Abstract: A cooling system for a machine tool utilizing an independently operated fan. The machine tool power transmission housing mounts the fan to draw the cool, ambient air through the housing in a heat exchange relationship with the heat generating elements of the power transmission means. The fan is automatically operated by means of a temperature monitoring switch mounted on the power transmission housing. The drive motor housing is independent of the power transmission housing and is constructed and defined to permit the motor to draw in the cool ambient air in a heat exchange relationship with the motor when it is operative and to expel the hot air therefrom.