Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01C—ROTARY-PISTON OR OSCILLATING-PISTON MACHINES OR ENGINES
  • F01C17/00—Arrangements for drive of co-operating members, e.g. for rotary piston and casing
  • F01C17/02—Arrangements for drive of co-operating members, e.g. for rotary piston and casing of toothed-gearing 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
  • F04C2/00—Rotary-piston machines or pumps
  • F04C2/08—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing
  • F04C2/10—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of internal-axis type with the outer member having more teeth or tooth-equivalents, e.g. rollers, than the inner member
  • F04C2/102—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of internal-axis type with the outer member having more teeth or tooth-equivalents, e.g. rollers, than the inner member the two members rotating simultaneously around their respective axes
• • 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
  • F04C15/00—Component parts, details or accessories of machines, pumps or pumping installations, not provided for in groups F04C2/00 - F04C14/00
  • F04C15/0096—Heating; Cooling
• • 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
  • F04C18/14—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 toothed rotary pistons
  • F04C18/16—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 toothed rotary pistons with helical teeth, e.g. chevron-shaped, screw 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
  • F04C2/00—Rotary-piston machines or pumps
  • F04C2/08—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing
  • F04C2/082—Details specially related to intermeshing engagement type machines or pumps
  • F04C2/084—Toothed wheels
• • 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
  • F04C2240/402—Plurality of electronically synchronised 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
  • F04C29/04—Heating; Cooling; Heat insulation
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05C—INDEXING SCHEME RELATING TO MATERIALS, MATERIAL PROPERTIES OR MATERIAL CHARACTERISTICS FOR MACHINES, ENGINES OR PUMPS OTHER THAN NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES
  • F05C2251/00—Material properties
  • F05C2251/14—Self lubricating materials; Solid lubricants

