Abstract: An airflow control arrangement for a direct-drive wind-turbine with a generator comprising a rotor and a stator, which airflow control arrangement comprises an outflow fan arranged to draw an exit airflow through an exit duct, which exit duct extends from an interior cavity of the stator to the exterior of the wind turbine. The invention further describes a direct-drive wind turbine comprising such an airflow control arrangement. The invention further describes a method of controlling an airflow in a direct-drive wind-turbine with a generator comprising a rotor and a stator is provided.

Abstract: A pole shoe element for an electrical machine is described. The electrical machine has a stator, a rotor and an air gap between the stator and the rotor. The pole shoe element contains a magnet receiving section which extends in a longitudinal direction of the pole shoe element, in which the pole shoe element in a peripheral direction of the rotor has a first width in a first radial inner position and in the peripheral direction has a second width in a second radial outer position. The second width is smaller than the first width.

Abstract: A pole shoe arrangement for a rotor or a stator of an electrical machine having an air gap between the stator and the rotor is disclosed. The pole shoe arrangement has a pole shoe element having an inner end and an outer end opposing the inner end. The inner end lies opposite the air gap when the pole shoe element is in an assembled state. The pole shoe element has a receiving surface for receiving a permanent magnet between the inner end and the outer end. The pole shoe arrangement has a guiding facility to guide the permanent magnet in a radial direction from the outer end to the inner end and to limit a movement of the permanent magnet at right angles to the radial direction.

Abstract: A method of inspecting an air-gap of an electrical machine, which method including the steps of directing at least one laser beam (L) into the air-gap; detecting the laser beam (L) after reflection; determining the distance (dOK, dF) travelled by the laser beam (L); and analysing the travelled distance (dOK, dF) to detect an irregularity (Fpole, Foval, Fobject) in the air-gap is provided. The invention further describes an air-gap inspection apparatus for detecting an irregularity in the air-gap of an electrical machine, which apparatus including a laser module realised to direct at least one laser beam (L) into the air-gap and to detect the laser beam (L) after reflection; a computation unit realised to determine the distance (dOK, dF) travelled by the laser beam (L); and an analysis unit realised to analyse the travelled distance (dOK, dF) to detect an irregularity in the air-gap.

Abstract: An airflow control arrangement for a direct-drive wind-turbine with a generator comprising a rotor and a stator, which airflow control arrangement comprises an outflow fan arranged to draw an exit airflow through an exit duct, which exit duct extends from an interior cavity of the stator to the exterior of the wind turbine. The invention further describes a direct-drive wind turbine comprising such an airflow control arrangement. The invention further describes a method of controlling an airflow in a direct-drive wind-turbine with a generator comprising a rotor and a stator is provided.

Abstract: A pole shoe element for an electrical machine is described. The electrical machine has a stator, a rotor and an air gap between the stator and the rotor. The pole shoe element contains a magnet receiving section which extends in a longitudinal direction of the pole shoe element, in which the pole shoe element in a peripheral direction of the rotor has a first width in a first radial inner position and in the peripheral direction has a second width in a second radial outer position. The second width is smaller than the first width.

Abstract: A pole shoe arrangement for a rotor or a stator of an electrical machine having an air gap between the stator and the rotor is disclosed. The pole shoe arrangement has a pole shoe element having an inner end and an outer end opposing the inner end. The inner end lies opposite the air gap when the pole shoe element is in an assembled state. The pole shoe element has a receiving surface for receiving a permanent magnet between the inner end and the outer end. The pole shoe arrangement has a guiding facility to guide the permanent magnet in a radial direction from the outer end to the inner end and to limit a movement of the permanent magnet at right angles to the radial direction.