Rotor/shaft combination for an electric machine (1, 200), wherein the rotor/shaft combination comprises a rotor (4, 41) and a shaft (5, 25), - wherein the rotor (4, 41) has a support device and a heat-conducting device for removing waste heat from the rotor (4, 41) by way of the shaft (5, 25), - wherein the shaft (5, 25) can be rotationally mounted, about a rotational axis of the shaft (5, 25), in a first bearing device of the electric machine (1, 200) and in a second bearing device of the electric machine (1, 200), - wherein the support device is a laminated core having sheets which are stacked in an axial direction, - wherein the rotor (4, 41) is secured to the shaft (5, 25) or can be secured at the correct position to the associated shaft (5,25), - wherein the heat-conducting device has, for removing the waste heat from the rotor (4, 41) by way of the shaft (5, 25), an axial part (301, 2301) of the shaft (5, 25) with a first material having a specific thermal conductivity which is greater than 100 Wm -1 K, - wherein the sheets are fixed in the laminated core by means of a connecting device (26, 226), wherein the connecting device (26, 226) has a short-circuiting ring with a second material, wherein the short-circuiting ring is secured to a first axial end of the support device, wherein, for the purpose of removing the waste heat from the rotor (4, 41) by way of the shaft (5, 25), the short-circuiting ring is linked directly to the axial part of the shaft (5, 25) or, by securing the rotor (4, 41), can be linked at the correct position on the associated shaft (5, 25), wherein the quantified difference between the coefficients of thermal expansion of the first material and the second material is less than 4 x 10 -6 K -1. - wherein the rotor (4, 41) has a support device and a heat-conducting device for removing waste heat from the rotor (4, 41) by way of the shaft (5, 25), - wherein the shaft (5, 25) can be rotationally mounted, about a rotational axis of the shaft (5, 25), in a first bearing device of the electric machine (1, 200) and in a second bearing device of the electric machine (1, 200), - wherein the support device is a laminated core having sheets which are stacked in an axial direction, - wherein the rotor (4, 41) is secured to the shaft (5, 25) or can be secured at the correct position to the associated shaft (5,25), - wherein the heat-conducting device has, for removing the waste heat from the rotor (4, 41) by way of the shaft (5, 25), an axial part (301, 2301) of the shaft (5, 25) with a first material having a specific thermal conductivity which is greater than 100 Wm -1 K, - wherein the sheets are fixed in the laminated core by means of a connecting device (26, 226), wherein the connecting device (26, 226) has a short-circuiting ring with a second material, wherein the short-circuiting ring is secured to a first axial end of the support device, wherein, for the purpose of removing the waste heat from the rotor (4, 41) by way of the shaft (5, 25), the short-circuiting ring is linked directly to the axial part of the shaft (5, 25) or, by securing the rotor (4, 41), can be linked at the correct position on the associated shaft (5, 25), wherein the quantified difference between the coefficients of thermal expansion of the first material and the second material is less than 4 x 10 -6 K -1.