CA2546063A1 - Method for controlling the drive motor of a positive-displacement vacuum pump - Google Patents
Method for controlling the drive motor of a positive-displacement vacuum pump Download PDFInfo
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- CA2546063A1 CA2546063A1 CA002546063A CA2546063A CA2546063A1 CA 2546063 A1 CA2546063 A1 CA 2546063A1 CA 002546063 A CA002546063 A CA 002546063A CA 2546063 A CA2546063 A CA 2546063A CA 2546063 A1 CA2546063 A1 CA 2546063A1
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- inlet pressure
- speed
- drive motor
- range
- curve
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Classifications
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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
- F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
- F04B49/06—Control using electricity
- F04B49/065—Control using electricity and making use of computers
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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
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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
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
- F04B49/06—Control using electricity
-
- 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
- F04B2203/00—Motor parameters
- F04B2203/04—Motor parameters of linear electric motors
- F04B2203/0409—Linear speed
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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
- F04B2205/00—Fluid parameters
- F04B2205/01—Pressure before the pump inlet
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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
- F04B2207/00—External parameters
- F04B2207/02—External pressure
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05B—INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
- F05B2210/00—Working fluid
- F05B2210/10—Kind or type
- F05B2210/12—Kind or type gaseous, i.e. compressible
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05B—INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
- F05B2270/00—Control
- F05B2270/30—Control parameters, e.g. input parameters
- F05B2270/301—Pressure
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S417/00—Pumps
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Computer Hardware Design (AREA)
- Compressors, Vaccum Pumps And Other Relevant Systems (AREA)
- Control Of Positive-Displacement Pumps (AREA)
- Applications Or Details Of Rotary Compressors (AREA)
Abstract
The invention relates to a method for controlling the drive motor of a positive-displacement vacuum pump, comprising the following steps: storing a curve (32) that indicates a speed value n of the drive motor for an input pressure value p, said curve (32) comprising: an upper range (34) for input pressure values p that are greater than or equal to an upper threshold pressure p1, with which a single constant upper speed value n1 is associated, and a range of alteration (36) for input pressure values p smaller than the upper threshold pressure p1, wherein various speed values nv are associated with the input pressure values p in the range of alteration: determining the input pressure value p, determining the speed n associated with the input pressure value p in the curve (32) and operating the drive motor with the determined speed n. The inventive method which provides for a range of alteration allows operation of the positive displacement pump at a speed at which the effective displacement capacity of the displacement pump is maximal.
Description
Sg/Schm Method for controlling a drive motor of a positive displacement vacuum pump The invention relates to a method for controlling a drive motor of a positive displacement vacuum pump, and to a positive displacement vacuum pump comprising a drive motor control.
Positive displacement vacuum pumps are, for example, membrane pumps, rotary vane pumps, piston pumps or Roots pumps, and are frequently used as fore vacuum pumps in combination with a high vacuum pump. A special fea-io ture of these positive displacement vacuum pumps is that the final pressure attainable by said pumps, i.e. the fore vacuum pressure, is speed-dependent to a high extent, wherein the speed must be high at high inlet pressures, and must be low at low inlet pressures for attaining an optimum suction capacity.
This can be explained by the fact that at low inlet pressures filling of the suc-tion space takes place at a relatively slow rate due to the small difference be-tween inlet pressure and suction pressure in the working chamber. This re-sults in a poor filling level of the positive displacement vacuum pump at low inlet pressures, which filling level can only be improved by extending the opening times of the inlet valve, i.e. a speed reduction.
From DE 198 16 241 C1 a positive displacement vacuum pump is known which is operated, in dependence on an inlet pressure value, at two different speeds, namely at a high speed for evacuation purposes, and at a low speed for reaching the lowest final pressure possible. Relatively much time is re-quired between the beginning of the pumping process and reaching of the fi-nal pressure.
It is an object of the invention to provide a method and a positive displace ment vacuum pump with the aid of which the final pressure can be more rap 3o idly reached.
According to the invention, this object is achieved with the features of claims 1, 3 and 10.
Positive displacement vacuum pumps are, for example, membrane pumps, rotary vane pumps, piston pumps or Roots pumps, and are frequently used as fore vacuum pumps in combination with a high vacuum pump. A special fea-io ture of these positive displacement vacuum pumps is that the final pressure attainable by said pumps, i.e. the fore vacuum pressure, is speed-dependent to a high extent, wherein the speed must be high at high inlet pressures, and must be low at low inlet pressures for attaining an optimum suction capacity.
