US20160265532A1 - Vacuum pump - Google Patents
Vacuum pump Download PDFInfo
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- US20160265532A1 US20160265532A1 US15/062,380 US201615062380A US2016265532A1 US 20160265532 A1 US20160265532 A1 US 20160265532A1 US 201615062380 A US201615062380 A US 201615062380A US 2016265532 A1 US2016265532 A1 US 2016265532A1
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- Prior art keywords
- vacuum pump
- rotors
- rotor chamber
- disposed
- stage
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C27/00—Sealing arrangements in rotary-piston pumps specially adapted for elastic fluids
- F04C27/005—Axial sealings for working fluid
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B37/00—Pumps having pertinent characteristics not provided for in, or of interest apart from, groups F04B25/00 - F04B35/00
- F04B37/10—Pumps having pertinent characteristics not provided for in, or of interest apart from, groups F04B25/00 - F04B35/00 for special use
- F04B37/14—Pumps having pertinent characteristics not provided for in, or of interest apart from, groups F04B25/00 - F04B35/00 for special use to obtain high vacuum
- F04B37/16—Means for nullifying unswept space
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C25/00—Adaptations of pumps for special use of pumps for elastic fluids
- F04C25/02—Adaptations of pumps for special use of pumps for elastic fluids for producing high vacuum
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C18/00—Rotary-piston pumps specially adapted for elastic fluids
- F04C18/08—Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing
- F04C18/12—Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type
- F04C18/123—Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type with radially or approximately radially from the rotor body extending tooth-like elements, co-operating with recesses in the other rotor, e.g. one tooth
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C18/00—Rotary-piston pumps specially adapted for elastic fluids
- F04C18/08—Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing
- F04C18/12—Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type
- F04C18/126—Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type with radially from the rotor body extending elements, not necessarily co-operating with corresponding recesses in the other rotor, e.g. lobes, Roots type
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C29/00—Component parts, details or accessories of pumps or pumping installations, not provided for in groups F04C18/00 - F04C28/00
- F04C29/0092—Removing solid or liquid contaminants from the gas under pumping, e.g. by filtering or deposition; Purging; Scrubbing; Cleaning
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C29/00—Component parts, details or accessories of pumps or pumping installations, not provided for in groups F04C18/00 - F04C28/00
- F04C29/12—Arrangements for admission or discharge of the working fluid, e.g. constructional features of the inlet or outlet
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C2280/00—Arrangements for preventing or removing deposits or corrosion
- F04C2280/02—Preventing solid deposits in pumps, e.g. in vacuum pumps with chemical vapour deposition [CVD] processes
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C23/00—Combinations of two or more pumps, each being of rotary-piston or oscillating-piston type, specially adapted for elastic fluids; Pumping installations specially adapted for elastic fluids; Multi-stage pumps specially adapted for elastic fluids
- F04C23/001—Combinations of two or more pumps, each being of rotary-piston or oscillating-piston type, specially adapted for elastic fluids; Pumping installations specially adapted for elastic fluids; Multi-stage pumps specially adapted for elastic fluids of similar working principle
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Applications Or Details Of Rotary Compressors (AREA)
Abstract
There is provided a vacuum pump capable of preventing foreign materials from flowing into a gap between rotors or the like and obtaining low ultimate pressure. The vacuum pump includes two rotating shafts formed extending in a first axial direction, a rotor casing, rotors, and a shielding portion. The rotor casing includes a rotor chamber disposed along the two rotating shafts, a suction port communicating with the rotor chamber, and an exhaust port communicating with the rotor chamber. The rotors are mounted on the two rotating shafts and disposed in the rotor chamber. The shielding portion is configured to prevent a gas sucked from the suction port into the rotor chamber from directly flowing into a gap between the rotors and is disposed between the suction port and inside the rotor chamber.
Description
- This application claims priority to Japanese Application Nos. 2015-046274, filed Mar. 9, 2015 and 2016-018054, filed Feb. 2, 2016, the entire contents of which are hereby incorporated by reference.
- The present invention relates to a vacuum pump.
- In a fabrication process of a semiconductor device and a liquid crystal device, a dry vacuum pump is connected to a vacuum chamber to exhaust a process gas introduced into the vacuum chamber by the vacuum pump. The process gas to be exhausted by the vacuum pump may include a material solidified by reaction or the like inside the vacuum chamber or an easily solidified material mixed in as a foreign material.
- The dry vacuum pump is designed to have a small gap (clearance) between a rotor and a rotor or between a rotor and a casing. Accordingly, when solidified materials enter inside the pump, the solidified materials may be deposited or trapped in a gap therebetween inside the pump, which may block rotor rotation. For this reason, a suction port of the dry vacuum pump may include a trap or a filter to prevent solidified materials from entering inside the pump.
