlet channel and a gas acceleration area close to the end of the gas outlet channel.

3. A vacuum pump pressure reduction apparatus according to claim 2, wherein the pressure reduction chamber further comprises a gas acceleration module for controlling a flow velocity of gas in the gas acceleration zone, the gas flow velocity in the gas inflow zone being less than the gas flow velocity in the gas acceleration zone.

4. A vacuum pump pressure reduction device according to claim 2, wherein the angle between the surface of the baffle on the side close to the gas acceleration region and the inner wall of the pressure reduction chamber is in the range of 45 ° to 90 °, and the baffle rotates within the angle range.

5. A vacuum pump decompression arrangement according to claim 3, wherein the baffle further divides the predetermined gas flow path into gas guiding regions, the gas guiding regions are located between the gas inflow regions and the gas acceleration regions for guiding gas from the gas inflow regions into the gas acceleration regions, and the gas acceleration modules do not control the flow rate of gas within the gas guiding regions.

6. A vacuum pump pressure reduction device according to claim 5, wherein the gas acceleration module is provided with a valve for controlling the flow velocity of the gas in the gas acceleration zone.

7. A vacuum pump pressure reduction arrangement according to claim 2, wherein the pressure reduction chamber further comprises a dust collection assembly disposed within the extent of overlap of the baffle with the gas inflow region.

8. A vacuum pump pressure reducing device according to claim 7, wherein an openable and closable dust exhaust port is provided on an outer wall of the pressure reducing chamber, and the dust exhaust port is attached to the dust collecting assembly and used for exhausting dust from the dust collecting assembly.

9. A vacuum pump pressure reducing device according to claim 7, wherein the dust discharge port is provided with a transparent mirror.

10. A vacuum pump for reducing pressure, comprising the vacuum pump pressure reducing apparatus according to any one of claims 1 to 9, wherein an intake passage end of the vacuum pump pressure reducing apparatus is connected to an exhaust end of the vacuum pump.

Technical Field

The invention relates to the field of semiconductor manufacturing, in particular to a vacuum pump pressure reducing device and a pressure reducing vacuum pump.

Background

In recent years, the semiconductor industry has been rapidly developed, and the market has made higher demands on the product quality and production efficiency of semiconductors. Therefore, manufacturers must continuously improve and perfect their own production equipment and process level to meet the new market demand.

Currently, a common technical means for the processing of semiconductor devices is a processing process such as etching and physical vapor deposition. Since the above process has very high requirements for cleanliness and vacuum degree of the process chamber, it is necessary to reduce the pressure in the process chamber from atmospheric pressure to a vacuum state by means of a vacuum pump device such as a mechanical pump and a molecular pump.

According to statistics, more than 90% of vacuum pump replacement is caused by the fact that the air pressure at the exhaust end of the vacuum pump is too high, so that the rotor of the main pump is abraded or overloaded due to too fast rotation speed, a common preventive maintenance mode is to define fixed time for replacement (Overhaul) to reduce risks, and replacement of the vacuum pump needs to consume a large amount of manpower, money and machine use time resources.

Disclosure of Invention

In view of the above, it is necessary to provide a vacuum pump pressure reducing device and a pressure reducing vacuum pump, aiming at the technical problem that the excessive pressure at the exhaust end of the vacuum pump causes the abrasion or overload of the main pump.

In order to realize the purpose of the invention, the invention adopts the following technical scheme:

a vacuum pump pressure reducing device is provided with:

an intake passage end;

an exhaust passage end;

the pressure reducing cavity is connected with the air inlet channel end and the air outlet channel end, a preset airflow path is arranged in the pressure reducing cavity, air output by the air inlet channel end enters the air outlet channel end along the preset airflow path, and positive pressure difference exists between the air inlet channel end and the air outlet channel end.

The technical solution is further explained below:

in one embodiment, a baffle is arranged in the decompression chamber; the baffle is used for limiting the predetermined gas flow path and dividing the predetermined gas flow path into a gas inflow area close to the end of the gas inlet channel and a gas acceleration area close to the end of the gas outlet channel.

In one embodiment, the decompression chamber further comprises a gas acceleration module for controlling the flow velocity of the gas in the gas acceleration zone, and the gas flow velocity in the gas inflow zone is less than the gas flow velocity in the gas acceleration zone.

In one embodiment, an included angle between a surface of the baffle plate, which is close to one side of the gas acceleration area, and the inner wall of the decompression chamber ranges from 45 degrees to 90 degrees, and the baffle plate rotates in the included angle range.

