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
  • 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
  • F04C23/005—Combinations of two or more pumps, each being of rotary-piston or oscillating-piston type, specially adapted for elastic fluids; Pumping installations specially adapted for elastic fluids; Multi-stage pumps specially adapted for elastic fluids of dissimilar working principle
• • 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
  • F04C18/082—Details specially related to intermeshing engagement type pumps
  • F04C18/084—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
  • 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
  • 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
  • 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
  • F04C2220/00—Application
  • F04C2220/10—Vacuum
  • F04C2220/12—Dry running
• • 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
  • F04C2240/20—Rotors
• • 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
  • F04C2240/30—Casings or housings
• • 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
  • F04C2250/00—Geometry
  • F04C2250/20—Geometry of the rotor

Definitions

• the present invention relates to the field of pumping and compressing gases. More specifically, it relates to a dry gas pump, as well as a set of several dry gas pumps.
• a screw pump consists of two screws that interpenetrate and are driven in opposite directions each on one of two parallel axes of rotation.
• each screw belongs to a rotor which further comprises a lobe portion so that the screw pump and a lobe pump are combined one after the other as is. for example the case in the American patent US Pat. No. 7,611,340 B2.
• the screw threads can vary along the screw, to define an internal compression ratio of the gas between the upstream end of the screws and their downstream end.
• screw threads can vary with a gradual or stepped change in the pitch of each thread.
• a modification of the compression ratio requires producing, for each screw, a new form of screw whereas, in screw pumps, the shape of the screws with variable thread is very complex and therefore very difficult to design and to be machined.
• the aim of the invention is at least to simplify the design and / or production of a range of dry gas pumps having different compression ratios. More particularly, the object of the invention is to provide a range of dry gas pumps offering, for the same or similar constraints in terms of size, energy consumption, etc., the flexibilities and advantages of a screw pump. with variable pitch, but with rotors with a profile that is easier to design and / or machine.
• a dry gas pump comprising a first rotor comprising a first lobe portion and a first screw, a second rotor comprising a second lobe portion and a second screw, as well as a envelope in which the first and second rotors are rotatably mounted so that the first and second screws interpenetrate and the first and second lobe portions mesh with each other.
• the envelope defines an internal volume in which there are both the first and the second screw and the first and the second lobed portion. At least one inlet opens into the internal volume at the level of the first and second lobe portions. At least one outlet of the internal volume is opposite the inlet with respect to the first and second screw.
• Each of the first and second screws has an invariable thread along its length.
• the first and second rotors rotate in opposite directions so as to be able to be successively in: ⁇ a first configuration wherein the first and second lobe portions, a portion of the first screw, a portion of the second screw and the shell together define a chamber which is closed,
• the first and second screws serve to seal and open the chamber.
• the role of the first and second lobe portions is to effect the compression.
• the first and second screws may thus not have the role of compressing and the thread of each of them is invariable along its length. As a result, these first and second screws are not difficult to design, nor to produce, compared to screws with variable threads.
• the compression ratio is a function of the first and second lobe portions.
• This compression ratio can be modified by varying the size of the first and second lobe portions in the axial direction. From a first given screw and from a second given screw, it is therefore possible to build pumps that do not have the same compression ratios, depending on the axial dimension of the lobe portions that are associated with these first and second screw. However, the lobed portions are much less difficult to produce than screws. Thus, a range of dry gas pumps having different compression ratios can be designed and produced more easily by virtue of the invention.
• the dry gas pump defined above may incorporate one or more other advantageous features, singly or in combination, in particular among those defined below.
• the first and second lobe portions comprise lobes each of which is extended by one of the helical threads of the threads of the first and second screws.
• the number of lobes of the first lobe portion is equal to the number of helical threads of the thread of the first screw, the number of lobes of the second lobe portion being equal to the number of helical threads of the thread of the second screw.
• the outlet is located at a distance from the first and second screw.
• the chamber is one of several successive chambers that the first and second rotors and the casing define together.
• one of the successive chambers is a collecting chamber which has the outlet of the internal volume.
• the thread of the first screw and the thread of the second screw define helical grooves, the downstream ends of the helical grooves being open and opening into the collecting chamber whatever the angular positions of the first and second rotors.
