Rotor of an electric machine, having a rotor body which is rotatable about a rotor axis, comprises at least one rotor body element, in particular a rotor laminated core, and has in each case one or more cooling ducts which each have a cooling duct opening (8.1, 8.2) at their ends, wherein the one cooling duct opening (8.1) of one of the cooling ducts is in each case arranged radially farther outside than the other cooling duct opening (8.2) of the same cooling duct, in such a way that an air flow is established in the cooling duct owing to the centrifugal forces when the rotor rotates, wherein a first cover element is provided on one of the two end sides of the rotor body and covers a radially innermost partial cross section of at least one of the cooling duct openings (8.1) of at least one of the cooling ducts, characterized in that - the first cover element covers the radially innermost partial cross section of the respective cooling duct opening (8.1) by way of a radially outer edge portion with respect to the rotor axis and in each case leaves a radially outermost partial cross section of the same cooling duct opening (8.1) uncovered as cooling duct outlet (8.1), in that - the other cooling duct opening (8.2) of the same cooling duct is in each case a cooling duct inlet, and in that a respective axial inflow with respect to the rotor axis is provided upstream of the cooling duct inlets (8.2), in that - the geometric centre of the cooling duct outlet (8.1) is offset in the radial direction with respect to the rotor axis in each case in relation to the geometric centre of the cooling duct inlet (8.2) of the same cooling duct, in that - a second cover element is arranged on the other end side of the rotor body, and one of the cooling duct inlets (8.2) is covered in each case by one of the two cover elements (10, 12) at a radially outermost partial cross section, and the assigned cooling duct outlet (8.1) of the same cooling duct is covered in each case by the other cover element (10, 12) at a radially innermost partial cross section, in such a way that a respective radial offset between the uncovered or open cross sections of the two cooling duct openings (8.1, 8.2) of one of the cooling ducts is generated. - the first cover element covers the radially innermost partial cross section of the respective cooling duct opening (8.1) by way of a radially outer edge portion with respect to the rotor axis and in each case leaves a radially outermost partial cross section of the same cooling duct opening (8.1) uncovered as cooling duct outlet (8.1), in that - the other cooling duct opening (8.2) of the same cooling duct is in each case a cooling duct inlet, and in that a respective axial inflow with respect to the rotor axis is provided upstream of the cooling duct inlets (8.2), in that - the geometric centre of the cooling duct outlet (8.1) is offset in the radial direction with respect to the rotor axis in each case in relation to the geometric centre of the cooling duct inlet (8.2) of the same cooling duct, in that - a second cover element is arranged on the other end side of the rotor body, and one of the cooling duct inlets (8.2) is covered in each case by one of the two cover elements (10, 12) at a radially outermost partial cross section, and the assigned cooling duct outlet (8.1) of the same cooling duct is covered in each case by the other cover element (10, 12) at a radially innermost partial cross section, in such a way that a respective radial offset between the uncovered or open cross sections of the two cooling duct openings (8.1, 8.2) of one of the cooling ducts is generated.