Abstract: In an electronically commutated DC motor having a stator unit (5) and a rotor unit (1) which is in the form of an external rotor, and having stationary sintered bearings (8, 9), the invention proposes that the rotor unit (1) is conductively connected to the shaft (3) in order to connect a conductive shielding, which is formed on the rotor unit (1), to a defined electrical potential, and that the sintered bearing (8, 9) is conductively connected to the potential, so that the shielding of the rotor unit (1) is capacitively coupled to the potential by means of the electrically insulating, oil-filled bearing gap which is arranged between the shaft (3) and the sintered bearing (8, 9). Therefore, a sliding contact is not required.

Abstract: In an electronically commutated DC motor having a stator unit (5) and a rotor unit (1) which is in the form of an external rotor, and having stationary sintered bearings (8, 9), the invention proposes that the rotor unit (1) is conductively connected to the shaft (3) in order to connect a conductive shielding, which is formed on the rotor unit (1), to a defined electrical potential, and that the sintered bearing (8, 9) is conductively connected to the potential, so that the shielding of the rotor unit (1) is capacitively coupled to the potential by means of the electrically insulating, oil-filled bearing gap which is arranged between the shaft (3) and the sintered bearing (8, 9). Therefore, a sliding contact is not required.

Abstract: The invention relates to a multipole commutator motor (14) having at least four stator poles (16-19) and having armature coils (31-42) that work together with these stator poles and that, for the supply of power, are each connected electrically with two commutator bars (1-12) of a commutator (22), and whose number is greater than the number of the stator poles (16-19), it being provided that, in order to reduce the number of brushes (20, 21; 23, 24) contacting the commutator (22), armature coils (31-42), that form armature poles having identical magnetic orientation are connected in parallel through electrical bridge conductors (43-48) at the armature. For the commutator motor (14), it is proposed that the bridge conductors (43-48) be routed at least partially via armature slots (71-82).

Abstract: The invention concerns a commutator (22; 22a; 22b) for a multi-pole commutator motor (14) having at least four stator poles (16-19) and armature coils (31-42) interacting with them that are electrically interconnected with two commutator bars (1-12) each of the commutator (22; 22a; 22b) to supply current, and the number of which said armature coils is greater than the number of stator poles (16-19), whereby, in order to reduce the number of brushes (20, 21; 23, 24) contacted by the commutator (22; 22a; 22b), armature coils (31-42) forming armature poles having an identical magnetic polarity are connected in parallel by armature-end, electrical bridge conductors (43-48). With regard for the commutator (22; 22a; 22b), it is proposed that the bridge conductors (43-48) are a component of the commutator (22; 22a; 22b). The invention further concerns a multi-pole commutator motor (14) having a commutator (22; 22a; 22b) of this type.

Abstract: An electric motor, including at least two permanent magnet segments disposed around a motor longitudinal axis, in which each permanent magnet segment has end faces extending in the direction of the motor longitudinal axis and is encompassed by two independent yoke ring segments that have a gap between them parallel to a symmetry plane extending through the motor longitudinal axis and the center of the permanent magnet segments in order to reduce the armature transverse field. In addition to the reduction of the armature transverse field, a weight reduction of the electric motor is also achieved. To this end, in a first region close to the end faces of the permanent magnet segments, the one-piece magnetically conductive yoke is provided with a larger cross section than in a second region close to the symmetry plane extending through the center of the permanent magnet segments. The construction is particularly suited for small electric motors, in particular d.c. motors that are excited by permanent magnets.