• the first and second screws do not compress.
• one of the successive chambers is an intake chamber which communicates with the entrance.
• the first rotor is a male rotor, the second rotor being a female rotor.
• the second rotor comprises one more lobe than the first rotor.
• the first rotor comprises several lobes which are two in number, the second rotor comprising several lobes which are three in number.
• the first rotor has a cross section which is the same at the level of the first lobed portion and at the level of the first screw, except for its angular orientation, while the second rotor has a cross section which is the same at the level of the second portion with lobes and at the level of the second screw, within its angular orientation.
• the first rotor comprises at least two one-piece elements, held together, which are a first one-piece element comprising at least the first screw and a second one-piece element comprising at least part of the first portion with lobes.
• the subject of the invention is also a set of several dry gas pumps as defined above.
• the first screws of a first dry gas pump in the set and a second dry pump for gas in the set are identical, the second screws of the first dry pump for gas gas and the second dry gas pump being identical, the first and second lobe portions of the first dry gas pump having an axial dimension which is a first axial dimension, the first and second lobe portions of the second dry gas pump being gas having an axial dimension which is a second axial dimension different from the first axial dimension.
• FIG. 1 is a schematic view in axial section of a dry gas pump according to one embodiment of the invention
• FIG. 2 is a perspective view which shows two rotors constituting the pump of Figure 1 and which is simplified in that the shafts of these rotors are omitted;
• FIG. 3 is an exploded side view, which shows only one of the two rotors of the pump of Figure 1 and which is simplified in that the shaft of the rotor shown is omitted;
• FIG. 4 is a view which is simplified like Figures 2 and 3, which shows the same rotors as in Figure 2, as well as chambers partially delimited by these rotors in the pump of Figure 1, and where the rotors are seen by one end;
• FIG. 5 is a perspective view which is simplified like Figures 2 and 3 and which shows the same rotors as in Figure 2, as well as the chambers partially delimited by these rotors in the pump of Figure 1;
• - Figure 6 is a perspective view showing a chamber among the chambers visible in Figures 4 and 5;
• FIG. 7 is a perspective view which shows the same chamber as Figure 6 but later, that is to say at a time after the time at which this chamber is as shown in Figure 6;
• FIG. 8 is a perspective view which shows the same chamber as Figures 6 and 7 but later, that is to say at a time after the time at which this chamber is as shown in Figure 7 ;
• FIG. 9 is a graph showing the evolution of the capacity of the chamber of Figures 6 to 8 over time.
• a dry gas pump according to one embodiment of the invention comprises a first rotor 1 and a second rotor 2, which are mounted in a casing 3 made of several parts held together.
• bearings 5 support a shaft 6 of the first rotor 1 so that this first rotor 1 is rotatable on an axis of rotation Xi-X'i.
• bearings 7 support a shaft 8 of the second rotor 2 so that this second rotor 2 rotates on an axis of rotation X2-X'2 parallel to the axis of rotation Xi-X'i.
• the axial direction is the direction parallel to the axes of rotation Xi-X'i and X2-X 2
• an axial dimension is a dimension along the direction parallel to the axes. axes of rotation Xi-X'1 and X2-X'2.
• One end of shaft 8 is coupled to a motor 10
• the shaft 8 of the second rotor 2 carries a toothed wheel 11 which meshes with a toothed wheel 12 carried by the shaft 6 of the first rotor 1.
• the toothed wheels 11 and 12 form a gear whose gear ratio equal to 3/2 is such that the first rotor 1 turns faster than the second rotor 2.
• the first rotor 1 comprises a first portion with lobes 1A and a first screw 1B which follow one another axially without distance between them.
• the second rotor 2 comprises a first portion with lobes 2A and a first screw 2B which follow one another axially without distance between them.
• the first lobe portion 1 A, the first screw 1 B, the second lobe portion 2A and the second screw 2B are all located in the same internal volume 14, which delimits the casing 3 without partitioning it.
• An inlet 15 for the admission of gas passes through the casing 3 and opens into the internal volume 14, at the level of the first and second lobe portions 2A and 2B, on one side of the plane passing through the axes of rotation Xi -X'i and X2-X'2.
• An outlet 16 for the delivery of gas passes through the casing 3 and communicates with the internal volume 14, at the level of a collecting chamber 18 which consists of a downstream portion of this internal volume 14 and which is located at the bottom. exit from the first and second screws 1B and 2B, that is to say opposite the first and second lobe portions 1A and 2A with respect to these first and second screws 1B and 2B.
• the internal volume 14 is cylindrical at least at the level of the first and second screws 2A and 2B, being constituted by the union of two interpenetrating cylinders of revolution, the respective axes of which are the axes of rotation Xi-X'i and X2 -X'2.
• the internal volume 14 is cylindrical in an identical manner, at least on the side opposite the entry 15 with respect to the plane containing the axes of rotation Xi-X'i and X2 -X2.
• a downstream and lateral portion of the internal volume 14 can constitute an inlet chamber where the internal volume 14 is enlarged laterally and where the inlet 15 opens.
• the references 17 designate devices each of which provides a seal between the casing 3 and one of the shafts 6 and 8.