- [Patent Literature 1] Japanese Patent Laid-Open No. 5-332285.
- When a process gas is prevented from entering the suction port of the dry vacuum pump, the ultimate pressure of the vacuum chamber connected to the dry vacuum pump will increase. Therefore, a trap or the like disposed in the suction port of the dry vacuum pump is configured to comprise a large trap or a plurality of stages of traps, and such a configuration causes an increase in size and cost of the fabrication apparatus. In addition, solidified materials deposited in the trap or the like causing clogging also prevent the dry vacuum pump from sucking the process gas, which may often require maintenance such as cleaning and replacement of the trap or the like.
- In addition, as the dry vacuum pump, there have been known a screw type vacuum pump, a roots type vacuum pump, and a claw type vacuum pump. In general, the screw type vacuum pump is less affected by foreign materials than the roots type vacuum pump and the claw type vacuum pump. However, particularly in cases where light gases such as hydrogen are used as the process gas, the roots type vacuum pump and the claw type vacuum pump can have a lower ultimate pressure than the screw type vacuum pump.
- In view of the above problems, an embodiment has been made, and an object of the embodiment is to provide a vacuum pump that can prevent foreign materials from entering into gaps such as between rotors and can have low ultimate pressure.
- The vacuum pump of an embodiment includes two rotating shafts formed extending in a first axial direction; a rotor casing; rotors; and a shielding portion. The rotor casing includes a rotor chamber disposed along the two rotating shafts; a suction port communicating with the rotor chamber; and an exhaust port communicating with the rotor chamber. The rotors are mounted on the two rotating shafts and disposed in the rotor chamber. The shielding portion is configured to prevent a gas sucked from the suction port into the rotor chamber from directly flowing into a gap between the rotors and is disposed between the suction port and inside the rotor chamber.
- According to this vacuum pump, the shielding portion is disposed between the suction port and inside the rotor chamber. This shielding portion prevents a gas sucked from the suction port into the rotor chamber from directly flowing into a gap between rotors. Thus, foreign materials can be prevented from being deposited or trapped in gaps between rotors.
- In addition, the rotors may be roots type rotors or claw type rotors.
- This configuration can achieve low ultimate pressure by the vacuum pump particularly in cases where light gases such as hydrogen are used as the process gas.
- In addition, when viewed from the suction port toward inside the rotor chamber, the shielding portion may be disposed in front of a gap between the rotors.
- This configuration can prevent foreign materials from directly flowing into the gap between the rotors.
- In addition, the shielding portion may be disposed upstream of the rotors and may be disposed between the two rotating shafts when viewed from the suction port toward inside the rotor chamber.
- This configuration can prevent foreign materials from directly flowing into the gap between the rotors.
- In addition, the shielding portion may have a tapered shape narrow on an upstream side and wide on a downstream side. The shielding portion may also have a curved surface shape protruding toward upstream.
- This configuration can effectively prevent foreign materials from directly flowing into the gap between the rotors.
- In addition, the rotor chamber may comprise multistage rotor chambers connected to each other through a gas flow path. The rotors may comprise multistage rotors, each disposed in each of the multistage rotor chambers. The shielding portion may be disposed between the suction port and inside a first stage rotor chamber of the multistage rotor chambers.
- This configuration can prevent foreign materials from directly flowing into the gap between the rotors inside the first stage rotor chamber.
- In addition, the vacuum pump may further comprise a foreign material capture unit having at least one of a trap and a filter disposed in the gas flow path connecting between stages of the multistage rotor chambers.
- This configuration allows the foreign material capture unit in the gas flow path to capture foreign materials contained in the gas. In addition, the foreign material capture unit for capturing foreign materials is disposed between stages of the multistage rotor chambers, and hence the foreign material capture unit does not prevent suction from the vacuum chamber to the first stage rotor chamber, whereby low ultimate pressure can be obtained. In addition, the foreign material capture unit is disposed downstream of the first stage rotor chamber whose pressure is greater than that of the suction port, thus allowing a simply configured foreign material capture unit to be used. Furthermore, even if foreign materials are deposited in the foreign material capture unit, this little affects the suction of the first stage rotor chamber, thus reducing frequency of maintenance of the foreign material capture unit.
- In addition, the foreign material capture unit may be disposed in the gas flow path connecting between the first stage rotor chamber and a next stage rotor chamber of the multistage rotor chambers.
- The gap between the rotor casing and the multistage rotors or the gap between the multistage rotors in each of the multistage rotor chambers downstream of the foreign material capture unit may be formed smaller than the gap therebetween upstream thereof.
- This configuration can prevent foreign materials from being deposited or trapped upstream than the foreign material capture unit and allows the vacuum pump to achieve low ultimate pressure.
