This paper shows the approach of applications of magnetic liquids in electromechanical drive systems. Magnetic fluids consist of colloidal ferromagnetic nanoparticles, a particle surfactant and carrier liquid. These fluids are divided into two groups called ferrofluids and magneto-rheological fluids (MRF). Both liquids are examined in two different kinds of electric motor prototypes. Following the ideas of Nethe , a ferrofluid is located in the air gap of an electrical drive. The influence on torque and especially heat transfer is shown by experiments. The system is also studied analytically as a classical Taylor-Couette-System. A second motor prototype is a novel and innovative magnetorheological assisted electrical machine. The construction and the functional principle are presented in this paper. In addition, some of first measurements are shown.