This can be explained by the fact that at low inlet pressures filling of the suc-tion space takes place at a relatively slow rate due to the small difference be-tween inlet pressure and suction pressure in the working chamber. This re-sults in a poor filling level of the positive displacement vacuum pump at low inlet pressures, which filling level can only be improved by extending the opening times of the inlet valve, i.e. a speed reduction.
From DE 198 16 241 C1 a positive displacement vacuum pump is known which is operated, in dependence on an inlet pressure value, at two different speeds, namely at a high speed for evacuation purposes, and at a low speed for reaching the lowest final pressure possible. Relatively much time is re-quired between the beginning of the pumping process and reaching of the fi-nal pressure.
It is an object of the invention to provide a method and a positive displace ment vacuum pump with the aid of which the final pressure can be more rap 3o idly reached.
According to the invention, this object is achieved with the features of claims 1, 3 and 10.
The method according to the invention as claimed in claim 1 for controlling a drive motor of a positive displacement vacuum pump comprises the method steps of storing a pressure-speed curve, determining the inlet pressure value, s determining the speed value from the curve, and operating the drive motor at the determined speed value.
First, a curve is stored in which a single constant upper speed value n1 is as-sociated with inlet pressure values p larger than or equal to an upper limit io pressure p1, and which comprises an alteration range for inlet pressure values p smaller than the upper limit pressure p1, wherein in the alteration range dif-ferent speed values n~ are associated with the inlet pressure values p.
During operation of the drive motor the inlet pressure value p is permanently is determined, the associated speed n is determined from the inlet pressure value p of the curve, and the drive motor is operated at the determined speed n. While at high inlet pressure values p above the upper limit value p1 the drive motor is operated at a maximum constant speed n1, a corresponding speed value n" is approximately continuously associated for speeds above the ao upper limit value p1 in dependence on the inlet pressure value p. In this man-ner, the effective suction capacity of the positive displacement pump can be kept at the highest level possible for each inlet pressure value. Thus, the time between beginning of evacuation and reaching of the final pressure is de-creased. By adapting the speed to the inlet pressure value, the required drive a5 energy and, due to the lower average speed level, the wear are reduced.
Thereby, the maintenance and operating costs are reduced, and thus the effi-ciency of the positive displacement vacuum pump is improved.
Preferably, the curve comprises a lower range for inlet pressure values p 3o smaller than or equal to a lower limit pressure pZ, wherein a single constant lower speed value n2 is associated with the lower range, and the alteration range is limited to inlet pressure values p larger than the lower limit pressure range p2. The curve thus comprises both an upper pressure range of constant speed and a lower pressure range of constant speed, as well as an alteration range of non-constant speed between said two ranges. Such a curve is, for example, necessary and useful for fore vacuum pumps which need a given minimum speed for pumping action since below the minimum speed no pump-s ing capacity can be attained, in particular due to backflow losses. This applies, for example, to oil-sealed rotary vane pumps. Thus it is ensured that the posi-tive displacement vacuum pump is always operated above a speed at which the pumping function is still guaranteed even at very low inlet pressures.
io According to a further independent claim 3, the curve comprises, in contrast to method claim 1, instead of an upper range, a lower range for inlet pressure values p smaller than or equal to a lower limit pressure p2, wherein a single constant lower speed nZ is associated with the lower range.
y i5 Preferably, in the alteration range decreasing speeds n" are associated with ~
decreasing inlet pressure values p, i.e. low speed values n" are associated'' y with low inlet pressure values p.
Preferably, the upper limit pressure p1 ranges between 20 mbar and 1 mbar, ao and the lower pressure p2 ranges between 1.0 mbar and 0.005 mbar, wherein the upper limit pressure p1 is larger than the lower limit pressure p2.
According to a preferred aspect, the upper constant speed value n1 ranges between 2,200 and 1,000 rpm, and the lower constant speed value n2 ranges 25 between 300 and 1,300 rpm, wherein the upper constant speed value n1 is larger than the lower constant speed value nZ.
Preferably, the positive displacement pump is a fore vacuum pump arranged upstream of a high vacuum pump, and the inlet pressure value p is the suc-3o tion-side pressure of the high vacuum pump. The inlet pressure value p thus is the pressure in the recipient evacuated by the high vacuum pump. Alterna-tively, the inlet pressure value p may also be the fore vacuum pressure im-mediately before the inlet of the fore vacuum pump.
