Patent ID: 7868501

Claim:
A rotor for an electric motor comprising: a plurality of annular rotor discs stacked into an axial disc assembly; and a plurality of axially elongated permanent magnets having substantially a rectangular cross-sectional shape and distributed around a circumference of the rotor; wherein the plurality of annular rotor discs are for securing the plurality of axially elongated permanent magnets, wherein each of the annular rotor discs includes a plurality of pockets, each of the pockets having a substantially corresponding rectangular cross-sectional shape for accommodating and securing the axially elongated permanent magnets in such a way that adjacent axially elongated permanent magnets installed in adjacent ones of the plurality of pockets form an angle to one another and to a radius of the rotor, and that at least a portion of one end edge of each axially elongated permanent magnet is exposed to an outer periphery of the axial disc assembly, and wherein the plurality of pockets for adjacent and mutually diverging axially elongated permanent magnets, as viewed in a radial direction from a centre of the rotor in each annular rotor disc delimit a substantially triangular disc part, the substantially triangular disc part flexibly connected to a radially inner part of the annular rotor disc only by a radially inner web portion and forming a flexible clamping joint between the adjacent ones of the plurality of pockets, the flexible clamping joint operable to secure the axially elongated permanent magnets installed in the adjacent ones of the plurality of pockets.