In one embodiment, the baffle further divides the predetermined gas flow path into a gas guiding region, the gas guiding region is located between the gas inflow region and the gas acceleration region for guiding the gas from the gas inflow region into the gas acceleration region, and the gas acceleration module does not control the flow rate of the gas in the gas guiding region.

In one embodiment, the gas acceleration module is provided with a valve for controlling the flow velocity of the gas in the gas acceleration zone.

In one embodiment, the reduced pressure chamber further comprises a dust collection assembly disposed within an overlap of the baffle and the gas inflow region.

In one embodiment, an openable dust exhaust port is formed in the outer wall of the decompression cavity, and the dust exhaust port is attached to the dust collection assembly and used for exhausting dust of the dust collection assembly.

In one embodiment, the dust exhaust port is provided with a transparent mirror.

The technical scheme of the invention also provides a decompression vacuum pump which comprises the vacuum pump decompression device, wherein the air inlet channel end of the vacuum pump decompression device is connected with the exhaust end of the vacuum pump.

According to the vacuum pump pressure reducing device, the gas flow velocity in the gas acceleration area is larger than the gas flow velocity in the gas inflow area by arranging the gas acceleration module, according to the Bernoulli principle (the larger the gas flow velocity is, the smaller the pressure intensity is), the positive pressure difference is generated between the gas inlet channel end and the gas outlet channel end which are close to each other in original pressure intensity through the speed change, and the gas flow velocity of the gas inlet channel end is driven to be increased by the pressure intensity difference generated at the two ends. Thereby, the exhaust resistance at the end of the air inlet channel is relieved, the rotation speed of the rotor of the vacuum pump is reduced, the excessive abrasion of the vacuum pump is prevented, and the service life of the vacuum pump is prolonged.

The decompression vacuum pump accelerates the gas flow speed at the end of the gas inlet channel and reduces the gas pressure at the end of the gas inlet channel through the decompression device of the vacuum pump. Along with the reduction of the gas pressure at the exhaust end of the vacuum pump, the exhaust resistance of the vacuum pump is reduced at the same time, so that the rotation speed of the rotor of the vacuum pump is reduced, the excessive abrasion of the vacuum pump is prevented, and the service life of the vacuum pump is prolonged.

Drawings

FIG. 1 is a block diagram showing a structure of a vacuum pump pressure reducing apparatus according to an embodiment;

FIG. 2 is a schematic cross-sectional view of a decompression chamber in one embodiment;

FIG. 3 is a schematic cross-sectional view of a decompression chamber in another embodiment;

FIG. 4 is a schematic view of the vacuum pump;

FIG. 5 is a schematic illustration of the main pump pressure of a vacuum pump in a conventional method of use;

FIG. 6 is a schematic illustration of a main pump pressure of a vacuum pump coupled to a vacuum pump pressure reduction device in one embodiment;

fig. 7 is a block diagram showing the structure of a decompression vacuum pump in one embodiment.

Detailed Description

To facilitate an understanding of the invention, the invention will now be described more fully with reference to the accompanying drawings. Alternative embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

Fig. 1 is a block diagram showing a vacuum pump pressure reducing device according to an embodiment.

In the present embodiment, the vacuum pump decompression device is provided with an intake passage end 110, a decompression chamber 120, and an exhaust passage end 130.

A decompression chamber 120, said decompression chamber 120 connecting said intake passage end 110 and said exhaust passage end 130. As shown in fig. 2, a predetermined airflow path 122 is provided in the decompression chamber, the gas output from the inlet channel end 110 enters the outlet channel end 130 along the predetermined airflow path 122, and a positive pressure difference exists between the inlet channel end 110 and the outlet channel end 130.

The shape of the decompression chamber 120 is not limited, and may be a regular shape such as a spherical shape, a cylindrical shape, or a rectangular shape, or an irregular shape such as a special shape. The gas volume of the decompression chamber 120 is matched with the caliber of the gas inlet passage end 110 and the pumping speed of the vacuum pump, and in practical use, the shape and the size of the decompression chamber 120 can be selected according to the use environment and the decompression requirement.

And an exhaust channel end 130 for connecting the tail gas collecting device, so that the decompression chamber 120 is communicated with the tail gas collecting device, and the gas in the decompression chamber 120 is exhausted. The caliber of the exhaust channel end 130 is equivalent to the caliber of the intake channel end 110, and the exhaust channel end 130 is movably connected with the exhaust gas collecting device, and specifically can be one of threaded connection, snap connection and riveting.