First, a curve is stored in which a single constant upper speed value n1 is as-sociated with inlet pressure values p larger than or equal to an upper limit io pressure p1, and which comprises an alteration range for inlet pressure values p smaller than the upper limit pressure p1, wherein in the alteration range dif-ferent speed values n~ are associated with the inlet pressure values p.
During operation of the drive motor the inlet pressure value p is permanently is determined, the associated speed n is determined from the inlet pressure value p of the curve, and the drive motor is operated at the determined speed n. While at high inlet pressure values p above the upper limit value p1 the drive motor is operated at a maximum constant speed n1, a corresponding speed value n" is approximately continuously associated for speeds above the ao upper limit value p1 in dependence on the inlet pressure value p. In this man-ner, the effective suction capacity of the positive displacement pump can be kept at the highest level possible for each inlet pressure value. Thus, the time between beginning of evacuation and reaching of the final pressure is de-creased. By adapting the speed to the inlet pressure value, the required drive a5 energy and, due to the lower average speed level, the wear are reduced.
Thereby, the maintenance and operating costs are reduced, and thus the effi-ciency of the positive displacement vacuum pump is improved.
Preferably, the curve comprises a lower range for inlet pressure values p 3o smaller than or equal to a lower limit pressure pZ, wherein a single constant lower speed value n2 is associated with the lower range, and the alteration range is limited to inlet pressure values p larger than the lower limit pressure range p2. The curve thus comprises both an upper pressure range of constant speed and a lower pressure range of constant speed, as well as an alteration range of non-constant speed between said two ranges. Such a curve is, for example, necessary and useful for fore vacuum pumps which need a given minimum speed for pumping action since below the minimum speed no pump-s ing capacity can be attained, in particular due to backflow losses. This applies, for example, to oil-sealed rotary vane pumps. Thus it is ensured that the posi-tive displacement vacuum pump is always operated above a speed at which the pumping function is still guaranteed even at very low inlet pressures.
io According to a further independent claim 3, the curve comprises, in contrast to method claim 1, instead of an upper range, a lower range for inlet pressure values p smaller than or equal to a lower limit pressure p2, wherein a single constant lower speed nZ is associated with the lower range.
y i5 Preferably, in the alteration range decreasing speeds n" are associated with ~
decreasing inlet pressure values p, i.e. low speed values n" are associated'' y with low inlet pressure values p.
Preferably, the upper limit pressure p1 ranges between 20 mbar and 1 mbar, ao and the lower pressure p2 ranges between 1.0 mbar and 0.005 mbar, wherein the upper limit pressure p1 is larger than the lower limit pressure p2.
According to a preferred aspect, the upper constant speed value n1 ranges between 2,200 and 1,000 rpm, and the lower constant speed value n2 ranges 25 between 300 and 1,300 rpm, wherein the upper constant speed value n1 is larger than the lower constant speed value nZ.
Preferably, the positive displacement pump is a fore vacuum pump arranged upstream of a high vacuum pump, and the inlet pressure value p is the suc-3o tion-side pressure of the high vacuum pump. The inlet pressure value p thus is the pressure in the recipient evacuated by the high vacuum pump. Alterna-tively, the inlet pressure value p may also be the fore vacuum pressure im-mediately before the inlet of the fore vacuum pump.
According to a preferred aspect, the inlet pressure-speed curve is saved in a characteristic diagram storage. In the characteristic diagram storage, a corre-sponding speed n is associated with each inlet pressure value p.
Preferably, the drive motor is an asynchronous motor driven by a correspond-ingly driven frequency converter. However, the drive motor may also be con-figured as a synchronous motor.
~o The positive displacement vacuum pump according to the invention comprises a drive motor, an inlet pressure sensor and a drive motor control which con-trots the speed n of the drive motor in dependence on the inlet pressure value p determined by the inlet pressure sensor. Further, the drive motor control comprises a storage for storing a curve that indicates a respective speed n of the drive motor for the inlet pressure values p of the inlet pressure sensor, wherein the curve comprises two ranges: the first range is an upper range for inlet pressure values p larger than or equal to an upper limit pressure pt, with a single constant upper speed value nl being associated with said first range.
The second range is an alteration range for inlet pressure values p smaller ao than the upper limit pressure pt, wherein in the alteration range different speed values n~ are associated with the inlet pressure values p.
