Cooling of an electric machine

An electric machine, comprising:

• a housing;
• a stationary part non-rotatably mounted in the housing;
• a runner rotatably mounted in a receiving space of the stationary part;
• a cooling device configured to discharge heat from the housing by providing a closed cooling circuit for a cooling fluid on a machine side;
• a heat exchanger arranged on the housing and coupled to the cooling device, said heat exchanger being configured to allow cooling air to act on the heat exchanger and to allow passage of the cooling fluid, with the cooling fluid and the cooling air being separated in the heat exchanger by guiding the cooling air through cooling tubes of the heat exchanger and the cooling device being fluidically coupled to the heat exchanger;
• a cooling-air duct for supply and/or discharge of the cooling air;
• and
• a fan configured as a two-channel shaft fan for introducing the cooling air into the cooling-air duct, said fan including a fan housing having two opposing air inlet openings configured as nozzles, respectively, a two-sided radial fan wheel rotatably mounted in the fan housing and arranged between the air inlet openings so as to allow intake of cooling air through the two air inlet openings and conveyance thereof into the cooling-air duct, and a single air outlet opening which is arranged in a radial direction of the fan wheel and through which the cooling air provided by the fan is conveyed into the cooling-air duct.