Classifications

• • 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
• • 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
• • 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
• • 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
  • F04C23/02—Pumps characterised by combination with, or adaptation to, specific driving engines or motors
• • 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
  • F04C29/0042—Driving elements, brakes, couplings, transmissions specially adapted for pumps
• • 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
  • F04C29/0042—Driving elements, brakes, couplings, transmissions specially adapted for pumps
  • F04C29/0085—Prime movers
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K1/00—Details of the magnetic circuit
  • H02K1/06—Details of the magnetic circuit characterised by the shape, form or construction
  • H02K1/22—Rotating parts of the magnetic circuit
  • H02K1/27—Rotor cores with permanent magnets
  • H02K1/2706—Inner rotors
  • H02K1/272—Inner rotors the magnetisation axis of the magnets being perpendicular to the rotor axis
  • H02K1/2726—Inner rotors the magnetisation axis of the magnets being perpendicular to the rotor axis the rotor consisting of a single magnet or two or more axially juxtaposed single magnets
  • H02K1/2733—Annular magnets
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K16/00—Machines with more than one rotor or stator
  • H02K16/04—Machines with one rotor and two stators
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K7/00—Arrangements for handling mechanical energy structurally associated with dynamo-electric machines, e.g. structural association with mechanical driving motors or auxiliary dynamo-electric machines
  • H02K7/14—Structural association with mechanical loads, e.g. with hand-held machine tools or fans
• • 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
  • F04C2240/00—Components
  • F04C2240/40—Electric motor
• • 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
  • F04C2270/00—Control; Monitoring or safety arrangements
  • F04C2270/02—Power
• • 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
  • F04C2270/00—Control; Monitoring or safety arrangements
  • F04C2270/60—Prime mover parameters
• • 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

