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RU-2861696-C1 - IMPELLER OF CENTRIFUGAL TURBOMACHINE WITH REINFORCEMENT AND METHOD FOR ITS REINFORCEMENT

RU2861696C1RU 2861696 C1RU2861696 C1RU 2861696C1RU-2861696-C1

Abstract

FIELD: mechanical engineering. SUBSTANCE: invention relates to wheels of turbomachines and methods for reinforcing same, which can be used in compressors, expanders and pumps, and other centrifugal turbomachines. Disclosed is a reinforcement method and an impeller with such reinforcement, in the design of which the main disc 1 with protrusions 5 is mated by means of a tongue-and-groove type connection 6 with the grooves 5 of the cover disc 2, each of which is fixed by a weld seam along the perimeter, wherein on the surface of the cover disc, a spiral groove 7 is made, in which from one to three reinforcing threads 8 and a binder substance 9 are placed. Wherein the groove depth - a, the groove width - b, and the number of reinforcing threads depends on the groove parameters: if b<a, one reinforcing thread is placed in the groove, if aЈb<2a, two reinforcing threads are placed in the groove, if bі2a, three reinforcing threads are placed in the groove. EFFECT: increase in the reliability of the impeller of a centrifugal turbomachine. 18 cl, 5 dwg

Inventors

  • Vetkin Sergei Alekseevich
  • Kostiukova Olga Sergeevna
  • Stepanov Anton Valerevich
  • Tselmer Mark Leonidovich

Dates

Publication Date
20260507
Application Date
20250812

Claims (18)

  1. 1. An impeller of a centrifugal machine comprising a main disk with blades and a cover disk, a spiral groove is made on the cover disk, in which one or more reinforcing threads and a binder are placed, characterized in that the cover disk has grooves, and the blades of the main disk have projections that are connected to the grooves by means of tongue-and-groove connections, wherein each tongue-and-groove connection of the projections of the blades of the main disk and the grooves of the cover disk is fixed by a weld along the perimeter of the connection, and the groove is made over the weld, and the depth of the groove is a, the width of the groove is b, and the number of reinforcing threads depends on the parameters of the groove.
  2. 2. The impeller of a centrifugal machine according to paragraph 1, characterized in that the groove is made according to the Archimedes spiral.
  3. 3. The impeller of a centrifugal machine according to paragraph 1, characterized in that the groove is made along a logarithmic spiral.
  4. 4. The impeller of a centrifugal machine according to paragraph 1, characterized in that the groove is made with a U-profile cross-section.
  5. 5. The impeller of a centrifugal machine according to paragraph 1, characterized in that b<a, and one reinforcing thread is placed in the groove.
  6. 6. The impeller of a centrifugal machine according to paragraph 1, characterized in that a≤b<2a, and two reinforcing threads are placed in the groove.
  7. 7. The impeller of a centrifugal machine according to paragraph 1, characterized in that b≥2a, and three reinforcing threads are placed in the groove.
  8. 8. The impeller of a centrifugal machine according to paragraph 1, characterized in that the groove has a depth a of 1 to 6 millimeters.
  9. 9. The impeller of a centrifugal machine according to paragraph 1, characterized in that the binder is a thermosetting polymer.
  10. 10. The impeller of a centrifugal machine according to paragraph 1, characterized in that the reinforcing threads are placed at equal distances from each other and from the outer edge of the groove.
  11. 11. A method for reinforcing an impeller which includes joining the projections of the main disk blades with the grooves of the cover disk by means of a tongue-and-groove joint followed by a groove in which reinforcing threads and a binder are placed, characterized in that each tongue-and-groove joint of the projections of the main disk blades and the grooves of the cover disk is fixed with a weld along the perimeter of the joint, a groove is made over the weld, where the groove depth is a, the groove width is b, while the groove is made in a spiral from the center, after which one or more reinforcing threads are placed in the groove and filled with a binder, with the excess subsequently removed.
  12. 12. The method for reinforcing the impeller according to paragraph 11, characterized in that one reinforcing thread is placed in the groove, in the case where b<a.
  13. 13. The method of reinforcing the impeller according to paragraph 11, characterized in that two reinforcing threads are placed in the groove, in the case where a≤b<2a.
  14. 14. The method of reinforcing the impeller according to paragraph 11, characterized in that three reinforcing threads are placed in the groove, in the case where b≥2a.
  15. 15. The method for reinforcing the impeller according to paragraph 11, characterized in that the groove is machined with rounded edges of a U-profile section with a depth of 1 to 6 millimeters.
  16. 16. The method for reinforcing the impeller according to paragraph 11, characterized in that after laying the reinforcing threads and before filling with the binder, the threads are impregnated with epoxy resin followed by polymerization.
  17. 17. The method for reinforcing the impeller according to paragraph 11, characterized in that the groove is machined along the Archimedes spiral so that the center of the spiral is the center of the impeller.
  18. 18. The method for reinforcing the impeller according to paragraph 11, characterized in that the groove is machined along a logarithmic spiral so that the center of the spiral is the center of the impeller.

