Device with a stator and a sleeve

An apparatus with a stator and with a sleeve resting at least in part on the stator for an electric motor, characterized in that the sleeve and the stator together form a bayonet mount, said sleeve being rotatable relative to said stator in a predetermined direction to convert said bayonet mount from said open state to said closed state, said stator having a plurality of stator pole teeth, said sleeve having a plurality of inner shoulders and an inner face located in a vicinity of each of said shoulders and formed so that in a direction of revolution which is opposite to said predetermined direction a spacing of said inner face from a center axis of the apparatus decreases, so that when said sleeve is rotated in said predetermined direction, said sleeve wedges with at least one of said stator pole teeth.