Patent ID: 7550882

Claim:
Cooling arrangement for an electric motor or generator that includes a housing, a slotless tubular stator lamination, a rotor with permanent magnets and electric windings which are provided between the stator lamination and the rotor, comprising a cooler upon which said windings are provided, said cooler comprising a mainly cylindrical cooling element provided between the stator lamination and the rotor, said cooling element having one or several axially extending passages defined therein, the passages defining a space for a cooling fluid, the cooling element being provided on an inner wall thereof with teeth directed radially towards the rotor and which extend in an axial direction of the stator and in between which axially directed grooves are defined, such that the cooling element has an external form of a conventional stator lamination with teeth for providing said windings; wherein the windings are provided on the cooler within the grooves between the teeth and separated from the space inside the passages to prevent contact between the windings and the cooling fluid.