- In addition, the vacuum pump may further comprise a pressure sensor disposed in the gas flow path upstream of the foreign material capture unit for detecting a pressure.
- This configuration can measure timing of maintenance of the foreign material capture unit based on the detection of the pressure sensor.
- In addition, the foreign material capture unit may comprise a reticulated or porous filter.
- This configuration can suitably capture foreign materials flowing through the gas flow path.
- In addition, the suction port may be connected to a chamber where a gas containing non-sublimated foreign materials occurs.
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FIG. 1 is a schematic configuration view illustrating a vacuum pump apparatus according to the present embodiment; -
FIG. 2 is a schematic configuration view of the vacuum pump apparatus according to the present embodiment; -
FIG. 3 is a sectional view schematically illustrating inside of a first stage rotor chamber according to the present embodiment; -
FIG. 4 is a sectional view schematically illustrating inside of a second stage rotor chamber according to the present embodiment; -
FIG. 5 is a schematic view illustrating an example of a foreign material capture unit; -
FIG. 6 is a schematic view illustrating another example of the foreign material capture unit; -
FIG. 7 is a schematic configuration view illustrating a vacuum pump apparatus according to a first modification; and -
FIG. 8 is a block diagram schematically illustrating a vacuum pump apparatus according to a second modification. -
FIG. 1 is a schematic configuration view illustrating a vacuum pump apparatus according to the present embodiment.FIG. 2 is a detailed configuration view of the vacuum pump apparatus according to the present embodiment. The vacuum pump apparatus according to the present embodiment is connected, for example, to a vacuum chamber (unillustrated) where CVD processing is performed and exhausts gas from the vacuum chamber. The vacuum pump apparatus according to the present embodiment can be suitably used for a vacuum chamber where a gas inside the vacuum chamber contains solid foreign materials, particularly in cases where the solid foreign materials are non-sublimated, but is not limited to this. In addition, the vacuum pump apparatus according to the present embodiment can be suitably used for a vacuum chamber where light gases such as hydrogen occur, but is not limited to this. -
FIG. 1 illustrates a cross section of avacuum pump apparatus 100 including an axial line AR1 of apump rotor 310 of a pair ofpump rotors FIG. 2 illustrates a cross section of thevacuum pump apparatus 100 including axial lines AR1 and AR2 as respective rotational centers of the pair ofpump rotors pump rotor 310 is omitted fromFIG. 1 for ease of illustration. Note also thatFIG. 1 also illustrates a block diagram of apressure sensor 620 and acontrol unit 700 constituting thevacuum pump apparatus 100. - As illustrated in
FIGS. 1 and 2 , thevacuum pump apparatus 100 includes a pair of main shafts (two rotating shafts) 300 and 400; a pair ofpump rotors motor 200; acasing 500; a foreignmaterial capture unit 600; apressure sensor 620; and acontrol unit 700. - The
main shafts main shafts casing 500 bybearings main shafts main shafts motor 200. Thepump rotors main shafts main shafts - The pair of
pump rotors pump rotor 310 includes a first stage rotor (initial stage rotor) 312, a second stage rotor (next stage rotor) 314, and a third stage rotor 316 (last stage rotor), which are mounted, spaced apart, on themain shaft 300. In addition, thepump rotor 410 includes a first stage rotor (initial stage rotor) 412, a second stage rotor (next stage rotor) 414, and a third stage rotor (last stage rotor) 416, which are mounted, spaced apart, on themain shaft 400. - The
casing 500 includes amultistage rotor chamber 520, asuction port 510, anexhaust port 540, andgas flow paths casing 500 also includes a shieldingportion 580 disposed between thesuction port 510 and inside the firststage rotor chamber 522, namely, upstream of thefirst stage rotors - The
multistage rotor chamber 520 includes a first stage rotor chamber (initial stage rotor chamber) 522, a second stage rotor chamber (next stage rotor chamber) 524, and a third stage rotor chamber (last stage rotor chamber) 526. The firststage rotor chamber 522, the secondstage rotor chamber 524, and the thirdstage rotor chamber 526 store thefirst stage rotors second stage rotors third stage rotors pump rotors stage rotor chamber 522 communicates with thesuction port 510 connected to a vacuum chamber (unillustrated), and the thirdstage rotor chamber 526 communicates with theexhaust port 540. In addition, the firststage rotor chamber 522 is connected to the secondstage rotor chamber 524 through thegas flow path 530 disposed on an outer peripheral side of therotor chamber 520. Likewise, the secondstage rotor chamber 524 is connected to the thirdstage rotor chamber 526 through thegas flow path 532 disposed on the outer peripheral side of therotor chamber 520. According to such a configuration, when a process gas is introduced from thesuction port 510 into the firststage rotor chamber 522, then the process gas is passed through thegas flow path 530, the secondstage rotor chamber 524, thegas flow path 532, the thirdstage rotor chamber 526, in that order, and finally exhausted outside from theexhaust port 540. -
