Each of the magnet coils is configured as a concentrated winding coil with an air core including an upper base part, a lower base part, and two leg parts. The upper base part of one of the magnet coils is housed in the air core region of a different one of the magnet coils which is adjacent to the one magnet coil at the side of the miner base part, and the upper base part and the leg parts of one of the magnet coils are aligned in a circular direction with corresponding ones of the upper base part and the leg parts of another different one of the magnet coils which is adjacent to the one magnet coil at the side of the lower base part, without overlapping corresponding ones of the upper base part and the leg parts of the another different magnet coil in a radial direction.

A motor coil substrate includes a flexible insulating substrate having a cylindrical shape, wirings formed on a first surface of the flexible insulating substrate and a second surface of the flexible insulating substrate on the opposite side with respect to the first surface, and via conductors including copper plating penetrating through the flexible insulating substrate such that the via conductors are connecting the wirings formed on the first surface and the wirings formed on the second surface. The wirings and the via conductors form coils formed in spiral shapes, and the flexible insulating substrate is wound more than one turn in a circumferential direction of the cylindrical shape such that the first surface on an inner side of the cylindrical shape and the second surface on an outer side of the cylindrical shape oppose each other.

A motor coil substrate includes a flexible insulating substrate having a cylindrical shape, wirings formed on a first surface of the flexible insulating substrate and a second surface of the flexible insulating substrate on the opposite side with respect to the first surface, and via conductors including copper plating penetrating through the flexible insulating substrate such that the via conductors are connecting the wirings formed on the first surface and the wirings formed on the second surface. The wirings and the via conductors form coils formed in spiral shapes, and the flexible insulating substrate is wound more than one turn in a circumferential direction of the cylindrical shape such that the first surface on an inner side of the cylindrical shape and the second surface on an outer side of the cylindrical shape oppose each other.

The DC electric motor has a stator which comprises a permanent magnet with a number p of pole pairs, and has a rotor which can rotate in relation to the stator and has a hollow-cylindrical iron-free winding with a geometric axis and a number Q of sub-coils, and a collector with a number K of collector segments, wherein the sub-coils are arranged distributed over the periphery of the rotor. The brush-commutated DC electric motor furthermore has at least one pair of brushes which are in contact with the collector and by means of which the sub-coils are energized. The arrangement of the brushes and the interconnection of the sub-coils are selected in such a way that in each case a number n2 of sub-coils, which are each arranged offset by 360/n in a rotationally symmetrical manner with respect to the axis of the rotor, are always supplied with the same current at the same time.

The invention relates to an electric motor/gear mechanism unit including a housing, an iron-free rotor winding rotatably arranged in the interior of the housing, a collector connected to the rotor winding, a rotor shaft extending through the collector, and a gear mechanism which is connected to the rotor shaft and which has an output shaft. The present invention is so conceived that the gear mechanism is produced from a non-magnetic material and arranged in the interior of the rotor winding.

The invention relates to an electric motor/gear mechanism unit including a housing, an iron-free rotor winding rotatably arranged in the interior of the housing, a collector connected to the rotor winding, a rotor shaft extending through the collector, and a gear mechanism which is connected to the rotor shaft and which has an output shaft. The present invention is so conceived that the gear mechanism is produced from a non-magnetic material and arranged in the interior of the rotor winding.

A two-pole brush-commutated DC electric motor with a stator and a rotor with a hollow-cylindrical ironless winding having n coil segments and a commutator having n commutator segments. Each coil segment being electrically connected to two adjacent commutator segments. An axis of gravity intersects the rotor axis perpendicularly and passes through the center of gravity of a coil segment or a center line of the coil segment that passes through the center of gravity and the rotor axis spanning a coil plane that defines the angular position of the associated coil segment. Two brush contact surfaces of the commutator segments are electrically connected to this coil segment have a distance bisector intersecting the rotor axis perpendicularly. The distance bisector and the rotor axis span a commutator plane which defines the angular position of the associated commutator segments.