Patent ID: 7420307

Claim:
A brushless DC motor ( 10 ; 50 ) having an at least two-pole permanent magnet rotor ( 20 ; 60 ) and an at least two-pole stator ( 12 ; 52 ) whose poles ( 14 ; 54 ) carry an at least single-strand stator winding ( 18 ; 58 ) which can be energized with a current according to the rotor position by means of an electronic commutation device ( 40 ), there being a substantially uniform cylindrical air gap ( 24 ; 64 ) between the rotor and the stator, characterized in that the motor is a sensorless motor and at least one stator pole ( 14 ; 54 ), or a specially provided auxiliary pole ( 26 ) having an auxiliary winding ( 28 ; 34 ; 68 ; 70 ), is provided which is energized with a current to start up the motor.