FIG. 3 is a sectional view schematically illustrating the inside of the first stage rotor chamber according to the present embodiment.FIG. 3 illustrates a cross section perpendicular to the axial lines AR1 and AR2 inside the firststage rotor chamber 522. Thefirst stage rotors stage rotor chamber 522. Minute gaps CF1 and CF2 are formed between thefirst stage rotors first stage rotors casing 500, respectively. As themain shafts first stage rotors suction port 510. At this time, the gas is pumped so as to pass through between thefirst stage rotors casing 500 without passing through between thefirst stage rotors 312 and 412 (see bold arrows inFIG. 3 ). - A gas inlet to the
first stage rotors portion 580. When viewed from thesuction port 510 to a gas outlet of the first stage rotor chamber 522 (viewed along a direction AD inFIG. 3 ), the shieldingportion 580 is disposed so as to cover a gap CF1 (seal portion) between thefirst stage rotors suction port 510 to the gas outlet of the firststage rotor chamber 522, the shieldingportion 580 is disposed between themain shafts portion 580 is preferably formed so that a boundary between thefirst stage rotors suction port 510 to the gas outlet of the firststage rotor chamber 522. The shieldingportion 580 may be formed integrally with thecasing 500, or the shieldingportion 580 may be made of materials different from those of thecasing 500 and assembled into thecasing 500. - The shielding
portion 580 guides the gas sucked from thesuction port 510 into the firststage rotor chamber 522 in a direction away from the gap CF1 between thefirst stage rotors portion 580 may be designed so as to suitably guide the gas. For example, the shieldingportion 580 may be made of a tapered shaped member narrow on the upstream side and wide on the downstream or may be made of a curved surface shaped member protruding toward upstream. The thus made shieldingportion 580 can prevent the gas sucked from thesuction port 510 into the firststage rotor chamber 522 from directly flowing into the gap CF1 between thefirst stage rotors first stage rotors first stage rotors first stage rotors casing 500. In contrast to this, according to the present embodiment, the shieldingportion 580 can prevent foreign materials from being trapped in the gap CF1 between thefirst stage rotors vacuum pump apparatus 100. -
FIG. 4 is a sectional view schematically illustrating the inside of the second stage rotor chamber according to the present embodiment. Note thatFIG. 1 is a sectional view along line I-I ofFIGS. 3 and 4 . As illustrated inFIGS. 3 and 4 , thesecond stage rotors stage rotor chamber 524 in the same manner as in the firststage rotor chamber 522. In addition, minute gaps CL1 and CL2 are formed between thesecond stage rotors second stage rotors casing 500. - Here, according to the present embodiment, the gap CL1 between the
second stage rotors stage rotor chamber 524 is smaller than the gap CF1 between thefirst stage rotors stage rotor chamber 522. In other words, the gap CF1 between thefirst stage rotors second stage rotors first stage rotors portion 580. The reason for this is also based on findings that even a larger gap CF1 of the firststage rotor chamber 522 to be connected to the vacuum chamber little affects the performance of thevacuum pump apparatus 100. Therefore, the above described configuration can secure the performance of thevacuum pump apparatus 100 and can further prevent foreign materials from being deposited or trapped in the gap CF1 between thefirst stage rotors - Further, according to the present embodiment, the gap CL2 between the
second stage rotors casing 500 in the secondstage rotor chamber 524 is smaller than the gap CF2 between thefirst stage rotors casing 500 in the firststage rotor chamber 522. In other words, the gap CF2 between thefirst stage rotors casing 500 is formed larger than the gap CL2 between thesecond stage rotors casing 500. The above described configuration can secure the performance of thevacuum pump apparatus 100 and can remarkably prevent foreign materials from being deposited or trapped in the firststage rotor chamber 522. Note that according to the present embodiment, a gap in the thirdstage rotor chamber 526 located downstream from the foreignmaterial capture unit 600 is also formed smaller than the gaps CF1 and CF2 in the firststage rotor chamber 522 in the same manner as the gaps CL1 and CL2 in the secondstage rotor chamber 524. - Now, refer back to
FIG. 1 . The foreignmaterial capture unit 600 captures foreign materials (for example, solidified materials) contained in the process gas. As illustrated inFIG. 1 , the foreignmaterial capture unit 600 is disposed in thegas flow path 530 connecting the firststage rotor chamber 522 and the secondstage rotor chamber 524. More specifically, the gas exhausted from the firststage rotor chamber 522 is passed through the foreignmaterial capture unit 600 and flowed into the secondstage rotor chamber 524. - For example, as illustrated in
