The invention relates to a cooling device for an electric machine, in particular, for an electric motor comprising a stator (2) and a rotor. According to the invention, axial channeled recesses (6) are provided on the outside of the stators (2), in which a cooling tube or cooling hose may be introduced and/or which may be sealed by means of a cover (10) to give a cooling air channel, an electric motor with such a cooling device and a core sheet (4) for a lamination bundle of a stator (2), the core sheet (4) comprising amongst other things a number of stator grooves (5). The core sheet (4) comprises recesses (6) with a channel cross-section on the outer edge thereof. The invention further relates to an electric machine the stator (2) of which has a lamination bundle made up of a plurality of such core sheets (4). The invention also relates to a production method for such electric machines. The cooling tubes or cooling hoses can be simply inserted in the half-open channeled recesses from without for cooling.