Preferably, the drive motor control comprises a processor which has con-nected therewith the inlet pressure sensor and evaluates the signals from the a5 inlet pressure sensor. The evaluated inlet pressure sensor signals can be sup-plied to a pressure indicator associated with the positive displacement vacuum pump. The inlet pressure sensor signals are thus not only evaluated by the drive motor control with regard to controlling the drive motor, but also con-vented into an indication format, and finally supplied to an indicator associated 3o with the vacuum pump. Thus a separate evaluating and indicating device for indicating the inlet pressure is not required.
An embodiment of the invention will now be described in greater detail with ref-erence to the figures in which:
Fig. 1 shows a schematic representation of a pump assembly comprising a positive displacement vacuum pump according to the invention config-s ured as a fore vacuum pump, and a high vacuum pump, and Fig. 2 shows an inlet pressure-speed curve according to which the speed of the drive motor of the positive displacement vacuum pump is con-trolled.
io Fig. 1 schematically shows a pump assembly 10 for generating a high vacuum in a recipient 12. For the purpose of generating the high vacuum in the recipi-ent 12, two pumps are arranged in series, namely a high vacuum pump 14, for example a turbomolecular pump, and a positive displacement vacuum i5 pump 16 configured as a fore vacuum pump, for example a membrane, piston or rotary vane pump.
The positive displacement vacuum pump 16 essentially comprises a pump de-vice 18 having a displacement body arranged in a pumping chamber, a drive ao motor 20 for driving the pump device 18, and a drive motor control 22 for controlling and supplying energy to the drive motor 20. The drive motor 20 is configured as a synchronous motor.
Further, the pump assembly 10 comprises two inlet pressure sensors 24,26, a5 wherein one of the inlet pressure sensors 24 determines the fore vacuum pressure immediately at the inlet of the positive displacement vacuum pump 16, and the other inlet pressure sensor 26 determines the high vacuum pres-sure in the recipient 12. Both inlet pressure sensors 24,26 are connected with a processor 28 of the drive motor control 22, said processor 28 being continu-30 ously supplied with inlet pressure values p by the inlet pressure sensors 24, 26. The drive motor control 22 further comprises a frequency converter 30 driven by the processor 28, and is connected with the drive motor 20. Fur-ther, the inlet pressure sensor 24 associated with the positive displacement vacuum pump 16 may be integrated in the positive displacement vacuum pump 16.
The processor 28 comprises a characteristic diagram storage for saving a s curve 32 in which a respective speed n of the drive motor 20 is associated with inlet pressure values p.
The curve 32 comprises an upper range 34 extending from the atmospheric pressure of 1,013 mbar to an upper limit pressure p1 of 10 mbar. A single io constant upper speed value n1 is associated with the upper range 34 of the curve 32. Between the upper limit pressure pi and a lower limit pressure pZ of approximately 0.01 mbar, the curve 32 comprises an alteration range 36 in which various speed values n,, are associated with the inlet pressure values p.
In the alteration range 36 of the curve 32 decreasing speeds n~ are associated 15 with decreasing inlet pressure values p. In the alteration range 36 a different speed value n~ is associated with each inlet pressure value p. The curve 32 further comprises a lower range 38 for inlet pressure values p smaller than or equal to the lower limit pressure p2. In the lower range 38 of the curve 32 a single speed value nZ is associated with all inlet pressure values p.
In a pump device 18 configured as a piston pump, the upper speed value n1 is approximately 1,800 rpm, and the lower speed value nZ is 500 rpm. In a pump device 18 configured as an oil-sealed rotary vane pump, the upper speed value n1 is, for example, 2,100 rpm, and the lower speed value nZ is 1,000 rpm.
The high vacuum pressure serves as the inlet pressure value p which is sup-plied by the inlet pressure sensor 26 arranged at the recipient 12 and on the suction side of the high vacuum pump 14. Alternatively, the fore vacuum 3o pressure of the inlet pressure sensor 24 may be used for determining the inlet pressure values p.
The shape of the curve 32, the limit pressures p1 and pz, and the upper and lower speed values n1 and nZ are determined in test series for establishing for each inlet pressure value p a drive motor 20 speed at which a maximum ef-fective suction capacity of the positive displacement pump 16 is attained. The determined curve is subsequently stored in the characteristic diagram storage of the processor 28. During operation of the pump assembly 10, the drive motor control 22 determines, from the curve 32 saved in the characteristic diagram storage, the speed n of the drive motor 20 in dependence on the high vacuum inlet pressure value p. The determined speed value n is fed to to the frequency converter 30 which generates corresponding rotating fields in the stator coils of the drive motor 20 configured as asynchronous or synchro-nous motor, and operates the motor at the determined speed. In this manner, the positive displacement pump 16 can always be operated at the maximum effective suction capacity.
