A drone for triggering naval mines, which drone includes a drive having an electric motor for locomotion in the water, wherein the electric motor can be used additionally to trigger the naval mines during operation of the drone, by an external magnetic field formed by the operation of the electric motor. The electric motor includes a stationary stator and a rotor, which is mounted for rotation relative to the stator. The stator includes at least one magnetic and/or electromagnetic element for forming an excitation field. The rotor includes at least one armature winding, which electromagnetically interacts with the excitation field during operation of the electric motor, whereby a superordinate magnetic field is formed. The external magnetic field formed outside of the electric motor during operation is in the form of a constant magnetic field.

A rotor of an electric motor includes a rotating shaft, a rotor core and a commutator fixed to the rotating shaft, and a first sleeve, a second sleeve and a third sleeve arranged around the rotating shaft. The first sleeve is located on a side of the rotor core away from the commutator and abuts against the rotor core, the second sleeve is located between the rotor core and the commutator, and the third sleeve is located on a side of the commutator away from the rotor core.

A rotor of an electric motor includes a rotating shaft, a rotor core and a commutator fixed to the rotating shaft, and a first sleeve, a second sleeve and a third sleeve arranged around the rotating shaft. The first sleeve is located on a side of the rotor core away from the commutator and abuts against the rotor core, the second sleeve is located between the rotor core and the commutator, and the third sleeve is located on a side of the commutator away from the rotor core.

A synchronous electrical machine includes a stator having a circumferential row of teeth carrying stator windings. The electrical machine further includes a coaxial rotor having a circumferential row of poles carrying field windings. Each pole has first and second side flanks and a tip surface which extends continuously there between to form an air gap to the teeth of the stator. On a transverse cross-section through the machine, one of the side flanks forms a leading edge of the pole, and the other side flank forms an opposite, trailing edge of the pole. Each pole carries a row of permanent magnets which extends across the tip surface from one of the side flanks to the other side flank, the permanent magnets compensating for armature magnetic reaction. The radial thickness of the permanent magnets increases smoothly with progressive distance across the tip surface from one of the side flanks to the other side flank.

A synchronous electrical machine includes a stator having a circumferential row of teeth carrying stator windings. The electrical machine further includes a coaxial rotor having a circumferential row of poles carrying field windings. Each pole has first and second side flanks and a tip surface which extends continuously there between to form an air gap to the teeth of the stator. On a transverse cross-section through the machine, one of the side flanks forms a leading edge of the pole, and the other side flank forms an opposite, trailing edge of the pole. Each pole carries a row of permanent magnets which extends across the tip surface from one of the side flanks to the other side flank, the permanent magnets compensating for armature magnetic reaction. The radial thickness of the permanent magnets increases smoothly with progressive distance across the tip surface from one of the side flanks to the other side flank.

A brush motor having a 4-pole 24-slot 2-brush structure includes a motor housing, a plurality of stators provided at intervals on an inner circumferential surface of the motor housing, a rotor rotatably installed inside the stators, a plurality of commutators installed on a rotation center shaft of the rotor, and a plurality of brushes configured to supply electric power to the commutators, the rotor including a plurality of slots formed at intervals on an outer circumferential surface thereof and a plurality of coils wound in the slots. The number of the stators is four, the number of the brushes is two, the number of the slots is twenty four, and the number of the coils is twenty four.

A brush motor having a 4-pole 24-slot 2-brush structure includes a motor housing, a plurality of stators provided at intervals on an inner circumferential surface of the motor housing, a rotor rotatably installed inside the stators, a plurality of commutators installed on a rotation center shaft of the rotor, and a plurality of brushes configured to supply electric power to the commutators, the rotor including a plurality of slots formed at intervals on an outer circumferential surface thereof and a plurality of coils wound in the slots. The number of the stators is four, the number of the brushes is two, the number of the slots is twenty four, and the number of the coils is twenty four.

A rotor of an electric motor includes a rotating shaft, a rotor core and a commutator fixed to the rotating shaft, and a first sleeve, a second sleeve and a third sleeve arranged around the rotating shaft. The first sleeve is located on a side of the rotor core away from the commutator and abuts against the rotor core, the second sleeve is located between the rotor core and the commutator, and the third sleeve is located on a side of the commutator away from the rotor core.

A rotor of an electric motor includes a rotating shaft, a rotor core and a commutator fixed to the rotating shaft, and a first sleeve, a second sleeve and a third sleeve arranged around the rotating shaft. The first sleeve is located on a side of the rotor core away from the commutator and abuts against the rotor core, the second sleeve is located between the rotor core and the commutator, and the third sleeve is located on a side of the commutator away from the rotor core.

A synchronous electrical machine includes a stator having a circumferential row of teeth carrying stator windings. The electrical machine further includes a coaxial rotor having a circumferential row of poles carrying field windings. Each pole has first and second side flanks and a tip surface which extends continuously there between to form an air gap to the teeth of the stator. On a transverse cross-section through the machine, one of the side flanks forms a leading edge of the pole, and the other side flank forms an opposite, trailing edge of the pole. Each pole carries a row of permanent magnets which extends across the tip surface from one of the side flanks to the other side flank, the permanent magnets compensating for armature magnetic reaction. The radial thickness of the permanent magnets increases smoothly with progressive distance across the tip surface from one of the side flanks to the other side flank.