Definitions

• the present invention relates to a dry type vacuum pump and more particularly to a synchronous motor of said vacuum pump.
• the invention also relates to a method for controlling a synchronous vacuum pump motor.
• the primary vacuum pumps comprise one or more series pumping stages in which a gas to be pumped between a suction and a discharge circulates.
• known primary vacuum pumps those with rotary lobes also known as “Roots” with two or three lobes or with double beaks, also known under the name “Claw” or those with double screws.
• Roots-type vacuum pumps or “Roots Blowers” are also known which are used upstream of the primary vacuum pumps, to increase the pumping capacity in a high flow situation.
• vacuum pumps comprise two pumping rotors of identical profiles rotating in opposite directions inside a stator. During the rotation, the gas to be pumped is trapped in the volume generated by the rotors and the stator and is driven by the rotors to the next stage, then gradually until the discharge of the vacuum pump.
• the pumping load changes significantly in use. This is the case in particular between, on the one hand, a high gas flow pumping step, such as a vacuum stage from atmospheric pressure, and, on the other hand, a low load standby stage, such as a vacuum maintenance step. It is understood that the engine of the vacuum pump must respond to very different load levels. Very heavily loaded at the time of emptying the enclosure, the motor is only subject to a small load at the limit vacuum pressure. It is thus difficult to optimize the motor of the vacuum pump for these two extreme situations. A consequence of this is that optimization of the engine for the highest load results in significant stator losses in limit vacuum pressure.
• One of the aims of the present invention is to provide a dry type vacuum pump whose motor can be better adapted to the pumping load.
• the subject of the invention is a dry type vacuum pump comprising: two shafts respectively bearing at least one pump rotor, the pump rotors being configured to rotate synchronously in opposite directions to drive a gas to be pumped from suction of the vacuum pump to delivery, and
• a synchronous motor configured to drive one of the shafts in rotation, the synchronous motor comprising:
• a first winding stator arranged around the rotor characterized in that the synchronous motor comprises at least one second winding stator arranged around said rotor, the windings of the stators being able to be powered individually or simultaneously to adapt the power of the synchronous motor to the pumping load.
• stator windings are configured to be individually energized when the pumping load of the vacuum pump is below a load threshold and to be fed simultaneously when the pumping load of the vacuum pump is greater than equal to said load threshold.
• a single rotor is used and the two stators can be received in the same housing of the synchronous motor of the vacuum pump. This limits the manufacturing and assembly costs of the vacuum pump. In addition, the vacuum pump is compact.
• the vacuum pump is especially called "dry” because in operation, the at least one rotor rotates inside the stator without any mechanical contact with the stator, which makes it possible not to use oil in the pumping stage. .
• the vacuum pump may comprise one or more features described hereinafter, taken alone or in combination.
• a vacuum pump comprising two rotary shafts is for example a rotary lobe vacuum pump such as "Roots” type or such as a "Claw” or screw type vacuum pump.
• the rotary shaft In the case of a multi-stage vacuum pump, the rotary shaft carries rotors extending into each pumping stage.
• the power ratio between the power generated by the first stator and the power generated by the second stator is for example between 1 and 10.
• the vacuum pump is for example a primary vacuum pump comprising a plurality of pump stages connected in series, the power ratio between the power generated by the first stator and the power generated by the second stator being between 1 and 5. .
• the vacuum pump is for example a Roots type vacuum pump, intended to be connected to an enclosure, in series and upstream of a primary vacuum pump.
• the rotor comprises electromagnets.
• the rotor comprises permanent magnets.
• At least one permanent magnet of the rotor may be composed of a plurality of permanent magnet elements aligned along the rotor.
• the permanent magnet elements of the rotor extend for example in the rotor only facing winding stators.
• the vacuum pump comprises for example a first variable speed drive connected to the first winding stator and a second frequency converter connected to the second winding stator.
• the vacuum pump comprises, for example, a control unit connected to the variable speed drives configured to supply the windings of the stators individually or simultaneously to adapt the power of the synchronous motor to the pumping load as a function of at least one signal representative of the load. pumping.
• the signal representative of the pumping load is for example a current limiting output of one of the variable speed drives, representative of the current consumed by the vacuum pump.
