Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/25—Component parts, details or accessories; Auxiliary operations
  • B29C48/36—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die
  • B29C48/375—Plasticisers, homogenisers or feeders comprising two or more stages
  • B29C48/38—Plasticisers, homogenisers or feeders comprising two or more stages using two or more serially arranged screws in the same barrel
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B7/00—Mixing; Kneading
  • B29B7/30—Mixing; Kneading continuous, with mechanical mixing or kneading devices
  • B29B7/34—Mixing; Kneading continuous, with mechanical mixing or kneading devices with movable mixing or kneading devices
  • B29B7/38—Mixing; Kneading continuous, with mechanical mixing or kneading devices with movable mixing or kneading devices rotary
  • B29B7/46—Mixing; Kneading continuous, with mechanical mixing or kneading devices with movable mixing or kneading devices rotary with more than one shaft
  • B29B7/48—Mixing; Kneading continuous, with mechanical mixing or kneading devices with movable mixing or kneading devices rotary with more than one shaft with intermeshing devices, e.g. screws
  • B29B7/488—Parts, e.g. casings, sealings; Accessories, e.g. flow controlling or throttling devices
  • B29B7/489—Screws
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B7/00—Mixing; Kneading
  • B29B7/74—Mixing; Kneading using other mixers or combinations of mixers, e.g. of dissimilar mixers ; Plant
  • B29B7/7476—Systems, i.e. flow charts or diagrams; Plants
  • B29B7/7495—Systems, i.e. flow charts or diagrams; Plants for mixing rubber
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/25—Component parts, details or accessories; Auxiliary operations
  • B29C48/36—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die
  • B29C48/395—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die using screws surrounded by a cooperating barrel, e.g. single screw extruders
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/25—Component parts, details or accessories; Auxiliary operations
  • B29C48/36—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die
  • B29C48/395—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die using screws surrounded by a cooperating barrel, e.g. single screw extruders
  • B29C48/40—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die using screws surrounded by a cooperating barrel, e.g. single screw extruders using two or more parallel screws or at least two parallel non-intermeshing screws, e.g. twin screw extruders
  • B29C48/402—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die using screws surrounded by a cooperating barrel, e.g. single screw extruders using two or more parallel screws or at least two parallel non-intermeshing screws, e.g. twin screw extruders the screws having intermeshing parts
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion

Definitions

• the present invention relates to positive displacement pumps intended in particular for rubber mixtures and, more particularly, gear pumps.
• volumetric gear pumps for high viscosity plastic materials such as that described in publication US 5 120 206.
• a gear comprising a motorized toothed drive wheel, "driving wheel”, and a second wheel in engagement with the first and driven in rotation by the latter, as well as a booster screw which makes it possible to forcefully feed said pump of high viscosity plastic material.
• the rubber mixtures also have a very high viscosity which causes a very high resistive torque on the driving wheel.
• This resistant torque is all the more important when one seeks to achieve high flow rates by increasing the width of the toothed wheels.
• the positive displacement pump in particular for rubber mixtures, comprising force-feeding means for discharging the material towards an enclosure opening onto an outlet orifice and in which two counter-rotating screws rotate meshing with one another by through the respective helical threads they carry, the axial length of the meshing zone of these screws being greater than or equal to the sum of the thread pitch of the threads and the pitch of the propeller multiplied by the number of threads of each screws multiplied by 2.
• the counter-rotating screws are meshed without contact.
• This embodiment makes it possible to ensure the volume of the pumping and the reliability of the pump by transmitting a motor torque to each screw.
• FIG. 1 is a longitudinal section of the pump according to the invention along the plane passing through the axes of rotation of each of the screws,
• FIG. 2 is a radial section of the pump according to the invention according to line II-II shown in Figure 1.
• the gear pump 1 comprises a body 10 which carry two counter-rotating screws 2 and 3 with axes parallel to each other.
• the free ends 24 and 34 of these two screws 2 and 3 cooperate with one another by means of their helical threads, inside an enclosure 11 carried by the body 10 so as to pump volumetrically. Note that only the screw threads of screw 3 have been shown in dotted lines in FIG. 1.
• the ends 24 and 34 form an association of elements comparable to a gear although there is no contact between the ends 24 and 34, nor between their threads.
• each screw 2, 3 thus comprises several zones whose function and environment are different, which will be called zones A, B, C and D in Figures 1 and 2 for clarity.
• Each screw 2, 3 thus has:
• a feeding zone B which follows zone A in the direction of advancement of a mixture during the rotation of the screws, in which the parts 22, 32 of each screw 2, 3 rotate in a common chamber 4 without, however, the threads of the screws being in contact, one of the screws 2 having in this zone a diameter greater than the other screw,
• zone C for the transmission of material flows follows zone B where there has been a separation of the flows of mixtures arriving on the corresponding parts of screws 23 and 33, the chamber 4 having been divided into two chambers 42 and 43 In this area the two screws 2 and 3 have the same diameter.
• Zone A corresponds to the motorization of the pump by the motorization of each of the screws 2 and 3.
• a single motor is used with a specific reduction gear to drive each of the screws. This reducer imposes an angular clearance between the screws 2 and 3 which preserves from mechanical contact their free ends 24 and 34.
• bilateral mechanical stops not shown , in zone A axially position the two screws 2 and 3.
• the zone B for supplying the mixture is itself axially divided into a zone B 'and a zone B "delimited by the radial wall 6, the zone B' being delimited by the internal wall 15 of the body 10.
• the chamber 4 located in zone B is supplied by a single supply orifice 5 disposed in zone B 'circumferentially in between the axes of the two screws 2 and 3 therefore at the level of parts 22' and 32 'of the two screw.
• the zone 32 ′ of the screw 3 of smaller diameter plays the role of a feed roller for the other screw, this zone having no thread and its diameter bringing it into contact with the wall 15 of the body 10.
• the passage of the mixture between the axes of the two screws to the chamber 4 is produced by a thread 16 cut in the body 10 which opens into the zone B ".
• the difference in diameter in this zone B in general makes it possible to facilitate the supply of mixture and thus to make the force-feeding of the pump.
• zone B "to zone C consists of a division in two of the chamber 4 and a conical part 23 'of the screw 3 in order to reduce its diameter to a diameter identical to that of the screw 3.
• the screws 2 and 3 must indeed have same twist and same flow upstream of their free ends so that the pump can operate.
• each screw has a conical zone respectively 24 'and 34' making it possible to increase their diameter to adjust the flow rate between zones C and D.
• an interesting form is to use involutes of circles for the sides of the nets.
• the enclosure 11 opens onto a system converging towards an outlet 17 as seen in FIG. 2.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Rotary Pumps (AREA)
• Extrusion Moulding Of Plastics Or The Like (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=8866581

Family Applications (1)

Country Status (5)

Families Citing this family (3)

Family Cites Families (11)

• 2002
  • 2002-08-09 EP EP02764840A patent/EP1420933A1/de not_active Withdrawn
  • 2002-08-09 CN CNA028159837A patent/CN1543395A/zh active Pending
  • 2002-08-09 WO PCT/EP2002/008969 patent/WO2003016024A1/fr active Application Filing
  • 2002-08-09 JP JP2003520560A patent/JP2004538182A/ja active Pending
• 2004
  • 2004-02-17 US US10/778,208 patent/US20040161356A1/en not_active Abandoned

Non-Patent Citations (1)

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