FIG. 5 , the foreignmaterial capture unit 600 includes acylindrical casing 640 and afilter 650 stored in thecasing 640. Thefilter 650 may be made of porous or reticulated materials. Thefilter 650 may be designed so that foreign materials contained in the process gas are suitably captured and the resistance in passing through thefilter 650 is in an acceptable range. For example, thefilter 650 may be made of porous materials having holes smaller than foreign materials based on the foreign materials contained in the process gas. In addition, the foreignmaterial capture unit 600 may include a plurality of stages of filters with small resistance so as to reduce the resistance of the process gas passing therethrough. In addition, as illustrated inFIG. 6 , the foreignmaterial capture unit 600 may include acasing 640 and a plurality offilters 660 each having ahole 662. In the example illustrated inFIG. 6 , thefilters 660 are stored in thecylindrical casing 640 so that eachhole 662 is disposed at different positions with respect to the flow direction of the process gas. In the example illustrated inFIG. 6 , onehole 662 is formed for eachfilter 660, but two ormore holes 662 may be formed. In this case, for example, eachfilter 660 may be stored in thecylindrical casing 640 so that eachhole 662 is disposed at different positions betweenadjacent filters 660 with respect to the flow direction of the process gas. - The
pressure sensor 620 is disposed upstream of the foreignmaterial capture unit 600 to detect a pressure of thegas flow path 530. More specifically, thepressure sensor 620 is disposed between the firststage rotor chamber 522 and the foreignmaterial capture unit 600. Thepressure sensor 620 is configured to detect an exhaust pressure of the firststage rotor chamber 522 and a suction pressure of the foreignmaterial capture unit 600. Thepressure sensor 620 sends the detected pressure signal of thegas flow path 530 to thecontrol unit 700. - The
control unit 700 not only controls the overall operation of thevacuum pump apparatus 100 but also functions as adata storage unit 710, adata analysis unit 720, and anotification unit 730. According to the present embodiment, thecontrol unit 700 is configured as an information processing apparatus having a CPU and a memory; and when the CPU executes programs stored in the memory, thecontrol unit 700 performs the required functions. Note that at least some of the functions of thecontrol unit 700 may be implemented by a dedicated hardware circuit. Note also that each function of thecontrol unit 700 may be distributed across two or more devices. - The
data storage unit 710 receives a detection signal from thepressure sensor 620 and stores the detection signal for a predetermined period of time. Thedata storage unit 710 stores an initial value of a pressure detected by thepressure sensor 620. The initial value is a value actually detected by thepressure sensor 620 during rated operation while thevacuum pump apparatus 100 is operating in a state in which there is no foreign material inside the foreignmaterial capture unit 600, or at a time of replacement or maintenance of the foreignmaterial capture unit 600. The initial value may be measured or stored before thevacuum pump apparatus 100 is shipped or after thevacuum pump apparatus 100 is installed at a location to be used (for example at a test operation). Note that the initial value may be a predesigned value. - Based on the detection signal from the
pressure sensor 620, thedata analysis unit 720 analyzes the deposition state of foreign materials in the foreignmaterial capture unit 600. According to the present embodiment, thedata analysis unit 720 determines whether or not a pressure detection value stored for a predetermined period of time (for example, one hour) in thedata storage unit 710 is different by a predetermined degree from the initial value stored in thedata storage unit 710. If a determination is made that at least one of the pressure detection values is different by the predetermined degree from the initial value, thedata analysis unit 720 determines that the foreignmaterial capture unit 600 needs to be replaced or maintained. Note that thedata analysis unit 720 may use an average value instead of or in addition to an instantaneous value for analysis. - The
notification unit 730 notifies of the analysis results by thedata analysis unit 720. The notification may be performed by any method such that thecontrol unit 700 itself may issue an alarm by sound or screen display or may send an alarm signal to a central control room. The user of thevacuum pump apparatus 100 can measure the timing of replacement or maintenance of the foreignmaterial capture unit 600 based on the notification of thenotification unit 730. - In the
vacuum pump apparatus 100, when themotor 200 is driven, thetiming gear 380 and thepump rotor 310 are rotatably driven. When the timing gears 380 and 480 are engaged with each other, thepump rotor 410 is also rotatably driven. The pair ofpump rotors rotor chamber 520, and between thefirst stage rotors second stage rotors third stage rotors pump rotors suction port 510 is pumped and sent by thefirst stage rotors second stage rotors third stage rotors exhaust port 540. - According to the
