Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D29/00—Details, component parts, or accessories
  • F04D29/18—Rotors
  • F04D29/22—Rotors specially for centrifugal pumps
  • F04D29/2205—Conventional flow pattern
  • F04D29/2222—Construction and assembly

Definitions

• the invention relates to a closed-type impeller for pumps, which is joined together by welding from a plurality of sheet metal parts, the blades of which are designed as individual parts and welded to the cover disks attached thereto, the blades being only partially fastened along their length.
• Such impellers are known from EP-B 0 283 825 and SU-A 130 348. Their impellers are welded together by so-called fillet welds, ie the fillet weld is created on two components that are at an angle to one another in the joint area by means of welding electrodes. To a certain extent, the impellers are assembled from the inside and this requires good access to the welding point. In the case of a usually curved and covered blade duct, this is only easily possible in the beginning and end area. On the other hand, there are such tight spatial conditions in the central region of the blade channel that welding the blades to the cover disks is very difficult there, at least when a blade channel is closed by a cover disk to be attached to it.
• the blades can be positioned in the cover disks.
• One or both impeller cover disks can have recesses corresponding to the blade contour.
• the blades can then be fixed in place during assembly and then welded from the outside. This can be done with or without the help of welding additives.
• the blade parts which have a gap to the cover disk in the inlet region are plastically deformable.
• This gap in the area of the suction and / or pressure-side cover plate makes it possible that with the help of a U-shaped tool suitable position of the blade entry area can be generated for the respective intended use of the impeller. This possibility therefore allows both an angular change of the blade leading edges and a subsequent change in shape of the entire blade entry area.
• the impeller 1 has a hub 2 which is connected to a pressure-side cover disk 3.
• Several blades 5 are located between the pressure-side cover disk 3 and a suction-side cover disk 4.
• the parts can be securely positioned and welded by welding devices 6, 7 acting on the cover disks 3, 4 from the outside.
• Columns 8, 9 remain in the inlet area of the impeller between the cover disks 3, 4 and the blades 5.
• the inlet area with its curved geometry has elasticity, while the middle and outer blade area, which are subjected to higher centrifugal forces, have homogeneous and high-quality, continuous welded connections having. Even in the usually inaccessible middle blade area.
• the weld connection is made here using known welding processes.
• the blades 5 positioning recesses can be made. However, it is equally possible to hold the blades in suitable devices during the welding process.
• the cover disks 3, 4 are connected to the edges of the blades 5 by means of the welding process acting on the outside of the impeller.
• the gaps form a significant advantage in that they provide the possibility of subsequently shaping the blade beginnings or the blade entry areas.
• the blade shape that is suitable for the respective purpose of use of the impeller could then be generated by means of forming technology.
• only one gap can also be provided. This would then only be present in the area of the suction or pressure side cover plate.
• the inlet area of the blades can thus be optimized in terms of flow technology for a desired pump size. This is particularly interesting if blades for several sizes are designed uniformly.

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=6508876

Family Applications (1)

Country Status (6)

Cited By (2)

Families Citing this family (5)

Citations (7)

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• 1994
  • 1994-01-28 DE DE4402493A patent/DE4402493A1/de not_active Withdrawn
• 1995
  • 1995-01-07 DE DE59504144T patent/DE59504144D1/de not_active Expired - Lifetime
  • 1995-01-07 EP EP95905125A patent/EP0741840B1/de not_active Expired - Lifetime
  • 1995-01-07 AT AT95905125T patent/ATE173062T1/de not_active IP Right Cessation
  • 1995-01-07 WO PCT/EP1995/000050 patent/WO1995020724A1/de active IP Right Grant
  • 1995-01-07 DK DK95905125T patent/DK0741840T3/da active
  • 1995-01-07 JP JP7519854A patent/JPH09511557A/ja active Pending

Patent Citations (7)

Non-Patent Citations (2)

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