Enhanced Torque Density in Electric Motors Through Liquid-Cooled Hollow Conductors

This paper deals with some consideration about the design of high torque density motors, adopting hollow conductors which are directly cooled by liquid. A copper coil has been produced by means of additive manufacturing characterized by a inner channel, where a fluid is forced inside. Some experimental measures are carried out to compute the heat convection factors of the internally-cooled hollow conductors. The impact of such a winding on the performance of two synchronous motors, a surface-mounted permanent magnet motor and a reluctance motor, is analysed and discussed.