Classifications

• • 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
  • F04B43/00—Machines, pumps, or pumping installations having flexible working members
  • F04B43/12—Machines, pumps, or pumping installations having flexible working members having peristaltic action
  • F04B43/1253—Machines, pumps, or pumping installations having flexible working members having peristaltic action by using two or more rollers as squeezing elements, the rollers moving on an arc of a circle during squeezing

Definitions

• the present invention relates to a drive shaft for a peristaltic pump and its manufacturing method.
• drive shafts are used to rotate rollers, which crush deformable tubes containing the liquid to be conveyed.
• the drive axes are connected by all appropriate links to a control motor.
• the control motor rotates the drive axis, which acts on at least one roller adjacent to it.
• the drive axes are metallic, they are more particularly made of stainless steel, while the rollers are made of various plastics.
• a bad drive of a rotary roller by an axis does not allow to have a regular and appropriate crushing of the deformable tube, with which a rotary roller comes into contact and, consequently, a good routing of the liquid to be conveyed.
• the present invention overcomes the aforementioned drawbacks by providing a drive axis r of rotating rollers, with which one obtains a slip-free drive of a roller by the shaft.
• the drive is obtained without crushing the rollers and with a very low engine torque.
• the present invention also relates to the method of manufacturing such an axis.
• the present invention therefore creates a drive axis of at least one rotary roller, which is characterized in that the external part of said drive axis has surfaces treated by projection of particles to give it a controlled roughness capable of allowing a drive without sliding of the roller relative to the axis.
• the present invention also relates to a method of manufacturing a drive shaft of a peristaltic pump with rotary rollers from a cylindrical metal axis, in which the zone intended to come into contact with a rotary roller is turned, then rectified, in order to obtain a controlled uniform surface condition, which is characterized in that at least part of said zone intended to come into contact with a roller is surface treated by spraying a material for give it a controlled roughness.
• the present invention also relates to the following characteristics, considered in isolation or according to all their technically possible combinations:
• the treated surfaces are produced selectively on one or more zones of the drive axis
• the surface treatment is a shot peening, in which glass beads, particles of tungsten, sand, or the like, are projected onto the external surface of the drive axis;
• the upper part of the axis has a rounded conical shape; the radius of curvature of the axis cone is approximately equal to half the diameter of the axis at the rollers;
• the treated parts intended to come into contact with the rollers correspond to the upper part and to the lower part of a roller, which produces the crushing of the tube by its middle part;
• FIG. 1 is a top view of part of a peristaltic pump
• FIG. 2 is a section taken on the line II-II of Figure 1;
• FIG. 3 is a partial schematic section of an axis and a roller. As shown in Figure 1, there is schematically and partially illustrated a peristaltic pump 4, with which three rollers 2 are rotated by a drive shaft 1 driven by a motor not shown.
• the drive shaft 1 has several different zones on its outer surface coming into contact with at least one roller 2 housed in the peristaltic pump 4.
• the drive shaft 1 is secured to a shoulder ent 12 ensuring its retention in the peristaltic pump body.
• the control motor 5 of the drive shaft 1 is connected to the latter by a link 13, which can take any suitable form.
• the external surface 6 of the drive axis l, coming into contact with at least one roller 2, comprises treated surfaces 7, 7 'cooperating with selective parts of the roller 2.
• Figure 2A shows the detail A of the top nozzle of the drive shaft 1 r.
• the upper part 8 of the drive shaft 1 has a rounded conical shape.
• the radius of curvature 9 of the cone is substantially equal to half the diameter 10 of the drive axis 1 at the level of the rollers 2.
• Figure 3 shows the cooperation between an example of a drive axis 1 according to the present invention, and a particular example of a rotary roller having a bulged configuration.
• the tube 3 is compressed by the middle part 11 of the rotary roller 2.
• the surface treatment of the drive axis 1 of the rollers 2 is what is known as shot blasting or billing.
• particles are projected at a certain angle and under a determined pressure, in order to obtain a controlled roughness of the selective parts of the drive axis having received the projections. solid particles.
• projections of solid particles can be, for example, projections of glass beads, tungsten particles, particles of various hard materials such as diamond. Naturally, it can also be various particles of sand.
• the drive shaft is manufactured under the following conditions.
• the axle is made of a material, for example steel, stainless.
• the axis is carried by a rotary head and is subjected to the projections of an oriented nozzle, approximately perpendicular to the axis, and driven by an alternating movement parallel thereto.
• the nozzle thus scans the selective parts 7, 7 ′ of the axis to be shot blasted.
• Shot blasting balls are glass balls or diamond crystals with an average size of
• the projection time was 5 seconds, at a distance of 100 mm, at a shooting angle of 90 °.
• the pressure of the machine projecting the abrasive was
• the axis is then subjected to a heat treatment accompanied by a deposit of titanium nitride, for example with a thickness equal to 2 micrometers.
• This treatment makes it possible to increase the surface hardness of the axis without changing its surface condition.
• the shot peening or blasting treatment applied to the drive shaft 1 of the present invention ensures good drive of the roller (s) 2, without wear or abrasion of said roller (s) 2. There is no also no transfer of plastic particles on the axis, which could lead to blockage of the craters created by shot blasting or billing.
• the part of the drive shaft is fully polished before billing and, after the billing operations, the dimensions of the drive shaft 1 are not not modified, which makes it possible to obtain excellent dimensional precision of the diameter of the drive axis 1.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Reciprocating Pumps (AREA)
• External Artificial Organs (AREA)
• Shafts, Cranks, Connecting Bars, And Related Bearings (AREA)
• Press Drives And Press Lines (AREA)
• Rolls And Other Rotary Bodies (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=9429256

Family Applications (1)

Country Status (9)

Families Citing this family (2)

Family Cites Families (4)

• 1992
  • 1992-04-24 FR FR9205114A patent/FR2690484B1/fr not_active Expired - Fee Related
• 1993
  • 1993-04-22 AT AT93911815T patent/ATE142311T1/de not_active IP Right Cessation
  • 1993-04-22 DE DE69304502T patent/DE69304502T2/de not_active Expired - Fee Related
  • 1993-04-22 ES ES93911815T patent/ES2092308T3/es not_active Expired - Lifetime
  • 1993-04-22 WO PCT/FR1993/000396 patent/WO1993022559A1/fr not_active Ceased
  • 1993-04-22 CA CA002110981A patent/CA2110981A1/fr not_active Abandoned
  • 1993-04-22 JP JP5518986A patent/JPH06508669A/ja active Pending
  • 1993-04-22 AU AU42635/93A patent/AU663793B2/en not_active Ceased
  • 1993-04-22 EP EP93911815A patent/EP0604604B1/de not_active Expired - Lifetime

Non-Patent Citations (1)

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