The processor 28 of the drive motor control 22 further carries out evaluation and conversion of the signals from the inlet pressure sensor 24 into an indica-tion format. The inlet pressures converted into the indication format are sup-plied to an indicating device arranged at the positive displacement vacuum ao pump 16, for example at the housing of the drive motor control 22. The indi-cating device may further be used for speed indication.
Preferably, the drive motor is an asynchronous motor driven by a correspond-ingly driven frequency converter. However, the drive motor may also be con-figured as a synchronous motor.
~o The positive displacement vacuum pump according to the invention comprises a drive motor, an inlet pressure sensor and a drive motor control which con-trots the speed n of the drive motor in dependence on the inlet pressure value p determined by the inlet pressure sensor. Further, the drive motor control comprises a storage for storing a curve that indicates a respective speed n of the drive motor for the inlet pressure values p of the inlet pressure sensor, wherein the curve comprises two ranges: the first range is an upper range for inlet pressure values p larger than or equal to an upper limit pressure pt, with a single constant upper speed value nl being associated with said first range.
The second range is an alteration range for inlet pressure values p smaller ao than the upper limit pressure pt, wherein in the alteration range different speed values n~ are associated with the inlet pressure values p.
Preferably, the drive motor control comprises a processor which has con-nected therewith the inlet pressure sensor and evaluates the signals from the a5 inlet pressure sensor. The evaluated inlet pressure sensor signals can be sup-plied to a pressure indicator associated with the positive displacement vacuum pump. The inlet pressure sensor signals are thus not only evaluated by the drive motor control with regard to controlling the drive motor, but also con-vented into an indication format, and finally supplied to an indicator associated 3o with the vacuum pump. Thus a separate evaluating and indicating device for indicating the inlet pressure is not required.
An embodiment of the invention will now be described in greater detail with ref-erence to the figures in which:
Fig. 1 shows a schematic representation of a pump assembly comprising a positive displacement vacuum pump according to the invention config-s ured as a fore vacuum pump, and a high vacuum pump, and Fig. 2 shows an inlet pressure-speed curve according to which the speed of the drive motor of the positive displacement vacuum pump is con-trolled.
io Fig. 1 schematically shows a pump assembly 10 for generating a high vacuum in a recipient 12. For the purpose of generating the high vacuum in the recipi-ent 12, two pumps are arranged in series, namely a high vacuum pump 14, for example a turbomolecular pump, and a positive displacement vacuum i5 pump 16 configured as a fore vacuum pump, for example a membrane, piston or rotary vane pump.
The positive displacement vacuum pump 16 essentially comprises a pump de-vice 18 having a displacement body arranged in a pumping chamber, a drive ao motor 20 for driving the pump device 18, and a drive motor control 22 for controlling and supplying energy to the drive motor 20. The drive motor 20 is configured as a synchronous motor.
Further, the pump assembly 10 comprises two inlet pressure sensors 24,26, a5 wherein one of the inlet pressure sensors 24 determines the fore vacuum pressure immediately at the inlet of the positive displacement vacuum pump 16, and the other inlet pressure sensor 26 determines the high vacuum pres-sure in the recipient 12. Both inlet pressure sensors 24,26 are connected with a processor 28 of the drive motor control 22, said processor 28 being continu-30 ously supplied with inlet pressure values p by the inlet pressure sensors 24, 26. The drive motor control 22 further comprises a frequency converter 30 driven by the processor 28, and is connected with the drive motor 20. Fur-ther, the inlet pressure sensor 24 associated with the positive displacement vacuum pump 16 may be integrated in the positive displacement vacuum pump 16.
The processor 28 comprises a characteristic diagram storage for saving a s curve 32 in which a respective speed n of the drive motor 20 is associated with inlet pressure values p.
The curve 32 comprises an upper range 34 extending from the atmospheric pressure of 1,013 mbar to an upper limit pressure p1 of 10 mbar. A single io constant upper speed value n1 is associated with the upper range 34 of the curve 32. Between the upper limit pressure pi and a lower limit pressure pZ of approximately 0.01 mbar, the curve 32 comprises an alteration range 36 in which various speed values n,, are associated with the inlet pressure values p.
