as is customary a rotor housing 2 in which the spinning cup of a spinning rotor 3 rotates at a high speed spinning rotor 3 is driven by electric individual drive 52 and is fixed by its rotor shaft 4 in bearing arrangements 49 26 44 45 46 of magnetic support 5 which supports spinning rotor 3 both radially and axially as is customary rotor housing 2 which is open to the front is closed during operation by pivotably supported cover element 8 equipped with a conduit plate with seal 9 not shown in detail moreover rotor housing 2 is connected via an appropriate suction removal line 10 to vacuum source 11 which produces the spinning vacuum necessary in rotor housing 2 conduit plate adapter 12 is arranged in cover element 8 and in the conduit plate which adapter 12 comprises yarn take offjet 13 and the mouth area of yarn guide conduit 14 yarn take off jet 13 is followed by small yam take off tube 15 in addition opening cylinder housing 17 is fastened on cover element 8 which is mounted so that it can rotate in a limited manner about pivot axis 16 cover element 8 also comprises bearing brackets 19 20 on its rear side for supporting opening cylinder 21 and sliver draw in cylinder 22 opening cylinder 21 is driven in the area of.