A hollow shaft arrangement may include a hollow shaft, such as a rotor shaft of an electric motor, for example, through which a fluid can pass for cooling purposes. Surface-enlarging cooling structures for transferring thermal energy from the hollow shaft to the fluid may be arranged in an inner space of the hollow shaft. The surface-enlarging cooling structures may be connected to the hollow shaft, but may be part of a cooling body that is formed separately from the hollow shaft. Further, the cooling body may include a sleeve-like main body from which the surface-enlarging cooling structures project radially inwardly, and the sleeve-like main body may include an axial gap that permits a circumference of the main body to be adjustable. In some cases an outer diameter of the cooling body is larger than an inner diameter of the bearing.