Pump and electric motor

A motor comprising a stator and a rotor rotatable relative to the stator, wherein the stator comprises a magnetic core and a winding wound around the magnetic core, the magnetic core is mounted to a base body, the base body has at least one recess adjoining the magnetic core for receiving debris produced by mutual friction between the magnetic core and the base body, the base body has a sleeve receiving the rotor, the magnetic core comprises a pair of pole shoes, inner wall surfaces of the pair of pole shoes are recessed to form pole are surfaces surrounding the sleeve, the pole arc surfaces of the pole shoes lay on an outer wall surface of the sleeve, a slot is defined between pole tips of the pair of pole shoes, and the sleeve has an axially-extending rib which is slidably inserted into the slot between the pole tips of the pole shoes to guide an axial movement of the sleeve relative to the magnetic core, wherein the base body has a step projecting radially outwardly from an outer wall surface of the sleeve with an axial end surface of the step contacting the magnetic core, the at least one recess is defined in the step, and the at least one recess and the magnetic core are disposed at two sides of the axial end surface.