• the invention also relates to a method for controlling a synchronous motor of a dry type vacuum pump as described above, for pumping an enclosure connected to the vacuum pump, characterized in that feeds windings of the stators individually when the pumping load of the vacuum pump is below a load threshold and the windings are fed simultaneously when the pumping load of the vacuum pump is higher than said load threshold to adapt the power of the synchronous motor the pumping load as a function of at least one signal representative of the pumping load.
• the most powerful of the two stators or the two stators is fed simultaneously, at the start of the vacuum pump or in a step of emptying from the atmospheric pressure.
• a step of emptying from the atmospheric pressure and a pumping step in a vacuum limit can for example take place cyclically in the chamber.
• Figure 1 shows a schematic view of a dry type vacuum pump according to a first embodiment, connected to an enclosure.
• Figure 2 shows a partial schematic view in longitudinal section of a synchronous motor of the vacuum pump of Figure 1.
• Figure 3 shows a schematic cross-sectional view of the synchronous motor of the vacuum pump of Figure 1.
• Figure 4 shows a flow diagram of a method of controlling a synchronous motor of a dry type vacuum pump.
• Figure 5 shows a partial schematic view in longitudinal section of a synchronous motor of a vacuum pump according to a second embodiment.
• Figure 6 shows a partial schematic view in longitudinal section of a synchronous motor of a vacuum pump according to a third embodiment.
• Figure 7 shows a schematic view of a dry type vacuum pump according to another embodiment, connected to an enclosure.
• the "minimum pressure” defines the minimum pressure obtained by a vacuum pump in the absence of introduction of gas flow.
• the primary vacuum pump defines a volumetric vacuum pump which, by means of two rotors, sucks, then transfers the gas to be pumped at atmospheric pressure.
• Roots vacuum pump (also known as “Roots Blower”) is a volumetric vacuum pump which, by means of Roots-type pumping rotors, sucks, then transfers the gas to be pumped.
• a Roots type vacuum pump is mounted upstream and in series of a primary vacuum pump.
• Primary Vacuum and Roots pumps are dry vacuum pumps.
• upstream an element which is placed before another in relation to the direction of flow of the gas.
• downstream is understood to mean an element placed after another relative to the direction of flow of the gas to be pumped, the element situated upstream being at a lower pressure than the element situated downstream at a pressure higher.
• FIG. 1 represents a first example of a dry type vacuum pump 1 connected to an enclosure 2 via an isolation valve 3.
• Pumping load variations can take place in the chamber 2. For example, a step of emptying from the atmospheric pressure and a pumping step in limit vacuum follow one another in the chamber 2. The succession of these two steps can be produce cyclically.
• the enclosure 2 is for example a chamber lock load and unloading (or "load lock" in English).
• a chamber for loading and unloading comprises a first door communicating the interior of the chamber with an atmospheric pressure zone, such as a clean room, for loading at least a substrate and a second gate for discharging the substrate into the process chamber after evacuation.
• an atmospheric pressure zone such as a clean room
• Each loading or unloading of substrates requires going down then alternately to raise the pressure in the enclosure of the airlock.
• the chamber of loading and unloading lock allows to maintain an acceptable rate and to avoid the presence of any impurity and any pollution in the atmosphere surrounding the substrate.
• the loading and unloading chambers are used in particular for the production of flat screens for display or photovoltaic substrates or for the manufacture of semiconductor substrates.
• the vacuum pump 1 is a multi-stage primary vacuum pump.
• a Roots type vacuum pump or a turbomolecular vacuum pump may be interposed between the vacuum pump 1 and the chamber 2.
• the vacuum pump 1 of this first embodiment comprises a plurality of pump stages T1-T5, for example five, connected in series between a suction 4 and a discharge 5 of the vacuum pump 1.
• Each pump stage T1 -T5 includes a respective input and output.
• the successive pump stages T1-T5 are connected in series one after the other by respective inter-stage channels connecting the output (or discharge) of the pumping stage which precedes the input (or the suction) of the next stage.
• the vacuum pump 1 further comprises two shafts 6, 7, a drive shaft 6 and a driven shaft 7, each carrying pump rotors 8 extending in the pump stages T1-T5.
• the vacuum pump 1 also comprises a synchronous motor 9 configured to drive the driving shaft 6 in rotation.
• the driven shaft 7 is rotated by a synchronization device of the vacuum pump 1.
• the pump rotors 8 have, for example, lobes of identical profiles, such as "Roots” type ("eight” or “bean” shaped cross-section) or "Claw” type. In another example, the pump rotors 8 are of the "screw” type.
• the shafts 6, 7 rotate synchronously in the opposite direction.
• the gas sucked from the inlet is trapped in the volume generated by the pump rotors 8, then is driven by the rotors 8 to the next stage (the direction of gas flow is illustrated by the arrows on Figure 1).
• the vacuum pump 1 is particularly called “dry” because in operation, the rotors 8 rotate inside the stator without any mechanical contact with the stator, which makes it possible not to use oil in the pump stages T 1 -T5.
