Abstract: An inductive device comprises a toroidal core and at least one electric conductor wound around the toroidal core and constituting at least one winding. The inductive device comprises a cooling element constituting a cylindrical cavity that contains the toroidal core and the electric conductor so that the axial direction of the toroidal core is parallel with the axial direction of the cylindrical cavity. The shape of the cylindrical cavity and the cross-section of the electric conductor are adapted to match each other to improve heat transfer from the electric conductor to the wall of the cylindrical cavity so that a wall of the cylindrical cavity is provided with axially directed grooves occupied by portions of the electric conductor on an outer perimeter of the winding.

Abstract: An electric motor construction is provided with a planetary gear system, including an annular thin-rimmed stator (1) as well as a torque takeoff shaft (2) concentric relative thereto. The construction includes inside the stator (1) an annular thin-rimmed rotor (3); a sun gear (4) fixedly coupled to the rotor and concentric with the takeoff shaft (2); an intra-rotor immovably coupled ring gear (5) with a toothed inner surface; planet gears (6) meshing with the ring gear and the sun gear; a planet carrier (7) that the planet gears are supported on; as well as a coupling arrangement (8) for transmitting torque of the rotor optionally directly or by way of the planet carrier to the torque takeoff shaft.

Abstract: An inductive device includes a toroidal core and at least one electric conductor wound around the toroidal core and constituting at least one winding. The inductive device includes a cooling element constituting a cylindrical cavity that contains the toroidal core and the electric conductor so that the axial direction of the toroidal core is parallel with the axial direction of the cylindrical cavity. The shape of the cylindrical cavity and the cross-section of the electric conductor are adapted to match each other so as to improve heat transfer from the electric conductor to the wall of the cylindrical cavity. The cylindrical cavity can have for example a circular base and the electric conductor can have for example a rectangular cross-section that matches the shape of the wall of the cylindrical cavity better than a round electric conductor.

Abstract: An electric motor construction is provided with a planetary gear system, including an annular thin-rimmed stator (1) as well as a torque takeoff shaft (2) concentric relative thereto. The construction includes inside the stator (1) an annular thin-rimmed rotor (3); a sun gear (4) fixedly coupled to the rotor and concentric with the takeoff shaft (2); an intra-rotor immovably coupled ring gear (5) with a toothed inner surface; planet gears (6) meshing with the ring gear and the sun gear; a planet carrier (7) that the planet gears are supported on; as well as a coupling arrangement (8) for transmitting torque of the rotor optionally directly or by way of the planet carrier to the torque takeoff shaft.