A locking system for axially securing a rotor onto a rotatably mounted shaft. The arrangement includes a plurality of locking levers which are each pivotably mounted about axes extending perpendicularly to the shaft between a locking position and an unlocking position in planes containing the axes. The locking levers can each be automatically transferred between an unlocking position and a locking position depending on rotational speed. The locking levers are mounted on the rotor and an annular groove is provided on the shaft and engages with the locking levers in the locking position, wherein the locking levers are prestressed in the unlocking position. Advantageously, the rotor can be both installed and removed without tools by merely placing the rotor onto or removing the rotor from the shaft, in each case depending on rotational speed.