Coil assembly for use with an electric motor

Coil assemblies ( 2 ) of electric motors ( 1 ) produce heat that can be a disadvantage when needing the electric motor ( 1 ) for high precision positioning applications. To reduce the negative impact of the heat, the coils ( 26 a , 26 b , 26 c) are arranged in an internally cooled housing ( 21 ). The housing ( 21 ) has an outermost layer ( 25 ) at least on the side lacing the magnet assembly ( 3 ) of the electric motor ( 1 ), the outermost layer ( 25 ) being made of low or non-electrically conductive, non-magnetic or nearly non-magnetic material. The outermost layer ( 25 ) prevents heat radiation to the environment.