In the alteration range 36 of the curve 32 decreasing speeds n~ are associated 15 with decreasing inlet pressure values p. In the alteration range 36 a different speed value n~ is associated with each inlet pressure value p. The curve 32 further comprises a lower range 38 for inlet pressure values p smaller than or equal to the lower limit pressure p2. In the lower range 38 of the curve 32 a single speed value nZ is associated with all inlet pressure values p.
In a pump device 18 configured as a piston pump, the upper speed value n1 is approximately 1,800 rpm, and the lower speed value nZ is 500 rpm. In a pump device 18 configured as an oil-sealed rotary vane pump, the upper speed value n1 is, for example, 2,100 rpm, and the lower speed value nZ is 1,000 rpm.
The high vacuum pressure serves as the inlet pressure value p which is sup-plied by the inlet pressure sensor 26 arranged at the recipient 12 and on the suction side of the high vacuum pump 14. Alternatively, the fore vacuum 3o pressure of the inlet pressure sensor 24 may be used for determining the inlet pressure values p.
The shape of the curve 32, the limit pressures p1 and pz, and the upper and lower speed values n1 and nZ are determined in test series for establishing for each inlet pressure value p a drive motor 20 speed at which a maximum ef-fective suction capacity of the positive displacement pump 16 is attained. The determined curve is subsequently stored in the characteristic diagram storage of the processor 28. During operation of the pump assembly 10, the drive motor control 22 determines, from the curve 32 saved in the characteristic diagram storage, the speed n of the drive motor 20 in dependence on the high vacuum inlet pressure value p. The determined speed value n is fed to to the frequency converter 30 which generates corresponding rotating fields in the stator coils of the drive motor 20 configured as asynchronous or synchro-nous motor, and operates the motor at the determined speed. In this manner, the positive displacement pump 16 can always be operated at the maximum effective suction capacity.
The processor 28 of the drive motor control 22 further carries out evaluation and conversion of the signals from the inlet pressure sensor 24 into an indica-tion format. The inlet pressures converted into the indication format are sup-plied to an indicating device arranged at the positive displacement vacuum ao pump 16, for example at the housing of the drive motor control 22. The indi-cating device may further be used for speed indication.
Claims (11)
1. A method for controlling a drive motor (20) of a positive displacement vacuum pump (16), the method comprising the following steps:
storing a curve (32) indicating a respective speed n of the drive motor (20) for inlet pressure values p, wherein the curve (32) comprises:
- an upper range (34) for inlet pressure values p larger than or equal to an upper limit pressure p1, with a single constant upper speed value n1 being associated with said upper range (34), and - an alteration range (36) for inlet pressure values p smaller than the upper limit pressure p1, wherein in the alteration range dif-ferent speed values n v are associated with the inlet pressure val-ues p, determining the inlet pressure value p, determining the speed n associated with the inlet pressure value p in the curve (32), and operating the drive motor (20) at the determined speed n.
storing a curve (32) indicating a respective speed n of the drive motor (20) for inlet pressure values p, wherein the curve (32) comprises:
- an upper range (34) for inlet pressure values p larger than or equal to an upper limit pressure p1, with a single constant upper speed value n1 being associated with said upper range (34), and - an alteration range (36) for inlet pressure values p smaller than the upper limit pressure p1, wherein in the alteration range dif-ferent speed values n v are associated with the inlet pressure val-ues p, determining the inlet pressure value p, determining the speed n associated with the inlet pressure value p in the curve (32), and operating the drive motor (20) at the determined speed n.
2. The method according to claim 1, characterized in that the curve (32) comprises a lower range (38) for inlet pressure values p smaller than or equal to a lower limit pressure p2, a single constant lower speed value n2 is associated with the lower range (38), and the alteration range (36) is limited to inlet pressure values p larger than the lower limit pressure p2.