In the embodiment shown in fig. 2, a baffle 121 is disposed in the cavity of the decompression chamber 120, the baffle 121 is disposed between the intake channel end 110 and the exhaust channel end 130, and is used for defining the predetermined gas flow path 122 and dividing the predetermined gas flow path 122 into a gas inflow region 123 near the intake channel end and a gas acceleration region 124 near the exhaust channel end. The baffle 121 and the inner wall of the decompression chamber 120 are partially connected and partially spaced to communicate the gas inflow region 123 with the gas acceleration region 124, and the gas can flow from the gas inflow region 123 to the gas acceleration region 124 through the communicating passages.

Further, the vacuum pump decompression device 100 further comprises a gas acceleration module 140, wherein the gas acceleration module 140 is configured to control a flow velocity of the gas in the gas acceleration region 124, and a flow velocity of the gas in the gas inflow region 123 is smaller than a flow velocity of the gas in the gas acceleration region 124.

When the gas in the gas acceleration region 124 is subjected to an external force of the gas acceleration module 140, and the gas flow speed becomes fast, the gas flow speed and the pressure in the gas acceleration region 124 satisfy the following bernoulli equation:

therefore, on the premise that the gas density rho, the gravity acceleration g and the height h of the cavity are kept unchanged, if the gas flow speed v is increased, the pressure p in the area is correspondingly reduced.

Correspondingly, in this embodiment, by providing the gas acceleration module 140, the gas flow rate in the gas acceleration region 123 is greater than the gas flow rate in the gas inflow region 124, and according to the bernoulli principle (the greater the gas flow rate, the smaller the pressure intensity), the positive pressure difference is generated between the intake channel end 110 and the exhaust channel end 130, which have originally similar pressure intensities, and the pressure difference generated therebetween drives the gas flow rate at the intake channel end 110 to increase. Thereby relieving the exhaust resistance of the intake passage end 110 and reducing the rotation rate of the rotor of the vacuum pump, thereby preventing the excessive wear of the vacuum pump and prolonging the service life of the vacuum pump.

In one embodiment, the material of the baffle 121 may be a simple metal such as copper, iron, etc., an alloy such as nickel-copper, etc., or a metal-nonmetal mixture such as stainless steel, etc. In order to realize better corrosion resistance, corresponding corrosion resistant materials can be sprayed or electroplated on the inner wall of the decompression cavity 120 and the surface of the baffle 121 according to the pH value or the pH value of the air extracted by the vacuum pump, so that the acid-base corrosion resistance of the inner wall of the decompression cavity 120 and the surface of the baffle 121 are improved, and the service life of the vacuum pump decompression device 100 is prolonged.

In one embodiment, the interior of the baffle 121 may be hollow, reticulated, or solid. The baffle 121 with the solid structure has optimal stability, and when the gas flow of the vacuum pump is large and the flow rate is high, the baffle 121 is not easy to damage. The baffle 121 with a hollow structure has the lightest weight and is suitable for scenes with small flow and the need of frequent movement of a vacuum pump and a pressure reducing device. The baffle 121 of the mesh structure can adjust the corresponding characteristics between the above two structures by adjusting the density of the mesh structure. An operator can select the baffle 121 with a corresponding structure according to an actual use scene, so that the vacuum pump pressure reduction device 100 has better scene compatibility.

In this embodiment, the baffle 121 is fixedly attached to the inner wall of the decompression chamber 120.

In one embodiment, if the baffle 121 and the decompression chamber 120 are made of the same material, they can be manufactured by one-time casting, which is simple in operation and low in cost of time and money; if the material of the baffle 121 and the decompression chamber 120 is different, the two components may be separately processed and then joined by welding such as resistance spot welding or arc welding. By choosing different manufacturing methods, greater flexibility in the choice of materials for the baffle 121 and the decompression chamber 120 is possible.

In the embodiment shown in fig. 3, the baffle 121 is movably connected to the inner wall of the decompression chamber 120. Through the swing joint structure, the working position of the baffle 121 can be adjusted, thereby being suitable for different use requirements.