Definitions

• This invention relates to an improved screw type volumetric machine. More particularly, this invention relates to a volumetric machine comprising a housing with a first rotor and a second rotor which are rotatably mounted in the housing and which are driven in opposite directions with respect to each other.
• volumetric rotary machines In the field of vacuum technology (or vacuum technology), volumetric rotary machines have been used for many years as compressible gas pumping machines.
• so-called "screw" pumps are particularly used. They typically include a housing and two twin rotors, rotatably mounted in this housing and driven in opposite directions relative to each other.
• the rotors of this type of pump are constituted by pieces in the form of screws, that is to say parts comprising a core which carries one or more threads whose pitch can be constant or variable along the longitudinal dimension of the rotor.
• Rotors in a conventional screw pump are normally driven by an asynchronous electric motor.
• An asynchronous motor typically consists of two main parts, namely a stator made of a ferromagnetic material which serves as a support and which includes a winding connected to the network or a variable speed drive and a cylinder-shaped rotor, also in a ferromagnetic material, which is fixed to the stator by bearings.
• the rotor comprises a winding consisting of short-circuited conductors.
• the con- The rotor ducts are traversed by currents induced by the magnetic field which is created by the stator currents.
• one of the two screws of the pump is directly connected to the rotor of the asynchronous motor so that it is automatically driven by the motor.
• a connection piece between the rotor of the motor and the rotor axis but it is important to note that the rotation of the rotor of the motor is transmitted directly to one of the rotors of the rotor. the pump. Thanks to a gear that connects the two screws of the pump, the rotation of the first screw which is directly driven by the motor is transmitted directly to the other screw.
• this conventional structure also has significant disadvantages, particularly caused by the need for lubrication of the gear. Indeed, being a gear that transmits significant torque, it is known that the wheels in the gear undergo torques of order of several kNm, which makes good lubrication with mineral oils or grease absolutely necessary. Lubricated gears mean more complicated maintenance. On the other hand, the presence of oils or greases can negatively influence the performance of the pump, especially in applications requiring a strict level of hygiene (eg in the food or pharmaceutical industry). To overcome these problems, it has already been proposed to modify a screw pump by replacing the drive by a single asynchronous motor as described above by driving two synchronous motors.
• An asynchronous motor exactly like a synchronous motor, consists of a rotating part (or the rotor), and a fixed part (or the stator).
• the rotor in a synchronous motor is rotated by a magnetic field which comes either from permanent magnets or from coils which are fed with direct current.
• the rotor in low power motors uses permanent magnets, while electromagnets are used in motors with larger powers.
• each of the two rotors (or screws) of the pump is driven by one of the two motors.
• the synchronization of the movements of the two rotors is carried out directly by means of the two motors. Indeed, as the speed of rotation of the synchronous motors corresponds by default to the speed of rotation of the rotating field, it is easy to control the speed of rotation of the two screws by using a corresponding control module. Thanks to this unified control module for both motors, the rotational speed of the two rotors of the pump can be synchronized.
• the object of the present invention is therefore to overcome the aforementioned drawbacks and to provide a volumetric machine of the "screw" type which is both less complex, less cumbersome and also less expensive than machines of the same type known.
• Another object of the present invention is to propose a volumetric machine of the "screw" type which is absolutely free of any lubricating means which could pollute the pumped fluids.
• a "screw" type volumetric machine comprising a housing with a first rotor and a second rotor which are rotatably mounted in the housing and which are driven in directions which are opposed relative to each other, the volumetric machine comprising a first motor and a second motor which are arranged in a drive housing and which are connected to the housing so that the first rotor is driven by the first motor and that the second rotor is driven by the second motor.
• the advantage of this invention lies in the fact that the rotors of the proposed volumetric machine are driven individually. Thanks to such an individual training, the two rotors can be driven in a more precise way and more adapted to the concrete needs of the particular use.
• the first motor and / or the second motor is an asynchronous motor.
• This embodiment of the invention has the advantage, among other things, that
• asynchronous motors makes the production of the volumetric machine much cheaper than in the case of the use of synchronous motors, as proposed in the state of the art.
• an asynchronous motor can typically be maintained and controlled in an easier manner compared to a synchronous motor comparable in performance.
• the rotating part of the first motor is connected to the first rotor and / or the rotating part of the second motor is connected to the second rotor.
• the advantage of this embodiment of the present invention can be found, among other things, in a simple construction of the volumetric machine. Indeed, the rotors (the rotating parts) of the motors can be directly connected to the rotors of the machine, but it is also possible to insert one or more connecting elements between the rotating parts of the motors and the rotors of the pump.
• a first synchronizing wheel and a second synchronizing wheel which meshes with each other are provided, connected to the first rotor and the second rotor respectively. Thanks to these synchronization wheels, a synchronized movement of the two rotors of the volumetric machine is possible even in the event of stopping of one of the two motors. Indeed, as the two synchronization wheels are connected to two rotors and as they mesh at any time a movement, a non-synchronized rotation of the two rotors is not possible. Thus, damage to the screws is not possible either.
• the contact surface between the first synchronization wheel and the second synchronization wheel is not lubricated.
• the advantage of this embodiment of the invention is, among other things, that it allows for a volumetric machine absolutely free of any lubricating means. Due to this fact, such machines can also be used in sensitive applications, where high hygiene standards must be respected. Also, these machines are simpler to maintain since they do not need draining or other treatments of the lubricating means.
• Another embodiment of the present invention provides that the surface of the teeth of the first synchronization wheel and / or the second synchronization wheel is coated with a layer of a material having a low coefficient of friction.
• This embodiment is advantageous, among other things, because it creates synchronization wheels that are capable of to support the transmission of high torque between them, due to the fact that the friction at the contact surface of the two wheels is reduced.
• Materials that can be used as a coating are different types of metals and / or alloys (eg ferrous, copper, tin, lead alloys, etc.) as well as ceramics or various synthetic products (such as eg Teflon® or others).
• the machine includes a starter for synchronizing the starting of the first motor and the second motor.
• the advantage of this embodiment of the present invention lies, among other things, in a coordinated operation of the motors. Thanks to such coordinated start-up, the operating parameters of both motors (eg rotation speed and other parameters) can be synchronized to the maximum.
• FIG. 1 a partial sectional view of an exemplary embodiment of a volumetric machine according to an embodiment of the present invention
• FIG. 2 a perspective view of one end of the rotors of a volumetric machine according to an embodiment of the present invention, one of the two rotors is shown in section;
• FIG. 3 a view of a portion of the outer body of the volumetric machine according to an embodiment of the present invention.
• FIG. 1 is a diagrammatic sectional illustration of an exemplary embodiment of a volumetric machine according to the present invention.
• the volumetric machine according to the invention necessarily has other elements so that it can be operational.
• the volumetric machine 1 in Figure 1 essentially comprises a housing 2 which includes two rotors 3 'and 3 "2.
• the housing 2 of the machine 1 can be made as a single piece or, as shown in FIG. Typically, the housing 2 is open to one side and a cover 21 is used to close the housing 2 to create a closed enclosure.
• the rotors 3 ', 3 each comprise an axis 31', 31" on which are installed the two screws (not shown) with specific profiles.
• the two screws of the rotors 3 ', 3 are symmetrical with respect to the average axis A of the machine 1.
• the rotors 3', 3" are rotated in the directions opposed to each other.
• the drive principle of the rotors 3 ', 3 "in the volumetric machine 1 will be explained below.
• Solidarity of the housing 2 of the machine 1 is a drive casing 5 which comprises two motors 4 'and 4 "Of course, it is also conceivable to have two different drive casings, one for each of the motors 4 ', 4', or even any other solution.
• the 4 ', 4' motors are asynchronous electric motors which are composed of rotors 41 ', 41 "and stators 42', 42". While the stators 42 ', 42 “are immobile (and typically integral) with respect to the drive housing 5, the rotors 41', 41” are rotated (and thus represent rotating parts of the motors 4 ', 4 ") thanks to the magnetic fields created by currents in the stators 42 ', 42 "which induce currents in windings of rotors 41', 41".
• These elements well known asynchronous motors are not shown in Figure 1 since a skilled person is absolutely able to grasp their location and mode of operation in a real engine.
• the axes 31 ', 31 "of the rotors 3', 3” taper towards the motors 4 ', 4 "in the tapered areas 32', 32".
• These zones 32 ', 32 “of the rotors 3', 3” are connected to the rotors (to the rotating parts) 41 ', 41 “of the motors 4', 4" and can thus rotate directly with them.
• the rotors 3 ', 3 are typically rotatably supported by bearings 7', 7" which are housed between the drive casing and the enclosure enclosed by the casing 2.
• bearings 7', 7 are housed between the drive casing and the enclosure enclosed by the casing 2.
• synchronization wheels 6', 6" are provided, integral with the rotors 3 'and 3 ", respectively
• the teeth of the synchronizing wheels 6 ', 6" are not normally supposed to transmit torque between the two rotors 3', 3 ", the difference being the friction of the components and the variations of the However, this is possible thanks to the symmetry - albeit in the opposite direction - of the left part (with the rotor 3 'and the motor 4') and the right part (with the rotor 3 "and the motor 4") of the machine 1.
• the synchronizing wheels 6 ', 6 are used to guarantee a synchronization of the movements even in the case of a fault of one of the two motors, to guarantee that the rotation of the two rotors 3', 3" will remain identical.
• the wheels 6 ', 6 play the role of a" conventional "gear and transmit the torque from one rotor to the other. Thanks to this structure, the machine 1 can continue to operate for a gradual and safe stop for the entire installation.
• the object of the invention is to operate the pump equipped with an asynchronous motor for each rotor. These engines then rotate in a non-electronically synchronized manner with the dry or non-oil lubricated gear train.
• This object of the present invention is achieved by means of a structure of the volumetric machine as described above.
• toothings of synchronization wheels 6 ', 6 by calculation by optimizing certain parameters, the most of which important are the slip speed and the mechanical efficiency of the transmission.
• various suitable materials may be used to increase the desired performance of the 6 ', 6 "wheels, ie steels of different types (eg carburizing, nitriding, carbonitriding, tooling, etc.). as well as various synthetic or plastic materials.
• appropriate heat treatments can be applied to the wheel materials 6 ', 6 "to obtain high surface hardnesses as well as depth to the heart of the teeth, and appropriate machining and finishing for good gear precision. but also superfinitions to obtain a smoothest possible surface state are imaginable, especially to improve the coefficient of friction.It is obvious that appropriate machining and finishing can also be used to put the surfaces in a necessary state. for deposition of thin-film coatings.
• Coatings one or several successive, including PVD and CVD type that do not soak steels already treated with high hardness and provide even higher hardness, can also be applied to improve the coefficient of friction and reduce the wear.
• Figure 2 shows an end of the rotors of the volumetric machine, one of the two rotors being shown in section.
• a plastic toothing 63 which is fixed on a steel hub 61 and retained by a metal cover 64. This structure is blocked by the screws 62.
• these screws may in particular be in greater number than really necessary for mechanical fixing. Indeed, these screws 62 pass through the plastic toothing 63 and are in contact therewith, so as to serve as heat sink collecting calories and leading to the outer faces of the hub 61 and the cover 64.
• the outer face of the cover 64 and / or the face of the hub 61 may have grooves 641 which, by rotation, serve to facilitate the heat exchange with the air.
• one or more openings 22 of suitable shape and positioning can be provided to allow the circulation of air inside the machine for thus improve the extraction of heat.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Applications Or Details Of Rotary Compressors (AREA)
• Connection Of Motors, Electrical Generators, Mechanical Devices, And The Like (AREA)
• Rotary Pumps (AREA)
• Injection Moulding Of Plastics Or The Like (AREA)
• Mixers Of The Rotary Stirring Type (AREA)
• Transmission Devices (AREA)