3. A method for controlling a drive motor (20) of a positive displacement vacuum pump (16), the method comprising the following steps:
storing a curve (32) indicating a respective speed n of the drive motor (20) for inlet pressure values p, wherein the curve (32) comprises:
- a lower range (38) for inlet pressure values p smaller than or equal to a lower limit pressure p2, with a single constant lower speed value n2 being associated with said lower range (38), - an alteration range (36) for inlet pressure values p larger than the lower limit pressure p2, wherein in the alteration range (36) different speed values n v are associated with the inlet pressure values p, determining the inlet pressure value p, determining the speed n associated with the inlet pressure value p in the curve (32), and operating the drive motor (20) at the determined speed n.
storing a curve (32) indicating a respective speed n of the drive motor (20) for inlet pressure values p, wherein the curve (32) comprises:
- a lower range (38) for inlet pressure values p smaller than or equal to a lower limit pressure p2, with a single constant lower speed value n2 being associated with said lower range (38), - an alteration range (36) for inlet pressure values p larger than the lower limit pressure p2, wherein in the alteration range (36) different speed values n v are associated with the inlet pressure values p, determining the inlet pressure value p, determining the speed n associated with the inlet pressure value p in the curve (32), and operating the drive motor (20) at the determined speed n.
4. The method according to any one of claims 1-3, characterized in that in the alteration range (36) decreasing speeds n v are associated with de-creasing inlet pressure values p.
5. The method according to any one of claims 1-4, characterized in that the upper limit value p1 ranges between 20 mbar and 1 mbar, and the lower limit value p2 ranges between 1.0 mbar and 0.005 mbar.
6. The method according to any one of claims 1-5, characterized in that the upper constant speed value n1 ranges between 2,200 and 1,000 rpm, and the lower constant speed value n2 ranges between 300 and 1,300 rpm.
7. The method according to any one of claims 1-6, characterized in that the positive displacement vacuum pump (16) is a fore vacuum pump arranged upstream of a high vacuum pump (14), and the inlet pressure p is the suction-side pressure of the high vacuum pump (14).
8. The method according to any one of claims 1-7, characterized in that the curve (32) is saved in a characteristic diagram storage.
9. The method according to any one of claims 1-8, characterized in that the drive motor (20) is an asynchronous motor.
10. A positive displacement vacuum pump (16) comprising a drive motor (20), an inlet pressure sensor (24) and a drive motor control (22) for controlling the speed n of the drive motor (20) in dependence on the inlet pressure value p determined by the inlet pressure sensor (24), wherein the drive motor control (22) comprises a storage for storing a curve (32) which indicates a respective speed n of the drive motor (20) for inlet pressure values p of the inlet pressure sensor (24), wherein the curve (32) comprises:
an upper range (34) for inlet pressure values p larger than or equal to an upper limit pressure p1, with a single constant upper speed value n1 being associated with said upper range (34), and an alteration range (36) for inlet pressure values p smaller than the upper limit pressure p1, wherein in the alteration range (36) different speed values n v are associated with the inlet pressure values p.
an upper range (34) for inlet pressure values p larger than or equal to an upper limit pressure p1, with a single constant upper speed value n1 being associated with said upper range (34), and an alteration range (36) for inlet pressure values p smaller than the upper limit pressure p1, wherein in the alteration range (36) different speed values n v are associated with the inlet pressure values p.
11. The positive displacement vacuum pump according to claim 10, charac-terized in that the drive motor control (22) comprises a processor (28) which has connected therewith the inlet pressure sensor (24) and evaluates the signals of the inlet pressure sensor (24).