In this embodiment, one end of the baffle 121 is rotatably connected with the inner wall of the decompression chamber 120 through a hinge structure 126, a locking member 127 is disposed at one end of the baffle 121 away from the hinge structure 126, and the baffle 121 is locked at a set working position by the locking member 127. One end of retaining member 127 is connected with baffle 121, and the other end supports the inner wall of decompression chamber 120, and at vacuum pump pressure relief device 100 during operation, retaining member 127 makes baffle 121 not take place to rock in the position of setting for, has guaranteed vacuum pump pressure relief device 100's even running.

In one embodiment, the inner wall of the decompression chamber 120 is provided with a groove or a bump, and when the baffle 121 is in different working positions, the locking member 127 can abut against the corresponding groove or bump, so that relative sliding between the locking member 127 and the inner wall of the decompression chamber 120 is avoided, and the stability of the baffle 121 is further improved.

In one embodiment, the material of the locking member 127 may be a simple metal such as copper, iron, etc., an alloy such as nickel-copper, etc., or a metal-nonmetal mixture such as stainless steel, etc. According to different gas flow rates of the vacuum pump, a material with proper hardness is specifically selected to prevent the locking member 127 from bending when the vacuum pump decompression device 100 works.

In one embodiment, the angle θ between the surface of the baffle 121 on the side close to the gas acceleration zone 124 and the inner wall of the decompression chamber 120 is in the range of 45 ° to 90 °, and the baffle 121 rotates within the range of the angle. If the angle between the baffle 121 and the inner wall of the decompression chamber 120 is too small, the baffle 121 cannot effectively divide the decompression chamber 120 into the gas inflow section 123 and the gas acceleration section 124, i.e., the pressure reduction at the gas inlet passage end 110 and the exhaust end of the vacuum pump cannot be achieved by accelerating the gas flow velocity at the gas acceleration section 124.

In one embodiment, the surface of the baffle 121 close to the gas inflow region 123 is an arc surface, and if foreign matters exist in the inflowing gas, when the gas reaches the baffle 121 through the gas inlet channel end 110, the arc surface prevents the foreign matters carried in the gas from splashing upwards along the baffle 121 under the obstruction of the arc surface, so that the foreign matters are prevented from reaching and blocking the output port of the gas acceleration module 140, and the normal operation of the vacuum pump pressure reducing device 100 is ensured.

In one embodiment, the baffle 121 further divides the predetermined gas flow path 122 into a gas guiding region 125, the gas guiding region 125 is located between the gas inflow region 123 and the gas acceleration region 124 for guiding the gas from the gas inflow region 123 into the gas acceleration region 124, and the gas acceleration module does not control the flow rate of the gas in the gas guiding region 125.

In the embodiment shown in fig. 3, the gas acceleration module 140 includes a gas feed 141, the gas feed 141 is in communication with the gas acceleration zone 124, and the gas outflow direction of the gas feed 141 is the same as the gas flow direction in the gas acceleration zone 124. If the gas flowing out direction of the gas delivery pipe 141 is opposite to or at a certain angle with respect to the gas flowing direction in the gas acceleration region 124, the gas in the gas acceleration region 124 cannot be accelerated most effectively, resulting in waste of the gas flowing out from the gas delivery pipe 141. In the present embodiment, the specific position of the air supply pipe 141 is not limited, and the air supply pipe 141 may satisfy the gas outflow direction.

In one embodiment, the gas outflow rate of the gas delivery pipe 141 is not less than 50 psi, and when the gas outflow rate satisfies this requirement, the vacuum pump deceleration device can make the pressure at the gas inlet channel end 110 reach a vacuum state with less gas consumption, and the gas pressure at the gas outlet end of the vacuum pump can also be reduced from 760 torr, which is the case when the vacuum pump decompression device is not installed, to 130 torr, i.e., from a state of normal atmospheric pressure to a state of near vacuum. Figure 4 is a schematic diagram of the construction of a vacuum pump comprising two parts, a booster pump and a main pump, which cooperate to achieve a desired compression ratio and a desired pumping speed, reducing power requirements. Specifically, the gas in the cavity to be evacuated is sucked into the booster pump from the air inlet end of the vacuum pump, is continuously pressurized by the rotors at all stages driven by the motor of the main pump, and is finally discharged from the air outlet end of the vacuum pump.

