Patent ID: 7812488

Claim:
An electronically commutated external-rotor motor ( 21 ) comprising an internal stator ( 50 ); an external rotor ( 22 ) equipped with a permanent magnet ( 28 ), which rotor is separated by an air gap from the internal stator ( 50 ) and has, for journaling on the stator, a shaft ( 34 ) on which is mounted a yoke element ( 24 ) made of magnetically conductive material and on which yoke element the permanent magnet ( 28 ) is arranged, which magnet has a leakage flux region adjacent an end face ( 27 ) thereof, facing toward an opening of the yoke element ( 24 ); a circuit board ( 46 ) arranged on the internal stator ( 50 ), which board is equipped, on a side ( 47 ) thereof, facing away from the external rotor ( 22 ), with a printed circuit ( 46 ′, 48 ); a first aperture ( 48 ′) provided in the circuit board ( 46 ) in said leakage flux region of the permanent magnet ( 28 ), in which aperture is arranged a galvanomagnetic sensor ( 48 ) that generates, during motor operation, rotor position signals as a function of a rotational position of the rotor ( 22 ) relative to the stator ( 50 ); a second aperture ( 43 ) provided in the circuit board ( 46 ), at an edge of which aperture is provided an electrical conductor ( 95 ′, 95 ″) connected to ground ( 112 ), to which conductor any charge, that builds up in the motor ( 21 ) during operation, can discharge.