The invention relates to a spur gear (1) for a transmission (35) for a brushless electric motor (10), having a toothed portion (32), with a receiving bore (38) formed in the region of the toothed portion (32) in order to receive a rotor shaft (30), and having a signal generating portion (34) rotationally fixed to the toothed portion (32) with multiple magnetic field generating regions (48), which are adapted to interact with a magnetic field sensing element (50) especially a Hall element, in order to detect the rotary angle position of the spur gear (1) as it turns about an axis of rotation (20).