As shown in fig. 5, the conventional method for using the vacuum pump is to directly discharge the pumped gas to the atmosphere, and the gas pressure of the atmosphere is 760 torr, so that the exhaust resistance at the exhaust end of the vacuum pump is very high, and in order to facilitate the discharge of the gas, the gas pressure in the main pump needs to be increased from 0.06 torr at the 1-stage rotor (R1) to 130 torr at the 5-stage rotor (R5), the main pump increases the pressure continuously by increasing the rotation speed of the rotors at all stages, and the excessive rotation speed of the rotors at all stages increases the operating temperature and the loss of the main pump. In this embodiment, the extracted gas is exhausted into the vacuum pump pressure reducing device, and based on the special mechanical structure of the vacuum pump pressure reducing device, the gas pressure at the exhaust end of the vacuum pump can be reduced to 130 torr, the exhaust resistance at the exhaust end of the vacuum pump is obviously reduced, and the gas pressure and the rotating speed which need to be realized by each stage of rotor are also reduced correspondingly, specifically, as shown in fig. 6, the gas pressure at the 5-stage rotor (R5) can be reduced to 20 torr from 130 torr when the vacuum pump pressure reducing device is not connected, so as to realize the effect of reducing the loss of the vacuum pump.

In one embodiment, the gas output from the gas delivery tube 141 is an inert gas used to accelerate the gas flow velocity in the gas acceleration zone 124. Alternatively, the inert gas may be one of nitrogen, argon, helium, neon, or the like.

In one embodiment, the gas supply pipe 141 is provided with a valve 142 for controlling a gas outflow rate of the gas supply pipe 141. According to the bernoulli equation, the gas flow velocity and the pressure in the region have an inverse correlation, i.e. the higher the gas flow velocity, the lower the pressure in the region. When the pressure difference between the gas acceleration region 124 and the gas inflow region 123 changes, the spontaneous flow rate of the gas in the gas inflow region 123 into the gas acceleration region 124 also changes, and the pressure change of the corresponding inlet channel end 110 also changes, so that the pressure of the inlet channel end 110 can be adjusted by adjusting the gas outflow rate of the gas feeding pipe 141.

In the present embodiment, when the gas outflow speed of the gas feeding pipe 141 is greater than the gas flow speed of the gas inflow region 123, the pressure reduction of the gas inlet passage end 110 can be achieved. When the vacuum degree requirement of the exhaust end of the vacuum pump is low, the gas outflow speed of the gas feed pipe 141 can be slowed down by adjusting the valve 142, and the gas consumption is reduced; when the pumping speed of the vacuum pump is high, the gas outflow speed of the gas feeding pipe 141 can be increased, so that the gas flow speeds of the gas inflow region 123 and the gas acceleration region 124 are matched, and the pressure at the gas inlet channel end 110 is further reduced.

In one embodiment, the valve 142 may be an electric or pneumatic ball valve or a butterfly valve. The pneumatic valve is sensitive in response, safe and reliable, but needs to be matched with an air source for use; for the occasions where the air source is inconvenient to install; the electric valve only needs the support of a power supply, and the control system is relatively simple. By selecting different valves 142 for different scenes, the compatibility of the vacuum pump pressure reduction device 100 to different situations can be improved.

In one embodiment, the pressure reducing chamber 120 is further provided with a dust collecting region, which can be a section of the pressure reducing chamber wall with an inclined design corresponding to the overlapping region of the baffle 121 and the gas flow-in region 123, or a dust collecting assembly 151 disposed in the overlapping region of the baffle 121 and the gas flow-in region 123.

In one embodiment, the decompression chamber 120 is provided with an openable dust exhaust port 152, and the dust exhaust port 152 is attached to the dust collection assembly 151 for exhausting dust from the dust collection assembly 151. In this embodiment, an opening is formed on the side of the dust collecting assembly 151 close to the dust outlet 152, so that the foreign matters in the dust collecting assembly 151 can be effectively discharged, thereby preventing the foreign matters from being accumulated in the dust collecting assembly 151. By providing the dust exhaust port 152, the vacuum pump decompression device 100 can be suitably applied to a chamber in which gas in the decompression chamber 120 contains solid foreign matter, particularly, to a case in which the solid foreign matter is a non-sublimable solid.

In one embodiment, the dust exhaust port is provided with a transparent mirror 153. The material of the transparent mirror 153 may be one of plastic, glass, acryl, or sapphire. The surface of the transparent mirror 153 may be provided with a protective layer by one of sintering, spraying, and the like, and the material of the protective layer may be one of mylar, glass glaze, and the like. By providing the protective layer on the surface of the transparent mirror 153, the abrasion resistance and the acid and alkali resistance of the transparent mirror 153 can be improved, and the transparent mirror 153 is effectively prevented from being corroded by solid foreign matter or acid and alkali gases in the decompression chamber 120.