vacuum pump apparatus 100 of the above described present embodiment, the reticulated or porous foreignmaterial capture unit 600 for capturing foreign materials contained in the process gas is disposed in thegas flow path 530 between the firststage rotor chamber 522 and the secondstage rotor chamber 524. Thus, the foreignmaterial capture unit 600 does not prevent suction from the vacuum chamber to the firststage rotor chamber 522. Therefore, thevacuum pump apparatus 100 can reduce the ultimate pressure inside the vacuum chamber. In addition, the foreignmaterial capture unit 600 is disposed downstream of the firststage rotor chamber 522 whose pressure is greater than that of thesuction port 510, thus allowing a simply configured foreignmaterial capture unit 600 to be used. Furthermore, even if foreign materials are deposited in the foreignmaterial capture unit 600, this little affects the suction of the firststage rotor chamber 522, thus reducing frequency of maintenance of the foreignmaterial capture unit 600. - In addition, according to the
vacuum pump apparatus 100 of the present embodiment, the foreignmaterial capture unit 600 is disposed in thegas flow path 530 connecting themultistage rotor chamber 520 along the two rotating shafts. Thus, for example, a system for connecting a main pump at a subsequent stage of a booster pump can reduce the number of elements constituting the system in comparison with a system for providing the foreignmaterial capture unit 600 between the booster pump and the main pump. Therefore, the present embodiment can provide a simplified configuration including the control system and thus can provide an inexpensive and compact configuration. - Furthermore, according to the
vacuum pump apparatus 100 of the present embodiment, thepressure sensor 620 is disposed between the foreignmaterial capture unit 600 and the firststage rotor chamber 522, and hence the timing of maintenance of the foreignmaterial capture unit 600 can be measured based on the detection of thepressure sensor 620. - In addition, the
vacuum pump apparatus 100 of the present embodiment includes the shieldingportion 580 which covers the gap between thefirst stage rotors suction port 510 to a gas outlet (exhaust port) of the firststage rotor chamber 522. Thus, the shieldingportion 580 can prevent foreign materials from directly flowing into the gap CF1 between thefirst stage rotors vacuum pump apparatus 100. - The
vacuum pump apparatus 100 of the above embodiment has been described as a roots type vacuum pump apparatus, but may be a claw type vacuum pump apparatus. In addition, thevacuum pump apparatus 100 has been described to have three compression stages but may be a multistage vacuum pump apparatus having two or four or more compression stages, or may be a vacuum pump apparatus having a single compression stage instead of a plurality of compression stages. - The
vacuum pump apparatus 100 of the above embodiment has been described to provide the foreignmaterial capture unit 600 in thegas flow path 530 between the firststage rotor chamber 522 and the secondstage rotor chamber 524. However, the foreignmaterial capture unit 600 may be disposed in a gas flow path connecting between the stages in themultistage rotor chamber 520. For example, as illustrated by avacuum pump apparatus 100A of a modification inFIG. 7 , a foreign material capture unit 600A may be disposed in thegas flow path 532 between the secondstage rotor chamber 524 and the thirdstage rotor chamber 526. The reason for this is based on findings that even an increase in gap upstream near the vacuum chamber between thecasing 500 and thepump rotors rotor chamber 520 or a gap between thepump rotors pump apparatus 100A. Therefore, the design may be such that the foreign material capture unit 600A is disposed in the gas flow path between the stages in themultistage rotor chamber 520, and thereby foreign materials little affect the upstream side from the foreign material capture unit 600A and may secure the performance of thepump apparatus 100A on the downstream side. - The
vacuum pump apparatus 100 of the above embodiment has been described, focusing on themultistage pump rotors rotor chamber 520 along the twomain shafts material capture unit 600 may be disposed in a vacuum pump system having a plurality of compression stages for vacuum pumping the vacuum chamber.FIG. 8 is a block diagram schematically illustrating a vacuum pump system according to another modification. As illustrated inFIG. 8 , a vacuum pump system 100B includes a plurality of compression stages 20 for vacuum pumping thevacuum chamber 10. The foreignmaterial capture unit 600 is disposed in agas flow path 40 between afirst compression stage 20A and anext compression stage 20B connected to thevacuum chamber 10. Here, thefirst compression stage 20A may be a first pump apparatus (for example, a booster pump), and the compression stage following the next stage may be a second pump apparatus (for example, a main pump) having a plurality of compression stages. The above configuration can also exert similar effects to the above described embodiments. - The
vacuum pump apparatus 100 of the above embodiment has been described such that the foreignmaterial capture unit 600 has the reticulated orporous filter 650. However, the foreignmaterial capture unit 600 is not limited to the above embodiment, but may have at least one of a trap and a filter. In addition, the foreignmaterial capture unit 600 may be made of a material such as a nonwoven fabric having irregularly formed holes. - The