• the synchronous motor 9 comprises a rotor 10 coupled to the driving shaft 6 (it is for example threaded onto the shaft 6 or fixed to the shaft 6 by elastic coupling or the rotor and the shaft are in one piece), a first stator 12 with windings 13 arranged around the rotor 10 and at least one second stator 14 with windings 15 also arranged around the rotor 10.
• the second stator 14 is arranged next to the first stator 12 along the rotor 10, around a distinct portion of the rotor 10.
• the stators 12, 14 are adjacent, coaxial and connected in series.
• the stators 12, 14 are received in a housing 16 of the synchronous motor 9.
• the rotor comprises electromagnets.
• a first stator 12 with windings 13 is thus arranged around the rotor facing electromagnets of the rotor and at least one second stator 14 with windings 15 is also arranged around the rotor facing electromagnets of the rotor.
• the rotor 10 comprises permanent magnets 1 1.
• a first stator 12 with windings 13 is thus arranged around the rotor 10 facing permanent magnets 1 1 of the rotor 10 and at least one second stator 14.
• windings 15 is also arranged around the rotor 10 opposite permanent magnets 1 1 of the rotor 10.
• Permanent magnets 11 are for example integrated in the rotor 10. They are also called “IPM” for "Interior Permanent Magnet” in English.
• the permanent magnets 1 1 located opposite a first and a second stator 12, 14 are in one piece. They extend at least from the first stator 12 to the second stator 14 along the rotor 10.
• the windings 13, 15 of the stators 12, 14 can be powered individually or simultaneously to adapt the power of the synchronous motor 9 to the evolution of the pumping load.
• the vacuum pump 1 may comprise a control unit 18 and two variable speed drives, a first variable speed drive 23 being dedicated to the supply of the winding 13 of the first stator 12, a second variable speed drive 24 being dedicated to the supplying the winding 15 of the second stator 14.
• the control unit 18 comprises one or more controllers or processors adapted to control individually one or the other of the variable speed drives 23, 24 or both simultaneously.
• the control unit 18 is for example formed by an electronic control card.
• the power supply of the windings 13, 15 of the stators 12, 14 of the synchronous motor 9 of the vacuum pump 1 is modified as a function of at least one signal representative of the pumping load in order to adapt the power to at least one load threshold.
• the control unit 18 increases the electromotive force of the synchronous motor 9 when the pumping load exceeds the load threshold by simultaneously supplying several windings 13, 15 and reduces the electromotive force when the pumping load is lower than the load threshold by feeding individually, one or the other of the windings 13, 15 of the stators 12, 14 of the synchronous motor 9.
• the signal representative of the pumping charge may comprise a signal coming from a sensor 21 of the enclosure 2, such as a pressure sensor, or may come from the equipment 22 controlling the progress of the process in the enclosure 2
• the signal coming from the equipment 22 can be a closure of a contact resulting for example from the opening / closing of a door of the enclosure 2.
• the load threshold is crossed when the pressure in the enclosure 2 exceeds a predetermined threshold or when the contact changes state.
• the signal representative of the pumping charge is, for example, a signal from a vacuum pump sensor 1, such as a pressure sensor 19 configured to measure the discharge pressure of the vacuum pump 1 or such that a power or current sensor configured to measure the power or the current consumed by the vacuum pump 1.
• the load threshold is crossed when the discharge pressure of the vacuum pump 1 or the power or the current consumed by the vacuum pump 1 exceeds a respective predetermined threshold.
• the signal representative of the pumping load is a current limiting output of one of the variable speed drives 23, 24, representative of the current consumed by the vacuum pump 1.
• thresholds of current may already be provided in the variable speed drives 23, 24 to protect against overcurrent, which may occur for example in the startup phase of the vacuum pump 1.
• the power ratio between the power generated by the first stator 12 and the power generated by the second stator 14 is equal to 1.
• the windings of the first and second stators 12, 14 produce equivalent electromotive forces when subjected to an equivalent current supply. The simultaneous supply of the two stators 12, 14 doubles the electromotive force.
• the power ratio between the power generated by the first stator 12 and the power generated by the second stator 14 is greater than 1.
• the windings 13, 15 of the stators 12, 14 produce forces electromotive equipment when subjected to an equivalent power supply.
• the number of possibilities of available powers is then equal to three.
• the power ratio is, for example, less than five for a multi-stage primary vacuum pump (FIG. 1).
• Winding stators producing different powers can be obtained for example by increasing the number of turns of the winding 13, 15 of one of the stators 12, 14 or by increasing the diameter of the wire of the winding 13, 15 of one of the stators 12, 14.