• the first rotor 1 is a male rotor.
• the first lobe portion 1 A comprises several lobes 20 which are identical and which are two in number in the embodiment shown.
• the screw 1 B comprises a thread consisting of as many helical threads 21 as there are lobes 20. This thread is invariable over the entire length of the screw 1 B. Its pitch, its average diameter and its profile, c ' that is to say the shape and dimensions of its section along an axial plane passing through the axis of rotation Xi-X'i, are invariable over the entire length of the screw 1 B.
• Each lobe 20 is extended by the one of the two helical threads 21, which are identical.
• the number of lobes 20 may be different from two. The same applies to the number of helical threads 21.
• the second rotor 2 is a female rotor.
• the second lobe portion 2A comprises several lobes 22 which are identical and which are three in number in the embodiment shown.
• the screw 2B comprises a thread consisting of as many helical threads 23 as there are lobes 22. This thread is invariable over the entire length of the screw 2B. Its pitch, mean diameter and profile, that is to say the shape and dimensions of its section along an axial plane passing through the axis of rotation X2-X 2, are invariable over the entire length of the screw 2B.
• Each lobe 22 is extended by one of three helical threads 23, which are identical. The number of lobes 22 may be different from two. The same applies to the number of helical threads 23.
• the first lobe portion 1 A meshes with the second lobe portion 1 B.
• the first and second screws 1 B and 2B interpenetrate.
• the first rotor 1 has a cross section which is the same at the level of the first lobe portion 1 A and at the level of the first screw 1 B, except for its angular orientation.
• the second rotor 2 has a cross section which is the same at the level of the second lobe portion 2A and at the level of the second screw 2B, except for its angular orientation.
• the first rotor 1 results from the assembly of several monobloc elements, a first of which comprises the first portion with lobes 1 A and a second of which comprises the first screw 1 B.
• the shaft 6 can form part of the first one-piece element of the first rotor 1 or of the second one-piece element of the first rotor 1.
• a third one-piece element of the first rotor 1 can form the shaft 6.
• the second rotor 2 results of the assembly of several single-piece elements, a first of which comprises the second lobe portion 2A and a second of which comprises the second screw 2B.
• the shaft 8 can form part of any of the first and second single-piece elements of the second rotor 2.
• first rotor 1, second rotor 2 and casing 3 jointly define several successive chambers which are visible in FIG. 4, for some, and in FIG. 5, for all.
• the chamber 30 is as shown in Figure 6.
• the chamber 30 has the shape and position that chamber 31 has in Figures 3 and 4.
• the chamber 30 is as shown in Figure 8.
• the chamber 30 has the shape and position that the chamber 32 has in Figures 3 and 4.
• the chamber 30 is closed by being closed, at its downstream end, that is to say at P1, by the crossing of a helical thread 21 and a helical thread 23.
• the first and second lobe portions 1 A and 2A, a portion of the first screw 1 B, a portion of the second screw 2B and the casing 3 together delimit the chamber 30, which has almost reached its maximum capacity .
• first and second lobe portions 1 A and 2A reach a configuration from which together they reduce the capacity of the chamber 30, the downstream end of which is still closed at P1 by the crossing of a helical thread 21 and a helical thread 23.
• the chamber 30 is shown at a chosen time. while the first and second lobe portions 1A and 2A together reduce the capacity of chamber 30. At the same time as the first and second lobe portions 1A and 2A together reduce the capacity of chamber 30, there occurs a compression of the gas present in this chamber 30.
• Curve C in FIG. 9 is the graphic representation of the capacity V of chamber 30 as a function of time t.
• the role of the first and second screws 1 B and 2B is not to effect a reduction in capacity and therefore compression.
• the role of the first and second screws is to perform a succession of obturations identical to the obturation at P1, which retains gas when, in chamber 30, this gas is compressed by the first and second lobe portions 1 A and 2A.
• the first and second screw also have the role of effecting a succession of plugs identical to the plugging in P2, which isolates the gas present in the chamber 30 from the first and second lobe portions 1 A and 2A after the compression of this gas.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Applications Or Details Of Rotary Compressors (AREA)
• Sampling And Sample Adjustment (AREA)

Priority Applications (1)

Applications Claiming Priority (1)

Publications (3)

Family

ID=65904380

Family Applications (1)

Country Status (11)

Families Citing this family (1)

Family Cites Families (18)

• 2019
  • 2019-03-14 US US17/439,018 patent/US11920592B2/en active Active
  • 2019-03-14 PL PL19712929.9T patent/PL3938657T3/pl unknown
  • 2019-03-14 AU AU2019433234A patent/AU2019433234B2/en active Active
  • 2019-03-14 CA CA3128596A patent/CA3128596A1/fr active Pending
  • 2019-03-14 JP JP2021554379A patent/JP7315693B2/ja active Active
  • 2019-03-14 ES ES19712929T patent/ES2951988T3/es active Active
  • 2019-03-14 CN CN201980093824.9A patent/CN113544384B/zh active Active
  • 2019-03-14 WO PCT/EP2019/056501 patent/WO2020182317A1/fr not_active Ceased
  • 2019-03-14 EP EP19712929.9A patent/EP3938657B1/de active Active
  • 2019-03-14 KR KR1020217033262A patent/KR102583846B1/ko active Active
• 2020
  • 2020-03-09 TW TW109107704A patent/TWI831938B/zh active

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