vacuum pump apparatus 100 of the above embodiment has been described such that thecontrol unit 700 notifies of the timing of maintenance of the foreignmaterial capture unit 600 based on the detection signal from thepressure sensor 620, but only the detection value of thepressure sensor 620 may be stored or notified of. Alternatively, instead of providing thepressure sensor 620, the timing of maintenance of the foreignmaterial capture unit 600 may be analyzed based on the ultimate pressure of the vacuum chamber or the like. Still alternatively, the maintenance of the foreignmaterial capture unit 600 may be performed for each predetermined period of time. - The
vacuum pump apparatus 100 of the above embodiment has been described such that the shieldingportion 580 is disposed upstream of thefirst stage rotors portion 580 may not be disposed. In addition, the shieldingportion 580 may be applied to a single stage vacuum pump apparatus. In addition, the shieldingportion 580 may be disposed only between thesuction port 510 and the inside of the firststage rotor chamber 522, or may be disposed upstream of themultistage rotor chamber 520, for example, as illustrated inFIG. 7 . Furthermore, as illustrated inFIG. 7 , the shieldingportion 580 is disposed in therotor chamber 520 located upstream from the foreign material capture unit 600 (see the shieldingportions rotor chamber 520 downstream. - The
vacuum pump apparatus 100 of the above embodiment has been described such that the gap CL1 between thesecond stage rotors first stage rotors pump rotors 310 and 410 (in the direction perpendicular to the axial lines AR1 and AR2 of themain shafts 300 and 400), the gap CL2 between thesecond stage rotors casing 500 is smaller than the gap CF2 between thefirst stage rotors casing 500. However, the configuration is not limited to this embodiment. For example, the gap CL2 between thesecond stage rotors casing 500 in a direction of the axial lines AR1 and AR2 of themain shafts first stage rotors FIG. 2 ). In addition, at least one of the gap CF1 between thefirst stage rotors first stage rotors casing 500 may be larger than the gap CL1 between thesecond stage rotors second stage rotors casing 500. The above configuration can also exert similar effects to thevacuum pump apparatus 100 of the above embodiments. - Hereinbefore, the embodiments of the present invention have been described. The embodiments of the invention described above are intended to facilitate understanding of the present invention, but not to limit the present invention. It is readily understood that the present invention can be modified or improved without departing from the spirit thereof, and that the present invention encompasses equivalents thereof. It should be noted that within a range capable of solving at least some of the above described problems or within a range of exerting at least some of the effects, any combination of embodiments and modifications can be used and any combination of the components described in the scope of claims and the description can be used or can be omitted.
-
- 10 vacuum chamber
- 20 plurality of compression stages
- 20A first compression stage
- 20B next compression stage
- 40 gas flow path
- 100 vacuum pump
- 300, 400 main shaft
- 310, 410 pump rotor
- 312, 412 first stage rotor
- 314, 414 second stage rotor
- 316, 416 third stage rotor
- 500 casing
- 510 suction port
- 520 rotor chamber
- 522 first stage rotor chamber
- 524 second stage rotor chamber
- 526 third stage rotor chamber
- 530, 532 gas flow path
- 540 exhaust port
- 580 shielding portion
- 600 foreign material capture unit
- 620 pressure sensor
- 640 casing
- 650 filter
- 660 filter
- 662 hole
- 700 control unit
Claims (13)
1. A vacuum pump comprising:
two rotating shafts formed extending in a first axial direction;
a rotor casing including a rotor chamber disposed along the two rotating shafts, a suction port communicating with the rotor chamber, and an exhaust port communicating with the rotor chamber;
rotors mounted on the two rotating shafts and disposed in the rotor chamber; and
a shielding portion configured to prevent a gas sucked from the suction port into the rotor chamber from directly flowing into a gap between the rotors and disposed between the suction port and inside the rotor chamber.
2. The vacuum pump according to claim 1 , wherein
the rotors are roots type rotors or claw type rotors.
3. The vacuum pump according to claim 1 , wherein
when viewed from the suction port toward inside the rotor chamber, the shielding portion is disposed in front of a gap between the rotors.
4. The vacuum pump according to claim 1 , wherein
the shielding portion is disposed upstream of the rotors and is disposed between the two rotating shafts when viewed from the suction port toward inside the rotor chamber.
5. The vacuum pump according to claim 1 , wherein
the shielding portion has a tapered shape narrow on an upstream side and wide on a downstream side.
6. The vacuum pump according to claim 1 , wherein
the shielding portion has a curved surface shape protruding toward upstream.
7. The vacuum pump according to claim 1 , wherein
the rotor chamber comprises multistage rotor chambers connected to each other through a gas flow path,
the rotors comprise multistage rotors, each disposed in each of the multistage rotor chambers, and
the shielding portion is disposed between the suction port and inside a first stage rotor chamber of the multistage rotor chambers.
