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EP-4542828-B1 - SINGLE-PIECE CASING FOR ROTATING ELECTRIC MACHINES AND CORRESPONDING ROTATING ELECTRIC MACHINE

EP4542828B1EP 4542828 B1EP4542828 B1EP 4542828B1EP-4542828-B1

Inventors

  • FELIPE, Gustavo
  • BARBOSA PASSOS, Alex Sandro
  • RIBEIRO, Eduardo Antonio

Dates

Publication Date
20260506
Application Date
20231129

Claims (13)

  1. Single-piece casing for rotating electric machines, comprising at least one internal cooling coil (200), at least one inspection window (300) comprising a through-opening (330) and at least one inspection cap (400), wherein the single-piece casing (100) and the internal cooling coil (200) are formed in a single piece, characterized in that protrusions (430, 431) of the inspection cap (400) continue with the turns (214) of the internal cooling coil (200) in the region of the through-opening (330).
  2. Single-piece casing for rotating electric machines, according to claim 1, characterized in that the internal cooling coil (200) comprises turns (214) with an inter-turn distance (215), and that it extends from a cooling coil inlet (216) to a cooling coil outlet (217), both formed on the external surface part of the cylindrical main body (110), wherein the internal cooling coil (200) runs in an axial direction across the entire wall (120) of the single-piece casing (100).
  3. Single-piece casing for rotating electric machines, according to claim 1, characterized in that the inspection cap (400) comprises a base platform (410), an intermediate platform (420), and a plurality of protrusions (430, 431) extending from the intermediate platform (420).
  4. Single-piece casing for rotating electric machines, according to claim 3, characterized in that the flat surface of the base platform (410) surrounds the intermediate platform (420) and forms a flat face comprising a short smaller face (411), a long smaller face (412), and two narrow larger faces (413), wherein the base platform (410) comprises a base height (414) and a perimeter chamfer (415).
  5. Single-piece casing for rotating electric machines, according to claim 3, characterized in that the intermediate platform (420) comprises an intermediate height (421), wherein all protrusions (430, 431) extend perpendicularly from the flat surface of the intermediate platform (420) and have protrusion height (432).
  6. Single-piece casing for rotating electric machines, according to claim 3 or 5, characterized in that the larger protrusion (430) is arranged flush with the short smaller face (411) and its face opposite the short smaller face (411) comprises a protrusion inclination (433).
  7. Single-piece casing for rotating electric machines, according to claim 6, characterized in that the smaller protrusions (431) have the protrusion inclination (433).
  8. Single-piece casing for rotating electric machines, according to claim 1, characterized in that a distance (434) between the first smaller protrusion (431) and the larger protrusion (430) is equal to the distance between each of the smaller protrusions (431).
  9. Single-piece casing for rotating electric machines, according to claim 1, characterized in that the distance (434) is equal to the pitch (212) of the channel (210), and wherein the smaller protrusions (431) have a thickness (435) equal to or smaller than the inter-turn distance (215) of the channel (210).
  10. Single-piece casing for rotating electric machines, according to claim 1, characterized in that the base platform (410) is shaped compatible with the shape of the upper edge (310), wherein the sizing of the upper edge (310) are greater than or equal to the sizing of the base platform (410), preferably the sizing of the upper edge (310) are greater than the sizing of the base platform (410).
  11. Single-piece casing for rotating electric machines, according to claim 1, characterized in that the intermediate platform (420) is shaped and sized compatible with the shape of the through-opening (330).
  12. Single-piece casing for rotating electric machines, according to claim 1, characterized in that the inspection window (300) comprises an upper edge (310), a recess (320) with a flat surface parallel to the horizontal plane of the longitudinal axis (130) of the single-piece casing (100) and a through-opening (330), wherein the flat surface of the recess (320) comprises a short smaller face (321), a long smaller face (322), and two narrow major faces (323).
  13. Rotating electric machine, characterized in that it comprises a single-piece casing (100), as defined in any one of claims 1 to 12, and a cooling fluid.

Description

Field of application The present invention pertains to the field of rotating electric machines, in particular casings for rotating electric machines comprising cooling coils for circulating cooling fluids. Background of the Invention Rotating electric machines are equipment used for transforming electric energy into mechanical energy, in the case of motors, and for transforming mechanical energy into electric energy, in the case of generators. Basically, they consist of four basic structures, which are stator, rotor, bearings/caps, and casing, in addition to other components and accessories needed for their operation such as cooling systems, one or more connection boxes and the like. The stator is the static active (energized) component responsible for transmitting the magnetic flux for rotating the rotor, in the case of motors, and for transmitting the energy generated by the rotor, in the case of generators, whereas the rotor is the active (energized) component of the rotating electric machine. The rotor, in turn, is basically composed of a shaft onto which one or more cages, coils, or permanent magnets are arranged, depending on the construction type and operating principle of the rotating electric machine. The bearings are the elements responsible for coupling the rotating parts to the static parts of a rotating electric machine, performing, for example, the coupling, bearing, and centralization of the (rotating) rotor in relation to the (static) stator, allowing relative movement between rotor and stator, as well as the transmission of forces therebetween, whilst the caps generally close the electric machine ends. The casing is a static element, generally cast in metal, responsible for integrating the structures of the rotating electric machine, which can also perform additional functions such as promoting cooling through, for example, turn-shaped channels or cooling coils through the which a fluid is pumped to help in the removal of heat generated during the operation of the electric machine. The use of cooling coils significantly complement or even replaces the heat exchange carried out by the usual auxiliary air cooling or ventilation systems (self-ventilation with fans or forced ventilation by external elements) when the latter are insufficient or cannot be used. Give that rotating electric machines operate under a myriad of conditions of rotation, mechanical load, temperature, and environments, they need an efficient, effective, and reliable heat exchange. In this context, cooling coils are a viable and effective alternative to ensure the removal of heat in electric machines subjected to intense operating regimes and which are often installed in closed or poorly ventilated compartments. In the known state of the art, the casings of electric machines of the nature discussed here are normally constructed in two or even more pieces, so as to facilitate the removal of casing segments from the molding box and, when comprising internal cooling coils, to enable the collapse of the internal core of the cooling coil model and thus facilitate the removal of sand or salt from inside the obtained final piece. The use of bipartite molds, however, requires a series of different process steps, starting with the casting of two pieces, machining the interfaces therebetween and the mold parting lines, pressing and fixing the two pieces in order to ensure impermeability, in addition to final machining to ensure the finish. In order to avoid this substantial number of processes to obtain the final casing, an alternative is producing it in a single piece. However, in the single piece concept, there is the challenge of completely removing sand from the central core which will form the channels inside the piece, given that, for this cleaning and sand removal to be effective, it is necessary to add openings or windows large enough for all this material to be removed from the inside of the casing. When adding said windows, interruptions and discontinuities are accrued in the cooling coil channels, impairing the cooling system's performance and making its application unfeasible in cases which require greater power density. The challenge lies therefore in designing a casing cast in a single body, equipped with one or more inspection caps constructed and positioned so as to ensure integrity and impermeability of the cooling coil in the inspection window regions, and that are, at the same time, of simple construction and manufacturing, with optimization of both the use of raw materials and the manufacturing and assembly process. Furthermore, the challenge lies in ensuring that the inspection caps are assembled so that the final piece is free from interruptions and misalignments in the water channels which harm the piece's thermal performance. State of the art There are, in the state of the art, several solutions intended for the circulation of cooling fluids through the casings of rotating electric machines. One such example