A device for providing rotational torque includes a stator with a permanent magnet rotatably mounted contained within, a rotor arranged on one side of the stator, a pair of permanent magnets rotatably mounted on oppositely spacing sides of the rotor, which stator and rotors are arranged with gaps left therebetween in an axial direction of the driveshaft, the rotor being mounted to the driveshaft. For further acceleration of the rotor, there are mounted several permanent magnets in the stator housing, arranged in a circumferential arrangement relative to the rotor. These acceleration magnets are arranged such that the size increases with each acceleration magnet approaching the stator magnet.