In one embodiment, the size of the transparent mirror 153 matches the size of the dust exhaust port 152, i.e., the dust exhaust port 152 may be shielded by the transparent mirror 153. By shielding the dust exhaust port 152, gas is prevented from flowing in through the dust exhaust port 152, and the gas environment in the decompression chamber 120 is prevented from being damaged; the harm to the operator caused by the environmental pollution or the splashed foreign matters outside the decompression chamber 120 due to the discharge of the foreign matters through the dust discharge port 152 under the condition that the operator is unknown can also be avoided.

In one embodiment, the transparent mirror 153 is movably connected to the outer wall of the decompression chamber 120, and the dust discharge port 152 is exposed by the relative movement of the transparent mirror 153 and the outer wall of the decompression chamber 120, so as to discharge the foreign matter in the decompression chamber 120. The transparent mirror 153 can be movably connected with the outer wall of the decompression chamber 120 through a roller, that is, the transparent mirror 153 can be turned up and down around the roller, when the foreign matters need to be discharged, the transparent mirror 153 is turned up to expose the dust discharge port 152, and when the foreign matters do not need to be discharged, the transparent mirror 153 is turned down to cover the discharge port. The transparent mirror 153 can also be movably connected with the outer wall of the decompression cavity 120 through a clamping groove, namely, the clamping groove with the size equivalent to that of the transparent mirror 153 is arranged on the outer wall of the decompression cavity 120, when the foreign matters need to be discharged, the transparent mirror 153 is pulled out from the clamping groove to expose the dust discharge port 152, and when the foreign matters do not need to be discharged, the transparent mirror 153 is inserted into the clamping groove to cover the discharge port.

In this embodiment, the transparent mirror 153 is used to observe the deposition of the foreign matters in the dust collecting assembly 151, so that the operator can observe the interior of the dust collecting assembly 151 through the transparent mirror 153, conveniently determine whether the deposition amount of the foreign matters in the dust collecting assembly 151 exceeds a threshold value, and timely discharge the foreign matters from the dust collecting assembly 151 through the dust discharge port 152. Further, a foreign matter deposition amount line may be provided on the transparent mirror 153 as a threshold mark, and when the foreign matter deposition amount is lower than the foreign matter deposition amount line, the foreign matter does not need to be discharged, and when the foreign matter deposition amount is higher than the foreign matter deposition amount line, the transparent mirror 153 needs to be opened in time to prevent the foreign matter from being accumulated in the dust collection assembly 151.

In one embodiment, the vacuum pump decompression device 100 further includes a dust collection bucket 154 for receiving the foreign substances discharged through the dust discharge port 152. The shape of the dust collection tub 154 is not limited, and may be a regular shape such as a cylindrical shape or a rectangular shape, or an irregular shape such as a special shape. The size of the dust collection bucket 154 can be adjusted accordingly according to the size of the decompression chamber 120 and the suction amount of the vacuum pump.

In one embodiment, in order to prevent the dust collecting barrel 154 from being corroded by the foreign matters, the dust collecting barrel 154 may be made of a corrosion-resistant material according to the processing material and the process of the vacuum pump connected to the vacuum pump decompression device 100, or the surface of the dust collecting barrel 154 may be coated or plated with the corrosion-resistant material, so as to effectively prevent the dust collecting barrel 154 from being corroded and damaged to cause the leakage of the foreign matters.

In the embodiment shown in fig. 7, there is also provided a reduced-pressure vacuum pump including the vacuum pump pressure reducing device 100 and the vacuum pump 200 as described above, wherein the inlet passage end 110 of the vacuum pump pressure reducing device 100 is connected to the outlet end of the vacuum pump 200.

In the vacuum pump, the vacuum pump pressure reducing device 100 reduces the gas pressure at the exhaust end of the vacuum pump 200. As the gas pressure at the exhaust end of the vacuum pump 200 decreases, the exhaust resistance of the vacuum pump 200 also decreases at the same time, so that the rotation rate of the rotor of the vacuum pump 200 decreases, thereby preventing excessive wear of the vacuum pump 200 and extending the service life of the vacuum pump 200. Meanwhile, by reducing the rotation rate of the rotor, the vacuum pump in the embodiment can save 30% to 70% of electric power and 50% of cooling water.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.