8. The vacuum pump according to claim 7 , further comprising
a foreign material capture unit having at least one of a trap and a filter disposed in the gas flow path connecting between stages of the multistage rotor chambers.
9. The vacuum pump according to claim 8 , wherein
the foreign material capture unit is disposed in the gas flow path connecting between the first stage rotor chamber and a next stage rotor chamber of the multistage rotor chambers.
10. The vacuum pump according to claim 8 , wherein
the gap between the rotor casing and the multistage rotors or the gap between the multistage rotors in each of the multistage rotor chambers downstream of the foreign material capture unit is formed smaller than the gap therebetween upstream thereof.
11. The vacuum pump according to claim 8 , further comprising
a pressure sensor disposed in the gas flow path upstream of the foreign material capture unit for detecting a pressure.
12. The vacuum pump according to claim 8 , wherein
the foreign material capture unit comprises a reticulated or porous filter.
13. The vacuum pump according to claim 1 , wherein
the suction port is connected to a chamber where a gas containing non-sublimated foreign materials occurs.
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2015046274 | 2015-03-09 | ||
JP2015-046274 | 2015-03-09 | ||
JP2016-018054 | 2016-02-02 | ||
JP2016018054A JP6630174B2 (en) | 2015-03-09 | 2016-02-02 | Vacuum pump |
Publications (1)
Publication Number | Publication Date |
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US20160265532A1 true US20160265532A1 (en) | 2016-09-15 |
Family
ID=56886498
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US15/062,380 Abandoned US20160265532A1 (en) | 2015-03-09 | 2016-03-07 | Vacuum pump |
Country Status (2)
Country | Link |
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US (1) | US20160265532A1 (en) |
CN (1) | CN105952614B (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR3112171A1 (en) * | 2020-10-16 | 2022-01-07 | Pfeiffer Vacuum | A method of controlling the operating power of a vacuum pump and vacuum pump |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN113389725A (en) * | 2021-07-22 | 2021-09-14 | 浙江湖井流体技术有限公司 | High stability hydrogen circulating pump |
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US1923268A (en) * | 1931-01-09 | 1933-08-22 | Amos V Jensen | Pump |
US5468132A (en) * | 1992-01-07 | 1995-11-21 | Snell (Hydro Design) Consultancy Limited | Water turbines |
US20030223896A1 (en) * | 2002-05-28 | 2003-12-04 | Denis Gilbert | Multi-chamber positive displacement fluid device |
US20140007958A1 (en) * | 2010-05-18 | 2014-01-09 | Ckd Corporation | Coupling apparatus for chemical fluid flow channel |
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GB622873A (en) * | 1947-04-10 | 1949-05-09 | Thomas Desmond Hudson Andrews | Improvements in or relating to rotary blowers |
JPS5521054Y2 (en) * | 1975-04-11 | 1980-05-21 | ||
US5439358A (en) * | 1994-01-27 | 1995-08-08 | Weinbrecht; John F. | Recirculating rotary gas compressor |
GB0515905D0 (en) * | 2005-08-02 | 2005-09-07 | Boc Group Plc | Vacuum pump |
JP5227056B2 (en) * | 2008-03-24 | 2013-07-03 | アネスト岩田株式会社 | Multistage pump |
GB2490517B (en) * | 2011-05-04 | 2017-12-13 | Edwards Ltd | Rotor for pump |
JP6110231B2 (en) * | 2013-06-27 | 2017-04-05 | 株式会社荏原製作所 | Vacuum pump system, method of reporting abnormal signs of vacuum pump |
-
2016
- 2016-03-07 US US15/062,380 patent/US20160265532A1/en not_active Abandoned
- 2016-03-08 CN CN201610131171.7A patent/CN105952614B/en active Active
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1923268A (en) * | 1931-01-09 | 1933-08-22 | Amos V Jensen | Pump |
US5468132A (en) * | 1992-01-07 | 1995-11-21 | Snell (Hydro Design) Consultancy Limited | Water turbines |
US20030223896A1 (en) * | 2002-05-28 | 2003-12-04 | Denis Gilbert | Multi-chamber positive displacement fluid device |
US20140007958A1 (en) * | 2010-05-18 | 2014-01-09 | Ckd Corporation | Coupling apparatus for chemical fluid flow channel |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR3112171A1 (en) * | 2020-10-16 | 2022-01-07 | Pfeiffer Vacuum | A method of controlling the operating power of a vacuum pump and vacuum pump |
WO2022078738A1 (en) * | 2020-10-16 | 2022-04-21 | Pfeiffer Vacuum | Method for controlling an operating power of a vacuum pump, and vacuum pump |
Also Published As
Publication number | Publication date |
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CN105952614A (en) | 2016-09-21 |
CN105952614B (en) | 2020-04-21 |
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