This paper presents an experimental study of direct coil cooling applied to a stator tooth of a switched reluctance motor where a direct contact is realized between the winding and fluid. Experiments were performed with a setup consisting of one tooth of a SRM without rotor, but including stator iron and one preformed winding. Three configurations of the cooling method were investigated: slot cooling, end winding cooling and a combination of the two by pumping an Automatic Transmission Fluid (ATF) over the designated sides of the winding. The setup is equipped with 17 thermocouples integrated within the components to determine the temperatures. Three inlet temperatures (21, 33 and 44°C) and four flow rates (1.5, 2, 3.5 and 5 l/min) of the coolant were tested at four different heat losses in the winding (10, 30, 50 and 70W). The results show that the maximum temperature is always located in the centre of the winding and is the lowest for the combined cooling (73.0°C), followed by the slot cooling (79.7°C) and then by the end winding cooling (91.6°C) for the lowest ATF inlet temperature and the highest heat losses and flow rate. With a determined current density in the range 13.8A/mm² to 19.5 A/mm², all three direct coil cooling methods show a great potential in increasing the power density of electric motors
