Induction motor with hybrid rotor bars

Abstract

An induction motor (1) comprising: a squirrel cage rotor (5) comprising: a rotor core (9) having a first axial end (9a) and a second axial end (9b), and a plurality of axial rotor slots (9c) extending from the first axial end (9a) to the second axial end (9b), a rotor cage comprising: a plurality of rotor bars arranged in a respective rotor slot (9c), each rotor bar being composed of at least one elongated metal element extending along the respective rotor slot (9c) and cast metal filling up space around all the metal elements in the rotor slot (9c), wherein at each of the first axial end (9a) and the second axial end 0 (9b) of the rotor core (5), the metal elements have connecting portions, each connecting portion extending between two rotor slots (9c) and directly electrically connecting two metal elements arranged in different rotor slots (9c), the connecting portions being arranged such that every metal element in every rotor slot (9c) is directly electrically connected to a metal element in another rotor slot (9c) via a connecting portion at each of the first axial end (9a) and the second axial end (9b), and such that at each of the first axial end (9a) and the second axial end (9b), a connecting portion extends along an end surface of the first axial end (9a) and the second axial end (9b), respectively, between every pair of adjacent rotor slots (9c).

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