Description

Field of technology The invention relates to the field of mechanical engineering, namely to turbomachine wheels and methods for reinforcing them, which can be used in compressors, expanders, pumps, and other centrifugal turbomachines. State of the art A method for manufacturing a gas turbine engine blade from a composite material, the resulting blade, and a gas turbine engine incorporating such a blade are known. Patent RU 2678479 (convention priority: May 22, 2014) comprises a turbine or compressor wheel for a gas turbine engine, including blades made of composite material manufactured using multiple layers of reinforcing threads. A disadvantage of this solution is the limited strength and reliability provided by composite elements, with the reinforcement extending only to the blades, not providing sufficient reinforcement on the surfaces of the impeller discs. A composite reinforced rotor is known from US Patent No. 11,268,388. It comprises a main disk with blades and first and second reinforcing rings made of fiber-reinforced materials. The rings are conical in shape, with their upper surfaces aligned with the upper edges of the first and second retaining elements, and a radial thickness decreasing from the center to the edge of the disk. The composite reinforcing rings can be manufactured separately from the rotor system components and installed during assembly, or removed and reinstalled. A disadvantage of this solution is the limited number of reinforcements located on the disk, as well as the insignificant degree of reinforcement provided by composite elements not anchored to the metal. A stator sector for a gas turbine engine is known from patent RU 2684075, in which each opening in the first platform has a continuous edge, and each continuous edge is in continuous contact with the corresponding first end of the corresponding blade. The first and second platforms and the first and second ends of the blade are formed and positioned so as to be joined with a tenon joint. The design does not contain seals on the tenon joint, and all components are made of ceramic matrix composite materials. A relevant prior art analog is the impeller of a submersible centrifugal pump according to patent RU 11277, which discloses an impeller comprising a disc with grooves mating with the blade projections. The projections are taller than the thickness of the cover disc, and a locking joint formed by the surface of the cover disc grooves and the projections of the supporting disc. The locking joint is formed by simultaneously melting the projections until they are aligned. A disadvantage of the RU 11277 analog is that the tongue-and-groove joint connecting the blades to the cover disc does not provide sufficient mechanical strength and reliability for the centrifugal impeller. A common drawback of turbomachine impeller analogs is the use of tongue-and-groove connections between the wheel discs and blades or similar fasteners, which do not provide sufficient reliability. Furthermore, complex welding equipment and limited access to the surfaces being welded lead to early deformation of the wheels during operation. A method for manufacturing a turbine impeller from composite materials is known according to patent RU 2280767, which consists of winding carbon fiber, pre-impregnated with a heat-resistant binder, through cuts in the main and cover disks, alternating directions, winding is carried out in alternating layers until the tooling is completely filled, after completing the winding of the blank, the carbon fibers are stretched and after this, interblade liners are installed between them, carbon fibers extending beyond the interblade liners on the outside are cut off, an auxiliary technological ring is removed, the assembled tooling with the wound blank of the turbine impeller is placed in a matrix and pressed with a punch, and after curing of the binder, the impeller is removed from the press mold and the interblade liners are removed. The disadvantage of this method is the multi-stage winding process, the use of additional auxiliary tools: molds and inserts, as well as the need to saw through the cover and main discs, binding them with carbon fibers. A gas turbine engine component and its manufacturing method are known from patent RU 2632065, wherein the strands of interwoven fiber reinforcement extend continuously in a circumferential direction along the entire segment of the inner shroud, and the strands of interwoven fiber reinforcement extend continuously in a circumferential direction along the entire segment of the outer shroud (sun-shaped). The component comprises an inner shroud sector, an outer shroud sector, and at least three guide vanes extending between the shroud sectors and attached to them. This can be considered as impeller disks connected by blades having reinforcement; however, this design is made entirely of composite material and assumes full reinforcement along both disks continuously along a comp