Priority Applications (11)

Applications Claiming Priority (2)

Publications (2)

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ID=48539131

Family Applications (1)

Country Status (11)

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Family Cites Families (9)

• 2013
  • 2013-05-27 CN CN201380027129.5A patent/CN104350281A/zh active Pending
  • 2013-05-27 WO PCT/EP2013/060887 patent/WO2013175019A2/fr active Application Filing
  • 2013-05-27 KR KR1020147036391A patent/KR20150011397A/ko not_active Application Discontinuation
  • 2013-05-27 CA CA2872548A patent/CA2872548A1/fr not_active Abandoned
  • 2013-05-27 AU AU2013265173A patent/AU2013265173A1/en not_active Abandoned
  • 2013-05-27 IN IN2227MUN2014 patent/IN2014MN02227A/en unknown
  • 2013-05-27 US US14/400,614 patent/US20150098853A1/en not_active Abandoned
  • 2013-05-27 BR BR112014028701A patent/BR112014028701A2/pt not_active IP Right Cessation
  • 2013-05-27 JP JP2015513223A patent/JP2015520824A/ja active Pending
  • 2013-05-27 RU RU2014152812A patent/RU2014152812A/ru not_active Application Discontinuation
• 2015
  • 2015-06-04 HK HK15105314.1A patent/HK1204803A1/xx unknown

Non-Patent Citations (1)

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