• the number of turns of the windings 15 of the second stator 14 is for example greater than the number of turns of the windings 13 of the first stator 12.
• the synchronous motor 9 may also have more than two winding stators, such as three or four winding stators.
• the various winding stators have, for example, a respective increasing electromotive force.
• FIG. 1 An example of a control method 100 of a synchronous motor 9 of a vacuum pump 1 connected to a loading and unloading chamber as shown in FIG. 1 will now be described, considering that the pressure in the enclosure 2 is initially the atmospheric pressure and that the isolation valve 3 is closed.
• the equipment 22 controls the opening of the valve 3
• a signal from the equipment 22 is received at the control unit 18 of the vacuum pump 1.
• the control unit 18 supplies then simultaneously the two stators 12, 14 of the synchronous motor 9 to have a maximum of power.
• the pressure in the chamber 2 begins to decrease (emptying step 101, Figure 4).
• the isolation valve 3 is closed and the pressure in the chamber 2 is raised to atmospheric pressure for charging a new substrate.
• FIG. 5 shows a second exemplary embodiment in which each permanent magnet 11 of the rotor 10 comprises several permanent magnet elements 25.
• the permanent magnet elements 25 are aligned along the rotor 10. They are placed end to end along the rotor 10 and extend between the first stator 12 and the second stator 14. A permanent magnet 11 made by several separate elements end-to-end is easier to achieve than a permanent magnet 11 in one piece.
• the permanent magnet elements 25 are for example inserted one behind the other in a groove formed in the rotor 10.
• FIG. 6 shows another exemplary embodiment in which each permanent magnet 11 of the rotor 10 comprises several permanent magnet elements 25.
• the permanent magnet elements 25 are aligned along the rotor 10, but in this case for example, extend in the rotor 10 only in the regions of the rotor 10 located opposite a stator 12, 14 with windings 13, 15.
• Fillers for example made of plastic, can be inserted in the groove between an element d permanent magnet 25 facing the first stator 12 with windings 13 and a permanent magnet element 25 facing the second stator 14 with windings 15. This limits the costs by avoiding the arrangement of unnecessary permanent magnets.
• FIG. 7 represents an example of a "Blower Roots" type vacuum pump connected to an enclosure 2.
• the vacuum pump 30 is connected in series and upstream of a primary vacuum pump 31.
• the vacuum pump 30 comprises a single pump stage T1 having a suction 4 and a discharge 5, two shafts 6, 7 each carrying a pump rotor 8 and a synchronous motor 9 configured to drive the driving shaft 6 in rotation.
• the pump rotors 8 have lobes of identical Roots profiles which are angularly offset and driven to rotate synchronously in opposite directions in the pump stage T 1.
• the Roots vacuum pump 30 differs mainly from the primary vacuum pump 1 in having a larger pumping capacity, larger clearance tolerances and the fact that the Roots vacuum pump 30 does not discharge to the pump. atmospheric pressure but shall be used in series mounting upstream of a primary vacuum pump 31.
• the synchronous motor 9 comprises a rotor 10 with permanent magnets 11 mounted on the drive shaft 6, a first stator 12 with windings 13 arranged around the rotor 10 and at least one second stator 14 with windings 15. also arranged around the rotor 10.
• the windings 13, 15 of the first and second stators 12, 14 can produce equivalent or different electromotive forces.
• the power ratio between the power generated by the first stator 12 and the power generated by the second stator 14 is for example between 1 and 10.
• the power generated by the first stator 12 is of the order of 1, 5kW and the power generated by the second stator 14 is of the order of 8.5kW.
• the power supply of the windings 13, 15 of the stators 12, 14 of the synchronous motor 9 of the vacuum pump 1 is modified as a function of at least one signal representative of the pumping load in order to adapt the power to at least one load threshold.
• the pumping load When the pressure in the chamber 2 exceeds a predetermined load threshold, the pumping load has dropped sufficiently for the control unit 18 to feed only one of the two stators 12 (pumping step in a vacuum limit 102 Figure 4). The available power is then of the order of 1.5 kW.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Applications Or Details Of Rotary Compressors (AREA)
• Compressors, Vaccum Pumps And Other Relevant Systems (AREA)
• Connection Of Motors, Electrical Generators, Mechanical Devices, And The Like (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=62092050

Family Applications (1)

Country Status (8)

Families Citing this family (4)

Family Cites Families (20)

• 2018
  • 2018-01-09 FR FR1850164A patent/FR3076582B1/fr active Active
  • 2018-11-28 TW TW107142409A patent/TWI753219B/zh active
  • 2018-12-05 US US16/768,907 patent/US11396875B2/en active Active
  • 2018-12-05 KR KR1020207021827A patent/KR20200104893A/ko active IP Right Grant
  • 2018-12-05 EP EP18829216.3A patent/EP3737864A1/fr not_active Withdrawn
  • 2018-12-05 WO PCT/EP2018/083695 patent/WO2019137700A1/fr unknown
  • 2018-12-05 JP JP2020557381A patent/JP2021510192A/ja not_active Ceased
  • 2018-12-05 CN CN201880079549.0A patent/CN111527309A/zh active Pending

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