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE10354205A DE10354205A1 (en) | 2003-11-20 | 2003-11-20 | Method for controlling a drive motor of a vacuum displacement pump |
| DE10354205.1 | 2003-11-20 | ||
| PCT/EP2004/012529 WO2005050021A1 (en) | 2003-11-20 | 2004-11-05 | Method for controlling the drive motor of a positive-displacement vacuum pump |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2546063A1 true CA2546063A1 (en) | 2005-06-02 |
Family
ID=34609147
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002546063A Abandoned CA2546063A1 (en) | 2003-11-20 | 2004-11-05 | Method for controlling the drive motor of a positive-displacement vacuum pump |
Country Status (8)
| Country | Link |
|---|---|
| US (1) | US20070071610A1 (en) |
| EP (1) | EP1697639B1 (en) |
| JP (1) | JP4553262B2 (en) |
| KR (1) | KR20060097741A (en) |
| CN (1) | CN100460676C (en) |
| CA (1) | CA2546063A1 (en) |
| DE (2) | DE10354205A1 (en) |
| WO (1) | WO2005050021A1 (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| JP4737770B2 (en) * | 2006-09-12 | 2011-08-03 | アネスト岩田株式会社 | Vacuum pump operation control device and method |
| DE102006050943B4 (en) | 2006-10-28 | 2020-04-16 | Pfeiffer Vacuum Gmbh | Vacuum pump and method for operating the same |
| ATE552423T1 (en) * | 2010-02-12 | 2012-04-15 | Allweiler Ag | OPERATIONAL CONTROL DEVICE FOR A DISPLACEMENT PUMP, PUMP SYSTEM AND METHOD FOR OPERATING SAME |
| BR112013012171B1 (en) * | 2010-11-17 | 2022-03-29 | KSB SE & Co. KGaA | Method for variable rotational speed control of a displacement pump unit, control device and displacement pump arrangement |
| DE102011050017A1 (en) * | 2011-04-29 | 2012-10-31 | Allweiler Gmbh | Control means for driving a frequency converter and driving method |
| CN102278310A (en) * | 2011-07-14 | 2011-12-14 | 温州市欧弗斯机械有限公司 | Intelligently-regulated vacuum system |
| DE102014214952A1 (en) * | 2014-07-30 | 2016-02-04 | Ksb Aktiengesellschaft | Method for motor control of a synchronous reluctance motor for a pump and pump with synchronous reluctance motor |
| EP3067560B1 (en) * | 2015-03-12 | 2020-11-18 | Pfeiffer Vacuum GmbH | Vacuum pump with at least one pump stage |
| DE102017203474A1 (en) * | 2017-03-03 | 2018-09-06 | KSB SE & Co. KGaA | Method for controlling a variable-speed circulating pump and circulating pump |
| EP3438460B1 (en) * | 2017-08-04 | 2024-03-20 | Pfeiffer Vacuum Gmbh | Vacuum pump |
| JP7019513B2 (en) * | 2018-06-05 | 2022-02-15 | 株式会社荏原製作所 | Control devices, control systems, control methods, programs and machine learning devices |
| GB2592573A (en) | 2019-12-19 | 2021-09-08 | Leybold France S A S | Lubricant-sealed vacuum pump, lubricant filter and method. |
| DE102020128369A1 (en) * | 2020-10-28 | 2022-04-28 | Leybold Gmbh | Process for operating a scroll pump and scroll pump |
| GB2603892A (en) * | 2021-02-03 | 2022-08-24 | Edwards Ltd | Pump apparatus and system |
| DE102022100843A1 (en) | 2022-01-14 | 2023-07-20 | VON ARDENNE Asset GmbH & Co. KG | Method, control device, storage medium and vacuum arrangement |
| CN116641881B (en) * | 2023-04-25 | 2024-01-23 | 北京通嘉宏瑞科技有限公司 | Vacuum pump control method, device, computer equipment and storage medium |
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| US3788076A (en) * | 1972-03-20 | 1974-01-29 | Parker Hannifin Corp | Hydraulic system with series wound pump drive motor |
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-
2003
- 2003-11-20 DE DE10354205A patent/DE10354205A1/en not_active Withdrawn
-
2004
- 2004-11-05 DE DE502004009187T patent/DE502004009187D1/en not_active Expired - Lifetime
- 2004-11-05 CN CNB2004800342164A patent/CN100460676C/en not_active Expired - Fee Related
- 2004-11-05 WO PCT/EP2004/012529 patent/WO2005050021A1/en active Application Filing
- 2004-11-05 US US10/580,128 patent/US20070071610A1/en not_active Abandoned
- 2004-11-05 KR KR1020067012266A patent/KR20060097741A/en not_active Application Discontinuation
- 2004-11-05 EP EP04818757A patent/EP1697639B1/en not_active Expired - Lifetime
- 2004-11-05 JP JP2006540230A patent/JP4553262B2/en not_active Expired - Fee Related
- 2004-11-05 CA CA002546063A patent/CA2546063A1/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| US20070071610A1 (en) | 2007-03-29 |
| CN100460676C (en) | 2009-02-11 |
| EP1697639A1 (en) | 2006-09-06 |
| DE502004009187D1 (en) | 2009-04-30 |
| WO2005050021A1 (en) | 2005-06-02 |
| CN1882782A (en) | 2006-12-20 |
| DE10354205A1 (en) | 2005-06-23 |
| JP4553262B2 (en) | 2010-09-29 |
| EP1697639B1 (en) | 2009-03-18 |
| KR20060097741A (en) | 2006-09-14 |
| JP2007511703A (en) | 2007-05-10 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Discontinued | ||
| FZDE | Discontinued |
Effective date: 20121105 |