Dipping varnish-coated cooling shell of a housing for an electric machine

A coolable housing shell for an electric machine, which is produced as a cast part, accommodates a concentric interior rotor/stator arrangement, coils, and end windings, and comprises a clear, open, through passage that is embodied in a symmetric, concentric, and/or coaxial manner relative to an imaginary axis of rotation of the machine. Said housing shell is interspersed with one or several cooling channels so as to form a coolant circuit. The inner surfaces of the shell and the inner walls of the channel/s have a coating via a cathodic dipping varnish method.